To secure the excellent quality of Berlin’s drinking water now and in the future, we monitor it continuously and at each point in the drinking water cycle – in the soil, in the wells, in our waterworks, in the pipelines and at the user outlet.
Drinking Water Ordinance
As the legal basis, the German Drinking Water Ordinance (Trinkwasserverordnung - TrinkwV) requires a high quality, from the water supplier through to the tap in the home.
The consumption or use of water must not endanger human health at any time – is what the Drinking Water Ordinance stipulates. The water supply companies that operate the supply networks and the owners or operators of drinking water installations, i.e. home owners and managers, must take this into account. This obligation does not exist for home owners who use their property for themselves only or for tenants.
To secure the legally specified high water quality, the companies or persons responsible must meet the following requirements:
- The chemical and microbiological quality of water must meet the requirements of the Drinking Water Ordinance at all times. The local health authorities must monitor this.
- Recognised rules of good engineering practice must be followed in the abstraction, treatment and distribution of water. Among other things, this means the provisions of the German Institute for Standardisation (Deutsches Institut für Normung - DIN) and the German Technical and Scientific Association for Gas and Water (Deutsche Verein des Gas- und Wasserfaches - DVGW).
The legislator sets the highest requirements for drinking water. According to the Drinking Water Ordinance (TrinkwV) it must be clear, colourless, odourless, cool, flawless taste and without any health damaging properties.
We comply with these regulations and in some cases we achieve values that are significantly below the legally defined limits. To achieve this, we test the water quality along all the stations of the drinking water cycle continuously. Starting with the groundwater, we keep a continuous eye on our more than 2,500 monitoring wells. We also take samples directly from our wells and re-examine the groundwater critically under the microscope directly after it has been pumped to the surface. The waterworks carry out daily monitoring to determine the chemical and biological composition of the treated drinking water. This is supplemented by permanent measurement of indicator parameters in real time.
To ensure that the water quality is not impaired on the way to the consumer – perhaps due to construction work or leaks in the pipe network – samples are taken at dense spacings along the way through the network and at 180 Berlin consumers. These samples are then analysed in our accredited laboratories. The dense analysis chain ensures that we can detect and remove contamination in the drinking water cycle at any time and in good time.
For the “Quality and image of drinking water in Germany” study, almost 10,000 people were surveyed online within a year. Of whom, 86.2 % certified that Berlin’s water is top quality (national average: 85.9 %). 74.1 % find our service good to very good (corresponds to the national average), and 45.6 % confirmed its good to very good value for money (national average: 44.7 %).
This quality is natural in origin: Berlin’s drinking water is a pure natural product, which we completely abstract from our regional groundwater. Ideal geological conditions, extensive water protection areas and our strict precautionary principle ensure the highest water quality.
As drinking water and for use in households, our water needs no aftertreatment whatsoever. Our complex wastewater treatment, the large water protection areas in the city and the soil layers that clean the water naturally, all ensure good groundwater. In our waterworks we merely reduce the iron and manganese it contains, which impair the taste and can colour the water, but are not harmful to health. There are no chemical additives. With our drinking water you therefore enjoy pure nature.
We pay particular attention to the natural management of our resources. This includes natural water treatment, groundwater replenishment and thorough treatment of the wastewater, which flows back into the natural cycle after use.
Berlin’s drinking water contains minerals and trace elements. It is abstracted from the groundwater resources of the Berlin glacial valley and is top quality. Berlin’s water is in its natural state and does not have to be chlorinated. Additives, such as fluorides to prevent tooth decay, are not used.
Please note: Drinking water is not sufficient to cover the vital need for minerals. It is also important to eat a balanced and healthy diet.
|As of 2018||Value in mg/l||Limit in mg/l*||Recommended daily allowance in mg**|
*Limits under the Drinking Water Ordinance (Trinkwasserverordnung - TrinkwV)
**Recommended Daily Allowances (EU-RDA) acc. to Directive 90/496/EEC
Did you know that water in Berlin is managed in a cycle? This functions almost naturally when we treat groundwater without chemical additives and distribute it in the city through our pipes. We take back the used water, pipe it through sewers into the wastewater treatment plant and after treating it we return it to nature. The greatest challenge lies in also filtering out the invisible pollutants. This is because, wittingly and unwittingly, humans leave behind many microscopically small traces which can only be removed by complex processes.
Questions and answers on the subject of trace substances
Can I still drink Berlin’s tap water?
Yes, not only Berliner Wasserbetriebe says that, but also the German Environment Agency (Umweltbundesamt). It recently certified that especially the drinking water from larger water supplies is of “excellent quality” (press information dated 12/2/2015, http://www.umweltbundesamt.de/presse/presseinformationen/deutsches-trinkwasser-erhaelt-wieder-die-note-sehr). And: Berlin’s tap water is drinking water. This is not only a name, but rather says that our water is subject to the requirements of the Drinking Water Ordinance (Trinkwasserverordnung) – the strictest food regulations in Germany.
