Coliform Bacteria in Water: Safe Levels for Well Water, Spring Water, Pools & Drinking Water

We all know that clean water is a must to be as healthy as possible. If we don’t pay attention to the cleanliness of our water, waterborne diseases and sickness are possible. Out of all of the potential bacteria that may exist in your water, one common type is coliform bacteria.

Coliform bacteria are a type of bacteria that are usually present in soil, wells, springs, pools, and surface water. Coliform bacteria are also present in human and animal feces as well as in the gastrointestinal tract of many organisms.

Is Coliform Bacteria in Water Dangerous?

The presence of coliform bacteria in drinking water typically does not cause illness on its own. Different species of coliforms are present in the environment all around us, as well as within our bodies. When water is tested for the presence of coliforms, it is often measured as “total coliform bacteria.” Negative or low levels are often not cause for concern. However, detecting moderator to high levels of coliform bacteria in your water may signal a greater problem.

Coliform as an “Indicator Organism”

As the name suggests, coliform bacteria can function as an indicator organism. The presence of coliform bacteria raises suspicions that other disease-causing bacteria may also be present.

Water first becomes contaminated with coliform bacteria when a contaminated source is introduced. This might be from surface runoff that introduces animal or human waste into the water supply. It could also be caused by a nearby septic system that is failing, as may be the case with older residential septic tanks.

By detecting coliform bacteria in your water, it may indicate that other, more harmful bacteria could be present. Coliform bacteria serve as an indicator that the water has likely been contaminated with unclean runoff or waste.

Can coliform bacteria in water affect your health?

Aside from its utility as an indicator organism, readers are typically interested in learning whether the presence of coliform bacterium in water can be directly harmful to their health. Many also wonder what symptoms may result from drinking water that contains coliforms.

As discussed earlier, most of the time coliform bacteria does not directly impact human health. Many species of coliforms are not dangerous. However, there are some disease-causing strains that can be harmful.

If disease-causing bacteria are present in water, common symptoms including gastrointestinal tract infections, general abdominal pain, fever, diarrhea, and abdominal cramps may result.

Interestingly, people often become immune to drinking contaminated water in their own household by developing immunity against the strains of coliform bacteria that are present in their drinking water. However, problems arises when guests drink the contaminated water and develop symptoms.

Besides general, mild infections, more serious illnesses are also possible, including:

1. UTIs

E. coli is can be a very dangerous disease-causing bacteria. A person that drinks contaminated well water has the possibility of developing an infection of E. coli in the urinary tract.

Getting E. coli can result in various health problems, specific pain in the pelvis, and difficulty in urination. Consult with a health professional in this case.

2. Typhoid

Typhoid is a very serious health condition that requires hospitalization and treatment by a health professional. The vaccine for Typhoid is common these days, however if a unvaccinated person drinks contaminated well water, they may develop typhoid.

How to Prevent Coliform Bacteria Contamination of Well Water

If you want to restrict the entry of coliform bacteria into your well water, you must first know how these bacteria are most commonly introduced.

When it rains, if your well doesn’t have proper sealing, then it is possible that the rainwater can wash the surrounding bacteria through the soil and into your well.

Below are some of the common culprits that enable the entry of coliform in well water. If you suspect one of these pathways may be an issue, you should immediately seek the help of a licensed well driller or professional pump installer.

  • Bacteria enter the well through the top if the well cap is not sealed properly or there’s seepage in the well casing
  • Bacteria enter through a loose well pipe if the sealing is not effective
  • Bacteria enter though the well’s pipes or pumps if they are not watertight

It is important to consider the location of the well as well. Wells should not be located near any source of animals or human feces, like agricultural fields or septic symptoms. Most of the time, it’s not the design of the well that creates the problem but the location that leads to coliform in well water.

Testing for Coliform Bacteria in Well Water

It is important to test for coliform in well water at least once a year to ensure you maintain good water quality. These tests can confirm whether or not there are coliform bacteria is present in your well.

The most common way to test well water is by paying for laboratory testing. You can also check our detailed guide on how to test well water to learn the different methods.

Laboratory Testing 

Private laboratory testing can help ensure that the well water is safe enough to drink. There are many benefits of trusting a private laboratory confirm whether or not there are any coliform bacteria in the well water. It is also relatively cheap compared to other methods of water testing.

