1. New Guidance for Air Quality Impact Assessment A Review
Michael C. Murphy, PhD, P.Eng.
IAIA 2017 – Montreal, Quebec
April

2. Outline Objective Comments Review of Each Implementation Summary
Talk to the slide content

3. Objective Provide Review Comments on the Air Quality Guidance Document
Talk to the slide content
Hotel Industry Power Plant

4. Comments / Suggestions
Writing is organized, easy to read
Scoping is super important – bring this out more
Worse Case Impacts – emissions, weather, + more
Add project phases - construction, operation
ToR often “not comprehensive”, still need screening
Preparing Emission Inventory = the Key
Careful re “conservative”
Presenting the results
How to implement the Guidance
Talk to the slide content

5. Writing Writing is organized, easy to read No jargon, few acronyms
Concepts are clearly described
Not easy to do
Some diagrams or charts might be useful
Talk to the slide content

6. Scoping Bring this out more Decide - what to assess
Understand the project activities
What to include, why
What to exclude, why
Include “all substantive emissions”
Define “substantive” – …e.g., predicted values within 10% of ambient standards
Talk to the slide content

7. Worse Case Impacts
Worse Case emissions combined with worst case weather
“Worst case”, a screening approach, is correct
Can be more to it
What if there are exceedances?
Next steps?
Talk to the slide content

8. Add Project Phases Project activities - construction, operation
Can occur over years
dust, noise, odour, intermittent
Commissioning
“first start up” - emissions + impacts can be high
Operation
Often constant releases
some variation with time
Maintenance startup, shutdown
Talk to the slide content

9. Terms of Reference (ToR)
ToR often “not comprehensive”
Study “main sources” + “main air contaminants”
Other “smaller” sources - may have bigger impact
In some cases, sources are missed altogether
Talk to the slide content

10. Preparing Emission Inventory
the Key
A foundational step
important to get it right
There are “general methods”, but…
Need to understand the activities that generate emissions
How do you know if it is “7.2 million tonnes/year”?
Review in detail with proponent, get sign off
Talk to the slide content

11. Careful re “Conservative”
Be clear on what is meant by “conservative”
Sometimes it means low, sometimes its high
Not always clear, OR not described adequately
When building a dispersion model, know that
“stacking conservative assumptions” can lead to
overly conservative assessment
Example – new professional service building, power needs
Assumed: 4 diesel generator sets run 24/7 365 d/y.
Actual: gensets, running < 500 hrs per year
Talk to the slide content

12. Presenting the Results
Add a note on this
Contour plot is not a simulation
Predicted concentration data for a set of receptors
(i.e. set of locations)
Maximums only
And, 2nd highest, 9th highest
Percentiles, mean, minimum
Talk to the slide content

13. Example Modelling Results
Project
Maximum 1-hour
Cumulative
Maximum 1-hour
Background = 63 µg/m Background = µg/m3
Maximum GLC = 312 µg/m Maximum GLC = 634 µg/m3
Maximum Permissible GLC = 450 µg/m

14. Example - Frequency
Example – Frequency Distribution

15. Air Quality Guidance - Implementation
Some jurisdictions have guidance re Air Quality Modeling
Many do not
Objective – to standardize the approach – with a minimum set of guide elements / directives
Identify it to those organizations that need help
Get international folks on board - World Bank, WHO, IFC
Provide opportunity to host Workshop(s)
Clearly show the benefits of adopting…
Talk to the slide content

16. Air Quality - Summary Clearly show the benefits of adopting and using…
Scoping is super important – bring this out more
Add project phases - construction, operation
Careful re “conservative”
Preparing Emission Inventory = the Key
Presenting the results
Clearly show the benefits of adopting and using…
Talk to the slide content

17. Thank you! …questions/thoughts? mike.murphy@stantec.com
Dave Flynn and Mary Murdoch have been involved in this revision along with Jeff Green and can be contacted for comment / discussion.
Thank you! …questions/thoughts?