9VAC25-32-560. Biosolids utilization methods.
A. Requirements applicable to land application of biosolids.
1. All biosolids application rates, application times and other site management operations shall be restricted as specified in the biosolids management plan. The biosolids management plan shall include a nutrient management plan as required by 9VAC25-32-410 and prepared by a certified nutrient management planner as stipulated in regulations promulgated pursuant to § 10.1-104.2 of the Code of Virginia.
2. Biosolids shall be treated to meet standards for land application as required by Part IX (9VAC25-32-303 et seq.) of this chapter prior to delivery at the land application site. No person shall alter the composition of biosolids at a site approved for land application of biosolids under a Virginia Pollution Abatement Permit. Any person who engages in the alteration of such biosolids shall be subject to the penalties provided in Article 6 (§ 62.1-44.31 et seq.) of Chapter 3.1 of Title 62.1 of the Code of Virginia. The addition of lime or deodorants to biosolids that have been treated to meet standards for land application as required by Part IX (9VAC25-32-303 et seq.) of this chapter shall not constitute alteration of the composition of biosolids. The board may authorize public institutions of higher education to conduct scientific research on the composition of biosolids that may be applied to land.
B. Agricultural use. Agricultural use of biosolids is the land application of biosolids to cropland or pasture land to obtain agronomic benefits as a plant nutrient source and soil conditioner.
1. Biosolids treatment. As a minimum, biosolids that are applied to the land or incorporated into the soil shall be treated by a Class II pathogen treatment process and shall be treated or managed to provide an acceptable level of vector attraction reduction.
2. Site soils.
a. Depth to bedrock or restrictive layers shall be a minimum of 18 inches.
b. Biosolids application shall not be made during times when the seasonal high water table of the soil is within 18 inches of the ground surface. If Natural Resources Conservation Service soil survey information regarding depth of seasonal water table is not available, the water table depth shall be determined by soil characteristics or water table observations. If the soil survey or such evidence indicates that the seasonal water table can be less than 18 inches below the average ground surface, soil borings shall be conducted within seven days prior to land application operations during periods of high water table for the soil series present to verify the actual water table depth. The use of soil borings and water table depth verification may be required for such sites from November to May (during seasonal high water table elevations) of each year depending on soil type. Constructed channels (agricultural drainage ditches) may be utilized to remove surface water and lower the water table as necessary for crop production and site management.
c. The pH of the biosolids and soil mixture shall be 6.0 or greater at the time of each biosolids application if the biosolids cadmium concentration is greater than or equal to 21 mg/kg. The soil pH must be properly tested and recorded prior to land application operations during which a pH change of one-half unit or more may occur within the zone of incorporation (i.e., use of biosolids containing lime or other alkaline additives at 10% or more of dry solid weight).
d. When soil test pH is less than 5.5 S.U., the land shall be supplemented with lime at the recommended agronomic rate prior to or during biosolids application if the biosolids to be land applied have not been alkaline stabilized.
e. When soil test potassium levels are less than 38 parts per million (Mehlich I analytical procedure or equivalent), the land shall be supplemented with potash at the recommended agronomic rate prior to or during biosolids application.
3. Management practices.
a. Site specific application rates shall not exceed the rates established in the nutrient management plan nor result in exceedance of the cumulative trace element loading rates specified in 9VAC25-32-356 Table 3.
b. Agricultural use of stabilized septage shall be in accordance with the same requirements as biosolids.
c. Infequent application. If biosolids are applied to a field only once in a three-year period, biosolids may be applied such that the total crop needs for nitrogen is not exceeded during a one-year crop rotation period including the production and harvesting of two crops in succession within a consecutive 12-month growing season. The infrequent application rate may be restricted (i) down to 10% of the maximum cumulative loading rate (9VAC25-32-356 Table 3) for cadmium and lead or (ii) to account for all sources of nutrients applied to the site, including existing residuals.
(1) Field management. The application rate of all application equipment shall be routinely measured as described in a biosolids management plan. Liquid biosolids shall not be applied at rates exceeding 14,000 gallons per acre, per application. Sufficient drying times shall be allowed between subsequent applications. Application vehicles shall be suitable for use on agricultural land. Pasture and hay fields shall be grazed or clipped to a height of approximately six inches prior to biosolids application. Biosolids shall be applied such that uniform application is achieved. If application methods do not result in a uniform distribution of biosolids, additional operational methods shall be employed following application such as dragging with a pasture harrow, followed by clipping if required, to achieve a uniform distribution of the applied biosolids.
(2) Surface incorporation may be required on cropland by the department, or the local monitor with approval of the department, to mitigate malodors when incorporation is practicable and compatible with a soil conservation plan or contract meeting the standards and specifications of the U.S. Department of Agriculture Natural Resources Conservation Service.
(3) Slopes above 15%. Biosolids shall not be applied to site slopes exceeding 15%. This restriction may be waived by the department for the establishment and maintenance of perennial vegetation or based on site specific criteria and BMPs in place in the field.
