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s., specifically, where excavating had succeeded in removing the contaminated soil. PHASE II IN-SITU VAPOR RECOVERY Two areas of soil contamination remained in the pump island areas, the southern end of the excavation of the western pup island (P3) and the northern end of the eastern pump island area (P1) . These he 26 two areas were th then deithnle4"with a roundedackhoe to clean peatgravelftottheeplo ` and then backfilled w / was also backfilled foot depth. The tank field excavation (E) hen "Typar" matting with 1/4" pee gravel to the 10 foot depth,layer of AB gravel was was . pieced over the pea gravel and a 6 used to hold the "Typar" in place. The remaing excavated areas th the clean where an aerated native soil in two then backfilled wi ates foot lifts and compacted fromf ill the 25a defoot depthrto3the�40icfoot areas of contaminated so depth. On October 8 and 9, 1990, the P1, P3 and EX areas where drilled to the 40 foot an depth using 10" hollow od, see wisteamgures 38uands4D d 2" PVC extraction wells were Inst A pilot test for vapor extraction was conducted from December 10, slot 1990 to January 4, 1991, see Table 3A. After evaluatingfor P application for Au San CloasuinctCountyVaAir test results an app Y extraction was proposed and received by q ublic Quality (S3CAQ3 on April 28, 1991. SJCAQ were unable to review the application for at least 90 days so a variance waspresented comment was in by WEGE, The public hearing p991. An by Mr. hack Napper of WEGE on wicklands behalf raction prior May 9, the or ex Interim Variance was granted for sxtraotiontoommenced onoApril hearing on March 29, 1991, p Appendix A, dated July 26, 26, 1991 (see Update Status Report rated pp 1991) , Vapor extractiobutoalsoteffected the ground water(beneath depth to 40 foot depth) the site, see Vapor extraction Tables 3A, 3g199� and Ground Water Monitoring Data Table 2. As of October 3, and of gasoline range hydrocarbons have been removed from thDurdslfrom ground water at this site. Of this, approximately 626 p e vapor extraction wells P1, P3 and EX and the soil around th 11,284 pounds from the sotlthis and sitenhasashown eardramatic rdecline MW1 and MW5. Monitoring a per da to 0.3 pounds per in vapor recovery at P3 from 2-5 pounds 0.03ypaunds per day, P1 day and at EX from 2-3 pounds ger daybeen an never produced signlwell andcant rvaporoinfluenceand smonitarswell$s see ambient air injection Figure 3C. luence Figures 5A through 5D ted show the 1at�thisdsite�,umandfcomparedctoathe by the vacuum extraction systemFigure 3A, indicates that the ------ --------------------k_________---areas--of known soil contamination, g or removed the vacuuum extraction---has-successfully--lowered and/ _ _ ___--_- ______ hydrocarbon contamination that existeet between the 25 40 foot-- page 2