November 26, 2024
Contact: India Southern, Water Quality Standards Analyst, India.Southern@deq.idaho.gov
BOISE – The Idaho Department of Environmental Quality (DEQ) today published the final use attainability analysis (UAA) for Bucktail Creek, recommending no change in beneficial use designations.
Bucktail Creek is a small stream draining on the north side of the Blackbird Mine in Lemhi County, Idaho. Early mining operations resulted in contaminated mine drainage in Bucktail Creek and surrounding water bodies, leading to extensive water quality restoration efforts.
DEQ first published a UAA for Bucktail Creek in 2002 in order to assess the physical, chemical, and biological characteristics of the water body and determine the appropriate beneficial use designations (i.e., recreation, water supply, aquatic life, agriculture, etc.). In that analysis, DEQ examined the designated beneficial uses for Bucktail Creek and determined that it could not support aquatic life due to copper and cobalt concentrations that were many times greater than the acute and chronic water quality criteria. The UAA removed the contact recreation uses based on natural low-flow conditions and removed the aquatic life beneficial use based on copper and cobalt concentrations.
In 2024, DEQ updated the 2002 UAA, reviewing available surface water quality data between 2003 and 2022. DEQ determined that total and dissolved copper and cobalt concentrations in Bucktail Creek decreased due to extensive remediation work within the drainage. Copper and cobalt concentrations in Bucktail Creek also decreased in downstream waters in South Fork Big Deer Creek. However, pollutant concentrations, specifically copper, are still above criteria due to human-caused conditions that have not been remedied to a point where the water body meets water quality standards or could support beneficial uses.
The final Review of Use Attainability Analysis for Bucktail Creek is available on DEQ’s website, and additional information can be found on DEQ’s Water Quality Standards web page.