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beneath Gaodspring Creek. The recharge areas for the sandstone are south of the germit area in the higher elevations or where the Trout Creek sandstone is exposed at the ground level and subsequently has been eroded above the Goodspring Creek elevation. Hydraulic conductivities of the sandstones below the coal seams to be mined aze variable but low, with average transmissivity of 40 gallons per day per foot. Little water is either recharged, transmitted or discharged from the permit area. Drawdown analysis of two wells, Taylor No. 1 and No. 3; both drilled into the Trout Creek Sandstone, showed an average transmissivity of 40 and 260 gallons per day per foot and hydraulic conductivity of 3.4 and 0.13 gallons per squaze foot, respectively. Porosity and permeability characteristics of this aquifer were not calculated due to the depth of the sandstone and lack of corresponding data from other locations within the Iles Formation: Storage coefficient for one well, TaylorNo. 1, was 0.066, but should only be considered a factor for that well and not the Iles Formation as a whole since no reference data is available. - The proposed mining operations are not expected to decrease the water quality or quantity ofthe Trout Creek aquifer. Since the Trout Creek Sandstone member underlies the deepest coal seam to be mined by 800 feet, it is estimated that Colowyo's operations should not impact this aquifer in any manner. Underlying the Iles Formation is the. Mancos Shale, a unit 5,000 feet thick; consisting of marine shales and limestones. This unit is impermeable and creates the.confining base for. the Trout Creek Sandstone aquifer. Continued operations in the active pits €rom 1451 tQgresent strgport the assertion that little avatar exists above the coal stratum to be mined. What water does exist has only been experienced under perched conditions. Seeps encountered during operations have been consumed by the face or evaporated from the floor of the pit. Excavation to the lower coal seams has produced dry conditions, indicating there is no lateral or vertical continuity in the connecfion between the Iles and the Williams Fork Formations; so t1Le probability o€ aquifee cross- eontamsrration is negligible. The quality of ground water within the permit site has been rated poor by the USGS and designated far lirrrited agricultural-use ogly. -The chemical compostion of the: area's water was tested by the USGS in 1478 and found to be somewhat salirie; allaline and hard (see pages 2.04:7-12 and I3 in the Permit and Table 1). pH vanes from 72 to 8.4. Tlie USGS n:port indicates that concentrations of trace metals rarely exceed health limits. Specific conductivity averages 1440-1390 mmhos with a range between 720 and 2700 mmhos, exceeding Environmental Protection Agency (EPA) secondary drinking water standazds (see permit pages 2.04.7-14 through 18 and Table 2). The above factors, coupled with low selenium levels ranging from 0.001 to 0.002, allow the water to be used for stock watering. An EPA report entitled "Environmental Effects of Western Coal Mining, Part III" suggested that the alkaline nature of western water (including that within this permit azea) may limit or reduce October 21, 2002 32