Shopping Cart

Your cart is currently empty.

Coliform Bacteria Testing: Why do it, How to do it, & How Often?

bacteria in water glassHealth authorities strongly recommend annual coliform bacteria testing for private water wells as contamination can occur without any change in taste or odor to the water.  There are many ways that well water can become contaminated by coliform bacteria, but it is most important to test:

  • Once a year for all private residential water wells
  • After a new well has been constructed
  • After recent work has been done on the well
  • If you suspect or see any indication that contamination has taken place, such as if the well was covered with flood water.

What Is Coliform Bacteria?

Generally, there are two categories of coliform bacteria that are found in well water, total coliform, and fecal coliform or E.coli.

Total coliforms are found naturally in the environment and are found in the soil, in water that has been influenced by surface water, and in human or animal waste. The presence of total coliform, by itself, doesn’t imply that the resource is contaminated, but it can reveal that one, if not more of the more serious types of harmful bacteria, such as fecal or E. coli bacteria, may be present.

Fecal coliforms are the group of the total coliforms that are considered to be present specifically in the gut and feces of warm-blooded animals and are considered a more accurate indication of animal or human waste than the total coliforms.

Escherichia coli (E. coli) is the major species in the fecal coliform group and is considered to be the best indicator of fecal pollution and the possible presence of pathogens. Most coliform bacteria do not cause disease. However, some rare strains of E. coli, particularly the strain 0157:H7, can cause serious illness. Recent outbreaks of disease caused by E. coli 0157:H7 have generated much public concern about this organism. E. coli 0157:H7 has been found in cattle, chickens, pigs, and sheep. Most of the reported human cases have been due to eating under cooked hamburger. Cases of E. coli 0157:H7 caused by contaminated drinking water supplies are rare. For more info on fecal bacteria visit the EPA’s page on the subject: https://water.epa.gov/type/rsl/monitoring/vms511.cfm

shutterstock_94154512What Should I Test For?

Testing for bacteria is the only reliable way to know if your water is safe. You cannot tell by the look, taste, or smell of the water if disease-causing organisms are in it. It is recommended that well owners test their water for coliform bacteria at least once a year and more frequently if bacteria has been a problem in the past.

Frequently, concentrations of pathogens from fecal contamination are small, and the number of different possible pathogens is large. As a result, it is not practical to test for pathogens in every water sample collected. Instead, the presence of pathogens is determined by indirect evidence by testing for an “indicator” organism such as coliform bacteria

The most basic test for bacterial contamination of a water supply is the test for total coliform bacteria. Total coliform counts give a general indication of the sanitary condition of a water supply.

Which Test Kit Do I Need?

The at-home test is an easy, fast, and effective method for determining if your well water has coliform and E.coli or not. When using this simple test the media turns blue-green in the presence of coliform bacteria.

Coliform Bacteria EZ Culture 24 Hour Test

Also, our UV light works great with the Coliform Bacteria EZ Cult 24 Hour Test to test for coliform bacteria. When using this simple test, the sample turns blue-green in the presence of coliform bacteria, but E. coli growth is confirmed by blue fluorescence under UV light. Simply shine the UV light on the sample to see if E.coli is present.

uv light for coliform bacteria test

For more extensive or state required testing (such as applying for a new daycare center license) we recommend the Watercheck which offers Professional EPA-certified laboratory results available for the fraction of the cost of regular laboratory testing.

 

How Do I Collect a Water Sample For The WaterCheck?

  • Wash your hands with soap and warm water.
  • Take the sample from a cold water tap. Use a tap without a screen or remove the screen before you collect the sample.
  • Let the cold water run constantly for at least 2 minutes before you collect the sample.
  • Hold the bottle near the base of the tap to get the sample. Fill it past the 200 mL mark (to the shoulder of the bottle). Do not overfill the bottle.
  • Put the cap on the bottle right away. Make sure the cap is secure, but do not over-tighten it.
  • Put the identification label from the requisition form on the bottle.

Fill out the requisition form and include the information below. If you miss anything on the requisition, your sample might not be processed.

  • Name and daytime phone number
  • Mailing address and postal code
  • Collection site (e.g., kitchen sink)
  • Legal land description and/or civic address
  • Date and time sample was collected
  • Name of person who collected the sample

On the requisition form, write down if this is a re-sample. You also need to fill out section A (Drinking Water) and add any comments or special requests at the bottom of the requisition.

  • Put the sample and requisition form in the plastic bag that came with the sample bottle.
  • Put the sample in a cooler filled with ice packs and bring it to a drop-off location near you right away, or if sent by express, use overnight next day morning option.

