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Assuming that the Bond and Cow Camp Creeks alluvial water is tributary to that of <br />the Fish Creek alluvium, Seneca Coal Company performed aquifer tests on the Cow <br />Camp Creek alluvial aquifer to obtain a travel time estimate for the potential salt <br />plume through the alluvial aquifer. These tests resulted in an estimated <br />transmissivity value of 4.1 to 5.6 ftZ/day. Based upon this value, a hydraulic <br />conductivity (K) value of 0.32 feet/day was derived. Using the derived K value, and <br />an assumed effective porosity of 0.3G, tt was determined that flow velocities within <br />the Bond and Cow Camp Creek alluvial aquifers aze 0.15 ft/day and 0.13 ft/day, <br />respectively. Based upon these calculations, it is thought that travel time to Fish <br />Creek within these alluvial bodies is 200 years and 300 years for the Bond Creek <br />alluvium and Cow Creek alluvium, respectively. <br />It would appear that the transmissivity range of 4. l to 5.6 ftZ/day and the calculated <br />travel times are extremely low for an alluvial system. To verify these calculations <br />and assumptions, Seneca Coal Company has placed a monitoring well in both the <br />Cow Camp and Bond Creek drainages. These wells were placed, completed and <br />monitored in such a manner so that the travel time and velocity predictions made can <br />be verified. Results of the monitoring have not yet been compiled, but will be <br />compiled and included in the revised Probable Hydrologic Consequences section of <br />the permit application package. <br />Seneca Coal Company also performed an aquifer test at a well completed in the Fish <br />Creek alluvium neaz the confluence of Bond and Fish Creeks. This test indicates <br />that the Fish Creek alluvial aquifer is capable of storing and transmitting <br />substantially more water than that of the sub-drainages. Slug injection tests <br />indicated that the transmissivity of this aquifer is about 37.6 ftZ/day, while the K <br />value was calculated to be 7.5 ft/day. Therefore, it is thought that the potential <br />impacts to the baseline water quality of the Fish Creek alluvial aquifer, due to the <br />poor quality inflows from tributary alluvial aquifers, will be mitigated by dilution. <br />The Division has reviewed the 1987-1996 Annual Hydrology Reports for the Seneca <br />II Mine, and previous statements of probable hydrologic consequences compiled by <br />Seneca Coal Company and the Division. Pursuant to Rule 2.07.6(2)(c), the <br />assessment of the probable consequences of the proposed mining operation and [he <br />assessment of the probable cumulative impact of all anticipated mining in the area <br />on the hydrologic balance, as required by Rule 2.05.6(3) have been made. The <br />proposed operation has been found to prevent material damage to the hydrologic <br />balance outside the permit area. <br />34 <br />