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a 0 the boring for lithologic logging and field screening. The soil samples will be field screened for volatile organic compounds (VOCs) using a photoionization detector (PID). The well will be constructed with 4-inch diameter, Schedule 80 polyvinyl chloride (PVC) blank casing and screen. The screened interval will be 0.02-inch machine-slotted and 15 feet long (from approximately 98 feet to 113 feet bgs) (Figure 4). The filter material will consist of 2/12 Monterey Sand or equivalent, and placed to at least 2 feet above the top of the screen. A minimum 3-foot-thick bentonite seal will be placed above the top of the filter pack. The remaining annulus space will be backfilled with neat bentonite- cement slurry. The well will be completed with a traffic-rated steel cover and monument set in concrete. The wellhead will be flush-finish with surface grade. The construction of the well may be modified based on field observations. After the well has been completed for at least 48 hours, the well will be developed by surging and bailing or pumping. The northing, easting, and top-of-casing elevation of the well will be surveyed by a licensed land surveyor. Groundwater Sampling and Analysis A minimum of 24 hours after well development, depth to water (DTW) in well MW-27 will be measured using an electric sounder. After DTW measurement, the well will be micro- purged using a peristaltic pump similar to the method used for purging and sampling other existing groundwater monitoring wells at the Site. The purge rate will range from approximately 0.2 to 0.5 liter per minute. Field parameters including temperature, pH, electrical conductivity, dissolved oxygen, and reduction-oxidation potential will be recorded during well purging. After the field measurements have stabilized, a groundwater sample will be collected in containers provided by the laboratory. The sample will be placed in a chilled ice-cooler for delivery to a state-certified laboratory using chain-of-custody procedures. The groundwater sample collected from MW-27 will be analyzed for PAHs using EPA Method 8310 after being filtered by the laboratory using a 0.7-micron glass filter. Investigation-derived Residuals The soil cuttings, well development water, and well purge water generated from this assessment will be contained in DOT-rated drums or roll-off bins and temporarily placed within the PG&E property. The materials will be profiled and subsequently transported for off-site disposal at an appropriate facility. 10 ENV.': A M E R I C A P:\PGMAPGE-05-01 Stockton MW26R InvestigationWW26 Work PIan1PGE Stockton MW26R WP.doc