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LOVA S S O C I UAT E S I N C . L2_1 Soil Boring Advancement and Sampling Drilling was conducted on May 4 and 5, 1999 by West Hazmat Drilling (State C57 license no. L 554979) utilizing a hollow stem auger drill rig. Soil borings SBI, SB2, and SB3 were advanced at the locations shown on Figure 2. Soil boring SBI was advanced to 51.5 feet below ground L surface (bgs). Soil and groundwater encountered in boring SBI appeared to be clean based on field observations so soil borings SB2 and SB3 were terminated at 41.5 feet bgs and the proposed boring location for SB3 was moved closer to the former UST at the request of Ms. Carol Oz of PHS/EHD. A field geologist logged drill cuttings and soil samples utilizing the Unified Soil Classification System. Descriptions of soil types encountered and sample collection intervals are included on the boring logs contained in Appendix A. Copies of field notes are contained in Appendix B. The cored soil samples were collected at five-foot intervals or significant changes in lithology Lusing a 2-inch diameter split-spoon sampler containing three brass tubes. The cored samples and drill cuttings were characterized for soil type, moisture content, and visual evidence of petroleum hydrocarbons. A photoionization detection meter (PID) was used as a field screening device for the detection of petroleum hydrocarbon vapors in drill cuttings and cored samples. Drill cuttings were temporarily stored on site in 55-gallon DOT approved steel drums. LAt the request of Ms. Carol Oz of PHS/EHD, a grab groundwater sample was collected from boring SBI. A disposable bailer was lowered into the boring to collect a grab groundwater sample. After samples were collected, soil borings SBI and SB2 were grouted with a bentonite grout mixture to the surface and to four feet bgs, respectively. ATC attempted to grout soil boring SB3 to the surface, but the grout mixture would not rise above seventeen feet. ATC called the City of Stockton Municipal Utilities Department (MUD) to the site to verify that there were no utilities or piping at the boring location. Mr. Michael McDonald of MUD stated that the boring location was clear. ATC placed bentonite pellets in boring SB3 in an attempt to plug the hole. The next day, ATC returned to the site to grout boring SB3 and top off the grout in SB2 which had dropped approximately 10 feet. ATC placed additional pellets in SB3 and a bentonite grout mixture in boring SB2. Both attempts to grout the borings were unsuccessful. ATC recommended using a thick cement mixture to backfill the borings. This was verbally approved by Ms. Carol Oz of PHS/EHD. On May 14, 1999, ATC backfilled boring SB2 with the thick cement mixture. ATC heard running r water in boring SB3 and called MUD to the site. At this time, it was verified that a 42" storm drain had been punctured and attempts to grout the boring have been postponed until the pipe is repaired. A 55-gallon drum filled with soil was placed over the boring but was later removed by t vandals. On June 4, 1999, ATC personnel excavated a sixteen inch area around soil boring SB3 down to t approximately five inches bgs. ATC then placed a piece of plywood over soil boring SB3 and wA163931repwU\sumi.doc 2