Note: Samples must be collected from the cold water supply line. do not:

  • Rinse the sampling bottle
  • Let water overflow or splash down the side of the bottle
  • Put the cap on a countertop (it can get contaminated)
  • Open the bottle until you are ready to collect your sample
  • Touch the inside of the cap, mouth, or neck of the bottle
  • Collect samples from a garden hose, outside tap, or other places that might be dirty

 When Should I Test and How Often?

Late spring or early summer are the best times to test your well, since coliform contamination is most likely to show up during wet weather. Whether your test results are positive or negative, understand that the sample you collected is just a “snapshot” of your well’s water quality. The more samples you have tested, the more confident you can be about the quality of the water you are drinking.

What Do The Results Mean?

If coliform bacteria are present in your drinking water, your risk of contracting a water-borne illness is increased. Although total coliforms can come from sources other than fecal matter, a positive total coliform sample indicates the possibility of pollution in your well. Positive fecal coliform results, especially positive E. Coli results, should be considered an indication of fecal pollution in your well.

What Should be Done if Coliform Bacteria are Detected in Your Well?

If E.coli or fecal coliform are detected in the drinking water, the first step should be an emergency chlorination, which can last two to five days. At the same time a system is being disinfected, it is recommended to vigorously boil the drinking and cooking water for one minute before using it. It is also very important to continue testing the water because if anything happens to the chlorine residual, or if the chlorine-demand changes, and the consumer doesn’t know about it, the water can become unsafe again. However, If fecal coliform or E. coli are detected in well water, the first step should not only be to disinfect your system but to identify the source of your bacteria contamination.

What Kinds of Defects Can Allow Contamination?

  • A missing or defective well cap – seals around wires, pipes, and where the cap meets the casing may be cracked, letting in contaminants
  • Contaminant seepage through the well casing – cracks or holes in the well casing allow water that has not been filtered through the soil to enter the well. This seepage is common in the wells made of concrete, clay tile, or brick
  • Contaminant seeping along the outside of the well casing – many older wells were not sealed with grout when they were constructed
  • Well flooding – a common problem for wellheads located below the ground in frost pits that frequently flood during wet weather.

For more on figuring out the source of contamination, read our previous blog post:

“Sources of Coliform Bacteria Contamination in Home Well Water”

Long-Term Options for Dealing with Bacterial Contamination of a Well

  •     Connecting to the regional public water system, if possible
  •     Inspecting wells for defects and repairing them if possible
  •     Constructing a new well
  •     Installing continuous disinfection equipment
  •     Using bottled water for drinking and food preparation

Sources of  Bacterial Infections in Well Water

water purity concernHuman, as well as rodent waste products, can be a principal source of bacterial contamination in well water. These sources of bacterial contamination consist of run-off out of yards, feedlots, pastures, canine runs, and other

These sources of bacterial contamination consist of run-off out of yards, feedlots, pastures, canine runs, and other farmland areas where animal wastes are deposited. Bugs, rats or rodents or wildlife entering the well can also be sources of contaminants.

Some other sources include things like leaking coming from septic tanks as well as sewage treatment services.

Bacteria from these sources can enter home water wells if these wells are:

1) Open on the surface

2) Don’t have watertight casings or caps

3) Do not have a seal of grout in the space (the space between the wall of the well and the outside of the well casing).

Coliform bacteria

Generally, there are three categories of coliform bacteria that need to be tested. These are total coliform, fecal coliform, and E. coli.

The presence of total coliform, by itself, doesn’t necessarily imply that the resource is contaminated.

Coliform Bacteria

Coliform bacteria are living in soil, on plants and flowers, and in surface water.  They are found in the intestines of warm-blooded animals and their feces and are known as E.coli.

A number of strains of coliform bacteria can easily survive for long periods in soil and water.  Insects can also transport bacteria into well casings. Coliform bacteria are the most common contaminants seen in private water systems. Your well should be tested at least once a year for bacteria.

In many instances, whenever total coliform is detected, additional tests are performed to verify either the presence or absence of fecal or E. coli bacteria.

Wells which have recently been worked on can become contaminated by the work itself

The introduction of coliform bacteria into your well can occur from the tools that are used. These are the drilling pipe, fluids used in the drilling, and any number of other items used in drilling and servicing wells. Anything can happen such as tools or dirt falling down into the well while it is being worked on or even airborne particles being carried down into the well.

Anything can happen such as tools or dirt falling down into the well while it is being worked on or even airborne particles being carried down into the well.

