Hurst, P.
2019 SMART Remediation, 7 February, Ottawa, Canada. 16 slides, 2019

A plastics manufacturing plant with documented indoor air concentrations of TCE above the state's response levels required a multi-pronged approach to mitigate both indoor air and sub-slab sources of TCE. Following data review to understand TCE sources and building conditions, an assessment of contamination sources and transport pathways was completed through a combination of multiple rounds of grid-based indoor air and sub-slab vapor testing of TCE and other chlorinated solvents, the use of an on-site portable lab that provided low-level air concentration data at a high resolution, video surveys of utilities, continuous differential pressure monitoring to assess gradients that could affect contaminant mobility, and flux chamber testing to assess potential indoor air TCE sources. Air conveyance testing was conducted to support design of a sub-slab depressurization system. Interim mitigation included the provision of climate-controlled fresh air to increase the effective air exchanges rates and reduce TCE concentrations. Understanding how indoor air TCE concentrations responded to increased air exchanges informed needed modifications to the building HVAC system as part of the overall VI mitigation program. https://2ziapbmm3zh1x23mj335vjxt-wpengine.netdna-ssl.com/wp-content/uploads/2018/02/SMART-Remediation-Ottawa-2019-Paul-Hurst.pdf