US EPA’s New AERMOD Version 22112 and its Potential Impact on Ontario’s Regulatory Dispersion Model Version

The United States Environmental Protection Agency (EPA) released new versions (22112) of the AERMOD dispersion model and the AERMET preprocessor on June 27, 2022. The EPA invited industry and consultants to join the 2022 Virtual EPA Regional/State/Local Dispersion Modelers' Workshop to introduce the latest updates. This blog provides information on the background, release updates, future development plan and potential impact on Ontario’s regulatory dispersion model versions.

Background

In 2005, the American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD) was promulgated as the EPA’s preferred near-field dispersion model for regulatory applications, replacing the Industrial Source Complex (ISC) model. There were a variety of regulatory formulation and related implementation updates to the AERMOD Modeling System in 2017. AERMOD was designed to accept more robust meteorological data, including multi-level profiles of wind, temperature, and turbulence to simulate the atmospheric boundary layer more accurately.

In accordance with the Ontario Regulation 419/05: Air Pollution – Local Air Quality (“the Regulation”) and Ontario Guideline A-11, facilities may only choose between SCREEN3 and AERMOD to assess compliance with the air standards in Schedule 3. Use of SCREEN3 is considered to represent a conservative Tier 1 screening type of modelling assessment while the use of AERMOD represents a more comprehensive approach and is categorized as either a Tier 2 or Tier 3 type of assessment. As noted in the Regulation, the regulatory version of AERMOD model may be amended from time to time. This means that there is a specific version of each of these models that is considered to be an “approved dispersion model.” Currently, the Ontario Ministry of the Environment, Conservation and Parks (MECP) adopts the 2019 AERMOD version 19191 and AERMET version 19191. MECP’s next window to provide pre-notification of updates to the Ontario regulatory AERMOD version is October 1, 2022.

AERMOD Version 22112 Updates

AERMOD Version 22112 updates include code maintenance, general bug fixes for tall stacks, buoyline sources, and the urban dispersion option. The new “experimental” ALPHA options include NO2 conversion methods, low wind handling, “sidewash” point source (developed by Cornell University),and platform downwash for offshore sources. Other model updates in a BETA peer review phase include R-line for refined transportation projects and the non-regulatory Generic Reaction Set Method (GRSM) for NO2 conversion, which are potentially ready for consideration as regulatory options. AERMET version 21112 is re-configured to eliminate stage 2 (merge stage), which simplify the process to generate the AERMOD ready met data.

Future Development Plan

Model formulation updates to the AERMOD Modeling System last occurred in 2017 when EPA finalized updates to the Guideline on Air Quality Models. EPA is planning to propose an update to the Guideline in 2023. The formulation updates are developed and implemented through model development, model evaluation and model review & application. The current improvement priorities for the regulatory release include:

• Overwater Modeling–Refine / evaluate the platform downwash algorithm and add shoreline fumigation capability to AERMOD

• NO2 Conversion –Testing of GRSM and TTRM/TTRM2 as the more advanced conversion options

• Mobile Source Modeling / RLINE–Push from BETA to regulatory, improve treatment of terrain, and edge effects within the barrier algorithm

• Low Wind –Evaluate current low wind options against field dataset

• Urban meteorology –Improve inputs and processing for the URBAN option

Potential Impact on Ontario Regulatory Version

ORTECH is of the opinion that the changes in the version 22112 are minor and therefore the likelihood for Ontario MECP to adopt this version is low. This combined with US EPA’s proposed 2023 updates, including formula updates, would potentially represent a major upgrade to the AERMOD model. If the 2023 improvement priorities for regulatory updates are completed, MECP may consider adopting the 2023 updated versions. Under current MECP policy a six-month pre-notification period will be provided, prior to officially adopting a new regulatory version of AERMOD.

ORTECH has been conducting air quality assessments for over 40 years and continues to monitor developments in dispersion modelling and how these may impact our industrial and other clients. Please contact Leo Sun at lsun@ortech.ca for more information.

Releases of Air or Noise Emissions: Do you need a permit?

By: Scott Manser 

If your Ontario business is emitting compounds into the air, or has sources of noise associated with its operations, you will most likely need to register through the provincial Environmental Sector Activity Sector (EASR) system.  The EASR system is the default path, with exclusions for specified industry codes and process operations.  Facilities covered either in whole or in part by these exclusions are required to obtain an Environmental Compliance Approval (“ECA”). 

