Air Dispersion Modelling for Permits and Impact Assessments

Saudi Environmental Studies provides air dispersion modelling coordination in Saudi Arabia for permit applications, EIAs, ESIAs, expansions and design studies. Air dispersion modelling predicts how emissions may travel and contribute to concentrations at selected receptors under defined scenarios, and we coordinate the scope through air-quality modellers and appropriately licensed environmental consultants.

You receive a written proposal setting out the modelling scope, inputs required, deliverables, timeline and price. Request a quotation

We scope, coordinate and manage the work. The modeller, software, version and method are confirmed for the applicable authority and project, and the authority decides on acceptance of the results.

Define the regulatory and design question

A model may support a new facility, capacity increase, fuel change, stack alteration, cumulative-impact assessment or control-option comparison. The brief identifies the competent authority, project stage, averaging periods, pollutants, scenarios, receptors and required output format. NCEC or Royal Commission requirements may differ, and current project instructions are checked before the method is fixed.

For an integrated assessment, environmental impact assessment and ESIA connects predicted air effects with other environmental topics. An NCEC environmental permit application or Royal Commission PAP also needs its own confirmed document and review pathway.

Air dispersion modelling inputs we control

Point sources require coordinates, stack height and diameter, exit temperature and velocity, operating schedule and pollutant emission rate. Volume, area or line sources need method-specific geometry and release assumptions. The source inventory distinguishes existing, proposed, normal, startup or other required scenarios and identifies whether rates come from testing, design guarantees, calculations or controlled assumptions.

Buildings can influence plume behaviour, while terrain and land characteristics affect model treatment. Receptor grids and discrete receptors cover project boundaries, communities and other sensitive locations relevant to the study question. GIS and sensitive-receptor mapping provides traceable coordinates and constraints.

Select meteorology and model method

Meteorological inputs require a justified period, station or modelled dataset, representativeness review and preprocessing. Surface characteristics, missing data and station distance can matter. The modeller documents why inputs and model options are suitable.

The US EPA’s official SCRAM resources describe preferred and recommended models including the AERMOD system and its preprocessors. This is useful primary technical guidance, but AERMOD is not automatically mandated for every Saudi project: the current authority requirement controls selection.

Software is only one part of competence. The responsible modeller demonstrates relevant experience, documents version and options, conducts input checks and retains reproducible files.

Compare scenarios and evaluate uncertainty

The study may assess:

• baseline or background treatment;
• project-only contribution;
• cumulative sources;
• alternative layouts and mitigation.

Results are compared with the criteria specified by the licensed consultant for the applicable submission. The report avoids presenting a prediction as a measurement.

Sensitivity checks can test emission rates, meteorology, source configuration or uncertain parameters. Model performance evaluation may be possible where suitable observations exist, but monitoring data and predictions have different spatial and temporal meanings. Operational air-monitoring equipment is a separate monitoring-system scope; this service covers formal air-dispersion study coordination and interpretation.

Deliver a reviewable study

A complete package typically includes scope and regulatory basis, conceptual model, source inventory, meteorological review, terrain and building inputs, receptor design, background approach, software/version, quality checks, results, uncertainty, mitigation implications and electronic files. The licensed lead consultant integrates findings into the permit or impact assessment.

The coordination proposal names the modeller and responsible consultant, client inputs, survey or testing needs, programme, review stages and exclusions. Air dispersion modelling coordination is available for projects across Saudi Arabia, including Dammam, Jubail, Riyadh and Jeddah; nearby industrial sources and sensitive receptors are considered according to the agreed scope.