ECT continues to work closely with Wisconsin Department of Natural Resources officials to assess and eliminate exposure pathways existing beneath a repurposed 440,000-square-foot manufacturing building in Wisconsin. The client’s goal is to reduce the concentrations of a chlorinated solvent (trichloroethylene [TCE]) in the indoor air to acceptable levels on an accelerated schedule. During 2020 a closure requested was submitted based upon the reduction in vapor levels.
As part of the remedy during 2017, ECT designed and oversaw the performance of in-situ chemical treatments (groundwater media), which ultimately demonstrated a ninety percent reduction of source area contaminants. ECT also designed and implemented a soil vapor extraction system (SVE) for concrete slab depressurization. The system supports two extraction zones and dual carbon treatment cells, and during the first 12 months of operation extracted and treated approximately 61,812,000 ft³ of subsurface air.
An air exchange system was installed in the basement of the facility, which supports an air space of approximately 1,280,000 ft³. The system operates at approximately 300 ft³/minute (completely exchanging the air in the basement every 72 hours).