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The iron sulfide minerals in the spoil pile and near surface spoil are <br />continually exposed to oxygen in the atmosphere, in soil gases, or <br />dissolved in percolating soil waters. Available soluble salts and acidity <br />are therefore increased slightly in spoils compared to undisturbed <br />c/ overburden. <br />1~,~,~ All salinity values which exceeded 5 mmhos/cm in spoil were always <br />ssociated with extremely unsuitable acidic strata. Since pH and ABP are <br />~_ included on the regraded spoil parameter list, salinity data will not <br />~' provide additional primary data needed to determine regraded spoil <br />.~ .1' suitability. The analytical cost associated with the salinity analysis <br />~~ cannot be justified for the remaining spoil samples which will be <br />collected from the 300 foot grid in the Wolf Creek reclamation area. <br />Peabody proposes to CMLRD to discontinue the saturated paste extract EC <br />analysis on regraded spoil samples collected from the 300 foot grid in the <br />Wolf Creek reclamation area. The salinity analysis will continue to be <br />completed on topsoil and spoil samples collected from postmine soil pits <br />located near representative revegetation monitoring sites. <br />Manganese. Mean extractable Mn values for the selectively handled spoil <br />topdressing, mixed spoil, and premine overburden are 7.8, 30.5, and 18.0 <br />ppm, respectively. The Mn values ranged from 1.3 to 34.8 ppm in the spoil <br />topdressing, from 2.2 to 116.0 ppm in the mixed spoil, and from 1.0 to <br />103.2 ppm in the premine overburden. For comparative purposes, Mn values <br />in the premine soil ranged from 33.7 to 91.8 ppm with a mean of 62.1 ppm. an(~ <br />Eleven Mn values in the mixed spoil, five Mn values in the apremine ex~e~all <br />overburden, and four Mn values in the premine soil ~._ '.. _.. __ __ _. <br />the maximum allowable level of 60 ppm for suitable material (Seneca II <br />Mine PAP, Tab 6, Table 6-3). <br />The elevated extractable Mn values are confined to specific soil and <br />overburden strata. The premine soils, with their high organic matter <br />level, have high Mn levels because Mn is chelated by the organic fraction. <br />The overburden increments which have elevated Mn levels often encapsulate <br />or include acidic strata. Lastly, 80 percent of the spoil samples which <br />have Mn concentrations greater than 50 ppm had unsuitable pH and/or ABP <br />values. <br />The following two revisions to the regraded spoil monitoring program are <br />recommended. First Peabod proposes to CMLRD to raise the threshold <br />~~`~ I level for Mn unsuitability rom to 70 °pm based upon existing values <br />ouf nd--in non=toxi~e premine topsoil, an extensive literature search <br />completed by Sutton et. al., (1981), and the approved overburden and spoil <br />suitability guidelines presented in Tab 6, Attachment 6-1, Table 6-1-3 of <br />~ the Nucla Mine PAP. Second Paahndv prnDOSeS to discontinue the Mn <br />~2 analy_sis on spoil samples_cal_lected_from_the 300 foot rg id in the Wolf <br />Creek recl_ama_tion ar~a._ Mn is considered to be a secondary suits- b lid <br />criterion in the Wolf Creek mining and reclamation area. All Mn values <br />which exceeded 70 ppm in spoil were always associated with extremely <br />unsuitable acidic strata. Since pH and ABP are included on the <br />regraded spoil parameter list, Mn data will not provide additional primary <br />data needed to determine regraded spoil suitability. The analytical cost <br />associated with the Mn analysis cannot be justified for the remaining <br />spoil samples which will be collected from the 300 foot grid in <br />