Current through Register Vol. 54, No. 25, June 22, 2024
Section 288.624 - Attenuating soil(a)Disposal of residual waste. Residual waste may not be disposed at a Class III residual waste landfill, unless attenuating soil exists in the disposal area or has been placed on the entire disposal area. (1) At least 4 feet separate the seasonal high water table, perched water table or bedrock from the lowest area where waste is deposited. Soil mottling may indicate the presence of a seasonal high water table. The seasonal high water table and perched water table may not be artificially manipulated. The seasonal high water table may not be located within the attenuating soil base.(2) At least 8 vertical feet separate the regional groundwater table from the lowest area where waste is deposited. The regional groundwater table may not be artificially manipulated. The regional groundwater table may not be located within the attenuating soil base.(b)Standards of performance. The attenuating soil shall meet the following standards of performance:(1) The attenuating soil shall prevent migration of contaminants to the surface and groundwater to the greatest degree that is technologically possible.(2) The performance of the attenuating soil may not be affected by the physical or chemical characteristics of the waste.(3) The attenuating soil shall cover the bottom and sidewalls of the facility.(c)Alternative design requirements. Unless alternative design requirements to meet the performance standards in subsection (b) are approved as part of the permit under § 287.231 (relating to equivalency review procedure) where site-specific conditions are included in the demonstration, the attenuating soil shall meet the requirements of subsection (d). If a design under this section is modified, the modification shall be a major permit modification.(d)Requirements. The attenuating soil required by this section shall meet the following requirements:(1) The soil shall fall within the United States Department of Agriculture textural classes of sandy loam, loam, sandy clay loam, silty clay loam, loamy sand and silt loam.(2) At least 40% by weight of the fragments in the soil shall be capable of passing through a 2 millimeter, No. 10 mesh sieve.(3) The soil may not include rock fragments greater than 6 inches in diameter.(4) The soil shall have a cation exchange capacity of at least 10 milliequivalents per 100 grams of soil.(5) The soil shall have an organic carbon content of at least 0.1%.The provisions of this § 288.624 amended January 12, 2001, effective 1/13/2001, 31 Pa.B. 235. This section cited in 25 Pa. Code § 288.611 (relating to description of soil base); and 25 Pa. Code § 288.621 (relating to basic requirements).