Montana Department of Environmental Quality About Us Permitting & Operator Assistance Public Participation

Water Quality | Assessment Methods | Comment Period Closes October 6, 2024

  • August 05 2024

DEQ released three assessment methods for public comment August 5, 2024. The assessment methods will be used to consistently evaluate if state waters meet pollutant standards and support beneficial uses for a waterbody. These technical guidance documents provide guidance for DEQ staff when analyzing data to inform future impaired waters listings. 

The Dissolved Oxygen Assessment Method for Streams and Rivers explains how DEQ will identify dissolved oxygen problems in Montana’s flowing waters. The Ammonia Assessment Method outlines how DEQ will detect harmful ammonia to protect fish and aquatic life in lakes, reservoirs and streams.

A Selenium Assessment Method for Lake Koocanusa and the Kootenai River in Montana applies only to Lake Koocanusa (from the US-Canada international boundary to Libby Dam) and the Kootenai River (from the outflow below Libby Dam to the Montana-Idaho border). This method provides steps for evaluating water and fish tissue samples to determine if selenium standards are met or exceeded in these two waterbodies.

Associated Materials:

Comment Period Closes: October 6, 2024

Send Comments To:

Department of Environmental Quality
Water Quality Planning Bureau
PO Box 200901
Helena, MT 59620

Or electronically to jmadison@mt.gov 


Tags: Public Comment and Water