Laserfiche WebLink
monitoring at Site 5W-N3 instead of Site SW-N2 in the lower reach <br />• of Tuttle Draw. Site SW-N2 was referred to in the first paragraph <br />of items (B) and (D) on page A-3 of Appendix A. However, <br />monitoring at Site SW-N2 was discontinued in November of 1980. <br />Peabody has historically monitored Site SW-N3 in lieu of SW-N2, <br />because this site is located on Tuttle Draw and is far enough <br />downstream from mining to reflect all potential mining impacts. <br />Site SW-N2 is not located on Tuttle Draw, rather, its location lies <br />upstream of the confluence of Tuttle Draw and a minor tributary. <br />The second clarification involves the historic monitoring of Sites <br />SW-N7 and SW-N6. Since 1980, Peabody has historically monitored <br />Site SW-N6 for flow and quality. This site was originally <br />established as the upstream monitoring site for the West Return <br />Ditch. Subsequent mine plan proposals, specifically the proposal <br />to mine the "triangle" area which lies updrainage of SW-N6, <br />led to Peabody's decision to add a monitoring site above SW-N6 on <br />the West Return Ditch. As a result, Peabody established Site SW-N7 <br />. in 1986 and has monitored flow and quality at this site to the <br />present. Site SW-N7 is located in the West Return Ditch above Site <br />SW-N6 at the permit boundary (see Exhibit 1). The addition of <br />monitoring at Site SW-N7 in combination with ongoing monitoring at <br />Sites SW-N6 and SW-N5 provides up and downstream monitoring of the <br />West Return Ditch. <br />Lastly, one deficiency which has only recently come to <br />PCC's attention is that the required laboratory analysis of <br />silver (Ag) and chromium (Cr) has inadvertently been overlooked <br />for the period of record. Because of the extreme unlikelihood <br />of these two chemical parameters being present in the ground <br />and surface water in any measurable amount, PCC requested a <br />conditional variance to exempt PCC from sampling for these <br />parameters in the Nucla mine Permit Revision submitted to <br />MLRD on 11/04/86. Silver (Ag) and chromium (Cr) have been <br />analyzed for during the December sampling and will be analyzed <br />• for during the first quarter of 1987. If either chemical <br />constituent is found to be present in measurable amounts, PCC <br />15 Revised 03/06/87 <br />