Coliform Bacteria in Well Water: Effective Solutions


Drinking water from a contaminated well with coliform bacteria can have a range of negative effects on human health.

While most types of coliform bacteria are harmless, their presence in well water can indicate the possible presence of other harmful microorganisms that can cause illness.

Consuming well water contaminated with coliform bacteria can lead to a range of symptoms, including diarrhea, stomach cramps, nausea, and vomiting.

In some cases, exposure to harmful bacteria can also lead to more serious illnesses, such as hepatitis A, typhoid fever, and dysentery.

Infants, young children, pregnant women, and people with weakened immune systems are at a higher risk of experiencing severe illness from exposure to contaminated water.

In addition to the immediate health effects, long-term exposure to contaminated well water can also have negative effects on overall health.

For example, exposure to certain types of bacteria in well water has been linked to an increased risk of certain types of cancer, including bladder and colon cancer.

In this article, we will discuss the causes and risks of coliform bacteria in well water, as well as solutions for preventing and treating contamination

Coliform – What is it and is it harmful?

While coliform bacteria themselves are not typically harmful, their presence in well water can indicate that other, more harmful pathogens may be present. For example, coliform bacteria are often found in water that has been contaminated with fecal matter or animal waste, which can contain harmful pathogens such as E. coli and giardia.

Exposure to these pathogens (e. coli) can cause a range of health problems, including:

Gastrointestinal Illness: The most common symptoms of gastrointestinal illness include nausea, vomiting, diarrhea, and stomach cramps. These symptoms can be particularly severe in young children, elderly individuals, and those with weakened immune systems.

Hepatitis A: Hepatitis A is a viral infection that can be transmitted through contaminated water or food. Symptoms include fatigue, nausea, and jaundice.

Cryptosporidiosis: Cryptosporidiosis is a parasitic infection that can cause diarrhea, stomach cramps, and dehydration. Therefore, they cause severe degradation to your water quality.

Giardiasis: Giardiasis is a parasitic infection that can cause diarrhea, abdominal pain, and nausea.

What is the mechanism of Coliform entering well water and drinking water?

There are several potential sources of coliform bacteria in drinking water, and it is very likely due to the following few scenarios. The first scenario is whereby the Coliform bacteria can readily enter your drinking water if you reside close to any agricultural regions.

These microorganisms are spread to undesirable locations by irrigation, rain, and melting snow.

This is especially true if the well is shallow or located near a body of drinking water, as it is more likely to become contaminated with the Coliform bacteria from the surface water.

Furthermore, runoff from feedlots or any form of animal waste may also be quite dangerous.

Some other factors that may contribute to the presence of coliform bacteria in your drinking water include the poor construction of the well itself, as it may allow coliform bacteria to enter the well through rain or any sort of natural sources.

Again, it is important to stress that the well should always be sealed properly in order to keep animals away from the well at all times.

If livestock or wildlife have access to the well, they could potentially contaminate the drinking water with their feces.

Additionally, poorly built septic systems, or systems that were not regularly maintained may have leaks or overflows which may contribute to the issue of having coliform to get into your well water as the water could release coliform bacteria into the surrounding soil, which can then cause water contamination.

Coliform Testing for Your Water Supply

We advise coliform testing once a year to keep yourself safe from illnesses and infections. But, if you reside in a high-risk location, more regular testing could be required.

It’s critical that you get in touch with a local water expert right away if you see any of the following: an abrupt shift in the water quality, including its flavor, color, and general appearance; flooding close to the wellhead; members of the family who exhibit inexplicable symptoms like vomiting, diarrhea, or fever, or Your septic system need repair or upkeep.

We also advise more regular testing and enhanced awareness if your well is 50 feet or less from a farm or septic system. Although testing kits are easily accessible, they are not always reliable.

The only person you can rely on to do an exhaustive water test is a trained professional. It’s crucial for well owners to collaborate with a knowledgeable water firm. Since 1993, Hague Quality Water has provided consumers with water treatment solutions.

Additionally, each of our devoted professionals has received certification from the Water Quality Association (WQA). We’ll work with you to get rid of any pollutants, viruses, or hazardous microorganisms that are discovered.

The pure water you adore can then be enjoyed once more.

Prevention methods for getting Coliform Bacteria in Well Water

There are several steps that homeowners can take to prevent total coliform bacteria contamination in their well water, including:

Regular Testing: Regular testing of well water is essential to ensure that it is safe for consumption. Testing should be done at least once a year, and more frequently if there is a suspected problem.

Proper Well Construction: A well should be properly constructed to prevent water contamination. This includes ensuring that the well is properly sealed and that the casing extends above ground level.

Protection from Animals: The area around the well should be protected from animals, including livestock and wildlife. Fencing can be used to prevent animals from accessing the well.

Regular Maintenance of Septic Systems: Septic systems should be regularly maintained to prevent leaks and overflows.

Treatment Options for Water Contaminated with Coliform Bacteria

It’s critical to take action right away if you’ve just learned that your well water contains fecal coliform bacteria. Consider buying bottled water while you wait to be treated appropriately.

To eliminate coliform and E. coli, you can also boil your water for one minute at a full boil. Then, this supply can be kept for later use.

There is no reason to panic, even though coliform is a worry. If the appropriate treatment options are used, this issue can be solved as there are several water treatment options available.


Chlorination is a common method used to treat well water contaminated with fecal coliform bacteria. Chlorine is a strong oxidizing agent that is effective at killing harmful bacteria, viruses, and other microorganisms that can be present in drinking water.

When chlorine is added to water, it reacts with organic matter and microorganisms to form compounds that can disinfect the water and eliminate harmful pathogens.

