Successful cooperation for almost fifty years
The example of the Saanen water supply in the Bernese Oberland shows how the 50-year-old SCHEIDEGGER Trinkwasser company, which is part of STEBATEC, has shaped the Swiss water supply landscape. The municipality of Saanen also includes world-famous Gstaad, Saanenmöser and the hamlets of Abländschen and Turbach.
The municipality’s territory is very large and extensive, and the use of water for tourism brings with it large fluctuations in consumption. A small anecdote from the «early days» illustrates how the monitoring of the outdoor facilities used to work. One of the reservoirs was only connected to the post office via a telephone cable. If the float triggered a water level alarm, a bell rang in the post office, whereupon an employee forwarded the alarm to the water supply by telephone.
«This way, the alarm could only be raised during opening hours of the post office».
The cooperation with SCHEIDEGGER in Saanen goes back to 1973, when the company’s founder, Paul Scheidegger, equipped individual parts of the system with his technology and installed the first cable network and an electromechanical control system. This control system remained in operation for forty years until 2013, when it was converted to a stored-program control system. For the automation of the drinking water supply, all system parts relevant to the supply were connected with cable harnesses, except for two remote outdoor installations; the two outdoor stations currently still communicate via the mobile network. In Saanen, the control system based on setpoint curves is in use.
Management via setpoint curves
The control system manages all processes in the widely ramified supply area and continuously records all relevant data.
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. Particularly 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 appropriate settings, all system parts are used in a chronological sequence.
To ensure even flows, which UV treatment plants require, for example, the system is also used in combination with control dampers and frequency converters.
Arno Romang, the operations manager of the water supply, was able to state with satisfaction «the new control system allows a finer interaction of the system parts, which saves operating energy year after year.»
But water consumption is also declining. This is mainly due to the new pipes and the improved monitoring possibilities with the control system.
New groundwater pumping station
Today, Saanen covers more than 70 per cent of its drinking water needs from a total of twelve spring wells, but it also has two groundwater wells. One groundwater pumping station is brand new (status: 2021). It was built to meet the cantonal requirement for a redundant water supply. Three wells with a total of six pumps can pump up to 12,000 litres per minute, which would supply the entire community – even in the event of a power failure, thanks to a diesel generator. The four powerful pumps that feed the supply system are followed by valves to avoid possible pressure surges. The drive and control of these flaps also come from SCHEIDEGGER.
The quality of our drinking water will probably become much more important in the future, especially as the regulations on hygiene and maximum loads of pollutants are constantly being tightened. Saanen, situated at a high altitude, may be less affected by this, but the opportunity of the new building was immediately taken to also set up a test road on which the quality values are continuously recorded. Of course, these measured values can also be called up at any time via the control system.
Further information at www.scheidegger-trinkwasser.ch