Viruses can easily contaminate our water supply and remain infectious for up to 10 months. Ideally, viruses should be removed from your water before you drink it, but not all water filters or purifiers can remove viruses from water.
Distillation, nanofiltration, reverse osmosis and UltraViolet water treatment systems remove viruses from water. Ultrafiltration systems can also be moderately effective at removing viruses, depending on the pore size of the filter,
This article contains all the information you need to know about waterborne viruses and HOW to remove them. There is also detailed information about the different types of viruses and how long they can survive in water and remain infectious – with some viruses able to survive up to 300 days!
First, let’s cover how viruses get into our water and how to remove them.
Can water filters remove viruses?
Viruses make their way into our water supply through contaminated water – usually water that is contaminated with feces.
There are many ways that feces can enter our water, but the most common ways are:
- Agricultural runoff
- Sewage overflows
- Sewage systems that are not working properly
- Polluted storm water runoff
Unbelievably, just 1 oz of feces from an infected person can contain as many as 280,000,000,000 viruses.
It’s scary to think about how contaminated our drinking water can actually be! Not only that, but fecal contamination is also responsible for introducing nasty bacteria to your drinking water!!
In fact, nearly 25% of the world’s population is drinking fecally-contaminated water!Ref7
So, it is perfectly natural to want to purify your water so that not only do you have peace of mind, but more importantly clean water to drink.
Unfortunately, the majority of water filters and purifiers on the market can’t remove viruses from water. Especially counter-top systems or faucet-mounted filters.
Check out the list below to find out which filters and purifiers are able to remove viruses – then keep reading to find out which ones just remove viruses and which ones are able to kill them.
|Method of filtration or purification||Removes viruses|
|Ultrafiltration||✘ / ✔|
Distillation is amazing at removing viruses, and not just viruses either. This method of water purification removes a ton of other nasty things you don’t want in your water.
The reason distillation is so effective at removing viruses from water is because the water is boiled.
During the distillation process, water is heated until it boils and turns to steam. This steam is then collected, and cooled back into liquid water – ready for you to drink.
Now, most contaminants, such as metals or chemicals, are simply left behind when the water turns to steam. But not viruses. Distillation doesn’t just remove viruses it KILLS them.
So not only will distillation remove
But it will kill
and most importantly
A good advantage of distillation is that they are available to buy as both large systems or small on-the-counter ones. Just remember not to let the treated water sit for too long in the storage tank, otherwise bacteria can start to grow in it.
Nanofiltration is 1 of only 2 water filtration systems that are able to remove viruses from water. All the other systems are water purifiers (e.g. distillation and UltraViolet systems) that don’t rely on filters, but use other methods to kill viruses.
According to the CDC…
Nanofiltration is highly effective at removing viruses from water because of the filters small pore size.
Nanofilters usually have a pore size of 0.001 micron – Although they can vary filter to filter by up to 0.01 micron.
This small pore size stops the virus from passing through the nanofilter as the water flows through.
But not all nanofilters are created equal. The National Sanitation Foundation (NSF) only certifies nanofiltration systems that are actually able to remove viruses from water.
So, if a nanofiltration system claims to remove viruses then it should carry NSF certification 244 (NSF-244). That way you know that not only is the pore size of the filter the correct, but you know that it has passed the NSF testing at actually removing viruses!
NSF testing is not mandatory, but I figure if a company truly believes in their product then they will take the time to get certified, and to reassure the public that their product is as good as what they claim it to be.
If you are interested in using a nanofilter at home to treat your water and remove viruses then I recommend this filter pitcher. I really like drinking cold water as I find it more refreshing, so I really like this pitcher because I can keep it in the fridge.
Plus, it’s certified to remove viruses from water, which is super rare – usually it’s just point-of-use or point-of-entry systems that get certified.
Ultrafiltration is a tricky one. While this method can remove some viruses, it can’t remove all of them.
