Developers look at piping methane from wastewater plant

(Sentinel photo by Magdalene Landegent) Ron Kayser, Le Mars' wastewater superintendent, explains how the bacteria that helps clean the city's wastewater also produces methane, which is used to heat the plant and could also be piped to Merrill to heat the Plymouth Energy ethanol and the Plymouth Oil plant. [Click to enlarge]

That could be the motto of Le Mars' wastewater plant.

The plant already makes 100 percent of what comes in into usable products.

Now officials are talking with a local renewable energy developer about using the wastewater plant's methane to help fuel the Plymouth Energy ethanol and corn oil plants north of Merrill.

Dave Hoffman, president of Plymouth Energy, has visited with wastewater Superintendent Ron Kayser about building a pipeline to allow the Merrill plants to tap into the wastewater plant's methane.

"It's all in the talking stages," Kayser said.

Methane gas is produced in the wastewater plant's process to clean the water.

Currently, that methane is used as fuel to heat the plant. Excess is burned off.

Hoffman's proposal would mean any excess methane would be cleaned up and piped to the Merrill ethanol and corn oil plant site.

"It would replace some of the natural gas we are purchasing for our boilers used to heat both plants," Hoffman said.

Developers are looking into a feasibility study to see how effective it would be to pipe methane from the wastewater plant on the north end of Le Mars down to the energy plants north of Merrill, about seven miles.

If the cost is prohibitive, the project will be a no go.

Chevron Energy Solutions, a subsidiary of Chevron Oil, is handling the study.

"They're the experts in creating sustainable waste water treatment plants," said Dr. Karen Korth, the president of the board of directors of a nonprofit group seeking to build collaboration and education for projects like this.

The group, Community Health and Energy Center (CHEC) has been working with Hoffman and the City of Le Mars on the proposed project for months.

"We've brought all groups together, and our intention is to take that collaborative approach to the Iowa Power Fund," said Russ Martin, CHEC's executive director. "We want to set a model across the state."

The group is also hoping to receive dollars from the Iowa Power Fund.

If Chevron Energy Solutions finds the project is feasible, the permitting process with the DNR will begin, Kayser noted.

There's also the possibility, Martin said, that methane could be captured from other sources in town like the dairy and ice cream industries.

At the wastewater plant the methane production has highs and lows, Kayser said, depending on the time of year and how much wastewater Le Mars' industries are pumping out.

"In the summer months we have a lot of excess," he said. "Certain times of day we make extremely high amounts of methane but there's nowhere to store it. That's why we burn it off with the flame."

If a pipeline was built, that excess wouldn't go to waste.

"For me it would be a plus-plus," Kayser said.

The Le Mars wastewater plant has used the methane on and off since the 1980s, but really locked into it a few years ago when they added a boiler designed specifically for methane.

Since methane is a "dirtier" gas and highly corrosive, the special boiler takes more maintenance. But the payoff is good, he added.

The plant uses a lot of heat -- the digesters with the wastewater in them have to stay at about 95 degrees to keep the active bacteria alive.

"We use methane to heat three buildings and the contents of two digesters," Kayser said.

Using the methane limits how much they use their secondary, natural gas boiler. They have to pay for natural gas.

"In the coldest part of winter, the natural gas boiler will run about two hours a day," Kayser said. "In the summer, the natural gas boiler won't go on at all."

Le Mars is not alone in using, and possibly selling, the wastewater plant's methane.

"Des Moines sells it, Waterloo sells it, and Ames runs it into a methane generator that creates electricity," Kayser said.