Although E. coli and Fecal coliforms are typically harmless, a positive test can indicate that harmful germs are lurking in your water supply.
This guide will cover everything you need to know about E. coli in water so you know what to look for and how to protect yourself if harmful bacteria are present.
- E. coli strands in water are an indication of animal waste or sewage contamination where other disease-causing organisms may be present.
- There is no safe level of E. coli in drinking water as the EPA maximum contaminant level goal is zero, however, a count of 1–10 MPN/100 ml is considered low risk while a count above those levels is medium risk
- Common symptoms of e coli exposure include diarrhea, abdominal cramps, and vomiting within 2 – 5 days after ingesting the bacteria.
- Removing E coli from drinking water can be done by boiling your water, using disinfectant chemicals, or with specially designed filters like reverse osmosis or UV light.
- The only method to detect the exact level of E. coli in your drinking water is to use a certified lab test kit that scans for bacteria.
What Is E Coli In Water?
Escherichia coli (E. coli) is a type of gram-negative coliform bacteria. It belongs to the fecal coliform group specifically, which includes bacteria that are found in the intestines of warm-blooded animals. Like viruses, bacteria also develop different strains. Some E. coli strains are harmful to humans and some are not.
The most common ways that humans unintentionally consume pathogenic E. coli bacteria are from foods that contain the E. coli bacteria or undercooked ground beef or cross-contamination with raw meat, consumption of contaminated food, or consumption of unpasteurized (raw) milk, but harmful E. coli strains can also enter the water supply.
How Does E Coli Get In Water?
These disease-causing organisms can enter the water supply through fecal contamination. E. coli bacteria are found in the intestinal tract of warm-blooded animals, including humans. E. coli from humans can reach surface water sources from wastewater treatment plant runoff, broken or leaky sewer pipes, or from faulty septic systems. We can get sick from the consumption of this water that has not been disinfected.
The most common strain that raises public health concerns is E. coli O157, which is found in the intestines of cattle. Animal waste from livestock and feedlots that are near surface water supplies like rivers and streams can lead to contaminated water. Wells located near these sources of animal waste can also become infected with E. coli, especially ones with structural impairments.
E. coli is also used as an indicator organism since it is easy to sample. Fecal contamination in water from E. coli can indicate that other disease-causing pathogens are present that cause more serious diseases like typhoid or cholera.
What Are The Symptoms Of E Coli In Water
As mentioned above, not all coliform bacteria are harmful to humans. Some E. coli bacteria live in our digestive tract and are actually beneficial to health. There are six known pathogenic strains of E. coli.
1. Shiga toxin-producing E. coli (STEC): This type is also referred to as Verocytotoxin-producing E. coli (VTEC) or enterohemorrhagic E. coli (EHEC. When we hear of an “E. coli outbreak,” it is normally in reference to the STEC virus.
Most previously healthy people recover from STEC in a week. Hemolytic uremic syndrome (HUS) is a potentially life-threatening complication of an STEC infection. Children under five, adults older adults over 60, and those that are immunocompromised are more likely to develop HUS. The most common symptoms of a STEC infection are:
- diarrhea (often bloody)
- severe stomach cramps
2. Enterotoxigenic E. coli (ETEC): This is a type of E. coli bacteria that is associated with traveler’s diarrhea.
3. Enteropathogenic E. coli (EPEC): This type tends to cause watery or bloody diarrhea. It is more common in developing nations.
4. Enteroaggregative E. coli (EAEC): This type causes prolonged diarrhea, especially in children.
5. Enteroinvasive E. coli (EIEC): This type causes fever and diarrhea.
6. Diffusely adherent E. coli (DAEC): This type also causes fever and diarrhea.
Most strains of E. coli are nothing to be concerned about. An infected person will need fluids and rest to recover but are unlikely to need further treatment. The exception is when vulnerable individuals are exposed to the STEC strain E. coli O157:H7.
What Are The Regulatory Limits For E Coli In Water
Microorganisms are regulated in the public water supply by the EPA under the National Drinking Water Standards (NDWS). Of course, private wells are not regulated and must be monitored by the well owner.
