Rising use of corn ethanol stresses Midwestern groundwater

Source: Elizabeth Harball, E&E reporter • Posted: Tuesday, January 29, 2013

USDA Drought Monitor

A long and severe drought lingers over much of the Corn Belt. Map courtesy of the University of Nebraska, Lincoln.

Biofuel production is often touted as a boon to rural development, but a University of Iowa engineering professor is worried about the effect of corn ethanol plants on his and other states’ water supplies.

At a biofuels energy symposium hosted by the Institute of Medicine of the National Academies last week in Washington, D.C., professor Jerald Schnoor said corn ethanol production facilities require large quantities of high-purity water during the fermentation process.

A long and severe drought lingers over much of the Corn Belt. Map courtesy of the University of Nebraska, Lincoln.

This water is obtained from underground aquifers, and as ethanol production reaches a fever pitch in Iowa, the state’s water supply is threatened. Even in 2009, Iowa state geologists warned that the Jordan aquifer was being pumped at an unsustainable rate in several counties, exceeding the state’s 1975 base line within the next two decades.

“We’re near record devotion of acres to corn right now,” said Schnoor, who also headed the Iowa Climate Change Advisory Council in 2007. Up to 40 percent of corn production in the United States now goes to ethanol fuel. Schnoor estimated that up to three-quarters of corn crops in his home state are devoted to ethanol production, stressing Iowa’s groundwater sources.

He cited the Lincolnway Energy Plant in Nevada, Iowa, as an example. This plant, which Schnoor acknowledged was older and less efficient than newer plants, produces 50 million gallons of ethanol every year by processing 100,000 acres of corn. He said this process requires 200 million gallons of water per year.

 Big consumption in small areas

The Lincolnway Energy Plant’s 2012 annual report gives a number closer to 100 million gallons a year, but it does describe its water use as “significant.”

According to a 2007 report Schnoor authored for the National Academy of Sciences, “because water use in biorefineries is concentrated into a smaller area, such facilities’ effects can be substantial locally.” The report added that “a biorefinery that produces 100 million gallons of ethanol per year, for example, would use the equivalent of the water supply for a town of about 5,000 people.”

In the western United States, where corn must be irrigated because precipitation is less reliable, Schnoor said the strain on the underground water supply is even greater.

“People don’t realize that we’re unsustainably pumping down these aquifers,” he said, calling for an end to the expansion of biofuel use for this reason.

Theresa Selfa, a professor at the State University of New York’s College of Environmental Science and Forestry, examined the socio-economic impacts of corn ethanol on small communities in Kansas and Iowa in a 2011 study. After extensive interviews, she found communities were often proud of the biofuel plants, despite the perceived impacts on the water supply.

“We did get more positive than negative comments on the survey,” she said.

Drought underscores the problem

These communities had relatively high poverty rates — one more than 20 percent — so residents appreciated the boost to the local economy, however small. “These plants don’t really have a lot of direct jobs,” Selfa said.

“Any job in this town is better than none at all,” said a resident in Selfa’s study from Russell, Kan.

Also, she said that relative to the environmental impacts of other industries in the Midwest, like feed lots, oil refineries and meat packing plants, “the ethanol industry seemed pretty benign.”

But in Russell, home to a plant owned by U.S. Energy Partners, 67 percent of community members expressed concern about the water resources used by the plant. In May 2012, Russell was placed under water restrictions due to drought.

Selfa thought that had these communities been aware of ethanol production’s impact on the local water supply, support for the plants may not have been as strong.

“I think people in general were not that well-informed,” Selfa said, concluding that “biofuels are not an overwhelming win-win for rural communities.”