Wastewater may come to New Ulm

Critics: 1,200 trucks a year may reach treatment plant; city official says 466 is a more likely number

By KEVIN SWEENEY

Journal Editor

NEW ULM -- A critic of the Lakefield Junction Power Plant in Trimont has peppered New Ulm residents with a mailed warning that the plant could send 1,200 tanker trucks full of wastewater a year to the New Ulm wastewater treatment plant.

The mailing, called the "Martin County Monitor," was published by an organization called LASER, Inc. of Gridley, Calif. The organization describes itself as a non-profit corporation dedicated to improving safety, honesty and productivity in the construction industry.

While most of the criticism in the six-page paper is aimed at the city of Trimont, and TIC, the Colorado-based contractor that is building the plant, the paper also carries a warning to New Ulm residents that the plant could send 1,200 tanker trucks a year to the New Ulm wastewater treatment plant.

That isn't necessarily so, according to Bob Stevenson, Director of Utilities for New Ulm. According to the contract approved a year ago by the Public Utilities Commission, the city will accept up to 10 million gallons of water from the power plant per year, said Stevenson.

"But we don't know how much the plant is going to be used," he said.

The Lakefield Junction Power Plant is a peak-generating plant, said Stevenson. It is owned by Great River Energy, a power cooperative that serves, among other utilities, the Brown County REA. The plant is being built to generate power at times of peak demand, said Stevenson.

The number of trucks would be driven by electrical demand, he said. The plant would most likely run during hot summer weather which produces the highest peak demand as people run air conditioners and fans to stay cool. Cooler weather produces less demand.

At the maximum, with 6,000 gallons per tanker, 10 million gallons would mean about 1,600 trucks coming to the plant. But Stevenson said a more likely figure would be that the plant would run about 400 hours a year, producing 7,000 gallons of wastewater per hour, or a total of about 2.8 million gallons, or about 466 tankers a year.

Since those truckloads of water would be produced during a short period of time, traffic would also be concentrated, said Stevenson. The city has negotiated that no more than two tankers per hour can be unloaded to prevent long lines of trucks waiting.

The trucks would be coming up from the south on Highway 15 to the wastewater treatment plant, which is located on the south side of town near Kraft. They would not be coming through town.

Stevenson said the wastewater that would be brought to New Ulm is a non-polluting byproduct of the reverse osmosis filters that will be in operation at the plant. He explained that the plant will generate power by burning natural gas, similar to the gas generating turbine in New Ulm. Combustion of natural gas can lead to the formation of nitrogen oxides. When nitrogen in the air in the combustion chambers is exposed to high heat, said Stevenson, it combines with oxygen in the air to form nitrogen oxides, which are a component of smog. By injecting water into the combustion chamber along with the fuel, the combustion temperature can be kept at a cooler point that prevents the formation of nitrogen oxides.

The water injected into the combustion chamber is run through a reverse osmosis system to remove minerals and other impurities, so they won't build up deposits in the combustion chamber. The reject water from the RO system is what Lakefield Junction Power Plant will ship to New Ulm. It is water with a higher concentration of minerals. The Minnesota Pollution Control Agency is requiring, however, that the water be disposed of through a wastewater treatment plant.

Trimont doesn't want the expense of building a new wastewater treatment plant to handle the water, so the power cooperative made an arranagement with New Ulm to take the water.

Stevenson said the waste water is clean water that would simply dilute the sewage coming through the plant.

"We're happy to take it," said Stevenson. "It's like finding money on the sidewalk."

The city will receive $2.34 per thousand gallons. Ten million gallons a year would produce $23,400 in revenue and no expense for the utility, said Stevenson. The city's only investment was a few hundred dollars to install a pipe connection where the trucks can drain their load.