2001-12-11_REPORT - C1980007 - Laserfiche WebLink

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• • HYDROLOGIC MONITORING ACTIVITIES r.:xs;.:zx:xz^r...zs•:e~:s~<:s.:e~:s,a~z:.c'x~...e~:.~:s.a'r::.r:;~;sr:..,nxa:~ns<.:M's•.;~~::e:;y::,,:z;;;:s;uz>::~:s.:.:.:amzr::a;.x::x ;zx:<r.:<xz:.:s;::.::;c;:c:;y:;s;'sxc::s-x:.wx:~::::'u'~s-r.:rs::::.^'m The hydrologic monitoring program at the Mt. Gunnison No. 1 Mine began in 1974 with the completion of several groundwater observation wells. This preliminary monitoring network was expanded considerably and in 1981, with the approval of the Mt. Gunnison No. 1 Mine, Mining and Reclamation plan (M and R Plan), became the "approved" hydrology monitoring program. In 1984, 1987, and 1989 the program was revised. The 1984 and 1987 revisions were made to more efficiently monitor possible effects from mining and provide data Cor future permitting. The 1989 revision incorporated provisions for the collection of "B" seam baseline data and monitoring for potential mining impacts in anticipation of the 1990 opening of the "B" Seam. All revisions were approved by the Colorado Mined Land Reclama- tion Division (CMLRD). • Data from monthly water level and water quality measurements at two wells com- pleted in the "B" seam coal. • Data from measurements of mine water discharges, and mapping of inflow loca- tions. SURFACE WATER MONITORING West Elk Coal Company's (WECC) surface water monitoring program includes nine monitoring locations (Table 1). The locations of these moni- toring stations are shown on Exhibit I. Daily flow estimates (including mean, maximum, and mini- mum flows) for the five WECC gauges are summa- rized in Appendix A. Except for stations with a few mechanical problems, the records are complete. The 1989 Annual Hydrology Report contains the following: • Data from five continuous Bow monitor- ing stations; • Data from two U. S. Geological Survey (USGS) continuous Bow monitoring sta- tions; • Data from seasonal water quality sampling at two surface water quality monitoring stations; • Data from seasonal measurements of pH, temperature, dissolved oxygen, turbidity, and conductivity at the six stream gauging stations in the Minnesota Creek Basin and Sylvester Gulch; • Data from seasonal tncasurements of discharge and water quality sampling at seven springs issuing from or below the "F' seam coal; • Data from seasonal water Icvel and water quality measurements at 19 wells; and TABLE L Summary of Surface Water Moni- toring Program at the 117t. Gun- nison No. l Mine Station Flow Water Quality Sylvester Gulch Continuous 3 limes per year USGS/WECC Gaging Station Continuous 3 times per year Fast Fork Minnesota Crttk Flume Continuous 3 limes per year Lower Dry Fork Flume Continuous )limes per year Upper Dry Fork Flume Continuous 7 times per year Lick Creek Flume Continuous 3 limes per year North Fork Upper -- 3 times per year North Fork Lower -- 3 times per year USGS North Fork gaging station near Somerset Continuous -- Stilling wells at the five WECC gauges began freezing in late November. By the end of Decem- ber all were frozen. By mid March all stilling wells had thawed. Debris buildup in the flumes was minimal during 1989 and no data were lost due to debris. 2