Mill Permits Permit Wide Swath of Air Quality Concerns
November 1 2009
It comes as no surprise to those suffering from frequent "bad air days" around BC's pulp mills. A new study of the air quality impacts of the Crofton pulp mill reveals that the air pollution permit levels could expose a wide swath of the countryside to air quality worse than provincial or federal guidelines.
Reach for Unbleached and the Crofton Airshed Citizens Group commissioned RWDI Air to model the potential impacts of mill emissions if the mill were to pump out pollution at the levels allowed by the permits from the provincial government. The pollutants studied were particulate matter, total reduced sulphur (TRS), chlorine dioxide (ClO2), and dioxins and furans (PCDD/DFs).
In the case of chlorine dioxide, real emissions numbers were available to the scientists. The mill is persistently out of compliance with its permit levels on chlorine dioxide emissions, and the study found that an area immediately around the mill exceeded the Alberta one hour air quality objective (BC has none) 8% of the time, which would be about 29 days of the year.
Even more concerning are the results for TRS (the “smell of money” pollutant) and particulate. If the mill were to output TRS at the levels which it is allowed under the permits, an area about 5 by 20 kilometres, from Maple Bay almost to Chemainus and including the west side of Saltspring Island, would be exposed to TRS over the BC 24 hour “Level A” objective 5% of the time, about 18 days a year. Worse, a substantial area closer to the mill would exceed that level 20% of the time – one day in five.
TRS is annoying and makes some people feel ill, but very fine particulate matter (PM 2.5) is a confirmed health risk. There are no permit standards for PM2.5 but there are ambient air measurements for the Crofton area, and it is generally known that PM2.5 forms about 70% of pulp mill particulate. From the models, it appears that BC 24 hour objectives could be exceeded for a similar, although slightly smaller area with somewhat different contours, when the mill output is combined with background air concentrations from other sources.
Areas with a maximum predicted TSP concentration greater than 13 µg/m3 in the map (Figure E-3) would exceed the PM2.5 objective based on these assumptions.
In all cases, two of the three air monitors in the area are outside the predicted areas of major impact.
Download jpgs of the modelling maps:
Figure E-1: TRS Frequency of Exceedence of BC Level A 24-hour Objective