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February 28, 2018 Project No. 2154-1817-01 Ms. Vera Fischer, P.G., RWQCB Work Plan for Additional Site Assessment 1817 South Fresno Avenue, Stockton, CA Page 5 Mark boring locations and contact Underground Service Alert to locate underground utilities in the vicinity of the work site, and Notify SJCEHD, the RWQCB, the City of Stockton, and Mr. Barnes of the scheduled field activities. Task 2: Field Activities CPT Borings Stratus will retain a C-57 licensed contractor to advance the CPT borings. CPT consists of advancing a cone-tipped cylindrical probe (1.7 inches in diameter) into the ground while simultaneously measuring the resulting resistance to penetration. A computer- generated CPT log is plotted in the field, providing a continuous log of Site lithology. Upon completion of CPT profiling, to a depth of approximately 90 feet bgs at location CPT-2, the profiling borehole will be pressure grouted from the bottom of the borehole up to surface grade. At the request of the USTCF, CPT profiling will only be completed at one of the three proposed work locations (CPT-2) in order to reduce project costs. Once the CPT profiling has been performed at CPT-2 (the centrally located boring), hydropunch groundwater sampling will be performed from adjacent borings at locations CPT-1 through CPT-3. The hydropunch sampler will be pushed to the bottom of the sampling interval using 2-inch diameter steel rods. The steel rods will then be retracted approximately four feet, exposing the screen, allowing for the collection of depth-discrete groundwater samples. The groundwater samples will be collected using a clean bailer, transferred to laboratory-supplied glass vials, properly labeled, and placed in an ice- chilled cooler. The groundwater samples will be transported under strict chain-of- custody protocol to a California-certified analytical laboratory for chemical analysis. Upon completion of groundwater sampling, the sampling boreholes will be pressure grouted from the bottom of the borehole up to surface grade. The USTCF and the RWQCB have requested collection of groundwater samples at approximately 60 and 90 feet bgs at each of the three sampling locations. Stratus will utilize these requested depths of sampling as a guide for the sampling; however, Stratus will ultimately review the CPT log obtained at CPT-2 and utilize geologic conditions to select sampling locations. Permeable (sandy) strata will be preferentially targeted for groundwater sampling, as contaminants could preferentially migrate within these permeable strata. KABames Trucking\Work Plans \bames trucking cpt work plan 2018.doc STRATUS