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Annual Report - 2009 <br />Henderson Mine and Mill Reclamation Activities <br />Permit No. M-1977-342 <br />2.3.2 - Flood Storage Capacity <br />Semi-annual analyses of flood storage capacity in the Mill tailings impoundment were carried out <br />by W.W. Wheeler, per DRMS requirements stipulated for Technical Revision (TR) 14. These are <br />included as Attachment 2. <br />2.3.3 - Interceptor Canal Improvements <br />Stormwater improvements were made to the interceptor canal at the toe of the north abutment of <br />1 Dam. 1,300 feet of 42" HDPE pipe was placed in the main interceptor canal channel and 650 <br />feet of 18" HDPE was placed in a tributary channel directly adjacent to the main channel. The <br />purpose of this project was to minimize the potential for contamination of fresh waters associated <br />with the interceptor canal system by process-affected waters. <br />Additional repairs and maintenance along the interceptor canal was performed to stabilize slopes <br />and increase vegetation. <br />2.3.4 - Seepwater Return Pipeline Extension <br />The seepwater return pipeline which pumps the seepwater from the toes of 1-Dam and 3-Dam to <br />the impoundment surface was extended by 750 feet using 18" HDPE pipe. This project allows <br />for seepwater to be delivered to the surface of the tailing impoundment up to 8,900 ft. elevation. <br />2.3. 5 - Lower Flood Bypass <br />Investigation of the Lower Flood Bypass continued with URS exposing a section of the bypass <br />structure near the toe of 1-Dam. Evaluations made by URS indicate that a closure more <br />substantial than the existing concrete plug may be required to manage any future concerns <br />associated with piping. Further investigation will entail drilling through the pipe above the <br />existing concrete plug to evaluate the condition of the pipeline above the existing plug. Further <br />investigations will be forthcoming in 2010. <br />2.3.6 - 3 Dam Seepwater Line Leak-Down Test <br />The annual 3-Dam seepwater line leak-down test was completed in 2009. <br />3.0 Anticipated 2010 Activities <br />Activities scheduled at Henderson for 2010 include: <br />• Continued and increased topsoil salvage and stockpiling at the Henderson Mill tailings <br />impoundment. <br />• Final investigations & closure of Lower Flood Bypass <br />Page 2 of 2