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October 2012 <br />3.0 HYDROLOGIC CONSEQUENCES <br />Page 3 -1 <br />Hydrologic consequences of mining activities are considered from two primary <br />perspectives: effects on water quantity and effects on water quality. These effects are addressed <br />through flow and water quality measurements of springs and seeps, streams and rivers, ponds <br />and direct discharges, and depths to water level and water quality of alluvial wells, and bedrock <br />wells. However, water quantity and quality are not independent functions of each other. Surface <br />water and groundwater quantities and water uses are components of the hydrologic balance of <br />the region. Natural water quality varies as a function of flows, type (groundwater or surface <br />water), and location. Discharge of underground mine water and runoff or discharge from mine <br />surface activities modify natural water quality. Analysis of potential impacts associated with <br />mining and refuse disposal has been completed and are contained in the mine permit document. <br />This report focuses on describing the water quality and quantity of the Purgatoire River, side <br />canyons and groundwater within the permit and adjacent areas. <br />3.1 Water Quantity <br />3.1.1 Springs and Seeps <br />Assessment of springs and seeps indicate that mine operations at the New Elk Mine have <br />not affected current uses of springs and seeps. Theoretically, these resources in the vicinity of <br />mining activity, especially over those areas of longwall mining, could be affected. There is some <br />potential for the loss of spring and seep flows into the underground mine workings by fracture <br />systems developed through land subsidence. No impacts to flow have been documented to date. <br />The monitoring requirement for these sites was terminated in 1999 with the liability release for <br />areas of underground mining. Spring and seep monitoring was not performed during the year. <br />Historic spring monitoring records are presented in Appendix C. <br />3.1.2 Purgatoire River System (Surface [Streams and Rivers], Ponds and direct Discharges, <br />and Alluvial Groundwater) <br />Use of the river in the area of the mine is limited to livestock watering, habitat for fish <br />and terrestrial wildlife, flood irrigation on bottom land terraces, and water supply for the New <br />Elk Mine preparation plant. Because of closure of the Golden Eagle Mine and no processing of <br />coal at the New Elk prep plant during the year, there was no consumptive water use at the mine. <br />The average water year runoff of the Purgatoire River at Madrid (USGS site 071244200) <br />between 1972 and 2011 is 50,320 ac -ft. Only 25,400 ac -ft of run -off occurred during the 2011 <br />water year. <br />There is a slight potential that flows in the Purgatoire River might be diminished by <br />recharge seepage into the mine along the river. Vertical permeability of the overburden on the <br />mine property has been estimated at 0.00021 ft per day (mine permit document). When this low <br />permeability is multiplied by the horizontal surface area of saturated alluvium in the area of the <br />mine, downward flows 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 <br />