There are two basic ways coliform bacteria can get into a well.

One is by the original drilling and installation of the pump. The other is when the well or pump is being repaired. Original drilling processes include the activities related to the original construction of the well, including the original pump installation.

This represents the first and usually most severe exposure of the well to bacterial contamination. Because there are so many different ways to introduce bacteria into the system, the original well construction can often be the cause of an ongoing bacteria problem that can go on for many years.

All water used in the drilling process must be chlorinated-treated water or, at the very least, free from any bacteria or viruses.  Do a thorough chlorination of all water used during drilling and before it is introduced into the well.

Do not assume that the water used for drilling obtained from a neighboring well is free from bacteria.  Add chlorine of not less than 50 PPM (mg/L)to any water entering the well, no matter where the water came from.

Other sources of contamination

Equipment and tools lying on the ground or the bed of a service truck also represent excellent paths for bacteria or viral contamination. This equipment should be kept as dry and clean as possible, covered until needed, and washed down with a chlorinated solution before placing into the well.

coliform bacteria testing
Flood contamination of well water

Flood water can contaminate your well water with bacteria, parasites, and other pollutants. Do not drink water from your well if it has been covered by flood water. If your well is older than 10 years and is less than 50 feet deep, it may be impacted by contamination, even if the actual wellhead is not covered. Shallow wells and/or older wells with bad well seals can be under the influence of surface water, even if the surface water is not directly covering the top of well.

Shallow wells and/or older wells with bad well seals can be under the influence of surface water, even if the surface water is not directly covering the top of well.

Do not drink water from your well if it has been covered by flood water. If your well is older than 10 years and is less than 50 feet deep, it may be impacted by contamination, even if the actual well head is not covered.

Shallow wells and/or older wells with bad well seals can be under the influence of surface water, even if the surface water is not directly covering the top of well.

Before disinfecting your well check the condition of the well. Make sure there is no exposed or damaged wiring. Shock Hazard! Contact a well professional before the disinfection process if you have any doubt about the integrity or condition of your well. Do not attempt to do this yourself until your well has been inspected.

Do It Yourself  (DIY) Well Water Kits for Coliform Bacteria

coliform bacteria testing Health Departments and EPA guidelines recommend testing your well water at least twice a year for coliform bacteria.

Bacteria can contaminate a well without any change in taste or odors to the water.

Now you can analyze for unhealthy bacteria at home utilizing state-of-the-art, low-cost test kits. These professional kits make it easy for you to keep an eye on your home

These professional kits make it easy for you to keep an eye on your home well drinking water supplies for contamination through consistent water testing of your water well.

DIY Coliform Test Kits Now Available

uv light for coliform bacteria testing
UV Light for E.coli Detection in Bacteria Test

The EZ Coliform Cult is an easy, fast, and effective presence/absence test for total coliforms and E.coli in water. If you do detect bacteria we recommend further testing be done by a state certified lab.

Coliform Bacteria Testing, How It Works

Fill the bottle with untreated well water. The media will turn blue-green if coliform bacteria is present, or will remain clear-yellow if coliform bacteria is absent.

For 24 hour results for coliform bacteria testing, heat the sample to 95*F for 24 hours. If kept at 77*F, the test will take 48 hours.

Heating the sample is not required and does not affect the accuracy, only the timing of the test.

The UV light is not necessary for the coliform bacteria test. However in our opinion, if coliform bacteria is detected, the water should be disinfected (or not consumed at all) regardless of whether E. coli is specifically present.

E.coli Testing is easy

E. coli growth is confirmed by blue fluorescence under UV light. This tool can confirm the presence of e.coli bacteria:  UV Light.   (Just select the UV Light from the button selection menu.)

Get your Coliform bacteria test kit now to find out if your water is safe.  Protect your family from pathogens in your water. Test it and if found to be unfit,  have your water treated first.

 

For more help on removing bacteria from your water, visit our Bacteria page on our Water Problems tab. If you still have questions, don’t hesitate to e-mail us at support@cleanwaterstore.com, leave us a message on Facebook, or use our online contact form for prompt, personalized assistance from our trained professionals.  Thanks for reading!

The Complete Guide Home Chlorination Systems For Well Water
Just text CHLORINE to 44222
Well Water Chlorination System

print

Share Button
Print Friendly, PDF & Email
  • Clean Water Systems & Stores, Inc., Water Treatment Equipment,Service & Supplies, Santa Cruz, CA
  •  

Visa, Discover, MasterCard, American Express, & PayPal

Font Resize