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February 2000 Summary Pa a S-9 developed in this zone; however, numerous seasonal springs and seeps issue from these zones and have been developed for livestock watering and also support wildlife. - The primary bedrock water-bearing zones in the North Fork of the Gunnison River Basin are in the sandstone and conglomerate units and fractured zones of the Lower Cretaceous Burro Canyon Formation and the Late Cretaceous Dakota Sandstone. Minor groundwater occurrence is reported in the Late Cretaceous Mancos Shale, Mesa Verde and Tertiary Wasatch formations. Well yields from these formations range from about 0.5 to 25 gpm, with a typical average of approximately 10 gpm. Water quality from bedrock wells is generally sodium bicarbonate/sulfate type with TDS concentrations ranging from 490 to 8,200 mg/I, averaging about 2,569 mg/I. Concentrations of sulfate, TDS, manganese, and Fluoride typically exceed federal drinking water guidelines. Past and current mining activities have affected groundwater quantity and quality in the region. For example, mine discharge from the abandoned Oliver Mine and the abandoned Hawk's Nest Mine has somewhat elevated levels of TDS, iron, and manganese. Past and current activities other than mining have also affected groundwater quality. Livestock grazing causes minor impacts to springs and seeps due to erosion, sedimentation, and water quality (i.e., fecal coliforn). Unauthorized off-road vehiGe use also causes erosion and sedimentation that affect spring and seep areas. Rural septic systems may impact local groundwater quality. Environmental Consequences - Exploration activities should not noticeably impact groundwater resources. The strata are not uniformly saturated, so there is little concern for inter-strata communication. The drill holes would be small diameter and cause little disturbance to the strata. Longwall mining of the lease tracts would cause bedrock fracturing and land subsidence above longwall panels. By potentially providing pathways for groundwater to move downward toward the mine horizon, fracturing and subsidence may divert water from saturated horizons and surface water bodies above and adjacent to caved areas. Impacts to groundwater systems may result in a decrease in natural discharge rates from springs and seeps or changes in water levels and yields in area wells. Mining would dewater the coal horizon and water saturated horizons immediately above and below the coal horizon. Degradation of water quality could occur when groundwater flows through active or abandoned mine workings. Diversion of groundwater resulting from dewatering of the coal seam could also occur as a result of underground mining. Water rights could be affected if area spring Flows and associated pond levels are diminished. There is also a potential for increased sedimentation to area springs from construction and use of surface fadlities (exploration drill pads and associated access roads). After mining, mine voids could fill with groundwater. The groundwater would be exposed to collapsed and abandoned mine workings, and the quality of the water may be impacted. The most likely impact would be an increased concentration of TDS, iron, manganese, and possibly sulfate. The groundwater flow direction in the coal seams of the lease tracts is to the northeast, beneath the Grand Mesa. There are no known wells or springs down gradient of the lease tracts that could be affected by any possible groundwater degradation. S3.7 Vegetation Existing Conditions -Eight upland vegetation types were mapped at the reconnaissance level within and surrounding the coal lease tracts and exploration license area. These vegetation types inGude the following communities: Oak Aspen Final Environmental Impact Statemenf