Article 1. General [Repealed]
12VAC5-590-640. General design considerations.
A. Waterworks shall conform to the Public Water Supply Law, Article 2 of Chapter 6 of Title 32.1 of the Code of Virginia. Community waterworks shall be designed to provide for the estimated water demand for 10 to 30 years hence under predicted growth conditions. All waterworks shall be designed so that they can readily be increased in capacity except where circumstances preclude the probability of expansion. Expansion by modular steps should be considered.
B. Waterworks design shall be based on sound engineering practice substantiated in the engineer's design and approved by the department. Historical data or typical usage figures of waterworks with similar service area characteristics and appropriate peaking factors shall be used to support the design. USBC and design standards may be referenced for noncommunity waterworks, as appropriate.
1. Community waterworks shall be designed to meet or exceed the estimated maximum daily water demand of the service area at the design year. The design shall account for diurnal demand patterns and special demands placed on the waterworks such as firefighting, industrial use, and wholesale customers.
2. Noncommunity waterworks shall be designed to meet or exceed the peak hour demand of the proposed services. Either pump capacity or storage capacity or both may be utilized to meet the peak hour demand.
3. Effective storage.
a. Community waterworks shall provide sufficient finished water effective storage to enable the waterworks to meet the estimated maximum daily water demand at the design year. Compliance with this requirement is normally determined by the use of a hydraulic model. In the absence of a hydraulic model, effective storage shall be a minimum of one-half of estimated maximum daily water demand of the waterworks at the design year.
b. There is no minimum finished water effective storage requirement for noncommunity waterworks.
c. Effective storage of atmospheric storage tanks shall be the volume available to store finished water in atmospheric reservoirs or tanks, measured as the difference between the overflow elevation, or the normal maximum operating level, and the minimum storage elevation. For atmospheric tanks that use a portion of their volume to generate distribution system pressure, the minimum storage elevation is that elevation of water in the tank that can provide a minimum pressure of 20 psig throughout that tank's service area under distribution system-wide maximum daily water demand.
d. Effective storage of pressure storage tanks shall be one-third of the nominal pressure vessel storage capacity.
C. Waterworks shall be designed to provide a minimum residual pressure of 20 psig at all service connections. Design shall be based on the most restrictive conditions, defaulting to the greater of peak hour demand or maximum daily water demand plus applicable fire flows. Fire flow design values shall be identified by the engineer after coordination among the owner, local and state building officials, and fire officials. Distribution system hydraulic modeling may be used to demonstrate compliance with this requirement.
D. Materials used in the construction of waterworks that are in contact with the product water shall comply with NSF/ANSI/CAN Standard 61-2020 or an approved equivalent.
Statutory Authority
§§ 32.1-12 and 32.1-170 of the Code of Virginia.
Historical Notes
Derived from VR355-18-007.01 § 3.1, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.
12VAC5-590-650. (Repealed.)
Historical Notes
Derived from VR355-18-007.02 § 3.2, 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.
12VAC5-590-660. Site location.
A. Wells and water treatment plants shall be located above the projected 100-year flood elevation. A lower elevation may be considered if it can be adequately shown that the wells or treatment plants can be protected from flooding. Site grading and adequate drainage shall be provided. Springs subject to flooding shall not be approved. See 12VAC5-590-840 E for additional well location requirements.
B. The waterworks pumping and treatment facilities shall be readily accessible in all seasons. Access roads shall be provided.
C. Functional aspects of the site shall be considered in design, including the convenience of transportation facilities to the site and the availability of electric power from more than one source.
Statutory Authority
§§ 32.1-12 and 32.1-170 of the Code of Virginia.
Historical Notes
Derived from VR355-18-007.03 § 3.3, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.
12VAC5-590-670. Site size.
A. The area reserved around a well or spring site shall conform to 12VAC5-590-840 D and 12VAC5-590-840 E.
B. The treatment plant site shall be of ample size to accommodate expansion, and ample space shall be provided at the treatment site for adequate handling of treatment plant residuals.
C. The disposal of water treatment plant residuals shall conform to the State Water Control Law, Chapter 3.1 of Title 62.1 of the Code of Virginia.
Statutory Authority
§§ 32.1-12 and 32.1-170 of the Code of Virginia.
Historical Notes
Derived from VR355-18-007.04 § 3.4, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.
12VAC5-590-680. Treatment process selection and BAT.
A. The following shall be considered when selecting treatment processes: (i) the quality and variability of the source water and (ii) possible future changes in the quality and quantity of the source water.
B. The design shall employ best available technologies (BAT) for achieving compliance with the PMCLs for organic chemicals listed in 40 CFR 141.61 and BAT for achieving compliance with the PMCLs for inorganic chemicals listed in 40 CFR 141.62.
