Administrative Code

Virginia Administrative Code
10/27/2021

Part III. General Criteria and Methods for Conducting Site Evaluations

Article 1
Evaluation Criteria for Subsurface Soil Absorption Systems

12VAC5-610-450. General.

Article 1
Evaluation Criteria for Subsurface Soil Absorption Systems

Soil evaluation for a subsurface soil absorption system shall follow a systematic approach including consideration of physiographic province, topography, available area, degree of slope, and soil profile (thickness of each horizon, color, permeability, and texture). The evaluation is intended to document sufficient information to conclude whether or not the site can accommodate an onsite sewage treatment and dispersal system listed in Part IV (12VAC5-610-591 et seq.) of this chapter. The topography, available area, seasonal water table, drinking water supplies, bodies of water, shellfish growing areas, soil horizon, depth, rate of absorption, or combination of any of the above shall be considered in such evaluation. A percolation test may be required as a prerequisite to the issuance of a permit. When the district or local health department questions the estimated percolation rate, the district or local health department may require a percolation test. Percolation tests shall be analyzed as only one of many criteria in determining soil suitability for absorption of treated sewage.

Statutory Authority

§§ 32.1-12 and 32.1-164 of the Code of Virginia.

Historical Notes

Derived from VR355-34-02 § 3.1, eff. February 5, 1986; amended, eff. May 11, 1988; Virginia Register Volume 16, Issue 16, eff. July 1, 2000.

12VAC5-610-460. Site and structure identification.

A site plan (sketch) showing dimensions of property, proposed and/or existing structure or structures, driveways, underground and overhead utilities on the property and adjacent sewage disposal systems, bodies of water, drainage ways, agricultural drain tile, wells, cisterns, and springs for a minimum of 200 feet radius of the center of the proposed building or drainfield is necessary in order to evaluate the suitability of a subsurface soil absorption system for that site. In addition, for new construction, the boundary of the lot and building site shall be staked. As a minimum, prior to issuance of the construction permit the perimeter of the soil absorption area site or sites shall be shown on a copy of a surveyed plat of the property. When a parcel of land consisting of a single lot is involved on which an onsite sewage disposal system is proposed to be located and is not directly influenced by the off site location of any sewage disposal system, well, body of water, etc., the requirement for the surveyed plat may be waived by the district or local health department.

Statutory Authority

§§ 32.1-12 and 32.1-164 of the Code of Virginia.

Historical Notes

Derived from VR355-34-02 § 3.2, eff. February 5, 1986; amended, eff. May 11, 1988.

12VAC5-610-470. Physical features.

A. Physical features including soil features, slope, depth of rock, the location of rock outcrops, drainage ways, marshes, swamps, sink holes, flood plains, artificial drainage systems, and various structures and topographic features found in Tables 4.1 through 4.4 shall be fully and accurately documented in writing as part of the site and soil evaluation.

B. Drainage way. A drainage way is a concave portion of the landscape in which surface water or rain water run-off gathers intermittently to flow to a lower elevation.

C. Fill material. Fill material means soil transported and deposited by man as well as soil recently transported and deposited by natural erosion forces. Recent natural soil transportation and deposit is evidenced by one or more of the following.

1. No or indistinct soil horizons;

2. Depositional stratification;

3. Presence of a buried organic layer; and

4. Position in the landscape.

D. Minimum depth to seasonal water table. As used herein, "seasonal water table" means that portion of the soil profile where a color change has occurred in the soil as a result of saturated soil conditions or where soil concretions have formed. Typical colors are gray mottlings, solid gray or black. The depth in the soil at which these conditions first occur is termed "seasonal water table."

E. Artificial drainage. Where soils are artificially drained, soil coloration may no longer be an accurate indicator of the position of the seasonal water table. Three types of artificial drainage systems which are generally considered are as follows:

1. A water table depressor system of buried conduits, i.e., agricultural drainage tile;

2. A lateral ground water movement interceptor is a buried conduit for the purpose of intercepting lateral ground water movement, i.e., a French drain; and

3. Open ditches with the bottom elevation of the ditch below the seasonal water table.

Statutory Authority

§§ 32.1-12 and 32.1-164 of the Code of Virginia.

