EPA Approves Use of Narrative Nutrient Criteria for Montana’s Wadable Streams

The U.S. Environmental Protection Agency (EPA) has approved the use of narrative nutrient water quality standards for Montana’s wadable streams and select large river segments. The Department of Environmental Quality (DEQ) submitted revised nutrient water quality standards to EPA for review on May 7, 2025, after Governor Greg Gianforte signed House Bill 664, a bipartisan measure that reforms water quality permitting and planning, on May 1, 2025.

 

“We are incredibly grateful to the EPA, in particular Regional Administrator Cyrus Western, for approving the use of narrative standards,” DEQ Director Sonja Nowakowski said. “Thanks to this approval, and the bipartisan legislation signed into law by Governor Gianforte, DEQ will now move forward with water quality permitting and planning for permittees while also protecting our treasured water resources.”

 

Narrative standards describe conditions to be avoided and allow DEQ to identify impairments and develop plans to improve water quality. The new law provides regulatory predictability for permittees and ensures DEQ uses the best science available to protect water sources based on the agency’s understanding of local, site-specific conditions.

 

DEQ has been using narrative nutrient criteria to protect Montana waterbodies for decades. The repealed numeric nutrient criteria (DEQ-12A) never applied to many of Montana’s waterbodies. DEQ-12A only applied to wadable streams and select large river segments.

 

Nowakowski continued, “A return to narrative nutrient standards will allow DEQ to take a localized approach and better tailor water quality assessments and permits to the specific stressors of a watershed and protect its beneficial uses.”

 

DEQ will assist permittees in understanding the narrative nutrient standards and will develop guidance documents to help with the transition.

 

To learn more about DEQ’s water quality standards development, monitoring and assessment, and projects addressing issues in Montana waters, visit DEQ’s website.