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Confirmation Soil Vapor Survey Workplan Moore Petroleum Bulk Plant,5491 F Street,Banta,California Page 2 1995, at which time it was temporarily removed from the site. On November 27, 1995,the system was returned to the subject site and restarted. May 31, 1995 —An air sparge system was installed and started. The air sparge system was used in conjunction with the SVE system. The air sparge system operated intermittently through August 30, 1995, at which time its operation began to coincide with the operation of the R.S.I. system. The air sparge system consisted of a 1 horsepower(hp) electric motor which powers a 10 cubic feet per minute oil-less compressor. The compressor injected air through an air sparge point located midway between VEW-1 and MW-1. April 29, 1997—Apex received permission from the SJCEHD to shut down the air sparge system and SVE system due to low influent soil vapor concentrations. As of April 29, 1997,the remediation system had extracted a total of 1,730 pounds of total petroleum hydrocarbons as gasoline (TPHg) and 19.9 pounds of benzene. September 10, 1997—Apex submitted an Over Excavation & Groundwater Removal Workplan proposing overexcavation, dewatering, and sampling of the bulk loading rack and tank basins during the removal of nine underground storage tanks (USTs). August 17 and September 8, 1998—Apex supervised the removal of two 350-gallon USTs(tanks T-8 and T-9). Tank T-8 held kerosene and tank T-9 cleaning solvent. Also, seven 10,000-gallon USTs were removed on September 8, 1998. Following the removal of tank T-9, soil was overexcavated and an exploratory trench was dug. Apex collected two soil samples and one groundwater sample from the overexcavation and exploratory trench. One soil sample was collected from beneath tank T-8. After the removal of the seven 10,000-gallon USTs, Apex collected four soil samples and one groundwater sample from the tank pit. Apex then collected six soil samples and two water samples from beneath the tank basin. Nine soil samples from the area beneath the former bulk loading rack were submitted for analysis. The results of all soil and water sampling were documented in Apex's Tank Closure Results and Recommendations Report, dated December 23, 1998. April 8 and 9, 1999—Apex personnel supervised the advancement of eight soil borings at the subject property. The results of all soil and water sampling were documented in Apex's Results Report for Subsurface Investigation and Second Quarter 1999 Groundwater Monitoring, dated June 1, 1999. August 6, 1999—Apex submitted a Workplan for Limited Subsurface Investigation proposing the installation of four additional groundwater monitoring wells (MW-4A, MW-7, MW-8,and MW-9). During installation,well MW-8 was installed with the screen and filter pack extending into the unsaturated zone for possible future use as a vapor extraction well. In addition, underground piping was installed from well MW-8 (VEW-3)to the former remediation compound. April 27, 2000—Apex submitted a Workplan for Limited Subsurface Investigation proposing the installation of three additional groundwater monitoring wells and one deep soil boring.