Find out the Warsaw's tap water secret
Let's be on time, let's drink tap water
From sources to taps
Check the path of the water that goes to your tap
Sources of Warsaw’s tap water
Since its beginnings, Warsaw has been inextricably linked to the Vistula River. It is the Queen of Polish Rivers that has been and continues to be the main source of water for the city’s residents, enabling its development.
In 1963, a reservoir was created on the Narew River – Zegrze Reservoir – which soon became another source of water for the capital’s residents. Two decades later, in 1986, a Northern Plant in Wieliszew was commissioned and the reservoir became the second source of drinking water for the Warsaw agglomeration.
The Zegrze Reservoir and the Vistula are our two independent natural sources from which we draw water for Warsaw. They cover around 99% of the demand, with the remaining 1% coming from local deep-water intakes located in the Wawer and Wesoła districts.
Infiltration water, i.e. water extracted from beneath the Vistula bed, covers around 70% of the city’s demand and is treated in the Central Plant’s two stations: Filtry and Praga Water Treatment Plants. Water from the Zegrze Reservoir is treated by the Northern Plant in Wieliszew.
How does it work?
Approximately 7 m below the bottom of the Vistula, drains are laid to catch infiltration water. In the infiltration process, water percolates through the sand and gravel layer of the river bed. The drains need to have adequate capacity, so regular bottom flushing is important. This is taken care of by specialised vessels – hydraulic scarifiers, the so-called ‘Chude Wojtki’ [Thin Wojteks], which use perssurised jets of water to wash away the top, most contaminated layer of sand lying on the river bed. The capital has six shore intakes and a primary intake – ‘Gruba Kaśka’ [Fat Kathy] infiltration well, Europe’s largest facility of this kind located in the river.
Where are the stations?
The highest quality of Warsaw’s tap water is guaranteed by our treatment stations:
Filtry Water Treatment Station – water from this station is supplied to the residents of the central and south-western left-bank part of Warsaw, as well as to Pruszków, Piastów, Michałowice, Reguły and parts of Raszyn, and the Brwinów commune. Water from the Filtry Water Treatement Station can also be transferred to Dolny Mokotów, Wilanów and Powsin.
Prague Water Treatment Station – water is directed to the residents of: Praga Południe, Rembertów, Wawer and parts of Wesoła, Mokotów, Wilanów and Powsin. The Praga Water Treatment Station, within the structure of the Central Plant, is responsible for the operation of local water intakes in the Wesoła district, as well as in Radość and Falenica (Wawer district).
Northern Plant – water from this plant is received by the residents of Białołęka, Bielany, Bemowo, Targówek and Praga Północ, as well as parts of Wola and Żoliborz.
The water supply network is interconnected and some parts of the city receive water from two stations. These are known as mixing zones.
Treatment process
Before water is distributed to residents, it must undergo a multi-stage treatment process, the proper course of which is supervised by engineers along with maintenance workers, laboratory technicians equipped with modern equipment and a team of technologists. Regardless of their work, the water parameters are also constantly monitored by the Sanitary and Epidemiological Station. This way, we can be sure that Warsaw’s tap water meets exactly the same quality requirements* as the tap water drank by Londoners or Parisians. What’s more, it is rich in minerals such as magnesium and calcium, and costs less than 1 grosz per litre.
*In accordance with the Regulation of the Minister of Health of 7 December 2017 on the quality of water intended for human consumption (Polish Journal of Laws of 2017, item 2294) as well as European Union standards and World Health Organization guidelines.
Intake
Warsaw’s waterworks draw water from two independent sources: from under the bottom of the Vistula River and directly from the Zegrze Lake. Due to the impurities in the raw water, including organic matter and high levels of iron and manganese compounds, it requires treatment at our facilities.
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Aeration
Raw water contains elevated levels of iron and manganese compounds. These are the cause of its characteristic smell and taste.
Thanks to the aeration process, i.e. the introduction of sufficient oxygen into the water, these compounds take the form of oxides, which are precipitated as sediment.
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Sedimentation
Larger suspended solids in the water sink (sediment) under their own weight to the bottom of the tanks, from where they are then removed.
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Coagulation and sedimentation or flotation
The next stage of treatment removes impurities that are present in dissolved form. They are responsible for the turbidity and colour of the water. In our facilities, we use two methods to eliminate them:
a) the process of coagulation and sedimentation – individual hard-to-fall particles join together to form sediment, which, under the influence of pulsating motion in special tanks (pulsators), clumps into even larger “flocs.” The suspended solids sink to the bottom, and the treated water is directed to rapid filters. This process is used to treat water drawn from beneath the bottom of the Vistula River;
b) the process of coagulation and flotation – micro-bubbles introduced into the water coat like balloons the impurities clumped into “flocs” and lift them to the surface (i.e. flotation), forming a froth-like sediment. We use the process to treat water drawn from the Zegrze Lake.
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Rapid filtration
After preliminary treatment (processes 1–4), the water goes into huge tanks filled with fine quartz sand and gravel. The filtration, which takes place at a speed of 5 m/h and lasts about 30 minutes, removes suspended solids and iron and manganese compounds. The rapid filters are regularly flushed with compressed air and water.
