The U.S. Environmental Protection Agency is warning the public not to expect any quick solutions after samples taken along the American shore of the Detroit River turned up several harmful toxins.
Toxins like mercury, cadmium, and lead along with PCBs were found in more than 800 samples taken along a 51.4-kilometre stretch. The most common contaminant was polycyclic aromatic hydrocarbons (PAHs), which come from burning trash, fuel, wood, and tobacco.
Project Manager Rose Ellison told BlackburnNews.com the toxins are common in former industrial sites.
She said the clean-up would have to be done piecemeal, and it will take decades.
A pile of petroleum coke being removed, by ship, from Detroit's riverfront, July 24, 2013.
"It's taken over 100 years for the river to get into the condition it's in," she said. "The last number of years we've been able to make big strides, but it's a long-term process."
While those contaminants are known risks to human health, Ellison stresses the amount is meagre, in the parts per billion. She said the immediate danger is to aquatic life, not directly to human health, although the toxins do pass upward along the food chain.
"That's why on the Detroit River there are fish consumption advisories. So, you can fish, but you have to be careful how much you eat, because of some of the chemicals that do get in the fish from the basis of the food chain," said Ellison.
Toxin levels vary species to species, but the Michigan Department of Health and Human Services recommends eating no more than one eight-ounce serving of Northern Pike per month.
The agency has to find partners to help fund the separate clean-up projects, and while some have already come on board, the cost will be tremendous.
"Each project is unique," explained Ellison. "This is an old number, but the rule of thumb that we go with still is that it costs about $250 a cubic yard."
If 5.1-million cubic metres or 6.6 million cubic yards are contaminated, it could cost $1.6-billion to restore the shoreline.
For those living on the Canadian side of the Detroit River, there is some good news. Ellison said because of the flow of the Detroit River, there has not been a lot of cross-channel contamination to the Canadian shore.