David Chadder is a Senior Project Director and Principal with RWDI AIR Inc., and lead author of the airquality studies for the Trans Mountain Expansion Project. We connected with David to learn more about these studies, TMEP’s low impact on air quality in Burnaby and the exceptional level of detail that went into this important research on behalf of the Project.

How much of an impact will Trans Mountain Expansion Project have on air quality in the vicinity of Burnaby Terminal and Westridge Marine Terminal?

Depending on the chemical, Project-related marine and land-side emissions are expected to contribute three per cent or less of existing annual emissions in the smallest computational model domain (12,500 km2).

What value does the study provide to Metro Vancouver?

The CMAQ (Community Multi-scale Air Quality) study should be helpful to Metro Vancouver and other regulators since TMEP, in combination with other publicly announced projects, is not going to cause any significant adverse effects on air quality in the Lower Mainland. As such, the study should be useful for municipal planning purposes.

What is a photochemical contaminant and what does it do in the atmosphere?

Photochemical contaminants (sometimes called smog) are secondary products like ozone and PM2.5 (respirable particulate matter) that form in the atmosphere through a series of complex chemical reactions. They require a suitable mixture of pre-cursor chemicals like NOx (nitrogen oxides), ammonia and VOC’s (volatile organic compounds) with sunlight as an energy source for their formation.

What is atmospheric modelling?

Atmospheric modelling is a mathematical representation of complex atmospheric conditions. The modelling relies upon very fast computers undertaking a large number of computations. In that sense, atmospheric modelling is similar to weather forecasting, which is also computationally intensive. Photochemical modelling adds another layer of complexity by modelling thousands of chemical reactions as the atmosphere evolves.

Why was it necessary to look at air quality data from Northwest Territories, Los Angeles, Winnipeg and more than 1,000 nautical miles out into the North Pacific Ocean?

The chemical reactions that take place in the atmosphere are complex and the CMAQ modelling domain needs to consider contributions from a variety of emission sources, both naturally occurring and man-made (anthropogenic). Over the course of the modelled one-week episodes, emissions and their chemical products can be transported over several hundred kilometers into the Lower Mainland.

You’re presenting Trans Mountain study results in North Carolina at an international conference organized by the Community Modelling and Analysis System (CMAS) Center. This is one of the world’s leading research groups for environmental modelling. How does your work for Trans Mountain fit into this?

Presenting the CMAQ modelling results at the forthcoming CMAS conference provides an opportunity for international experts to learn of the approach and findings of this significant study. It is quite unique for a non-governmental organization to undertake these sophisticated studies and it is worthy of discussion among scientific professionals and regulators. This annual conference provides a suitable forum.

How many people were involved in the Trans Mountain study?

Up to 10 RWDI staff were involved in the study including meteorologists, atmospheric chemists, engineers and the project manager. The updated CMAQ photochemical modelling required about three months to complete with about 1,000 hours of effort.

This RWDI study goes far beyond regulatory requirements for an energy pipeline review for the National Energy Board, doesn’t it?

Yes, that’s true. Undertaking photochemical modelling for an industrial project application is very uncommon in my 37-year work experience. This is only the second time for me where CMAQ modelling was completed by a proponent. The first project was in support of a proposal for two new power plants in southern Ontario near Toronto. Kinder Morgan has agreed to report on net effects from the Project twice using the CMAQ photochemical model – in 2013 and this 2015 update. Again, this is quite uncommon for a regulatory process but very commendable in terms of social responsibility.