From 1.11.2011 there is a new drinking water regulation. Afterwards, all hot water systems with a storage volume of 400 l or more must be tested annually for legionella by officially approved laboratories. These tests must be communicated to the health authorities. The health authorities must be informed immediately if the limit values are exceeded. When renting, these costs can be apportioned, ie they can be apportioned to the tenant as operating costs.

The obligation to investigate applies to the following institutions without an official request: 

• estate management
• landlord
• hospitals
• hotels
• schools
• Retirement homes
• sports facilities
• Swimming pools
• dormitories