PFAS in Köln's tap water: 8.8 ng/L, 17.6x our 0.5 ng/L benchmark
Last PFAS check: · Source: RheinEnergie
PFAS in drinking water
17.6× above our health benchmark
0.5 ng/L is our benchmark, not an official limit. Same EFSA method as Sweden, Denmark and the Netherlands, but stricter. It's a yearly average, compared here with the latest check.
The PFAS figures come from the sampling point "Köln rechtsrheinisch (Wasserwerke Höhenhaus und Zündorf)", the one with the highest PFAS-4 value among the 2 waterworks or sampling points serving Köln. The others are in the table of all values; the tap often carries a blend of several works.
More about this result
The US also limits PFOA and PFOS to 4 ng/L each, per substance.
Substances below the detection limit count as 0, so the real total may be higher.
One of these four, PFOA, is classified as causing cancer in humans by the WHO's cancer research agency (IARC).
More PFAS than in 80% of the cities we track
checked on 31 December 2025
20 PFAS (see each substance)
| PFAS substance | Value |
|---|---|
| PFBA | 0.0021 µg/L |
| PFPeA | 0.0017 µg/L |
| PFHxA | 0.0025 µg/L |
| PFHpA | <0,001 µg/L |
| PFOA | 0.0027 µg/L |
| PFNA | <0,001 µg/L |
| PFDA | <0,001 µg/L |
| PFUnDA | <0,001 µg/L |
| PFDoDA | <0,001 µg/L |
| PFTrDA | <0,001 µg/L |
| PFBS | 0.0077 µg/L |
| PFPeS | <0,001 µg/L |
| PFHxS | 0.003 µg/L |
| PFHpS | <0,001 µg/L |
| PFOS | 0.0031 µg/L |
| PFNS | <0,001 µg/L |
| PFDS | <0,001 µg/L |
| PFUnDS | <0,001 µg/L |
| PFDoDS | <0,001 µg/L |
| PFTrDS | <0,001 µg/L |
Above our health benchmark. Here are some filter options.
- Legal limit (Germany and EU)
- 23 ng/L sum of 20 PFAS, below the 100 ng/L limit
- Last PFAS test
- 31 December 2025
- Water supplier
- RheinEnergie
In Köln, the 4 most closely watched PFAS (PFAS-4) add up to 8.8 ng/L (0.0088 µg/L) at the latest PFAS check on 31 December 2025. That's 17.6 times our 0.5 ng/L health benchmark, and above Sweden's legal limit of 4 ng/L. Sum of 20 PFAS: 23 ng/L (0.023 µg/L), below the EU legal limit (100 ng/L). Source: RheinEnergie – Trinkwasseranalyse, Jahresmittelwerte 2025.
Details and sources
What the latest check found
The authorities have not published an overall verdict for this water.
See all 17 test results
| What was tested | Value | Limit | Status |
|---|---|---|---|
| PFAS-4 (PFOA + PFOS + PFNA + PFHxS) · sampling point Köln linksrheinisch (Wasserwerke Hochkirchen und Weiler) | <0,001 µg/L | ≤ 0.004 µg/L | within the limit |
| Sum of 20 PFAS · sampling point Köln linksrheinisch (Wasserwerke Hochkirchen und Weiler) | 0.014 µg/L | ≤ 0.1 µg/L | within the limit |
| Nitrate | 22 mg/L | ≤ 50 mg/L | within the limit |
| Nitrite | <0,01 mg/L | ≤ 0.5 mg/L | within the limit |
| Lead | <0,0005 mg/L | ≤ 0.01 mg/L | within the limit |
| Copper | <0,02 mg/L | ≤ 2 mg/L | within the limit |
| Nickel | <0,001 mg/L | ≤ 0.02 mg/L | within the limit |
| Arsenic | <0,0005 mg/L | ≤ 0.01 mg/L | within the limit |
| Cadmium | <0,0001 mg/L | ≤ 0.003 mg/L | within the limit |
| Chromium | <0,0005 mg/L | ≤ 0.05 mg/L | within the limit |
| Uranium | 0.0007 mg/L | ≤ 0.01 mg/L | within the limit |
| Fluoride | 0.14 mg/L | ≤ 1.5 mg/L | within the limit |
| Water hardness | 3.24 mol/m³ | no limit | for reference |
| Chloride | 58 mg/L | ≤ 250 mg/L | within the limit |
| Sulphate | 73 mg/L | ≤ 250 mg/L | within the limit |
| Sodium | 35 mg/L | ≤ 200 mg/L | within the limit |
| Iron | <0,02 mg/L | ≤ 0.2 mg/L | within the limit |
Frequently asked questions
Is tap water in Köln safe to drink?
