The Wisconsin Department of Natural Resources (DNR) Remediation and Redevelopment (RR) Program is sending a reminder letter regarding vapor intrusion to parties responsible for cleanup at open remediation sites in Wisconsin. A copy of the letter will also be sent to the responsible party’s (RP) environmental consultant.

The letter is a reminder to RPs and consultants that the potential for short-term (i.e., acute) health risks associated with trichloroethylene (TCE) in indoor air are serious enough that it should be one of the first things evaluated as part of a site investigation. This is especially true on sites where contamination may impact sensitive populations and should be routinely reassessed throughout a project’s life to ensure protectiveness.

RPs should be diligent about screening for TCE in vapors to determine if immediate or interim actions are warranted to reduce harmful exposure. More information on the acute health risks associated with TCE is also available in Sections 3.4.1 and 7.1 of Addressing Vapor Intrusion at Remediation and Redevelopment Sites in Wisconsin (RR-800).

During initial site scoping, environmental consultants should consider the site history, chemicals used at the site or facility, preferential pathways, including their connection to occupied buildings (e.g., sanitary sewers) and the occupants’ demographics. RPs should work with their environmental consultant to determine the appropriate next steps.

For more information on vapor intrusion, please visit the DNR’s website.

The DNR will provide additional information on the short-term health risks associated with TCE in indoor air during the Issues & Trends webinar on April 20, 2021.