Drinking water testing - who, when, how?

After a change in the Drinking Water Ordinance, the owners of apartment buildings are under certain circumstances obligated to have a regular check of the drinking water carried out. Whoever has to take this exam, how it is to be carried out and what exactly is being tested, can be read here.

Duty to inspect the apartment building

The Drinking Water Ordinance states in its new version that owners of multi-family houses must have their drinking water checked at intervals of no more than three years. But affected are only the owners of buildings, for the following applies:

  • The building consists of more than two residential units, of which at least one is rented
  • There is a central system for hot water preparation available (at least 400 liters volume) or
  • The way from the hot water treatment to the farthest point of extraction contains at least 3 liters of water

In the usual house installation, the last rule corresponds to an approximate distance of 15 to 20 meters between the hot water system and the remotest hot water withdrawal point.

The owner is obliged to check the building. This does not only apply to private persons, but also commercial landlords and housing cooperatives.

Subject of the test

The subject of the drinking water test is a test of whether the hot water system is contaminated with Legionella. Legionella means a high health hazard, so the strict and at least three-year test is mandatory.

Carrying out the test

According to the provisions of the Drinking Water Ordinance, a water sample must be taken from at least three test sites. For this purpose, appropriate removal points have to be set up. This is done by GWH specialist companies. The costs are borne by the homeowner, he may not transfer them to the tenant.

The water samples are then to be tested in a certified laboratory. In the case of detection of Legionella above the so-called technical value of measures, the health authority must be informed, which then determines further measures.

On the other hand, the homeowner may transfer the running costs for the regular inspections to the tenants as part of the operating costs. Depending on the examination costs, the examination costs amount to around 200 EUR.

Tips & Tricks

To prevent Legionella infestation, the hot water system can also be equipped with a so-called Legionella circuit. It heats the water periodically to a temperature of 70° C and thus leads to the death of Legionella. The operating temperature of hot water systems should always be above 55° C.