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<br />Tally near the vicinity of the nose of the anticline), special <br />handling of the overburden in general will not be necessary as <br />the random mixing of spoil in the backfill areas will lower the <br />overall sodium concentrations which are presently so high." How- <br />ever, the applicant does not provide adequate support for this <br />contention, especially as it applies to using Phase VI - Pit 2 <br />material for backfilling Phase I - Pit 1 (see Backfilling and <br />Grading portion of Section III of this TEA). In addition, <br />because the Upper Sandy Member of the Pierre Formation is separ- <br />ated by 30 feet or less from the lowest coal seam to be mined, <br />and it is dissected by numerous faults that will come in contact <br />with the replaced spoils, groundwater present in this aquifer may <br />be adversely affected by leaching of the highly sodic spoil <br />material. Since this aquifer is the source for the Kerr Well, <br />and has the potential to be the source for other wells, any <br />adverse impacts to the quality of the water needs to be deter- <br />mined. As a result, the following stipulation is made in order <br />to evaluate potential impacts to the groundwater systems. <br />To insure that the post-mining ground Mater qual- <br />.' ~,) ity will be acceptable, especially in the Upper Sandy <br />Member of the Pierre Formation, the applicant must <br />submit a plan for special handling of spoil material <br />~~ ~ ~ containing abnormally high sodium levels. The plan <br />c should, if nec~~es.s_ar_X, include methodology(s), loco- <br />. tion(s) of Stockpile and a supporting narrative <br />(with appropriate maps) explaining the proposed opera- <br />4~ <br />tions. An alternative to this plan is to quantify <br />• potential impacts of the high-sodium spoils on post- <br />mining ground water quality, i.e. prediction of post- <br />• mining levels of sodium, TDS, and any other related, <br />pertinent water quality variables (reference: Kerr <br />~ ,~ Coal Company's Marr Strip operation).Methodology(s), <br />`~~ assumptions, relevant data, conclusions, and recom- <br />,. ~ <br />mendations should be included in a detailed narrative <br />~ that will support the applicant's contention that the <br />~` ) -81- . <br />~~ <br />~{~{,, <br />j" Y <br />,~•ti <br />~~ <br />y ~ <br />~ ~ , <br />~ , <br />~~~ <br />~~ <br />~n. <br />v <br />_~ <br />~ J <br />w <br />S <br />