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The installed monitoring wells will be developed after a minimum of 72 hours following well completion. The wells will be developed using a combination of ...- pumping and surging until the physical water quality parameters (conductivity, pH, temperature, and turbidity) have stabilized. Stabilization will be defined as three consecutive readings within 10%. For initial well development, a minimum of five well volumes will be removed prior to sampling. Well development water will be stored in 55 gallon 17 E/H drums. The wells will be surveyed by a California-registered land surveyor. The elevation of the top of the casing will be measured to the nearest 0.01 foot at a designated mark (V-notch cut into the north side of the well casing) with reference to an established benchmark. The location of the wells will be surveyed to 0.1 feet. The existing wells will also be surveyed using the same level of accuracy at this time. V-notches will be cut into the north sides of these well casings if this has not yet been done. After the wells have been developed, an electronic oil/water interface probe will be used to determine whether free product is present. Using a clear bailer, a volume of groundwater will be pulled from the well and checked for petroleum hydrocarbons with a PID or FID, then visually observed for sheen. Groundwater levels will be measured in each well at this time using the interface probe. The groundwater will be sampled no sooner than 12 hours after development. One groundwater sample will be collected from each new well and submitted to the District laboratory for TPH-g and BTEX. Ten percent of the samples will be submitted for total lead analyses. The analytical methods, sample containers, preservatives, and holding times are specified in Appendix C. During collection of the groundwater samples in the 40 ml vials, the vials will be filled without headspace and capped to minimize loss of volatile constituents. The samples will be numbered and packaged as detailed in Section 3A. In addition to collecting samples from the newly installed wells, BVWST will collect groundwater samples from four of the existing wells, MW-1, MW-2, MW-4, and MW-7, and submit the samples to the District laboratory for TPH-g and BTEX analyses. The samples will be numbered and packaged in accordance with Section 93822 East Bay Municipal Utility District 40429200.wp 18 Work Plan-Stockton Service Center r 6r