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• Environmental Consequences, No Action: There would be no project-related releases. <br />Mitigative Measures: None <br />Name of specialist and date: Jennifer Maiolo, 05/02/08 <br />WATER QUALITY - GROUND <br />Affected Environment: Tertiary underground strata. <br />Environmental Consequences, Proposed Action: Some blasting could affect regional <br />fracture patterns and cause an alteration in the flow of groundwater to local wells. <br />Environmental Consequences, No Action: Ground water quality would not be affected. <br />Mitigative Measures: Should nearby well water changes occur during blasting, operator <br />should be responsible for mitigating/restoring well-water flow to existing wells. <br />Name of specialist and date: Marilyn Wegweiser, 4/29/08 <br />• WATER QUALITY - SURFACE <br />Affected Environment: Runoff from the area affected by the proposed action would flow to <br />Fish Creek, which is a perennial tributary to Trout Creek. The water quality of Fish Creek <br />must support the following beneficial uses: Aquatic Life Cold 1, Recreation 1 a and <br />Agriculture. <br />Longwall mining in the vicinity has occurred since about 1988 and runoff water from the <br />subsided areas, as well as, mine inflow water derived from the mined coal aquifer has <br />flowed or been released into Fish Creek. Twentymile Coal makes use of and recycles much <br />of the mine inflow water in the conduct of various mining activities, especially dust <br />suppression; subsequent handling and holding of this water tends to increase the TDS levels. <br />Colorado Department of Public Health and Environment, Water Quality Control Division <br />has issued Pollutant Discharge Elimination System Permits (NPDES) for various discharge <br />points, including Fish Creek. Current levels of Total Dissolved Solids in these creeks are <br />monitored upstream of the mine activities and discharge is regulated. Discharged water is <br />also treated with sodium hydroxide (NaOH) to maintain the pH of the water between 8.8 and <br />9 to precipitate iron and lower the TDS. When the creeks are surging with spring runoff <br />water more of the mine inflow water is released to the streams and the dilution effect <br />reduces the concentration of TDS, iron and sodium to acceptable levels to meet classified <br />uses downstream. Conversely, when low or no flows occur, the amount of water discharged <br />• is reduced accordingly.