DEQ seeks comment on draft Jordan Creek Mercury Total Maximum Daily Load

Accepting comments from March 27, 2025, through April 28, 2025.

The Idaho Department of Environmental Quality (DEQ) seeks comment on the draft Jordan Creek Mercury Total Maximum Daily Load.

The total maximum daily load (TMDL) sets mercury load limits for five impaired assessment units (i.e., the portions of a stream between two tributary intersections) in the Jordan Creek subbasin. These segments are designated as impaired on Idaho’s 303(d) list in the 2024 Integrated Report.

The Jordan Creek subbasin spans from southwestern Idaho into southeastern Oregon. Historic mining practices led to elevated mercury levels in parts of the system. Under the Clean Water Act, states are required to develop TMDLs when state water quality standards are not achieved. To comply with these requirements, DEQ prepared the draft Jordan Creek Mercury Total Maximum Daily Load, which establishes water quality targets and load capacities, estimates existing pollutant loads, and allocates responsibility for load reductions needed to return listed waters to a condition meeting Idaho’s water quality standards. The draft TMDL document was developed in consultation with the Jordan Creek Watershed Advisory Group.

The draft TMDL is available for review on DEQ’s Public Comment Opportunities web page and at DEQ’s State Office (1410 North Hilton Street, Boise, Idaho 83706). Written comments will be accepted through April 28, 2025, at 5 p.m. Mountain Time. Submit comments electronically using the form below or by mail or email to:  

Melissa Wigton-Hill
1445 N. Orchard St.
Boise, ID 83706
melissa.wigton-hill@deq.idaho.gov

Related Documents

Jordan Creek Mercury Total Maximum Daily Load

Accessibility Services: The Idaho Department of Environmental Quality will provide reasonable language access services and/or disability services for documents at no charge. To request an accommodation under Title VI of the Civil Rights Act of 1964 or Americans with Disabilities Act, contact DEQ’s nondiscrimination coordinator at (208) 373-0271 or accessibility@deq.idaho.gov. Para obtener información en español, visite https://www.deq.idaho.gov/about-us/accessibility/.