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Probably Hydrologic Con.requencrs- Chimn~v Rock Mint <br />• Fruitland Formation was estimated from a pump test performed on wells MW-9 and MW-10 in <br />the Barren Ridge area. Transmissivity of the formation was estimated at 130 g/d/ft and <br />storativity was estimated at 1.3 x 10'" (Piteau and Associates, 1982). Relationships of the above <br />units are detailed in Figures 2,3,4,5 and 6. <br />Water quality in these areas was determined from water samples obtained from wells installed <br />for baseline and ongoing monitoring purposes. Four wells each were previously installed in the <br />Fruitland Formation and the alluvium. An additional well was installed in the spoil. Water <br />samples obtained from wells located in the Fruitland Formation are a mixed ion calcium- <br />sulfate/bicarbonate type. Water samples obtained from wells completed in the alluvium are <br />generally consistent with the parameters found in the water samples from Stollsteimer Creek. <br />The water is a mixed ion calcium magnesium-sulfate/bicarbonate type. <br />PROBABLE HYDROLOGIC CONSEQUENCES <br />The site is an inactive former open pit coal mine. Surface reclamation of the site has been <br />completed and the pits backfilled. Data from water samples obtained from the wells and surface <br />water stations within and outside of the permit area have indicated little effect on the waters in <br />the area. Data from the wells and surface sampling stations is reported in the Annual <br />Hydrologic Reports. Future impacts could be related to the infiltration of surface and <br />• groundwaters into the backfilled pit areas. Since the areas have been disturbed, the <br />transmissivity of these areas is anticipated to be higher than the surrounding areas. <br />ALLUVIAL AQUIFER AND SURFACE WATER IMPACTS <br />This aquifer is associated with Stollsteimer Creek, has a high transmissivity and is unconfined. <br />Possible impacts to this aquifer would be associated with the infiltration of lower quality water <br />from the pit areas, effects from the dewatering conducted in the area, and water quality <br />deviations caused by surface infiltration of lower quality runoff water. <br />The preferential flowpath of materials from the filled pits would tend to be horizontal with <br />discharge into the alluvial material. This is indicated by the difference in the relative horizontal <br />to vertical permeability of the formation, the shales that exist between the pit areas and the <br />sandstone, and the distance to the discharge point in the alluvium. <br />Considering the possible effects of infiltration from the pit areas, a velocity calculation can be <br />performed based upon the parameters determined for the Fruitland Formation in the report by <br />Piteau and Associates (1982). Seepage velocity (v,), the true velocity representing the rate the <br />groundwater flows through the pore spaces can be calculated utilizing the formula: <br />v~ = Kdh/rtrdl <br /> <br />R 1.05 313107 48-95(9:79am) 3 <br />