Reductive Remediation Achieves Closure of Brownfields Site
A former manufacturing facility was entered into the state’s brownfield program. With additional financial backing from the Clean Ohio Revitalization Fund (CORF), a redevelopment company purchased the property and sought environmental cleanup and regulatory approvals to realize a revitalized commercial property. The 20.8-acre site includes building structures to be improved and reoccupied. However, chlorinated impacts in the area of former storage tanks near the building remained above permissible risk-based action levels. Environmental consulting and remediation support was needed.
GES was contracted to design a remedial action plan to clean up the site and monitor concentrations to ensure that they remained within permissible levels. This plan hinged on in-situ chemical reduction to create a reductive subsurface condition and allow the naturally-occurring microbes to break down the chemicals of concern. A limited excavation was completed to remove approximately 800 tons of soil from the site. Chemical injection was completed using direct-push technology to inject fluids through drilling rods and via permanent injection wells. Four injection events were completed over several months; the initial two-week event was followed by three events, each lasting three to four days. Pre- and post-injection sampling was completed to monitor concentration levels and tailor the remedial plan accordingly. Results showed a reduction in TCE by more than 98%. The byproduct, vinyl chloride, was addressed via bioremediation. The installation of a sub-slab depressurization system beneath the plant further protected future building occupants from any potential vapor intrusion issues.
GES’ cost-to-objective contractual mechanism gave the property owner the assurance that GES could and would protect their investment and support their business goals. The aggressive in-situ reductive injection approach eliminated the need to install and operate a long-term remediation system on site. The site has achieved regulatory closure and “no further action” status, allowing redevelopment to move forward.