Boil water advisories are supposed to become less common with improvements in water purifying technologies, but extreme climate events and our desire to live outside cities nearer to nature and animals ensure that they keep happening. The aim of this article is to describe all the dos and don’ts during a boil water advisory.
Water should be boiled or disinfected during boil water advisories. Since microbiological organisms are harmful when they enter our bodies, all common practices that bring tap water into contact with our food, mouths, and open wounds must be changed.
In a scientific survey in 2020, researchers found that only 47 percent of media articles included scientific advice regarding the actions that are admissible or prohibited during a boil water advisory. For example, is it safe to shower, wash your dishes, visit a restaurant, and use your water filter?
This puts people at risk of illness because they don’t know what a boil advisory means and how to comply with it to keep themselves safe. This article solves this problem by providing all the answers to questions about what tap water can and cannot be used for during a boil water notice, including:
A boil water advisory, notice, or order is a notification from your local health authority together with your local water supplier that tap water in your area is, or might be, contaminated with microbiological organisms that can make you sick.
The Safe Drinking Water Act, enacted in 1974, includes the Public Notification Rule whereby local authorities must notify consumers about a potential problem with water quality within 24 hours after its discovery.
These boil water notices are usually distributed via the local media, social media, websites of water providers and municipalities, and via phone calls, text messages, and emails to registered water users.
Information in a boil advisory typically includes:
It is important to distinguish a boil water advisory from do not drink and do not use water advisories.
A boil advisory lasts until your local health authority and water system issue a notice that they have lifted the advisory. Such an end-of-advisory notice normally includes post-advisory guidance for washing containers, flushing pipes, throwing away water filters, and so on.
Most local authorities require two consecutive days of clean water samples before advisories can be lifted, which means that the average advisory tends to last between 48 and 72 hours.
Let’s try an example of the best-case scenario. If a main pipe breaks on Monday morning and it takes six hours to repair it, the first post-repair water samples can be taken and sent to a laboratory on Monday midday.
The second set of samples must be taken during the following 24 hours, let’s say halfway through Monday night.
Let’s further assume that it takes the laboratory 18 hours to verify that both the sample sets are clean, say by late Tuesday afternoon.
That means that Monday morning’s boil advisory can be lifted on Tuesday night.
In cases where the laboratory takes longer than 18 hours, where some samples don’t test clean, or where the cause of contamination takes longer to resolve, you can expect these advisories to be active for days.
Advisories are issued either when water suppliers are aware of an event that may potentially have degraded water quality (a precautionary advisory), or when their tests show that water has definitely been contaminated with a parasite, bacteria, or virus (a mandatory advisory).
Microbiological organisms like parasites, bacteria, and viruses exist in soil, plants, and animals. The most common sources of water contamination are animal feces and urine, either directly from animals, from fertilizers, or from soil.
As such, some common causes of boil water advisories are the following:
Most microbiological organisms that trigger a boil water advisory act on the gastrointestinal system if consumed, with the most common symptoms being diarrhea, stomach cramps, nausea, and vomiting.
These are unpleasant for healthy teenagers and adults, but can be serious or even fatal for small children, the elderly, and immune compromised individuals like those on cancer or post-transplant treatment, those on high-dose corticosteroids, or those with autoimmune diseases.
All states require the following organisms and their accompanying diseases to be reported to their health departments. They are the most common water-borne organisms and infections.
