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Probable Hydrologic Consequences(PHC),predictions in <br /> V. Minimization of section 4.8.3 of Trapper's permit appear to be accurate. <br /> disturbance to the Significant changes in the point of compliance wells do <br /> hydrologic CDRMS not appear to have occurred in 2019. <br /> balance within regulation Comment <br /> 4.05.1(1) Probable Hydrologic Consequences(PHC),predictions in <br /> and adjacent to section 4.8.3 of the permit appear accurate. Significant <br /> the permit area changes in surface water quality or quantity have not been <br /> observed for 2019. <br /> W. Prevention of <br /> material damage CDRMS Probable Hydrologic Consequences(PHC),predictions in <br /> to the hydrologic regulation Comment section 4.8.3 of Trapper's permit appear to be accurate for <br /> balance outside 4.05.1(1) both surface and ground water. <br /> the permit area <br /> Overall,PHC predictions appear to be accurate,as <br /> illustrated by the following examples. <br /> Per the PHC,Trapper does not anticipate recharge to the <br /> shallow aquifer systems to be adversely affected by mining <br /> operations. Water levels in wells GC-2,GP-9, and P-8 (used <br /> to monitor the Third White Sandstone)have remained stable <br /> during recent monitoring. GC-2 is showing an increasing <br /> overall trend. <br /> Per the PHC,constituent concentrations in backfill aquifers, <br /> namely TDS and sulfate,are expected to be higher than pre- <br /> mining concentrations for an extended period of time after <br /> mining. The data for TDS concentrations in wells in <br /> backfill aquifers have shown apparent impacts from mining. <br /> X. Agreement of TDS concentrations in GD-3 continue to increase and GF-5 <br /> observed remains stable,both are somewhat higher to those of native <br /> hydrologic CDRMS aquifers in these areas. TDS values for wells GF-7 and GF- <br /> impacts with regulation Comment 11 were higher than the naturally observed concentrations in <br /> PHC projected in 2.05.6(3) the 1990s and 2000s,but remain below historic high <br /> permit concentrations. Sulfate concentrations continue to exhibit <br /> similar trends as TDS for wells GF-7 and GF-11. Sulfate <br /> concentrations increased in GD-3 and GD-2 in 2019 <br /> continuing a trend that appears to have begun around 2008. <br /> TDS/Sulfate levels in these wells should be watched closely <br /> in future years. <br /> Trapper predicts higher TSS levels in surface water for a <br /> few years after mining,declining as vegetation becomes <br /> well established. This is observed in phase III bond <br /> release areas and associated sediment demonstrations.Pre <br /> mine manganese and total iron concentrations were <br /> relatively high and this is predicted to remain the case. <br /> Backfill aquifers will continue to have an impact on <br /> surface base flow water quality(TDS),conditions. <br /> Y. Adequacy of CDRMS <br /> groundwater regulation Yes <br /> monitoring 4.05.13(1) <br /> program <br /> Page 6 <br />