Fraser Valley - Air Quality

Air Quality

As the valley population grows and traffic increases, air pollution becomes an increasingly important issue; various controversies have risen over the years (most recently over "Sumas 2", a defeated proposal for a power plant just south of the Canadian/USA border) as to whether or not air pollution is a problem, and if it is a problem, how this should be addressed.

Air quality monitoring has improved in recent years and it is now possible to compare BC communities on a variety of measures. Comparative data on four measures—fine particulate matter, ground-level ozone, nitrogen dioxide and sulpher dioxide—shows the Fraser Valley to rank lower than Vancouver on several measures of air quality. For example, Fraser Valley communities had less than half the levels of nitrogen dioxide, and were lower in fine particulate matter and sulphur dioxide (on the latter measure, Abbotsford and Chilliwack were among the lowest of all BC sites).

In certain weather conditions during the summer, prevailing westerly winds blow air pollution from vehicles and from ships in Vancouver harbour east up the triangular delta, trapping it between the Coast Mountains on the north and the Cascades on the southeast. Air quality suffers. This usually occurs during a temperature inversion, and lasts for a few days. Ground-level ozone tends to be from local sources in the valley and varies with prevailing winds. With prevailing winds from the northeast during the late fall and winter, air quality is seldom a problem.

Air quality in the Fraser Valley at times exceeds the Canada-Wide Standard (CWS) for ozone (at Hope) and is close to exceeding the CWS for Particulate Matter.