The chlorination process involves adding chlorine to the water supply at a controlled rate to achieve the desired level of disinfection.

Chlorine can be added to water in several ways, including as a gas, liquid, or solid.

The type of chlorine used and the dosage rate will depend on the specific contaminants present in the water and the desired level of disinfection.

One of the advantages of chlorination is that it is relatively easy to implement and maintain. Chlorine is readily available and can be easily added to the water supply using a variety of equipment, such as injectors or feeders.

However, it is important to note that over-chlorination can cause health problems and can also result in the formation of harmful disinfection byproducts (DBPs) such as trihalomethanes (THMs) and haloacetic acids (HAAs), which are linked to cancer and other health issues.

UV Disinfection

UV disinfection is a highly effective and popular method used to treat well water contaminated with harmful bacteria.

UV light disinfection uses high-intensity UV light to kill microorganisms, including harmful bacteria, viruses, and parasites, by disrupting their DNA and preventing them from reproducing.

UV disinfection is a simple and easy-to-use technology that requires minimal maintenance and does not introduce any chemicals into the water supply.

It is also effective at eliminating many different types of microorganisms, including those that may be resistant to chemical disinfectants.

To ensure effective UV disinfection, it is important to properly size and install the UV system and to regularly maintain and replace the UV lamps to ensure they are providing the correct level of UV output.

It is also important to regularly monitor the water quality to ensure that the UV system is providing adequate disinfection and that coliform bacteria and other microorganisms are being effectively eliminated.


Filtration is a common treatment method used to remove coliform bacteria and other contaminants from well water.

There are a variety of filtration systems available, ranging from simple, point-of-use filters to more complex, whole-house filtration systems.

Filtration systems work by physically trapping or adsorbing contaminants as water passes through a filter medium.

The filter medium can be made from a variety of materials, including activated carbon, sand, ceramic, and other materials. The size of the filter pores will determine the types of contaminants that can be removed from the water.

In general, filtration systems are effective at removing sediment, particulates, and some types of bacteria and viruses.

However, not all filters are equally effective at removing all types of contaminants, and it is important to choose a filter that is specifically designed to remove the contaminants present in your well water.

In addition to choosing the right filter medium, it is also important to properly maintain the filtration system to ensure that it continues to effectively remove contaminants from the water.

This may involve periodic cleaning or replacement of the filter media, as well as regular testing of the water to ensure that the filtration system is working effectively.

Overall, this method is also considered an effective treatment method for removing coliform bacteria and other contaminants from the well water in general.


Coliform bacteria are a common concern for homeowners who rely on well water for their drinking water supply.

While coliform bacteria themselves are not typically harmful, their presence in well water can indicate the presence of more harmful pathogens that can cause a range of health problems even in your bottled water.

Preventing and treating coliform bacteria contamination in well water requires regular testing, proper well construction, protection from animals, regular maintenance of septic systems, and water treatment options if contamination is detected.

By taking these steps, homeowners can help ensure that their well water is safe and free from harmful contaminants.


How much does it cost to treat well water contaminated with coliform bacteria?

The cost of treating well water contaminated with coliform bacteria will vary depending on the treatment method used and the severity of the contamination.

For example, chlorination is a relatively inexpensive treatment method, with costs ranging from $50 to $200 for materials and installation.

On the other hand, UV disinfection and filtration systems can cost several hundred to several thousand dollars to install, depending on the size and complexity of the system.

How long does it take to treat well water contaminated with coliform bacteria?

The length of time it takes to treat well water contaminated with coliform bacteria will depend on the treatment method used and the severity of the contamination.

Chlorination is a relatively quick treatment method and can be completed in a matter of hours.

UV disinfection is also a relatively quick treatment method, with most systems able to treat water in a matter of seconds or minutes.

Filtration can take longer to treat water, especially if the water contains high levels of sediment or other contaminants, and may require regular maintenance and filter replacement to maintain effectiveness.

What are some quick ways to disinfect my drinking water for emergency disinfection?

Shock chlorination is a process of using high doses of chlorine to disinfect water systems such as tanks, wells, and distribution systems. It is usually performed when there is confirmed evidence of microbiological contamination in the water supply.

This method is effective in killing harmful microorganisms and bacteria that may pose a risk to human health and cut down total coliform levels.

The process of shock chlorination involves introducing a concentrated chlorine solution into the water system.

The chlorine solution used in shock chlorination can come in various forms, including granular or liquid. For disinfection, liquid household bleach is commonly used as the source of chlorine.

It is important to note that proper safety precautions should be followed when performing shock chlorination. Protective gear such as gloves and goggles should be worn, and the area should be well-ventilated.

The chlorine solution should also be handled with care, as it is a corrosive substance and can cause harm if ingested or inhaled.

After the shock chlorination process is complete, the water system should be thoroughly flushed to remove any excess chlorine.

It is recommended to test the water quality to ensure that the chlorine levels are within safe limits before using the water for drinking or other purposes.

Shock chlorination is an effective method for emergency disinfection of water systems that have been contaminated with harmful bacteria and microorganisms.

Are there any ongoing costs associated with treating well water contaminated with coliform bacteria?

Yes, there may be ongoing costs associated with treating well water contaminated with coliform bacteria.

Chlorination may require regular monitoring and occasional adjustment of chlorine levels, as well as periodic replacement of chlorine tablets or solution.

UV disinfection systems may require periodic replacement of UV lamps to maintain effectiveness, and filtration systems may require regular filter replacement or maintenance to ensure optimal performance.

It is important to factor in these ongoing costs when considering water treatment options for well water contaminated with coliform bacteria.

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