| NEW YORK
NEW YORK The U.S. ethanol rush could drain
drinking water supplies in parts of the country because corn --
a key source of the country's alternative fuel -- requires vast
quantities of water for irrigation, the National Research
Council reported on Wednesday.
President George W. Bush has called for production of 35
billion gallons per year of alternative motor fuels including
ethanol by 2017, as part of an effort to wean the country from
foreign oil. U.S. capacity to make the fuel, believed to emit
low levels of greenhouse gases, has spiked about 28 percent
this year to nearly 7 billion gallons.
But the use of more corn to make ethanol could drain water
supplies like the Ogallala, or High Plains, aquifer, which
extends from west Texas up into South Dakota and Wyoming.
"The aquifer is already being mined to the extent that
recharge of precipitation into it is much, much less than
withdrawals, and that would be exacerbated by any increase in
corn or any increase in irrigated agriculture in the region,"
Jerald Schnoor, a professor of environmental engineering at the
University of Iowa, told reporters on a conference call about
the report. Schnoor chaired a committee set up to develop the
Large portions of Ogallala show water declines of more than
100 feet, said the report from the Council, which advises
Congress and the federal government on scientific matters.
Corn requires more irrigation than other crops like
soybeans and cotton in the Plains states across the middle of
the country, the report said. Much of the water used to
irrigate corn, the main source of ethanol in the United States,
is lost to the ecosystem as it evaporates from the plant and
from the ground.
Schnoor said poor water supplies in some parts of the U.S.
Midwest have already stopped a few ethanol refineries, also
heavy water users, from being built in Iowa and Minnesota. If
they had been built, water supplies to a few towns there may
have suffered, he said.
In addition, fertilizers used to produce corn could
increase the runoff of oxygen-starving nitrogen into streams
that run down the Mississippi River into the Gulf of Mexico.
Such runoff has been blamed for forming "dead zones" in the
Gulf where many forms of marine life cannot survive.
Schnoor said each gallon of ethanol made from corn can
leave behind about 8 grams, or about the weight of three
pennies, of nitrogen that can wind up in water supplies.
A similar report from nonprofit group Environmental Defense
this summer said ethanol could increase demand for scarce water
supplies by 2 billion gallons a year.
Ethanol industry sources have said concerns about ethanol's
impact on water supplies are overblown and that ethanol plants
will not be locating where water availability is a question.
The NRC report said technological developments could help
protect water supplies. Ethanol producers are learning to
recycle water in refineries that make the fuel, and an emerging
fuel, called cellulosic ethanol, could lead to reliance on
feedstocks like switchgrass, which may require less irrigation