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Hrdrofogic Data /nrerpremrian and 1mpaR AssesJ'menr for the Permit and Adjaartr Arear <br /> <br />SOM-129-H. These levels are expected to <br />continue to drop, reflecting the vicinity of <br />the mine face, until the well is compromised <br />by extraction of the coal seam. <br />Baseline Characterization of <br />Water Quality and <br />Streamflow <br />• <br /> <br />Rollins Sandstone <br />Well SOM 128-H was set to monitor water <br />levels in the Rollins Sandstone, a member <br />below the "B" Seam. After an initial rise in <br />water levels of over 150 feet during a period <br />of two years, the water level appears to have <br />plateaued. This data is interpreted as the <br />gradual (due to low transmissivity of the <br />Rollins Sandstone) inflow of groundwater <br />into the well bore. The water surface is <br />expected to slowly rise until the confined <br />potentiometric surface (height) is reached. <br />No sustained floor flows have been encoun- <br />tered during mining of the `F" or the "B" <br />seams. Mining activities, in both the "F" <br />and the "B" seams, are thought to have had <br />no impact on groundwater in the Rollins <br />Sandstone to date. <br />Assessment of Surface <br />Water and AVF'S <br />The purpose of monitoring the river waters <br />is to evaluate potential changes in surface <br />water quality due to mining activities at the <br />West Elk Mine. In addition, continuous <br />monitoring of stream flows and periodic <br />monitoring of spring discharge rates are <br />performed to provide the long term data <br />base from which possible impacts of mining <br />can be assessed. <br />14 <br />A baseline characterization of North Fork <br />water quality was performed to evaluate the <br />potential changes in North Fork water quali- <br />ty that could result from discharges at the <br />West Elk Mine. Baseline characterization <br />was perforttted downstream of the mine <br />before the start of construction in August <br />1981. Data sources were the USGS stream <br />gauging station on the North Fork near <br />Somerset, above the mine facilities and the <br />Mountain Coal Company's water quality <br />monitoring station on the North Fork below <br />the mine. The MCC station is downstream <br />of the surface facilities area and downstream <br />of all discharge points. Baseline data and <br />analysis of these data are provided in the <br />Mining and Reclamation Plan for the West <br />Elk Mine and in the first annual hydrology <br />report. <br />Comparison of Baseline <br />Water Qualify with Opera- <br />tional Data <br />Of the ten parameters selected for baseline <br />characterization, seasonal trends are appar- <br />ent for Total Dissolved Solids (TDS), Total <br />Suspended Solids (TSS), and total iron. The <br />other parameters do not exhibit seasonal <br />variation. Total dissolved solids are least <br />concentrated in the North Fork during the <br />period between about May and July. The <br />likely reason for this pattern is during this <br />period high-TDS water is diluted by snow <br />runoff. Total suspended solids are most <br />concentrated from April to ]uly. Total iron <br />is most concentrated during this period <br />probably reflecting condition with the higher <br />levels of TSS. <br />