2012-02-21_REPORT - C1980001 (4)

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1.0 INTRODUCTION The Edna Mine is currently in a post - reclamation phase. Mining disturbance at the site in terms of overburden removal ceased in December of 1994. Coal production continued through September 1995. All reclamation activities were completed by December 31, 1996. Currently, site activity is limited to monitoring and maintenance of reclaimed lands and retained buildings. Bond release has been attained for all lands except for those included within SL -11. Bond release SL -11 for phases II and III was applied for May 13, 2009 and deemed complete by Colorado Division of Reclamation, Mining and Safety (CDRMS) on June 29, 2009. SL -11 (West Ridge Area, Moffat Area and Support Facilities Area) includes 1197.6 acres of land that had previously reached phase I release (SL -2, SL -4 and SL -7). CDRMS postponed a proposed decision until the success of weed control measures and the evaluation of the presence of weeds can be reevaluated. The Edna mine is currently in the final stages of bond release. Therefore, the monitoring program has been reduced accordingly. A water quality monitoring program was initiated at the Edna Mine in 1987. The intent of the program was to monitor specific chemical characteristics of Trout Creek, and the alluvium associated with Trout Creek, which may be affected by mining and reclamation operations. The program was detailed enough to describe seasonal variations in concentration levels of the parameters monitored, as well as indicate if mining activities and /or reclamation activities were impacting the natural seasonal fluctuations. The monitoring program has been altered via Technical Revisions 47 and 48. Monitoring wells 215W, 215L, 218W, 218L, M892S and M892L were discontinued September 21, 2007 in accordance with TR -47. Monitoring wells TR -1.5, TR -3, TR -4, WR -1 and TCS -1, surface water flow monitoring sites TR -a and TR -b and surface water quality monitoring sites TR -A, TR -B, TR -C and TR -D were discontinued September 2, 2009 in accordance with TR -48. The purpose of this report is to provide updated information pertaining to the on -going hydrologic monitoring program developed for the Edna Mine. The previous report, dated February 2011, reported monitoring activities through the end of 2010. The 2009 report contains historical data for discontinued sites at the Edna Mine, these data are not replicated in this report. This report provides a discussion of monitoring activities performed through 2011. The report is divided into several sections including: Hydrologic Monitoring Network; Spring and Seep Survey; and Moffat Stability Monuments. /6>&" V V V VCENGINEERING Page 1