What are trace substances?
Trace substances are chemical compounds that occur in water in very low concentrations – that is, within a range of one microgram (μg) per litre or less. The organic trace substances in surface water, groundwater or drinking water include, for example, pharmaceutical substances, industrial chemicals and artificial sweeteners. By way of explanation: One microgram is one millionth of a gram.
How do they get into the drinking water?
In Berlin there is a natural water cycle: Berlin’s drinking water – as in most other areas of Germany – is abstracted from groundwater and bank filtrate. Our waterworks draw water from the soil through deep wells, which has previously infiltrated and percolated there – through precipitation and from surface waters (which is the bank filtrate). The water reaches the citizens through the pipe network and after they have used it, it is returned through the sewer system to the wastewater treatment plants. There it is treated and then discharged into waters such as the Tegeler See lake, the River Spree or the Teltow Canal. The cycle starts all over again.
Organic trace substances enter the water cycle in different ways: air, wastewater treatment plants, rainwater gullies, sewage sludge - or waste disposal or contaminated sites. Human medicinal products primarily get into wastewater via the toilet, pass through the wastewater treatment plant and from there they get into the water cycle. It is therefore important that expired or no longer needed medicines are never disposed of down the toilet, but are handed in to the hazardous substance collection points of the waste management company, BSR (www.bsr.de).
In what concentrations do trace substances occur?
Berliner Wasserbetriebe analyses its water for a range of trace substances and publishes the analysis values on the internet (www.bwb.de/wasser). All these substances exist in concentrations in the order of micrograms (μg) per litre – some with far smaller concentrations. One μg is one millionth of a gram. Two examples clearly illustrate what this quantity means: 1 μg/L is as if you were to dissolve a sugar cube in as much water as can be carried by 100 road tankers. Or in other words: A tablet contains 400 milligrams of active ingredients (that is 400,000 micrograms, i.e. four million times as much as in one litre of drinking water.) To ingest this dose through drinking water, you would have to drink two litres of it a day – for more than 2,000 years.
A note on measuring: Measurement methods and instruments are becoming increasingly finer – but this does not mean that what is measured can always be assessed. Science – and we too – has this problem with numerous trace substances that we find in the water cycle. An example of the fineness of today’s measuring instruments: If, after ingesting an X-ray contrast medium, you went to the toilet and the contents of the toiler flowed untreated into the Tegeler See lake (which naturally does not happen), we could then measure this X-ray contrast medium. (The calculation behind this: Assumption - 26g X-ray contrast medium in 26 million cubic metres of water.) However, at present it is not yet known how harmful it is for the animals in the lake and later for the water cycle and the drinking water. There are therefore so-called indicative health values (GOW - Gesundheitlicher Orientierungswert).
What is an indicative health value (Gesundheitlicher Orientierungswert - GOW)?
A GOW is not a limit value, but merely a precautionary value for substances that cannot yet be conclusively assessed. They are very conservative values. Their short to medium-term exceedance (up to ten years) by three to ten times the limit “does not give any cause for health concern” according to the German Environment Agency (UBA). In simpler terms: GOW are values with built-in safety margins, in order to exclude a health hazard. (Source: German Environment Agency (UBA), The German Federal Institute for Risk Assessment (Bundesamt für Risikobewertung - BfR).
If, thanks to our modern measurement methods, we find new substances in the drinking water, we report them to the Berlin State Office for Health and Social Affairs (Landesamt für Gesundheit and Soziales - LAGeSo) and the UBA as the competent authorities and apply for a GOW. If a GOW is exceeded, water suppliers must consult the health authorities and agree short and medium-term measures to be taken to minimise this value. We do this (see Question 8).
What is a limit value?
Limit values (limits) are maximum concentrations for natural constituents, active ingredient residues and environmental pollutants in food, commodities and also in water and the air. These values are specified in laws and ordinances. If they are exceeded, the responsible establishments – this can be water companies, as well as industrial companies or pharmaceutical producers – must take immediate steps to reduce the values and to prevent hazards. The German Drinking Water Ordinance defines a range of limits for lead, cadmium, sodium and uranium, for example. Berlin's drinking water achieves values that are far below these limits. You can also find information on water quality, the constituents and the Drinking Water Ordinance here: www.bwb.de/wasser.
What does Berliner Wasserbetriebe do against trace substances in the water cycle?
For Berliner Wasserbetriebe, safeguard the high drinking water quality is its highest priority,which is why we monitor our drinking water at more than 3,300 monitoring wells, for example, at the groundwater wells, in the waterworks and in the pipe network.
