Forever chemicals and microplastics: what’s in Vienna’s tap water? Since 2026, testing for forever chemicals has been required for the first time.

At the source and in the mains: yes. Wiener Wasser publishes its measured values on an ongoing basis, and they are good. But the pipes inside your building are the building owner’s responsibility, and for substances such as TFA or drug residues there is no limit value in the Austrian Drinking Water Ordinance.

The water test shows you how your water measures up on nitrate, hardness and dissolved substances, right at your tap. TFA or drug residues can only be determined in a laboratory. The reverse osmosis membrane does hold back substances like these, though.

Not automatically. Since January 2026, a limit value for 20 PFAS has applied to tap water. The Austrian Mineral Water Ordinance lists limit values for 15 naturally occurring substances such as arsenic, lead or nitrate. PFAS and TFA are not among them. Mineral water must come from a protected source and be of “original purity”.

In early 2025, GLOBAL 2000 and the Upper Austrian Chamber of Labour had twenty-three Austrian mineral and medicinal waters tested. The laboratory found TFA in 14 of them, with values below the currently known health guideline values. On top of that come plastic particles from the bottle, the lugging and the cost.

With mineral water, only choose one labelled “suitable for the preparation of infant food”. Only then do stricter maximum values apply, such as 10 mg/l nitrate and 20 mg/l sodium. For ordinary mineral water from Austria, up to 25 mg/l nitrate is permitted.

With tap water: do not use water that has been standing in the pipes for a long time, for example overnight. Let it run until it turns noticeably colder. This is what Wiener Wasser recommends where there are lead pipes. At the free water test, we measure how much nitrate your water contains, right at your tap.

Nitrate, conductivity, hardness level and limescale, plus the saturation of the water. We measure directly at your tap and you see the result immediately.

The test is worth about €80 and is free for you, with no obligation. You get your result and an honest assessment. Whether you want a system afterwards is entirely up to you.

Because I would like to use the opportunity to show you what a Bela Aqua system does to your water. Whether you want one is up to you. You get your measurement result either way.

The membrane also holds back minerals. That is why there are the Minerale and Brillance variants: a mineral filter returns calcium, magnesium and trace elements to the water. We discuss which variant suits you at the test.

The OBLIGE is only 14 cm wide and disappears into the cupboard under your sink. The purified water comes from its own slim tap. At the appointment, we look at the space together.

Little. You change the filters yourself, without a technician. For the pre-filter, Bela Aqua recommends a change every 6 months in line with DIN 1988. How often the other filters are due depends on your water and how much you use.

With the OBLIGE, every 1 litre of purified water comes with 0.6 litres of flush water. This is how the membrane flushes out the substances it has held back.

Bela Aqua builds both: the OBLIGE without a tank (Directflow) and the Evolution with a tank. Both designs have their merits.

With Directflow, the system only filters when you draw water. That gives higher output in litres per minute and takes up less space. Bela Aqua itself points out one peculiarity: after you open the tap, there is a short start-up time in which the conductivity of the water is slightly higher. Conductivity is a measure of dissolved substances.

With a tank system, a store of filtered water is ready immediately. In return, it needs more space. Which suits you better depends on how much water you regularly need and on the space you have. We discuss this at the water test.

Pre-filters and post-filters are usually changed every 6 to 12 months, the RO membrane every 12 to 24 months. This can vary depending on the system and the water.

The OBLIGE monitors the filters and the membrane. Three lights on the display show the remaining life of the filters. You make the change yourself, without a specialist. You can see the three steps in the filter change section.

Yes. The OBLIGE has a pump and a display. The system needs a power connection near where it is installed, for example a socket in the cupboard under the sink. Bela Aqua’s product page gives no figure for power consumption.

The OBLIGE flushes its filters automatically every 24 hours (Autoflush), even on holiday. If hygiene is particularly important to you, Bela Aqua recommends leaving the system connected.

If safety matters most to you, you can disconnect the system from the power and close the angle valve. If the system has been disconnected for more than 14 days, Bela Aqua recommends disinfecting it before putting it back into operation. The details are in the instructions for use.

The leak sensor sits in the base of the system. If there is a leak, the AquaStop closes all valves, water production stops and the system warns you with light and sound. More in the Safety and hygiene section.

If you are sure that water is escaping from inside the system, Bela Aqua recommends contacting support.

That depends on the model, the variant and the installation. At the water test you see which system suits your water, and you receive a fixed price. Without obligation.

Christoph Speiser, your Bela Aqua consultant for Vienna and the surrounding area. He measures your water, explains the values and answers your questions. Afterwards, a technician carries out the installation.