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The post-mining uses of ground water in the permit area will be for <br /> agriculture and livestock/wildlife watering. Only the three large <br /> sandstone aquifers within the upper Williams Fork Formation at <br /> Trapper(Twenty Mile Sandstone, Second White Sandstone,and <br /> Third White Sandstone),could reasonably be expected to yield <br /> enough high quality water to serve as a local supply source. Coal <br /> aquifers in the area possess neither the deliverability nor water <br /> quality to be considered for reliable water supplies. <br /> The Second and Third White Sandstone aquifers overlie the <br /> stratigraphic sequence being mined at Trapper. TDS concentrations <br /> in both of these aquifers have increased over the years based on <br /> monitoring of wells P-5 (2"d WSS),and P-8 (3,d WSS),which are in <br /> the East Pyeatt Gulch basin. Well GC-2 (2"d WSS)has shown an <br /> increase in TDS from the mid 80's to early 90's,TDS levels appear <br /> to have stabilized at levels above pre-mining levels. Sulfate Levels in <br /> well P-8 are above the baseline levels. TDS and Sulfate levels in the <br /> point of compliance well GP-9 do not appear to have been impacted <br /> U. Impacts to by mining at this time. However,given the elevated TDS and Sulfate <br /> ground water that CDRMS levels in up-gradient well GC-2 and well P-8,elevated TDS and <br /> adversely impact regulations sulfate levels may occur in the future at well GP-9. <br /> the postmining 4.05.1(2) and Elevated TDS levels in backfill aquifers are likely according to the <br /> land use within 4.05.11 PHC section of Trapper's permit. Wells GD-3,GD-5,GF-7 and <br /> the permit area GF-11 are completed in backfilled spoil. Well GD-2 is down- <br /> gradient of GD-3. The elevated TDS levels in the backfill aquifers <br /> may be due to leaching from backfill material,reported levels are <br /> within their natural limits. <br /> In 2020,GMP-1,completed in the HI aquifer,continues to increase <br /> in higher concentrations of TDS and Sulfate. This well is down <br /> gradient from the reclaimed A-pit and is likely showing fluctuations <br /> from the backfilled aquifer. According to the report,other wells <br /> monitored in this specific area and aquifers have TDS/Sulfate levels <br /> that naturally vary significantly over the area. <br /> Trapper believes the TDS and conductivity concentrations will <br /> eventually subside,possibly hundreds of years after mining and <br /> reclamation,as discussed in Section 4.8.3 of the permit. suitability <br /> of Trapper's ground water for livestock and wildlife is expected to <br /> continue into the future based on long-term trends in Trapper's water <br /> quality data. <br /> Page 6 <br />