2010-12-09_GENERAL DOCUMENTS - C1982057

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for the H-W South Extension Area. The majority of the springs and seeps occur in valley bottoms. The recharge to these valley bottom springs may be from a discontinuous alluvial aquifer, from colluvial slumps, or from perched aquifers draining to stream sediments. Several springs issue from the Williams Fork Formation, while two others issue from the overlying Twenty Mile Sandstone. Some of the springs are used to fill stock ponds in the area, while the majority either contribute flow to the creeks or provide recharge to downgradient alluvium. Olson Spring, which has an adjudicated domestic water right associated with it, issues from the Dry Creek Alluvium about 20 feet from Dry Creek. This spring is located about 9,000 feet downstream from mining. Both Hubberson Gulch and Dry Creek may potentially be impacted by mining, specifically by spoils discharge recharging the streams. Dependent upon the time of year, Dry Creek may be recharging its alluvium, or the alluvium may be adding water to the creek. Furthermore, dependent upon local conditions, discharges from the predicted spoils aquifer may infiltrate the Hubberson Gulch alluvium. This water may flow through the alluvium downgradient to recharge the Dry Creek alluvium from which Olson Spring issues. It is projected by the applicant that, due to dilution, there will be no impact to Olson Spring quality which may be attributed to mining. An alluvial cross-section of wells in Hubberson Gulch upgradient of the spring will help monitor the advance of any plume in that gulch. Monitoring was conducted at Olson Spring (Site 5-45) up until 2005 to provide baseline data and allow for future monitoring if deemed necessary. The spring is actually a 3 foot diameter culvert clearwell placed in the alluvium of Dry Creek. Since a well was drilled on the Olson Ranch in 1980, it has not been put to use. Discontinuance of monitoring at 5-45 was approved in TR-52, in 2005. Ten springs which are present in or adjacent to the permit area were chosen for further study. At each of these sites, three water quality and discharge measurements were made during the summer and fall of 1983. Typically, quality and quantity varied from spring to spring. In general, the water was very hard with average TDS values ranging from 458 mg/1 to 2,150 mg/1. Sulfate was generally more dominant than bicarbonate. All but two springs experienced a decline in flow during the course of the summer. Five had dried up by late August, three others flowed less water during base flow and two were flowing at about the same rate in October as in June. Three springs, Olson Spring (5-45 on Dry Creek), S-5 (on an 006 Gulch tributary), and 5-41 (in the 006 Gulch channel), were projected to be impacted by mining within the original permit area. S-41., which fed a registered stock pond (Temple Pond No. 2) was mined through and was buried in spoils in 1998. Pond 006 will replace the Seneca II-W Findings Document 33 C1982057 Permit Renewal No. 5 December 9, 2010