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collection, the equipment will be decontaminated as it is retrieved to the ground surface. Boreholes will be grouted with neat cement grout from the bottom up using the Hydropunch rods as tremie pipe. If groundwater does not readily infiltrate the screen, a temporary PVC well casing will be put in the borehole to assess whether the seepage is sufficient to allow groundwater to accumulate in a manner that will allow a groundwater sample to be collected. If no groundwater accumulates in the temporary well, the PVC materials will be retrieved and the direct punch borehole will be advanced approximately 5 or 10 feet (based on the direction of the Field Project Manager) and the sampling process will be repeated. All soil and groundwater grab sample containers will be labeled and stored in an ice-filled cooler chilled to 4 degrees Celsius (°C). The samples will be shipped or couriered under proper chain of custody protocol to a California State-certified laboratory for analysis. 5.10.2 Soil Vapor Sampling Soil vapor samples will be collected in accordance with the procedures outlined in the July 2015 Advisory -Active Soil Gas Investigations, jointly issued by Los Angeles Regional Water Quality Control Board and DTSC. The soil vapor samples will be collected from soil gas probes installed in sub-slab or shallow soil borings following the procedures presented below. Samples collected at each location will be tested for VOCs at an onsite mobile laboratory. Soil Vapor Implant Installation and Sampling Methods Sub-slab soil gas probes will be installed using an electric-powered rotary hammer to drill two-inch diameter holes in the building concrete floor (slab). A two-inch diameter hole will allow for observation of the sub-slab material. Sub-slab soil gas probes consisting of sample tubing and a porous tip will be inserted to approximately four to six inches below the concrete floor. Flexible sampling tubing will be 1/4 - inch in diameter made of Teflon that will not react or interact with VOCs. Clean, dry, dedicated tubing will be used for sampling. No moisture, water, or any unknown material will be present in the probes prior to insertion.After use at each location, Teflon sampling tubes will be properly discarded. During installation of the probes, clean sand will be used to support the sample tip and hydrated bentonite will be used to seal around the probe at slab surface to reduce ambient air intrusion. To allow for the subsurface to equilibrate o representative conditions, each probe will not be purged or sampled for at least two hours following probe installation. The sample probes will be covered with a shroud (plastic tote) during the sampling process. The temporary soil gas probes will be secured and completed to prevent infiltration of water or ambient air into the subsurface and to prevent accidental damage or vandalism. The tubing will be marked at the surface to identify the probe location and depth. A gas-tight valve or fitting for capping will be affixed to the sampling tube. Permanent soil gas probes will be installed in borings using hydraulically-powered direct-push drilling technology. Each boring will include a single sampling implant. The implants will be constructed as follows: Drill rods will be advanced to a total depth of approximately 5 feet bgs and then retracted, Sampling and Analysis Plan Tracy Corners Shopping Center 3225 North Tracy Boulevard Tracy,California 95376 Partner Project Number SM14-129814 Docket Number HAS-VCA 14/15-108 August 15,2016 Page 23