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s r 5- 07 07 May 2009 AGE-NC Project No. 97-0343 Page 2of7 2.1. ADVANCEMENT OF SOIL PROBE BORINGS On 14 and 15 April 2009,two soil probe borings (P1 and P-2)were advanced to total depths of 50 feet below surface grade (bsg) utilizing a van-mounted Geoprobe 5400 direct-push probing unit equipped with 1.25-inch diameter probing rods;the probing unit advances soil probe borings using a hydraulic hammer to drive soil sampling tools to specified depths. To assess the extent of petroleum hydrocarbon contamination remaining after termination of SVE remediation conducted on-site, confirmation boring P1 was advanced within the former UST area, immediately south of monitoring well MW-9;while confirmation boring P2 was advanced south of the former UST area, immediately southeast of dual completed well MWNW-2. Figure 2 depicts the locations of the confirmation soil borings. 2.2. SOIL SAMPLE COLLECTION Discrete soil samples were collected using the Geoprobe push-driven 2-inch diameter soil sampler fitted with four one-inch diameter,six-inch long stainless steel sleeves at 5-foot intervals,beginning at 5 feet bsg and terminating at the total depth of the borings (50 feet bsg). Soil samples were preserved by covering both ends of the second stainless steel sleeve with Teflon sheets, capping and sealing with tape. Each preserved sample sleeve was labeled with soil boring location, depth, time, date and sampler's initials and stored in a chilled container under ice. Soil samples retrieved from the borings were visually classified on a boring log by AGE personnel in accordance with the Unified Soil Classification System(USCS); soil boring logs are provided in Appendix B. Additionally, soil samples were field-screened for the presence of volatile organic compounds using an organic vapor meter [OVM] equipped with a photo-ionization detector(PID: Thermo Environmental 580, 10.0 eV, calibrated to isobutylene); concentration readings were recorded on the boring logs. 2.3. LABORATORY ANALYSIS OF SOIL SAMPLES Selected soil samples were transported under chain-of-custody procedures to Cal Tech Environmental Laboratories, a Department of Public Health Services(DPHS)-certified laboratory, and for analyzed for: • Total petroleum hydrocarbons quantified as gasoline (TPH-g) and diesel (TPH-d) in accordance with EPA Method 8015 Modified; • Compounds benzene, toluene, ethylbenzene and xylenes (BTEX) in accordance with EPA Advanced GeoEnvironmental,Inc.