C. The design shall employ BAT for achieving compliance with the PMCLs for radionuclides listed in 40 CFR 141.66, including radium-226, radium-228, uranium, gross alpha particle activity, beta particle, and photon radioactivity. The design shall consider the system size and use limitations for specific technologies listed in 40 CFR 141.66.
D. Alternative technologies may be employed when approved by the department.
E. When treatment technique requirements have been established instead of PMCLs or ALs, the design shall employ processes specified by these requirements.
F. POU devices shall not be used to achieve compliance with the treatment technique for microbial contaminants. POE or POU devices may be considered for short-term interim use when approved as a condition of a variance or exemption issued by the commissioner.
G. For softening, TDS removal, organics removal, and other treatment purposes, the use of RO and NF shall be in accordance with ANSI/AWWA Standard B114-16, or as allowed by the department on a case-by-case basis.
Statutory Authority
§§ 32.1-12 and 32.1-170 of the Code of Virginia.
Historical Notes
Derived from VR355-18-007.05 § 3.5, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.
12VAC5-590-690. (Repealed.)
Historical Notes
Derived from VR355-18-007.06 § 3.6, 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.
12VAC5-590-700. Metering total water production.
A. The design of all community waterworks shall provide metering of total water production.
B. The design of all NTNCs that provide treatment or have a design capacity of greater than 300,000 gallons per month shall provide metering of total water production.
C. The design of all TNCs that provide treatment or have a design capacity of greater than 300,000 gallons per month shall provide metering of total water production.
D. If the waterworks treatment process results in a waste flow, including filter backwash, ion exchange regenerate, or residual solids, then the design shall provide metering of total source water withdrawn and finished water produced.
E. Metering of total water production at waterworks that do not meet the conditions found in subsections A through D of this section should be provided.
Statutory Authority
§§ 32.1-12 and 32.1-170 of the Code of Virginia.
Historical Notes
Derived from VR355-18-007.07 § 3.7, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.
12VAC5-590-710. (Repealed.)
Historical Notes
Derived from VR355-18-007.08 § 3.8, 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.
12VAC5-590-720. Building design and construction.
A. In accordance with the USBC, Chapter 6 (§ 36.97 et seq.) of Title 36 of the Code of Virginia, and the Statewide Fire Prevention Code (§ 27.94 et seq.) of Title 27 of the Code of Virginia, all waterworks building design and construction shall include necessary features that will assure a functional and safe environment, including adequate ventilation, lighting, heating, drainage, dehumidification, and accessibility to equipment for operation and maintenance.
B. Consistent with subdivision A of this section, the waterworks building design and layout shall incorporate safety provisions to protect waterworks operators and other personnel, in accordance with Article 1 (§ 40.1-22) of Chapter 3 of Title 40.1 of the Code of Virginia. These provisions must comply with federal occupational safety and health standards and regulations promulgated under 29 USC § 651 et seq. and shall include separation of incompatible chemicals, confined space entry, handrails and guards, ladders, lighting, warning signs, smoke detectors, chlorine leak detectors, protective equipment, safety showers, eye washes, and fire extinguishers.
C. Positive identification of the contents of a piping system shall be by lettered legend giving the name of the contents. Arrows shall be used to indicate the direction of flow. Legends shall be applied close to valves, adjacent to changes in direction and branches, where pipes pass through walls and floors, and at frequent intervals on straight pipe runs. The lettering shall be of such color, size, and location so as to be clearly visible and readable.
D. Common division walls between basins or conduits containing nonpotable water and potable water are prohibited. Vertical double division walls, where separated sufficiently to permit ready access for inspection, are permissible where the division walls are monolithic in construction and are properly keyed into their footings or are cast monolithically with their footings.
E. Shop space and storage facilities shall be provided.
F. Wherever pipes pass through walls of concrete structures, extra wall castings to facilitate expansion and future uses shall be provided.
Statutory Authority
§§ 32.1-12 and 32.1-170 of the Code of Virginia.
Historical Notes
Derived from VR355-18-007.09 § 3.9, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.
12VAC5-590-725. Automated monitoring and control systems.
The design of computers, including supervisory control and data acquisition (SCADA) systems if used to monitor and control water treatment and distribution system facilities, shall meet the following general requirements:
1. Data security.
a. Automated systems used to display and record data or control functions that are connected to the internet shall be secure.
b. Backup power supply shall be provided to allow orderly shutdown of the computer system and prevent corruption of data. The protection shall also power associated communications equipment.
c. Adequate hardware shall be in place to allow a high degree of SCADA and computer system reliability and data security.
d. Adequate hardware and associated facilities shall be provided for data archiving.
