New-build sewage treatment plant Weesp

Project information

 2018 - 2021

Country: The Netherlands

Client: Mobilis B.V.



Project description 

Constructed in 1974, the old sewage treatment plant in Weesp has reached the end of its lifespan and was no longer satisfying the discharge requirements set for it. Waternet (on behalf of Regional Public Water Authority Amstel, Gooi & Vecht) tasked Mobilis and its construction partners TAUW, Xylem, Pannekoek GWW, RWB, Moekotte and CroonWolter&Dros with building the new sewage treatment plant in Weesp in line with Xylem’s ICEAS concept.

The ICEAS sewage treatment plant will mean secondary sedimentation tanks are no longer required and everything will be done in a single step. In the case of ICEAS treatment, the cyclical treatment process (reaction, sedimentation, decantation) is fully automated and the supply flows continuously. Savings are made in terms of space and construction costs due to the cycle running in a single treatment tank rather than in multiple tanks. The system is exceptionally straightforward and can be extended modularly to accommodate future developments. Virtual Reality and BIM have been incorporated into the climate-adaptive design and build.

The ICEAS concept forms the basis of the new sewage treatment and was designed by technology provider Xylem. TAUW checked this design and embedded it within the overall sewage treatment plant design, retaining responsibility for the integrated design. In addition to this, we were also closely involved in the launch and provided the ‘detailed survey’ that was required in that regard.


How did the cooperation with the client go? 

Besides the traditional design components for a sewage treatment plant (a technological design, preliminary design, definitive design and civil engineering implementation design), the process entailed one new aspect, namely compiling a BIM file throughout the project.

TAUW took care of the integrated BIM Coordination during the design process, including such things as the clash checks, interim trial deliveries and the use of Virtual Reality. The entire design was produced with the aid of a 3D model. Thus making it possible to check and experience the design beforehand. We walked through the new sewage treatment plant with its future operators in a VR session. This provided them with some insight into the future day-to-day utilisation of the plant and added considerable value to the collaboration.

The results

Once the sewage treatment plant was built, the integrated model was revised to AsBuilt and enriched with the requested details. After all, the project included a request to deliver 3D geometry and data in parallel with the traditional documentation. This makes Waternet a pioneer among the district water boards.

The Netherlands’ first full-scale ICEAS was commissioned at the sewage treatment plant in Weesp in February 2020. Treatment performance in terms of COD, BOD, nitrogen and phosphate is extremely good. We did also run into a few issues when commissioning the plant, for which a team of experts carried out a Detailed Survey, which was successful. The Detailed Survey during the launch phase provided bespoke charting and documentation of the operational window for sewage treatment management for Weesp over the coming years until 2040. The plant was successfully handed over to Waternet on 3 August 2021.


"On behalf of all the construction partners, we would like to thank TAUW for all their efforts, which resulted in positive completion of the surveys specified as well as satisfactory completion of the project with Waternet."- Ferry de Bruin, Mobilis


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