Bacterial pollution, measured as the concentration of fecal coliform or E. coli organisms, is fairly common in Minnesota's streams and rivers and is largely caused by runoff from livestock facilities and leaking septic tanks. High levels of bacteria make waters unsafe for swimming and are responsible for numerous beach closings throughout Minnesota in the summertime. Swallowing water contaminated by excess bacteria poses a significant risk to public health, causing waterborne diseases like gastroenteritis and hepatitis A.
Oddly, however, the Minnesota Pollution Control Agency does not test levels of bacterial pollution in lakes—only in streams and rivers—despite the fact that lakes are used much more for swimming. As of 2010, 302 river segments in Minnesota were listed as impaired by excessive bacteria, including recreational destinations such as Whitewater River State Park. Less than half of these rivers have had a Total Maximum Daily Load study conducted. Many of those rivers where the study has been done can be found in southeastern Minnesota, where the first TMDL was prepared by the Pollution Control Agency for fecal coliform contamination in the lower Mississippi region.
MCEA filed a lawsuit in federal district court challenging the EPA’s approval of this TMDL over concerns that the target contamination was set too high to meet health-based water quality standards. In June 2005, United States District Court Judge Donovan Frank issued a decision wholly supporting MCEA, and sent the TMDL back to the federal and state environmental agencies to correct it so that the bacterial target for each covered stream met water quality standards. The revised TMDL was approved by the federal Environmental Protection Agency in April 2006, and the Minnesota Pollution Control Agency developed a plan to implement it in September 2007.
More information:
2005 TMDL case court decision
Lower Mississippi River Basin TMDL: Regional Fecal Coliform Implementation Plan (September 2007)
· Map: impairments for fecal coliform