Administrative Code

Virginia Administrative Code
6/16/2024

Chapter 590. Waterworks Regulations

Part I
General Framework for Waterworks Regulations

Article 1
Definitions [Repealed]

12VAC5-590-10. Definitions and units of measurement.

A. Definitions. As used in this chapter, the following words, terms, and abbreviations shall have meanings respectively set forth unless the context clearly requires a different meaning:

"Action level" or "AL" means the concentration of lead or copper in water specified in 12VAC5-590-385, which determines, in some cases, the treatment requirements contained in 12VAC5-590-405 that an owner is required to complete.

"Administrative Process Act" or "APA" means Chapter 40 (§ 2.2-4000 et seq.) of Title 2.2 of the Code of Virginia. The APA is the basic law conferring authority on agencies either to make regulations or case decisions as well as to standardize court review thereof.

"Air gap separation" means the unobstructed vertical distance through the free atmosphere between the lowest point of the potable water outlet and the flood rim of the receiving vessel.

"ANSI" means the American National Standards Institute.

"Applied water" means water that is ready for filtration.

"ASME" means the American Society of Mechanical Engineers.

"ASSE" means the American Society of Sanitary Engineering.

"ASTM" means the American Society for Testing and Materials.

"Auxiliary water system" means any water supply or system on or available to the premises of the consumer other than the waterworks. These may be polluted or contaminated, objectionable, or of questionable quality and constitute an unapproved water supply or system over which the waterworks owner does not have control.

"AWWA" means the American Water Works Association.

"Backflow" means the undesirable reversal of flow of water or mixtures of water and other liquids, gases, or other substances into a waterworks.

"Backflow elimination method" means the air gap separation or physical disconnection that will eliminate the cross-connection.

"Backflow prevention assembly" means a mechanical unit, designed to control various cross-connections and stop the reversal of flow that includes an inlet and outlet shutoff valve and test cocks to facilitate testing of the assembly. Backflow prevention assemblies include the reduced pressure principle backflow prevention assembly, the double check valve assembly, and the pressure vacuum breaker assembly.

"Backflow prevention device" means a mechanical unit designed to control cross-connections and stop the reversal of flow that is not testable because it does not have inlet and outlet shutoff valves or test cocks. A backflow prevention device is not generally designed or constructed to withstand continuous pressure over 12 hours, or to control high hazards. A backflow prevention device generally includes the atmospheric type vacuum breakers and the dual check valve type devices.

"Backpressure backflow" means backflow caused by pressure in the downstream piping that is superior to the supply pressure at the point of consideration.

"Backsiphonage" means backflow caused by a reduction in pressure that causes a partial vacuum, creating a siphon effect.

"Bag filters" means pressure-driven separation devices that remove particulate matter larger than one micrometer using an engineered porous filtration media. Bag filters are typically constructed of a nonrigid, fabric filtration media housed in a pressure vessel in which the direction of flow is from the inside of the bag to outside.

"Bank filtration" means a water treatment process that uses a well to recover surface water that has naturally infiltrated into groundwater through a river bed or bank. Infiltration is typically enhanced by the hydraulic gradient imposed by a nearby pumping water supply or other well.

"Best available technology" or "BAT" means the best practicable technology, treatment techniques, or other means that the department finds, after examination for efficacy under field conditions and not solely under laboratory conditions, that are available (taking cost into consideration).

"Board" means the State Board of Health.

"Boil water advisory" and "boil water notice" mean a statement that informs consumers that drinking water is or may be contaminated and that the water should be boiled before being used for human consumption.

"BSSP" means a bacteriological sample siting plan.

"CAP" means a corrective action plan.

"Cartridge filters" means pressure-driven separation devices that remove particulate matter larger than one micrometer using an engineered porous filtration media. Cartridge filters are typically constructed as rigid or semi-rigid, self-supporting filter elements housed in pressure vessels in which flow is from the outside of the cartridge to the inside.

"Case decision" means an agency determination as defined in § 2.2-4001 of the Code of Virginia.

"CCCP" means a cross-connection control program.

"CCR" means consumer confidence report.

"CDC" means the Centers for Disease Control and Prevention.

"CFE" means the combined filter effluent.

"CFR" means the Code of Federal Regulations.

"Clean compliance history" means a record of no PMCL violations for microbiological contaminants, no monitoring violations under 12VAC5-590-370, and no coliform treatment technique trigger exceedances or treatment technique violations under 12VAC5-590-392.

"Coagulation" means a process using coagulant chemicals and mixing by which colloidal and suspended materials are destabilized and agglomerated into floc.

"Combined distribution system" means the interconnected distribution system consisting of the distribution systems of wholesale waterworks and of the consecutive waterworks that receive finished water.

"Commissioner" means the State Health Commissioner, who is the executive officer of the board.

"Community waterworks" means a waterworks that serves at least 15 service connections used by year-round residents or regularly serves at least 25 year-round residents.

"Compliance cycle" means the nine-year calendar year cycle during which a waterworks shall monitor. Each compliance cycle consists of three three-year compliance periods. The first calendar year cycle began January 1, 1993, and ended December 31, 2001, with subsequent compliance cycles continuing thereafter.

"Compliance period" means a three-year calendar year period within a compliance cycle. Each compliance cycle consists of three three-year compliance periods. The first compliance period began January 1, 1993, and ended December 31, 1995, with subsequent compliance periods continuing thereafter.

"Comprehensive business plan" means a plan detailing the technical, managerial, and financial commitments that the owner will make in order to assure that the waterworks will have the capability to provide water that complies with this chapter over the long term.

"Confirmation sample" means a sample to be collected by the owner within a specified time after the results of the initial sample are known to have exceeded a specified limit or standard in order to validate the initial result and to determine compliance.

"Confluent growth" means a continuous bacterial growth covering the entire filtration area of a membrane filter, or a portion thereof, in which bacterial colonies are not discrete.

"Consecutive waterworks" means a waterworks that receives some or all of its finished water from one or more waterworks. Consecutive waterworks may provide additional treatment to finished water. Delivery may be through a direct connection or through the distribution system of one or more consecutive waterworks.

"Consolidated" means rock made from sedimentary, igneous, or metamorphic materials that have been metamorphosed or cemented together forming strata or bodies of rock.

"Consumer" means any person receiving water for human consumption from a waterworks.

"Consumer's water system" means any water system located on the consumer's premises, supplied by or in any manner connected to a waterworks.

"Containment" means the safeguard against backflow into a waterworks from a consumer's water system by installing an appropriate backflow prevention assembly, backflow prevention device, or backflow elimination method at the service connection or downstream of the service connection but before any unprotected takeoffs.

"Contaminant" means any objectionable or hazardous physical, chemical, biological, or radiological substance or matter in water.

"Conventional filtration treatment" means a series of processes including coagulation, flocculation, sedimentation, and filtration resulting in substantial particulate removal.

"Corrosion inhibitor" means a substance capable of reducing the corrosivity of water toward metal plumbing materials, especially lead and copper, by forming a protective film on the interior surface of those materials.

"Cross-connection" means any actual or potential link, connection, or physical arrangement, direct or indirect, between used water, an auxiliary water system, or other source of contamination or pollution to the waterworks through which backflow can occur.

"DBPPs" means disinfection byproduct precursors.

"DBPs" means disinfection byproducts.

"DCLS" means the Virginia Department of General Services, Division of Consolidated Laboratory Services.

"Department" means the Virginia Department of Health.

"DEQ" means the Virginia Department of Environmental Quality.

"Diatomaceous earth filtration" means a process resulting in substantial particulate removal in which (i) a precoat cake of diatomaceous earth filter media is deposited on a support membrane (septum), and (ii) while the water is filtered by passing through the cake on the septum, additional filter media known as body feed is continuously added to the feed water to maintain the permeability of the filter cake.

"Direct filtration" means a series of processes including coagulation and filtration but excluding sedimentation resulting in substantial particulate removal.

"Disinfectant" means any chemical and physical agents, including chlorine, chlorine dioxide, chloramines, ozone, and UV light, added to water in any part of the treatment or distribution process for the purpose of killing or inactivating pathogenic organisms.

"Disinfection" means a process that inactivates or destroys pathogenic organisms in water by use of a disinfectant.

"Disinfection profile" means a summary of Giardia lamblia or virus inactivation through the water treatment plant.

"Distribution main" means a water pipeline whose primary purpose is to convey drinking water to service connections.

"Distribution system" means a network of pipelines and appurtenances by which a waterworks delivers drinking water to its consumers.

"DOC" means the dissolved organic carbon in a water sample.

"Double check valve assembly" or "double check detector backflow assembly" means a backflow prevention assembly composed of two single independently acting check valves including tightly closing shutoff valves located at each end of the assembly and test cocks to facilitate testing of the assembly, used for low hazard situations.

"DPOR" means the Virginia Department of Professional and Occupational Regulation.

"Drawdown" means the difference, measured vertically, between the static water level in the well and the water level during pumping.

"Dual sample set" means a set of two samples collected at the same time and same location, with one sample analyzed for TTHM and the other sample analyzed for HAA5.

"Enhanced coagulation" means the addition of sufficient coagulant for improved removal of disinfection byproduct precursors by conventional filtration treatment.

"Enhanced softening" means the improved removal of disinfection byproduct precursors by precipitative softening.

"Entry point" means the place where water from the source after application of any treatment is delivered to the distribution system. Where two or more sources are combined before distribution, the entry point is the location that is representative of the blended water following all treatment.

"EPA" means the U.S. Environmental Protection Agency.

"Exemption" means allowing a waterworks that satisfies the criteria in 12VAC5-590-150 to deviate from a specific PMCL or treatment technique requirement that is granted to the waterworks for a limited period of time.

"Filter profile" means a graphical representation of individual filter performance, based on continuous turbidity measurements or total particle counts versus time for an entire filter run, from start-up to backwash inclusively, that includes an assessment of filter performance while another filter is being backwashed.

"Filtration" means a process for removing particulate matter from water by passage through porous media.

"Finished water" means water that is introduced into the distribution system of a waterworks and is intended for distribution and consumption without further treatment, except as treatment is necessary to maintain water quality in the distribution system (e.g., booster disinfection).

"Flocculation" means a process to enhance agglomeration or collection of smaller floc particles into larger, more easily settleable particles through gentle stirring by hydraulic or mechanical means.

"Flowing stream" means a course of running water flowing in a definite channel.

"Free available chlorine" means that portion of the total chlorine residual remaining in water at the end of a specified contact period that will react chemically and biologically as hypochlorous acid or hypochlorite ion.

"GAC" means granular activated carbon.

"Gross alpha particle activity" means the total radioactivity due to alpha particle emission as inferred from measurements on a dry sample.

"Gross beta particle activity" means the total radioactivity due to beta particle emission as inferred from measurements on a dry sample.

"Groundwater" means all water obtained from sources not classified as surface water.

"Groundwater system" means any waterworks that uses groundwater as its source of supply; however, a waterworks that combines all its groundwater with surface water or with groundwater under the direct influence of surface water before treatment is not a groundwater system. Groundwater systems include consecutive waterworks that receive potable water from another groundwater source.

"Groundwater under the direct influence of surface water" or "GUDI" means any water beneath the surface of the ground with (i) significant occurrence of insects or other macroorganisms, algae, or large-diameter pathogens such as Giardia lamblia or Cryptosporidium or (ii) significant and relatively rapid shifts in water characteristics such as turbidity, temperature, conductivity, or pH that closely correlate to climatological or surface water conditions. GUDI source determinations shall be made by the department in accordance with 12VAC5-590-430.

"GWMA" means the groundwater management area designation by the State Water Control Board.

"Haloacetic acids (five)" or "HAA5" means the sum of the concentrations of the haloacetic acids, expressed in milligrams per liter (mg/L) as rounded to two significant figures. For the purpose of this chapter the HAA5 shall mean monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, and dibromoacetic acid.

"Halogen" means one of the chemical elements chlorine, bromine, fluorine, astatine, or iodine.

"Health hazard" means any condition, device, or practice in a waterworks or its operation that creates, or may create, a danger to the health and well-being of the water consumer.

"HPC" means the heterotrophic plate count of a bacterial population.

"Human consumption" means drinking, food preparation, dishwashing, bathing, showering, hand washing, teeth brushing, and maintaining oral hygiene.

"Hypochlorite" means the ionic component from the disassociation of hypochlorous acid that performs the function of disinfection. It is the available active ingredient in liquid hypochlorite disinfectants such as sodium and calcium hypochlorite.

"Initial compliance period" means the compliance period in which chemical and radiological monitoring began, and it is represented by the first full three-year compliance period beginning at least 18 months after rule promulgation. It applies to inorganic, organic, and radionuclide contaminants listed in Tables 340.1, 340.2, and 340.4, respectively.

"Isolation" means the safeguard against backflow into a waterworks from a consumer's water system by installing an appropriate backflow prevention assembly or device or by installing a backflow elimination method at the sources of potential contamination in the consumer's water system. This is also called point-of-use isolation.

"Karst geology" means an area predominantly underlain by limestone, dolomite, or gypsum and characterized by rapid underground drainage. These areas often feature sinkholes, caverns, and sinking or disappearing creeks.

"Lake or reservoir" means a natural or man-made basin or hollow on the Earth's surface in which water collects or is stored that may or may not have a current or single direction of flow.

"Lead free" means the following: (i) when used with respect to solders and flux, refers to solders and flux containing not more than 0.2% lead; and (ii) when used with respect to pipes, pipe fittings, plumbing fittings, and plumbing fixtures, refers to the weighted average of wetted surfaces of pipes, pipe fittings, plumbing fittings, and plumbing fixtures containing not more than 0.25% lead.

"Lead service line" means a pipeline made of lead that connects the distribution main to the building inlet and any lead pigtail, gooseneck, or other fitting that is connected to the lead pipeline.

"Leakage" means the loss of potable water from the distribution system, up to the points of service connections, through breaks or defects in piping and piping appurtenances.

"Legionella" means a genus of bacteria, some species of which cause a type of pneumonia called Legionnaires disease.

"Level 1 assessment" means an evaluation to identify the possible presence of sanitary defects, defects in distribution system coliform monitoring practices, and, when possible, the likely reason that the waterworks triggered the assessment.

"Level 2 assessment" means an evaluation to identify the possible presence of sanitary defects, defects in distribution system coliform monitoring practices, and, when possible, the likely reason that the waterworks triggered the assessment in a more comprehensive investigation than a Level 1 assessment.

"Locational running annual average" or "LRAA" means the average of sample analytical results for samples taken at a particular monitoring location during the previous four calendar quarters.

"Log inactivation" means the inactivation of organisms expressed on a logarithmic scale. For example, a 99.9% inactivation is a 3-log inactivation; whereas a 99.99% inactivation is a 4-log inactivation.

"Log removal" means the removal of organisms expressed on a logarithmic scale. For example, a 99.9% is a 3-log removal; whereas a 99.99% removal is a 4-log removal.

"Maximum contaminant level" or "MCL" means the maximum permissible level of a contaminant in potable water that is delivered to any consumer of a waterworks. MCLs are set as close to the MCLGs as feasible using the BAT. MCLs may be either "primary" (PMCL), meaning based on health considerations, or "secondary" (SMCL), meaning based on aesthetic considerations.

"Maximum contaminant level goal" or "MCLG" means the maximum level of a contaminant in drinking water at which no known or anticipated adverse effect on the health of persons would occur and that allows an adequate margin of safety. Maximum contaminant level goals are nonenforceable health goals.

"Maximum residual disinfectant level" or "MRDL" means a level of a disinfectant added for water treatment that may not be exceeded at the consumer's tap without an unacceptable possibility of adverse health effects.

"Maximum residual disinfectant level goal" or "MRDLG" means the maximum level of a disinfectant added for water treatment at which no known or anticipated adverse effect on the health of persons would occur, and that allows an adequate margin of safety. MRDLGs are nonenforceable health goals and do not reflect the benefit of the addition of the chemical for control of waterborne microbial contaminants.

"Maximum total trihalomethane potential" or "MTP" means the maximum concentration of total trihalomethanes (TTHMs) produced in a given water containing a residual disinfectant after seven days at a temperature of 25°C or above.

"Membrane filtration" means a pressure or vacuum-driven separation process in which particulate matter larger than one micrometer is rejected by an engineered barrier, primarily through a size exclusion mechanism, and that has a measurable removal efficiency of a target organism that can be verified through the application of a direct integrity test. Included in this definition are the common membrane classifications of microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO).

"Membrane module" means the smallest component of a membrane unit in which a specific membrane surface area is housed in a device with a filtrate outlet.

"Membrane technology" means a process that uses a permeable membrane to remove ions, molecules, or particles from the process stream, such as MF, UF, NF, RO, and electrodialysis reversal (EDR).

"Membrane unit" means a group of membrane modules that share common valving that allows the unit to be isolated from the rest of the system for the purpose of integrity testing or other maintenance.

"Method detection limit" or "MDL" means the minimum concentration of a substance that can be measured and reported with 99% confidence that the analyte concentration is greater than zero and is determined from analysis of a sample in a given matrix containing the analyte.

"Microfiltration" or "MF" means a pressure-driven membrane technology that separates particles, based on the pore-size rating of the membrane, from a feed stream by using a sieving mechanism. Typically, MF can remove particles down to 0.1 micrometer in size.

"Most probable number" or "MPN" means the density or number of organisms per unit volume most likely to be present in a water sample and obtained from method-specific statistical MPN tables.

"MPA" means the microscopic particulate analysis method approved by EPA for use in the determination of whether a groundwater is under the influence of surface water.

"Nanofiltration" or "NF" means a pressure-driven membrane technology designed to remove multivalent ions ("softening") and other constituents based on the pore size, which ranges from one to 10 nanometers. Nanofiltration membranes typically operate under a pressure range of 600 to 1100 psi.

"Noncommunity waterworks" means a waterworks that is not a community waterworks, but operates at least 60 days out of the year.

"Nonpotable water" means water not classified as pure water.

"Nontransient noncommunity waterworks" or "NTNC" means a waterworks that is not a community waterworks and that regularly serves at least 25 of the same persons over six months out of the year. When used in the context of an NTNC, "regularly serves" means four or more hours per day, for four or more days per week, for 26 or more weeks per year.

"NSF" means NSF International, formerly known as the National Sanitation Foundation. NSF collaborates with ANSI and Canadian authorities on drinking water standards development (NSF/ANSI/CAN).

"One hundred year flood elevation" or "100-year flood elevation" means flood elevation that has a 1.0% probability of being equaled or exceeded in any given year.

"Operating staff" means individuals employed or appointed by an owner to work at a waterworks. Included in this definition are operators, whether or not the operator's license is appropriate for the classification and category of the waterworks, and unlicensed individuals.

"Operator" means any individual with the requisite skills, employed or appointed by any owner, who is designated by the owner to be the person having full responsibility for the waterworks operations and any subordinate operating staff. The individual may be a supervisor, a shift operator, or a substitute in charge, and have duties including testing or evaluation to control waterworks operations. Not included in this definition are superintendents or directors of public works, city engineers, or other municipal or industrial officials whose duties do not include the actual operation or direct supervision of waterworks.

"Optimal corrosion control treatment" means the corrosion control treatment that minimizes the lead and copper concentrations at consumers' taps while ensuring that the treatment does not cause the waterworks to violate any other section of this chapter.

"Optimum fluoride ion concentration" means that fluoride ion concentration recommended by the U.S. Public Health Service for protection from dental caries.

"Owner" means an individual, group of individuals, partnership, firm, association, institution, corporation, governmental entity, or the federal government that supplies or proposes to supply water to any person within the Commonwealth from or by means of any waterworks.

"PAC" means powdered activated carbon.

"PCBs" means polychlorinated biphenyls.

"PER" means a preliminary engineering report.

"Permit" means an authorization granted by the commissioner to construct or operate a waterworks.

"Permitted capacity" means the limiting hydraulic capability of the waterworks, taking into consideration the source water capacity, treatment facilities, finished water storage, delivery, and distribution system.

"Person" means any individual, corporation, partnership, association, cooperative, limited liability company, trust, joint venture, government, political subdivision, or any other legal or commercial entity and any successor, representative, agent, or instrumentality thereof.

"pH" means the negative logarithm of the hydrogen ion concentration of an aqueous solution.

"Physical disconnection" means the removal or absence of pipes, fittings, or fixtures that connect a waterworks directly or indirectly to any other water system.

"Picocurie" or "pCi" means that quantity of radioactive material producing 2.22 nuclear transformations per minute.

"PMCL" means the primary maximum contaminant level of a contaminant based on health considerations.

"Point of disinfectant application" means the point where the disinfectant is applied and water downstream of that point is not subject to recontamination by surface runoff.

"Point-of-entry device" or "POE device" means a treatment device applied to the water entering a house or building for the purpose of reducing contaminants in the water distributed throughout the house or building.

"Point-of-use device" or "POU device" means a treatment device applied to a single tap for the purpose of reducing contaminants in the water at that one tap.

"Pollution" means the presence of any foreign substance (chemical, physical, radiological, or biological) in water that tends to degrade its quality so as to constitute an unnecessary risk to human health or impair the usefulness of the water.

"Potable water" means the same as "pure water."

"Practical quantitation level" or "PQL" means the lowest level that can be reliably measured within specified limits of precision and accuracy during routine laboratory conditions.

"Prechlorination" means the application of chlorine to water before filtration.

"Presedimentation" means a preliminary treatment process used to remove gravel, sand, and other particulate material from the source water through settling before the water enters the primary clarification and filtration processes in a water treatment plant.

"Pressure vacuum breaker assembly" means a backflow prevention assembly (i) designed to prevent backsiphonage and used for high hazard or low hazard situations; (ii) composed of an independently operating spring-loaded check valve, an independently operating spring-loaded air-inlet valve, and tightly closing shutoff valves located at each end of the assembly; and (iii) fitted with properly located test cocks to facilitate testing of the assembly.

"Primary disinfection" means disinfection to achieve a desired level of inactivation of targeted pathogenic organisms in water by chemical or physical agents as an integral part of the treatment process.

"Process fluids" means any fluid or solution that may be chemically, biologically, or otherwise contaminated or polluted that would constitute a health, environmental, or system hazard if introduced into the waterworks. This includes (i) polluted or contaminated water; (ii) used waters; (iii) cooling waters; (iv) contaminated natural waters taken from wells, lakes or reservoirs, streams, or irrigation systems; (v) chemicals in solution or suspension; or (vi) oils, gases, acids, alkalis, and other liquid and gaseous fluid used in industrial or other processes.

"Process water" means water used for dissolving dry chemicals; diluting liquid chemicals; and operating chemical feeders, treatment facilities, or equipment.

"Project documents" means the engineer's report, design criteria, preliminary and final plans, specifications, and procurement documents for the construction of new waterworks or modifications to existing waterworks.

"Pure water" means water fit for human consumption that is (i) sanitary and normally free of minerals, organic substances, and toxic agents in excess of reasonable amounts and (ii) adequate in quantity and quality for the minimum health requirements of the persons served.

"QCRV" means the quality control release value used in challenge tests of microfiltration (MF) and ultrafiltration (UF) membrane filters.

"RAA" means running annual average.

"Reduced pressure principle backflow prevention assembly" or "reduced pressure zone backflow prevention assembly" or "RPZ assembly" means an assembly designed to prevent backsiphonage or backpressure backflow and used for high or low hazard situations, composed of two independently operating spring-loaded check valves together with an independent, hydraulically operating pressure differential relief valve located between the two check valves. During normal flow and at the cessation of normal flow, the pressure between these two checks shall be less than the supply pressure. The assembly shall include tightly closing shutoff valves located at each end of the RPZ assembly and shall be fitted with properly located test cocks to facilitate testing of the assembly.

"REM" means the unit of dose equivalent from ionizing radiation to the total body or any internal organ or organ system. A millirem (mrem) is 1/1000 of an REM.

"Repeat compliance period" means any subsequent compliance period after the initial compliance period.

"Residual disinfectant concentration" means the concentration of disinfectant measured in mg/L in a representative sample of water.

"Reverse osmosis" or "RO" means a membrane technology designed to remove salts, low-molecular weight solutes, and all other constituents up to 0.0001 micron in size by applying a pressure in excess of osmotic pressure to force water through a semi-permeable membrane from a region of high solution concentration to a region of lower solution concentration.

"Sanitary defect" means a defect that could provide a pathway of entry for microbial contamination into the distribution system or that is indicative of a failure or imminent failure in a protective barrier that is already in place.

"Sanitary survey" means an evaluation conducted by the department of a waterworks' water supply, facilities, equipment, operation, maintenance, monitoring records, and overall management to ensure the provision of potable water.

"SDWA" means the Safe Drinking Water Act (42 USC § 300f et seq.) and its amendments.

"Seasonal waterworks" means a noncommunity waterworks that is not operated as a waterworks on a year-round basis, and starts up and shuts down at the beginning and end of each operating season.

"Secondary disinfection" means disinfection by chemical oxidants or equivalent agents applied at the entry point or in the distribution system to provide a residual disinfectant in water to maintain water quality and safeguard against chance contamination from permeation, leaching, intrusion, regrowth, or biofilms.

"Sedimentation" means a process for removal of solids before filtration by gravity or separation.

"Service connection" means the point of delivery of finished water from a waterworks to a consumer's water system, fire protection system, irrigation system, and to all other points where finished water is delivered through the distribution system to a consumer. Generally, the service connection occurs at the water meter, or at the distribution main if no water meter is installed, or in the case of an owner of both the waterworks and the building supplied, the point of entry into the building. Service connections may be permanent, temporary, or emergency.

"Service line" means the pipeline or service pipe between the service connection and the building connection.

"Sewer" means any pipe or conduit used to convey sanitary sewage, stormwater, or industrial waste streams. Combined sewers convey both stormwater and sanitary sewage.

"Significant deficiency" means any defect in a waterworks' design, operation, maintenance, or administration, as well as the failure or malfunction of any waterworks component that may cause or has the potential to cause, an unacceptable risk to health or could affect the reliable delivery of potable water to consumers.

"Single-family structure" means, for the purpose of 12VAC5-590-375 B only, a building constructed as a single-family residence that is currently used as either a residence or a place of business.

"Site visit" means a tour of a waterworks by the department or other authorized persons for purposes including assessing and documenting its physical condition, operations, and compliance activities.

"Slow sand filtration" means a process involving passage of source water through a bed of sand at low velocity (generally less than 0.4 m/h), resulting in substantial particulate removal by physical and biological mechanisms.

"SMCL" means the secondary maximum contaminant level of a contaminant. SMCLs are based on aesthetic qualities related to the public acceptance of drinking water.

"SOP" means standard operating procedure.

"Source water" means water as it is pumped or otherwise withdrawn from a well, spring, stream, lake or reservoir, or any body of surface water (natural or impounded), and before any treatment.

"Supervisory control and data acquisition" or "SCADA" means a computer-controlled system used by a waterworks to monitor its operations. Typical design features may be specific to individual waterworks and include alarm, response, control, and data acquisition.

"Surface water" means all water open to the atmosphere and subject to surface runoff.

"SUVA" means specific ultraviolet absorption at 254 nanometers (nm), an indicator of the humic content of the water. It is a calculated parameter obtained by dividing a sample's ultraviolet absorption at a wavelength of 254 nm (UV254) (in m-1) by its concentration of DOC (in mg/L).

"Synthetic organic chemical" or "SOC" means a man-made organic compound, generally utilized for agriculture or industrial purposes. Table 340.2 lists SOCs regulated as contaminants.

"System hazard" means a condition posing an actual, or threat of, damage to the physical properties of the waterworks or a consumer's water system.

"TDS" means total dissolved solids.

"TMF" means the technical, managerial, and financial capabilities to operate and maintain a waterworks.

"Too numerous to count" or "TNTC" means that the total number of bacterial colonies exceeds 200 on a 47-mm diameter membrane filter used for coliform detection.

"Total organic carbon" or "TOC" means total organic carbon in milligrams per liter (mg/l) measured using heat, oxygen, ultraviolet irradiation, chemical oxidants, or combinations of these oxidants that convert organic carbon to carbon dioxide, rounded to two significant figures.

"Total trihalomethanes" or "TTHM" means the sum of the concentrations of the trihalomethanes (THMs) expressed in milligrams per liter (mg/L) and rounded to two significant figures. For the purpose of this chapter, TTHM shall mean trichloromethane (chloroform), dibromochloromethane, bromodichloromethane, and tribromomethane (bromoform).

"Transient noncommunity waterworks" or "TNC" means a noncommunity waterworks that is not a nontransient noncommunity waterworks (NTNC). A TNC serves at least 25 persons daily for at least 60 days out of the year.

"Treatment" means any process that changes the chemical, physical, radiological, or bacteriological quality of water.

"Treatment technique" or "TT" means a technology or process demonstrated to the satisfaction of the department to lead to a reduction in the level of a specific contaminant sufficient to comply with this chapter.

"Triggered source water monitoring" means monitoring required of any groundwater system as a result of a total coliform-positive sample in the distribution system.

"Trihalomethane" or "THM" means one of the family of organic compounds, named as derivatives of methane, wherein three of the four hydrogen atoms in methane are each substituted by a halogen atom in the molecular structure.

"Ultrafiltration" or "UF" means a membrane technology designed to remove particles up to 0.01 micron in size.

"Unconsolidated" means loose sediment that has not been compacted, cemented, lithified, or metamorphosed into rock. Sediment may be derived from a sedimentary-type, igneous-type, metamorphic-type rock, which includes clay, silt, sand, gravel, and mixtures of these particle types.

"Uncovered finished water storage facility" means a tank, reservoir, or other facility used to store water that will undergo no further treatment to reduce microbial pathogens (except residual disinfection) and is directly open to the atmosphere.

"Unregulated contaminant" or "UC" means a contaminant for which a monitoring requirement has been established, but for which no MCL or treatment technique requirement has been established.

"USBC" means the Uniform Statewide Building Code (13VAC5-63).

"Used water" means any water supplied by a waterworks to a consumer's water system after it has passed through the service connection and is no longer under the control of the owner.

"UV" means ultraviolet.

"Variance" means allowing a waterworks that satisfies the criteria in 12VAC5-590-140 to provide drinking water that does not fully comply with this chapter. A PMCL variance is a variance to a primary maximum contaminant level, or a treatment technique requirement. An operational variance is a variance to an operational regulation or a SMCL.

"Virus" means a virus of fecal origin that is infectious to humans by waterborne transmission and must be preemptively inactivated through disinfection before human consumption.

"Volatile organic chemical" or "VOC" means an organic compound generally characterized by its low molecular weight and its tendency to vaporize rapidly at relatively low temperatures and pressures. Table 340.2 lists VOCs regulated as contaminants.

"VOSH" means the Virginia Occupational Safety and Health program.

"Waiver" means permission from the department to deviate from the monitoring and reporting requirements in this chapter for a specific contaminant.

"Waterborne disease outbreak" means the significant occurrence of acute infectious illness, epidemiologically associated with the ingestion of water from a waterworks that is deficient in treatment, as determined by the commissioner or the State Epidemiologist.

"Water supply" means the source of water taken into a waterworks including wells, streams, springs, lakes or reservoirs, and other bodies of surface waters (natural or impounded), and the tributaries thereto, and all impounded groundwater. The term "water supply" shall not include any waters above the point of intake of the waterworks.

"Water treatment plant" means that portion of a waterworks intended specifically for water treatment; it may include, among other operations, coagulation, sedimentation, filtration, and disinfection.

"Waterworks" means a system that serves piped water for human consumption to at least 15 service connections or 25 or more individuals for at least 60 days out of the year. "Waterworks" includes all structures, equipment, and appurtenances used in the storage, collection, purification, treatment, and distribution of potable water except the piping and fixtures inside the building where such water is delivered.

"Waterworks business operation plan" means the same as "comprehensive business plan."

"Wholesale waterworks" means a waterworks that treats source water as necessary to produce potable water and then delivers some or all of that potable water to another waterworks. Delivery may be through a direct connection or through the distribution system of one or more consecutive waterworks.

B. As used in this chapter, the following units of measurement shall use the abbreviations as shown in this subsection:

C – degrees Celsius

CU – color units

ft2 – square feet of area

ft/min – feet per minute

ft/sec – feet per second

gpd – gallons per day

gpd/ft2 – gallons per day per square foot

gpm – gallons per minute

gpm/ft – gallons per minute per foot

gpm/ft2 – gallons per minute per square foot

in – inches

lb – pounds

lb/day – pounds per day

lb/ft2 – pounds per square foot

MFL – million fibers per liter

MGD – million gallons per day

mg/L – milligrams per liter

min – minutes

mJ/cm2 – millijoules per square centimeter

mrem – millirem

nm – nanometer (10-9 meter)

NTU – nephelometric turbidity units

pCi – picocuries

pCi/L – picocuries per liter

ppb – parts per billion, or micrograms per liter (μg/L)

ppm – parts per million, or milligrams per liter (mg/L)

ppq – parts per quadrillion, or pictograms per liter (pq/L)

ppt – parts per trillion, or nanograms per liter (ng/L)

psi – pounds per square inch

psig – pounds per square inch gauge

scfm/ft2 – standard cubic feet per minute per square foot

µm – micrometers (10-6 meter or microns)

µg/L – micrograms per liter

µS/cm – microSiemens per centimeter

W/m2 – Watts per square meter

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-001.02 § 1.1, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 12, Issue 2, eff. November 15, 1995; Volume 18, Issue 19, eff. July 3, 2002; Volume 19, Issue 17, eff. June 4, 2003; Volume 21, Issue 13, eff. April 6, 2005; Volume 22, Issue 24, eff. September 6, 2006; Volume 25, Issue 5, eff. December 10, 2008; Volume 27, Issue 1, eff. October 13, 2010; Volume 28, Issue 5, eff. December 7, 2011; Volume 28, Issue 19, eff. June 21, 2012; Volume 31, Issue 1, eff. October 10, 2014; Volume 33, Issue 3, eff. November 2, 2016; Volume 37, Issue 20, eff. June 23, 2021; Errata, 37:22 VA.R. 3447 June 21, 2021.

Article 2
General Information [Repealed]

12VAC5-590-20. (Repealed.)

Historical Notes

Derived from VR355-18-002.01 § 1.3, eff. August 1, 1991; repealed, Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-30. (Repealed.)

Historical Notes

Derived from VR355-18-002.02 § 1.4, eff. August 1, 1991; repealed, Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-35. Delegation of authority.

The commissioner, or the commissioner's designee, may perform any act of the board provided under this chapter, except as limited by § 32.1-20 of the Code of Virginia.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-40. Administration of this chapter.

A. The board is responsible for promulgating, amending, and repealing regulations to ensure a supply of potable water.

B. The commissioner is vested with all the authority of the board when it is not in session, subject to such rules and regulations as may be prescribed by the board.

C. The department is designated as the primary agent of the board for the purpose of administering this chapter. It examines the technical aspects of all applications and plans for waterworks projects before drafting a permit for final approval by the commissioner. It also has primary responsibility for monitoring waterworks operations to ensure that water supplied to consumers is potable water.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-002.03 § 1.5, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 20, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-45. Waterworks Advisory Committee.

A. A Waterworks Advisory Committee (WAC) shall be formed by the commissioner to review and make recommendations regarding the regulatory, policy, and legislative aspects of the department's authorities. WAC members shall consist of industry professionals employed outside the department with longstanding expertise or vested interest in waterworks operations and represent a diverse group of stakeholders. Members shall be experts in the fields of water treatment technologies, public health, water quality, economics, environmental science, public utilities, community development, or industry regulations. A minimum of nine persons shall be appointed to the committee by the commissioner.

B. The WAC will convene at least quarterly.

C. WAC meetings will be considered public meetings. Notice of scheduled meetings will be posted on the Virginia Regulatory Town Hall at least three working days before the date of the meeting. Meeting minutes will be posted to the Virginia Regulatory Town Hall within 10 working days after the meeting.

D. Each member of the WAC shall hold office for a term of three years, except that:

1. With approval by the commissioner, members are eligible for reappointment to consecutive terms.

2. Each member of the WAC serves at the pleasure of the commissioner.

E. The commissioner shall appoint the chair of the WAC.

F. The WAC shall have a member of the department serve as secretary.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-50. Application of  this chapter to waterworks in operation or planned before  June 23, 2021.

A. The owner shall comply with Part II (12VAC5-590-340 et seq.) of this chapter unless a variance or exemption is issued by the commissioner.

B. Compliance with design criteria set forth in Part III of this chapter is limited to modifications to existing waterworks and for all construction of new waterworks commenced after June 23, 2021. Portions of waterworks not being modified are not required to comply with the design criteria of Part III (12VAC5-590-640 et seq.). Waterworks construction or modification is deemed to be commenced for purposes of this section upon issuance of the construction permit.

C. Compliance with the requirements set forth in Part III of this chapter including those for materials, construction methods, and disinfection is necessary for all repairs to pipes, tanks, pumps, and appurtenances that are part of a waterworks.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-002.04 § 1.6, eff. August 1, 1991; amended, Virginia Register Volume 12, Issue 2, eff. November 15, 1995; Volume 27, Issue 1, eff. October 13, 2010; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-55. Relationship of this chapter to the Uniform Statewide Building Code.

A. This chapter governs waterworks facilities from any source water to all service connections.

B. In accordance with § 36-98 of the Code of Virginia and the USBC, the USBC governs the construction of buildings and structures, including plumbing systems and backflow prevention. The USBC also governs the water service piping from the service connection to a building or structure.

C. Notwithstanding subsections A and B of this section, this chapter shall govern:

1. Water treatment, storage, pumping facilities, and water piping that are part of a waterworks and housed in any building or structure; and

2. Backflow prevention assemblies or elimination methods, or both, installed for containment and located downstream from the service connection, including where located in any building or structure.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

Article 3
Procedures [Repealed]

12VAC5-590-60. (Repealed.)

Historical Notes

Derived from VR355-18-003.01 § 1.7, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; repealed, Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-70. Powers and procedures.

The board reserves the right to utilize any lawful procedure for the enforcement of this chapter.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-003.02 § 1.8, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-80. (Repealed.)

Historical Notes

Derived from VR355-18-003.03 § 1.9, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; repealed, Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-90. [Reserved]. (Reserved)

12VAC5-590-100. Exception; emergency regulations.

If the establishment of a regulation is necessary to meet any emergency not provided for by this chapter, the board or commissioner acting on behalf of the board when it is not in session may immediately promulgate and adopt the necessary regulation by complying with the procedures set forth in either § 2.2-4011 or § 32.1-13 of the Code of Virginia.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-003.05 § 1.11, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-110. Enforcement.

A. Notice. Whenever the department has reason to believe that a violation of Title 32.1 of the Code of Virginia or of any section of this chapter may have occurred or may be occurring, the department shall notify the alleged violator. The notice shall (i) be in writing; (ii) cite the statute or regulations that are allegedly being violated; (iii) state the facts that form the basis for believing that the violation may have occurred or may be occurring; and (iv) include information on the process for obtaining a final decision or fact finding from the department on whether or not a violation has occurred. This notification is not an official finding, case decision, or adjudication but may include a request to the owner to respond timely and to take specific corrective action by a stated deadline.

B. Orders. Pursuant to § 32.1-26 of the Code of Virginia, the board may issue orders to require any owner to comply with the provisions of any law administered by it, the commissioner, or the department; any regulations promulgated by the board, including any section of this chapter; or any case decision of the board or commissioner. The commissioner, acting on behalf of the board when it is not in session, will sign the order, and the order may require:

1. The immediate cessation or correction of the violation;

2. The acquisition or use of additional equipment, supplies, or personnel to ensure that the violation does not recur;

3. The submission of a plan to prevent future violations;

4. The submission of an application for a variance or exemption;

5. Any other corrective action deemed necessary for proper compliance with this chapter; or

6. An evaluation and approval of the required submissions, if appropriate.

C. Compliance with effective orders and this chapter. The commissioner may act as the agent of the board to enforce all effective orders and this chapter. Should any owner fail to comply with any effective order or this chapter, the commissioner may:

1. Institute an administrative proceeding to revoke the owner's permit in accordance with 12VAC5-590-320 and § 32.1-174 of the Code of Virginia or other appropriate administrative remedies;

2. Request the criminal prosecution by a Commonwealth's attorney with the appropriate jurisdiction in accordance with § 32.1-27 of the Code of Virginia;

3. Request civil action by the Attorney General to impose a civil penalty, seek injunctive relief, or other appropriate legal remedies pursuant to §§ 32.1-27 and 32.1-176 of the Code of Virginia; or

4. Do any combination of subdivision C 1, C 2, or C 3 of this section.

D. Special order. Pursuant to § 32.1-175.01 of the Code of Virginia, the commissioner may, after an informal fact-finding proceeding held in accordance with § 2.2-4019 of the Code of Virginia, issue a special order that may include a civil penalty against an owner who violates the Public Water Supplies Law, §§ 32.1-167 through 32.1-176 of the Code of Virginia, this chapter, or any order of the board.

E. Graduated enforcement actions. Nothing in this section shall prevent the commissioner or department from making efforts to obtain voluntary compliance through conference, warning, or other appropriate means before issuance of an order, instituting an administrative proceeding, or requesting an action by a Commonwealth's Attorney or the Attorney General.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-003.06 § 1.12, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-115. Administrative proceedings.

A. Types of administrative proceedings. Administrative proceedings before the board, the commissioner, or the commissioner's designee, shall include the following forms depending upon the nature of the controversy and the interests of the named party involved.

1. An informal fact-finding proceeding is an informal conference between the department and the named party held in accordance with § 2.2-4019 of the Code of Virginia.

2. A formal hearing is an adjudicatory proceeding before the commissioner or a designated hearing officer held in accordance with § 2.2-4020 of the Code of Virginia.

B. Request for administrative proceeding. The named party may request an administrative proceeding by sending a request in writing to the department.

C. Administrative proceeding as a matter of right. The named party whose rights, duties, or privileges have been or may be affected by any action or inaction of the board, commissioner, or department in the administration of this chapter, has a right to both an informal fact-finding proceeding and a formal hearing; however, the commissioner reserves the right to require participation in an informal fact-finding proceeding before granting the request for a formal hearing.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-120. Emergency orders.

A. The commissioner may, pursuant to § 32.1-175 of the Code of Virginia, issue emergency orders in any case where there is an imminent danger to the public health resulting from the operation of any waterworks or the source of a water supply.

B. An emergency order may be communicated by the best practical notice under all the circumstances and is effective immediately upon receipt. The commissioner may order the immediate cessation of the operation of any waterworks or the use of any water supply or the correction of any condition causing the production or distribution of any water constituting an imminent danger to the public health and welfare.

C. Violation of an emergency order is subject to civil enforcement and is punishable as a criminal misdemeanor.

D. Emergency orders shall be effective for a period determined by the commissioner.

E. Emergency orders may be appealed in accordance with the provisions of the APA.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-003.07 § 1.13, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-125. Chronically noncompliant waterworks.

A. If the commissioner or department determines that a waterworks is a chronically noncompliant waterworks, as defined in § 32.1-167 of the Code of Virginia, then the commissioner shall issue an order to the owner containing a schedule to bring the waterworks into compliance with this chapter and require the submission of a waterworks business operation plan. If capital improvements are necessary to bring the waterworks into compliance, and the owner does not possess sufficient assets to make the necessary improvements, the order shall require the owner to make annual, good faith applications for loans, grants, or both, to appropriate financial institutions to secure funding for such improvements, until the improvements are complete and operational. The owner shall provide a copy of the order to each consumer within 10 calendar days of issuance of the order.

B. Within 15 calendar days of issuance of the commissioner's order, the owner shall certify in writing that a copy of the order was distributed to each consumer within the 10-day period specified in subsection A of this section.

C. The commissioner shall send a copy of the order to the chief administrative officer of the locality in which the waterworks is located for appropriate action under § 15.2-2146 of the Code of Virginia.

D. In addition to the provisions of § 32.1-27 of the Code of Virginia, any owner who violates this chapter, an order of the board, or a statute governing public water supplies shall be subject to those civil penalties provided in Article 2 (§ 32.1-167 et seq.) of Chapter 6 of Title 32.1 of the Code of Virginia.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 28, Issue 19, eff. June 21, 2012; amended, Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-130. Suspension of this chapter.

If, in the case of a man-made or natural disaster, the commissioner determines that certain regulations cannot be complied with, then the enforcement of those regulations may be suspended for designated waterworks and a provisional regulatory scheme instituted until the conditions that brought about the suspension have abated.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-003.08 § 1.14, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-140. Variances.

A. The commissioner may grant a variance to a PMCL, SMCL, treatment technique requirement, or an operational regulation by following the appropriate procedures set forth in this section.

1. Requirements for a variance. A variance may be granted to a waterworks from any requirement with respect to a PMCL or SMCL upon a finding that:

a. Alternative water supplies are not reasonably available to the waterworks;

b. The characteristics of the source water that is reasonably available to the waterworks prevents the waterworks from meeting the PMCL or SMCL requirements, and on condition that the waterworks installs the BAT, treatment techniques, or other means, that the department finds are generally available (taking costs into consideration); and

c. The granting of a variance will not result in an unreasonable risk to the health of persons served by the waterworks.

2. The commissioner may grant one or more treatment technique variances to a waterworks from any requirement of a specified treatment technique upon a finding that the waterworks applying for the variance has demonstrated that the treatment technique is not necessary to protect the health of persons because of the nature of the source water at the waterworks.

3. The commissioner may grant a variance to a waterworks from an operational regulation if a thorough investigation reveals that the hardship imposed outweighs the benefits that may be received by the public and that the granting of the variance does not subject the public to unreasonable health risks.

4. An operational variance may not be issued from monitoring, reporting, or public notification requirements.

B. Request for a variance. Any owner may apply in writing for a variance. The request shall be sent to the department for evaluation. All requests for a variance shall include the following:

1. A citation of the regulation from which a variance is requested;

2. The nature and duration of the variance requested;

3. Relevant analytical results of water quality sampling of the waterworks, including results of relevant tests conducted pursuant to the requirements of this chapter;

4. A statement of the hardship to the owner and the anticipated impacts to the public health and welfare if a variance were granted;

5. Suggested conditions that might be imposed on the granting of a variance that would limit its detrimental impact on public health and welfare;

6. Other information, if any, believed by the owner to be pertinent to the request; and

7. Any other information as may be required by the commissioner to make the determination.

C. For any request made for a PMCL variance, the owner shall also include:

1. An explanation in full and evidence of the BAT;

2. The economic and legal factors relevant to the owner's ability to comply;

3. The analytic results of source water quality relevant to the variance request;

4. A proposed compliance schedule including the date each step toward compliance will be achieved. The schedule shall include as a minimum the following dates:

a. The date by which arrangement for an alternative source water or improvement of an existing source water will be completed;

b. The date of initiation of the connection of the alternative source water or improvement of the existing source water; and

c. The date by which final compliance is to be achieved.

5. A plan for the provision of potable water in the case of an excessive rise in the contaminant level for which the variance is requested;

6. A plan for interim control measures during the effective period of the variance; and

7. A plan for notifying the consumers at least once every three months, or more frequently if determined by the commissioner, that the waterworks is operating under the conditions of a variance.

D. For any request made for a treatment technique variance, the owner must also include a statement that monitoring and other reasonable requirements prescribed by the commissioner as a condition to the variance will be performed.

E. Consideration of a variance request.

1. The commissioner shall act on any variance request submitted pursuant to subsection B of this section within 90 days of receipt of the submittal.

2. The commissioner will consider comments received during the comment period and testimony in the record of a public hearing held before making a determination.

3. In the commissioner's consideration of whether the waterworks is unable to comply with a contaminant level required by this chapter because of the nature of the source water, the commissioner shall consider such factors as the following:

a. The availability and effectiveness of BAT for which the variance is requested; and

b. The cost and other economic considerations such as implementing treatment, improving the quality of the source water, or using an alternate source.

4. In the commissioner's consideration of whether a waterworks should be granted a variance to a required treatment technique because the treatment is unnecessary to protect the public health, the commissioner shall consider such factors as the following:

a. Quality of the source water including water quality data and pertinent sources of pollution; and

b. Source protection measures employed by the waterworks.

5. In the commissioner's consideration of whether a waterworks should be granted a variance to a required operational procedure, the commissioner shall consider such factors as the following:

a. The effect that such a variance would have on the adequate operation of the waterworks, including operator safety in accordance with VOSH laws and regulations;

b. The cost and other economic considerations imposed by this requirement; and

c. The effect that such a variance would have on the protection of the public health.

F. Disposition of a variance request.

1. The commissioner may reject any request for a variance by sending a rejection notice to the applicant. The rejection notice shall be in writing and shall state the reasons for the rejection. A rejection notice constitutes a case decision. If the commissioner proposes to deny the variance, the owner shall be provided with an opportunity for an informal fact-finding proceeding as provided in § 2.2-4019 of the Code of Virginia.

2. If the commissioner grants the variance, the applicant shall be notified in writing of this decision. The notice shall identify the variance, the waterworks covered, and shall specify the period of time for which the variance will be effective.

a. For a PMCL variance as specified in subdivision A 1 of this section, the notice shall provide that the variance will be terminated when the waterworks comes into compliance with the applicable regulation and may be terminated upon a finding by the commissioner that the waterworks has failed to comply with any requirements of a final schedule issued pursuant to subdivision F 3 of this section.

b. For a treatment technique variance as specified in subdivision A 2 of this section, the notice shall provide that the variance may be terminated at any time upon a finding by the commissioner that the nature of the source water is such that the specified treatment technique for which the variance was granted is necessary to protect the public health or upon a finding that the waterworks has failed to comply with monitoring and other requirements prescribed by the commissioner as a condition to the granting of the variance.

c. For an operational variance as specified in subdivision A 3 of this section, the notice shall provide that the variance will be terminated when the waterworks comes into compliance with the applicable regulation and may be terminated upon a finding by the commissioner that the waterworks has failed to comply with any requirements or schedules issued in conjunction with the variance. The effective date of the operational variance shall be the date of its issuance. A public hearing is not required before the issuance of an operational variance.

3. Schedules pursuant to PMCL and treatment technique variances:

a. The proposed schedule for compliance shall specify dates by which steps toward compliance are to be taken, including where applicable:

(1) Date by which arrangement for the alternative source water or improvement of the existing source water will be completed;

(2) Date of connection to the alternative source water or improvement of the existing source water; and

(3) Date by which final compliance is to be achieved.

b. If the waterworks has no access to an alternative source water and can effect or anticipate no adequate improvement of the existing source water, then the proposed schedule may specify an indefinite time period for compliance until a new and effective treatment technology is developed, at which time a new compliance schedule shall be prescribed by the commissioner.

c. The schedule for implementation of interim control measures during the period of variance shall specify interim treatment techniques, methods, and equipment and dates by which steps toward meeting the interim control measures are to be met.

d. The schedule shall be prescribed by the commissioner at the time the variance is granted.

e. For a PMCL variance specified in subdivision A 1 of this section, the commissioner shall propose a schedule for:

(1) Compliance (including increments of progress) by the waterworks with each contaminant level requirement covered by the variance; and

(2) Implementation by the waterworks of such control measures as the commissioner may require for each contaminant level covered by the variance.

G. Public hearings on PMCL and treatment technique variances and their schedules.

1. Notice of a public hearing shall be provided before a variance and schedule proposed by the commissioner pursuant to subsection F of this section may take effect. A notice given pursuant to this subsection may cover the granting of more than one variance and a public hearing held pursuant to such notice shall include each of the variances covered by the notice.

2. Notice of a public hearing on a request for a variance and its schedule shall be advertised in at least one major newspaper of general circulation in the region in which the waterworks is located. The notice shall include a summary of the proposed variance and its schedule and shall contain the time, date, and place of the public hearing. If the schedule exceeds five years from the date of the variance, then the rationale for the extended compliance schedule shall be discussed in the notice.

H. Issuance of variance.

1. Within 30 days after the public hearing, the commissioner shall, taking into consideration information obtained during such hearing, revise the proposed variance as necessary and prescribe the final schedule for compliance and interim measures for the waterworks granted a variance. If the schedule for compliance exceeds five years from the date of issuance of the variance, then the commissioner shall document the rationale for the extended compliance schedule.

2. The compliance schedule shall establish the timetable by which the waterworks shall comply with each contaminant level and treatment technique requirement prescribed by this chapter. Such schedule shall also consider if the waterworks is to become part of a regional waterworks. The compliance schedule shall provide the shortest practicable time schedule under the circumstances.

I. Posting of variances. All variances granted to any waterworks are nontransferable. Each variance must be attached to the permit of the waterworks to which it is granted. Each variance is a condition to that permit and is revoked when the permit is revoked.

J. No variances shall be granted to 12VAC5-590-380, 12VAC5-590-388, 12VAC5-590-395, or 12VAC5-590-411.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-003.09 § 1.15, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 19, Issue 24, eff. September 10, 2003; Volume 21, Issue 16, eff. May 18, 2005; Volume 33, Issue 3, eff. November 2, 2016; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-150. Exemptions.

A. The commissioner may grant an exemption to any PMCL or treatment technique requirement by following the procedures set forth in this section. An exemption may be granted to a waterworks upon a finding that:

1. The waterworks must be unable to implement measures to develop an alternative water supply;

2. The waterworks cannot reasonably make management or restructuring changes that will result in compliance or improve the quality of the drinking water;

3. Due to compelling factors (which may include economic factors), the waterworks is unable to comply with contaminant level or treatment technique requirements;

4. The granting of the exemption will not result in an unreasonable risk to the health of persons served by the waterworks;

5. The waterworks was in operation on the effective date of such contaminant level or treatment technique requirements; and

6. The waterworks has not been granted a variance.

B. The owner may request an exemption for a waterworks by submitting a written request to the department for evaluation. All requests for an exemption shall include the following information:

1. A citation to the regulation from which the exemption is requested;

2. The nature and duration of the exemption requested;

3. The relevant analytical results of water quality sampling of the waterworks, including results of relevant tests conducted pursuant to the requirements of this chapter;

4. An explanation of the compelling factors such as time or economic factors that prevent such waterworks from achieving compliance;

5. Other information believed by the owner to be pertinent to the request;

6. A proposed compliance schedule, including the date when each step toward compliance will be achieved; and

7. Other information as may be required by the commissioner to make the determination.

C. Consideration of an exemption request.

1. The commissioner shall act on any exemption request submitted pursuant to subsection B of this section within 90 days of receipt of the request.

2. In the commissioner's consideration of whether the waterworks is unable to comply due to compelling factors, the commissioner shall consider such factors as the following:

a. The construction, installation, or modification of treatment equipment or systems;

b. The time needed to put a new water treatment plant into operation to replace an existing water treatment plant that is not in compliance;

c. The economic feasibility of compliance;

d. The availability of Drinking Water State Revolving Fund, a department program to assist waterworks in achieving the public health protection objectives of the SDWA, assistance or any other federal or state program that is reasonably likely to be available within the period of the exemption;

e. The consideration of rate increases, accounting changes, the appointment of a licensed operator under the state operator's licensure program, or contractual agreements for joint operation with one or more waterworks;

f. The activities consistent with Virginia's capacity development strategy to help the waterworks acquire and maintain technical, financial, and managerial capacity to come into compliance;

g. The ownership changes, physical consolidation with another waterworks, or other feasible and appropriate means of consolidation that would result in compliance; and

h. The availability of an alternative source of drinking water, including the feasibility of partnerships with neighboring waterworks, as identified by the waterworks or by the commissioner consistent with the capacity development strategy.

D. Disposition of an exemption request.

1. The commissioner may reject any request for an exemption by sending a rejection notice to the owner. The rejection notice shall be in writing and shall state the reasons for the rejection. A rejection notice constitutes a case decision. If the commissioner proposes to deny the exemption, then the owner shall be provided with an opportunity for an informal fact-finding proceeding as provided in § 2.2-4019 of the Code of Virginia.

2. If the commissioner grants the exemption, then the owner shall be notified in writing of this decision. The notice shall identify the exemption and the waterworks covered and shall specify the termination date of the exemption. Exemptions shall be terminated when the waterworks comes into compliance with the applicable regulation and may be terminated upon a finding by the commissioner that the waterworks has failed to comply with any requirements of a final schedule issued pursuant to subsection F of this section.

3. The commissioner shall propose a schedule for:

a. Compliance (including increments of progress) by the waterworks with each contaminant level and treatment technique requirement covered by the exemption; and

b. Implementation by the waterworks of such control measures as the commissioner may require for each contaminant level and treatment technique requirement covered by the exemption.

4. The schedule shall be prescribed by the commissioner at the time the exemption is granted.

5. For a waterworks that serves a population of not more than 3,300 persons and that needs financial assistance for the necessary improvements under the initial compliance schedule, an exemption granted by the commissioner may be for one or more additional two-year periods, but not to exceed a total of six additional years, only if the commissioner establishes that the waterworks is taking all practicable steps to meet the requirements of the exemption and the established compliance period. The commissioner will document the findings in granting an extension under this subdivision.

E. Public hearings on exemptions and their schedules.

1. Notice of a public hearing shall be provided before an exemption and schedule proposed by the commissioner pursuant to subsection D of this section may take effect. Such notice may cover the granting of more than one exemption, and a public hearing held pursuant to the notice shall include each of the exemptions covered by the notice.

2. Notice of a public hearing on a request for an exemption and its schedule shall be advertised in at least one major newspaper of general circulation in the region in which the waterworks is located.

3. The notice shall include a summary of the proposed exemption and its schedule and shall contain the time, date, and place of the public hearing.

F. Issuance of exemption.

1. Within 30 days after the public hearing, the commissioner shall, taking into consideration information obtained during the hearing, revise the proposed exemption as necessary and prescribe the final compliance schedule and interim measures before issuing the exemption to the waterworks.

2. The schedule shall establish the timetable by which the waterworks shall comply with each contaminant level and treatment technique requirement prescribed by this section. If the schedule for compliance exceeds five years from the date of issuance of the exemption, then the commissioner shall document the rationale for the extended compliance period. Such schedule shall also consider if the waterworks is to become part of a regional waterworks.

G. Posting of exemptions. All exemptions granted to any waterworks are nontransferable. Each exemption must be attached to the operation permit of the waterworks to which it is granted. Each exemption is a condition to that permit and is revoked when the permit is revoked.

H. No exemption shall be granted to 12VAC5-590-380, 12VAC5-590-388, or 12VAC5-590-395.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-003.10 § 1.16, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 19, Issue 24, eff. September 10, 2003; Volume 21, Issue 16, eff. May 18, 2005; Volume 33, Issue 3, eff. November 2, 2016; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-160. (Repealed.)

Historical Notes

Derived from VR355-18-003.11 § 1.17, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; repealed, Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-170. (Repealed.)

Historical Notes

Derived from VR355-18-003.12 § 1.18, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; repealed, Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-180. (Repealed.)

Historical Notes

Derived from VR355-18-003.13 § 1.19, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; repealed, Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-190. Permits.

A. No owner or other person may cause or allow any waterworks to be operated in the Commonwealth without a written operation permit issued by the commissioner.

B. No owner or other person shall cause or allow the construction or change in the manner of transmission, storage, purification, treatment, or distribution of water (including the extension of water pipes for the distribution of water) at any waterworks in the Commonwealth without a written construction permit or a general permit for distribution mains from the commissioner.

C. Construction permits may not be required for the extension of water distribution piping having a diameter of eight inches or less and serving less than 15 connections (see § 32.1-172 A of the Code of Virginia).

D. Individual construction permits for distribution mains are not required for waterworks that obtain a general permit (see 12VAC5-590-300).

E. Conditions may be imposed on the issuance of any permit, and no waterworks may be constructed, modified, or operated in violation of these conditions.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-003.14 § 1.20, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-200. Procedure for obtaining a construction permit.

A. Construction permits are issued by the commissioner, but all requests for a construction permit are directed initially to the department. The procedure for obtaining a construction permit includes the following steps:

1. Owners shall notify the department of all proposed construction projects, except distribution main projects that are permitted under the provisions of a general permit for distribution mains (see 12VAC5-590-300), or when the project is for the extension of water distribution piping having a diameter of eight inches or less and serving less than 15 connections (see § 32.1-172 A of the Code of Virginia).

2. The submission of a Waterworks Permit Application to the department on a form approved by the department.

3. Based on the application received, the department shall notify the owner if a preliminary engineering conference is required. A preliminary engineering conference shall be required for projects proposed using alternative delivery methods authorized under § 2.2-4380 of the Code of Virginia. The preliminary engineering conference shall define the scope of the project, project phasing, milestones, and deliverables. An evaluation procedure shall be agreed upon and the conference shall be documented.

4. The submission of preliminary engineering or intermediate design reports if required by the department. The need for and scope of the reports shall be established during the preliminary engineering conference.

5. The submission of a waterworks business operation plan that demonstrates the waterworks TMF capabilities. The waterworks business operation plan consists of four primary components:

a. Waterworks information that includes ownership data, a waterworks facility description, operator requirements, staffing needs, and staff training.

b. Management information that identifies critical business practices necessary for effective management and operation of the waterworks. Management information includes the requirements essential for managing and operating the waterworks and defines the processes, methods, and tasks necessary for complying with this chapter.

c. Financial information that identifies projects, considering the waterworks revenues and cash flow, which will be sufficient for meeting the cost of operation and maintenance for at least five full years from the initiation of operations. Financial information also demonstrates the owner's ability to direct the waterworks' finances to support technical and managerial capacities and includes a self-assessment consisting of the following financial metrics: operating cash reserve, debt service coverage, emergency reserve, and revenue sufficiency.

d. Sustainability improvements that are identified throughout the waterworks business operation plan to address TMF aspects of the waterworks' business processes that need improvement.

6. The submission of plans, specifications, final design criteria, and other supporting design data. This submission may include manufacturers equipment data sheets, drawings, and specifications when the specific materials or equipment to be used in the project have been preselected by the owner with the engineer's concurrence.

B. Well site inspection. When, upon inspection by the department, one or more well locations are found suitable for well sites, tentative approval in writing shall be furnished to the owner authorizing the drilling of wells, the exact location where each well is to be drilled, and the well construction requirements. This tentative approval will become void after a 12-month period.

C. Plans for waterworks construction shall provide the following information, where applicable:

1. A general layout that includes:

a. Suitable title, to include name of waterworks;

b. Name of owner of waterworks;

c. Area or institution to be served;

d. Scale;

e. North Point;

f. Datum used;

g. Date, address, and name of owner's engineer;

h. Location and size of existing distribution system; and

i. Location and nature of existing waterworks structures and appurtenances affecting the proposed construction noted on one sheet.

2. Detailed plans that include, where applicable:

a. Stream crossings, providing profiles with elevations of the stream bed and the normal water level;

b. Profiles having a horizontal scale of not more than 100 feet to the inch and a vertical scale of not more than 10 feet to the inch, with both scales clearly indicated;

c. Location and size of property to be used for groundwater development with respect to known references such as street intersections or section lines;

d. Topography and arrangement of present or planned wells or structures, with contour intervals not greater than two feet;

e. Elevation of highest known flood, floor of structure, upper terminal of protective casing, and outside surrounding grade, using United States Coast and Geodetic Survey, United States Geological Survey, or equivalent elevations where applicable as a reference;

f. A completed Uniform Water Well Completion Report, Form GW-2, and schematic drawings of well construction, showing diameter and depth of drill holes, casing and liner diameters and depths, grouting depths, elevations and designation of geological formation, water levels, and other details to describe the proposed well completely;

g. If not previously submitted in the preliminary engineering report (PER): the location of all potential sources of pollution within 1,000 feet of drilled wells, 100 feet of treated water storage facilities, five miles upstream from surface water intakes, and the entire drainage area of springs;

h. Size, length, identity, and location of sewers, drains, distribution systems, and water treatment plant structures;

i. Schematic flow diagrams and hydraulic profiles showing the flow through various water treatment plant units;

j. Piping in sufficient detail to show flow through the water treatment plant, including waste lines;

k. Location of all chemical feeding equipment and points of chemical application;

l. All appurtenances, specific structures, equipment, water treatment plant waste disposal units, and point of discharge having any relationship to the plans for distribution system or waterworks structures;

m. Location of sanitary or other facilities such as lavatories, showers, toilets, and lockers;

n. Location, dimensions, and elevations of all proposed water treatment plant facilities; and

o. Adequate description of all features not otherwise covered by the specifications.

D. Specifications for waterworks construction improvements shall provide the following information, where applicable:

1. A program for keeping existing waterworks facilities in operation during construction of additional facilities so as to minimize interruption of service;

2. The laboratory facilities and equipment, as well as sampling taps and their locations;

3. The number and design of treatment process components;

4. The materials or proprietary equipment for sanitary or other facilities including any necessary backflow or backsiphonage backflow protection;

5. Workmanship; and

6. Other equipment.

E. Design criteria. A summary of complete design criteria shall be submitted for the proposed project, containing but not limited to the following information, where applicable:

1. Source water capacity;

2. Estimated water consumption, including average day, maximum day, and peak hour flows;

3. Number and type of proposed services;

4. Firefighting requirements;

5. Basin capacities;

6. Retention times;

7. Unit loadings;

8. Filter area and proposed filtration rate;

9. Backwash rate; and

10. Feeder capacities and ranges.

F. For community waterworks, a copy of the duly recorded (i) plat plan of the well lot or subdivision plan showing the well lot and (ii) dedication document stating that the well lot shall be used only for waterworks appurtenances as long as the lot is utilized as part of a waterworks.