There are regulatory limits for total coliform bacteria. Bacteria are measured in colony forming units (CFU) per 100 mL. To meet the EPA’s standards, no more than five percent of samples collected that month can contain coliforms. The rule for total coliform bacteria requires public water systems (PWS) to conduct a level 1 or level 2 assessment if there are concerns of contamination.
The maximum containment level goal (MCLG) for E. coli in drinking water is zero. Public water systems (PWS) must produce a boil water advisory if there are reports of harmful E. coli bacteria in the water supply. Currently, the maximum contaminant level (MCL) is based on certain conditions like sampling locations and frequency. The revised total coliform rule (RTCR) was initiated in 2013 and aims to set an MCL for E. coli in drinking water as well as monitoring guidelines for E. coli in water for public water systems to adhere to.
How To Test For E Coli In Well Water
Those with private wells should be particularly aware of the signs or indicators of E. coli in drinking water. If you suspect E. coli in your water supply, there are some sensory observations one can make, however, the most accurate method to detect bacteria is with a lab test kit.
If your water tests positive for E. coli, it’s important to contact your local health department to make them aware in case there are signs of an outbreak or water contamination in the area.
Certified Lab Test
The best method to determine if water is contaminated is through a certified lab test. I recommend the Freshnss Labs water test kit that scans for E. coli, coliform bacteria, and total bacteria. The kit includes everything you need to properly collect a sample and send it to a certified lab to be professionally analyzed. Within 3 business days, you will receive a comprehensive report with the exact contaminants detected, any health or plumbing alerts, and the best treatment options based on your test data.
DIY Test Kit
A do-it-yourself test kit can be used to determine the presence of E. coli in drinking water. Of course, these are less reliable as there will be more room for error. However, these tests can be useful as a first line of testing for your water.
If your DIY test kit indicates the presence of bacteria, it is recommended to then proceed to purchase a laboratory test kit to determine the type and concentration levels of the bacteria in your water.
E Coli Observations
Oftentimes water contaminated with E. coli will have a sewage-like smell, have a slimy texture, or appear to have an increased amount of foaming agents or a metallic sheen.
Treatment Methods To Remove E Coli From Drinking Water
Boiling contaminated water is a short-term solution if you discover that your water supply has E. coli bacteria in it. According to the Centers for Disease Control and Prevention (CDC), water should be boiled for at least one minute and for three minutes at altitudes above 6,500 feet.
Ultra Violet Purification
Ulta violet (UV) purification is an excellent method for removing bacteria since it doesn’t waste water and can be applied to a variety of situations. These systems work when UV light neutralizes DNA making it unable to replicate.
If used correctly with proper pre-filtration, ultraviolet lights are able to kill up to 99.9% of harmful pathogens in drinking water. It’s oftentimes used to treat private well water. UV systems can be employed as whole-house systems or under-the-sink filters.
Reverse osmosis (RO) filtration systems effectively remove most containments from water, including bacteria. Since the pores of a reverse osmosis membrane are .0001 microns, they are able to remove most microorganisms including Salmonella, Shigella, and Campylobacter. Some reverse osmosis systems also incorporate UV purification into the process so you get the best of both worlds.
Chlorination is the act of using chlorine as a disinfectant in well water. Chlorine effectively kills E. coli bacteria in water as well as other disease-causing organisms. With shock chlorination, users can’t drink or come into contact with the water for 12 hours. A downside of frequent shock chlorination is that this can produce disinfection byproducts (DBPs), which may have harmful long-term effects on humans.
Frequently Asked Questions
Can you shower In E. coli Water?
Adults can technically shower in water contaminated with E. coli, although it’s important to ensure that no water is consumed through your mouth or eyes. It’s recommended that children bathe using a sponge bath.
How long does E. coli last in water?
The bacteria may be able to survive for around three months when from drinking water sources like water treatment plants and surface water.
How do you get rid of E. coli in water?
You can remove E. coli from water using several purification techniques like ultraviolet purification, reverse, osmosis, and shock chlorination.