(4) Biosolids application timing and slope restrictions shall conform to criteria contained in regulations promulgated pursuant to § 10.1-104.2 of the Code of Virginia.
(5) Snow. Biosolids may only be applied to snow-covered ground if the snow cover does not exceed one inch and the snow and biosolids are incorporated within 24 hours of application. If snow melts during biosolids application, incorporation is not necessary.
e. Setback distances.
(1) Setback distances. The land application of biosolids shall not occur within the following minimum setback distance requirements (Table 1 of this section):
(2) In cases where more than one setback distance is involved, the most restrictive distance governs.
(3) Waivers. Waivers from adjacent property residents and landowners may only be used to reduce setback distances from occupied dwellings and property lines.
(4) Extended setback distances. The department may increase setback requirements based on site specific features, such as agricultural drainage features and site slopes.
f. Voluntary extensions of setback distances. If a permit holder negotiates a voluntary agreement with a landowner or resident to extend setback distances or add other more restrictive criteria than required by this regulation, the permit holder shall document the agreement in writing and provide the agreement to the department. Voluntary setback increases or other management criteria will not become an enforceable part of the land application permit unless the permit holder modifies the biosolids management plan to include the additional restriction.
g. Extension of setback distances with phosphorus index. If the application rate included in a nutrient management plan for a biosolids land application site is dependent upon an extended setback distance calculated using the phosphorus index, the phosphorus index calculations shall be included in the nutrient management plan. The extended setback distance shall be an enforceable part of the permit.
C. Forestland (Silviculture). Silvicultural use includes application of biosolids to timber and fiber production land, as well as federal and state forests. The forestland may be recently cleared and planted, young plantations (two-year-old to five-year-old trees), or established forest stands.
1. Biosolids standards. Refer to the standards of this article.
2. Site suitability.
a. Site suitability requirements shall conform to the requirements contained in subdivision B 2 of this section.
b. Notwithstanding the requirements of subdivision B 2 of this section the soil pH shall be managed at the natural soil pH for the types of trees proposed for growth.
c. Notwithstanding the requirements of subdivision B 2 of this section the soil test potassium level is not required to be at a minimum level at the time of biosolids application.
3. Management practices.
a. Application rates. Biosolids application rates shall be in accordance with the biosolids management plan. The biosolids management plan shall include information provided by the Virginia Department of Forestry.
(1) Field management.
(a) High pressure spray shall not be utilized if public activity is occurring within 1,500 feet downwind of the application site. Public access to the site shall be controlled following application in accordance with Article 3 (9VAC25-32-490 et seq.) of this part.
(b) Biosolids application vehicles shall have adequate ground clearance to be suitable for silvicultural field use.
(c) Application scheduling included in the biosolids management plan shall take into account rainfall and periods of freezing conditions.
(d) Monitoring requirements shall be site specific and may include groundwater, surface water or soils, for frequent application sites.
(2) Setbacks. Setbacks shall conform to those for agricultural utilization. Refer to Table 1 of this section.
D. Reclamation of disturbed land.
1. Biosolids standards. Refer to the standards of this article.
2. Site suitability. Site suitability requirements shall conform to the requirements contained in subdivision B 2 of this section. Exceptions may be considered on a case-by-case basis.
3. Management practices.
a. Application rates. The biosolids application rates shall be established in the biosolids management plan in consultation with the Virginia Department of Mines, Minerals and Energy, the Virginia Department of Conservation and Recreation, and the Department of Crop and Soil Environmental Sciences of the Virginia Polytechnic Institute and State University. The nutrient management plan shall be approved by the Department of Conservation and Recreation prior to permit issuance where land application is proposed at greater than agronomic rates.
b. Vegetation selection. The land shall be seeded with grass and legumes even when reforested. The biosolids management plan shall include information on the seeding mixture and a detailed seeding schedule.
(1) The soil pH shall be maintained at 6.0 or above if the cadmium level in the biosolids applied is at or above 21 mg/kg. during the first year after the initial application. Soil samples should be analyzed by a qualified laboratory. The application rate shall be limited by the most restrictive cumulative trace element loading (9VAC25-32-356 Table 3).
(2) Surface material shall be turned or worked prior to the surface application of liquid biosolids.
(3) Unless the applied biosolids are determined to be Class A or have been documented as subjected to Class I treatment, crops intended for direct human consumption shall not be grown for a period of three years following the date of the last biosolids application. No animals whose products are intended for human consumption may graze the site or obtain feed from the site for a period of six months following the date of the last biosolids application.
§ 62.1-44.15 of the Code of Virginia.
Derived from Virginia Register Volume 24, Issue 6, eff. January 1, 2008; amended, Virginia Register Volume 29, Issue 24, eff. September 1, 2013; Errata, 30:3 VA.R. 329 October 7, 2013.