U.S. study says Iowa among main Gulf polluters

Des Moines Register; 30 January 2008


Washington, D.C. – Farms in Iowa and eight other Midwestern and Southern states are causing most of the pollution that creates a "dead zone" in the Gulf of Mexico, a government study says.

The study by the U.S. Geological Survey also says that manure runoff from pasture, rangeland and feedlots is a bigger contributor to the problem than previously thought.
 The dead zone, which lies along the coast of Louisiana and Texas, is created when phosphorus and nitrogen flow out of the Mississippi River and encourage the growth of algae in the Gulf. The algae growth robs the water of oxygen, forcing fish, shrimp, crabs and other sea life from the region.

Fertilizer runoff from corn and soybean farms is the largest source of nitrogen that reaches the Gulf and a leading source of phosphorus. Scientists worry that production of biofuels will make the problem worse, as farmers increase corn acreage and nitrogen fertilizer to keep up with the demand for ethanol.
The study, released Tuesday, said Illinois, Iowa, Indiana, Missouri, Arkansas, Kentucky, Tennessee, Ohio and Mississippi contribute 75 percent of the nitrogen and phosphorus that reaches the Gulf. Those states represent just one-third of the land drained by the Mississippi River or its tributaries.

Iowa is the second leading source of nitrogen, after Illinois, that reaches the Gulf, and the third leading source of phosphorus, after Illinois and Missouri.
The study suggests that Iowa is not as big a source of nitrogen as previously estimated and that states to the east and south are also contributing to the problem, said Dean Lemke, chief of the water resource bureau of the Iowa Department of Agriculture and Land Stewardship.

The study estimates that 11 percent of the nitrogen that reaches the Gulf originates in Iowa. Previous estimates have been in the range of 18 percent to 22 percent, Lemke said.
A task force of federal and state officials is expected to use the findings of the report in its recommendations for shrinking the dead zone.

The study will help the government "cut the size of the dead zone in faster and fairer ways," said Benjamin Grumbles, the Environmental Protection Agency’s assistant administrator for water.

Scientists advising the EPA have recommended the government set targets to reduce nitrogen and phosphorus by 45 percent to cut the size of the dead zone in half.
The study is based on a computer modeling of land use and water flows. Critics say the study is flawed because it relied on land use data from a 1992 agricultural census.

Since then, many farms have taken measures to prevent pollution streams, including installing fences to keep cattle out of the water, said Don Parrish, who follows the Gulf issue for the American Farm Bureau Federation.

But the study showed that Congress needs to target land-conservation measures in states such as Iowa where the pollutants originate, said Michelle Perez, an agricultural policy analyst for the Environmental Working Group, an advocacy organization. Versions of a farm bill passed by the House and Senate do not address the issue adequately, she said.
Iowa farmers have taken steps to minimize runoff of nitrogen from fields, but the cost and effectiveness varies, said Rick Robinson, environmental policy adviser for the Iowa Farm Bureau.

A joint federal-state initiative to develop wetlands that can prevent nitrates from reaching rivers and streams has been hampered by rules that discourage landowners from participating, he said.

"There are things we are doing in Iowa, but there are things the federal government can do, too, instead of just pointing fingers at Midwestern farmers and saying, ‘It’s your fault,’ " Robinson said.
Reporter Philip Brasher can be reached at (202) 906-8138 or pbrasher@dmreg.com