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On page 14-15 of the permit application, it is stated that "soil sampling will be done prior <br />to excavation to define the limits of excavation on the borrow areas which will have soils <br />stripped. Sampling for SAR and EC in these areas will be done on a frequency of 1 per <br />acre, approximately 200' centers, and 2' depth intervals". There is similar narrative on <br />page 14-B, with a statement indicating that ..."in cases where spot SAR and EC levels <br />are high, calculated blending ratios may be usetl to maintain the values of the backfill <br />material within the desired range". CBA-2 soil analyses indicate that the sampling within <br />the borrow area was done at 5 foot depth intervals rather than 2 foot intervals, which was <br />apparently consistent with the procedure employed in 1993 sampling of the same area. <br />The narrative does not indicate the extent to which blending ratios were used to maintain <br />the values within the desired range. <br />RSRDA <br />Roadside borrow area pre-salvage soils data intlicated comparatively high quality soiis, <br />with all 16 sampled zones meeting subsoil quality criteria for both EC and SAR, and only <br />4 of the 16 marginally exceeding quality criteria for topsoil. Average values for EC and <br />SAR were well below the permit specified criteria for topsoil. Re-spread sample data <br />verify the generally high quality of the salvaged soils; EC and SAR levels were lower than <br />the topsoil quality threshold in all 11 samples. <br />------------------------------------------- <br />Based on our review of the information provided, we conclude that permit compliance <br />was demonstrated for CRDA-2 subsoil quality, CRDA-1 subsoil quality, and RSRDA <br />subsoil and topsoil quality. Documentation of re-spread topsail quality was not provided <br />for CRDA-2, and specified topsoil quality criteria for EC and SAR were exceeded on <br />numerous locations at CRDA-1. W e have the following requests. <br />a) Please collect re-spread topsoil samples (top 6 Inch increment) from roughly the <br />same locations that subsoil samples were obtained on CRDA-2, and submit the EC <br />and SAR data within responses to this review. <br />b) Please amend the narrative on amended page 9-4 to reference and explain the <br />"additional samples" CRDA2-14, 15, and 16. <br />c) Please explain why CBA-2 sampling was done in 5 foot increments rather than <br />the permit specified 2 foot increments. <br />d) Please address the extant to which "calculated blending" was or was not <br />utilized to maintain soil values within the desired range, with respect to soil <br />salvaged from C8A-2. <br />e) Finally, Appendix pages 8-5-2 through 8-5.4 provide 1993 pre-salvage soils data <br />by 5' depth increments for borrow areas CBA-1 and CBA-2, conducted in <br />anticipation of the 1994 reclamation projects performed by Powderhorn Coal <br />Company. Presumably, sampling of respread soils on the lower benches of <br />CRDA-1 and CRbA-2 was undertaken following completion of the cover-soiling <br />operations in the summer or fall of 1994, but such data was apparently not <br />incorporated into the permit. Please review your records and submit the data as <br />tables for Inclusion in the permit document. H this data Is not available, additional <br />sampling of these areas and analysis for EC and SAR (separate analyses for each <br />sample location by top 6" increment and lower "subsoil" Increment) will need to be <br />conducted, and the analyses submitted with the response to this review, <br />7 <br />