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Water not wasted

St. Paul, Minn. — In the “Land of 10,000 Lakes,” water resources are a growing concern as Minnesota’s industrial, economic development and environmental interests sometimes collide.

Using treated municipal wastewater or “reclaimed water” instead of fresh groundwater for nonpotable industrial uses might be a cost-effective solution.

Minnesota’s nearly 600 municipal treatment plants can process about 425 million gallons of wastewater a day; at the same time, state processing industries demand more than 440 million gallons of water daily.

AURI and the Metropolitan Council Environmental Services are collaborating to evaluate how value-added ag processing facilities could take advantage of reclaimed water to conserve both money and natural resources.

At times, “siting a new agri-processing facility has been difficult because of a lack of water resources,” says Jennifer Wagner-Lahr, AURI project director. Using reclaimed water could help.

Metropolitan Council Environmental Services collects and treats about 300 million gallons of wastewater a day at eight regional facilities. MCES principal engineer Deborah Manning says most of the treated wastewater is discharged back into rivers.

“Industry often uses ground water as a source even though they don’t always need that quality,” Manning says. “If we can replace this high-quality water with reclaimed water that still meets industry needs, we can conserve a finite resource for its best use and perhaps save some money.”

In 2007, the Legislative-Citizen Commission on Minnesota Resources funded an MCES project to look at industrial opportunities for using reclaimed wastewater for nonpotable water uses. An AURI-MCES project is expanding that work to evaluate economic, technical and environmental benefits of using treated water in value-added ag processing, including case studies of a Minnesota ethanol plant and another ag processor (to be determined). AURI will hold statewide industry forums to share findings, expected by June 2009.

Across the country and in Minnesota, industries have already started using reclaimed water, including a Mankato natural-gas powered electrical plant using it for cooling. A North Dakota ethanol plant in Casselton is piping in reclaimed water from Fargo, 27 miles away.

“If reclaimed water is a lower-cost alternative and conserves the high-quality water resources, it can be a factor in sustainable economic growth,” Manning says.

Reclaimed water may not be feasible in all industrial applications and “water use hasn’t necessarily been a big concern to this point,” says Wagner-Lahr. “But it could become a big issue in the future for all types of industries.”