justnorth posted on December 06, 2007 19:37 :: 931 Views
Onshore treatment of ballast water discharged from international ships arriving in Great Lakes ports is an economically and environmentally feasible option to eliminate the pathway by which dozens of invasive species have arrived in the Great Lakes, according to a recently released study.
The Department of Natural Resources-funded study concludes that a barge pulled alongside a ship to collect, store and treat the ballast water appears to be feasible and potentially the most cost effective option. The water then would be treated using filtering screens and ultraviolet light disinfection to eliminate organisms, according to study authors, the Milwaukee Office of Brown and Caldwell, a national environmental engineering consulting firm.
While the study focused on the Port of Milwaukee, its authors conclude that such an approach could work in other Great Lakes ports. Brown and Caldwell estimated that installing the system at a Great Lakes port would cost $1 to $2 million.
“This is good news in the fight against invasive species,” says DNR Secretary Matthew Frank. “Further study and a pilot project still need to be done, but these study results take us one step closer to finding a way to turn off the spigot of invasive species arriving in the Great Lakes via ballast water discharge.”
Ballast water has been the primary way by which more than 180 invasive species, including zebra mussels and round gobies, have arrived in the Great Lakes in the last century.
Brown and Caldwell researchers concluded that onshore treatment would have the ability to address a wide range of aquatic invasive species, from large, visible fish species down to microscopic viruses and pathogens, like viral hemorrhagic septicemia, or VHS for short. VHS is the fish disease that has caused large fish kills in the lower Great Lakes and was found in May 2007 in the Lake Michigan and Lake Winnebago systems.
The feasibility study assumed that the onshore treatment would be done on overseas vessels, not domestic ships, and from that smaller group, those that discharge ballast water. The Port of Milwaukee alone handles 322 commercial vessels carrying nearly 4 million tons of commodities, including 82 overseas vessels. Coal, salt, grain and cement are the top four commodities handled, according to Eric Reinelt, with the Port of Milwaukee.
Frank says the study complements the Great Ships Initiative, a multi-state, multi-agency effort underway to explore options for more cost effective treatment of ballast water. “On-shore treatment offers a less expensive route that can address the smaller ships that may find on-board treatment prohibitive,” he says. “Together, they represent an important, locally-based solution to this problem.”
The impetus for the study came through Gov. Jim Doyle’s Conserve Wisconsin initiative, which identified controlling the introduction of invasive species as a priority. DNR staff met with representatives of environmental organizations, the U.S. Coast Guard, shipping interests and port authorities in June 2006. A consensus developed at the meeting that there should be a study to investigate whether treatment could be done on ballast water and whether or not shore based treatment was feasible.
The department received funding for the study through the Great Lakes Protection Fund www.glpf.org a private, nonprofit corporation formed in 1989 by the Governors of the Great Lakes States as a permanent environmental endowment to support collaborative actions to improve the health of the Great Lakes ecosystem.
Wisconsin and other states continue to urge Congress to address invasive species comprehensively, including tackling ballast water discharges. “Unfortunately, the federal government has been slow to act, prompting consideration of state legislation and other measures such as shore-based treatment, to address the problem,” Frank says.
FOR MORE INFORMATION CONTACT: Roger Larson, DNR (608) 266-2666; Julie McMullin, Brown and Caldwell (414) 203-2904; Eric Reinelt, Port of Milwaukee (414) 286-8130
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