Zermatt, Wastewater treatment, Switzerland
Client:Municipality of Zermatt
Capacity:60,000 p.e.


  • Treatment of the wastewater of Zermatt to reach stringent effluent standards. 
  • Engineering, supply, erection and start-up of the new membrane biology (MBR).
  • The complete WWTP is housed in caverns in the mountain due to space and air condition reasons (in a depth of up to 200m). Due to tourism and seasonal load variations the plant masters capacities from minimum 6,000 up to maximum 60,000 PE.

Process steps

  • Mechanical pre-treatment
  • Wastewater lifting
  • Coagulation
  • Primary sedimentation
  • Fine screen
  • Biology
  • Membrane filtration in seperate basin
  • Neutralisation
  • Phosphorus elimination by pre- and simultaneous precipitation
02 Denitrifikationsbecken, hinten links und rechts Nitrifikation und Membranfiltration-web