PFAS in Heemstede's tap water: 4.41 ng/L, 8.8x our 0.5 ng/L benchmark
Last PFAS check: · Source: Waternet
PFAS in drinking water
8.8× 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 "Productielocatie Leiduin", the one with the highest latest published PFAS-4 value among the 2 production locations or delivery series serving Heemstede. The others are in the table of all values; the tap often carries a blend of several locations.
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 85% of the cities we track
checked on 31 December 2025
36 PFAS (see each substance)
| PFAS substance | Value |
|---|---|
| PFBA | 0.0036 µg/L |
| PFBS | 0.0036 µg/L |
| PFOA (L+B) | 0.0032 µg/L |
| PFPeA | 0.0032 µg/L |
| PFHxA | 0.0025 µg/L |
| PFHpA | 0.0015 µg/L |
| PFHxS (L+B) | 0.0007 µg/L |
| PFOS (L+B) | 0.0005 µg/L |
| 11Cl-PF3OUdS | <0,001 µg/L |
| 4:2 FTS | <0,0002 µg/L |
| 6:2 FTS | <0,0005 µg/L |
| 8:2 diPAP | <0,001 µg/L |
| 8:2 FTS | <0,0002 µg/L |
| 8:2 FTUCA | <0,001 µg/L |
| 9Cl-PF3ONS | <0,0002 µg/L |
| DONA | <0,0002 µg/L |
| FBSA | <0,0005 µg/L |
| FHxSA | <0,0005 µg/L |
| FOSA | <0,0002 µg/L |
| HFPO-DA | <0,0002 µg/L |
| N-EtFOSAA (L+B) | <0,0002 µg/L |
| N-MeFOSAA (L+B) | <0,0002 µg/L |
| PFDA | <0,0005 µg/L |
| PFDoA | <0,0005 µg/L |
| PFDoS | <0,0002 µg/L |
| PFDS | <0,0002 µg/L |
| PFHpS | <0,0002 µg/L |
| PFHxDA | <0,002 µg/L |
| PFNA | <0,0005 µg/L |
| PFNS | <0,0002 µg/L |
| PFPeS | <0,0002 µg/L |
| PFTeDA | <0,001 µg/L |
| PFTrDA | <0,001 µg/L |
| PFTrDS | <0,002 µg/L |
| PFUdA | <0,0005 µg/L |
| PFUdS | <0,0002 µg/L |
Fails a current legal limit. Here are some filter options.
- EU legal limit
- 20 ng/L sum of 20 PFAS, below the 100 ng/L limit
- Last PFAS test
- 31 December 2025
- Water supplier
- Waternet
In Heemstede, the 4 most closely watched PFAS (PFAS-4) add up to 4.41 ng/L (0.0044 µg/L) at the latest PFAS check on 31 December 2025. That's 8.8 times our 0.5 ng/L health benchmark, and above Sweden's legal limit of 4 ng/L. Sum of 20 PFAS: 20 ng/L (0.02 µg/L), below the EU legal limit (100 ng/L). Source: Waternet, Drinkwater wettelijk te meten stoffen, jaar 2025 en 1e kwartaal 2026.
For comparison, RIVM advises 4.4 ng/L PFOA equivalents. That's a weighted sum, a different measure from our sum of four PFAS (PFOA, PFOS, PFNA, PFHxS) with its 0.5 ng/L benchmark.
Details and sources
What the latest check found
The authorities have not published an overall verdict for this water.
Values to watch
These results are close to their legal limit, or over it.
| What was tested | Value | Limit | Status |
|---|---|---|---|
| Trifluoroacetic acid (TFA) | 1.2 µg/L | ≤ 1 µg/L | over the limit |
| Trifluoroacetic acid (TFA) | 0.5 µg/L | ≤ 1 µg/L | within the limit |
See all 34 test results
| What was tested | Value | Limit | Status |
|---|---|---|---|
| PFAS-4 (PFOA + PFOS + PFNA + PFHxS) | 0.0028 µg/L | ≤ 0.004 µg/L | within the limit |
| PFAS-4 (PFOA + PFOS + PFNA + PFHxS) | 0.0042 µg/L | ≤ 0.004 µg/L | over the limit |
| PFAS-4 (PFOA + PFOS + PFNA + PFHxS) | 0.0043 µg/L | ≤ 0.004 µg/L | over the limit |
| PFAS-4 (PFOA + PFOS + PFNA + PFHxS) | 0.0064 µg/L | ≤ 0.004 µg/L | over the limit |
| PFAS-4 (PFOA + PFOS + PFNA + PFHxS) | 0.0056 µg/L | ≤ 0.004 µg/L | over the limit |
| Sum of 20 PFAS | 0.015 µg/L | ≤ 0.1 µg/L | within the limit |
| Sum of 20 PFAS | 0.013 µg/L | ≤ 0.1 µg/L | within the limit |
| Sum of 20 PFAS | 0.016 µg/L | ≤ 0.1 µg/L | within the limit |
| Sum of 20 PFAS | 0.025 µg/L | ≤ 0.1 µg/L | within the limit |
| Sum of 20 PFAS | 0.021 µg/L | ≤ 0.1 µg/L | within the limit |
| Sum of 20 PFAS | 0.023 µg/L | ≤ 0.1 µg/L | within the limit |
| Sum of 20 PFAS | 0.019 µg/L | ≤ 0.1 µg/L | within the limit |
| Trifluoroacetic acid (TFA) | 1.2 µg/L | ≤ 1 µg/L | over the limit |
| Trifluoroacetic acid (TFA) | 0.5 µg/L | ≤ 1 µg/L | within the limit |
| Nitrate | 5.4 mg/L | ≤ 50 mg/L | within the limit |
| Nitrite | <0,010 mg/L | ≤ 0.1 mg/L | within the limit |
| Lead | <0,2 µg/L | ≤ 5 µg/L | within the limit |
| Copper | 1.1 µg/L | ≤ 2,000 µg/L | within the limit |
| Nickel | 0.6 µg/L | ≤ 20 µg/L | within the limit |
| Arsenic | 1.82 µg/L | ≤ 10 µg/L | within the limit |
| Cadmium | <0,02 µg/L | ≤ 5 µg/L | within the limit |
| Chromium | 0.2 µg/L | ≤ 50 µg/L | within the limit |
| Fluoride | 0.12 mg/L | ≤ 1 mg/L | within the limit |
| Escherichia coli | 0 kve/100 ml | ≤ 0 kve/100 ml | within the limit |
| Enterococci | 0 kve/100 ml | ≤ 0 kve/100 ml | within the limit |
| Coliform bacteria | 0 kve/100 ml | ≤ 0 kve/100 ml | within the limit |
| pH | 8.09 pH | 7–9.5 pH | within the limit |
| Water hardness | 1.41 mmol/L | no limit | within the limit |
| Electrical conductivity | 528 µS/cm | ≤ 1,250 µS/cm | within the limit |
| Chloride | 61 mg/L | ≤ 150 mg/L | within the limit |
| Sulphate | 44.5 mg/L | ≤ 150 mg/L | within the limit |
| Sodium | 63 mg/L | ≤ 150 mg/L | within the limit |
| Iron | <5 µg/L | ≤ 200 µg/L | within the limit |
| Turbidity | <0,03 FTE | ≤ 1 FTE | within the limit |
Frequently asked questions
Is tap water in Heemstede safe to drink?
