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been reclaimed (2013 -2014) has not yet occurred. Therefore, the impacts to the receiving waters <br />will be evaluated for both high and low cases, with and without irrigation, and including the <br />predicted spoil spring flows from New Horizon Mine and the existing spoil spring flow from the <br />old Peabody Nucla Mine (New Horizon 1 permit area). The irrigation case corresponds to the <br />September /October time period when flows are fairly low in the San Miguel River. The non- <br />irrigation period corresponds to March/April when flows in the San Miguel are usually at peak. As <br />described previously, irrigation of the reclaimed NHN Mine will produce a flow in the spoil of <br />about 81 ac- ft. /yr,( at full irrigation). Over the length of the irrigation season (165 days) this is an <br />average of about 0.248 cfs. During the non - irrigation season the flow from the NHN backfill <br />spring will mimic flow levels from the old Peabody Mine or about 0.041 cfs. The TDS values for <br />the NHN backfill spring discharge were averaged from sample analyses from NPDES 001 <br />discharges from 1987 to 2000 and reported on Table 2.05.6(3) -4 of the New Horizon #2 Area <br />permit. The Tuttle Draw TDS and flow values were also averaged from analyses and <br />measurements from 1987 through 2000 and likewise reported, (see Table 2.05.6(3) -4 of the New <br />Horizon #2 Area permit), as taken at surface water site SW -N3. Table 2.05.6(3) -2b included in <br />Appendix 2.05.6(3) -2 shows this information for these as well as other sample points. <br />Table 2.05.6(3) -2 shows the predicted impact of the NHN backfill spring discharge on the <br />receiving waters of Tuttle Draw. During the irrigation season, the predicted TDS for Tuttle Draw <br />is an increase of about 9 mg/1 or about 0.5 %. During the non - irrigation season the predicted TDS <br />for Tuttle Draw is an increase of 26 mg/1 or about 1.2 %. <br />The spoil water inflows from NHN Mine will influence the quality of Tuttle Draw to a minor <br />degree. However, within about 2 miles, this flow enters the San Miguel River where the flow is so <br />much larger than the Tuttle Draw flow that the impact is negligible. Further, the water in Tuttle <br />Draw is too high in dissolved solids for domestic drinking water or for use in irrigation without <br />treatment. Also, these impacts are for the time when the spoil material is leaching salts at a <br />maximum. As described earlier, the TDS levels will drop over time as pyrite is oxidized and other <br />salts are leached out of the spoil which will lessen the impact to the waters downstream over time. <br />Six months prior to NHN Mine startup, monitoring of Spoil Spring #1, 001 discharge site, and <br />SW -N3 (on Tuttle Draw) will be resumed if at that time it has been suspended. The approved <br />"hydrologic monitoring plan" is described in Appendix 2.05.6(3) -3 at the end of this section. <br />Impacts to receiving Waters — Meehan Draw <br />The Meehan Draw barrier pillar will serve as a dam of sorts (see discussion on "Spoil Water <br />Infiltration Into Low Wall" on page 23 above and Figure 2.05.6(3) -1) for water in the backfill of <br />the reclaimed pit. It is anticipated that water accumulating behind the low wall will eventually <br />issue as a "spoil spring ", (Spoil Spring 44 (projected)). Based on the structure contour map (see <br />Map 2.04.6 -1 in Section 2.04.6), the overburden depth, and the topography the expected location <br />of this spring is in the vicinity of NW 1/4, SW '/4, NW 1/4 of Section 25, T. 17 N., R. 16 W., (see SS <br />:tion 2.05.6(3) Page 26 February 2012 <br />