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Indirect ozonisation
At this stage, we break down the organic matter particles in the water into smaller particles that are easier to filter on the surface of activated carbon. For this we use ozone, which we introduce in gaseous form using diffusers.
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Sorption on the surface of activated carbon
After the ozonisation process, the water is directed to filters filled with granular activated carbon characterized by high porosity. During filtration, which lasts about 24 minutes, particles of organic matter are trapped in the carbon micropores. This significantly reduces the content of impurities that affect the colour, taste and smell of water. The carbon deposit is regularly washed using water and compressed air.
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Periodic oxygenation
Oxygenation is carried out only during the summer, when oxygen levels in the water are too low due to high temperatures. Its adequate concentration is necessary for the processes that later take place in slow filters. Oxygen is needed for the growth of beneficial micro-organisms that form a biological layer in the top of the sand and activated carbon.
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Slow filtration
The final stage of impurities removal is the slow filtration that occurs in historic Lindley’s Filters (Warsaw Water Filters). In one hour, about 10–15 cm of water column seeps through a layer of activated carbon, sand, gravel and stones. In the upper parts of the filter bed, a so-called biological layer is formed.
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Disinfection
The final stage of treatment is disinfection of the water, that is, protecting it from the possibility of secondary contamination in the water mains. To this end, we add small amounts of disinfectant to Warsaw’s tap water. This ensures that it remains clean and safe from the moment it is pumped into the mains until it reaches your home.
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Where can you taste Warsaw’s tap water?
Sustainable development
Water is our common good and we must respect it. Unfortunately, it is also one of our
planet’s most endangered resources, which is why it is so important to take care of it
every day.
Check what you can do to use water rationally:
Respect water in the kitchen
- Tighten the taps and keep them tight. Even around 15 litres of water a day can accumulate from a dripping tap.
- Use a dishwasher and load it full. We can use up to 100 litres of water when hand washing dishes, while one dishwasher cycle is about 15 litres.
- Install aerators. A standard water flow rate of a kitchen tap is approximately 13 litres per minute, the use of an aerator reduces the flow rate to 5 litres per minute.
- Wash fruit and vegetables in a bowl. When washing fruit in a bowl, you use much less water than when washing it under running water, plus you can use the water from the bowl to water your plants.
- Check the installation for leaks. A leaking sink tap can mean a loss of up to 150 litres of water per day.
- Do not wash dishes under a stream of water. While washing dishes under a running tap, several times more water is used than when washing them in a water-filled sink or bowl.
Respect water in the bathroom
- Brush your teeth with the tap off. We lose up to 15 litres of water when we brush our teeth with the tap on.
- Take a quick shower instead of a bath. Up to 200 litres are consumed during a bath, and around 50 litres during a five-minute shower.
- Use a water-saving flush mode whenever possible. A traditional flush will use as much as 10 litres of water each time, while fitting a flushing set with a water- saving mode can reduce consumption to 3 litres.
- Repair flushing sets and taps whenever they leak. A leaking tap or a flushing set in the toilet is a loss of up to 6,000 litres of water per year.
- Load your washing machine to its full capacity and pay attention to appliance parameters. A washing machine uses up to 80 litres of water per wash cycle, an economical model uses just 30 litres.
- Do not flush rubbish down the toilet. Things that should not be in the toilet can cause clogging of a drain pipe and flooding of the flat.
Respect water in the garden
- Water the plants at the coolest time of day. Water will not evaporate so quickly if you water your lawns and plants in the garden at the right time of day.
- Collect rainwater and use it in the garden. During one rainy day, water from the roof of a detached house can fill a 300-litre tank.
- Set up sprinklers so that they water only the plants and not the pavements. On average, 100 m 2 of lawn needs 500 litres of water per day, which amounts to around 100,000 litres per season.
- For watering use water already used, e.g. after washing fruit. You can reuse the water after rinsing fruit and vegetables or boiling eggs or rice, for example, for watering plants.
- Water your plants properly. The water jet from the watering can directed at the stem, not the leaves, reaches the root system directly.
- Put mulch around the plants to retain water. The mulch counteracts excessive soil heating and drying by reducing water evaporation.
- Collect rainwater and use it in the garden. The roof of a 1,000 m 2 house can drain approximately 2,280 litres of water, which can fill 456 5-litre buckets.
Take care of water resources
Our daily choices (including purchasing choices) and the prudent use of water for domestic purposes (washing, cleaning, cooking) are of paramount importance. Although you cannot see it, water is also hidden in products and services – this is known as a water footprint. The term was created to help more accurately estimate the amount of water used by residents and thus their impact on water resources.
The water footprint determines how much water is in all the products we use and buy every day. Remember about water when buying clothes, food and using various services!
Educational activities
Educational activities are an important part of our mission. We believe that promoting the right attitudes will contribute to improving the quality of our daily lives, including respecting water resources and caring for the environment by choosing Warsaw’s tap water.
You can learn more about our programmes here: