Laserfiche WebLink
I <br /> , <br /> 3.3 Tier 2 Vapor Intrusion Risk Assessment <br /> To further evaluate.the inhalation of indoor air exposure pathway associated with gasoline <br /> hydrocarbons remaining in site soil and groundwater, and to further evaluate the suitability of the <br /> site for case closure, Ramage Environmental will complete a Tier 2 Vapor]ntrusion Risk <br /> Assessment. ' <br /> To evaluate risks associated with constituents detected in soil vapor, Ramage.Environ mental will <br />( use the RISC4—Risk Integrated Software for Clean-ups (RISCO) software program developed by <br /> 4 RR <br /> { BP Oil International. The dataset to be used in the assessment will consist of vapor sample <br /> analytical results from the proposed soil vapor samples, and the maximum detected <br /> concentrations of gasoline compounds in soil and groundwater. Ramage Environmental will <br /> consider benzene, toluene, ethylbenzene, xylenes, and TPH-as�gasolne. Since the RISC4 <br /> chemical database does not include TPH-as-gasoline, the maximum detected TPH-as-gasoline <br /> concentration will be comprised equally of aliphatic petroleum hydrocarbons in the C5 through C6, <br /> iC6 through C8, and C8 through C10 carbon ranges. <br /> 3.4 Waste Management <br /> An waste soil and water generated during drilling and samplingactivities will be contained in <br /> Y 9 9 9 P g <br /> separate 55-gallon drums for temporary on-site storage, pending waste profiling and proper <br /> disposition. The disposition of the waste will be based on the analytical results of soil and <br /> groundwater samples analyzed during the investigation. <br /> i <br /> 3.5 Project Reporting <br /> j <br /> The results of the proposed work will be documented in an environmental site investigation report. <br /> k� The report will be prepared according-to the Tri-Regional Board'Staff Recommendations for <br /> Preliminary Investigation and Evaluation of Underground Tank Sites, Appendix A, reviewed and <br /> stamped by a state of California Professional Geologist or Engineer, and submitted to EHD and <br /> RWQCB. <br /> i <br /> 11 <br /> !� <br />