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Water Quality Monitoring Report <br /> is French Camp Landfill <br /> QA/QC procedures were exercised, and the water quality samples collected from the French <br /> Camp Landfill appear to be representative of water quality at the site. <br /> 4.3 Groundwater Elevations and Contours <br /> Prior to purging and sampling, each well was sounded for water depth using a weighted <br /> electronic sounder, and the static water level was recorded on a Well Data Sheet (Appendix C). <br /> The groundwater elevations were calculated for each well by subtracting the depth-to-water <br /> measurement from the top-of-casing reference elevation. The current and historical <br /> groundwater elevation data for the French Camp Landfill is summarized in Table 5. <br /> The groundwater elevation data obtained during the monitoring period were used to generate <br /> the groundwater elevation contour maps shown on Figures 1 through 3. As shown on Figure 1, <br /> groundwater flowed to the south and southeast in January 2016 at a hydraulic gradient of <br /> 0.002 ft/ft to 0.006 ft/ft. As shown on Figure 2, groundwater elevation measurements <br /> collected in late March 2016 indicate groundwater flow to the northeast at a hydraulic gradient <br /> of 0.001 ft/ft to 0.002 ft/ft. May 2016 groundwater elevations depict groundwater flow to the <br /> southeast at a hydraulic gradient of 0.001 ft/ft (Figure 3). <br /> To calculate the approximate linear groundwater flow velocity for the site, conservative <br /> assumptions were used, including a hydraulic conductivity of 0.014 cm/sec, and an estimated <br /> effective porosity of 35 percent (CH2M Hill, 2000). The estimated groundwater flow velocity <br /> was calculated using Darcy's Law: <br /> Ki cm 0.006 sec— ft <br /> V = = [(0.014 —)* ]*2835 = 0.68 ft l day <br /> ne sec 0.35 cin —day <br /> where: V= Groundwater flow velocity. <br /> K= Hydraulic conductivity of the water-bearing unit (0.014 cm/sec). <br /> i= Maximum hydraulic gradient: i=0.006 for the site during the monitoring period. <br /> n,= Effective porosity(ne=0.35); an estimated value. <br /> The groundwater flow rate is calculated to be 0.68 feet/day(248 feet/year). <br /> 4.4 Detection Monitoring Program <br /> Field and laboratory results from the current monitoring period for DMP monitoring wells (MW- <br /> 6A, MW-7A, MW-8A, MW-9A, MW-913, and MW-10A) are summarized in Table 2. <br /> Project No.2016.0007 3 <br />