In fact, the CDC says…
Don’t get me wrong… a ‘moderate effectiveness’ is better that not being effective at all. But, you want to be able to trust your water purification system and more importantly trust the water you are drinking is clean and safe.
Ultrafiltration just doesn’t tick those boxes.
If, like me, you want peace of mind then I would choose one of the other ways to remove viruses, which are:
- Reverse osmosis
If you prefer the filtration method of removing viruses, then nanofiltration or reverse osmosis is the way to go. But if you want to kill the viruses then best to pick distillation or UltraViolet water treatment.
Reverse osmosis systems are one of the absolute best ways to purify water. These systems get rid of just about anything – feel free to check out this post I wrote about all the things they remove (and the 3 things they don’t).
Reverse osmosis systems are able to remove such a large range of contaminants, including viruses because of the incredibly small pore size of the semi-permeable membrane.
According to the CDC…
That means the semi-permeable membrane of a reverse osmosis system has a pore size 10 times smaller than a nanofilter.
It’s hard to imagine anything making it through a reverse osmosis system… except for water of course.
Reverse osmosis systems should carry NSF-244 certification, as this means they have been tested by the NSF and can definitely remove viruses, including…
- Enteric viruses
- Hepatitis A
Ultraviolet germicidal irradiation (UVGI) disinfects water by using UltraViolet light.
While there are 3 types of UltraViolet (UV) light:
It is UVC-light that is the most harmful to viruses. It is so harmful in fact, that it can kill any viruses (and bacteria) that are in water.
The UVC light is so potent that it kills viruses at a DNA level, completely disrupting their ability to function or repair themselves.
Just like nanofiltration and reverse osmosis systems, UltraViolet water treatment systems should be certified by the NSF to prove they can actually kill viruses.
Under the NSF these systems are called ‘UltraViolet Microbial Water Treatment Systems’ and have NSF/ANSI 55 certification.
These are labeled Class A systems.
Both large residential systems and small portable UltraViolet water treatment systems use UVC to disinfect water and can be NSF certified, so you can rest assured both are able to kill any viruses in your drinking water.
If you want to protect yourself and your family from dangerous viruses that live in water then I would purchase an UltraViolet water treatment system. I recommend this UltraViolet system from Amazon (affiliate link), because it has the NSF-55 certification (be careful as a lot on the market do not carry this certification). Click on the image below to get it from Amazon.
Alternatively, if you would like a portable UltraViolet system, so that you always know your water is safe to drink no matter where you are, then I would grab a Steripen. Steripen has been a trusted name in water purification for decades and this is a really good one that is available on Amazon – click on the image below to head over to Amazon (affiliate link).
What viruses can you get from water?
A large number of viruses are waterborne – which means they can survive in water and infect anyone that drinks it.
As we discussed earlier, waterborne viruses typically enter our water supply through fecal contamination! That’s right – from feces being in our drinking water supply. Which is a totally disgusting thought!
Currently, there is no way to test for viruses in water. But, you can test for fecal contamination by testing for fecal coliform. Fecal coliform is a bacteria that is found in almost all mammal feces.
So, by testing for fecal coliform, you can find out if your water is contaminated by feces, the very thing that introduces viruses to water in the first place – and then you know not to drink it!
I recommend this test from Amazon (affiliate link) because not only does it test for fecal coliform, but it is actually affordable… unlike some others on the market, and it has great reviews. Click on the image below to get it from Amazon.
But even if you choose not to test your water, you have good reason to worry that your water might not be safe to drink.
Water spreads these viruses, which are able to infect anyone that drinks the water, or even touches it and then touches their eyes, nose or mouth.
The most common viruses you can get from water are:
- Hepatitis A
- Hepatitis E
- Meningitis (viral)
Adenoviruses are really common. According to the CDC, they cause any of a number of symptoms, including cold-like symptoms, bronchitis, diarrhea, fever, sore throat, pneumonia, and even PINK EYE!!! (conjunctivitis).
While adenoviruses are waterborne, it is more likely you would get infected by breathing in another persons sneeze or cough, or touching surfaces or people with adenovirus on them and then touching your own face.
