2009-03-25_REPORT - M1988112 - Laserfiche WebLink

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San Luis Project CDRMS Annual Report March 23, 2009 Page 3 flow rates ranged from 31 to 43.23 gpm with a mean under drain flow rate of 37.086 gpm. As specified in TR-31 and TR-32 monitoring plans, monthly and quarterly pond analysis were conducted and reported to the Division. The tailing embankment piezometers were inspected monthly. Each of these installations either remained dry or contained less than 12 inches of accumulated water within the piezometer casing. Results of these inspections were reported to the Division in the monthly reports. The tailing collection pond leak detection system was evacuated monthly and quarterly sampled and analyzed in accordance with the applicable technical revision monitoring plan. Laboratory analytical reports were submitted to the Division upon receipt from the Laboratory. The 2008 collection pond leak detection system return flow rates ranged from 16.55 to 26.77 GPAD with a mean annual collection pond return flow rate of 23.554 GPAD. Water treatment plant sludge removal was conducted twice during the 2008 calendar year; approximately 235 tons were removed from the water treatment ponds and place to the drying pad containment. Approximately, 120 tons of sludge material was transported from the water treatment plant to the tailing facility during 2008. The material was extracted from the water treatment plant ponds and transported to the tailing facility for final placement. The remaining sludge volume will be transported from the drying pad in 2009. The December 2008 monthly report summarizes the 2008 sludge management activities. Technical Revisions/Permit Amendments BMRI continued implementation of TR-26 as approved on May 23, 2000. BMRI has been actively managing the West Pit and Rito Seco alluvial hydrologic systems since July 1999, and the water management techniques developed in TR-26 has been fully implemented accordingly. The water management techniques employed since the submission of TR-26 to the Division has reversed and maintained the West Pit hydrologic gradient at a ground water elevation (8582 ft amsl) below the Rito Seco stream channel since February 8, 2000 eliminating any surface water expressions. Ground water recovery wells M-32 and M-33 installed during the calendar year 2000 to capture and remove contaminates contained in the Rito Seco alluvial ground water system continued to be operated throughout the 2008 calendar year. Ground water recovered from these wells was pumped back to the West Pit water treatment plant, treated and discharged in accordance with the Colorado Department of Public Health and Environment discharge