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l�� <br />APPENDIX <br />Groundwater elevations in the monitoring wells were obtained this semester. These <br />measurements were used to define the direction and gradient of groundwater flow in the vicinity <br />of the North County Sanitary Landfill. The groundwater flow direction is to the south-southeast. <br />The average groundwater velocity in this area was calculated using the following equation <br />(Darcy's Law): <br />C <br />0 <br />n <br />0 <br />7 <br />C <br />V = Ki <br />n <br />V = maximum linear velocity <br />K = permeability <br />i = hydraulic gradient <br />n = porosity <br />K = 9.8 x 10-3 centimeters per second (cm/s) <br />= 10,100 feet per year (ft/yr) <br />i = 0.0026 foot per foot (ft/ft) <br />n = 0.30 <br />There was no groundwater gradient observed during the 3rd Quarter 2013. <br />The groundwater flow velocity was 87.53 ft/yr for the fourth quarter and was calculated as <br />follows: <br />V = 10,100 ft/yr (0.0026 ft/ft) <br />0.30 <br />= 87.53 ft/yr <br />Permeability coefficients determined with a slug test in well G-1 ranged from 8.3 x 10-3 to 9.8 x <br />10-3 cm/s in the water -bearing zone beneath the landfill. The highest measured permeability <br />value of 9.8 x 10-3 cm/s was selected because it would produce the greatest groundwater <br />velocity. An average porosity value of 0.3 was used, based on published porosity values for <br />similar geologic materials. <br />North County RC&SL Public Works/Solid Waste <br />2"d Semester and Annual 2013 Groundwater Monitoring County of San Joaquin —January 25, 2014 <br />