Lakes Environmental Software has announced the acquisition of the CALPUFF atmospheric dispersion modelling system from Exponent. This transaction, confirmed on 5 May 2024, marks another step in the evolution of CALPUFF, a model widely used by researchers, environmental consultants, and regulatory agencies globally.
CALPUFF is a US EPA Guideline model for all applications > 50km, it is also the guideline model for all near-field applications where the steady state assumption does not apply, i.e., complex terrain and complex meteorological environments (Sea breeze, boundary layers, etc.). In addition, it is a model widely used in odour modelling. The code of this model, while being publicized as "freely available," is not open source, as far as we know. Over the years, the ownership of the code has changed from SRC to TRC, Earth Tech, Exponent, and now Weblakes.
The previous owners announced at that time a GUI named CALApps that will probably be dead at this stage, as we have not heard much about this development since 2014. Also, Weblakes has already a GUI pretty much used al around the world.
In 2016, the US EPA approved version 5.8.5 of this model, and a year later, we learnt that the website of the Support Center for Regulatory Atmospheric Modeling (SCRAM) no longer included the CALPUFF model as a recommended dispersion model. This decision meant that one of the most widely dispersion models used for odour modelling was not recommended by the US EPA anymore. This decision had serious consequences for the odour community. In 2019,
In 2019, Jennifer Barclay explained a bit better why CALPUFF stopped being a regulatory model and why this situation did not affect to its use in odour impact assesments.
We hope this new ownership will help to develop an improve this model in key points for odour modellers, which we already mentioned ten years ago. I remember at that time, that after this talk in a conference in Chile, Joe Scire approached me to get some dinner. During that night at one point, Joe pulled out a small paper napkin on which he had jotted down several ideas he wanted to discuss, to improve CALPUFF. Unfortunately, those ideas never came to reality.
The acquisition of CALPUFF by Lakes Environmental represents an exciting and promising phase for the odour modelling community. With a renewed commitment to accessibility and continuous improvement, CALPUFF is expected to remain an indispensable tool for odour dispersion studies and regulatory applications in the coming years.
Get the press note here.
If you find this article interesting, you might be also interested in these articles.
- A new CALPUFF update by the US EPA recently published
- CALPUFF and Odours Training Course Insights
- Odour impact of a new waste management plant: zero-situation characterised by VDI3940 field observations and predictive odour assessment by CALPUFF modelling
- CALPUFF Model, History and Current Status – Part 1
- CALPUFF website is now owned by Exponent
