On average, each Portuguese person consumes nearly 146 litres of bottled water per year — one of the highest figures in Europe. At the same time, the water that comes out of our taps meets legal quality criteria in practically 99% of analyses carried out in accredited laboratories.
There's a clear contradiction here. If the water is good, why do we continue to carry large bottles from the supermarket? The answer, in most cases, has nothing to do with safety. It has to do with taste, chlorine, and limescale — three different things that are often confused as one.
In this article, we're going to separate facts from assumptions: what official reports say, why water tastes like chlorine, why it tastes different in Faro than in Porto, and what solutions truly exist — from the free option to the countertop purifier.
What the Official Numbers Say
In Portugal, the ERSAR (Regulatory Entity for Water and Waste Services) is responsible for regulating and overseeing the quality of water for human consumption. Every year, it publishes the RASARP — the sector's annual report.
According to the RASARP published in 2025, with data relating to 2024:
- The "Safe Water" indicator stood at 98.86% in mainland Portugal;
- It was the tenth consecutive year that the country met the 99% target;
- More than 600,000 analyses were carried out in accredited laboratories;
- 225 municipalities (more than 80% of the total) showed quality equal to or greater than 99%.
In other words: in sanitary terms, tap water in mainland Portugal is, in the vast majority of cases, safe for consumption. This is not a marketing opinion — it's a public indicator, measured at the consumer's tap and audited.
What this indicator measures: compliance with legal parametric values (microbiological, chemical, physical) and the performance of the minimum number of foreseen analyses. What it does not measure: taste, hardness, or the condition of your building's internal plumbing. We'll come back to this below.
So why does the water taste like chlorine?
Because it has to. Residual chlorine is not an oversight — it's a technical requirement.
Between the treatment plant and your tap, there can be dozens of kilometres of pipes, reservoirs, and branches. The free residual disinfectant is what prevents bacterial recontamination along this entire route. That's why managing entities maintain a minimum concentration of chlorine up to the consumer's tap, following guidance from the World Health Organization and ERSAR itself.
The swimming pool taste is, therefore, the price of a guarantee. But it's a taste that can be easily resolved:
- Resting — filling a pitcher and leaving it uncovered in the refrigerator for 1 to 2 hours significantly reduces free chlorine, which is volatile. Cost: zero.
- Cold — cold water masks the taste of chlorine much better than room temperature water.
- Activated carbon — this is the material that any filter jug, tap filter, or purifier uses to remove chlorine and associated tastes. It is the cheapest and most effective step for this specific problem.
If your only complaint is the taste of chlorine, you don't need to spend hundreds of euros. A filter jug will solve it. The problem is when the inconvenience is something else.
Limescale: the reason that varies from region to region
Water hardness is the amount of dissolved calcium and magnesium, measured in milligrams per litre of calcium carbonate (mg/L CaCO₃). It's why the same "tap water" tastes completely different depending on where you live.
| Classification | Hardness (mg/L CaCO₃) | What you notice |
|---|---|---|
| Soft | < 60 | Soap lathers a lot, no deposits |
| Moderately hard | 60 – 120 | Slight marks on taps and kettle |
| Hard | 120 – 180 | Visible limescale, film on tea and coffee |
| Very hard | > 180 | Heating elements and showers scale up quickly |
How it is distributed in Portugal
Geology explains almost everything. Water dissolves the ground it passes through:
- North and interior (Minho, Trás-os-Montes, granitic Beiras) — granite and schist terrains, not very soluble. Water is generally soft. Here, the usual complaint is chlorine, not limescale.
- Central and coastal (Lisbon, Leiria, Santarém, Setúbal) — sedimentary and clay-limestone terrains. Water is moderately hard to hard, with large variations from municipality to municipality.
- Alentejo and Algarve — aquifers that cross extensive limestone formations. This is where the country's hard to very hard waters are found, especially in the eastern Algarve.
- Madeira and Azores — volcanic, basaltic soil. Water is predominantly soft.
A concrete example: EPAL indicates that the water distributed in the city of Lisbon ranges between 40 and 170 mg/L of CaCO₃, with an average value of 80 mg/L — meaning from soft to hard depending on the area and the source of extraction, with an average in the moderate range. This clearly shows that "Lisbon water" is not a single entity.
Is limescale harmful to health?
No. For potability purposes, relatively high hardness values are permitted, and the calcium and magnesium in water are, in fact, useful minerals. Within the ranges found in Portugal, hardness does not pose a risk to the consumer.
What hard water affects is something else:
- The taste — very hard water has a "heavier," more mineral taste; soft water tastes smoother.
