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The Consolidated Mutual Water Company <br /> -� 11/25/2013 <br /> 6. WATER STORAGE EVALUATION AND OPINIONS <br /> To evaluate the water storage potential for the Ralston Quarry, the quality and quantity of fractures within the <br /> rock was determined and water pressure tests were performed at the proposed elevations for the reservoir <br /> walls and bottom.Additionally,three dimensional computer modeling of the probable final reservoir slopes was <br /> conducted to evaluate potential storage volume. <br /> 6.1 Analysis of Hydraulic Conductivity <br /> Brierley was able to conduct eight of eleven borings to a depth 50 ft below the proposed final pit floor elevation <br /> of 6,000 ft.The rock core retrieved from the borings was observed for indications of how it would respond with <br /> respect to water storage. Rock fracture frequency, RQD,openness,and infill were observed and recorded on the <br /> Rock Core Boring Reports provided in Appendix A. The RQD ranged from 41 to 100 percent within the planned <br /> reservoir zone. Low RQD is an indicator of fractured rock.The fractures within the cored bedrock generally had <br /> variable spacing between fractures,fracture openings typically less than 1/101'of an inch,with mineral infilling. <br /> In-situ permeability testing was performed in boreholes LH-01, LH-02, BA-4, and BA-813 utilizing a single packer <br /> system for the purpose of evaluating the hydraulic conductivity within the rock mass. Packer testing was <br /> performed in general accordance with ASTM D4630. Depth intervals were selected based on the proposed <br /> bottom elevation and surface water elevation of the reservoir.Two single packer tests were performed on each <br /> boring. For borings LH-01, LH-02, and BA-4,the first test interval was located 50 ft above the bottom of the <br /> boring and was tested to evaluate the bottom of the reservoir.The second test interval was located 50 ft above <br /> the top of the first test interval and was tested to include the reservoir walls within the test interval. BA-88's <br /> two intervals were similar but in 30 ft increments.The results of the first test interval(lower)was subtracted <br /> from the second (higher)test interval to give an indication of the hydraulic conductivity for the bedrock walls of <br /> the filled reservoir.The basalt/shale contact was located in borings LH-01 and BA-86,the lower packer test in <br /> this boring evaluated only the shale while the upper packer results revealed the hydraulic conductivity at the <br /> basalt/shale contact. <br /> The hydraulic conductivity of the bedrock ranged from 9.3 x 10-7 centimeters per second (cm/sec)to 2.4 x 10-5 <br /> cm/sec when measurable by water pressure testing. For some intervals of the water pressure tests,the <br /> apparent hydraulic conductivity of the bedrock was below the sensitivity of the water pressure tests, as <br /> indicated by no measurable flow,or negative flow, during the test. A summary of the measured hydraulic <br /> conductivity for the bedrock was presented in the Phase I report. Based on the results of the packer testing, <br /> Brierley has concluded that the bedrock will provide water retention consistent with use as a water storage <br /> reservoir. <br /> 6.2 Evaluation of Water Storage and Seepage Losses <br /> Brierley performed an analysis of groundwater seepage for the water in the planned reservoir into the <br /> surrounding rock.SEEP/W(GEO-SLOPE International) uses finite element modeling to evaluate the seepage and <br /> excess pore-water pressure dissipation. <br /> BRIERLEY �2 <br /> ASSOCIATES <br /> Creating 5 xrre Underground <br />