Sustaining our water quality

In addition to water supply and infrastructure issues, water quality is a problem in many Canadian communities. Generally speaking, the decline in water quality is a function of the way we use water. Even something as simple as rinsing dishes in the kitchen creates wastewater that is contaminated to some degree. Once this water enters the sewer system, it must be treated in a sewage treatment plant. These facilities are never 100 percent effective, which means that some water quality deterioration remains after the treatment process. 

Specific causes of impaired water quality are numerous, including: agricultural runoff containing the residues of fertilizers, pesticides and other chemicals, industrial pollution, either directly from the facility, or indirectly from the leaching of chemicals from landfills, or pollution from average households in the form of improperly treated municipal sewage (refer to Freshwater Series A-3, Clean Water – Life Depends in It!) Nearly 75% of Canadians are serviced by municipal sewer systems. In 1999, 97% of the Canadian population on sewers received some form of wastewater treatment. The remaining 3% of Canadians served by sewage collection systems were not connected to wastewater treatment facilities in 1999 and discharged their untreated sewage directly into receiving water bodies.

For the roughly 25 percent of the Canadian population served by private wells and septic disposal systems, the news is not much better. These systems were originally designed for houses that were widely separated from their nearest neighbour, such as farmhouses and the occasional rural residence. Yet, today, in many parts of the country, individual private wells are being installed in subdivisions at suburban densities. The primary danger here is that too many wells may pump too much water for the aquifer to sustain itself. 

Septic treatment systems associated with these developments can stress the environment in a number of other ways. They are often allowed in less than satisfactory soil conditions and are seldom maintained properly. They are also unable to treat many household cleaners and chemicals which, when flushed down the drain or toilet, often impair or kill the bacterium needed to make the system work (The same applies in urban systems). The end results are improper treatment of wastewater – if not outright failure of the system – and the contamination of adjacent wells with septic effluent containing bacterium, nitrates and other pollutants. 

Once these contaminants are in the groundwater, they eventually reach rivers and lakes. In other words, once we have a pollution problem, we may be only a step away from a water supply problem.

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