So… don’t touch your face.
Human astrovirus is a nasty virus that causes serious bouts of diarrhea.
Even worse is that it is a major cause of acute diarrhea in children worldwideRef1. Although it can cause vomiting, headaches and fever as well.
Astrovirus appears just 2-3 days after infection, but thankfully it also only lasts 2-3 days.
Enteroviruses are actually a group of viruses, which is made up of 2 different groups of viruses:
- polio related
- non-polio related
The poliovirus is very contagious and usually infects people through contaminated feces. In fact, according to the CDC…
Thankfully, there are vaccines for poliovirus and after they began immunizations across the U.S. in 1955, it wasn’t long before Polio was completely eliminated from the U.S. by 1979.
So, you don’t really have to worry about getting poliovirus from your drinking water. But what about the non-polio related enteroviruses?
Well, unfortunately the non-polio enteroviruses are the viruses to be concerned about. Because…
These enteroviruses are found everywhere in the U.S., and across the world.
Enteroviruses can be found in all water supplies, but especially in wells. In fact, these viruses can be in any water that is contaminated by feces.
Remember, feces can enter the water supply by:
- Flood waters
- Sewage overflows
- Sewage systems that are not working properly
- Polluted storm water runoff
Hepatitis A is actually a contagious liver disease! The disease caused by the hepatitis A virus can last for a few weeks or a few MONTHS!
Hepatitis A is found across the U.S. and just like enteroviruses enter our water supply through contaminated feces.
The hepatitis E virus (HEV) is also a liver disease. But thankfully HEV is super rare in the U.S. Which is good news, since HEV causes:
- Loss of appetite
- Abdominal pain
- Dark urine
- Clay-colored stool
- Joint pain
And even death! Although, during an outbreak the case mortality rate is just 1%
There is actually a bacteria, viral and fungal form of meningitis!
However, viral meningitis is the most common type – but, fortunately it is less severe than bacterial meningitis.
Meningitis is inflammation of the lining of the brain and spinal cord. So, ‘viral meningitis’ just means it is inflammation caused by a virus (rather than bacteria or fungi)
The most common cause of viral meningitis is the non-polio related enteroviruses! It is also possible to get viral meningitis from the mumps, measles and flu viruses, but enteroviruses account for the vast majority of viral meningitis cases.
According to the CDC , the common symptoms of viral meningitis are:
- Stiff neck
- Eyes being more sensitive to light
- Sleepiness or trouble waking up from sleep
- Lack of appetite
- Lethargy (a lack of energy)
You may have heard of norovirus by its old name – “Norwalk-like viruses” or NLV.
Noroviruses cause gastroenteritis, which is an intestinal illness.
Noroviruses are common across the whole of the U.S. and found in all sorts of water supplies – especially towns on groundwater or domestic wells.
Even though noroviruses are found in fecal contaminated water, they are responsible for outbreaks on cruise ships and in restaurants, camps and schools. That means our drinking water can become contaminated no matter where it is sourced from.
These viruses got their name because they are wheel-shaped (“rota-“).
According to the CDC, rotavirus causes…
Thankfully in 2006, the rotavirus vaccine was introduced across the U.S. and drastically reduced infection rates. Which is a great thing, because rotaviruses still cause more than 600,000 children to die each year around the world.
Like most other waterborne viruses, rotavirus enters our water supply by fecal contamination. Something, I am sure we would all like to avoid.
As well as the waterborne viruses there are insect-borne diseases that are associated with water, such as Dengue Fever. Dengue Fever is transmitted by mosquitoes that carry the Dengue virus!
The CDC says dengue fever causesRef1
- Aches and pains
But severe dengue fever can cause shock, internal bleeding and even death.
How long do viruses live in water?
Viruses are only ever truly alive when they are living inside a host that they have infected. ‘Hosts’ come in the form of living cells – such as those belonging to humans.
So the real question isn’t how long do viruses live in water, but rather how long can a virus survive in water – without a host for it to infect?!
