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<br />!frrLnlnxm :fi.'m'nirc M.m •;w lac ,taw fLwrw~ <br />watt; sources of .omparabic yuamity and quality. Ai desrioed in Lha ware: auemenmtion <br />pian. WFC has a :11 ;u:re foot consumptive use right on the Highline Canal which would <br />be used [o mitigate the potential 26 acre Foot impact on surface Ovate: ri¢ht users from pi[ <br />intlow drawdown. <br />Impact on groundwater rights. No surface or azoundwater dgh[s have been iden[itied within <br />the Vew Horizon '_ mine area. Therefore. there will be no direct impatx from the approved <br />mining plan on any local water rights. <br />Im~ct of snot] material on groundwater flow and recharge. The mine pi[ will remain open <br />only until [he coal has been removed. Following the short-term water level decline on the <br />groundwater system as a result of pumpage of groundwater inflow m the pit. a potential <br />long-term impact to the lopl groundwater flow is the period of time necessary for <br />resaturation of the spoil maceriat and reestablishment of a Oow gradient. Spoil material at <br />the Atew Horizon mine will be replaced using techniques which will resmre petmeabilities <br />of the taterial_ Thus, the mining operation vnL not diminish vertical or horizontal <br />permeabilides but may increase these permeab0ities. As a result, there should be no <br />signi8cane impacts from the mining opemtion on groundwater flow and rcchazge rntes. The <br />• time period required for the spot? material to resaturnte should be greatly reduced because <br />of the irrigation recharge as the mined area w01 be revegetaced Cor an irrigadon type oC posy <br />mining land use. <br />Containment of pit inflow and imnacss on water avality- rVl runoff and pi[ pumpage from <br />duturbed areas will be routed through sedimenmtion pond 007. The pond is designed and <br />constructed to impound tunotf and pit pumpage from areas disturbed by mining and provide <br />sufficient residence time to insure chat the pond discharge water chemistry meets the effluent <br />requiremenu speci5ed in the tvPDES Permit. A review of the chemical and Dow data <br />indicates that the potential far any discharge From Pond 007 to exceed receiving sueam or <br />federal smndards is minimal. Past history of mine operations a[ [he Vucla Mine indicate <br />very few tYCeedances of the standards over the years of operations. As previously discussed, <br />highest pit intlow is predicted to occur in year i ac aoproritnately 5.600 cubic Eeec per day. <br />To assess the impac: of this inflow on Calamity Drnw and the San Ytigue] water quality, it <br />was assumed [hat [he entire flow war discharged and [hat the TDS level For the overburden <br />aquifer was representative of the chemical )pad. The durndon of the water quality impacts <br />is reladvely short term (i years) and the signiflcantt of the impact is negligble as TDS <br />increases in the range of 0.08 to 1S percent are projected on the San Miguel River and <br />Calamity Dmw, respectively. These increases in TDS will be additional magnesium/sodium- <br />sulfate type water which may result in a slight inaease in salinity. Tltese projected changes <br />in TDS levels will in no way affect the present and potentitl uses oC the surface water and <br />are so small that they may no[ be measurable. <br />l t `• <br />_-a ~ . <br />• <br />Attachment 2.04.7-5-14 <br />