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discharge from the Sanborn Creek Mine, consisting primarily of natural mine water inflows and <br />some runoff of imported (from the North Fork intake) water from the mining sections. The mine <br />water discharge (CDPS discharge point 011) commingled with upper Sanborn Creek flow for a <br />distance of approximately 300 feet through culverts under the railroad and highway prior to <br />discharging into the North Fork of the Gunnison River. The S -2 sample site is located at the <br />outlet of the culvert, prior to the confluence with the river. Because of the 2003 closure of the <br />Sanborn Creek mine, and the termination of discharge Outfall point 011, the S -2 sample site was <br />no longer needed and, thus, eliminated from the OMLLC hydrologic monitoring program in <br />2004. (see TR -45). <br />Sanborn Creek, an ephemeral stream, flows at monitoring point S -1 during spring runoff and <br />significant precipitation events. During 2013, S -1 had the usual minimal flows and by mid -June <br />flows had ceased altogether. An analysis of the limited data shows somewhat elevated sodium, <br />calcium, and TDS levels but the reduced levels of the TSS and sulfates encountered in 2011. <br />The data suggests there is no adverse impact of the Sanborn Creek mine to Sanborn Creek. <br />C -1 — Lower Coal Gulch <br />Surface water monitoring point C -1 - Lower Coal Gulch, an ephemeral drainage, is monitored to <br />verify that the Sanborn Creek mine does not have an adverse affect on the quality of runoff in <br />this drainage. During 2013 there was, again, minimal flow in Coal Gulch during spring <br />snowmelt, and no flow after snowmelt was completed. Previous elevated levels of chloride <br />dropped while TSS, conductivity, and sodium appeared to increase during the short spring <br />runoff. An analysis of the data suggests there is no adverse impact of the Sanborn Creek mine to <br />Lower Coal Gulch. <br />NF -1 and NF -3 — North Fork of the Gunnison River <br />Surface water monitoring points NF -1 (North Fork upstream) and NF -3 (North Fork <br />downstream) were selected to monitor the water quality in the North Fork of the Gunnison River <br />above and below the disturbed surface mine site of the Sanborn Creek and Elk Creek Mines. <br />Monitoring point NF -3 was established in September 1997 to monitor for any mining- related <br />water quality impacts from the West Valley coal refuse pile. It should be noted that NF -3 is also <br />downstream from the town of Somerset and monitoring results for this station most likely <br />include impacts from domestic water use, possible leakage from sanitary sewers, the Bear Mine <br />discharges, and other factors that are not related to the Sanborn Creek or Elk Creek Mines. <br />Similarly, both sample locations are located downstream of the adjacent Mountain Coal <br />Company, West Elk Mine discharge points and potentially other less distinct historic mine <br />discharges scattered along the river. <br />Flow in the river reflects natural seasonal flows from upland drainages plus regulated flows from <br />Paonia Reservoir and significant other upland irrigation water storage facility releases during the <br />summer irrigation season. During 2013, the spring time flow in the river was increased compared <br />to 2012, and appeared to be close to the 20 year average and contained significant amounts of <br />sediment from the routine annual sediment scouring of the Paonia Reservoir. Due to dangerous <br />ice conditions, no sampling was conducted in January 2014. Summer and early fall flows reflect <br />discharges from upland storage reservoirs used downstream by the water rights holders. <br />Irrigation water return from upstream agriculture activities does also occur. <br />0 <br />