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Soil Assessment Report <br /> 324 East 11th Street <br /> Tracy, California <br /> October 12,2017 <br /> • The additional site assessment did not encounter a former waste oil tank or a significant second <br /> source area. The lack of any significant potential waste oil tank constituents (e.g., VOCs, <br /> SVOCs, PCBs, etc) suggest that potential impact from a waste oil tank (if formerly present) is <br /> limited. The detected arsenic concentrations likely represent background conditions or are <br /> associated with pesticides/herbicides from former agricultural use at the site. <br /> • Current and prior field observations and analytical results suggest that petroleum hydrocarbon <br /> impact is primarily located in shallow soil near borings B-1 and B-7. The hydrocarbon impact to <br /> groundwater is primarily located at boring location B-1, with some additional impact in nearby <br /> boring B-7,and lower impact in crossgradient borings B-4 and B-6. <br /> • Petroleum hydrocarbons in select soil and groundwater samples exceed conservative <br /> environmental screening levels (ESLs), but are below LTCP criteria. The extent of hydrocarbon <br /> impact appears to be adequately delineated by this investigation and downgradient data from the <br /> adjacent and closed case at Tracy High School. <br /> • Pangea understands the SJCEHD and Regional Water Quality Control Board will review this <br /> information to determine if case closure is merited pursuant to the LTCP. The site appears to <br /> meet all the general and media-specific criteria of LTCP except for the proximity of water wells <br /> (< 1,000 ft). However, based on the shallow and limited extent of site impact and the distance to <br /> the identified water wells Pangea recommends case closure. Pangea concludes that the plume <br /> poses a low threat to human health and safety and the environment and water quality objectives <br /> will be achieved within a reasonable time frame. <br /> ATTACHMENTS <br /> Figure 1 —Soil Boring Location Map <br /> Figure 2—Geotracker GAMA Well Survey Map <br /> Table 1 —Soil Analytical Data <br /> Table 2—Groundwater Analytical Data <br /> Table 3—Geotracker GAMA 1,000 ft Radius Well Survey <br /> Appendix A—Regulatory Correspondence <br /> Appendix B—Permit <br /> Appendix C—Standard Operating Procedures <br /> Appendix D—Boring Logs <br /> Appendix E—Laboratory Analytical Reports <br /> 8 <br />