Water shortage – also in Switzerland
The example of the large water supply in the Bernese Seeland shows how the 50-year-old company SCHEIDEGGER Trinkwasser, which belongs to STEBATEC, shapes the Swiss water supply landscape. SCHEIDEGGER has been looking after the Grosses Moos (Wagrom) water association in the Bernese Seeland for a long time. It was founded in the 1980s, when the individual municipal water supplies reached their limits in terms of the quantity and quality of drinking water due to population growth and increasing nitrate inputs from agriculture, and therefore formed the first smaller associations.
The current managing director of Wagrom, Daniel Bongni, remembers from his youth the village guard who rode through the village on a moped while ringing a bell. Everyone understood the message, it was:
«There will be no water this afternoon.»
Automated drinking water supply through new, clear control system
SCHEIDEGGER lieferte dem neuen Wasserverbund die lokalen, elektromechanischen Steuerungen für die verschiedenen Aussenobjekte, das zugehörige Leitsystem stammte aber von Landis + Gyr sowie später von Siemens. Als Siemens ankündigte, dass in absehbarer Zeit keine Ersatzteile mehr zur Verfügung stehen würden, suchte der Verbund nach Alternativen. In einem Offertverfahren erhielt SCHEIDEGGER den Auftrag, ein neues Leitsystem zu implementieren. Die ursprünglichen Probleme – Menge, Qualität und Druck des Trinkwassers – hatte man zwar schon im Griff, das neue System sollte aber bedienerfreundlicher sein und die Übersichtlichkeit erhöhen. Immerhin umfasst Wagrom mit seinem rund 100 Kilometer langen Wasserverbundnetz 17 Gemeinden sowie weitere Vertragspartner, weist eine Vielzahl von Reservoirs und Pumpstationen und überdies Schnittstellen zu benachbarten Versorgern auf.
Management via setpoint curves
The SCHEIDEGGER control system controls all processes in the widely ramified supply area and continuously records all relevant data.
Figure: With setpoint curves, limit values for the management of the water network are event-controlled and dynamically changed based on time sequences. In order to ensure that all parts of the system are used regularly or to avoid standing water for hygiene reasons, the water withdrawals are thus dynamised. The system uses several setpoint curves that are automatically applied, for example, in the event of fire, technical faults or other criteria.
The setpoint curve controller serves as the central intelligence for managing the water quantities. The curves are visually easy to read and facilitate the overview, while quite complex control targets can be set and tracked. The system allows several setpoint curves to be created, each of which is automatically applied at different times or conditions (e.g. fire event or system failure) if the criteria are met. Especially with regard to the hygienic requirements that water in basins and pipes must not stand for long periods of time, the unique setpoint curve controller offers considerable advantages, because with the appropriate settings, all system parts are used in a chronological sequence.
Further information: www.scheidegger-trinkwasser.ch
