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C A M B R I A MW-7 for future remediation Two additional groundwater monitoring wells (MW-8 and MW-9) were installed in March 1990 Groundwater pumping and vapor extraction tests were conducted during March 1990 to obtain hydrogeologic data, hydrocarbon concentration levels, and flow parameters for remedial system design A free product skimming system was installed to collect free product from well MW-2 in April 1990 The skimmer was later moved to well MW-7 Approximately 180 gallons of free product were skimmed from the wells Off-site groundwater monitoring well MW-10 was installed in July 1991 A soil vapor extraction (SVE) system was installed and operated full time from September 1992 to September 1993 The system removed an estimated 14,980 pounds of hydrocarbons from the subsurface during the first year of operation The system operated intermittently through November 1996 During March 2000, four cone penetration test (CPT) borings were advanced onsite (CPT-1 through CPT-4) Cambria collected depth-discrete groundwater samples from each of these borings Total petroleum hydrocarbons as gasoline (TPHg) and benzene were detected in groundwater from all of the borings at concentrations ranging from 688 to 439,000 parts per billion (ppb) and from 152 to 13,200 ppb, respectively The highest concentrations were from the sample collected at 47 feet below grade (fbg) from boring CPT-4, located adjacent to the existing USTs The complete results of this investigation may be found in Cambria's July 20, 2000 Site Investigation Report Based on results from this investigation, Cambria recommended advancing additional CPT borings and SJCPHS/EHD requested the submittal of a work plan Cambria submitted a work plan on November 5, 2001 and the results are presented below INVESTIGATION RESULTS Personnel Present Cambria geologist Geno Mammini directed the field activities, working under the supervision of California Registered Geologist Joe Neely 0778 2