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3.0 HYDROLOGIC CONSEQUENCES <br />Precipitation in the 2001 calendaz year was dryer than average due predominantly to a lack of <br />summer thunderstorms. <br />Hydrologic consequences of mining activities are considered from two primaryperspectives: 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 vanes <br />as a function of flows, type (groundwater or surface water), and location. Discharge ofunderground <br />mine water and runoff or discharge from mine surface activities modify natural water quality. <br />Analysis of potential impacts associated with mining and refuse disposal have been completed and <br />are 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 />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 B) indicate that mine operations at the New Elk Mine have not affected current uses of <br />springs and seeps. Theoretically, these resources in the vicinity of mining 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. 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 ofthe river in [he area ofthe mine is limited to livestock watering, habitat for fish and terrestrial <br />wildlife, flood irrigation on bottom land terraces, and water supply for the New Elk Mine preparation <br />plant. Because of closure of the Golden Eagle Mine and no processing of coal at the New Elk prep <br />plant, there was no consumptive water use a[ the mine. The average annual runoff of the Purgatoire <br />River at Madrid (USGS site 07124200) between 1972 and 1995 is 51,740 ac fr. <br />There is a slight potential that flows in the Purgatoire River might be diminished by recharge <br />seepage into the mine along the river. V ertical permeability of the overburden on the mine property <br />has been estimated at 0.00021 feet per day (mine permit document). When this ]ow permeability is <br />multiplied by the horizontal surface azea of saturated alluvium in the area of the mine, downward <br />flow of water is estimated at 2.3 gpm. With the flow measured in the Purgatoire River, this small <br />water loss would not be detectable. Similarly, any loss in alluvial groundwater would likely be <br />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 />626-Annual Hydrolic Monitoring (Apr.9.02).doc 14 <br />April 17, 2002 <br />