First NEREDA® reactor in operation at the Kloten-Opfikon WWTP

As a result of the continuous development of the catchment area and increased demands on water pollution control, the Kloten Opfikon WWTP, designed in 1993 for 54,500 PE, is expanded to a capacity of 125,000 PE. This is being done without requiring additional space, made possible with the use of the extremely compact NEREDA® process, which operates with aerobic granular biomass. In summer 2021, the first of 4 NEREDA® reactors was successfully commissioned, followed by two further stages of conversion and expansion starting in December 2021, which will be completed in 2024.

Plant engineering made to measure.

Turnkey projects.

Consulting, planning, engineering, coordination, delivery, installation, commissioning, training, and handover.

Our vision.

sustainable solutions. for a better life.

Your expert partner for planning, constructing, and operating water treatment plants.

Drinking water treatment.

Ground water. Spring water. Surface water.

Any type of water can be treated. But the crucial factors to bear in mind are sustainability and ensuring that treatment technologies are used strategically.

Wastewater treatment.

Municipal applications. Industrial applications.

State-of-the-art technologies for constructing wastewater treatment plants, expanding their capacity, and modernizing them.


Water. The basis of all life.

Our aim is to preserve and improve this valuable resource.

We are a company that specializes in the planning and construction of drinking water/wastewater treatment plants at both a national and international level. And it is in this capacity that we offer sustainable and innovative solutions. When it comes to preserving and supplying the world's most precious resource, we think of our work as both a daily challenge and as a responsibility toward society. But also as one of the most important investments that can be made in a viable future.

Our customers are right to place their trust in our innovative, self-developed technologies and our long-term experience in plant engineering. After all, it was by perfectly harnessing the synergies between outstanding quality, long-standing experience, and state-of-the-art technology that we managed to establish ourselves as one of the world's most renowned companies for water technology.



Aufbereitung von Grundwasser


Treatment of ground, spring, and surface water.

WABAG Water Technology Ltd offers a comprehensive range of technologies for use in drinking water treatment. We devise and implement technically advanced and individually tailored solutions for public authorities and industrial companies alike. These cover everything from ultrafiltration and multi-barrier systems through to special applications such as iron and micropollutant removal.



Treatment of municipal and industrial wastewater.

As Switzerland's leading provider of technology and systems for wastewater treatment plants (WWTP), WABAG has the in-depth knowledge and state-of-the-art technologies required to construct, expand, and modernize WWTPs. We have got every aspect of the process technology covered: preliminary treatment, biological treatment, tertiary treatment, removal of micropollutants, and sludge treatment.



Who are WABAG?

Mechanical engineers, process engineers, and design engineers have always been the backbone of WABAG Water Technology Ltd – right back to the days when the company was called Sulzer Chemtech. Every single employee is also a researcher and developer with a strong personal interest in creating fresh, clean water. Find out more!



Good advice from WABAG.

Customer service should leave no wish unfulfilled and highly focused commitment is the key. We have been concentrating on this – and nothing else – for more than 60 years.

WABAG - Dienstleistungen

sustainable solutions. for a better life.

WABAG Water Technology Ltd
Bürglistrasse 31
P.O. Box
CH-8401 Winterthur

Tel. +41 52 218 14 14 
Fax +41 52 218 14 99


© 2021 WABAG Water Technology Ltd