By Don Butler, Ottawa Citizen, August 22, 2016
In the 19th century, it was choked with sawdust within sight of Parliament Hill. Half a century ago, sewage discharges routinely fouled its waters.
Today, the Ottawa River is much improved. “It’s definitely healthier than in the 1960s and ’70s, which was the height of pollution,” says Meredith Brown who, as Ottawa Riverkeeper, has closely monitored the river’s condition for more than a decade.
http://ottawacitizen.com/news/local-news/a-cleaner-river-struggles-still-with-threats-to-its-health