What we deliver

Modelling that supports confident decisions

SRJ Consulting provides air dispersion modelling to quantify ambient concentrations from project and operational emissions. We focus on transparent assumptions, regulator-ready documentation, and results you can use for design, permitting, and stakeholder communication.

Regulatory modelling & screening

Appropriate model selection, receptor grids, averaging periods, and comparison to applicable air quality criteria and guidelines.


Source characterization

Point, area, volume, and line sources with defensible parameters (stack data, release conditions, building dimensions, and operating scenarios).


Meteorology & terrain

Use of representative meteorological datasets and terrain/land-use inputs to reflect site conditions and sensitivity where needed.


Results, interpretation & reporting

Clear figures and tables, exceedance assessment, contribution analysis, and practical recommendations for mitigation and next steps.

How we work

A practical, defensible modelling workflow

Define the question

Clarify project phase, compliance pathway, contaminants of concern, and the decisions the model needs to support.

Build a transparent model

Document inputs and assumptions, develop scenarios (normal and worst-case), and ensure traceability from emissions to results.

Communicate outcomes

Translate outputs into clear takeaways for permitting packages, design teams, and non-technical stakeholders.

Abstract 3D terrain visualization suggesting atmospheric modelling and contours
Typical applications

New & modified sources

Permitting support

Assess impacts from stacks, vents, and fugitive sources and support approvals with regulator-ready documentation.

Facility changes

Design decisions

Compare scenarios, evaluate mitigation options, and identify the drivers of predicted concentrations.

Community questions

Clear communication

Summarize results with maps, contours, and plain-language interpretation for stakeholders.

We tailor the modelling approach to the project contextโ€”balancing conservatism, realism, and clarity so results are useful and defensible.

See industries we support โ†’ โ†’

Air dispersion modelling FAQs

A few common questions we receive when supporting projects across Canada (with a focus in Ontario).

Which dispersion model do you use?

We select the model and options that best fit the regulatory context and source types (e.g., screening vs. refined), and we document the rationale and settings used.

What inputs do you need from us?

Typically: site location, operating scenarios, stack/source parameters, building dimensions (if applicable), and emissions estimates or monitoring data. We can help develop missing inputs where feasible.

How long does a study take?

Timelines depend on complexity and data readiness. Many projects progress in stagesโ€”initial screening, refinement, and reportingโ€”so decisions can be made early while details are finalized.

Can you model multiple scenarios or future expansions?

Yes. We commonly evaluate baseline vs. project conditions, different operating cases, mitigation options, and phased expansions to support planning and permitting.

Do you provide regulator-ready reporting?

Yes. We prepare clear, well-structured documentation with transparent assumptions, inputs, and results to support submissions and technical review.

Can you support us after the modelling is complete?

We can help interpret feedback, respond to technical questions, and align next steps such as monitoring plans, emissions inventory refinement, or mitigation evaluation.