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<br />of ~~~ <br />/%w~°~9 <br />IN¢~ - . Irk Flo <br />~• `_~; *~ <br />~/~ <br />Fic hartl D Lamm <br />Governor <br />DATE: <br />T0: <br />FROM: <br />RE: <br />~~ <br />• iii iiiiiiiiiiiiiiii <br />DEPARTMENT OF NATURAL RESOURCES <br />Davitl H Getches. Ezecutrve Director <br />MINED LAND RECLAMATION DIVISION <br />DAVID C. SHELTON, Director <br />July 5, 1985 <br />Fred Banta <br />Dan Mathews <br />Projected and Obse ved Hydrologic Conditions <br />Coal Company's E man Park Mine and Mine No. <br />File No. 79-177 <br />at Colorado Yampa <br />1 <br />Colorado Yampa Coal Company's (CYCCj Mine No. 1 and Eckman Park are typical <br />20-mile basin dip-slope area strip mine operations. Mining began in the <br />mid-1960's at Mine No. 1. Eckman Park is essentially an extension to the <br />southwest along the same ridge. At current production levels, permitted coal <br />reserves will be exhausted in 2 - 2 1/2 years. <br />The original permit application (as revised 1/80) predicted a temporary <br />increase in TDS concentrations on Foidel Creek due primarily to the <br />evaporative concentration effect of sediment ponds. Based on projected <br />inflow, outflow and storage capacity of the spoils aquifer, the applicant <br />concluded that, "...groundwater will not pool up within the spoils aquifer to <br />the extent of causing springs to develop at the lowermost backfilled pit." <br />TDS conc. of spoils leachate was projected to be 3,600 mg/l. Chemical <br />analyses of overburden and spoil leaching tests indicated "no toxic materials" <br />were present. <br />Regarding the potential for the development of spoils springs, the applicant's <br />PHC projections were not in agreement with those made in the Green River Hams <br />Fork Final EIS (8/80). That document predicted the development of "new, <br />possible larger springs lower on the slopes following completion of <br />reclamation and resaturation of spoils aquifers." The EIS predicted <br />3,000 mg/1 maximum TDS conc. in spoils waters. <br />The spoils aquifer at Mine No. 1 began discharging from a spring at a down <br />gradient location of Mine No. 1, above Pond Fin 1984. TDS has averaged <br />3,660 mg/1 (range 1,200 - 4,600 mg/1). Through the summer of 1984, discharge <br />from the spring averaged 65 gpm with a projected maximum flow of 100 gpm. <br />Based on the observed spring development at Mine No. 1, the permittee revised <br />the PHC in August, 1984. The revised PHC concludes that discharge of spoil <br />aquifer water at the lowest edge of the most down-gradient pit may occur in <br />other locations in the future. Presumably, springs would be anticipated upon <br />423 Centennial Building, 1313 Sherman Street Denver, Colorado 80203 Tel. (303) 866-3567 <br />