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3.0 HYDROLOGIC CONSEQUENCES <br />Hydrologic consequences ofmining activities are considered from two primary perspectives: effects <br />on water quantity and effects on water quality. These effects are addressed through flow and water <br />quality measurements of springs and seeps, streams and rivers, ponds and direct discharges, and <br />depths to water level and water quality of alluvial wells, and bedrock wells. However, water quantity <br />and quality are not independent functions of each other. Surface water and groundwater quantities <br />and water uses are components of the hydrologic balance of the region. Natural water quality varies <br />as a function of flows, type (groundwater or surface water), and location. Discharge of underground <br />mine water and runoff or dischazge from mine surface activities modify natural water quality. <br />Analysis of potential impacts associated with mining and refuse disposal have been completed and <br />aze contained in the mine permit document. This report focuses on describing the water quality and <br />quantity of the Purgatoire River, side canyons and groundwater within the permit and adjacent areas. <br />All data collected is presented in Appendices A and B of this report. <br />3.1 WATER QUANTITY <br />3.1.1 Springs and Seeps <br />The annual spring and seep survey took place August 11, 2001. Assessments of springs and seeps <br />(Appendix 13) indicate that mine operations at the Golden Eagle Mine have not affected current uses <br />of springs and seeps. Theoretically, these resources in the vicinity ofmining activity, especially over <br />those areas of longwall mining, could be affected. There is some potential for the loss of spring and <br />seep flows into the underground mine workings by fracture systems developed through land <br />subsidence. However, no springs overlie the Golden Eagle Mine. Springs 15, 20, and 21 are nearest <br />to the workings. No impacts to flow have been documented to date. <br />3.1.2 Purgatoire River System [Surface (Streams and Rivers), Ponds <br />and Direct Discharges, and Alluvial Groundwater] <br />Use of the river in the area of the mine is limited to livestock watering, habitat for fish and terrestrial <br />wildlife, flood irrigation on bottom land terraces, and supply for mining at the Golden Eagle Mine. <br />Because of closure at the mine, there was no consumptive water use. The average annual runoff of <br />the Purgatoire River at Madrid (USGS site 07124200) between 1972 and 1995 is 51,740 ac ft. <br />There is a slight potential that flows in the Purgatoire River might be diminished by recharge seepage <br />into the mine along the river. Vertical permeability of the overburden on the mine property has been <br />estimated at 0.00021 feet per day (mine permit document). When this low permeability is multiplied <br />by the horizontal surface area of saturated alluvium in the azea of both the Golden Eagle and New <br />Elk mines, downward 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. Similarly, any loss in alluvial <br />groundwater would likely be undetected. Flows of the river replenish any alluvial groundwater lost <br />to seepage. However, as the theoretical permeability is very low, no loss of river or alluvial water <br />has been detected. <br />200lIANRepnn-RPT(1')2J/April 19, ?OOI 13 <br />