Parker, J. and J. Crum. | Great Lakes Environmental Remediation & Redevelopment Conference, 16-18 October, Lansing, MI, 33 slides, 2019

Historical commercial activities at an orphaned site in Michigan resulted in 10 acres of PVOC and CVOC releases in the heart of a historic city and adjacent to a variety of active land uses, including an antique district and a residential neighborhood. An extensive intrusive off-site investigation utilizing direct push technology borings, groundwater monitoring wells, soil vapor monitoring, and indoor air sampling was completed in two phases over ~6 months. In 12 months, the project team investigated a three-block area to develop property-specific volatilization to indoor air pathway (VIAP) conceptual site models and successfully mitigated homes at five properties where sample results demonstrated that TCE posed an unacceptable risk to occupants. Immediate interim actions included installation of indoor air purifying units (APUs) and expeditious design and installation of sub-slab depressurization systems at four of the five buildings. A fifth commercial building is currently managed via operation of multiple APUs. The VIAP was also investigated at seven other properties, and one year of quarterly monitoring indicates that the VIAP is not complete. Source remediation began after the initial VIAP sampling events. After only 6 months of operation, in situ TCE groundwater treatment systems have produced notable reductions in the TCE-contaminated groundwater and vapor plumes. https://www.michigan.gov/documents/egle/egle-tou-GLERRCpresentation-VIAP-Parker-HampMathews_670763_7.pdf For more information on VIAP, see workshop presentations at https://www.michigan.gov/egle/0,9429,7-135-3308_3333-459064--,00.html.