An airshed is generally described as an area where the movement of air (and, therefore, air pollutants) can be hindered by local geographical features such as mountains, and by weather conditions. The
most obvious example in British Columbia is a mountain valley. Since air pollution knows no political boundaries, airshed activities may be focused on a single community or on a number of neighbouring
communities faced with similar air quality problems and requiring similar action.
An airshed plan provides a blueprint to help communities manage development and control air-contaminant sources. It also provides stakeholders with a clear understanding of community air-quality priorities
and how future growth may be accommodated. In addition, an airshed plan ensures that the air quality goals of various levels of government are met. Community-based airshed plans are key to meeting B.C.'s
obligations under the Canada-wide Standards for Particulate Matter and Ozone.
Some airsheds, such as the Lower Fraser Valley airshed and the Georgia Basin-Puget Sound airshed, have been defined, and jurisdictions on both side of the border are taking joint action to improve and
protect air quality.
Lower Fraser Valley Airshed
The Lower Fraser Valley (LFV) Airshed includes Metro Vancouver and the Fraser Valley Regional District (FVRD). It
extends from Horseshoe Bay to Hope. The Air Quality Monitoring Network collects data at 27 stations in the
airshed, monitoring air pollutants such as carbon monoxide (CO), particulate matter (PM2.5 and PM10) and ozone (O3).
Metro Vancouver, the FVRD and other agencies in Canada and Washington have formed the Lower Fraser Valley Air Quality Co-ordinating Committee, which develops air quality programs and actions for the
LFV Airshed, and the larger Georgia Coast Cascade Air Basin.
Georgia Coast Cascade Air Basin
The Lower Fraser Valley is included in a larger regional airshed called the Georgia Coast Cascade Air Basin. It is bordered by the Strait of Georgia, the Coast Mountains to the north and Washington's
Cascade Mountains to the southeast. Agencies in Canada and Washington State co-ordinate airshed activities through the Lower Fraser Valley Air Quality Co-ordinating Committee.
/ Puget Sound Airshed
The Georgia Basin / Puget Sound airshed straddles the border of Canada and the United States, along the west coast. It is composed of two smaller airsheds: the Georgia Basin and Puget Sound.
and U.S. government agencies are taking numerous actions to reduce air pollution and its impacts in this region, under the Georgia
Basin / Puget Sound International Airshed Strategy.
Click on this "thumbnail" for a larger map of the Georgia Basin / Puget Sound Airshed.
Other Areas in B.C.
Airsheds have been defined for the purpose of airshed management in a number of other parts of the province. In some cases, airshed boundaries have followed political boundaries, to reflect the area
in which there is support and authority for air quality action. This includes individual municipalities or regional districts, and multiple regional districts where there are common issues requiring
solutions across a broader area.
To date, airshed plans are under development or being implemented in the following areas of British Columbia:
- municipalities: Merritt, Prince George, Quesnel, Whistler, Williams Lake, Grand Forks;
- regional districts: Fraser Valley Regional District, Metro Vancouver (formerly the Greater Vancouver Regional District), Regional District of Okanagan-Similkameen, Regional District of Central
Okanagan, Regional District of North Okanagan; and
- multiple regional districts: Bulkley Valley-Lakes District (Kitwanga to Endako), Sea-to-Sky Corridor (Bowen Island to just north of Pemberton).
In this section: