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HLrmdn& Hrlen s Marina- First Quarter 1999 Groundwater Monitoring April IS 1999 i Page R- TABLE 5 ' Laboratory Analytical Results of Surface Water Samples Sample I D Analytes ' BTEX TPH-G Gasoline Oxygenates/Additives DDN ND ND 980 (MTBE) 9 8 (TAME) DDS 8 3 (toluene) ND* 3,500 (MTBE) A 28 (TAME) IDC E ND ND ND ' IDC W ND ND 2 2 (MTBE) All concentrations arc.to µg/1 trccpt IPI 1-6 which is in mg/l BTEX=benzene toluene ethyl benzene and xylene ' TPH-G=total petroleum hydrocarbons quantified as gasoline. T)=not detected at or above laboratory rtported detection limit ND* -not detected at or above a raised laboratory reported detection hTnit see laboratory report for dcte,ction limit .T. - all other BTEX constituents were not detected at or above raised laboratory reported detection limits ' Gasoline Oxygenates/Additives=methyl tertiary butyl ether(MTBE) ethanol tt ruary-butanol di-isopropyl ether(DIPF) ethyl tertiary-butyl ether(FTBE) and tertiary amyl methyl ether(TAME) ' 5. SUMMARY/CONCLUSIONS On March 26, 1999, Condor conducted quarterly groundwater and surface water monitoring at Ferman & Helen's Marina located at Venice Island Ferry in Stockton, California Laboratory analytical results of the groundwater samples collected during the first quarter, 1999, monitoring event were generally consistent with historical quarterly groundwater analytical data ' Groundwater elevation measurements collected at the site on March 26, 1999, indicated that the average depth to groundwater was approximately 5 5 feet below the monitor well and surface water station measuring points This average depth to water is 0 1 feet greater than measured on December 30, 1998 Groundwater elevation contours for March 26, 1999, indicated that the groundwater gradient at the site is generally consistent with the ' historical groundwater gradient Laboratory analytical results of the surface water samples collected during the first quarter, 1999, monitoring ' event were generally consistent with historical surface water analytical data for BTEX and TPH-G MTBE, however, was detected for the first time in the sample collected from IDCW (2 2 gg/1) MTBE was detected in samples DDN and DDS at significantly higher concentrations during the current monitoring event(980 and 3,500 ' ltg/l, respectively) than in historical monitoring events As previously mentioned in Section 2 , Mr Ronald Rowe of the PHS/EHD has requested that nine soil borings be ' installed to further evaluate the eastern extent of groundwater contamination at the site The installation and sampling of the soil borings is pending receipt of site access authorization from off-site property owners 1 • CONDOR