Vapor Intrusion Investigation at Dry Cleaner Facility

Weston was contracted by the State of Michigan Environment, Great Lakes and Energy (EGLE) to complete a vapor intrusion (VI) investigation at an existing dry cleaner facility in a mixed residential-commercial area in downtown Howell, MI. The dry cleaners conducted a preliminary investigation (soil, groundwater, and vapor sampling) that indicated all three media were contaminated with dry cleaning solvents (PCE and TCE), which was reported to the state. Weston was contracted to conduct an emergency evaluation and mitigation of VI exposure risks. The VI instigation was completed by installing vapor monitoring points inside the buildings to collect vapor (soil gas) samples from beneath the concrete, following the State of Michigan vapor sampling guidance. Weston determined that the presence of dry-cleaning solvents and associated vapors present in the soils beneath the building posed unacceptable exposure risks. Due to the serious health risks associated with the VI, several businesses were shut down and buildings were evacuated while Weston installed mitigations systems in the affected properties. As a result of the expedited and highly efficient mitigation implementation, including extended day and weekend work, business owners were allowed to return to their buildings within 1 month of the evacuation order, fully protected from exposure to contamination.