Air dispersion, noise and water modelling
We build the models regulators and lenders check: air , noise and vibration, flood and drainage, coastal and outfall plumes, and underwater noise from piling and dredging, with every input traceable.
What this means for you. A model predicts how far pollution, noise or heat will spread from your project and whether neighbours will be above the limits. It decides where monitoring stations and mitigation go.
- Scope
- Air dispersion: AERMOD, CALPUFF, screening
Noise and vibration: construction and operation
Hydrology, flood risk and drainage
Thermal and brine outfall plumes
Underwater noise from piling, dredging and vessels - What we need from you
- Source inventory: stacks, flows, sound power, discharges
Layout and terrain
Site or representative weather data
Receptor list and target limits - What you receive
- Contours and receptor tables against the limits
Model input and output files
Assumptions and sensitivity register
Mitigation sizing - Standards
- US EPA 40 CFR 51 Appendix W
ISO 9613-2
IFC EHS General Guidelines (2007)
NOAA Fisheries acoustic guidance v3.0 (2024)
Questions clients ask
AERMOD or CALPUFF?
is the US EPA preferred model for near-field applications under 40 CFR 51 Appendix W. CALPUFF suits long-range transport and complex wind fields where the reviewing authority accepts it. We choose the model the reviewer will expect for your distances and terrain.
How much weather data does an air model need?
Appendix W calls for at least one year of site-specific data or five years of representative National Weather Service data. Outside the US we apply the same logic with the best available station or prognostic data, and state the choice.
What noise limits do lenders apply?
The IFC EHS General Guidelines set one-hour LAeq limits of 55 by day and 45 dB(A) at night for residential s, or no more than a 3 dB increase over background. National limits apply where they are stricter.
Which thresholds do you use for marine mammals?
The NOAA Fisheries technical guidance version 3.0, published in 2024, with injury and temporary threshold shift onset ranges reported for each hearing group.
Related technical notes
Tell us about the project. We reply shortly with the questions a lender, regulator or verifier is likely to raise.