All the values shown here (31 December 2025) are within the legal limits, but the authorities have not published an overall verdict for this water.
How high are PFAS levels in Köln's drinking water?
The total of 20 PFAS ("forever chemicals") was last measured at 23 ng/L. The EU limit is 100 ng/L, so this water is at 23 % of the limit. (below the EU limit)
Does the water in Köln also meet the strictest limits in Europe?
No. The four most harmful PFAS add up to 8.8 ng/L. That is 2.2 times Sweden's legal limit of 4 ng/L, in force since 2026. Germany will set a similar one in 2028. The water still passes the current EU legal limit (100 ng/L for the total of 20 PFAS).
Which PFAS limits apply in Germany?
Germany's Trinkwasserverordnung of 2023 adopts the EU limit of 100 ng/L for the sum of 20 PFAS, binding since 12 January 2026. For the four most harmful PFAS (PFAS-4) a limit of 20 ng/L applies from 12 January 2028. This site's 0.5 ng/L benchmark and the 4 ng/L used as the health reference (Sweden's limit) are stricter than both.
How hard is the water in Köln?
The water hardness in Köln is 3.2 mol/m³ (soft). This mainly matters for household appliances and detergent dosing, not for health.
Where does this data come from?
All values come from official publications: RheinEnergie – Trinkwasseranalyse, Jahresmittelwerte 2025. Retrieved on 28 September 2026.
Nearby cities
The closest to Köln on this site.
Data source
- RheinEnergie – Trinkwasseranalyse, Jahresmittelwerte 2025
- https://www.rheinenergie.com/privatkunden/wasser/wasserqualitaet/
- License
- Veröffentlichung von RheinEnergie AG; Sachdaten mit Quellenangabe wiedergegeben (keine offene Lizenz angegeben)
- Retrieved
- 28 September 2026
- Supply networks
- Köln linksrheinisch (Wasserwerke Hochkirchen und Weiler), Köln rechtsrheinisch (Wasserwerke Höhenhaus und Zündorf)
RheinEnergie: Drinking-water analysis per supply zone (left and right bank of the Rhine), annual means with itemised PFAS (PDF). Latest value dated 31 December 2025. Annually, the next edition expected in the spring of the following year.
Limits in Germany. Germany's Trinkwasserverordnung of 2023 adopts the EU limit of 100 ng/L for the sum of 20 PFAS, binding since 12 January 2026. For the four most harmful PFAS (PFAS-4) a limit of 20 ng/L applies from 12 January 2028. This site's 0.5 ng/L benchmark and the 4 ng/L used as the health reference (Sweden's limit) are stricter than both.
Jahresmittelwerte 2025 je Versorgungsgebiet aus den Trinkwasseranalysen der RheinEnergie (PDF je Gebiet, Ausgabe 2026), Angaben in mg/l in µg/L umgerechnet. Linksrheinisch wird aus den Wasserwerken Hochkirchen und Weiler versorgt, rechtsrheinisch aus Höhenhaus und Zündorf; die PFAS-Einzelstoffe sind je Gebiet aufgeführt. Für Köln liegen 2 Werke bzw. Messstellen vor (Köln linksrheinisch (Wasserwerke Hochkirchen und Weiler), Köln rechtsrheinisch (Wasserwerke Höhenhaus und Zündorf)). Die PFAS-Kennzahl der Seite stammt aus „Köln rechtsrheinisch (Wasserwerke Höhenhaus und Zündorf)“, der Messstelle mit dem höchsten PFAS-4-Wert; die übrigen stehen in der Tabelle. Nächste Aktualisierung: Ausgabe 2027 mit den Jahresmittelwerten 2026, voraussichtlich im Frühjahr 2027
Water report for Köln
Get new PFAS results for Köln, with a short explanation. At most one update a week, only when there's something new.
This site is a data project, not an official source. If in doubt, check with your water supplier or local authority.