In addition, Berlin Wasserbetriebe together with the competent authorities, LAGeSo and UBA, as well as the scientific institutions test further steps that lead to permanent reduction of the trace substance concentration in the entire Berlin water cycle. These steps include the use of ozone, flocculation filtration and activated carbon for further wastewater treatment in Schönerlinde wastewater treatment plant and the implementation of a further 4 treatment steps in our other four wastewater treatment plants.
In addition, we sample and analyse the collected raw water and the drinking water in the waterworks continuously, two to three times a week. The some 650 wells and quality monitoring wells within the catchment area of the waterworks are additionally sampled and analysed at least once a year. This monitoring extends beyond the legal scope specified in the Drinking Water Ordinance.
Moreover, for years Berliner Wasserbetriebe have actively participated in numerous research projects concerning the detection, assessment and reduction of trace substances in the water cycle. For example, the ASKURIS research project (askuris.tu-berlin.de), which is concerned with finding, assessing and removing trace substances in the water cycle and has supplied us with valuable information on wastewater treatment. In other projects, together with partners in science, we examine trace substances in Berlin’s surface waters and rainwater outlets/gullies and test how to integrate the removal of trace substances into the further treatment stage of wastewater treatment plants. Further information about research and development at the Berliner Wasserbetriebe is available at http://www.bwb.de/forschung.
What can I do to reduce the input of trace substances into the water cycle?
Every single one of us can do their bit to reduce trace substances, for example, by targeted and sparing taking of medicines. Ask your doctor whether they know anything about the environmental integrity of the prescribed medication and whether there is an equally effective alternative that is less harmful for the environment and the water cycle. Because there are medicines that are completely degraded in the wastewater treatment plant or on the way into the groundwater at the latest. It is also important that you never throw away unused or expired medicines in the toilet but instead dispose of them in an environmentally compatible way through the hazardous substances collection points of the BSR (www.bsr.de). Cleaning agents and other chemicals should be used sparingly and never thrown away in the toilet. The same applies to paints and varnishes, because they also otherwise get into the water cycle.
Who can I contact if I want to know more?
On www.bwb.de/wasser you will not only find information about trace substances but also about the constituents in water in general. The precise analysis values of our waterworks are published there. The ASKURIS research project (Anthropogenic Trace Substances and Pathogens in the Urban Water Cycle: assessment, barriers and risk communication) also has an internet site on which lots of information on the topic is published: www.askuris.de. Further information is also available, for example, on the internet sites of the German Environment Agency www.uba.de, the Berlin Centre of Competence for Water, www.kompetenz-wasser.de, the Micropollutants Competence Centre Baden-Württemberg, www.koms-bw.de, the German Association for Water, Wastewater and Waste (DWA) www.dwa.de and the RWTH Aachen university, www.spurenstoffe.net.
Cosmetics, clothing or car tyres - many everyday items and products contain or cause microplastics and therefore impact the environment. Berlin’s drinking water is free from microplastics, yet microplastic particles are increasingly detectable in the wastewater. Each person must therefore be called upon to prevent inputs of microplastics in wastewater. We explain this topic to you on our service page.
Berlin’s water contains many valuable minerals and trace elements. With a total hardness of 14 °dH, its character tends to be hard. What is casually called "chalky" is good for the human body, but not for the coffee maker, dishwasher and other household appliances.
What does water hardness mean?
Berlin’s water contains many valuable minerals and trace elements. Under the action of water molecules, the minerals are decomposed into ions with hydrate shells and are responsible for the electrical conductivity, the pH value and the calcite dissolution capacity of water.
It is commonly known that hard water requires more soap for washing than soft water. The so-called water hardness is traditionally given in “German hardness grades" (°dH). Until now it was disputed whether this fully covered the magnesium content of water. Today we know that it is not covered by it.
It is therefore correct to talk of "calcium deposits” (limescale) from Berlin’s water, because they do not contain any magnesium carbonate, but instead solely calcium carbonate. For this reason, the wording of § 9 of the German Detergent and Cleaning Agent Act (Wasch- und Reinigungsmittelgesetz) is applied strictly when determining the hardness range in Berlin:
- “Medium hardness range: 1.5 to 2,5 millimole calcium carbonate per litre”
- “Hard hardness range: more than 2.5 millimole calcium carbonate per litre”
The unit millimole per litre (mmol/l) needs some getting used to, but is universal and cannot only be applied to calcium and magnesium, but also to sodium, hydrogen carbonate, chloride, sulphate and other ions in water.
1 mmol/l equals 5.6 °dH.
Traditional expression of the hardness range
|Total hardness [°dH]||Water character|
|less than 8.4 °dH||soft water|
|8.4 to 14 °dH||medium-hard water|
|more than 14 °dH||hard water|
*According to the new version of the German Detergent and Cleaning Agent Act (WRMG); enacted
on 1 February 2007 by the German Bundestag,came into effect on 5 May 2007