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TM fl <br /> Project Status Update Report <br /> Holt Brothers Tractor Co , Stockton,CA <br /> Site Code 1988(Protect No W0402 00) <br /> Page 2 <br /> Groundwater samples were collected from wells MW2, MW3, MW4, MW5, and MW6, after <br /> purging at least three casing volumes of water or until the well went dry Each well was <br /> allowed to recover at least 80% prior to collecting a groundwater sample No floating <br /> hydrocarbon product was observed in well MW1, however, a sheen was evident on water <br /> collected from the well Under the regulatory guidance of PHSIEHD no sample was collected <br /> from this well Monitoring wells MW2 through MW6 were purged and sampled according to <br /> RESNA's Quality Assurance/Quality Control Plan (on file) Well purge logs are included as <br /> Attachment 1 <br /> LABORATORY ANALYSIS <br /> The groundwater samples were transported under chain of custody protocol to Sequoia Analytical <br /> Laboratory (Redwood City, CA) for analysis of benzene, toluene, ethylbenzene, and xylenes <br /> (BTEX) utilizing EPA method 8020, total petroleum hydrocarbons as gasoline (TPHG) and as <br /> � diesel (TPHD) utilizing EPA modified method 8015, and halogenated volatile VOCs organics g (VOCs) <br /> utilizing EPA method 8010 <br /> Laboratory analysis of the sample collected from well MW2 indicates the presence of TPHD <br /> (340 ppb), the sample collected from well MW5 indicates the presence of benzene (5 9 ppb), <br /> ethylbenzene (3 6 ppb), total xylenes (6 7 ppb), TPHG (540 ppb) and TPHD (1,800 ppb), and <br /> the sample collected from well MW6 contained TPHD (180 ppb) Review of the <br /> chromatograms from the above samples indicate a non-gasoline compound and non-diesel mix <br /> patterns in the respective carbon ranges of gasoline (C4-C12) and diesel (C9-C20) <br /> VOCs were also detected in samples collected from MW5 and MW6 VOCs detected in well <br /> MW5 include 1,4-dichlorobenzene (23 ppb), 1,2-dichlorobenzene (39 ppb), 1,1-dichloroethane <br /> (1 7 ppb), cis-l,2-dichloroethene (5 4 ppb), trans-l,2-dichloroethene (12 ppb), and <br /> trichloroethene (12 ppb) VOCs detected in well MW6 include 1,1-dichloroethane (5 2 ppb) and <br /> cis-1,2-dichloroethene (0 92 ppb) <br /> No analytes were detected at or above method detection limits in the samples collected from <br /> wells MW3 and MW4 The analytical results are presented on Tables 2 and 3 The laboratory <br /> data sheets and chain-of-custody documentation are presented in Attachment 2 <br /> PSUR493 FNL <br />