The other benefit of private laboratory testing is that it gives you the most accurate results and can also give you an overall estimation of the bacterial growth in the water.

For testing, I recommend you check out Tap Score which is one of the best-certified labs for water testing.

TapScore-Universal Bacteria Genetic Identification Test

Typically, laboratories will ask for a sample of the well water and will later inform you of the results through email or over the phone.

It’s recommended that you use bottled water until the testing report is received from the laboratory. If you don’t have bottled water, you should boil water as per the Water Systems Council’s recommendations for use.

Beyond a general report of total coliform bacteria present, you can also test well water for other specific types of coliform bacteria, like E. coli or fecal coliform bacteria, which are known to be harmful.

Drinking water contaminated with E. coli can cause disease, especially for people who have not built up immunity against this bacteria. You can find plenty of E. coli water testing kits that are available online or could consider laboratory testing.

Common Disinfection Methods to Treat Coliform Bacteria in Drinking Water

If the well water tests positive for coliform bacteria, there are several procedures available to kill the pathogens that are present and ensure clean drinking water.

1. Chlorination

Chlorination is the most common method that is famous not just in the United States but also in many other countries. This method is affordable and easy to perform. It has become a popular method of water purification that is used both for individual households and for larger systems, like municipal or public water.

During this process, a chlorine solution or dry powder is injected into the water. Chlorine then kills all the bacteria in the water. In addition, chlorine can also play a role in reducing certain impurities that may be present in the water, including hydrogen sulfide and iron.

Chlorine demand means the amount of chlorine that is required to purify the drinking water. It varies from situation to situation. On average, 0.3 to 0.5 milligrams of chlorine is used, but we recommend you consult a professional to ensure the chlorination process is done properly.

You can also use this method to treat coliform bacteria in pool water

2. Ultraviolet (UV) Light

One popular alternative to chlorination is UV light. With this method, there is no need to add chemicals to the well water and taste is not impacted. However, this method is only effective with lower concentrations of coliform bacteria. UV light purification will not work for concentrations of total coliform that exceeds 1000 colonies per 100Ml or fecal coliform concentrations that exceed 100 colonies per 100ML.

If you are planning to use UV light to purify your well water, it is important to ensure that you clean the water prior to UV treatment. The water should be free of any sediment or turbidity.

You can check some of the best whole-house sediment water filters to ensure the water sediment-free prior to treatment with UV light.

3. Boiling

If you are looking for the cheapest method compared to chlorination and UV light, boiling can be an attractive option.

Boiling is a very common in certain regions of the world and can easily be done at home. If you only need to clean a small amount of water, it can be effective to kill pathogens. However, this method is not popular for commercial use as it cannot purify water in bulk quantities.

4. Ozonation Method

This method has recently become more popular to kill bacteria in water well and ensure it is safe to drink. Like chlorination, ozone is an oxidant that kills dangerous bacteria in water. However, this method is often costlier than the other methods discussed above making it less common for household use. However, some large-scale facilities utilize ozone to eliminate bacteria and other harmful contaminants. For example, the removal of E. coli, iron, and manganese.

For personal household use when contaminates like iron and manganese are present, check our review for the best whole-house iron filters for well water.

For some of the best water filters for coliform bacteria check out: Best Whole House Water Filter Cartridges

FAQs

What should be the time duration between water testing?

As per the guidelines by EPA and the New York State Department of Health, one must test their well at least once a year, but if you’re worried about the water quality going down or causing health issues, test more frequently.

What is the most expensive and least expensive method for the treatment of well water?

The most common and cheapest method that everyone can practice in their households is the boiling method, but it is not a very good method if you strive for long-term, bulk purification.

The ozonation method is the most expensive method for the treatment of well water.

Conclusion

Coliform bacteria are common in various sources of water, including wells, springs, pools, and drinking water. While some types of coliform bacteria are harmless, others can cause illness and disease in humans.

Therefore, it is important to monitor and maintain acceptable levels of coliform bacteria in water sources to ensure that they are safe for consumption and use.

Regular testing, proper sanitation practices, and adherence to guidelines set by local health authorities are essential to prevent the spread of harmful coliform bacteria and protect public health.