Boil water advisory: what should you do now?

Reading time: ~11 minutes

What is a boil water advisory?

A card drops through the letterbox, or a text message arrives: boil your drinking water for 3 minutes. That is a boil water advisory. It is not a warning that your water is dangerous, and it is not an outage where nothing comes out of the tap. The water keeps flowing, you are simply not allowed to drink it as it is.

The difference from an outage matters, because it determines what you have to do. If no water at all comes out of the tap, that is a supply problem and boiling will not help you; what to do in that case is covered in no tap water from the tap. During a boil water advisory there is water, the water utility simply cannot guarantee the microbiological quality for the time being.

The advisory is deliberately kept simple. Not because there is anything to hide, but because boiling for 3 minutes is the only measure that works in every kitchen, whatever appliances are in it.

Why do you get a boil water advisory?

Almost always for the same reason: an indicator bacterium has been found. Water utilities test their water continuously for two bacteria, E. coli and enterococci. According to the RIVM these should not be in there, and if they are present anyway it means that human or animal faeces have ended up in the drinking water.

Those bacteria themselves usually do not make healthy people ill. The problem is what comes along with them: other bacteria, viruses and parasites from those same faeces, which can indeed cause stomach and intestinal complaints. For young children, older people, pregnant women and people with a weakened immune system the consequences can be more serious. That is why the water utility steps in as soon as a measurement deviates, and not only once complaints come in. More about these two bacteria is in the article on enterococci and E. coli in tap water.

Such a bacterium never comes from the treatment process itself; it always comes from outside, for example through a burst pipe or work on the network. To spot that in time, the Dutch water utility Vitens tests the water around 200,000 times a year. At sector level, according to the Dutch water industry association Vewin, 99.9% of all measurements meet the standards, and drinking water is monitored more strictly than food in the supermarket.

So a boil water advisory is not a sign that the system is failing. It is proof that the system works: something was noticed before anyone became ill from it. How such contamination ends up in the network is explained in faecal bacteria in tap water.

What do you have to boil, and what not?

This is the question most people get stuck on, and the answer is broader than you think. The boil water advisory only applies to water you take in or that comes into contact with food you eat raw. The rest of your household simply carries on.

Sources differ on brushing your teeth, and that is worth knowing. The RIVM writes that it is not dangerous to use unboiled water for showering, brushing your teeth or washing up. Vitens, Waternet and Brabant Water, also Dutch water utilities, do advise using boiled water for brushing your teeth. That is a stricter line, and the advice from your own water utility is what counts. It costs you nothing, and it removes the doubt.

How do you boil the water properly?

Three minutes sounds like a detail, but it is the entire measure. The clock only starts running once the water is really boiling, not when it gets hot. That is exactly where most kitchen appliances fall short.

Pan or stovetop kettle: the safe standard

Bring the water to the boil in a pan or stovetop kettle and then let it boil for 3 minutes. This is the method every water utility names, because you can see for yourself that the water is boiling and you keep track of the time yourself. Then let it cool down under a lid.

Electric kettle: possible, but take care

An electric kettle switches off as soon as the water boils, so after a few seconds. Vitens therefore advises leaving the lid open, which makes most kettles keep boiling. There is a warning attached to that: the boil-dry protection may no longer work, so first check the instruction manual to see whether your appliance is suitable for prolonged boiling. Brabant Water advises against the electric kettle entirely for that reason and points to the pan. If in doubt, take the pan.

Coffee machine: do not rely on it

A filter coffee machine or espresso machine heats the water to somewhere between 90 and 96 degrees Celsius and lets it run straight through. That is too short and too cool. Both Vitens and Waternet say it explicitly: coffee machines often do not boil for long enough. So boil the water in a pan for 3 minutes first, let it cool down and fill your reservoir with that. The same applies to water dispensers, ice makers and the fridge water tap.

Does the boil water advisory also apply to your Quooker?

This is the question asked most often about the Quooker, a boiling water tap that is common in the Netherlands, and the one the water utilities answer differently. So it is worth writing it down precisely.

Underneath this lies a technical difference. A tank model keeps a supply of water permanently close to 100 degrees Celsius, and that is something other than water that shoots past a heating element once, briefly. Which type you have in your kitchen is known by the manufacturer, not by your water utility.

The practical conclusion: during a boil water advisory, do not rely on your boiling water tap unless your supplier explicitly confirms that the model holds the temperature for 3 minutes. The pan is always fine. And watch out for the other misconception surrounding this tap: a Quooker handles temperature and convenience, but it does not filter out PFAS, microplastics or heavy metals. That is set out on the page about combining a water filter with a Quooker.

How long does a boil water advisory last?

A boil water advisory is always temporary, but it lasts longer than most people expect. The stated periods vary per utility: Waternet puts it at usually 3 or 4 days, Vitens asks you to allow for 4 to 8 days, and Brabant Water generally mentions 5 to 8 days. In exceptional situations it can take longer.

That spread comes from the procedure. The utility first has to find the cause, then flush the pipe or the storage reservoir, and after that take samples and let them grow in the laboratory. A bacterial culture simply takes time, and there have to be several clean results in a row before the advisory can be lifted.

You will be notified when it is over, by email, text message or a card. Brabant Water works with colours: a red or orange card means boil, a green card means you can drink normally again. Were you away during the boil water advisory and did you not use any water? Then let your taps run for 1 minute afterwards, and also flush through any outlets where the water has been standing still.

Most utilities are clear about compensation: bottled water is not handed out and usually not reimbursed either, because boiled tap water is safe. Vitens applies a threshold of €40 for costs directly related to the boiling; in most cases that amount is not reached.

How do you know whether the advisory applies to you?

