Americans in the state of Washington are not happy that Canadians are dumping all of their pollution in the US and don't want to pay the $1 billion it will cost to clean it up so they are suing in court. The Canadians say British Columbia is not actually part of the United States so a US court ruling is meaningless, and they didn't mean to dump all that slag from their giant lead and zinc smelter into America. It seems that when that factory started no one was aware pollution could travel 10 miles down a river. They also contend it is not pollution. I guess that is how awesome refuse from Canadian factories is.
The company being targeted by the lawsuit, Teck, says it is not to blame. They say it is the almost 1,000 other metals mines and mills also dumping pollution into the river that are mucking up Washington state. Since they are not the sole culprit, the Canadian and US governments should pay to clean up their pollution, they contend, but Canada's government protests even a joint clean-up, which means American taxpayers would be on the hook. Teck also notes that the Lake Roosevelt National Recreation Area isn't actually being polluted by their slag, since it is not harmful. Maybe brochures could highlight black sand as a tourist attraction.
Canadians have it easy. To the US EPA, even clean water is considered a pollutant in rivers. In Canada, nothing is considered pollution - if it ends up over the US border.