What is a Precautionary Boil Advisory?

A Precautionary Boil Advisory is a public statement advising people to boil their tap water before using it, typically in response to an event that could allow contaminants to enter the water distribution system. Such events include a water main break or loss of system pressure.

Depending on the size of the area that may be affected by the Precautionary Boil Advisory, the Evansville Water and Sewer Utility may or may notify the media of the event. If the affected area has been isolated to a small area of the water distribution system, typically 40 customers or less, the Utility will place door hangar notices on each customer’s door notifying them of the Precautionary Boil Advisory. For larger areas, the Utility will not place individual door hangar notices on each customer’s door but will instead notify the local media outlets, consisting of television, radio, and newspaper. The specific area that is affected by the Precautionary Boil Advisory will be given to the media along with instructions of what to do in the event an advisory is issued.

The Precautionary Boil Advisory information will also be posted on the Utility website.

What should I do during a Precautionary Boil Advisory?

You should boil tap water vigorously for at least five minutes prior to using it for drinking or cooking. This includes water used for brushing teeth, making ice, washing raw foods, preparation of drinks, and water for pets. Wait for the water to cool before using it, or store it in the refrigerator in a clean container. Boiling removes harmful bacteria in the water that may cause illness. You should throw away ice made during the time the advisory or notice was issued, as freezing does not kill bacteria.

After an advisory or order has been lifted (if contamination of the water system did occur), you should flush household pipes, ice makers, water fountains, etc. prior to using for drinking or cooking. Flushing simply means letting the water run to ensure that no contaminated water remains in your pipes. Follow these guidelines for flushing:

  • Run all cold water faucets in your home for one minute
  • To flush automatic ice makers, make three batches of ice and discard 
  • Run water softeners through a regeneration cycle 
  • Run drinking water fountains for one minute 
  • Run water coolers with direct water connections for five minutes.

Do I still need to boil my water if I have a filter system on my faucet or refrigerator?

Most point-of-use (POU) filters are designed to improve the aesthetics of water (improve taste and odor), not remove harmful bacteria. You can learn about the capability of your filter by contacting the manufacturer or NSF International, an independent testing group located in Ann Arbor, Michigan (Ph. 1-800-673-8010). If in doubt, you should boil your water or use bottled water even if you have a filtering system.

Is the water safe for washing dishes, laundry, and bathing?

The water is safe for washing dishes, but you should use hot, soapy water (you may add one tablespoon of bleach per gallon as a precaution) and rinse dishes in boiled water. There are no restrictions on doing laundry. The water is also safe for bathing during an advisory or notice; if the water is contaminated by a chemical that will cause harm on contact, The Evansville Water and Sewer Utility will issue a Do Not Use Notice, meaning the water should not be used for bathing.

How long must a Precautionary Boil Advisory be in effect?

An advisory will remain in effect until test samples show the water is safe to drink. The Indiana Department of Environmental Management, the State agency which regulates the drinking water industry in Indiana, requires that two successive tests taken at least 24 hours apart confirm that no bacteria is present prior to lifting the advisory. Each sample is incubated for 18-24 hours, depending on the type of test, to actually grown bacteria, if any are present. As a result, advisories will be in effect for at least 48 hours. If any bacteria are found in the samples, the water line will continue to be flushed by the Utility and the advisory will remain in effect until two consecutive samples have shown the absence of bacteria.

What are total coliform bacteria?

Total coliform bacteria are a collection of microorganisms that live in large numbers in the intestines of humans and animals, as well as in most soils and surface water. A sub-group of these microorganisms is the fecal coliform bacteria, the most common member being E coli. These bacteria occur naturally in lakes and streams, but indicate that the water is contaminated with human or animal waste and therefore may pose a health risk to people who drink it. The water treatment process removes these bacteria from the water, but events such as a water main break or a loss of pressure in the water distribution system may allow these bacteria to enter water lines through cracks in pipes or back-siphoning from a residential plumbing system. Boiling water vigorously for one minute will kill these bacteria and make water safe to drink, although the Utility recommends boiling the water for five minutes to remove any doubt or differences of interpretation of how long the water has actually been at the boiling point.

How will I be notified if my home/business is affected by an advisory?

The Evansville Water and Sewer Utility engages in certain public notification efforts, which include dissemination to media outlets or door-to-door notification. If at any time, you feel your home or business may have been affected by an event that typically results in an advisory and you didn’t receive a door hangar notice or you didn’t hear or read about an advisory through the media outlets, you may call the Water Department at 421-2130 to inquire whether you are affected by the advisory.

Under what circumstances will The Evansville Water and Sewer Utility issue a Precautionary Boil Advisory?

The Indiana Department of Environmental Management regulates water utilities throughout the state and specifies instances when an advisory must be issued.
An advisory must be issued in the following instances:

  • If untreated water reaches the distribution system
  • Distribution system pressure falls below 20 psi 
  • A water main break where dirt and debris may have entered the distribution piping

How will I know when the advisory has been lifted?

The Evansville Water and Sewer Utility will issue a Precautionary Boil Advisory Lifted notice when the samples have confirmed that no contamination is present. The Utility will post information on this web site and notify customers by the same method that the advisory was issued. If you received a door hangar notice when the advisory was issued, you will receive a door hangar notice when it has been lifted. If the advisory was issued by a media press release, the advisory will be lifted by a media press release.

Since an advisory is a precautionary measure, will I get sick if I drink the water?  What if I drank some water before I found out about the advisory?

Until test results show the water is safe to drink, you should not drink the water without boiling it first. During an advisory, chances are, if you are in good health, you will not get sick from drinking the water; however, young children, some of the elderly, and people with severely compromised immune systems should not drink the water until it is deemed safe to drink. Symptoms of illness caused by bacteria in the water may include diarrhea, cramps, nausea, headaches, or other symptoms. Please note that these symptoms are not caused only by organisms in drinking water. If you experience any of these symptoms and they persist, you may want to seek medical advice.

For more information about Precautionary Boil Advisories, please contact The Evansville Water and Sewer Utility water laboratory at (812) 428-0568.

Last updated: 6/9/2016 8:19:43 AM