|Giardiasis||Giardia lamblia||Diarrhea with foul-smelling and greasy stools, stomach pain, bloating, dehydration, fatigue|
|Cryptosporidiosis||Cryptosporidium parvum||Watery diarrhea, nausea, bloating, weight loss, vomiting, dehydration|
|Amoebiasis||Entamoeba histolytica||Diarrhea, stomach pain, weight loss, fatigue, bloody stools, fever|
|Acanthamoeba keratitis||A. castellanii and A. polyphaga||Red eyes, blurry vision, tearing, eye pain, light sensitivity, permanent blindness|
|E. coli||E. coli||Bloody diarrhea, severe dehydration, stomach cramps, vomiting, fever, kidney failure|
|Salmonellosis||Salmonella species||Diarrhea, vomiting, stomach pain, fever|
|Typhoid||Salmonella typhi||Fever, diarrhea, fatigue, weakness, cough, skin rash, delirium, enlarged organs, death|
|Vibriosis||Vibrio species||Watery stools, stomach pain, fever, chills, delirium, weakness|
|Cholera||Vibrio cholerae||Watery diarrhea, vomiting, leg cramps, thirst, nosebleed, rapid heart rate, shock, death|
|Dysentery, shigellosis||Shigella species||Bloody stools, bloody vomit, fever, stomach pain|
|Campylobacteriosis||Campylobacter species||Bloody stools, bloody vomit, stomach pain, fever|
|Hepatitis A||Hepatitis A virus||Fatigue, nausea, jaundice, fever, weight loss|
|Various||Adenoviruses||Flu, fever, sore throat, bronchitis, pneumonia, pink eye, diarrhea, vomiting, stomach pain|
|Hepatitis E liver infection||Hepatitis E virus||fatigue, vomiting, jaundice, fever, loss of appetite, weight loss, dark urine|
|Polio||Poliovirus||Usually symptom-free, flu-like symptoms, headache, delirium, meningitis, paralysis, death|
|Various||Echo viruses||Usually symptom-free, croup, sore throat, skin rash, mouth sores, nausea, vomiting, headache, meningitis|
|Hand, foot, and mouth disease||Coxsackie Virus||Runny nose, sore throat, fever, blisters on hands, feet, and inside the mouth|
|Various||Coxsackie virus||Muscle pain, headache, stomach pain, heart inflammation (myocarditis), brain inflammation (encephalitis), meningitis|
|Rotavirus||Rotaviruses||Watery diarrhea, vomiting, stomach pain, fever|
|Gastroenteritis||Caliciviruses||Diarrhea, vomiting, abdominal pain, fever, headache|
During a boil advisory heat water in a pot until bubbles rise quickly from the bottom to the top, which is called a rolling boil. Leave it on a rolling boil for one minute. You can then move it to a back plate or burner and allow it to cool before you pour it into a clean container with a tight-fitting or screw-on top.
This means that you cannotuse devices like kettles that switch off when the water starts to boil. Neither can you rely on appliances like hot water heaters, since you cannot see whether the water is actually boiling and for how long it continues to do so.
Since water boils at lower temperatures at elevations above 6,500 feet (~2000m), you should boil water for threeminutesinstead of one minute if you are located in such a region.
To improve the taste of the boiled water, you can add one pinch of salt for each quart of water, or simply allow it to re-oxygenate by pouring it from one container to another and stirring it.
If the water is cloudy or discolored, filter it through a coffee filter or paper towel before you boil it.
Some harmless bacteria like clostridium and bacillus can survive being boiled, but no organisms that are currently understood to cause disease can. Health authorities recommend one minute of boiling because that will definitely kill all disease-causing organisms, but many organisms actually die at lower temperatures.
Boiled or even hot water kills microbiological organisms by damaging their structural components and by disrupting the processes that keep them alive.
Research shows that parasites like Giardia are deactivated at a temperature of 131°F. Similarly, potentially harmful bacteria in milk are neutralized when milk is pasteurized at 149°F for 30 seconds.
Both of these temperatures are below boiling point, so you can be confident that health authorities have set the one-minute boil rule as a conservative method that kills all disease-causing microbiological organisms.
The expiry of stored water depends entirely on the nature of the container, the substances stored around it, and the contamination levels of the original water. The Federal Emergency Management Agency (FEMA) proposes six months for disinfected water, but only under certain circumstances.
The best containers in which to store boiled or disinfected water are bottles that originally contained store-bought water or soft drinks. Since milk proteins and fruit sugars are almost impossible to remove from plastic, bottles that originally stored milk and juice are breeding grounds for bacteria.
Once you have found an appropriate container:
Under these conditions, it should last six months, which is much longer than almost all boil water advisories.
If you cannot boil water during a boil water advisory because the electricity is off after a large storm, for example, you will have to add a disinfectant to the water before you can drink it. For example, add eight drops (using a medicine dropper) or one-eighth of a teaspoon of unscented (Regular Scent) chlorine liquid bleach to one gallon of water and let it stand for 30 minutes before drinking.
