Contact: India Southern, Water Quality Standards Analyst, india.southern@deq.idaho.gov
BOISE – The Idaho Department of Environmental Quality (DEQ) released the 2026 Triennial Review of Idaho Water Quality Standards. The review will guide water quality standards rulemaking and subprogram development for the next three years.
The Clean Water Act § 303(c) requires states to modify and improve their water quality standards at least once every three years. Under this triennial review process, states must review, modify, and adopt applicable water quality standards, taking into consideration public concerns, US Environmental Protection Agency (EPA) guidance, and new scientific and technical information.
DEQ provided opportunities for public participation by publishing three water quality standards issue papers for public review and hosting two in-person meetings in Lewiston and Idaho Falls, and one hybrid meeting in Boise. The public meetings communicated triennial review requirements, proposed issues for prioritization, and solicited feedback from stakeholders.
Materials related to the 2026 Triennial Review are available on DEQ’s Water Quality Standards web page under the Triennial Review drop-down.