"TRAVERSE CITY, Mich. -- The Environmental Protection Agency issued new requirements Thursday for cleansing ballast water dumped from ships, which scientists believe has provided a pathway to U.S. waters for invasive species that damage ecosystems and cost the economy billions of dollars."
"Commercial vessels are equipped with tanks that can hold millions of gallons of water to provide stability in rough seas. But live creatures often lurk in the soupy brews of water, seaweed and sediment. If they survive transoceanic journeys and are released into U.S. waters, they can multiply rapidly, crowding out native species and spreading diseases.
Ships are currently required to dump ballast water 200 miles from a U.S. shoreline. But under the new general permit released by the EPA, vessels longer than 79 feet—which includes an estimated 60,000 vessels—must also treat ballast water with technology such as ultraviolet light or chemicals to kill at least some of the organisms.
The new guidelines don't apply to vessels staying within the Great Lakes, a decision that environmentalists criticized as leaving the door open for ships to ferry invasive species around the lakes."