Environmental Consulting

Air Dispersion Modeling

Trinity provides a wide range of air quality modeling consulting services for regulatory applications, emergency planning, and human health assessments.

For more than 40 years, Trinity Consultants has performed air dispersion modeling for industrial facilities, utilities, and government agencies. Trinity is recognized nationally and internationally for our skills and advanced modeling software/infrastructure, enabling Trinity to formulate and conduct dispersion modeling studies for numerous applications.


Air Dispersion Modeling allows us to create a simulation of how atmospheric processes disperse pollutants in the ambient atmosphere using mathematical formulations to provide quantitative air concentration and surface deposition data.

Trinity Consultants can assist you with the following:
  • Assessing impacts of air emissions
  • Assessing impacts of offshore emissions
  • Assessing visible plumes, icing, and fogging
  • Performing off-site consequence analyses
  • Evaluating individual and cumulative human and ecological risk
  • Conducting off-site impact and deposition studies
  • Performing fatal flaw analyses
  • Predicting the impact of roadway air emissions
  • Conducting regional modeling studies
  • Conducting odor concentration modeling
  • Analyzing potential risks associated with release of liquefied fuel gas (LFG) and liquefied natural gas (LNG)
  • Predicting structural damage and personnel injury from the detonation of high explosives and vapor cloud explosions
  • Processing model-ready meteorological data
Specific Air Dispersion Modeling Services

Trinity provides a wide range of air quality modeling consulting services for regulatory applications, emergency planning, and human health assessments.
  • Regulatory air dispersion modeling
  • Class I area PSD impact and regional haze analyses
  • Photochemical Grid Modeling
  • Multi-pathway risk assessment dispersion modeling
  • High-performance computing solutions
  • Model development and training

How Else We Can Help

Related Services

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Air Quality Permitting

Trinity Consultants are experts in air permitting support for compliance with the Clean Air Act, offering comprehensive services from strategy, application development, and agency negotiations.
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Ambient Monitoring and Service Integration

Trinity’s ambient air quality monitoring expertise ranges from the design and implementation of monitoring stations to routine operations, data validation, and official reporting to meet EPA and state requirements.
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Regional Haze Support

Trinity's Regional Haze Support services guide clients through the intricacies of the Regional Haze Rule (RHR), ensuring compliance and progress towards natural visibility goals for Class 1 areas.
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BREEZE Software

Our Results

Featured Projects

Government Steam Plant Streamlines Environmental Permitting and Compliance

The plant has engaged Trinity since 2008 for a wide variety of continual compliance activities that span air, oil pollution, waste, and water programs.

Trinity Brings Calm Vigilance to Packaging Giant’s Multisite Environmental Reporting Requirements

A very large packaging company in Illinois partnered with Trinity Consultants to evaluate and improve their environmental program.

A Global Chemicals Company Integrates for HSE Compliance Visibility

A long-time Trinity client engaged the air and Digital Solutions teams to support permitting and software installation needs.

Regulatory Background

Air Modeling Tools

Photochemical Grib Modeling (PGM)

The Environmental Protection Agency (EPA) employs Photochemical Grid Modeling (PGM) as a crucial tool in its regulatory arsenal to safeguard air quality and public health. This sophisticated modeling technique is instrumental in understanding the complex interactions between air pollutants over vast geographical areas. By simulating the atmospheric conditions that affect the distribution, chemical transformation, and eventual deposition of pollutants, PGM provides the EPA with an invaluable predictive capability. This insight is essential for making informed decisions about air quality management, crafting regulations that effectively reduce emissions, and achieving compliance with national air quality standards. The modeling extends to both chemically reactive pollutants, which undergo transformations in the atmosphere, and inert pollutants that remain unchanged. The ability to accurately model these processes at regional scales is vital for addressing pollution from both single and multiple sources, enabling the EPA to develop strategies that protect both the environment and public welfare.


The U.S. Environmental Protection Agency (EPA) widely recognizes and routinely utilizes Photochemical Grid Modeling (PGM) for regulatory analysis and attainment demonstrations. Trinity provides comprehensive modeling for both PGM and regional air quality studies by offering such modeling services to our clients nationally and internationally. For more than 10 years, experts at Trinity have been supporting clients with PGM and regional scale modeling services.

Partnering with Trinity

Let’s collaborate. What can we help you achieve?

We invite you to contact us with your specific challenges. Let’s see how we can succeed together! Contact us to discuss how we can work together and achieve your goals. 

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