PFAS in Guissény's tap water: under 6 ng/L, none of the four main PFAS detected

Last PFAS check: · Source: Hub'eau

PFAS in drinking water

No PFAS detected

Amount found in the water < 6 ng/L the 4 most harmful PFAS (PFAS-4) · the lab's detection limit 20 PFAS looked for, none found
Our health benchmark 0.5 ng/L

The lab sees nothing below 6 ng/L, 12 times our benchmark of 0.5 ng/L. Water above our benchmark would pass this check unnoticed.

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.

Sample taken in Plounéour-Brignogan-plages, on the same distribution network as Guissény (BRIGNOGAN-KERLOUAN (BAS-LEON)). The health authority samples one tap per network; a network carries the same treated water everywhere.

More about this result

The US also limits PFOA and PFOS to 4 ng/L each, per substance.

The lab detects each of the four substances from 1 to 2 ng/L upward. None reached that limit, so their total is below 6 ng/L rather than zero.

20 PFAS (see each substance)
PFAS substance Value
Acide perfluoro tridecanoique (PFTrDA) <0,002 µg/L
Acide sulfonique de perfluorobutane (PFBS) <0,005 µg/L
Acide perfluorobutanoïque (PFBA) <0,005 µg/L
Acide perfluorododécanoique (PFDoDA) <0,002 µg/L
Acide perfluorodecane sulfonique (PFDS) <0,001 µg/L
Acide perfluorododécane sulfonique (PFDoDS) <0,001 µg/L
Acide perfluoro undecanoïque (PFUnA) <0,002 µg/L
Acide perfluorononane sulfonique (PFNS) <0,001 µg/L
Acide perfluoro tridecane sulfonique (PFTrDS) <0,001 µg/L
Acide perfluoroheptane sulfonique (PFHpS) <0,002 µg/L
Acide perfluoro-nonanoïque (PFNA) <0,001 µg/L
Acide perfluoro undecane sulfonique (PFUnDS) <0,001 µg/L
Acide perfluorohexanoïque (PFHXA) <0,005 µg/L
Perfluorohexane sulfonate (PFHXS) <0,002 µg/L
Acide perfluoropentanoïque (PFPEA) <0,002 µg/L
Acide perfluoro-decanoïque (PFDA) <0,002 µg/L
Acide perfluoropentane sulfonique (PFPS) <0,001 µg/L
Acide perfluoro-octanoïque (PFOA) <0,002 µg/L
Acide sulfonique de perfluorooctane (PFOS) <0,001 µg/L
Acide perfluoroheptanoïque (PFHPA) <0,005 µg/L

None found. The lab sees nothing below 6 ng/L, so our 0.5 ng/L benchmark cannot be checked.

EU legal limit
none detected sum of 20 PFAS below the detection limit, limit 100 ng/L
Last PFAS test
27 January 2026
Water supplier
COMMUNAUTE LESNEVEN COTE DES LEGENDES (CLCL)

In Guissény, none of the 4 most closely watched PFAS (PFAS-4) was detected at the latest PFAS check on 27 January 2026. The total is below 6 ng/L, the sum of the detection limits and 12 times our 0.5 ng/L benchmark. Sum of 20 PFAS: <SEUIL µg/L, below the EU legal limit (100 ng/L). Sampled in Plounéour-Brignogan-plages, on the same network. 4 checks since 5 May 2025: PFAS-4 up to 1.6 ng/L, sometimes below the detection limit, averaging at least 0.53 ng/L over 12 months (non-detects as 0). Source: Hub'eau, Qualité de l'eau potable (Ministère de la Santé / OFB / BRGM).

Details and sources
Water supplier: COMMUNAUTE LESNEVEN COTE DES LEGENDES (CLCL) Latest water check: 25 March 2026 Data updated on

PFAS over time in Guissény

5 PFAS checks since 4 March 2025, from the published measurements. Samples from 2 communes on the same network: it's the same water, so each one applies to Guissény. Samples come from 2 distribution networks. The trend refers to the network “GUISSENY (BAS-LEON)*”.

“Calculated”: PFAS-4 worked out from the four substances in the same sample. The chart, averages and trends use lab-published sums only.

