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2021 AHR Review: New Elk Mine <br /> 14. Prevention of impacts to surface water adversely impacting the postmining land use <br /> CDRMS regulation 4.051(2) <br /> Upon completion of mining, New Elk's pond network will be reclaimed as they do not hold <br /> consistent water throughout the year. The post mining land use is rangeland/wildlife. No pond <br /> discharges occurred thus no exceedances of standards occurred in 2021. Dewatering discharge is <br /> treated before release to the Purgatoire River. The expectation of impacts comprises an average <br /> increase in TDS downstream of the mine. Mine dewatering predicts a potential drawdown of 200 <br /> feet in the Allen and Apache seams. No water quality impacts are predicted for surface water or <br /> springs due to dewatering. <br /> 15. Adequacy of surface water monitoring program <br /> CDRMS regulation 4.05.13(2) <br /> Adequate <br /> 16. Interim Narrative Standard for Ground Water <br /> CWQCC regulation 41 <br /> Two bedrock wells (264440, 442 or NE-1-10), are located in the Allen Seam, well 284213,is owned by <br /> NECC is also monitored. Four shallow alluvial wells (12, 13, 14, and PAW-9), are situated 400 feet <br /> above the mining horizon. Th-201,TH-202, and TH-203 comprise three RDA monitoring wells <br /> penetrating the refuse down to the basal bedrock and are monitored quarterly. Table 1 RDA of the AHR <br /> compiles the data from these wells. Annual monitoring occurred on Paw-1, Paw-2, Paw-8, and Paw-9 <br /> sites, sites NE-6-10a and NE-6-10b. All monitoring data fell within historic ranges. <br /> 17. Sampling frequency of ground water monitoring wells <br /> Table 4.8-13a for CDRMS mining permit C81012 <br /> Three Refuse Disposal Area (RDA), monitoring wells (TH 01, TH 02 and TH 03), are monitored <br /> quarterly for depth of water. <br /> Groundwater wells PAW 1, PAW 8, PAW 9 and mine water wells New 2,New 4,NE 1-10 and New 3 <br /> are monitored semiannually. PAW 2 is a ground water well located downstream of a backfill located in a <br /> short reach of the Middle Fork of the Purgatoire River channel is a calcium bicarbonate water and is <br /> monitored semi annually. The monitoring frequency was met. <br /> 18. Parameters to be analyzed in ground water samples <br /> Table 28 of CDRMS mining permit <br /> Required groundwater parameter sampling comprise: TSS and TDS As (mg/1), Carbonate, <br /> Bicarbonate, Chloride, Sulfate, Manganese total dissolved, Potassium, Sodium, Calcium, <br /> Magnesium, Iron total dissolved and total recoverable, Hardness calculated, and the Sodium <br /> Absorption Ratio <br /> 19. Basic Standards for Ground Water <br /> CWQCC regulations 41.4and 41.5 <br /> The 2021 data from groundwater wells fell within historical ranges. All PAW monitoring <br /> stations showed a decrease of TSS in 2019 and 2020 with the exception of PAW2, where an <br /> increase was noted. PAW 8 showed a dramatic decrease in TSS between 2019 and 2020 while <br /> Paw 8 was similar to previous years and also while decreasing TSS between Q2 and Q4 <br /> Page 3 of 6 <br />