Protecting water resources in biofuels production

The Energy Independence and Security Act of 2007 mandates a five-fold increase in current biofuels production. This will substantially increase the current production of corn-based ethanol despite widespread concerns over its negative impact on the availability and quality of already stressed water resources. The National Academy of Sciences' (NAS) recently-released report on water use in biofuels production (principally corn-based ethanol) proposes improved on-farm irrigation efficiency and water recycling within biorefineries to reduce the impact on water availability. In a classic case of unintended consequences, we demonstrate that these measures may decrease the sustainability of biofuels production by increasingly stressing water supplies. Instead, these measures may be more effective in reducing the water quality impact of biofuels production-a role that the NAS report does not emphasize.