Laserfiche WebLink
7 ~` <br /> <br />STATE OF COLORADO <br />Roy Romer, Governor <br />DEPARTMENT OF NATURAL RESOURCES <br />MINED LAND RECLAMATION DIVISION <br />DAVID C. SHELTON, Director <br />DATE: April 1, 1987 <br />T0: John Doerfer <br />FROM: Steve Renner <br />RE: CANADIAN STRIP AHR, 1986 WATER YEAR (C-81-026) <br />Per your request, I have reviewed the Canadian Strip Mine 1986 Annual <br />Hydrologic Report (AHR). <br />The approved ground water monitoring plan consists of five (5) wells (one <br />spoil completion, two underburden, one each coal, and overburden). Each well <br />is monitored annually for depth to water and a full suite water quality sample <br />is taken at that time. <br />Depth to water information from wells 1, lA, 16, and 1C indicates that the <br />ground water levels have been rising over the last three years, (1984, 1985, <br />1986). The spoils completion well, Well No. 7, was reported in the AHR as <br />being dry during the period 1981 to 1984. In 1985 and 1986 the <br />depth-to-water was measured at -100.7 and -102.0 feet, respectively. A review <br />of the permit application, however, indicates that the well is at least 110 <br />feet deep, and that a depth-to-water measurement of -104.0 feet was made in <br />early 1981. Based upon this data it is thought that a spoil aquifer is slowly <br />developing in the backfilled pit. It is expected that backfilling of Pit No. <br />2 will also result in the formation of a spoils aquifer. Therefore, it is <br />recommended that a spoils well be completed in this area also. <br />The general trend of rising ground water levels is most likely attributable to <br />the fairly wet recent winters. <br />The general quality of the undisturbed monitoring points has not significantly <br />changed over time, as indicated by analytical results of total dissolved <br />solids (TDS) concentrations. Generally, the TDS measurements in Wells 1, lA, <br />1B, and 1C average between 990 mg/1 and 1850 mg/1. Well No. 7 averages about <br />970 mg/1. Future monitoring of the spoil completion well in Pit No. 2 and in <br />the adjacent Marr Strip 720 Pit will help verify the spoil water quality <br />characteristics in this area. <br />The only surface water monitoring at the Canadian Strip is the NPDES 001. <br />NPDES Forms submitted by Wyoming Fuels indicate that this pond discharged <br />small quantities of water in January, 1986 and in June, 1986. Neither of <br />these discharges exceeded any NPDES permit requirements. <br />/pjh <br />8587E <br />423 Centennial Building, 1313 Sherman Street Denver, Colorado 80203-2273 Tel. (303) 866-3567 <br />