Tap water in France: safe, but not contaminant-free

Tap water is the most controlled food product in France — over 60 quality criteria defined by the Public Health Code. In the vast majority of cases, it is safe to drink and poses no immediate risk to health.

But "compliant" doesn't mean "free of contaminants". Traces of pesticides, pharmaceutical residues, PFAS (per- and polyfluoroalkyl substances) and microplastics are regularly detected in distribution networks, at concentrations below regulatory thresholds. Since January 2026, a European directive has imposed a maximum threshold of 100 ng/L for 20 PFAS in drinking water — which has reignited the debate on domestic filtration.

Add to that taste issues (chlorine, water sitting in pipes), hardness (limescale) and quality that varies by municipality. The real question isn't whether to filter, but which technology fits your situation.

The six main domestic filtration technologies

1. The filter jug (activated carbon)

The most common solution in France. Activated carbon effectively removes chlorine, certain pesticides and compounds that affect taste and smell. Main advantage: no installation required, low entry price (€20 to €40).

Its limitations are real and often poorly communicated by manufacturers. Brita's MAXTRA PRO cartridges — the market reference — filter from 30 µm: the finest microplastics pass straight through. On PFAS, only long-chain PFOS and PFOA are captured (up to 96% according to Test-Achats Belgium), but short-chain PFAS like TFA — highly present in French water — largely pass through. Nitrates and heavy metals are barely filtered at all.

On real cost: Brita states on its own website that 12 Maxtra Pro cartridges per year (monthly replacement for 150 L per cartridge) amounts to approximately €74 to €84 per year excluding the initial jug purchase — for just 1,800 litres of filtered water.

Best for: taste improvement only, already good quality water, very tight budget.

2. The tap-mounted filter

Attaches directly to the existing tap, generally using activated carbon and sometimes a hollow fibre membrane. No plumbing, installs in minutes. Reduced flow rate, cartridges to replace every 3 to 6 months depending on the model.

Effective on chlorine and organic compounds, but the same limited spectrum as the filter jug on dissolved contaminants (nitrates, short-chain PFAS, heavy metals). Suitable for taste improvement without any installation commitment.

Best for: renters, small budgets, good quality water with only a taste issue.

3. The under-sink multi-stage filter

Installed between the water inlet and the tap, combining several cartridges (activated carbon, ion exchange resin, ceramic, anti-PFAS resin depending on the model). Capacity far exceeds a filter jug: 5,000 to 12,000 litres depending on cartridges, replacement every 6 to 12 months.

More effective than a jug across a wider range of contaminants, but still falls short of reverse osmosis on the finest dissolved contaminants. Requires a plumbing connection and often a dedicated tap.

Best for: homeowners wanting intermediate filtration without the cost of reverse osmosis, generally good water with a few specific contaminants.

4. Reverse osmosis

The most comprehensive technology available for domestic use. Its membrane filters at 0.0001 µm — several thousand times finer than the best filter jugs. It removes up to 99.9% of contaminants: bacteria, viruses, nitrates, pesticides, heavy metals, PFAS (including short-chain), pharmaceutical residues, microplastics.

It also removes the water's natural minerals. For those who prefer remineralised water, a dedicated cartridge can be added downstream. It's the recommended solution in areas with hard water or detected contamination (pesticides, PFAS).

On real long-term cost, reverse osmosis is often more economical than it appears. The OneZero French Eaux runs without electricity, filters up to 7,000 litres per cartridge set, and replacement cartridges cost €95 — approximately €0.014 per litre filtered. By comparison, a Brita jug with Maxtra Pro cartridges costs around €0.042 per litre on the same basis — three times more expensive, for incomparably less complete filtration.

Best for: households wanting maximum purity, areas with contaminated or very hard water, vulnerable people (immunocompromised, infants, pregnant women).

5. Ultrafiltration (UF)

Between an under-sink filter and reverse osmosis, UF filters at 0.01 to 0.1 µm — effective on bacteria, viruses, microplastics and fine particles. Its main advantage over reverse osmosis: it preserves the water's natural minerals, no remineralisation needed.

Its limits: the finest dissolved contaminants (nitrates, low molecular weight pesticides, short-chain PFAS) pass through. It's the technology built into most mains-connected water fountains (Aquila Pro French Eaux, Oceane French Eaux) for a clean result without demineralisation.

Best for: chemically good quality water, preference for keeping natural minerals, use in a water fountain.

6. UV-C disinfection

UV-C lamps destroy bacteria and viruses through photolysis without adding any chemical. Effective on micro-organisms but eliminates no chemical contaminants whatsoever (heavy metals, nitrates, PFAS). Used alone, they're reserved for microbiologically dubious water (wells, spring water). Combined with mechanical filtration, they add an extra layer of safety — which is exactly what the Horizon RO French Eaux does, pairing reverse osmosis with permanent UV-C disinfection.

Best for: spring or well water, complement to an existing mechanical filtration system.

Quick comparison of the six technologies

Which solution for your situation?

There's no universally best water filter. The right choice depends on three parameters: the actual quality of your water (searchable by municipality on the French Ministry of Health website), whether you're renting or own your home, and what you're actually trying to remove.

Your water tastes of chlorine but is otherwise good quality: an under-sink filter or ultrafiltration water fountain is more than enough. No need for reverse osmosis.

Your municipality is in a zone with elevated pesticides, nitrates or detected PFAS: only reverse osmosis guarantees effective filtration of these dissolved contaminants.

You're renting: a countertop or under-sink osmosis unit avoids any structural modification. The OneZero installs with a simple connection to the cold water inlet — no drilling, no permanent changes.

You also want sparkling or instant hot water: a mains-connected filtered water fountain is more suitable than a standalone reverse osmosis unit.

Find the right solution for your needs

Frequently asked questions

Does a Brita jug remove PFAS?

Partially. According to Test-Achats Belgium testing, Maxtra Pro cartridges capture up to 96% of long-chain PFAS (PFOS, PFOA), but short-chain PFAS like TFA — the most prevalent in French water — largely pass through. Only reverse osmosis guarantees effective filtration across the full PFAS spectrum.

Does reverse osmosis remove minerals?

Yes. The reverse osmosis membrane removes virtually all dissolved substances, including beneficial minerals (calcium, magnesium). For those who want to keep these minerals, a remineralisation cartridge can be added downstream of the system.

Which system for well water?

Well water can contain bacteria, viruses and chemical contaminants not present in the public network. The combination of reverse osmosis + UV-C is most recommended, as in the Horizon RO French Eaux fountain which integrates both technologies.

Can I filter my water without touching the plumbing?

Yes. A tap-mounted filter is the simplest option (screws directly on). The OneZero reverse osmosis unit requires a connection to the cold water inlet under the sink, but involves no structural modification to the property — compatible with rented accommodation subject to landlord agreement.

What's the real cost of a reverse osmosis unit compared to a filter jug?

On consumables alone, the OneZero French Eaux (€95 in cartridges for 7,000 litres, or €0.014/L) costs approximately three times less per litre filtered than a Brita jug with Maxtra Pro cartridges (€74 to €84/year for 1,800 litres, or €0.042/L) — for incomparably more complete filtration.