G. For noncommunity waterworks, the department may on a case-by-case basis require a copy of a duly recorded plat plan of a well lot and a dedication document stating that the well lot shall be used only for waterworks appurtenances as long as the lot is utilized as part of a waterworks. In imposing such a requirement, the department shall take into consideration public health protection and the waterworks operations, treatment processes, and appurtenances.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-003.15 § 1.21, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-210. Requirements for the submission of engineering data.

A. In accordance with Chapter 4 (§ 54.1-400 et seq.) of Title 54.1 of the Code of Virginia, all drawings, specifications, and engineer's reports submitted for approval shall be prepared by or under the supervision of a licensed professional engineer qualified to practice in Virginia, unless submitted under § 54.1-408 of the Code of Virginia for practice of land surveying in subdivisions.

B. The quantity, format, and method of submission shall meet the evaluation needs of the department and shall be consistent with the requirements in Chapter 42.1 (§ 59.1-479 et seq.) of Title 59.1 of the Code of Virginia.

C. All reports, plans, and specifications shall be submitted to the department at least 60 days before the date upon which action by the department or commissioner is desired.

D. If the procedures for obtaining a construction permit in 12VAC5-590-200 are not complied with or if plans and specifications are found to be incomplete or inadequate for evaluation, then the plans and specifications will be returned to the submitting party. If revisions to the plans or specifications or both are necessitated, the owner and engineer who prepared them will be notified in writing of the necessary revisions. Revised plans, specifications, or both constitute a resubmission. Every effort will be made to complete the evaluation of these revisions promptly.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-003.16 § 1.22, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-220. Compliance with the Manual of Practice.

A. The design guidelines set forth in Part III Manual of Practice for Waterworks Design (12VAC5-590-640 et seq.) of this chapter (Manual of Practice) specify general criteria for the design and construction of waterworks. The commissioner may impose standards or requirements that are more stringent than those contained in the Manual of Practice when required to meet drinking water quality standards. Any special standards or requirements with a federal mandate shall take precedence over the criteria in the Manual of Practice and will be items that warrant careful consideration at the preliminary engineering conference, referenced in 12VAC5-590-200.

B. Designs submitted for waterworks must demonstrate that the waterworks will adequately safeguard public health. Submissions that are in substantial compliance with the Manual of Practice and any additional requirements of the commissioner, as noted in subsection A of this section, will be approved. Justification for a design may be required for those portions of the submitted design that differ from the criteria set forth in the Manual of Practice and any established by the commissioner. Deviations from mandatory criteria contained in the Manual of Practice shall be identified and justified. For each deviation, the commissioner may issue a design exception or require compliance with the criteria.

C. Final, complete, and detailed plans and specifications submitted in accordance with the provisions of 12VAC5-590-200 and 12VAC5-590-210 will be evaluated by the department as soon as practicable upon receipt. Plans and specifications will be approved if they demonstrate substantial compliance with the design criteria set forth in the Manual of Practice and any established by the commissioner and if the waterworks, as constructed or modified, will be able to function in compliance with Part II (12VAC5-590-340 et seq.) of this chapter.

D. Compliance with the Manual of Practice for transient noncommunity waterworks is allowed the following exceptions as long as the conditions in subsection E of this section are satisfied:

1. The design of a transient noncommunity waterworks is not required to satisfy the professional engineer licensure requirement of 12VAC5-590-210 under the following conditions:

a. The waterworks shall serve no more than 100 persons per day.

b. The waterworks shall consist only of one supply of source water, a pressure tank no greater than 250 gallon capacity, and a single service connection.

c. The single service connection shall be a building or structure of less than 5,000 square feet total floor space. The determination of square footage shall be calculated using the outside perimeter of the building or structure.

2. Although the owner of a transient noncommunity waterworks is required to use a water well systems provider certified by DPOR for drilling wells, the remainder of the waterworks facility construction at a transient noncommunity waterworks may be performed by a master plumber or a certified water well systems provider, as defined in § 54.1-1129.1 of the Code of Virginia.

E. The conditions for exceptions to the Manual of Practice for transient noncommunity waterworks specified in subsection D of this section are as follows:

1. The owner shall submit a signed and dated statement attached to the permit application, certifying that subsection D of this section will be satisfied.

2. The owner shall submit information related to the design, construction, and materials used as required by the department.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-003.17 § 1.23, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-230. Issuance of the construction permit.

A. Upon approval of the plans and specifications, the commissioner will issue a permit to the owner to construct or modify the waterworks in accordance with the approved plans and specifications.

B. The construction permit shall be valid for a period of five years. If construction has not begun within five years but were to proceed in the future, then the owner shall reapply for a new construction permit.

C. The construction permit may include conditions for securing equipment certifications and performance validations.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-003.18 § 1.24, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-240. Revisions of approved plans.

A. Any deviations from the approved plans and specifications affecting capacity, hydraulic conditions, operating units, the functioning of water treatment processes, or the quality of water to be delivered must be approved by the department before any of these deviations are implemented.

B. Revised plans and specifications shall be submitted in time to allow the evaluation and approval of these plans or specifications before any construction work that will be affected by these changes may begin.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-003.19 § 1.25, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-250. Statement required upon completion of construction.

A. Upon completion of the construction or modification of the waterworks, the owner shall submit to the department a statement signed by a licensed professional engineer stating that the construction work was completed in accordance with the approved plans and specifications, revised only in accordance with the provisions of 12VAC5-590-240. This statement is called a statement of completion of construction and shall be based upon inspections of the waterworks during and after construction or modifications. These inspections are to be adequate to ensure the truth of the statement of completion of construction.

B. The project documents may require a performance validation report to confirm the design, performance criteria, and appropriate emergency procedures for specific processes and equipment. The project documents may also require operator training. If these requirements are included in the project documents, then the statement of completion of construction shall also include the performance validation report and a certification of successful operator training, as applicable.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-003.20 § 1.26, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-260. Issuance of the operation permit.

A. Upon receipt of the statement of completion of construction, receipt of all required certifications and test results, inspection by the department to ensure that the project has been satisfactorily completed in accordance with the approved design documents, and verification that bacteriological test results comply with the requirements set forth in Part II of this chapter, as appropriate, the commissioner will issue an operation permit.

B. The owner shall not operate a waterworks without first having obtained an operation permit except as provided in 12VAC5-590-290.

C. The commissioner shall establish the type (community waterworks, NTNC, or TNC), classification, and permitted capacity of the waterworks and specify these on the operation permit. Conditions may be included with the permit for operator, monitoring, and reporting requirements.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-003.21 § 1.27, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-270. Start-up testing and inspections.

A. Before placing a new or modified waterworks into operation following construction, the owner shall test the water at the entry point to the distribution system in a manner acceptable to the department. The owner shall notify the department of the time and place of the tests. The owner shall send the results of the tests to the department.

B. The commissioner and department have a right to inspect any waterworks and to be present for any testing in accordance with Title 32.1 of the Code of Virginia.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-003.22 § 1.28, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-280. (Repealed.)

Historical Notes

Derived from VR355-18-003.23 § 1.29, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; repealed, Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-290. Issuance of a temporary operation permit.

A. Water treatment methods, processes, and equipment that are not covered by the design criteria of Part III (12VAC5-590-640 et seq.) of this chapter, and that in principle or application are new or nonconventional, are subject to a temporary permit application procedure instead of that set forth in 12VAC5-590-200. A temporary permit may be issued only after detailed evaluation of all engineering data and after a period of extensive monitoring of the water treatment plant performance.

B. The department encourages the development of any new or nonconventional methods, processes, and equipment that by virtue of treatability studies appear to have application for water treatment. However, these new or nonconventional developments shall have been thoroughly tested in a full-scale or representative pilot plant installation before these methods, processes, and equipment are approved and an operation permit issued. The results shall be submitted to the department. The testing required on new or nonconventional developments shall generally follow these guidelines:

1. All procedures used in validating the process shall be conducted under the supervision of (i) a licensed professional engineer experienced in the field of environmental engineering, (ii) the owner's engineering staff, or (iii) a testing firm acceptable to the department;

2. Samples shall be collected and analyzed in a manner that shall demonstrate water treatment plant effectiveness and efficiency under adverse conditions and over extended periods of time in the area of the proposed installation;

3. The data shall be from the continuous operation of a full-scale or pilot plant treating the type of water to be handled;

4. Automatic indicating, recording, and totalizing equipment shall be provided, and the total flow shall be measured and recorded daily;

5. If the source water receives upstream discharges of treated industrial wastes or treated wastewater, then automatic indicating and recording equipment shall be provided for continuously monitoring the pH of the source and finished water in addition to the chlorine residual of the finished water;

6. The minimum sampling and analysis program will be established by the department in accordance with the process under investigation; and

7. All analyses shall utilize methods that are consistent with 12VAC5-590-440.

C. Detailed plans shall be submitted where possible showing how, in case of nonacceptance, the water treatment plant or water treatment methods, processes, and equipment will be converted to, or replaced with, a proven process. Also, financial resources must be assured to make the conversion (for example, funds placed in escrow or a bond posted.

D. After evaluation of the plans and testing data, the commissioner will issue a construction permit if the performance data verifies that the method, process, or equipment may efficiently produce water in accordance with the design specifications and the operation standards of Part II (12VAC5-590-340 et seq.) of this chapter.

E. Upon completion of construction or modification, a temporary permit for a definite period of time will be issued for the operation of the new or nonconventional methods, processes, and equipment. Not more than one temporary permit will be granted for a similar installation during the evaluation period. The temporary operation permit shall require that:

1. The evaluation period shall be a minimum of 12 months and no longer than 18 months; and

2. The holder of a temporary operation permit shall submit reports on operation during the evaluation period as required by the department. The reports shall be prepared by (i) a licensed professional engineer experienced in the field of environmental engineering, (ii) the owner's operating or engineering staff, or (iii) a testing organization.

F. The commissioner may issue a temporary operation permit if the waterworks is not in compliance with this chapter and public health will not be jeopardized. The temporary permit may be issued for a period of time and subject to conditions as the commissioner may deem appropriate for the owner to achieve compliance with this chapter.

1. The commissioner may require, as a condition to a temporary operation permit, the submission of a waterworks business operation plan by new waterworks and existing waterworks that have demonstrated limited TMF capabilities or significant noncompliance with this chapter.

2. The waterworks business operation plan shall satisfy the requirements of 12VAC5-590-200 A 5.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-003.24 § 1.30, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-300. Issuance of a general permit for construction of distribution mains.

A. Instead of obtaining a permit for each distribution main project, an owner may elect to obtain a general permit for the construction of distribution mains. These general permits are issued by the commissioner, but all requests for a general permit are directed initially to the department.

B. The following requirements shall be satisfied for the issuance of a general permit:

1. The owner shall develop, adopt, and have the department's approval of general specifications and plan details covering distribution main design and construction. The general specifications shall be at least as stringent as the requirements contained in this chapter.

2. The owner shall enter into a memorandum of understanding (MOU) with the department. The department will outline the waterworks-specific requirements, and the owner's method of compliance with the requirements. The waterworks-specific requirements include the following:

a. The maximum size of pipe to be covered by the general permit;

b. The means for modifying the department's approved general specifications and plan details;

c. The maintenance of engineering capabilities satisfactory to the department, either on-staff or through contractual arrangements;

d. The preparation of engineering plans and specifications for individual projects;

e. The maintenance of up-to-date distribution system maps and other appropriate records; and

f. The submission by the owner to the department of appropriate reports, including an annual report and summary, concerning all projects constructed under the terms of the MOU and information concerning changes to the distribution system.

C. Once the general specifications are approved and the MOU is agreed to by the department, the commissioner will issue a general permit for distribution mains with the MOU attached.

D. The general permit allows for the construction of distribution mains. The duration for the general permit is five years.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-003.25 § 1.31, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-310. Amendment or reissuance of operation permits.

A. The commissioner may amend or reissue an operation permit (i) when there is a change in the manner of storage, treatment, or supply of source water at the permitted location; (ii) when the existing permit is no longer valid; (iii) for any other cause incident to the protection of the public health; or (iv) for the supplying of potable water. A notice may be required to be given to the owner, and if one is required, a hearing held in accordance with the provisions of 12VAC5-590-115.

B. The commissioner may require submission of a waterworks business operation plan as a condition to amend or reissue an operation permit. The waterworks business operation plan shall satisfy the requirements of 12VAC5-590-200 A 5.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-003.26 § 1.32, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-320. Revocation of an operation permit.

A. The commissioner may revoke an operation permit in accordance with the APA. Reasons for revocation include:

1. The waterworks can no longer be depended upon to furnish potable water;

2. The capacity of the waterworks is inadequate for the purpose of furnishing potable water;

3. The owner has failed to abide by an order issued by the commissioner;

4. The owner has abandoned the waterworks and discontinued supplying potable water; or

5. The owner has failed to pay the waterworks operation fee required by § 32.1-171.1 of the Code of Virginia.

B. Procedure for revocation of operation permit. When revoking an operation permit in accordance with subsection A of this section, the commissioner shall:

1. Send a written notice of intent to revoke by certified mail to the last known address of the owner. The notice shall state the reasons for the proposed revocation of the operation permit, the authority under which the commissioner proposes to act, and offer the opportunity for an administrative proceeding in accordance with 12VAC5-590-115.

2. Provide at least 30 days advance notice of the administrative proceeding.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-003.27 § 1.33, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-330. Monitoring, records, and reporting.

A. The commissioner or department may require the owner to install, use, and maintain monitoring equipment for the control and testing of water flowing through the water treatment plant to:

1. Identify and determine the cause of operational problems;

2. Determine the necessary corrective actions for these problems;

3. Ensure compliance with Part II of this chapter; and

4. Prepare the finished water for entry into the distribution system.

B. Sampling and testing shall be by methods approved by the department. Test results shall be recorded, compiled, and reported to the department in an acceptable manner and format.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-003.28 § 1.34, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

Part II
Operation Regulations for Waterworks

Article 1
General [Repealed]

12VAC5-590-340. Compliance standards.

A. All physical, chemical, bacteriological, or radiological analyses for the purpose of demonstrating compliance with the requirements of this chapter shall be performed by laboratories that have received certification by EPA or DCLS as specified in 12VAC5-590-440. The owner is responsible for the collection and submission of all samples. The department may require sampling and testing that exceeds the minimal requirements specified in this chapter. A sample is deemed to have been collected only when its results are made known to the department.

B. Specific limits. No attempt has been made to prescribe specific limits for every contaminant that might occur in a water supply or a waterworks. Although the need exists for continued attention to the entry of chemical, physical, bacteriological, and radiological substances into drinking water, the limits are confined to substances recognized as being detrimental to the health or well-being of the consumer or that cause significant degradation of the usefulness of the water. Limits for innumerable substances would require an impossible burden of analytical examination. The specific limits included in this chapter are listed in Tables 340.1 through 340.7.

C. Compliance is determined:

1. Based on sample results or calculated averages, where appropriate, rounded to the same number of significant figures as the PMCL, SMCL, AL, or MRDL of the contaminant in question, or

2. By the application of the specific treatment technique for particular contaminants (see 12VAC5-590-391).

TABLE 340.1

Inorganic Chemicals

SUBSTANCE

PMCL (mg/L)

Antimony

0.006

Arsenic

0.010a

Asbestos

7 million fibers/liter (longer than 10 µm)

Barium

2

Beryllium

0.004

Cadmium

0.005

Chromium

0.1

Cyanide (as free Cyanide)

0.2

Fluoride

4.0b

Mercury

0.002

Nickel

No limits designated

Nitrate (as N)

10c

Nitrite (as N)

1.0c

Total Nitrate and Nitrite (as N)

10c

Selenium

0.05

Thallium

0.002

SUBSTANCE

SECONDARY MAXIMUM CONTAMINANT LEVEL (mg/L)

Aluminum

0.05-0.2d

Chloride

250c

Copper

1.0

Corrosivity

Noncorrosive

Fluoride

2.0

Foaming agents

0.5e

Iron

0.3

Manganese

0.05

Silver

0.1

Sodium

No limits designatedf

Sulfate

250c

Zinc

5

SUBSTANCE

ACTION LEVEL (mg/L)

Lead

0.015

Copper

1.3

aArsenic sampling results shall be reported to the nearest 0.001 mg/L.

bThe fluoride PMCL applies only to community waterworks.

cSignificant figures are noted as shown. For values with trailing zeros, significant figures are noted as shown. The limits for nitrate and nitrate-nitrite have two significant figures. The limits for chloride and sulfate have three significant figures.

dVarying water quality and treatment situations necessitates a flexible range for the aluminum SMCL. The owner is encouraged to maintain an aluminum concentration as low as possible. If the aluminum concentration in the finished water causes discoloration, then the owner is urged to contact the department.

eConcentrations reported in terms of Methylene Blue Active Substances.

fMonitoring and reporting in accordance with 40 CFR 141. 41 and 12VAC5-590-372 D 6.

TABLE 340.2

Organic Chemicals

SUBSTANCE

PMCL (mg/L)

VOC

Benzene

0.005

Carbon tetrachloride

0.005

Chlorobenzene (also called Monochlorobenzene)

0.1

o-Dichlorobenzene

0.6

p-Dichlorobenzene

0.075

1,2-Dichloroethane (also called Ethylene dichloride)

0.005

1,1-Dichloroethylene (also called Dichloroethene)

0.007

cis-1,2-Dichloroethylene

0.07

Trans-1,2-Dichloroethylene

0.1

Dichloromethane (also called Methylene chloride)

0.005

1,2-Dichloropropane

0.005

Ethylbenzene

0.7

Styrene

0.1

Tetrachloroethylene (PCE) (also called Perchloroethylene)

0.005

Toluene

1

1,2,4-Trichlorobenzene

0.07

1,1,1-Trichloroethane

0.2

1,1,2-Trichloroethane

0.005

Trichloroethylene (TCE)

0.005

Vinyl Chloride

0.002

Xylene (total)

10a

SOC

Acrylamide

TTb

Alachlor (also called Lasso)

0.002

Atrazine

0.003

Benzo(a)pyrene

0.0002

Carbofuran

0.04

Chlordane

0.002

Dalapon

0.2

Di(2-ethylhexyl)adipate (also called Bis(2-ethylhexyl)adipate)

0.4

Di(2-ethylhexyl)phthalate (also called Bis(2-ethylhexyl)phthalate)

0.006

1,2-Dibromo-3-chloropropane (DBCP)

0.0002

2,4-Dichlorophenoxyacetic Acid (2,4-D)

0.07

Dinoseb

0.007

Diquat

0.02

Endothall

0.1

Endrin

0.002

Epichlorohydrin

TTb

Ethylene dibromide (EDB) (also called 1,2-Dibromoethane)

0.00005

Glyphosate

0.7

Heptachlor

0.0004

Heptachlor epoxide

0.0002

Hexachlorobenzene

0.001

Hexachlorocyclopentadiene

0.05

Lindane (also called gamma-HCH and gamma BHC)

0.0002

Methoxychlor

0.04

Oxamyl (Vydate)

0.2

Pentachlorophenol (PCP)

0.001

Picloram

0.5

Polychlorinated biphenyls (PCBs)

0.0005

Simazine

0.004

2,3,7,8-TCDD (Dioxin)

3 X 10-8

Toxaphene

0.003

2,4,5-Trichlorophenoxypropionic Acid (2,4,5-TP or Silvex)

0.05

aThe limit for xylene has two significant figures.

bEach waterworks must certify annually to the department that when acrylamide and epichlorohydrin are used to treat water, the combination (or product) of dose and monomer level does not exceed the levels specified as follows: (i) acrylamide = 0.05% dosed at 1 mg/L (or equivalent) and (ii) epichlorohydrin = 0.01% dosed at 20 mg/L (or equivalent). The certification shall be in writing, using third-party certification approved by the department or the manufacturer's certification.

TABLE 340.3

Physical Quality

PARAMETER

STANDARD

CONCENTRATION

Color

SMCL

15 Color Units (CU)

Odor

SMCL

3 Threshold odor numbers

pH

SMCL

6.5-8.5

Total dissolved solids (TDS)

SMCL

500 mg/La

Turbidity

Treatment Technique

See 12VAC5-590-395 A 2 bb

aTDS has three significant figures.

bOperational goal: Surface water treatment plants with gravity flow granular media filters are capable of producing filtered water with a turbidity consistently less than 0.10 NTU. Therefore, for water treatment plants, the operational goal for filter effluent turbidity for each filter, before any post-filtration chemical addition, is 0.10 NTU.

TABLE 340.4

Radiological Quality

PARAMETER

PMCL

Combined radium-226 and radium-228.

5 pCi/L

Gross alpha particle activity (excluding Radon and Uranium)

15 pCi/L

Beta particle and photon radioactivity.

4 mrem/yr a, b

Uranium

30 µg/Lc

aThe average annual concentration of beta particle and photon radioactivity from man-made radionuclides in drinking water shall not produce an annual dose equivalent to the total body or any internal organ greater than 4 mrem/year.

bExcept for the radionuclides listed in Schedule I, the concentration of man-made radionuclides causing 4 mrem total body or organ dose equivalents shall be calculated on the basis of a 2 liter per day drinking water intake using the 168-hour data listed in "Maximum Permissible Body Burdens and Maximum Permissible Concentrations of Radionuclides in Air and in Water for Occupational Exposure," NBS Handbook 69 issued June 5, 1959, and amended August 1963, U.S. Department of Commerce. If two or more radionuclides are present, the sum of their annual dose equivalent to the total body or to any organ shall not exceed 4 mrem/year.

cThe limit for uranium has two significant figures.

Schedule 1

Average annual concentrations assumed to produce a total body organ dose of 4 mrem/year.

RADIONUCLIDE

CRITICAL ORGAN

pCi/L

Tritium

Total Body

20,000d

Strontium-90

Bone Marrow

8

dThe limit for tritium has five significant figures.

TABLE 340.5

Microbial Contaminants

CONTAMINANT

PMCL or TT

Cryptosporidium

TT

Minimum 99% (2-log) removal plus additional log removal or inactivation based upon bin classification in 12VAC5-590-401 D.

Giardia lamblia

TT

99.9% (3-log) removal or inactivation.

Viruses

TT

99.99% (4-log) removal or inactivation

Legionella

TT

No limit, but if Giardia lamblia and viruses are removed or inactivated, according to the treatment techniques in 12VAC5-590-395, Legionella will also be controlled.

Heterotrophic plate count (HPC)

TT

No more than 500 bacterial colonies per milliliter. (HPC is not a contaminant, it is an analytic method used to measure a variety of bacteria found in water.)

Escherichia coli (E. coli)

PMCL

(1) Any E. coli-positive repeat sample following a total coliform-positive routine sample.

(2) Total coliform-positive repeat sample following an E. coli-positive routine sample.

(3) Failure to collect all require repeat samples following an E. coli-positive routine sample.

(4) Failure to test for E. coli when any repeat sample tests positive for total coliform.

TABLE 340.6

Disinfection Byproducts

PARAMETER

PMCL (mg/L)

TTHM

Bromodichloromethane

Bromoform

Chloroform

Dibromochloromethane

0.080a

HAA5

Bromoacetic acid

Dibromoacetic acid

Dichloroacetic acid

Monochloroacetic acid

Trichloroacetic acid

0.060a

Bromate

0.010a

Chlorite

1.0a

aThe limits for TTHM, HAA5, and bromate have three significant figures. The limit for chlorite has two significant figures.

TABLE 340.7

Maximum Residual Disinfectant Level Goals (MRDLG) and Maximum Residual Disinfectant Levels (MRDL) for Disinfectants

RESIDUAL DISINFECTANT

MRDLG and MRDL (mg/L)

Chlorine

4.0 (as Cl2)a

Chloramines

4.0 (as Cl2)a

Chlorine Dioxide

0.8 (as ClO2)

aChlorine and chloramines have two significant figures.

D. Notwithstanding the MRDLs in Table 340.7, an owner may increase the residual disinfectant level of chlorine or chloramines (but not chlorine dioxide) in the distribution system to a level and for a time necessary to protect public health. This may include specific microbiological contamination problems caused by circumstances such as distribution line breaks, storm runoff events, water supply contamination events, or cross-connection events.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-004.01 § 2.1, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 12, Issue 2, eff. November 15, 1995; Volume 28, Issue 5, eff. December 7, 2011; Volume 37, Issue 20, eff. June 23, 2021; Errata, 37:22 VA.R. 3447 June 21, 2021.

12VAC5-590-350. Assessments and sanitary surveys.

A. Frequent assessments shall be made by the owner of the water supply and waterworks to locate and identify health hazards to the waterworks. The manner and frequency of making these assessments, and the rate at which discovered health hazards are to be removed, shall be the responsibility of the owner. Every effort shall be made by the owner, to the extent of his jurisdiction, to prevent the degradation of the quality of water supplies.

B. The department is required to perform sanitary surveys and site visits to assess the condition of a waterworks and its source water. Pursuant to § 32.1-25 of the Code of Virginia, the department shall, upon presentation of appropriate credentials and with the owner's consent, have the right of entry onto the waterworks property and the facilities to inspect, investigate, evaluate, conduct tests, and collect samples for testing for the purposes of determining compliance with the provisions of any law, regulation, or order administered by the board or commissioner or any conditions in a permit, license, or certificate issued by the board or commissioner. The owner shall provide any existing information requested by the department that will enable the department to conduct the sanitary survey or site visit.

C. A sanitary survey includes an evaluation of all of the following eight components:

1. Source;

2. Treatment;

3. Distribution system;

4. Finished water storage;

5. Pumps, pumping facilities, and controls;

6. Monitoring, reporting, data verification, and a special monitoring evaluation during each sanitary survey to determine whether the waterworks monitoring is appropriate or needs modification;

7. Waterworks system management and operation; and

8. Number and classification of operators. Operators shall also comply with all applicable regulations promulgated by the Virginia Board for Waterworks and Wastewater Works Operators and Onsite Sewage System Professionals and DPOR.

D. Significant deficiencies discovered as a result of a sanitary survey shall be addressed in accordance with the following:

1. The department shall issue written notification describing the significant deficiency to the owner.

2. Within 30 days of the significant-deficiency notification, the owner shall consult with the department regarding the appropriate corrective action with a schedule for implementing the corrective action. A waterworks with one or more significant deficiencies must have a CAP as described in 12VAC5-590-421 A.

3. Within 45 days of the significant-deficiency notification, the owner shall submit to the department a CAP with a schedule for meeting the requirements of 12VAC5-590-421 A.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-004.02 § 2.2, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 28, Issue 5, eff. December 7, 2011; Volume 33, Issue 3, eff. November 2, 2016; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-360. Responsibilities of the owner.

A. The owner shall provide and maintain conditions throughout the entirety of the waterworks in a manner that will assure a high degree of capability and reliability to comply with Part II (12VAC5-590-340 et seq.) of this chapter. This requirement shall pertain to the source water, transmission, treatment, storage, and distribution system facilities and the operation thereof. The owner shall identify and evaluate factors with the potential for impairing the quality of the water delivered to the consumers. Preventative control measures identified in Part II of this chapter shall be promptly implemented to protect public health.

B. For the purpose of achieving compliance with this chapter, the owner shall exercise control of the waterworks from the source water to the service connection. This requirement does not imply ownership of or maintenance for any portion of the service line where local agreements and conditions dictate otherwise.

C. The property owner shall exercise control of all buildings, structures, and equipment up to the point of the service connection to the waterworks. This requirement does not limit or modify ownership of or maintenance for the service line, that may be specified by local agreements and conditions.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-004.03 § 2.3, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

Article 2
General Information [Repealed]

12VAC5-590-370. Monitoring requirements.

A. Bacteriological monitoring.

1. The owner shall collect total coliform samples at specific sites and according to a schedule that is representative of water quality throughout the distribution system, which shall be documented in a written BSSP. The BSSP shall be established or approved by the department after investigation of the source water, method of treatment and storage, and the final delivery of the drinking water through the distribution system. The BSSP shall include the following:

a. Specific routine, repeat, and triggered source water monitoring sites, identified by address or location.

b. Distribution maps showing the location where specific sampling sites will be selected with all monitoring sites identified.

c. A minimum of three routine sample sites identified for each required routine sample for waterworks serving 3,300 or fewer people.

d. A sample collection schedule with the number of routine samples required per monitoring period in accordance with Table 370.1 and subdivision A 4 of this section.

e. Repeat sample sites for each routine sample site that shall include the original routine location, at least one tap within five service connections upstream, and at least one tap within five service connections downstream with the following exceptions:

(1) Alternative repeat sample sites may be allowed when a routine site is one connection away from or at the end of a distribution system main or as approved by the department;

(2) A groundwater system serving 1,000 or fewer people may propose repeat sample sites, such as an entry point to the distribution system, that differentiate potential source water and distribution system contamination; or

(3) A groundwater system serving 1,000 or fewer people with a single well source and no treatment may propose that one repeat sample be collected at the triggered source water monitoring site, provided that representative sampling of the distribution system is still achieved.

f. A repeat sampling site shall not be eliminated from future collections solely based on a history of questionable water quality unless the sampling point is unacceptable as determined by the department.

g. A seasonal waterworks may collect special samples in accordance with an approved start-up procedure pursuant to subdivision A 12 a of this section.

2. The minimum number of bacteriological samples for total coliform evaluation to be collected and analyzed monthly from the distribution system of a community waterworks, or a NTNC shall be in accordance with Table 370.1. The owner of a (i) TNC that uses a surface water source or a groundwater source under the direct influence of surface water or (ii) a large TNC (serving 1,000 or more persons per day) shall collect and submit samples monthly for analysis in accordance with Table 370.1. For all other TNCs, the owner shall collect and submit samples for analysis each calendar quarter in accordance with Table 370.1. The minimum number of samples must be collected and submitted even if the waterworks has exceeded the E. coli PMCL or the total coliform treatment technique triggers.

3. The samples shall be collected at evenly spaced time intervals as practical throughout the month, except that a waterworks that uses only groundwater and serves 4,900 or fewer people may have the required samples collected on a single day if the samples are collected from different sites.

4. If the results of a sanitary survey or other factors determine that some other frequency is more appropriate than that stated in subdivisions A 2 and A 3 of this section, then a modified BSSP may be required. The altered frequency shall be confirmed or changed on the basis of subsequent sanitary surveys or as otherwise determined by the department.

5. The owner may conduct more compliance monitoring than is required by this section to investigate potential problems in the distribution system and to assist in uncovering problems. The owner may collect more than the minimum number of required routine samples. If the samples are collected in accordance with the existing BSSP and are representative of water quality throughout the distribution system, then all of the results shall be included in determining whether a coliform treatment technique has been triggered.

6. The owner may propose repeat monitoring locations believed to be representative of a pathway for contamination of the distribution system. The owner may elect to specify either alternative fixed locations or criteria for selecting repeat sampling sites on a situational basis in a SOP in its BSSP. The owner shall design the SOP to focus on the collection of repeat samples at locations that best verify and determine the extent of potential contamination of the distribution system based on specific situations. The department shall require modifications to the SOP or require alternative monitoring locations as needed.

TABLE 370.1

Bacteriological Monitoring

POPULATION SERVED PER DAY

MINIMUM NUMBER OF SAMPLESa

25 to 1,000b

1

1,001 to 2,500

2

2,501 to 3,300

3

3,301 to 4,100

4

4,101 to 4,900

5

4,901 to 5,800

6

5,801 to 6,700

7

6,701 to 7,600

8

7,601 to 8,500

9

8,501 to 12,900

10

12,901 to 17,200

15

17,201 to 21,500

20

21,501 to 25,000

25

25,001 to 33,000

30

33,001 to 41,000

40

41,001 to 50,000

50

50,001 to 59,000

60

59,001 to 70,000

70

70,001 to 83,000

80

83,001 to 96,000

90

96,001 to 130,000

100

130,001 to 220,000

120

220,001 to 320,000

150

320,001 to 450,000

180

450,001 to 600,000

210

600,001 to 780,000

240

780,001 to 970,000

270

970,001 to 1,230,000

300

1,230,001 to 1,520,000

330

1,520,001 to 1,850,000

360

1,850,001 to 2,270,000

2,270,001 to 3,020,000

3,020,001 to 3,960,000

3,960,001 or more

390

420

450

480

aMonthly monitoring is required for the following waterworks: (i) community, (ii) nontransient noncommunity, (iii) all noncommunity waterworks that use a surface water source, a GUDI source, or both, (iv) all seasonal waterworks, and (v) large noncommunity (serving more than 1,000 people per day). Quarterly monitoring is required for noncommuntity waterworks not specifically identified in the monthly requirements. Annual monitoring may be allowed at a TNC that meets the criteria specified in subdivision A 8 of this section.

bIncludes a waterworks that have at least 15 service connections, but serve fewer than 25 persons.

7. All bacteriological analyses shall be performed in accordance with 12VAC5-590-440 by the DCLS or by a laboratory certified by the DCLS for drinking water samples.

8. Annual monitoring. The department may reduce the bacteriological monitoring frequency at a well-operated TNC from a quarterly sample to one annual sample, and the waterworks may remain at the annual monitoring frequency provided that all of the following conditions are continuously met:

a. The waterworks serves 1,000 or fewer people per day.

b. The waterworks uses groundwater only and is not under the influence of surface water.

c. The waterworks has a clean compliance history for a minimum of 12 consecutive months.

d. The most recent sanitary survey shows that the waterworks is free of sanitary defects or has corrected all identified sanitary defects.

e. The waterworks has a protected water source.

f. The waterworks meets existing approved construction standards.

g. The department has conducted an annual site visit within the last 12 months, and all identified sanitary defects have been corrected. For the purposes of this section, an annual site visit is equivalent to a voluntary Level 2 assessment that meets the criteria in 12VAC5-590-392 C. A sanitary survey may meet the requirement for an annual site visit in the year in which the sanitary survey is completed if all identified sanitary defects have been corrected.

9. Increased monitoring.

a. A TNC on quarterly or annual monitoring shall begin monthly monitoring in the month following an event if any of the following occurs: (i) the waterworks triggers a Level 2 assessment or two Level 1 assessments under the provisions of 12VAC5-590-392 in a rolling 12-month period, (ii) the waterworks has an E. coli PMCL violation, (iii) the waterworks has a coliform treatment technique violation, (iv) the owner has two monitoring violations under 12VAC5-590-370 A 2, or (v) the owner has one monitoring violation under 12VAC5-590-370 A 2 and one Level 1 assessment under 12VAC5-590-392 in a rolling 12-month period. The owner shall continue monthly monitoring until the requirements in subdivisions A 10 a and A 10 b of this section are met. A waterworks on monthly monitoring for other reasons is not considered to be on increased monitoring for the purpose of this subdivision.

b. A TNC on annual monitoring that experiences one monitoring violation of 12VAC5-590-370 must begin quarterly monitoring in the quarter following the event. The owner shall continue quarterly monitoring until the conditions in subdivision A 11 of this section are continuously met and the department reduces the monitoring frequency.

10. Returning to quarterly routine monitoring. The department may return the monitoring frequency of a TNC subject to subdivision A 9 a of this section and using groundwater not under the influence of surface water to quarterly monitoring if:

a. The department has completed a sanitary survey or a site visit within the last 12 months, and the TNC is free of sanitary defects and has a protected water source; and

b. The waterworks has maintained a clean compliance history for a minimum of 12 consecutive months following the event.

11. Returning to annual routine monitoring. The department may reduce the monitoring frequency of a TNC subject to subdivision A 9 of this section and using groundwater not under the influence of surface water to annual monitoring if:

a. An annual site visit or sanitary survey is conducted by the department, and all identified sanitary defects are corrected. The waterworks may substitute a voluntary Level 2 assessment for the annual site visit.

b. The waterworks has a protected water source and maintained a clean compliance history for a minimum of 12 consecutive months following the event.

c. The waterworks has in place or has adopted one or more of the following additional barriers to contamination: (i) an approved cross-connection control program, (ii) a licensed operator, (iii) continuous disinfection and maintenance of a residual in the distribution system in accordance with criteria specified by the department, (iv) demonstration of maintenance of at least a 4-log removal or inactivation of viruses in accordance with 12VAC5-590-379 A, or (v) other equivalent enhancements approved by the department.

12. Seasonal waterworks monitoring.

a. A seasonal waterworks shall demonstrate completion of an approved start-up procedure that may include start-up sampling before serving water.

b. A seasonal waterworks shall monitor every month that it is in operation.

c. The department may waive any seasonal waterworks from some or all of the requirements for seasonal waterworks if the entire distribution system remains pressurized during the entire period that the waterworks is not operating.

d. Failure to complete an approved start-up procedure before serving water is a treatment technique violation and requires the owner to provide public notification under Tier 2 conditions in 12VAC5-590-540 A 2.

e. Failure to submit certification of completion to the department after the owner completes an approved start-up procedure is a reporting violation and requires the owner to provide public notification under Tier 3 conditions in 12VAC5-590-540 A 3.

13. Additional routine monitoring in the month following a total coliform-positive sample.

a. The owner collecting samples on a quarterly or annual frequency shall collect at least three additional routine samples during the month following one or more total coliform-positive samples, with or without a Level 1 treatment trigger. The owner shall use the results of additional routine samples in coliform treatment technique trigger calculations under 12VAC5-590-392 B.

b. The requirements specified in subdivision A 13 a of this section may be waived by the department if:

(1) The department conducts a site visit before the end of the next month in which the waterworks provides water and has determined whether additional monitoring or corrective action is needed;

(2) The department has determined why the sample was total coliform positive and has established that the owner corrected the problem or will correct the problem before the end of the next month in which the waterworks serves water. In this case, the decision and the rationale for the decision shall be documented and approved in writing by the department. The department shall make this document available to EPA and the public. The documentation shall describe the specific cause of the total coliform-positive sample and what action the owner has taken or will take to correct this problem; or

(3) The department determines that the owner has corrected the contamination problem before collecting the set of repeat samples required in 12VAC5-590-380 D 3, and all repeat samples are total coliform negative. The department may waive the requirement for additional routine monitoring the next month.

c. The requirements specified in subdivision A 13 a of this section may not be waived by the department solely on the grounds that all repeat samples are total coliform negative.

14. Any one of the following is a monitoring violation: (i) failure to collect every required routine or additional routine sample in a compliance period, and (ii) failure to analyze for E. coli following a total coliform-positive sample. For each violation, the owner is required to provide public notification under Tier 3 conditions in 12VAC5-590-540 A 3.

15. Any one of the following is a reporting violation: (i) failure to submit monitoring results after the owner properly conducts monitoring, (ii) failure to submit a completed assessment form, and (iii) failure to notify the department following an E. coli-positive sample. The reporting requirements in 12VAC5-590-530 are applicable to this subdivision. For each violation, the owner is required to provide public notification under Tier 3 conditions in 12VAC5-590-540 A 3.

B. Chemical monitoring. The location of sampling points, the chemicals measured, the frequency, and the timing of sampling within each compliance period shall be established or approved by the department at the time of issuance of a waterworks operation permit because of changes in this chapter or conditions at the waterworks.

1. The department may increase required monitoring where necessary to detect variations within the waterworks and to provide quality control for any treatment processes that are employed.

2. Analysis of field composite samples shall not be allowed.

3. Samples for contaminants that may exhibit seasonal variations shall be collected during the period of the year when contamination is most likely to occur.

4. Failure to comply with the sampling schedules in this section, which includes the collection of confirmation samples cited in 12VAC5-590-382 A for inorganic chemicals, 12VAC5-590-382 B for nitrate and nitrite, and 12VAC5-590-383 A for organic chemicals, is a monitoring violation and shall require public notification pursuant to 12VAC5-590-540 A 3.

C. The department may allow a consecutive waterworks that obtains potable water from another waterworks to limit monitoring to bacteriological, residual disinfectant, DBPs, and lead and copper.

D. Monitoring requirements for a waterworks developing new sources of source water are provided in 12VAC5-590-820, 12VAC5-590-830, and 12VAC5-590-840.

E. The department may require an owner to collect additional samples to provide quality control for any treatment processes that are employed.

F. Surface water sampling requirements specified in 12VAC5-590-372 through 12VAC5-590-378 apply to GUDI sources.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-004.04 § 2.4, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 12, Issue 2, eff. November 15, 1995; Volume 16, Issue 21, eff. August 3, 2000; Errata, 18:22 VA.R. 2953 July 15, 2002; amended, Virginia Register Volume 18, Issue 19, eff. July 3, 2002; Volume 19, Issue 17, eff. June 4, 2003; Volume 19, Issue 24, eff. September 10, 2003; Volume 21, Issue 13, eff. April 6, 2005; Volume 22, Issue 15, eff. May 3, 2006; Volume 22, Issue 24, eff. September 6, 2006; Volume 25, Issue 5, eff. December 10, 2008; Volume 27, Issue 1, eff. October 13, 2010; Volume 28, Issue 5, eff. December 7, 2011; Volume 33, Issue 3, eff. November 2, 2016; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-372. Inorganic chemicals monitoring.

A. The owner of a community waterworks or a NTNC shall conduct monitoring to determine compliance with the PMCLs and SMCLs listed in Table 340.1 in accordance with this section. The owner of a TNC shall conduct monitoring to determine compliance with the nitrate, nitrite, and nitrate-nitrite PMCLs listed in Table 340.1 in accordance with this section.

B. If a waterworks draws water from more than one source and the sources are combined before distribution, then the owner shall sample at an entry point to the distribution system during periods of normal operating conditions (i.e., when water is representative of all sources being used).

C. When the results of sampling for antimony, arsenic, asbestos, barium, beryllium, cadmium, cyanide (as free cyanide), chromium, fluoride, mercury, nickel, selenium, or thallium exceed the applicable PMCL, the owner shall collect a confirmation sample, at the same sampling site, within two weeks of notification of the analytical results of the first sample.

D. Monitoring frequency.

1. Asbestos. The department has granted a statewide waiver for asbestos. If the statewide waiver is removed or if site-specific waterworks conditions warrant monitoring for asbestos, then monitoring to determine compliance with the PMCL for asbestos specified in Table 340.1 shall be conducted as follows:

a. The owner of a community waterworks or a NTNC shall monitor for asbestos during the first three-year compliance period of each nine-year compliance cycle.

b. If the statewide waiver is removed, and the owner believes the waterworks is not vulnerable to asbestos contamination from either its source water or due to corrosion of its asbestos-cement pipe, then the owner may apply to the department for a monitoring waiver for asbestos. If the department grants the monitoring waiver, then the owner is not required to monitor.

c. The department may grant a waiver based on a consideration of the following factors:

(1) Potential asbestos contamination of the source water; and

(2) The use of asbestos-cement pipe for finished water distribution and the corrosive nature of the water.

d. A waiver remains in effect until the completion of the compliance period (i.e., three years).

e. The owner of a waterworks vulnerable to asbestos contamination due solely to corrosion of its asbestos-cement pipe shall collect one sample at a tap served by the asbestos-cement pipe and under conditions where asbestos contamination is most likely to occur.

f. The owner of a waterworks vulnerable to asbestos contamination due to its source water shall monitor at the entry points.

g. The owner of a waterworks vulnerable to asbestos contamination due both to its source water and corrosion of its asbestos-cement pipe shall collect one sample at a tap served by the asbestos-cement pipe and under conditions where asbestos contamination is most likely to occur.

h. The owner of a waterworks that exceeds the PMCL as determined in 12VAC5-590-382 A shall monitor quarterly beginning in the next quarter after the exceedance occurred.

i. The department may decrease the quarterly monitoring requirement to the frequency specified in subdivision D 1 a of this section provided the department has determined that the waterworks is reliably and consistently below the PMCL. In no case shall the department make this determination unless the owner of a groundwater system collects a minimum of two quarterly samples or the owner of a waterworks that uses a surface water source, in whole or in part, collects a minimum of four quarterly samples.

2. Antimony, arsenic, barium, beryllium, cadmium, chromium, cyanide (as free cyanide), fluoride, mercury, nickel, selenium, and thallium. Monitoring to determine compliance with the PMCL for these contaminants specified in Table 340.1 shall be conducted as follows:

a. The owner shall collect one sample at each groundwater source entry point during each compliance period.

b. The owner shall collect one sample annually at each surface water source entry point, in whole or in part.

c. The owner may apply to the department for a waiver from the monitoring frequencies specified in subdivisions D 2 a and D 2 b of this section.

(1) A condition of the waiver shall require that the owner collect a minimum of one sample while the waiver is effective. The waiver remains in effect for one compliance cycle (i.e., nine years).

(2) The department may grant a waiver provided the owner has monitored surface water source entry points, in whole or in part, annually for at least three years and has conducted a minimum of three rounds of monitoring at groundwater source entry points. At least one sample shall have been collected since January 1, 1990. The owner shall demonstrate that all previous analytical results were less than the PMCL. A waterworks that uses a new groundwater or surface water source is not eligible for a waiver until three rounds of monitoring from the new source have been completed.

(3) In determining the appropriate reduced monitoring frequency, the department shall consider:

(a) The reported concentrations from all previous monitoring;

(b) The degree of variation in reported concentrations; and

(c) Other factors that may affect contaminant concentrations such as changes in groundwater pumping rates, changes in the waterworks configuration, changes in the waterworks operating procedures, or changes in stream flows or characteristics.

(4) A decision by the department to grant a waiver shall be made in writing and shall set forth the basis for the determination. The request for a waiver may be initiated by the department or upon an application by the owner. The owner shall specify the basis for the request. The department shall evaluate and, where appropriate, revise the determination of the appropriate monitoring frequency when the owner submits new monitoring data or when other data relevant to the appropriate monitoring frequency become available.

(5) No arsenic waivers shall be granted by the department.

d. The owner of a waterworks that exceed the PMCLs as calculated in 12VAC5-590-382 shall monitor quarterly beginning in the next quarter after the exceedance occurred. The department may decrease the quarterly monitoring requirement to the frequencies specified in subdivision D 2 a, D 2 b, or D 2 c of this section provided a determination has been made that the analytical results are reliably and consistently below the PMCL. In no case may the department make this determination unless the owner collects a minimum of two quarterly samples from each groundwater source entry point and a minimum of four quarterly samples from each surface water source entry point, in whole or in part.

3. Nitrate and combined nitrate-nitrite as nitrogen. Monitoring to determine compliance with the PMCL for nitrate and combined nitrate-nitrite as nitrogen specified in Table 340.1 shall be conducted as follows:

a. The owner shall collect one sample annually at each groundwater source entry point.

b. The owner shall collect one sample quarterly at each surface water source entry point, in whole or in part.

c. For groundwater source entry points at community and NTNCs, the repeat monitoring frequency shall be quarterly for at least one year following any one sample in which the concentration is greater than 50% of the PMCL. After four consecutive quarters of monitoring, the department may allow the owner to reduce the sampling frequency to annually after determining the results are reliably and consistently less than the PMCL.

d. For surface water source entry points, in whole or in part, the department may allow the owner to reduce the sampling frequency to annually if all analytical results from four consecutive quarters are less than 50% of the PMCL. The waterworks shall return to quarterly monitoring if the concentration found in any one sample is greater than or equal to 50% of the PMCL.

e. After any round of quarterly sampling is completed as required by subdivisions D 3 c and D 3 d of this section, the owner who is monitoring annually shall collect subsequent samples during the quarter that previously resulted in the highest analytical result.

f. No monitoring waivers shall be issued for nitrate or combined nitrate-nitrite as nitrogen.

4. Nitrite. Monitoring to determine compliance with the PMCL for nitrite specified in Table 340.1 shall be conducted as follows:

a. The owner shall collect one sample at each entry point during the initial compliance period.

b. After the initial sample, the owner of a waterworks where an analytical result for nitrite is less than 50% of the PMCL shall monitor at the frequency specified by the department.

c. The repeat monitoring frequency for an owner shall be quarterly for at least one year following any one sample in which the concentration is greater than 50% of the PMCL. The department may allow an owner to reduce the sampling frequency to annually after determining the analysis results are reliably and consistently less than the PMCL.

d. The owner of a waterworks that is monitoring annually shall collect each subsequent sample during the quarter that previously resulted in the highest analytical result.

e. No monitoring waivers shall be issued for nitrite.

5. Aluminum, chloride, copper, corrosivity, fluoride, foaming agents (surfactants), iron, manganese, silver, sulfate, and zinc. Monitoring to determine compliance with the SMCL for these contaminants specified in Table 340.1 shall be conducted as follows:

a. The owner shall collect one sample at each groundwater source entry point during each compliance period.

b. The owner shall collect one sample annually at each surface water source entry point, in whole or in part.

6. Sodium. All community waterworks shall monitor for sodium as follows:

a. The number of samples to be collected shall be determined by the department based on the waterworks infrastructure and occurrence concentrations where applicable.

(1) The owner shall collect at least one sample annually at each surface water source entry point, in whole or in part.

(2) The owner shall collect one sample at each groundwater source entry point at least every three years.

(3) The department may require the owner to collect and analyze water samples for sodium more frequently where sodium content is variable.

b. Sodium shall be analyzed in accordance with methods and laboratory requirements identified in 12VAC5-590-440.

c. Sample results shall be submitted to the department in accordance with 12VAC5-590-530.

d. The department shall notify local and state health officials of the sodium levels.

e. The results of the special monitoring for sodium shall be included in the Consumer Confidence Report in accordance with 12VAC5-590-545 C 5 f.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-373. Organic chemicals monitoring.

A. The owner of a community waterworks or a NTNC shall conduct monitoring to determine compliance with PMCLs listed in Table 340.2 in accordance with this section. Where two or more sources are combined before distribution, the owner shall sample at the entry point for the combined sources during periods of normal operation conditions.

1. The owner of a waterworks that uses groundwater shall collect a minimum of one sample at each entry point.

2. The owner of a waterworks that uses surface water, in whole or in part, shall collect a minimum of one sample at each entry point.

B. During the initial compliance period and each subsequent compliance period, the owner shall monitor during four consecutive calendar quarters for each contaminant listed in Table 340.2. A minimum of one sample at each entry point shall be collected during each calendar quarter.

C. Reduced monitoring.

1. Volatile organic chemicals (VOCs).

a. The requirement for four quarterly samples during initial monitoring as specified in subsection B of this section may not be reduced.

b. The department may decrease the requirement for quarterly monitoring during subsequent compliance periods provided it has been determined that the analytical results are reliably and consistently below the PMCL. In no case shall the department make this determination unless:

(1) The owner collects a minimum of two quarterly samples at each groundwater source entry point; or

(2) The owner collects a minimum of four quarterly samples at each surface water source entry point, in whole or in part.

c. If the department determines that the waterworks is reliably and consistently below the PMCL, then the department may allow the owner to monitor annually. The owner who monitors annually shall monitor during the quarter that previously yielded the highest analytical result.

d. For a groundwater system only. After a minimum of three years of annual sampling, the department may allow the owner with no previous detection of any VOCs listed in Table 340.2 to collect one sample during each compliance period.

e. The owner of a groundwater system that has three consecutive annual samples with no detection of a contaminant may apply to the department for a waiver, in accordance with 12VAC5-590-373 F.

2. Synthetic organic chemicals (SOCs).

a. The owner of a waterworks serving more than 3,300 persons that does not detect any SOCs listed in Table 340.2 in the initial compliance period may reduce the sampling frequency to a minimum of two quarterly samples in one year during each repeat compliance period.

b. The owner of a waterworks serving fewer than or equal to 3,300 persons that does not detect any SOCs listed in Table 340.2 in the initial compliance period may reduce the sampling frequency to a minimum of one sample during each repeat compliance period.

c. The department may reduce the quarterly monitoring required by subdivision B or D of this section provided the department has determined that the analytical results are reliably and consistently below the PMCL. In no case shall the department make this latter determination unless:

(1) The owner collects a minimum of two quarterly samples at each groundwater source entry point.

(2) The owner collects a minimum of four quarterly samples at each surface water source entry point, in whole or in part.

d. If the department determines that the analytical results are reliably and consistently below the PMCL, the department may allow the owner to monitor annually. The owner of a waterworks that monitors annually shall monitor during the quarter that previously yielded the highest analytical result.

e. The owner of a waterworks that has three consecutive annual samples with no detection of a contaminant may apply to the department for a waiver for SOC monitoring by submitting a waiver application as specified in subdivisions F 1 b and F 2 b of this section. The waiver remains in effect for one compliance period (i.e., three years).

D. Increased monitoring.

1. If the owner of a waterworks that is on reduced monitoring detects a contaminant listed in Table 340.2 (see 12VAC5-590-383 A regarding confirmation samples), then the owner shall monitor quarterly at each sampling point where the contaminant was detected unless:

a. That contaminant was previously detected and the department determined it was reliably and consistently below the PMCL according to subdivisions C 1 b and C 2 c of this section;

b. The historical sampling data do not indicate a meaningful increase in the contaminant concentration; and

c. The contaminant concentration does not exceed the PMCL.

2. The owner of a waterworks that exceeds the PMCLs listed in Table 340.2 for VOCs or SOCs, as determined by 12VAC5-590-383, shall monitor quarterly.

a. If, after a minimum of four consecutive quarterly samples that show the waterworks is in compliance as specified in 12VAC5-590-383; and

b. The department determines that the analytical results are reliably and consistently below the PMCL; then

c. The owner may monitor at the frequency and time specified in subdivisions C 1 c and C 2 d of this section.

E. Other monitoring requirements.

1. Vinyl chloride.

a. The owner of a groundwater system that has detected one or more of the following two-carbon organic compounds: trichloroethylene, tetrachloroethylene, 1,2-dichloroethane, 1,1,1-trichloroethane, cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, or 1,1-dichloroethylene, shall monitor quarterly for vinyl chloride. A vinyl chloride sample shall be collected at each sampling point at which one or more of the two-carbon organic compounds were detected. If the results of the first analysis do not detect vinyl chloride, then the department may reduce the quarterly monitoring frequency of vinyl chloride monitoring to one sample during each compliance period.

b. The owner of a waterworks that uses surface water in whole or in part is required to monitor for vinyl chloride as specified by the department.

2. If monitoring detects one or more of certain related contaminants (heptachlor and heptachlor epoxide), then subsequent monitoring shall analyze for all related contaminants.

3. For entry points sampled and analyzed for contaminants listed in Table 340.2, the following detection limits apply:

a. A VOC is detected at a level equal to or greater than 0.0005 mg/L; and

b. A SOC is detected at a level equal to or greater than defined by EPA under 40 CFR 141.24(h)(18) or by the department.

F. Monitoring waivers.

1. Groundwater source entry points.

a. The owner of a waterworks that does not detect a VOC contaminant listed in Table 340.2 may apply to the department for a waiver from the subsequent compliance period requirements of subsection B and subdivision C 1 c of this section after completing the initial monitoring. A waiver shall be effective for no more two compliance periods (i.e., six years).

b. The owner of a waterworks may apply to the department for a SOC monitoring waiver from the requirements of subsection B and subdivision C 2 of this section. The owner must reapply for a waiver for each subsequent compliance period (i.e., three years).

2. Surface water source entry points, in whole or in part.

a. No VOC monitoring waivers shall be issued.

b. The owner of a waterworks that does not detect a SOC contaminant listed in Table 340.2 may apply to the department for a SOC monitoring waiver from the requirements of subsection B and subdivision C 2 of this section. The owner must reapply for a waiver for each subsequent compliance period (i.e., three years).

3. Monitoring waiver applications. The owner shall submit a monitoring waiver application for evaluation on a form approved by the department. The department may grant a waiver after an evaluation of the use, transport, storage, or disposal of any organic contaminant within the watershed or zone of influence of the source.

a. If an evaluation by the department reveals no previous use of the contaminants within the watershed or zone of influence, then a waiver may be granted.

b. If an evaluation by the department reveals either previous use of the contaminants or that use is unknown, then the following factors shall be used to determine whether a waiver is granted:

(1) Previous analytical results.

(2) The proximity of the source water to land use activities that are potential point or nonpoint sources of organic contamination and to potential conduits to groundwater. Point sources include spills and leaks of chemicals at or near a waterworks or at manufacturing, distribution, or storage facilities or from hazardous or municipal waste landfills and other waste handling or treatment facilities. Nonpoint sources for SOCs include the use of pesticides to control insects and weed pests on agricultural areas, forest lands, home and gardens, and other land application uses.

(3) The environmental persistence and transport of the contaminants listed in Table 340.2.

(4) The implementation of a watershed protection program for surface water systems and wellhead protection measures for groundwater systems by the owner.

(5) For groundwater well sources: well construction, well depth, soil type, geological conditions, and well structure integrity.

(6) Special factors, as follows:

(a) For VOCs, the number of persons served by the waterworks and the proximity of a smaller waterworks to a larger waterworks.

(b) For SOCs, elevated nitrate levels at the waterworks' source water.

(c) For SOCs, use of PCBs in equipment used in the production, storage, or distribution of water (i.e., PCBs used in pumps, transformers, and other equipment).

c. An entry point at which treatment has been installed to remove VOCs or SOCs is not eligible for a monitoring waiver for the VOCs or SOCs for which treatment has been installed.

d. All waterworks are granted a waiver from monitoring dioxin, endothall, and glyphosate unless the department determines that there is a source of these contaminants that poses a threat to the source water.

4. Condition for waivers.

a. Groundwater source entry points.

(1) As a condition of the VOC waiver, the owner shall collect one sample at each entry point during the time the waiver is effective (i.e., one sample during two compliance periods or six years) and update the waterworks vulnerability assessment. Based on this data, the department may reconfirm that the source is nonvulnerable. If the department does not make this reconfirmation within three years of the initial determination, then the waiver is invalidated and the owner is required to sample annually.

(2) There are no conditions to SOC waivers.

b. Surface water source entry points, in whole or in part. There are no conditions to VOC and SOC waivers for waterworks in regard to these entry points.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-374. Residual disinfectant, disinfection byproducts, and disinfection byproduct precursors monitoring.

A. Unless otherwise noted, an owner of a waterworks that uses a chemical disinfectant shall comply with the requirements of this section as follows:

1. The owner of a community waterworks or a NTNC shall comply with this section.

2. The owner of a TNC that uses any combination of a surface water source, a GUDI source, or a groundwater source and uses chlorine dioxide as a disinfectant or oxidant shall comply with all the requirements for chlorine dioxide in this section.

B. The owner shall collect all samples during normal operating conditions.

1. Analysis under this section for DBPs (TTHM, HAA5, chlorite, and bromate) shall be conducted by laboratories that have received certification by EPA or DCLS as specified in 12VAC5-590-440, except as noted in subdivisions B 2 and B 3 of this section.

2. Measurement under this section of daily chlorite samples at the entry point to the distribution system, residual disinfectant (free chlorine, combined chlorine, total chlorine, and chlorine dioxide), alkalinity, bromide, TOC, SUVA (DOC and UV254), pH, and magnesium shall be made by a party approved by the department.

3. Residual disinfectant concentrations for free chlorine, combined chlorine, total chlorine, and chlorine dioxide shall be made using equipment deemed satisfactory by the department.

C. Monitoring plan. The owner required to monitor under this section shall develop and implement a monitoring plan. The owner shall maintain the plan and make it available for inspection by the department and the general public. The owner of a community waterworks or a NTNC that uses a surface water source, a GUDI source, or both and serves more than 3,300 people shall submit a copy of the monitoring plan to the department no later than the date of the first report required under 12VAC5-590-531 A. The department may also require the plan to be submitted by any other owner. After evaluation, the department may require changes in any of the plan elements. The plan shall include at least the following:

1. Specific locations and schedules with monitoring dates for collecting samples for any parameters included in this section.

2. How the owner will calculate compliance with PMCLs, MRDLs, and treatment techniques.

3. The sampling plan for a consecutive waterworks shall reflect the entire consecutive distribution system.

4. All new waterworks shall comply with the monitoring location requirements of 40 CFR 141 Subpart U, Initial distribution system evaluations, in the development of the waterworks monitoring plan.

D. Failure to monitor in accordance with the monitoring plan required under subsection C of this section is a monitoring violation. Failure to monitor shall be treated as a violation for the entire period covered by the annual average where compliance is based on an RAA of monthly or quarterly samples or averages, and the owner's failure to monitor makes it impossible to determine compliance with PMCLs or MRDLs.

E. The owner may use only data collected under the provisions of this section to qualify for reduced monitoring.

F. TTHM and HAA5 monitoring. The owner of a community waterworks or a NTNC shall conduct the LRAA monitoring for TTHM and HAA5 at the frequency given below, unless otherwise indicated.

1. This subdivision establishes monitoring and other requirements for achieving compliance with PMCLs based on the LRAA for TTHM and HAA5, and for achieving compliance with MRDLs for chlorine and chloramines for certain consecutive waterworks.

2. This subdivision applies to a community waterworks or a NTNC that uses a primary or secondary disinfectant other than UV light or delivers water that has been treated with a primary or secondary disinfectant other than UV light.

3. Routine monitoring.

a. If the waterworks is a NTNC serving fewer than 10,000 people, then the owner shall monitor at the location or locations and dates identified in the monitoring plan in subsection C of this section, updated as required by subdivision F 3 e of this section.

b. The owner shall monitor at no fewer than the number of locations identified in Table 374.1:

TABLE 374.1

Monitoring Frequency by Source Water Type for TTHM and HAA5

SOURCE WATER TYPE

POPULATION SIZE CATEGORY

MONITORING FREQUENCYa

DISTRIBUTION SYSTEM MONITORING LOCATION TOTAL PER MONITORING PERIODb

Surface water or GUDI Source

Less than 500

per year

2

500 - 3,300

per quarter

2

3,301 - 9,999

per quarter

2

10,000 - 49,999

per quarter

4

50,000 - 249,999

per quarter

8

250,000 - 999,999

per quarter

12

1,000,000 - 4,999,999

per quarter

16

Equal to or greater than 5,000,000

per quarter

20

Groundwater

Less than 500

per year

2

500 - 9,999

per year

2

10,000 - 99,999

per quarter

4

100,000 - 499,999

per quarter

6

Equal to or greater than 500,000

per quarter

8

aThe owner shall monitor during the month of highest DBP concentrations.

bThe owner of a waterworks on quarterly monitoring (except those using a surface water source, a GUDI source, or both and serving 500 to 3,300 people) shall collect dual sample sets every 90 days at each monitoring location. A groundwater system serving 500 to 9,999 people shall collect dual sample sets annually at each monitoring location. A waterworks serving fewer than 500 people and a waterworks using a surface water source, a GUDI source, or both and serving 500 to 3,300 people shall collect individual TTHM and HAA5 samples (instead of a dual sample set) at the locations with the highest TTHM and HAA5 concentrations, respectively. A waterworks serving fewer than 500 people shall sample annually, and a waterworks using a surface water source, a GUDI source, or both and serving 500 to 3,300 people shall sample every 90 days. For a waterworks serving fewer than 500 people, only one location with a dual sample set per monitoring period is needed if the highest TTHM and HAA5 concentrations occur at the same location (and month, if monitoring annually).

c. The owner of a waterworks not using disinfection that then begins using a disinfectant other than UV light shall consult with the department to identify compliance monitoring locations. The owner shall develop a monitoring plan under subdivision F 3 e of this section to include those monitoring locations.

d. The owner shall use an approved method listed in 12VAC5-590-440 for TTHM and HAA5 analyses. Analyses shall be conducted by laboratories that have received certification by EPA or DCLS as specified in 12VAC5-590-440.

e. The owner may revise the monitoring plan to reflect changes in treatment, distribution system operations and layout (including new service areas), or other factors that may affect TTHM or HAA5 formation, or for reasons approved by the department after consultation with the department regarding the need for changes and the appropriateness of the changes. If the owner changes monitoring locations, then the owner shall replace existing compliance monitoring locations with the lowest LRAA with new locations that reflect the current distribution system locations with expected high TTHM or HAA5 levels. The department may also require modifications in the monitoring plan. The owner of a waterworks using a surface water source, a GUDI source, or both and serving more than 3,300 people shall submit a copy of the modified monitoring plan to the department before the date the owner is required to comply with the revised monitoring plan.

4. Reduced monitoring.

a. The owner may reduce monitoring to the level specified in Table 374.2 any time the LRAA is less than or equal to 0.040 mg/L for TTHM and less than or equal to 0.030 mg/L for HAA5 at all monitoring locations. The owner may only use data collected under the provisions of this section to qualify for reduced monitoring. In addition, the source water annual average TOC level, before any treatment, shall be less than or equal to 4.0 mg/L at each water treatment plant treating a surface water source, a GUDI source, or both based on monitoring conducted under subsection J of this section.

