Do Water Filters Remove E Coli? | Find Out The Facts

Written by Tim Rhodes Last Updated: Sep 4, 2024

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Water filtering is extremely important to prevent diseases and contamination by toxins, but do water filters remove E coli? 

Although we all know filtering water is essential to our well-being, many of us are not quite so clear on what the filters themselves remove.

A good water filter can remove impurities and make your water taste, smell, and look better, but the question remains – do water filters remove E coli?

It can also deactivate and eliminate living organisms that might be harmful to human beings and animals.

Among them a very common bacteria, that can be found in many places but at the wrong place at the wrong time can cause severe consequences.

With so many models and kinds of water filters available in the market, it’s only natural that we start by understanding how filtration works and what are the water filters available out there.

How Do Water Filters Work?

Water filters usually offer a physical or chemical barrier to contaminant particles present in the water.

There are many different methods to achieve that.

Some methods are as simple as a DIY project you can do at home or if you enjoy being outdoors, you could use these DIY methods while hitchhiking or camping, for example.

Some other methods are more complex and after years of development, many companies have come up with more effective and advanced technology.

But it’s important to know that there’s not a single filtering method that works fast and could guarantee 100% of the purity of your water.

That is because different kinds of particles you’re trying to filter have not only different sizes but also have other characteristics, which make them react differently to different chemicals and processes.

For example, sand particles have 0.8 millimeters to 1.25 millimeters in diameter.

While bacteria are between 1 to 2 micrometers long.

That is almost 1000 times smaller than sand particles.

To clean the water from both bacteria and sand particles, filters have to be fine enough to trap both these molecules.

But that would mean a lot of problems with clogging the pores from the filter and with bacteria accumulation.

One of the main concerns households have when it comes to pathogens in the water regards a group of bacteria called E. coli, very common everywhere (in fact, you most probably have many of them in your body doing just fine) but that could potentially bring diseases.

What Is E. coli?

E. coli stands for Escherichia coli and it’s one of the most common groups of bacteria present in foods, water, the environment, animals, and humans.

It’s often found in the intestines of humans and animals to help with the regulation of our guts.

Rainfalls, hurricanes, strong winds, and other precipitations can cause the bacteria to end up in rivers, lakes, and other water sources.

When a large quantity of it is constantly found in the same water supply, though, it could be a clear indication of sewage or animal waste being disposed of near or inside that water source.

Most of the bacteria E. coli are harmless to humans, but there are rare types that release a toxin and cause diseases that affect the blood and other parts of the body.

E. coli contamination can cause bloody stools, severe anemia, traveler’s diarrhea, and even kidney failure in extreme cases.

Most cities make use of disinfectants like chlorine to eliminate E. coli and other bacteria at their water treatment plants.

But it’s a long way from the water plant to your house and your water could be contaminated through the pipes by then.

Although in most of the developed countries it’s very safe to drink water fresh from the tap, you can find purifying methods that fit your budget and give yourself and your loved one’s extra protection.

How To Detect E. coli In Water?

The bad news is that E. coli has no taste or smell, so you probably wouldn’t be able to detect it by yourself.

You would need to send a sample of water to a laboratory to be analyzed and the results would be back in a few days.

Faster tests are being developed, though

Some of them work like the universal indicator strips you may remember from measuring the pH of different solutions back in your high school chemistry class.

These tests would make it possible for you to know if your water is contaminated in a few minutes just by observing the color change of the special paper.

But unfortunately, it doesn’t seem like the tests have made it to market just yet.

The good news is it’s not very hard to eliminate E. coli from water.

How Do You Eliminate E. coli From Water?

One of the safest and simplest methods would be to simply boil your water.

Boiling water not only kills bacteria but viruses and other living pathogens that might be present in it.

The one thing that boiling water doesn’t do is to remove or neutralize some chemicals from the water.

So many households prefer to have their water filters.

They come in many styles and sizes.

Some water filters can even be installed directly on your tap so you wouldn’t have to refill it now and then, making them very convenient.

What Kind Of Filters Eliminate E. coli?

Here are some kinds of filters and other water purification products you can buy and use at home: 

Ultraviolet Water Purifiers

These types of water purifiers use a special lamp that emits UV light in your whole house’s water supply and deactivates living organisms like bacteria and viruses.

The purifier is a cylinder that you attach to your main water supply pipes.

Inside a cylinder, there’s a UV lamp that emits radiation specifically targeting microbes.

This radiation uses a wavelength of light which is too short for your eyes to see it, but that destroys the DNA of these microorganisms, stopping them from reproducing.

Even though we say radiation, you don’t need to worry about making your water radioactive.

