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The 2007 TSS values were small and similar to the low range of previously observed values. <br />As expected, a general increase in TSS for an increase in flow is seen at the plots for the <br />historical data from the sampled sites, with the 2007 data supporting the historical relationship <br />between flow and TSS. The TDS of the surface water from the mine area is similar to the TDS <br />from the non-mined area and; therefore, an increase has not been defined, except for an <br />increase in TDS during low flow conditions at NPDES sites 001 and 011. Field pH values for <br />all sites were similar to previous data collected. <br />2. PHC: Trapper does not anticipate recharge to the shallow aquifer systems to be <br />adversely affected by mining operations in the Third White Sandstone. Short term <br />localized disruptions may occur with respect to the Third White Sandstone. Trapper <br />predicts the post-mining recharge to this unit will equal or exceed the pre-mining rate due <br />to the enhanced permeability associated with backfill materials (PAP page 4/237). <br />Wells GC-2, P-8, and GP-9 are used to monitor the Third White Sandstone. Well GP-9 showed <br />a water-level rise in 2007 prior to a sharp decline in the forth quarter, showing good recharge <br />with the above average precipitation over the last few years. The forth quarter decline is <br />thought to be an error, as the first quarter 2008 was similar to the third quarter 2007. The water <br />levels in P-8 were steady in 2007. Water levels in GC-2 gradually rose in 2007. These changes <br />are thought to be natural. Variations in natural recharge to the 2°d White Sandstone affect the <br />aquifer greatly. Mining effects on the system have not been detected. <br />3. PHC: Groundwater quality constituent concentrations for some parameters are expected <br />to be higher than pre-mining concentrations for an extended period of time after mining <br />(PAP page 4-238b). Estimates indicate that higher sulfate and TDS concentrations from <br />some of the backfilled aquifers at Trapper Mine may, in the absence of any ameliorating <br />factors, last for several hundred years under a worse case scenario in which the entire <br />mass of pyrite available in the spoil body is oxidized (PAP page 4-438b). Elevated TDS <br />concentrations can develop as spoil aquifers are re-saturated following mining (PAP page <br />4-438d). <br />The TDS of water in backfilled wells GD-3 and GF-5 (QR Aquifer) are some what higher but <br />similar to those of native aquifers in these areas. TDS values for backfilled wells GF-7 and <br />GF-1 Tare much higher than the naturally observed concentrations and are declining from peaks <br />observed in the 1990's. The water in HI aquifer well GP-3, which is in the proximity of <br />reclaimed A pit, has not been influenced by mining. The 3`d White Sandstone wells are down <br />gradient of mining starting in 2000 and changes in water quality in these wells in 2007 are <br />similar to previous natural changes. <br />Sulfate concentrations in wells GD-3 and GF-4 were fairly steady in 2007 and have been fairly <br />steady the last few years. Sulfate concentrations in P-8 increased in 2007 after six years of <br />declining values. Sulfate in wells GD-3, GF-7, GMP-1, GF-11 and P-8 have likely been <br />affected by mining while the remainder of the increases could be from natural variations, <br />mining or a combination of both.