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units. Thus, more emphasis must be placed on the ABP analysis which I <br />indicates the ultimate reserve acidity or alkalinity of a spoil sample • <br />following oxidation and weathering of exchangeable bases associated with <br />carbonate and acid-forming cations associated with sulfur forms such as <br />pyrite. Current literature suggests an ABP value of -5 be utilized to <br />separate suitable versus unsuitable material. <br />Critical ABP values of -1, -9, and -18 were identified for samples <br />collected from Sites WC-60, WC-64, and WC-65, respectively (see Exhibit <br />9-4, Postmine Topsoil and Spoil Sample Locations). These sample sites <br />were located in a low overburden cover area where the potential for <br />successful dragline/blasting/dozer/scraper mixing was low. The acid <br />spoil problem in this area will be mitigated by utilizing one of the <br />following two methods. Suitable spoil will be transported by dragline, <br />scraper, and/or dozer to the problem area and distributed to a thickness <br />of two to three feet. Analyses for this suitable overburden topdressing <br />material ar•e presented in Table 1 (samples 56, 57, and 62) with geology <br />Comment 2. Otherwise, sufficient quantities of agricultural grade <br />limestone will be applied and incorporated into the upper 12 to 24 <br />inches of spoil to neutralize the excess active and reserve acidity. <br />Pages 6-29, 6-30, 6-33, 6-34, 6-145, 6-146, 6-151, 6-153, and 6-164 in <br />Tab 6 of SKIP C-80-005 were revised to incorporate the ABP and selective <br />handling requirements. <br />The following guidelines will be utilized when lime is to be applied to <br />acid spoil. Lime application rates will be based upon results obtained <br />from the ABP test. Sufficient quantities of lime will be added and <br />incorporated into the upper 12 to 24 inches of spoil to theoretically <br />raise the pH to between 5.5 and 7. Lime will be applied to the spoil <br />surface utilizing bulk spreader trucks, scrapers, front-end loaders, <br />haul trucks, dozers, or other suitable pieces of available equipment. <br />The lime will be thoroughly incorporated into the upper 12 to 24 inches <br />of spoil utilizing a chisel plow, ripper, and/or disk. <br />Potential acidity problems have also been recently identified in older • <br />Wolf Creek reclamation areas which have been topsoiled and seeded. <br />8 <br />