Laserfiche WebLink
III IIIIIIIIIIIIIIII <br />sss <br />:. <br />Doc Date:12/11/2001 <br />SECTION 2.0 Annual Hydrology Report for Trapper Mine (1990) <br />Section 4.8.5 of our mining permit requires Trapper provide the CMLRD with an annual <br />hydrology report (AHR). <br />2.1 Climatological Data <br />We are submitting the 1990 NWS Cooperative summaries and a historical monthly <br />precipitation summary (1979-1990). Trapper has been the official NOAA station near <br />Craig, Colorado, since 1979. <br />2.2 Pit Dewatering Data for 1990 <br />During 1990, Trapper pumped 78.12 acre-feet from all pits and an additional 27.06 acre- <br />feet of water from the three dewatering wells in Derringer pit. Table 1-2 (Section 2.5) <br />shows the monthly pumping water volumes for each pit. The 78.12 acre-feet represent a <br />35.5% decrease in pump dewatering in 1989, which is directly related to completing the <br />dewatering of Brasil and Sims pit prior to Browning pit's stripping in 1990. There was no <br />dewatering necessary for Enfield pit again this year. <br />Pumping from the three Derringer pit dewatering wells (Table 1-2) shows Trapper <br />• pumped 27.06 acre-feet of water from the boxcut toe and spoils. This is a decrease of <br />19% below 1989 pumping. In 1990, the first and second well were deactivated in May <br />and a fourth and fifth well were installed and activated in May. The same installation <br />specifications used for the 1988 wells (filed in the 1988 report, Figures 2.2-1 to 2.2-4.) <br />were used for the 1990 wells. <br />23 Mining Advancement and Ash Disposal Sites <br />Enclosed is a revised Annual Hydrology Report (AHR) map for 1990 which shows the <br />following mining activities through year end: <br />a. Project-to-date (PTD) utility waste disposal. <br />b. PTD pit advancement. <br />c. PTD proximal monitoring and dewatering wells, plus spoil seeps >5 gpm. <br />2.4 Monitoring Points PTD <br />Rather than submitting a separate map with this report, we refer the Division to the cur- <br />rent Map M52 which shows our operational hydrologic monitoring points. Operations <br />added two dewatering wells and abandoned two dewatering wells in Derringer pit in <br />1990. <br />2.5 1990 Hydrological Data <br />Enclosed is Hydro-Engineering Inc.'s collation of the 1990 hydrological data for Trapper <br />Mine. The report addresses: <br />