What's New 2026 - WEST
With the latest WEST update, you can visualise mass balance behaviour through bar graph plots, generate standardised MLE and A2O wastewater treatment plant designs with minimal input, and work more efficiently with improved NDHA model calibration and full Spanish language support.
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Webinar: 2026 What's new in WEST | On-demand
Join our webinar to review the newest improvements in WEST for dynamic wastewater treatment plant modelling, covering updates to simulation engines, features, models and tools in the software.
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MIKE 2025 Update 1
Track mass flow in seconds with the new 'Mass Balance' tool
A new 'Mass Balance' tool automatically creates a .csv output with mass flow rates for all state components (plus familiar aggregates like COD, BOD, TSS, TN, and TP) at each terminal of your layout.
Simply select Simulation Mass Balance under Project > Miscellaneous to generate a file ready for review and editing in Excel.
Access the WEST interface and tools now available in French
The WEST interface and tools are now available in French.
Just go to Options in the main menu, select Popular, and choose French from the language dropdown. C’est simple!
Speed up setup with the new built-in compiler
WEST now includes a built-in 64bit C compiler, so you no longer need to install or configure an external tool.
The new compiler is faster too, helping you compile and run models more quickly. Everything is handled automatically during installation, saving you time and effort.
Enable enhanced performance with standard 64-bit support
WEST is now fully 64bit, bringing better performance, improved stability, and support for larger, more complex models.
With expanded memory access and faster compilation, you can build and simulate without the old 32bit limitations.
Say goodbye to MSL and hello to Modelica
The old MSL library has officially been retired and all standard projects now run on the more flexible and widely supported Modelica language.
You can still run and edit old MSL projects if you have the library stored locally, but all new development should be Modelica-based.
Improve accuracy with smarter micropollutant modelling
The IUWS4 library for MPs has been upgraded for clarity and consistency.
Users can now simulate the fate of carbamazepine across your entire system while accounting for energy use, ozone dosing, and operational costs.
New options include TSS impact on scavenging and pH sensitivity in ozonation.
Enhance precision with more reliable N₂O emission modelling
We’ve upgraded the N₂O model with improved stripping mechanics and better parameter consistency across N-removal models.
You can now include N₂O emissions in your cost balance using two methods—via influent load correlations or simulated production—and account for effluent-based emissions to get a more accurate carbon footprint.