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Chevron Products Company 11 Former Chevron service Station 95775, 301 West Kettleman Lane, Lodi, California March 30, 2000 (Table 2) Assuming a saturated aquifer thickness of 445 feet, hydraulic conductivity of the aquifer is approximately 3 5 ft/day This is consistent with literature hydraulic conductivity values for silty to clean sand aquifers (Freeze and Cherry) Capture Zone Analysts The purpose of conducting a capture zone analysis was to estimate the capture zone created from remediation efforts at the site The results of modeling efforts are based on the assumptions listed below To evaluate capture zone, SECOR utilized the Environmental Protection Agency (EPA) WHPA modeling program module Multiple Well Capture Zone (MWCAP) MWCAP is designed to provide efficient delineation of capture zones for one or more pumping wells in homogeneous aquifers Assumptions The following is a summary of WHPA modeling efforts conducted For this modeling effort, the following inputs were utilized • The aquifer in unconfined, • Reference head is 58 feet, . • Aquifer porosity is 0 30, 0 • Hydraulic gradient is 0 001, • Angle of Ambient Groundwater Flow is 225° (southwest), • Transmissivity of the aquifer is 1,497 ft2/d This is assuming an aquifer thickness of 445 feet, • Area Recharge rate is 0, • No boundary conditions exist in the vicinity of the site, • The municipal well southwest of the site is not operating, • Discharge from the onsite extraction well (EX -3) is constant at approximately 1,636 ft3/d (8 5 gpm), • The inputs were from based on data collected during groundwater monitoring and pump test activities To begin model simulations, a grid of 20 rows and 20 columns was input Spatial distance of rows and columns was set at 50 feet Minimum and maximum x and y coordinates were set 11Chevron1957751Aquifer testlRevtsed195775Aquifertestrevised doc