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~~ <br />STATE OF COLORADO <br />DIVISION OF MINERALS AND GEOLOGY <br />Department of Natural Resources <br />1 31 }Sherman 51., Room 21 S <br />Denver, Colorado 80203 <br />Phone 1303) 866 f 567 <br />FA%: (30}I BJ L8106 <br />To: Dan Mathews <br />From: Barbara Pavlik <br />Date: June 14, 1995 <br />Re: Review of Roadside Portals 1994 Annual Hydrology Report <br />~~~ <br />DEPARTMENT OF <br />NATURAL <br />RESOURCES <br />Roy Romer <br />Governor <br />dames S Lxhhead <br />Exrcmive Dircanr <br />Michael B. long <br />Uivis~on Diieaor <br />I have reviewed the groundwater portion of the above referenced AHR <br />and have the following comments: <br />1) A semi-pervasive problem throughout the AHR is a lack of <br />units used in data tables. Examples include but are not <br />limited to: <br />Roadside North Portal Inflows - Conductivity <br />Cottonwood Creek & Rapid Creek Groundwater <br />Page GA-2 <br />Unit Train Loadout Groundwater - Page GB-1 <br />Cameo Refuse Disposal Area Groundwater - Page <br />GC-3 <br />2) On the Roadside South Portals Inflows table, for Station <br />14, the 9/92 measurement was reported as "flow greater <br />than 156 gpm flume capacity." Subsequent measurements <br />for 9/93 and 9/94 were reported as 166.0 and 166.1 gpm, <br />respectively. Please have the operator clarify whether <br />the flume was replaced with a larger flume. <br />3) The mine is discharging more than 4 tons of dissolved <br />solids to the surface water system per day. The TDS <br />concentrations in discharges from NPDES outfall 001 have <br />remained fairly stable since 1989 with some outliers. <br />TDS concentrations in outfall 002 have steadily decreased <br />between 1992 and 1994, although these concentrations are <br />up since 1989. TDS concentrations in outfall 004 <br />experienced a downward trend beginning in 1982 and <br />stabilized after 1987. <br />With the recent opening of the Roadside North Portal, the <br />trend in dissolved solids concentrations should be <br />followed closely to determine if additional impacts will <br />result from mining the Roadside North Portal. <br />