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Based on the results of a study conducted on the Roadside Refuse Disposal Area over <br /> a period of 10 years, and associated physical and chemical analysis which <br /> demonstrated that requirements of Rule 4.15 can be met with less than four feet of <br /> cover material, the Division has approved a variance from the four foot refuse cover <br /> depth requirement of Rule 4.10.4(5). Technical Revision 16, approved by the <br /> Division in January, 1994, approved minimum cover replacement depths of 18" on <br /> the RSRDA, CRDA-1 and CRDA-3, and a minimum of 24" on CRDA-2. Non-toxic <br /> cover borrow areas,and topsoil and subsoil suitability levels and sampling plans were <br /> defined by TR-17,in April, 1994. Reclamation of refuse areas will entail replacement <br /> of a minimum 6" topdressing layer with SAR of 12 or less and EC of 8 or less. The <br /> lower 12" to 18" of cover, as applicable, will have maximum limits of 25 and 15, for <br /> SAR and EC,respectively. <br /> During adequacy review associated with RN-4 and TR-42,the Division requested that <br /> the operator submit soils data, evaluation, and mapping, pertinent to pre-salvage and <br /> post-spread sampling conducted in association with 2002 refuse area cover-soiling <br /> and top-soiling operations. The requested soils data and mapping were presented in <br /> new Appendix 9-7,with narrative evaluation on amended pages 9-4 through 9-7, and <br /> amended pages 14-6 through 14-8, and 14-11 of the reclamation plan. <br /> At CRDA-2, subsoil was obtained primarily from excavation within and adjacent to <br /> the Coal Creek channel and from construction of the new upper diversion;topsoil was <br /> from long-term stockpiles. At CRDA-I, the entire cover soil thickness (subsoil and <br /> topsoil) was obtained from the CBA-2 borrow area. At the RSRDA,the entire cover <br /> soil thickness was obtained from the RSRDA soil borrow area. Soil Stockpile No. 3 <br /> was the primary source of topsoil used in the North Portal Facilities Area reclamation <br /> project. 2002/2003 sample results for areas reclaimed in 2002 are summarized below. <br /> CRDA-2 <br /> Data indicates that CRDA-2 subsoil was relatively high quality, with only 1 minor <br /> exceedance of the EC subsoil criteria out of 15 samples (avg. EC=8.0), and no <br /> exceedances of the SAR subsoil criteria (avg. SAR=6.9). Texture was silt loam or <br /> silty clay loam. Sample data for the 6 inch respread topsoil layer at CRDA-2 <br /> indicates that, in general, the topsoil was similar or lower quality growth medium <br /> than the subsoil. There were 5 exceedances of the EC topsoil criteria out of 15 <br /> samples (avg. EC=7.1), and 4 exceedances of the SAR topsoil criteria (avg. <br /> SAR=10.8). <br /> CRDA-1 <br /> CRDA-1 respread soils data reflect sampling of the entire 18 inch cover soil thickness <br /> (subsoil and topdressing combined). The material in general meets the subsoil <br /> criteria(only three of 16 samples exceeded either EC or SAR criteria). However, 12 <br /> of the 16 samples exceeded the topsoil criteria for either or both parameters. Average <br /> 38 <br />