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Limited Site Investigation ±19.41 Acres Vacant Land r Manteca, California 1 Terracon June 12, 2017■ Terracon Project No. N6177049 one to three soil samples will be collected from each boring. Selected samples may be held by the laboratory pending initial results. All soil samples will be collected in clean, laboratory-supplied 4-ounce glass jars. Sample jars with be labeled and stored inside water-proof bags and placed in a cooler with ice. All samples will be logged on a chain-of-custody manifest, maintained under the supervision of Terracon field staff until delivered to a certified analytical laboratory. Groundwater Sampling The soil borings will be converted to temporary sampling wells (TSWs) by installing 5 feet of 3/4- inch diameter, 0.010-inch machine slotted PVC well screen with a threaded bottom cap, with 3/4- inch diameter, threaded, flush-joint PVC riser pipe to surface. A groundwater sample will be collected from each TSW using a 1/2" disposable polypropylene bailer or a 1/4 inch dedicated tubing and check valve assembly. Following completion of sampling activities, the temporary well material will be removed and the borings will be backfilled with a neat cement/bentonite mixture applied with a hose-type tremie. Field Documentation A field log will be completed for each boring by the on-site geologist during drilling activities that will include the number and depth of each boring completed, date, description of drilling and construction activities, facility site features, PID readings, and soil description (color, moisture, odor, etc.)for continuously sampled borings. Decontamination Drilling equipment will be cleaned prior to drilling. Cleaning will be conducted on a trailer mounted wash rack. Sampler and drilling parts not subjected to cleaning on the trailer mounted wash rack will be triple rinsed in two tap water immersions and then distilled water after being decontaminated in a solution of appropriate detergent and water. Prior to collection of each soil sample, all reusable sampling equipment will be washed in a solution of Alconox®detergent (or equivalent) and water, and rinsed with tap water and distilled water. Cleaning will be conducted in such a manner so as to contain the water, which will be placed in appropriate containment vessels, labeled, sealed, and stored prior to disposal. Disposal methodologies will be contingent upon field observations and/or analytical results. Waste Management Drill cuttings and decontamination water will be properly containerized and stored as necessary during site activities. Disposal methodologies will be contingent upon field observations and/or analytical results. Sampling and analysis will be completed to characterize these wastes to Responsive ■ Resourceful ■ Reliable 3