9VAC20-81-210. Leachate Control.

A. 디자인 계획. 설계 계획에는 침출수 관리가 포함되어야 합니다. 이 설계 계획에는 다음 사항이 포함되어야 합니다:

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. 침출수 저장을 위한 탱크 및 표면 저수 시설은 이 조항 A 1 에 따라 시설의 수명 기간 동안 어떤 7일 기간에 대한 최대 예상 침출수 생산량과 동일하거나 그 이상인 유량 균형 및 급증 용량을 갖추어야 합니다. 침출수 저장 용량은 라이너 시스템 내 또는 표면에 축적된 침출수를 포함하지 않을 수 있습니다. 저장 탱크 및 저수지는 필요에 따라 통풍을 실시하여 냄새를 방지하고 통제해야 합니다.

C. 침출수 저장을 위한 표면 저수지는 침출수를 생성하는 매립지의 라이너가 제공하는 인간 건강 및 환경 보호 수준과 동일하거나 더 높은 보호를 제공하는 라이너 시스템을 갖추어야 합니다.

D. 수집된 침출수는 다음 조건을 충족해야 합니다:

1. 직접 배출되거나 사전 처리 후 공공 소유의 처리 시설로 연결되는 배수관로 또는 기타 허가된 폐수 처리 시설로 배출되는 경우;

2. 차량으로 운반되어 허가된 외부 폐수 처리 시설로 이동됩니다;

3. 매립지 내에서 재순환되는 경우, 관개 구역이 EPA 또는 재순환을 위한 연구, 개발 및 실증 계획에서 승인한 복합 라이너 또는 기타 라이너 시스템으로 덮여 있고 작업 시 유출, 고임 또는 불쾌한 악취가 발생하지 않는 경우에 한합니다;

4. VPDES 허가 하에 현장 처리 후 표면 수체로 방류되거나; 또는

5. 부서에서 승인한 기타 치료 또는 처리 방법.

E. 수집된 침출수는 지하 배수장으로 배출되어서는 안 됩니다.

F. 침출수 유출. 침출수 유출이 발생할 경우, 소유자 또는 운영자는 유출을 수리하고 다음 조치를 취해야 합니다:

1. 공중 보건 및 안전을 보호하기 위해 필요한 모든 즉각적인 조치를 취하십시오. 이는 비상 계획에서 요구하는 조치도 포함됩니다.

2. 침투를 최소화하거나 통제하거나 제거하기 위해 즉시 조치를 취하고, 침투의 원천에서 침출액을 차단하고 적절히 관리하십시오.

3. 폐기물 처분이 허용된 방수 처리 구역 외부에 유출된 모든 침출수는 적절히 수집되어 처리되어야 합니다.

[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.