At the latest check, the water was over at least one limit.
How high are PFAS levels in Heemstede's drinking water?
The total of 20 PFAS ("forever chemicals") was last measured at 20 ng/L. The EU limit is 100 ng/L, so this water is at 20 % of the limit. (below the EU limit)
Does the water in Heemstede also meet the strictest limits in Europe?
No. The four most harmful PFAS add up to 4.41 ng/L. That is 1.1 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 the Netherlands?
The Netherlands applies the EU limit of 100 ng/L for the sum of 20 PFAS in the Drinkwaterbesluit. The RIVM advises a health-based value of 4.4 ng PEQ/L (PFOA equivalents) for all PFAS together; that is an advisory, not a limit. There is no national PFAS-4 limit; the health reference is EFSA's 4 ng/L. This site's 0.5 ng/L benchmark is stricter than all three.
How hard is the water in Heemstede?
The water hardness in Heemstede is 1.4 mmol/L (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: Waternet, Drinkwater wettelijk te meten stoffen, jaar 2025 en 1e kwartaal 2026. Retrieved on 28 September 2026.
Same water network
Same distribution network as Heemstede, so in principle the same water.
Nearby cities
The closest to Heemstede on this site.
Data source
- Waternet, Drinkwater wettelijk te meten stoffen, jaar 2025 en 1e kwartaal 2026
- https://www.waternet.nl/siteassets/ons-water/drinkwater/waterkwaliteit-rapporten/2025/drinkwater-leiduin-wettelijk-2025-jaar.pdf
- License
- Bron: Waternet (gemeente Amsterdam), Drinkwater productielocatie Leiduin, wettelijk te meten stoffen, jaar 2025 (geen open licentie, overgenomen met bronvermelding); Bron: Waternet (gemeente Amsterdam), Drinkwater productielocatie Weesperkarspel, wettelijk te meten stoffen, jaar 2025 (geen open licentie, overgenomen met bronvermelding)
- Retrieved
- 28 September 2026
- Supply networks
- Productielocatie Leiduin, Productielocatie Weesperkarspel
Waternet: Statutory drinking-water parameters per production location (Leiduin, Weesperkarspel), annual means and latest quarter with itemised PFAS (PDF) (annually, with quarterly reports in between). Latest value dated 31 March 2026. Waternet publishes the annual report in the spring of the following year and quarterly reports a few weeks after the quarter.
Limits in the Netherlands. The Netherlands applies the EU limit of 100 ng/L for the sum of 20 PFAS in the Drinkwaterbesluit. The RIVM advises a health-based value of 4.4 ng PEQ/L (PFOA equivalents) for all PFAS together; that is an advisory, not a limit. There is no national PFAS-4 limit; the health reference is EFSA's 4 ng/L. This site's 0.5 ng/L benchmark is stricter than all three.
Jaargemiddelden 2025 per productielocatie uit Waternets rapporten "Wettelijk te meten stoffen" (PDF, Het Waterlaboratorium), ng/l omgerekend naar µg/L. Waternet publiceert geen PFAS-4-som; de PFAS-4-waarde is de optelling van de gepubliceerde sommen van lineaire en vertakte isomeren (LB, lower bound: niet aangetoond telt als 0) van PFOA, PFOS, PFNA en PFHxS. De som van 20 is Waternets "som 20-EU PFAS LB"; de MB-variant (middle bound) en de jaarmaxima staan in de tabel. Leiduin en Weesperkarspel leveren beide aan het hele voorzieningsgebied; welke locatie uw kraan bedient, publiceert Waternet niet. Voor Heemstede zijn 2 locaties bekend (Productielocatie Leiduin, Productielocatie Weesperkarspel). De PFAS-waarde van de pagina komt van Productielocatie Leiduin, de locatie met de hoogste PFAS-4-waarde; de overige locaties staan in de tabel. Volgende update: Waternet publiceert kwartaalrapporten ongeveer drie maanden na het kwartaal en het jaarrapport in het voorjaar van het volgende jaar.
Water report for Heemstede
Get new PFAS results for Heemstede, 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.