TABLE 374.2

Reduced Monitoring for TTHM and HAA5

SOURCE WATER TYPE

POPULATION SIZE CATEGORY

MONITORING FREQUENCYa

DISTRIBUTION SYSTEM MONITORING LOCATION PER MONITORING PERIOD

Surface water or GUDI Source

Less than 500

Monitoring may not be reduced.

500 - 3,300

per year

One TTHM and one HAA5 sample: one at the location and during the quarter with the highest TTHM single measurement, one at the location and during the quarter with the highest HAA5 single measurement; one dual sample set per year if the highest TTHM and HAA5 measurements occurred at the same location and quarter.

3,301 - 9,999

per year

Two dual sample sets: one at the location and during the quarter with the highest TTHM single measurement, one at the location and during the quarter with the highest HAA5 single measurement.

10,000 - 49,999

per quarter

Two dual sample sets: at the locations with the highest TTHM and highest HAA5 LRAAs.

50,000 - 249,999

per quarter

Four dual sample sets: at the locations with the two highest TTHM and two highest HAA5 LRAAs.

250,000 - 999,999

per quarter

Six dual sample sets: at the locations with the three highest TTHM and three highest HAA5 LRAAs.

1,000,000 - 4,999,999

per quarter

Eight dual sample sets: at the locations with the four highest TTHM and four highest HAA5 LRAAs.

Equal to or greater than 5,000,000

per quarter

Ten dual sample sets: at the locations with the five highest TTHM and five highest HAA5 LRAAs.

Groundwater

Less than 500

every third year

One TTHM and one HAA5 sample: one at the location and during the quarter with the highest TTHM single measurement, one at the location and during the quarter with the highest HAA5 single measurement; one dual sample set per year if the highest TTHM and HAA5 measurements occurred at the same location and quarter.

500 - 9,999

per year

One TTHM and one HAA5 sample: one at the location and during the quarter with the highest TTHM single measurement, one at the location and during the quarter with the highest HAA5 single measurement; one dual sample set per year if the highest TTHM and HAA5 measurements occurred at the same location and quarter.

10,000 - 99,999

per year

Two dual sample sets: one at the location and during the quarter with the highest TTHM single measurement, one at the location and during the quarter with the highest HAA5 single measurement.

100,000 - 499,999

per quarter

Two dual sample sets: at the locations with the highest TTHM and highest HAA5 LRAAs.

Equal to or greater than 500,000

per quarter

Four dual sample sets: at the locations with the two highest TTHM and two highest HAA5 LRAAs.

aThe owner of a waterworks on quarterly monitoring shall collect dual sample sets every 90 days.

b. The owner may remain on reduced monitoring as long as the TTHM LRAA is less than or equal to 0.040 mg/L and the HAA5 LRAA is less than or equal to 0.030 mg/L at each monitoring location (for waterworks with quarterly reduced monitoring) or each TTHM sample is less than or equal to 0.060 mg/L and each HAA5 sample is less than or equal to 0.045 mg/L (for waterworks with annual or less frequent monitoring). In addition, the source water annual average TOC level, before any treatment, shall be less than or equal to 4.0 mg/L at each water treatment plant treating a surface water source or a GUDI source, based on monitoring conducted under subsection J of this section.

c. If the LRAA based on quarterly monitoring at any monitoring location exceeds either 0.040 mg/L for TTHM or 0.030 mg/L for HAA5 or if the annual (or less frequent) sample at any location exceeds either 0.060 mg/L for TTHM or 0.045 mg/L for HAA5, or if the source water annual average TOC level, before any treatment, is greater than 4.0 mg/L at any water treatment plant treating a surface water source, a GUDI source, or both then the owner shall resume routine monitoring under subdivision F 3 of this section or begin increased monitoring if subdivision F 5 of this section applies.

d. A waterworks may return to routine monitoring at the department's discretion.

5. Increased monitoring.

a. The owner of a waterworks required to monitor at a particular location annually or less frequently than annually under subdivision F 3 or F 4 of this section, shall increase monitoring to dual sample sets once per quarter (collected every 90 days) at all locations if a TTHM sample is greater than 0.080 mg/L or a HAA5 sample is greater than 0.060 mg/L at any location.

b. The owner may return to routine monitoring once the waterworks has conducted increased monitoring for at least four consecutive quarters and the LRAA for every monitoring location is less than or equal to 0.060 mg/L for TTHM and less than or equal to 0.045 mg/L for HAA5.

G. Chlorite. The owner of a community waterworks or a NTNC using chlorine dioxide, for disinfection or oxidation, shall conduct monitoring for chlorite.

1. Routine monitoring.

a. The owner shall collect daily samples at the entry point to the distribution system. For any daily sample that exceeds the chlorite PMCL listed in Table 340.6, the owner shall collect additional samples in the distribution system the following day at the locations required by subdivision G 1 c of this section, in addition to the sample required at the entrance to the distribution system.

b. The owner shall collect a three-sample set each month in the distribution system. The owner shall collect one sample at each of the following locations: near the first customer, at a location representative of average residence time, and at a location reflecting maximum residence time in the distribution system. Any additional routine sampling shall be conducted in the same manner (as three-sample sets, at the specified locations). The owner may use the results of additional monitoring conducted under subdivision G 1 c of this section to meet the requirement for monitoring in this subdivision G 1 b.

c. On each day following a routine sample monitoring result that exceeds the chlorite PMCL listed in Table 340.6 at the entrance to the distribution system, the owner is required to collect three chlorite distribution system samples at the following locations: as close to the first customer as possible, in a location representative of average residence time, and as close to the end of the distribution system as possible (reflecting maximum residence time in the distribution system).

2. Reduced monitoring.

a. Chlorite monitoring at the entrance to the distribution system required by subdivision G 1 a of this subsection may not be reduced.

b. Chlorite monitoring in the distribution system required by subdivision G 1 b of this section may be reduced to one three-sample set per quarter after one year of monitoring where no individual chlorite sample collected in the distribution system under subdivision G 1 b of this section has exceeded the chlorite PMCL listed in Table 340.6 and the owner has not been required to conduct monitoring under subdivision G 1 c of this section. The owner may remain on the reduced monitoring schedule until either any of the three individual chlorite samples collected quarterly in the distribution system under subdivision G 1 b of this section exceeds the chlorite PMCL or the owner is required to conduct monitoring under subdivision G 1 c of this section, at which time the owner shall revert to routine monitoring.

H. Bromate.

1. The owner of a community waterworks or a NTNC water treatment plant using ozone for disinfection or oxidation shall collect one sample per month and analyze it for bromate. The owner shall collect samples monthly at the entrance to the distribution system while the ozonation system is operating under normal conditions.

2. The owner required to analyze for bromate may reduce monitoring from monthly to quarterly if the waterworks RAA bromate concentration is less than or equal to 0.0025 mg/L based on monthly bromate measurements under subdivision H 1 of this section for the most recent four quarters. If a waterworks has qualified for reduced bromate monitoring under this subdivision, then the owner may remain on reduced monitoring as long as the RAA of quarterly bromate samples is equal to or less than 0.0025 mg/L. If the RAA bromate concentration is greater than 0.0025 mg/L, then the owner shall resume routine monitoring required by subdivision H 1 of this section.

I. Monitoring requirements for the residual disinfectant.

1. Chlorine and chloramines.

a. The owner of a waterworks that uses chlorine or chloramines shall measure the residual disinfectant level in the distribution system at the same point in the distribution system and at the same time as total coliform bacteria are sampled, as specified in 12VAC5-590-370 A and 12VAC5-590-380 D. The owner of a waterworks using a surface water source, a GUDI source, or both may use the results of the residual disinfectant concentration sampling found in 12VAC5-590-376 D instead of collecting separate samples.

b. Residual disinfectant level monitoring may not be reduced.

2. Chlorine dioxide.

a. The owner of a waterworks that uses chlorine dioxide for disinfection or oxidation shall collect daily samples at the entrance to the distribution system. For any daily sample that exceeds the MRDL listed in Table 340.7, the owner shall collect samples in the distribution system the following day at the locations required by subdivision I 2 b of this section, in addition to the sample required at the entrance to the distribution system.

b. On each day following a routine sample monitoring result that exceeds the MRDL listed in Table 340.7, the owner is required to collect three chlorine dioxide distribution system samples. If chlorine dioxide or chloramines are used to maintain a residual disinfectant in the distribution system, or if chlorine is used to maintain a residual disinfectant in the distribution system and there is no rechlorination after the entry point, then the owner shall collect three samples as close to the first customer as possible, at intervals of at least six hours. If chlorine is used to maintain a residual disinfectant in the distribution system and there are one or more rechlorination points after the entry point, then the owner shall collect one sample at each of the following locations: as close to the first customer as possible, in a location representative of average residence time, and as close to the end of the distribution system as possible (reflecting maximum residence time in the distribution system).

c. Chlorine dioxide monitoring may not be reduced.

3. Ozone. Ozone residual levels shall be monitored continuously and recorded. A portable ozone meter is recommended as a backup.

4. Additional monitoring and reporting requirements are specified in 12VAC5-590-500 to demonstrate log inactivation or removal of Giardia lamblia, virus, and Cryptosporidium.

J. Monitoring requirements for DBPPs.

1. The owner of a community waterworks or a NTNC using a surface water source, a GUDI source, or both and using conventional filtration treatment, as defined in 12VAC5-590-10, shall monitor each water treatment plant for TOC no later than the point of CFE turbidity monitoring and representative of the treated water. The owner shall also monitor for TOC in the source water before any treatment at the same time as monitoring for TOC in the treated water. These samples (source water and treated water) are referred to as paired samples. At the same time as the source water sample is collected, the owner shall monitor for alkalinity in the source water before any treatment. The owner shall collect one paired sample and one source water alkalinity sample per month per water treatment plant at a time representative of normal operating conditions and influent water quality.

2. The owner of a community waterworks or a NTNC that uses a surface water source, a GUDI source, or both with an average treated water TOC of less than 2.0 mg/L for two consecutive years, or less than 1.0 mg/L for one year, may reduce monitoring for both TOC and alkalinity to one paired sample and one source water alkalinity sample per water treatment plant per quarter. The owner shall revert to routine monitoring in the month following the quarter when the annual average treated water TOC is equal to or greater than 2.0 mg/L.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-375. Lead and copper monitoring.

A. The owner of a community waterworks or a NTNC shall monitor for lead and copper in tap water (subsection B of this section), water quality (corrosion) parameters in the distribution system and at entry points (subsection C of this section), and lead and copper in water supplies (subsection D of this section).

B. Monitoring requirements for lead and copper in tap water.

1. Sample site location.

a. By the date determined by the department for commencement of monitoring under subdivision B 4 a of this section, the owner shall complete a materials evaluation of the distribution system to identify a pool of targeted sampling sites that meets the requirements of this subdivision, and that is sufficiently large to ensure that the owner can collect the number of lead and copper tap samples required in subdivision B 3 of this section. All sites from which first-draw samples are collected shall be selected from this pool of targeted sampling sites. Sampling sites may not include faucets that have POU devices or POE devices designed to remove inorganic contaminants.

b. When the distribution system evaluation required in subdivision B 1 a of this section is insufficient to locate the requisite number of lead and copper sampling sites that meet the targeting criteria of this section, the owner shall review the sources of information listed in subdivisions B 1 b (1), B 1 b (2), and B 1 b (3) of this section to identify a sufficient number of sampling sites. In addition, the owner shall seek to collect such information where possible in the course of its normal operations (e.g., checking service line materials when reading water meters or performing maintenance activities):

(1) All plumbing codes, permits, and records in the files of the building department that indicate the plumbing materials that are installed within publicly and privately owned structures connected to the distribution system;

(2) All inspections and records of the distribution system that indicate the material composition of the service connections that connect a structure to the distribution system; and

(3) All existing water quality information, which includes the results of all prior analyses of the waterworks or individual structures connected to the waterworks, indicating locations that may be particularly susceptible to high lead or copper concentrations.

c. The sampling sites selected for a community waterworks' sampling pool (Tier 1 sampling sites) shall consist of single-family structures that:

(1) Contain copper pipes with lead solder installed between January 1983 and April 1986 or contain lead pipes; or

(2) Are served by a lead service line.

When multiple-family residences comprise at least 20% of the structures served by a waterworks, the owner may include these types of structures in the sampling pool.

d. The owner of a community waterworks with insufficient Tier 1 sampling sites shall complete the sampling pool with Tier 2 sampling sites consisting of buildings, including multiple-family residences that:

(1) Contain copper pipes with lead solder installed between January 1983 and April 1986 or contain lead pipes; or

(2) Are served by a lead service line.

e. The owner of a community waterworks with insufficient Tier 1 and Tier 2 sampling sites shall complete the sampling pool with Tier 3 sampling sites, consisting of single family structures that contain copper pipes with lead solder installed before 1983. The owner of a community waterworks with insufficient Tier 1, Tier 2, and Tier 3 sampling sites shall complete the sampling pool with representative sites throughout the distribution system. For the purpose of this subdivision, a representative site is a site in which the plumbing materials used at that site would be commonly found at other sites served by the waterworks.

f. The sampling sites selected for a NTNC (Tier 1 sampling sites) shall consist of buildings that:

(1) Contain copper pipes with lead solder installed between January 1983 and April 1986 or contain lead pipes; or

(2) Are served by a lead service line.

g. The owner of a NTNC with insufficient Tier 1 sites that meet the targeting criteria in subdivision B 1 f of this section shall complete the sampling pool with sampling sites that contain copper pipes with lead solder installed before 1983. If additional sites are needed to complete the sampling pool, the owner of a NTNC shall use representative sites throughout the distribution system. For the purpose of this subdivision, a representative site is a site in which the plumbing materials used at that site would be commonly found at other sites served by the waterworks.

h. The owner of a waterworks whose distribution system contains lead service lines shall draw 50% of the samples the owner collects during each monitoring period from sites that contain lead pipes, or copper pipes with lead solder, and 50% of the samples the owner collects from sites served by a lead service line. The owner who cannot identify a sufficient number of sampling sites served by a lead service line shall collect first-draw tap samples from all of the sites identified as being served by these lines.

2. Sample collection methods.

a. All tap samples for lead and copper, with the exception of lead service line samples collected under 12VAC5-590-405 C 4 and samples collected under subdivision B 2 e of this section, shall be first-draw samples.

b. Each first-draw tap sample for lead and copper shall be one liter in volume, have stood motionless in the plumbing system of each sampling site for at least six hours, and have been collected without flushing the tap. First-draw samples from residential housing shall be collected from the cold-water kitchen tap or from a bathroom sink tap. First-draw samples from a nonresidential building shall be one liter in volume and shall be collected at an interior tap from which water is typically drawn for consumption. Non-first-draw samples collected instead of first-draw samples pursuant to subdivision B 2 e of this section shall be one liter in volume and shall be collected at an interior tap from which water is typically drawn for consumption. First-draw samples may be collected by the owner or the owner may allow residents to collect first-draw samples after instructing the residents of the sampling procedures specified in this subdivision. To avoid problems of residents handling nitric acid, acidification of first-draw samples may be done up to 14 days after the sample is collected. After acidification to resolubilize the metals, the sample must stand in the original container for the time specified in the approved EPA method before the sample can be analyzed. If an owner allows residents to perform sampling, then the owner may not challenge, based on alleged errors in sample collection, the accuracy of sampling results.

c. Each lead service line sample collected pursuant to 12VAC5-590-405 C 4 for the purpose of avoiding replacement shall be one liter in volume and have stood motionless in the lead service line for at least six hours. Lead service line samples shall be collected in one of the following three ways:

(1) At the tap after flushing the volume of water between the tap and the lead service line. The volume of water shall be calculated based on the interior diameter and length of the pipe between the tap and the lead service line;

(2) Tapping directly into the lead service line; or

(3) If the sampling site is a building constructed as a single-family residence, then allowing the water to run until there is a significant change in temperature that would be indicative of water that has been standing in the lead service line.

d. The owner shall collect each first-draw tap sample from the same sampling site from which the owner collected a previous sample. If, for any reason, the owner cannot gain entry to a sampling site to collect a follow-up tap sample, then the owner may collect the follow-up tap sample from another sampling site in the sampling pool as long as the new site meets the same targeting criteria and is within reasonable proximity of the original site.

e. The owner of a NTNC, or a community waterworks that meets the criteria of 12VAC5-590-405 D 2 e (2) that does not have enough taps that can supply first-draw samples, as defined in subdivision B 2 b of this section, may apply to the department in writing to substitute non-first-draw samples. If approved by the department, then an owner shall collect as many first-draw samples from appropriate taps as possible and identify sampling times and locations that would likely result in the longest standing time for the remaining sites.

3. Number of samples.

a. The owner shall collect at least one sample during each monitoring period specified in subdivision B 4 of this section from the number of sites listed in the first column (standard monitoring) of Table 375.1. The owner of a waterworks conducting reduced monitoring under subdivision B 4 d of this section shall collect at least one sample from the number of sites specified in the second column (reduced monitoring) of Table 375.1 during each monitoring period specified in subdivision B 4 d of this section. Reduced monitoring sites shall be representative of the sites required for standard monitoring. The department may specify sampling locations when an owner is conducting reduced monitoring.

b. The owner of a waterworks that has fewer than five drinking water taps that are normally used for human consumption meeting the sample site criteria of subdivision B 1 of this section to reach the required number of sample sites listed in Table 375.1 shall collect at least one sample from each tap and then shall collect additional samples from those taps on different days during the monitoring period to meet the required number of sites. Alternatively, the department may allow the owner to collect a number of samples less than the number of sites specified in Table 375.1, provided that 100% of all taps that are normally used for human consumption are sampled. The department shall approve this reduction of the minimum number of samples in writing based on a request from the owner or onsite verification by the designated department representative.

c. The lead and copper tap sample table is as follows:

TABLE 375.1

Tap Samples for Lead and Copper

WATERWORKS SIZE
(Number of People Served)

NUMBER OF SITES (Standard Monitoring)

NUMBER OF SITES (Reduced Monitoring)

Greater than 100,000

100

50

10,001-100,000

60

30

3,301 to 10,000

40

20

501 to 3,300

20

10

101 to 500

10

5

Less than or equal to 100

5

5

4. Timing of monitoring.

a. Initial tap sampling. The first six-month monitoring period for small (serving less than 3,300 population), medium (serving 3,301 to 50,000 population), and large waterworks (serving greater than 50,000 population) shall be established by the department.

(1) The owner of a large waterworks shall monitor during two consecutive six-month periods.

(2) The owner of a small or a medium waterworks shall monitor during each six-month monitoring period until the waterworks exceeds the lead or copper AL and is therefore required to implement the corrosion control treatment requirements under 12VAC5-590-405 A 2, in which case the owner shall continue monitoring in accordance with subdivision B 4 b of this section, or the waterworks meets the lead and copper ALs during two consecutive six-month monitoring periods, in which case the owner may reduce monitoring in accordance with subdivision B 4 d of this section.

b. Monitoring after installation of corrosion control and source water treatment.

(1) The owner of a large waterworks that installs optimal corrosion control treatment pursuant to 12VAC5-590-405 A 2 d (4) shall monitor during two consecutive six-month monitoring periods by the date specified in 12VAC5-590-405 A 2 d (5).

(2) The owner of a small or a medium waterworks that installs optimal corrosion control treatment pursuant to 12VAC5-590-405 A 2 e (5) shall monitor during two consecutive six-month monitoring periods by the date specified in 12VAC5-590-405 A 2 e (6).

(3) The owner of a waterworks that installs source water treatment pursuant to 12VAC5-590-405 B 1 c shall monitor during two consecutive six-month monitoring periods by the date specified in 12VAC5-590-405 B 1 d.

c. Monitoring after the department specifies water quality parameter values for optimal corrosion control. After the department specifies the values for water quality control parameters under 12VAC5-590-405 A 1 f, the owner shall monitor during each subsequent six-month monitoring period, with the first monitoring period to begin on the date the department specifies the optimal values.

d. Reduced monitoring.

(1) The owner of a small or a medium waterworks that meets the lead and copper ALs during each of two consecutive six-month monitoring periods may reduce the number of samples in accordance with subdivision B 3 of this section, and reduce the frequency of sampling to once per year. The owner of a small or a medium waterworks collecting fewer than five samples, as specified in subdivision B 3 b of this section, that meets the lead and copper ALs during each of two consecutive six-month monitoring periods may reduce the frequency of sampling to once per year. In no case may the owner reduce the number of samples required below the minimum of one sample per available tap. This sampling shall begin during the calendar year immediately following the end of the second consecutive six-month monitoring period.

(2) The owner of a waterworks that meets the lead AL and maintains the range of values for the water quality control parameters reflecting optimal corrosion control treatment specified by the department under 12VAC5-590-405 A 1 f during each of two consecutive six-month monitoring periods may reduce the frequency of monitoring to once per year and to reduce the number of lead and copper samples in accordance with subdivision B 3 of this section if the owner receives written approval from the department. This sampling shall begin during the calendar year immediately following the end of the second consecutive six-month monitoring period. The department shall evaluate monitoring, treatment, and other relevant information submitted by the owner in accordance with 12VAC5-590-532 and shall notify the owner in writing when a determination is made that the owner is eligible to commence reduced monitoring pursuant to this subdivision. The department shall evaluate and, where appropriate, revise the determination when the owner submits new monitoring or treatment data or when other data relevant to the number and frequency of tap sampling becomes available.

(3) The owner of a small or a medium waterworks that meets the lead and copper ALs during three consecutive years of monitoring may reduce the frequency of monitoring for lead and copper from annually to once every three years. The owner of a waterworks that meets the lead AL and maintains the range of values for the water quality control parameters reflecting optimal corrosion control treatment specified by the department under 12VAC5-590-405 A 1 f during three consecutive years of monitoring may reduce the frequency of monitoring from annually to once every three years if the owner receives written approval from the department. Samples collected once every three years shall be collected no later than every third calendar year. The department shall evaluate monitoring, treatment, and other relevant information submitted by the owner in accordance with 12VAC5-590-532 and shall notify the owner in writing when a determination is made that the owner is eligible to commence reduced monitoring pursuant to this subdivision. The department shall evaluate and where appropriate, revise the determination when the owner submits new monitoring or treatment data, or when other data relevant to the number and frequency of tap sampling becomes available.

(4) The owner of a waterworks that reduces the number and frequency of sampling shall collect these samples from representative sites included in the pool of targeted sampling sites identified in subdivision B 1 of this section. The owner sampling annually or less frequently shall conduct the lead and copper tap sampling during the months of June, July, August, or September. For a NTNC that does not operate during the months of June through September, the department shall designate an alternate monitoring period that represents a time of normal operation for the waterworks. This sampling shall begin in the calendar year immediately following the end of the second consecutive six-month monitoring period for the owner initiating annual monitoring, and during the three-year period following the end of the third consecutive calendar year of annual monitoring for the owner initiating triennial monitoring.

(5) The owner of a waterworks that demonstrates for two consecutive six-month monitoring periods that the tap water lead level computed under 12VAC5-590-385 C is less than or equal to 0.005 mg/L and the tap water copper level computed under 12VAC5-590-385 C is less than or equal to 0.65 mg/L may reduce the number of samples in accordance with subdivision B 3 of this section and reduce the frequency of sampling to once every three calendar years.

(6) The owner of a small or a medium waterworks subject to reduced monitoring that exceeds the lead or copper AL shall resume sampling in accordance with subdivision B 4 c of this section and collect the number of samples specified for standard monitoring under subdivision B 3 of this section. The owner shall also conduct water quality parameter monitoring in accordance with subdivisions C 2, C 3, and C 4 of this section (as appropriate) during the monitoring period in which the AL is exceeded. The owner of a waterworks may resume annual monitoring for lead and copper at the tap at the reduced number of sites specified in subdivision B 3 of this section after it has completed two subsequent consecutive six-month rounds of monitoring that meet the criteria of subdivision B 4 d (1) of this section or may resume triennial monitoring for lead and copper at the reduced number of sites after it demonstrates through subsequent rounds of monitoring that it meets the criteria of either subdivision B 4 d (3) or B 4 d (5) of this section.

(7) The owner of a waterworks subject to the reduced monitoring frequency that fails to meet the lead ALs during any four-month monitoring period or that fails to operate at or above the minimum value or within the range of values for the water quality parameters specified by the department under 12VAC5-590-405 A 1 f for more than nine days in any six-month period specified in subdivision C 4 of this section shall conduct tap water sampling for lead and copper at the frequency specified in subdivision B 4 c of this section, collect the number of samples specified for standard monitoring under subdivision B 3 of this section, and resume monitoring for water quality parameters within the distribution system in accordance with subdivision C 4 of this section. This standard tap water sampling shall begin no later than the six-month period beginning January 1 of the calendar year following the lead AL exceedance or water quality parameter excursion. The owner of such a waterworks may resume reduced monitoring for lead and copper at the tap and for water quality parameters within the distribution system under the following conditions:

(a) The owner may resume annual monitoring for lead and copper at the tap at the reduced number of sites specified in subdivision B 3 of this section after completion of two subsequent six-month rounds of monitoring that meet the criteria of subdivision B 4 d (2) of this section and the owner has received written approval from the department that it is appropriate to resume reduced monitoring on an annual frequency. This sampling shall begin during the calendar year immediately following the end of the second consecutive six-month monitoring period.

(b) The owner may resume triennial monitoring for lead and copper at the tap at the reduced number of sites after demonstration through subsequent rounds of monitoring that it meets the criteria of either subdivision B 4 d (3) or B 4 d (5) of this section and the owner has received written approval from the department that it is appropriate to resume triennial monitoring.

(c) The owner may reduce the number of water quality parameter tap water samples required in accordance with subdivision C 5 a of this section and the frequency with which it collects these samples in accordance with subdivision C 5 b of this section. The owner of such a waterworks may not resume triennial monitoring for water quality parameters at the tap until it demonstrates, in accordance with the requirements of subdivision C 5 b of this section, that it has requalified for triennial monitoring.

(8) The owner of a waterworks subject to a reduced monitoring frequency under subdivision B 4 d of this section shall notify the department in writing in accordance with 12VAC5-590-530 and 12VAC5-590-532 of any upcoming long-term change in the treatment or addition of a new source water as described in this section. The department shall evaluate and approve the addition of a new source water or long-term change in the water treatment before it is implemented by the owner. The department may require the owner to resume sampling in accordance with subdivision B 4 c of this section and collect the number of samples specified for standard monitoring under subdivision B 3 of this section or take other appropriate steps such as increased water quality parameter monitoring or re-evaluation of its corrosion control treatment given the potentially different water quality considerations.

5. Additional monitoring by owner. The results of monitoring conducted in addition to the minimum requirements of this section shall be considered by the owner and the department in making determinations (i.e., calculating the 90th percentile lead or copper level) under 12VAC5-590-385 C.

6. Invalidation of lead or copper tap water samples. A sample invalidated under this subdivision does not count toward determining lead or copper 90th percentile levels under 12VAC5-590-385 C or toward meeting the minimum monitoring requirements of subdivision B 3 of this section.

a. The department may invalidate a lead or copper tap water sample if at least one of the following conditions is met:

(1) The laboratory establishes that improper sample analysis caused erroneous results.

(2) The department determines that the sample was collected from a site that did not meet the site selection criteria of this section.

(3) The sample container was damaged in transit.

(4) There is substantial reason to believe that the sample was subject to tampering.

b. The owner shall report the results of all samples to the department and all supporting documentation for samples the owner believes should be invalidated.

c. To invalidate a sample under subdivision B 6 a of this section, the decision and the rationale for the decision shall be documented in writing. The department may not invalidate a sample solely on the grounds that a follow-up sample result is higher or lower than that of the original sample.

d. The owner shall collect a replacement sample for a sample invalidated under this section if after the invalidation of one or more samples, the owner has too few samples to meet the minimum requirements of subdivision B 3 of this section. A replacement sample shall be collected as soon as possible, but no later than 20 days after the date the department invalidates the sample or by the end of the applicable monitoring period, whichever occurs later. Replacement samples collected after the end of the applicable monitoring period shall not also be used to meet the monitoring requirements of a subsequent monitoring period. The replacement samples shall be collected at the same locations as the invalidated samples or, if that is not possible, at locations other than those already used for sampling during the monitoring period.

7. Monitoring waivers for small waterworks. The owner of a small waterworks that meets the criteria of this subdivision may apply to the department to reduce the frequency of monitoring for lead and copper to once every nine years (i.e., a full waiver) if the owner meets all of the materials criteria specified in subdivision B 7 a of this section and all of the monitoring criteria specified in subdivision B 7 b of this section. The owner of a small waterworks that meets the criteria in subdivisions B 7 a and B 7 b of this section only for lead, or only for copper, may apply to the department for a waiver to reduce the frequency of tap water monitoring to once every nine years for that contaminant only (i.e., a partial waiver).

a. Materials criteria. The owner shall demonstrate that the distribution system service lines and plumbing connected to the waterworks, including plumbing conveying drinking water within all residences and buildings connected to the waterworks, are free of lead-containing materials or copper-containing materials, as those terms are defined in this subdivision, as follows:

(1) Lead. To qualify for a full waiver, or a waiver of the tap water monitoring requirements for lead (i.e., a lead waiver), the owner shall provide certification and supporting documentation to the department that the waterworks is free of all lead-containing materials, as follows:

(a) It contains no plastic pipes that contain lead plasticizers, or plastic service lines that contain lead plasticizers;

(b) Solders and flux contain no more than 0.2% lead; and

(c) The weighted average of wetted surface of pipes, pipe fittings, plumbing fittings, and plumbing fixtures contain no more than 0.25% lead.

(2) Copper. To qualify for a full waiver, or a waiver of the tap water monitoring requirements for copper (i.e., a copper waiver), the owner shall provide certification and supporting documentation to the department that the waterworks contains no copper pipes or copper service lines.

b. Monitoring criteria for waiver issuance. The owner shall have completed at least one six-month round of standard tap water monitoring for lead and copper at sites approved by the department and from the number of sites required by subdivision B 3 of this section and demonstrate that the 90th percentile levels for any and all rounds of monitoring conducted since the owner became free of all lead-containing or copper-containing materials, as appropriate, meet the following criteria:

(1) Lead levels. To qualify for a full waiver, or a lead waiver, the owner shall demonstrate that the 90th percentile lead level does not exceed 0.005 mg/L.

(2) Copper levels. To qualify for a full waiver, or a copper waiver, the owner shall demonstrate that the 90th percentile copper level does not exceed 0.65 mg/L.

c. Department approval of waiver application. The department shall notify the owner of the waiver determination, in writing, setting forth the basis of the decision and any condition of the waiver. As a condition of the waiver, the department may require the owner to perform specific activities (e.g., limited monitoring, periodic outreach to customers to remind them to avoid installation of materials that might void the waiver) to avoid the risk of lead or copper concentration of concern in tap water. The owner of a small waterworks shall continue monitoring for lead and copper at the tap as required by subdivisions B 4 a through B 4 d of this section, as appropriate, until it receives written notification from the department that the waiver has been approved.

d. Monitoring frequency for owners with waivers.

(1) The owner with a full waiver shall conduct tap water monitoring for lead and copper in accordance with subdivision B 4 d (4) of this section at the reduced number of sampling sites identified in subdivision B 3 of this section at least once every nine years and provide the materials certification specified in subdivision B 7 a of this section for both lead and copper to the department along with the monitoring results. Samples collected every nine years shall be collected no later than every ninth calendar year.

(2) The owner with a partial waiver shall conduct tap water monitoring for the waived contaminant in accordance with subdivision B 4 d (4) of this section at the reduced number of sampling sites specified in subdivision B 3 of this section at least once every nine years and provide the materials certification specified in subdivision B 7 a of this section pertaining to the waived contaminant along with the monitoring results. The owner also shall continue to monitor for the nonwaived contaminant in accordance with requirements of subdivisions B 4 a through B 4 d of this section, as appropriate.

(3) The owner with a full or partial waiver shall notify the department in writing in accordance with 12VAC5-590-532 B 3 of any upcoming long-term change in the treatment or addition of a new source water, as described in 12VAC5-590-532. The department shall evaluate and approve the addition of a new source water or a long-term change in water treatment before it is implemented by the owner. The department has the authority to require the owner to add or modify waiver conditions (e.g., require recertification that the waterworks is free of lead-containing or copper-containing materials; require additional round or rounds of monitoring), if it deems these modifications are necessary to address treatment or source water changes at the waterworks.

(4) If an owner with a full or partial waiver becomes aware that it is no longer free of lead-containing or copper-containing materials, as appropriate (e.g., as a result of new construction or repairs), then the owner shall notify the department in writing no later than 60 days after becoming aware of the change.

e. Continued eligibility. If the owner continues to satisfy the requirements of subdivision B 7 d of this section, then the waiver will be renewed automatically, unless any of the conditions listed in subdivision B 7 e (1), B 7 e (2), or B 7 e (3) of this section occurs. The owner whose waiver has been revoked may reapply for a waiver when the owner again meets the appropriate materials and monitoring criteria of subdivisions B 7 a and B 7 b of this section.

(1) A waterworks with a full waiver or a lead waiver no longer satisfies the materials criteria of subdivision B 7 a (1) of this section or has a 90th percentile lead level greater than 0.005 mg/L.

(2) A waterworks with a full waiver or a copper waiver no longer satisfies the materials criteria of subdivision B 7 a (2) of this section or has a 90th percentile copper level greater than 0.65 mg/L.

(3) The department notifies the owner, in writing, that the waiver has been revoked, setting forth the basis of the decision.

f. Requirements following waiver revocation. A waterworks whose full or partial waiver has been revoked by the department is subject to the corrosion control treatment and lead and copper tap water monitoring requirements, as follows:

(1) If the waterworks exceeds the lead or copper AL, then the owner shall implement corrosion control treatment in accordance with the deadlines specified in 12VAC5-590-405 A 2 e and any other applicable requirements of this section.

(2) If the waterworks meets both the lead and the copper ALs, then the owner shall monitor for lead and copper at the tap no less frequently than once every three years using the reduced number of sample sites specified in subdivision B 3 of this section.

g. Pre-existing waivers. Waivers for small waterworks approved by the department in writing before April 11, 2000, shall remain in effect under the following conditions:

(1) If the waterworks has demonstrated that it is both free of lead-containing and copper-containing materials, as required by subdivision B 7 a of this section and that its 90th percentile lead levels and 90th percentile copper levels meet the criteria of subdivision B 7 b of this section, then the waiver will remain in effect so long as the owner continues to meet the waiver eligibility criteria of subdivision B 7 e of this section. The first round of tap water monitoring conducted pursuant to subdivision B 7 d of this section shall be completed no later than nine years after the last time the owner has monitored for lead and copper at the tap.

(2) If the waterworks has met the materials criteria of subdivision B 7 a of this section but has not met the monitoring criteria of subdivision B 7 b of this section, then the owner shall conduct one six-month round of standard tap water monitoring for lead and copper at sites approved by the department demonstrating that it meets the criteria of subdivision B 7 b of this section. Thereafter, the waiver shall remain in effect as long as the owner meets the continued eligibility criteria of subdivision B 7 e of this section. The first round of tap water monitoring conducted pursuant to subdivision B 7 d of this section shall be completed no later than nine years after the round of monitoring conducted pursuant to subdivision B 7 b of this section.

C. Monitoring requirements for water quality parameters. The owners of all large waterworks and all small and medium waterworks that exceed the lead or copper AL shall monitor for water quality parameters in addition to lead and copper in accordance with this section.

1. General requirements.

a. Sample collection methods.

(1) Tap samples shall be representative of water quality throughout the distribution system taking into account the number of persons served, the different sources of water, the different treatment methods employed by the waterworks, and seasonal variability. Tap sampling under this section is not required to be conducted at taps targeted for lead and copper sampling under subdivision B 1 of this section. The owner may find it convenient to conduct tap sampling for water quality parameters at sites approved for coliform sampling.

(2) Samples collected at the entry point or points to the distribution system shall be from locations representative of each source water after treatment. If a waterworks draws water from more than one source water and the source waters are combined before distribution, then the owner shall sample at an entry point to the distribution system during periods of normal operating conditions (i.e., when water is representative of all source waters being used).

b. Number of samples.

(1) The owner shall collect two tap samples from the standard monitoring number of sites given in Table 375.2 for applicable water quality parameters during each monitoring period specified under subdivisions C 2 through C 5 of this section.

TABLE 375.2

Water Quality Monitoring for Lead and Copper

NUMBER OF SITES FOR WATER QUALITY PARAMETERS

WATERWORKS SIZE

(Number of People Served)

STANDARD MONITORING

REDUCED MONITORING

Greater than 100,000

25

10

10,001-100,000

10

7

3,301 to 10,000

3

3

501 to 3,300

2

2

101 to 500

1

1

Less than or equal to 100

1

1

(2) Except as provided in subdivision C 3 c of this section, the owner shall collect two samples for each applicable water quality parameter at each entry point to the distribution system during each monitoring period specified in subdivision C 2 of this section. During each monitoring period specified in subdivisions C 3, C 4, and C 5 of this section, the owner shall collect one sample for each applicable water quality parameter at each entry point to the distribution system.

2. Initial sampling. The owner of a large waterworks shall measure the applicable water quality parameters as specified below at taps and at each entry point to the distribution system during each six-month monitoring period specified in subdivision B 4 a of this section. The owner of a small or a medium waterworks shall measure the applicable water quality parameters at the locations specified below during each six-month monitoring period specified in subdivision B 4 a of this section during which the waterworks exceeds the lead or copper AL.

a. At taps:

(1) pH;

(2) Alkalinity;

(3) Orthophosphate, when an inhibitor containing a phosphate compound is used;

(4) Silica, when an inhibitor containing a silicate compound is used;

(5) Calcium;

(6) Conductivity; and

(7) Water temperature.

b. At each entry point to the distribution system: all of the applicable parameters listed in subdivision C 2 a of this section.

3. Monitoring after installation of corrosion control. The owner of a large waterworks that installs optimal corrosion control treatment pursuant to 12VAC5-590-405 A 2 d (4) shall measure the water quality parameters at the locations and frequencies specified below during each six-month monitoring period specified in subdivision B 4 b (1) of this section. The owner of a small or a medium waterworks that installs optimal corrosion control treatment shall conduct monitoring during each six-month monitoring period specified in subdivision B 4 b (2) of this section in which the waterworks exceeds the lead or copper AL.

a. At taps, two samples for:

(1) pH;

(2) Alkalinity;

(3) Orthophosphate, when an inhibitor containing a phosphate compound is used;

(4) Silica, when an inhibitor containing a silicate compound is used; and

(5) Calcium, when calcium carbonate stabilization is used as part of corrosion control.

b. Except as provided in subdivision C 3 c of this section, at each entry point to the distribution system, at least one sample no less frequently than every two weeks (biweekly) for:

(1) pH;

(2) When alkalinity is adjusted as part of optimal corrosion control, a reading of the dosage rate of the chemical used to adjust the alkalinity and the alkalinity concentration; and

(3) When a corrosion inhibitor is used as part of optimal corrosion control, a reading of the dosage rate of the inhibitor used and the concentration of orthophosphate or silica (whichever is applicable).

c. The owner of a groundwater system may limit entry point sampling described in subdivision C 3 b of this section to those entry points that are representative of water quality and treatment conditions throughout the waterworks. If water from untreated groundwater sources mixes with water from treated groundwater sources, then the owner shall monitor for water quality parameters both at representative entry points receiving treatment and representative entry points receiving no treatment. Before the start of any monitoring under this subdivision, the owner shall provide to the department written information identifying the selected entry points and documentation, including information on seasonal variability, sufficient to demonstrate that the sites are representative of water quality and treatment conditions throughout the waterworks.

4. Monitoring after the department specifies water quality parameter values for optimal corrosion control. After the department specifies the values for applicable water quality control parameters reflecting optimal corrosion control treatment under 12VAC5-590-405 A 1 f, the owner of a large waterworks shall measure the applicable water quality parameters in accordance with subdivision C 3 of this section and determine compliance with the requirements of 12VAC5-590-405 A 1 g every six months with the first six-month period to begin on either January 1 or July 1, whichever comes first, after the department specifies the optimal values under 12VAC5-590-405 A 1 f. The owner of a small or a medium waterworks shall conduct monitoring during each six-month monitoring period specified in this subdivision in which the waterworks exceeds the lead or copper AL. For the owner of a small or a medium waterworks that is subject to a reduced monitoring frequency pursuant to subdivision B 4 d of this section at the time of the AL exceedance, the start of the applicable six-month period under this subdivision shall coincide with the start of the applicable monitoring period under subdivision B 4 d of this section. Compliance with the department-designated optimal water quality parameter values shall be determined as specified under 12VAC5-590-405 A 1 g.

5. Reduced monitoring.

a. The owner of a waterworks that maintains the range of values for the water quality parameters reflecting optimal corrosion control treatment during each of two consecutive six-month monitoring periods under subdivision C 4 of this section shall continue monitoring at the entry point or points to the distribution system as specified in subdivision C 3 b of this section. The owner of the waterworks may collect two tap samples for applicable water quality parameters from the reduced number of sites during each six-month monitoring period shown in Table 375.2.

b. The owner of a waterworks that maintains the range of values for the water quality parameters reflecting optimal corrosion control treatment specified by the department under 12VAC5-590-405 A 1 f during three consecutive years of monitoring may reduce the frequency with which the owner collects the number of tap samples for applicable water quality parameters specified in subdivision C 5 of this section from every six months to annually. This sampling begins during the calendar year immediately following the end of the monitoring period in which the third consecutive year of six-month monitoring occurs. The owner of a waterworks that maintains the range of values for the water quality parameters reflecting optimal corrosion control treatment specified by the department under 12VAC5-590-405 A 1 f during three consecutive years of annual monitoring under this subdivision may reduce the frequency with which it collects the number of tap samples for applicable water quality parameters specified in subdivision C 5 a of this section from annually to every three years. This sampling begins during the calendar year immediately following the end of the monitoring period in which the third consecutive year of six-month monitoring occurs.

c. The owner of a waterworks may reduce the frequency with which tap samples are collected for applicable water quality parameters specified in subdivision C 5 a of this section to every three years if the owner demonstrates during two consecutive monitoring periods that the tap water lead level at the 90th percentile is less than or equal to the PQL for lead (0.005 mg/L), that the tap water copper level at the 90th percentile is less than or equal to 0.65 mg/L for copper, and that the owner also has maintained the range of values for water quality parameters reflecting optimal corrosion control treatment specified by the department under 12VAC5-590-405 A 1 f. Monitoring conducted every three years shall be done no later than every third calendar year.

d. The owner of a waterworks that conducts sampling annually shall collect these samples evenly throughout the year so as to reflect seasonal variability.

e. The owner of a waterworks subject to the reduced monitoring frequency that fails to operate at or above the minimum value or within the range of values for the water quality parameters specified by the department under 12VAC5-590-405 A 1 f for more than nine days in any six-month period specified in 12VAC5-590-405 A 1 g shall resume distribution system tap water sampling in accordance with the number and frequency requirements in subdivision C 4 of this section. The owner may resume annual monitoring for water quality parameters at the tap at the reduced number of sites specified in subdivision C 5 of this section after completion of two subsequent consecutive six-month rounds of monitoring that meet the criteria of that subdivision or may resume triennial monitoring for water quality parameters at the tap at the reduced number of sites after demonstration through subsequent rounds of monitoring that the criteria of either subdivision C 5 b or C 5 c of this section has been met.

6. Additional monitoring by owners. The results of any monitoring conducted in addition to the minimum requirements of this section shall be considered by the owner and the department in making any determinations under this section or 12VAC5-590-405 A 1.

D. Monitoring requirements for lead and copper in water supplies (source water).

1. Sample location, collection methods, and number of samples.

a. The owner of a waterworks that fails to meet the lead or copper AL on the basis of tap samples collected in accordance with subsection A of this section shall collect lead and copper source water samples in accordance with the following requirements regarding sample location, number of samples, and collection methods:

(1) The owner of a waterworks served by groundwater sources shall collect a minimum of one sample at every entry point to the distribution system. The owner shall collect one sample at the same sampling point unless conditions make another sampling point more representative of each source water or water treatment plant.

(2) The owner of a waterworks served by surface water sources shall collect a minimum of one sample at every entry point to the distribution system. The owner shall collect each sample at the same sampling point unless conditions make another sampling point more representative of each source water or water treatment plant. Note that for the purpose of this subdivision, a waterworks served by a surface water source includes waterworks served by a combination of surface water and groundwater sources.

(3) If a waterworks draws water from more than one source water and the source waters are combined before distribution, then the owner shall collect samples at an entry point to the distribution system during periods of normal operating conditions (i.e., when water is representative of all source waters being used).

(4) The department may reduce the total number of samples that must be analyzed by allowing the use of compositing. Compositing of samples shall be done by certified laboratory personnel. Composite samples from a maximum of five samples are allowed, provided that if the lead concentration in the composite sample is greater than or equal to 0.001 mg/L or the copper concentration is greater than or equal to 0.160 mg/L, then either a follow-up sample shall be collected and analyzed within 14 days at each sampling point included in the composite; or if duplicates or sufficient quantities from the original samples from each sampling point used in the composite are available, then the owner may use these instead of resampling.

b. Where the results of sampling indicate an exceedance of maximum permissible source water levels established under 12VAC5-590-405 B 4, the department may require that one additional sample be collected as soon as possible after the initial sample was collected (but not to exceed two weeks) at the same sampling point. If a confirmation sample required by the department is collected for lead or copper, then the results of the initial and confirmation sample shall be averaged in determining compliance with the department-specified maximum permissible levels. A sample value below the MDL shall be considered to be zero. A value above the MDL but below the PQL shall either be considered as the measured value or be considered one-half the PQL. The PQL for lead is equal to 0.005 mg/L, and the PQL for copper is equal to 0.050 mg/L.

2. Monitoring frequency after a waterworks exceeds a tap AL. The owner of a waterworks that exceeds the lead or copper AL at the tap shall collect one source water sample from each entry point to the distribution system no later than six months after the end of the monitoring period during which the lead or copper AL was exceeded. For monitoring periods that are annual or less frequent, the end of the monitoring period is September 30 of the calendar year in which the sampling occurs, or if the department has established an alternate monitoring period, the last day of that period.

3. Monitoring frequency after installation of source water treatment. The owner of a waterworks that installs source water treatment pursuant to 12VAC5-590-405 B 1 c shall collect an additional source water sample from each entry point to the distribution system during two consecutive six-month monitoring periods by the deadline specified in 12VAC5-590-405 B 1 d.

4. Monitoring frequency after the department specifies maximum permissible source water lead and copper levels or determines that source water treatment is not needed.

a. The owner shall monitor at the frequency specified in subdivisions D 4 a (1) and D 4 a (2) of this section in cases where the department specifies maximum permissible source water lead and copper levels under 12VAC5-590-405 B 1 e or determines that the owner is not required to install source water treatment under 12VAC5-590-405 B 2 b.

(1) The owner of a waterworks using only groundwater shall collect samples once during the three-year compliance period in effect when the applicable department determination under subdivision D 4 a of this section is made. The owner shall collect samples once during each subsequent compliance period. Triennial samples shall be collected every third calendar year.

(2) The owner of a waterworks using surface water (or a combination of surface water and groundwater) shall collect samples once during each year, the first annual monitoring period to begin during the year in which the applicable department determination is made under subdivision D 4 a of this section.

b. The owner is not required to conduct source water sampling for lead or copper if the waterworks meets the AL for the specific contaminant in tap water samples during the entire source water sampling period applicable to the waterworks under subdivision D 4 a (1) or D 4 a (2) of this section.

5. Reduced monitoring frequency.

a. The owner of a waterworks using only groundwater may reduce the monitoring frequency for lead and copper in source waters to once during each nine-year compliance cycle provided that the samples are collected no later than every ninth calendar year and if the owner meets one of the following criteria:

(1) The owner demonstrates that the finished water entering the distribution system has been maintained below the maximum permissible lead and copper concentrations specified by the department under 12VAC5-590-405 B 1 e during at least three consecutive compliance periods under subdivision D 4 a of this section; or

(2) The department has determined that source water treatment is not needed and the owner demonstrates that, during the last three consecutive compliance periods in which sampling was conducted under subdivision D 4 a of this section, the concentration of lead in the source water was less than or equal to 0.005 mg/L and the concentration of copper in the source water was less than or equal to 0.65 mg/L.

b. The owner of a waterworks using surface water (or a combination of surface water and groundwater sources) may reduce the monitoring frequency for lead and copper in source waters to once during each nine-year compliance cycle provided that the samples are collected no later than every ninth calendar year and if the owner meets one of the following criteria:

(1) The owner demonstrates that finished water entering the distribution system has been maintained below the maximum permissible lead and copper concentrations specified by the department under 12VAC5-590-405 B 1 e for at least three consecutive years; or

(2) The department has determined that source water treatment is not needed and the owner demonstrates that, during the last three consecutive years, the concentration of lead in the source water was less than or equal to 0.005 mg/L and the concentration of copper in the source water was less than or equal to 0.65 mg/L.

c. The owner of a waterworks that uses a new source water is not eligible for reduced monitoring for lead or copper until concentrations in samples collected from the new source water during three consecutive monitoring periods are below the maximum permissible lead and copper concentrations specified in 12VAC5-590-405 B 1 e.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 27, Issue 1, eff. October 13, 2010; amended, Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-376. Surface water and GUDI sources treatment monitoring.

A. The owner of a waterworks that uses a surface water source, a GUDI source, or both and provides filtration treatment shall monitor in accordance with this section.

B. Turbidity measurements shall be performed on representative samples of the filtered water every four hours (or more frequently) that the waterworks serves water to the public. The owner may substitute continuous turbidity monitoring for grab sample monitoring if the owner validates the continuous measurement for accuracy on a regular basis using a protocol approved by the department. For a waterworks using slow sand filtration or filtration treatment other than conventional treatment, direct filtration, or diatomaceous earth filtration, the department may reduce the sampling frequency to once per day if the department determines that less frequent monitoring is sufficient to indicate effective filtration performance. For a waterworks serving 500 or fewer persons, the department may reduce the turbidity sampling frequency to once per day, regardless of the type of filtration treatment used, if the department determines that less frequent monitoring is sufficient to indicate effective filtration performance.

1. The owner of a waterworks supplied by a surface water source, a GUDI source, or both using conventional filtration treatment or direct filtration shall conduct continuous monitoring of turbidity for each individual filter. The turbidimeter shall be calibrated using the procedure specified by the turbidimeter manufacturer. The owner shall record the results of individual filter turbidity monitoring a minimum of every 15 minutes.

2. If there is a failure in the continuous turbidity monitoring equipment, then the owner shall conduct grab sampling every four hours instead of continuous monitoring but for no more than five working days (for a waterworks serving 10,000 or more persons) or 14 days (for a waterworks serving fewer than 10,000 persons) following the failure of the equipment.

3. If a waterworks serving fewer than 10,000 persons consists of two or fewer filters, continuous monitoring of the CFE may be used instead of individual filter monitoring.

C. The residual disinfectant concentration of the water entering the distribution system shall be monitored continuously, and the lowest and highest values shall be recorded each day. If there is a failure in the continuous monitoring equipment, then grab sampling every four hours shall be conducted instead of continuous monitoring, but such grab sampling shall be conducted for no more than five working days following the failure of the equipment. The owner of a waterworks serving 3,300 or fewer persons may collect grab samples instead of continuous monitoring on an ongoing basis at the frequencies prescribed in Table 376.1.

1. The day's samples cannot be collected at the same time.

2. The sampling intervals are subject to department's evaluation and approval.

3. If at any time the residual disinfectant concentration falls below 0.2 mg/L in a waterworks using grab sampling instead of continuous monitoring, then the owner shall collect a grab sample every four hours until the residual disinfectant concentration is equal to or greater than 0.2 mg/L.

TABLE 376.1

Grab Sample Monitoring Frequency

WATERWORKS SIZE BY POPULATION

SAMPLES/DAY

500 or less

1

501 - 1,000

2

1,000 - 2,500

3

2,501 - 3,300

4

D. The residual disinfectant concentration shall be measured at least at the same points in the distribution system and at the same time as total coliform bacteria are sampled, as specified in 12VAC5-590-370 A and 12VAC5-590-380 D, except that the department may allow the owner of a waterworks that uses a groundwater source along with a surface water source, a GUDI source, or both to collect residual disinfectant samples at points other than the total coliform sampling points if the department determines that these points are more representative of treated (disinfected) water quality within the distribution system. Heterotrophic bacteria, measured as HPC as specified in 12VAC5-590-395 A 2 a (3), may be measured instead of residual disinfectant concentration.

E. The following information on the samples collected in the distribution system in conjunction with total coliform monitoring pursuant to 12VAC5-590-395 A 2 shall be reported monthly to the department by the owner:

1. Number of instances where the residual disinfectant concentration is measured;

2. Number of instances where the residual disinfectant concentration is not measured but heterotropic plate count (HPC) is measured;

3. Number of instances where the residual disinfectant concentration is measured but not detected and no HPC is measured;

4. Number of instances where no residual disinfectant concentration is detected and where the HPC is greater than 500/mL;

5. Number of instances where the residual disinfectant concentration is not measured and HPC is greater than 500/mL; and

6. For the current and previous month the waterworks serves water to the public, the value of "V," in percent, in the following formula:

V = [(c + d + e) / (a + b)] X 100

where

a = the value in subdivision E 1 of this section;

b = the value in subdivision E 2 of this section;

c = the value in subdivision E 3 of this section;

d = the value in subdivision E 4 of this section;

e = the value in subdivision E 5 of this section.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-377. Physical constituent monitoring.

A. Monitoring to determine compliance with the SMCLs for color, odor, pH, and total dissolved solids as specified in Table 340.3 shall be conducted as follows:

1. The owner shall collect one sample at each groundwater source entry point during each compliance period.

2. The owner shall collect one sample annually at each surface water source entry point, in whole or in part.

B. Onsite daily turbidity measurements may be required to be performed on representative samples collected at each entry point for groundwater sources not required to filter, to determine compliance set forth in 12VAC5-590-379 B. The turbidity monitoring requirements for a waterworks required to filter are specified in 12VAC5-590-376 B.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-378. Radiological monitoring.

A. The location of sampling points, the radionuclides measured in community waterworks, the frequency, and the timing of sampling within each compliance period shall be established or approved by the department. The department may increase required monitoring where necessary to detect variations within the waterworks. Failure to comply with the sampling schedules in this section will require public notification pursuant to 12VAC5-590-540 A 3.

B. The owner of a community waterworks shall conduct monitoring to determine compliance with the PMCLs listed in Table 340.4 and 12VAC5-590-388 in accordance with this section.

1. Monitoring requirements for gross alpha particle activity, radium-226, radium-228, and uranium.

a. The owner shall conduct initial monitoring to determine compliance with the PMCLs listed in Table 340.4 for gross alpha particle activity, radium-226, radium-228, and uranium. For the purposes of monitoring for gross alpha particle activity, radium-226, radium-228, uranium, and beta particle and photon radioactivity in drinking water, "detection limit" is defined as specified in Table 378.1.

(1) Applicability and sampling location for an existing community waterworks or its sources. The owner using groundwater, surface water, or both groundwater and surface water shall sample at every entry point to the distribution system that is representative of all sources being used under normal operating conditions. The owner shall collect each sample at the same entry point unless conditions make another sampling point more representative of each source.

(2) Applicability and sampling location for a new community waterworks or its sources. A new community waterworks or a community waterworks that uses a new source water shall begin to conduct initial monitoring for the new source water within the first quarter after initiating use. The owner shall conduct more frequent monitoring when directed by the department in the event of possible contamination or when changes in the distribution system or treatment processes occur that may increase the concentration of radioactivity in the finished water.

b. Initial monitoring. The owner shall conduct initial monitoring for gross alpha particle activity, radium-226, radium-228, and uranium as follows:

(1) The owner shall collect four consecutive quarterly samples at all entry points.

(2) For gross alpha particle activity, uranium, radium-226, and radium-228 monitoring, the department may waive the final two quarters of initial monitoring for an entry point if the results of the samples from the previous two quarters are below the detection limit as defined by and as specified in Table 378.1.

(3) If the average of the initial monitoring results for an entry point is above the PMCL, then the owner shall collect and analyze quarterly samples at that entry point until the owner has results from four consecutive quarters that are at or below the PMCL, unless the owner enters into another schedule as part of a formal compliance agreement with the department.

c. Reduced monitoring. The department may allow the owner to reduce the future frequency of monitoring from once every three years to once every six or nine years at each entry point, based on the following criteria:

(1) If the average of the initial monitoring results for each contaminant (i.e., gross alpha particle activity, uranium, radium-226, or radium-228) is below the detection limit as specified in Table 378.1, then the owner shall collect and analyze for that contaminant using at least one sample at that entry point every nine years.

(2) For gross alpha particle activity, combined radium, and uranium, if the average of the initial monitoring results for each contaminant is at or above the detection limit as specified in Table 378.1, but at or below half of the PMCL, then the owner shall collect and analyze for that contaminant using at least one sample at that entry point every six years.

(3) For gross alpha particle activity, combined radium, and uranium, if the average of the initial monitoring results for each contaminant is above half the PMCL but at or below the PMCL, then the owner shall collect and analyze at least one sample at that entry point every three years.

(4) The owner shall use the samples collected during the reduced monitoring period to determine the monitoring frequency for subsequent monitoring periods (e.g., if a waterworks entry point is on a nine-year monitoring period, and the sample result is above half the PMCL, then the next monitoring period for that entry point is three years).

(5) If the owner has a monitoring result that exceeds the PMCL while on reduced monitoring, then the owner shall collect and analyze quarterly samples at that entry point until the results from four consecutive quarters are below the PMCL, unless the waterworks enters into another schedule as part of a formal compliance agreement with the department.

d. Compositing. To fulfill quarterly monitoring requirements for gross alpha particle activity, radium-226, radium-228, or uranium, the owner may composite up to four consecutive quarterly samples from a single entry point if analysis is done within a year of the first sample. The department will treat analytical results from the composited sample as the average analytical result to determine compliance with the PMCLs and the future monitoring frequency. If the analytical result from the composited sample is greater than half the PMCL, then the department may direct the owner to collect additional quarterly samples before allowing the owner to sample under a reduced monitoring schedule.

e. A gross alpha particle activity measurement may be substituted for the required radium-226 measurement provided that the measured gross alpha particle activity does not exceed 5 pCi/L. A gross alpha particle activity measurement may be substituted for the required uranium measurement provided that the measured gross alpha particle activity does not exceed 15 pCi/L. The gross alpha measurement shall have a confidence interval of 95% (1.65 σ, where σ is the standard deviation of the net counting rate of the sample) for radium-226 and uranium. When an owner uses a gross alpha particle activity measurement instead of a radium-226 or uranium measurement, the gross alpha particle activity analytical result will be used to determine the future monitoring frequency for radium-226 or uranium. If the gross alpha particle activity result is less than the detection limit as specified in Table 378.1, then half the detection limit will be used to determine compliance and the future monitoring frequency.

2. Monitoring requirements for beta particle and photon radioactivity. To determine compliance with the PMCL in Table 340.4 for beta particle and photon radioactivity, an owner shall monitor at a frequency as follows:

a. The owner (using surface water or groundwater sources) designated by the department as vulnerable shall sample for beta particle and photon radioactivity. The owner shall collect quarterly samples for beta emitters and annual samples for tritium and strontium-90 at each entry point to the distribution system, beginning within one quarter after being notified by the department. A waterworks already designated by the department shall continue to sample until the department evaluates and either reaffirms or removes the designation.

(1) If the gross beta particle activity minus the naturally occurring potassium-40 beta particle activity at an entry point has an RAA (computed quarterly) less than or equal to 50 pCi/L (screening level), then the department may reduce the frequency of monitoring at that entry point to once every three years. The owner shall collect all samples required in subdivision B 2 a of this section during the reduced monitoring period.

(2) For a waterworks in the vicinity of a nuclear facility, the department may allow the owner to utilize environmental surveillance data collected by the nuclear facility instead of monitoring at the waterworks entry point, where the department determines the data is applicable to a particular waterworks. In the event that there is a release from a nuclear facility, the owner who is using surveillance data shall begin monitoring at the waterworks entry point in accordance with subdivision B 2 a of this section.

b. The owner (using a surface water, a groundwater source, or both) designated by the department as utilizing waters contaminated by effluents from nuclear facilities shall sample for beta particle and photon radioactivity. The owner shall collect quarterly samples for beta emitters and iodine-131 and annual samples for tritium and strontium-90 at each entry point to the distribution system, beginning within one quarter after being notified by the department. The owner of a waterworks already designated by the department as using waters contaminated by effluents from nuclear facilities shall continue to sample until the department evaluates and either reaffirms or removes the designation.

(1) Quarterly monitoring for gross beta particle activity shall be based on the analysis of monthly samples or the analysis of a composite of three monthly samples. The former procedure, analysis of monthly samples, is recommended.

(2) For iodine-131, a composite of five consecutive daily samples shall be analyzed once each quarter. As directed by the department, more frequent monitoring shall be conducted when iodine-131 is identified in the finished water.

(3) Annual monitoring for strontium-90 and tritium shall be conducted by means of the analysis of a composite of four consecutive quarterly samples or analysis of four quarterly samples. The latter procedure, analysis of monthly samples, is recommended.

(4) If the gross beta particle activity minus the naturally occurring potassium-40 beta particle activity at a sampling point has an RAA (computed quarterly) less than or equal to 15 pCi/L (screening level), then the department may reduce the frequency of monitoring at that sampling point to every three years. The owner shall collect all samples required in subdivision B 2 b of this section during the reduced monitoring period.

(5) For a waterworks in the vicinity of a nuclear facility, the department may allow the owner to utilize environmental surveillance data collected by the nuclear facility instead of the monitoring at the waterworks entry point, where the department determines the data is applicable to a particular waterworks. In the event that there is a release from a nuclear facility, the owner who is using surveillance data shall begin monitoring at the waterworks entry point in accordance with subdivision B 2 b of this section.

c. The owner of a waterworks designated by the department to monitor for beta particle and photon radioactivity cannot apply to the department for a waiver from the monitoring frequencies specified in subdivision B 2 a or B 2 b of this section.

d. The owner may analyze for naturally occurring potassium-40 beta particle activity from the same or equivalent sample used for the gross beta particle activity analysis. The owner is allowed to subtract the potassium-40 beta particle activity value from the total gross beta particle activity value to determine if the screening level is exceeded. The potassium-40 beta particle activity shall be calculated by multiplying elemental potassium concentrations (in mg/L) by a factor of 0.82.

e. If the gross beta particle activity minus the naturally occurring potassium-40 beta particle activity exceeds the appropriate screening level, then an analysis of the sample shall be performed to identify the major radioactive constituents present in the sample and the appropriate doses shall be calculated and summed to determine compliance with the PMCL for beta particles and photon radioactivity. Doses shall also be calculated and combined for measured levels of tritium and strontium to determine compliance.

f. The owner shall monitor monthly at each entry point that exceeds the PMCLs listed in Table 340.4 beginning the month after the exceedance occurs. The owner shall continue monthly monitoring until the waterworks has established, by a rolling average of three monthly samples, that the PMCL is being met. The owner who establishes that the PMCL is being met shall return to quarterly monitoring until the requirements set forth in subdivision B 2 a (1) or B 2 b (4) of this section are met.

3. General monitoring requirements for radionuclides.

a. The department may require more frequent monitoring than specified in subdivisions B 1 and B 2 of this section or may require confirmation samples at the department's discretion. The results of the initial and confirmation samples shall be averaged for use in compliance determinations.

b. The owner shall monitor at the time designated by the department during each compliance period.

c. The department has the discretion to delete results of obvious sampling or analytic errors.

d. Table 378.1 provides the minimum detection limits for radiological analyses.

TABLE 378.1

Minimum Detection Limits for Radiological Analyses

CONTAMINANT

DETECTION LIMIT
(pCi/L unless otherwise noted)

Gross alpha

3

Gross beta

4

Cesium-134

10

Iodine-131

1

Radium-226

1

Radium 228

1

Strontium-89

10

Strontium-90

2

Tritium

1,000

Uranium

1 (µg/L)

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-379. Groundwater system monitoring.

A. General monitoring requirements.

1. The owner of a groundwater system, including consecutive and wholesale waterworks, shall conduct monitoring in accordance with this section, except that requirements do not apply to waterworks that combine all of their groundwater sources with surface water sources or with GUDI sources before treatment in accordance with 12VAC5-590-395.

2. Source water monitoring by the owner of a groundwater system that does not provide 4-log treatment of viruses for their groundwater sources before or at the first customer is described in subsection B of this section.

3. The owner of a groundwater system that provides at least 4-log treatment of viruses before or at the first customer is required to conduct compliance monitoring in accordance with 12VAC5-590-421 C.

4. The owner of a groundwater system that has confirmed E. coli contamination, as determined by source water monitoring conducted under subsection B of this section or has been notified of a significant deficiency as described in 12VAC5-590-350 D shall implement one or more of the corrective actions outlined in 12VAC5-590-421 A 1, as prescribed by the department.

