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05 September 2002 AGE-NC Project No. 99-0605 Page 4 of 6 6.1. SOIL VAPOR EXTRACTION WELL INSTALLATION On 19 March 2002, one soil boring ( B5) was advanced at the site for completion as a soil vapor well. Boring B5 was advanced to a total depth of 43 feet bsg and completed as soil vapor well (VW-1.), screened from, 18 to 43 feet bsg. (Appendix A). Four soil sample were collected during the soil boring operation and analyzed for TPH-g,BTEX and MTBE; two of the samples were analyzed for soluble MTBE by EPA Method 8260. TPH-g,BTEX, and MTBE were not detected in the analyzed soil samples; however, soluble MTBE was detected _ in two samples at 2.3 and 2.0 micrograms per Iiter(µg/1), respectively. Analytical results of the soil samples are summarized in Tables 3. Laboratory data for the soil vapor sample are included in Appendix B. 6.2. SOIL VAPOR EXTRACTION FEASIBILITY PILOT TEST On 27 March 2002, an 8-hour soil vapor extraction (SVE) feasibility test was initiated at the site to provide SVE data prior to determining ifremediation ofthe MTBE-impacted soil was necessary.The test was conducted using a VACLEEN 1000 SVE system, manufactured by Environmental Techniques. The VACLEEN unit consists of a positive-displacement blower, driven by an internal combustion (IC) engine. Hydrocarbon vapor was destroyed as part of the internal combustion process. Propane was used as a supplemental fuel source to start the engine and maintain performance. Emissions from the engine were routed through two catalytic converters to maximize the destruction rate of the extracted hydrocarbon vapors. 6.2.1. Procedures The test was initiated at 8:15 am and continued for approximately 8 hours. An induced vacuum potential was applied to the casing of vapor well VW-1;the vacuum-induced pressure reduction was only measured at vapor well VW-1, with Magnehelic vacuum gauges fitted to the extraction well. A sample port was tapped into the PVC near the wellhead and a portable organic vapor meter equipped with a photo-ionization detector(PID: Thermo 580A calibrated to isobutylene) was used to measure organic vapor(OV)concentrations.The organic vapor concentrations,the vacuum at the extraction well, extracted soil gas flow rate, and operation of the SVE unit were measured at one- hour intervals and logged on field sheets. Pilot test field data is included in Appendix D. A total of five soil vapor samples were collected from the inlet of the extraction well during the pilot test to measure hydrocarbon concentrations in the extracted soil vapor. Soil vapor samples were w collected at a one-hour interval after the start of the test and then at two-hour intervals after the initiation of the test. The samples were collected in TedIar bags using an air pump. Samples were Advanced GeoEnviron mental,Inc.