New fuels may hurt water, report says

Bill Scanlon, Rocky Mountain News

Thursday, October 11, 2007

Colorado's eastern plains could be a big player in producing automobile fuels in the next decade, but there are downsides, a National Academy of Sciences report says.

The fascination with corn- based ethanol for cars likely will strain America's water quality, loading rivers and groundwater with pesticides and fertilizers, the report says.

The report's authors said that rather than using "row crops" such as corn, farmers could consider the switch grass, miscanthus, poplar and willows that are part of the prairie ecosystem. Those would hold the soil and nutrients in place better and wouldn't need nearly as much water, fertilizer or pesticides.

"Switch grass or wheat grass and woody crops could be used to make ethanol and would be more suitable for Colorado," said Jerald Schnoor, chairman of the committee on Water Implications of Biofuel Production in the United States, which produced the report for the National Academy of Sciences.

"Poplars and willows grow really fast," said Schnoor, co-director of the Center for Global and Regional Environmental Research at the University of Iowa. "They wouldn't need as much nitrogen or phosphorus as corn, and because they're perennial crops, they'll hold the soil in place. You just cut them at the stump and they grow right back, while their roots stay in place."

Colorado scientists are excited about the possibility, but agree with the report's authors that technological hurdles probably mean commercial viability is about 10 years away.

The prairie ecosystem is comprised mainly of cellulose, rather than glucose, the sugar that is in corn kernels, said Bryan Willson, interim director of the Clean Energy Supercluster at Colorado State University.

That's a plus in that cellulose requires few chemicals and not much additional water in this climate, he said. "There's a lot of concern that using corn for biofuels could tax our resources, particularly water, pulling down the aquifers for irrigation," Willson said.

But cellulose has a problem. The sugar in corn is right at the surface, but cellulose material holds onto sugars.

Researchers at CSU, the National Renewable Energy Laboratory in Golden and other Colorado universities are using enzymes to transform cellulose -into sugar in the labs.

President Bush has pushed corn-based ethanol as a way to ease the nation's reliance on foreign sources of fuel. Bush has called for 35 billion gallons of ethanol production by 2017.