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For 2017 Dryland Pasture DP3 the desirable forage makes up 95% of the herbaceous productivity <br /> (739.8 lbs./acre). In 2018 the desirable forage made up 76.9% of the herbaceous productivity. The <br /> Dryland Pasture met the success criteria for diversity for 2017 and 2018. <br /> Hydrology <br /> Hydrologic demonstration is included in Appendix F of the SL22 application. The submitted analysis <br /> and subsequent review allow the Division to evaluate the degree that onsite impacts have been <br /> minimized to the extent predicted in the approved Probable Hydrologic Consequences section of the <br /> permit. The analysis allows for determination that offsite impacts and material damage have been <br /> prevented in accordance with the approved Probable Hydrologic Consequences section(2.05.6(3))and <br /> existing Cumulative Hydrologic Impact Analysis. <br /> Water quality trends were assessed through evaluation of annual hydrology reports, and results of <br /> hydrologic monitoring plans. Spoil aquifer and other groundwater impact predictions typically <br /> encompass time periods much longer than 10 years. The Division's analysis will focused on trends <br /> which would support or refute long-term stability in quantity and quality data. <br /> ERMR predicted groundwater drawdown in the overburden of 8 feet. Ground water monitoring wells <br /> GW-N 18-P 1 and GW-N44 demonstrated that post-mining,groundwater levels in the overburden aquifer <br /> are recovering as predicted. <br /> Ground water flow and discharge of groundwater to Calamity Draw and Tuttle Draw saw slight <br /> increases in flow downstream of the mine. At surface water monitoring site SW-N 103 on Calamity <br /> Draw the average flow rate downstream of the mine increased from 9.0 cubic feet per second(cfs)pre- <br /> mining to 9.5 cfs post-mining. Average flowrate in Tuttle Draw was measured downstream of the mine <br /> at surface water monitoring site SW-N3. ERMR measured a slight increase in flow from 2.1 cfs pre- <br /> mining,to 3.3 cfs post-mining. These results would indicate that mining has not resulted in a decrease of <br /> groundwater flow to Tuttle Draw or Calamity Draw. These results are in agreement with the operator's <br /> Probable Hydrologic Consequence predictions regarding groundwater flow to the adjacent streams. <br /> The PHC predicted that recharge into the mine spoil backfill would develop a spoil spring at the <br /> northwest extent of the pit,near Pond 013. A spoil spring identified as SS-4 formed as predicted <br /> upgradient from Pond 013. The location of spoil spring surface expression is not a part or this bond <br /> release area. <br /> The PHC predicted that irrigation water filtering into the mine spoils will increase groundwater TDS due <br /> to dissolution of soluble minerals in the backfilled spoil. The pre-mining overburden TDS was in the <br /> range of 3,300 mg/L. The predicted increase in TDS was estimated to be approximately 3,425 mg/L <br /> with a maximum of 4,000 mg/L. ERMR has calculated that the TDS from the spoil spring is <br /> approximately 3,594 mg/L. This is within the predicted levels. <br /> The operator provided analysis of impacts to surface water quality by spoil water discharge. ERMR <br /> predicted that spoil spring discharge from SS-4 would influence the water quality in Tuttle Draw. Due <br /> Permit Number C1981-008:SL22 Page 15 of 17 <br />