2012-01-06_PERMIT FILE - C1982057 (18)

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Analytical Procedures. At the lab, cores were air dried, split and composited according to lithologic and stratigraphic sequence, crushed to pass a 10-mesh sieve, and bagged for storage. Detailed field procedures used for logging and sampling the overburden cores are listed in Appendix 6-2. Overburden chip samples were collected from two-foot vertical increments. Adjacent two-foot chip samples of similar strata were composited into four-, six-, eight-, or ten-foot vertical increments in the field before shipment to the laboratory. The chip samples were air dried, crushed to pass a 10 and/or 20 mesh sieve, and bagged for storage. All core samples collected prior to 1982 were chemically and physically analyzed at Peabody Central Laboratory using the procedures listed in Table 6-2. The parameter and procedure list was developed by Peabody's soil scientist IG. Wendt) in consultation with reclamation specialists from CMLRD, OSMRE, and WATEC. Extensive reference was made to the Division's September 16, 1981 draft Water Quality and Overburden Geochemistry Guideline. All samples from Sites 3080C and 3152C were chemically and physically analyzed at InterMountain Laboratory using the procedures listed in Table 6-2A. The parameter and procedure list was developed by Peabody's soil scientist IG. Wendt) and hydrologist (H.T. Smith) in consultation with the Division's reclamation specialists IS. Renner and L. Routtenl. Extensive reference was made to the Division's 1982 Water Quality and Overburden Geochemistry Guideline (CMLRD, 19821. The samples from WWCU-24 were analyzed by ACZ Laboratories using procedures listed on Table 6-2B. Overburden Characteristics. Analytical data for the 19 bore and core holes are provided in Appendix 6-3. In general, the physical and chemical data generated by the overburden testing are typical for the Williams Fork, Iles, and Lewis Formations which form the Mesaverde Group. stratigraphic units predominantly consist of fine-grained, interbedded, sandstone and shales with lesser amounts of sandy shale, siltstone, and coal. Lithologic descriptions for the bore and core samples are presented in Appendix 6-1. The overburden particle distribution shows a high clay, silt, and very fine sand content reflecting the fine-grained nature of the depositional units. Salt levels li.e., conductivities) are low while pH ranges typically from slightly acidic to mildly alkaline. Nitrate levels are low except for Core Hole 1128-E which exhibits comparatively higher levels. SAR levels are consistently low and trace element concentrations are generally at normally expectetl background levels. The criteria for assessing the suitability of overburden for a root growth medium or aquifer restoration material are listed in Table 6-3. The suspect limits for each parameter are documented by current literature citings. PR03 18 Revised 01/02