Rio Tinto’s air quality monitoring station in the Service Centre area of Kitimat will be designated a KPI (key performance indicator) attainment site as of January.
KPI attainment sites are a requirement of the company’s Environmental Effect Monitoring (EEM) plan. There are currently three in the Kitimat area at Riverlodge, Whitesail and Kitamaat Village.
Ambient air quality measurements at these sites for sulfur dioxide (SO2) emissions are compared to the Human Health KPI as set out in Rio Tinto’s Pollution Prevention Permit.
That KPI is based on the province’s 1-hour standard of 70 parts per billion. That SO2 objective “is achieved if the fourth highest daily maximum value each year (averaged over three years), is less than or equal to 70 ppb,” according to a memo by Ben Weinstein, a senior B.C. air quality meteorologist.
The memo followed a review by the province’s environment ministry technical staff whether the data collected at the Service Centre station since it was set up in 2019 was sufficient to designate the site a KPI attainment site.
If concentrations at any of the four KPI sites indicate non-attainment of the 1-hour standard, the smelter is required to reduce SO2 emissions.
In making the decision to designate the site, the ministry took into account that the four stations reflect areas of the Kitimat area where differences in air quality are expected due to geography and dispersion patterns and where risk to human health from emissions is a concern.
Once the site is designated, the three-year average will be reviewed annually. If the site shows non-attainment of the human health KPI and the company does not reach attainment by the following year, the ministry can impose a reduction in the permitted amount of emissions from the smelter.