German Drinking Water Ordinance: What Commercial Property Operators Need to Know

A drinking-water installation can be out of sight for months, even though its condition affects everyone using a building. For operators of offices, retail premises, hotels and other commercial properties, Germany’s Drinking Water Ordinance (Trinkwasserverordnung, TrinkwV) makes water quality an operational issue. The questions are which installation and type of supply are present, whether the specific Legionella testing duty applies, and how an abnormal result is handled.

Responsibility attaches to the operator of the relevant water supply installation. In a leased property, ownership, day-to-day control and contractual maintenance tasks may be divided between landlord, tenant and facility manager. Record who has access to plant rooms, who commissions sampling, who receives laboratory results and who can arrange immediate repairs. A service contract can distribute work, but the statutory duties of the responsible operator still need to be fulfilled.
The basic requirement is drinking water that meets the ordinance’s quality standards at the point where it is supplied. Installations should be built and operated in line with the generally recognised rules of technology. Keep an inventory of hot-water generation, circulation, outlets and rarely used areas; changes in occupancy or conversion of a floor can change the risk profile.

Section 31 TrinkwV requires systematic Legionella testing only where several conditions coincide. The drinking water must be supplied in a commercial or public activity; the building must have a large hot-water installation and showers or other outlets that produce aerosols. One- and two-family homes are excluded from this particular rule. A large installation exists where a storage or central instantaneous heater holds more than 400 litres, or a pipe between heater outlet and draw-off point holds more than three litres; circulation pipe volume is excluded from the latter calculation.
A simple “every commercial building must test every three years” rule is therefore inaccurate. A hotel with guest showers, an office without showers and a small shop with an electric point-of-use heater may fall into different categories. Map the actual system and its use before ordering a sampling programme. Sampling and analysis belong with a laboratory approved for drinking-water testing under the ordinance; the sampling points must represent the system.

The technical action value is 100 colony-forming units per 100 millilitres (100 CFU/100 ml). Reaching it triggers action under § 51 TrinkwV; it is an action threshold, not a general drinking-water limit value. The operator must immediately ensure that the health authority is informed if the laboratory has not already notified it. The operator must arrange an investigation, including an on-site inspection and a check against the generally recognised rules of technology, prepare a written risk assessment and take the necessary protective measures.
The German search term “Gefährdungsanalyse Trinkwasser” is still common. The current ordinance calls the written assessment a “Risikoabschätzung”. It should follow the Federal Environment Agency’s recommendation and link findings to the actual water system and exposure routes. The measures must be reported to the health authority; the assessment must be provided on request. Records of completed measures must be retained for ten years. Protective action can include restricting affected outlets where warranted, but the specific response should be coordinated with the competent specialists and authority.

• Maintain an up-to-date diagram of heaters, circulation, outlets, sampling locations and areas with intermittent use.
• Set the next required sample date and track laboratory reports centrally across properties.
• Log complaints, maintenance work and changes in use; investigate stagnant branches and unusual temperature patterns with qualified specialists.
• For an exceedance, document notification, inspection, risk assessment, protection, remediation and verification as one traceable case.

The sampling schedule is only one part of control. A building that stands partly empty, a renovated shower area or a changed occupancy pattern may call for earlier technical review even before the next routine sample is due. The responsible operator should also check any separate testing or notification duties that apply to its type of installation.

Wowworks helps facility teams organise suitable local trades for plumbing repairs and other building-technology work across commercial sites in Germany. Work orders, access and completion records can be followed centrally when a water-system assessment identifies technical measures. The operator commissions the required approved laboratory and qualified assessment and remains responsible for statutory notifications and decisions.