MANKATO — The CHS Oilseed Plant in Mankato releases more “respiratory toxins” than any power or industrial plant in Minnesota, according to a new report.

Mankato also had the 12th-ranked plant — the ADM Oilseed Plant.

The CHS plant released 520,000 pounds of toxins in 2004, while the ADM plant released 300,000 pounds.

Both plants meet all state and federal air emission regulations. The CHS plant is along the Blue Earth River, near Sibley Park. The Archer Daniels Midland plant is off of Highway 14 on the north side of town.

Mankato is one of the largest soybean oil processing centers in the world.

“There are a number of factors to look at for a specific plant, but these are the first numbers the public should look at as they begin to ask questions,” said Alex Fidis, a staff attorney with the U.S. Public Interest Research Group in Washington, D.C.

Lisa Graham-Peterson, of the Inver Grove Heights-based CHS, said the plant has done much to reduce emissions and will continue to.

“In the past two decades, emissions have been cut in half there. It’s come primarily from improved technology and best practices. We’re continually looking at how we’re doing things,” she said.

“We’re concerned about our employees and the residents.”

The CHS plant processes nearly 4,000 tons of soybeans per day, creating about 1,600 tons per day of oil.

There are a variety of toxins released that can affect the respiratory system, particularly in the elderly, pregnant women, children or those with asthma or other respiratory ailments.

No other plants in the nine-county Mankato area ranked among the top emitters.

The other companies releasing the most respiratory toxins included the Boise wood mill in International Falls, a soybean plant in Brewster and the Larson-Glastron Boats Co. in Little Falls.

This is the second national pollution study released by PIRG. The group uses figures supplied by businesses to the Environmental Protection Agency. The 2004 figures are the most recent available. The last study covered data from 2000.

Fidis said this could be the last time people have access to such a complete set of information. That’s because the EPA recently changed its reporting rules to limit what is available to the public.

“There is a move in Congress to override the rule changes. But if that doesn’t succeed, this could be the last year this kind of information is available,” Fidis said.

He said making the complete data available to the public helps pressure industries and states to do better at limiting pollution. He said the EPA’s own reports show a 57 percent nationwide decrease in toxic pollution since it began requiring the reports in 1998.

Graham-Peterson said CHS fully supports keeping the reporting rules complete and open.

“We support the public right to know. If you’re a responsible business and doing things right, then you have nothing to worry about,” she said.

Fidis said residents, unions and employees have used the information to push for reduced emissions at plants.

He said people should ask what measures a company has taken to reduce its pollution and what the state has done to reduce pollutants. “Having this information, states can be successful in working with companies on strategies to reduce pollutants.”

He said residents near a plant with high emissions have reason for concern.

“I would worry about the releases. With respiratory toxins, obviously those who are living downwind and around that facility should be concerned.”

The study also ranked companies based on other pollutants, including dioxins and “reproductive toxicants.”

The CHS plant has a significant role in Minnesota’s pollution laws. An accident at the plant in 1963 actually led to the creation of the Minnesota Pollution Control Agency.

The plant was then called Honeymead — Cennex Harvest States (CHS) purchased it in 2000. On Jan. 23, 1963, a 3.5-million gallon tank of crude soybean oil split open, sending oil into the Blue Earth River.

During the next months, as the ice melted, the goo floated down the Minnesota River, through the Twin Cities and into Lake Pepin. About 10,000 ducks were believed killed. New Gov. Carl Rolvaag, responding to public outrage, pushed for a list of environmental regulations, including the start of the Pollution Control Agency.