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Ms Lon Duncan <br /> Page 3 of 4 <br /> • GROUNDWATER ANALYTICAL RESULTS <br /> Groundwater samples were analyzed for TPHd and TPHg using EPA Method 8015M, BTEX using EPA <br /> Method 8020, and VOCs using EPA method 8260B No samples were collected from well MW3 due to <br /> the presence of free product <br /> No TPHd, TPHg, BTEX, or oxygenated gasoline additives were present above method detection <br /> limits in any groundwater samples collected at the site <br /> Tetrachloroethene (PCE) was detected in wells MW 1, MW2, and MW4 at concentrations of 20 parts <br /> per billion (ppb), 15 ppb, and 13 ppb, respectively Chloroform was detected in wells MW1, MW2, <br /> and MW4 at 2 6 ppb, 3 2 ppb, and 3.2 ppb, respectively Trichloroethene (TCE) and cis-1,2- <br /> dichlorethene (cis-1,2-DCE) were detected in well MWl at 2 4 ppb and 2 8 ppb, respectively No <br /> cis-1,2-DCE or TCE were detected in wells MW2 or MW4 <br /> Groundwater analytical results are summarized on Table 3 Attachment D contains laboratory reports and <br /> chain of custody documentation <br /> SUNE%4ARY <br /> Groundwater levels and the direction of groundwater flow beneath the site were generally consistent <br /> . with historical measurements An average of 0 50 feet of free product was measured in well MW3 <br /> during the reporting period <br /> Concentrations of chloroform, TCE and cis-1,2 DCE detected at the site remain below their respective <br /> primary Maximum Contaminant Levels (MCLS) of 80 ppb, 5 ppb and 6 ppb, as established by the <br /> State of California Department of Health Services However, PCE was present at levels exceeding its <br /> primary MCL of 5 0 ppb in all site wells <br /> CONCLUSIONS <br /> Petroleum hydrocarbon contamination is apparent in groundwater within close proximity to the former <br /> UST, however, neither free product nor the dissolved petroleum hydrocarbon plume extends to perimeter <br /> wells located approximately 20 feet southwest, 3 5 feet north, and 40 feet northeast of the former UST <br /> Concentrations of PCE in groundwater samples collected from site wells have generally been <br /> decreasing since the wells were first sampled in December 2000, with wells NMI, MW2, and MW4 <br /> exhibiting decreases of up to 44%, 39%, and 38%, respectively from their historic highs <br /> The next monitoring ansamplingdevent is scheduled for March 2003 EHD will be notified at Ieast 48 <br /> hours prior to conducting any fieldwork <br /> G 1GROUNDZE\GA13BARDlrcports14QM2002 doc <br />