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The groundwater is located at approximately 12 feet below ground surface (bgs) accord7tostanding water level measurement of the new on-site domestic well. The Lines of Equamap published by the San Joaquin County Flood Control District indicates the groundw <br /> to be approximately 10 feet. The groundwater directional flow is to the northwest as indicated on <br /> the attached Lines of Equal Elevation map. <br /> The groundwater gradient is considerably flat and is estimated to be: 10 ft - 13,200 ft= 0.000758 <br /> ft/ft. This gradient is based upon linear distance connecting the 10 foot contour elevation line and <br /> the 0-foot contour line as this imaginary lines crosses under the de Snayer Dairy facility. This is <br /> illustrated on the Lines of Equal Elevation groundwater map. Based upon Darcy's equation <br /> estimates for hydraulic conductivity, porosity, and the calculated groundwater gradient, the <br /> _ velocity of groundwater movement under the de Snayer Dairy facility is approximately 0.23 ft/day <br /> or 84 ft/yr: <br /> Va= K (h,-h21 <br /> L <br /> 7.5 • p <br /> Where: <br /> Va= groundwater velocity in feet per day <br /> K=hydraulic conductivity in gallons per sq ft per day <br /> h, - h2 = difference in hydraulic head <br /> L = distance along flowpath between h, and h2 <br /> 7.5 = number of gallons per ft3 <br /> p = porosity of medium <br /> Va = 100 (10 - 0) Va = 0.23 ft/day <br /> 13,200 <br /> 7.5 • 0.40 <br /> Historical groundwater depth information near the de Snayer Dairy site was obtained from the <br /> California Department of Water Resources (DWR). Data from the closest well to the dairy <br /> (Well Number: 04N05E22A001 M), approximately one mile to the west of the dairy facility was <br /> reviewed for historical depths. The data shows the depth to water below ground surface to range <br /> from 2.8 to 10.3 feet, and mostly around five feet since 1948. Since this well is one mile west of <br /> the dairy facility, these groundwater depths are plausible and substantiate the likelihood of <br /> groundwater under the dairy to range between 10 and 15 feet b.g.s. over this approximate 55-year <br /> period of time. <br /> -5- <br /> Chesney Consulting <br />