The public comment period ends next week for publication RR-649, Guidance for Documenting the Investigation of Human-made Preferential Pathways Including Utility Corridors.
The document can be found on the RR Program’s Public Notices & Guidance web page under the “Program Guidance” tab. Comments may be submitted through May 3, 2021, to Jim Walden at email@example.com or DNRRRGuidance@wisconsin.gov.
The guidance is intended for persons who perform and document investigation and remediation of sites with environmental contamination under Wisconsin Administrative Code (Wis. Admin. Code) chs. NR 700-799, including the Wisconsin Department of Natural Resources (DNR) staff who review such submittals.
This guidance document presents ways that utility corridors and other human-made preferential pathways can influence contaminant migration, and ways to assess and potentially sample these pathways to meet the requirements of Wis. Admin. Code § NR 716.11(5)(a). Vapor migration through human-made preferential pathways and utility conduits is of particular importance.
These preferential pathways may allow contaminant vapors to move from source areas into buildings, and to migrate beyond plume boundaries and historically recommended screening distances. This document focuses on vapor migration in utility conduits, but also relates to the preferential migration of contaminated groundwater, soil, or surface water in the multitude of human-made features.