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S ECOR <br /> Mr. Michael Infurna <br /> San Joaquin County Environmental Health Department <br /> March 27, 2007 <br /> Page 7 of 8 <br /> The wells will be screened across the upper 10 feet of the first-encountered water- <br /> bearing zone, assumed to be present in the upper 35 feet bgs. Following installation, <br /> the wells will be developed, sampled, and surveyed relative to mean sea level or the <br /> local vertical datum. <br /> Monitoring Well Installation, Development and Sampling <br /> Groundwater monitoring wells will be installed by Woodward. The three monitoring wells <br /> will be constructed of 2-inch-diameter Schedule 40 PVC with approximately 10 feet of <br /> machine-slotted screen and installed using 8-inch-diameter hollow-stem augers. Well <br /> construction specifications and materials will comply with California and county well <br /> construction standards. The wells will be completed with locking caps and flush- <br /> mounted well boxes. Up to two soil samples will be collected and retained for laboratory <br /> analysis of petroleum hydrocarbon constituents as detailed elsewhere in this Work Plan. <br /> Following installation, the monitoring wells will be allowed to equilibrate for at least two <br /> days before development. The wells will be developed by alternately surging and bailing <br /> the well, and periodically monitoring physical groundwater parameters such as pH, <br /> conductivity, and turbidity. SECOR anticipates the removal of approximately 10 casing <br /> volumes from each well to achieve hydraulic communication between the well and the <br /> surrounding formation. <br /> Following development and stabilization of the groundwater parameters, the wells will be <br /> gauged for depth-to-groundwater and sampled. Samples will be submitted to <br /> Calscience for analysis of TPHd, TPHmo, TPHg, BTEX, and MTBE. <br /> Well Survey <br /> Following installation, the monitoring well tops-of-casing will be surveyed by a licensed <br /> professional land surveyor. Horizontal and vertical coordinates will be used in <br /> conjunction with depth-to-water measurements to calculate groundwater flow direction <br /> and gradient. <br /> Waste Management <br /> Wastes generated during monitoring well installation will be containerized and stored <br /> with the wastes generated during the previous soil borings. <br /> I:\PG&E\French Camp\additional 2007 investigation\work plan\2007 Investigation Work Plan_Final.doc March 27,2007 <br /> Project No.050T.50351.01 <br />