Item 7. Discussion on PWB 2023-24 work related to adaptation
Understanding the Role of Air Quality Modeling in Environmental Compliance
1. www.all4inc.com
Philadelphia | 610.933.5246
Atlanta | 678.460.0324
Houston | 281.937.7553
Understanding the Role of
Air Quality Modeling in
Environmental Compliance
Mark Wenclawiak, CCM| mwenclawiak@all4inc.com | 678-460-0324
February 10, 2015
Presented to The American Society of Safety Engineers
Augusta/Aiken Chapter
by All4 Inc.
2. 2 Your environmental compliance is clearly our business.
Agenda
What are air quality models?
Why do we perform air quality modeling?
What goes into an air quality model?
Questions and answers
3. 3 Your environmental compliance is clearly our business.
ALL4
Environmental consulting firm
Founded 2002 – currently 40+ employees
Offices in Philadelphia, Atlanta, Houston
Specialize in air quality consulting
• Complex air permitting and strategy development
• Air dispersion modeling
• Ambient air quality monitoring
Dispersion modeling as a company-wide initiative
www.all4inc.com
4. 4 Your environmental compliance is clearly our business.
The Old Days of Modeling
6. 6 Your environmental compliance is clearly our business.
Air Quality Models
Models are predictive tools
• Past performance is not a predictor of future results
Mathematical and numerical techniques to
simulate the physical and chemical processes that
affect air pollutants as they disperse and react in
the atmosphere
• Conservative assumptions
8. 8 Your environmental compliance is clearly our business.
Models and the Real World…
Speaking of complex…how do you model this?
9. 9 Your environmental compliance is clearly our business.
Types of Air Quality Models
Screening
Refined
Photochemical
Long-range transport
Mobile sources
U.S. EPA’s preferred/recommended models
• 40 CFR Part 51, Appendix W
11. 11 Your environmental compliance is clearly our business.
Support air permit applications
• Construction projects
• GEPD and SCDHEC air toxics analyses
Conduct risk assessments
• Human health and environmental impacts
Play detective (forensics evaluations)
• Nuisance dusts and odor complaints
Proactively evaluate compliance
• Facility expansions
• Preparing for upcoming regulations
Modeling is Performed to…
13. 13 Your environmental compliance is clearly our business.
Emissions information
Meteorological data
Building dimensions
Topography
Agency-approved protocol
Data Input
14. 14 Your environmental compliance is clearly our business.
Data Input
Hourly Data
Wind Speed
Wind Direction
Ambient Temperature
Land Use Patterns
Topography
Building Dimensions
Stack Dimensions
Exhaust Velocity
Exhaust Temperature
Emission Rates
Predicted Ground Level
Ambient
Concentrations
Beware – Garbage In, Garbage Out!
15. 15 Your environmental compliance is clearly our business.
Short-term emission rates
Exhaust (stack) characteristics
May or may not be readily available
Emissions Information
16. 16 Your environmental compliance is clearly our business.
Surface data and upper air data
National Weather Service or on-site data
• Not your Sky Mall weather station
Meteorological Data
23. 23 Your environmental compliance is clearly our business.
Terrain elevation
Land use
From these, develop a receptor grid
• Exclude onsite receptors
Topography
24. 24 Your environmental compliance is clearly our business.
Typical receptor grid spacing:
• 100 meters out to 2 kilometers
• 200 meters out to 5 kilometers
• 500 meters out to 10 kilometers
• 25 meter spacing along fenceline, assuming that only
offsite receptors are being modeled
Public access must be restricted in some way
(e.g., fence, armed guards, attack dogs, moat) in
order for onsite receptors to be disregarded in
the modeling analysis
Receptor Grid