Shipping companies that transport iron ore, coal and other materials across
the Great Lakes are using the lakes as a dumping ground for leftover cargo,
despite federal laws and an international treaty that prohibit the practice.
U.S. and Canadian freighters dump about 2 million pounds of so-called "cargo
sweepings" into the Great Lakes each year, according to federal data. Cargo
sweepings are residual materials left on deck and inside freighters after a
ship is unloaded; those residuals must be removed to avoid contaminating
future cargo loads.
Shipping companies have discarded cargo sweepings for more than 75 years by
pumping the materials and wash water into the Great Lakes. Because the
dumping usually takes place several miles offshore -- where each ship dumps
anywhere from a few pounds to a few thousand pounds of cargo residuals --
few people outside the industry know about it.
Federal officials have known about the dumping for nearly two decades. But
regulators have turned a blind eye because shipping industry officials and
some scientists claim cargo sweeping is environmentally harmless and contend
there are no viable disposal alternatives.
But there could be changes on the horizon.
The U.S. Coast Guard is about to launch the first scientific study to
determine whether "dry cargo sweeping" is harming the Great Lakes. That
study could determine whether government agencies restrict the practice or
ban it outright; at the present time, the Coast Guard wants to permit cargo
The shipping industry, of course, is opposed to any restrictions.
"Banning cargo sweeping would be catastrophic to the shipping industry -- it
would shut down power production, steel production and all kinds of
construction activities in the region," said James Weakley, president of the
Lake Carriers Association, a shipping industry group based in Cleveland,
One Great Lakes expert questioned why government agencies that spend
billions to keep pollutants out of surface waters would allow freighters to
dump tons of iron ore, coal, salt and cement dust into the world's largest
source of fresh surface water.
"We have to ask ourselves if this is good public policy. Are there better
alternatives?" said Mark Coscarelli, a Lansing environmental consultant who
worked in Michigan's Office of the Great Lakes for more than a decade.
Coscarelli said the huge volume of cargo sweepings dumped in the lakes over
the past 75 years has left what could best be described as underwater gravel
roads on the bottom of lakes Michigan, Huron, Superior, Erie and Ontario.
Most of the sweepings are discarded in or near shipping lanes, according to
Weakley said the cargo sweepings dumped overboard do not contain hazardous
"It's the equivalent of sweeping out my garage," he said. "I'm pretty sure
the dust and dirt I sweep out of my garage is non-toxic, but I don't have
any scientific data to back that up."
Weakley said every human activity has some impact on the environment. "We
don't stop farming because of soil erosion and the environmental impact it
causes," he said.
The federal Clean Water Act prohibits waste dumping in the Great Lakes. So
does an international shipping treaty, called MARPOL Annex V, that Congress
adopted in 1990.
U.S. officials who approved MARPOL V, which banned trash dumping at sea,
apparently were unaware at the time that the treaty effectively outlawed
cargo sweeping in the Great Lakes.
Instead of banning cargo sweeping, the U.S. Coast Guard in 1993 adopted an
interim exemption policy that allowed the practice to continue virtually
unregulated. The Coast Guard now wants to make that interim policy a
permanent rule, a move that would essentially legitimize an illegal activity
but increase reporting requirements for shipping firms.
U.S. and Canadian freighters dumped 432,242 pounds of cargo sweepings in
Lake Michigan in 2001, according to federal data. The biggest load of cargo
sweepings that year, 680,300 pounds, was dumped in Lake Huron.
The cargo sweepings discarded in Lake Michigan in 2001 included 187,530
pounds of iron ore, 80,132 pounds of coal and 138,548 pounds of stone,
according to federal data.
Coast Guard officials said it would be impractical to outlaw cargo sweeping
in the lakes. Great Lakes freighters were not designed to carry cargo
residuals, and disposing of the material while docked would be too
expensive, according to federal officials.
Coast Guard officials said there is no scientific evidence that cargo
sweeping is harming water quality or suffocating fish habitat in the Great
Lakes. And they noted that the amount of cargo residue dumped overboard is
less than 1 percent of the cargo freighters transport on the lakes.
But there has never been a thorough scientific study of the environmental
risks associated with cargo sweeping. Scientists at a 1993 conference
convened to examine the issue said 75 years of dumping iron ore, coal and
other minerals into the lakes could cause environmental problems.
"Iron ore, coal, petroleum coke and slag were determined by the committee to
have the potential for both acute and chronic environmental impacts and were
worthy of more intense scrutiny," according to a report titled "The
environmental implications of cargo sweeping in the Great Lakes."
"Of greatest concern to the committee, however, is the repetitive addition
and probable buildup of these materials in bottom sediments and the
potential chronic effects on both hard and soft bottom habitats," the report
Coal that is shipped to power plants around the Great Lakes contains traces
of heavy metals and other chemicals that can be toxic to humans, fish and
wildlife if ingested. Iron ore and slag contain metals that can be "quite
toxic," according to the report.
The 1993 report urged more study to determine whether cargo sweeping was
burying fish habitat or causing other problems in the lakes. But those
studies never materialized, federal officials said.
"If all the Coast Guard does is take the interim policy from 13 years ago
and make it permanent, that doesn't make me very happy," said Eric Reeves,
the retired chief of environmental safety at the Coast Guard's Cleveland
Reeves wrote the Coast Guard's interim policy in 1993. He said he hoped the
interim policy would prompt more studies of cargo sweeping.
Though Coast Guard officials have repeatedly defended cargo sweeping, a 2003
report by the agency said "discharges greater than 1,000 pounds should be
Reeves said the Coast Guard should not adopt a final policy on cargo
sweeping without a thorough scientific examination of the issue.
"Let's conduct the scientific studies and not just say the problem is solved
just because they have an administrative solution to it," Reeves said.