The Zermatt sewage treatment plant, which was built underground in rock caverns, was completely rehabilitated, almost doubling its biological treatment capacity. From the mandate of electrical planning and execution, a close cooperation developed, which today covers the entire measurement and control technology.
Tasks
- Analysis of the existing plants and equipment
- Development of an overall EMSR concept
- Preparation of cost estimate
- Complete EMSR planning
- Site management: electrical installations, switchgear and control systems, measurement technology
Initial situation / existing situation
In 2008, Ryser Ingenieure AG, which was commissioned with the renovation of the Zermatt wastewater treatment plant, called in STEBATEC AG for the electrical planning. This marked the beginning of a collaboration with the municipality of Zermatt for what is probably one of the most unusual wastewater treatment plants in Switzerland. The wastewater treatment plant, completed in 1982, is located completely underground in rock caverns. However, it was only designed for 38,000 population equivalents and was thus soon too small. The biological treatment system in particular was overloaded and no longer met the legal requirements. But many other installations and systems were also outdated and had to be renewed or adapted to the new capacity of 60,000 population equivalents. Fortunately, the wastewater treatment plant had two sewage roads, which greatly facilitated the conversion.
- Reliable electrical installations for the renovated, larger WWTP
- Reliable solutions for an electrical connected load of 1000 kVA
- Increased operational safety of the WWTP
- User- and maintenance-friendly installations
- Cost control and monitoring
Prior to the actual renovation, the operations centre was brought up to date in order to create a secure basis for all further work. In the summer half-years, which are less busy for tourism, one wastewater route was shut down and completely renewed in each of 2012 and 2013. For reasons of space, biological treatment is no longer carried out using the activated sludge process, but instead using the membrane biology process; the area of over 32,000 m2 used in Zermatt even represents the national record.
Safe ventilation was important during the conversion: the demolition work in the caverns was dusty and the gases from the WWTP dangerous. Moreover, everything had to be dismantled in order to be able to pass through the narrow tunnels on electric vehicles or on the specially installed crane track to the exit. STEBATEC’s high level of commitment and flexibility paid off, however, and the company is now Zermatt’s first contact not only for electrical planning, but also for the entire control and measurement technology.
