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15 August 2002 AGE-NC Project 02-0946 Page 3 of 7 3.2. SOIL PROBE BORINGS On 24 July 2002, soil probe borings PB-1 through PB-3 were advanced at the site to further define the extent of petroleum hydrocarbon-impacted soil and ground water. Probe borings PB-1 and PB-2 were advanced adjacent to borings B-2 and B-5, respectively, to define the vertical extent of impacted soil that was previously identified at those boring locations; soil samples collected from boring B-5 in May 2002 contained the highest concentrations of petroleum hydrocarbons. Probe boring PB-3 was advanced to define the lateral extent of impacted soil towards the north of the property. Soil probe borings PBA through PB-3 were advanced utilizing a van-mounted Geoprobe 5400 equipped with 1.125-inch diameter probe rods with an attached 2.15-inch diameter soil sampler, using "direct push" technology. Probe borings PB-1 and PB-3 were advanced vertically to depths of 30 feet bsg; boring PB-2 was advanced to 41 feet bsg in order to collect a grab ground water sample in addition to soil samples. 3.2.1. Soil Sampling and Analysis Discrete soil samples were collected at 5-foot intervals, beginning at 10 feet bsg in each boring to the total depth of each boring. Soil samples were collected using a Geoprobe soil sampling assembly loaded with four pre-cleaned 1.125-inch by 6-inch brass sleeves. One sleeve of each soil sample was preserved by covering both ends of the brass sleeve with Teflon sheets, capping, and sealing with tape. Each sample sleeve was labeled with the soil probe boring location, depth, time, date and sampler's initials. Subsequently, the preserved samples were logged on a chain-of-custody form, placed in a chilled container and transported to Cal Tech Environmental Laboratories (CTEL), a State of California Department of Health Service (DHS)-certified laboratory, for analysis. Selected samples were analyzed for: • TPH-g in accordance with EPA Method 8015 Modified; and • Benzene, toluene, ethylbenzene and total xylenes (BTEX) and methyl tert-butyl ether (MTBE) in accordance with EPA Method 8 02 1. In addition, the duplicate sleeves of each soil sample were monitored for the presence of organic vapor using an organic vapor meter equipped with a photo-ionization detector (PID: Thermo Environmental 580A, 10.0 eV, calibrated to isobutylene). Advanced GeoEnvironmental,Inc.