Boil Water Advisory/Notice

What is a Boil Water Advisory?

A boil water 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 large water main break, widespread loss of system pressure, or a natural disaster.

Boil water advisories are rarely issued. This is because in most cases, our crews can isolate a main break by closing the nearest valves, then repair the pipe, disinfect it, and flush it before putting it back into service. This prevents contamination from soil and bacteria, which is why boil water advisories are not issued after routine water main repairs.

If we do have to issue a boil water advisory, we will notify the media, post information on this web site and on our phone system, and take other appropriate notification measures, such phone calls and electronic sign boards.

Below are some frequently asked questions about boil water advisories and notices. You can also learn more by visiting the SC Department of Health and Environmental Control's web site.

FAQ's

What is a Boil Water Advisory? Is it the same as a Boil Water Notice?

What should I do during a Boil Water Advisory or Notice?

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

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

How long must a Boil Water Advisory or Notice be in effect?

What are total coliform bacteria?

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

Under what circumstances will Charleston Water System issue a Boil Water Advisory or Notice?

Why must DHEC issue a Boil Water Advisory in preparation for a hurricane?

How will I know when the advisory or notice has been lifted?

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?

What are a Do Not Drink Notice and a Do Not Use Notice?

What is a Boil Water Advisory? Is it the same as a Boil Water Notice?
A Boil Water Advisory (BWA) is a public statement advising customers to boil tap water before consuming it. Advisories are issued when an event has occurred allowing the possibility for the water distribution system to become contaminated. An advisory does not mean that the water is contaminated, but rather that it could be contaminated; because the water quality is unknown, customers should assume the water is unsafe to drink and take the appropriate precautions. An advisory is different from a Boil Water Notice, which is issued when contamination is confirmed in the water system. During a notice, all customers must boil their water before consuming it or use bottled water.

What should I do during a Boil Water Advisory or Notice?
You should boil tap water vigorously for at least one full minute prior to using it for drinking or cooking (the minute starts when the water begins to bubble). 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 notice 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 the 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, Charleston Water System will issue a Do Not Use Notice , meaning the water should not be used for bathing.

How long must a Boil Water Advisory or Notice be in effect?
An advisory or notice will remain in effect until test samples show the water is safe to drink. Testing for bacteria requires 18-24 hours to complete, depending on the type of test used. The samples are incubated to actually grown bacteria, if any are present. As a result, advisories and notices will be in effect for at least 18-24 hours.

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.

How will I be notified if my home/business is affected by an advisory or notice?
By regulation, Charleston Water System must follow certain public notification efforts, which include dissemination to media outlets, door-to-door notification, and any other means to notify water users.

Under what circumstances will Charleston Water System issue a Boil Water Advisory or Notice?
The South Carolina Department of Health and Environmental Control (SCDHEC), through the State Primary Drinking Water Regulation (R. 61-58), regulates water utilities and specifies instances when an advisory or notice must be issued.
An advisory must be issued in the following instances:

If untreated water reaches the distribution system
Loss of pressure in the entire distribution system or a significant portion of the system
A water main break where dirt and debris have entered the distribution piping
Prior to a hurricane making landfall (in this situation, the advisory would be issued by DHEC).

A Boil Water Notice must be issued under the following circumstances:

When test samples indicate the presence of total coliform bacteria.

These situations are not the only times when an advisory or notice should be issued. Specific situations, upon consultation with DHEC, may also require an advisory or notice.

Why must DHEC issue a Boil Water Advisory in preparation for a hurricane?
State drinking water regulations require DHEC to issue a Boil Water Advisory for the affected geographic areas before a Hurricane makes landfall. Because a hurricane may cause damage to the water system that may make the water unsafe to drink, and because the hurricane may disrupt methods of public notification after a storm, the advisory must be issued before the hurricane strikes. After the storm, you should stay tuned to radio reports for further instructions. Charleston Water System will dispatch crews to begin surveying damage and making repairs immediately after the storm. If sampling shows that the water has been contaminated by bacteria, Charleston Water System will issue a Boil Water Notice; if tests show the water is safe to drink, Charleston Water System will lift the advisory.

How will I know when the advisory or notice has been lifted?
Charleston Water System will issue a repeal of the advisory or notice when the water is safe to drink; stay tuned to radio and television stations for updates. Charleston Water System will also post information on this web site and post an automated message on the Customer Service phone menu system, which can be access by dialing (843) 727-6800.

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.

What are a Do Not Drink Notice and a Do Not Use Notice?
A Do Not Drink Notice will be issued when the water contains a chemical contaminant that cannot be removed by boiling. In this case, bottled water should be used for drinking or cooking.

A Do Not Use Notice will be issued if there is a contaminant in the water that may be inhaled or otherwise harmful on contact.

For more information about Boil Water Advisories or Notices, please contact Charleston Water System at (843) 727-6800 or the SC Department of Health and Environmental Control.