PFAS in the tap water of Monségur (Landes): under 17 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 < 17 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 17 ng/L, 34 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 Pécorade, on the same distribution network as Monségur (TURSAN). 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 2 to 5 ng/L upward. None reached that limit, so their total is below 17 ng/L rather than zero.

20 PFAS (see each substance)
PFAS substance Value
Acide perfluoroheptanoïque (PFHPA) <0,005 µg/L
Acide perfluorodecane sulfonique (PFDS) <0,005 µg/L
Acide perfluorobutanoïque (PFBA) <0,02 µg/L
Acide perfluoro tridecane sulfonique (PFTrDS) <0,002 µg/L
Acide perfluorododécane sulfonique (PFDoDS) <0,005 µg/L
Acide sulfonique de perfluorooctane (PFOS) <0,005 µg/L
Acide perfluoropentane sulfonique (PFPS) <0,005 µg/L
Acide perfluoro-decanoïque (PFDA) <0,005 µg/L
Acide perfluoro undecane sulfonique (PFUnDS) <0,002 µg/L
Acide perfluorononane sulfonique (PFNS) <0,005 µg/L
Acide perfluoro tridecanoique (PFTrDA) <0,005 µg/L
Acide perfluoropentanoïque (PFPEA) <0,005 µg/L
Perfluorohexane sulfonate (PFHXS) <0,002 µg/L
Acide perfluoro-nonanoïque (PFNA) <0,005 µg/L
Acide perfluoro-octanoïque (PFOA) <0,005 µg/L
Acide perfluoroheptane sulfonique (PFHpS) <0,002 µg/L
Acide sulfonique de perfluorobutane (PFBS) <0,002 µg/L
Acide perfluorohexanoïque (PFHXA) <0,005 µg/L
Acide perfluoro undecanoïque (PFUnA) <0,005 µg/L
Acide perfluorododécanoique (PFDoDA) <0,005 µg/L

None found. The lab sees nothing below 17 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
23 February 2026
Water supplier
SYNDICAT MARSEILLON ET TURSAN

In Monségur, none of the 4 most closely watched PFAS (PFAS-4) was detected at the latest PFAS check on 23 February 2026. The total is below 17 ng/L, the sum of the detection limits and 34 times our 0.5 ng/L benchmark. Sum of 20 PFAS: <0,1 µg/L, below the EU legal limit (100 ng/L). Sampled in Pécorade, on the same network. 2 checks since 30 April 2025, sum of 20 PFAS always below the detection limit (100 ng/L). Source: Hub'eau, Qualité de l'eau potable (Ministère de la Santé / OFB / BRGM).

Details and sources
Water supplier: SYNDICAT MARSEILLON ET TURSAN Latest water check: 23 February 2026 Data updated on

PFAS over time in Monségur

2 PFAS checks since 30 April 2025, from the published measurements.

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

DatePFAS-4Sum of 20 PFASSampled at
< 17 ng/L · calculated< 100 ng/LPécorade
< 17 ng/L · calculated< 100 ng/LPécorade

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
See all 16 test results
What was tested Value Limit Status
Nitrate <0,1 mg/L ≤ 50 mg/L within the limit
Nitrite <0,01 mg/L ≤ 0.5 mg/L within the limit
Lead <1 µg/L ≤ 10 µg/L within the limit
Copper 0.055 mg/L ≤ 2 mg/L within the limit
Nickel <1 µg/L ≤ 20 µg/L within the limit
Cadmium <0,025 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 7.8 unité pH 6.5–9 unité pH within the limit
Water hardness 14.7 °f no limit for reference
Electrical conductivity 320 µS/cm 200–1,100 µS/cm within the limit
Chloride 5.4 mg/L ≤ 250 mg/L within the limit
Sulphate 13 mg/L ≤ 250 mg/L within the limit
Turbidity <0,5 NFU ≤ 2 NFU within the limit

Frequently asked questions

Is tap water in Monségur safe to drink?

Yes. At the check on 23 February 2026, the tap water in Monségur 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 Monségur's drinking water?

At the latest check the total of 20 PFAS ("forever chemicals") was below the laboratory's reporting limit of 100 ng/L. The EU limit is 100 ng/L, so this water is under 100 % of the limit. (below the EU limit)

Does the water in Monségur 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 17 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 Monségur's tap water?

Calculated PFAS-4 values are listed in the table. The chart uses laboratory-published sum-of-20 results; there are too few laboratory-published PFAS-4 sums for the existing trend calculation.

How hard is the water in Monségur?

The water hardness in Monségur is 14.7 °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 Monségur, so in principle the same water.

Nearby communes

The closest to Monségur 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=40190
License
Licence Ouverte / Open Licence (Etalab)
Retrieved
12 September 2026
Supply networks
TURSAN

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