Current through Register Vol. 54, No. 45, November 9, 2024
Section 273.253 - Subbase(a) The subbase shall meet the following performance standards. The subbase shall: (1) Bear the weight of the liner system, waste, waste cover material and equipment operating on the facility without causing or allowing a failure of the liner system.(2) Accommodate potential settlement without damage to the liner system.(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 subbase shall meet the following design requirements. The subbase shall: (1) Be at least 6 inches thick and compacted to a standard proctor density of at least 95%.(2) Be no more permeable than 1 x 10-5 cm./sec., based on laboratory and field testing unless the clay component of a composite liner is designed and constructed directly above the subbase.(3) Be hard, uniform, smooth and free of debris, rock, plant materials and other foreign material.(4) Have a postsettlement slope of at least 2% and no more than 33%.The provisions of this §273.253 amended December 22, 2000, effective 12/23/2000, 30 Pa.B. 6685. This section cited in 25 Pa. Code § 273.161 (relating to liner system and leachate control plan); 25 Pa. Code § 273.251 (relating to scope and requirements); and 25 Pa. Code § 285.123 (relating to impoundment-general).