5. The owner of a groundwater system that does not provide 4-log treatment of viruses before or at the first customer and is not performing compliance monitoring shall provide a triggered source water monitoring plan to the department.

6. Any source water sample collected in accordance with this section shall be analyzed for E. coli using one of the analytical methods in 40 CFR 141.402(c).

B. Groundwater source microbial monitoring.

1. Triggered source water monitoring.

a. General requirements. The groundwater system owner shall conduct triggered source water monitoring if both the conditions identified in subdivisions B 1 a (1) and B 1 a (2) of this section exist.

(1) The groundwater system owner does not provide at least 4-log treatment of viruses before or at the first customer for each groundwater source; and

(2) The groundwater system owner is notified that a sample collected under 12VAC5-590-370 A is total coliform positive and the sample is not invalidated under 12VAC5-590-380 E.

b. Sampling requirements. The groundwater system owner shall collect, within 24 hours of notification of the total coliform-positive sample, one source water sample from each groundwater source in use at the time the total coliform-positive sample was collected under 12VAC5-590-370 A, except as provided in this subdivision B 1 b.

(1) The department may extend the 24-hour time limit on a case-by-case basis if the owner cannot collect the source water sample within 24 hours due to circumstances beyond his control. In the case of an extension, the department shall specify how much time the owner has to collect the sample.

(2) If approved by the department, the owner of a waterworks with more than one groundwater source may meet the requirements of this subdivision B 1 by sampling representative groundwater sources. The owner shall submit for the department's approval a triggered source water monitoring plan that identifies one or more groundwater sources that are representative of each monitoring site in the waterworks' bacteriological sample siting report or that identifies groundwater sources that are hydrogeologically similar and clearly identifies which sources will be sampled.

(3) A groundwater system serving 1,000 people or fewer may use a triggered source water sample collected from a groundwater source to meet both the requirements of 12VAC5-590-380 and to satisfy the monitoring requirements of this subdivision B 1 for a groundwater source.

c. Additional requirements.

(1) If an E. coli-positive triggered source water sample collected under this subdivision B 1 is not invalidated under subdivision B 2 of this section, then the groundwater system owner shall provide public notification and collect five additional source water samples from the same source within 24 hours of being notified of the E. coli-positive sample.

(a) If the E. coli-positive triggered source water sample is also used as a repeat sample, then an E. coli PMCL violation is incurred under 12VAC5-590-380 B 1 a.

(b) If a waterworks collects more than one repeat sample at the monitoring location required for triggered source water monitoring, then the number of additional source water samples required under subdivision B 1 c (1) of this section may be reduced by the number of repeat samples collected at that location that were not E. coli positive.

(2) If any of the five additional samples are E. coli positive, the groundwater system owner shall comply with the treatment technique requirements of 12VAC5-590-421.

d. Consecutive and wholesale waterworks.

(1) A consecutive groundwater system owner that has a total coliform-positive sample collected in accordance with 12VAC5-590-370 A shall notify the wholesale waterworks owner and the department within 24 hours of being notified of the total coliform-positive sample.

(2) The wholesale groundwater system owner shall comply with the following:

(a) The wholesale groundwater system owner that receives notice from a consecutive waterworks it serves that a sample collected in accordance with 12VAC5-590-370 A is total coliform positive shall, within 24 hours of being notified, collect a sample from each groundwater source as described in subdivision B 1 of this section.

(b) If the sample collected under this subdivision B 1 is E. coli positive, then the wholesale groundwater system owner shall within 24 hours notify all consecutive waterworks served by that groundwater source of the E. coli-positive source water sample as described in 12VAC5-590-540 and shall meet the requirements of subdivision B 1 c of this section.

e. Exception to the triggered source water monitoring requirements. A groundwater system owner is not required to comply with the source water monitoring requirements of this subdivision B 1 if the department determines and documents in writing that:

(1) The total coliform-positive sample collected in accordance with 12VAC5-590-370 A is invalidated under 12VAC5-590-380 E.

(2) The total coliform-positive sample collected in accordance with 12VAC5-590-370 A is caused by a distribution system deficiency (sanitary defect).

(3) The total coliform-positive sample collected in accordance with 12VAC5-590-370 A was caused by distribution system conditions that will cause total coliform-positive samples.

2. Invalidation of an E. coli-positive groundwater source sample.

a. The groundwater system owner may obtain the department's invalidation of an E. coli-positive groundwater source sample collected under subdivision B 1 of this section only under the following conditions:

(1) The groundwater system owner provides the department with written notice from the laboratory that improper sample analysis occurred; or

(2) The department determines and documents in writing that there is substantial evidence that the E. coli-positive groundwater source sample is not related to source water quality.

b. If the department invalidates an E. coli-positive groundwater source sample, then the groundwater system owner shall collect another source water sample under subdivision B 1 of this section within 24 hours of being notified by the department of the invalidation decision and have the source water sample analyzed for E. coli.

3. Sampling location. All groundwater source samples required under subdivision B 1 of this section shall be collected at a location before any treatment of the groundwater source unless otherwise approved by the department.

4. Public notification. The owner of a groundwater system with a source water sample collected under this subsection that is E. coli positive and that is not invalidated under subdivision B 2 of this section, including consecutive waterworks served by the groundwater source, shall conduct public notification as required in 12VAC5-590-540 A 1.

5. Monitoring violations. Failure to meet the monitoring requirements of subdivision B 1 of this section is a violation and requires the groundwater system owner to provide public notification as required in 12VAC5-590-540 A 3.

C. Monitoring requirements for source water.

1. The owner of a groundwater source utilizing chlorine disinfection or any other treatment or chemical addition that may alter or affect the bacteriological quality of the source water shall collect source water samples for bacteriological analysis in accordance with this section.

2. All bacteriological samples under this section shall be collected from the source water before any treatment or chemical addition.

a. The owner shall provide a suitable source water sample tap at each groundwater source.

b. If conditions indicate that it is not possible to install a source water sample tap, then an alternate sample location acceptable to the department may be utilized for this monitoring.

3. All samples shall be analyzed by a test method that will yield a most probable number (MPN) result for both total coliforms and E. coli.

4. Number of samples.

a. The number of routine source water samples to be collected and the frequency of sampling shall be determined by the department. The department will notify the owner of the source water sampling requirements.

b. As a minimum, the owner shall collect source water samples in accordance with Table 379.1.

TABLE 379.1

Monitoring Requirements for Source Water Samples

SOURCE TYPE

MINIMUM ROUTINE SOURCE WATER MONITORING FREQUENCY

PARAMETERS

Well located in non-karst geology

One sample per year

Total coliforms MPN
and E coli MPN

Well located in karst geology

One sample per calendar quarter

Total coliforms MPN
and E coli MPN

Spring

One sample per month

Total coliforms MPN
and E coli MPN

c. When a single sample result from a groundwater source that requires a routine source water monitoring frequency of less than monthly indicates total coliforms in excess of 50 colonies/100 mL or the presence of E. coli, the owner shall collect one confirmation sample within seven calendar days after notification of the results.

d. The department may require that additional source water samples be collected and will establish the specific number of samples and the monitoring frequency.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 28, Issue 5, eff. December 7, 2011; amended, Virginia Register Volume 33, Issue 3, eff. November 2, 2016; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-380. Bacteriological compliance.

A. The owner needs only to determine the presence or absence of total coliforms and E. coli for routine bacteriological monitoring at entry points or distribution system locations.

B. PMCLs for microbial contaminants.

1. A waterworks is in compliance with the PMCL for E. coli unless any of the conditions identified in this subdivision occur. A violation may pose an acute risk to public health and is a Tier 1 condition requiring public notification as described in 12VAC5-590-540 A 1 when:

a. A repeat sample following a total coliform-positive routine sample is E. coli positive;

b. A repeat sample following an E. coli-positive routine sample is total coliform positive;

c. The owner fails to collect all required repeat samples following an E. coli-positive routine sample; or

d. The owner fails to test for E. coli when any repeat sample tests positive for total coliform.

2. Compliance shall be determined with the PMCL for E. coli for each monitoring period for which monitoring for total coliforms is required.

C. The best available technology (BAT), treatment techniques, or other means available for achieving compliance with the PMCL for E. coli shall be:

1. Protection of wells from contamination by coliforms by appropriate placement, construction, and maintenance of the wells;

2. Maintenance of a detectable residual disinfectant throughout the distribution system;

3. Proper maintenance of the distribution system including appropriate pipe replacement and repair procedures, water main flushing programs, proper operation and maintenance of storage tanks and reservoirs, continual maintenance of positive water pressure in all parts of the distribution system, and an approved cross-connection control program;

4. Filtration and disinfection of a surface water source, a GUDI source, or both; and

5. Disinfection of groundwater using strong oxidants such as chlorine, chlorine dioxide, or ozone.

D. A total coliform-positive result is indicative of a breakdown in the protective barriers and shall be cause for repeat monitoring and special follow-up action to locate and eliminate the cause of contamination.

1. For each routine sample found to be total coliform positive, the owner shall collect a set of three repeat samples within 24 hours of being notified of the positive result. The department may extend the 24-hour limit on a case-by-case basis. For groundwater systems, the requirements of 12VAC5-590-379 shall also apply, and all repeat samples must be analyzed for E. coli using one of the analytical methods in 40 CFR 141.402(c).

a. The owner shall collect at least one repeat sample from the sampling tap where the original total coliform-positive sample was collected, and at least one repeat sample at a tap within five service connections upstream and at least one repeat sample at a tap within five service connections downstream of the original sampling site. If a total coliform-positive sample is at the end of the distribution system or one service connection away from the end of the distribution system, the owner must still collect all required repeat samples.

b. The owner shall collect an additional set of repeat samples if one or more repeat samples in the current set of repeat samples is total coliform positive. The owner shall collect the additional set of repeat samples within 24 hours of being notified of the positive results, unless the department extends the limit as provided in this section. The owner shall continue to collect additional sets of repeat samples until either total coliforms are not detected in one complete set of repeat samples or the owner determines that a coliform treatment technique trigger specified in 12VAC5-590-392 B has been exceeded as a result of a repeat sample being total coliform positive and notifies the department. If a trigger identified in 12VAC5-590-392 B is exceeded as a result of a routine sample being total coliform positive, then the owner is required to conduct only one round of repeat monitoring for each total coliform-positive routine sample.

c. If the owner collects a routine sample before learning the results of the previous routine sample, and the sample is collected within five service connections of the initial routine sample, then the owner may count the subsequent sample as a repeat sample when the initial sample results are found to be total coliform positive.

d. If one or more repeat samples collected at the monitoring location required for triggered source water monitoring are E. coli positive, then the owner has exceeded the E. coli PMCL and must comply with the groundwater system treatment technique requirements specified in 12VAC5-590-421.

e. If all repeat samples collected at the monitoring location required for triggered source water monitoring are E. coli negative, and a repeat sample collected at a monitoring location other than the one required for triggered source water monitoring is E. coli positive, then the owner has exceeded the E. coli PMCL. However, the owner is not required to collect five additional source water samples from the same source within 24 hours of learning the E. coli-positive result.

f. The owner shall collect all repeat samples on the same day, except the department may allow the owner of a waterworks with a single service connection to collect the required set of repeat samples over a three-day period or to collect a larger volume repeat sample in one or more sample containers of any size as long as the total volume collected is at least 300 ml.

g. If a repeat sample collected at the monitoring location required for triggered source water monitoring is E. coli-positive, then the owner has exceeded the E. coli PMCL and must collect five additional source water samples from the same source within 24 hours of learning the E. coli-positive result.

2. Results of all routine and repeat samples not invalidated by the department shall be used to determine compliance with the PMCL for E. coli and whether a treatment technique trigger specified in 12VAC5-590-392 B has been exceeded.

3. Special-purpose samples, such as those collected to determine whether disinfection practices are sufficient following pipe placement, replacement, or repair, and samples collected before start-up of a seasonal waterworks, shall not be used to determine compliance. Repeat samples are not considered special-purpose samples.

E. A total coliform-positive sample invalidated under this subsection does not count toward meeting the minimum monitoring requirements of this section. To invalidate a total coliform-positive sample under this subsection, the written decision and rationale shall be evaluated, approved, and signed by the department. The department shall make this document available to EPA and the public. The written documentation shall state the specific cause of the total coliform-positive sample and what action the owner has taken, or will take, to correct this problem. The department shall not invalidate a total coliform-positive sample solely on the grounds that all repeat samples are total coliform negative.

1. The department may invalidate a total coliform positive sample if any of the following conditions are met:

a. The laboratory establishes that improper sample analysis caused the total coliform-positive result;

b. The department, on the basis of the results of repeat samples collected as required by subdivision D 1 of this section, determines that the total coliform-positive sample resulted from a domestic or other nondistribution system plumbing problem. The department cannot invalidate a sample on the basis of repeat sample results unless all repeat samples collected at the same tap as the original total coliform-positive sample are also total coliform positive, and all repeat samples collected at a location other than the original tap are total coliform negative (e.g., the department cannot invalidate a total coliform-positive sample on the basis of repeat samples if all the repeat samples are total coliform negative or if the waterworks has only one service connection); or

c. The department has substantial grounds to believe that a total coliform-positive result is due to a circumstance or condition that does not reflect water quality in the distribution system. In this case, the owner shall still collect all repeat samples required under subdivision D 1 of this section, and use them to determine whether a coliform treatment technique trigger in 12VAC5-590-392 B has been exceeded.

2. A laboratory must invalidate a sample because of sampling interference (i.e., turbid culture in absence of (i) gas production, or (ii) acid reaction; exhibition of confluent growth; or production of colonies too numerous to count). The owner shall collect a replacement sample from the same location within 24 hours, and have it analyzed for the presence of total coliforms. The owner must continue to resample within 24 hours and have the samples analyzed until a valid result is obtained. The department may waive the 24-hour time limit on a case-by-case basis.

F. Escherichia coli (E. coli).

1. If a routine, repeat, or replacement sample is total coliform positive, then the owner shall analyze the total coliform-positive culture medium to determine if E. coli are present. If E. coli are present, then the owner shall notify the department by the end of the day when the owner is notified of the test result, unless the department is closed, in which case the department must be notified before the end of the next business day.

2. The department has the discretion to allow an owner, on a case-by-case basis, to forgo E. coli testing on a total coliform-positive sample if the owner assumes that the total coliform-positive sample is E. coli positive. Accordingly, the owner must notify the department as specified in subdivision F 1 of this subsection and the provisions of subdivision B 1 of this section apply.

G. Groundwater sources.

1. Groundwater sources shall be disinfected in accordance with 12VAC5-590-421 A 1 d when the results of the source water monitoring samples specified in 12VAC5-590-430 B 2 or 12VAC5-590-840 K 1 a indicate a total coliform concentration (geometric mean) of the 20 samples to be greater than 3 colonies/100 mL but less than 100 colonies/100 mL. The value 1.0 shall be used to represent a zero coliform result in the calculation of the geometric mean.

2. Groundwater source monitoring results conducted in accordance with 12VAC5-590-430 B 2 or 12VAC5-590-840 K 1 a that indicate a total coliform concentration equal to or greater than 100 colonies/100 ml constitutes contamination that is not treatable by single-barrier disinfection treatment alone.

3. Groundwater sources shall be disinfected in accordance the requirements of 12VAC5-590-421 A 1 d when the source water quality contributes to the waterworks' failure to meet the bacteriological PMCL specified in subsection B of this section.

4. If the results of the source water monitoring required by 12VAC5-590-379 C or 12VAC5-590-430 B 2 indicate the presence of E. coli in two or more samples collected during any running six-month period, then the owner shall:

a. Issue a Tier 1 public notice in accordance with 12VAC5-590-540 A 1.

b. Provide disinfection treatment to achieve a 4-log virus inactivation and removal as specified in 12VAC5-590-421 A 1 d.

c. Conduct compliance monitoring as specified in 12VAC5-590-421 B and 12VAC5-590-421 C.

5. If the results of the source water monitoring required in 12VAC5-590-379 C indicate total coliform concentration in excess of 50 colonies/100 mL in three or more samples collected during any running six-month period or the presence of E. coli in two or more samples collected during any running six-month period, then the source water shall be reevaluated for GUDI determination in accordance with 12VAC5-590-430.

6. The department may require that any groundwater source be disinfected in accordance with the requirements of 12VAC5-590-421 A 1 d.

H. All samples shall be analyzed by laboratories that have received certification by EPA or DCLS as specified in 12VAC5-590-440 for drinking water analyses.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-004.05 § 2.5, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 19, Issue 24, eff. September 10, 2003; Volume 28, Issue 5, eff. December 7, 2011; Volume 33, Issue 3, eff. November 2, 2016; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-382. Inorganic chemicals compliance.

A. When the results of sampling for antimony, arsenic, asbestos, barium, beryllium, cadmium, cyanide (as free cyanide), chromium, fluoride, mercury, nickel, selenium, or thallium exceed the applicable PMCL, the owner shall collect a confirmation sample at the same sampling point within two weeks of notification of the analytical results of the first sample. The fluoride PMCL applies only to community waterworks.

1. The results of the initial and confirmation samples shall be averaged to determine compliance with subsection A of this section. The department has the discretion to delete results of obvious sampling errors.

2. Compliance with the PMCLs for antimony, arsenic, asbestos, barium, beryllium, cadmium, cyanide (as free cyanide), chromium, fluoride, mercury, nickel, selenium, and thallium listed in Table 340.1 shall be determined based on the analytical results obtained at each sampling point.

a. For the owner of a waterworks that conducts monitoring more frequently than annually, compliance with the PMCL for antimony, arsenic, asbestos, barium, beryllium, cadmium, cyanide (as free cyanide), chromium, fluoride, mercury, nickel, selenium, or thallium is determined by an RAA at each sampling point. If the average at any sampling point is greater than the PMCL, then the waterworks is out of compliance. If any single sample would cause the annual average to be exceeded, then the waterworks is out of compliance immediately. A sample result below the MDL shall be calculated as zero for the purpose of determining the annual average. If the owner fails to collect the required number of samples, compliance (average concentration) shall be based on the total number of samples collected.

b. For the owner of a waterworks that monitors annually or less frequently, the waterworks is not out of compliance with the PMCL for antimony, arsenic, asbestos, barium, beryllium, cadmium, cyanide (as free cyanide), chromium, fluoride, mercury, nickel, selenium, or thallium if the average of the original sample and a confirmation sample of a contaminant at any sampling point is greater than the PMCL. If sample results for the owner monitoring annually or less frequently exceed the PMCL, the owner shall begin quarterly sampling. The owner shall not be considered in violation of the PMCL until one year of quarterly sampling has been completed and the RAA is exceeded. However, if the confirmation sample is not collected, the owner is in violation of the PMCL for antimony, arsenic, asbestos, barium, beryllium, cadmium, cyanide (as free cyanide), chromium, fluoride, mercury, nickel, selenium, or thallium. If the owner fails to collect the required number of samples, then compliance (average concentration) shall be based on the total number of samples collected.

B. Compliance with the PMCLs for nitrate and nitrite shall be determined based on the analytical results obtained at each sampling point. The waterworks is not out of compliance with the PMCL if the concentrations of these contaminants are equal to or below the PMCLs. Where nitrate or nitrite sample results exceed the PMCL, the owner shall collect a confirmation sample, from the same sampling point that exceeded the PMCL within 24 hours of the owner's receipt of the analytical results of the first sample. The results of the initial and confirmation sample shall be averaged to determine compliance. The owner unable to comply with the 24-hour sampling requirement shall immediately notify the consumers in the area served by the waterworks in accordance with 12VAC5-590-540 A 1. The owner exercising this option shall collect and analyze a confirmation sample within two weeks of notification of the analytical results of the first sample. The department may require more frequent monitoring. The department has the discretion to delete results of obvious sampling errors.

1. Nitrate nitrogen (NO3-N) levels not exceeding 20 mg/L may be allowed in a noncommunity waterworks if the owner:

a. Demonstrates to the satisfaction of the department that this water will not be available to children under six months of age;

b. Provides continuous posting of the fact that NO3-N levels exceed 10 mg/L and the potential health effects of exposure;

c. Notifies health officials annually of NO3-N levels that exceed 10 mg/L; and

d. The department shall determine that no adverse health effects will result.

2. Nitrite in water poses a significant health hazard. Water with nitrite-nitrogen concentrations over 1 mg/L should not be used for infant feedings.

C. Compliance with the SMCLs for aluminum, chloride, copper, corrosivity, fluoride, foaming agents, iron, manganese, silver, sulfate, or zinc shall be determined based on the analytical results obtained at each sampling point. When the result of a sample exceeds the applicable SMCL, the owner shall collect a confirmation sample at the same sampling point within two weeks of notification of the analytical results of the first sample. The results of the initial and confirmation samples shall be averaged to determine compliance. If the average concentration level of any of these constituents exceeds the SMCL, then the department shall determine whether treatment for the constituents can be accomplished or more suitable source waters are, or can be made, available. This determination shall be made as quickly as possible. If either of these alternatives is feasible, then corrective action shall be promptly implemented by the owner if deemed necessary by the department. Exceeding the fluoride SMCL requires annual public notice in accordance with 12VAC5-590-540 G.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-383. Organic chemicals compliance.

A. When the results of sampling indicate positive results for contaminants listed in Table 340.2, the owner shall collect a confirmation sample at the same sampling point within two weeks of notification of the analytical results of the first sample.

B. The results of the initial and confirmation samples shall be averaged to determine waterworks compliance in accordance with subsection C of this section. The department has the discretion to delete results of obvious sampling errors.

C. Compliance with Table 340.2 shall be determined based on the analytical results obtained at each sampling point. A sample result below the detection limit shall be calculated as zero for the purposes of determining the annual average. If the owner fails to collect the required number of samples, then compliance (average concentration) shall be based on the total number of samples collected.

1. For the owner of a waterworks that conducts monitoring more frequently than annually, compliance is determined by an RAA of all samples collected at each sampling point. If the annual average of any sampling point is greater than the PMCL, then the waterworks is out of compliance. If the initial sample or a subsequent sample would cause the annual average to be exceeded, then the waterworks is out of compliance immediately. A sample result below the detection limit shall be calculated as zero for purposes of determining the annual average.

2. If the owner is conducting monitoring annually or less frequently, then the owner is not in violation if the average of the initial and confirmation samples is greater than the PMCL for that contaminant; however, the owner shall begin quarterly sampling. The owner will not be considered in violation of the PMCL until one year of quarterly sampling has been completed and the RAA is exceeded. If any sample will cause the RAA to exceed the PMCL at any sampling point, then the waterworks is immediately out of compliance with the PMCL.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-384. Residual disinfectant, DBPs, and DBPPs compliance.

A. General requirements.

1. Where compliance is based on an RAA of monthly or quarterly samples or averages and the owner fails to monitor for TTHM, HAA5, or bromate, this failure to monitor shall be treated as a monitoring violation for the entire period covered by the annual average. Where compliance is based on an RAA of monthly or quarterly samples or averages and the owner's failure to monitor makes it impossible to determine compliance with MRDLs for chlorine and chloramines, this failure to monitor shall be treated as a monitoring violation for the entire period covered by the annual average.

2. All samples collected and analyzed under the provisions of this section shall be included in determining compliance, even if that number is greater than the minimum required.

3. The owner is in violation of the PMCL when the LRAA exceeds the PMCLs listed in Table 340.6 calculated based on four consecutive quarters of monitoring, or the LRAA calculated based on fewer than four quarters of data if the PMCL would be exceeded regardless of the monitoring results of subsequent quarters. The owner is in violation of the monitoring requirements for each quarter that a monitoring result would be used in calculating the LRAA if the owner fails to monitor.

B. Disinfection byproducts.

1. TTHM and HAA5.

a. The owner of a waterworks required to monitor quarterly shall calculate the LRAAs for TTHM and HAA5 using monitoring results collected under 12VAC5-590-374 F and determine that each LRAA does not exceed the PMCL in order to comply with the PMCLs listed in Table 340.6. If the owner fails to complete four consecutive quarters of monitoring, then the owner shall calculate compliance with the PMCL based on the average of the available data from the most recent four quarters. If the owner collects more than one sample per quarter at a monitoring location, then the owner shall average all samples collected in the quarter at that location to determine a quarterly average to be used in the LRAA calculation.

b. The owner of a waterworks required to monitor annually or less frequently shall determine that each sample collected is less than the PMCL in order to determine compliance with the PMCLs listed in Table 340.6. If any sample result exceeds the PMCL, then the owner shall comply with the requirements of 12VAC5–590-374 F 5. If no sample result exceeds the PMCL, then the sample result for each monitoring location is considered the LRAA for that monitoring location.

c. The owner is in violation of the monitoring requirements for each quarter that a monitoring result would be used in calculating an LRAA if the owner fails to monitor.

d. A waterworks has exceeded the operational evaluation level at any monitoring location where the sum of the two previous quarters' TTHM results plus twice the current quarter's TTHM result, divided by four to determine an average, exceeds 0.080 mg/L, or where the sum of the two previous quarters' HAA5 results plus twice the current quarter's HAA5 result, divided by four to determine an average, exceeds 0.060 mg/L.

(1) The owner of a waterworks that exceeds the operational evaluation level shall conduct an operational evaluation and submit a written report of the evaluation to the department on a form approved by the department no later than 90 days after being notified of the analytical result that caused the waterworks to exceed the operational evaluation level. The written report shall be made available to the public upon request.

(2) The operational evaluation report shall include an examination of the waterworks treatment and distribution operational practices, including source water conditions, storage tank operations, excess storage capacity, distribution system flushing, changes in source water or source water quality, and treatment changes or problems that may contribute to TTHM and HAA5 formation and what steps could be considered to minimize future exceedances.

(3) The owner may request and the department may allow the owner to limit the scope of the evaluation if the owner is able to identify the cause of the operational evaluation level exceedance. The request to limit the scope of the evaluation does not extend the schedule in subdivision B 1 d (1) of this section for submitting the written report. The department shall approve this limited scope of evaluation in writing, and the owner shall keep that approval with the completed report.

2. Bromate. Compliance shall be based on a running annual arithmetic average, computed quarterly, of monthly samples collected by the owner as prescribed by 12VAC5-590-374 H. For months in which the owner collects more than one sample, compliance is based on the average of all samples collected during the month. If the average result of the samples covering any consecutive four-quarter period exceeds the PMCL listed in Table 340.6, then the owner is in violation of the PMCL and shall notify the public pursuant to 12VAC5-590-540 A 2, in addition to reporting to the department pursuant to 12VAC5-590-530 and 12VAC5-590-531. If the owner fails to complete 12 consecutive months of monitoring, then compliance with the PMCL for the last four-quarter compliance period shall be based on the average of the available data.

3. Chlorite. Compliance shall be based on an arithmetic average of each three-sample set collected in the distribution system as prescribed by 12VAC5-590-374 G. If the arithmetic average of any three-sample set exceeds the PMCL listed in Table 340.6, then the owner is in violation of the PMCL and shall notify the public pursuant to 12VAC5-590-540 A 2, in addition to reporting to the department pursuant to 12VAC5-590-530 and 12VAC5-590-531.

C. Residual disinfectant.

1. Chlorine and chloramines.

a. Compliance shall be based on a running annual arithmetic average, computed quarterly, of monthly averages of all samples collected by the owner under 12VAC5-590-374 I 1 a. If the average covering any consecutive four-quarter period exceeds the MRDL listed in Table 340.7, then the owner is in violation of the MRDL and shall notify the public pursuant to 12VAC5-590-540 A 2, in addition to reporting to the department pursuant to 12VAC5-590-530 and 12VAC5-590-531.

b. In cases where the owner switches between the use of chlorine and chloramines for residual disinfection during the year, compliance shall be determined by including together all monitoring results of both chlorine and chloramines in calculating compliance. Reports submitted pursuant to 12VAC5-590-530 and 12VAC5-590-531 shall clearly indicate which residual disinfectant was analyzed for each sample.

c. Notwithstanding the MRDLs listed in Table 340.7, operators may increase the residual disinfectant levels of chlorine or chloramines in the distribution system to a level and for a time necessary to protect public health to address specific microbiological contamination problems caused by circumstances such as water main breaks in the distribution system, storm runoff events, source water contamination, or cross-connections.

2. Chlorine dioxide.

a. Acute violations. Compliance shall be based on consecutive daily samples collected by the owner under 12VAC5-590-374 I 2 a. If any daily sample collected at the entrance to the distribution system exceeds the MRDL listed in Table 340.7, and on the following day one or more of the three samples collected in the distribution system exceed the MRDL, then the owner is in violation of the MRDL and shall take immediate corrective action to lower the level of chlorine dioxide below the MRDL and shall notify the public pursuant to the procedures for Tier 1 conditions in 12VAC5-590-540 A 1 in addition to reporting to the department pursuant to 12VAC5-590-530 and 12VAC5-590-531. Failure to collect samples in the distribution system the day following an exceedance of the chlorine dioxide MRDL at the entrance to the distribution system shall also be considered an MRDL violation, and the owner shall notify the public of the violation in accordance with the provisions for Tier 1 conditions in 12VAC5-590-540 A 1 in addition to reporting to the department pursuant to 12VAC5-590-530 and 12VAC5-590-531.

b. Nonacute violations. Compliance shall be based on consecutive daily samples collected by the owner under 12VAC5-590-374 I 2 a. If any two consecutive daily samples collected at the entrance to the distribution system exceed the MRDL listed in Table 340.7 and all distribution system samples collected are below the MRDL, then the owner is in violation of the MRDL and shall take corrective action to lower the level of chlorine dioxide below the MRDL at the point of sampling and shall notify the public pursuant to the procedures for Tier 2 conditions in 12VAC5-590-540 A 2 in addition to reporting to the department pursuant to 12VAC5-590-530 and 12VAC5-590-531. Failure to monitor at the entrance to the distribution system the day following an exceedance of the chlorine dioxide MRDL at the entrance to the distribution system is also an MRDL violation, and the owner shall notify the public of the violation in accordance with the provisions for Tier 2 conditions in 12VAC5-590-540 A 2 in addition to reporting to the department pursuant to 12VAC5-590-530 and 12VAC5-590-531.

D. Disinfection byproduct precursors (DBPPs).

1. Compliance shall be determined as specified by 12VAC5-590-411 A 3.

2. For the owner required to meet Step 1 TOC removals, if the value calculated under 12VAC5-590-411 A 3 a (4) is less than 1.00, then the owner is in violation of the treatment technique requirements and shall notify the public pursuant to 12VAC5-590-540 A 2 in addition to reporting to the department pursuant to 12VAC5-590-530 and 12VAC5-590-531.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-385. Lead and copper AL compliance.

A. The lead AL is exceeded if the concentration of lead in more than 10% of tap water samples collected during any monitoring period conducted in accordance with 12VAC5-590-375 B is greater than 0.015 mg/L (i.e., if the 90th percentile lead level is greater than 0.015 mg/L).

B. The copper AL is exceeded if the concentration of copper in more than 10% of tap water samples collected during any monitoring period conducted in accordance with 12VAC5-590-375 B is greater than 1.3 mg/L (i.e., if the 90th percentile copper level is greater than 1.3 mg/L).

C. The 90th percentile lead and copper levels shall be computed as follows:

1. The results of all lead or copper samples taken during a monitoring period shall be placed in ascending order from the sample with the lowest concentration to the sample with the highest concentration. Each sampling result shall be assigned a number, ascending by single integers beginning with the number 1 for the sample with the lowest contaminant level. The number assigned to the sample with the highest contaminant level shall be equal to the total number of samples taken.

2. The number of samples taken during the monitoring period shall be multiplied by 0.9.

3. The contaminant concentration in the numbered sample yielded by the calculation in subdivision C 2 of this section is the 90th percentile contaminant level.

4. For a waterworks serving fewer than 100 people, and the owner collects five samples per monitoring period, the 90th percentile is computed by taking the average of the highest and second highest concentrations.

5. For the owner that has been allowed by the department to collect fewer than five samples in accordance with 12VAC5-590-375 B 3, the sample result with the highest concentration is considered the 90th percentile value.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 27, Issue 1, eff. October 13, 2010; amended, Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-388. Radiological compliance.

A. MCLGs for radionuclides are listed in Table 546.1 of 12VAC5-590-546 B.

B. PMCLs for radionuclides are applicable to community waterworks only and are listed in Table 340.4. Compliance with PMCLs will be determined based on the analytical results obtained at each entry point. If the sample result at one entry point exceeds the PMCL, then the owner is in violation of the PMCL.

1. For the owner that is monitoring more than once per year, compliance with the PMCL is determined by an RAA of the analytical results at each entry point. If the average result at any entry point is greater than the PMCL, then the waterworks is out of compliance with the PMCL.

2. For the owner of a waterworks that monitors more than once per year, if any sample result will cause the RAA to exceed the PMCL at any entry point, then the waterworks is out of compliance with the PMCL immediately.

3. All samples collected and analyzed under the provisions 12VAC5-590-378 shall be included in determining compliance, even if that number is greater than the minimum required.

4. If the owner does not collect all required samples when compliance is based on an RAA result of quarterly samples, then compliance will be based on the RAA result of the samples collected.

5. If a sample result is less than the detection limit as specified in Table 378.1, then zero will be used to calculate the RAA unless a gross alpha particle activity result is being used instead of radium-226 or uranium. If the gross alpha particle activity result is less than the detection limit as specified in Table 378.1, then one half the detection limit will be used to calculate the RAA.

C. Radiological (gross alpha, combined radium-226 and radium-228, uranium, and man-made radioactivity).

1. Compliance with the radiological PMCLs shall be based on the RAA results. PMCLs are indicated in Table 340.4. Sampling for radiological analysis shall be in compliance with 12VAC5-590-378.

2. Compliance shall be determined by rounding off results to the same number of significant figures as the PMCL for the radionuclide in question.

D. If a PMCL for radioactivity listed in Table 340.4 is exceeded, then the owner shall give notice to the department pursuant to 12VAC5-590-530 and to the public as required by 12VAC5-590-540 A 2.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-390. Physical constituent compliance.

A. Color, odor, pH, and total dissolved solids.

1. When the sampling results for color, odor, pH, or total dissolved solids exceed the applicable SMCL, the owner shall collect a confirmation sample at the same sampling site within two weeks of notification of the analytical results of the first sample.

2. The results of the initial and confirmation samples shall be averaged to determine compliance with 12VAC5-590-340 C. The department has the discretion to void results of obvious sampling errors.

3. If the average concentration level of any contaminant of color, odor, pH, or total dissolved solids is greater than the SMCL listed in Table 340.3, then the department shall determine whether treatment to remove that contaminant can be accomplished or more suitable supplies of source water are, or can be made, available.

B. Turbidity in groundwater sources not required to filter shall not:

1. Interfere with disinfection throughout the distribution system;

2. Cause taste and odors upon disinfection; or

3. Cause consumers to question the safety of their drinking water.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-004.06 § 2.6, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 12, Issue 2, eff. November 15, 1995; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-391. Treatment technique requirements.

A. When it is not technically or economically feasible to monitor for a particular PMCL or a contaminant, one or more specific treatment techniques that lead to a reduction in the concentration level of that contaminant shall be required. The application of that treatment technique reduces the contaminant in question to a concentration level that achieves compliance with this chapter.

B. Failure to continuously maintain the treatment technique is a violation of this chapter and public notification in accordance with 12VAC5-590-540 A 2 is required.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-392. Coliform treatment technique triggers and assessment requirements.

A. Assessments shall be conducted in accordance with subsections C, D, and E of this section after exceeding treatment technique triggers.

B. Treatment technique triggers.

1. Level 1 treatment technique triggers:

a. For the owner required to collect 40 or more samples per month, the number of total coliform-positive samples exceeds 5.0% of the number of samples collected for the month.

b. For the owner required to collect fewer than 40 samples per month, when there are two or more total coliform-positive samples in the same month.

c. The owner fails to collect every required repeat sample after any single total coliform-positive sample.

2. Level 2 treatment technique triggers:

a. An E. coli PMCL violation, as specified in 12VAC5-590-380 B 2.

b. A second Level 1 trigger occurs within a rolling 12-month period, unless the department has determined a likely reason for the first Level 1 treatment technique trigger and that the owner has corrected the problem.

C. Assessment requirements.

1. Level 1 and 2 assessments shall be conducted to identify the possible presence of sanitary defects and defects in the distribution system coliform monitoring practices. The owner shall be responsible for conducting Level 1 assessments. Level 2 assessments shall be conducted by the department.

2. When conducting Level 1 and Level 2 assessments, the assessor shall include:

a. An evaluation and identification of inadequacies in sample sites, sampling protocol, and sample processing;

b. An evaluation of atypical events that could affect distributed water quality or indicate that distributed water quality was impaired;

c. An evaluation of changes in distribution system maintenance and operation that could affect distributed water quality, including water storage;

d. An evaluation of source and treatment considerations that impact distributed water quality; and

e. An evaluation of existing water quality monitoring data.

3. Level 1 assessment.

a. The owner shall complete the assessment and document the assessment on a form approved by the department. The owner shall submit the assessment form, as soon as practical, but within 30 days after the owner learns that a trigger in subdivision B 1 of this section has been exceeded.

b. If the department evaluates the completed Level 1 assessment and determines that the assessment is not sufficient, including any proposed timetable for any corrective actions, then the department shall consult with the owner. If the department requires revisions after the consultation, then the owner shall submit a revised assessment form to the department on an agreed upon schedule not to exceed 30 days from the date of consultation.

c. Upon completion and submission of the assessment form by the owner, the department shall determine if the owner has identified a likely cause for the Level 1 trigger and, if so, confirm that the owner has corrected the problem or has included a schedule acceptable to the department for correcting the problem.

4. Level 2 assessment.

a. The department will complete the assessment and document the assessment on a form approved by the department. The department will consult with the owner during the assessment and complete the assessment within 30 days upon learning that the waterworks has exceeded any trigger in subdivision B 2 of this section.

b. The department will send to the owner the completed assessment form, which will describe any detected sanitary defects, corrective actions completed or needed and, if needed, a timetable to complete the corrective actions. The owner will return the form within seven days with a signature that indicates concurrence with the listed actions needed and timetable to complete the corrective actions. If the owner does not concur with either an action or timetable to complete a corrective action, then the owner shall notify the department, complete consultation with the department, and develop a revised corrective action schedule. The owner shall submit the revised schedule to the department for evaluation and approval within 30 days of the date of the consultation.

D. Corrective actions.

1. The owner shall correct sanitary defects found through either the Level 1 or the Level 2 assessment conducted under subsection C of this section.

2. The owner shall complete the corrective actions in compliance with the timetable approved by the department in consultation with the owner. The owner shall notify the department no later than seven days after each scheduled corrective action is completed.

E. Consultation.

1. At any time during the assessment or corrective action phase, either the owner or the department may request a consultation with the other party to determine the appropriate actions to be taken.

2. The owner may consult with the department on all relevant information that may impact the ability to comply with subsection D of this section.

F. Violations. Failure to conduct the required assessment or corrective actions in accordance with subsections C and D of this section, after exceeding a treatment technique trigger specified in subsection B of this section, is a treatment technique violation. The owner shall provide public notification as required under Tier 2 conditions specified in 12VAC5-590-540 A 2.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 33, Issue 3, eff. November 2, 2016; amended, Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-395. Surface water and GUDI sources, polymers, and recycle treatment techniques.

A. Surface water and GUDI source treatment techniques.

1. The filtration and disinfection provisions of this section are required treatment techniques for a waterworks supplied by a surface water source, a GUDI source, or both. These treatment technique requirements are in place of a PMCL for the following contaminants: Giardia lamblia, viruses, heterotrophic bacteria, Cryptosporidium, Legionella, and turbidity. A waterworks that uses a surface water source, a GUDI source, or both shall provide treatment of that source water that complies with these treatment technique requirements. See 12VAC5-590-401 for filtration log removal credits and required log inactivation for Cryptosporidium. See 12VAC5-590-500 for log removal credits and required log inactivation for Giardia lamblia and viruses. These treatment technique requirements consist of installing and properly operating water treatment processes that reliably achieve:

a. At least 99.9% (3-log) removal or inactivation of Giardia lamblia between a point where the source water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer;

b. At least 99.99% (4-log) removal or inactivation of viruses between a point where the source water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer; and

c. At least 99% (2-log) removal of Cryptosporidium between a point where the source water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer.

2. A waterworks that uses a surface water source, a GUDI source, or both is considered to be in compliance with the requirements of subdivision A 1 of this section if it meets the following disinfection and filtration requirements:

a. Disinfection requirements.

(1) The disinfection treatment shall be sufficient to ensure that the total treatment processes of that waterworks achieve at least 99.9% (3-log) inactivation or removal of Giardia lamblia and at least 99.99% (4-log) inactivation or removal of viruses. If any physical process can achieve at least a 3-log removal of Giardia lamblia but cannot adequately remove pathogens, then the disinfection treatment shall provide a second treatment barrier for Giardia lamblia, Legionella, heterotrophic bacteria, and viruses. The disinfection treatment shall be sufficient to assure at least a 0.5 log inactivation of Giardia lamblia.

(2) The residual disinfectant concentration in the water entering the distribution system shall not be less than 0.2 mg/L for more than four hours.

(3) The residual disinfectant concentration in the distribution system, measured as total chlorine, free chlorine, combined chlorine, or chlorine dioxide, shall not be undetectable in more than 5% of the samples each month, for any two consecutive months that the waterworks serves water to the public. If the department determines that a waterworks is experiencing excessive coliform occurrences in its distribution system, then the department may require the owner to maintain minimum chlorine residual levels of 0.2 mg/L or monochloramine levels of 0.5 mg/L throughout the distribution system. Water in the distribution system with a heterotrophic bacteria concentration less than or equal to 500/mL, measured as HPC, is deemed to have a detectable residual disinfectant for the purposes of determining compliance with this requirement. Thus, the value "V," in percent, in the following formula shall not exceed 5% in one month, for any two consecutive months.

V = [(c + d + e) / (a + b)] X 100

where

a = number of instances where the residual disinfectant concentration is measured;

b = number of instances where the residual disinfectant concentration is not measured but HPC is measured;

c = number of instances where the residual disinfectant concentration is measured but not detected and no HPC is measured;

d = number of instances where no residual disinfectant concentration is detected and where the HPC is greater than 500/mL; and

e = number of instances where the residual disinfectant concentration is not measured and HPC is greater than 500/mL.

(4) The department may determine that the HPC compliance requirements of subdivision A 2 a (3) of this section do not apply based on site-specific considerations or if an owner has no means for having a sample transported and analyzed for HPC by a certified laboratory under the requisite time and temperature conditions and the waterworks is providing adequate disinfection in the distribution system.

b. Filtration requirements. A waterworks that uses a surface water source, a GUDI source, or both shall provide filtration treatment by using one of the following methods:

(1) Conventional filtration.

(a) Achieve a filtered water turbidity of less than or equal to 0.3 NTU in at least 95% of the measurements taken each month. Samples shall be representative of the waterworks' filtered water.

(b) The turbidity level of representative samples of a waterworks' filtered water shall at no time exceed one NTU, measured as specified in 12VAC5-590-440.

(c) A waterworks that uses lime softening may acidify representative samples before analysis using a protocol approved by the department.

(d) Water treatment plants utilizing conventional or direct filtration with gravity flow granular media filters are capable of producing filtered water with turbidity consistently less than 0.10 NTU. Therefore, for these types of water treatment plants, the operational goal for filter effluent turbidity for each filter, before any post-filtration chemical addition, shall be 0.10 NTU.

(2) Diatomaceous earth filtration.

(a) The turbidity level of representative samples of a waterworks' filtered water shall be less than or equal to one NTU in at least 95% of the measurements taken each month.

(b) The turbidity level of representative samples of a waterworks' filtered water shall at no time exceed five NTU.

(3) Slow sand filtration.

(a) The turbidity level of representative samples of a waterworks' filtered water shall be less than or equal to one NTU in at least 95% of the measurements taken each month, except that if the department determines there is no significant interference with disinfection at a higher turbidity level, then the department may substitute this higher turbidity limit for that waterworks.

(b) The turbidity level of representative samples of a waterworks' filtered water shall at no time exceed five NTU.

(4) Membrane filters, bag filters, and cartridge filters.

(a) The turbidity level of representative samples of a waterworks' filtered water shall be less than or equal to 0.3 NTU in at least 95% of the measurements taken each month, except that if the department determines there is no significant interference with disinfection at a higher turbidity level, then the department may substitute this higher turbidity limit for that waterworks.

(b) Water treatment plants utilizing membrane filtration are capable of producing filtered water with turbidity consistently less than 0.05 NTU. Therefore, for these types of water treatment plants, the operational goal for filter effluent turbidity for each filter, before any post-filtration chemical addition, is 0.05 NTU.

(c) The turbidity level of representative samples of a waterworks' filtered water shall at no time exceed one NTU.

(5) The owner may use a filtration technology not listed in this section if the owner demonstrates to the satisfaction of the department by full-scale, pilot plant, or challenge studies, or by other approved means that the alternative filtration technology, in combination with disinfection, will meet the requirements of this section.

3. Once the department has determined that a waterworks utilizes a surface water source, a GUDI source, or both (see 12VAC5-590-430), then filtration and disinfection treatments are required. The owner shall install and have in operation treatment units that meet the requirements described in subdivisions A 1 and A 2 of this section no later than 18 months following the department's determination. During the interim period, and until filtration and disinfection treatments are installed and in operation, the owner shall discontinue use of the surface water source, GUDI source, or both unless the source must remain in service because discontinuing the source is not a viable option, at which point the owner shall:

a. Issue a continuous boil water notice through the public notification procedure in 12VAC5-590-540 A 1 until the required filtration and disinfection treatments are installed and are in operation;

b. Provide disinfection treatment to achieve a 4-log inactivation of virus during the interim period before the filtration treatment is installed. Monitoring equipment shall be installed that will ensure compliance with this requirement; and

c. Increase bacteriological sampling frequency in the distribution system. For the owner required to collect routine distribution system bacteriological samples at a monthly frequency, the owner shall collect twice the number of samples required for that population each month. For the owner required to collect routine bacteriological samples at a quarterly frequency, the owner shall increase the sampling frequency to monthly.

B. Polymer treatment techniques.

1. The owner shall certify annually in writing to the department (using third-party or manufacturer's certification) that, when polymers containing acrylamide or epichlorohydrin are used by the waterworks, the combination (or product) of dose and monomer level does not exceed the following specified levels:

a. Acrylamide = 0.05% dosed at one ppm (or equivalent) of polymer.

b. Epichlorohydrin = 0.01% dosed at 20 ppm (or equivalent) of polymer.

2. Certifications may rely on the manufacturers or third parties as approved by the department.

C. Recycle treatment techniques.

1. If spent filter backwash water, thickener supernatant, or liquids from dewatering processes are recycled, in a waterworks supplied by a surface water source, a GUDI source, or both that employ conventional filtration or direct filtration treatment, then the waterworks is subject to the treatment technique requirement described in subsection A of this section.

2. Under this requirement, recycle flows shall be returned through all the processes of the treatment system or an alternative location approved by the department.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-400. (Repealed.)

Historical Notes

Derived from VR355-18-004.07 § 2.7, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 12, Issue 2, eff. November 15, 1995; Volume 19, Issue 24, eff. September 10, 2003; Volume 22, Issue 15, eff. May 3, 2006; repealed, Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-401. Enhanced filtration and disinfection for Cryptosporidium treatment techniques.

A. A waterworks using a surface water source, a GUDI source, or both shall comply with the requirements of this section based on their population or if the waterworks is a wholesaler, based on the population of the largest waterworks in the combined distribution system.

B. The owner shall conduct an initial and a second round of source water monitoring for each water treatment plant that treats a surface water source, a GUDI source, or both. This monitoring may include sampling for Cryptosporidium, E. coli, and turbidity to determine what level, if any, of additional Cryptosporidium treatment is required.

1. Initial round of source water monitoring. The owner shall conduct the following monitoring on the schedule in subdivision B 3 of this section unless the monitoring avoidance criteria in subdivision B 4 of this section are met.

a. The owner of a waterworks serving at least 10,000 people shall sample the source water for Cryptosporidium, E. coli, and turbidity at least monthly for 24 months.

b. The owner of a waterworks serving fewer than 10,000 people:

(1) Shall sample the source water for E. coli at least once every two weeks for 12 months, or

(2) May avoid E. coli monitoring if the owner notifies the department that the owner will monitor for Cryptosporidium as described in subdivision B 1 c of this section. The owner shall notify the department no later than three months before the date at which the owner is otherwise required to start E. coli monitoring.

c. The owner of a waterworks serving fewer than 10,000 people shall sample the source water for Cryptosporidium at least twice per month for 12 months or at least monthly for 24 months if the owner meets one of the following, based on monitoring conducted under subdivision B 1 b of this section:

(1) For a waterworks using source water from a lake or reservoir, the annual mean E. coli concentration is greater than 10 E. coli/100 mL.

(2) For a waterworks using source water from flowing stream, the annual mean E. coli concentration is greater than 50 E. coli/100 mL.

(3) The waterworks does not conduct E. coli monitoring as described in subdivision B 1 b of this section.

(4) The waterworks using a GUDI source shall comply with the requirements of this subdivision B 1 c based on the E. coli level that applies to the nearest surface water body. If no surface water body is nearby, the waterworks shall comply based on the requirements that apply to a waterworks using source water from a lake or reservoir.

d. For the waterworks serving fewer than 10,000 people, the department may approve monitoring for an indicator other than E. coli under subdivision B 1 b (1) of this section. The department also may approve an alternative to the E. coli concentration in subdivision B 1 c (1), B 1 c (2), or B 1 c (4) of this section to trigger Cryptosporidium monitoring. This approval by the department shall be provided to the owner in writing and shall include the basis for the department's determination that the alternative indicator or trigger level will provide a more accurate identification of whether a waterworks will exceed the Bin 1 Cryptosporidium level in subdivision B 1 a of this section.

e. The waterworks may sample more frequently than required under this section if the sampling frequency is evenly spaced throughout the monitoring period.

2. Second round of source water monitoring. The owner shall conduct a second round of source water monitoring that meets the requirements for monitoring parameters, frequency, and duration described in subdivision B 1 of this section, unless the monitoring exemption criteria in subdivision B 4 of this section are met. The owner shall conduct this monitoring on the schedule in subdivision B 3 of this section.

3. Monitoring schedule. The owner shall begin the monitoring required in subdivisions B 1 and B 2 of this section no later than the month beginning with the date listed in Table 401.1:

TABLE 401.1
Source Water Monitoring Starting Dates

OWNERS OF WATERWORKS THAT SERVE...

SHALL BEGIN THE FIRST ROUND OF SOURCE WATER MONITORING NO LATER THAN THE MONTH BEGINNING...

AND SHALL BEGIN THE SECOND ROUND OF SOURCE WATER MONITORING NO LATER THAN THE MONTH BEGINNING...

At least 100,000 people

October 1, 2006

April 1, 2015

From 50,000 - 99,999 people

April 1, 2007

October 1, 2015

From 10,000 - 49,999 people

April 1, 2008

October 1, 2016

Fewer than 10,000 and monitor for E. coli

October 1, 2008

October 1, 2017

Fewer than 10,000 and monitor for Cryptosporidiuma

April 1, 2010

April 1, 2019

aApplies to a waterworks that meet the conditions of subdivision B 1 c of this section.

4. Monitoring avoidance.

a. The owner is not required to conduct source water monitoring if the waterworks will provide a total of at least 5.5-log of treatment for Cryptosporidium, equivalent to meeting the treatment requirements of Bin 4 in subdivision D 2 of this section.

b. If the owner chooses to provide the level of treatment in subdivision B 4 a of this section, rather than start source water monitoring, then the owner shall notify the department in writing no later than the date the owner is otherwise required to submit a sampling schedule for monitoring under subdivision B 5 of this section. Alternatively, the owner may choose to stop sampling at any point after initiating monitoring if the owner notifies the department in writing that he will provide this level of treatment. The owner shall install and operate technologies to provide this level of treatment by the applicable treatment compliance date in subdivision D 3 of this section.

5. Sampling schedules.

a. The owner of a waterworks required to conduct source water monitoring in accordance with subsection B of this section shall submit a sampling schedule that specifies the calendar dates when the owner shall collect each required sample.

(1) The owner shall submit a sampling schedule to the department no later than three months before the applicable date listed in subdivision B 3 of this section for each round of required monitoring.

(2) If the department does not respond to the owner regarding the sampling schedule, then the owner shall sample at the reported schedule.

b. The owner shall collect samples within two days before or two days after the dates indicated in the sampling schedule (i.e., within a five-day period around the schedule date) unless one of the conditions of this subdivision b applies:

(1) If an extreme condition or situation exists that may pose danger to the sample collector or that cannot be avoided and causes the owner to be unable to sample in the scheduled five-day period, then the owner shall sample as close to the scheduled date as is feasible unless the department approves an alternative sampling date. The owner shall submit an explanation for the delayed sampling date to the department concurrent with the shipment of the sample to the laboratory.

(2) If the owner is unable to report a valid analytical result for a scheduled sampling date due to equipment failure, loss of or damage to the sample, failure to comply with the analytical method requirements, including the quality control requirements of 12VAC5-590-440, or the failure of an approved laboratory to analyze the sample, then the owner shall collect a replacement sample. The owner shall collect the replacement sample not later than 21 days after receiving information that an analytical result cannot be reported for the scheduled date unless the owner demonstrates that collecting a replacement sample within this timeframe is not feasible or the department approves an alternative resampling date. The owner shall submit an explanation for the delayed sampling date to the department concurrent with the shipment of the sample to the laboratory.

c. The owner of a waterworks that fails to meet the criteria of subdivision B 5 b of this section for any source water sample required under subsection B of this section shall revise the sampling schedule to add dates for collecting all missed samples. The owner shall submit the revised schedule to the department for approval before the owner begins collecting the missed samples.

6. Sampling locations.

a. The owner of a waterworks required to conduct source water monitoring under subsection B of this section shall collect samples for each water treatment plant that treats a surface water source, a GUDI source, or both. Where multiple water treatment plants draw source water from the same influent, such as the same pipe or intake, the department may approve one set of monitoring results to be used to satisfy the requirements of subsection B of this section for all water treatment plants.

b. The owner shall collect source water samples before chemical treatment, such as coagulants, oxidants, and disinfectants. However, the department may approve the collection of a source water sample after chemical treatment. To grant this approval, the department shall determine that collecting a sample before chemical treatment is not feasible for the owner and that the chemical treatment is unlikely to have a significant adverse effect on the analysis of the sample.

c. The owner of a waterworks that recycles filter backwash water shall collect source water samples before the point of filter backwash water addition.

d. Bank filtration.

(1) The owner that receives Cryptosporidium treatment credit for bank filtration under 12VAC5-590-395 A 2 b (1) shall collect source water samples from the surface water before bank filtration.

(2) The owner that uses bank filtration as pretreatment to a water treatment plant shall collect source water samples from the well (i.e., after bank filtration). The use of bank filtration during monitoring shall be consistent with routine operational practice. The owner collecting samples after a bank filtration process may not receive treatment credit for the bank filtration under subdivision E 4 c of this section.

e. Multiple sources. The owner of a waterworks that uses multiple source waters, including multiple surface water sources and blended surface water and groundwater sources, shall collect samples as specified in subdivision B 6 e (1) or B 6 e (2) of this section. The use of multiple source waters during monitoring shall be consistent with routine operational practice.

(1) If a sampling tap is available where the source waters are combined before treatment, then the owner shall collect samples from the tap.

(2) If a sampling tap is not available where the source waters are combined before treatment, then the owner shall collect samples at each source near the intake on the same day and shall follow either subdivision B 6 e (2) (a) or B 6 e (2) (b) of this section for sample analysis.

(a) The owner may composite samples from each source into one sample before analysis. The volume of sample from each source shall be weighted according to the proportion of the source water in the total water treatment plant flow at the time the sample is collected.

(b) The owner may choose to have samples analyzed from each source separately and calculate a weighted average of the analysis results for each sampling date. The weighted average shall be calculated by multiplying the analysis result for each source water by the fraction the source water contributed to the total water treatment plant flow at the time the sample was collected and then summing these values.

f. Additional requirements. The owner shall submit a description of each sampling location to the department at the same time as the sampling schedule required in subdivision B 3 of this section. This description shall address the position of the sampling location in relation to the waterworks' source waters and treatment processes, including pretreatment, points of chemical treatment, and filter backwash recycle. If the department does not respond to an owner regarding sampling location, then the owner shall sample at each reported location.

7. Analytical methods. All analytical methods shall be conducted in accordance with 12VAC5-590-440.

8. Approved laboratories.

a. Cryptosporidium. The owner shall have Cryptosporidium samples analyzed by a laboratory that has received reciprocal certification approved under the DCLS Laboratory Certification Program for Analysis of Cryptosporidium in Water.

b. E. coli. A laboratory certified by the DCLS for total coliform analysis under 12VAC5-590-440 is approved for E. coli analysis when the laboratory uses the same technique for E. coli that the laboratory uses under 12VAC5-590-440. Laboratories shall use methods for enumeration of E. coli in source water approved in 12VAC5-590-440.

c. Turbidity. Measurements of turbidity shall be made by a party approved by the department.

9. Reporting of the source water results shall be in accordance with 12VAC5-590-531.

10. The owner of a waterworks treating a surface water source, a GUDI source, or both, that operates for only part of the year shall conduct source water monitoring in accordance with this section, but with the following modifications:

a. The owner shall sample the source water only during the months that the waterworks operates unless the department specifies another monitoring period based on waterworks operating practices.

b. The owner of a waterworks that operates less than six months per year and that monitors for Cryptosporidium shall collect at least six Cryptosporidium samples per year during each of two years of monitoring. Samples shall be evenly spaced throughout the period the waterworks operates.

11. New sources.

a. The owner of a waterworks that begins using a surface water source, a GUDI source, or both, is required to begin monitoring under subdivision B 3 of this section and shall monitor the new source on a schedule approved by the department. Source water monitoring shall meet the requirements of this section. The owner shall also meet the bin classification and Cryptosporidium treatment requirements of subdivisions D 1 and D 2 of this section, for the new source on a schedule approved by the department.

b. The requirements of this section apply to a waterworks using a surface water source, a GUDI source, or both, that begins operation after the monitoring start date applicable to the size of the waterworks under subdivision B 3 of this section.

c. The owner shall begin a second round of source water monitoring no later than six years following the initial bin classification under subdivision D 1 of this section.

12. Failure to collect any source water sample required under this section in accordance with the sampling schedule, sampling location, analytical method, approved laboratory, and reporting requirements of subdivisions B 5 through B 9 of this section is a monitoring violation.

13. Grandparenting monitoring data. The owner may use monitoring data collected before the applicable monitoring start date in subdivision B 3 of this section (grandparented data) to meet the initial source water monitoring requirements in subdivision B 1 of this section. Grandparented data may be substituted for an equivalent number of months at the end of the monitoring period. All data submitted under this subdivision B 13 shall meet the requirements in subdivisions B 13 a through B 13 h of this section and be approved by the department:

a. The owner may grandparent Cryptosporidium samples to meet the requirements of this section when the owner does not have corresponding E. coli and turbidity samples. The owner who grandparents Cryptosporidium samples without E. coli and turbidity samples is not required to collect E. coli and turbidity samples when the owner completes the requirements for Cryptosporidium monitoring under this section.

b. The analysis of E. coli samples shall meet the analytical method and approved laboratory requirements of subdivisions B 7 and B 8 of this section.

c. The analysis of Cryptosporidium samples shall meet the requirements of subdivision B 8 of this section.

d. The sampling location shall meet the conditions in subdivision B 6 of this section.

e. Cryptosporidium sample collection intervals may vary for the conditions specified in subdivisions B 5 b (1) and B 5 b (2) of this section if the owner provides documentation of the condition when reporting monitoring results.

(1) The department may approve grandparenting of previously collected data where there are time gaps in the sampling frequency if the owner conducts additional monitoring the department specifies to ensure that the data used to comply with the initial source water monitoring requirements of subsection B of this section are seasonally representative and unbiased.

(2) The owner may grandparent previously collected data where the sampling frequency within each month varied. If the Cryptosporidium sampling frequency varied, then the owner shall follow the monthly averaging procedure in subdivision D 1 a (5) of this section when calculating the bin classification for a filtered waterworks.

f. The owner of a waterworks that requests to grandparent previously collected monitoring results shall report the following information by the applicable dates listed in the following subdivisions. The owner shall report this information to the department.

(1) The owner shall report the intent to submit previously collected monitoring results for grandparenting. This report shall specify the number of previously collected results the owner shall submit, the dates of the first and last sample, and whether an owner shall conduct additional source water monitoring to meet the requirements in subsection B of this section. The owner shall report this information no later than the date the sampling schedule listed in subdivision B 3 of this section is required.

(2) The owner shall report previously collected monitoring results for grandparenting no later than two months after the applicable date listed in subdivision B 3 of this section.

(a) For each sample result, the owner shall report the applicable data elements in 12VAC5-590-531 A 5.

(b) The owner shall certify that the reported monitoring results include all results the waterworks generated during the time period beginning with the first reported result and ending with the final reported result. This applies to samples that were collected from the sampling location specified for source water monitoring under subdivision B 1 of this section, not spiked, and analyzed using the laboratory's routine process for the analytical methods listed in this section.

(c) The owner shall certify that the samples were representative of a waterworks' source waters and the source waters have not changed. The owner shall report a description of each sampling location, which shall address the position of the sampling location in relation to the waterworks' source waters and treatment processes, including points of chemical addition and filter backwash recycle.

(d) For Cryptosporidium samples, the laboratory that analyzed the samples shall provide a letter certifying that the quality control criteria specified in the methods listed in subdivision B 8 of this section were met for each sample batch associated with the reported results. Alternatively, the laboratory may provide bench sheets and sample examination report forms for each field, matrix spike, initial precision and recovery (IPR), ongoing precision and recovery (OPR), and method blank sample associated with the reported results.

g. If the department determines that a previously collected data set submitted for grandparenting was generated during source water conditions that were not normal for the waterworks, such as a drought, the department may disapprove the data. Alternatively, the department may approve the previously collected data if the owner reports additional source water monitoring data, as determined by the department, to ensure that the data set used under subdivision D 1 of this section represents average source water conditions for the waterworks.

h. If the owner submits previously collected data that fully meets the number of samples required for initial source water monitoring under subdivision B 1 of this section and some of the data are rejected due to not meeting the requirements of this section, then the owner shall conduct additional monitoring to replace rejected data on a schedule approved by the department. The owner is not required to begin this additional monitoring until two months after notification that data have been rejected and additional monitoring is necessary.

C. The owner of a waterworks that plans to make a significant change to the disinfection practice shall develop disinfection profiles and calculate disinfection benchmarks as described in 12VAC5-590-500.

1. The owner shall notify the department before changing the disinfection practice and shall include in this notice the following information:

a. A completed disinfection profile and disinfection benchmark for Giardia lamblia and viruses;

b. A description of the proposed change in disinfection practice; and

c. An analysis of how the proposed change will affect the current level of disinfection.

2. Significant changes to the disinfection practice are defined as follows:

a. Changes to the point of disinfection;

b. Changes to any disinfectant used in the water treatment plant;

c. Changes to the disinfection process; or

d. Any other modification identified by the department as a significant change to disinfection practice.

D. The owner shall determine the Cryptosporidium treatment bin classification as described in subdivision D 1 of this section and provide additional treatment for Cryptosporidium, if required, as described in subdivision D 2 of this section. The owner shall implement Cryptosporidium treatment according to the schedule in subdivision D 3 of this section.

1. Bin classification for waterworks.

a. Following completion of the initial round of source water monitoring required under subdivision B 1 of this section, the owner shall calculate an initial Cryptosporidium bin concentration for each water treatment plant for which monitoring was required. Calculation of the bin concentration shall use the Cryptosporidium results reported under subdivision B 1 of this section and shall follow these procedures:

(1) For the owner who collects a total of at least 48 samples, the bin concentration is equal to the arithmetic mean of all sample concentrations.

(2) For the owner who collects a total of at least 24 samples, but not more than 47 samples, the bin concentration is equal to the highest arithmetic mean of all sample concentrations in any 12 consecutive months during which Cryptosporidium samples were collected.

(3) For the owner of a waterworks that serves fewer than 10,000 people and monitors for Cryptosporidium for only one year (i.e., collect 24 samples in 12 months), the bin concentration is equal to the arithmetic mean of all sample concentrations.

(4) For water treatment plants that operate only part of the year and that monitor fewer than 12 months per year under subdivision B 1 of this section, the bin concentration is equal to the highest arithmetic mean of all sample concentrations during any year of Cryptosporidium monitoring.

