2009-03-23_REPORT - C1981022 (2)

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spring snowmelt. An analysis of the limited data suggests there is no adverse impact of the Elk Creek mine to Lower Elk Creek. S-1 - Upper Sanborn Creek and S-2 - Lower Sanborn Creek Surface water monitoring points S-1 - Upper Sanborn Creek and S-2 - Lower Sanborn Creek were established to monitor the flow in ephemeral Sanborn Creek above and below the disturbed area of the Sanborn Creek Mine site. Sanborn Creek also received discharge water from the Sanborn Creek mine, consisting primarily of natural mine water inflows and some runoff of imported (from the North Fork intake) water from the mining sections. The mine water discharge (CDPS discharge point 011) commingled with upper Sanborn Creek flow for a distance of approximately 300 feet through culverts under the railroad and highway prior to discharging into the North Fork of the Gunnison River. The S-2 sample site is located at the outlet of the culvert, prior to the confluence with the river. Because of the 2003 closure of the Sanborn Creek mine, and the termination of discharge Outfall point 011, the S-2 sample site was no longer needed and, thus, eliminated from the OMLLC hydrologic monitoring program in 2004. (see TR-45). Sanborn Creek, an ephemeral stream, flows at monitoring point S-1 during spring runoff and significant precipitation events. During 2008, S-1 had the usual minimal flows and by mid-June flows had ceased altogether. An analysis of the limited data suggests there is no adverse impact of the Sanborn Creek mine to Sanborn Creek. is C-1 - Lower Coal Gulch Surface water monitoring point C-1 - Lower Coal Gulch, an ephemeral drainage, is monitored to verify that the Sanborn Creek mine does not have an adverse affect on the quality of runoff in this drainage. During 2008 there was, again, minimal flow in Coal Gulch during spring snowmelt, and no flow after snowmelt was completed. An analysis of the limited data suggests there is no adverse impact of the Sanborn Creek mine to Lower Coal Gulch. NF -1 and 3 - North Fork of the Gunnison River Surface water monitoring points NF-1 (North Fork upstream) and NF-3 (North Fork downstream) were selected to monitor the water quality in the North Fork of the Gunnison River above and below the disturbed surface mine site of the Sanborn Creek and Elk Creek Mines. Monitoring point NF-3 was established in September 1997 to monitor for any mining-related water quality impacts from the West Valley coal refuse pile. It should be noted that NF-3 is also downstream from the town of Somerset and monitoring results for this station most likely include impacts from domestic water use, possible leakage from sanitary sewers, the Bear Mine discharges, and other factors that are not related to the Sanborn Creek or Elk Creek Mines. Similarly, both sample locations are located downstream of the adjacent Mountain Coal Company, West Elk Mine discharge points and potentially other less distinct historic mine discharges. Flow in the river reflects natural seasonal flows from upland drainages plus regulated flows from Paonia Reservoir and other upland irrigation water storage facilities. During 2008, the typical spring flow in the river was substantially increased and contained significant amounts of 8