Laserfiche WebLink
of Sciences recommended drinking water criteria. These criteria may be found in <br />Volume 3, Tab 7, Tables 7 -20 and 7 -43 of the permit application. These waters are <br />unsuitable for use as a drinking supply, but may be used for livestock watering. <br />These waters also pose a high salinity hazard to intolerant plants, and therefore may <br />be unsuitable for use as irrigation water. <br />Wadge Coal Overburden <br />Six wells are used to monitor water quality and /or depth to water in the <br />Williams Fork Formation overburden above the Wadge coal seam. Two of the <br />wells, 40V1 and 4OV2 were down - gradient wells in the south extension area. Both <br />of these wells have been abandoned. A replacement Wadge overburden well, <br />WOV25, was drilled in 2004. <br />The Williams Fork is a 50 to 500 feet thick sequence of sandstone, siltstone, shale, <br />and thin coal, including the Lennox Coal Seam. Ground water in the Williams Fork <br />tends to flow downdip. The movement of water and the horizontal extent of the <br />formation 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 <br />or seasonally the formation may exhibit semi - confined conditions. Seasonal <br />fluctuations are probably the result of recharging and dewatering a perched aquifer <br />within the 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 <br />for the overburden could range from 3 to 20 gallons per day per foot (0.4 to 2.7 ft2 <br />per day), while storativity may vary from 1 x 10 -2 to 1 x 10 -5 as local conditions <br />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 <br />iron, TDS and manganese values preclude use of this water as a drinking supply. <br />Williams Fork water is suitable for stock watering and irrigation of salt tolerant <br />plants. <br />Seneca II -W Findings Document 30 C -1982 -057 <br />Permit Revision No. 6 January 6, 2012 <br />