Despite complaints about airborne dust from local gravel pit operations, Sechelt’s air quality is generally “excellent,” according to provincial air quality meteorologist Graham Veale.
In a report last month to Greg Deacon, secretary of the East Porpoise Bay Community Association, Veale summarizes the results of air quality sampling from a monitoring station at Trail Bail Centre since December 2012.
“With the exception of 2015, which was greatly influenced by a wildfire smoke episode in July, the table indicates that the station continues to measure low [particulate matter] concentrations. A significant number of samples returned values below the laboratory limit of detection,” Deacon wrote.
The monitoring station provides non-continuous coverage (24-hour samples every six days), but the schedule ensures that every day of the week is monitored over a long-term basis, Deacon explained.
“While a direct comparison of the discontinuous Sechelt data should be viewed with caution, it does indicate that the community would be ranked as the second lowest concentration in B.C., bettered only by another Sunshine Coast community – Powell River,” he wrote.
“In summary, particulate data from historic and current monitoring indicates that Sechelt usually experiences excellent air quality, with the exception of occasional impacts of smoke from wildfires.”
Regarding “historic and ongoing” complaints about dust, Deacon said it’s possible that the Sechelt area “is affected by intermittent, short-term (e.g. several hours) particulate episodes, such as might be related to industrial activities and/or high wind events. However, these do not appear to persist long enough to produce any exceedances of the short-term Ambient Air Quality Objectives (AAQOs), which are based on a 24-hour averaging period.
“Also, a portion of the airborne particulate may be larger (greater than 10 microns in diameter) than the size ranges measured by the monitoring equipment. This larger particulate could result in visible deposition on property and would be viewed as a ‘soiling’ or nuisance issue rather than a human health concern.”
To determine if “localized particulate episodes” were occurring at the neighbourhood level, samples were taken at homes in East Porpoise Bay from December 2012 until March 2014. The results, Deacon wrote, “show no significant difference from the Trail Bay Mall station, with no exceedances of the AAQOs.”