Historical Notes

Derived from VR355-34-02 § 3.3, eff. February 5, 1986; amended, eff. May 11, 1988; Virginia Register Volume 16, Issue 16, eff. July 1, 2000.

12VAC5-610-480. Soil profiles and patterns.

A. General. The purpose of determining the soil profiles and patterns is to identify the soil characteristics that affect installation of a subsurface soil absorption system.

B. Soil profile. A soil profile is a vertical section of the soil throughout all its horizons.

C. Profile holes.

1. Acceptable equipment.

a. Auger. An auger is defined as a mechanical device which is used to remove a soil sample for evaluation. Devices utilizing the Archimedes screw principle are prohibited because they blend and mast the true soil characteristics.

b. Other equipment. Other equipment may be used in addition to an auger to expose the soil profile as long as it does not mask or blend the true soil characteristics.

2. General location of profile holes. Profile holes to determine design requirements shall be located in the area that is unrestricted by the criteria contained in Part IV (12VAC5-610-591 et seq.) of this chapter and Table 4.2. Additional profile holes outside the unrestricted area may be required to make a complete evaluation of the site.

3. Depth of profile hole. The minimum depth of the profile hole shall be five feet unless prevented or made unnecessary by some physical feature of the soil such as gray coloration, rock or when a potential horizon is found at a lesser depth. Where a potential soil horizon is considered for use, the soil evaluation shall be extended below the potential horizon to assure that there is no interference with seasonal water table, rock or impervious strata (See Tables 4.3 and 4.4 of this chapter).

4. Number and location of profile holes. A minimum of five holes is necessary to determine the design requirements of an area for the placement of absorption trenches. Where there is uniform topography and the profile holes exhibit a uniform profile, a minimum of three holes is necessary. The size of the area investigated shall be based on the soil texture group encountered. As a minimum, holes shall be placed to be representative of the area under consideration for placement of the absorption trenches.

If more than one area is required in which to install the absorption trenches, each area shall be evaluated as described above. If any proposed absorption trench site is found unacceptable due to soil conditions, the site shall have been evaluated with a minimum of three holes which characterize the soil problem or problems and support the reasons for rejection. The actual area and number of holes to be investigated may be more than described above and shall be determined on a case-by-case basis.

5. In situations where a large area is to be evaluated, where the soil is highly variable, where the profile must be exposed below five feet or where the soil is "tight" (dense or compact) and/or rocky, the district or local health department may require that the owner have the soil profile in selected areas exposed by the digging of trenches, auger holes or pits. The actual area and number of holes to be investigated shall be determined on a case-by-case basis.

D. Soil profile documentation. Soil profiles shall be determined and a record made in writing of each boring. Additional documentation may be required by the district or local health department.

Statutory Authority

§§ 32.1-12 and 32.1-164 of the Code of Virginia.

Historical Notes

Derived from VR355-34-02 § 3.4, eff. February 5, 1986; amended, eff. May 11, 1988; Virginia Register Volume 16, Issue 16, eff. July 1, 2000.

12VAC5-610-490. Characteristics of soils that determine suitability.

A. Color. Color is a key indication of the suitability of a soil.

1. Red and yellow mottlings may indicate slow internal drainage and may indicate a seasonal water table.

2. Gray and/or gray mottlings indicate seasonal water tables for at least three weeks duration.

3. Black appearance may be due to organic matter which has accumulated due to poor soil drainage.

B. Texture. The term texture refers to the relative proportion of various size groups of individual soil grains in a mass of soil. Specifically it refers to the proportion of sand, silt, and clay.

1. Soil Classification. For the purpose of this chapter soils have been categorized into four groups based on texture as follows:

a. Texture Group I—sand and loamy sand;

b. Texture Group II—sandy loam, loam, and sandy clay loam. Texture Group II soils are subdivided into Texture Group IIa and IIb soils. Texture Group IIa soils consist of sandy loam soils with percolation rates less than 31 minutes per inch and no structure development. The remainder of soils within this texture group are Texture Group IIb soils;

c. Texture Group III—silt loam, clay loam, silty clay loam; and

d. Texture Group IV—sand clay, silty clay and clay.

