Agency: Pollution has 'impaired' rivers

Five rivers in Minnesota are considered seriously polluted by pesticides and the Minnesota Pollution Control Agency is recommending that they be designated as "impaired," which usually means there is a risk to aquatic life, but not human health.

It's the first time the state has recommended that designation due to pesticides. In the past, rivers have been classified as impaired from mercury, bacteria, phosphorus and other pollutants.

The MPCA said the middle branch of the Whitewater River and sections of four other rivers in southern Minnesota contain acetochlor, used to control weeds for corn crops. The chemical has been measured in the rivers at various times between 1998 and 2005 at concentrations up to five times higher than the state limit for what's considered environmentally sound.

"We don't want the pesticide that's applied in the field to end up killing the aquatic plants in the stream that are essential for the health of that stream," said Dave Christopherson, water quality research analyst for the MPCA.

The issue highlights the potential conflict of cultivating a growing corn crop in the same watershed that the public expects to be pristine.

Sold under the brand names of Harness and Surpass, acetochlor is usually applied in late spring, near planting time, but before corn plants have emerged. Farmers say it controls weeds and boosts yields _ important as the demand for corn increases with the demand for ethanol.

Farmers have halved their use of the chemical in recent years, said Steve Sodeman, a crop consultant in the St. James area of south-central Minnesota. Sodeman, who also serves on the board of the Minnesota Corn Growers Association, said just because scientists can measure chemicals does not mean extremely low concentrations are risky.

"Some people are working very hard to get rid of atrazine (another herbicide) and are now focusing on acetochlor," he said. "Whatever's out there, certain groups or elements will take potshots at it and try to eliminate it, the extremists or environmentalists or whatever."

Environmentalists and trout fishermen say growing more corn and using more chemicals near streams is not worth the cost of contamination.

"This is like bells and sirens," said Janette Brimmer, legal director for the Minnesota Center for Environmental Advocacy. "It's about time MPCA took action, and this is just barely scratching the surface."

After federal authorities approve the state's recommendation for the five waterways, pollution officials must come up with a plan to find out where the acetochlor is coming from and how to reduce it.

Jeff Broberg, a geologist in Rochester and president of the Minnesota Trout Association, said the water is susceptible to contamination because area soil is relatively thin and is atop limestone, which can speed surface chemicals into groundwater.

Broberg said he's concerned about how little scientists know about herbicides, including the possibility that some ingredients may disrupt normal sexual development and reproduction of frogs, fish and other wildlife.

Hydrologist Paul Wotzka said because of the interaction of surfacewater and groundwater in southeastern Minnesota, some drinking water might be laced with pesticides, and the state should help people test their wells.

Wotzka filed a whistle-blower lawsuit recently against the state claiming that he was fired in retaliation for wanting to testify at a legislative hearing in March about his previous research.

"We're on a dead-fish, sick-human policy track," Wotzka said. "That is to say, when fish go belly up and when people get sick, that's when state agencies will start paying attention to these problems."

Greg Buzicky, director of the Pesticide and Fertilizer Management Division at the Minnesota Department of Agriculture, said the state encourages farmers to leave strips of brush and trees along streams and to take other steps to reduce the runoff of herbicides from their fields.

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Information from: Star Tribune, http://www.startribune.com