FAQs: Public Health and Drinking Water

Questions and answers about health concerns as they relate to drinking water supplies.

Questions and answers about health concerns as they relate to drinking water supplies. How can a consumer find out more about the health impacts of certain ingredients or contaminants in their drinking water? Is bottled water safer to drink than public drinking water? What is a boil water alert? What is an acceptable level of risk? Answers to these questions and more.

Frequently Asked Questions

When should someone with an immune-syndrome deficiency be concerned if their water exceeds certain standards?

People with weakened immune systems should contact their health care provider if MCLs are exceeded for microbiological contaminants such as Cryptosporidium, E.coli, and Giardia.

Should people be advised to contact their health care providers if they feel they have a health problem that might be related to something in the drinking water?

Yes, the medical community is knowledgeable about the effect of common contaminants found in water, such as bacteria. A person who is immuno-compromised, pregnant, undergoing dialysis or chemotherapy, or sensitive to chemicals, may want to check with their health care provider.

How can a consumer find out more about the health impacts of certain ingredients or contaminants in their drinking water?

There are numerous drinking-water-related sites on the Internet. However, the best sources for health-related fact sheets are MassDEP's Office of Research and Standards, the Safe Drinking Water Hotline at 800-426-4791, and the consumer's local Board of Health. Fact sheets are also accessible on the US EPA's website.

Is bottled water safer to drink than public drinking water?

To some consumers, bottled water may taste better than the water that comes out of your tap, but it is a lot more expensive and is not necessarily "healthier." Bottled water is regulated as a food by the U.S. Food and Drug Administration. Water bottled in Massachusetts is regulated by the Massachusetts Department of Public Health (DPH) and has to meet public drinking water standards. MassDEP assists DPH in approving sources in Massachusetts. However, bottled water companies do not have to produce annual Consumer Confidence Reports.

For more information, contact DPH at 617-983-6700; the Safe Drinking Water Hotline at 800-426-4791; or the US EPA website. For a survey of bottled water companies, contact the National Resources Defense Council at 212-727-2700, or visit their Web site: http://www.nrdc.org/.

What are the common contaminant problems here in Massachusetts that might cause a public health problem? (E.coli, Giardia, Cryptosporidium)

E.coli is a common bacterium found in all animals, including humans. When it is found in water it is usually associated with fecal matter and indicates there could be a public health problem.

Giardia is a parasite carried by beavers and other mammals. It is only found in surface water supplies. If there is a possibility that Giardia is present the system must test for this organism.

Cryptosporidium is a parasite commonly found in lakes and rivers, especially when the water is contaminated with sewage and animal wastes. It is very resistant to disinfection and even a well-operated water treatment system cannot ensure that drinking water will be completely free of this parasite.

Immune-compromised people and people with gastrointestinal diseases who wish to take extra precautions should consult their health care provider about measures to reduce risk of Cryptosporidium, Giardia, and bacterial infections. Boiling water is one way of removing Cryptosporidium and bacteria. Point-of-use treatment devices might be considered. See US EPA's fact sheet, Guidance for People with Severely Weakened Immune Systems, on their Web site: www.epa.gov/safewater/.

What are "total coliforms"? What are "fecal coliforms"?

Total coliforms include several types of bacteria common in the environment, and are generally not harmful themselves. However, the presence of these bacteria in drinking water generally means there is a problem with water treatment or the distribution pipes and indicates that the water may be contaminated with organisms that can cause disease.

The presence of fecal coliforms in drinking water is serious because they are usually associated with sewage or animal wastes and are infectious to humans. Your water system routinely tests for these bacteria. If US EPA's safety standards for these contaminants are exceeded, your system will act to correct the problem and, in the interim, issue an alert with guidance on how to protect yourself and your family.

What is a boil water alert?

If a boil water alert is issued in a community, it means the PWS has discovered one or more microbiological contaminants at levels exceeding those allowed by US EPA. The boil water alert is a temporary advisory to protect public health. The PWS must take appropriate corrective action, continue to monitor its water supply, and notify customers when it has remedied the problem. The PWS should be able to provide more details, or consumers can check the US EPA fact sheets on contaminants.

If something is detected and reported, should consumers consider putting in home treatment/filtering units? Does MassDEP approve home treatment devices?

A violation of an MCL occurs when the contaminant level exceeds the MCL for the contaminant. If treatment does not eliminate the problem, the source is taken off-line and an alternative source of water would be supplied by the local public water system. In most cases, a system has several sources of water, such as groundwater from wells, to use in the event another source is closed. Generally, it is not necessary to put in a home treatment unit if you are on a public water system. Neither the US EPA nor the MassDEP approve home treatment units. Contact NSF International at 1-800-NSF-MARK for their listing of treatment units for specific contaminants.

What is an acceptable level of risk?

Both the US EPA and the MassDEP set maximum contaminant levels (MCLs) for all substances and contaminants that are known to impact health. These MCLs consider both cancer and non-cancer effects and are developed to protect sensitive individuals.

Are there any positive benefits to chemicals such as chlorine, fluoride, and other compounds added in the treatment process?

Disinfection is needed to destroy harmful bacteria in the water. Fluoride was an ingredient added after extensive research showed it would help inhibit tooth decay. Other compounds are used to treat the physical parameters such as taste, color, color, turbidity (cloudiness), and alkalinity. These compounds are used at levels that have been scientifically determined to have no significant impact on public health. The use of these compounds is strictly regulated.

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