Ambient Air Quality Assessments

Technical, defensible assessments that support permitting, design decisions, and stakeholder confidence—aligned with Canadian and Ontario regulatory expectations.

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What this service delivers

Clear answers on compliance, impacts, and risk

Ambient air quality assessments evaluate how project emissions may affect off-site concentrations and how results compare to applicable criteria. We translate complex inputs—emissions, meteorology, terrain, and receptors—into a clear, decision-ready narrative.

Regulatory-ready documentation

Methods, assumptions, and results presented in a format suitable for permitting and technical review.

Actionable mitigation options

Practical controls and operational strategies to reduce impacts and improve confidence in outcomes.

Scope & deliverables

What’s included in an ambient air quality assessment

Each project is tailored to the site, sector, and regulatory pathway. Typical components include:

Emissions characterization

Identify emission sources, operating scenarios, and input parameters (rates, temperatures, exit velocities, stack geometry, and controls).


Assessment methodology

Define applicable standards and averaging periods, receptor selection, background concentrations (as appropriate), and modelling approach consistent with guidance.


Results & interpretation

Summarize predicted concentrations, compare to criteria, and highlight key drivers and sensitivities.


Mitigation & next steps

Recommend feasible controls, design refinements, monitoring considerations, and a clear path to close any remaining gaps.

Why it matters

Reduce uncertainty and keep projects moving

Confident permitting decisions

Support approvals with transparent assumptions and defensible results.

Early identification of constraints

Flag potential exceedances and sensitive receptors before they become schedule risks.

Design and operations optimization

Evaluate control options and operating scenarios to find practical, cost-aware solutions.

Aerial view of a natural gas power station

Ambient air quality assessment FAQs

Common questions we help clients answer during planning, permitting, and operational changes.

When do I need an ambient air quality assessment?

Typically when a new project, expansion, or process change could affect off-site air concentrations or triggers permitting requirements. We can help confirm the appropriate pathway early.

How is this different from air dispersion modelling?

Dispersion modelling is usually a core technical component. The assessment adds context—criteria selection, scenario definition, interpretation, mitigation, and documentation for review.

What inputs do you need from us?

Process details, operating schedules, stack/source parameters, control equipment information, site layout, and any existing emissions or monitoring data. We’ll provide a clear request list.

Can you work with limited emissions data?

Yes. We can develop screening-level estimates, refine with engineering calculations, and recommend targeted measurements where needed to improve confidence.

Do you support Ontario (MECP) requirements?

Yes. SRJ Consulting supports projects across Canada with a focus on Ontario, aligning work with applicable guidance and regulatory expectations.

What does the final deliverable look like?

A concise technical report with methods, assumptions, results tables/figures, compliance comparison, and recommended mitigation or next steps.