The Thunder Bay Operation was constructed in the early 1920s and like the mill, the adjacent City has continued to grow and prosper. As a result the mill has a number of residential neighbours within 1 kilometre.
In response to increasing concerns regarding
odour emissions, we undertook a project to try to understand the source. We wanted to develop a tool that could be used to identify sources of odour in order to reduce the number of episodes. This led to the development of “BowaterView”, an advanced, real-time, air dispersion model based on accepted regulatory models.
In Ontario, the regulatory limits for air emissions are based on a number measured offsite—something called Point of Impingement (POI). Unlike other jurisdictions, which based emission limits on what is coming out of the individual stacks or vents, Ontario has chosen to look at the effect of all the sources as they impact in the community. Companies which discharge air emission must demonstrate compliance with these POI limits using a computer model that takes into account where the emissions come from as well as atmospheric conditions or by actual
ambient air monitoring results.
There are a number of models available, ranging from the very simple Regulation 346 model used by the Ministry of the Environment, to the very complex models used by the United States Environmental Protection Agency. Usually these models are run on a one-time basis, using a snapshot of emissions and historical weather data, with a report prepared for government submission.
Compliance with government regulations is also measured by monitoring stations. These are usually located downwind from an industry. These stations continually measure for various types of air emissions, and record the data either real-time or in sampling instruments for future analysis. The drawback of this type of monitoring is that the only time emissions from an industrial facility can be measured is when the wind is blowing directly over the station.
Resolute Forest Products worked with the air dispersion modeling company, Lakes Environmental, to develop the first real-time dispersion model to utilize the USEPA’s AERMOD/PRIME model.
This dispersion model takes into account continuous emission data from the mill and models emission movement based on the data from surrounding terrain and weather data from stations located near the mill. At any given time, not only can the mill tell in which direction the odour emissions are blowing, but also tell what the source is.
As this model becomes refined, it will be a powerful tool for the mill to use when trying to address odour concerns from the facility.