A boil water advisory follows the pipes, not the municipal boundary. The next village can be right in the middle of it while your street falls just outside it, and the other way round. That is why the postcode checker of your own water utility is what counts, and not the map on waterstoring.nl, the Dutch outage map, which according to Vitens only gives an indication of the area.

• You are notified: by email, text message or a card through the letterbox. So check that your contact details at your water utility are up to date, because that is the fastest route.
• You check your postcode: during a large boil water advisory the water utility puts a postcode checker online. That information is what counts.
• You are not notified but your postcode does fall within the area: then the advisory applies to you as well.
• You rent or live in a VvE, a Dutch homeowners association: then the message may have gone to the landlord or to the association instead of to you. Ask about it in the neighbourhood app.

The practical advice every utility repeats: call on your neighbours or share the message in the neighbourhood app. Not everyone has passed on their details, and older neighbours in particular quite often miss a text message.

Storing boiled water: how long does it keep?

Nobody boils glass by glass for eight days. It is more practical to boil one large pan once a day and store that supply properly. How long it keeps depends entirely on how you do that.

Those figures come from Vitens. The key lies in two things: the bottle has to be clean and it has to be closed. An open jug on the worktop simply picks up dust and bacteria from the air again, and then the boiling was for nothing. Rinse the bottle out with boiled water first, fill it to the brim and keep it cold. More about how long tap water keeps in general is in how long you can store tap water.

Are you getting water from a water tanker or emergency tank that the water utility puts out? Then boil that for 3 minutes as well, Waternet warns. Not because the water in the tank is dirty, but because your own jerrycan, bottle or pan may be.

Does a water filter replace a boil water advisory?

No. We sell water filters and this is the most honest answer we can give: a household water filter, ours included, is not a substitute for a boil water advisory. Keep boiling for as long as your water utility asks you to.

That is because filters and boil water advisories are about two different problems. The certifications good filters are tested against, NSF/ANSI 42 and 53, were made for taste and odour (42) and for chemical and health-related substances such as lead, VOCs and PFAS (53). For a microbiological guarantee there are separate standards, such as NSF/ANSI 55 for UV systems. So a filter certified to 42 and 53 says nothing about bacteria and viruses, and that is precisely what a boil water advisory is about.

Vitens mentions a second variant that people take out of their emergency kit: filter tablets. These can purify water, but the utility points out that you have to follow the instructions carefully, that it is usually more expensive, takes more time and affects the taste. The advice simply remains: boil for 3 minutes. What is worth having in the house is covered in what belongs in an emergency kit and in storing drinking water at home.

What a fixed filter is actually for

A boil water advisory lasts a week, perhaps twice in your lifetime. The substances a filter is made for are in the water the other 51 weeks, and boiling does not make them disappear. On the contrary: boiling evaporates water and actually concentrates dissolved substances slightly. That is the difference in one sentence.

The Mineral+ with five filter stages removes PFAS, microplastics, heavy metals, fluoride, nitrates, medicine residues and chlorine from your tap water, and as a final step adds calcium, magnesium and potassium back via Swedish Mineral Rock™. Purify first, then mineralise: that order is the whole point. The unit costs €149.00 including the first filter. A replacement filter costs €65.00 and lasts around twelve months with 1 to 3 people, around six months with 4 to 6 people; the duo with two cartridges costs €115.00. Worked out per litre, that is less than one cent. If you would rather not think about it, the Filterplan sends the cartridges automatically and on time for €48.00 or €86.00 per delivery.

At PureFilter we see that after a boil water advisory in their region, customers often look into their tap water for the first time, and then get stuck on a completely different question: what is in it the rest of the year? Which filter technology is meant for what, we have written out in the differences between the filter technologies at a glance. The installation itself takes 5 to 10 minutes: you do not need a plumber, you use one pair of water pump pliers to connect it to the cold water pipe, and you change the cartridge later with the supplied key. Step by step, that is in the guide to installing a water filter, and our fixed under-sink filters are in the webshop.

What you can arrange right now

A boil water advisory comes unannounced. Four things will cost you five minutes today and save you half a day of improvising later.

1. Check your contact details in the customer area of your water utility. Without an up-to-date mobile number or email address you will get no text message and no email, and that is the reason people miss a boil water advisory.
2. Bookmark the postcode checker of your water utility. During a large advisory that is the only source that is exactly right.
3. Put two clean bottles with caps ready. With those you can store boiled water for weeks instead of one day in a pan.
4. Ask your supplier whether your boiling water tap holds 100 degrees Celsius for 3 minutes. Then you no longer have to ask that question in the middle of a boil water advisory.

And the question that stands apart from all this, but that often comes up after a week like that: is my tap water actually fine for the rest of the year? The answer is yes, comfortably so. It is only about what you want to add on top of that yourself.

Frequently asked questions

Conclusion

A boil water advisory for drinking water asks one thing of you: boil tap water for 3 minutes before you drink it, use it to make coffee or infant formula, wash vegetables you eat raw with it or brush your teeth with it. The rest of your household, from the shower to the washing machine, simply carries on with unboiled water.

The figures to remember: boiling for 3 minutes in a pan or stovetop kettle, 3 to 8 days total duration, running the taps for 1 minute if you have been away, and a maximum of 1 day of shelf life in an open pan compared with weeks in a sealed bottle in the fridge. Vitens tests its water 200,000 times a year, and 99.9% of all measurements in the Netherlands meet the standard; a boil water advisory is proof that this monitoring works, not that it fails.

Two things are mixed up most often here. Your boiling water tap is not a certainty, because the water utilities do not agree among themselves on which models stay hot for long enough. And neither is your water filter: filters are built for PFAS, lead, microplastics and taste, not for bacteria. Those two things solve different problems, and that is exactly why they do not replace each other.