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Pitch Reclamation Project Colorado Mined Land Reclamation Board — 2013 Annual Reclamation <br />The inclinometer data indicate that all are below the threshold of error for the three installations. The non- <br />linear features on the plots for 198 -1 may indicate very minor displacement, but the magnitudes of the <br />non - linear portions of the plots are below the error threshold for this installation. Therefore, it is more <br />accurate to interpret the data as not indicative of slope displacement. The plots for 198 -2 and 198 -3 also <br />indicate no slope displacement at these locations. However, given the isolated slope displacement on <br />the northeast corner of the North Pit and the resaturation of the Pinnacle underground mine workings in <br />the area of the south wall of the North Pit as discussed below, these inclinometers will continued to be <br />monitored each summer. <br />4.3 Pinnacle Mine Workings Monitoring <br />A concrete plug was constructed in the Pinnacle adit in September 1995. Authorization for the placement <br />of the Pinnacle adit plug was requested by Homestake in April 1995, through Technical Revision #4 <br />(TR4) — Pinnacle adit Closure, Pitch Project, Technical Revision for Permit #77 -4HR (Golder Associates, <br />Inc.). Conditional approval of the Technical Revision request was granted by the Colorado Division of <br />Minerals and Geology, in a letter dated May 26, 1995. <br />The intention of the plug was to partially seal the Pinnacle adit and allow the historical underground <br />working and adjacent area to resaturate. The resaturation of the workings was expected to re- establish a <br />geochemically reducing environment and lower the solubility of uranium and radium within the <br />underground workings of the Pinnacle Mine. The Division's approval of TR-4 required Homestake to <br />monitor the effects of resaturation in the Pinnacle workings for five years or until hydrologic conditions <br />stabilized. Components in the Monitoring Plan outlined in TR4 (Section 4.0), included continuation of <br />discharge water quality monitoring at the POC (SW -33), monitoring of groundwater resaturation levels, <br />annual spring and seep surveys in areas down - gradient from Pinnacle workings, and monitoring for <br />changes in water quality that could be attributable to resaturation. The stated purpose of the monitoring <br />program is to verify the intended effectiveness of the adit plug. Homestake has continued to monitor the <br />following facets of resaturation through 2013: <br />• Survey of springs and seeps; <br />• Groundwater levels in piezometers installed in the area of the Pinnacle workings; <br />• Water quality and flow from the Pinnacle adit at sampling point PP -01; and <br />• Monitor discharges from the property at the CDPS permit POC SW -33. <br />4.3.1 Spring and Seep Monitoring <br />Spring and seep surveys were conducted to monitor changes in shallow groundwater conditions due to <br />construction of the Pinnacle Adit plug. These surveys have been conducted annually since July 1995 and <br />were repeated in 2013. In general, flow from some springs and seeps increased for a brief period after <br />the adit plug installation and have declined to a steady state since the spring of 1997. Small variances <br />noted since 1997, are believed to be attributable to a variety of conditions including precipitation, depth of <br />snow pack, timing of snowmelt, and the potential for infiltration with respect to frozen ground. All "active" <br />spring and seep locations are shown in Figure 3. Springs and seeps currently designated as "inactive" <br />(no flow or seepage observed over the past five years) are not shown, but can be found on maps issued <br />with past reports. A new spring (IC -12) was found and monitored in 2008. Its flow rate was consistent <br />with the other springs. Table 1 shows spring and seep data, including flow measurements, from 1995 to <br />the present. Spring IC -4 has experienced an increased flow over the past couple of years due to higher <br />snow packs at the site since 2005. The flow in IC -4 and all springs decrease rapidly during the early <br />summer months to a point where there is little to no flow in the fall. <br />Pitch 2013 Reclamation Report 14April2014.Docx 21 <br />