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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 <br />generally less than 5 feet. Water quality analyses of two alluvial wells indicate that <br />these 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. <br />These waters do meet stock watering criteria, and may be used for irrigation <br />dependent upon 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 />for the II -W South Extension Area. The majority of the springs and seeps occur in <br />valley bottoms. The recharge to these valley bottom springs may be from a <br />discontinuous alluvial aquifer, from colluvial slumps, or from perched aquifers <br />draining to stream sediments. Several springs issue from the Williams Fork <br />Formation, while two others issue from the overlying Twenty Mile Sandstone. <br />Some of the springs are used to fill stock ponds in the area, while the majority either <br />contribute flow to the creeks or provide recharge to downgradient alluvium. <br />Olson Spring, which has an adjudicated domestic water right associated with it, <br />issues from the Dry Creek Alluvium about 20 feet from Dry Creek. This spring is <br />located about 9,000 feet downstream from mining. <br />Both Hubberson Gulch and Dry Creek may potentially be impacted by mining, <br />specifically by spoils discharge recharging the streams. Dependent upon the time of <br />year, Dry Creek may be recharging its alluvium, or the alluvium may be adding <br />water to the creek. Furthermore, dependent upon local conditions, discharges from <br />the predicted spoils aquifer may infiltrate the Hubberson Gulch alluvium. This <br />water may flow through the alluvium downgradient to recharge the Dry Creek <br />alluvium from which Olson Spring issues. <br />It is projected by the applicant that, due to dilution, there will be no impact to Olson <br />Spring quality which may be attributed to mining. An alluvial cross - section of wells <br />in Hubberson Gulch upgradient of the spring will help monitor the advance of any <br />plume in that gulch. Monitoring was conducted at Olson Spring (Site 5 -45) up until <br />2005 to provide baseline data and allow for future monitoring if deemed necessary. <br />The spring is actually a 3 foot diameter culvert clearwell placed in the alluvium of <br />Dry Creek. Since a well was drilled on the Olson Ranch in 1980, it has not been <br />put to use. Discontinuance of monitoring at S -45 was approved in TR -52, in 2005. <br />Seneca II -W Findings Document 31 C- 1982 -057 <br />Permit Revision No. 6 January 6, 2012 <br />