OVER THE PAST TWO DECADES, managing the discharge of ballast water has evolved into a complicated tangle of international, federal, and state law — and lawsuits. Here's a glimpse at what's happening now.

On the global stage, the International Maritime Organization, a United Nations agency focused on shipping safety and pollution, has developed a legal framework to regulate ballast water. In February 2004, at a diplomatic conference in London, representatives from member countries adopted a treaty with a very long title: the International Convention for the Control and Management of Ships' Ballast Water and Sediments. In addition to a ballast water exchange standard, the convention created discharge standards for treatment methods (for example, the number of living organisms that can remain in the water). The convention allows countries to create their own stricter standards — an important stipulation for the United States, which reportedly lobbied for more stringent discharge standards than those finally adopted. For the convention to enter into force, 30 countries, representing 35 percent of the world's merchant shipping tonnage, must sign on. The U.S. has not yet ratified the treaty.

In the United States, the Coast Guard regulates ballast water management under the National Aquatic Nuisance Prevention and Control Act of 1990, later reauthorized as the National Invasive Species Act of 1996. Starting in 2009, the Environmental Protection Agency (EPA) is exercising regulatory authority as well.

Why the shift? In 2003, environmental groups brought a lawsuit against the EPA for failing to regulate ballast water as pointsource pollution under the Clean Water Act. The EPA had exempted ballast water as a point source and later noted that Congress had directed the Coast Guard, not them, to regulate ballast water. After years of appeal, in 2008, the Ninth Circuit held that the EPA could no longer exempt ballast water or other discharges normal to the operation of a ship.

Forced to enter the ballast water arena, the EPA created a blanket permit that, in effect, called for following the Coast Guard's ballast water regulations. This socalled Vessel General Permit, which went into effect in February 2009, disappointed some states and environmental groups that hoped EPA would use this opportunity to enact stricter ballast protocols. The Coast Guard reports that it's working with the EPA to minimize complications that could arise with two different agencies, working under different statutes, regulating the same thing.

And the situation continues to evolve. The EPA's new administrator, Lisa Jackson, told the Great Lakes Commission that the permit "doesn't begin to address some of the concerns that are out there."

Many states have taken ballast water management into their own hands. Fearing that federal (and international) policies don't do enough to protect their waters from invasive species, some states require ships to take additional measures before discharging ballast water in their ports. California, Oregon, and Washington, for example, require coastwise vessels to undergo ballast exchange 50 nautical miles from shore. California has also developed treatment standards that call for zero organisms in discharged ballast water by 2020. Recently, many states took advantage of a provision in the Clean Water Act that allowed them to require vessels to meet more stringent state standards than those included in the EPA's new Vessel General Permit.

The shipping industry largely denounces state measures as patchwork regulations that complicate their ability to do business. "A vessel that goes to New York has to do one thing, but when it goes to Baltimore, it's got to do something else," says Kathy Metcalf of the Chamber of Shipping of America. She says the industry wants a federal ballast water management program that creates one national standard and preempts states from "creating their own and often conflicting programs." "My organization can support the most stringent standard necessary that is technologically achievable," she says. "As long as it's the only standard around the nation." Environmentalists and concerned states want to make sure that any national standard is in fact stringent.

Jessica Smits