Drinking tap water, buying large water bottles or installing a filter at home is a decision many families keep putting off, torn between doubts about the chlorine taste, the limescale marks on the kettle and the volume of plastic that piles up in the bin every week. The three options meet the same need, but not in the same way.
Comparing tap water, filtered water and bottled water against simple criteria helps you choose with more confidence. This guide starts from what regulation guarantees in Portugal, explains where the most common complaints come from and shows what each option actually changes in the day-to-day life of a household.
Tap water in Portugal: what regulation guarantees
Tap water in mainland Portugal is controlled and, in the vast majority of cases, safe to drink. According to the annual report released in September 2026 by the Water and Waste Services Regulation Authority (ERSAR), Portugal’s regulator, 98.84% of the water supplied to taps in 2025 was safe water.
What “safe water” means
ERSAR’s safe water indicator combines two dimensions: the percentage of mandatory analyses actually carried out and the percentage of those analyses that comply with the parametric values set by law. In 2025, the water reaching homes alone underwent around 393,000 analyses. According to the data released by the regulator, it was the 11th consecutive year in which this indicator remained close to 99%.
How to find out about the water in your area
The results do not stay in the national report alone. Each water utility, whether a municipality, a municipal service or a concession company, publishes water quality notices with the results of the analyses carried out in its supply area. For each parameter analysed, these documents show the values obtained and whether they comply with the legislation.
Checking the notice is useful above all in three situations:
- when you move house and want to know whether the water in the new area is harder or softer;
- when a specific question arises about the taste, colour or smell of the water;
- before choosing a filter, to know what is worth correcting and what is already within the legal values.
If the water changes suddenly and persistently, the water utility is always the first point of contact.
Where the exceptions are
The same report shows that 81% of municipalities reached values equal to or above 99%. Failures cluster mainly in small systems, often in the interior of the country, where ERSAR acknowledges greater management difficulties. Water from private boreholes and wells, on the other hand, is not part of this public network control, and anyone who drinks it should rely on laboratory testing.
A European policy in favour of the tap
The European Union has revised its legislation on water intended for human consumption with an additional objective. According to the European Commission, the directive in force requires Member States to actively promote the consumption of tap water and seeks to significantly reduce single-use plastic waste, for example through more water access points in public spaces.
Why many people do not like the taste of tap water
If mains water is safe, why do so many people still avoid it? In most cases, the answer lies in the taste, the smell and limescale, not in its sanitary quality.
The taste of chlorine
Chlorine is added to water to keep the distribution network disinfected all the way to the tap. The Drinking Water Inspectorate (DWI) for England and Wales explains that typical levels in drinking water are around 0.5 mg/l or less, well below the World Health Organization (WHO) guideline value of 5 mg/l, and that chlorine is safe at these levels.
Even so, some people are sensitive to the taste. The same body suggests two simple steps: keeping the water in a jug in the fridge, which is often enough to soften the taste, and running the cold water when the tap has gone unused for several hours. If you notice a strong and persistent taste that differs from usual, report it to the water utility.
Limescale and hard water
Hard water is water with a high concentration of dissolved calcium and magnesium, which come from the rocks the water passes through before abstraction. That is why hardness varies greatly from region to region.
The WHO reference document on water hardness does not propose any health-based guideline value. The most visible effects are domestic: hard water can leave limescale deposits in pipes and appliances and means you need more soap to make a lather. The WHO also states that the taste of calcium becomes noticeable between 100 and 300 mg/l, depending on the other minerals present. The Filtrarte article on shower cleaning shows how to deal with limescale on bathroom surfaces.
Plumbing in the building itself
Not every taste comes from the public network. The DWI points out that pipes, appliance hoses and some taps or kettles can change the taste of the water. So an odd taste that only appears at one tap in the house usually points to the internal plumbing rather than the network.
Filtered water: types of filter and what they change
Filtered water is mains water that passes through a filter before you drink it, to reduce substances that affect taste and smell, such as chlorine, or to trap sediment. The choice of filter depends on what you want to improve, because not all filters act on the same substances.
Filter jugs
They are the simplest way to start. Activated carbon cartridges are the option the DWI suggests for people who are sensitive to the taste of chlorine. However, they have limited capacity, and the same body recommends throwing away any water not used within 24 hours and washing the jug regularly.
Tap water filter and under-sink microfiltration
A tap water filter can be fitted directly to the spout or, in more complete solutions, installed under the sink and connected to the kitchen tap. This is the case with Filtrarte’s microfiltration systems. The TP 12000 uses a two-stage composite filter, with a 10-micron sediment filter and a carbon block, and is described as removing residual chlorine and other chemicals without removing the minerals from the water. The NP 9000 follows the same two-stage principle, in an under-sink installation.
Reverse osmosis
Reverse osmosis passes water through a very fine membrane that retains most dissolved substances, including the minerals responsible for limescale. It requires more space and a dedicated installation. To serve this water without mixing it with mains water, there are three-way taps such as the Patagonia tap, which combines hot water, cold water and reverse osmosis water in a single unit, each with its own outlet.
Maintenance: the point that matters most
A filter only does its job if you maintain it. The DWI stresses that you must follow the manufacturer’s instructions strictly, because a poorly maintained filter can lead to contamination and hygiene problems. In practice, this means respecting the cartridge replacement intervals and not extending use beyond the indicated period.
| Type of filter | Where to install it | Mainly acts on | What to bear in mind |
|---|---|---|---|
| Filter jug | Worktop or fridge | Chlorine taste and smell | Limited capacity, frequent cartridge changes |
| Filter on the tap spout | On the tap itself | Chlorine, sediment, taste | Compatibility with the tap, slower flow |
| Under-sink microfiltration | Sink cupboard, connected to the tap | Residual chlorine, sediment, taste and odour | Keeps the minerals, so it does not reduce limescale |
| Reverse osmosis | Sink cupboard, with its own tap or a three-way tap | Most dissolved substances, including minerals | More complex installation, technical maintenance |
Bottled water: convenience, cost and plastic
Bottled water has a clear role in specific situations: travel, work away from home, areas without a public network or times when there is an interruption to the tap water supply. At home, habit carries more weight.
