Permitting and environmental assessment
New facilities, modifications, permit renewals, environmental-impact documentation, and comparison with applicable air-quality criteria.
Atmospheric dispersion · impact assessment
Air quality modeling for decisions that must withstand review.
We quantify ambient concentrations and deposition, test emission scenarios, and prepare defensible technical evidence for permitting, compliance, environmental assessment, design, and litigation.
Sources, meteorology, terrain, receptors, concentration fields, deposition, and regulatory statistics.
25+ yearsof atmospheric modeling experience
Hundreds of studiesfor industrial and infrastructure projects
Model-independent advicemethod selected for the actual problem
Complete evidence packageinputs, results, maps, and technical reporting
What we provide
More than a model run.
A useful assessment connects the regulatory question, emission inventory, meteorology, terrain, model configuration, uncertainty, and decision criteria. We manage that complete chain.
Compliance and operational scenarios
Normal operation, start-up and shutdown, maintenance, upset cases, alternative fuels, production changes, and cumulative impacts.
Emission and source characterization
Point, area, volume, line, road, fugitive, buoyant, intermittent, and time-varying sources, including building geometry and downwash inputs.
Meteorological and geophysical preparation
Observed data, WRF simulations, AERMET, MMIF, CALMET, terrain, land use, coastlines, surface parameters, and site representativeness.
Mitigation and design evaluation
Compare stack parameters, emission controls, operating schedules, layouts, source relocation, and alternative project configurations.
Independent review and litigation support
Audit third-party studies, reproduce calculations, test assumptions, explain technical disagreements, and support expert evidence.
Model selection
The right model depends on the atmospheric problem.
We select and document the modeling system according to jurisdiction, source characteristics, spatial and temporal scale, terrain, coastal or calm-wind effects, chemical transformation, deposition, and the statistics required by the assessment.
- 01AERMOD
Commonly used for near-field regulatory assessments of stationary sources, including building downwash and terrain effects where its assumptions and local guidance are appropriate. - 02CALMET / CALPUFF
Considered for non-steady meteorology, complex or coastal settings, longer transport scales, time- and space-varying winds, deposition, or other cases requiring a puff-model framework. - 03LAPMOD
Our three-dimensional Lagrangian particle model for complex terrain, inert or radioactive gases and aerosols, deposition, odors, and specialized non-stationary applications. - 04Screening and specialist tools
AERSCREEN and other fit-for-purpose methods may be used for conservative screening, roads, offshore sources, cooling towers, flares, or project-specific calculations. - 05Regulatory alignment
The final method follows the requirements and accepted practice of the competent authority; no single model is automatically suitable for every project.
Assessment method
A traceable path from question to conclusion.
Define the decision
Establish pollutants, scenarios, averaging periods, receptors, legal or project criteria, and the questions the study must answer.
Characterize baseline conditions
Review monitoring data, nearby sources, existing air quality, climate, terrain, land use, and sensitive receptors.
Build the emission inventory
Check source parameters, operating profiles, emission factors or measurements, temporal variation, and scenario assumptions.
Prepare meteorology and geography
Select representative years and observations or run WRF; process terrain, land cover, surface parameters, coastlines, and buildings.
Configure and quality-check
Document model version, options, domain, receptors, background treatment, chemistry, deposition, and quality-assurance checks.
Run scenarios and sensitivity tests
Evaluate baseline and alternatives, identify controlling sources and conditions, and test influential assumptions where useful.
Postprocess the required statistics
Calculate maxima, annual means, percentiles, rolling averages, deposition, source contributions, and cumulative concentrations.
Georeferenced graphical representation of results
Create maps, contours, receptor plots, and GIS-ready outputs that show concentrations, deposition, and source contributions in a spatially meaningful form.
Interpret and report
Compare results with applicable criteria, explain limitations, identify mitigation, and prepare maps and a review-ready technical report.
Applications
Source-specific modeling across industry and infrastructure.
Each source class has different emission behavior and modeling needs. We adapt the inventory, meteorology, model options, receptors, and outputs accordingly.
Industrial plants and energy
Stacks, turbines, boilers, furnaces, process vents, fugitive releases, storage, manufacturing, minerals, metals, chemicals, and energy facilities.
Construction, quarrying, and earthworks
Exhaust, material handling, stockpiles, wind erosion, unpaved-road resuspension, demolition, and phased construction scenarios using recognized emission-factor methods.
Roads, transport, ports, and logistics
Traffic activity, fleet composition, speed, road links, parking, ships, trains, airports, handling equipment, and induced transport demand.
Cooling towers and wet plumes
Drift deposition, dissolved solids, visible plume occurrence, fogging, icing, shadowing, and equipment or vegetation exposure using specialist models such as WetPlume and SACTI.
Flares and buoyant releases
Flare emissions, effective release parameters, operating scenarios, atmospheric dispersion, and integration with thermal and acoustic assessment through FLARES.
Waste, wastewater, agriculture, and odor
Landfills, treatment plants, composting, livestock, and other sources where air pollutants and odors require coordinated—but distinct—assessment methods. See our odor services.
Study outputs
Results that can be reviewed, reproduced, and used.
The final package is scaled to the project and authority requirements, from a focused screening memorandum to a complete regulatory assessment.
01Technical report
Scope, data, methodology, assumptions, quality checks, results, limitations, and conclusions.
02Compliance tables
Required statistics at grids, property boundaries, sensitive receptors, and other points of interest.
03Maps and GIS outputs
Georeferenced contours, receptor results, source locations, KML/KMZ, and other agreed formats.
04Model archive
Input files, configuration, run logs, postprocessing controls, and structured outputs where included in scope.
05Scenario comparison
Source contributions, alternatives, mitigation performance, and controlling meteorological conditions.
06Review support
Responses to authority comments, meetings, presentations, technical clarification, and expert review.
Permitting, compliance, and environmental assessment
We can join at project definition, review an existing scope, prepare a complete study, or respond to authority comments.
Discuss the assessment →Peer review and litigation support
We audit modeling studies, reproduce analyses, assess uncertainty, and provide scientific support on disputed atmospheric-dispersion issues. US assignments can be supported with EnviroComp, Inc.
Request an independent review →Regulatory context: model selection and acceptance depend on the competent authority and project jurisdiction. For EU industrial installations, studies may support permitting under the Industrial Emissions Directive 2010/75/EU as amended by Directive (EU) 2024/1785, together with national and local requirements.
Start with the decision you need to make
Bring us the site, sources, and assessment question.
We will help define the emissions, meteorology, model, scenarios, receptors, and outputs needed for a proportionate and defensible study.