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Site Background Information: Former Ocampo Property Page 6 of 6 SOIL VAPOR EXTRACTION (SVE) PILOT TEST On 29 July 2008, a 12-hour SVE pilot test was conducted at the site using vaporwell VW-1 (screened 10 feet to 35 feet) as the extraction well. TPH-g was reported in the Influent soil- vapor samples at concentrations ranging from 40,000 pg/I to 84,000 pg/I; benzene, toluene, ethylbenzene and total xylenes were reported in the soil-vapor samples at concentrations as high as 310 pg/I benzene, 4,200 pg/I toluene, 510 pg/I ethylbenzene and 2,840 pg/I total xylenes; TAME was reported at a maximum concentrations of 280 pg/I. Utilizing data gathered from the SVE pilot test, at a vacuum potential of 0.10 inches of water, the radius of influence is approximately 40 feet; at an induced vacuum potential of 1 .0 inches of water, the radius of influence is approximately 27 feet; at 10.0 inches of water, the radius of influence is approximately 9 feet. During the operational period, the combined mass of SVE hydrocarbons extracted by SVE operations was calculated to be approximately 153 lbs of gasoline, or equivalent to a volume of approximately 24.5 gallons of gasoline. Based on overall high hydrocarbon concentrations in soil-vapor samples and the calculated effective radius of influence (approximately 40 feet), AGE concluded, SVE could be used as a feasible remediation method at the site as SVE should effectively reduce adsorbed hydrocarbon concentrations in vadose zone soils through the use of a vacuum that creates a negative pressure gradient to cause movement of vapors toward the extraction wells. SOIL VAPOR EXTRACTION REMEDIATION Between 28 December 2010 and 28 March 2011, an SVE remediation system was operated at the site. On 04 February 2011 the natural gas-fired, thermal oxidizer SVE system was removed from the site and replaced with a granular activated carbon (GAC) adsorption vessels SVE system to continuously apply an induced vacuum to well VW-1. SVE procedures for the site were described in AGE-prepared Interim Remedial Action Work Plan(dated 14 September 2009)and Interim Remedial Action Work Plan Addendum (dated 10 February 2010), and approved by the San Joaquin County Environmental Health Department (SJCEHD) by letter dated 08 October 2009. Based on SVE vapor remediation data collected between 05 August and 06 June 2011, AGE concludes the SVE system appears to be effective at extracting hydrocarbons from the subsurface. A total of 1,306 gallons or 8,165 pounds of hydrocarbons as gasoline have been extracted since startup of the soil vapor extraction system. Advanced GeoEnvironmental,Inc.