Ultraviolet is a type of light that has enough energy to destroy living organisms, which is why you should always remember to wear your sunscreen, but it does not leave any particle of radiation lingering in the water afterward.

The UV lamp needs electricity to work, so the purifier will be inactive for as long as you run out of power.

Can UV Filters Eliminate E. coli?

Yes, it’s an extremely effective method for eliminating E. Coli and other pathogens that might be present in the water.

While this method is effective at killing microbes, it can’t substitute filtering.

The UV doesn’t affect non-living particles or chemicals.

It also doesn’t remove (or add) odors, or bad taste from water.

Therefore it’s very safe to use, as long as you don’t get in direct contact with the UV light inside of the purifier.

But to improve the taste and remove chemical impurities, you would have to use it in association with a water filtering system.

Overall, UV could be a good substitute for using chlorine as water treatment, as it doesn’t present any danger for human consumption.

Portable UV Light Purifier

You could also get a portable option that wouldn’t require any installation or electricity from the wall to run.

The portable option is just like a common flashlight.

It works like a miniature version of the bigger cylinder you would install at your home.

The small size makes it perfect for you to bring it with you in your purse or your backpack.

To purify your water, you just have to place it inside your water glass or bottle, turn it on and wait for the recommended amount of time.

It usually takes less than 1 minute and then you have water ready to drink.

It’s simple as that and it’s perfect to take with you on a trip to a city where you don’t know if it’s safe to drink from the tap.

It’s also a favorite among people who enjoy outdoors, such as campers and hitchhikers.

Reverse Osmosis

Reverse Osmosis filters work using the natural pressure of your water supply.

It pushes the water through a semi-permeable membrane that removes contaminants from it by only letting the water particles through because they are smaller than the contaminants particles.

This system can filter many chemicals, sediments, bacteria, and viruses.

It’s a more complex and complete method and can have 3, 4, or 5 stages of filtration.

The standard ones coming with at least three basic stages.

The first stage is a sediment filter, which will filter out solids from the water.

The second stage is a carbon filter, responsible for filtering out most chemicals that could be present in it, such as chlorine, herbicides, and other substances that could be poisonous or otherwise harmful in high enough doses.

The third stage is the membrane.

This one would filter out larger molecules, like viruses and bacteria, removing up to 98% of dissolved solids from your water.

If your water comes from a private well, you have the option to add other personalized components to your filtering system depending on the exact composition of the water from your well.

It will all depend on your needs.

This system can change the color and the odor of what you’re drinking.

Simply because it removes salts, sand, chlorine, herbicides, heavy metals, among many others.

This often also improves the flavor of your water, although some people do prefer the flavor of water with some minerals in it.

Tips To Maintain Your Reverse Osmosis System

You have to be careful and keep your system always well maintained.

If the membrane is not properly working, it can cause bacteria to deposit on it which would contaminate your water.

You’ll know when the membrane is not working properly because your system will slowly decrease in the production of water.

As soon as you notice any changes in the quantity of water coming out of your tap, you should have your system checked.

With good maintenance, your system could last you from 10 to 15 years.

To keep it well-maintained, you can:

• Replace your filters every 6 months or 1 year, per the manufacturer’s recommendation
• Drain your Reverse Osmosis Tank every 2 week
  
• Sanitize your tank every year – there are special products you can buy for this purpose

If you need any help or if you notice any change in the water production, you can always schedule a maintenance visit with your filter’s provider or contact your local water treatment professional.

Activated Carbon Filter (ACF)

The Activated Carbon Filter is made of a special kind of powdered carbon designed to have a very large surface area that absorbs the contaminants in the water.

It’s specialized to clean it from pesticides, herbicides, and other chemicals.

By using chemical absorption, it traps contaminant molecules in between and inside of its molecular structure.

It’s very helpful in eliminating the bad odor and taste from water.

They can be made of different types of materials.

The most common are wood-based media and coconut shell media.

Wood-based media is based on finely ground and burned wood.

This media was used in Ancient Egypt nearly 6,000 years ago.

Now the coconut shell media is the most eco-friendly one.

Because it uses the coconut’s harder exterior, it doesn’t cause any allergic reactions or leaves any sort of odor behind.

Can Activated Carbon Filters Eliminate E. coli From Water?

By itself, unfortunately, no.

Because of its molecular structure, pockets of stationary water can form inside the filter.

These pockets would then become the perfect environment for bacteria to grow and reproduce.

It’s important to notice that this applies to the vast majority of the activated carbon filters.

Although some filters are certified to eliminate coliforms, like E. coli.

