Section 277.254. Leachate detection zone

(a) The leachate detection zone shall meet the following performance standards. The leachate detection zone shall:

(1) Rapidly detect and collect liquid entering the leachate detection zone, and rapidly transmit the liquid to the leachate treatment system.

(2) Withstand chemical attack from waste or leachate.

(3) Withstand anticipated loads, stresses and disturbances from overlying waste, waste cover materials and equipment operation.

(4) Function without clogging.

(5) Prevent the liner from cracking, tearing, stretching or otherwise losing its physical integrity.

(6) Cover the bottom and sidewalls of the facility.

(b) Unless alternative design requirements to meet the performance standards in subsection (a) are approved as part of the permit under § 271.231 (relating to equivalency review procedure), the leachate detection zone of a liner system shall meet the following design requirements:

(1) Be at least 12 inches thick.

(2) Contain no material exceeding 0.5 inches in particle size.

(3) Create a flow zone between the subbase and the liner more permeable than 1 x 10^-2 cm./sec. based on laboratory testing and, when required by the Department, field testing.

(4) Contain a perforated piping system capable of detecting and intercepting liquid within the leachate detection zone and conveying the liquid to a collection sump for storage, processing or disposal. The sump shall be separate from the leachate collection sump and shall be of a sufficient size to transmit leachate that is generated. The piping system shall also meet the following:

(i) The slope, size and spacing of the piping system shall assure that liquids drain from the leachate detection zone.

(ii) The pipes shall be installed primarily perpendicular to the flow and shall have a minimum postsettlement grade of at least 2%.

(iii) The minimum diameter of the perforated pipe shall be 4 inches with a wall thickness of Schedule-80 or greater as specified by ASTM or equivalent.

(iv) The pipes shall be cleaned and maintained as necessary.

(5) The leachate detection zone shall have a minimum bottom slope of 2%.

(6) Contain stone or aggregates without sharp edges.

(c) The operator shall monitor the leachate detection zone weekly to determine whether liquid is flowing from the zone.

(d) If liquid is flowing from the leachate detection zone the operator shall:

(1) Immediately notify the Department in writing.

(2) Estimate, on a weekly basis, the volume of liquid flowing from the zone.

(3) Sample and analyze the liquid, on a quarterly basis, for pH, specific conductivity, total organic carbon and chlorides. The Department may also require sampling and analyses for other constituents expected to be found in the waste.

(4) Provide written copies of the flow and analysis data to the Department.

(e) If leachate flow is greater than 100 gallons per acre of lined collection area per day or more than 10% of leachate generation, the operator shall:

(1) Submit to the Department a plan within 30 days for locating the source of leachate in the leachate detection zone, and for determining the severity and cause of leachate penetration.

(2) Implement the plan upon Department approval, and complete the plan in a reasonable time not to exceed 6 months.

(3) Submit to the Department, within 45 days after completion of the plan, a report containing the new data collected, analysis of the data and recommendations concerning a remedial plan.

(4) Conduct quarterly sampling and analysis for the parameters in § 277.284(1) (relating to sampling and analysis), and submit copies of the results of the analysis to the Department.

(f) If sampling results indicate the presence of constituents at concentrations that could result in degradation of groundwater, the operator shall:

(1) Submit to the Department a remedial plan for controlling the source of leachate in the leachate detection zone, and implement the plan upon Department approval.

(2) Submit to the Department a permit modification application under § 271.222 (relating to permit modification) for increased groundwater monitoring, giving consideration to monitoring frequency, number of wells and other factors, and conduct increased groundwater monitoring upon Department approval of the application.

The provisions of this § 277.254 amended December 22, 2000, effective December 23, 2000, 30 Pa.B. 6685. Immediately preceding text appears at serial pages (226304) to (226305).

Notation

Cross References

This section cited in 25 Pa. Code § 277.161 (relating to liner system and leachate control plan); 25 Pa. Code § 277.164 (relating to application requirements for noncoal mine disposal); 25 Pa. Code § 277.251 (relating to scope and requirements); and 25 Pa. Code § 277.282 (relating to number, location and depth of monitoring points).