Nitrate 50, lead 10, copper 2,000, uranium 10, PFAS 100: what the numbers mean, how they come about, where Germany is stricter than the EU and where mineral water is regulated more loosely.
In short
- Limit values are precautionary values: lifelong consumption of 2 litres a day without risk.
- Key values: nitrate 50 mg/l, lead 10 µg/l, copper 2 mg/l, uranium 10 µg/l, arsenic 10 µg/l.
- New since 2023: a PFAS total of 100 ng/l from 2026, bisphenol A, and mandatory Legionella testing in rented apartment buildings.
- Mineral water has no limit value for uranium and is tested less often.
What a limit value is
The limit values of the Drinking Water Ordinance (Trinkwasserverordnung) are set so that a person can drink two litres of this water every day for a whole lifetime without a health risk arising. They include safety factors of 10 to 1,000 relative to the dose at which first effects appeared in studies. A value slightly above the limit is therefore not an acute emergency, but it is a signal that the supplier has to follow up.
The key values
| Substance | Limit value | Source | Why it matters |
|---|---|---|---|
| Nitrate | 50 mg/l | fertiliser, slurry | infants: blue baby syndrome; nitrosamines |
| Nitrite | 0.5 mg/l | conversion from nitrate | as with nitrate, but more direct |
| Lead | 10 µg/l, 5 µg/l from 2028 | old pipes | nervous system, children |
| Copper | 2 mg/l | new copper pipes | stomach, liver in infants |
| Nickel | 20 µg/l | fittings | allergy |
| Uranium | 10 µg/l | rock, phosphate fertiliser | kidneys |
| Arsenic | 10 µg/l | rock | cancer |
| Pesticides | 0.1 µg/l per substance, 0.5 in total | agriculture | precaution, not toxicological |
| PFAS (20 substances) | 100 ng/l from 2026, 4 substances 20 ng/l from 2028 | industry, firefighting foam | immune system, liver |
| E. coli, enterococci | 0 in 100 ml | faeces | infections |
| Legionella | 100 CFU in 100 ml (action value) | hot water systems | pneumonia |
| pH value | 6.5 to 9.5 | origin of the water | corrosion of pipes |
What changed in 2023
The amended ordinance brought limit values for PFAS and for bisphenol A (2.5 µg/l), a lower limit for lead (5 µg/l from 2028), an obligation to remove lead pipes by 2026, and a risk assessment of catchment areas by the suppliers. For apartment buildings with central hot water heating, Legionella testing every three years continues to apply.
Where mineral water is looser
The Mineral and Table Water Ordinance (Mineral- und Tafelwasserverordnung) has no limit value for uranium, only a recommendation of 10 µg/l for water for infants. Arsenic and manganese are in part allowed at higher levels, and testing is less frequent. That is no reason to avoid mineral water, but it is a reason to bury the myth of “purer bottled water”. More in the article Tap water vs. mineral water.
What to do with the numbers
Compare your supplier’s analysis (see Regions) with the table. Nitrate values close to the limit are typical of agricultural regions, see Nitrate in groundwater. Your supplier does not measure lead, copper and nickel in your house; that is up to you, see Testing water at home.
Frequently asked questions
Why is the nitrate limit 50 and not lower?
It protects infants from methaemoglobinaemia, which can occur from about 100 mg/l. For adults, concerns about nitrosamines are the reason not to raise the value. For baby food, under 10 is recommended.
Are limit exceedances common?
With central supply they are rare and usually brief. Over 99 per cent of samples meet all values. Small systems and private wells are affected more often.
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