By Lori Ehde
As thoughts turn to spring, local "nasal rangers," as they're affectionately called, are turning their noses in the air.
Since the Agri-Energy Ethanol Plant in Luverne installed its new 175-foot stack in January, Concerned Citizens for Quality Life have been hoping the modification will improve the smell.
The taller $300,000 stack is intended to reduce corn processing odor by sending emissions a greater distance through air dispersion before odors fall on the city.
"We have never stated we will eliminate it all," said plant manager Rick Serie. "Can we reduce it? Absolutely. Have we reduced it? Absolutely."
Some say the baked bread and sour beer smell has lessened. Others say it's as bad as it's always been and are demanding further action.
The fact is, any real improvement in air quality won't be measurable until spring returns southwesterly breezes.
On April 27 the air surrounding the ethanol plant will be scientifically tested for odor.
It was a year ago at that time when consultant Chuck McGinley measured air quality in Luverne to establish a baseline for improvement.
At that time he measured all emissions coming out of the plant.
Despite efforts to diminish the smell, some residents say it's affecting their health.
"I think we can deal with the odor, but there are toxins coming out of that plant," resident Tom Studer told the Star Herald.
"I feel my family has suffered health problems because of the plant, but we haven't been able to prove it yet."
Serie said he's aware of residents' health concerns, but he said the plant has already met stringent state guidelines, before the building was even constructed.
"It took a year and a half to get the plans approved," Serie said. "It was a very extensive EAW (Environmental Assessment Worksheet)."
Since the plant began operating in 1998, it remains under constant monitoring of the Minnesota Pollution Control Agency, EPA and most recently the Minnesota Health Department.
"If there's a health concern, I want to be the first to know about it," Serie said.
"I live here, too, and our 29 employees and their families live here. We want to make the situation the best for everyone."
Meanwhile, in addition to raising the stack, the plant is exploring other ways to improve air quality.
One approach the plant is taking toward odor reduction is marketing its modified wet feed.
Nearly 90 percent of the plant's odors come from the process of drying corn by-products, so the plant is actively selling the modified wet feed to niche cattle markets.
So far, this has reduced the amount of syrup in the dryers by nearly 24 percent. "This is where we'll see the most improvement," Serie said. "That's 24 percent less going through the dryer."
Plant management is also considering a larger blower for the fermentation scrubber stack. Only about 6 percent of the plant's odor comes from the fermentation process, but Serie said it may be worth doing.
"It's logical to concentrate on the larger dryer stack, but to me, the fermentation scrubber is where the sour beer smell comes from," he said.
Another promising area for improvement may be in the process of separating ethanol from the other compounds.
Serie said a plant in Preston cut its emissions of volatile organic compounds by 50 percent after improving this process.
"It's a substantial capital improvement," Serie said. "But it would also increase plant efficiencies, so we're taking a close look at this upgrade."
Both residents and ethanol plant staff are now waiting for the results of McGinley's April 27 air test.
"Everything's subjective at this point," Serie said. "What we need is objective data."