Biodiesel has taken a bit of a hit from a study recently published in Environmental Science & Technology magazine. The study looks at the amount of water required to produce enough corn to create sufficient ethanol to propel a diesel vehicle one mile. The result was an average of 50 gallons of water per mile.

The study accounted for not only the water necessary for growing the corn but also the water resources that would be impacted by the agriculture or, as the study calls it, the water footprint.

The National Biodiesel Board responded to the study stating that biodiesel production methods differ and crops are not farmed solely for the use of biodiesel and that in 2008 the entire U.S. biodiesel industry used less water in processing biofuel than was used in the irrigation of two Sun Belt golf courses.