REP28646 - Laserfiche WebLink

Home Browse Search

• • flydrningr .traruurriny Anrvities times per year. Monitored parameters included water level, pH. conductivity, temperature, total dissoved solids. total suspended solids, total iron, and «xal manga- nese. Results of the sampling efforts are summa- rized in AppendLx H. Hydrographs depicting water levels from 1973 to the present have been included as Appendix I. Minimum and maximum c~mpari- sons are presented in Appendix E. Water level and sampling records for water tear 1992 were complete (or ten wells. Water in 11 wells was either nonexistent or insufficient fur sampling. Neither water level or quality samples were acquired from the lost wells SOM-~8-H2 and SOM-38-H3. ~ON,~ ~ct~ ~Jx Mine Water Monitoring (J\ Mine water inflows in areas beinC actively mined were mapped during water year 1992. Areas of previous mine inflows were monitored by occasion- al visits. Exhibit 3 shows locations of inflow-s and estimated amounts of mine inflows in the "B" seam. Areas of standing water are also shown. During 1992, samples of mine discharges were taken from the MB-1, MB-2, and MB-6 sediment ponds. They were tested for pH, electrical cunduc- tivity, total suspended solids, total dissolved solids, and total iron. Results of the analyses are shown on Table 5. The higher levels of conductivity, TDS, and iron are probably due to discharges of the more mineralized water and refuse associated with the B seam. However, the overall quality o(water sampled was good and posed no problem for direct discharge to a stream or other surface feature. "F" Seam No new minine occurred in the F scam and no new inflows were observed. The I West, 1 East, and 1 Northwest Submains were sealed off at the Southwest and South Main Intakes and nu further monitoring of these areas can be conducted. Existing inflows in the Main Intakes were similar ro those shown last year. Refer to the map entitled "F Scam Mine Map -Hydrologic C~ndi- tions - Water Ycar 1991" in the 1991 Annual Hydrolofry Report. "B" Seam ~~M1 L Small quantitites of water (<1 GPM) were encountered during development mining in 1991. Because dripping and water inFluw gencralh subsided within ''-d hours, the water appears to be contained within Fractures and found in association with roof joints, minor fauhs, or rock spars. Areas of damp top persisted lucall_v along the more pronounced fracture trends. Water inflows were greatest along the more highly fractured zones. Initial water inllotvs were estimat- ed as hi:h as 20 gpm. After fractures were de- watered, inflows dropped substantially. No loca- tions produced sustained Oows ul water (Exhibit ±). No seasonal variation in flows was observed. The mine water balance, based on actual and estimated flows, is shown in Table 6. The quantity of water discharged or pumped from the mine was approximately 37 acre feet. Water unaccounted for is lost through seepage and evaporation into the ventilating air. Both of these losses can be large, depending on conditions. •