GENERAL43367 - Laserfiche WebLink

Home Browse Search

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 Twen[y 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 downgradien[ 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 downgradien[ 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. A water quality monitoring plan was initiated at Olson Spring to provide baseline data of this spring. Seneca Coal Company has included a plan for an alternative water supply in the event that local water rights are adversely impacted by mining. The plan is included in Tab 16 of the permit. Ten springs which are present in or adjacent to the permit area were chosen for further study. At each of these si[es, 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, [he water was very hard with average TDS values ranging from 458 mg/I 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 sutruner. 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, S-5, and 5-41, are expected to be impacted by mining, one of which, S-41, feeds a registered stock pond. Olson Spring is an adjudicated domestic water right. A discussion of this can be found in Section III F. - Assessment of Probable Hydrologic Consequences of Mining. Seneca II-W Findings Document 24 June I5, 2(101 Permit Renewal No. 3