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LEHDER News

Pre-Notification of Updates to Ontario’s Air Dispersion Models

     Posted by LEHDER News on

On Monday October 2,2017,  the MOECC issued the pre-notification for updates to the air dispersion models utilized for Ontario Regulatio 419/05: Air Pollution - Local Air Quality.  The pre-notification details are provided below but can also be found at https://www.ontario.ca/page/pre-notification-updates-ontarios-air-dispersion-models

Ontario will be adopting new air dispersion models that are based on latest available science, to provide clarity and consistency to the regulated community and stakeholders.

Ontario’s local air quality regulation (O. Reg. 419/05: Air Pollution – Local Air Quality) under the Environmental Protection Act is part of the province’s air management framework. It regulates air contaminants released into communities by various sources, including local industrial and commercial facilities.

The regulation includes three compliance approaches for industry to demonstrate environmental performance and make improvements when required. Industry can:

  • meet the air standard
  • request and meet a site-specific standard,
  • or register and meet the requirements under a sector-based technical standard (if available).

Most Ontario facilities are regulated by the air standards compliance approach (i.e., meet the air standard), although all three approaches are allowable under the regulation. Models are part of the air standards and site-specific standards compliance approaches. Section 6 of O. Reg. 419/05 provides a list of approved dispersion models for use in assessing compliance with air standards or site-specific standards under the regulation. Currently, the approved dispersion models include:

1. The AERMOD dispersion model (version 14314) and AERMET meteorological preprocessor (version 14314) available from the Ministry of the Environment and Climate Change (MOECC) website.

2. The ASHRAE method of calculation. Section 1(1) of O. Reg. 419/05 defines the “ASHRAE method of calculation” to mean the method of calculation described in Chapter 44 (Building Air Intake and Exhaust Design) of the 2015 ASHRAE Handbook — HVAC Applications, published by the American Society of Heating, Refrigerating and Air-Conditioning Engineers.

3. The SCREEN3 dispersion model on the USEPA’s website, or available from the MOECC.

4. The method of calculation required by the Appendix to Regulation 346, if section 19 of O. Reg. 419/05 applies to the discharges.

In addition, section 13 of O. Reg. 419/05 references regional surface and upper air meteorological data for use with AERMOD that must be processed by the AERMET computer program.

Under subsection 177 (6) of the Environmental Protection Act, the adoption of an amendment to a document that has been incorporated by reference (e.g. AERMOD/AERMET/ASHRAE), comes into effect once the MOECC publishes a notice of the amendment in either The Ontario Gazette or the Environmental Registry under the Environmental Bill of Rights (EBR), 1993.

Accordingly, in April 2018 the MOECC will be posting an Information Notice on the Environmental Registry to replace current regulatory air dispersion models under O. Reg. 419/05 with the following updated model versions:

  • AERMOD dispersion model
    • Will be updated to AERMOD version 16216r (version date December 20, 2016)
  • AERMET meteorological pre-processor
    • Will be updated to AERMET version 16216 (version date December 20, 2016), and
  • ASHRAE method of calculation
    • Will be updated to Chapter 45 (Building Air Intake and Exhaust Design) of the 2015 ASHRAE Handbook – HVAC Applications

The ministry will make the approved dispersion models available through the Ministry of the Environment and Climate Change (MOECC) website.

Ontario Regional Meteorological data sets that have been reprocessed with AERMET 16216 (version date December 20, 2016) will also be available at the above noted website link once the Information Notice is posted on the Environmental Registry (under EBR). Until that time, proponents may request copies of the re-processed meteorological datasets from the Environmental Monitoring and Reporting Branch at MetDataENE@ontario.ca.

Because air dispersion models will continue to evolve in the future, MOECC developed an implementation plan for model version updates, with input from stakeholders, which provides clarity. Key elements of this annual process include the following:

  • Monitoring and assessing regulatory model update developments on an ongoing basis and discussing with stakeholders, as required.
  • Notifying stakeholders, every year, six months in advance of formally adopting updated versions of the models. This will give facilities time to determine if they will be affected by model updates and if so, to contact their local district office for assistance in developing a path forward, as needed.
  • Posting an Information Notice on the Environmental Registry (EBR) six months following pre-notification to formally adopt the updated model versions. We will adopt updated model versions annually as necessary.
  • Updating regulatory data files/instruments, and guidance materials to reflect the adoption of updated model versions, as necessary.

Additional information may also be obtained from:

Ontario Ministry of the Environment and Climate Change
Air Quality Monitoring and Transboundary Air Sciences Section
Environmental Monitoring and Reporting Branch
125 Resources Road, Toronto, ON M9P 3V6
E-mail: MetDataENE@ontario.ca
General Inquiries: 416-235-6171

For more information, please contact Penny McInnis.