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3.0 HYDROLOGIC CONSEQUENCES <br />• Precipitation in the 2005 calendaz yeaz was neaz average with the normal late winter snow events and summer <br />thunderstortns from late July to eazly August. The fourth quarter was dry with only occasional light precipitation <br />recorded. <br />Hydrologic consequences of mining activities aze considered from two primary perspectives: effects on water <br />quantity and effects on water quality. These effects are addressed through flow and water quality measurements of <br />springs and seeps, streams and rivers, ponds and direct dschazges, and depths to water level and water quality of <br />alluvial wells, and bedrock wells. However, water quantity and quality aze not independent functions of each other. <br />Surface water and groundwater quantities and water uses aze components of the hydrologic balance of the region. <br />Natural water quality varies as a function of flows, type (groundwater or surface water), and location. Dischazge of <br />underground mine water and runoff or dischazge from mine surface activities modify natural water quality. Analysis <br />of potential impacts associated with mining and refuse disposal has been completed and aze contained in the mine <br />permit document. This report focuses on describing the water quality and quantity of the Purgatoire River, side <br />canyons and grcundwater within the permit and adjacent areas. <br />3.1 WATER QUANTITY <br />3.1.1 Springs and Seeps. <br />The annual spring and seep survey took place August 18, 2005. Assessments of springs and seeps <br />• (Appendia C7 indicate that mine operations at the New Elk Mine have not affected current uses of springs and <br />seeps. Theoretically, these resources in the vicinity of mining activity, especially over those areas of longwall <br />mining, could be affected. There is some potential for the loss of spring and seep flows into the andergound mine <br />workings by fracture systems developed through land subsidence. No impacts to flow have been documented to <br />date. The monitoring requvement for these sites was terminated in 1999 with the liability release for azeas of <br />andergoand mining <br />3.1.2 Purgatoire River System (Surface {Streams and Rivers), Ponds and Direct Discharges, aad Alluvial <br />Groundwater) <br />Use of the river in the area of the mine is limited to livestock watering habitat for fish and terrestrial wildlife, flood <br />irrigation on bottom land terraces, and water supply for the New Elk Mine preparation plant. Because of closure of <br />the Golden Eagle Mine and no processing of coal at the New Elk prep plant, there was no consumptive water use at <br />the mine. The average amual runoff of the Purgatoire River at Madrid (USGS site 07124200) between 1972 and <br />1995 is 51,740 ac ft. <br />There is a slight potential that flows in the Purgatoire River might be diminished by rechazge seepage into the mine <br />along the river. Vertical permeability of the overburden on the mine property has been estimated at 0.00021 feet per <br />day (mine permit document). When this low permeability is multiplied by the horizontal surface area of saturated <br />alluvium in the azea of the mine, downwazd flow of water is estimated at 2.3 gpm. With the flow measured in the <br />Purgatoire River, this small water loss would not be detectable. Similazly, any loss in alluvial goundwater would <br />likely be undetected. Flows of the river replenish any alluvial groundwater lost to seepage. However, as the <br />theoretical permeability is very low, no loss of river or alluvial water has been detected. <br />• <br />14 <br />