Although numerous exemptions from the requirement to register or obtain an ECA exist, the Ministry of Environment, Conservation and Parks (MECP) has made it clear that exempt sources still require an assessment against the provincial air quality criteria.  Often, we find that permitting and assessment requirements are not well understood, and the value that is driven from it may not be clear. At ORTECH we make every effort to help the process move along rapidly, and strive to help you understand our methods.

Regardless of the regulatory system in place it is important that all contaminants (including noise) emitted into the environment by your facility are assessed.  It is also imperative for facilities to understand that planned modifications trigger a re-assessment of emissions and an amendment to either the EASR or ECA.  These planned modifications may include (but are not limited to) the addition of equipment, changes in process rates, or a reformulation of existing materials. 

For facilities subject to the EASR system, modifications can be assessed and registered within a relatively short time frame (a few weeks).  For facilities requiring an amendment to an ECA approval, MECP is currently providing a one-year service standard.  For this reason subject facilities may also apply for an ECA with Limited Operational Flexibility which permits most modifications from occurring without having to receive an amendment to the ECA.  In a fast-paced market condition, this allows facilities to adapt quickly, meet new customer requirements, or expand product lines.

How ORTECH can help

Practicing an "Educate-Plan-Comply" progression to ensure our clients comprehend the ECA process, our aim is for you to fully know the implications for your company.  We have worked on countless applications and have fine-tuned our approach, concentrating on a client-centric focus. 

ORTECH can assist you in determining the regulatory requirements of your air and noise emissions: EASR, ECA or exempt.  As part of our service offerings ORTECH can:

• Discuss the pros and cons of an ECA with Limited Operational Flexibility;

• Work with the client to assemble documentation and information required to support the assessment results;

• Complete a site visit;

• Review your current Emission Summary and Dispersion Modelling (ESDM) Report, if available, and update to include any changes;

• Complete dispersion modelling and compare results to MECP air quality limits;

• Complete primary or secondary noise screening and coordinate an Acoustic Assessment Report (AAR), if required;

• For EASR documents, provide the required Professional Engineer seal and signatures;

• Assemble the ECA application, including all supporting documents and forms;

• Regularly follow up with the MECP to check the status of the application;

• Assist in answering technical questions the MECP review engineer may have; and

• Review the draft ECA to ensure the Terms and Conditions are appropriate and accurate.

ORTECH can assist you with maintaining compliance with the new permit by providing the following services, if applicable:

• Assist in preparing an operating manual;

• Complete source testing and/or odour testing;

• Prepare and maintain a modification log;

• Review facility operations and assess modifications which may require an update to the ESDM Report; and

• Prepare the Annual Written Summary Forms and supporting documentation for ECAs with Limited Operational Flexibility.

Operating an Internal Combustion Generator in Ontario? Apply for the Right Environmental Permit.

By: Limin Sun

Are you installing a new generator for daily use or converting an existing emergency generator?  You may find the permitting process to be a little daunting. 

In Ontario, there are two types of internal combustion generators allowed.  The first type, standby generators, is typically used for shorter operation periods and in emergency situations.  The second type, power generators, is used more often and for non-emergency situations. 

Both types of generators have their own applicable regulatory requirements in Ontario. 

The Ministry of Environment, Conservation and Parks is the Ontario Government body through which the generator permitting process takes place.  Through them you will apply for an Environmental Compliance Approval (ECA).  To obtain the correct permit in a timely manner, you have to understand the approval timing as well as the potential permitting barriers and solutions. Also, it certainly helps to prepare a good permitting plan in advance.

To help with perspective, a comparison of the two types of generators is summarized below.

If you have any questions, please contact Limin Sun at lsun@ortech.ca.

Coming Changes to Environmental Compliance Approvals (ECAs). Is your facility ready?

Photo by Flo Dnd.

Schedule 3 standards will apply to all facilities as of February 1st, 2020—is your facility ready?

