An appeals judge says the Environmental Protection Agency must regulate the water discharged from ships as a way to protect local ecosystems from invasive species.

A handful of environmental groups and states had sued the EPA to require that ship discharges be subject to federal permit requirements under the 1972 Clean Water Act.

A federal court in San Francisco had ruled against the EPA in 2006. An appeals court judge upheld that ruling Wednesday.

The ship discharges included in the lawsuit range from laundry soap on cruise ships to ballast water on cargo ships.

The EPA has drafted rules on ship discharges already and is taking public comments this month.