In the 1960's, the waters of the Rhine were so severely contaminated that by the time they flowed into the North Sea by Rotterdam the river was effectively dead, with no to extremely limited life in it.
It wasn't even the fault of Rotterdam's nature as Europe's biggest port and a key oil refining city, with multiple, massive oil refineries build on the river shore.
Rather, it was the cumulative effect of municipalities, industries and the general public dumping waste and waste water directly into the river along practically the entire length of the river.
It took decades of activism and legislative effort across three countries (France, Germany and the Netherlands) to clean the river up, and it has cleaned up quite well now. I wouldn't advise drinking it without some proper filtering, but at least it won't poison you when you fall in.
It wasn't even the fault of Rotterdam's nature as Europe's biggest port and a key oil refining city, with multiple, massive oil refineries build on the river shore.
Rather, it was the cumulative effect of municipalities, industries and the general public dumping waste and waste water directly into the river along practically the entire length of the river.
It took decades of activism and legislative effort across three countries (France, Germany and the Netherlands) to clean the river up, and it has cleaned up quite well now. I wouldn't advise drinking it without some proper filtering, but at least it won't poison you when you fall in.