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Focused Groundwater Investigation Work Plan Deuel Vocational Institution(DVI), Tracy, California Sampling and Analysis • All equipment will then be decontaminated and secured as required. 4.3.2 Borehole Abandonment Per previous investigations conducted on site, CVWB recommended using a minimum of 5 feet of neat cement grout above the bentonite slurry to ensure a good seal to the surface while limiting the impact of the elevated pH of the cement in the saturated zone. URS agreed and will backfill each boring with a bentonite slurry to 5 feet bgs and the remaining upper 5 feet will be backfilled with neat cement grout for this investigation. 4.3.3 Laboratory Analysis Samples will be analyzed for selected VOCs by United States Environmental Protection Agency (USEPA)Method SW826013, anions by USEPA Method 300.0, dissolved metals by USEPA Method 6020,total organic compounds, silica, carbon dioxide, and alkalinity. 4.4 Phase 2 - Well Installation Activities If the analysis of the grab GW samples shows elevated concentrations above the maximum contaminant levels,up to three permanent GW MWs may be installed in the area surrounding MW-9-13P.At each boring location,DPT will be advanced to first water(historically approximately 4 to 8 feet bgs). 4.4.1 Well Installation Using a DP rig,URS will install up to three pre-packed wells,constructed of 0.75-inch-diameter, Schedule 40 polyvinyl chloride (PVC) casing. Soil cuttings will be logged by a URS geologist using the Unified Soil Classification System(American Society for Testing and Materials 1985). Soil descriptions will include the following: moisture content, color, grain size(most abundant to least abundant), angularity, and other pertinent textural or mineralogical properties, and visual and/or olfactory indications of impact. Soil descriptions will be used to assess site-specific geologic and hydrogeologic properties. Soil will also be collected for headspace readings. The well assembly will consist of standard, slotted PVC well screen pipe surrounded by a stainless-steel mesh with threaded PVC riser pipe. The pre-packed well will consist of 0.010-inch slot size and a 20/40 mesh sand factory packed in a stainless steel screen. The screen interval will be determined based on the results of the Hydropunch samples. A pre-packed bentonite barrier will be situated directly above the filter pack to prevent the sanitary seal from entering the screen. The sanitary seal will be composed of bentonite slurry from the top of the seal to approximately 2 feet bgs. The well will be secured in a traffic- rated steel box. If drilling conditions are not conductive to DP,then the well will be installed using a hollow-stem auger drill rig. Soil samples will be collected from 5 feet above the screen to the bottom of the screen using a California-modified split-spoon sampler for headspace readings and lithologic logging. The MW will be drilled using a drilling rig equipped with an 8.25-inch-outer-diameter,hollow-stem auger. The well will be constructed using a 2-inch-diameter, flush-threaded, Schedule 40 PVC well casing.A 0.010-inch, machine-slotted well screen will be used.A Monterey silica sand filter pack(#2/12 or equivalent)will be installed from the bottom of the boring to 3 feet above the top of the well screen. A 2-foot transition sand will be installed approximately above the filter pack, followed by a 2-foot bentonite seal. Bentonite will 4-2