By: Giulia Celli

As of February 1st, 2020 Schedule 3 standards will apply to all facilities and the Reg346 model will no longer be an “approved dispersion model” under O.Reg.419/05 (the Regulation). However, as of February 1st, 2019, all Environmental Compliance Approval (ECA) applications must already include Emission Summary and Dispersion Modelling (ESDM) reports showing compliance with Schedule 3 standards and using SCREEN3 or AERMOD models.

What is the difference between Schedule 2 and Schedule 3 standards?

Schedule 2 and Schedule 3 of the Regulation both provide a list of contaminants and the respective concentration of each contaminant that is not to be exceeded at a point of impingement. In the Schedule 2 list of contaminants, these limits are based on half hour averaging periods, whereas Schedule 3 limits are based on variable averaging periods. The approved dispersion model when Schedule 2 contaminants are evaluated is the Reg346 model. Schedule 3 contaminants are to be evaluated using the SCREEN3 and AERMOD models. For most facilities, Schedule 2 standards apply from January 31, 2010 to February 1, 2020. Schedule 3 standards will apply as of February 1st, 2020.

Do facilities need to update their ESDM reports now to maintain compliance?

The next time you prepare or update your ESDM report you need to ensure that the Schedule 3 standards, as well as the applicable models are used. This could occur during an annual update of an ESDM report – either as required by regulation (which is to be done each year by March 31st) or as required by a condition of an ECA. An ESDM report update may also be triggered by making any modifications to the facility or by a follow-up action from an inspection or audit.

ORTECH can help you prepare for the 2020 phase-in of Schedule 3 standards. Please contact us for more information.

Does my Municipal Building Need an Environmental Approval (ECA or EASR)?

By: Giulia Celli

The answer to this question depends on several factors such as the equipment you have installed, the location of the equipment and the potential for any environmental impacts.  Let’s back up and provide a bit of context.  The Ontario Government’s environmental rules say that if your business emits any contaminants to the air, you must comply with the regulation however, there are exemptions to this rule.  Section 9 (3) of the Ontario Environmental Protection Act, R. S. O. 1990, (the EPA) and O. Reg. 524/98 specify the (limited) types of equipment, activities, and operations that are exempt from needing an Environmental Compliance Approval (ECA) or an Environmental Activity and Sector Registry (EASR) registration. These exemptions include low capacity natural gas comfort heating systems, and standby power systems. Systems that you would generally find in a municipal building.

For example, an HVAC system that meets the following criteria is likely to be exempt:

·         Each combustion unit uses only natural gas, propane or both natural gas and propane as fuel, and

·         The thermal input rating of each combustion unit is not greater than 10.5 million kilojoules per hour.

·         If the HVAC system includes a cooling tower, drift loss from the cooling tower is controlled by drift eliminators.

And a standby power system that meets the following criteria is likely to be exempt:

·         The system is used and operated only during power outages or for testing or performing maintenance on the system;

·         The standby power system uses only one or more of the following as fuel: biodiesel, diesel, natural gas, and propane;

·         Each exhaust stack that is part of the standby power system is oriented vertically (and not obstructed by a rain cap);

·         Each generation unit that is part of the standby power system and that uses diesel or biodiesel as fuel, must meet, at a minimum, the Tier 1 Emission Standards set out in Table 1 of 40 CFR 89.112 (United States)

·         Each generation unit that is part of the standby power system and that uses propane or natural gas as fuel, must have a maximum discharge of 9.2 grams of nitrogen oxides per kilowatt hour

Other exemptions include things such as equipment used for food and beverage preparation at retail locations, items associated with low occupancy dwellings, some mobile equipment, and more. To complicate matters, the equipment may be exempt from requiring a permit but the facility itself is still required to meet this standard from the EPA:

“…despite any other provision of this Act or the regulations, a person shall not discharge a contaminant or cause or permit the discharge of a contaminant into the natural environment, if the discharge causes or may cause an adverse effect.” 

For municipal operations in multi-tenant buildings this general provision of the EPA can create some issues when air intakes are not sufficiently separated from equipment which would be otherwise exempt from obtaining an ECA or EASR permit.   

For due diligence, it is recommended to have all equipment that emits any contaminants (including noise and odour) to the air assessed for compliance. It is recommended that a letter from a qualified person stating that the facility is in compliance with Ontario regulations is kept with the facility.

If you have any questions about this post, please reach out to Giulia Celli at gcelli@ortech.ca.