0.5 ng/L1.6 ng/L05 May 202527 January 2026
PFAS-4 sum per check in ng/L. Dashed line: pfasnearme's 0.5 ng/L benchmark. Hollow dots: below the detection limit.
DatePFAS-4Sum of 20 PFASSampled atNetwork
< detection limit< detection limitPlounéour-Brignogan-plagesBRIGNOGAN-KERLOUAN (BAS-LEON)
< detection limit< detection limitKernilisBRIGNOGAN-KERLOUAN (BAS-LEON), GUISSENY (BAS-LEON)* +1
1.6 ng/L1.6 ng/LKernilisBRIGNOGAN-KERLOUAN (BAS-LEON), GUISSENY (BAS-LEON)* +1
< detection limit< detection limitKernilisBRIGNOGAN-KERLOUAN (BAS-LEON), GUISSENY (BAS-LEON)* +1
< 6 ng/L · calculated< detection limitKernilisBRIGNOGAN-KERLOUAN (BAS-LEON), GUISSENY (BAS-LEON)* +1

Calculated values: “<” is an upper bound from published thresholds, “≥” a lower bound, “–” means no published sum or complete measurement. How to read a PFAS result

What the latest check found

At the latest check, the water was within every limit tested.

Microbiology: within the limit Chemistry: within the limit

Values to watch

These results are close to their legal limit, or over it.

What was tested Value Limit Status
Nitrate 34 mg/L ≤ 50 mg/L within the limit
See all 14 test results
What was tested Value Limit Status
Nitrate 34 mg/L ≤ 50 mg/L within the limit
Nitrite <0,01 mg/L ≤ 0.5 mg/L within the limit
Cadmium <0,1 µg/L ≤ 5 µg/L within the limit
Chromium <1 µg/L ≤ 50 µg/L within the limit
Escherichia coli 0 n/(100mL) ≤ 0 mL) within the limit
Enterococci 0 n/(100mL) ≤ 0 mL) within the limit
Coliform bacteria 0 n/(100mL) ≤ 0 mL) within the limit
pH 8.3 unité pH 6.5–9 unité pH within the limit
Water hardness 14 °f no limit for reference
Electrical conductivity 427 µS/cm 200–1,100 µS/cm within the limit
Chloride 32.6 mg/L ≤ 250 mg/L within the limit
Sulphate 50 mg/L ≤ 250 mg/L within the limit
Iron <5 µg/L ≤ 200 µg/L within the limit
Turbidity 0.12 NFU ≤ 2 NFU within the limit

Frequently asked questions

Is tap water in Guissény safe to drink?

Yes. At the check on 25 March 2026, the tap water in Guissény was within every limit tested. “Eau d'alimentation conforme aux exigences de qualité en vigueur pour l'ensemble des paramètres mesurés.”

How high are PFAS levels in Guissény's drinking water?

The total of 20 PFAS ("forever chemicals") was last measured at –. The EU limit is 100 ng/L, so this water is at – of the limit. (below the EU limit)

Does the water in Guissény also meet the strictest limits in Europe?

The check cannot say. None of the four compounds was quantified, but the laboratory's detection limits add up to 6 ng/L, above Sweden's legal limit of 4 ng/L in force since 2026, so a value between the two would go unnoticed.

Are PFAS levels rising in Guissény's tap water?

Too few quantified checks to say (1 since 4 March 2025). pfasnearme adds each new publication weekly; a trend needs at least three quantified values. These history statistics use laboratory-published sums only.

How hard is the water in Guissény?

The water hardness in Guissény is 14 °f (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: Hub'eau, Qualité de l'eau potable (Ministère de la Santé / OFB / BRGM). Retrieved on 12 September 2026.

Same water network

Same distribution network as Guissény, so in principle the same water.

Nearby communes

The closest to Guissény on this site.

Data source

Hub'eau, Qualité de l'eau potable (Ministère de la Santé / OFB / BRGM)
https://hubeau.eaufrance.fr/api/v1/qualite_eau_potable/resultats_dis?code_commune=29077
License
Licence Ouverte / Open Licence (Etalab)
Retrieved
12 September 2026
Supply networks
BRIGNOGAN-KERLOUAN (BAS-LEON), GUISSENY (BAS-LEON)*

This site is a data project, not an official source. If in doubt, check with your water supplier or local authority.