1. (a) For Class II residual waste landfills in surface mined areas in which the disposal area abuts a vertical highwall, the operator shall design, construct and maintain a barrier between the highwall and the disposal area that meets the following performance standards:

   1. (1) The barrier shall prevent the lateral migration of leachate from the disposal area.
   2. (2) The effectiveness of the barrier in preventing the lateral migration of leachate may not be adversely affected by solid waste, solid waste constituents or leachate from the facility.
   3. (3) The barrier shall meet the requirements of § 288.261(a) (relating to mineral resources).

2. (b) Unless alternative design requirements to meet the performance standards in subsection (a) are approved as part of the permit under § 287.231 (relating to equivalency review procedure), the barrier shall meet the following design requirements. The barrier shall be:

   1. (1) Twelve horizontal feet in thickness.
   2. (2) No more permeable than 1.0 x 10^-7 cm/sec. based on laboratory and field testing.
   3. (3) Made of clay as specified in Appendix A, Table II (relating to minimum liner design standards).
3. (c) The barrier shall be designed, installed and maintained according to a quality assurance and quality control plan approved by the Department.
4. (d) The barrier shall be inspected for uniformity, damage and imperfections during construction and installation.

Cross References

This section cited in 25 Pa. Code § 287.114 (relating to interim operational requirements for unpermitted processing or disposal facilities); 25 Pa. Code § 287.116 (relating to interim operational requirements); 25 Pa. Code § 288.512 (relating to liner system and leachate control plan); 25 Pa. Code § 288.521 (relating to basic limitations); and 25 Pa. Code § 288.531 (relating to scope and requirements).