Rules of its own
Natural mineral waters and spring waters have a specific legal framework. In Portugal, the Directorate-General for Energy and Geology (DGEG) oversees the extraction and bottling of natural mineral waters, under the European directive on the exploitation and marketing of these waters.
Cost and logistics
Unlike mains water, bottled water involves a recurring expense, storage space and carrying bottles and large containers. In a family that mainly drinks this type of water, the weekly volume of packaging quickly becomes visible at the recycling point.
Microplastics and nanoplastics
The topic gained prominence with a study published in 2024 in the scientific journal Proceedings of the National Academy of Sciences (PNAS) by researchers at Columbia University. Using a new imaging technique, the team counted an average of around 240,000 plastic particles per litre in three brands of bottled water sold in the United States, of which nearly 90% were nanoplastics. The authors stress that the health effects of these particles remain unknown for now.
In its report on microplastics in drinking water, the WHO considered the risk low based on the information available, but acknowledged that the evidence is limited, called for more research and argued that this does not lessen the need to reduce plastic pollution.
Comparison table: tap, filtered or bottled
The side-by-side comparison shows that none of the three options wins on every criterion. Tap water stands out because it requires no equipment or packaging, filtered water addresses taste complaints without giving up the public network, and bottled water keeps the advantage of convenience away from home.
| Criterion | Tap water | Filtered water | Bottled water |
|---|---|---|---|
| Quality control | Control regulated by ERSAR, results published in notices | Starts from controlled mains water, with quality depending on filter maintenance | Specific regime for natural mineral and spring waters |
| Taste and smell | Chlorine may be noticeable, depending on the area and each person’s sensitivity | Chlorine and odours reduced, depending on the type of filter | Varies with each brand’s mineral composition |
| Limescale | Depends on the hardness of the local water | Only reverse osmosis significantly reduces minerals | Depends on the brand |
| Everyday cost | Included in the water bill | Equipment and periodic filter replacement | Recurring purchase of bottles and large containers |
| Plastic | No packaging | No packaging, only filter cartridges | Single-use packaging |
| Convenience away from home | Requires a reusable bottle | Requires a reusable bottle | High |
| Maintenance | None | Filter changes at the indicated intervals | Storage and transport |
How to choose: recommendations by profile
There is no single answer. The right choice depends on what bothers you at home and on each family’s routines:
- If you like the taste of mains water: tap water, chilled in a glass jug, does the job with the least effort.
- Sensitive to the taste of chlorine: a jug with activated carbon is a first solution; for daily use by the whole family, microfiltration connected to the kitchen tap saves you filling and washing jugs.
- Living in a hard water area and wanting less limescale in your drinking water: reverse osmosis is the technology that reduces dissolved minerals, with its own tap or a three-way tap.
- If you want to reduce plastic: tap or filtered water, taken out of the house in a reusable bottle.
- Often away from home: bottled water is still practical when travelling, and a reusable bottle filled at home is the everyday alternative.
- If you have a borehole or well: before choosing any filter, a laboratory analysis of the water will indicate the appropriate treatment.
Whatever the option, the habit that matters most is drinking water regularly throughout the day, a topic covered in Filtrarte’s Complete Guide to Hydration. If you would like to explore home filtration solutions, you will find them all in the Water purification category.
Frequently asked questions about tap, filtered and bottled water
Is tap water in Portugal safe to drink?
In the vast majority of cases, yes. According to ERSAR, 98.84% of the water supplied to taps in mainland Portugal in 2025 was safe water. You can check the quality in each area in the water quality notices that the local water utility publishes.
Why does tap water taste of chlorine?
Because chlorine serves to keep the water disinfected throughout the network until it reaches your home. At typical levels it is safe, but some people notice the taste. Keeping the water in a jug in the fridge usually softens it, and an activated carbon filter reduces chlorine more consistently.
Is limescale in water bad for your health?
The WHO has not set a health-based guideline value for water hardness. The most common effects are domestic: white marks on taps and crockery, deposits in kettles and appliances, and higher use of detergent and soap.
Does a tap water filter remove limescale?
It depends on the type. Activated carbon filters and microfiltration act mainly on chlorine, sediment and taste, and keep the minerals, so they do not significantly reduce limescale. Reverse osmosis reduces dissolved minerals, and water softeners are available to protect the plumbing throughout the home.
Is filtered water better than bottled water?
They are different solutions. Filtered water starts from mains water, which is already controlled, and avoids packaging, provided you maintain the filter properly. Bottled water is practical away from home, but it involves recurring purchases and more plastic waste.
Does bottled water contain microplastics?
It can. A study published in PNAS in 2024 counted an average of around 240,000 plastic particles per litre in three brands sold in the United States, most of them nanoplastics. The WHO considers the risk low based on the information available, but calls for more research.
How often should you change your water filter?
The interval depends on the equipment and the volume of water filtered, and should always follow the manufacturer’s instructions. Using a cartridge beyond the recommended period can compromise the filter’s hygiene.
Content developed by the Filtrarte well-being team.
This content is for information purposes only and does not replace the advice of a health professional or the information provided by the local water utility.