Verify on the label that it says five to nine percent of sodium hypochlorite. It is important that you do not use bleach that is labeled scented, color safe, splashless, or mixed with other cleaners.
As unappetizing as it sounds, the water must smell a little bit like bleach before you drink it. If it does not, add another four drops of bleach and let it stand for another 15 minutes.
Another good disinfectant is the tincture of iodine that should be in your medicine cupboard. Add five to ten drops of two percent tincture of iodine to each quart of water, depending on its cloudiness. Let it stand for 30 minutes before drinking.
You can also buy water disinfection tablets from Amazon, a pharmacy or adventure/hiking retailer and follow the instructions on the label.
In times of extended emergencies, your state, your water utility, or your emergency response agency may set up bulk water haulers to station tankers in your neighborhood where you can fill containers. Once you have verified that they are legitimate, you can trust that the water is clean without further disinfection
You must verify that the hauler is certified by your state. This means that they meet certain requirements regarding, for example, the cleanliness of their water tankers. Ask the operators from which office they received their certification.
You should also ask the hauler where the water comes from, for example, from a source approved by your state’s health department or from another water system in a nearby location that is not under the boil water notice.
Most common water filters like pitchers and faucet-mounted filters cannot remove biological organisms from water, and are thus unsafe to use.Well maintained distillers and devices that use ultraviolet light and antimicrobial substances like silver can kill such organisms and are good alternatives to boiling.
The health organization NSF International certifies water filters for the type of contaminants they can remove from water.Those with an NSF/ANSI 231 certification have been independently tested and verified for biological organism removal and are safe to use during a boil advisory.
But it is crucial to follow the manufacturer’s advice regarding maintenance and change of filter cartridges religiously, otherwise it won’t remove anything.
The Epic Nano Water Filter Pitcher is able to remove up to 99.999% of all tap water contaminants including bacteria, giardia, cryptosporidium, and viruses, and is NSF/ANSI 231 certified.
Drinking water filtered by the Epic Nano during a boil advisory is absolutely fine. One filter will produce up to 150 gallons of clean drinking water.
Whereas pitcher filters like Brita and PUR tend to have a basic mesh screen that catch large particles, an activated carbon filter that removes minerals and chlorine, and a specialized ion Exchange Resin filter that targets specific metals like cadmium.
Accordingly, they cannot remove biological organisms and cannot be used to treat the water during a boil advisory. Even though they can get certified NSF/ANSI 53 for removing most contaminants with a health effect and NSF/ANSI 42 for removing aesthetic impurities like chlorine, they cannot be NSF/ANSI 231 certified.
Faucet-mounted filters are activated carbon filters that can remove chlorine, some metals, and minerals, also earning themselves NSF/ANSI 53 and NSF/ANSI 42 certification. But biological organisms are not removed and are not safe to use during a boil advisory.
Filters that are based on ion Exchange Resin technology, like the ZeroWater pitcher, remove all metal, mineral, chlorine, and other chemical particles that aren’t hydrogen or oxygen. But they cannotdo anything about biological organisms and should not be used during a boil advisory unless the water is already boiled.
Reverse osmosis systems can be either whole-house or under-sink filtration systems with multiple filters that are incredibly thorough. But research shows that they do let through some biological organisms.
Many models, like the popular Express Water RO5DX Reverse Osmosis Filtration system, have the great advantage that they can fit additional filtration attachments, including ultraviolet filters that can remove biological organisms. This makes them good filters to have during boil water advisories.
Distillers are equally good to have during a boil water notice. They boil the water and then collect the water vapor when it condenses and, because biological organisms cannot convert to gas, they are removed very effectively.
If your boil water notice occurs during a big storm that knocks out the power, however, a distiller is not going to work.
Filters that use ultraviolet light or an antimicrobial substance like silver are allowed to carry NSF/ANSI 231 certification for the removal of biological organisms. The Epic Nano Water Filter Pitcher is a popular example. This eliminates the need for boiling during a boil water advisory.
If you test your private well for bacteria around once a year, it should be safe during boil water notices, except when there has been a significant risk of contamination. These risks include the well being submerged under flood water, a change in the water color, or nearby wells being contaminated.
If any of these conditions are present, you will have to boil your water too and have your well water tested.
In case of microbiological contamination, you will have to disinfect both the well and the plumbing with unscented chlorine bleach and replace the cartridges in water filter devices with new ones after the disinfection.
This post contains detailed instructions on how to conduct shock chlorination on a well.
It is usually safe to take a bath or shower during a boil advisory, so long as you do not swallow any water. It is safer to sponge bathe babies and young children to prevent the possibility of swallowing.
If you have an open wound or broken skin, apply a waterproof bandage that seals on all four sides, followed by a disposable shower patch made of film and medical-grade adhesives. Another option is to put cling wrap on the wound and tape a plastic trash bag over that.
You can use tap water to shave during a boil water notice, except if you have the tendency to nick yourself. Since microbiological organisms can enter through nicks in the skin, it is safer to use bottled or boiled water if you are a wild shaver with a track record of nicking.
You should brush your teeth with bottled or boiled water to prevent the biological contaminants from ending up in your blood stream during a boil advisory. Brushing your teeth with contaminated water can cause illness, such as diarrhea and vomiting.
If possible, use disposable plates, cups, and utensils for the duration of the advisory. This is not only safer, but less work for you.
If this is not an option, you will have to incorporate liquid chlorine bleach (sodium hypochlorite) into your dishwashing routine as follows:
Dishwashers are safe to use during a boil advisory only if they have at least one of the following two features:
It is safe to do laundry as usual, linen and clothes should be washed in hot water (113°F) for at least 20 minutes. The clothes should be completely dry before they are worn, and it is important to remember that white clothing might be discolored if the water is cloudy or discolored during the advisory.
The CDC states that it is usually safe to wash your hands during a boil advisory, unless your local health authority has issued a warning that it is not. Similarly, you can wash your hair and face, so long as you don’t have any open wounds and keep the water out of your mouth and eyes.
Scrub your hands with soap and water for 20 seconds, after which you can rinse them under the water.
If the advisory states explicitly that it’s not safe to wash hands with tap water, use an alcohol-based hand sanitizer that contains at least 60 percent alcohol.
Some health authorities recommend that you apply an alcohol-based hand sanitizer after washing your hands with tap water and soap, even if the water boil notice doesn’t require it explicitly. This can be a good approach for people who care for young children or elderly relatives.
It is advisable to wash your hands with boiled, bottled, or disinfected water before handling food, regardless of whether or not the advisory mentions it.
If you have already touched the tap water and you want to clean your hands before preparing your food, non-alcohol-based hand sanitizers or those with an alcohol percentage below 60 percent aren’t good enough, as even medium-concentration alcohol is weak against cryptosporidium and some bacteria.
Rather use disinfected water that contains one tablespoon of unscented (Regular Scent) chlorine liquid bleach per one gallon of water.
If you bite your nails or you habitually touch your face, you may transfer the organisms into your mouth. If this sounds like you, wash your hands with disinfected, boiled, or bottled water and soap.
In a boil advisory it is safer to boil the water before you add food to it, since this is the best way to ensure that it boils nonstop for one minute. This is especially important if you cook soft green vegetables or even pasta that don’t require much rolling boiling.
But if you cook meat or beans that take 20 or 30 minutes to be ready, the water will be at or near boiling temperature for so long that no biological organism can survive it. In these cases, you don’t have to boil the water first before tossing in the food.
You cannot use tap water to make ice, whether it’s in an automatic ice maker or manually in ice trays. Freezing does not kill all the microbiological organisms that can contaminate the water during a boil advisory.
If the ice was made the day before the advisory, you can use it safely. Otherwise, discard it, clean the appliance or the ice trays with disinfected water, and fill them with bottled or boiled water to make new ice.
In a boil advisory it is safer to use your coffee maker with water that has already been boiled for one minute, as coffee makers do not maintain a hot enough temperature for long enough to kill all biological organisms.
Theoretically, the chance is good that your coffee maker runs hot enough to de-activate the most common nasties like E. coli, cryptosporidium, and Norovirus, and some health agencies are comfortable if you let the coffee stand for 5-10 minutes before drinking it.
But if you have young children, elderly relatives, or immune-compromised people who share your home, it is better to be safe and use your coffee maker with already-boiled water.
You should use boiled, bottled, or disinfected water to clean any washable surfaces or objects that may make contact with food. You can disinfect water by adding between one teaspoon and one tablespoon of unscented chlorine bleach per one gallon of water, but because such sanitizing solutions lose their strength over time, you should make new disinfected water every two or three days during the advisory.
The easiest option is to use ready-to-use formula for your infant if possible. during a boil advisory.Otherwise, health authorities suggest that you keep water at a rolling boil for two minutes before mixing it with baby formula, after sterilizing all bottles, rings, nipples, and other utensils in boiling water for two minutes before use.
The reason for increasing the typical one-minute boil to a two-minute boil is because the immune systems of infants are completely incapable of neutralizing potentially harmful biological organisms. Typical symptoms like diarrhea or vomiting are also far more destructive at this age.
To protect your vulnerable baby from water-borne organisms even further, follow the same steps for wiping kitchen counters when cleaning diapering and bathing areas.
In almost all circumstances, you can continue to use your toilet as normal during a boil advisory. The two exceptions are when a do-not-use advisory is in place, or when a boil water advisory explicitly demands that you save water because the available water supply is almost exhausted.
In case of the former, you should not flush at all because skin contact with, or inhalation of, the water can make you sick. In such cases, the water supply is likely to be turned off anyway.
If a water conservation order is issued along with the boil water advisory, you should flush only after defecating, consistent with the water conservation motto: “if it’s yellow, let it mellow; if it’s brown, flush it down”.
Warm-blooded animals can get sick from the same germs that affect people and dogs, cats, hamsters, and other pets should therefore not drink tap water during a boil water Order. Instead, give your pets bottled water or completely cooled boiled water.
Like in cases of other animals, it is not good for birds to overload their water supply with bacteria and viruses. They already drink from many contaminated sources out in nature, often become ill, and permanently carry germs. You can save them from this plight by filling your bird bath with completely cooled boiled water.
Since birds often carry germs and infect each other at your bird bath, this sanitizing process should become a once or twice monthly part of your routine.
Fish, frogs, snakes, and other reptiles tend to be resistant to the organisms that infect warm-blooded animals, but it is still unhealthy for them to be exposed to high levels of bacteria.
Another problem for fish is that chlorine and chloramines in tap water can make them very sick and kill them. Since your water system might temporarily increase these disinfectants during a boil water advisory, it is better to wait until the advisory is over to fill the fish tank with water from which chlorine has been filtered, like you normally do.
It is safe to water your garden and indoor plants with tap water during a boil water advisory, but this does not apply to food-bearing plants like tomatoes, berries, herbs, and so forth. Water your food-bearing plants with cooled boiled water.
You should not fill a kiddie pool with tap water during a boil water advisory, because kids might get it in their mouths. Even larger pools with salt or chlorine chlorinators should not be filled during this period, because some common organisms like cryptosporidiosis are notoriously resistant to chlorine.
Restaurants must operate according to guidelines provided by environmental health officers to ensure that food and water are safe. The health department of every state has rules for such establishments to observe if they want to remain open, so ask the restaurant about its compliance and the exact rules with which it complies.
If you have drunk the tap water during the boil advisory and develop symptoms, which are usually gastrointestinal ones like diarrhea, abdominal cramps, nausea, and vomiting, visit a doctor to identify the cause of the symptoms. This is especially important in young children, the elderly, and other immune-compromise people for whom infection could become serious.
The immune systems of healthy adults and teenagers can successfully combat the most common water-borne organisms with time, but you must drink enough fluids to make sure you do not dehydrate because of the constant expulsion of food and water.
Your local health authority usually announces the steps to take when the advisory is lifted. If the advisory was precautionary and the water was never contaminated, you usually don’t have to do anything. If the water was contaminated, take the following steps to clean your pipes and appliances:
It is important to keep tap water away from your mouth, your food, and your open wounds during a boil water advisory. For all practices that risk introducing microbiological organisms to the inside of your body, you need to use bottled, boiled, or disinfected water.