This is a problem that's been ongoing for over a dozen years-- not the pollution, but the U.S. trying to get Canada to stop it. Unfortunately, mercury is not the only contaminant. There are a lot of heavy metals, and as I recall, some other nasties in the mix as well.

As for environmental laws, Canada does have some-- for instance, they require that Victoria monitors its outfall to see if there is a water-quality problem. This is where they dump raw sewage (it might be screened) into the Strait. If there is a problem, they have something like three years to find a solution.

Go Canada!

Keith