2007-11-23_HYDROLOGY - M1977300 (4)

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Appendix C - Monitoring Well Logs 1 • 1. ALLUVIAL MONITORING WELLS Nine wells were completed in the alluvium and fill adjacent to Ralston Creek. Completion data are summarized in the following table, and well logs are provided in this appendix. Table 1. Completion Data for Alluvial Monitoring Wells Well ID Completion Date Total Depth (ft) Depth to Bedrock (ft) Well Construction Screened Interval (ft) Completion Depth to Water ft MW00 11/4/98 27.3 25 4" PVC 16.9-26.9 10.25 MWI 11/12/81 25.5 23 2 1/2" PVC 17 - 22 7 MW2 11/12/81 15.4 21 21/2"PVC 8.4-13.4 10 MW3A 6/19/89 14 Not Penetrated 4" PVC 8.6-13.6 10.0 MW4 6/16/89 38.9 36.3 2" PVC 25.9-35.9 31.4 MWSR 1/19/99 20 17 4" PVC 9.5-19.5 15.5 MW6 6/20/89 15 13 2" PVC 5-15 40 MW7 6/20/89 11 8 2" PVC 5-10 3.5 MW8 12/8/90 12 10 4" PVC 7-12 Dry MW9 1/19/99 19.2 16 6" PVC 9-19 10 2. BEDROCK MONITORING WELLS Two wells were completed in bedrock on the hillside above the mine. Completion and water level data are summarized in the following table, and well logs are provided in this appendix. Table Z Water Levels and Well Data for Bedrock Monitoring Wells MW10 and MW11 Depth to Collar Water Top of Well Bottom of Mid-Point of Date Well Water Elevation Elevation Screen Well Screen Saturated (ft. btoc) (ft. amsl) (ft.amsl) (ft.amsl) (ft.amsl) Screen ft.amsl 5/27/99 MW10 67.20 7393.86 7326.66 7370.36 7320.36 7323.51 MWII 82.89 7394.27 7311.38 7244.27 7194.27 7219.27 9/21/99 MW10 71.25 7393.86 7322.61 7370.36 7320.36 7321.49 MWI1 89.10 7394.27 7305.17 7244.27 7194.27 7219.27 11/02/07 MW10 >77.6 7393.86 <7316.26 7370.36 7320.36 N/A MW11 182.0 7394.27 7212.27 7244.27 7194.27 7219.27 Table 3. Calculation of Vertical Gradients in Shallow Bedrock Elevation Mid-Point Vertical Date Well Head Elevation y, -y2 111-112 Gradient H -H / 5/27/99 MW10 7326.66 7323.51 104 24 28 15 15 0 MW11 7311.38 7219.27 . . . 9/21/99 MW10 7322.61 7321.49 102 22 17 44 17 0 MW11 7305.17 7219.27 . . . 4109B.071105 Whetstone Associates