The Minnesota Court of Appeals has rejected an environmental group's argument that the state's ballast water permit program is inadequate to protect Lake Superior.
The Minnesota Center for Environmental Advocacy sued the state, saying the permit standards for ballast water in Lake Superior don't take effect quickly enough and aren't strict enough to protect the cleanest Great Lake.
The MCEA's legal director, Matt Norton, said the permit system doesn't take effect quickly enough, and has standards too low to prevent invasive species from getting into the Lake.
The permit calls for ships to have treatments on board to kill unwanted organisms in their ballast water by 2016.
"The decision means new invasive species like zebra mussel and potentially worse, viral hemorrhagic septicemia, will continue to be entering and allowed to enter Minnesota waterways," Norton said.
Viral hemorrhagic septicemia has been killing fish in the lower lakes, but so far has apparently not reached Lake Superior.
The Appeals Court said the Minnesota Pollution Control Agency followed state rules in developing the permit.
Norton said his group is considering further legal action.