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, . i <br /> Groundwater samples were collected from the on-site wells by EMC personnel Prior to sample <br /> collection, at least three well volumes of groundwater were removed from each well by a <br /> portable submersible pump or bailer During the purging of groundwater, pH, conductivity, <br /> temperature and turbidity were monitored at selected intervals This data is included in <br /> Appendix A along with the gauging data for the reporting period All equipment was cleaned <br /> using a solution of Alconox and water followed by two tap water rinses The actual <br /> groundwater samples were collected with a teflon bailer equipped with a bottom emptying device <br /> before being transferred into the laboratory supplied 40 ml VOA vials pending analyses The <br /> chain-of-custody documentation is presented in Appendix B <br /> ANALYTICAL DATA <br /> Each groundwater sample was transported on ice in a light-proof chest to Orange Coast <br /> Analytical, Inc The samples were analyzed for total hydrocarbons (TPHg) and volatile aromatic <br /> compounds (BTEX) by EPA methods 8015 and 8020, respectively Table 1 presents a summary <br /> of the TPHg and BTEX data The complete laboratory reports for the current samples are <br /> included in Appendix B <br /> The results indicate the presence of a slight free product sheen in two of the six wells on-site <br /> Wells MW2 and MW3, which have consistently had high concentrations of dissolved <br /> hydrocarbon, showed evidence of free product Well MW8 contained 27,000 ug/l TPH, and <br /> MW7 had 410 ug/l TPH Wells MW 1 and MW4 had less than detectable levels of dissolved <br /> . hydrocarbon A benzene iso-con map is presented on Figure 2 <br /> CLOSING <br /> Based on the site investigation and monitoring program, it appears that the shallow water zone <br /> found beneath the site exhibits the presence of dissolved hydrocarbons The monitoring events <br /> accomplished to date suggest the flow direction of groundwater across the site is generally to the <br /> east-southeast Thrifty will continue to monitor the on-site wells on a quarterly basis If you <br /> have any questions, please contact Raymond C Friednchsen at (310) 923-9876 ext 376 <br /> Very truly yours, <br /> Peter D'Amico - <br /> Manager Environmental Affairs <br /> cc CVRWQCB, Elizabeth Thayer <br />