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+� Ms Lori Duncan <br /> Page 3 of 3 <br /> reporting period The measurable product thickness has been steadily declining since Ground Zero initiated <br /> a program of regular product bailing from the well No petroleum hydrocarbon constituents have been <br /> detected in any of the other site wells (MWI, MW2, MW4) PCE and chloroform were detected in well <br /> MWI, MW2, and MW4, however The concentrations of PCE in groundwater samples collected in <br /> December 2001 ranged from 21 to 23 ppb, which exceeds the MCL of 5 0 ppb <br /> CONCLUSIONS <br /> Petroleum hydrocarbon contamination is apparent in groundwater within close proximity to the former UST <br /> Neither free product nor the dissolved petroleum hydrocarbon plume extend to perimeter wells, however <br /> The perimeter wells are located approximately 20 feet southwest, 35 feet north, and 40 feet northeast of the <br /> former UST PCE concentrations in groundwater remain above the MCL in site wells <br /> RECOMMENDATIONS <br /> Based upon the groundwater data collected to date, Ground Zero recommends continuing periodic free <br /> product removal from well MW3, and periodic monitoring and sampling of wells MWI, MW2 and <br /> MW4 Ground Zero also recommends discontinuing analysis of total lead, TRPH, TPHgBTEX, and <br /> TPHd in site perimeter wells based upon historical non-detect results Groundwater samples collected <br /> from site wells will continue to be sampled for VOCs using EPA method 8260 If free product is not <br /> present in well MW3, groundwater samples will be collected and analyzed for TPHg, TPHd, TRPH, <br /> BTEX,oxygenated gasoline additives,VOCs, and lead <br /> Please feel free to contact John Lane of Ground Zero at(209) 83 8-98 88 if you have any questions regarding <br /> this submittal <br /> Respectfully, <br /> Ground Zero Analysis,Inc <br /> Sean Garvey, G <br /> Staff Geologist �Olp <br /> JOHN P <br /> LA <br /> No 6795 <br /> John P Lane NN tiQ <br /> CA Registered Geologist No 6795 <br /> D� CA <br /> Attachments <br /> cc Mr Gary Gabbard <br /> Mr Patrick Riddle, Attorney at Law <br /> Mr Marty Hartzell, RWQCB-Central Valley Region <br /> \1GZA_FSISYS011Data1GROUNDZEIGABBARDIreports14QM2001 da, <br />