2. The soil texture shall be estimated by field testing. The field test that shall be applied is contained in APPENDIX F and is entitled "Field Guide to Soil Texture Classes." Laboratory estimation of texture by sieve and sedimentation analysis may be substituted for the field test at the owner's request and expense. Samples shall be collected by the laboratory under supervision of the district or local health department.

C. Permeability. The term permeability pertains to the characteristics of the soil that enable water or air to move through its pores. The permeability of a soil profile may be limited by the presence of one nearly impermeable horizon, even though the others are permeable.

1. Estimated rates. The soil classifications contained in subdivision B 1 of this section have been assigned the following estimated rates in minutes per inch for the purpose of design. These rates may be modified when experience has shown that because of soil structure the texture group has a demonstrated rate different from that assigned.

a. Texture Group I—up to 16;

b. Texture Group IIa—17 to 30;

c. Texture Group IIb—31 to 45;

d. Texture Group III—46 to 90; and

e. Texture Group IV—equal to or greater than 91.

2. Percolation tests. When the estimated percolation rates are in question, percolation tests may be performed, however, the district or local health department may require percolation tests to determine "measured" percolation rates.

a. Requirements. Percolation tests are to be performed under the supervision of the district or local health department. Test holes shall be located at points and depths selected and/or approved by the district or local health department. A minimum of three holes representative of the absorption area are required. When the results of the individual test holes have a spread of more than 30 minutes/inch, five holes with at least one hole in the center of the proposed absorption area are required. Records of all percolation tests performed shall be attached to the application (See APPENDIX G).

b. Procedure. All percolation tests shall be performed in accordance with the procedure contained in APPENDIX G.

c. Records. Data on swelling, saturation and measurement of the percolation rate shall be recorded on forms by the district or local health department; examples of these forms are contained in APPENDIX G.

d. Interpretation of percolation test results. The absorption area shall be based on the average percolation rate measured in the test holes. The average percolation rate shall be computed by determining the percolation rate (minutes/inch) for each hole and averaging those values. When the percolation rate for an individual hole is in excess of 240 minutes/inch, the area represented may be retested one time and the most favorable rate used to calculate the percolation rate.

D. Soil restrictions. A soil restriction is a feature in the soil that impedes the percolation of water. Restrictions generally consist of a layer of soil horizon within a soil that is firmly compacted or is very rich in clay. Soils containing restrictions may require verification of the percolation rate by percolation tests. Examples of restrictions are listed below.

1. Pans. The term pans include hard pans, fragipans, clay pans, plowpans, traffic pans, iron pans, and plinthic horizons.

2. Stoniness. The term stoniness pertains to the relative proportions of stones present in a soil. Stoniness reduces the soil volume for absorption, and therefore, may require a larger subsurface soil absorption field than would be indicated by soil texture.

E. Soil concretions. Soil concretions as hard grains, pellets, or nodules from concentrations of compounds in the soil that cement the soil grains together. Concretions are indicative of slow percolation rates, restrictions, and/or seasonal water tables.

F. Shrink-swell soils. Shrink-swell soils may exhibit satisfactory percolation rates when dry and therefore must be thoroughly wetted before a percolation test is performed.

Statutory Authority

§§ 32.1-12 and 32.1-164 of the Code of Virginia.

Historical Notes

Derived from VR355-34-02 § 3.5, eff. February 5, 1986; amended, eff. May 11, 1988; Virginia Register Volume 16, Issue 16, eff. July 1, 2000.

12VAC5-610-500. Availability of suitable soils.

Sufficient suitable soils shall be available to install the subsurface soil absorption system and reserve area. Design criteria for subsurface soil absorption systems are contained in Article 5 (12VAC5-610-900 et seq.) of Part V of this chapter and reserve area requirements are contained in 12VAC5-610-710.

Statutory Authority

§§ 32.1-12 and 32.1-164 of the Code of Virginia.

Historical Notes

Derived from VR355-34-02 § 3.6, eff. February 5, 1986; amended, eff. May 11, 1988; Virginia Register Volume 16, Issue 16, eff. July 1, 2000.

12VAC5-610-510. (Repealed.)

Historical Notes

Derived from VR355-34-02 §§ 3.7 to 3.11, eff. February 5, 1986; amended, eff. May 11, 1988; repealed, Virginia Register Volume 16, Issue 16, eff. July 1, 2000.

