DNR Seeks Comments On Updated Surface Water Assessment Guidance

The Wisconsin Department of Natural Resources (DNR) is seeking public comment on guidance that helps water management specialists evaluate the status of the state’s surface water quality.

The Wisconsin Consolidated Assessment and Listing Methodology, known as WisCALM, provides guidance to assess surface water quality using standards set by the Clean Water Act and Wisconsin State statute. The methodology is updated for each biennial surface water assessment cycle, and the current guidance is being updated for the 2024 cycle.

This year’s updates include:

  • Distinction between biological thresholds and water quality criteria
  • New biological metrics (macrophytes, algae)
  • New phosphorus biological response indicators (macrophytes, algae, diatoms)
  • New oxythermal standards for Two-Story Fishery Lakes
  • New water quality criteria for PFOS and PFOA

Assessing water bodies against water quality standards and identifying impaired waters that don’t meet standards is part of the overarching federal Clean Water Act framework for restoring impaired waters. Under the Clean Water Act, states are required to monitor and assess their waters to determine if they meet water quality standards and support the designated uses they are intended to provide.

“Wisconsin’s surface water quality is good and improving in many areas,” said Ashley Beranek, DNR Water Resources Management Specialist. “By updating the technical guidance and maintaining the impaired waters list, the state works to address water quality issues through targeted improvement plans.”

The public comment period will be held from Jan. 12 to Feb. 24, 2023. For a downloadable copy of the draft guidance and more about these changes, visit the WisCALM webpage.