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<br />35 <br />• determined from the auger hole tests ranged from 0.014 ft/d to 2 ft/d. <br />Attempts to conduct an auger hole test at AL 4-2 failed because the permea- <br />bility was too high. In lieu of the auger hole test, this well was pumped <br />at 30 gpm until an approximately steady state was reached and, from the <br />observed drawdown, the permeability was estimated to be about 1880 ft/d. The <br />water-table depth in the alluvial wells ranged from about 4 ft. to 6 ft. <br />below ground surface and is largely controlled by the water level in the <br />adjacent stream. <br />The hydraulic conductivity values reported in this section were used <br />to estimate the potential effects on the surface and near-surface waters <br />caused by mining beneath the valley. These computations are presented in <br />the section dealing with the hydrologic balance. <br />WATER QUALITY <br />The effects of the Maxwell and Allen Mines on the quality of the eaters <br />in the Purgatoire River are discussed separately in this section. Following <br />• ~ the discussion of the effects of mining, some comments relative to other <br />factors influencing the water quality are provided. <br />Maxwell Mine <br />I <br />• I~ <br />1 <br />. The concentrations of chemical species dissolved in both stream and <br />mine waters vary from sample to sample for reasons that often cannot <br />be reliably traced. The variation of water quality makes it difficult to <br />present the data in a completely meaningful way. Table 5 shows the range <br />and mean values for several water quality parameters in the Purgatoire <br />River at Stonewall and in the discharges from the two mines. The Stonewall <br />data is selected for comparison because the station is upstream of both <br />mines. Ten data points were averaged for most of the parameters to obtain <br />the means at Stonewall. The data are from the USGS reports of water quality <br />at station No. 07124050. The data in Table 5 for the two mines were taken <br />from 6 analyses of A11en Mine discharge and 5 analyses of Maxivell Mine <br />discharge. Commercial Testing and Engineering Co. made the analytical <br />determinations and copies of their reports are included in Appendix E. <br />The qualities of the mine discharges and the water at Stonewall are <br />