Well, like most things in life… it depends.
It depends on the
- Type of water
- Temperature of water
- Type of virus.
1. Type of water
Viruses survive for different amounts of time in different types of water, including disinfected tap water, surface water (e.g. rivers) and salt water. That’s because different types of water have different properties and microorganisms.
Take the salt in seawater for example. The salt is thought to result in a much faster reduction in infectious viruses, as opposed to freshwater, which has barely any salt in it.
Or take the microorganisms that live in our freshwater. The presence of microorganisms in our rivers and lakes has been shown to drastically reduce the survival time of a virus in water.
But this also means that disinfected water allows viruses to survive much longer. This is because all of the helpful microorganisms are killed during the disinfection process at our water treatment plants.
Unfortunately, that also means that if our water supply becomes contaminated with infected feces AFTER the treatment plants have disinfected our water then viruses would thrive, survive and spread much more efficiently – and could pose a real threat to public health.
Let’s hope that doesn’t happen!
2. Temperature of water
The temperature of the water also affects how long a virus can survive.
The cooler the water the longer a virus will survive. This is called a temperature effect.
It means the decay or true death of a virus is much faster at high temperatures.
And I’m not talking about extreme temperatures. Water at just 40°F (4.4°C) will allow viruses to survive for an incredibly long time. Whereas water temperatures of 68°F (20°C) will destroy a virus quite quickly.
Now we come to the most important factor in how long a virus will survive.
3. Type of virus
Check out the table below for a list of the most common types of waterborne viruses and how long each can survive in water – as tested by scientists at 68°F in freshwater.
|Virus||Survival time in water||Reference|
|Enterovirus (Poliovirus 1)||41 days||2|
|Hepatitis A||56 days||2|
|Hepatitis E||56 days||4|
*Adenoviruses are a group of viruses, where the survival time of each virus in water varies, with most surviving between 92 and 304 days.
How do you remove bacteria from water? Distillation and UltraViolet water treatment systems are the only devices able to kill bacteria and remove them from water. UltraViolet systems that can remove bacteria have NSF/ANSI 55 certification. Other methods capable of removing some bacteria from water include boiling, and the addition of iodine or chlorine. Get the full answer to how to remove bacteria from water here.
Do water filters remove amoeba? Water filters that have NSF-53 or NSF58 certification are able to remove amoeba from water. Other water filters that have an absolute pore size of 1 micron or smaller can also remove amoeba. For all the information on amoeba in tap water and which brands of filters can remove amoeba check out this detailed post.
1Jeong, H. S., Jeong, A., & Cheon, D. S. (2012). Epidemiology of astrovirus infection in children. Korean journal of pediatrics, 55(3), 77.
2Enriquez, C. E., Hurst, C. J., & Gerba, C. P. (1995). Survival of the enteric adenoviruses 40 and 41 in tap, sea, and waste water. Water Research, 29(11), 2548-2553.
3Abad, F. X., Pinto, R. M., Villena, C., Gajardo, R., & Bosch, A. (1997). Astrovirus survival in drinking water. Appl. Environ. Microbiol., 63(8), 3119-3122.
4Parashar, D., Khalkar, P., & Arankalle, V. A. (2011). Survival of hepatitis A and E viruses in soil samples. Clinical Microbiology and Infection, 17(11), E1-E4.
5Ngazoa, E. S., Fliss, I., & Jean, J. (2008). Quantitative study of persistence of human norovirus genome in water using TaqMan real‐time RT‐PCR. Journal of Applied Microbiology, 104(3), 707-715.
6Raphael, R. A., Sattar, S. A., & Springthorpe, V. S. (1985). Long-term survival of human rotavirus in raw and treated river water. Canadian Journal of Microbiology, 31(2), 124-128.
7Gall, A. M., Mariñas, B. J., Lu, Y., & Shisler, J. L. (2015). Waterborne viruses: a barrier to safe drinking water. PLoS pathogens, 11(6).