Air Dispersion Modelling Services
Modelling for Compliance and Permitting
ORTECH have extensive experience and expertise in selecting relevant models to demonstrate regulatory compliance against current and proposed air quality standards, criteria and guidelines using short range, medium range and long range air dispersion models. ORTECH also has extensive experience in interfacing with clients and other stakeholders to select both the models and the specific parameters required for representative and cost-effective modelling and results.
Odour and Other Assessments
ORTECH also has extensive dispersion modelling experience in using odour sampling results to predict maximum odour concentrations at sensitive receptor locations, performing analysis of the frequency that certain odour levels might be expected to occur and comparing modelling results to ambient sampling to assess the accuracy of the dispersion modelling. ORTECH can also use dispersion modelling in combination with ambient odour sampling results to estimate fugitive source emission rates which is valuable when developing a comprehensive inventory of odour sources for your site.
ORTECH also has experience in special topics including fogging and icing issues related to water vapor releases from cooling towers.
Meteorological Data Sets
Some authorities provide preprocessed meteorological data sets for dispersion modeling. However, in some cases it is desirable or necessary to use or create site specific data sets, for example to conduct refined modelling analysis for the purpose of comparing ambient monitoring results to modelled results in odour assessments or combined analyses. Whether the required data set is for a single day or a five year period, ORTECH can generate quality control checked and model-ready meteorological data files.
Combined Ambient Monitoring and Modelling (CAMM) Analysis
ORTECH was involved in the first two Alternate Standard applications in Ontario including the dispersion modelling for the combined monitoring and modelling analysis in support of these successful projects. ORTECH continues to be involved in modelling and monitoring analyses. We can assist in all modelling aspects of the combined analysis from selecting or preparing site specific meteorological data to statistical analysis of the modelling results.
ORTECH has assisted various industries in assessing impacts and compliances resulting from accidental releases, explosions and fires. Particularly, ORTECH can assist you in planning for these types of releases even before they occur.
Regional Airshed Modelling
ORTECH has extensive experience in solving conflicts related to regional development and air quality issues. ORTECH has also developed a Pesticide Emissions Model to predict local and long-range pesticide transport, for existing and potential new pesticide formulations.
Special Modelling Studies and Testimony
The interpretation of air dispersion modeling, whether it is for regulatory compliance or health impact study, can be very challenging. ORTECH understands the science and recognizes the applications, limitations and uncertainties associated with the use of predictive models. ORTECH has a history of assisting industries in understanding these limitations and uncertainties to tailor their environmental compliance frameworks and present their positions.
Air Dispersion Models
ORTECH has the ability to run and understand over 20 models including:
- US EPA AERMOD (with and without building downwash algorithms)
- TRC CALPUFF
- Cambridge ADMS4
- Ontario Regulation 346 Appendix Models
- ASHRAE Handbook HVAC Applications Chapter 44
- Lawrence Livermore SLAB
- US EPA SCREEN3 and ISC3
- US EPA CALINE3, CAL3QHC/CAL3QHCR
- US EPA Mobile6 and EC Mobile 6C
- US EPA OCD
- USEPA BLP
- US EPA DEGADIS
- US NOAA ALOHA
- SACTI; and
- US EPA WATER 9.
ORTECH provides a comprehensive range of other services that complement our dispersion modeling activities.
- Ambient Air Quality Monitoring Services
- Compliance and Permitting Services
- Emission Testing Services
- GIS and Mapping Services
- Meteorological Data Instrumentation, Collection and Analysis Services
- Odour Assessment Services