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C A M B R I A <br /> The SCM and the supporting documents are presented in Appendix D A summary of the SCM <br /> is presented below <br /> Some key findings of the SCM are listed below <br /> • The constituents of concern (COCl)for this site are TPHg and benzene <br /> • Only manor amounts of MTBE have been detected in the groundwater beneath the site <br /> • The lateral extent of gasoline constituents an soil beneath the site has been delineated in the <br /> shallow zone <br /> • No receptors are present within 2,000 feet of the subject site <br /> • Historical groundwater analytical data indicate the TPHg, benzene, and MTBE plumes are <br /> stable and decreasing an concentration <br /> • Natural biodegradation is occurring beneath the site <br /> CONCLUSIONS <br /> Two soil borings were sampled along the southern edge of the site to provide lateral and vertical <br /> delineation of soil and groundwater to the depth of 150 fbg The investigation findings show that <br /> gasoline constituents are present in the vicinity of CPT-8 at low levels in some of the depths <br /> sampled Soil data collected from CPT-9 indicate only low level benzene is present at two of the <br /> five depth intervals sampled The groundwater data collected from CPT-9 showed higher levels <br /> of TPHg and benzene at 85 fbg than the soil data suggests is present The groundwater samples <br /> collected below the 85 fbg sample all contain similar concentrations of TPHg and benzene <br /> These similar concentrations suggest that impacted shallow groundwater may have been <br /> introduced to the deeper zones during drilling or sampling activities, as it as unlikely that TPHg <br /> and benzene are distributed at these similar concentrations from 108 to 146 fbg <br /> TPHg, benzene, and MTBE an the soil have been delineated vertically at bonngs CPT-8 and <br /> CPT-9 Hydrocarbons detected an the groundwater samples below 85 fbg may be caused by <br /> shallow groundwater being dragged down into the deeper zones during drilling operations <br /> The low levels of TBA, DIPE, and 1,2-DCA detected in groundwater during this investigation <br /> are consistent with historical site data which suggests these compounds are not the pnmary <br /> constituents of concern for this site due to their low concentrations In the case of 1,2-DCA, it <br /> appears this compound may originate from an offsite source as the highest levels are found in <br /> MW-14 <br /> 1399 6 <br />