- Tea and coffee — the film that forms on the surface of tea is limescale. It also alters coffee extraction.
- Appliances — deposits on heating elements of washing machines, water heaters, and kettles increase energy consumption and shorten the appliance's lifespan.
- Cleaning — in hard water, soap dissolves poorly, and white marks are left on dishes, taps, and shower bases.
What about my building's plumbing?
This is the point that escapes national statistics and is worth understanding honestly.
The managing entity is responsible for the water up to the meter. From there, the building's network — the plumbing of the building and the apartment — is the responsibility of the owner or the condominium. The current legal regime for water quality (Decree-Law No. 69/2023, which transposes Directive (EU) 2020/2184) precisely reinforced attention to this final part of the journey.
In old buildings, with degraded plumbing or long periods of stagnation — a closed holiday home, an apartment vacant for weeks — water can reach the tap in worse condition than it left the public network.
Two simple and free measures: let the water run for 10 to 30 seconds before filling a glass for the first time in the day, and always use the cold water tap for drinking and cooking (hot water passes through the water heater and is not suitable for consumption).
Five solutions, from free to definitive
Choosing well begins by identifying what your problem is. It's not the same problem everywhere.
| Solution | Resolves | Does not resolve | Indicative cost |
|---|---|---|---|
| Pitcher in the fridge | Most of the chlorine taste | Limescale, mineral taste | 0 € |
| Filter jug | Chlorine, taste, some metals | Little effect on hardness; requires filter change every month | 20–40 € + filters |
| Tap filter | Chlorine and sediments | Dissolved salts; reduces flow rate | 25–60 € + filters |
| Reverse osmosis under the sink | Chlorine, limescale, most dissolved solids | Requires plumbing work, additional tap, and drain connection | 150–500 € + installation |
| Countertop reverse osmosis purifier | The same treatment, with hot and cold water on demand | Takes up counter space; higher initial investment | 400–1,200 € |
Practical rule for deciding:
- If you live in the North and the only problem is chlorine → a filter jug is perfectly sufficient.
- If you live in the South, Algarve, or Alentejo, have hard water, and don't like the taste → only reverse osmosis will significantly change the result.
- If you are in a rented home, have a small kitchen, or don't want to drill anything → the countertop version performs the same treatment without any work.
Frequently Asked Questions
Is tap water safe in Portugal?
Yes. According to the ERSAR report of 2025 (2024 data), the "Safe Water" indicator was 98.86% in mainland Portugal, the tenth consecutive year to meet the 99% target. People's reservations are mainly related to taste, chlorine, and limescale, not microbiological safety.
Does boiling water eliminate limescale?
It only eliminates what is called temporary hardness — that which results from carbonates and bicarbonates, and which is deposited at the bottom of the kettle. Permanent hardness (chlorides, nitrates, and sulphates) is not removed by boiling. Boiling also does not remove dissolved salts or improve the mineral taste.
Does reverse osmosis remove important minerals?
Reverse osmosis removes most dissolved salts, including calcium and magnesium. It is important to remember that the main source of these minerals in the diet is food, not water. Nevertheless, those who value the mineral component can opt for ultrafiltration systems, which retain particles and microorganisms but retain dissolved salts.
Do I need to do construction work to have filtered water?
Not necessarily. Filter jugs and countertop purifiers work without any plumbing connection: you fill the reservoir and the appliance treats the water. Only systems installed under the sink require connection to the mains and drain.
How do I know the hardness of the water in my area?
Your municipality's managing entity publishes quality control results, usually on its website, and is obliged to provide this information at the consumer's request. There are also over-the-counter test strips that provide an approximate reading in a few seconds.
In summary
Portuguese tap water is safe — this has been documented and audited for a decade. What continues to drive families to bottled water is the taste, and taste has two concrete causes: the chlorine necessary for disinfection and the hardness imposed by local geology.
These are solvable problems, and not all require investment. Before deciding, understand your situation — and choose a solution proportionate to the problem.
If you want to understand the technical differences between reverse osmosis, ultrafiltration, and filter jugs, read our water purifier buying guide.
If you want to do the math before deciding, see how much bottled water actually costs a Portuguese family per year.
At UMBOX, we work with countertop reverse osmosis water purifiers, without installation and with free shipping to mainland Portugal.
Sources: ERSAR — Annual Report of Water and Waste Services (RASARP 2025, 2024 data); Portuguese Environment Agency — Environmental Status Report, "Water for human consumption" sheet; EPAL — technical sheet on water hardness; Decree-Law No. 69/2023, of August 21.
This article is for informational purposes only and does not replace information from your municipality's water managing entity.