Contact: Cathy Rofshus, 507-206-2608
Mankato, Minn. – Water clear enough to support fish and other aquatic life is the goal of a study of the Greater Blue Earth River Basin in south central Minnesota. The Minnesota Pollution Control Agency is accepting comments through May 29 on the study, which includes the Blue Earth, Le Sueur and Watonwan rivers that flow through 11 counties in south-central Minnesota. The Greater Blue Earth River Basin includes the cities of Fairmont, St. James, Blue Earth, part of Waseca and part of Mankato.
This study, conducted by Minnesota State University-Mankato, addresses turbidity, or cloudy water. Turbidity is caused by suspended sediment, which consists of soil and other particles in the water column. Turbidity can harm aquatic life by limiting the growth of plant species needed for food, reducing visibility for fish searching for food, affecting gill function, and damaging spawning habitat. Water quality monitoring on the rivers in this basin has shown that their turbidity levels frequently violate state standards.
The turbidity levels of the rivers vary by season and flow condition. Targeting practices that reduce sediment levels during high flows will be the key to this project’s success.
This is a Total Maximum Daily Load (TMDL) project, a term which refers to the maximum amount of a pollutant ─ in this case, sediment ─ that the river can accept and still meet state water-quality standards. The TMDL is part of a nationwide effort under the federal Clean Water Act to identify and clean up pollution in streams, rivers and lakes. The TMDL process establishes the allowable amount of pollutants, identifies possible sources, and outlines steps to reduce the pollutants.
The MPCA believes the Greater Blue Earth River Basin study can guide improvement activities and further research, benefiting fish, waterfowl and mussels, and improving the aesthetic appearance of water bodies in the basin.
The draft Greater Blue Earth River TMDL report is available online at www.pca.state.mn.us/0agx998 and at the MPCA Mankato office, 12 Civic Center Plaza, Suite 2165. For more information or to submit comments, contact MPCA project manager Paul Davis at 507-344-5246 or Paul.A.Davis@state.mn.us.
Comments must be received in writing at the MPCA office by 4:30 p.m. May 29, and must include an explanation of the commenter’s interest in the TMDL report, a clear statement of any recommended changes (including references to specific sections of the report), and specific reasons for any suggested changes.
The MPCA also invites comments on two related projects, the pollution-reduction reports for the Minnesota River and South Metro Mississippi. Research shows that the Greater Blue Earth River system is a major contributor of sediment to the Minnesota River, which in turn is a major contributor to the Mississippi.
Once the study has been approved, the MPCA will develop a plan to reduce the amount of sediment entering the rivers and upstream waters.