2. Equipment protection. SCADA and computer systems shall have adequate protection from voltage surges and spikes on the power supply, external data links, and environmental conditions.
3. Data displaying and recording.
a. SCADA and computer systems used to meet the continuous recording requirements of this chapter shall record an observation on a minimum frequency of once per 15 minutes, unless a greater recording frequency is required.
b. SCADA and computer systems used to meet the indicating and recording requirements of this chapter shall provide displays that show a minimum 24-hour trend of results for each parameter. The display panel shall be located in an area where it can be routinely viewed by the waterworks operators.
c. SCADA and computer systems used to meet the indicating and recording requirements of this chapter shall monitor the values and provide alerts for the operator by visual display and audible alarms. Alarm conditions shall be recorded into an alarm log.
4. Waterworks pumps, chemical feeders, and other essential electrical equipment controlled through a SCADA or an automated control system shall have the capability for independent manual operation. Where a high degree of reliability is required, a backup control system shall be provided.
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.
12VAC5-590-730. Alternate power sources.
A. An emergency management plan for extended power outages shall be developed for each community waterworks as specified in 12VAC5-590-505.
B. Alternative power sources at all waterworks shall be considered in the design to maintain a minimum level of service during an electrical power outage.
Statutory Authority
§§ 32.1-12 and 32.1-170 of the Code of Virginia.
Historical Notes
Derived from VR355-18-007.10 § 3.10, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.
12VAC5-590-740. (Repealed.)
Historical Notes
Derived from VR355-18-007.11 § 3.11, 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.
12VAC5-590-750. (Repealed.)
Historical Notes
Derived from VR355-18-007.12 § 3.12, 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.
12VAC5-590-760. Laboratory facilities.
A. The design of laboratory facilities shall be compatible with the equipment provided, the water supply, and the design and complexity of the water treatment.
B. The design of community waterworks and NTNCs shall provide for adequate floor and bench space, adequate ventilation, adequate light, adequate separation of incompatible activities, adequate environmental controls, and auxiliary facilities sufficient to carry out reliable testing.
C. Certified analytical laboratory facilities analyzing drinking water shall comply with 1VAC30-41.
Statutory Authority
§§ 32.1-12 and 32.1-170 of the Code of Virginia.
Historical Notes
Derived from VR355-18-007.13 § 3.13, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.
12VAC5-590-770. Sampling and monitoring equipment.
A. Sample taps shall be provided so that water samples can be obtained from each source water and each entry point to the distribution system. At waterworks providing treatment, sample taps shall be provided at the entrance and exit of each unit treatment process and at the entry point to the distribution system.
1. For surface water treatment plants, a master control sink shall monitor source water, chemically treated water, settled water, combined filter water, and at the entry point to the distribution system.
2. All sample taps shall discharge in the downward direction and be provided with a suitable air gap to prevent cross-connection.
B. Continuous monitoring instrumentation shall have electronic sensors that continuously read the parameter and shall display results in real time. Continuous recording equipment shall be provided with the monitoring instrument to store in memory or print one data point at least every 15 minutes. Each result shall be a single result at that time; if signal averaging is applied, the averaging period shall not exceed 30 seconds. The recording equipment shall be capable of producing a paper copy or equivalent electronic file showing daily trends, including maximum, minimum, and average values.
Statutory Authority
§§ 32.1-12 and 32.1-170 of the Code of Virginia.
Historical Notes
Derived from VR355-18-007.14 § 3.14, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.
12VAC5-590-780. (Repealed.)
Historical Notes
Derived from VR355-18-007.15 § 3.15, 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.
12VAC5-590-790. Process water.
Process water shall be taken from the finished water. An approved backflow prevention assembly or device shall be installed on the process water supply pipe before connection to the treatment process or equipment.
Statutory Authority
§§ 32.1-12 and 32.1-170 of the Code of Virginia.
Historical Notes
Derived from VR355-18-007.16 § 3.16, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993.
12VAC5-590-800. (Repealed.)
Historical Notes
Derived from VR355-18-007.17 § 3.17, 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.
12VAC5-590-810. Components, materials, and products.
All components, materials, and products that will be in contact with source water, partially treated water, finished water, or water treatment chemicals shall comply with NSF/ANSI/CAN Standard 61-2020.
Statutory Authority
§§ 32.1-12 and 32.1-170 of the Code of Virginia.
Historical Notes
Derived from VR355-18-007.18 § 3.18, eff. August 1, 1991; amended, Virginia Register Volume 9, Issue 17, eff. June 23, 1993; Volume 37, Issue 20, eff. June 23, 2021.