DEQ seeks comment on updates to the Implementation Guidance for the Idaho Copper Criteria for Aquatic Life

August 5, 2024

Contact: India Southern, Water Quality Standards Analyst, [email protected]

BOISE - The Idaho Department of Environmental Quality (DEQ) is seeking comment on updates to the 2021 Implementation Guidance for the Idaho Copper Criteria for Aquatic Life.

The purpose of the document is to provide guidance to DEQ staff, the regulated community, and the general public for calculating the copper criteria for aquatic life, including providing background on copper toxicity and how DEQ will implement the criteria using the biotic ligand model (BLM). In 2024, DEQ updated the guidance to clarify the copper BLM model implementation. In addition, DEQ added details on using the fixed monitoring benchmark method, statistical methods for reconciling multiple instantaneous water quality criteria, and interpreting toxicity units.

The draft updated Implementation Guidance for the Idaho Copper Criteria for Aquatic Life is available for review at DEQ's State Office (1410 North Hilton Street, Boise, Idaho) and on DEQ's Public Comment Opportunities web page. Written comments will be accepted through September 4, 2024, at 5 p.m. (MDT). Submit comments electronically via DEQ's public comment form or by mail or email:

India Southern
1410 N. Hilton St.
Boise, ID 83706
[email protected]