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6. The mitigating measures undertaken, and their success as documented . <br />in the field, pertaining to high SAR values in the overburden, <br />should be discussed by Peabody. <br />RESPONSE: <br />High overburden SAR values are associated with the Lennox outcrop in the <br />extreme soutfrwest portion of the Seneca Mine near Drill Hole Site 2614E <br />(see SMP C-80-005, Tab 6, Table 6-7, Page 6-27 and Appendix 4, Table 6, <br />Page 6-155). Mitigative measures are described in the response to <br />adequacy review geology description comment Number 1. <br />7. Peabody should more clearly describe how a wet care sample, when <br />received by the lab, can affect the nitrate analysis as drastically <br />as indicated in the original permit application. Furthermore, the <br />original application states that nitrate toxicity problems are not <br />anticipated. Peabody should further address this question based <br />upon field observation and current literature. <br />RESPONSE: <br />Excessive levels of nitrate in the overburden at Seneca were reported in <br />samples collected at Drill Hole Sites 2034E, 2613E, and 2614E (Page <br />6-149). All three sites are located in the extreme southern portion of <br />the ti'adge mining area (see revised Exhibit 6-1, Drill Hole Location <br />Map). Sites 2034E and 2614E occur on the eastern and western edges of <br />the disturbance limits, respectively, near the Lennox coal outcrop, <br />while Site 2613E is centrally located. <br />Three major forms of soil nitrogen are typically found in soil and <br />overburden material: 1) organic nitrogen associated with soil humus; 2) <br />ammonium nitrogen associated with clay minerals and organic matter; and <br />3) soluble nitrate compounds. Most of the soil nitrogen is in the <br />organic form and is slowly released, through microhial action, as <br />ammonium and nitrate. These mineralization and nitrification processes <br />require nitrifying bacteria, a carbon source, oxygen, water, and <br />favorable soil temperatures (Traynor, 1980). • <br />10 <br />