REP25820 - Laserfiche WebLink

Home Browse Search

• • Hydrologic Monitoring Activities The hydrologic monitoring program for 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. i Mine Mining and Reclamation plan (M and R Plan), became the "approved" hydrology monitoring program. In 1984, 1937, and 1989 the program was revised. The 1984 and 1987 revisions were made to more efficiently monitor possible effects from mining and provide data for future permitting. The 1989 revision incorporated provisions for collecting "B" scam baseline data and monitoring for potential mining impacts in anticipation of the 199(1 opening of the "B" Seam. All revisions wcrc approved by the Colorado Mined Land Reclamation Division (CMLRD). The 1990 Annual Hydrology Report contains the Collowing: • Data from five continuous flow monitoring stations; • Data from two U. S. Geological Survey (USGS) continuous flow monitoring stations; • Data from seasonal water quality sampling at Iwo surface water quality monitoring stations; 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 two stations with a Cew mechanical problems, the records are complete. 'fable 1 Summary of Surtace Wuter Moni- turing Prngrum at the ML Cun- nison No. l Mine SlnUon 6lowAOa xily Walcr Quality Afh:~dor wE<C Sylvester Gulch Continuous A 3 lima per year D USGS/WECC Gaging Station Coninuous Q 3 time per year D East Fork Minnesota wr« Creek Flume Continuous A 3 lima per year D Wece Lower Dry Fork Flume Continuous A 3 lima per year G WtU Upper Dry Fork Flume Continuous A 3 time per year b Wc.ec Lick Creek Flume Continuous /1 3 lima per year D North Fork Upper -- 3 time per year A North Fork Lower -- 31ima per year D USGS North Fork gaging station near Somerset Continuous ~ -- • 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 measurements of dis- charge and water quality sampling at seven springs issuing from or below the "F' scam coal; • Data from seasonal water level and water quality measurements at 23 wells; and • Data from measuremenu of mine water discharges and mapping oC inflow locations. Stilling wells at the five WECC gauges began freezing in October. By the middle of the Decem- ber, all were frozen. Thawing began in February, but it was early April before all stilling wells had (hawed. Debris buildup in the flumes was minimal during 1990 and no data wcrc lost due to debris. In addition to the five WECC monitoring loca- tions, (low data arc available from two USGS monitoring stations. These stations are Minnesota Creek downstream of Dry Creek and the North Fork of the Gunnison River near Somerset, Colo- rado. The North Fork station is located approxi- mately'/a-mile upstream of the mine site. Because the USGS gauging stations arc heated, they were unaffected by freezing temperatures. Data for the