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STATE OF COLORADO <br />Roy Romer, Gove <br />DEPARTMENT OF NATURAL RESOURCES <br />MINED LAND RECLAMATION DIVISION <br />FRED R. BANTA, Dlreetor <br />DATE: April 14, 1989 <br />T0: Gregg Squire <br />G <br />FROM: Bill Crick`' <br />RE: Trapper Mine (C-81-010) 1988 Annual Hydrologic Report, <br />Ground Water and Surface Water Monitoring <br />I have reviewed Trapper's Annual Hydrologic Report for 1988. In this memo I <br />will comment on the status of their hydrologic monitoring and effects of <br />mining on the water quality and quantity. A second memo will serve as <br />response to the adequacy issues of Technical Revision 44, particularly <br />reconstructed drainages, water harvesting ditches, stock ponds, and a proposed <br />change to their ground water monitoring requirements. <br />1988 was a dry year at the mine, with just over 11 inches of precipitation. <br />Accordingly, most alluvial wells experienced water level declines and <br />increased concentrations of dissolved solids. An exception was well J1 in <br />Johnson Gulch, which showed little change in either property. <br />Bedrock aquifers show only isolated changes in water quality and quantity. <br />Water level in the KLM coal aquifer has fallen steadily through 1987 and 1988, <br />probably due to lower recharge and possibly some effects of mining. Levels of <br />Total Dissolved Solids have been steady in KLM. The HI coal aquifer, which <br />was extensively dewatered by mining in 1983-1985, has shown recovering water <br />levels for several years, with little change in water quality. The QR coal <br />aquifer (being mined in the Derringer pit) appears to be more sensitive to <br />precipitation variations and mine dewatering than the others. IJater level in <br />well GEl (QR aquifer) has risen 160 feet since early 1986. The proximity of <br />GE-1 to the Eagle No. 9 underground mine (about 2,000 feet to the west) <br />suggests a hydraulic connection with those flooded workings. There have been <br />no significant water quality changes in either the QR or Twentymile Sandstone <br />aquifers. The Third White Sandstone aquifer has undergone erratic water level <br />changes and minor degradation of water quality, probably due to both mining <br />and amount of recharge. Finally, the GLUX-1 well produced samples of good <br />quality similar to the Lux domestic well, <br />215 Centennial Building, 1313 Sherman Street Denver, Colorado 80203.2273 Tel. (303) 866-3567 <br />J II i, 1 <br />