The Remediation and Redevelopment (RR) Program is seeking input on the updated publication Guidance: Investigation of Human-made Preferential Pathways Including Utility Corridors (RR-649). The publication explains how human-made preferential pathways can influence contaminant migration of vapor and groundwater, soil or surface water and includes specific information on vapor migration in utility corridors. 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) and incorporates new information from studies and investigations published since 2021. 

The document can be found at the RR Program’s Public Notices & Guidance webpage under Current Notices. Comments may be submitted through Sept. 7, 2026, to DNRRRGuidance@wisconsin.gov.