REP09159 - Laserfiche WebLink

Home Browse Search

• Trout Creek Sandstone. Veil GY-55-TC is used as the potable water supply for the Seneca II Mine facilities. It displays a Na-504X[03 type water. TDS values show no discernible trend. Spoils. Three wells that are used for monitoring water quality in the spoils above the Vadge Impoundment ere 25-5, 26-5, and 27-5. Yell 25-5, the upper spoils well, did not have enough water in its casing to sample this year, although in the past it displayed a MgC a-504 type water. Veil 26-5, the middle spoils well, displayed a HgC a-504 type eater. Veil 27.5, the lower spoils well, also displayed a MgCe-504 type water. TDS decreases in these three spoil wells in the downgradient direction. This is probably due to the diluting effect of the Lower TDS Vadge Impoundment water in direct communication with spoils aquifer water. Year to year fluctuations in TD5 are difficult to delineate probably due to the effects of fluctuating Vadge reservoir water levels. Seven spoils wells were completed in the summer of 1987. Three (Wells 59-5 to 61-S) were completed above Spoils Spring #3 (also known as the Spring Creek area). Four (Veils 62-5 to 65-5) were completed above Spoils Spring k1 (also known as the Cow Camp Creek • area). Starting in 1990, the furthest downgradient well in each area was sampled for water quality (Veils 61-5 and 62-5). Data collected by PCC and the U.S. Geological Survey (USGS) in prior years indicate that water quality from the spoils wells in each respective area are similar. VeIL 61-5 displays a HgC a-504 type water, while Vell 62-5 displays a CaMg-504 type water. Average TDS values for Vell 61-5 have decreased the last tuo years, while [he average TDS value for Well 62-5 has decreased this year after two straight years of increase. Comparison of Ground Vater ouality to Water Use Standards. The Colorado Department of Health ([DOH) drafted basic standards for ground water, including standards for agricultural use (i.e., livestock and irrigation). These standards have been summarized and are presented in Table 77 (Appendix A). Parameters denoted with an asterisk on this table pertain to livestock standards, while those not asterisked pertain to irrigation standards. Results of analyses performed on samples obtained from monitoring wells during the 1992 Water Year have been compared to these standards, and the comparison results are presented in Table 12 (Appendix A). • Table 12 shows that Alluvial 4ells b-A, 32-A, 33-A, 46-A, 31-A2, 68-A, and 69-A, Volf Creek Overburden 4ell 7-VCO and Spoils Yells 26-5, 27-5, and 61-5 all exceed the 9