5. December 2023

Public LeCo seminar 15 April 2021: A field study of Legionella in shower water of domestic drinking water installations with 110 buildings (in German)

15 April 2021, 4:00 – 5:00 pm

Free online participation: https://hslu.zoom.us/j/67614709041?pwd=YVlXdzU0ckFFc0taOUdZUDFNd01adz09

(Meeting-ID: 676 1470 9041, Kenncode: 924670)

For questions: email hidden; JavaScript is required (041 349 38 44)


In 2019, the SPF Institute for Solar Technology conducted a Legionella field study in 110 buildings. This involved taking more than 300 shower water samples and more than 100 samples from the lower part of boilers and analysing them for Legionella. Owners or operators were informed of the results and recommendations for elimination and prevention of Legionella were made if the results were positive. One year later, 14 properties were re-sampled. These were exclusively properties where Legionella > 1000 CFU/L was detected in at least one shower water sample in the previous year. In five of these properties, further measures were necessary until no more Legionella could be detected by re-sampling. In the seminar, the study and its results are presented in detail.

The presentation will be given in German.

Invited Speaker: Dr. Michel Haller

  • Studies of environmental sciences at ETH Zurich (Switzerland)
  • PhD at TU Graz (Austria) in the field of heat supply with renewable energies (solar and wood)
  • Since 2015 head of research at the SPF Institute for Solar Technology at the OST – Ostschweizer Fachhochschule in Rapperswil
  • For several years he has been working on the topic of legionella in domestic drinking water systems, in particular on issues arising for the safe operation of renewable energy systems.
  • Member of the SIA 385 Commission “Domestic hot water systems in buildings” and member of CEN/TC164 “Water supply”