Following a public comment period and consideration of the comments received, the publication Guidance: Investigation of Human-made Preferential Pathways Including Utility Corridors (RR-649) is now posted and available online.  

The guidance focuses on vapor migration in utility corridors and explains how other human-made preferential pathways can influence contaminant migration of vapor and groundwater, soil or surface water. The guidance describes methods and options to assess and sample the pathways to meet the requirements of Wis. Admin. Code § NR 716.11(5)(a). 

A virtual training presented by the Wisconsin Department of Natural Resources is scheduled for Sept. 17, 2026. Presenters will review the role of conduits in vapor intrusion and review the updated Guidance: Investigation of Human-made Preferential Pathways Including Utility Corridors (RR-649).  

Conduit Vapor Intrusion: Application of RR-649 and RR-800  
Sept. 17, 2026, 11:30 a.m. to 1 p.m. 
Register to attend by Zoom  

Additional documents and guidance from the Remediation and Redevelopment Program may be found using the search tools available on the publications and forms webpage.