Sigma investigates and mitigates off-site vapor intrusion risk
The Sigma Group was retained to investigate subsurface contamination at a former dry cleaning facility located in downtown Elkhorn, Wisconsin. Extensive site investigation activities indicated subsurface groundwater impacts were mitigating off-site and had the potential to pose a vapor intrusion risk to an adjacent residential property.
Sigma coordinated access with the adjacent property owner to complete sub-slab vapor testing, the results of which indicated the need to install a vapor intrusion mitigation system. Sigma subsequently completed diagnostic testing and installation of a sub-slab depressurization system, along with post-installation commissioning to ensure the system was effectively mitigating the identified vapor intrusion risk.
Sigma coordinated communication between the responsible party, adjacent property owner and their tenant, and the Wisconsin Department of Natural Resources throughout the investigation and mitigation scope of work to ensure successful completion in a timely manner.