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Date: July 29,2003 Quarter: 2nd Quarter,2003 • • The elevated reporting limits in the Method 8260B analysis of sample VW-5D were due to the presence of elevated levels of total petroleum hydrocarbons as gasoline(TPHg). • The elevated reporting limits reported in the Method 8260B analysis of samples MW-1 and MW-1 UNP were due to the presence of high concentrations of non-target analytes in this sample. • Two sample aliquots received by the laboratory were labeled MW-6(collected 613/03 at 0859). These aliquots were not analyzed since they did not match the data on the chain-of-custody records. Air samples collected on 4/15/03: Based on the review of the analytical and hardcopy data(chain-of-custody records, blanks, dilutions, holding times, LCS/LCSD results,MS/MSD results,and surrogate recoveries),the data are acceptable as reported by the laboratory with the following limitations: • The reported results for Xylenes in samples INF Total Air and INF Cat Air should be considered estimated because the associated continuing calibration standard was outside of acceptance criteria. Air samples collected on 5/28/03: Based on the review of the analytical and hardcopy data(chain-of-custody records, blanks, dilutions, holding times, LCS/LCSD results, MS/MSD results, and surrogate recoveries), the data are acceptable as reported by the laboratory. Air samples collected on 6/24/03: Based on the review of the analytical and hardcopy data(chain-of-custody records, blanks, dilutions, holding times, LCS/LCSD results,MS/MSD results, and surrogate recoveries),the data are acceptable as reported by the laboratory with the following limitations: • The toluene result in sample INF Total Air are estimated due to the primary and confirmation results varying by greater than 40% relative percent difference. DISCUSSION: Additional groundwater samples were collected (unpreserved and preserved) from site wells MW-1 through MW-6 to further investigate the source of ethanol hits reported in site wells MW-1 and MW-6 during the previous sampling event. Ethanol was not reported above method detection limits in any of the groundwater samples collected from site wells this quarter. The analytical results are presented in Table 3. Total petroleum hydrocarbons as gasoline (TPHg), benzene, toluene, ethylbenzene, total xylenes (BTEX), methyl tert-butyl ether (MtBE), tertiary-butyl alcohol (TBA), and 1,2-dichloroethane (1,2-DCA) were reported in groundwater samples collected from site wells this quarter. Analyte concentrations were generally consistent with historical data with the following exceptions; MtBE concentrations in MW-1 and TPHg concentrations in VW-5D continue a decreasing trend. Groundwater elevations generally increased during this quarter. The approximate groundwater flow direction was to the southeast with a gradient of 0.02 ft/ft. Groundwater flow direction is consistent with the previous reporting period. Three site visits were conducted to optimize and maintain the SVE/AS system. Approximately 22.5 lbs of TPHg were removed during the second quarter 2003, with a cumulative mass of 1,740 lbs since startup (09128/00). The SVE system was in compliance with the San Joaquin Valley Unified Air Pollution Control.District permit to operate. KAWprocesmVS BP ARC0100548%QuaneY1yl2 QTR 031548 CWMR 2Q03.&)c Page 2