9VAC20-81-210. Leachate Control.

A. Design plan. The design plan shall provide for leachate management. This design plan shall include the following:

1. An estimate of the quality and quantity of leachate to be produced annually by the facility. The estimate shall include the 30-day leachate volume and average flow rate of each month of the year. A separate estimate shall be submitted for anticipated leachate generation at the end of five year increments of operation for 20 years, or until closure, whichever date is earlier. For existing facilities, current leachate generation shall be included with this separate estimate. 2.
2. Plans, designs, and cross sections for the proposed collection and handling system.
3. Plans, designs, and cross sections for onsite leachate storage or treatment systems, including system appurtenances for storage, pretreatment, or treatment of leachate from the facility.
4. The liner system must include a primary leachate collection and removal system that is designed to maintain no more than 12 inches of leachate depth (head) above the primary liner, except during 24-hour, 25-year storm events and except in sump areas. The leachate collection and removal system must be designed to function with proper maintenance throughout the active life, post-closure period, and custodial care period of the landfill.
   1. The primary leachate collection and removal system must be a minimum of two feet thick.
   2. On slopes less than or equal to 10 percent, the 24 inches of primary leachate collection and removal system must have a hydraulic conductivity of 1.0 centimeter per second or greater. Alternatively, the upper 12 inches of primary leachate collection and removal system may have a hydraulic conductivity of 0.1 centimeter per second or greater if the lower 12 inches has a hydraulic conductivity of 1 centimeter per second or greater.
   3. On slopes greater than 10 percent, the entire 24 inch thickness of the primary leachate collection and removal system must have a hydraulic conductivity of 0.1 centimeter per second or greater.
5. The liner system must include a secondary leachate collection and removal system placed between the primary and secondary liners with a design capacity of at least 1,000 gallons per acre per day and a maximum detection time of 24 hours using steady state flow calculations in a saturated medium.
   1. On slopes less than or equal to 10 percent, the secondary leachate collection and removal system must include a geosynthetic drainage layer and a minimum of 1 foot of soil drainage media with a hydraulic conductivity of 0.1 centimeter per second or greater, and a maximum leachate depth (head) of 1 inch.
   2. On all slopes greater than 10 percent, the secondary leachate collection system may be constructed of a geosynthetic drainage layer system designed to meet the hydraulic and mechanical needs of the landfill with a head that does not exceed the thickness of the confined drainage layer.
6. Plans, designs, and cross sections for the proposed collection and handling system.
7. Plans, designs, and cross sections for onsite leachate storage or treatment systems, including system appurtenances for storage, pretreatment, or treatment of leachate from the facility.

B. Tanks and surface impoundments used for storage of leachate shall have a flow equalization and surge capacity at least equal to the maximum expected production of leachate for any seven-day period for the life of the facility estimated under subdivision A 1 of this section. Leachate storage capacity may not be considered to include leachate that may have collected in or on the liner system. Storage tanks and impoundments shall be aerated, as necessary, to prevent and control odors.

C. Surface impoundments used for storage of leachate shall be equipped with a liner system that shall provide equal or greater protection of human health and the environment than that provided by the liner of the landfill producing the leachate.

D. The collected leachate shall be:

1. Discharged directly or after pretreatment into a line leading to the publicly owned treatment works or other permitted wastewater treatment facility;

2. Transported by a vehicle to an offsite permitted wastewater treatment facility;

3. Recirculated within the landfill, provided that the irrigated area is underlain by a composite liner or other liner system approved by EPA or Research, Development, and Demonstration plan for recirculation, and that the operation causes no runoff, ponding, or nuisance odors;

4. Treated onsite and discharged into surface water when authorized under VPDES permit; or

5. Other methods of treatment or disposal as approved by the department.

E. The collected leachate shall not be discharged to an underground drain field.

F. Leachate seeps. If a leachate seep(s) occurs, the owner or operator shall repair the seep(s) and do the following:

1. Take all immediate steps necessary to protect public health and safety including those required by the contingency plan.

2. Take immediate action to minimize, control, or eliminate the seep, and to contain and properly manage the leachate at the source of the seep.

3. Any leachate released outside the lined area permitted for waste disposal shall be properly collected and disposed.

[Current language in §A(2) is stricken in this proposal.]

Justification:    Landfills are particularly worrisome uses that carry a significant risk to water supply – both surface and groundwater sources. In 2003, the United States Geological Survey in cooperation with the Virginia Department of Health-Office of Drinking Water published Aquifer Susceptibility in Virginia, 1998-2000, in which it concluded that groundwater within the study area had a 100% susceptibility to contamination over a 50-year period. The U.S. Environmental Protection Agency has stated that “even the best liner and leachate collection systems will ultimately fail due to natural deterioration.” 53 Fed. Reg. 33345.

The proposed amendment to 9VAC20-81-210 will not preclude the risk of failure of landfills, but the amendment would provide substantial reduction to the risk posed by landfills to potentially affected water supplies. Once groundwater is contaminated, there is no practical means of remediating the damage to that supply, which in many parts of the Commonwealth is the exclusive source of drinking water. Requiring a more effective leachate collection and removal system for all new landfills will reduce the impact of the failure of liners, which EPA considers inevitable as a consequence of natural deterioration.