A University of Minnesota study on water usage and ethanol production is already generating a flood of negative headlines and it hasn’t even been officially published yet.
“Biofuel Production Threatens Water Supplies,” “Bioethanol’s Impact On Water Supply Three Times Higher Than Once Thought,” and “Ethanol Production Consumed 861 B Gallons of Water in ‘07″ are just a sample of the headlines from the report which is scheduled for publication Wednesday in the journal Environmental Science and Technology. However, the headline on the press release from the U of MN (which was supposedly embargoed until 12:01 a.m. Wednesday) reads more positively - “Midwestern ethanol plants use less water than western counterparts.”
The study is the first to compare water use in corn-ethanol production on a state-by-state basis - which they found ranges from as little as six gallons of water for each gallon of ethanol in Iowa - the number one ethanol producing state - to as much as 2,100 gallons in California, which produces very little ethanol. The authors used agricultural and geologic data from 2006-2008 to develop a ratio showing how much irrigated water was used to grow and harvest the corn and to process it at ethanol plants. The study “highlights the need to strategically promote ethanol development in states with lower irrigation rates and less groundwater use,” the authors say.
As always, the problem with this issue is perspective. Check out some of the EPA’s Water Trivia Facts, which includes this little tidbit: How much water does an acre of corn give off per day in evaporation? The answer is 4,000 gallons. Is that counted when determining water usage for corn ethanol production?
And how does ethanol production compare to gasoline production? According to the same trivia facts (converted to gallons from barrels) it takes at least 44 gallons of water to refine one gallon of crude oil. Does that count the water used to pump the oil out of the ground?
Here’s another little fun trivia fact. A typical 40-million-gallon-a-year ethanol plant uses almost exactly the same amount of water per as an average 18-hole municipal golf course. But then, golf courses don’t have to defend their water usage - only the people who are trying to produce food and fuel for our country do.
I took a peek at that report earlier. It uses data on water use from David Pimentel, the retired Cornell professor and lifelong ethanol critic. Nuff said.
The last figures I saw showed that very little of the nation’s corn crop is irregated — about 5%. In Minnesota, were I live, it’s even less — about two percent.
Bob Moffitt Says:
April 14th, 2009 at 5:57 am