Article 2

Sewage Handling and Septage Management

12VAC5-610-560. Sewage handling; general.

A. In accordance with 12VAC5-610-240 B, a sewage handler shall have a written sewage handling permit issued by the commissioner.

B. It is the obligation of every sewage handler to assure that the sewage, sludge or septage handled are transported and disposed of in a safe and sanitary manner in conformance with this chapter. Treatment and management of sewage and sewage sludge are regulated by the Sewage Regulations (12VAC5-580-10 et seq.).

C. All sewage handling equipment in contact with sewage shall be washed in such a manner and location that the wastewater from washing it is conveyed to an approved sewerage system or treatment works.

D. Disposal of sewage sludges or septage into bodies of water or streams is prohibited.

Statutory Authority

§§ 32.1-12 and 32.1-164 of the Code of Virginia.

Historical Notes

Derived from VR355-34-02 § 3.12, eff. February 5, 1986; amended, eff. May 11, 1988; Virginia Register Volume 16, Issue 16, eff. July 1, 2000.

12VAC5-610-570. (Repealed.)

Historical Notes

Derived from VR355-34-02 § 3.13, eff. February 5, 1986; amended, eff. May 11, 1988; repealed, Virginia Register Volume 16, Issue 16, eff. July 1, 2000.

12VAC5-610-580. Septage management; general.

Ultimate management of septage generally falls into one of two categories, landfilling or land spreading. Landfilling requires that the septage be stabilized and dewatered to increase solids content nearly fivefold to avoid leaching problems. Land spreading of both stabilized and unstabilized septage is permissible under controlled conditions for agricultural purposes. The preferred methods for septage disposal are disposal in an approved sewage treatment plant or stabilization and subsequent disposal by land application or landfilling in accordance with the Biosolids Use Regulations (12VAC5-585-10 et seq.).

Statutory Authority

§§ 32.1-12 and 32.1-164 of the Code of Virginia.

Historical Notes

Derived from VR355-34-02 § 3.14, eff. February 5, 1986; amended, eff. May 11, 1988; Virginia Register Volume 16, Issue 16, eff. July 1, 2000.

12VAC5-610-590. Acceptable disposal sites.

A. Sewerage system or treatment works. Any sewerage system or treatment works for which a certificate to operate has been issued jointly by the department and State Water Control Board or a system which has been issued a separate permit by the commissioner is considered an approved disposal site for vehicular transported sewage sludge or septage provided permission is obtained from the owner of the sewerage system or treatment works and the department and the State Water Control Board, as applicable, determine that the disposal of the sewage sludge or septage will not overload the facility.

B. Special facility. A special facility is a treatment works especially designed and constructed for the stabilization or disposal of septage including land as well as physical works. All special facilities are Type III sewage disposal systems (see 12VAC5-610-250 C). Industrial waste sludges and sludges containing chemical concentrations in violation of state hazardous waste regulations and applicable federal regulations shall not be placed in a special facility.

Exception: Special facilities related to lime stabilization or direct injection may not require formal plans and specifications to be submitted.

C. Processes which may be utilized in special facilities designed for stabilization of septage.

1. The following processes are described with associated criteria in the Commonwealth of Virginia Sewerage Regulations, State Department of Health, State Water Control Board, February 1977 (Sewerage Regulations, 12VAC5-580-10 et seq.):

a. Aerobic digestion;

b. Anaerobic digestion;

c. Chemical oxidation; and

d. Incineration.

2. The following processes are described in Article 9 of this chapter:

a. Anaerobic lagooning; and

b. Lime stabilization.

3. Other processes may be considered on a case-by-case basis if supported by operating and test data satisfactory to the department.

D. Land as a special facility for ultimate disposal of septage.

1. Landfilling. Prior to landfilling, septage must be stabilized and dewatered. All landfilling operations utilizing septage must be in conformance with the regulations of the Commonwealth of Virginia Department of Waste Management governing disposal of solid waste.

