From Todays Strib.
http://www.startribune.com/local/171542141.html
Mississippi River cleaner than ever, says new report
Article by: JOSEPHINE MARCOTTY , Star Tribune Updated: September 27, 2012 – 10:59 AM
But new chemical contaminants turn up in a study of the river’s health.
The Mississippi River as seen from an overlook at Great River Bluffs State Park, southeast of Winona, Minn.
Photo: , Star Tribune
The Mississippi River is cleaner and healthier than it’s been in a generation, according to a first-ever report card on the state of the river made public today by the National Park Service and an environmental group.
After four decades of declining pollution following the implementation of the federal Clean Water Act and other federal laws, the section of the river flowing through the Twin Cities boasts world class fisheries, a healthy population of bald eagles, and water that’s clean enough for swimming – most of the time.
“This was intentional,” said Whitney Clark, executive director of Friends of the Mississippi River, the advocacy group that shared in putting the scientific assessment together. “It took bold and decisive policy action at the state and federal level. And it gives us a road map for the other issues we are trying to address.”
The review, however, also found some new and looming environmental concerns along the 72-mile stretch running between Dayton and Hastings — the Mississippi National River and Recreation Area that is part of the National Park Service.
Rising levels of a contaminant called triclosan have turned up in sediment studies in Lake Pepin. The compound starts as a antibacterial ingredient used in soap, toothpaste and many other consumer products. When exposed to chlorine in water treatment facilities and sunlight in the water, it becomes a dioxin, one in a class of toxins harmful to people and wildlife.
While other dioxins have declined in the Mississippi since the 1960s, toxins derived from triclosan have increased by up to 250 percent, according to research conducted by scientists at the University of Minnesota-Duluth.
And since the mid 1970s, nitrates — a pollutant from fertilizer and excess organic material from urban and agricultural areas — has increased by as much as 47 percent in some years, according to data from the Metropolitan Council. Nitrates are one of the pollutants that contributes to the dead zone at the mouth of the Mississippi in the Gulf of Mexico.
The report issed Thursday tracks 13 indicators of river health — everything from that amount of water flowing through the Twin Cities, which is up significantly thanks to agricultural drainage, urban runoff and bigger rain storms, to mussel populations.
The Park Service and the Friends of the Mississippi said this will be the first of regular reports to document trends in the Mississippi.
Josephine Marcotty • 612-673-7394