(5) If the monthly Cryptosporidium sampling frequency varies, then the owner shall first calculate a monthly average for each month of monitoring. The owner shall then use these monthly average concentrations, rather than individual sample concentrations, in the applicable calculation for bin classification in subdivisions D 1 a (1) through D 1 a (4) of this section.

b. The owner shall determine the initial bin classification from Table 401.2 using the Cryptosporidium bin concentration calculated under subdivision D 1 a of this section:

TABLE 401.2
Bin Classification for Filtered Waterworks

FOR OWNERS OF WATERWORKS THAT ARE...

WITH A CRYPTOSPORIDIUM BIN CONCENTRATION OFa...

THE BIN CLASSIFICATION IS...

Required to monitor for Cryptosporidium under subdivision B 1 of this section

Cryptosporidium less than 0.075 oocysts/L

Bin 1

Cryptosporidium equal to or greater than 0.075 oocysts/L but less than 1.0 oocysts/L

Bin 2

Cryptosporidium equal to or greater than 1.0 oocysts/L but less than 3.0 oocysts/L

Bin 3

Cryptosporidium equal to or greater than 3.0 oocysts/L

Bin 4

Serving fewer than 10,000 people and NOT required to monitor for Cryptosporidium under subdivision B 1 c of this section

Not Applicable

Bin 1

aBased on calculations in subdivision D 1 a or D 1 c of this section, as applicable.

c. Following completion of the second round of source water monitoring required under subdivision B 2 of this section, the owner shall recalculate the Cryptosporidium bin concentration using the Cryptosporidium results reported under subdivision B 2 of this section and following the procedures in subdivisions D 1 a (1) through D 1 a (4) of this section. The owner shall then redetermine the bin classification using this bin concentration and Table 401.3.

d. Reporting of bin classifications.

(1) The owner shall report the initial bin classification under subdivision D 1 b of this section to the department for approval no later than six months after the waterworks is required to complete the initial source water monitoring based on the schedule in subdivision B 3 of this section.

(2) The owner shall report the bin classification under subdivision D 1 c of this section to the department for approval no later than six months after the owner is required to complete the second round of source water monitoring based on the schedule in subdivision D 1 a (3) of this section.

(3) The bin classification report to the department shall include a summary of source water monitoring data and the calculation procedure used to determine bin classification.

e. Failure to comply with the conditions of subdivision D 1 d of this section is a violation of the treatment technique requirement.

2. Waterworks additional Cryptosporidium treatment requirements.

a. A waterworks shall provide the level of additional treatment for Cryptosporidium specified in this subdivision based on the bin classification as determined under subdivision D 1 of this section and according to the schedule in subdivision D 3 b of this section.

TABLE 401.3.
Cryptosporidium Treatment Requirements

IF THE WATERWORKS BIN CLASSIFICATION IS...

AND THE WATERWORKS USES THE FOLLOWING FILTRATION TREATMENT IN FULL COMPLIANCE WITH 12VAC5-590-395 A 1 AND 12VAC5-590-395 A 2, THEN THE ADDITIONAL CRYPTOSPORIDIUM TREATMENT REQUIREMENTS ARE...

Conventional filtration treatment (including softening)

Direct filtration

Slow sand or diatomaceous earth filtration

Alternative filtration technologies

Bin 1

No additional treatment

No additional treatment

No additional treatment

No additional treatment

Bin 2

1-log treatment

1.5-log treatment

1-log treatment

a

Bin 3

2-log treatment

2.5-log treatment

2-log treatment

b

Bin 4

2.5-log treatment

3-log treatment

2.5-log treatment

c

aAs determined by the department such that the total Cryptosporidium removal and inactivation is at least 4.0-log.

bAs determined by the department such that the total Cryptosporidium removal and inactivation is at least 5.0-log.

cAs determined by the department such that the total Cryptosporidium removal and inactivation is at least 5.5-log.

b. Additional treatment.

(1) The owner shall use one or more of the treatment and management options listed in subsection E of this section, termed the microbial toolbox, to comply with the additional Cryptosporidium treatment required in subdivision D 2 a of this section.

(2) A waterworks classified in Bin 3 and Bin 4 shall achieve at least 1-log of the additional Cryptosporidium treatment required under subdivision D 2 a of this section using either one or a combination of the following: (i) bag filters, (ii) bank filtration, (iii) cartridge filters, (iv) chlorine dioxide, (v) membranes, (vi) ozone, or (vii) UV as described in subdivisions E 3 through E 7 of this section.

c. Failure by a waterworks in any month to achieve treatment credit by meeting criteria in subdivisions E 3 through E 7 of this section for microbial toolbox options that is at least equal to the level of treatment required in subdivision D 2 a of this section is a violation of the treatment technique requirement.

d. If the department determines during a sanitary survey or an equivalent source water assessment that after an owner completed the monitoring conducted under subdivision B 1 or B 2 of this section, significant changes occurred in the waterworks watershed that could lead to increased contamination of the source water by Cryptosporidium, then the owner shall take actions specified by the department to address the contamination. These actions may include additional source water monitoring or implementing microbial toolbox options listed in subdivision E 2 of this section.

3. Schedule for compliance with Cryptosporidium treatment requirements.

a. Following the initial bin classification in accordance with subdivision D 1 b of this section, the owner shall provide the level of treatment for Cryptosporidium required under subdivision D 2 of this section according to the schedule in subdivision D 3 b of this section.

b. If the bin classification for a filtered waterworks changes following the second round of source water monitoring, as determined under subdivision D 1 c of this section, then the owner shall provide the level of treatment for Cryptosporidium required under subdivision D 2 of this section on a schedule approved by the department.

E. The owner of a waterworks required to provide additional treatment for Cryptosporidium shall implement microbial toolbox options that are designed and operated as described in subdivisions E 1 through E 7 of this section.

1. The owner receives the treatment credits listed in Table 401.4 by meeting the conditions for microbial toolbox options described in subdivisions E 3 through E 7 of this section. The owner shall apply these treatment credits to meet the treatment requirements in subdivision D 2 of this section.

2. Microbial Toolbox Summary Table: Options, Treatment Credits and Criteria.

TABLE 401.4
Microbial Toolbox Summary: Options, Treatment Credits and Criteria

TOOLBOX OPTION

CRYPTOSPORIDIUM TREATMENT CREDIT WITH DESIGN AND IMPLEMENTATION CRITERIA

Source Protection and Management Toolbox Options

Alternative source and intake management

No prescribed credit. The owner may conduct simultaneous monitoring for treatment bin classification at alternative intake locations or under alternative intake management strategies. Specific criteria are in subdivision E 3 b of this section.

Prefiltration Toolbox Options

Presedimentation basin with coagulation

0.5-log credit during any month that presedimentation basins achieve a monthly mean reduction of 0.5-log or greater in turbidity or alternative performance criteria approved by the department. To be eligible, basins shall be operated continuously with coagulant addition and all water treatment plant flow shall pass through basins. Specific criteria are in subdivision E 4 a of this section.

Two-stage lime softening

0.5-log credit for two-stage softening where chemical addition and hardness precipitation occur in both stages. All water treatment plant flow shall pass through both stages. Single-stage softening is credited as equivalent to conventional treatment. Specific criteria are in subdivision E 4 b of this section.

Bank filtration

0.5-log credit for 25-foot setback; 1.0-log credit for 50-foot setback; aquifer shall be unconsolidated sand containing at least 10% fines; average turbidity in wells shall be less than 1 NTU. A waterworks using wells followed by filtration when conducting source water monitoring shall sample the well to determine bin classification and is not eligible for additional credit. Specific criteria are in subdivision E 4 c of this section.

Treatment Performance Toolbox Options

Combined filter performance

0.5-log credit for CFE turbidity less than or equal to 0.15 NTU in at least 95% of measurements each month. Specific criteria are in subdivision E 5 a of this section.

Individual filter performance

0.5-log credit (in addition to 0.5-log combined filter performance credit) if individual filter effluent turbidity is less than or equal to 0.15 NTU in at least 95% of samples each month in each filter and is never greater than 0.3 NTU in two consecutive measurements in any filter. Specific criteria are in subdivision E 5 b of this section.

Additional Filtration Toolbox Options

Bag or cartridge filters (individual filters)

Up to 2-log credit based on the removal efficiency demonstrated during challenge testing with a 1.0-log factor of safety. Specific criteria are in subdivision E 6 a of this section.

Bag or cartridge filters (in series)

Up to 2.5-log credit based on the removal efficiency demonstrated during challenge testing with a 0.5-log factor of safety. Specific criteria are in subdivision E 6 a of this section.

Membrane filtration

Log credit equivalent to removal efficiency demonstrated in challenge test for device if supported by direct integrity testing. Specific criteria are in subdivision E 6 b of this section.

Second stage filtration

0.5-log credit for second separate granular media filtration stage if treatment train includes coagulation before first filter. Specific criteria are in subdivision E 6 c of this section.

Slow sand filters

2.5-log credit as a secondary filtration step; 3.0-log credit as a primary filtration process. No prior chlorination for either option. Specific criteria are in subdivision E 6 d of this section.

Inactivation Toolbox Options

Chlorine dioxide

Log credit based on measured CT in relation to Table 401.5. Specific criteria in subdivision E 7 b of this section.

Ozone

Log credit based on measured CT in relation to Table 401.6. Specific criteria in subdivision E 7 b of this section.

UV

Log credit based on validated UV dose in relation to Table 401.7; reactor validation testing required to establish UV dose and associated operating conditions. Specific criteria in subdivision E 7 c of this section.

3. Source toolbox components.

a. Reserved.

b. Alternative source.

(1) The owner may conduct source water monitoring that reflects a different intake location (either in the same source or for an alternate source) or a different procedure for the timing or level of withdrawal from the source (alternative source water monitoring). If the department approves, then the owner may determine the bin classification under subdivision D 1 of this section based on the alternative source water monitoring results.

(2) If the owner conducts alternative source water monitoring under subdivision E 3 b (1) of this section, then the owner shall also monitor the current water treatment plant intake concurrently as described in subsection B of this section. "Plant intake" means the works or structures at the head of a conduit through which source water is diverted (e.g., river or lake) into the water treatment plant.

(3) Alternative source water monitoring under subdivision E 3 b (1) of this section shall meet the requirements for source water monitoring to determine bin classification, as described in subdivisions B 1 through B 13 of this section. The owner shall report the alternative source water monitoring results to the department, along with supporting information documenting the operating conditions under which the samples were collected.

(4) If the owner determines the bin classification under subdivision D 1 of this section using alternative source water monitoring results that reflect a different intake location or a different procedure for managing the timing or level of withdrawal from the source, then the owner shall relocate the intake or permanently adopt the withdrawal procedure, as applicable, no later than the applicable treatment compliance date in subdivision D 3 of this section.

4. Prefiltration treatment toolbox components.

a. Presedimentation. The owner receives 0.5-log Cryptosporidium treatment credit for a presedimentation basin during any month the process meets the following criteria:

(1) The presedimentation basin shall be in continuous operation and shall treat the entire water treatment plant flow at a waterworks using a surface water source, a GUDI source, or both.

(2) A coagulant shall be continuously added to the presedimentation basin.

(3) The presedimentation basin shall achieve the performance criteria in either of the following:

(a) Demonstrates at least 0.5-log mean reduction of influent turbidity. This reduction shall be determined using daily turbidity measurements in the presedimentation process influent and effluent and shall be calculated as follows: log10 (monthly mean of daily influent turbidity) - log10 (monthly mean of daily effluent turbidity).

(b) Complies with the performance criteria approved by the department that demonstrate at least 0.5-log mean removal of micron-sized particulate material through the presedimentation process.

b. Two-stage lime softening. The owner receives an additional 0.5-log Cryptosporidium treatment credit for a two-stage lime softening plant if chemical addition and hardness precipitation occur in two separate and sequential softening stages before filtration. Both softening stages shall treat the entire plant flow taken from a surface water source, a GUDI source, or both.

c. Bank filtration. The owner receives Cryptosporidium treatment credit for bank filtration that serves as pretreatment to a water filtration plant by meeting the criteria in this subdivision. The owner using bank filtration upon beginning source water monitoring under subdivision B 1 of this section shall collect samples as described in subdivision B 6 d of this section and is not eligible for this credit.

(1) Wells with a groundwater flow path of at least 25 feet receive 0.5-log treatment credit; and wells with a groundwater flow path of at least 50 feet receive 1.0-log treatment credit. The groundwater flow path shall be determined as specified in subdivision E 4 c (4) of this section.

(2) Only wells in granular aquifers are eligible for treatment credit. Granular aquifers are those comprised of sand, clay, silt, rock fragments, pebbles or larger particles, and minor cement. The owner shall characterize the aquifer at the well site to determine aquifer properties. The owner shall extract a core from the aquifer and demonstrate that in at least 90% of the core length, grains less than 1.0 mm in diameter constitute at least 10% of the core material.

(3) Only horizontal and vertical wells are eligible for treatment credit.

(4) For vertical wells, the groundwater flow path is the measured distance from the edge of the surface water body under high flow conditions (determined by the 100-year flood elevation boundary or by the floodway, as defined in Federal Emergency Management Agency flood hazard maps) to the well screen. For horizontal wells, the groundwater flow path is the measured distance from the bed of the river under normal flow conditions to the closest horizontal well lateral screen.

(5) The owner shall monitor each wellhead for turbidity at least once every four hours while the bank filtration process is in operation. If monthly average turbidity levels, based on daily maximum values in the well, exceed 1 NTU, the owner shall report this result to the department and conduct an assessment within 30 days to determine the cause of the high turbidity levels in the well. If the department determines that microbial removal has been compromised, the department may revoke treatment credit until the owner implements corrective actions approved by the department to remediate the problem.

(6) Springs and infiltration galleries are not eligible for treatment credit under this section.

(7) Bank filtration demonstration of performance. The department may approve Cryptosporidium treatment credit for bank filtration based on a demonstration-of-performance study that meets the criteria in this subdivision. This treatment credit may be greater than 1.0-log and may be awarded to bank filtration that does not meet the criteria in subdivisions E 4 c (1) through E 4 c (5) of this section.

(a) The study shall follow a protocol approved by the department and shall involve the collection of data on the removal of Cryptosporidium or a surrogate for Cryptosporidium and related hydrogeologic and water quality parameters during the full range of operating conditions.

(b) The study shall include sampling both from any production well and from monitoring wells that are screened and located along the shortest flow path between the surface water source and the production well.

5. Treatment performance toolbox components.

a. Combined filter performance. The owner using conventional filtration treatment or direct filtration treatment receives an additional 0.5-log Cryptosporidium treatment credit during any month the waterworks meets the criteria in this subdivision. Combined filter effluent (CFE) turbidity shall be less than or equal to 0.15 NTU in at least 95% of the measurements. Turbidity shall be measured as described in 12VAC5-590-376 B.

b. Individual filter performance. The owner using conventional filtration treatment or direct filtration treatment receives 0.5-log Cryptosporidium treatment credit, which can be in addition to the 0.5-log credit under subdivision E 5 a of this section, during any month the waterworks meets the criteria in this subdivision. Compliance with these criteria shall be based on individual filter turbidity monitoring as described in 12VAC5-590-376 B.

(1) The filtered water turbidity for each individual filter shall be less than or equal to 0.15 NTU in at least 95% of the measurements recorded each month.

(2) No individual filter may have a measured turbidity greater than 0.3 NTU in two consecutive measurements collected 15 minutes apart.

(3) The owner that has received treatment credit for individual filter performance and fails to meet the requirements of subdivision E 5 b (1) or E 5 b (2) of this section during any month does not receive a treatment technique violation under subdivision D 2 c of this section if the department determines the following:

(a) The failure was due to unusual and short-term circumstances that could not reasonably be prevented through optimizing water treatment plant design, operation, and maintenance.

(b) The waterworks has experienced no more than two failures in any calendar year.

6. Additional filtration toolbox components.

a. Bag and cartridge filters. The owner receives Cryptosporidium treatment credit of up to 2.0-log for individual bag or cartridge filters and up to 2.5-log for bag or cartridge filters operated in series by meeting the criteria in subdivisions E 6 a (1) through E 6 a (10) of this section. To be eligible for this credit, the owner shall report the results of challenge testing that meets the requirements of subdivisions E 6 a (2) through E 6 a (9) of this section to the department. The filters shall treat the entire water treatment plant flow taken from a surface water source, a GUDI source, or both.

(1) The Cryptosporidium treatment credit awarded to bag or cartridge filters shall be based on the removal efficiency demonstrated during challenge testing that is conducted according to the criteria in subdivisions E 6 a (2) through E 6 a (9) of this section. A factor of safety equal to 1-log for individual bag or cartridge filters and 0.5-log for bag or cartridge filters in series shall be applied to challenge testing results to determine removal credit. The owner may use the results from challenge testing conducted before January 5, 2006, if the prior testing was consistent with the criteria specified in subdivisions E 6 a (2) through E 6 a (9) of this section.

(2) Challenge testing shall be performed on full-scale bag or cartridge filters, and the associated filter housing or pressure vessel, that are identical in material and construction to the filters and housings the waterworks will use for removal of Cryptosporidium. Bag or cartridge filters shall be challenge tested in the same configuration that the waterworks will use, either as individual filters or as a series configuration of filters.

(3) Challenge testing shall be conducted using Cryptosporidium or a surrogate that is removed no more efficiently than Cryptosporidium. The microorganism or surrogate used during challenge testing is referred to as the challenge particulate. The concentration of the challenge particulate shall be determined using a method capable of discreetly quantifying the specific microorganism or surrogate used in the test; gross measurements such as turbidity shall not be used.

(4) The maximum feed water concentration that can be used during a challenge test shall be based on the detection limit of the challenge particulate in the filtrate (i.e., filtrate detection limit) and shall be calculated using the following equation:

Maximum Feed Concentration = 1 x 104 x (Filtrate Detection Limit)

(5) Challenge testing shall be conducted at the maximum design flow rate for the filter as specified by the manufacturer.

(6) Each filter evaluated shall be tested for a duration sufficient to reach 100% of the terminal pressure drop that establishes the maximum pressure drop under which the filter may be used to comply with the requirements of this subdivision E 6.

(7) Removal efficiency of a filter shall be determined from the results of the challenge test and expressed in terms of log removal values using the following equation:

LRV = LOG10(Cf) - LOG10(Cp),

where LRV = log removal value demonstrated during challenge testing;

Cf = the feed concentration measured during the challenge test; and

Cp = the filtrate concentration measured during the challenge test.

In applying this equation, the same units shall be used for the feed and filtrate concentrations. If the challenge particulate is not detected in the filtrate, then the term Cp shall be set equal to the detection limit.

(8) Each filter tested shall be challenged with the challenge particulate during three periods over the filtration cycle: within two hours of start-up of a new filter; when the pressure drop is between 45% and 55% of the terminal pressure drop; and at the end of the cycle after the pressure drop has reached 100% of the terminal pressure drop. An LRV shall be calculated for each of these challenge periods for each filter tested. The LRV for the filter (LRV filter) shall be assigned the value of the minimum LRV observed during the three challenge periods for that filter.

(9) If fewer than 20 filters are tested, then the overall removal efficiency for the filter product line shall be set equal to the lowest LRV filter among the filters tested. If 20 or more filters are tested, then the overall removal efficiency for the filter product line shall be set equal to the 10th percentile of the set of LRV filter values for the various filters tested. The percentile is defined by (i/(n+1)), where i is the rank of n individual data points ordered lowest to highest. If necessary, the 10th percentile may be calculated using linear interpolation.

(10) If a previously tested filter is modified in a manner that could change the removal efficiency of the filter product line, then challenge testing to demonstrate the removal efficiency of the modified filter shall be conducted and submitted to the department.

b. Membrane filtration.

(1) The owner receives Cryptosporidium treatment credit for membrane filtration that meets the criteria of this subdivision E 6 b. Membrane cartridge filters that meet the definition of membrane filtration in 12VAC5-590-10 are eligible for this credit. The level of treatment credit the owner receives is equal to the lower of the values determined as follows:

(a) The removal efficiency demonstrated during challenge testing conducted under the conditions in subdivision E 6 b (2) of this section.

(b) The maximum removal efficiency that can be verified through direct integrity testing used with the membrane filtration process under the conditions in subdivision E 6 b (3) of this section.

(2) Challenge Testing. The membrane used by the waterworks shall undergo challenge testing to evaluate removal efficiency and the owner shall report the results of the challenge testing to the department. Challenge testing shall be conducted according to the criteria in subdivisions E 6 b (2) (a) through E 6 b (2) (g) of this section. The owner may use data from challenge testing conducted before January 5, 2006, if the prior testing was consistent with the following criteria:

(a) Challenge testing shall be conducted on either a full-scale membrane module, identical in material and construction to the membrane modules used in the waterworks treatment facility, or a smaller-scale membrane module, identical in material and similar in construction to the full-scale module. A module is defined as the smallest component of a membrane unit in which a specific membrane surface area is housed in a device with a filtrate outlet structure.

(b) Challenge testing shall be conducted using Cryptosporidium or a surrogate that is removed no more efficiently than Cryptosporidium. The organism or surrogate used during challenge testing is referred to as the challenge particulate. The concentration of the challenge particulate, in both the feed and filtrate water, shall be determined using a method capable of discretely quantifying the specific challenge particulate used in the test; gross measurements such as turbidity shall not be used.

(c) The maximum feed water concentration that can be used during a challenge test is based on the detection limit of the challenge particulate in the filtrate and shall be determined according to the following equation:

Maximum Feed Concentration = 3.16 x 106 x (Filtrate Detection Limit)

(d) Challenge testing shall be conducted under representative hydraulic conditions at the maximum design flux and maximum design process recovery specified by the manufacturer for the membrane module. Flux is defined as the throughput of a pressure-driven membrane process expressed as flow per unit of membrane area. Recovery is defined as the volumetric percent of feed water that is converted to filtrate over the course of an operating cycle uninterrupted by events such as chemical cleaning or a solids removal process (i.e., backwashing).

(e) Removal efficiency of a membrane module shall be calculated from the challenge test results and expressed as a log removal value according to the following equation:

LRV = LOG10(Cf) - LOG10(Cp),

where LRV = log removal value demonstrated during the challenge test;

Cf = the feed concentration measured during the challenge test; and

Cp = the filtrate concentration measured during the challenge test.

Equivalent units shall be used for the feed and filtrate concentrations. If the challenge particulate is not detected in the filtrate, then the term Cp is set equal to the detection limit for the purpose of calculating the LRV. An LRV shall be calculated for each membrane module evaluated during the challenge test.

(f) The removal efficiency of a membrane filtration process demonstrated during challenge testing shall be expressed as a log removal value (LRVC-Test). If fewer than 20 modules are tested, then LRVC-Test is equal to the lowest of the representative LRVs among the modules tested. If 20 or more modules are tested, then LRVC-Test is equal to the 10th percentile of the representative LRVs among the modules tested. The percentile is defined by (i/(n+1)), where i is the rank of n individual data points ordered lowest to highest. If necessary, the 10th percentile may be calculated using linear interpolation.

(g) The challenge test shall establish a QCRV for a nondestructive performance test that demonstrates the Cryptosporidium removal capability of the membrane filtration module. This performance test shall be applied to each production membrane module used by the waterworks that was not directly challenge tested to verify Cryptosporidium removal capability. Production modules that do not meet the established QCRV are not eligible for the treatment credit demonstrated during the challenge test.

(h) If a previously tested membrane is modified in a manner that could change the removal efficiency of the membrane or the applicability of the nondestructive performance test and associated QCRV, then additional challenge testing to demonstrate the removal efficiency of, and determine a new QCRV for, the modified membrane shall be conducted and submitted to the department.

(3) Direct integrity testing. The owner shall conduct direct integrity testing in a manner that demonstrates a removal efficiency equal to or greater than the removal credit awarded to the membrane filtration process and meets the requirements described in subdivisions E 6 b (3) (a) through E 6 b (3) (f) of this section. A direct integrity test is defined as a physical test applied to a membrane unit to identify and isolate integrity breaches (i.e., one or more leaks that could result in contamination of the filtrate).

(a) The direct integrity test shall be independently applied to each membrane unit in service. A membrane unit is defined as a group of membrane modules that share common valving that allows the unit to be isolated from the rest of the waterworks for the purpose of integrity testing or other maintenance.

(b) The direct integrity method shall have a resolution of three micrometers or less, where resolution is defined as the size of the smallest integrity breach that contributes to a response from the direct integrity test.

(c) The direct integrity test shall have a sensitivity sufficient to verify the log treatment credit awarded to the membrane filtration process by the department, where sensitivity is defined as the maximum log removal value that can be reliably verified by a direct integrity test. Sensitivity shall be determined using the approach in either of the following as applicable to the type of direct integrity test the waterworks uses:

(i) For direct integrity tests that use an applied pressure or vacuum, the direct integrity test sensitivity shall be calculated according to the following equation:

LRVDIT = LOG10(Qp /(VCF x Qbreach)),

where LRVDIT = the sensitivity of the direct integrity test;

Qp = total design filtrate flow from the membrane unit;

Qbreach = flow of water from an integrity breach associated with the smallest integrity test response that can be reliably measured; and

VCF = volumetric concentration factor.

The volumetric concentration factor is the ratio of the suspended solids concentration on the high-pressure side of the membrane relative to that in the feed water.

(ii) For direct integrity tests that use a particulate or molecular marker, the direct integrity test sensitivity shall be calculated according to the following equation:

LRVDIT = LOG10(Cf) - LOG10(Cp),

where LRVDIT = the sensitivity of the direct integrity test;

Cf = the typical feed concentration of the marker used in the test; and

Cp = the filtrate concentration of the marker from an integral membrane unit.

(d) The owner shall establish a control limit within the sensitivity limits of the direct integrity test that is indicative of an integral membrane unit capable of meeting the removal credit awarded by the department.

(e) If the result of a direct integrity test exceeds the control limit established under subdivision E 6 b (3) (d) of this section, then the owner shall remove the membrane unit from service. The owner shall conduct a direct integrity test to verify any repairs, and may return the membrane unit to service only if the direct integrity test is within the established control limit.

(f) The owner shall conduct direct integrity testing on each membrane unit at a frequency of not less than once each day that the membrane unit is in operation. The department may approve less frequent testing based on demonstrated process reliability, the use of multiple barriers effective for Cryptosporidium, or reliable process safeguards.

(4) Indirect integrity monitoring. The owner shall conduct continuous indirect integrity monitoring on each membrane unit according to the criteria in subdivisions E 6 b (4) (a) through E 6 b (4) (e). Indirect integrity monitoring is defined as monitoring some aspect of filtrate water quality that is indicative of the removal of particulate matter. The owner that implements continuous direct integrity testing of membrane units in accordance with the criteria in subdivisions E 6 b (3) (a) through E 6 b (3) (f) of this section is not subject to the requirements for continuous indirect integrity monitoring. The owner shall submit a monthly report to the department summarizing all continuous indirect integrity monitoring results triggering direct integrity testing and the corrective action that was taken in each case.

(a) Unless the department approves an alternative parameter, continuous indirect integrity monitoring shall include continuous filtrate turbidity monitoring.

(b) Continuous monitoring shall be conducted at a frequency of no less than once every 15 minutes.

(c) Continuous monitoring shall be separately conducted on each membrane unit.

(d) If indirect integrity monitoring includes turbidity and if the filtrate turbidity readings are above 0.15 NTU for a period greater than 15 minutes (i.e., two consecutive 15-minute readings above 0.15 NTU), direct integrity testing shall immediately be performed on the associated membrane unit as specified in subdivisions E 6 b (3) (a) through E 6 b (3) (f) of this section.

(e) If indirect integrity monitoring includes an alternative parameter approved by the department and if the alternative parameter exceeds a control limit approved by the department for a period greater than 15 minutes, then direct integrity testing shall immediately be performed on the associated membrane units as specified in subdivisions E 6 b (3) (a) through E 6 b (3) (f) of this section.

c. Second stage filtration. The owner receives 0.5-log Cryptosporidium treatment credit for a separate second stage of filtration that consists of sand, dual media, GAC, or other fine grain media following granular media filtration if approved by the department. To be eligible for this credit, the first stage of filtration shall be preceded by a coagulation step and both filtration stages shall treat the entire water treatment treatment plant flow taken from a surface water source, a GUDI source, or both. A cap, such as GAC, on a single stage of filtration is not eligible for this credit. The department shall approve the treatment credit based on an assessment of the design characteristics of the filtration process.

d. Slow sand filtration as secondary filter. The owner is eligible to receive 2.5-log Cryptosporidium treatment credit for a slow sand filtration process that follows a separate stage of filtration if both filtration stages treat the entire water treatment plant flow taken from a surface water source, a GUDI source, or both and no residual disinfectant is present in the influent water to the slow sand filtration process. The department shall approve the treatment credit based on an assessment of the design characteristics of the filtration process. This subdivision does not apply to treatment credit awarded to slow sand filtration used as a primary filtration process.

7. Inactivation toolbox components.

a. Calculation of CT values.

(1) CT is the product of the disinfectant contact time (T, in minutes) and disinfectant concentration (C, in milligrams per liter). The owner of a waterworks with treatment credit for chlorine dioxide or ozone under subdivision E 7 b of this section shall calculate CT at least once each day, with both C and T measured during peak hourly flow in accordance with the procedure listed in 12VAC5-590-500.

(2) A waterworks with several disinfection segments in sequence may calculate CT for each segment, where a disinfection segment is defined as a treatment unit process with a measurable residual disinfectant level and a liquid volume. Under this approach, the owner shall add the Cryptosporidium CT values in each segment to determine the total CT for the treatment plant.

b. CT values for chlorine dioxide and ozone.

(1) The owner receives the Cryptosporidium treatment credit listed in Table 401.5 by meeting the corresponding chlorine dioxide CT value for the applicable water temperature, as described in subdivision E 7 a of this section.

TABLE 401.5
CT Values (mg-min/L) for Cryptosporidium Inactivation by Chlorine Dioxidea

WATER TEMPERATURE, oC

LOG CREDIT

≤0.5

1

2

3

5

7

0.25

159

153

140

128

107

90

0.5

319

305

279

256

214

180

1.0

637

610

558

511

429

360

1.5

956

915

838

767

643

539

2.0

1275

1220

1117

1023

858

719

2.5

1594

1525

1396

1278

1072

899

3.0

1912

1830

1675

1534

1286

1079

WATER TEMPERATURE, oC

LOG CREDIT

10

15

20

25

30

0.25

69

45

29

19

12

0.5

138

89

58

38

24

1.0

277

179

116

75

49

1.5

415

268

174

113

73

2.0

553

357

232

150

98

2.5

691

447

289

188

122

3.0

830

536

347

226

147

aThe owner may use this equation to determine log credit between the indicated values: Log credit = (0.001506×(1.09116)Temp)× CT.

(2) The owner receives the Cryptosporidium treatment credit listed in Table 401.6 by meeting the corresponding ozone CT values for the applicable water temperature, as described in subdivision E 7 a of this section.

TABLE 401.6
CT Values (mg-min/L) for Cryptosporidium Inactivation by Ozonea

LOG CREDIT

WATER TEMPERATURE, °C

≤0.5

1

2

3

5

7

10

15

20

25

30

0.25

6.0

5.8

5.2

4.8

4.0

3.3

2.5

1.6

1.0

0.6

0.39

0.5

12

12

10

9.5

7.9

6.5

4.9

3.1

2.0

1.2

0.78

1.0

24

23

21

19

16

13

9.9

6.2

3.9

2.5

1.6

1.5

36

35

31

29

24

20

15

9.3

5.9

3.7

2.4

2.0

48

46

42

38

32

26

20

12

7.8

4.9

3.1

2.5

60

58

52

48

40

33

25

16

9.8

6.2

3.9

3.0

72

69

63

57

47

39

30

19

12

7.4

4.7

aThe owner may use this equation to determine log credit between the indicated values: Log credit = (0.0397×(1.09757)Temp)× CT.

c. UV light. The owner receives Cryptosporidium, Giardia lamblia, and virus treatment credits for UV light reactors by achieving the corresponding UV dose values shown in subdivision E 7 c (1) of this section. The owner shall validate and monitor UV reactors as described in subdivisions E 7 c (2) and E 7 c (3) of this section to demonstrate that they are achieving a particular UV dose value for treatment credit.

(1) UV dose table. The treatment credits listed in Table 401.7 are for UV light at a wavelength of 254 nm as produced by a low-pressure mercury vapor lamp. To receive treatment credit for other lamp types, the owner shall demonstrate an equivalent germicidal dose through reactor validation testing as described in subdivision E 7 c (2) of this section. The UV dose values listed in Table 401.7 are applicable only to post-filter applications of UV in filtered waterworks.

TABLE 401.7
UV Doses for Cryptosporidium, Giardia lamblia and Virus Inactivation Credit

LOG CREDIT

CRYPTOSPORIDIUM UV DOSE (mJ/cm2)

GIARDIA LAMBLIA UV DOSE (mJ/cm2)

VIRUS UV DOSE (mJ/cm2)

0.5

1.6

1.5

39

1.0

2.5

2.1

58

1.5

3.9

3.0

79

2.0

5.8

5.2

100

2.5

8.5

7.7

121

3.0

12

11

143

3.5

15

15

163

4.0

22

22

186

(2) Reactor validation testing. The owner shall use UV reactors that have undergone validation testing to determine the operating conditions under which the reactor delivers the UV dose required in subdivision E 7 c (1) of this section (i.e., validated operating conditions). These operating conditions shall include flow rate, UV intensity as measured by a UV sensor, and UV lamp status.

(a) When determining validated operating conditions, the owner shall account for the following factors: (i) UV absorbance of the water; (ii) lamp fouling and aging; (iii) measurement uncertainty of online sensors; (iv) UV dose distributions arising from the velocity profiles through the reactor; (v) failure of UV lamps or other critical waterworks components; and (vi) inlet and outlet piping or channel configurations of the UV reactor.

(b) Validation testing shall include the following: full-scale testing of a reactor that conforms uniformly to the UV reactors used by the waterworks and inactivation of a test microorganism whose dose-response characteristics have been quantified with a low-pressure mercury vapor lamp.

(c) UV reactor validation testing shall be in accordance with EPA's recommended validation protocol for UV reactors, as described in EPA's "Ultraviolet Disinfection Guidance Manual for the Final Long Term 2 Enhanced Surface Water Treatment Rule," November 2006, EPA Office of Water. Alternative protocols may be considered for approval by the department on a case-by-case basis.

(d) Validation testing, whether onsite or offsite, shall be performed by a third party independent of the UV reactor manufacturer and the owner to ensure that validation testing and data analysis are conducted in a technically sound manner without bias.

(e) To receive credit for lamp types other than low-pressure types, the owner shall demonstrate an equivalent germicidal dose through reactor validation testing.

(f) A validation report shall be submitted and approved by the department to receive disinfection credit.

(3) UV reactor monitoring.

(a) The owner shall monitor the UV reactors to determine if the reactors are operating within validated conditions as determined under subdivision E 7 c (2) of this section. This monitoring shall include UV intensity as measured by a UV sensor, flow rate, lamp status, and other parameters the department designates based on UV reactor operation. The owner shall verify the calibration of UV sensors and shall recalibrate sensors in accordance with a protocol approved by the department.

(b) To receive treatment credit for UV light, the owner shall treat at least 95% of the water delivered to the public during each month by the UV reactors operating within validated conditions for the required UV dose as described in subdivisions E 7 c (1) and E 7 c (2) of this section. The owner shall demonstrate compliance with this condition by the monitoring required under subdivision E 7 c (3) (a) of this section.

F. The owner shall comply with the applicable recordkeeping and reporting requirements described in 12VAC5-590-530, 12VAC5-590-531, 12VAC5-590-550, and 12VAC5-590-570.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-405. Lead and copper treatment techniques.

A. Lead and copper corrosion control techniques.

1. Corrosion control treatment requirements. The owner of a community waterworks or a NTNC shall install and operate optimum corrosion control treatment by completing the corrosion control treatment requirements described below which are applicable to these waterworks under subdivision A 2 of this section.

a. Owner's proposal regarding corrosion control treatment. Based upon the results of lead and copper tap monitoring and water quality parameter monitoring, the owner of a small or a medium waterworks exceeding the lead or copper AL shall propose installation of one or more of the corrosion control treatments listed in subdivision A 1 c (1) of this section that the owner believes constitutes optimal corrosion control for that waterworks. The department may require the owner to conduct additional water quality parameter monitoring in accordance with 12VAC5-590-375 C 2 to assist the department in evaluating the proposal.

b. Applicability of studies of corrosion control treatment (applicable to small and medium waterworks). The department may require the owner of a small or a medium waterworks that exceeds the lead or copper AL to perform corrosion control studies under subdivision A 1 c of this section to identify optimal corrosion control treatment for the waterworks.

c. Corrosion control studies.

(1) The owner of a waterworks required by the department to perform corrosion control studies shall evaluate the effectiveness of each of the following treatments, and, if appropriate, combinations of the following treatments to identify the optimal corrosion control treatment for that waterworks:

(a) Alkalinity and pH adjustment;

(b) Calcium hardness adjustment; and

(c) The addition of a phosphate-based or silicate-based corrosion inhibitor at a concentration sufficient to maintain an effective corrosion inhibitor residual concentration in all test tap samples, such that a passivating film is formed on the interior walls of the pipe.

(2) The owner shall evaluate each of the corrosion control treatments using either pipe rig or loop tests, metal coupon tests, partial-system tests, or analyses based on documented analogous treatments with other waterworks of similar size, water chemistry, and distribution system configuration.

(3) The owner shall measure the following water quality parameters in any tests conducted under subdivision A 1 c of this section before and after evaluating the corrosion control treatments listed in subdivision A 1 c (1) of this section:

(a) Lead;

(b) Copper;

(c) pH;

(d) Alkalinity;

(e) Calcium;

(f) Conductivity;

(g) Orthophosphate (when an inhibitor containing a phosphate compound is used);

(h) Silicate (when an inhibitor containing a silicate compound is used); and

(i) Water temperature.

(4) The owner shall identify all chemical or physical constraints that limit or prohibit the use of a particular corrosion control treatment and document such constraints with at least one of the following:

(a) Data and documentation showing that a particular corrosion control treatment has adversely affected other water treatment processes when used by another waterworks with comparable water quality characteristics; or

(b) Data and documentation demonstrating that the owner has previously attempted to evaluate a particular corrosion control treatment and has found that the treatment is ineffective or adversely affects other water quality treatment processes.

(5) The owner shall evaluate the effect of the chemicals used for corrosion control treatment on other water quality treatment processes.

(6) On the basis of an analysis of the data generated during each evaluation, the owner shall propose in writing to the department that the treatment option resulting from the corrosion control studies constitutes optimal corrosion control treatment for that waterworks. The owner shall provide a rationale for the recommendation along with all supporting documentation specified in subdivisions A 1 c (1) through A 1 c (5) of this section.

d. Approval of optimal corrosion control treatment.

(1) Based upon consideration of available information including, where applicable, studies performed under subdivision A 1 c of this section and the owner's proposed treatment alternative, the department shall either approve the corrosion control treatment option recommended by the owner, or designate alternative corrosion control treatment from among those listed in subdivision A 1 c (1) of this section. When approving optimal treatment, the department shall consider the effects that additional corrosion control treatment will have on water quality parameters and on other water quality treatment processes.

(2) The department shall notify the owner of the determination on optimal corrosion control treatment in writing and explain the basis for this determination. If the department requests additional information to aid an evaluation, then the owner shall provide the information.

e. Installation of optimal corrosion control. The owner shall properly install and operate throughout the waterworks the optimal corrosion control treatment approved by the department under subdivision A 1 d of this section. A construction permit is required before installation of any treatment in accordance with 12VAC5-590-200.

f. The department's evaluation of treatment and specification of the optimal water quality control parameters shall consist of the following:

(1) The department shall evaluate the results of all lead and copper tap samples and water quality parameter samples submitted by the owner and determine whether the owner has properly installed and operated the optimal corrosion control treatment approved by the department under subdivision A 1 d of this section. Upon evaluating the results of tap water and water quality parameter monitoring by the owner, both before and after the owner installs optimal corrosion control treatment, the department shall designate:

(a) A minimum value or a range of values for pH measured at each entry point to the distribution system;

(b) A minimum pH value, measured in all tap samples. The value shall be equal to or greater than 7.0, unless the department determines that meeting a pH level of 7.0 is not technologically feasible or is not necessary for the owner to optimize corrosion control;

(c) If a corrosion inhibitor is used, then a minimum concentration or a range of concentrations for the inhibitor, measured at each entry point to the distribution system and in all tap samples, that the department determines is necessary to form a passivating film on the interior walls of the pipes of the distribution system;

(d) If alkalinity is adjusted as part of the optimal corrosion control treatment, then a minimum concentration or a range of concentrations for alkalinity, measured at each entry point to the distribution system and in all tap samples; or

(e) If calcium carbonate stabilization is used as part of the corrosion control, then a minimum concentration or a range of concentrations for calcium, measured in all tap samples.

(2) The values for the applicable water quality control parameters listed in subdivision A 1 c (3) of this section shall be those that the department determines to reflect optimal corrosion control treatment for the waterworks. The department may designate values for additional water quality control parameters determined by the department to reflect optimal corrosion control for the waterworks. The department shall notify the owner in writing of these determinations and explain the basis for the decisions.

g. Continued operation and monitoring. The owner of a waterworks optimizing corrosion control shall continue to operate and maintain optimal corrosion control treatment, including maintaining water quality parameters at or above minimum values or within ranges designated by the department under subdivision A 1 f of this section as verified by all samples collected under 12VAC5-590-375 C 4,12VAC5-590-375 C 5, and 12VAC5-590-375 C 6. Compliance with the requirements of this subdivision shall be determined every six months, as specified under 12VAC5-590-375 C 4. The waterworks is out of compliance with the requirements of this subdivision for a six-month period if excursions occur for any department-specified parameter on more than nine days during the period. An excursion occurs whenever the daily value for one or more of the water quality parameters measured at a sampling location is below the minimum value or outside the range designated by the department. The department has discretion to delete results of obvious sampling errors from this calculation. Daily values shall be calculated as follows:

(1) On days when more than one measurement for the water quality parameter is collected at the sampling location, the daily value shall be the average of all results collected during the day regardless of whether they are collected through continuous monitoring, grab sampling, or a combination of both.

(2) On days when only one measurement for the water quality parameter is collected at the sampling location, the daily value shall be the result of that measurement.

(3) On days when no measurement is collected for the water quality parameter at the sampling location, the daily value shall be the daily value calculated on the most recent day on which the water quality parameter was measured at the sample site.

h. Modification of the department's treatment decisions. Upon the department's initiative or in response to a request by an owner or other interested party, the department may modify the determination of the optimal corrosion control treatment under subdivision A 1 d of this section or optimal water quality control parameters under subdivision A 1 f of this section. A request for modification by an owner or other interested party shall be in writing, explain why the modification is appropriate, and provide supporting documentation. The department may modify the determination where it is concluded that the change is necessary to ensure that the waterworks continues to optimize corrosion control treatment. A revised determination shall be made in writing, set forth the new treatment requirements, explain the basis for the department's decision, and provide an implementation schedule for completing the treatment modifications.

2. Corrosion control treatment steps.

a. The owner shall complete the applicable corrosion control treatment requirements described in subdivision A 1 of this section by the deadlines established in this subdivision.

(1) The owner of a large waterworks (serving greater than 50,000 persons) shall complete the corrosion control treatment steps specified in subdivision A 2 d of this section, unless the owner is deemed to have optimized corrosion control under subdivision A 2 b (2) or A 2 b (3) of this section.

(2) The owner of a small waterworks (serving fewer than or equal to 3300 persons) or a medium waterworks (serving greater than 3,300 and fewer than or equal to 50,000 persons) shall complete the corrosion control treatment steps specified in subdivision A 2 e of this section, unless the owner is deemed to have optimized corrosion control under subdivisions A 2 b (1) through A 2 b (3) of this section.

b. The owner is deemed to have optimized corrosion control and is not required to complete the applicable corrosion control treatment steps identified in this subdivision if the waterworks satisfies one of the criteria specified in subdivisions A 2 b (1) through A 2 b (3) of this section. The owner deemed to have optimized corrosion control under this subdivision and to have treatment in place shall continue to operate and maintain optimal corrosion control treatment and meet any requirements that the department determines appropriate to ensure optimal corrosion control treatment is maintained.

(1) The owner of a small or a medium waterworks is deemed to have optimized corrosion control if the waterworks meets the lead and copper ALs during each of two consecutive six-month monitoring periods conducted in accordance with 12VAC5-590-375.

(2) The owner may be deemed by the department to have optimized corrosion control treatment if the owner demonstrates to the satisfaction of the department that the owner has conducted activities equivalent to the corrosion control steps applicable to the waterworks under this section. If the department makes this determination, then the owner shall be provided with a written notice explaining the basis for the decision and the notice shall specify the water quality control parameters representing optimal corrosion control in accordance with subdivision A 1 f of this section. The owner deemed to have optimized corrosion control under this subdivision shall operate in compliance with the department designated optimal water quality control parameters in accordance with subdivision A 1 g and continue to conduct lead and copper tap and water quality parameter sampling in accordance with 12VAC5-590-375 B 4 c and 12VAC5-590-375 C 4, respectively. The owner shall provide the department with the following information to support a determination under this subdivision:

(a) The results of all test samples collected for each of the water quality parameters in subdivision A 1 c (3) of this section;

(b) A report explaining the test methods used by the owner to evaluate the corrosion control treatments listed in subdivision A 1 c (1) of this section, the results of all tests conducted, and the basis for the owner's selection of optimal corrosion control treatment;

(c) A report explaining how corrosion control has been installed and how it is being maintained to insure minimal lead and copper concentrations at consumers' taps; and

(d) The results of tap water samples collected in accordance with 12VAC5-590-375 B at least once every six months for one year after corrosion control treatment has been installed.

(3) A waterworks is deemed to have optimized corrosion control if the owner submits results of tap water monitoring conducted in accordance with 12VAC5-590-375 B and source water monitoring conducted in accordance with 12VAC5-590-375 D that demonstrates for two consecutive six-month monitoring periods that the difference between the 90th percentile tap water lead level, computed under 12VAC5-590-385 C, and the highest source water lead concentration is less than the PQL for lead (0.005 mg/L).

(a) The owner that submits monitoring results indicating that the highest source water lead level is below the MDL may also be deemed to have optimized corrosion control under this subdivision if the 90th percentile tap water lead level is less than or equal to the PQL for lead (0.005 mg/L) for two consecutive six-month monitoring periods.

(b) The owner deemed to have optimized corrosion control under this subdivision shall continue monitoring for lead and copper at the tap no less frequently than once every three calendar years using the reduced number of sites specified in 12VAC5-590-375 B 3 and collecting the samples at times and locations specified in 12VAC5-590-375 B 4 d (4).

(c) The owner deemed to have optimized corrosion control pursuant to this subdivision shall notify the department in writing pursuant to 12VAC5-590-532 B 3 of any upcoming long-term change in treatment or addition of a new source water as described in 12VAC5-590-532 B 3. The department shall evaluate and approve the addition of a new source water or long-term change in water treatment before it is implemented by the owner. The department may require the owner of a waterworks to conduct additional monitoring or to take other actions the department deems appropriate to ensure that minimum levels of corrosion control are being maintained in the distribution system.

(d) The owner is not deemed to have optimized corrosion control under this subdivision, and shall implement corrosion control treatment specified in subdivision A 2 b (3) (e) of this section, unless the copper AL is met.

(e) The owner of a waterworks triggered into corrosion control because the waterworks is no longer deemed to have optimized corrosion control under this subsection shall implement corrosion control treatment in accordance with the deadlines in subdivision A 2 e of this section. The owner of a large waterworks shall adhere to the schedule specified in subdivision A 2 e of this section for a medium waterworks, with the time period for completing each step being triggered by the date the owner is no longer deemed to have optimized corrosion control treatment under this subsection.

c. The owner of a small or a medium waterworks that is required to complete the corrosion control steps due to the exceedance of the lead or copper AL may cease completing the treatment steps whenever the waterworks meets both ALs during each of two consecutive six-month monitoring periods conducted pursuant to 12VAC5-590-375 B 4 a and submits the results to the department. If a waterworks thereafter exceeds the lead or copper AL during any monitoring period, the owner shall recommence completion of the applicable treatment steps, beginning with the first treatment step that was not previously completed in its entirety. The department may require the owner to repeat treatment steps previously completed where the department determines that this is necessary to properly implement the treatment requirements of this section. The department shall notify the owner in writing of the determination and explain the basis for the decision. The requirement for the owner of a small or a medium waterworks to implement corrosion control treatment steps in accordance with subdivision A 2 e of this section (including waterworks deemed to have optimized corrosion control under subdivision A 2 b (1) of this section) is triggered whenever a small or a medium waterworks exceeds the lead or copper AL.

d. Treatment steps and deadlines for large waterworks. Except as provided in subdivisions A 2 b (2) and A 2 b (3) of this section, the owner of a large waterworks shall complete the following corrosion control treatment steps (described in the referenced portions of subdivision A 1 of this section, 12VAC5-590-375 B, and 12VAC5-590-375 C).

(1) Step 1: The owner shall conduct initial monitoring (12VAC5-590-375 B 4 a and 12VAC5-590-375 C 2) during two consecutive six-month monitoring periods by a date specified by the department.

(2) Step 2: The owner shall complete corrosion control studies (subdivision A 1 c of this section) and submit the study and recommendations to the department no later than 18 months after the date that initial monitoring is completed as specified in Step 1.

(3) Step 3: The department shall approve optimal corrosion control treatment (subdivision A 1 d of this section) no later than 12 months following receipt of the corrosion control study required in Step 2.

(4) Step 4: The owner shall install optimal corrosion control treatment (subdivision A 1 e of this section) no later than 24 months following the department's approval of optimal corrosion control treatment specified in Step 3.

(5) Step 5: The owner shall complete follow-up sampling (12VAC5-590-375 B 4 b and 12VAC5-590-375 C 3) no later than 12 months following the installation of optimal corrosion control treatment specified in Step 4.

(6) Step 6: The department shall evaluate the installation of treatment and designate optimal water quality control parameters (subdivision A 1 f of this section) no later than six months following completion of follow-up sampling specified in Step 5.

(7) Step 7: The owner shall operate the waterworks in compliance with the department-specified optimal water quality control parameters (subdivision A 1 g of this section) and continue to conduct tap sampling (12VAC5-590-375 B 4 c and 12VAC5-590-375 C 4).

e. Treatment steps and deadlines for small and medium waterworks. Except as provided in subdivision A 2 b of this section, the owner of a small or a medium waterworks shall complete the following corrosion control treatment steps (described in the referenced portions of subdivision A 1 of this section, 12VAC5-590-375 B, and 12VAC5-590-375 C):

(1) The owner shall conduct initial tap sampling (12VAC5-590-375 B 4 a and 12VAC5-590-375 C 2) until the waterworks either exceeds the lead or copper AL or becomes eligible for reduced monitoring under 12VAC5-590-375 B 4 d. The owner of a waterworks exceeding the lead or copper AL shall propose optimal corrosion control treatment (subdivision A 1 a of this section) within six months after the end of the monitoring period during which it exceeds one of the ALs.

(2) Within 12 months after the end of the monitoring period during which a waterworks exceeds the lead or copper AL, the department may require the owner to perform corrosion control studies (subdivision A 1 b of this section). If the department does not require the owner to perform these studies, the department shall specify optimal corrosion control treatment (subdivision A 1 d of this section) within the following timeframes:

(a) For a medium waterworks, within 18 months after the end of the monitoring period during which the waterworks exceeds the lead or copper AL.

(b) For a small waterworks, within 24 months after the end of the monitoring period during which the waterworks exceeds the lead or copper AL.

(3) If the department requires the owner to perform corrosion control studies under subdivision A 2 e (2) of this section, then the owner shall complete the studies (subdivision A 1 c of this section) and submit the study and recommendations to the department within 18 months after the department requires that the studies be conducted.

(4) If the owner has performed corrosion control studies under subdivision A 2 e (2) of this section, then the department shall designate optimal corrosion control treatment (subdivision A 1 d of this section) within six months after completion of the provisions of subdivision A 2 e (3) of this section.

(5) The owner shall install optimal corrosion control treatment (subdivision A 1 e of this section) within 24 months after the department designates such treatment. A construction permit is required before installation of any treatment, in accordance with 12VAC5-590-200.

(6) The owner shall complete follow-up sampling (12VAC5-590-375 B 4 b and 12VAC5-590-375 C 3) within 36 months after the department designates optimal corrosion control treatment.

(7) The department shall evaluate the owner's installation of treatment and designate optimal water quality control parameters (subdivision A 1 f of this section) within six months after completion of the provisions of subdivision A 2 e (6) of this section.

(8) The owner shall operate the waterworks in compliance with the department-designated optimal water quality control parameters (subdivision A 1 g of this section) and continue to conduct tap sampling (12VAC5-590-375 B 4 c and 12VAC5-590-375 C 4).

B. Source water treatment technique requirements for lead and copper. The owner of a waterworks exceeding the lead or copper AL shall complete the applicable source water monitoring and treatment requirements (described in the referenced portions of subdivision B 2 of this section, and in 12VAC5-590-375 B and 12VAC5-590-375 D) by the following deadlines:

1. Deadlines for completing source water treatment steps.

a. The owner of a waterworks exceeding the lead or copper AL shall complete lead and copper source water monitoring (12VAC5-590-375 D 2) and submit a treatment proposal to the department (subdivision B 2 a of this section) no later than 180 days after the end of the monitoring period during which the lead or copper AL was exceeded.

b. The department shall make a determination regarding the need for source water treatment (subdivision B 2 b of this section) within six months after submission of monitoring results under subdivision B 1 a of this section.

c. If the department requires installation of source water treatment, then the owner shall install the treatment (subdivision B 3 of this section) within 24 months after completion of subdivision B 1 b of this section.

d. The owner shall complete follow-up tap water monitoring (12VAC5-590-375 B 4 b) and source water lead and copper monitoring (12VAC5-590-375 D 3) within 36 months after completion of subdivision B 1 b.

e. The department shall evaluate the owner's installation and operation of the source water treatment and specify maximum permissible source water lead and copper levels (subdivision B 4 of this section) within six months after completion of subdivision B 1 d of this section.

f. The owner shall operate the waterworks in compliance with the department-specified maximum permissible source water lead and copper levels (subdivision B 4 of this section) and continue source water monitoring (12VAC5-590-375 D 4).

2. Description of source water treatment requirements.

a. Waterworks treatment recommendation. The owner of a waterworks that exceeds the lead or copper AL shall propose in writing to the department the installation and operation of one of the source water treatments listed in subdivision B 2 b of this section. The owner may propose that no treatment be installed based upon a demonstration that source water treatment is not necessary to minimize lead and copper levels at consumer taps.

b. Department's determination regarding source water treatment. The department shall complete an evaluation of the results of all source water samples submitted by the owner to determine whether source water treatment is necessary to minimize lead or copper levels in water delivered to consumer taps. If the department determines that treatment is needed, then the department shall either require installation and operation of the source water treatment recommended by the owner or require the installation and operation of another source water treatment from among the following: (i) ion exchange, (ii) RO, (iii) lime softening, or (iv) coagulation or filtration. If the department requests additional information to aid in the evaluation, then the owner shall provide the information by the date specified by the department in the request. The department shall notify the owner in writing of the determination and set forth the basis for the decision.

3. Installation of source water treatment. The owner shall properly install and operate the source water treatment designated by the department under subdivision B 2 b of this section.

4. The department's evaluation of source water treatment and specification of maximum permissible source water lead and copper levels. The department shall evaluate the source water samples collected by the owner both before and after the owner installs source water treatment, and determine whether the owner has properly installed and operated the source water treatment designated by the department. Based upon the evaluation, the department shall designate the maximum permissible lead and copper concentrations for finished water entering the distribution system. The levels shall reflect the contaminant removal capability of the treatment properly operated and maintained. The department shall notify the owner in writing and explain the basis for the decision.

5. Continued operation and maintenance. The waterworks shall be operated to maintain lead and copper levels below the maximum permissible concentrations designated by the department at each sampling point monitored in accordance with 12VAC5-590-375 D. The waterworks is out of compliance with this subdivision B 5 if the level of lead or copper at any sampling point is greater than the maximum permissible concentration designated by the department.

6. Modification of the department's treatment decisions. Upon the department's initiative or in response to a request by an owner or other interested party, the department may modify the determination of the source water treatment under subdivision B 2 b of this section, or may modify the maximum permissible lead and copper concentrations for finished water entering the distribution system under subdivision B 4 of this section. A request for modification by an owner or other interested party shall be in writing, explain why the modification is appropriate, and provide supporting documentation. The department may modify the determination where the conclusion is made that the change is necessary to ensure that the waterworks continues to minimize lead and copper concentrations in source waters. A revised determination shall be made in writing, set forth the new treatment requirements, explain the basis for the department's decision, and provide an implementation schedule for completing the treatment modifications.

C. Lead service line replacement treatment technique requirements:

1. The owner of a waterworks that fails to meet the lead AL in tap samples collected pursuant to 12VAC5-590-375 B 4 b, after installing corrosion control or source water treatment (whichever sampling occurs later), shall replace lead service lines in accordance with the requirements of this section. If the owner is in violation of subdivision A 2 of this section or subsection B of this section for failure to install source water or corrosion control treatment, then the department may require the owner to commence lead service line replacement under this section after the date by which the owner was required to conduct monitoring under 12VAC5-590-375 B 4 b has passed.

2. The owner shall replace annually at least 7.0% of the initial number of lead service lines in its distribution system. The initial number of lead service lines is the number of lead lines in place at the time the replacement program begins. The owner shall identify the initial number of lead service lines in its distribution system based upon a materials evaluation, including the evaluation required under 12VAC5-590-375 B 1. The first year of lead service line replacement shall begin on the first day following the end of the monitoring period in which the lead AL was exceeded under subdivision C 1 of this section. If monitoring is required annually or less frequently, then the end of the monitoring period is September 30 of the calendar year in which the sampling occurs. If the department has established an alternate monitoring period, then the end of the monitoring period will be the last day of that period.

3. The owner of a waterworks resuming a lead service line replacement program after the cessation of the lead service line replacement program as allowed by subdivision C 7 of this section shall update the inventory of lead service lines to include those sites that were previously determined not to require replacement through the sampling provision under subdivision C 4 of this section. The owner shall then divide the updated number of remaining lead service lines by the number of remaining years in the program to determine the number of lines that must be replaced per year (7.0% lead service line replacement is based on a 15-year replacement program; so, for example, the owner resuming lead service line replacement after previously conducting two years of replacement would divide the updated inventory by 13). For the owner that has completed a 15-year lead service line replacement program, the department will determine a schedule for replacing or retesting lines that were previously tested out under the replacement program when the waterworks re-exceeds the lead AL.

4. The owner is not required to replace an individual lead service line if the lead concentration in all service line samples from that line, collected pursuant to 12VAC5-590-375 B 2 c, is less than or equal to 0.015 mg/L.

5. The owner shall replace that portion of the lead service line that is owned by the waterworks. In cases where the owner does not own the entire lead service line, the owner shall notify the building owner, or the building owner's authorized agent, that the owner will replace that portion of the service line that is owned by the waterworks and shall offer to replace the building owner's portion of the line. The owner is not required to bear the cost of replacing the building owner's portion of the service line, nor is the owner required to replace the building owner's portion where the owner chooses not to pay the cost of replacing the building owner's portion of the line, or where replacing the building owner's portion would be precluded by state, local, or common law. The owner that does not replace the entire length of the service line also shall complete the following tasks:

a. At least 45 days before commencing with the partial replacement of a lead service line, the owner shall provide notice to the resident or residents of all buildings served by the line explaining that they may experience a temporary increase of lead levels in the drinking water, along with guidance on measures consumers can take to minimize their exposure to lead. The department may allow the owner to provide notice under the previous sentence less than 45 days before commencing partial lead service line replacement where the replacement is in conjunction with emergency repairs. In addition, the owner shall inform each resident served by the lead service line that the owner will, at the owner's expense, collect a sample from each partially replaced lead service line that is representative of the water in the service line for analysis of lead content, as prescribed in 12VAC5-590-375 B 2 c, within 72 hours after the completion of the partial replacement of the lead service line. The owner shall collect the sample and report the results of the analysis to the building owner and each resident served by the service line within three business days of receiving the results. Mailed notices post-marked within three business days of receiving the results shall be considered on time.

b. The owner shall provide the information required by subdivision C 5 a of this section to the residents of individual dwellings by mail or by other methods approved by the department. In instances where multi-family dwellings are served by the service line, the owner shall have the option to post the information at a conspicuous location.

6. The department shall require the owner to replace lead service lines on a shorter schedule than that required by this subsection, taking into account the number of lead service lines in the waterworks, where a shorter replacement schedule is feasible. The department shall make this determination in writing and notify the owner of the findings within six months after the waterworks is triggered into lead service line replacement based on monitoring referenced in subdivision C 1 of this section.

7. The owner may cease replacing lead service lines whenever first-draw tap samples collected pursuant to 12VAC5-590-375 B 2 b meet the lead AL during each of two consecutive six-month monitoring periods and the owner submits the results to the department. If the first-draw tap samples collected in a waterworks thereafter exceed the lead AL, then the owner shall recommence replacing lead service lines, pursuant to subdivision C 3 of this section.

8. To demonstrate compliance with subdivisions C 1 through C 5 of this section, an owner shall report to the department the information specified in 12VAC5-590-532.

D. Lead public education requirements. The owner shall deliver a consumer notice of lead tap water monitoring results to all persons served by the waterworks at sites that are tested in accordance with subdivision D 4 of this section. The owner of a waterworks that exceeds the lead AL based on tap water samples collected in accordance with 12VAC5-590-375 B shall deliver the public education materials contained in subdivision D 1 of this section in accordance with the requirements in subdivision D 2 of this section. The owner of a waterworks that exceeds the lead AL shall sample the tap water of any customer who requests it in accordance with subdivision D 3 of this section.

1. Content of written materials. The owner shall include the following text in all of the printed materials distributed through the lead public education program:

a. Community waterworks and NTNCs. The owner of community waterworks or a NTNC shall include the following elements in printed materials (e.g., brochures and pamphlets) in the same order as listed in this subdivision D 1 a. In addition, the language specified in subdivisions D 1 a (1) and D 1 a (2) and in subdivision D 1 a (6) of this section shall be included in materials, exactly as written, except for the text in brackets for which the owner shall include system-specific information. Any additional information presented by the owner shall be consistent with the information in this subdivision D 1 a and be in plain language that can be understood by the general public. The department may require the owner to obtain approval of the content of written material before delivery.

(1) IMPORTANT INFORMATION ABOUT LEAD IN YOUR DRINKING WATER. "(Insert name of waterworks) found elevated levels of lead in drinking water in some homes or buildings. Lead can cause serious health problems, especially for pregnant women and young children. Please read this information closely to see what you can do to reduce lead in your drinking water."

(2) Health effects of lead. "Lead can cause serious health problems if too much enters your body from drinking water or other sources. It can cause damage to the brain and kidneys, and can interfere with the production of red blood cells that carry oxygen to all parts of your body. The greatest risk of lead exposure is to infants, young children, and pregnant women. Scientists have linked the effects of lead on the brain with lowered IQ in children. Adults with kidney problems and high blood pressure can be affected by low levels of lead more than healthy adults. Lead is stored in the bones, and it can be released later in life. During pregnancy, the child receives lead from the mother's bones, which may affect brain development."

(3) Sources of lead.

(a) Explain what lead is.

(b) Explain possible sources of lead in drinking water and how lead enters drinking water. Include information on home or building materials and services lines that may contain lead.

(c) Discuss other important sources of lead exposure in addition to drinking water (e.g., paint).

(4) Discuss the steps the consumer can take to reduce their exposure to lead in drinking water.

(a) Encourage running the water to flush out the lead.

(b) Explain concerns with using hot water from the tap and specifically caution against the use of hot water for preparing baby formula.

(c) Explain that boiling water does not reduce lead levels.

(d) Discuss other options consumers can take to reduce exposure to lead in drinking water, such as alternative sources or treatment of water.

(e) Suggest that parents have their child's blood tested for lead.

(5) Explain why there are elevated levels of lead in the waterworks' drinking water (if known) and what the owner is doing to reduce the lead levels in homes and buildings.

(6) "For more information call us at (Insert owner's contact phone number), or if applicable, visit our website at (Insert waterworks' website URL here). For more information on reducing lead exposure around your home or building and the health effects of lead, visit EPA's website at http://www.epa.gov/lead or contact your health care provider."

b. In addition to including the elements specified in subdivision D 1 a of this section, the owner of a community waterworks shall:

(1) Tell consumers how to get their water tested.

(2) Discuss lead in plumbing components and the difference between low lead and lead free. "Lead free" means (i) when used with respect to solders and flux refers to solders and flux containing not more than 0.2% lead, and (ii) when used with respect to pipes, pipe fittings, plumbing fittings, and plumbing fixtures refers to the weighted average of wetted surfaces of pipes, pipe fittings, plumbing fittings, and plumbing fixtures containing not more than 0.25% lead.

