Effects on Nature

In this Section:

The Effects of Water Pollution

Pollution is not always visible. A river or lake may seem clean, but still be polluted. In groundwater, on which over one quarter of all Canadians rely for their water supply, pollution is especially difficult to discern. Nor are the effects of pollution necessarily immediate; they may take years to appear.

When pollution makes water unsuitable for drinking, recreation, agriculture and industry, it eventually also diminishes the aesthetic quality of lakes and rivers. Even more seriously, when contaminated water destroys aquatic life and reduces its reproductive abilities, it eventually menaces human health. Nobody escapes the effects of water pollution.

Accelerated Aquatic Plant Growth: Too Much, Too Fast

The growth and reproduction of aquatic plants is stimulated by eutrophication, a natural process which, over geological time, turns a lake into a bog and eventually into land. But today, in many places, this process is tremendously accelerated by high concentrations of phosphorus and nitrogen (from fertilizer, for example) which enrich the water with nutrients, causing the aquatic plants to bloom. As the plant growth explodes, it chokes off the oxygen supply normally shared with other organisms living in the water. When the plants die, their decomposition uses up even more oxygen. As a result, fish suffocate and die, and bacterial activity decreases.

Yet if phosphorus and nitrogen inputs are reduced or stopped, the system can recover by itself. In the late 1960s, Lake Erie experienced such an extreme case of eutrophication that fish were dying and the decomposing algae, washed up on bathing beaches, had to be removed with bulldozers.

The phosphorus (phosphate) in laundry detergents washed into the lake was the main culprit. A law was passed to reduce the substance. In 1972 laundry detergent phosphate contents were cut by approximately 90% and Lake Erie made a remarkable recovery.

Since 1989, the Phosphorus Concentration Regulations have required that all household, commercial and industrial laundry detergents contain no more than 2.2% phosphorus by weight. On July 1, 2010 the Regulations were amended and now household laundry detergents, household dish-washing compounds and household cleaners can contain no more than 0.5% phosphorus by weight. The long title of the regulations was changed to Concentration of Phosphorus in Certain Cleaning Products Regulations.

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