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The remedial process plan for solid source term materials (Figure 1) addresses water quality impacts to alluvial groundwater and Ralston Creek due to materials residing outside of the underground mine workings including: 1) the "alluvial fill" (a term collectively used to describe low -grade mineralized mine spoils or waste rock mixed with naturally occurring soils, alluvial sands and gravels along the valley floor), and 2) the South WRP which consists of an engineered mine waste rock repository that was partially constructed on top of alluvial fill. The first step to address solid source term materials (implemented over the past two years) was to intercept and treat impacted groundwater flowing underneath the South WRP and throughout the alluvial fill. The second step (operational since April 10, 2012) was to isolate Ralston Creek from these solid source term materials by diverting the creek past the site in a pipeline in order to prevent associated leaching of uranium. These measures, along with subsequent decision points, remedial measures and associated issues, challenges, and technical details, are presented in various sections of Exhibit E in this mine permit amendment application. The mine pool refers to flooded portions of the underground mine workings. Before mining operations were terminated in 2000, the mine was continually dewatered so that the underground workings could advance. When mining operations were terminated, dewatering pumps were turned off and the underground workings were allowed to flood in accordance with the 1983 and 2001 mine reclamation plans as approved by DRMS. As water levels in the mine pool rose over time, concentrations of uranium, radium, various metals and sulfate increased due to leaching of mine wall rock and rubble that had become oxidized during operational mine dewatering. Although the mine pool is contained within hundreds to thousands of feet of solid bedrock, dissolved uranium in mine pool water has the potential to migrate beyond the underground workings and impact groundwater and surface water. The remedial process plan for the mine pool (Figure 2) also relies on interception and treatment of alluvial groundwater and pipeline diversion of the creek, but requires further measures to address the source (thine dewatering and ex -situ treatment, and /or in -situ treatment). New bedrock monitoring wells are planned under TR -19 to better understand groundwater flow dynamics and associated hydraulic gradients in the vicinity of the mine workings. Basic strategies, decision points and remedial measures outlined in Figure 2, along with associated issues, challenges, and technical details, are also presented in Exhibit E of this mine reclamation permit amendment application. E -2 Interception and Treatment of Alluvial Groundwater' Since operational mine dewatering and treatment was terminated in 2000, water quality monitoring data have consistently demonstrated that uranium is the only parameter in alluvial groundwater and surface water in Ralston Creek that exceeds applicable water quality standards. Due to geomorphic valley features in the vicinity of the site, potentially impacted alluvial groundwater flows towards the creek in the lower portions of the alluvial fill. Stream monitoring station SW -BPL (just below the property line) is situated just below a geologic constriction in the valley that forces most of the alluvial groundwater flux to the surface and into the creek channel to become surface water. For this reason, station SW -BPL is considered a point of compliance for both alluvial groundwater and surface water. The highest priority remedial objective at the site is to continuously meet water quality standards at monitoring station SW -BPL, and the first steps taken were to refurbish the water treatment building, install 1 In fulfillment of the first of two requirements indicated in Item 5, Attachment A, to the DRMS letter dated January 30, 2012 (DRMS, 2012a). May I, 2012 10