2. Delivery of public education materials.

a. The owner of a waterworks serving a large proportion of non-English speaking consumers, as determined by the department, shall include in all public education materials information in the appropriate languages regarding the importance of the notice or contain a telephone number or address where persons served may contact the waterworks to obtain a translated copy of the public education materials or to request assistance in the appropriate language.

b. The owner of a community waterworks that exceeds the lead AL on the basis of tap water samples collected in accordance with 12VAC5-590-375 B, and that is not already conducting public education tasks, shall conduct the public education tasks under this subdivision within 60 days after the end of the monitoring period in which the exceedance occurred. For a waterworks that is required to conduct monitoring annually or less frequently, the end of the monitoring period is September 30 of the calendar year in which the sampling occurs, or, if the department has established an alternate monitoring period, the last day of that period. These public education tasks include:

(1) Delivering printed materials meeting the content requirements of subdivision D 1 of this section to all bill paying customers.

(2) Contacting customers who are most at risk by delivering education materials that meet the content requirements of subdivision D 1 of this section to the local health department even if they are not located within the waterworks service area, along with an informational notice that encourages distribution to all the organization's potentially affected customers or community waterworks consumers. The owner shall contact the local health department directly by phone or in person. The local health department may provide a specific list of additional community based organizations serving target populations, which may include organizations outside the service area of the waterworks. If these lists are provided, then the owner shall deliver education materials that meet the content requirements of subdivision D 1 of this section to all organizations on the provided lists.

(3) Contacting customers who are most at risk by delivering materials that meet the content requirements of subdivision D 1 of this section to the following organizations that are located within the waterworks service area, along with an informational notice that encourages distribution to all the organization's potentially affected customers or community waterworks users: (i) public and private schools or school boards; (ii) Women, Infants and Children (WIC) and Head Start programs; (iii) public and private hospitals and medical clinics; (iv) pediatricians; (v) family planning clinics; and (vi) local welfare agencies.

(4) Make a good faith effort to locate the following organizations within the service area and deliver materials that meet the content requirements of subdivision D 1 of this section to them, along with an informational notice that encourages distribution to all potentially affected customers or consumers. The good faith effort to contact at-risk customers may include requesting a specific contact list of these organizations from the local health department, even if the agencies are not located within the waterworks service area: (i) licensed childcare centers, (ii) public and private preschools, and (iii) obstetricians-gynecologists and midwives.

(5) No less often than quarterly, providing information on or in each water bill as long as the waterworks exceeds the AL for lead. The message on the water bill shall include the following statement exactly as written except for the text in brackets for which the owner shall include system-specific information: "(Insert name of waterworks) found high levels of lead in drinking water in some homes. Lead can cause serious health problems. For more information please call (insert name of waterworks) or (if applicable) visit our website at (insert waterworks website URL here)". The message or delivery mechanism can be modified in consultation with the department; specifically, the department may allow a separate mailing of public education materials to customers if the owner cannot place the information on water bills.

(6) Posting materials meeting the content requirements of subdivision D 1 of this section on the waterworks website if the waterworks serves a population greater than 100,000 persons.

(7) Submitting a press release to newspapers, television, and radio stations.

(8) In addition to the delivery requirements contained in subdivisions D 2 b (1) through D 2 b (7) of this section, the owner of a waterworks exceeding the lead AL shall implement at least three activities from one or more of the following categories: (i) public service announcements, (ii) paid advertisements, (iii) public area informational displays, (iv) emails to customers, (v) public meetings, (vi) household deliveries, (vii) targeted individual customer contact, (viii) direct material distribution to all multi-family homes and institutions, and (ix) other methods approved by the department. The educational content and selection of these activities shall be determined in consultation with the department.

(9) As long as a community waterworks exceeds the lead AL, the owner shall repeat the following public education activities:

(a) The owner of a community waterworks shall repeat the tasks contained in subdivisions D 2 b (1), D 2 b (2), D 2 b (3), and D 2 b (8) of this section every 12 months.

(b) The owner of a community waterworks shall repeat tasks contained in subdivision D 2 b (5) of this section with each billing cycle.

(c) The owner of a community waterworks serving a population greater than 100,000 shall post and retain the material on a publicly accessible website pursuant to subdivision D 2 b (6) of this section.

(d) The owner of a community waterworks shall repeat the task in subdivision D 2 b (7) of this section twice every 12 months on a schedule agreed upon with the department.

(10) The department may allow the public education activities described in subdivision D 2 b of this section to extend beyond the 60-day requirement if needed for implementation purposes on a case-by-case basis; however, this extension must be approved in writing by the department in advance of the 60-day deadline.

c. The owner of a NTNC that exceeds the lead AL on the basis of tap water samples collected in accordance with 12VAC5-590-375 B, and that is not already conducting public education tasks, shall conduct the public education tasks under this subdivision within 60 days after the end of the monitoring period in which the exceedance occurred. For a waterworks that is required to conduct monitoring annually or less frequently, the end of the monitoring period is September 30 of the calendar year in which the sampling occurs, or, if the department has established an alternate monitoring period, the last day of that period. These public education tasks include:

(1) Posting informational posters containing all of the public education elements contained in subdivision D 1 of this section in a public place or common area in each of the buildings served by the waterworks; and

(2) Distributing informational pamphlets or brochures on lead in drinking water containing all of the public education elements in subdivision D 1 of this section to each person served by the NTNC. The department may allow the owner to utilize electronic transmission instead of or combined with printed materials as long as it achieves at least the same coverage.

(3) The owner of a NTNC shall repeat the tasks contained in subdivisions D 2 c (1) and D 2 c (2) of this section at least once during each calendar year in which the waterworks exceeds the lead AL.

(4) The department may allow the public education activities described in subdivision D 2 c of this section to extend beyond the 60-day requirement if needed for implementation purposes on a case-by-case basis; however, this extension must be approved in writing by the department in advance of the 60-day deadline.

d. The owner may discontinue delivery of public education materials if the waterworks has met the lead AL during the most recent six-month monitoring period conducted pursuant to 12VAC5-590-375 B. The owner shall recommence public education in accordance with this subsection if the waterworks subsequently exceeds the lead AL during any monitoring period.

e. The owner of a community waterworks may apply to the department, in writing, (unless the department has waived the requirement for prior approval) to use only the text specified in subdivision D 1 a of this section instead of the text in subdivisions D 1 a and D 1 b of this section and to perform the tasks listed in subdivisions D 2 c (1) and D 2 c (2) of this section instead of the tasks in subdivisions D 2 b (1) through D 2 b (9) of this section if:

(1) The waterworks serves a facility, such as a prison or a hospital, where the population served is not capable of or is prevented from making improvements to plumbing or installing POU treatment devices; and

(2) The owner provides water as part of the cost of services provided and does not separately charge for water consumption.

f. The owner of a community waterworks serving 3,300 or fewer people may limit certain aspects of the public education programs as follows:

(1) With respect to the requirements of subdivision D 2 b (8) of this section, the owner of a waterworks serving 3,300 or fewer people shall implement at least one of the activities listed in that subdivision.

(2) With respect to the requirements of subdivision D 2 b (2) of this section, the owner of a waterworks serving 3,300 or fewer people may limit the distribution of the public education materials required under that subdivision to facilities and organizations served by the waterworks that are most likely to be visited regularly by pregnant women and children.

(3) With respect to the requirements of subdivision D 2 b (7) of this section, the department may waive this requirement for waterworks serving 3,300 or fewer persons as long as the owner distributes notices to every household served by the waterworks.

3. Supplemental monitoring and notification of results. The owner of a waterworks that fails to meet the lead AL on the basis of tap samples collected in accordance with 12VAC5-590-375 B shall offer to sample the tap water of any customer who requests it. The owner is not required to pay for collecting or analyzing the sample, nor is the owner required to collect and analyze the sample itself.

4. Notification of results. The owner of a community waterworks or a NTNC shall provide a notice of the individual tap results from lead tap water monitoring carried out under the requirements of 12VAC5-590-375 B to the persons served by the waterworks at the specific sampling site from which the sample was collected (e.g., the occupants of the residence or buildings where the tap was tested).

a. Timing of notification. The owner shall provide this consumer notice as soon as practical, but no later than 30 days after the owner learns of the tap monitoring results.

b. Content. The consumer notice shall include the results of lead tap water monitoring for the tap that was tested, an explanation of the health effects of lead, list steps consumers can take to reduce exposure to lead in drinking water, and contact information for the waterworks. The notice shall also provide the MCLG and the AL for lead and the definitions for these two terms from 12VAC5-590-10.

c. Delivery. The consumer notice shall be provided to persons served at the tap that was tested, either by postal mail or by another method approved by the department. For example, the owner of a NTNC may post the results on a bulletin board in the facility to allow consumers to review the information. The owner shall provide the notice to customers at sample taps tested, including consumers who do not receive water bills.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 27, Issue 1, eff. October 13, 2010; amended, Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-410. (Repealed.)

Historical Notes

Derived from VR355-18-004.08 § 2.8, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 12, Issue 2, eff. November 15, 1995; Volume 18, Issue 19, eff. July 3, 2002; Volume 19, Issue 24, eff. September 10, 2003; Volume 21, Issue 13, eff. April 6, 2005; Volume 22, Issue 15, eff. May 3, 2006; Volume 22, Issue 24, eff. September 6, 2006; Volume 25, Issue 5, eff. December 10, 2008; Volume 27, Issue 1, eff. October 13, 2010; Volume 28, Issue 5, eff. December 7, 2011; repealed, Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-411. Disinfection byproduct precursors, disinfection byproducts, and maximum residual disinfection level treatment techniques.

A. Treatment technique for control of DBPPs.

1. Applicability.

a. The owner of a community waterworks or a NTNC shall comply with treatment techniques for the control of DBPPs.

b. A waterworks that uses a surface water source, a GUDI source, or both using conventional filtration treatment shall operate with enhanced coagulation or enhanced softening to achieve the TOC percentage removal levels specified in subdivision A 2 of this section unless the waterworks meets at least one of the alternative compliance criteria listed in subdivision A 1 c or A 1 d of this section.

c. Alternative compliance criteria for enhanced coagulation and enhanced softening waterworks. A waterworks that uses a surface water source, a GUDI source, or both provided with conventional filtration treatment may use the alternative compliance criteria in subdivisions A 1 c (1) through A 1 c (6) of this section to comply with this section instead of complying with subdivision A 2 of this section. The owner shall comply with monitoring requirements in 12VAC5-590-374 I.

(1) The waterworks' source water TOC level is less than 2.0 mg/L, calculated quarterly as an RAA.

(2) The waterworks' treated water TOC level is less than 2.0 mg/L, calculated quarterly as an RAA.

(3) The waterworks' source water TOC level is less than 4.0 mg/L, calculated quarterly as an RAA; the source water alkalinity is greater than 60 mg/L (as CaCO3), calculated quarterly as an RAA; and no TTHM and HAA5 LRAAs are greater than 0.040 mg/L and 0.030 mg/L, respectively.

(4) No TTHM and HAA5 LRAAs are greater than 0.040 mg/L and 0.030 mg/L, respectively, and the waterworks uses only chlorine for primary disinfection and maintains a residual in the distribution system.

(5) The waterworks' source water SUVA, before any treatment and measured monthly, is less than or equal to 2.0 liters per milligram-meter (L/mg-m), calculated quarterly as an RAA.

(6) The waterworks' finished water SUVA, measured monthly, is less than or equal to 2.0 L/mg-m, calculated quarterly as an RAA.

d. Additional alternative compliance criteria for softening waterworks. A waterworks practicing enhanced softening that cannot achieve the TOC removals required by subdivision A 2 b of this section may use the alternative compliance criteria in subdivisions A 1 c (1) and A 1 c (2) instead of complying with subdivision A 2 of this section. A waterworks shall comply with monitoring requirements in 12VAC5-590-374 J.

(1) Softening that results in lowering the treated water alkalinity to less than 60 mg/L (as CaCO3), measured monthly and calculated quarterly as an RAA.

(2) Softening that results in removing at least 10 mg/L of magnesium hardness (as CaCO3), measured monthly and calculated quarterly as an RAA.

2. Enhanced coagulation and enhanced softening performance requirements.

a. A waterworks shall achieve the percentage reduction of TOC specified in subdivision A 2 b of this section between the source water and the CFE, unless the department approves an owner's request for alternate minimum TOC removal (Step 2) requirements under subdivision A 2 c of this section.

Required Step 1 TOC reductions, indicated in Table 411.1, are based upon specified source water parameters. A waterworks practicing softening is required to meet the Step 1 TOC reductions in the far-right column (source water alkalinity greater than 120 mg/L) for the specified source water TOC.

b. Required Step 1 TOC reductions are indicated in Table 411.1, Required Percentage Removals of TOC.

TABLE 411.1
Required Percentage Removals of TOCa,b

SOURCE WATER TOC, mg/L

SOURCE WATER ALKALINITY, mg/L as CaCO3

0 - 60

>60 - 120

>120c

>2.0 - 4.0

35.0%

25.0%

15.0%

>4.0 - 8.0

45.0%

35.0%

25.0%

>8.0

50.0%

40.0%

30.0%

aA waterworks meeting at least one of the conditions in subdivisions A 1 c (1) through A 1 c (6) of this section is not required to operate with enhanced coagulation.

bA waterworks utilizing softening and meeting one of the alternative compliance criteria in subdivision A 1 d of this section is not required to operate with enhanced softening.

cA waterworks practicing softening shall meet the TOC removal requirements in this column.

c. A waterworks that uses a surface water source, a GUDI source, or both with conventional treatment that cannot achieve the Step 1 TOC removals required by subdivision A 2 b due to water quality parameters or operational constraints shall apply to the department within three months of failure to achieve the TOC removals required by subdivision A 2 b of this section for approval of alternative minimum TOC (Step 2) removal requirements submitted by the owner. If the department approves the alternative minimum TOC removal (Step 2) requirements, then the department may make those requirements retroactive for the purposes of determining compliance. Until the department approves the alternate minimum TOC removal (Step 2) requirements, the waterworks shall meet the Step 1 TOC removals contained in subdivision A 2 b of this section.

d. Alternate minimum TOC removal (Step 2) requirements. Applications made to the department by the owner of a waterworks using enhanced coagulation for approval of alternative minimum TOC removal (Step 2) requirements under subdivision A 2 c of this section shall include, at a minimum, results of bench-scale or pilot-scale testing conducted under subdivision A 2 d (1) of this section. The submitted bench-scale or pilot-scale testing shall be used to determine the alternate enhanced coagulation level.

(1) Alternate enhanced coagulation level is defined as coagulation at a coagulant dose and pH as determined by the method described in subdivisions A 2 d (1) through A 2 d (5) of this section so that an incremental addition of 10 mg/L of alum (or equivalent amount of ferric salt) results in a TOC removal of equal to or less than 0.3 mg/L. The percentage removal of TOC at this point on the "TOC removal versus coagulant dose" curve is then defined as the minimum TOC removal required for the waterworks. Once approved by the department, this minimum requirement supersedes the minimum TOC removal requirements listed in Table 411.1. This requirement shall be effective until the department approves a new value based on the results of a new bench-scale and pilot-scale test. Failure to achieve the alternative minimum TOC removal levels set by the department is a violation of this section.

(2) Bench-scale or pilot-scale testing of enhanced coagulation shall be conducted by using representative water samples and adding 10 mg/L increments of alum (or equivalent amounts of ferric salt) until the pH is reduced to a level less than or equal to the enhanced coagulation Step 2 target pH shown in Table 411.2.

TABLE 411.2
Enhanced Coagulation

ALKALINITY (mg/L as CaCO3)

TARGET pH

0 - 60

5.5

>60 -120

6.3

>120 - 240

7.0

>240

7.5

(3) For source waters with alkalinities of less than 60 mg/L for which addition of small amounts of alum or equivalent addition of iron coagulant drives the pH below 5.5 before significant TOC removal occurs, the waterworks shall add necessary chemicals to maintain the pH between 5.3 and 5.7 in samples until the TOC removal of 0.3 mg/L per 10 mg/L alum added (or equivalent addition of iron coagulant) is reached.

(4) The waterworks may operate at any coagulant dose or pH necessary (consistent with other sections of this chapter) to achieve the minimum TOC percentage removal approved under subdivision A 2 c of this section.

(5) If the TOC removal is consistently less than 0.3 mg/L of TOC per 10 mg/L of incremental alum dose at all dosages of alum (or equivalent addition of iron coagulant), then the water is deemed to contain TOC not amenable to enhanced coagulation. The owner may then apply to the department for a waiver of enhanced coagulation requirements.

3. Compliance calculations.

a. A waterworks that uses a surface water source, a GUDI source, or both other than those identified in subdivision A 1 b or A 1 c of this section shall comply with requirements contained in subdivision A 2 b or A 2 c of this section. The owner shall calculate compliance quarterly, beginning after the waterworks has collected 12 months of data, by determining an annual average using the following method:

(1) Determine actual monthly TOC percentage removal, equal to:

[1-(treated water TOC/source water TOC)] X 100.

(2) Determine the required monthly TOC percentage removal (from either Table 411.1 or from subdivision A 2 c of this section).

(3) Divide the value in subdivision A 3 a (1) of this section by the value in subdivision A 3 a (2) of this section.

(4) Add together the results of subdivision A 3 a (3) of this section for the last 12 months and divide by 12.

(5) If the value calculated in subdivision A 3 a (4) of this section is less than 1.00, then the waterworks is not in compliance with the TOC percentage removal requirements.

b. The owner may use the provisions in subdivisions A 3 b (1) through A 3 b (5) of this section instead of the calculations in subdivisions A 3 a (1) through A 3 a (5) of this section to determine compliance with TOC percentage removal requirements.

(1) In any month that the waterworks' treated or source water TOC level is less than 2.0 mg/L, the waterworks may assign a monthly value of 1.0 (instead of the value calculated in subdivision A 3 a (3) of this section) when calculating compliance under the provisions of subdivision A 3 a of this section.

(2) In any month that a waterworks practicing softening removes at least 10 mg/L of magnesium hardness (as CaCO3), the waterworks may assign a monthly value of 1.0 (instead of the value calculated in subdivision A 3 a (3) of this section) when calculating compliance under the provisions of subdivision A 3 a of this section.

(3) In any month that the waterworks source water SUVA before any treatment is equal to or less than 2.0 L/mg-m, the waterworks may assign a monthly value of 1.0 (instead of the value calculated in subdivision A 3 a (3) of this section) when calculating compliance under the provisions of subdivision A 3 a of this section.

(4) In any month that the waterworks finished water SUVA is equal to or less than 2.0 L/mg-m, the waterworks may assign a monthly value of 1.0 (instead of the value calculated in subdivision A 3 a (3) of this section) when calculating compliance under the provisions of subdivision A 3 a of this section.

(5) In any month that the waterworks practicing enhanced softening lowers the alkalinity below 60 mg/L (as CaCO3), the waterworks may assign a monthly value of 1.0 (instead of the value calculated in subdivision A 3 a (3) of this section) when calculating compliance under the provisions of subdivision A 3 a of this section.

c. A waterworks that uses a surface water source, a GUDI source, or both and uses conventional treatment may also comply with the requirements of this section by meeting the criteria in subdivision A 1 b or A 1 c of this section.

4. Enhanced coagulation or enhanced softening is the treatment technique required to control the level of DBP precursors in water treatment and distribution system for a waterworks using a surface water source, a GUDI source, or both and using conventional treatment.

B. The BAT, treatment techniques, or other means available for achieving compliance with the PMCLs for DBPs shown in Table 340.6 are listed in this subsection:

1. The BAT, treatment techniques, or other means available for achieving compliance with the PMCLs for bromate and chlorite:

DISINFECTION BYPRODUCT

BEST AVAILABLE TECHNOLOGY

Bromate

Control of ozone treatment process to reduce production of bromate

Chlorite

Control of treatment processes to reduce disinfectant demand and control of disinfection treatment processes to reduce disinfectant levels

2. The BAT, treatment techniques, or other means available for achieving compliance with the RAA PMCLs for TTHM and HAA5:

DISINFECTION BYPRODUCT

BEST AVAILABLE TECHNOLOGY

TTHM and HAA5

Enhanced coagulation or enhanced softening or GAC10, with chlorine as the primary and residual disinfectant

3. The BAT, treatment techniques, or other means available for achieving compliance with the LRAA PMCLs for TTHM and HAA5 for a waterworks that disinfects its source water:

DISINFECTION BYPRODUCT

BEST AVAILABLE TECHNOLOGY

TTHM and HAA5

Enhanced coagulation or enhanced softening, plus GAC10; or NF with a molecular weight cutoff fewer than or equal to 1,000 Daltons; or GAC20

4. The BAT, treatment techniques, or other means available for achieving compliance with the LRAA MCLs for TTHM and HAA5 for a a consecutive waterworks and applies only to the disinfected water that a consecutive waterworks buys or otherwise receives:

DISINFECTION BYPRODUCT

BEST AVAILABLE TECHNOLOGY

TTHM and HAA5

A waterworks serving equal to or greater than 10,000 people: Improved distribution system and storage tank management to reduce residence time, plus the use of chloramines for residual disinfectant maintenance

A waterworks serving fewer than 10,000 people: Improved distribution system and storage tank management to reduce residence time

C. The BAT, treatment techniques, or other means available for achieving compliance with the MRDLs identified in Table 340.7 are the controls of treatment processes to reduce disinfectant demand and controls of disinfection treatment processes to reduce disinfectant levels.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-415. Uncovered finished water storage.

A. A waterworks with uncovered finished water storage facilities shall comply with the requirements to cover the facility as described in this section.

B. The owner shall immediately notify the department of the use of each uncovered finished water storage facility.

C. All uncovered finished water storage facilities shall be covered in compliance with a schedule approved by the department.

D. Failure to comply with the requirements of this section is a violation of the treatment technique requirement.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-420. (Repealed.)

Historical Notes

Derived from VR355-18-004.09 § 2.9, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 12, Issue 2, eff. November, 15, 1995; Volume 18, Issue 19, eff. July 3, 2002; Volume 19, Issue 17, eff. June 4, 2003; Volume 19, Issue 20, eff. July 16, 2003; Volume 21, Issue 13, eff. April 6, 2005; Volume 25, Issue 5, eff. December 10, 2008; Volume 27, Issue 1, eff. October 13, 2010; Volume 28, Issue 5, eff. December 7, 2011; repealed, Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-421. Groundwater system treatment techniques.

A. The owner of a groundwater system that (i) has a confirmed E. coli contamination as described in 12VAC5-590-379 B or (ii) has been notified in writing of a significant deficiency as described in 12VAC5-590-350 D shall meet the requirements of this section. Failure to meet any requirement of this section after the applicable time period specified is a treatment technique violation.

1. The owner shall implement one or more of the following corrective actions:

a. Correct all significant deficiencies;

b. Provide an alternate source of water;

c. Eliminate the source of contamination; or

d. Provide treatment of the groundwater source that reliably achieves at least 4-log treatment of viruses before or at the first customer.

2. Unless the department directs the owner to implement a specific corrective action, the owner shall consult with the department regarding the appropriate corrective action within 30 days of receiving written notification from the department or the laboratory. This consultation may take the form of a telephone conversation, email, meeting, or other mechanism agreed to by the department.

3. Within 45 days of receiving this notification, the owner shall submit a written corrective action plan (CAP) to the department that satisfactorily addresses the deficiency. The CAP shall include a schedule for completing individual actions, and it shall include one or more of the corrective actions in subdivision A 1 of this section. Approval of the CAP by the department constitutes an approved CAP.

4. Within 120 days of receiving written notification from the department or the laboratory, the owner shall either:

a. Have completed corrective actions in accordance with the department approved CAP including department specified interim measures; or

b. Be in compliance with a department approved CAP and schedule.

(1) Any subsequent modifications to a department approved CAP and schedule shall also be approved by the department.

(2) If the department specifies interim measures for protection of the public health pending the department's approval of the CAP and schedule or pending completion of the CAP, then the owner shall comply with these interim measures as well as with any schedule specified by the department.

5. When a significant deficiency is identified at a waterworks that uses both a groundwater and a surface water or a GUDI source, the owner shall comply with this section unless the department has determined that the significant deficiency is in a portion of the distribution system that is served solely by the surface water or the GUDI source.

B. The owner of a groundwater system that provides at least 4-log treatment of viruses before or at the first customer shall conduct compliance monitoring to demonstrate treatment effectiveness in accordance with subsection C of this section. The owner shall also conduct source water monitoring in accordance with 12VAC5-590-379 C.

The owner shall provide engineering, operational, or other information as required by the department to complete a determination of virus treatment effectiveness.

C. The owner of a groundwater system that provides at least 4-log treatment of viruses shall monitor the effectiveness and reliability of treatment for that groundwater source before or at the first customer as follows:

1. Chemical disinfection.

a. The owner of a groundwater system that serves greater than 3,300 people shall continuously monitor and record the residual disinfectant concentration using analytical methods specified in 12VAC5-590-440 at a location approved by the department and shall record the lowest residual disinfectant concentration each day that water from the groundwater source is served to the public. The owner shall maintain at least the department-determined residual disinfectant concentration every day the groundwater system serves water from the groundwater source to the public. If there is a failure in the continuous monitoring equipment, the owner shall conduct grab sampling every four hours until the continuous monitoring equipment is returned to service. The system shall resume continuous residual disinfectant monitoring within 14 days.

b. The owner of a groundwater system that serves 3,300 or fewer people shall monitor the residual disinfectant concentration using analytical methods specified in 12VAC5-590-440 at a location approved by the department and record the residual disinfection concentration each day that water from the groundwater source is served to the public. The owner shall maintain the department-determined residual disinfectant concentration every day the groundwater system serves water from the groundwater source to the public. The owner shall collect a daily grab sample during the hour of peak flow or at another time specified by the department. If any daily grab sample measurement falls below the department-determined residual disinfectant concentration, the owner shall collect follow-up samples every four hours until the residual disinfectant concentration is restored to the department-determined level. The owner of a groundwater system that serves 3,300 or fewer people may monitor continuously to meet the requirements of this subsection.

c. When the disinfection treatment is required based on confirmed E. coli contamination in the source water, the requirements in this section apply. When the disinfection treatment is required for any other reason or provided voluntarily by the owner, the department will determine the frequency of residual disinfectant monitoring.

d. Failure to maintain the department-specified minimum residual disinfectant concentration for a period of more than four hours is a violation of the treatment technique requirement.

2. The owner of a groundwater system that uses a department-approved alternative treatment to meet the requirements of this section by providing at least 4-log treatment of viruses before or at the first customer shall:

a. Monitor the alternative treatment in accordance with all department-specified monitoring requirements; and

b. Operate the alternative treatment in accordance with all department-specified compliance requirements necessary to achieve at least 4-log treatment of viruses.

3. Failure to meet the monitoring requirements of subsection C of this section is a violation and requires the owner to provide public notification as required in 12VAC5-590-540 A 3.

D. Discontinuing compliance monitoring or treatment.

1. The owner may discontinue compliance monitoring if the department determines and documents in writing that compliance monitoring is no longer necessary for that groundwater source. The owner of a groundwater systems that has department approval to discontinue compliance monitoring shall be subject to the triggered source water monitoring requirements of 12VAC5-590-379 B 1.

2. The owner of a groundwater system that is discontinuing compliance monitoring is still subject to the requirements of 12VAC5-590-380 G.

3. The owner that has been required by the department to provide at least 4-log treatment of viruses shall not discontinue treatment or monitoring.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 28, Issue 5, eff. December 7, 2011; amended, Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-425. (Repealed.)

Historical Notes

Derived from Virginia Register Volume 28, Issue 5, eff. December 7, 2011; repealed, Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-430. Determination of surface water influence of groundwater sources.

A. A groundwater source utilized by a waterworks, including wells, springs, and infiltration galleries, shall be evaluated by the department and a determination of surface water influence shall be made by the department. The owner shall provide to the department all necessary information to make this determination in accordance with the three-step procedure described in subsection B of this section.

B. The groundwater source shall be evaluated and subjected to the criteria in a stepwise fashion. Once the department has made a determination with regard to surface water influence, it is not necessary to continue to the next step:

1. Step 1. Evaluation of source history, construction, and location.

a. The source is under the direct influence of surface water if it has been directly associated with a biological waterborne disease outbreak.

b. The source is under the direct influence of surface water if there are any demonstrated or known direct connections between the source to surface water via surface water bodies, sinkholes, troughs, drainage ways, or other geologic features.

c. The source is under the direct influence of surface water if a sanitary survey reveals, or there is other evidence to indicate, that surface water is directly entering the source.

d. If the department has not determined that the source is influenced by surface water based upon the criteria in subdivisions B 1 a, B 1 b, and B 1 c of this section, then the source evaluation proceeds to Step 2.

2. Step 2. Microbiological water quality.

a. The owner shall collect a series of bacteriological samples directly from the source before any treatment. The specific number of samples to be collected, the sampling frequency, and the duration of sampling shall be determined by the department.

(1) At a minimum, a series of 20 samples collected on a weekly frequency is required. Sample collection may be adjusted within the week to collect samples immediately following rainfall events, whenever possible.

(2) All bacteriological analyses shall be performed by laboratories that have received certification by EPA or DCLS as specified in 12VAC5-590-440 for drinking water samples and by a test method that will yield both total coliform concentration and E. coli concentration.

(3) The department may utilize bacteriological results from source water samples collected in accordance with 12VAC5-590-379 C if the sample results cover at least a 20-week period that includes multiple significant rainfall events for this Step 2 evaluation.

b. The total coliform concentration sample results shall be evaluated as follows:

(1) If the results of the total coliform concentration samples indicate three or more samples with total coliform greater than 100 colonies/100 ml, then the source evaluation proceeds to Step 3.

(2) If the results of the total coliform concentration samples indicate a geometric mean equal to or greater than 100 colonies/100 ml, then the requirements of 12VAC5-590-380 G 2 will apply.

c. The E. coli concentration samples shall be evaluated as follows:

(1) If the results of the E. coli concentration samples indicate greater than or equal to five E. coli per 100 ml in three or more samples, then the source evaluation proceeds to Step 3.

(2) If the results of the E. coli concentration samples indicate the presence of E. coli in five or more samples, then the source evaluation proceeds to Step 3.

3. Step 3. Additional water quality monitoring.

a. The owner shall prepare and submit a written source water monitoring plan to the department for approval detailing additional water quality samples to be collected directly from the source before any treatment and if applicable from a nearby surface water source. The monitoring plan shall include the following:

(1) The specific parameters to be monitored.

(2) The monitoring frequency for each parameter.

(3) The duration of monitoring.

b. The source water monitoring plan shall include microscopic particulate analysis (MPA).

(1) A minimum of four source water MPA tests is required, two to be conducted during a wet period and two to be conducted during a dry period. All MPA tests shall be collected at least 60 days apart.

(2) All MPA tests shall be performed by a laboratory approved by the department and shall include both Giardia lamblia and Cryptosporidium.

(3) All MPA testing and reporting of results shall be in accordance with EPA "Consensus Method for Determining Groundwaters Under the Direct Influence of Surface Water Using Microscopic Particulate Analysis (MPA)," dated October 1992, Environmental Services Division.

c. The source water monitoring plan shall include monitoring of the physical parameters such as temperature, pH, turbidity, conductivity, and other parameters.

(1) If a surface water source is located near the groundwater source being evaluated, then monitoring of the nearby surface water source is required using the same physical parameters and frequency as the groundwater source.

(2) Records of rainfall and other climatological events shall be maintained and reported with the physical parameter results.

d. The owner shall provide the department with all of the monitoring results required in the approved monitoring plan. Results of all MPA tests shall be reported within 10 days of receipt by the owner. If any MPA result indicates the presence of Giardia lamblia or Cryptosporidium, then the owner shall notify the department within 24 hours of receipt. The results of the physical parameter monitoring shall be provided along with applicable rainfall or climatological data to the department in a summary report.

e. The additional water quality monitoring results shall be evaluated as follows:

(1) The source is under the direct influence of surface water if any single MPA test result indicates a score of equal to or greater than 20.

(2) The source is under the direct influence of surface water if any two MPA test results indicate a score of equal to or greater than 15.

(3) The source is under the direct influence of surface water if the results of physical parameter monitoring indicate a correlation between fluctuations in the groundwater source in direct response to a rainfall or other climatological event.

(4) The source is under the direct influence of surface water if the results of physical parameter monitoring indicate a direct correlation between the groundwater source being evaluated and the physical parameters of a nearby surface water source.

(5) The source is a groundwater source and is not under the direct influence of surface water if (i) all MPA test results indicate a score of equal to or less than 9, (ii) there are no fluctuations in source water monitored physical parameters in direct response to a rainfall or other climatological event, and (iii) there is no direct correlation in the monitored physical parameters between the groundwater source being evaluated and a nearby surface water source.

f. If the department has not determined that the source is under the direct influence of surface water based upon the criteria in subdivisions B 3 e (1) through B 3 e (4) of this section, and if at least one of the MPA test results indicate a score of greater than 9 but less than 15, then the department shall evaluate all available water quality monitoring data, source construction, location, geology, and any other relevant factors, and to determine that either:

(1) The source is a groundwater source and is not under the direct influence of surface water; or

(2) The source is at risk and requires continued source water monitoring as prescribed by the department.

C. If the source is subject to the requirements of subdivision B 3 of this section, then the owner shall perform the following interim measures until the department has made a final GUDI determination:

1. Provide disinfection treatment to achieve a 4-log inactivation of virus in accordance with 12VAC5-590-421 A 1 d;

2. Conduct compliance monitoring in accordance with 12VAC5-590-421 C 1;

3. If the disinfection treatment required in subdivision C 1 of this section has to be installed, then the owner shall issue a public notice in accordance with 12VAC5-590-540 A 1 advising consumers to boil the water before using it for human consumption. The boil water notice shall remain in effect until the disinfection treatment is installed and in operation; and

4. The department may require that the owner perform additional interim measures if deemed necessary to protect public health.

D. If the total coliform concentration criteria in subdivision B 2 b of this section or the E. coli concentration criteria in subdivision B 2 c of this section are exceeded or if the department has declared the source to be GUDI, then the owner may propose mitigation measures, a plan to correct deficiencies, or both.

1. Any proposed mitigation measures or corrective actions must be detailed in a report submitted to the department for approval. The report shall be prepared by a professional engineer licensed in Virginia, a professional geologist licensed in Virginia, or other licensed professional approved by the department. The report shall include:

a. A description of the proposed mitigation or corrective action activities such as the repair of structural defects, elimination of sources of contamination in proximity to the source, implementation of source water protection measures, or other mitigation or corrective action activities.

b. Specific milestones and milestone completion dates.

c. A follow-up source water monitoring plan to be implemented upon completion of the mitigation measures or of the corrective actions.

2. If the source must remain in operation during the period of time that the mitigation or corrective action activities are implemented and evaluated, then the department may require that the owner implement the interim measures described in 12VAC5-590-395 A 3 or subdivisions C 1 through C 4 of this section.

3. A final summary report detailing the mitigation measures, the corrective actions, or both that are completed; the results of the follow-up monitoring; conclusions; recommendations; and all other supporting data shall be submitted to the department for approval.

a. The final summary report shall be prepared by a professional engineer licensed in Virginia, a professional geologist licensed in Virginia, or other licensed professional approved by the department.

b. Upon evaluation of the final report and supporting data, the department will make a GUDI determination.

E. For any source previously determined to be a groundwater source and not under the direct influence of surface water, the department may:

1. Require that the source be reevaluated in accordance with procedures contained in this section; or

2. Waive any additional reevaluation under this section.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-004.10 § 2.10, eff. June 23, 1993; amended, Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-440. Analytical methods.

A. All drinking water analyses for compliance purposes shall be performed by analytical methods that are consistent with current EPA regulations found at 40 CFR Part 141 and 40 CFR Part 143. Standards for laboratories seeking certification to perform drinking water analyses are found in the Regulation for the Certification of Laboratories Analyzing Drinking Water (1VAC30-41) and regulations for the Accreditation for Commercial Environmental Laboratories (1VAC30-46) promulgated by the Department of General Services, DCLS.

B. For the purposes of determining compliance, the department will only accept results from samples that have been collected, handled, processed, and documented in accordance with the Regulation for the Certification of Laboratories Analyzing Drinking Water (1VAC30-41) and regulations for the Accreditation for Commercial Environmental Laboratories (1VAC30-46).

C. Testing for alkalinity, calcium, conductivity, residual disinfectant, orthophosphate, pH, silica, temperature, bromide, turbidity, TOC, DOC, SUVA, and UV254 for compliance may be performed by any person or party acceptable to the department in accordance with methods specified in 40 CFR Part 141.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-004.11 § 2.11, eff. June 23, 1993; amended, Virginia Register Volume 12, Issue 2, eff. November 15, 1995; Volume 18, Issue 19, eff. July 3, 2002; Volume 19, Issue 17, eff. June 4, 2003; Volume 19, Issue 24, eff. September 10, 2003; Volume 22, Issue 15, eff. May 3, 2006; Volume 22, Issue 24, eff. September 6, 2006; Volume 25, Issue 5, eff. December 10, 2008; Volume 28, Issue 5, eff. December 7, 2011; Volume 33, Issue 3, eff. November 2, 2016; Volume 37, Issue 20, eff. June 23, 2021.

Article 3
Operation of Waterworks [Repealed]

12VAC5-590-450. Facility and personnel management.

Waterworks operation comprises the constant oversight and management of the facilities and personnel. Consideration shall be given to such factors as the competency of personnel; water quality, including drinking water standards; water treatment plant maintenance and cleanliness; analytical laboratory control; and the operation and maintenance of the facilities, including water treatment plant equipment, distribution system equipment, and piping. As the complexity of the waterworks increases, so does the expertise and skill required of the operating staff.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-005.01 § 2.12, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-460. (Repealed.)

Historical Notes

Derived from VR355-18-005.02 § 2.13, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 28, Issue 5, eff. December 7, 2011; repealed, Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-461. Classification of waterworks, operator requirements, and operator attendance.

A. Classification of waterworks. All community and NTNC waterworks, including consecutive waterworks, fitting the classification protocol in this subsection shall be designated as classified waterworks. The department retains the discretion to assign the classification of the waterworks or treatment facility either higher or lower. Those community and NTNC waterworks failing to fall within one of the classifications listed in this subsection shall be designated an unclassified waterworks unless specified otherwise by the department. Normally, a TNC waterworks shall not be classified and shall not be required to have an operator unless the department determines that it is necessary to ensure satisfactory operation of the installed treatment. If a waterworks consists of multiple treatment facilities, then these facilities may be individually classified for the purpose of determining the operator requirements.

1. Class 1 means:

a. A waterworks or a water treatment plant serving 50,000 or more persons, or having a water treatment plant capacity of 5.0 MGD or more and employing conventional filtration or chemical coagulation in combination with membrane filtration; or

b. A waterworks designated by the department to be a Class 1 waterworks.

2. Class 2 means:

a. A waterworks or a water treatment plant serving 5,000 or more persons but fewer than 50,000 persons or having a water treatment plant capacity of 0.5 MGD or more but less than 5.0 MGD, whichever range applies, and employing rapid rate conventional filtration (see 12VAC5-590-874) or chemical coagulation in combination with membrane filtration;

b. A waterworks or a water treatment plant serving fewer than 50,000 persons or having a water treatment plant capacity of less than 5.0 MGD and employing high rate conventional filtration (see 12VAC5-590-874); or

c. A waterworks designated by the department to be a Class 2 waterworks.

3. Class 3 means:

a. A waterworks or a water treatment plant serving fewer than 5,000 persons or having a water treatment plant capacity less than 0.5 MGD, whichever is greater, and employing conventional filtration or chemical coagulation in combination with membrane filtration;

b. A waterworks or a water treatment plant serving 5,000 or more persons or having a water treatment plant capacity of 0.5 MGD or more, whichever is greater, and employing one or more of the following: disinfection other than with hypochlorination, caustic soda feed, iron and manganese removal, ion exchange, slow sand filtration, aeration, rechlorination other than with hypochlorination, activated carbon contactors, membrane or other filtration technologies without chemical coagulation, and fluoridation with a saturator or acid feed;

c. A waterworks or a water treatment plant employing fluoridation with other than a saturator not considered a Class 1 or Class 2 waterworks; or

d. A waterworks designated by the department to be a Class 3 waterworks.

4. Class 4 means:

a. A waterworks or a water treatment plant serving fewer than 5,000 persons or having a water treatment plant capacity of less than 0.5 MGD and employing one or more of the following: disinfection other than with hypochlorination, caustic soda feed, iron and manganese removal, ion exchange, slow sand filtration, aeration, rechlorination other than with hypochlorination, activated carbon contactors, membrane or other filtration technologies without chemical coagulation, and fluoridation with a saturator; or

b. A waterworks designated by the department to be a Class 4 waterworks.

5. Class 5 means:

a. A waterworks serving 400 or more persons that:

(1) Provides no treatment; or

(2) Employs one or more of the following treatment processes:

(a) Hypochlorination for disinfection;

(b) Corrosion control with calcite or magnesium oxide contactors or solution feed except with caustic soda; or

(c) Sequestration by solution feed.

b. A waterworks designated by the department to be a Class 5 waterworks.

6. Class 6 means:

a. A waterworks serving fewer than 400 persons that:

(1) Provides no treatment; or

(2) Employs one or more of the following treatment processes:

(a) Hypochlorination for disinfection;

(b) Corrosion control with calcite or magnesium oxide contactors or solution feed except with caustic soda; or

(c) Sequestration by solution feed.

b. A waterworks is designated by the department to be a Class 6 waterworks.

B. Operator requirements. The operation of all waterworks must rest in the hands of qualified staff. The number and qualifications of persons constituting the operating staff at a waterworks depend principally upon the capacity of the waterworks, the number of persons served by the waterworks, and the complexity of the treatment process or processes. If a classified waterworks or water treatment plant is without a required operator, then the owner shall notify the department as soon as practical but no later than 24 hours of such an occurrence.

1. The operator attendance requirements specified in subsection C of this section are a minimum to protect the health of the consumer and safety of the operating staff. The department may increase the required operating attendance when appropriate to protect human health.

2. A classified waterworks shall be operated by an operator having a valid license issued by the Commonwealth of Virginia (18VAC160-30-90) with a classification equal to or higher than the classification of the waterworks or water treatment plant being operated. (See definition of operator in 12VAC5-590-10).

3. Operators are not required at unclassified waterworks.

C. Minimum operator attendance at classified waterworks. For the purpose of this section and 12VAC5-590-570, all classified waterworks or individual water treatment plants shall maintain the minimum operator attendance as follows:

1. Class 1. The waterworks shall have a minimum of two operating staff in attendance whenever the water treatment plant is in operation; at least one of the operating staff must be an operator.

2. Class 2. The waterworks shall have a minimum of one operator in attendance whenever the water treatment plant is in operation.

3. Class 3. The waterworks employing conventional filtration or chemical coagulation in combination with membrane filtration shall have a minimum of one operator in attendance whenever the water treatment plant is in operation. All other treatment facilities may have operator attendance similar to a Class 4 waterworks.

4. Class 4. The waterworks shall be attended by an operator at least three days per week, except that water treatment plants employing membrane filters treating surface water sources or GUDI sources shall be attended by an operator daily. The attendance shall be for sufficient time to perform the necessary operations, monitoring, and maintenance.

5. Class 5 and Class 6.

a. Where no treatment is provided, the waterworks shall be attended by an operator at least twice a month.

b. When treatment is provided, the waterworks shall be attended by an operator at least once per week.

c. The attendance shall be for sufficient time to perform the necessary operations, monitoring, and maintenance.

D. Operator attendance alternatives.

1. Increased staffing attendance may be required by the department on a case-by-case basis to protect public health.

2. Reduced operator attendance for Class 3 through Class 6 waterworks may be considered by the department on a case-by-case basis.

3. When requiring increased operator attendance or considering reduced operator attendance the department will consider the following criteria, including:

a. Operational history;

b. Type of treatment;

c. Facility capacity and hours of operation;

d. Population served;

e. Type and reliability of remote monitoring controls, alarms, and communications;

f. Reliable staff communications; and

g. Emergency response plans and procedures.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-470. Waterworks condition.

The waterworks shall be maintained in a clean and orderly condition.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-005.03 § 2.14, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-475. Removal of wells from service.

A. Temporary inactivation.

1. A water well temporarily inactivated shall be sealed with a watertight cap or wellhead seal.

2. The well shall be maintained so that it will not be a source or channel for contamination during temporary inactivation.

3. The wellhead shall be visually inspected and observations documented to verify adequate sanitary integrity on a quarterly basis.

4. The well lot shall be maintained.

B. Permanent abandonment.

1. Well abandonment shall be supervised by a certified water well systems provider.

2. All well abandonments shall be documented on a Uniform Water Well Completion Report, Form GW-2, and submitted to the department within 30 days of completing the physical abandonment.

3. Groundwater wells that are abandoned shall be sealed by methods that will restore to the fullest extent possible the controlling geological conditions that existed before the wells were constructed.

4. Casing and screen materials may be salvaged.

5. The well shall be checked from land surface to the entire depth of the well before it is sealed to ascertain freedom from obstructions that may interfere with sealing operations. Effort shall be made to remove or clear any obstacles that may prohibit sealing by grouting the complete well depth.

6. The well shall be thoroughly chlorinated before sealing.

7. Bored wells and uncased wells shall be backfilled with clean fill to the water level. A two-foot-thick bentonite grout plug shall be placed immediately above the water level. Clean fill shall be placed on top of the bentonite grout plug and brought up to at least five feet from the ground surface. The top five feet of the well casing, if present, shall be removed from the bore hole. If an open annular space is present around the well casing, then the annular space shall be filled with bentonite grout to the maximum depth possible, but less than or equal to 20 feet. A one-foot-thick cement or bentonite grout plug that completely fills the bore void space shall be placed a minimum of five feet from the ground surface. As an alternative, bored wells and uncased wells may be completely filled with concrete, sand-cement, bentonite-cement, or neat cement grout to within a minimum of five feet from the ground surface by introduction through a pipe initially extending to the bottom of the well. The pipe shall be raised but remain submerged in grout or concrete as the well is filled. The remaining space shall be filled with clean fill that is mounded a minimum of one foot above the surrounding ground surface.

8. Non-bored wells constructed in unconsolidated formations shall be completely filled with concrete, sand-cement, bentonite-cement, or neat cement grout to within a minimum of five feet from the ground surface by introduction through a pipe initially extending to the bottom of the well. The pipe shall be raised but remain submerged in grout or concrete as the well is filled. The remaining space shall be filled with clean fill that is mounded a minimum of one foot above the surrounding ground surface.

9. Wells constructed in consolidated rock formations or that penetrate zones of consolidated rock may be filled with sand or gravel opposite the zones of consolidated rock. The top of the sand or gravel fill shall be at least five feet below the top of the consolidated rock and at least 20 feet below land surface. The remainder of the well shall be filled with concrete, sand-cement, bentonite-cement, or neat cement grout to within a minimum of five feet from the ground surface by introduction through a pipe initially extending to the bottom of the well. The pipe shall be raised but remain submerged in grout or concrete as the well is filled. The remaining space shall be filled with clean fill that is mounded a minimum of one foot above the surrounding ground surface.

10. The location of the well shall be permanently documented for future reference.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-476. Reactivation of wells.

A. The owner shall notify the department of the intent to reactivate a well.

B. Before bringing the well into service, the well shall be pumped to waste (purged) for a minimum of five well volumes but for not less than 30 minutes. The purged well water shall be discharged in a manner so that it will not return to the well, directly or indirectly, during the pumping period.

C. After the well is pumped, water quality samples shall be collected. If the well has been inactive for less than one year, then two samples shall be collected at least 30 minutes apart and tested for the presence of E. coli. If the well has been inactive for one or more years, then it shall be tested for total coliform density (MPN), nitrate, and, if determined by the department, inorganics, VOCs, SOCs, and radionuclides. Satisfactory test results shall be obtained before placing the well in service.

D. A well yield and drawdown test may be required by the department before bringing the well into service. The test shall be performed in accordance with 12VAC5-590-840 H, as applicable.

E. A well may be activated for emergency use before receipt of satisfactory monitoring results, even if public health and safety are unknowns and may be at risk, as determined by the department. However, in these circumstances, a special water advisory shall be approved by the department and issued by the waterworks at the same time the well is activated.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-480. Operational control testing and monitoring.

A. Water analyses and tests performed at waterworks are conducted for four main purposes: (i) to ensure compliance; (ii) to control water treatment plant operation; (iii) to record water treatment plant performance; and (iv) to provide information for improving water treatment plant performance. Tests designed to control operation shall present evidence that:

1. Each key process, such as mixing, coagulation, sedimentation, filtration, softening, iron and manganese removal, disinfection, and taste and odor control, is effective; and

2. The finished product is clean, is free from objectionable taste and odor, is free from undesirable chemical characteristics, and is safe for human consumption.

B. Testing for regulatory compliance purposes shall use an EPA-approved analytical method found in 40 CFR Parts 141 and 143. Instruments used for operational control purposes must be calibrated in accordance with manufacturer instructions. Calibrations shall be documented in a manner acceptable to the department.

C. Ample laboratory space shall be provided for all required laboratory analyses as specified in 12VAC5-590-760.

D. Required waterworks onsite laboratory analyses. The analyses listed in this subsection are the minimum required. Additional testing may be required by the department.

1. The owner of a waterworks employing chemical coagulation or lime softening in combination with any filtration treatment for turbidity removal or TOC reduction shall provide equipment for the analysis of pH, alkalinity, hardness, turbidity, water temperature, and coagulant dosage. A calibrated electric pH meter must be provided; however, a color comparator may be used as a backup unit. Turbidities must be determined by the use of a calibrated turbidimeter.

2. The owner of a waterworks employing membrane filtration without chemical coagulation or lime softening shall provide equipment for the analysis of turbidity and temperature. Turbidities shall be determined by the use of a calibrated turbidimeter.

3. The owner of a waterworks employing softening only and utilizing chemical precipitation shall provide equipment for the analysis of pH utilizing a calibrated electric pH meter, alkalinity, hardness, water temperature, and chemical dosage for precipitation utilizing a multiple jar stirring machine.

4. The owner of a waterworks employing iron and manganese removal by chemical precipitation shall provide equipment for the analysis of pH, alkalinity, iron, manganese, and water temperature.

5. The owner of a waterworks employing fluoridation shall provide equipment for the analysis of the fluoride ion concentration and water temperature.

6. The owner of a waterworks employing chlorination, rechlorination, chloramination, or rechloramination shall provide equipment for the analysis of the appropriate chlorine residual measurement and temperature.

7. The owner of a waterworks employing iron and manganese removal by ion exchange or softening by ion exchange shall provide equipment for the analysis of iron and manganese.

E. Process control instruments, monitors, gauges, and controllers, including reading, recording, and alarm features, required in Part III, Manual of Practice (12VAC5-590-640 et seq.), shall be maintained fully operational and calibrated in accordance with the manufacturer instructions.

1. The owner of a waterworks employing UV for inactivation credit shall perform UV sensor calibration checks. Calibrations and instrument checks shall be documented in a manner acceptable to the department. All UV sensors shall be calibrated with a reference UV sensor at least monthly. It is also recommended that offline and standby sensors be calibrated at the same time. At least one reference sensor for calibration of online sensors shall be provided. The reference UV sensor shall be calibrated at least yearly at a qualified facility, usually the manufacturer. Ultraviolet transmittance (UVT) analyzer calibration is required when used as a control instrument. The UVT analyzer shall be calibrated at least weekly by comparing online measurements to a benchtop spectrophotometer that is calibrated in accordance with manufacturer instructions. Instead of an online UVT analyzer, a benchtop spectrophotometer may be utilized to determine UV transmittance at least every four hours.

2. The owner of a waterworks employing ozone for inactivation credit shall perform calibration checks on continuous, online ozone residual monitors at least weekly. Inactivation credits for a multiple chamber contactor shall be based on only the chambers that have a measured ozone residual greater than 0.02 mg/L or higher, depending on residual analysis instrumentation.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-005.04 § 2.15, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-490. Adequate treatment.

A. Adequate treatment is any one or any combination of the controlled processes of coagulation, sedimentation, absorption, filtration, disinfection, or other processes that produce water consistently meeting the requirements of this chapter. The concept of adequate treatment also includes processes that are appropriate to (i) the source water; (ii) waterworks that are of adequate capacity to meet maximum demands without creating health hazards and that are located, designed, and constructed to eliminate or prevent cross-connections; and (iii) the conscientious operation by well-trained and competent personnel whose qualifications are commensurate with the responsibilities of the position and acceptable to the department.

B. A waterworks shall provide adequate treatment when required and in accordance with 12VAC5-590-680 to ensure the production of potable water.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-005.05 § 2.16, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-500. Disinfection criteria, determination of CT, disinfection profiles, and disinfection benchmarks for Giardia and virus inactivation.

A. A waterworks utilizing surface water sources or GUDI sources, in whole or in part, shall be disinfected in accordance with subsection C of this section and 12VAC5-590-1000.

B. The owner of a groundwater system subject to the requirements of 12VAC5-590-421 A 1 d shall provide primary disinfection treatment by means of one of the following:

1. A residual disinfectant concentration (C) and contact time (T) to achieve a 4-log removal or inactivation of viruses. CT shall be calculated in accordance with subsections C and D of this section, which contain information on calculation methods and contact tank baffling factors.

2. UV treatment to achieve a 4-log removal or inactivation of viruses. Log inactivation shall be determined in accordance with 12VAC5-590-401 E 7 c. A secondary disinfection residual in the distribution system may be required by the department.

C. Disinfection criteria.

1. An owner of a waterworks utilizing surface water sources, in whole or in part, or GUDI sources shall provide a minimum 3-log (99.9%) removal of Giardia cysts and a 4-log (99.99%) removal of viruses, respectively.

2. Additional inactivation levels that must be achieved by disinfection shall be in accordance with Table 500.1 for waterworks employing the filtration processes listed.

TABLE 500.1
Maximum Log Removal Credits for Various Filtration Technologies and the Resulting Minimum Required Logs of Inactivation by Disinfection

FILTRATION PROCESSa

MAXIMUM LOG REMOVAL CREDITS FOR FILTRATION

ADDITIONAL LOG INACTIVATION REQUIRED BY DISINFECTION

Giardia lamblia

Viruses

Giardia lamblia

Viruses

Conventional

2.5

2.0

0.5

2.0

Direct

2.0

1.0

1.0

3.0

Pre-engineered package

2.5

Zero

0.5

4.0

Diatomaceous Earth

2.0

1.0

1.0

3.0

Slow Sand

2.0

2.0

1.0

2.0

Membrane (MF or UF)

3.0

Zero

0.5

4.0

Bag or Cartridge

2.0

Zero

1.0

4.0

aRefer to Part III of this chapter for further description of the filtration processes.

D. A disinfection profile shall be developed in accordance with the procedures in subdivisions D 1, D 2, and D 3.

1. The owner shall monitor at least weekly for a period of 12 consecutive months to determine the total log inactivation for Giardia lamblia and viruses. If an owner monitors more frequently, then the monitoring frequency shall be evenly spaced. An owner of a waterworks that operates for fewer than 12 months per year shall monitor weekly during the period of operation.

2. The owner of a waterworks with a single point of disinfectant application before the entrance to the distribution system or with more than one point of disinfectant application shall conduct the monitoring in subdivisions D 2 a through D 2 e of this section.

a. For a waterworks using a disinfectant other than UV, the temperature of the disinfected water shall be measured at each residual disinfectant concentration sampling point during peak hourly flow or at an alternative location approved by the department.

b. For a waterworks using chlorine, the pH of the disinfected water shall be measured at each chlorine residual disinfectant concentration sampling point during peak hourly flow or at an alternative location approved by the department.

c. The residual disinfectant concentration (C) of the water before or at the first customer and before each additional point of disinfectant application shall be measured at peak hourly flow.

d. The disinfectant contact times (T) of the water before or at the first customer and before each additional point of disinfectant application shall be determined during peak hourly flow. The disinfectant contact time to be used for calculating CT is T10, which is the detention time at which 90% of the water passing through a unit is retained within that unit. T10 shall be determined either by calculations that involve the theoretical hydraulic detention time and baffling factors that account for the degree of short-circuiting that might be expected through any given unit or by tracer studies. The baffling factors listed in Table 500.15 shall be used in determining contact time if tracer studies are not performed.

e. Inactivation credits for ozone contactors will be based on only the chambers that have a measured ozone residual. A minimum of two dedicated online monitors per ozone contactor shall be installed at locations suited to the CT calculation method used. Ozone residual levels shall be monitored continuously and recorded. Methods for computing log inactivation of Giardia lamblia and virus shall be approved by the department. Tracer studies shall be required to verify T10 values before receiving inactivation credit.

3. Instead of conducting new monitoring under subdivision D 2 of this section, an owner may elect to meet the requirements of subdivision D 3 a or D 3 b of this section.

a. The owner who has at least one year of existing data that are substantially equivalent to data collected under the provisions of subdivision D 3 of this section shall use these data to develop disinfection profiles if the owner has neither made a significant change to the treatment practice nor changed sources since the data were collected. The owner may develop a disinfection profile using up to three years of existing data.

b. The owner may use a disinfection profile developed previously in accordance with the procedures in subdivisions D 1, D 2, and D 3 of this section, if the owner has neither made a change to the treatment practice nor changed sources since the profile was developed. An owner that has not developed a virus profile shall develop a virus disinfection profile using the same monitoring data on which the Giardia lamblia profile is based.

E. The owner shall calculate the total inactivation ratio for Giardia lamblia and viruses as specified in subdivisions E 1 through E 4 of this subsection based on CT99.9 (3-log) values using the appropriate values in Tables 500.2 through 500.14. Note that the 3-log values in the tables for Giardia lamblia also indicate that a 4-log virus inactivation can be achieved. pH and temperature values between the indicated values in Tables 500.2 through 500.14 shall be determined by linear interpolation, or the CT value at the lower temperature and at the higher pH shall be used. All parameters necessary to determine the total inactivation ratio shall be monitored during peak hourly flow.

1. The owner using only one point of disinfectant application shall determine the total inactivation ratio for the disinfection segment based on either of the following methods:

a. Determine one inactivation ratio (CTcalc/CT99.9) before or at the first customer during peak hourly flow.

b. Determine successive CTcalc/CT99.9 values, representing sequential inactivation ratios, between the point of disinfectant application and a point before or at the first customer during peak hourly flow. The owner shall calculate the total inactivation ratio by determining (CTcalc/CT99.9) for each sequence and then adding the (CTcalc/CT99.9) values together to determine total inactivation (∑ (CTcalc/CT99.9)).

2. The owner using more than one point of disinfectant application before the first customer shall determine the CT value of each disinfection segment immediately before the next point of disinfectant application, or for the final segment before or at the first customer, during peak hourly flow. The (CTcalc/CT99.9) value of each segment and (∑ (CTcalc/CT99.9)) shall be calculated using the method in subdivision E 1 a or E 1 b of this subsection.

3. The owner shall determine the total logs of inactivation of Giardia lamblia by multiplying the value calculated in subdivision E 1 a or E 1 b of this subsection by 3.0.

4. The owner shall determine the total logs of inactivation of viruses by multiplying the value calculated in subdivision E 1 a or E 1 b of this subsection by 4.0.

F. A disinfection benchmark shall be calculated following the procedures in subdivisions F 1, F 2, and F 3 of this subsection.

1. For each year of profiling data collected and calculated, an owner shall determine the lowest mean monthly level of both Giardia lamblia and virus inactivation. The owner shall determine the mean Giardia lamblia and virus inactivation for each calendar month for each year of profiling data by dividing the sum of daily or weekly Giardia lamblia and virus log inactivation by the number of values calculated for that month.

2. The disinfection benchmark is the lowest monthly mean value (for waterworks with one year of profiling data) or the mean of the lowest monthly mean values (for waterworks with more than one year of profiling data) of Giardia lamblia and virus log inactivation in each year of profiling data.

3. The owner of a waterworks using chloramines, ozone, or chlorine dioxide for primary disinfection shall calculate the disinfection benchmark for viruses from the data collected in the same manner used to calculate the Giardia lamblia disinfection benchmark.

G. The owner shall retain the disinfection profile in graphic form, as a spreadsheet or in some other format acceptable to the department for evaluation as part of sanitary surveys conducted by the department.

H. Before making a significant change to the waterworks disinfection practice, the owner shall review the disinfection benchmark and consult with the department.

1. Significant changes to disinfection practice are (i) changes to the point of disinfectant application, (ii) changes to the disinfectants used in the treatment plant, (iii) changes to the disinfection process, and (iv) any other modification identified by the department.

2. The owner shall submit the following information to the department as part of the consultation process: (i) a description of the proposed change; (ii) the disinfection profile and benchmarks established for Giardia lamblia and, if necessary, viruses; (iii) an analysis of how the proposed change will affect the current levels of disinfection; and (iv) any additional information to justify the change.

