The VI Diagnosis Toolkit for Assessing Vapor Intrusion Pathways and Mitigating Impacts in Neighborhoods Overlying Dissolved Chlorinated Solvent Plumes

The VI Diagnosis Toolkit for Assessing Vapor Intrusion Pathways and Mitigating Impacts in Neighborhoods Overlying Dissolved Chlorinated Solvent Plumes The VI Diagnosis Tookit for Assessing Vapor Intrusion Pathways and Mitigating Impacts in Neighborhoods Overlying Dissolved Chlorinated Solvent Plumes 1.0 Objective: The objective of this project is to demonstrate and validate a suite of tools that can improve our ability to more accurately, cost-effectively, and confidently assess vapor intrusion (VI) impacts and, if necessary, select appropriate remedies in neighborhoods overlying dilute chlorinated solvent plumes. This suite of tools is referred to here as the VI Diagnosis Toolkit. This project differs from previous efforts in that it recognizes that there can be multiple VI pathways, including: a) the traditional soil VI conceptualization (source->through soil->through foundation to indoor air), b) pipe flow VI from sources like land drains to sub-foundation regions, and c) sewer VI where vapors originate from sewers and travel to indoor air through sewer piping. It also recognizes that VI impacts might extend beyond dissolved plume boundaries due to impacted water distribution by sewers and other subsurface infrastructure, and that the VI pathways discussed above may be present but not discernible by traditional site characterization. This project will demonstrate and validate that use of the VI Diagnosis Toolkit is practicable and leads to correct outcomes under scenarios relevant to DoD. The outcomes using the VI Diagnosis Toolkit will be compared to outcomes from the conventional multiple lines of evidence (MLE) paradigm and will assess if conventional mitigation systems are less effective or possibly even amplifiers of VI impacts when alternate VI pathways are present.