Minn. town fights phosphorous rule

Moorhead, Minn., is fighting a new state pollution rule designed to protect water quality in Canada. For the first time, the Minnesota Pollution Control Agency wants to consider the effects of the discharge from Moorhead's wastewater treatment pl...

Moorhead, Minn., is fighting a new state pollution rule designed to protect water quality in Canada.

For the first time, the Minnesota Pollution Control Agency wants to consider the effects of the discharge from Moorhead's wastewater treatment plant on Lake Winnipeg, north of the U.S.-Canada border.

In a dispute about a 103-year-old treaty, pollution that crosses borders and regulations that don't, people in Moorhead are at odds with state officials over a proposed regulation designed to cut phosphorus emissions of the city's sewage plant.

The regulation largely aims to reduce phosphorus levels in the Red River, which flows north into Lake Winnipeg, the world's 10th largest freshwater lake. Canadian scientists estimate that the Red River dumps more than 40,000 pounds of phosphorus into Lake Winnipeg each day.

Phosphorus in the Red River contributes to huge summer algae blooms and a growing dead zone in the lake. Most of that phosphorus comes from farmland runoff, but some of it also comes from the Moorhead wastewater treatment plant.


Every day, about 4.5 million gallons of sewage flow through the plant. After newly arrived sewage fills large open tanks, solid waste is separated from water. Bacteria break down the remaining waste as it moves through the plant.

The Moorhead plant is a small part of a big problem. On average it emits 132 pounds of phosphorus each day, but that's less than one half of one percent of the phosphorus flowing into Lake Winnipeg.

The Minnesota Pollution Control Agency wants Moorhead and 13 other wastewater facilities to reduce phosphorus output. Three are American Crystal Sugar factories.

MPCA officials have asked the city to reduce phosphorus by about 100 pounds a day. That would require the plant to add chemicals to the water treatment, add a different type of bacteria that consumes phosphorus, or a combination of both -- changes that could cost Moorhead as much as $10 million.

Daily pollution

According to MPCA data, Moorhead and the 13 smaller facilities in the Red River Valley put about 280 pounds of phosphorus into the Red River each day. Across Minnesota, there are 301 wastewater facilities with phosphorus limits because they are upstream of a Minnesota lake, and required to follow the state rule on phosphorus.

But Moorhead officials say the state is not following its own rules for phosphorus limits, which is designed to protect Minnesota lakes.

MPCA pollution control specialist Denise Oakes confirmed that the agency seeks to apply a rule that governs discharges in state lakes, in large part to comply with the Boundary Waters Treaty of 1909.


"The rule says if it affects a lake, if it discharges to or affects a lake," Oakes says. "It's meant for Minnesota lakes but we kind of applied it to Lake Winnipeg because of the treaty."

According to the treaty, "water flowing across the border shall not be polluted to the injury of health or property on the other side."

Oakes says the agency essentially decided to act as if Lake Winnipeg were in Minnesota.

"The Canadians are concerned about it and the Canadians are doing something about their wastewater facilities," she says. "We felt we needed to take a look at what was coming from our facilities and going into the Red River that could impact Lake Winnipeg."

That's the reason for the new policy. But there's another twist to the story.

Moorhead city engineer Bob Zimmerman says that when Moorhead and the MPCA negotiated a new five-year wastewater permit, it had no phosphorus limit.

But when the draft permit was put up for public review, the Minnesota Center for Environmental Advocacy objected.

MCEA officials argued that Minnesota has a treaty obligation to protect Canadian waters. That's when the phosphorus limit was added, Zimmerman says.


"So is the logic behind the limit one where the limit is truly needed or is it an effort to avoid litigation with an environmental group?" he asks.

Oakes, the MPCA pollution specialist, agrees the phosphorus limit would not have been added if the environmental advocacy group had not intervened.

That challenge caused the state agency to rethink its policy on Red River pollution and impose phosphorus limits on Moorhead and other facilities affecting Lake Winnipeg, she says.

But Moorhead isn't the largest city along the Red River. Fargo, N.D., has a much larger wastewater treatment plant -- one that releases about three times more phosphorus each day than the Moorhead plant.

But North Dakota has no phosphorus limit, and no plans to add one.

Minnesota Center for Environmental Advocacy water quality associate Mike Schmidt said imposing the phosphorus limit on Minnesota cities isn't a perfect solution. But it's a start.

"Even if we can't solve the problem just by imposing a limit on our side of the Red River basin doesn't mean we should just ignore the problem entirely," he said.

What's next? Moorhead and MPCA plan to negotiate. The Center for Environmental Advocacy will be watching those negotiations closely.


Oakes, the MPCA pollution specialist, thinks there's a good chance the dispute will end up in court.

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