Environmental groups and the U.S. Environmental Protection
Agency have reached a deal requiring tougher federal regulations
for ships that dump ballast water in U.S. harbors, a leading way
in which invasive species are spread. Cargo ships often carry
millions of gallons of water and sediments in ballast tanks to
help keep vessels upright in rough seas. Ballast water teems
with fish, bacteria and other organisms that are released as
freight is taken on in port. Many of the foreign species spread
rapidly, starve out native competitors and upset the ecological
balance. Invaders such as zebra mussels cause billions of
dollars each year in damage and economic losses. EPA issued a
2008 permit requiring shippers to exchange their ballast water
at sea or, if the tanks were empty, rinse them with salt water
before entering U.S. territory. About a dozen environmental
groups sued, contending the requirement was too weak and
violated the federal Clean Water Act. Under the settlement
announced Tuesday, EPA will issue a ne