Phosphates from detergents and nitrates from fertilizers were disrupting Canadian water systems in the 1970s. Entire lakes were dying - deprived of the oxygen necessary to sustain life. Here the Freshwater Institute deliberately releases contaminants into experimental lakes to study their effects. Canada, which contains one third of the world's fresh water, later imposed restrictions on phosphate levels in detergents.
More info on this film in NFB catalogue »»