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' 26 March 2015 • • AGE Project No. 14-3289 Page 2 of 4 ' 2.0. SOIL VAPOR SAMPLING On 12 March 2015, AGE advanced four soil vapor borings (SV1 through SV4) at the ' subject property. Borings were advanced under SJCEHD Permit SR#: 71683 (Appendix A). Soil borings were advanced in the northwestern and southwestern corners of the subject property, along the western property boundary, and within the community center ' building. Approximate locations of each of the borings are illustrated in Figure 2. Soil vapor borings were advanced to a total depth of 5 to 10 feet below surface grade ' (bsg). Borings were advanced using a hand held hammer (rotohammer), equipped with a small diameter steel prove sampler and retractable screened vapor point. ' An expandable vapor tip was placed at the bottom of an assembly of 0.5-inch diameter hollow rods. Single use, '/4 -inch diameter disposable tubing was then attached to a tubing adapter on the expandable vapor tip. The assembly was advanced to the ' specified depth (i.e. 5, then 10 feet bsg) and retracted approximately six inches in order to disengage the bottom expendable point and expose a column of strata from which soil-vapor could be extracted. The borings were filled with filter pack material consisting ' of#2/12 sand and hydrated bentonite. Above ground, the surface around the soil-vapor sampler was sealed with bentonite tpowder and hydrated to prevent ambient air intrusion. Once the bentonite was hydrated, the end of the tubing above ground was purged using a vacuum pump for approximately two minutes. Once purging was complete, a 1-liter tedlar bag was filled using the 1 vacuum pump with vapor from the formation. To ensure that a reliable soil-vapor sample was collected with no ambient air breakthrough down the probe rod, AGE erected a plastic enclosure over the probe rod, and applied an appropriate amount (approximately ' 6 to 8 ounces) of Isopropyl Alcohol (IPA) as a tracer to a towel. The wetted towel was completely wrapped around the base of the probe rod where it contacted the surface and the bentonite seal. ' Vapor samples were labeled with sample ID, project name, date, time, and sampler's initials. The sample was logged on a chain-of-custody form, and placed into a dry ' shipping container (room temperature). Subsequently, all the collected soil-vapor samples were delivered to Cal Tech Environmental Laboratories, a State of California ' Department of Public Health (CDPH)-certified analytical laboratory, for analysis. All samples were analyzed for volatile organic compounds (VOCs) in accordance with EPA method 8260B. Samples SV1-5 and SV3-5 were also analyzed for total petroleum ' hydrocarbons quantified as gasoline (TPH-g) in accordance with EPA method 8015M. Prior to sample collection, vapor sampling equipment was thoroughly rinsed with clean ' water after being washed with a solution of Alconox. Probe rods were thoroughly cleaned prior to soil probe boring advancement. ' Advanced GeoEnvironmental,Inc.