German Drinking Water Ordinance: which version applies and which limit values

Four provisions came into force on 12 January 2026. All four were already in the text in 2023, with a later date of application.

The first limit value for PFAS. Since 12 January 2026, a limit value of 0.00010 mg/l has applied to the sum of PFAS-20. This refers to the sum of 20 per- and polyfluoroalkyl substances listed by name in Annex 2, including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS). Measured values below the limit of quantification are not counted when calculating the sum. Each individual substance must be reported separately. Where PFAS in water come from is explained in the guide to PFAS in drinking water.

Haloacetic acids. A limit value of 0.060 mg/l applies to the sum of HAA-5. This covers five reaction products formed during the disinfection or oxidation of water: monochloroacetic, dichloroacetic and trichloroacetic acid as well as monobromoacetic and dibromoacetic acid. A supplier may dispense with testing if it disinfects without treatment substances that form HAA-5.

Microcystin-LR. Since 12 January 2026, this liver toxin produced by cyanobacteria has had a limit value of 0.0010 mg/l. The letters LR stand for leucine and arginine, two amino acids that distinguish it from other microcystins. Testing is only required if potentially toxic cyanobacteria occur in the water source, for example during an algal bloom.

The end of lead pipes. Lead pipes had to be removed or decommissioned by the end of 12 January 2026. Since 13 January 2026, there has also been an obligation to provide proof to consumers.

The Ordinance classifies the chemical parameters according to whether their concentration can increase on the way through the network and the domestic installation. Annex 2 Part I lists 18 substances whose concentration does not normally increase any further. Part II lists 15 substances for which an increase is possible. This division determines where measurements are taken and who is answerable for the value.

Nitrate has a special feature that is often overlooked. In addition to the limit value of 50 mg/l, a sum formula applies. The nitrate concentration divided by 50 plus the nitrite concentration divided by 3 must not exceed the value 1. Water with 45 mg/l nitrate and 0.3 mg/l nitrite complies with both individual limit values and yet still violates the sum formula. How nitrate gets into groundwater is explained in the guide to nitrate in groundwater and drinking water. There is a separate guide on pesticides, covering plant protection products in tap water.

A strict measurement rule applies to lead, copper, nickel and arsenic. In staggered stagnation sampling, three samples are taken, designated S0, S1 and S2. If any one of them is above the limit value, the limit is deemed to have been exceeded. So a favourable average does not save the measurement. The same applies to a random sample.

Chlorate and chlorite come from disinfection and therefore have flexible values. For chlorate, 0.070 mg/l applies as standard, 0.20 mg/l with intermittent dosing, and 0.70 mg/l is permitted for short periods to avert a hazard. If measured at the waterworks outlet, a reference value of 0.020 mg/l applies. How chlorine is used in drinking water is explained in the guide to chlorine in drinking water.

The increase from 25 to 72 sections is mainly due to a new approach introduced by the revision. The old Ordinance only checked water quality at the tap. The current version additionally requires the entire route to be safeguarded, from the catchment area through treatment to the domestic installation. Part 7 calls this the risk-based approach.

In practice, this means mandatory risk management for water supply systems. Instead of simply taking samples, the operator must systematically identify and assess hazards and derive measures from them. The deadlines for this are staggered. Large systems supplying more than 100 cubic metres per day or more than 500 people must have completed this by the end of 12 January 2029. For smaller systems, the deadline runs until 12 January 2033.

Transparency obligations are also new. Every supplier must publish its analysis values online without a connected customer or consumer having to ask for them. What exactly has to be published there is explained in the guide to the origin and treatment of our drinking water.

The limit values themselves have changed in nine places: three substances tightened, six newly added. Lead, arsenic and chromium were tightened, each with transition periods. Newly added are bisphenol A, chlorate, chlorite, haloacetic acids, microcystin-LR and PFAS.

Treatment is also more tightly regulated. § 19 paragraph 2 prohibits adding substances other than treatment substances to raw water or drinking water. Under paragraph 3, only substances and disinfection methods from the list under § 20 are permitted. The list is kept by the Umweltbundesamt (German Environment Agency). Under paragraph 6, treatment substances must subsequently be removed again. An exception applies to substances that are intended to remain in the drinking water. Only unavoidable residues remain permissible. They must have no technological effect and be harmless to health.

§ 17 regulates lead drinking water pipes in six paragraphs. The core provision is in paragraph 1: the operator of a water supply system had to remove or decommission existing lead pipes or sections of them by the end of 12 January 2026. In a rented building, the operator is the owner.

The Ordinance provides for two extensions. Under paragraph 2, the public health office can extend the deadline if the operator commissioned a registered installation company before 12 January 2026. The company must certify that, for capacity reasons, the job will only be completed later.

Paragraph 3 allows an extension until the end of 12 January 2036 at the latest. For this, three conditions must be met at the same time. First, it is a building water supply system or a private water supply system. Second, the water is used only in one's own household. Third, there is no reason to fear harm to the health of the regular users, particularly with regard to age and sex. If minors, pregnant women or women of childbearing age move in, the operator must report this without delay. If ownership changes, the extended deadline ends one year after the transfer.

