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<br /> <br /> <br /> 40 C1981-041 RN7 findings <br />plant growth material and amended as necessary. Prior to redistribution of the topsoil, <br />the graded surface will be ripped to relieve compaction and limit surface slippage. <br /> <br />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 /> <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 /> <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-1, 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 /> <br /> CRDA-2 <br /> <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 /> <br />CRDA-1 <br /> <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