A federal appeals court has ordered the Environmental Protection Agency to rewrite its rules governing the release of ballast water from ships in the Great Lakes and other U.S. waterways.
The unanimous decision by the 2nd U.S. Circuit Court of Appeals in New York is a major victory for environmental groups that had argued the EPA's 2013 permit governing the discharge and treatment of ballast water was insufficient to curb the spread of aquatic invasive species like zebra mussels and the spiny water flea.
The EPA erred in numerous ways, according to the ruling (pdf), including by adopting international limits on live organisms in ballast water when technology was available to require tougher standards.
For example, the agency only evaluated on-board technologies to cleanse ballast water of invasive species, and failed to consider on-shore technologies that shipping companies could utilize, wrote Judge Denny Chin.
The court also ruled that so-called "lakers," ships that only ply the Great Lakes and don't travel to the Atlantic Ocean through the St. Lawrence Seaway, should be subject to some of the same ballast requirements as ocean-going vessels. The EPA's 2013 permit exempted lakers built before 2009 from meeting certain effluent limits.
The Natural Resources Defense Council, Northwest Environmental Advocates, Center for Biological Diversity and National Wildlife Federation sued the EPA over its 2013 permit. That permit will remain in effect until the EPA issues new regulations that comply with the Clean Water Act.
"This is a huge ruling," said Marc Smith, Policy Director for the National Wildlife Federation. "It basically, in our opinion, changes the seascape, for how we can set protections in place against aquatic invasive species into our Great Lakes."
A spokesman for the Lake Carriers' Association, which had intervened in the case, declined comment, saying his group was still reviewing the ruling. In the past shippers have argued that no sufficient technologies exist to economically purge ballast tanks of invasive species.
Ships take on and discharge enormous quantities of water — in some cases enough to fill 38 Olympic-sized swimming pools — into and out of ballast tanks for balance when they load and unload cargo.
But when a ship sucks in ballast water, it also can inadvertently pick up microscopic organisms and unknowingly transport them to distant waters where they can establish non-native populations that sometimes explode in their new environments.
An estimated 10,000 marine species each day hitch rides around the globe in the ballast water of cargo ships, according to the court ruling.
Zebra mussels, for example, were first introduced to Lake Erie in the 1980s by a freighter from Europe. The mussels have since infested lakes throughout Minnesota, the Midwest, and some western states, disrupting aquatic habitats and causing tens of millions of dollars of damage.