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APPENDIX D: FIELD INVESTIGATION PROCEDURES AND BORING LOGS DRILLING Well Destruction On July 14 through 16, 2010, The Benham Companies, LLC, an SAIC Company(SAIC- Benham) supervised WDC Wells and Exploration(C57#283326) in the proper destruction of monitoring wells MW-1 through MW-3 at US Can-Welty Road(the site) located in Vernalis, California(Figure 1). The condition of each well was inspected prior to destruction. The total depth of each well was measured and compared to the well construction details. An air knife was used to clear each well location to 8 feet below ground surface (bgs)to confirm the absence of utilities or other subsurface obstructions, complying with Science Applications International Corporation(SAIC) Environmental Health and Safety Procedure 130, "Subsurface Hazard Avoidance." The wells were over-drilled using a CME 85 truck-mounted drill rig equipped with 8.75-inch, hollow-stem augers. The boreholes were backfilled with neat cement using a tremie pipe from total depth to ground surface. A representative of the San Joaquin County Environment Health Department(SJCEHD) was on-site during a portion of the well destruction to ensure that proper procedures were utilized. Soil and Groundwater Investigation On July 20 through 22, 2010, SAIC-Benham observed PeneCore Drilling(C57#906899) advance soil borings SB-44 through SB-47 at the site as shown on Figure 2. Borings were advanced to 45 feet bgs. Geoprobe®-type drilling equipment was used to advance the soil borings, and a continuous- coring device was used to collect soil samples for soil characterization only. The completion of soil borings generally conformed to SAIC Field Technical Procedure (FTP)No. 525, "Soil Sampling Using an Auger." The samples were screened with a photoionization detector(PID),using procedures consistent with SAIC FTP No. 750, "Field Measurement Procedures—Organic Vapor Detection,"to detect the presence of residual petroleum in soil. The soil was logged in general accordance to the Unified Soil Classification System as presented in American Society for Testing and Materials 2488-90 under the supervision of a California Professional Geologist. Additionally, other information was entered into field logbooks to document where, when, how, and from whom any vital project information was obtained,using procedures described in SAIC FTP No. 1215, "Use of Field Logbooks." Soil and groundwater samples were submitted to Lancaster Laboratories, Inc. (Lancaster)' under SAIC chain-of-custody protocol. Following completion of the soil borings, each open borehole was plugged and abandoned according to SJCEHD requirements. 1. California State-certified laboratory,Environmental Laboratory Accreditation Program License Number 2116. D—IA The Benham Companies,LLC A Wholly Owned Subsidi,ry Hwn Sc"Ce fo Sol✓I'^rrs