2014-07-11_REPORT - C1980007 - Laserfiche WebLink

Home Browse Search

West Elk Mine 2013 Annual Hydrology Report 53 elevated sulfate concentration of 104 mg /L compared to the baseline maximum of 71 mg/L. MCC will continue to monitor the water quality of these springs to in order to discern any changes in water quality trends. 5.2.2 Impacts to Spring and Seep Water Quantity Routine (post - baseline) monitoring of spring and seep flow is conducted three times per year, corresponding with rising limb, peak flow, and low flow periods. As a result, spring and seep flows may be highly variable from year to year. However, subsidence associated with coal mining can reduce or eliminate spring flows, or alter spring locations due to stratigraphic changes. The spring flow hydrographs are presented in Appendix D. In general, spring and seep flows in WY 2013 were near to or lower than historical averages, due to a below average winter snowpack (SWE) (Figures 4 and 5). In WY 2013, spring and seep flows were near the historical averages at the following sites: Springs 24 -3, 13 -1, 13 -2, 13 -4, 26 -1, G -7, G -24, G -14, G -22, 11 -2, CR -12, G -28A, G -35, 35 -3, Deer Creek Spring, J2, Deep Creek Trail Spring, and 96 -2 -2 Area Spring. Spring flows in WY 2013 were lower than historical averages at the following sites: Springs 13 -3, 27 -1, G -16, 10 -1, G -25, G -49, J- 4, and WCC -24. Springs G -1 a, G -20, G -26A and G -30 have been continuously dry or damp at the time of monitoring for multiple years including WY 2013 and may have been impacted by mining. Flows at spring 27 -1 have been decreasing steadily since WY 2008, in spite of snowpack and precipitation trends, and this trend has most likely been caused by the deterioration and collapse of the discharge pipe. In the spring and summer of 2011, Spring J -7 was flowing and a new spring located several hundred feet east of J -7 was also flowing. It appears the some of the flow from Spring J -7 had migrated. In WYs 2012 and 2013 the original and new J -7 sites were both dry during all three monitoring rounds. The Spring J -7 migration (WY 2011) and subsequent cessation of flows (WYs 2012 and 2013) appear to be the result of recent mining activities in the Dry Fork drainage area. Flows at Spring J -7 are expected to recover after mining has moved through the Dry Fork drainage area. 5.3 Stock Ponds and USFS Water Resources Numerous stock ponds and USFS water resources are located in the permit area. The USFS water resource sites are summarized in Table 9 and shown on Map 37 in the Mine Permit document. There are no reported water losses or mining related water quality issues at any of these locations through WY 2013 and none are expected in the future (MCC, 2014). 5.4 Groundwater In WY 2013, MCC's groundwater monitoring program included 14 monitoring wells throughout the permit and lease areas. This number does not include 14 wells that have casings which were irreparably damaged, blocked, or have collapsed in prior years (Table 6). Field water quality and the depth to water are recorded three times annually, June 2014 HydroGeo, Inc.