2008-03-10_REPORT - C1981022 - Laserfiche WebLink

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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 Sanbo,:n Creek Mine site. Sanborn Creek also received discharge water from the Sanborn Creek mane, consisting primarily of natural mine water inflows and some runoff of imported (from th.e North Fork intake) water from the mining sections. The mine water discharge (CDPS discharge point O11) commingled with upper Sanborn Creek flow for a distance of appro:~cimately 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 culvc;rt, prior to the confluence with the river. Because of the closure of the Sanborn Creek mine, and t:he termination of discharge Outfall point 011, the S-2 sample site was no longer needed and, thus, eliminated from the OMLLC hydrologic monitoring program. (see TR- 45). Sanborn Creek, an ephemeral stream, flows at monitoring point S-1 during spring runoff and significant precipitation events. During 2007, 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 Greek mine to Sanborn Creek. 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 2007 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 - r(orth Fork of the Gunnison River Surface water monitoring points NF-~ (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 discrete 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 2007, the typical spring flow in the river was substantially increased and contained significant amounts of sediment from the scouring of the Paonia Reservoir. Summer and early fall flows reflect discharges from upland storage reservoirs used downstream by the water rights holders. No sigmficant chan€;es were noted, however, m the analytical data with nothing to suggest adverse impact by the Elk Creek Mine or Sanborn Creek Mine to the River.