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11111111 II1 IIIIIII1 f'~ V V STATE OF COLORADO DIVISION OF MINERALS AND GEOLOGY Department of Natural Resources 1713 Sherman St., Raom 215 Denver, CO 80205 Phone: 13031 8663567 FAX: 13031832-81D6 September 25, 1992 Mr. Jim Stover Minrec, Inc. 2768 Compass Drive, Suite 101 Grand Junction, CO 81506 OF' COQ a"'. ~g .,~;~; 'ie Rov Rom¢r Governor ~Hichael B. tong Drvis~on Director RE: 1991 Annual Hydrologic Report (AHR) Review; Red Canyon Mine; File No. C-81-034 Dear Mr. Stover; The Division has reviewed the 1991 Annual Hydrologic Report for the Red Canyon Mine. The required frequency of monitoring all surface and ground water sites has been met. Surface Water- The data for the Upper and Lower Ward Creek stations has been reviewed. The monthly average is helpful in comparing current flows. Seasonal flows are evident, however it is difficult to make a conclusion regarding impacts because of the times that readings are taken in May. But there appears to be no impact to Ward Creek from mining. Because of the limited amount of data for the conductivity of Springs 1 and 3, it is difficult to make a determination of impacts from the mining operation. As the data accumulates, it should become easier to make a determination. Conductivity for Spring 1 is lower, as compared to the historical data. Spring 3 shows a higher average conductivity as compared to the historical data, but has not reached the historical high of 666 mmhos/cm. There appears to be no indication that water from flooded mine workings are discharging to the glacial-alluvial aquifer. In May 1991, TSS for SP-D was 2180 mg/1 and at SP-DA, TSS increased to 2765 mg/1. This increase may indicate degradation, due to an increased sediment load from the mine site. However, since no water was discharged from the pond during this water year, there must be some other explanation for the increase in TSS. In the AHR, a possible explanation is due to the high flow which may have further eroded the ditch banks between the two monitoring points. The Division plans to inspect this channel during future inspections. The data obtained in the future for the Carbon Ditch should be watched closely for increases of TSS. There appears to be no impact to the Carbon Ditch by surface runoff from the mine site.