30 November 2018

The right measurements, in the right place, at the right time – with the right measuring systems: As a system integrator for a range of manufacturers, Rittmeyer covers all measurement technology applications and processes in the waste water treatment industry.
This was exactly the kind of expertise needed when the owners of the ARA water treatment plant in Windisch (Switzerland) decided to expand their facility.
The area, located in Brugg in the Swiss canton of Aargau, is where the three Alpine rivers – the Aare, the Reuss
and the Limmat – come together, earning it the name of the “Wasserschloss”, or “water castle”. At the heart of this important alluvial landscape is the ARA water treatment plant operated by the Brugg-Birrfeld waste water association and sewage works. It was this environment that inspired the name of the plant, which is referred to by locals as the ARA Wasserschloss.
More than double the capacity Between 2014 and 2017, the plant – which was originally commissioned in the 1960s – was the subject of an extensive program of renovations with a price tag of around 33 million Swiss francs, expanding its capacity to around 80,000 residents. This figure more than doubled the plant’s original capacity: “For a long time, we had been running the ARA at its limits. The expansion means that we now have sufficient reserves,” explains Plant Manager Armin Good.
The most important new addition to the plant – and the feature of which it is most proud – is the ultra-modern biofiltration system installed to replace the previous conventional biological activated sludge process. In the new system, two lines of eight cells process around six million cubic meters of water each year. “We decided on this process partly because it requires a lot less space than the conventional system,” explains Armin Good. The ARA water treatment plant is located in the middle of a protected natural area, and the land required by the plant was very difficult to acquire.

“This renovation left virtually no stone unturned,” says Armin Good. And the same thorough approach was applied to the plant’s measurement technology. All of the plant’s electrical wiring was redone; virtually all measurement points were replaced or completely rebuilt. The plant is now equipped with around 20 magnetic inductive flow measuring systems and approximately 70 different fill level measuring systems. “It’s important to us that we have the best systems at our disposal for each individual application. To achieve this, we rely on partners like Rittmeyer who are independent of the manufacturers,” says Armin Good, explaining the company’s choice of supplier.

For the plant manager, a personal partnership with his suppliers is key: “The technology and the price are, of course, important criteria when deciding who to award a contract to. However, in terms of overall costs, there is another decisive factor that comes into play in the long term: The ability to work with the partner on an equal footing, and to employ a partner who is available for me to talk to, who is committed and who helps to resolve our problems – in spite of all the challenges that inevitably arise with this type of contract.”