Knife River under reviewThe Minnesota Pollution Control Agency announced this week that a public comment period is now open through May 12 for a revised draft Knife River pollution report and cleanup plan.
The Minnesota Pollution Control Agency announced this week that a public comment period is now open through May 12 for a revised draft Knife River pollution report and cleanup plan.
MPCA water quality monitoring data indicate the 25-mile-long Knife River, part of a 53,000-acre watershed located south of Two Harbors in St. Louis and Lake counties, has turbidity levels in excess of state standards. Turbidity, one indicator of water clarity, is caused by erosion, suspended clay, silt, organic matter and algae. High turbidity levels can have significant impacts on aquatic ecosystems and affect the quality of local plant and fish communities.
The MPCA first sought public comments on the draft Knife River Turbidity Total Maximum Daily Load (TMDL) report in October and November.
Based on comments the MPCA received, the TMDL was revised to include Duluth Township in the pollutant load allocations.
A TMDL is the maximum amount of a pollutant, such as turbidity, that a water body can receive and still meet its designated uses and water quality standards.
When a water body exceeds a water quality standard for a pollutant, it is considered impaired. The MPCA is developing a process to identify the Knife River’s turbidity sources, determine voluntary and regulatory source reductions and establish a cleanup plan to help the river meet state water quality standards. Resident involvement, education, outreach and pollution prevention are key components of the TMDL process.
Draft implementation activities include stream bank and channel restoration, gully stabilization, water storage, tree plantings and best management practices for residential areas, ditch maintenance, construction storm-water runoff and riparian buffer zones.
This TMDL study is part of a nationwide effort under the federal Clean Water Act to identify and clean up pollution in streams, rivers and lakes. Every two years, states are required to submit a list of impaired waters to the U.S. Environmental Protection Agency.
The river was included on the MPCA’s 1998 list of impaired waters for excessive turbidity levels and impairment to aquatic life. The Knife River TMDL report will be submitted to the EPA. Once it is approved, local authorities will work with individuals and organizations to further develop and implement the plan.
- For more about draft Knife River TMDL study, contact Greg Johnson of the MPCA at (651) 757-2471 or (800) 657-3864.
- The revised draft TMDL study, along with information on the state’s impaired waters list and Total Maximum Daily Load studies, is available on the web at www.pca.state. mn.us.
- The Knife River Watershed Project web site is located at www.southstlouisswcd.org/ knife_TMDL.html.
- For more information, visit the MPCA web site at www.pca.state.mn.us.