For tenants, paragraph 5 is the most important. Since 13 January 2026, the operator has had to declare to affected consumers in text form, and prove in a suitable manner, that it has removed the lead pipes or holds an extension of the deadline. Anyone who lives in an old building and has doubts can request this proof.

Paragraph 6 obliges water supply and installation companies to report any lead pipes they find to the public health office without delay. Under paragraph 4, the operator must also prove to the public health office, without being asked, that it has fulfilled its obligation.

A common misconception concerns the terminology. It is steel pipes that are galvanised; lead is a pipe material in its own right. So there is no such thing as galvanised lead pipes. Lead can be recognised by its soft, grey surface, which can be scratched with a knife, and by the dull sound it makes when tapped. Why lead is particularly critical for children is explained in the guide to heavy metals in tap water.

For legionella, the ordinance deliberately sets no limit value but a technical action value of 100 colony-forming units per 100 ml. The difference is more than a matter of wording: a limit value marks the boundary of what is permissible, whereas a technical action value triggers obligations to act.

§ 51 defines the threshold precisely. If the action value is reached, the operator must act without delay. It reports the finding to the public health office, investigates the causes, including an on-site inspection, and prepares a written risk assessment in line with the recommendation of the Umweltbundesamt (German Environment Agency). The value does not need to be exceeded; reaching it is enough.

This applies to drinking water installations with large-scale water heating systems, as are common in blocks of flats. Legionella multiply most readily between 25 and 45 °C, which is why temperature management in the hot water tank determines the risk. How this can be solved technically is explained in the guide to the legionella filter.

Responsibility changes hands at a clear line: the water supplier is liable up to the house connection, and from there the owner bears responsibility for the drinking water installation. The owner's pipes, fittings and storage tanks determine the values of the 15 parameters from Annex 2 Part II that can rise within the building.

§ 10 calls the point at which the requirements must be met the point of compliance. For water supplied through pipes in buildings, it is at the outlet of the drinking water draw-off points, i.e. at the tap. This reference point at the tap explains why sampling at the waterworks alone says little about your own water.

This is precisely why Annex 2 divides the chemical parameters into two parts. Everything in Part II can rise within the building: lead, copper and nickel from pipes and fittings, bisphenol A from materials, trihalomethanes from disinfection. A good value at the waterworks is of little help with these if the last few metres contaminate the water again.

The obligations for landlords follow from this division. Anyone who supplies drinking water as part of a commercial activity operates a water supply system within the meaning of the ordinance, and letting property counts as such an activity. This gives rise to testing obligations, including legionella testing for large-scale water heating systems, as well as notification obligations towards the public health office and information obligations towards tenants. Testing may only be carried out by a testing laboratory approved under § 40.

Three much-discussed groups of substances have no limit value in the annexes: pharmaceutical residues, hormones and microplastics. For them, there is no value whose exceedance triggers measures, and they are not measured across the board either.

Nevertheless, the ordinance does have an instrument for substances without a limit value. § 35(1) no. 7 requires risk management to cover the substances on the European watch list. What counts is the version of the list in force at any given time under Article 13(8) of Directive (EU) 2020/2184. Through the list, substances can come under consideration before a limit value exists for them.

The reason for the gap lies in wastewater treatment. For micropollutants such as pharmaceutical residues, a fourth treatment stage would be needed in wastewater treatment plants, for example with ozonation or activated carbon. In Germany, the majority of wastewater treatment plants operate with three stages. What is known about pharmaceutical residues is explained in the guide to pharmaceutical residues in tap water.

Anyone who wants to reduce micropollutants in their own household relies on adsorption. Activated carbon binds organic compounds, chlorine and substances that affect taste to its surface. This does not apply to dissolved minerals and salts; their concentration remains unchanged. What activated carbon can do and where its limits lie is explained in the guide to the activated carbon filter for water.

The 33 limit values above apply uniformly nationwide, but the actual measured values depend on the supply area. The supplier must publish them online. Searching for the supplier's name together with the term “drinking water analysis” usually leads straight to the table.

The supplier's analysis says little about the last few metres inside the building. Lead, copper and nickel levels are determined by your own plumbing, and measuring them requires a sample from your own tap taken by an approved testing laboratory. Which methods are available and what they cost is explained in the guide to measuring water quality. The guide to substances in tap water gives an overview of all dissolved substances.

Five dates are still to come. All of them stem from the current version; no new ordinance is required for them.

The staggered arsenic limits illustrate the pattern. Until 11 January 2028, 0.010 mg/l applies to all systems. Systems newly commissioned from 12 January 2028 must meet 0.0040 mg/l straight away. Older systems may remain at the old value until 11 January 2036. From 12 January 2036, the stricter value applies without exception.

The Drinking Water Ordinance has been in force unchanged since 20 June 2023, and yet in 2026 it is a different ordinance from the one in 2023. Four provisions took effect on 12 January 2026, and five further dates will follow up to 2036. Anyone who wants to know what applies today should therefore check the date of application in Annex 2 rather than the year of publication.

Two points are of direct benefit to consumers. First, proof regarding lead pipes, which consumers have been able to request since 13 January 2026. Second, the supplier's analysis, which must be available online. For everything beyond the house connection, your own plumbing remains decisive.