PFAS in Le Tiercent's tap water: under 3.4 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 < 3.4 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 3.4 ng/L, 6.8 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 Saint-Marc-le-Blanc, on the same distribution network as Le Tiercent (COGLAIS_MONTOURS/PONT NEUF/COCARDIERE_ST MARC LE BLANC). 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 0.4 to 1 ng/L upward. None reached that limit, so their total is below 3.4 ng/L rather than zero.

20 PFAS (see each substance)
PFAS substance Value
Acide perfluoro-nonanoïque (PFNA) <0,0010 µg/L
Acide perfluoro tridecane sulfonique (PFTrDS) <0,00040 µg/L
Acide perfluoro undecanoïque (PFUnA) <0,0010 µg/L
Acide perfluoro tridecanoique (PFTrDA) <0,0010 µg/L
Acide perfluorodecane sulfonique (PFDS) <0,00040 µg/L
Acide sulfonique de perfluorooctane (PFOS) <0,0010 µg/L
Acide perfluorododécanoique (PFDoDA) <0,0010 µg/L
Acide perfluoroheptanoïque (PFHPA) <0,0010 µg/L
Acide perfluorobutanoïque (PFBA) <0,0050 µg/L
Acide perfluorohexanoïque (PFHXA) <0,0010 µg/L
Acide perfluorononane sulfonique (PFNS) <0,00040 µg/L
Acide perfluoropentane sulfonique (PFPS) <0,00040 µg/L
Perfluorohexane sulfonate (PFHXS) <0,00040 µg/L
Acide perfluoro-octanoïque (PFOA) <0,0010 µg/L
Acide perfluoropentanoïque (PFPEA) <0,0050 µg/L
Acide perfluoro-decanoïque (PFDA) <0,0010 µg/L
Acide perfluorododécane sulfonique (PFDoDS) <0,00040 µg/L
Acide perfluoro undecane sulfonique (PFUnDS) <0,00040 µg/L
Acide perfluoroheptane sulfonique (PFHpS) <0,00040 µg/L
Acide sulfonique de perfluorobutane (PFBS) <0,00040 µg/L

None found. The lab sees nothing below 3.4 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
24 February 2026
Water supplier
VEOLIA ILLE ET VILAINE NORD

In Le Tiercent, none of the 4 most closely watched PFAS (PFAS-4) was detected at the latest PFAS check on 24 February 2026. The total is below 3.4 ng/L, the sum of the detection limits and 6.8 times our 0.5 ng/L benchmark. Sum of 20 PFAS: <SEUIL µg/L, below the EU legal limit (100 ng/L). Sampled in Saint-Marc-le-Blanc, on the same network. 4 checks since 22 July 2025: PFAS-4 up to 6.56 ng/L, sometimes below the detection limit, averaging at least 1.64 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: VEOLIA ILLE ET VILAINE NORD Latest water check: 8 July 2026 Data updated on

PFAS over time in Le Tiercent

7 PFAS checks since 17 February 2025, from the published measurements. Samples from 4 communes on the same network: it's the same water, so each one applies to Le Tiercent.

“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/L6.56 ng/L022 July 202524 February 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 at
< detection limit< detection limitSaint-Marc-le-Blanc
< detection limit< detection limitLes Portes du Coglais
6.56 ng/L13.21 ng/LVal-Couesnon
< detection limit< detection limitLes Portes du Coglais
1.8 ng/L – < 3.8 ng/L · calculated1.8 ng/LVal-Couesnon
< 3.4 ng/L · calculated< detection limitLes Portes du Coglais
< 3.4 ng/L · calculated< detection limitLécousse

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 33.8 mg/L ≤ 50 mg/L within the limit
See all 17 test results
What was tested Value Limit Status
Nitrate 33.8 mg/L ≤ 50 mg/L within the limit
Nitrite <0,02 mg/L ≤ 0.5 mg/L within the limit
Lead <1,0 µg/L ≤ 10 µg/L within the limit
Copper 0.0054 mg(Cu)/L ≤ 2 mg(Cu)/L within the limit
Nickel 1.9 µg/L ≤ 20 µg/L within the limit
Cadmium <0,025 µg/L ≤ 5 µg/L within the limit
Chromium <1,0 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 8.2 unité pH 6.5–9 unité pH within the limit
Water hardness 13.3 °f no limit for reference
Electrical conductivity 399 µS/cm 200–1,100 µS/cm within the limit
Chloride 49.8 mg/L ≤ 250 mg/L within the limit
Sulphate 11.7 mg/L ≤ 250 mg/L within the limit
Iron <20 µg/L ≤ 200 µg/L within the limit
Turbidity <0,20 NFU ≤ 2 NFU within the limit

Frequently asked questions

Is tap water in Le Tiercent safe to drink?

Yes. At the check on 8 July 2026, the tap water in Le Tiercent 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 Le Tiercent'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 Le Tiercent also meet the strictest limits in Europe?

As far as this check can tell, yes. None of the four compounds was quantified, so their total is below 3.4 ng/L, the sum of the laboratory's detection limits, and under Sweden's legal limit of 4 ng/L in force since 2026.

Are PFAS levels rising in Le Tiercent's tap water?

Too few quantified checks to say (1 since 17 February 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 Le Tiercent?

The water hardness in Le Tiercent is 13.3 °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 21 September 2026.

Same water network

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

Nearby communes

The closest to Le Tiercent 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=35336
License
Licence Ouverte / Open Licence (Etalab)
Retrieved
21 September 2026
Supply networks
COGLAIS_MONTOURS/PONT NEUF/COCARDIERE_ST MARC LE BLANC

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