Saskatchewan s Air Modelling and Odour Guidelines Imran Maqsood, Ph.D., P.Eng. Ministry of Environment Air Quality in Saskatchewan, Saskatoon January 17, 2014
Outline Part 1: Air Modelling Guideline Part 2: Odour Guideline
Part 1 AIR MODELLING: GENERAL INFORMATION
Why Do We Need Guideline? To ensure consistency in conducting air modelling in Saskatchewan Regulatory approvals are treated equitably Promote efficient use of resources
How was Guideline Developed? Draft prepared in 2010 Reviewed internally & externally in 2011 First official guideline released in 2012 Review and update guideline periodically
Is Guideline Flexible? Ministry supports innovation We are open to new or improved methods Any deviation should be justified Pre-consultation with the ministry is recommended to discuss variations
Is it Consistent with Other Guidelines? Efforts were made to maintain consistency with modelling approaches in AB and BC New West Partnership between SK, AB & BC
What Standards to Use? Saskatchewan Air Quality Standards National or CCME Alberta Environment Ontario Ministry of the Environment Texas Commission on Environmental Quality
Part 1 AIR MODELLING: TECHNICAL GUIDANCE
What is Air Modelling? Mathematical simulation of how air pollutants disperse in atmosphere Meteorology, site configuration, emission and terrain impact transport of pollutants
Why is Modelling Conducted? Approval or permit applications Predict pollutant concentration Stack design Select monitoring sites Design plans for air quality management
What is SK s Modelling Approach? Screening Modelling Simple facility Limited number of sources Refined Modelling Complicated facility Multiple sources & contaminants Specialized Modelling Complex terrain, Land/water interface Chemical transformation, traffic
Screening Simple facility Limited number of sources Refined More complicated facility Multiple emission sources Multiple contaminants Specialized Complex terrain Land/water interface Chemical transformation Road or rail traffic SCREEN3 AERSCREEN Worst case emissions Limited number of sources refine AERMOD Worst case emissions refine refine CALPUFF CALQ3HCR Compliant? Compliant? Compliant? no no yes yes yes Stop Stop Stop
Air Modelling System
Meteorological Data for SK Free of Cost Download Regional Met Data Files Ministry website www.environment.gov.sk.ca Or Use AERMET to generate site specific files
Surface Class North Central Zone AERMOD-Ready Regional Meteorological Data Files Fully Processed Data Files Partially Processed AERMET Stage 3 Input File Surface/ Upper Air Station Forest Surface Profile Stage 3 Nipawin The Pas Agricultural Surface Profile Urban Surface Profile
Terrain Data for Saskatchewan Free download from GeoBase website www.geobase.ca Use 1:50,000 terrain data for improved accuracy
SK s Background Concentrations Compare (Model Results + Background) to Standards Pollutant Averaging Period Percentile Background Concentrations For Air Dispersion Modelling Northern North Central Central Southwestern Southeastern 90th 572.0 572.0 687.0 1 Hour Carbon Monoxide 99th 915.0 1030.0 1260.0 (µg/m3) 90th 572.0 458.0 687.0 8 Hour 99th 1030.0 1145.0 1260.0 90th 11.3 32.0 39.5 35.7 41.4 1 Hour Nitrogen Dioxide 99th 28.2 58.3 69.6 69.6 80.9 (µg/m3) 90th 9.4 28.2 32.0 30.1 37.6 24 Hour 99th 16.9 45.1 48.9 48.9 60.2 Annual 50th 3.8 5.6 15.1 9.4 18.8 90th 0.0 2.6 2.6 2.6 2.6 1 Hour Sulphur Dioxide 98th 5.2 5.2 5.2 5.2 7.9 (µg/m3) 90th 0.0 2.6 2.6 2.6 2.6 24 Hour 99th 2.6 2.6 5.2 5.2 5.2 Annual 50th 0.0 0.0 0.0 0.0 0.0 Fine Particulate Matter 90th 6.5 6.6 7.5 6.6 8.3 (PM 2.5 ) (µg/m 3 24 Hour ) 99th 13.9 14.3 13.9 8.4 14.7 Annual 50th 3.1 3.0 3.3 3.3 3.7 Particulate Matter 90th 23.1 36.3 (PM 10 ) (µg/m 3 24 hours ) 99th 49.1 63.3
Modelling Report Check List IV IV.A IV.B AMBIENT IMPACT SUPPORTING DOCUMENTATION Electronic Files List and description of electronic files Required e-files to be submitted with report o Input & output files for models o Input & output files for pre-processors (if applicable) o Input & output files for post-processors (if applicable) o Digital terrain files o Plot files o Final report Report shall include a discussion on deviations from the modelling checklist
Part 2 ODOUR GUIDELINE
Did you know? The human genome has 1 gene for hearing 3 genes for seeing 12 genes for tasting? genes for smelling? 1,000
Why odour is not an ordinary air contaminant? Odour is a complex mixture of compounds It is the results of a perception Perception and tolerance vary from individuals Individual compounds cannot represent the actual impact of a mixture Because of synergies, chemical measurements cannot be used to quantify odour Best tool of measuring odour is still the human nose
How is Odour Measured? Odour is measured using air dilution equipment and an odour panel Olfactometer dilutes an odour sample with odour-free air to various levels Diluted odorous air is presented to panel When half of odour panel can detect odour, it is called odour detection threshold or dilution ratio
Odour concentration can be expressed as: D/T - Detection Threshold or Dilution to Threshold OU - Odour Unit or Odour Unit per volume (OU/m 3 ) For example, 500 OU/m 3 means when 1 volume of odour sample is diluted with 500 volumes of fresh air and it can be detected by 50% of a panel.
All units have same conceptual meaning Different methods used to measure odour result in different units Use OU when measured by olfactometers Use D/T when measured by scentometers Olfactometry Lab Method (OU) Odour measured at source location Scentometer / Nasal Ranger (D/T) Odour measured at receptor location
Why is Odour Guideline Needed? No odour guideline in place Residents are less tolerant to odour and its impact on property value Guideline defines reference criteria to which odour impacts can be judged Guideline defines the process to demonstrate compliance with odour criteria
Odour Criteria for Field Investigation Odour criteria Averaging time Land use 2 D/T 4 D/T 2 tests not less than 15 minutes apart nor more than 60 minutes apart Residential/Urban zone Mixed residential and commercial/rural zone 7 D/T Industrial/Agricultural zone Nasal Ranger (D/T) Odour measured at receptor location
Odour Criteria for Modelling Odour Criteria Averaging Time Annual Frequency Land Use 1 OU/m 3 Urban residential zones 2 OU/m 3 Urban commercial zones or mixed residential and commercial zones 4 OU/m 3 6 OU/m 3 1 hour* 99.5% Industrial or restricted business zones and rural zones with mixed utilisation Industrial or agricultural zones with predominantly agricultural utilisation Olfactometry Lab Method (OU) Odour measured at source location
Odour Assesement Process Odour complaint received Conduct field odour investigation using Scentometer Yes Complaint verified? No Stop If measured odour level is 2 levels higher than the criteria Yes If 3 or more verified complaints exceed odour criteria in 30 days Quantify source odour emission using olfactometry method Conduct odour modelling
Next Steps Validation of odour criteria study is in progress Criteria will be used as a guideline - a tool for odour management in Sask. Guideline will be reviewed periodically
Questions?
For more information, please contact: Imran Maqsood, Ph.D., P.Eng. Manager, Air Science & Monitoring Saskatchewan Ministry of Environment imran.maqsood@gov.sk.ca (306) 787-1372