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(See the Surface Water section of this Probable Hydrologic Consequences statement for <br />further discussion regazding surface water impacts.) <br />Information supplied by Seneca Coal Company indicates that at their confluences with <br />Fish Creek, Cow Camp Creek and Bond Creek do not support flow during the months <br />of August and September. It is assumed that during this period of time, Cow Camp and <br />Bond Creek flow for about 2 miles beyond the disturbed area boundary before <br />becoming ephemeral. At the point where the streams become ephemeral, it is assumed, <br />for purposes of this discussion, that the flow in each drainage is 0.2 cfs with a TDS <br />concentration of 2,500 mg/1. <br />Assuming that the Bond and Cow Camp Creeks alluvial water is tributary to that of the <br />Fish Creek alluvium, Seneca Coal Company performed aquifer tests on the Cow Camp <br />Creek alluvial aquifer to obtain a travel time estimate for the potential salt plume <br />through the alluvial aquifer. These tests resulted in an estimated transmissivity value of <br />4.1 to 5.6 ftZ/day. Based upon this value, a hydraulic conductivity (K) value of 0.32 <br />feet/day was derived. Using the derived K value, and an assumed effective porosity of <br />0.30, it was determined that flow velocities within the Bond and Cow Camp Creek <br />alluvial aquifers are 0.15 ft/day and 0.13 fdday, respectively. Based upon these <br />calculations, it is thought that travel time to Fish Creek within these alluvial bodies is <br />200 yeazs and 300 yeazs for the Bond Creek alluvium and Cow Creek alluvium, <br />respectively. <br />It would appear that the transmissivity range of 4.1 to 5.6 ftZ/day and the calculated <br />travel times are extremely low for an alluvial system. To verify these calculations and <br />assumptions, Seneca Coal Company has placed a monitoring well in both the Cow <br />Camp and Bond Creek drainages. These wells were placed, completed and monitored <br />in such a manner so that the travel time and velocity predictions made can be verified. <br />Results of the monitoring have not yet been compiled, but will be compiled and <br />included in the revised Probable Hydrologic Consequences section of the PAP. <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 that <br />the Fish Creek alluvial aquifer is capable of storing and transmitting substantially more <br />water than that of the sub-drainages. Slug injection tests indicated that the <br />transmissivity of this aquifer is about 37.6 ftZ/day, while the K value was calculated to <br />be 7.5 ft/day. Therefore, it is thought that the potential impacts to the baseline water <br />quality of the Fish Creek alluvial aquifer, due to the poor quality inflows from tributary <br />alluvial aquifers, will be mitigated by dilution. <br />The Division has reviewed the 1987-2006 Annual Hydrology Reports for the Seneca II <br />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 assessment <br />of the probable consequences of the proposed mining operation and the assessment of <br />the probable cumulative impact of all anticipated mining in the area on the hydrologic <br />29 <br />