Optimisation work at the WWTP Innichen/Sexten



With the realisation of the project we have set ourselves the following objectives:

  • To increase the operational safety
    • To this end, it was planned to renew various pumps, gate valves, samplers and the screw trough pump at the intake
  • Increase the electrical and thermal energy balance
    • Biogas may no longer be flared, but another combined heat and power plant will be purchased and thus more electrical and thermal energy will be generated, which will make us more independent of the market.
    • Heat exchangers are installed in the ventilation systems to recover thermal energy
  • Optimising the wastewater treatment plant through the use of artificial intelligence (AI)
    • The aim is to reduce the energy consumption of the plant by continuously optimising the control parameters.
  • To renew the service water pipeline network
    • The service water pipeline is dilapidated and has repeatedly caused operational disruptions in recent years. It is to be replaced by a new PE pipe.
  • Renew the fire alarm control panel
    • The existing fire alarm control panel is no longer state of the art and is to be replaced by a new one.


The investment project was prepared and submitted by Ing. Konrad Engl in 2019. The work was completed in the years 2021-2022.

Results and conclusion

  • By replacing various system components, the operational safety of the system can be guaranteed.
  • The new combined heat and power plant has increased the production of electricity and thermal energy.
  • With the installation of the heat exchangers in the ventilation systems, around 18.000kWh of energy could be recovered in the month of January 2023, which now no longer has to be purchased and supplied in the form of primary energy.
  • The use of artificial intelligence brings us electrical energy savings of around 10% in the field of biology.
  • The new service water pipe is in operation and by using plastic pipes there should now be no problems with corrosion, deposits and leaks for many years.
  • The new faire alarm system is in operation and functions perfectly.

In conclusion, it can be said that the implementation of the project has intervened at many points in the wastewater treatment plant, which is associated with a wide variety of challenges to continuously maintain plant operation. Since 2011, when the San Candido/Sexten wastewater treatment plant still consumed around 963,000 kWh of electrical energy per year, only 639,000 kWh of electrical energy was consumed in 2022. This corresponds to a reduction of 33.6%.

Even though a lot has already been optimised, we will continue to try to follow this path, to clean our waste water according to the latest technology and to consume as little valuable primary energy as possible.