TABLE 500.2
CT Values for 3-Log Inactivation of Giardia lamblia by Free Chlorine at Less than 0.5oC

FREE RESIDUAL
(mg/L)

pH

≤ 6.06.5

7.0

7.5

8.0

8.5

≤ 9.0

≤ 0.4

137

163

195

237

277

329

390

0.6

141

168

200

239

286

342

407

0.8

145

172

205

246

295

354

422

1.0

148

176

210

253

304

365

437

1.2

152

180

215

259

313

376

451

1.4

155

184

221

266

321

387

464

1.6

157

189

226

273

329

397

477

1.8

162

193

231

279

338

407

489

2.0

165

197

236

286

346

417

500

2.2

169

201

242

297

353

426

511

2.4

172

205

247

298

361

435

522

2.6

175

209

252

304

368

444

533

2.8

178

213

257

310

375

452

543

3.0

181

217

261

316

382

460

552

TABLE 500.3
CT Values for 3-Log Inactivation of Giardia lamblia by Free Chlorine at 5oC

FREE RESIDUAL

(mg/L)

pH

≤ 6.0

6.5

7.0

7.5

8.0

8.5

≤ 9.0

≤ 0.4

97

117

139

166

198

236

279

0.6

100

120

143

171

204

244

291

0.8

103

122

146

175

210

252

301

1.0

105

125

149

179

216

260

312

1.2

107

127

152

183

221

267

320

1.4

109

130

155

187

227

274

329

1.6

111

132

158

192

232

281

337

1.8

114

135

162

196

238

287

345

2.0

116

138

165

200

243

294

353

2.2

118

140

169

204

248

300

361

2.4

120

143

172

209

253

306

368

2.6

122

146

175

213

258

312

375

2.8

124

148

178

217

263

318

382

3.0

126

151

182

221

268

324

389

TABLE 500.4
CT Values for 3-Log Inactivation of Giardia lamblia by Free Chlorine at 10oC

FREE RESIDUAL

(mg/L)

pH

≤ 6.0

6.5

7.0

7.5

8.0

8.5

≤ 9.0

≤ 0.4

73

88

104

125

149

177

209

0.6

75

90

107

128

153

183

218

0.8

78

92

110

131

158

189

226

1.0

79

94

112

134

162

195

234

1.2

80

95

114

137

166

200

240

1.4

82

98

116

140

170

206

247

1.6

83

99

119

144

174

211

253

1.8

86

101

122

147

179

215

259

2.0

87

104

124

150

182

221

265

2.2

89

105

127

153

186

225

271

2.4

90

107

129

157

190

230

276

2.6

92

110

131

160

194

234

281

2.8

93

111

134

163

197

239

287

3.0

95

113

137

166

201

243

292

TABLE 500.5
CT Values for 3-Log Inactivation of Giardia lamblia by Free Chlorine at 15oC

FREE RESIDUAL

(mg/L)

pH

≤ 6.0

6.5

7.0

7.5

8.0

8.5

≤ 9.0

≤ 0.4

49

59

70

83

99

118

140

0.6

50

60

72

86

102

122

146

0.8

52

61

73

88

105

126

151

1.0

53

63

75

90

108

130

156

1.2

54

64

76

92

111

134

160

1.4

55

65

78

94

114

137

165

1.6

56

66

79

96

116

141

169

1.8

57

68

81

98

119

144

173

2.0

58

69

83

100

122

147

177

2.2

59

70

85

102

124

150

181

2.4

60

72

86

105

127

153

184

2.6

61

73

88

107

129

156

188

2.8

62

74

89

109

132

159

191

3.0

63

76

91

111

134

162

195

TABLE 500.6
CT Values for 3-Log Inactivation of Giardia lamblia by Free Chlorine at 20oC

FREE RESIDUAL

(mg/L)

pH

≤ 6.0

6.5

7.0

7.5

8.0

8.5

≤ 9.0

≤ 0.4

36

44

52

62

74

89

105

0.6

38

45

54

64

77

92

109

0.8

39

46

55

66

79

95

113

1.0

39

47

56

67

81

98

117

1.2

40

48

57

69

83

100

120

1.4

41

49

58

70

85

103

123

1.6

42

50

59

72

87

105

126

1.8

43

51

61

74

89

108

129

2.0

44

52

62

75

91

110

132

2.2

44

53

63

77

93

113

135

2.4

45

54

65

78

95

115

138

2.6

46

55

66

80

97

117

141

2.8

47

56

67

81

99

119

143

3.0

47

57

68

83

101

122

146

TABLE 500.7
CT Values for 3-Log Inactivation of Giardia lamblia by Free Chlorine at 25oC and Higher

FREE RESIDUAL

(mg/L)

pH

≤ 6.0

6.5

7.0

7.5

8.0

8.5

≤ 9.0

≤ 0.4

24

29

35

42

50

59

70

0.6

25

30

36

43

51

61

73

0.8

26

31

37

44

53

63

75

1.0

26

31

37

45

54

65

78

1.2

27

32

38

46

55

67

80

1.4

27

33

39

47

57

69

82

1.6

28

33

40

48

58

70

84

1.8

29

34

41

49

60

72

86

2.0

29

35

41

50

61

74

88

2.2

30

35

42

51

62

75

90

2.4

30

36

43

52

63

77

92

2.6

31

37

44

53

65

78

94

2.8

31

37

45

54

66

80

96

3.0

32

38

46

55

67

81

97

TABLE 500.8
CT Values for Inactivation of Viruses by Free Chlorine, pH 6.0-9.0

LOG INACTIVATION CREDIT

WATER TEMPERATURE (°C)

0.5

1

2

3

4

5

6

7

8

2

6.0

5.8

5.3

4.9

4.4

4.0

3.8

3.6

3.4

3

9.0

8.7

8.0

7.3

6.7

6.0

5.6

5.2

4.8

4

12.0

11.6

10.7

9.8

8.9

8.0

7.6

7.2

6.8

LOG INACTIVATION CREDIT

WATER TEMPERATURE (°C)

9

10

11

12

13

14

15

16

17

2

3.2

3.0

2.8

2.6

2.4

2.2

2.0

1.8

1.6

3

4.4

4.0

3.8

3.6

3.4

3.2

3.0

2.8

2.6

4

6.4

6.0

5.6

5.2

4.8

4.4

4.0

3.8

3.6

LOG INACTIVATION CREDIT

WATER TEMPERATURE (°C)

18

19

20

21

22

23

24

25

2

1.4

1.2

1.0

1.0

1.0

1.0

1.0

1.0

3

2.4

2.2

2.0

1.8

1.6

1.4

1.2

1.0

4

3.4

3.2

3.0

2.8

2.6

2.4

2.2

2.0

TABLE 500.9
CT Values for Inactivation of Giardia lamblia by Chlorine Dioxide, pH 6.0-9.0

LOG INACTIVATION CREDIT

WATER TEMPERATURE (°C)

1

2

3

4

5

6

7

8

9

0.5

10.0

8.6

7.2

5.7

4.3

4.2

4.2

4.1

4.1

1

21.0

17.9

14.9

11.8

8.7

8.5

8.3

8.1

7.9

1.5

32.0

27.3

22.5

17.8

13.0

12.8

12.6

12.4

12.2

2

42.0

35.8

29.5

23.3

17.0

16.6

16.2

15.8

15.4

2.5

52.0

44.5

37.0

29.5

22.0

21.4

20.8

20.2

19.6

3

63.0

53.8

44.5

35.3

26.0

25.4

24.8

24.2

23.6

LOG INACTIVATION CREDIT

WATER TEMPERATURE (°C)

10

11

12

13

14

15

16

17

18

0.5

4.0

3.8

3.7

3.5

3.4

3.2

3.1

2.9

2.8

1

7.7

7.4

7.1

6.9

6.6

6.3

6.0

5.8

5.5

1.5

12.0

11.6

11.2

10.8

10.4

10.0

9.5

9.0

8.5

2

15.0

14.6

14.2

13.8

13.4

13.0

12.4

11.8

11.2

2.5

19.0

3.8

3.7

3.5

3.4

3.2

3.1

2.9

2.8

3

23.0

7.4

7.1

6.9

6.6

6.3

6.0

5.8

5.5

LOG INACTIVATION CREDIT

WATER TEMPERATURE (°C)

19

20

21

22

23

24

25

0.5

2.6

2.5

2.4

2.3

2.2

2.1

2.0

1

5.3

5.0

4.7

4.5

4.2

4.0

3.7

1.5

8.0

7.5

7.1

6.7

6.3

5.9

5.5

2

10.6

10.0

9.5

8.9

8.4

7.8

7.3

2.5

2.6

2.5

12.2

11.4

10.6

9.8

9.0

3

5.3

5.0

14.2

13.4

12.6

11.8

11.0

TABLE 500.10
CT Values for Inactivation of Virus by Chlorine Dioxide, pH 6.0-9.0

LOG INACTIVATION CREDIT

WATER TEMPERATURE (°C)

1

2

3

4

5

6

7

8

9

2

8.4

7.7

7.0

6.3

5.6

5.3

5.0

4.8

4.5

3

25.6

23.5

21.4

19.2

17.1

16.2

15.4

14.5

13.7

4

50.1

45.9

41.8

37.6

33.4

31.7

30.1

28.4

26.8

LOG INACTIVATION CREDIT

WATER TEMPERATURE (°C)

10

11

12

13

14

15

16

17

18

2

4.2

3.9

3.6

3.4

3.1

2.8

2.7

2.5

2.4

3

12.8

12.0

11.1

10.3

9.4

8.6

8.2

7.7

7.3

4

25.1

23.4

21.7

20.1

18.4

16.7

15.9

15.0

14.2

LOG INACTIVATION CREDIT

WATER TEMPERATURE (°C)

19

20

21

22

23

24

25

2

2.2

2.1

2.0

1.8

1.7

1.5

1.4

3

6.8

6.4

6.0

5.6

5.1

4.7

4.3

4

13.3

12.5

11.7

10.9

10.0

9.2

8.4

TABLE 500.11
CT Values for Inactivation of Giardia lamblia by Chloramines, pH 6.0-9.0

LOG INACTIVATION CREDIT

WATER TEMPERATURE (°C)

1

2

3

4

5

6

7

8

9

0.5

635

568

500

433

365

354

343

332

321

1

1,270

1,136

1,003

869

735

711

687

663

639

1.5

1,900

1,700

1,500

1,300

1,100

1,066

1,032

998

964

2

2,535

2,269

2,003

1,736

1,470

1,422

1,374

1,326

1,278

2.5

3,170

2,835

2,500

2,165

1,830

1,772

1,714

1,656

1,598

3

3,800

3,400

3,000

2,600

2,200

2,130

2,060

1,990

1,920

LOG INACTIVATION CREDIT

WATER TEMPERATURE (°C)

10

11

12

13

14

15

16

17

18

0.5

310

298

286

274

262

250

237

224

211

1

615

592

569

546

523

500

474

448

422

1.5

930

894

858

822

786

750

710

670

630

2

1,230

1,184

1,138

1,092

1,046

1,000

947

894

841

2.5

1,540

1,482

1,424

1,366

1,308

1,250

1,183

1,116

1,049

3

1,850

1,780

1,710

1,640

1,570

1,500

1,420

1,340

1,260

LOG INACTIVATION CREDIT

WATER TEMPERATURE (°C)

19

20

21

22

23

24

25

0.5

198

185

173

161

149

137

125

1

396

370

346

322

298

274

250

1.5

590

550

515

480

445

410

375

2

788

735

688

641

594

547

500

2.5

982

915

857

799

741

683

625

3

1,180

1,100

1,030

960

890

820

750

TABLE 500.12
CT Values for Inactivation of Virus by Chloramines, pH 6.0-9.0

LOG INACTIVATION CREDIT

WATER TEMPERATURE (°C)

1

2

3

4

5

6

7

8

9

2

1,243

1,147

1,050

954

857

814

771

729

686

3

2,063

1,903

1,743

1,583

1,423

1,352

1,281

1,209

1,138

4

2,883

2,659

2,436

2,212

1,988

1,889

1,789

1,690

1,590

LOG INACTIVATION CREDIT

WATER TEMPERATURE (°C)

10

11

12

13

14

15

16

17

18

2

643

600

557

514

471

428

407

385

364

3

1,067

996

925

854

783

712

676

641

605

4

1,491

1392

1292

1193

1,093

994

944

895

845

LOG INACTIVATION CREDIT

WATER TEMPERATURE (°C)

19

20

21

22

23

24

25

2

342

321

300

278

257

235

214

3

570

534

498

463

427

392

356

4

796

746

696

646

597

547

497

TABLE 500.13
CT Values for Inactivation of Giardia lamblia by Ozone

LOG INACTIVATION CREDIT

WATER TEMPERATURE (°C)

1

2

3

4

5

6

7

8

9

0.5

0.48

0.44

0.40

0.36

0.32

0.30

0.28

0.27

0.25

1

0.97

0.89

0.80

0.72

0.63

0.60

0.57

0.54

0.51

1.5

1.50

1.36

1.23

1.09

0.95

0.90

0.86

0.81

0.77

2

1.90

1.75

1.60

1.45

1.30

1.23

1.16

1.09

1.02

2.5

2.40

2.20

2.00

1.80

1.60

1.52

1.44

1.36

1.28

3

2.90

2.65

2.40

2.15

1.90

1.81

1.71

1.62

1.52

LOG INACTIVATION CREDIT

WATER TEMPERATURE (°C)

10

11

12

13

14

15

16

17

18

0.5

0.23

0.22

0.20

0.19

0.17

0.16

0.15

0.14

0.14

1

0.48

0.45

0.42

0.38

0.35

0.32

0.30

0.29

0.27

1.5

0.72

0.67

0.62

0.58

0.53

0.48

0.46

0.43

0.41

2

0.95

0.89

0.82

0.76

0.69

0.63

0.60

0.57

0.54

2.5

1.20

1.12

1.04

0.95

0.87

0.79

0.75

0.71

0.68

3

1.43

1.33

1.24

1.14

1.05

0.95

0.90

0.86

0.81

LOG INACTIVATION CREDIT

WATER TEMPERATURE (°C)

19

20

21

22

23

24

25

0.5

0.13

0.12

0.11

0.10

0.10

0.09

0.08

1

0.26

0.24

0.22

0.21

0.19

0.18

0.16

1.5

0.38

0.36

0.34

0.31

0.29

0.26

0.24

2

0.51

0.48

0.45

0.42

0.38

0.35

0.32

2.5

0.64

0.60

0.56

0.52

0.48

0.44

0.40

3

0.13

0.12

0.11

0.10

0.10

0.09

0.08

TABLE 500.14
CT Values for Inactivation of Virus by Ozone

LOG INACTIVATION CREDIT

WATER TEMPERATURE (°C)

1

2

3

4

5

6

7

8

9

2

0.90

0.83

0.75

0.68

0.60

0.58

0.56

0.54

0.52

3

1.40

1.28

1.15

1.03

0.90

0.88

0.86

0.84

0.82

4

1.80

1.65

1.50

1.35

1.20

1.16

1.12

1.08

1.04

LOG INACTIVATION CREDIT

WATER TEMPERATURE (°C)

10

11

12

13

14

15

16

17

18

2

0.50

0.46

0.42

0.38

0.34

0.30

0.29

0.28

0.27

3

0.80

0.74

0.68

0.62

0.56

0.50

0.48

0.46

0.44

4

1.00

0.92

0.84

0.76

0.68

0.60

0.58

0.56

0.54

LOG INACTIVATION CREDIT

WATER TEMPERATURE (°C)

19

20

21

22

23

24

25

2

0.26

0.25

0.23

0.21

0.19

0.17

0.15

3

0.42

0.40

0.37

0.34

0.31

0.28

0.25

4

0.52

0.50

0.46

0.42

0.38

0.34

0.30

TABLE 500.15
Baffling Classifications

BAFFLING CONDITION

T10/T

BAFFLING DESCRIPTION

Unbaffled (mixed flow)

0.1

None, agitated basin, very low length-to-width ratio, high inlet and outlet flow velocities

Poor

0.3

Single or multiple unbaffled inlets and outlets, no intra-basin baffles

Average

0.5

Baffled inlet or outlet with some intra-basin baffles

Superior

0.7

Perforated inlet baffle, serpentine or perforated intra-basin baffles, outlet weir or perforated launders

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-005.06 § 2.17, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 18, Issue 19, eff. July 3, 2002; Volume 21, Issue 13, eff. April 6, 2005; Volume 25, Issue 5, eff. December 10, 2008; Volume 28, Issue 5, eff. December 7, 2011; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-505. Emergency management plan for extended power outages.

A. The owner of a community waterworks (including consecutive waterworks) shall develop and maintain an emergency management plan for extended power outages.

B. The plan shall be kept current and shall be retained at a location that is readily accessible to the owner in the event of an extended power outage.

C. The owner of a community waterworks shall certify in writing to the department that the plan has been completed.

D. The plan shall address the following where applicable:

1. Identification of the criteria (events, duration of power outage, etc.) that will initiate activation of the plan.

2. How the owner will respond to an extended power outage lasting a minimum of five days.

3. Procedures for obtaining and distributing potable water in the event that the primary sources become unavailable.

4. Notification procedures and example notices to the public and media (local radio stations, television stations, local newspapers, etc.) including conservation notices and boil water advisories.

5. Emergency disinfection procedures for the distribution system and storage tank.

6. The point of contact for the department.

7. The points of contact for the waterworks personnel who should be notified.

8. The point of contact for the Local Emergency Coordinator designated by the Virginia Department of Emergency Management.

9. The points of contact for the electric power, natural gas, and propane distributors, or other energy supplier to the waterworks.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 23, Issue 1, eff. October 18, 2006; amended, Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-510. Acceptable operating practices.

A. This section is not intended to be all inclusive but reflects the concern for the public health significance of certain practices related to waterworks operation.

B. Filter operation.

1. Gravity flow granular media filters designed for pathogen and turbidity removal shall not be operated without adequate chemical coagulation as determined by the department.

2. A waterworks utilizing gravity flow granular media filtration shall not vary the rate of filtration through any single filter above its design capacity unless approved by the department.

3. Gravity flow granular media filters equipped with filter-to-waste facilities shall not be returned to service after backwashing until a thorough rinsing period has occurred so that the filter-to-waste water has a turbidity less than or equal to 0.3 NTU.

4. All MF and UF technologies employed for pathogen removal shall demonstrate removal efficiency equal to the removal (log inactivation) credit given in Table 500.1. A direct integrity test acceptable to the department shall be conducted and include the following:

a. The direct integrity test capability shall be provided for each filter unit; and

b. The direct integrity test shall be conducted at least daily for each day the filtration unit is in operation.

C. All waterworks shall provide a minimum working pressure of 20 psigauge (psig) at all service connections.

D. The board recommends that all community waterworks in the Commonwealth deliver the optimum fluoride ion concentration as determined by the U.S. Department of Health and Human Services.

E. A waterworks owner shall provide the commissioner at least 90 days prior written notice of the intent to initiate or discontinue a program to provide the optimum fluoride ion concentration.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-005.07 § 2.18, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-515. Use of chemicals.

A. All chemicals used in water treatment shall be compliant with NSF/ANSI/CAN Standard 60-2020. These chemicals shall include the following:

1. Corrosion and scale inhibitors;

2. Coagulants and flocculants;

3. Disinfectants and oxidants;

4. pH adjustment chemicals;

5. Regenerating agents; and

6. Membrane cleaning compounds.

B. Chemical containers shall bear the proper certification mark and identification consistent with the Safety Data Sheet for the chemical used.

C. The owner shall maintain documentation verifying that all chemicals meet NSF/ANSI/CAN Standard 60-2020 certification requirements.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-520. Waterworks capacity.

A. When the water production of a community waterworks reaches 80% of the permitted capacity for any consecutive three-month period, the owner shall prepare and submit a written plan within 30 days of notification by the department to address capacity needs. This plan shall be evaluated by the department and corrective actions shall be approved by the department.

B. The department may require the owner to reevaluate the source water capacity of a well by conducting a yield and drawdown test in accordance with 12VAC5-590-840 H when the well has demonstrated declining yield.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-005.08 § 2.19, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-530. Reporting.

A. The results of all required monitoring activity shall be reported by the owner or the owner's authorized agent to the department no later than (i) the 10th day of the month following the month during which the test results were received, or (ii) the 10th day following the end of the monitoring period, whichever is shorter, unless stipulated otherwise by the department. The results of any required monitoring activity shall be reported by the owner or the owner's authorized agent in a format and method prescribed by the department. For routine compliance samples analyzed for contaminants listed in Tables 340.1 through 340.7, the owner shall request that the certified analytical laboratory performing the analyses provide the data electronically to the department as per the requirements of this section.

B. It shall be the duty and responsibility of an owner to report to the department in the most expeditious manner for circumstances identified in subsections C through J of this section. The owner shall contact the department for the acceptable notification method. The official laboratory data report shall be sent to the department as soon as practical.

C. Bacteriological examination reporting.

1. When a bacteriological examination shows that samples are required (see 12VAC5-590-380 D), the owner shall collect the repeat samples within 24 hours of being notified of the positive result and shall report the repeat sample results to the department.

2. Microbial contamination, as evidenced by one or more routine distribution system water samples indicating the presence of E. coli or waterborne pathogens, shall be reported by the owner to the department by the end of the day when the owner was notified of the test result, unless the department is closed, in which case the department shall be notified before the end of the next business day.

3. An E. coli PMCL violation shall be reported by the owner to the department by the end of the day when the owner was notified of the test result, unless the department is closed, in which case the department shall be notified before the end of the next business day.

4. The owner who has failed to comply with the monitoring requirements of 12VAC5-590-370 shall report the monitoring violation to the department in writing within 10 days after the owner discovers the violation and shall notify the public in accordance with 12VAC5-590-540 A 3.

D. Turbidity reporting. For a waterworks required to filter for pathogen and turbidity removal, a report shall be made within 24 hours to the department if the filtered water turbidity measurement exceeds the following concentrations based on the filtration treatment type:

1. Conventional filtration -- one NTU.

2. Diatomaceous earth filtration -- five NTU.

3. Slow sand filtration -- five NTU.

4. Membrane, bag and cartridge filtration -- one NTU.

E. PMCL exceedance.

1. When a PMCL of an inorganic or organic chemical is exceeded for a single sample the owner shall report the exceedance within seven days. If a sample result would cause the compliance average to be exceeded, then the owner shall report the sample result, in context with the compliance average, to the department within 48 hours.

2. When the average value of the samples collected pursuant to 12VAC5-590-382 and 12VAC5-590-383 exceeds the PMCL of an inorganic or organic chemical, the owner shall report the exceedance to the department within 48 hours.

3. When the PMCL for a radionuclide has been exceeded as determined by Table 340.4, the results shall be reported to the department within 48 hours.

F. The owner shall report to the department within 48 hours of the failure to comply with the monitoring and sanitary survey requirements of this chapter.

G. The owner shall report to the department within 48 hours of the failure to comply with the requirements of the schedule prescribed pursuant to a variance or exemption.

H. The owner shall report a Tier 1 violation or situation, as described in 12VAC5-590-540 A 1, to the department as soon as practical, but no later than 24 hours after the owner learns of the Tier 1 violation or situation. At the same time the report is made, the owner shall consult with the department to determine the need for any additional actions to address the violation or situation.

I. Reporting requirements for coliform treatment technique violations.

1. The owner that has violated the treatment technique required in 12VAC5-590-392 B shall report the violation to the department no later than the end of the next business day after learning of the violation and shall notify the public in accordance with 12VAC5-590-540 A 2.

2. The owner that is required to conduct an assessment under 12VAC5-590-392 C shall submit the assessment report within 30 days to the department.

3. The owner shall notify the department in writing after each scheduled corrective action is completed for corrections that were not completed by the time of submission of the assessment form under the requirements of 12VAC5-590-392 C.

J. The owner of a seasonal waterworks shall submit the certification of completion of the approved start-up procedure on a form approved by the department before serving water.

K. Reporting requirements for groundwater systems. The owner shall report the following information in accordance with subsection A of this section:

1. The owner conducting compliance monitoring as required by 12VAC5-590-421 C shall notify the department as soon as practical, but no later than the next business day, whenever the groundwater system fails to meet the department-specified minimum residual disinfectant concentration for more than four hours.

2. The owner required to conduct corrective action as described in 12VAC5-590-421 A shall notify the department within 30 days of completion of corrective action.

3. The owner subject to the source water monitoring requirements of 12VAC5-590-379 that do not conduct this monitoring under the provision of 12VAC5-590-380 E shall provide documentation to the department within 30 days of the collection that the sample met the criteria defined in 12VAC5-590-380 E.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-005.09 § 2.20, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 12, Issue 2, eff. November 15, 1995; Volume 18, Issue 19, eff. July 3, 2002; Volume 19, Issue 17, eff. June 4, 2003; Volume 19, Issue 20, eff. July 16, 2003; Volume 19, Issue 24, eff. September 10, 2003; Volume 21, Issue 13, eff. April 6, 2005; Volume 22, Issue 21, eff. July 26, 2006; Volume 25, Issue 5, eff. December 10, 2008; Volume 27, Issue 1, eff. October 13, 2010; Volume 28, Issue 5, eff. December 7, 2011; Volume 33, Issue 3, eff. November 2, 2016; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-531. Reporting requirements for filtration treatment and disinfection treatment.

A. The owner of a waterworks using a surface water source, a GUDI source, or both shall report monthly to the department the following specified information.

1. Turbidity measurements as required by 12VAC5-590-376 B shall be reported within 10 days after the end of each month the waterworks serves water to the public. Information that shall be reported includes:

a. The total number of filtered water turbidity measurements collected during the month.

b. The number and percentage of filtered water turbidity measurements collected during the month that are less than or equal to the turbidity limits specified in 12VAC5-590-395 A 2 b for the filtration technology being used.

c. The owner of a waterworks that uses lime softening may apply to the department for alternative exceedance levels for the levels specified in subdivision A 1 b of this section if the owner can demonstrate that higher turbidity levels in individual filters are due to lime carryover only and not due to degraded filter performance.

2. The owner of a waterworks with combined distribution systems serving at least 10,000 persons using a surface water source, a GUDI source, or both that provides conventional filtration treatment or direct filtration shall report monthly to the department the information specified in subdivisions A 2 a and A 2 b of this section. Also, the owner of a waterworks that provides filtration approved under 12VAC5-590-395 A 2 b shall report monthly to the department the information specified in subdivisions A 2 a and A 2 b of this section.

a. Turbidity measurements collected to meet 12VAC5-590-395 A 2 b shall be reported within 10 days after the end of each month the waterworks serves water to the public. Information that shall be reported includes:

(1) The total number of filtered water turbidity measurements collected during the month.

(2) The number and percentage of filtered water turbidity measurements collected during the month that are less than or equal to the turbidity limits specified in 12VAC5-590-395 A 2 b.

(3) The date and value of any turbidity measurements collected during the month that exceed 1.0 NTU for waterworks using conventional filtration treatment or direct filtration or that exceed the maximum level set by the department under 12VAC5-590-395 A 2 b.

b. The owner shall maintain the results of individual filter monitoring collected under 12VAC5-590-376 B for at least three years. The owner shall report the completion of individual filter turbidity monitoring under 12VAC5-590-376 B within 10 days after the end of each month the waterworks serves water to the public. The owner shall report individual filter turbidity measurement results collected under 12VAC5-590-376 B within 10 days after the end of each month the waterworks serves water to the public only if measurements demonstrate one or more of the conditions in 12VAC5-590-395 A 2 b. The owner of a waterworks that uses lime softening may apply to the department for alternative exceedance levels for the levels specified in 12VAC5-590-395 A 2 b if the owner can demonstrate that higher turbidity levels in individual filters are due to lime carryover only and not due to degraded filter performance.

3. For a waterworks with combined distribution systems serving 10,000 or more persons.

a. For an individual filter that has a measured turbidity level of greater than 1.0 NTU in two consecutive measurements collected 15 minutes apart, the owner shall report the filter number, the turbidity measurement, and the dates on which the exceedances occurred. In addition, the owner shall either produce a filter profile for the filter within seven days of the exceedance if the owner is not able to identify an obvious reason for the abnormal filter performance and report that the profile has been produced or report the obvious reason for the exceedance.

b. For an individual filter that has a measured turbidity level of greater than 0.5 NTU in two consecutive measurements collected 15 minutes apart at the end of the first four hours of continuous filter operation after the filter has been backwashed or otherwise taken offline, the owner shall report the filter number, the turbidity, and the dates on which the exceedances occurred. In addition, the owner shall either produce a filter profile for the filter within seven days of the exceedance if the owner is not able to identify an obvious reason for the abnormal filter performance and report that the profile has been produced or report the obvious reason for the exceedance.

c. For an individual filter that has a measured turbidity level of greater than 1.0 NTU in two consecutive measurements collected 15 minutes apart at any time in each of three consecutive months, the owner shall report the filter number, the turbidity measurement, and the dates on which the exceedances occurred. In addition, the waterworks shall conduct a self-assessment of the filter within 14 days of the exceedances and report that the self-assessment was conducted. The self-assessment shall consist of at least the following components: assessment of filter performance, development of a filter profile, identification and prioritization of factors limiting filter performance, assessment of the applicability of corrections, and preparation of a filter self-assessment report.

d. For an individual filter that has a measured turbidity level of greater than 2.0 NTU in two consecutive measurements collected 15 minutes apart at any time in each of two consecutive months, the owner shall report the filter number, the turbidity measurement, and the dates on which the exceedances occurred. In addition, the owner shall arrange for the conduct of a comprehensive performance evaluation (CPE) by the department or a third party approved by the department no later than 30 days following the exceedance and have the evaluation completed and submitted to the department no later than 90 days following the exceedance. A CPE means a thorough evaluation and analysis of a water treatment plant's performance-based capabilities and associated administrative, operational, and maintenance practices. A CPE is conducted to identify factors that may be adversely impacting a water treatment plant's capability to achieve compliance and emphasizes approaches that can be implemented without significant capital improvements.

4. For a waterworks with combined distribution systems serving fewer than 10,000 persons.

a. For an individual filter or the turbidity of CFE for waterworks with two filters that monitor CFE instead of individual filters that has a measured turbidity level of greater than 1.0 NTU in two consecutive measurements collected 15 minutes apart, the owner shall report the filter numbers, the turbidity measurements, and the dates on which the exceedances occurred and the cause (if known) for the exceedances.

b. For an individual filter or the turbidity of CFE for a waterworks with two filters that monitor CFE instead of individual filters that has a measured turbidity level of greater than 1.0 NTU in two consecutive measurements collected 15 minutes apart at any time in each of three consecutive months, the owner shall conduct a self-assessment of the filters within 14 days of the day the filter exceeded 1.0 NTU unless a CPE as specified in subdivision A 4 c of this section was required. A waterworks with two filters that monitor the CFE instead of individual filters shall conduct a self-assessment on both filters. The self-assessment shall be reported to the department and consist of at least the following components: (i) date the self-assessment was triggered, (ii) date the self-assessment was completed, (iii) an assessment of filter performance, (iv) development of a filter profile, (v) identification and prioritization of factors limiting filter performance, (vi) assessment of the applicability of corrections, and (vii) preparation of a filter self-assessment report. The self-assessment shall be submitted within 10 days after the end of the month or 14 days after the self-assessment was triggered only if it was triggered during the last four days of the month.

c. For an individual filter or the turbidity of CFE for a waterworks with two filters that monitor CFE instead of individual filters that has a measured turbidity level of greater than 2.0 NTU in two consecutive measurements collected 15 minutes apart at any time in each of two consecutive months, the owner shall arrange for a CPE, as defined in subdivision A 3 d of this section, by the department or a third party approved by the department no later than 60 days following the day the filter exceeded 2.0 NTU in two consecutive months. The owner shall report within 10 days after the end of the month that a CPE is required and the date that it was triggered. If a CPE has been completed by the department or a third party approved by the department within the 12 prior months or the owner and the department are jointly participating in an ongoing comprehensive technical assistance project at the waterworks, then a new CPE is not required. If conducted, a CPE shall be completed and submitted to the department no later than 120 days following the day the filter exceeded 2.0 NTU in two consecutive measurements for the second straight month.

5. Reporting Cryptosporidium monitoring results.

a. The owner shall report results from the source water monitoring required in 12VAC5-590-401 B no later than 10 days after the end of the first month following the month when the sample is collected.

b. The owner shall report the following data elements for each Cryptosporidium analysis:

(1) Public water system (PWS) identification number;

(2) Facility identification number;

(3) Sample collection date;

(4) Sample type (field or matrix spike);

(5) Sample volume filtered (L), to nearest 1/4 L;

(6) Was 100% of filtered volume examined; and

(7) Number of oocysts counted.

c. Quality control for Cryptosporidium analysis:

(1) For matrix spike samples, the owner shall also report the sample volume spiked and the estimated number of oocysts spiked. These data are not required for field samples.

(2) For samples in which less than 10 L is filtered or less than 100% of the sample volume is examined, the owner shall also report the number of filters used and the packed pellet volume.

(3) For samples in which less than 100% of the sample volume is examined, the owner shall also report the volume of re-suspended concentrate and volume of this re-suspension processed through immunomagnetic separation.

d. The owner shall report the following data elements for each E. coli analysis:

(1) PWS identification number;

(2) Facility identification number;

(3) Sample collection date;

(4) Analytical method number;

(5) Method type;

(6) Source water type (flowing stream, lake or reservoir, GUDI source);

(7) E. coli/100 mL; and

(8) Turbidity.

e. The owner of a waterworks serving fewer than 10,000 persons and not required to monitor for turbidity under 12VAC5-590-401 B is not required to report turbidity with their E. coli results.

B. Reporting of requirements for enhanced treatment for Cryptosporidium.

1. The owner shall report sampling schedules under 12VAC5-590-401 B and source water monitoring results under 12VAC5-590-531 A 5, unless the owner notifies the department that the owner will not conduct source water monitoring due to meeting the criteria of 12VAC5-590-401 B 4.

2. The owner shall report the use of uncovered finished water storage facilities to the department as described in 12VAC5-590-415.

3. The owner of a waterworks that provide filtration shall report their Cryptosporidium bin classification as described in 12VAC5-590-401 D.

4. The owner shall report disinfection profiles and benchmarks to the department as described in 12VAC5-590-401 C 1 and C 2 before making a significant change in disinfection practice.

5. The owner shall report to the department in accordance with Table 531.1 for any microbial toolbox options used to comply with treatment requirements under 12VAC5-590-401 D 2. Alternatively, the department may approve a waterworks to certify operation within required parameters for treatment credit rather than reporting monthly operational data for toolbox options.

TABLE 531.1
Microbial Toolbox Reporting Requirements

TOOLBOX OPTION

OWNERS SHALL SUBMIT THE FOLLOWING INFORMATION:

ON THE FOLLOWING SCHEDULE:

Alternative source or intake management

Verification that the waterworks has relocated the intake or adopted the intake withdrawal procedure reflected in monitoring results.

No later than the applicable treatment compliance date in 12VAC5-590-401 D 3.

Presedimentation

Monthly verification of the following:
(i) Continuous basin operation;
(ii) Treatment of 100% of the flow;
(iii) Continuous addition of a coagulant; and
(iv) At least 0.5-log mean reduction of influent turbidity or compliance with alternative performance criteria approved by the department.

Monthly reporting within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 12VAC5-590-401 D 3.

Two-stage lime softening

Monthly verification of the following:
(i) Chemical addition and hardness precipitation occurred in two separate and sequential softening stages before filtration; and
(ii) Both stages treated 100% of the water treatment plant flow.

Monthly reporting within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 12VAC5-590-401 D 3.

Bank filtration

Initial demonstration of the following:
(i) Unconsolidated, predominantly sandy aquifer; and
(ii) Setback distance of at least 25 ft. (0.5-log credit) or 50 ft. (1.0-log credit).

No later than the applicable treatment compliance date in 12VAC5-590-401 D 3.

If monthly average of daily maximum turbidity is greater than 1.0 NTU then the waterworks shall report the result and submit an assessment of the cause.

Report within 30 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 12VAC5-590-401 D 3.

Combined filter performance

Monthly verification of CFE turbidity levels less than or equal to 0.15 NTU in at least 95% of the four-hour CFE measurements collected each month.

Monthly reporting within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 12VAC5-590-401 D 3.

Individual filter performance

Monthly verification of the following:
(i) Individual filter effluent turbidity levels less than or equal to 0.15 NTU in at least 95% of samples each month in each filter; and
(ii) No individual filter greater than 0.3 NTU in two consecutive readings 15 minutes apart.

Monthly reporting within 10 days following the month in which the monitoring was conducted, beginning on the applicable treatment compliance date in 12VAC5-590-401 D 3.

Demonstration of performance

Results from testing following a protocol approved by the department.

No later than the applicable treatment compliance date in 12VAC5-590-401 D 3.

As required by the department, monthly verification of operation within conditions of the department's approval for demonstration of performance credit.

Within 10 days following the month in which monitoring was conducted, beginning on the applicable treatment compliance date in 12VAC5-590-401 D 3.

Bag filters and cartridge filters

Demonstration that the following criteria are met:
(i) Process meets the definition of bag or cartridge filtration; and
(ii) Removal efficiency established through challenge testing that meets criteria in 12VAC5-590-401 E 6 a.

No later than the applicable treatment compliance date in 12VAC5-590-401 D 3.

Monthly verification that 100% of the water treatment plant flow was filtered.

Within 10 days following the month in which monitoring was conducted, beginning on the applicable treatment compliance date in 12VAC5-590-401 D 3.

Membrane filtration

Results of verification testing demonstrating the following:
(i) Removal efficiency established through challenge testing that meets criteria in subdivision B 5 of this section; and
(ii) Integrity test method and parameters, including resolution, sensitivity, test frequency, control limits, and associated baseline.

No later than the applicable treatment compliance date in 12VAC5-590-401 D 3.

Monthly report summarizing the following:
(i) All direct integrity tests above the control limit; and
(ii) If applicable, any turbidity or alternative indirect integrity monitoring approved by the department that results in triggering direct integrity testing and the corrective action that was taken.

Within 10 days following the month in which monitoring was conducted, beginning on the applicable treatment compliance date in 12VAC5-590-401 D 3.

Second stage filtration

Monthly verification that 100% of flow was filtered through both stages and the first stage was preceded by a coagulation step.

Within 10 days following the month in which monitoring was conducted, beginning on the applicable treatment compliance date in 12VAC5-590-401 D 3.

Slow sand filtration (as secondary filter)

Monthly verification that both a slow sand filter and a preceding separate stage of filtration treated 100% of flow from surface water or GUDI.

Within 10 days following the month in which monitoring was conducted, beginning on the applicable treatment compliance date in 12VAC5-590-401 D 3.

Chlorine dioxide

Summary of CT values for each day as described in 12VAC5-590-401 E 7 b (1).

Within 10 days following the month in which monitoring was conducted, beginning on the applicable treatment compliance date in 12VAC5-590-401 D 3.

Ozone

Summary of CT values for each day as described in 12VAC5-590-401 E 7 b (2).

Within 10 days following the month in which monitoring was conducted, beginning on the applicable treatment compliance date in 12VAC5-590-401D 3.

UV

Validation test results demonstrating operating conditions that achieve required UV dose.

No later than the applicable treatment compliance date in 12VAC5-590-401 D 3.

Monthly report summarizing the percentage of water entering the distribution system that was not treated by UV reactors operating within validated conditions for the required dose as specified in 12VAC5-590-401 E 7 c (1).

Within 10 days following the month in which monitoring was conducted, beginning on the applicable treatment compliance date in 12VAC5-590-401 D 3.

C. Disinfection information specified in this subsection shall be reported to the department within 10 days after the end of each month the waterworks serves water to the public. Information that shall be reported includes:

1. For each day, the lowest measurement of residual disinfectant concentration in mg/L in water entering the distribution system.

2. The date and duration of each period when the residual disinfectant concentration in water entering the distribution system fell below 0.2 mg/L and when the department was notified of the occurrence.

3. The following information on the samples collected in the distribution system in conjunction with total coliform monitoring pursuant to 12VAC5-590-395 A 2.

a. Number of instances where the residual disinfectant concentration is measured;

b. Number of instances where the residual disinfectant concentration is not measured but HPC is measured;

c. Number of instances where the residual disinfectant concentration is measured but not detected and no HPC is measured;

d. Number of instances where no residual disinfectant concentration is detected and where HPC is greater than 500/mL;

e. Number of instances where the residual disinfectant concentration is not measured and HPC is greater than 500/mL; and

f. For the current and previous month the waterworks serves water to the public, the value of "V," in percent, in the following formula:

a = the value in subdivision C 3 a of this section.

b = the value in subdivision C 3 b of this section.

c = the value in subdivision C 3 c of this section.

d = the value in subdivision C 3 d of this section.

e = the value in subdivision C 3 e of this section.

g. The department may determine that based on site-specific considerations if an owner has no means for having a sample transported and analyzed for HPC by a certified laboratory under the requisite time and temperature conditions and the waterworks is providing adequate disinfection in the distribution system, the HPC compliance requirements of subdivisions C 3 a through C 3 f of this section do not apply.

4. The owner need not report the data listed in subdivision C 1 of this section if all data listed in subdivisions C 1, C 2, and C 3 of this section remain on file at the waterworks and the department determines that the owner has submitted all of the information required by subdivisions C 1, C 2, and C 3 of this section for the last 12 months.

5. A waterworks using disinfection oxidants other than free chlorine after filtration shall continue to record disinfection profile measurements and incorporate log inactivation computations into their monthly operation reports, as described in 12VAC5-590-570.

D. Reporting requirements for DBPs. The owner shall report the following information to the department in accordance with 12VAC5-590-530. The department may choose to perform calculations and determine whether the PMCL was violated, instead of having the owner report that information.

1. Locational running annual average (LRAA) reporting:

a. The owner shall report the following information for each monitoring location to the department:

(1) Number of samples collected during the last quarter.

(2) Date and results of each sample collected during the last quarter.

(3) Arithmetic average of quarterly results for the last four quarters for each LRAA, beginning at the end of the fourth calendar quarter that follows the compliance date and at the end of each subsequent quarter. If the LRAA calculated based on fewer than four quarters of data would cause the PMCL to be exceeded regardless of the monitoring results of subsequent quarters, the owner shall report this information to the department as part of the first report due following the compliance date or anytime thereafter that this determination is made. If the owner is required to conduct monitoring at a frequency that is less than quarterly, then the owner shall make compliance calculations beginning with the first compliance sample collected after the compliance date, unless the owner is required to conduct increased monitoring under 12VAC5-590-374 F 5.

(4) Whether, based on 12VAC5-590-384 B 1, the PMCL was violated at any monitoring location.

(5) Any operational evaluation levels under 12VAC5-590-384 B 1 d that were exceeded during the quarter, and if so, the location and date and the calculated TTHM and HAA5 levels.

b. The owner of a waterworks using a surface water source, a GUDI source, or both seeking to qualify for or remain on reduced TTHM and HAA5 monitoring shall report the following source water TOC information for each water treatment plant that treats surface water or groundwater under the direct influence of surface water to the department within 10 days of the end of any quarter in which monitoring is required:

(1) The number of source water TOC samples collected each month during last quarter.

(2) The date and result of each sample collected during last quarter.

(3) The quarterly average of monthly samples collected during last quarter or the result of the quarterly sample.

(4) The RAA of quarterly averages from the past four quarters.

(5) Whether the RAA exceeded 4.0 mg/L.

2. The owner of a waterworks monitoring for chlorite under the requirements of 12VAC5-590-374 G shall report:

a. The number of entry point samples collected each month for the last three months.

b. The location, date, and result of each sample (both entry point and distribution system) collected during the last quarter.

c. For each month in the reporting period, the arithmetic average of all samples collected in each three sample set collected in the distribution system.

d. Whether, based on 12VAC5-590-384 B 3, the PMCL was violated, in which month, and how many times it was violated each month.

3. The owner of a waterworks monitoring for bromate under the requirements of 12VAC5-590-374 H shall report:

a. The number of samples collected during the last quarter.

b. The location, date, and result of each sample collected during the last quarter.

c. The arithmetic average of the monthly arithmetic averages of all samples collected in the last year.

d. Whether, based on 12VAC5-590-384 B 2, the PMCL was violated.

E. Reporting requirements for disinfectants. The owner shall report the information specified in this subsection to the department in accordance with 12VAC5-590-530. The department may choose to perform calculations and determine whether the MRDL was violated, instead of having the owner report that information:

1. The owner of a waterworks monitoring for chlorine or chloramines under the requirements of 12VAC5-590-374 I 1 shall report:

a. The number of samples collected during each month of the last quarter.

b. The monthly arithmetic average of all samples collected in each month for the last 12 months.

c. The arithmetic average of all monthly averages for the last 12 months.

d. Whether, based on 12VAC5-590-384 C 1, the MRDL was violated.

2. The owner of a waterworks monitoring for chlorine dioxide under the requirements of 12VAC5-590-374 I 2 shall report:

a. The dates, results, and locations of samples collected during the last quarter.

b. Whether, based on 12VAC5-590-384 C 2, the MRDL was violated.

c. Whether the MRDL was exceeded in any two consecutive daily samples and whether the resulting violation was acute or nonacute.

F. Reporting requirements for DBPPs and enhanced coagulation or enhanced softening. The owner shall report the following information to the department in accordance with 12VAC5-590-530. The department may choose to perform calculations and determine whether the treatment technique was met, instead of having the owner report that information:

1. The owner of a waterworks monitoring monthly or quarterly for TOC under the requirements of 12VAC5-590-374 J and required to meet the enhanced coagulation or enhanced softening requirements in 12VAC5-590-411 A 2 shall report:

a. The number of paired (source water and treated water) samples collected during the last quarter.

b. The location, date, and results of each paired sample and associated alkalinity collected during the last quarter.

c. For each month in the reporting period that paired samples were collected, the arithmetic average of the percent reduction of TOC for each paired sample and the required TOC percent removal.

d. Calculations for determining compliance with the TOC percentage removal requirements, as provided in 12VAC5-590-411 A 3.

e. Whether the waterworks is in compliance with the enhanced coagulation or enhanced softening percent removal requirements in 12VAC5-590-411 A 2 for the last four quarters.

2. The owner of a waterworks monitoring monthly or quarterly for TOC under the requirements of 12VAC5-590-374 J and meeting one or more of the alternative compliance criteria in 12VAC5-590-411 A 1 c or A 1 d shall report:

a. The alternative compliance criterion that the waterworks is using.

b. The number of paired samples collected during the last quarter.

c. The location, date, and result of each paired sample and associated alkalinity collected during the last quarter.

d. The running annual arithmetic average based on monthly averages (or quarterly samples) of source water TOC for a waterworks meeting a criterion in 12VAC5-590-411 A 1 c (1) or A 1 c (3) or of treated water TOC for waterworks meeting the criterion in 12VAC5-590-411 A 1 c (2).

e. The running annual arithmetic average based on monthly averages (or quarterly samples) of source water SUVA for a waterworks meeting the criterion in 12VAC5-590-411 A 1 c (5) or of treated water SUVA for a waterworks meeting the criterion in 12VAC5-590-411 A 1 c (6).

f. The RAA of source water alkalinity for a waterworks meeting the criterion in 12VAC5-590-411 A 1 c (3) and of treated water alkalinity for a waterworks meeting the criterion in 12VAC5-590-411 A 1 d (1).

g. The RAA for both TTHM and HAA5 for a waterworks meeting the criterion in 12VAC5-590-411 A 1 c (3) or A 1 c (4).

h. The RAA of the amount of magnesium hardness removal (as CaCO3, in mg/L) for a waterworks meeting the criterion in 12VAC5-590-411 ) A 1 d (2).

i. Whether the waterworks is in compliance with the particular alternative compliance criterion in 12VAC5-590-411 A 1 c or A 1 d.

G. Additional reporting requirements. The owner shall report the following incidents within 24 hours to the department:

1. A waterborne disease outbreak that is potentially attributable to that waterworks.

2. Chlorine residual of below 0.2 mg/L in the water entering the distribution system. The owner also shall notify the department by the end of the next business day whether or not the residual was restored to at least 0.2 mg/L within four hours.

Statutory Authority

§§ 32.-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-532. Reporting requirements for lead and copper.

A. The owner shall report all of the information in this section to the department in accordance with this section.

B. Reporting requirements for tap water monitoring for lead and copper and for water quality parameter monitoring.

1. Except as provided in subdivision B 1 g of this section, the owner shall report the information specified in this subsection for all tap water samples specified in 12VAC5-590-375 B and for all water quality parameter samples specified in 12VAC5-590-375 C within the first 10 days following the end of each applicable monitoring period specified in 12VAC5-590-375 B and C (i.e., every six months, annually, every three years, or every nine years). For monitoring periods with a duration less than six months, the end of the monitoring period is the last date samples can be collected during the period as specified in 12VAC5-590-375 B and C.

a. The results of all tap samples for lead and copper including location or a location site code and the criteria under 12VAC5-590-375 B 1 c through B 1 f or 12VAC5-590-375 C under which the site was selected for the waterworks sampling pool.

b. Documentation for each tap water lead or copper sample for which the owner requests invalidation pursuant to 12VAC5-590-375 B 6.

c. The 90th percentile lead and copper concentrations measured from among all lead and copper tap water samples collected during each monitoring period (calculated in accordance with 12VAC5-590-385 C) unless the department calculates the 90th percentile lead and copper levels under subsection I of this section.

d. With the exception of initial tap sampling conducted pursuant to 12VAC5-590-375 B 4 a, the owner shall designate any site that was not sampled during previous monitoring periods and include an explanation of why sampling sites have changed.

e. The results of all tap samples for pH, and where applicable, alkalinity, calcium, conductivity, temperature, and orthophosphate or silica collected under 12VAC5-590-375 C 2 through C 5.

f. The results of all samples collected at the entry point to the distribution system for applicable water quality parameters under 12VAC5-590-375 C 2 through C 5.

g. The owner shall report the results of all water quality parameter samples collected under 12VAC5-590-375 C 3 through 12VAC5-590-375 C 6 during each six month monitoring period specified in 12VAC5-590-375 C 4 within the first 10 days following the end of the monitoring period unless the department has specified a more frequent reporting requirement.

2. The owner of a NTNC, or a community waterworks meeting the criteria of 12VAC5-590-405 D 2 e, that does not have enough taps that can provide first-draw samples must either:

a. Provide written documentation to the department identifying standing times and locations for enough non-first-draw samples to make up the sampling pool under 12VAC5-590-375 B 2 e by the start of the first applicable monitoring period under 12VAC5-590-375 B 4, unless the department has waived prior approval of non-first-draw sample sites selected by the owner pursuant to 12VAC5-590-375 B 2 e; or

b. If the department has waived prior approval of non-first-draw sample sites selected by the owner, then the owner shall identify in writing each site that did not meet the six-hour minimum standing time and the length of standing time for that particular substitute sample collected pursuant to 12VAC5-590-375 B 2 e and include this information with the lead and copper sample results required to be submitted pursuant to subsection B of this section.

3. At a time specified by the department, or if no specific time is designated by the department, then as early as practical before the addition of a new source or any long-term change in water treatment, an owner (i) deemed to have optimized corrosion control under 12VAC5-590-405 A 2 b (3), (ii) subject to reduced monitoring pursuant to 12VAC5-590-375 B 4 d, or (iii) subject to a monitoring waiver pursuant to 12VAC5-590-375 B 7 shall submit written documentation to the department describing the change or addition. The department must approve the addition of a new source or a long-term change in treatment before it is implemented by the owner. Examples of long-term treatment changes include the addition of a new treatment process or modification of an existing treatment process. Examples of modification include switching secondary disinfectants, switching coagulants (e.g., alum to ferric chloride), or switching corrosion inhibitor products (e.g., orthophosphate to blended phosphate). Long-term changes can include dose changes to existing chemicals if the waterworks is planning long-term changes to its finished water pH or residual inhibitor concentration. Long-term treatment changes would not include chemical dose fluctuations associated with daily source water quality changes.

4. The owner of a small waterworks applying for a monitoring waiver under 12VAC5-590-375 B 7 or subject to a waiver granted pursuant to 12VAC5-590-375 B 7 c shall provide the following information to the department in writing by the specified deadline:

a. By the start of the first applicable monitoring period in 12VAC5-590-375 B 4, the owner of a small waterworks applying for a monitoring waiver shall provide the documentation required to demonstrate that the waiver criteria of 12VAC5-590-375 B 7 a and 12VAC5-590-375 B 7 b have been met.

b. No later than nine years after the monitoring previously conducted pursuant to 12VAC5-590-375 B 7 b or 12VAC5-590-375 B 7 d (1), the owner of a small waterworks desiring to maintain its monitoring waiver shall provide the information required by 12VAC5-590-375 B 7 d (1) and 12VAC5-590-375 B 7 d (2).

c. No later than 60 days after becoming aware that it is no longer free of lead-containing or copper-containing material, the owner of a small waterworks with a monitoring waiver shall provide written notification to the department setting forth the circumstances resulting in the lead-containing or copper-containing materials being introduced into the waterworks and what corrective action, if any, the owner plans to take to remove these materials.

5. The owner of a groundwater system that limits water quality parameter monitoring to a subset of entry points under 12VAC5-590-375 C 3 c shall provide by the commencement of the monitoring written correspondence to the department that identifies the selected entry points and includes information sufficient to demonstrate that the sites are representative of water quality and treatment conditions throughout the waterworks.

C. Source water monitoring reporting requirements.

1. The owner shall report the sampling results for all source water samples collected in accordance with 12VAC5-590-375 D within the first 10 days following the end of each source water monitoring period (i.e., annually, per compliance period, per compliance cycle) specified in 12VAC5-590-375 D.

2. With the exception of the first round of source water sampling conducted pursuant to 12VAC5-590-375 D 2, the owner shall specify any site that was not sampled during previous monitoring periods and include an explanation of why the sampling point has changed.

D. Corrosion control treatment reporting requirements. By the applicable dates under 12VAC5-590-405 A 2 a, an owner shall report the following information:

1. For the owner demonstrating that corrosion control has already been optimized, information required in 12VAC5-590-405 A 2 b (2) or 12VAC5-590-405 A 2 b (3).

2. For the owner required to optimize corrosion control, the owner's recommendation regarding optimal corrosion control treatment under 12VAC5-590-405 A 1 a.

3. For the owner required to evaluate the effectiveness of corrosion control treatments, the information required under 12VAC5-590-405 A 1 c.

4. For the owner required to install optimal corrosion control designated by the department under 12VAC5-590-405 A 1 d, a letter certifying that the owner has completed installing that treatment.

E. Source water treatment reporting requirements. By the applicable dates in 12VAC5-590-405 B, an owner shall provide the following information to the department:

1. If required under 12VAC5-590-405 B 2 a, the owner's recommendation regarding source water treatment; or

2. For an owner required to install source water treatment under 12VAC5-590-405 B 2 b, a letter certifying that the owner has completed installing the treatment designated by the department within 24 months after the department designated the treatment.

F. Lead service line replacement reporting requirements. The owner shall report the following information to the department to demonstrate compliance with the requirements of 12VAC5-590-405 C:

1. No later than 12 months after the end of a monitoring period in which a waterworks exceeds the lead AL in sampling referred to in 12VAC5-590-405 C 1, the owner shall submit written documentation to the department of the materials evaluation conducted as required in 12VAC5-590-375 B 1, to identify the initial number of lead service lines in the distribution system at the time the waterworks exceeds the lead AL, and provide the owner's schedule for annually replacing at least 7.0% of the initial number of lead service lines in its distribution system.

2. No later than 12 months after the end of a monitoring period in which a waterworks exceeds the lead AL in sampling referred to in 12VAC5-590-405 C 1, and every 12 months thereafter, the owner shall demonstrate to the department in writing that the owner has either:

a. Replaced in the previous 12 months at least 7.0% of the initial lead service lines or a greater number of lines specified by the department under 12VAC5-590-405 C 6 in the distribution system; or

b. Conducted sampling that demonstrates that the lead concentration in all service line samples from an individual line collected pursuant to 12VAC5-590-375 B 2 c is less than or equal to 0.015 mg/L. In these cases, the total number of lines replaced that meet the criteria in 12VAC5-590-405 C 4 shall equal at least 7.0% of the initial number of lead service lines identified under subdivision F 1 of this section or the percentage specified by the department under 12VAC5-590-405 C 6.

3. The annual letter submitted to the department under subdivision F 2 of this section shall contain the following information:

a. The number of lead service lines scheduled to be replaced during the previous year of the waterworks replacement schedule;

b. The number and location of each lead service line replaced during the previous year of the waterworks replacement schedule; and

c. If measured, the water lead concentration and location of each lead service line sampled, the sampling method, and the date of sampling.

4. The owner of a waterworks that collects lead service line samples following partial lead service line replacement required by 12VAC5-590-405 C shall report the results to the department within the first 10 days of the month following the month in which the owner receives the laboratory results or as specified by the department. The owner shall also report any additional information as specified by the department in a time and manner prescribed by the department to verify that all partial lead service line replacement activities have taken place.

G. Public education program reporting requirements. The owner shall report the following information to the department to demonstrate compliance with the requirements of 12VAC5-590-405 D.

1. The owner of a waterworks that is subject to the public education requirements in 12VAC5-590-405 D shall within 10 days after the end of each period in which the owner is required to perform public education tasks in accordance with 12VAC5-590-405 D 2 send written notice to the department that contains:

a. A demonstration that the owner has delivered the public education materials that meet the content requirements of 12VAC5-590-405 D 1 and the delivery requirements of 12VAC5-590-405 D 2; and

b. A list of all the newspapers, radio stations, television stations, and facilities and organizations to which the owner delivered public education materials during the period in which the owner was required to perform public education tasks.

2. Unless required by the department, an owner that previously has submitted the information required by subdivision G 1 b of this section need not resubmit the information required by subdivision G 1 b of this section, as long as there has been no changes in the distribution list and the owner certifies that the public education materials were distributed to the same list submitted previously.

3. No later than three months following the end of the monitoring period, the owner shall mail a sample copy of the consumer notification of tap results to the department along with a certification that the notification has been distributed in a manner consistent with the requirements of 12VAC5-590-405 D 4.

H. Reporting of additional monitoring data. The owner of a waterworks that collects sampling data in addition to that required by 12VAC5-590-375 shall report the results to the department within the first 10 days following the end of the applicable monitoring period under 12VAC5-590-375 B, 12VAC5-590-375 C, and 12VAC5-590-375 D during which the samples are collected.

I. Reporting of the 90th percentile lead and copper concentrations where the department calculates a waterworks' 90th percentile concentrations. The owner is not required to report the 90th percentile lead and copper concentrations measured from among all lead and copper tap samples collected during each monitoring period, as required by subdivision B 1 d of this section if:

1. The department has previously notified the owner that the department will calculate the waterworks' 90th percentile lead and copper concentrations based on the lead and copper tap results submitted pursuant to subdivision I 2 a of this section and has specified a date before the end of the applicable monitoring period by which the owner shall provide the results of the lead and copper tap water samples; and

2. The owner has provided the following information to the department by the date specified in subdivision I 1 of this section:

a. The results of all tap samples for lead and copper including the location of each site and the criteria under 12VAC5-590-375 B 1 c through 12VAC5-590-375 B 1 f or 12VAC5-590-375 B 1 g under which the site was selected for the waterworks sampling pool, pursuant to subdivision B 1 a of this section;

b. An identification of sampling sites utilized during the current monitoring period that were not sampled during the previous monitoring periods and an explanation why sampling sites have changed; and

c. The department has provided the results of the 90th percentile lead and copper calculations in writing to the owner before the end of the monitoring period.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-540. Public notices.

A. The owner shall give public notice to (i) persons served by the waterworks and (ii) the owner of any consecutive waterworks to which it sells or otherwise provides water under the following circumstances.

1. Tier 1.

a. When E. coli are present in the distribution system, or when the waterworks fails to test for E. coli when any repeat sample tests positive for total coliform;

b. Violation of the PMCL for E. coli;

c. Violation of the PMCL for nitrate, nitrite, or total nitrate and nitrite;

d. Failure to collect a confirmation sample within 24 hours of the waterworks receipt of the first sample showing an exceedance of the nitrate or nitrite PMCL;

e. Exceedance of the nitrate PMCL by a noncommunity waterworks, where permitted to exceed the PMCL by the department;

f. Violation of the MRDL for chlorine dioxide when one or more samples collected in the distribution system the day following an exceedance of the MRDL at the entry point to the distribution system exceed the MRDL;

g. Failure to monitor chlorine dioxide residuals in the distribution system the day following an exceedance of the chlorine dioxide MRDL at the entrance to the distribution system;

h. Violation of the treatment technique requirements for filtration and disinfection resulting from a single exceedance of the maximum allowable turbidity limit, where the department determines after consultation that a Tier 1 notice is required;

i. Failure to consult with the department within 24 hours after the owner learns of the violation of the treatment technique requirements for filtration and disinfection resulting from a single exceedance of the maximum allowable turbidity limit;

j. Occurrence of a waterborne disease outbreak or other waterborne emergency (such as a failure or significant interruption in key water treatment processes, a natural disaster that disrupts the water supply or distribution system, or a chemical spill or unexpected loading of possible pathogens into the source water that significantly increases the potential for drinking water contamination);

k. Detection of E. coli in groundwater source samples; or

l. Other violations or situations with significant potential to have serious adverse effects on human health as a result of short-term exposure, as determined by the commissioner or department on a case-by-case basis.

2. Tier 2.

a. All violations of the PMCL, MRDL, and treatment technique requirements, except where a Tier 1 public notice is required or where the department determines that a Tier 1 notice is required instead per subdivision A 1 l of this section;

b. Violations of the monitoring and testing procedure requirements, where the department determines that a Tier 2 rather than a Tier 3 public notice is required instead, taking into account potential health impacts and persistence of the violation;

c. Failure to comply with the terms and conditions of any variance or exemption in place; or

d. Failure to take corrective action or failure to maintain at least 4-log treatment of viruses (using inactivation, removal, or an approved combination of 4-log virus inactivation and removal) before or at the first customer under the treatment technique requirements for waterworks with groundwater sources.

3. Tier 3.

a. Monitoring violations, except where a Tier 1 public notice is required per subdivisions A 1 d and A 1 g of this section, or where the department determines that a Tier 2 public notice is required instead per subdivision A 2 b of this section;

b. Failure to comply with a testing procedure, except where a Tier 1 notice is required per subdivision A 1 b of this section or where the department determines that a Tier 2 notice is required instead per subdivision A 2 b of this section;

c. Operation under a variance or an exemption to a PMCL or treatment technique requirement;

d. Availability of UC monitoring results; or

e. Exceedance of the fluoride SMCL.

4. The department may require public notice for violations or other situations not listed in this section or may require a higher tier of public notice for specific violations and situations listed in this section.

a. The content and extent of distribution of these public notices shall be determined by the department.

b. The owner shall provide the public notice certification required in subsection N of this section.

c. At least 90 days before initiating or discontinuing a program to provide the optimum fluoride ion concentration, a waterworks owner shall deliver written notice to the waterworks' consumers. Notice to consumers shall be consistent with 12VAC5-590-540 C 2 d.

B. If a waterworks has a violation, failure, exceedance, or situation in a portion of the distribution system that is physically or hydraulically isolated from other parts of the distribution system, the department may allow the owner to limit distribution of the public notice to only those persons served by the portion of the waterworks that is out of compliance. The decision granting limited distribution of the public notice shall be issued in writing.

C. Public notice distribution requirements.

1. For Tier 1 violations, exceedances, or situations, the owner shall:

a. Provide a public notice as soon as practical but no later than 24 hours after the owner learns of the violation, exceedance, or situation;

b. Initiate consultation with the department as soon as practical, but no later than 24 hours after the owner learns of the violation, exceedance, or situation, to determine additional public notice requirements;

c. Comply with any additional public notice requirements, including any repeat notices or direction on the duration of the posted notices that are established as a result of the consultation with the department. These requirements may include the timing, form, manner, frequency, and content of repeat notices (if any) and other actions designed to reach all persons served; and

d. Provide the public notice in a form and manner reasonably calculated to reach all persons served. The form and manner shall fit the specific situation, and shall be designed to reach residential, transient, and nontransient users of the waterworks. To reach all persons served, owners shall use, at a minimum, one or more of the following forms of delivery:

(1) Appropriate broadcast media (such as radio and television);

(2) Posting of the public notice in conspicuous locations throughout the area served by the waterworks;

(3) Hand delivery of the public notice to persons served by the waterworks; or

(4) Another delivery method approved in writing by the department.

2. For Tier 2 violations, exceedances, or situations, the owner shall:

a. Provide the public notice as soon as practical, but no later than 30 days after the owner learns of the violation, exceedance, or situation. The department may allow, on a case-by-case determination, additional time for the initial notice of up to three months from the date the owner learns of the violation, exceedance, or situation; however, the department shall not grant an extension to the 30-day deadline for any unresolved violation, exceedance, or situation.

b. Repeat the public notice every three months as long as the violation, exceedance, or situation persists, unless the department determines that appropriate circumstances warrant a different repeat notice frequency. In no circumstance shall the repeat notice be given less frequently than once per year. Repeat notice frequency less than every three months shall not be allowed for (i) a violation as specified in 12VAC5-590-380 B and 12VAC5-590-392 F; (ii) a treatment technique violation for filtration and disinfection; and (iii) other ongoing violations, exceedances, or situations.

c. Consult with the department as soon as practical but no later than 24 hours after the owner learns of a violation of the treatment technique requirements for filtration and disinfection resulting from a single exceedance of the maximum allowable turbidity limit to determine whether a Tier 1 public notice is required to protect public health. If consultation does not take place within the 24-hour period, then the owner shall distribute a Tier 1 public notice of the violation within the next 24 hours (i.e., no later than 48 hours after the owner learns of the violation).

d. Provide the initial public notice and any repeat notices in a form and manner that is reasonably calculated to reach persons served in the required time period.

(1) For a community waterworks, the owner shall:

(a) Mail or otherwise directly deliver the public notice to each customer receiving a bill and to other service connections to which water is delivered by the waterworks; and

(b) Use any other distribution method reasonably calculated to reach other persons regularly served by the waterworks, if they would not normally be reached by the notice required in subdivision C 2 d (1) (a) of this section. These persons may include those who do not pay water bills or do not have service connection addresses (e.g., house renters, apartment dwellers, university students, nursing home patients, prison inmates, etc.). Other methods may include (i) publication in a local newspaper; (ii) delivery of multiple copies for distribution by customers that provide their drinking water to others (e.g., apartment building owners or large private employers); (iii) posting in public places served by the waterworks or on the Internet; or (iv) delivery to community organizations.

(2) For a noncommunity waterworks, the owner shall:

(a) Post the public notice in conspicuous locations throughout the distribution system frequented by persons served by the waterworks, or by mail or direct delivery to each customer and service connection (where known); and

(b) Use any other method reasonably calculated to reach other persons served by the system if they would not normally be reached by the notice required in subdivision C 2 d (2) (a) of this section. These persons may include those served who may not see a posted notice because the posted notice is not in a location they routinely pass by. Other methods may include (i) publication in a local newspaper or newsletter distributed to customers; (ii) use of email to notify employees or students; or (iii) delivery of multiple copies in central locations (e.g., community centers).

e. Maintain a posted public notice in place for as long as the violation, exceedance, or situation persists, but in no case for less than seven days, even if the violation, exceedance, or situation is resolved.

3. For Tier 3 violations, exceedances, or situations the owner shall:

a. Provide the public notice not later than one year after the owner learns of the violation, exceedance, or situation or begins operating under a variance or exemption.

b. Repeat the public notice annually for as long as the violation, exceedance, variance, exemption, or other situation persists.

c. Maintain a posted public notice in place for as long as the violation, exceedance, variance, exemption, or other situation persists, but in no case less than seven days even if the violation, exceedance, or situation is resolved.

d. Instead of individual Tier 3 public notices, the owner may use an annual report detailing all violations, exceedances, and situations that occurred during the previous 12 months, as long as the timing requirements of subdivision C 3 a of this section are met. For a community waterworks, the CCR may be used as a vehicle for the initial Tier 3 public notice and all required repeat notices, provided that:

(1) The CCR is provided to persons served by the waterworks no later than 12 months after the owner learns of the violation, exceedance, or other situation.

(2) The Tier 3 public notice contained in the CCR meets the content requirements in subsection D of this section.

