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Wadge Coal Overburden <br />Six wells are used to monitor water quality and/or depth to water in the Williams Fork <br />Formation overburden above the Wadge coal seam. Two of the wells, 40V1 and <br />40V2 were down-gradient wells in the south extension area. Both of these wells have <br />been abandoned. A replacement Wadge overburden well, WOV25, was drilled in <br />2004. <br />The Williams Fork is a 50 to 500 feet thick sequence of sandstone, siltstone, shale, and <br />thin coal, including the Lennox Coal Seam. Ground water in the Williams Fork tends <br />to flow downdip. The movement of water and the horizontal extent of the formation <br />are limited by outcrops in the eastern and central parts of the permit area. <br />Generally, the Williams Fork is found to be in an unconfined state, however, locally or <br />seasonally the formation may exhibit semi-confined conditions. Seasonal fluctuations <br />are probably the result of recharging and dewatering a perched aquifer within the <br />formation. <br />Although aquifer tests were not performed on the overburden at the site, aquifer <br />characteristics have been extrapolated from Colorado Yampa Coal, located about 15 <br />miles southeast. Data obtained from these tests indicate that transmissivity values for <br />the overburden could range from 3 to 20 gallons per day per foot (0.4 to 2.7 fe per <br />day), while storativity may vary from 1 x 10-2 to 1 x 10-5 as local conditions change. <br />Water quality analyses generally indicate that this is a magnesium - calcium <br />bicarbonate water with elevated levels of iron, manganese, and TDS. The high iron, <br />TDS and manganese values preclude use of this water as a drinking supply. Williams <br />Fork water is suitable for stock watering and irrigation of salt tolerant plants. <br />Hubberson Gulch Alluvium <br />The alluvium in Hubberson Gulch occurs in the lower reaches of the gulch in and <br />adjacent to the permit area. Depth to water data indicates that the aquifer may vary <br />from semi-confined to water table conditions. The amount of head, if any, is generally <br />less than 5 feet. Water quality analyses of two alluvial wells indicate that these <br />calcium-bicarbonate type waters do not meet U.S EPA drinking standards. <br />Manganese, sulfate, TDS, and chromium are found to be in excess of standards. These <br />waters do meet stock watering criteria, and may be used for irrigation dependent upon <br />crop and soil characteristics. <br />Springs and Seeps <br />An initial spring survey in July, 1979, located 49 springs and seeps in and near the <br />permit area. Two additional springs were identified during the 1997 baseline studies <br />Seneca II-W Findings Document 32 C1982057 <br />Permit Renewal No. 5 December 9, 2010