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Water Quality

Atmospheric Deposition

Atmospheric Deposition > Solutions > Resources and Links

Atmospheric Deposition

Gases and particulates released to the atmosphere from combustion sources such as motor vehicle emissions, slash burning, and industrial sources, contain nitrogen, sulphur, and metal compounds, which eventually settle to the ground as dust or fall to the earth in rain and snow. These pollutants, which may have distant origins, may be deposited directly into waterbodies, filter slowly into ground water, or in urban areas, be washed from roads, rooftops, and parking lots into surface waters. The gradual effect can be acidification of waters to a point where the natural buffering capacity of receiving waters is exceeded and aquatic life is threatened. Toxins, such as dioxins, furans, polychlorinated biphenyls, and polycyclic aromatic hydrocarbons, transported by atmospheric processes eventually accumulate in sediments, to the detriment of bottom-dwelling organisms and fish and their consumers.

aerial photo of smog

Automobile use in an area greatly affects the atmospheric deposition of NPS pollutants, and this is a concern linked to urban sprawl. British Columbia's Lower Fraser Valley, with its characteristic weather patterns and surrounding mountains, now has a serious air quality problem because of ever-increasing motor vehicle use. In the Greater Vancouver area between 1984 and 1991, the number of cars insured for driving to work increased twice as fast as the population. Greater Vancouver now has more cars per capita than Greater Los Angeles.

aerial photo of smog

An expanding population, expected to reach three million in the Lower Mainland by 2021, could mean a doubling of vehicle-kilometres travelled in the region. Greater congestion will lead to more stop-and-go traffic, increasing the emissions released per trip. From both an air quality and a water quality perspective, the increased risk to human health of these projections is of concern, given that the Lower Fraser Valley airshed is now at or above its capacity to accept contaminants. Significant efforts are being made to address these issues in British Columbia, especially to ensure the use of clean vehicles and fuels. Recent programs include:

Several legislative initiatives have also been completed:

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Ongoing efforts to manage point source of air discharge, regulating toxins in motor vehicle emissions, and, above all, reducing overall motor vehicle use are important strategies and will help address this source of NPS water pollution in British Columbia.

Individuals can also help reduce air pollution by following these tips:

On the road:

  • Reduce your vehicle use to reduce air pollution. Walk or cycle, take public transit or carpool instead of driving your car. When you have to drive, be sure to combine trips instead of making several individual short trips.

  • Keep your engine well tuned to ensure it is running as efficiently as possible.

  • Keep your tires maintained and properly inflated — this will improve your fuel efficiency and reduce emissions.

  • In the Greater Vancouver Regional District or the Lower Fraser Valley, report smoking heavy-duty vehicles by calling (604) 435-SMOG (7664).

At home:

  • Upgrade your home insulation and weather proof your doors and windows to reduce the amount of energy needed to heat your home. Emissions will be reduced because less fuel is being burned.

  • Use hand-powered or electric lawn mowers and tools which are cleaner than gas powered tools. On average, a car pollutes 10 times less than gas mowers and leaf blowers.
    Chip or compost yard wastes instead of burning which contributes particulates and other harmful particulates to the atmosphere.


Resources and Links

Environmental Quality Branch, British Columbia Ministry of Water, Land and Air Protection A Citizen's Action Guide



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