(3) The CCR is distributed in a manner meeting the delivery requirements in subdivision C 3 e (1) of this section.

e. For a community waterworks, the owner shall:

(1) Mail or otherwise directly deliver the public notice to each customer receiving a bill and to other service connections to which water is delivered by the waterworks; and

(2) Use any other method reasonably calculated to reach other persons regularly served by the waterworks if they would not normally be reached by the notice required in subdivision C 3 e (1) of this section. These persons may include those who do not pay water bills or do not have service connection addresses (e.g., house renters, apartment dwellers, university students, nursing home patients, prison inmates, etc.). Other methods may include (i) publication in a local newspaper, (ii) delivery of multiple copies for distribution by customers that provide their drinking water to others (e.g., apartment building owners or large private employers), (iii) posting in public places or on the Internet, or (iv) delivery to community organizations.

f. For a noncommunity waterworks the owner shall:

(1) Post the public notice in conspicuous locations throughout the distribution system frequented by persons served by the waterworks, or by mail or direct delivery to each customer and service connection (where known); and

(2) Use any other method reasonably calculated to reach other persons served by the waterworks, if they would not normally be reached by the notice required in subdivision C 3 f (1) of this section. These persons may include those who may not see a posted notice because the notice is not in a location they routinely pass by. Other methods may include (i) publication in a local newspaper or newsletter distributed to customers, (ii) use of email to notify employees or students, or (iii) delivery of multiple copies in central locations (e.g., community centers).

D. Public notice contents.

1. Each public notice for PMCL, MRDL, and TT violations and other situations requiring a public notice shall include the following elements:

a. A description of the violation, exceedance, or situation, including the contaminants of concern, and (as applicable) the contaminant levels;

b. When the violation, exceedance, or situation occurred;

c. Any potential adverse health effects from the violation, exceedance, or situation, including the standard language under subdivision 5 a or 5 b of this subsection, whichever is applicable;

d. The population at risk, including subpopulations particularly vulnerable if exposed to the contaminant in their drinking water;

e. Whether alternative water supplies should be used;

f. What actions consumers should take, including when they should seek medical help, if known;

g. What the owner is doing to correct the violation, exceedance, or situation;

h. When the owner expects the waterworks to return to compliance or resolve the situation;

i. The name, business address, and phone number of the owner, operator, or designee as a source of additional information concerning the notice; and

j. A statement to encourage the notice recipient to distribute the public notice to other persons served, using the standard language under subdivision 5 c of this subsection, where applicable.

2. Each public notice for a waterworks that has been granted a variance or exemption shall include the following elements:

a. An explanation of the reasons for the variance or exemption;

b. The date on which the variance or exemption was issued;

c. A brief status report on the steps the owner is taking to install treatment, find alternative sources of source water, or otherwise comply with the terms and schedules of the variance or exemption; and

d. A notice of any opportunity for public input in the evaluation of the variance or exemption.

3. Each public notice for a waterworks that violates the conditions of a variance or an exemption shall contain the 10 elements listed in subdivision D 1 of this section.

4. Each public notice shall:

a. Be displayed in a conspicuous way when printed or posted;

b. Not contain overly technical language or very small print;

c. Not be formatted in a way that defeats the purpose of the notice;

d. Not contain language that nullifies the purpose of the notice; and

e. Contain information in the appropriate languages, for waterworks serving a large proportion of non-English-speaking consumers, regarding the importance of the notice or contain a telephone number or address where persons served may contact the owner to obtain a translated copy of the notice or to request assistance in the appropriate language.

5. The public notice shall include the following standard language:

a. For PMCL or MRDL violations, treatment technique violations, and violations of the condition of a variance or an exemption, use standard health effects language as specified in 12VAC5-590-546 corresponding to each PMCL, MRDL, and treatment technique violation and for each violation of a condition of a variance or an exemption. For violation of the treatment technique requirement, the public notice shall also include one or both of the following statements, as appropriate:

(1) "We failed to conduct the required assessment."

(2) "We failed to correct all sanitary defects that were identified during the assessment."

b. For monitoring and testing procedure violations including failure to monitor for total coliform bacteria or E. coli before serving water from a seasonal waterworks, use standard language as specified below, including the language necessary to fill in the blanks:

"We are required to monitor your drinking water for specific contaminants on a regular basis. Results of regular monitoring are an indicator of whether or not your drinking water meets health standards. During (compliance period), we (did not monitor or test or did not complete all monitoring or testing) for (contaminants) and therefore cannot be sure of the quality of your drinking water during that time."

c. For all public notices, use standard language (where applicable), as specified in this subdivision c:

"Please share this information with all the other people who drink this water, especially those who may not have received this notice directly (e.g., people in apartments, nursing homes, schools, and businesses). You can do this by posting this notice in a public place or distributing copies by hand or mail."

d. For total coliform bacteria treatment technique violations the public notice shall include the following statement: "We found coliforms indicating the need to look for potential problems in our waterworks. When this occurs, we are required to conduct assessments to identify problems and correct any problems that are found." The public notice shall also include the following statements, as appropriate:

(1) "We failed to conduct the required assessment."

(2) "We failed to correct all sanitary defects that were identified during the assessment."

e. For E. coli treatment technique violations the public notice shall include the following statement: "We violated the standard for E. coli, indicating the need to look for potential problems in our waterworks. When this occurs, we are required to conduct a detailed assessment to identify problems and to correct any problems that are found." The public notice shall also include the following statements, as appropriate:

(1) "We failed to conduct the required assessment."

(2) "We failed to correct all sanitary defects that were identified during the assessment."

E. Public notice to new billing units or customers.

1. For a community waterworks, the owner shall give a copy of the most recent public notice for any continuing violation, exceedance, variance, exemption, or other ongoing situation requiring a public notice to all new billing units or new customers before or at the time service begins.

2. For a noncommunity waterworks, the owner shall continuously post the public notice in conspicuous locations to inform new consumers of any continuing violation, exceedance, variance, exemption, or other situation requiring a public notice for as long as the violation, exceedance, variance, exemption, or other situation persists.

F. Special notice of the availability of UC monitoring results.

1. The owner of a community waterworks or a NTNC shall notify persons served by the waterworks of the availability of the results of the sampling no later than 12 months after the monitoring results are known.

2. The special notice shall meet the requirements of a Tier 3 public notice and shall identify a person and telephone number to contact for information on the monitoring results.

G. Special notice for exceedance of the SMCL for fluoride.

1. A community waterworks that exceeds the SMCL of 2 mg/L but does not exceed the PMCL of 4 mg/L for fluoride shall provide public notice to persons served as soon as practical but no later than 12 months from the day the owner learns of the exceedance.

2. A copy of the notice shall be sent to all new billing units and new customers at the time service begins and to the department.

3. The owner shall repeat the notice at least annually for as long as the SMCL is exceeded.

4. If the public notice is posted, then the notice shall remain in place for as long as the SMCL is exceeded, but in no case less than seven days even if the exceedance is eliminated.

5. On a case-by-case basis, the department may require an initial notice sooner than 12 months and repeat notices more frequently than annually.

6. The form and manner of the public notice (including repeat notices) shall meet the requirements of a Tier 3 public notice.

7. The public notice shall contain the following language, including the language necessary to fill in the blanks:

"This is an alert about your drinking water and a cosmetic dental problem that might affect children under nine years of age. At low levels, fluoride can help prevent cavities, but children drinking water containing more than 2 milligrams per liter (mg/L) of fluoride may develop cosmetic discoloration of their permanent teeth (dental fluorosis). The drinking water provided by your community waterworks (name) has a fluoride concentration of (insert value) mg/L. Dental fluorosis, in its moderate or severe forms, may result in a brown staining and/or pitting of the permanent teeth. This problem occurs only in developing teeth, before they erupt from the gums. Children under nine should be provided with alternative sources of drinking water or water that has been treated to remove the excess fluoride to avoid the possibility of staining and pitting of their permanent teeth. You may also want to contact your dentist about proper use by young children of fluoride-containing products by young children. Older children and adults may safely drink the water. Drinking water containing more than 4 mg/L of fluoride (the U.S. Environmental Protection Agency's drinking water standard) can increase your risk of developing bone disease. Your drinking water does not contain more than 4 mg/L of fluoride, but we are required to notify you when we discover that the fluoride levels in your drinking water exceed 2 mg/L because of this cosmetic dental problem. For more information, please call (name of water system contact) of (name of community waterworks) at (phone number). Some home water treatment units are also available to remove fluoride from drinking water. To learn more about available home water treatment units, you may call NSF International at 1-877-867-3435 or email info@nsf.org."

H. Special notice for nitrate exceedances above PMCL by a noncommunity waterworks.

1. The owner of a noncommunity waterworks granted permission by the department to exceed the nitrate PMCL shall provide public notice to persons served meeting the requirements of a Tier 1 notice.

2. The public notice shall be posted continuously and shall indicate the fact that nitrate levels exceed 10 mg/L and the potential health effects of exposure, meeting the requirements of Tier 1 public notice delivery and content.

I. Special notice for repeated failure to conduct sampling of the source water for Cryptosporidium.

1. The owner who is required to sample source water shall provide public notice to persons served when the owner has failed to collect any three months of required samples. The form and manner of the public notice shall satisfy the requirements of a Tier 2 notice, and the notice shall be repeated in accordance with the requirements of a Tier 2 notice.

2. The notice shall contain the following language, including the language to fill in the blanks:

"We are required to monitor the source of your drinking water for Cryptosporidium. Results of the monitoring are to be used to determine whether water treatment at the (blank – fill in treatment plant name) is sufficient to adequately remove Cryptosporidium from your drinking water. We are required to complete this monitoring and make this determination by (blank – fill in required bin determination date) We "did not monitor" or "did not complete all monitoring or testing" on schedule and, therefore, we may not be able to determine by the required date what treatment modifications, if any, shall be made to ensure adequate Cryptosporidium removal. Missing this deadline may, in turn, jeopardize our ability to have the required treatment modifications, if any, completed by the deadline required, (blank – fill in date).

For more information, please call (blank – fill in name of waterworks contact) of (blank – fill in name of waterworks) at (blank – fill in phone number)."

3. The notice shall contain a description of what the owner is doing to correct the violation and when the owner expects the waterworks to return to compliance or resolve the situation.

J. Special notice for failure to determine bin classification or mean Cryptosporidium level.

1. The owner that is required to determine a bin classification or to determine mean Cryptosporidium level shall provide public notice to persons served when the determination has not been made as required. The form and manner of the public notice shall satisfy the requirements of a Tier 2 notice, and the notice shall be repeated in accordance with the requirements of a Tier 2 notice. However, a public notice is not required if the owner is complying with a schedule to address the violation approved by the department.

2. The notice shall contain the following language, including the language to fill in the blanks:

"We are required to monitor the source of your drinking water for Cryptosporidium in order to determine by [blank – fill in date] whether water treatment at the (blank – fill in treatment plant name) is sufficient to adequately remove Cryptosporidium from you drinking water. We have not made this determination by the required date. Our failure to do this may jeopardize our ability to have the required treatment modifications, if any, completed by the required deadline of (blank – fill in date). For more information, please call (blank – fill in name of waterworks contact) of (blank – fill in name of waterworks) at (blank – fill in telephone number)."

3. The notice shall contain a description of what the owner is doing to correct the violation and when the owner expects the waterworks to return to compliance or resolve the situation.

K. Special notice for significant deficiencies by a noncommunity groundwater system.

1. An owner of a noncommunity groundwater system that has not corrected a significant deficiency within one year of being notified by the department shall provide public notice to the consumers.

2. The form and manner of the public notice shall satisfy the requirements of a Tier 2 notice.

3. The owner shall continue to notify the public annually until the requirements of 12VAC5-590-421 have been satisfied. The notice shall include:

a. The nature of the significant deficiency and the date it was identified by the department; and

b. The department approved plan and schedule for correcting the significant deficiency including interim measures, progress to date, and which of the interim measures have been completed.

4. For a noncommunity groundwater system with a large proportion of non-English-speaking consumers, the notice shall contain information in the appropriate languages regarding the importance of the notice or contain a telephone number or address where the consumers may contact the owner to obtain a translated copy of the notice or assistance with the appropriate language.

5. If directed by the department, the owner of a noncommunity groundwater system with significant deficiencies that have been corrected shall inform the consumers of the significant deficiencies, how the deficiencies were corrected, and the date of correction.

L. The department may give notice to the public required by this section on behalf of the owner as long as the notice complies with the requirements of this section. However, the owner remains legally responsible for ensuring that the requirements of this section are met.

M. The department may require an owner to provide public notice for significant changes in water quality.

N. Within 10 days of completion of each initial and repeat public notice, the owner shall provide the department with the following:

1. A certification that the owner has fully complied with the public notice requirements; and

2. A representative copy of each type of notice that was distributed, published, posted, and made available to the persons served by the waterworks and to the media.

O. The owner shall maintain copies of each public notice and certification for at least three years after issuance.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-005.10 § 2.21, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 12, Issue 2, eff. November 15, 1995; Volume 18, Issue 19, eff. July 3, 2002; Volume 19, Issue 24, eff. September 10, 2003; Volume 21, Issue 13, eff. April 6, 2005; Volume 22, Issue 15, eff. May 3, 2006; Volume 25, Issue 5, eff. December 10, 2008; Volume 28, Issue 5, eff. December 7, 2011; Volume 33, Issue 3, eff. November 2, 2016; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-545. Consumer confidence reports.

A. Purpose and applicability.

1. The owner of a community waterworks shall deliver to the owner's customers an annual report that contains information on the quality of the water delivered by the waterworks and characterizes the risks, if any, from exposure to contaminants detected in the drinking water.

2. For the purpose of this section, customers are defined as billing units or service connections to which water is delivered by a community waterworks.

3. For the purpose of this section, a contaminant is detected when the laboratory reports the contaminant level as a measured level and not as "non-detect," "not detected," "ND," or less than a certain level. These express that an analyte in a test sample cannot be reliably detected with the test equipment or laboratory instrumentation and the method used.

B. Effective dates.

1. The owner of an existing community waterworks shall deliver the report by July 1 annually.

2. The owner of a new community waterworks shall deliver the first report by July 1 of the year after its first full calendar year in operation and annually thereafter.

3. The owner of a community waterworks that sells water to a consecutive waterworks shall deliver the applicable information necessary to comply with the requirements contained in this section to the consecutive waterworks by April 1 annually, or on a date mutually agreed upon by the seller and the purchaser and specifically included in a contract between the parties.

C. Content.

1. The owner of a community waterworks shall provide the owner's customers an annual report that contains the information on the source of the water delivered as follows:

a. The report shall identify the source of the water delivered by the community waterworks by providing information on:

(1) The type of the source water (e.g., surface water, ground water); and

(2) The commonly used name, if any, and location of the body of the source water.

b. Where a source water assessment has been completed, the report shall:

(1) Notify consumers of the availability of the assessment;

(2) Describe the means to obtain the assessment; and

(3) Include a brief summary of the waterworks' susceptibility to potential sources of contamination.

c. The owner is encouraged to highlight in the report significant sources of contamination in the source water area if the information is readily available.

2. For the purpose of compliance with this section, the report shall include the following definitions:

a. "Maximum contaminant level goal" or "MCLG" means the level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety.

b. "Maximum contaminant level" or "MCL" means the highest level of a contaminant that is allowed in drinking water. MCLs are set as close to the MCLGs as feasible using the best available treatment technology.

c. The report for a community waterworks operating under a variance or an exemption issued by the commissioner under 12VAC5-590-140 and 12VAC5-590-150 shall include the following definition: "Variances and exemptions" means state or EPA permission not to meet an MCL or a treatment technique under certain conditions.

d. The report that contains data on contaminants that EPA regulates using any of the following terms shall include the applicable definitions:

(1) "Treatment technique" means a required process intended to reduce the level of a contaminant in drinking water.

(2) "Action level" means the concentration of a contaminant that, if exceeded, triggers treatment or other requirements that an owner shall follow.

(3) "Maximum residual disinfectant level goal" or "MRDLG" means the level of a drinking water disinfectant below which there is no known or expected risk to health. MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contaminants.

(4) "Maximum residual disinfectant level" or "MRDL" means the highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for the control of microbial contaminants.

(5) "Level 1 assessment" means a study of the waterworks to identify potential problems and determine, if possible, why total coliform bacteria have been found in waterworks.

(6) "Level 2 assessment" means a very detailed study of the waterworks to identify potential problems and determine, if possible, why an E. coli PMCL violation has occurred and why total coliform bacteria have been found in waterworks on multiple occasions.

3. Information on detected contaminants.

a. This section specifies the requirements for information to be included in the report for contaminants subject to a PMCL, AL, MRDL, or treatment technique as specified in 12VAC5-590-340.

b. The data relating to these contaminants shall be displayed in one table or in several adjacent tables. Any additional monitoring results that an owner of a community waterworks chooses to include in the report shall be displayed separately.

c. The data shall be derived from data collected to comply with EPA and state monitoring and analytical requirements during the calendar year preceding the year the report is due, except that where an owner is allowed to monitor for contaminants specified in subdivision C 3 a of this section less often than once a year, the table shall include the date and results of the most recent sampling, and the report shall include a brief statement indicating that the data presented in the report are from the most recent testing done in accordance with this chapter. No data older than five years need be included.

d. For detected contaminants subject to a PMCL, AL, MRDL, or treatment technique as listed in Tables 340.1 through 340.7, the tables shall contain:

(1) The PMCL for that contaminant expressed as a number equal to or greater than 1.0 as provided in 12VAC5-590-546;

(2) The MCLG for that contaminant expressed in the same units as the PMCL as provided in 12VAC5-590-546;

(3) If there is no PMCL for a detected contaminant, then the tables shall indicate that there is a treatment technique, or specify the AL, applicable to that contaminant, and the report shall include the definitions for treatment technique, AL, or both, as appropriate, specified in subdivision C 3 d of this section;

(4) For contaminants subject to a PMCL, except turbidity and E. coli, the highest contaminant level used to determine compliance and the range of detected levels is as follows:

(a) When compliance with the PMCL is determined annually or less frequently, the highest detected level at any sampling point and the range of detected levels expressed in the same units as the PMCL.

(b) When compliance with the PMCL is determined by calculating an RAA of all samples collected at a sampling point, the highest average of any of the sampling points and the range of all sampling points expressed in the same units as the PMCL. For the PMCLs for TTHM and HAA5, the owner shall include the highest LRAA and the range of individual sample results for all sampling points expressed in the same units as the PMCL. If more than one location exceeds the TTHM or HAA5 PMCL, then the owner shall include the LRAAs for all locations that exceed the PMCL.

(c) When compliance with the PMCL is determined on a system-wide basis by calculating an RAA of all samples at all sampling points, the average and range of detection expressed in the same units as the PMCL. The range of detection for TTHM and HAA5 shall include the individual sample results for the purpose of establishing the monitoring locations for EPA's "Stage 2 Disinfectants and Disinfection Byproducts Rule" initial distribution system evaluation.

(5) For turbidity, the highest single measurement and the lowest monthly percentage of combined filter samples meeting the turbidity limits specified in 12VAC5-590-395 A 2 b for the filtration technology being used. The report should include an explanation of the reasons for measuring turbidity;

(6) For lead and copper, the 90th percentile value of the most recent round of sampling and the number of sampling sites exceeding the AL;

(7) For E. coli, the total number of positive samples; and

(8) The likely source or sources of the detected contaminants. Specific information regarding contaminants may be available in sanitary surveys and source water assessments, and should be used when available to the owner. If the owner lacks specific information on the likely source, then the report shall include one or more of the typical sources for that contaminant listed in 12VAC5-590-546 that are most applicable to the system.

e. If the owner of a community waterworks distributes water to the owner's customers from multiple hydraulically independent distribution systems that are fed by different source waters, then:

(1) The table shall contain a separate column for each service area and the report shall identify each separate distribution system; or

(2) The owner shall produce a separate report tailored to include data for each service area.

f. The table shall clearly identify any data indicating violations of PMCLs, MRDLs, or treatment techniques and the report shall contain a clear and readily understandable explanation of the violation including:

(1) The length of the violation;

(2) The potential adverse health effects using the relevant language of 12VAC5-590-546; and

(3) Actions taken by the owner to address the violation.

4. Information on Cryptosporidium, radon, and other contaminants:

a. If the owner has performed any monitoring for Cryptosporidium, which indicates that Cryptosporidium may be present in the source water or the finished water, then the report shall include:

(1) A summary of the results of the monitoring; and

(2) An explanation of the significance of the results.

b. If the owner has performed any monitoring for radon, which indicates that radon may be present in the finished water, then the report shall include:

(1) The results of the monitoring; and

(2) An explanation of the significance of the results.

c. If the owner has performed additional monitoring that indicates the presence of other contaminants in the finished water, then the report should include any results that may indicate a health concern, as determined by the commissioner or department. Detections above a proposed MCL or health advisory level may indicate possible health concerns. For these contaminants, the report should include:

(1) The results of the monitoring; and

(2) An explanation of the significance of the results noting the existence of a health advisory or a proposed regulation.

5. Compliance with other regulations. In addition to the requirements of subdivision C 3 f of this section, the report shall note any violation that occurred during the year covered by the report of a requirement listed in this subdivision 5:

a. Monitoring and reporting of compliance data;

b. Filtration and disinfection prescribed by 12VAC5-590-395. For an owner who has failed to install adequate filtration or disinfection equipment or processes or has had a failure of such equipment or processes that constitutes a violation, the report shall include the following language as part of the explanation of potential adverse health effects: "Inadequately treated water may contain disease-causing organisms. These organisms include bacteria, viruses, and parasites, which can cause symptoms such as nausea, cramps, diarrhea, and associated headaches";

c. Lead and copper control requirements prescribed by 12VAC5-590-375. For that fails to take one or more of the prescribed actions, the report shall include the applicable language of 12VAC5-590-546 for lead, copper, or both;

d. Treatment techniques for acrylamide and epichlorohydrin prescribed by 12VAC5-590-395 B. For an owner who violates the requirements of that section, the report shall include the relevant language from 12VAC5-590-546;

e. Recordkeeping of compliance data;

f. Special monitoring requirements for sodium; and

g. Violation of the terms of a variance, an exemption, or an administrative or judicial order.

6. Variances and exemptions. If a waterworks is operating under the terms of a variance or an exemption issued by the commissioner under 12VAC5-590-140 and 12VAC5-590-150, then the report shall contain:

a. An explanation of the reasons for the variance or exemption;

b. The date on which the variance or exemption was issued;

c. A brief status report on the steps the owner is taking to install treatment, find alternative sources of source water, or otherwise comply with the terms and schedules of the variance or exemption; and

d. A notice of any opportunity for public input in the evaluation or renewal of the variance or exemption.

7. Additional information.

a. The report shall contain a brief explanation regarding contaminants, which may reasonably be expected to be found in drinking water including bottled water. This explanation shall include the exact language of subdivisions 7 a (1), 7 a (2), and 7 a (3) of this subsection or the owner shall use comparable language following approval by the department. The report also shall include the exact language of subdivision 7 a (4) of this subsection.

(1) The sources of drinking water (both tap water and bottled water) include rivers, lakes or reservoirs, streams, ponds, reservoirs, springs, and wells. As water travels over the surface of the land or through the ground, it dissolves naturally occurring minerals and, in some cases, radioactive material, and can pick up substances resulting from the presence of animals or from human activity.

(2) Contaminants that may be present in source water include: (i) microbial contaminants, such as viruses and bacteria, which may come from sewage treatment plants, septic systems, agricultural livestock operations, and wildlife; (ii) inorganic contaminants, such as salts and metals, which can be naturally occurring or result from urban stormwater runoff, industrial or domestic wastewater discharges, oil and gas production, mining, or farming; (iii) pesticides and herbicides, which may come from a variety of sources such as agriculture, urban stormwater runoff, and residential uses; (iv) organic chemical contaminants, including SOCs and VOCs, which are byproducts of industrial processes and petroleum production, and can also come from gas stations, urban stormwater runoff, and septic systems; and (v) radioactive contaminants, which can be naturally occurring or be the result of oil and gas production and mining activities.

(3) To ensure that tap water is safe to drink, EPA prescribes regulations that limit the amount of certain contaminants in the water provided by waterworks. The U.S. Food and Drug Administration (FDA) regulations establish limits for contaminants in bottled water which must provide the same protection for public health.

(4) Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily indicate that water poses a health risk. More information about contaminants and potential health effects can be obtained by calling EPA's Safe Drinking Water Hotline (800-426-4791).

b. The report shall include the telephone number of the owner, operator, or designee of the community waterworks as a source of additional information concerning the report.

c. In communities with a large proportion of non-English-speaking residents, as determined by the department, the report shall contain information in the appropriate languages regarding the importance of the report or contain a telephone number or address where the residents may contact the waterworks to obtain a translated copy of the report or assistance in the appropriate language.

d. The report shall include the following information about opportunities for public participation in decisions that may affect the quality of the drinking water. The owner should consider including the following additional relevant information:

(1) The time and place of regularly scheduled board meetings of the governing body that has authority over the waterworks; and

(2) If regularly scheduled board meetings are not held, then the name and telephone number of a waterworks representative who has operational or managerial authority over the waterworks.

e. The owner may include additional information as deemed necessary for public education consistent with, and not detracting from, the purpose of the report.

f. For a community groundwater system:

(1) Where there is a significant deficiency that is uncorrected at the time of the report or an E. coli-positive source water sample that is not invalidated in accordance with 12VAC5-590-380 at the time of the report, the owner shall report the following:

(a) The nature of the significant deficiency or the source water, if known, of the E. coli contamination;

(b) The date the significant deficiency was identified by the department or the date or dates of the E. coli-positive source water samples;

(c) Whether the E. coli contamination has been addressed in accordance with 12VAC5-590-421 and the date of the action;

(d) The department-approved plan and schedule, including interim measures, progress to date, and which interim measures have been completed for correcting the significant deficiency or E. coli contamination; and

(e) The potential health effects language in 12VAC5-590-546 for an E. coli-positive source water sample that is not invalidated in accordance with 12VAC5-590-380.

(2) If directed by the department, where there are significant deficiencies that have been corrected at the time of the report, then the owner shall report the significant deficiencies, how the deficiencies were corrected, and the date or dates of correction.

D. Additional health information.

1. All reports shall prominently display the following language: Some people may be more vulnerable to contaminants in drinking water than the general population. Immuno-compromised persons such as persons with cancer who are undergoing chemotherapy, persons who have undergone organ transplants, people with HIV/AIDS or other immune system disorders, some elderly, and infants can be particularly at risk from infections. These people should seek advice about drinking water from their health care providers. EPA and Centers for Disease Control and Prevention guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbial contaminants are available from the Safe Drinking Water Hotline (800-426-4791).

2. The owner that detects arsenic at levels above 0.005 mg/L, but equal to or below the PMCL of 0.010 mg/L, shall include in the report the following informational statement about arsenic: "While your drinking water meets EPA's standard for arsenic, it does contain low levels of arsenic. EPA's standard balances the current understanding of arsenic's possible health effects against the cost of removing arsenic from drinking water. EPA continues to research the health effects of low levels of arsenic, which is a mineral known to cause cancer in humans at high concentrations and is linked to other health effects such as skin damage and circulatory problems."

Instead of the statement required in this subdivision, the owner may include the owner's educational statement after receiving approval from the department.

3. The owner that detects nitrate at levels above 5 mg/L, but below the PMCL, shall include in the report the following informational statement about the impacts of nitrate on children: "Nitrate in drinking water at levels above 10 ppm is a health risk for infants of less than six months of age. High nitrate levels in drinking water can cause blue baby syndrome. Nitrate levels may rise quickly for short periods of time because of rainfall or agricultural activity. If you are caring for an infant, then you should ask advice from your health care provider."

Instead of the statement required in this subdivision, the owner may include the owner's own educational statement after receiving approval from the department.

4. All reports shall prominently display the following language: "If present, elevated levels of lead can cause serious health problems, especially for pregnant women and young children. Lead in drinking water is primarily from materials and components associated with service lines and home plumbing. (Name of Utility) is responsible for providing high quality drinking water, but cannot control the variety of materials used in plumbing components. When your water has been sitting for several hours, you can minimize the potential for lead exposure by flushing your tap for 30 seconds to two minutes before using water for drinking or cooking. If you are concerned about lead in your water, then you may wish to have your water tested. Information on lead in drinking water, testing methods, and steps you can take to minimize exposure is available from the Safe Drinking Water Hotline (800-426-4791)."

Instead of the statement required in this subdivision, the owner may include the owner's educational statement after receiving approval from the department.

E. The owner of a community waterworks required to complete a Level 1 or a Level 2 assessment that is not due to an E. coli PMCL violation shall include in the report the text specified in subdivisions E 1, E 2, and E 3 of this section as appropriate, filling in the blanks accordingly, and shall include in the report the text specified in subdivision E 4 of this section, if appropriate.

1. "Coliforms are bacteria that are naturally present in the environment and are used as an indicator that other, potentially harmful, waterborne pathogens may be present or that a potential pathway exists through which contamination may enter the drinking water distribution system. We found coliforms indicating the need to look for potential problems in water treatment or distribution. When this occurs, we are required to conduct assessments to identify problems and to correct any problems that are found."

2. "During the past year, we were required to conduct (insert the number of Level 1 assessments) Level 1 assessments. (insert the number of Level 1 assessments) Level 1 assessments were completed. In addition, we were required to take t (insert the number of corrective actions) corrective actions and we completed (insert the number of corrective actions) of these actions."

3. "During the past year (insert the number of Level 2 assessments) Level 2 assessments were required to be completed for our waterworks. (insert the number of Level 2 assessments) Level 2 assessments were completed. In addition, we were required to take (insert the number of corrective actions) corrective actions and we completed (insert the number of corrective actions) of these actions."

4. An owner that failed to complete all of the required assessments or correct all identified sanitary defects shall also include one or both of the following statements, as appropriate:

a. "During the past year, we failed to conduct all of the required assessments."

b. "During the past year, we failed to correct all identified sanitary defects that were found during the assessments."

F. The owner of a community waterworks required to conduct Level 2 assessments due to an E. coli PMCL violation shall include in the report the text specified in subdivisions F 1 and F 2 of this section, filling in the blanks accordingly, and shall include in the report the text specified in subdivision F 3 of this section, if appropriate.

1. "E. coli are bacteria whose presence indicates that the water may be contaminated with human or animal wastes. Human pathogens in these wastes can cause short-term effects, such as diarrhea, cramps, nausea, headaches, or other symptoms. They may pose a greater health risk for infants, young children, the elderly, and people with severely compromised immune systems. We found E. coli, indicating the need to look for potential problems in water treatment or distribution. When this occurs, we are required to conduct assessments to identify problems and to correct any problems that are found."

2. "We were required to complete a Level 2 assessment because we found E. coli in our waterworks. In addition, we were required to take (insert number of corrective actions) corrective actions and we completed (insert number of corrective actions) of these actions."

3. Any owner that has failed to complete the required assessment or correct all identified sanitary defects shall also include one or both of the following statements, as appropriate:

a. "We failed to conduct the required assessment."

b. "We failed to correct all sanitary defects that were identified during the assessment that we conducted."

4. If E. coli is detected in a waterworks and the E. coli PMCL is violated, in addition to completing the table as specified in subdivision C 3 d of this section, the owner shall include one or more of the following statements to describe any noncompliance, as applicable:

a. "We had an E. coli-positive repeat sample following a total coliform-positive routine sample."

b. "We had a total coliform-positive repeat sample following an E. coli-positive routine sample."

c. "We failed to collect all the required repeat samples following an E. coli-positive routine sample."

d. "We failed to test for E. coli when any repeat sample tested positive for total coliform."

5. If E. coli is detected in a waterworks and the E. coli PMCL is not violated, in addition to completing the table as specified in subdivision C 3 d of this section, the owner may include a statement that explains that although E. coli was detected, the owner is not in violation of the E. coli PMCL.

G. Report delivery and recordkeeping.

1. The owner of a community waterworks shall mail or otherwise directly deliver one copy of the report to each customer, except as follows:

a. The owner serving fewer than 10,000 persons shall have the option to either mail (or otherwise directly deliver) a copy of the report to each customer or publish the report in a local newspaper or newspapers of general circulation serving the area in which the waterworks is located by July 1 of each year; and

b. If the owner chooses to publish the report, then the owner shall inform customers, either in the newspaper in which the report is to be published or by other means approved by the department, that a copy of the report will not be mailed to them and that a copy of the report will be made available to the public upon request.

2. The owner of a community waterworks shall make a good faith effort to deliver the report to the consumers who are served by the waterworks but are not bill-paying customers, such as renters or workers. This good faith effort shall include at least one, and preferably two or more, of the following methods appropriate to the particular waterworks:

a. Posting the reports on the Internet;

b. Mailing to postal patrons in metropolitan areas;

c. Advertising the availability of the report in the news media;

d. Publishing in a local newspaper;

e. Posting in public places such as libraries, community centers, and public buildings;

f. Delivering multiple copies for distribution by single-biller customers such as apartment buildings or large private employers;

g. Delivering to community organizations; or

h. Other methods as approved by the department.

3. No later than July 1 of each year, the owner of a community waterworks shall deliver a copy of the report to the department, followed within three months by a certification that the report has been distributed to customers and that the information in the report is correct and consistent with the compliance monitoring data previously submitted to the department.

4. No later than July 1 of each year, the owner of a community waterworks shall deliver the report to any other agency or clearinghouse specified by the department.

5. The owner of a community waterworks shall make the report available to the public upon request.

6. The owner of a community waterworks serving 100,000 or more persons shall post the current year's report to a publicly accessible site on the Internet.

7. The owner of a community waterworks shall retain copies of the report for no less than three years.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 16, Issue 21, eff. August 3, 2000; amended, Virginia Register Volume 22, Issue 24, eff. September 6, 2006; Volume 25, Issue 5, eff. December 10, 2008; Volume 27, Issue 1, eff. October 13, 2010; Volume 28, Issue 5, eff. December 7, 2011; Volume 28, Issue 11, eff. March 1, 2012; Volume 33, Issue 3, eff. November 2, 2016; Volume 37, Issue 20, eff. June 23, 2021; Errata, 37:22 VA.R. 3448 June 21, 2021.

12VAC5-590-546. Regulated contaminants for the consumer confidence reports and public notification.

A. Public notices and CCRs shall contain the appropriate mandatory language and information listed, as required by 12VAC5-590-540 and 12VAC5-590-545.

B. Information on regulated contaminants is presented in Table 546.1.

TABLE 546.1
Content Requirements of Consumer Confidence Reports and Public Notices

CONTAMINANT (UNITS)

TRADITIONAL PMCL IN mg/l

TO CONVERT FOR CCR, MULTIPLY BY

PMCL IN CCR UNITS

MCLG

MAJOR SOURCES IN DRINKING WATER

HEALTH EFFECTS LANGUAGE

Microbiological Contaminants

(1) Total Coliform Bacteria

TT

n/a

Naturally present in the environment

Coliforms are bacteria that are naturally present in the environment and are used as an indicator that other, potentially-harmful, waterborne pathogens may be present or that a potential pathway exists through which contamination may enter the waterworks.

(2) E. coli

PMCL: In compliance unless (i) the waterworks has an E. coli-positive repeat sample following a total coliform-positive routine sample; (ii) the waterworks has a total coliform-positive repeat sample following an E. coli-positive routine sample; (iii) the waterworks owner fails to collect all required repeat samples following an E. coli positive routine sample; or (iv) the waterworks owner fails to test for E. coli when any repeat sample tests positive for total coliform.

0

Human and animal fecal waste

E. coli are bacteria whose presence indicates that the water may be contaminated with human or animal wastes. Human pathogens in these wastes can cause short-term effects, such as diarrhea, cramps, nausea, headaches, or other symptoms. They may pose a greater health risk for infants, young children, the elderly, and people with severely-compromised immune systems.

(3) E. coli

TT

n/a

Human and animal fecal waste

E. coli are bacteria whose presence indicates that the water may be contaminated with human or animal wastes. Human pathogens in these wastes can cause short-term health effects, such as diarrhea, cramps, nausea, headaches, or other symptoms. They may pose a greater health risk for infants, young children, the elderly, and people with severely compromised immune system.

(4) Source water fecal indicator (E. coli)

TT

TT

0 for E. coli

Fecal indicators are microbes whose presence indicates that the water may be contaminated with human or animal wastes. Microbes in these wastes can cause short term health effects, such as diarrhea, cramps, nausea, headaches, or other symptoms. They may pose a special health risk for infants, young children, some of the elderly, and people with severely compromised immune system.

(5) Groundwater rule TT violations other than source water fecal indicator E. coli abovea

TT

TT

Inadequately treated or inadequately protected water may contain disease-causing organisms. These organisms can cause symptoms such as diarrhea, nausea, cramps, and associated headaches.

(6)Turbidity

TT

TT

n/a

Soil runoff

Turbidity has no health effects. However, turbidity can interfere with disinfection and provide a medium for microbial growth. Turbidity may indicate the presence of disease-causing organisms. These organisms include bacteria, viruses, and parasites that can cause symptoms such as nausea, cramps, diarrhea, and associated headaches.

(7) Giardia lamblia, viruses, Hetrotropic plate count, Legionella, Cryptosporidiuma

TTc

n/a

0

n/a

Inadequately treated water may contain disease-causing organisms. These organisms include bacteria, viruses, and parasites that can cause symptoms such as nausea, cramps, diarrhea, and associated headaches.

Radioactive Contaminants

(8) Beta/photon emitters (mrem/yr)

4 mrem/yr

4

0

Decay of natural and man-made deposits

Certain minerals are radioactive and may emit forms of radiation known as photons and beta radiation. Some people who drink water containing beta and photon emitters in excess of the PMCL over many years may have an increased risk of getting cancer.

(9) Alpha emitters (pCi/L)

15 pCi/L

15

0

Erosion of natural deposits

Certain minerals are radioactive and may emit a form of radiation known as alpha radiation. Some people who drink water containing alpha emitters in excess of the PMCL over many years may have an increased risk of getting cancer.

(10) Combined radium (pCi/L)

5 pCi/L

5

0

Erosion of natural deposits

Some people who drink water containing radium-226 or radium-228 in excess of the PMCL over many years may have an increased risk of getting cancer.

(11) Uranium (ppb)

30 μg/L

30

0

Erosion of natural deposits

Some people who drink water containing uranium in excess of the PMCL over many years may have an increased risk of getting cancer and kidney toxicity.

Inorganic Contaminants

(12) Antimony (ppb)

0.006

1000

6

6

Discharge from petroleum refineries; fire retardants; ceramics; electronics; solder

Some people who drink water containing antimony well in excess of the PMCL over many years could experience increases in blood cholesterol and decreases in blood sugar.

(13) Arsenic (ppb)

0.010

1000

10.

0

Erosion of natural deposits; Runoff from orchards; Runoff from glass and electronics production wastes

Some people who drink water containing arsenic in excess of the PMCL over many years could experience skin damage or problems with their circulatory system, and may have an increased risk of getting cancer.

(14) Asbestos (MFL)

7 MFL

7

7

Decay of asbestos cement water mains; Erosion of natural deposits

Some people who drink water containing asbestos in excess of the PMCL over many years may have an increased risk of developing benign intestinal polyps.

(15) Barium (ppm)

2

2

2

Discharge of drilling wastes; Discharge from metal refineries; Erosion of natural deposits

Some people who drink water containing barium in excess of the PMCL over many years could experience an increase in their blood pressure.

(16) Beryllium (ppb)

0.004

1000

4

4

Discharge from metal refineries and coal-burning factories; Discharge from electrical, aerospace, and defense industries

Some people who drink water containing beryllium well in excess of the PMCL over many years could develop intestinal lesions.

(17) Cadmium (ppb)

0.005

1000

5

5

Corrosion of galvanized pipes; Erosion of natural deposits; Discharge from metal refineries; Runoff from waste batteries and paints

Some people who drink water containing cadmium in excess of the PMCL over many years could experience kidney damage.

(18) Chromium (ppb)

0.1

1000

100

100

Discharge from steel and pulp mills; Erosion of natural deposits

Some people who drink water containing chromium well in excess of the PMCL over many years could experience allergic dermatitis.

(19) Copper (ppm)

AL=1.3

AL=1.3

1.3

Corrosion of household plumbing systems; Erosion of natural deposits

Copper is an essential nutrient, but some people who drink water containing copper in excess of the AL over a relatively short amount of time could experience gastrointestinal distress. Some people who drink water containing copper in excess of the action level over many years could suffer liver or kidney damage. People with Wilson's Disease should consult their personal doctor.

(20) Cyanide (ppb)

0.2

1000

200

200

Discharge from steel or metal factories; Discharge from plastic and fertilizer factories

Some people who drink water containing cyanide well in excess of the PMCL over many years could experience nerve damage or problems with their thyroid.

(21) Fluoride (ppm)

4

4

4

Erosion of natural deposits; Water additive that promotes strong teeth; Discharge from fertilizer and aluminum factories

Some people who drink water containing fluoride in excess of the PMCL over many years could get bone disease, including pain and tenderness of the bones. Fluoride in drinking water at half the PMCL or more may cause mottling of children's teeth, usually in children less than nine years old. Mottling, also known as dental fluorosis, may include brown staining or pitting of the teeth, and occurs only in developing teeth before they erupt from the gums.

(22) Lead (ppb)

AL=0.015

1000

AL=15

0

Corrosion of household plumbing systems; Erosion of natural deposits

Infants and children who drink water containing lead in excess of the AL could experience delays in their physical or mental development. Children could show slight deficits in attention span and learning abilities. Adults who drink this water over many years could develop kidney problems or high blood pressure.

(23) Mercury [inorganic] (ppb)

0.002

1000

2

2

Erosion of natural deposits; Discharge from refineries and factories; Runoff from landfills; Runoff from cropland

Some people who drink water containing inorganic mercury well in excess of the PMCL over many years could experience kidney damage.

(24) Nitrate (ppm)

10

10

10

Runoff from fertilizer use; Leaching from septic tanks, sewage; Erosion of natural deposits

Infants younger than the age of six months who drink water containing nitrate in excess of the PMCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue baby syndrome.

(25) Nitrite (ppm)

1

1

1

Runoff from fertilizer use; Leaching from septic tanks, sewage; Erosion of natural deposits

Infants younger than the age of six months who drink water containing nitrite in excess of the PMCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue baby syndrome.

(26) Total Nitrate and Nitrite

10

n/a

10

n/a

Infants younger than the age of six months who drink water containing nitrate and nitrite in excess of the PMCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue baby syndrome.

(27) Selenium (ppb)

0.05

1000

50

50

Discharge from petroleum and metal refineries; Erosion of natural deposits; Discharge from mines

Selenium is an essential nutrient. However, some people who drink water containing selenium in excess of the PMCL over many years could experience hair or fingernail losses, numbness in fingers or toes, or problems with their circulation.

(28) Thallium (ppb)

0.002

1000

2

0.5

Leaching from ore-processing sites; Discharge from electronics, glass, and drug factories

Some people who drink water containing thallium in excess of the PMCL over many years could experience hair loss, changes in their blood, or problems with their kidneys, intestines, or liver.

Synthetic Organic Chemicals including Pesticides and Herbicides

(29) 2,4-D (ppb)

0.07

1000

70

70

Runoff from herbicides used on row crops

Some people who drink water containing the weed killer 2,4-D well in excess of the PMCL over many years could experience problems with their kidneys, liver, or adrenal glands.

(30) 2,4,5-TP [Silvex] (ppb)

0.05

1000

50

50

Residue of banned herbicide

Some people who drink water containing silvex in excess of the PMCL over many years could experience liver problems.

(31) Acrylamide

TT

TT

0

Added to water during sewage or wastewater treatment

Some people who drink water containing high levels of acrylamide over a long period of time could have problems with their nervous system or blood and may have an increased risk of getting cancer.

(32) Alachlor (ppb)

0.002

1000

2

0

Runoff from herbicide used on row crops

Some people who drink water containing alachlor in excess of the PMCL over many years could have problems with their eyes, liver, kidneys, or spleen, or experience anemia and may have an increased risk of getting cancer.

(33) Atrazine (ppb)

0.003

1000

3

3

Runoff from herbicide used on row crops

Some people who drink water containing atrazine well in excess of the PMCL over many years could experience problems with their cardiovascular system or reproductive difficulties.

(34) Benzo(a)pyrene [PAH]

0.0002

1,000,000

200

0

Leaching from linings of water storage tanks and distribution lines

Some people who drink water containing benzo(a)pyrene in excess of the PMCL over many years could experience reproductive difficulties and may have an increased risk of getting cancer.

(35) Carbofuran (ppb)

0.04

1000

40

40

Leaching of soil fumigant used on rice and alfalfa

Some people who drink water containing carbofuran in excess of the PMCL over many years could experience problems with their blood, or nervous or reproductive systems.

(36) Chlordane (ppb)

0.002

1000

2

0

Residue of banned termiticide

Some people who drink water containing chlordane in excess of the PMCL over many years could experience problems with their liver or nervous system, and may have an increased risk of getting cancer.

(37) Dalapon (ppb)

0.2

1000

200

200

Runoff from herbicide used on rights of way

Some people who drink water containing dalapon well in excess of the PMCL over many years could experience minor kidney changes.

(38) Di(2-ethylhexyl) adipate (ppb)

0.4

1000

400

400

Discharge from chemical factories

Some people who drink water containing di(2-ethyhexyl)adipate well in excess of the PMCL over many years could experience toxic effects, such as weight loss, liver enlargement or possible reproductive difficulties.

(39) Di(2-ethylhexyl)phthalate (ppb)

0.006

1000

6

0

Discharge from rubber and chemical factories

Some people who drink water containing di(2-ethylhexyl)phthalate in excess of the PMCL over many years may have problems with their liver, or experience reproductive difficulties, and may have an increased risk of getting cancer.

(40) Dibromochloropropane (DBCP) (ppt)

0.0002

1,000,000

200

0

Runoff or leaching from soil fumigant used on soybeans, cotton, pineapples, and orchards

Some people who drink water containing DBCP well in excess of the PMCL over many years could experience reproductive problems and may have an increased risk of getting cancer.

(41) Dinoseb (ppb)

0.007

1000

7

7

Runoff from herbicide used on soybeans and vegetables

Some people who drink water containing dinoseb well in excess of the PMCL over many years could experience reproductive difficulties.

(42) Diquat (ppb)

0.02

1000

20

20

Runoff from herbicide use

Some people who drink water containing diquat in excess of the PMCL over many years could get cataracts.

(43) Dioxin [2,3,7,8-TCDD] (ppq)

0.00000003

1,000,000,000

30

0

Emissions from waste incineration and other combustion; Discharge from chemical factories

Some people who drink water containing dioxin in excess of the PMCL over many years could experience reproductive difficulties and may have an increased risk of getting cancer.

(44) Endothall (ppb)

0.1

1000

100

100

Runoff from herbicide use

Some people who drink water containing endothall in excess of the PMCL over many years could experience problems with their stomach or intestines.

(45) Endrin (ppb)

0.002

1000

2

2

Runoff of banned insecticide

Some people who drink water containing endrin in excess of the PMCL over many years could experience liver problems.

(46) Epichlorohydrin

TT

TT

0

Discharge from industrial chemical factories; An impurity of some water treatment chemicals

Some people who drink water containing high levels of epichlorohydrin over a long period of time could experience stomach problems and may have an increased risk of getting cancer.

(47) Ethylene dibromide (ppt)

0.00005

1,000,000

50

0

Discharge from petroleum refineries

Some people who drink water containing ethylene dibromide in excess of the PMCL over many years could experience problems with their liver, stomach, reproductive system, or kidneys, and may have an increased risk of getting cancer.

(48) Glyphosate (ppb)

0.7

1000

700

700

Runoff from herbicide use

Some people who drink water containing glyphosate in excess of the PMCL over many years could experience problems with their kidneys or reproductive difficulties.

(49) Heptachlor (ppt)

0.0004

1,000,000

400

0

Residue of banned pesticide

Some people who drink water containing heptachlor in excess of the PMCL over many years could experience liver damage and may have an increased risk of getting cancer.

(50) Heptachlor epoxide (ppt)

0.0002

1,000,000

200

0

Breakdown of heptachlor

Some people who drink water containing heptachlor epoxide in excess of the PMCL over many years could experience liver damage and may have an increased risk of getting cancer.

(51) Hexachlorobenzene (ppb)

0.001

1000

1

0

Discharge from metal refineries and agricultural chemical factories

Some people who drink water containing hexachlorobenzene in excess of the PMCL over many years could experience problems with their liver or kidneys or adverse reproductive effects and may have an increased risk of getting cancer.

(52) Hexachlorocyclopentadiene (ppb)

0.05

1000

50

50

Discharge from chemical factories

Some people who drink water containing hexachlorocyclopentadiene well in excess of the PMCL over many years could experience problems with their stomach or kidneys.

(53) Lindane (ppt)

0.0002

1,000,000

200

200

Runoff or leaching from insecticide used on cattle, lumber, gardens

Some people who drink water containing lindane in excess of the PMCL over many years could experience problems with their kidneys or liver.

(54) Methoxychlor (ppb)

0.04

1000

40

40

Runoff or leaching from insecticide used on fruits, vegetables, alfalfa, livestock

Some people who drink water containing methoxychlor in excess of the PMCL over many years could experience reproductive difficulties.

(55) Oxamyl [Vydate] (ppb)

0.2

1000

200

200

Runoff or leaching from insecticide used on apples, potatoes, and tomatoes

Some people who drink water containing oxamyl in excess of the PMCL over many years could experience slight nervous system effects.

(56) PCBs [Polychlorinated biphenyls] (ppt)

0.0005

1,000,000

500

0

Runoff from landfills; Discharge of waste chemicals

Some people who drink water containing PCBs in excess of the PMCL over many years could experience changes in their skin, problems with their thymus gland, immune deficiencies, or reproductive or nervous system difficulties and may have an increased risk of getting cancer.

(57) Pentachlorophenol (ppb)

0.001

1000

1

0

Discharge from wood preserving factories

Some people who drink water containing pentachlorophenol in excess of the PMCL over many years could experience problems with their liver or kidneys and may have an increased risk of getting cancer.

(58) Picloram (ppb)

0.5

1000

500

500

Herbicide runoff

Some people who drink water containing picloram in excess of the PMCL over many years could experience problems with their liver.

(59) Simazine (ppb)

0.004

1000

4

4

Herbicide runoff

Some people who drink water containing simazine in excess of the PMCL over many years could experience problems with their blood.

(60) Toxaphene (ppb)

0.003

1000

3

0

Runoff or leaching from insecticide used on cotton and cattle

Some people who drink water containing toxaphene in excess of the PMCL over many years could experience problems with their thyroid, kidneys, or liver and may have an increased risk of getting cancer.

Volatile Organic Chemicals

(61) Benzene (ppb)

0.005

1000

5

0

Discharge from factories; Leaching from gas storage tanks and landfills

Some people who drink water containing benzene in excess of the PMCL over many years could experience anemia or a decrease in blood platelets and may have an increased risk of getting cancer.

(62) Carbon tetrachloride (ppb)

0.005

1000

5

0

Discharge from chemical plants and other industrial activities

Some people who drink water containing carbon tetrachloride in excess of the PMCL over many years could experience problems with their liver and may have an increased risk of getting cancer.

(63) Chlorobenzene (ppb)

0.1

1000

100

100

Discharge from chemical and agricultural chemical factories

Some people who drink water containing chlorobenzene in excess of the PMCL over many years could experience problems with their liver or kidneys.

(64) o-Dichlorobenzene (ppb)

0.6

1000

600

600

Discharge from industrial chemical factories

Some people who drink water containing o-dichlorobenzene well in excess of the PMCL over many years could experience problems with their liver, kidneys, or spleen or changes in their blood.

(65) p-Dichlorobenzene (ppb)

0.075

1000

75

75

Discharge from industrial chemical factories

Some people who drink water containing p-dichlorobenzene in excess of the PMCL over many years could experience anemia, damage to their liver, kidneys, or circulatory systems.

(66) 1,2-Dichloroethane (ppb)

0.005

1000

5

0

Discharge from industrial chemical factories

Some people who drink water containing 1,2-dichloroethane in excess of the PMCL over many years may have an increased risk of getting cancer.

(67) 1,1-Dichloroethylene (ppb)

0.007

1000

7

7

Discharge from industrial chemical factories

Some people who drink water containing 1,1-dichloroethylene in excess of the PMCL over many years could experience problems with their liver.

(68) cis-1,2-Dichloroethylene (ppb)

0.07

1000

70

70

Discharge from industrial chemical factories

Some people who drink water containing cis-1,2-dichloroethylene in excess of the PMCL over many years could experience problems with their liver.

(69) trans-1,2-Dichloroethylene (ppb)

0.1

1000

100

100

Discharge from industrial chemical factories

Some people who drink water containing trans-1,2-dichloroethylene well in excess of the PMCL over many years could experience problems with their liver.

(70) Dichloromethane (ppb)

0.005

1000

5

0

Discharge from pharmaceutical and chemical factories

Some people who drink water containing dichloromethane in excess of the PMCL over many years could have liver problems and may have an increased risk of getting cancer.

(71) 1,2-Dichloropropane (ppb)

0.005

1000

5

0

Discharge from industrial chemical factories

Some people who drink water containing 1,2-dichloropropane in excess of the PMCL over many years may have an increased risk of getting cancer.

(72) Ethylbenzene (ppb)

0.7

1000

700

700

Discharge from petroleum refineries

Some people who drink water containing ethylbenzene well in excess of the PMCL over many years could experience problems with their liver or kidneys.

(73) Styrene (ppb)

0.1

1000

100

100

Discharge from rubber and plastic factories; Leaching from landfills

Some people who drink water containing styrene well in excess of the PMCL over many years could experience problems with their liver, kidneys, or circulatory system.

(74) Tetrachloroethylene (ppb)

0.005

1000

5

0

Discharge from factories and dry cleaners

Some people who drink water containing tetrachloroethylene in excess of the PMCL over many years could have problems with their liver and may have an increased risk of getting cancer.

(75) 1,2,4-Trichlorobenzene (ppb)

0.07

1000

70

70

Discharge from textile-finishing factories

Some people who drink water containing 1,2,4-trichlorobenzene well in excess of the PMCL over many years could experience changes in their adrenal glands.

(76) 1,1,1,-Trichloroethane (ppb)

0.2

1000

200

200

Discharge from metal degreasing sites and other factories

Some people who drink water containing 1,1,1-trichloroethane in excess of the PMCL over many years could experience problems with their liver, nervous system, or circulatory system.

(77) 1,1,2-Trichloroethane (ppb)

0.005

1000

5

3

Discharge from industrial chemical factories

Some people who drink water containing 1,1,2-trichloroethane well in excess of the PMCL over many years could have problems with their liver, kidneys, or immune systems.

(78) Trichloroethylene (ppb)

0.005

1000

5

0

Discharge from metal degreasing sites and other factories

Some people who drink water containing trichloroethylene in excess of the PMCL over many years could experience problems with their liver and may have an increased risk of getting cancer.

(79) Toluene (ppm)

1

1

1

Discharge from petroleum factories

Some people who drink water containing toluene well in excess of the PMCL over many years could have problems with their nervous system, kidneys, or liver.

(80) Vinyl Chloride (ppb)

0.002

1000

2

0

Leaching from PVC piping; Discharge from plastic factories

Some people who drink water containing vinyl chloride in excess of the PMCL over many years may have an increased risk of getting cancer.

(81) Xylenes (ppm)

10

10

10

Discharge from petroleum factories; Discharge from chemical factories

Some people who drink water containing xylenes in excess of the PMCL over many years could experience damage to their nervous system.

Disinfection Byproducts, Precursors, and Residuals

(82) TTHM [total trihalomethanes] (ppb)

0.080

1000

80

n/a

Byproduct of drinking water disinfection

Some people who drink water containing trihalomethanes (THMs) in excess of the PMCL over many years could experience problems with their liver, kidneys, or central nervous systems, and may have an increased risk of getting cancer.

(83) Haloacetic acids (HAA) (ppb)

0.060

1000

60

n/a

Byproduct of drinking water disinfection

Some people who drink water containing haloacetic acids in excess of the PMCL over many years may have an increased risk of getting cancer.

(84) Bromate (ppb)

0.010

1000

10

0

Byproduct of drinking water disinfection

Some people who drink water containing bromate in excess of the PMCL over many years may have an increased risk of getting cancer.

(85) Chloramines (ppm)

MRDL=4.0

MRDL=4.0

MRDLG=4

Water additive used to control microbes

Some people who use water containing chloramines well in excess of the MRDL could experience irritating effects to their eyes and nose. Some people who drink water containing chloramines well in excess of the MRDL could experience stomach discomfort or anemia.

(86) Chlorine (ppm)

MRDL=4.0

MRDL=4.0

MRDLG=4

Water additive used to control microbes

Some people who use water containing chlorine well in excess of the MRDL could experience irritating effects to their eyes and nose. Some people who drink water containing chlorine well in excess of the MRDL could experience stomach discomfort.

(87) Chlorine dioxide (ppb)b

MRDL=0.8

1000

MRDL=800

MRDLG=800

Water additive used to control microbes

Some infants and young children who drink water containing chlorine dioxide in excess of the MRDL could experience nervous system effects. Similar effects may occur in fetuses of pregnant women who drink water containing chlorine dioxide in excess of the MRDL. Some people may experience anemia.

(88) Chlorine dioxide, where any two consecutive daily samples collected at the entrance to the distribution system are above the MRDL.a

MRDL=0.8

MRDLG=0.8

The chlorine dioxide violations reported today are the result of exceedances at the treatment facility only, not within the distribution system that delivers water to consumers. Continued compliance with chlorine dioxide levels within the distribution system minimizes the potential risk of these violations to consumers.

(89) Chlorine dioxide, where one or more distribution system samples are above the MRDL.a

MRDL=0.8

MRDLG=0.8

The chlorine dioxide violations reported today include exceedances of EPA standard within the distribution system that delivers water to consumers. Violations of the chlorine dioxide standard within the distribution system may harm human health based on short-term exposures. Certain groups, including fetuses, infants, and young children, may be especially susceptible to nervous system effects from excessive chlorine dioxide exposure.

(90) Chlorite (ppm)

1.0

1.0

0.8

Byproduct of drinking water disinfection

Some infants and young children who drink water containing chlorite in excess of the PMCL could experience nervous system effects. Similar effects may occur in fetuses of pregnant women who drink water containing chlorite in excess of the PMCL. Some people may experience anemia.

(91) Total organic carbon (ppm)

TT

TT

n/a

Naturally present in the environment

Total organic carbon (TOC) has no health effects. However, total organic carbon provides a medium for the formation of disinfection byproducts. These byproducts include trihalomethanes (THMs) and haloacetic acids (HAAs). Drinking water containing these byproducts in excess of the PMCL may lead to adverse health effects, liver or kidney problems or nervous systems effects and may lead to an increased risk of getting cancer.

aThis information is for public notification purposes only.

bThis information is for the CCR purposes only.

cViolations of the treatment technique requirements for filtration and disinfection that involve turbidity exceedances may use the health effects language for turbidity instead.

Statutory Authority

§§ 32.1-12 and 32.1-70 of the Code of Virginia.

Historical Notes

Derived from Virginia Register Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-550. Recordkeeping.

A. The owner shall maintain all of the waterworks records in accordance with the Records Retention and Disposition Schedule of the Library of Virginia, General Schedule No. 7 for public utility records of county and municipal governments.

B. The owner shall retain at the waterworks or at a convenient location near the waterworks the following records for not less than the time periods specified:

1. Microbiological analyses and turbidity analyses, including records of any repeat samples collected and meeting the criteria for an extension of the 24-hour period for collecting repeat samples as required under 12VAC5-590-380 -- Five years.

2. Chemical Analyses -- 10 years.

3. The following information shall be provided for subdivisions B 1 and B 2 of this section:

a. Date, place, and time of sampling as well as the name of the person who collected the sample;

b. Identification of sample (e.g., routine, repeat, confirmation sample, source water, other);

c. Date of analysis;

d. Laboratory or person responsible for performing analysis;

e. Analytical method or technique used; and

f. Results of the analysis.

4. Individual filter monitoring required under 12VAC5-590-531 A 2 b -- Three years.

5. Results of disinfection profile including raw data and analysis -- Indefinitely.

6. Disinfection benchmarking including raw data and analysis -- Indefinitely.

7. Original records of all sampling data and analyses, reports, surveys, letters, evaluations, schedules, department determinations, and any other information required by 12VAC5-590-405 A 1 and 12VAC5-590-405 A 2, 12VAC5-590-405 B, 12VAC5-590-405 C, and 12VAC5-590-405 D pertaining to lead and copper -- 12 years.

8. Results from the initial round of source water monitoring under 12VAC5-590-401 B 1 and the second round of source water monitoring under 12VAC5-590-401 B 2 until three years after bin classification under 12VAC5-590-401 D 1 for the particular round of monitoring.

9. Any notification to the department that source water monitoring will not be conducted due to meeting the criteria of 12VAC5-590-401 B 4 -- Three years.

10. Results of treatment monitoring associated with microbial toolbox options under 12VAC5-590-401 E 3 through 12VAC5-590-401 E 7 and with uncovered finished water reservoirs under 12VAC5-590-415, as applicable, -- Three years.

11. Action taken to correct violations of this chapter-- Three years after last action with respect to violation involved.

12. The owner shall retain completed assessment forms for all Level 1 and Level 2 assessments conducted in accordance with 12VAC5-590-392 C, regardless of who conducts the assessment, and documentation of corrective actions completed as a result of those assessments, or other available summary documentation of the sanitary defects and correction actions taken under 12VAC5-590-392 D for a period not less than five years after completion of the assessment or corrective action, whichever is later.

13. Copies of reports, summaries, or communications relating to any sanitary surveys performed -- 10 years following inspection.

14. Variance or exemptions granted (and records related thereto) -- Five years following expiration of the variance or exemption.

15. Cross-connection control program records -- 10 years.

16. The owner of a waterworks that recycles flow, as stipulated in 12VAC5-590-395 C, shall collect and retain on file the recycle flow information for review and evaluation by the department. This information shall be retained for a minimum of 10 years. Information shall include, as a minimum:

a. Copy of the recycle notification submitted to the department.

b. List of all recycle flows and the frequency with which they are returned.

c. Average and maximum backwash flow rate through the filters and the average and maximum duration of the filter backwash process, in minutes.

d. Typical filter run length and a written summary of how the filter run length is determined.

e. The type of treatment provided for the recycle flow.

f. Data on the physical dimensions of the equalization or treatment units, typical and maximum hydraulic loading rates, type of treatment chemicals used, average dose, frequency of use, and frequency at which solids are removed, if applicable.

17. Copies of monitoring plans developed pursuant to this chapter shall be kept for the same period of time as the records of analyses taken under the plan are required to be kept under subsection A or B of this section, except as specified elsewhere in this chapter.

18. The owner shall retain the following additional records:

a. Plant operational records -- five years after the end of the calendar year;

b. Current organizational or staffing chart;

c. Record (As-built) engineering plans and specifications of facilities -- Retain for the life of the facility;

d. Equipment manuals for items in use -- Retain for the life of the equipment or facility;

e. Shop drawings of major equipment in use -- Retain for the life of the equipment;

f. Current list or chart of required laboratory tests with test frequencies and sampling locations;

g. Current preventive maintenance schedule;

h. Records of repair or replacement of equipment in use --
Retain for the life of the equipment;

i. Updated map of water distribution system; and

j. All accident reports -- Three years.

C. The owner of a waterworks with groundwater sources shall maintain the following records:

1. Corrective actions – --10 years.

2. Public notification as required by 12VAC5-590-540 -- Three years.

3. Invalidation of groundwater source samples -- Five years.

4. For consecutive waterworks, notification to the wholesale waterworks of coliform-positive samples -- Five years.

5. For a waterworks required to conduct compliance monitoring:

a. Department-specified minimum residual disinfectant --10 years.

b. Lowest daily residual disinfectant concentration -- Five years.

c. Dates and duration of any failure to maintain the department-specified minimum residual disinfectant concentration for a period of more than four hours -- Five years.

d. Department-specified compliance parameters for alternative treatment and records of the date and duration of any failure to meet the alternative treatment operating requirements for more than four hours -- Five years.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-005.11 § 2.22, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 12, Issue 2, eff. November 15, 1995; Volume 18, Issue 19, eff. July 3, 2002; Volume 19, Issue 20, eff. July 16, 2003; Volume 21, Issue 13, eff. April 6, 2005; Volume 25, Issue 5, eff. December 10, 2008; Volume 28, Issue 5, eff. December 7, 2011; Volume 33, Issue 3, eff. November 2, 2016; Volume 37, Issue 20, eff. June 23, 2021.

12VAC5-590-560. Safety.

The owner of a waterworks shall institute a safety program to inform personnel of the known hazards, preventive measures, and emergency procedures pertaining to the operation of the waterworks in accordance with VOSH laws and regulations.

Statutory Authority

§§ 32.1-12 and 32.1-170 of the Code of Virginia.

Historical Notes

Derived from VR355-18-005.12 § 2.23, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993;