Some companies also allow you to attach components to your filter, such as ones containing specially designed nano silver material which helps to kill microbes on contact.

When it comes to bacteria, Activated Carbon is not as safe of a method as UV light, for example.

Ceramic Filters

Ceramic filters are one of the oldest water filtering methods available in the market.

It uses the small pores on ceramic surfaces to slowly trap sediment and bacteria out of the water.

Its two main parts are the upper part where the water is filtered and the bottom part, which is used to collect the drinkable water.

It has a 0.5-micron filtration pore size, it’s inexpensive and it’s very easy to maintain.

For this reason, it’s ideal to be used in developing countries.

There are a few kinds of these.

Types of Ceramic Filters

• Pot-type 

Water is poured into the ceramic pot from the top and as it passes through the pores, it collects clean water in the container just below. 

After this, it’s ready for consumption.

• Candle-type

In this model, there’s a “candle” added to it.

And although they kind of look similar, it’s not like a traditional candle.

These are made of clay and placed inside the top part of the filter.

Whereas in the pot type filter the water is filtered by the bottom of the upper container, in a candle-type the water flows and is filtered through the sides of the candle(s) placed in the upper container.

This candle can have activated carbon to enhance the purification process.

It can also have colloidal silver added to it to stop bacteria from growing in it.

• Portable type

Ceramic filters can also come in a portable size.

It’s perfect for campers and hitchhikers.

Most of the models attach directly to a water bottle opening for immediate filtration, so you can safely drink directly from the filter.

There are also ones integrated into the straw so that you can drink directly from any water source.

Maintenance of Ceramic Filters

It’s very important to keep your filter always clean.

But for that, you’ll only need water and a plastic brush or some sort of cloth.

You should never use metallic brushes, sponges, or scrubbers since that could damage the pores of the ceramic.

If the filter hasn’t been used for two days you should dispose of the old water and change it and refill the filter.

Be careful when cleaning the candles, they are made of very delicate material and can easily break.

If they fall and didn’t visibly break, you can do a simple test to check for invisible damage.

Simply put the candle underwater and place your finger over the outlet.

If bubbles appear then you should replace the damaged candle.

Water Distillers

A water distiller boils the water, takes the steam, and then condenses it into a cleaner, more drinkable, and safer type of water.

The boiling process eliminates all bacteria and viruses, as well as other contaminants in the liquid.

The Process

Water first goes into a boiler equipped with a heating element.

Once the temperature rises, it kills all microbes that might be present in it.

The steam then proceeds to the condenser, which is also attached to a carbon filter.

It’s then transformed back to water ready for consumption.

Disadvantages Of Water Distillers

Firstly, although it’s just about the purest water you could get from home, the whole process is quite slow.

For countertop distillers that you’d get for your kitchen, the purification can take from 4-6 hours to produce a gallon of water.

Another disadvantage of countertop distillers is that they have a small water reserve.

It requires you to manually replenish the water every time a batch is finished.

This doesn’t apply to industrial-sized distillers, which can produce up to 12 gallons per machine in its reservoir.

Larger distillers with larger reservoirs are also usually automated to constantly work and replenish the water reserve by itself.

Due to its purity, distilled water can make drinking water very dull.

It is tasteless to most people.

If you don’t like drinking water, this might not be the best method for you.

Another major disadvantage of this method is the amount of energy needed to process each liter coming out.

The heating element requires a lot of electric power, which might affect your electric bill at the end of the month.

How To Remove E. coli If I Don’t Have A Filter Available?

If you find yourself in an emergency and if you don’t know if the water supply (a lake, a river, or just tap water) is safe for consumption, there are a few things you can do.

Boiling

Boiling is the easiest and safest way to clean any harmful contaminants and make water safe for consumption.

For this, you’d have to be sure to have a lighter or any other device to light up a fire.

Purification Tablets

Purification tablets are inexpensive and although they don’t leave a good taste in the water, they manage to make it safe for consumption.

Make sure you have a few if you’re going out there to the wilderness or to a city you’re not sure about the safety of the tap water.

Rainwater

If you don’t have any of these, try to collect and drink rainwater.

It’s the safest option and it would be almost impossible to find E. coli in it.

Final Thoughts

We hope we answered the question – do water filters remove E coli.

The most cost-effective way to eliminate E. coli is by using a UV purifier.

You can get these for your whole house or a portable one to take with you wherever you go.

These purifiers don’t filter the water, though.

But if you live in an urban area with access to water that your city has treated beforehand, a UV purifier should be just fine.

For people who live in rural areas or have their well, if associated with a filtering system like Reverse Osmosis, for example, the UV purifier would be just as ideal.