The taste of water

Lakes and streams are being fouled with a variety of pollutants including urban and industrial wastewater, fertilizers, pesticides and livestock manure.

About one-quarter of all Canadians rely on groundwater as their sole source for all their daily water needs. In 1999, the vast majority (97%) of Canadians living in a municipality received some level of sewage treatment, compared with 72% in 1983.

And each year, thousands of tonnes of industrial wastes pollute streams. In 2000, the National Pollutant Release Inventory reported 373,000 tonnes of on-site pollutant releases (less than a quarter of all releases). Of that number, approximately 12% were releases directly into water and more than 40% of on-site releases were in the form of underground injection (materials injected into underground wells).

Because of crop specialization and the race for higher yields, farmers are using more and more fertilizers. Under some conditions, these products may leach into the soil, polluting neighbouring waters. This additional load of nutrients promotes the growth of water plants, thereby reducing the oxygen content of the water and limiting the development of other forms of life. Excessive quantities of manure can have similar effects. Since drops of water ultimately reach the ocean, the harmful effects of all these substances are being felt there too. For example, a number of shellfish-harvesting areas on the Atlantic and Pacific coasts have been closed because of pollution. Because of the way they ingest food, shellfish tend to concentrate pollutants and can pose a danger to consumers.