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I i r� Workp`rrlFor Additional Assessment and FeasL)y Study Quik Stop Market No. 132 3555 West Hammer Lane Stockton, California The soil borings will be advanced to depths of between 10 feet to 30 feet below ground surface (bgs). Groundwater is anticipated at depths ranging from approximately 10 to 17 feet bgs in the upper aquifer and 24 to 29 feet bgs in the lower aquifer. The soil borings will be terminated at i depths sufficient to collect groundwater samples. All soil borings will be backfilled to the surface with neat cement slurry after sampling is completed. Backfilling will be completed under the supervision of a San Joaquin County Public Health Services Inspector. The borings adjacent to the existing wells will not be logged, however, the boring east of Boring SB3 will be logged in accordance with the Unified Soil Classification System (USCS) by an ATC geologist under the supervision of a California Registered Geologist. The boring east of Boring SB3 will be cored continuously. Soil cores will be obtained by pushing a Geoprobe r" sampler with liners into the subsurface. Samples will be screened using a photoionization detector (PID). Based on the PID readings, a section of the liner will be cut out at the selected sampling depth for submittal to a certified analytical laboratory. If the PID shows only low readings, a soil sample will be collected just above the groundwater table. The ends of the tubes containing the soil to be tested will be covered with Teflon 7" capped with plastic end- caps, and placed in sealable plastic bags. The soil sample(s) will be labeled and transferred to a California Certified analytical laboratory using proper chain-of-custody protocol. Shallow groundwater samples will be collected from each boring by either installing a temporary well to a depth of approximately 12 feet bgs (using ten feet of slotted polyvinyl chloride (PVC) screen and bailing a grab sample through the temporary casing), or by use of a HydropunchTM tool, or equivalent. Water samples will be collected from the borings at the water table. In the boring east of Boring SB3, a groundwater sample will also obtained from the lower local aquifer. In order to obtain a groundwater sample from the lower aquifer, an additional borehole may be drilled approximately 2 feet away from the original boring using smaller diameter rods. A depth discrete groundwater sample from the lower aquifer will be collected using a HydropunchTM tool, or equivalent. The samples will be properly labeled and placed in a cooler with ice, and transferred to a California Certified analytical laboratory using proper chain-of-custody protocol. A state-certified laboratory will analyze the soil and groundwater samples for the following: • Total petroleum hydrocarbon (TPH) as gasoline (TPH-G) using USEPA Method 8015 (modified) • Benzene, toluene, ethylbenzene, and xylenes [BTEX] and methyl tert-butyl ether [MTBE] using USEPA Method 8020 3 i