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' Mr. Dustin Czapla <br />Page 5 of 8 <br />Field Pilot Testing Program Summary <br />Overview: <br />The 2015 pilot test will include a recirculation -type injection of a mixture of sodium or <br />' potassium monobasic phosphate salts and phosphoric acid into the underground mine <br />workings. The pilot testing is intended to validate the "proof of concept" bench testing <br />which demonstrated that addition of phosphate to Pitch Reclamation Project surface <br />' water and groundwater resulted in rapid and near complete removal of uranium. A <br />tracer will also be injected as part of the pilot testing including sodium or potassium <br />bromide (analytical tracer) and/or sodium fluorescein (visual tracer). A combination of <br />' the existing (P-4 and P-5) and new (P-11 and P-12) piezometers will be used as <br />injection or extraction points. During and following injections, water quality will be <br />monitored within the underground mine workings and surface water monitoring points <br />as detailed below (Performance Monitoring). The Safety Data Sheets (SDSs) for the <br />reagents that may be used are provided in Attachment 1. No negative impacts to <br />groundwater quality are anticipated as a result of the pilot testing. In addition, <br />' compliance with the CDPS permit (# CO -0022756) conditions and Water Quality Control <br />Commission Regulation 85 (Nutrient Management Control Regulations) will be <br />maintained at the discharge POC (SW -33). <br />Infection Implementation: <br />The two existing piezometers and two new piezometers will be used for reagent <br />injection, recirculation, and/or monitoring. <br />Construction logs for the existing piezometers are provided in Attachment 2. P-4 has a <br />total depth of 325 ft bgs and is screened from 281 to 301 ft bgs. P-5 has a total depth of <br />250 ft bgs and is screened from 220 to 240 ft bgs. Bedrock was encountered at 10 ft <br />bgs in both P-4 and P-5. The piezometers are constructed of 4 -inch diameter polyvinyl <br />' chloride (PVC) and 4 -inch pre -packed screens. Bentonite seals were placed above the <br />screened intervals and grout was used to backfill the annular space from the bentonite <br />seal to ground surface. <br />Before initiation of pilot injection testing, two new piezometers will be installed along the <br />same north -south running transect that intersects P-4 and P-5. The locations of the <br />existing and proposed piezometers are presented in Figure 2 and Figure 3. The <br />proposed piezometers will be completed into the underground workings; however, the <br />exact locations may be adjusted prior to or during drilling activities. <br />The new piezometers will be constructed in accordance with Colorado Office of the <br />State Engineer guidelines (Colorado OSE, 2005). Piezometers will be constructed with <br />5 -inch schedule 80 PVC casing and screen. The 5 -inch diameter casing allows for more <br />water to collect in the well and aids in the deployment of instrumentation. The larger <br />diameter casing also minimizes bending of the casing that typically occurs in smaller <br />diameter wells. The screen will have a slot size of 0.010 inches and lengths will be <br />460 west 50 North, suite 500, salt lake Acv, Utah 84101 TEL(801)990--3746 <br />