2. Land spreading. For the purpose of this chapter land spreading is the controlled uniform application of either dewatered or undewatered septage to the land surface for ultimate disposal. Land spreading shall be accomplished in such a manner so as not to adversely affect future agricultural use of the land. All land spreading operations must take into consideration such factors as application rates, potential runoff of contaminants from the septage applied to soils, groundwater contamination, proximity to residences and people and other public health considerations. All land spreading operations require site specific management criteria and approval.

a. Stabilized septage may be disposed of by land spreading in accordance with the provisions of applicable portions of 12VAC5-580-720 of the Sewerage Regulations and any applicable federal regulations, except where stated in this chapter.

b. Unstabilized septage may be disposed of by land spreading in accordance with the provisions of subsection E, the Code of Virginia and any applicable federal regulations.

E. Land spreading of unstabilized septage. General. Land spreading of unstabilized septage via shallow injection plowing is permissible (see 12VAC5-610-560 D). Injection plowing is a technique which employs a device which injects septage into a cavity created below the ground surface with positive closure of the injection swath. Injection plowing shall be accomplished with a narrow shank injector at a depth between 6 and 12 inches. The injection device and any associated prime mover shall be equipped with high flotation tires so as not to damage the physical characteristics of the soil in relation to agricultural practices. All land spreading operations for unstabilized septage shall provide for:

1. Storage during periods when weather, soil conditions or cropping conditions do not allow for injection;

2. Sampling and monitoring of the septage before land spreading for quality control as may be requested;

3. Record keeping and reporting for quality control;

4. Controlled access to the public for 12 months;

5. No grazing for at least one month following the date of each injection by farm animals whose products are consumed by humans;

6. Compliance with applicable portions of 12VAC5-580-720 of the Sewerage Regulations except where stated in this chapter; and

7. Limiting the application rate so as not to exceed ½ acre-inches (13,600 gal./acre) at one time due to the low solids content and excessive hydraulic loading by septage.

F. Special facility operation.

1. Records and reports shall be kept in a manner satisfactory to the department. As a minimum, the records shall reflect the quantity of septage (gallons) discharged into the special facility daily, the quantity (gallons) removed daily for land application, the land application site, and for anaerobic lagoons, the date the last load was discharged into the anaerobic lagoon. Reports shall be submitted to the department on a quarterly basis (See APPENDIX H).

2. Sampling and analyses requirements for special facilities are as follows:

a. Anaerobic lagoon. In accordance with the provisions of 12VAC5-580-720 of the Sewerage Regulations.

b. Lime stabilization of domestic septage. The origin and the pH of each load must be determined and recorded by the hauler prior to land application. However, periodic sampling and analyses may be required by the department on a case-by-case basis (See paragraph F 1 of this section).

c. Shallow injection of unstabilized septage. Generally no sampling and analyses will be required by the department. The origin of each load must be determined and recorded by the hauler prior to injection. However, periodic sampling and analyses may be required by the department on a case by case basis.

3. An operations and maintenance manual shall be prepared for the septage stabilization facility and shall contain, as a minimum the following information:

a. Site security methods to prevent unauthorized entry.

b. Procedures to maintain the appropriate records.

c. Site management procedures including all-weather access road and ground maintenance.

d. Methods and equipment utilized for placing septage into and removing septage from, the lagoon facility, mixing facility or storage facility as applicable.

e. Plan for land application of septage and/or other disposal methods.

f. Methods for odor control which may include both physical methods such as lagoon depth control and the use of appropriate chemicals.

g. Methods and procedures for monitoring characteristics of the septage and groundwater quality.

4. The site and physical works shall be maintained in a condition free from tall grass and weed overgrowth and rodent harborage.

5. When an anaerobic lagoon is utilized for stabilization its contents shall not be removed for land application until a time period of at least 90 days has elapsed from the time the last load of septage has been discharged into the lagoon.

G. Special facility abandonment. In the event a septage stabilization facility ceases to operate, it shall be the responsibility of the owner to abandon the facility properly. The following steps are required.

1. The owner shall notify the department at least 30 days in advance that the facility is to be abandoned;

2. The contents of the facility shall be disposed of in an approved manner under the supervision of the department; and

3. The structure shall be dismantled and the site returned approximately to its natural contours.

Statutory Authority

§§ 32.1-12 and 32.1-164 of the Code of Virginia.

Historical Notes

Derived from VR355-34-02 § 3.15, eff. February 5, 1986; amended, eff. May 11, 1988.

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