A former industrial manufacturing facility in Greenville, SC was purchased for redevelopment in 2017. Building improvements were planned to include a warehouse, offices and self-storage units to serve a growing commercial area. Now located within an urban commercial land use area of Greenville, redevelopment plans included converting the industrial warehouse building into climate controlled self-storage units, and renovating the office into an apartment unit and office.
Prior to purchasing the site in 2017, the current site owners entered into a Voluntary Cleanup Contract and Brownfields agreement with the South Carolina Department of Health and Environmental Control (SCDHEC). The Brownfields agreement allowed
the site owners to purchase the site while receiving SCDHEC liability protection for existing environmental contamination by agreeing to perform certain environmental assessment, mitigation, or remediation activities.
To prepare for renovations to the existing structures, the site owners enlisted the expertise of Bunnell Lammons Engineering (BLE) to conduct various soil, groundwater, and vapor intrusion assessments while the site was vacant. Vapor intrusion assessments included collecting sub-slab soil gas samples and indoor air samples. Sub-slab soil gas samples detected various volatile organic compounds (VOCs) above the laboratory method detection limit. BLE utilized the Environmental Protection Agency (EPA) Vapor Intrusion Screening Level (VISL) calculator to model potential indoor air concentrations of VOCs base on the sub-slab soil gas results. Based on these calculations, two VOCs, chloroform and TCE, had estimated indoor air concentrations above their respective EPA Industrial/Commercial Risk Based Screening Level (RSL). The indoor air samples had detections of TCE above the EPA Residential RSL.
With the site’s prior history of industrial operations and the known vapor intrusion risks, the site owners and the SCDHEC determined a vapor mitigation system in the apartment and office space was necessary to help prevent potential exposure to VOCs, namely TCE and chloroform. BLE recommended the installation of Retro‑Coat®, a vapor intrusion mitigation coating system, in conjunction with a passive sub-slab depressurization system (SSDS) comprised of Vapor‑Vent to protect the structure from vapor intrusion. BLE’s recommendation was ultimately approved by the SCDHEC and accepted by the site owners.
