EPA should set nutrient limits to block dead zones, agency's inspector general says

The Environmental Protection Agency should move immediately to adopt enforceable limits on the release of nutrient pollutants -- such as fertilizer and sewage -- into rivers and streams to halt the creation of dangerously low oxygen areas in water bodies, and the dead zone in the Gulf of Mexico should be one of its first targets, the agency's Office of Inspector General said in a report made public today.

"We believe selecting nationally significant waters and acting to set standards for nutrients in them is a minimal first step if EPA is to meet the requirements of the (Clean Water Act)," the report said.

"Critical national waters such as the Gulf of Mexico and the Mississippi River require standards that, once set, will affect multiple upstream states," the report said. "These states have not yet set nutrient standards for themselves; consequently it is EPA's responsibility to act."

Nutrient pollution is regulated under the federal Clean Water Act, which requires federal and state governments to assure that rivers, streams, estuaries and coastal waters are "fishable and swimmable."

The report studied states whose nutrients were carried to the Gulf "because excess nutrients have resulted in its having one of the largest dead zones in the world."

Research has shown that the Gulf of Mexico's dead zone forms during the spring and summer after nutrients from 41 states -- including Midwest farms and sewage treatment plants -- is carried down the Mississippi River, where they provide food for the growth of algae.

The algae bloom in fresher surface water along the Louisiana and Texas coastlines and then die and sink into saltier water at the bottom, where its decomposition creates hypoxia, or low-oxygen water conditions. The result can be death for organisms living on the bottom, while fish and shrimp attempt to escape by swimming to water offshore containing more oxygen.

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