Laserfiche WebLink
<br />STATE OF COLORADO <br />DIVISION OF MINERALS AND GEOLOGY <br />Department of Na[ural Resources <br />1313 Sherman 51.. Room 215 <br />Denver, CO 80'03 <br />Phone: (303? 866-7567 <br />FAX: 13031 83'-8106 <br />February 16, 1993 <br />Attn: Linda Limbaph <br />Eastside Coal Company <br />P.O. Box 161 <br />Silt, CO 80652 <br />Re: 1991 and 1992 Annual Hydrology Review <br />Eastside Mine (C-84-063) <br />Dear Linda: <br />OF'~~(O <br />~~.~r <br />Ne~ G~ ^~pO. <br />~•:'p~. <br />Roy Romer <br />Governor <br />Michael B. Lang <br />Division Director <br />I have completed the review for 1991 and 1992's Annual Hydrology <br />Report and have the following comments. <br />In general, the reports are accurate and thorough with the summary <br />verifying the noticeable trends of surface water above and below <br />the mine. <br />All field parameters were checked, but in 1992's data, refer to <br />page 5, the pH value was inadvertently omitted in the box. Please <br />include this parameter in future reports. <br />Monitoring of all five stations was done appropriately and <br />according to permit specifications. <br />SURFACE WATER <br />The data for both years shows that the surface flow through Harvey <br />Gap is increasing, up 26.8% above the mine from 1990, and up 25.3% <br />below the mine, a loss of 1.5% of surface flow which is well within <br />permit limits. Despite the flow increases, EC is increasing below <br />the mine while EC values are decreasing above the mine. One would <br />expect the EC values to decrease both downstream and upstream with <br />increased flow amounts. Since the mine has remained inactive, the <br />source of increased EC values must therefore be from natural <br />geologic occurrences in the soil and outcrops. The soil series <br />Torriorthents and Dollard shale complex do indeed outcrop between <br />the two monitoring stations, in fact they outline the surficial <br />soil morphology of the creek. It is my opinion that increased EC <br />values are due to geologic occurrences, the soils in particular and <br />not the Eastside Mine. <br />