Serious health and safety problems in bottled and tap water in the U.S. are uncommon. Well water is safe if private wells are regularly tested and properly maintained, and if the surrounding source area is protected. Consumer preferences in terms of cost, convenience, and taste tend to affect water choices. Private water sources such as wells are the homeowner's responsibility and should be tested regularly (see the Wells and Supply page for more information). That page also has a section about public (tap, municipal) water systems. See the Contaminants and Testing page for more information on specific contaminants.
Tap water from a municipal drinking water treatment plant is regulated by the U.S. Environmental Protection Agency (EPA) and additional agencies in some states. It is tested frequently for close to a hundred chemicals and characteristics. Your supplier must notify the community if there are problems with the water supply.
Bottled water sold across state lines is regulated by the U.S. Food and Drug Administration (FDA). States have additional regulatory oversight of bottled water. Bottled water produced and sold only in New York State falls under New York state, but not FDA, regulations. The FDA standards for bottled water and the EPA standards for municipal (tap) drinking water are similar but not identical. Municipal plants are generally subject to much more frequent testing and inspection and must report test results to the public. See the link to the 2009 Government Accounting Office report below for more information.
Many major brands of bottled water use tap water as their water source, but may put it through additional treatment steps. The FDA has set specific definitions for different water source types, such as "spring water". Check the bottle label for information on the water source.
One of the main differences between tap water and some brands of bottled water is the type of disinfection treatment used. Municipal systems may use chlorine to provide long-term protection against microorganisms during distribution from the treatment plant through pipes to your tap. Water bottlers may be able to use ozonation or ultraviolet light, since they use sealed containers for distribution, and so they can avoid an aftertaste from chlorine treatment. On the other hand, ozonation byproducts and plastic bottles themselves may adversely affect the taste of bottled water. Consumers may need to do some research to find out what water treatment techniques are used on their tap and bottled water. See the Treatment page for more information about drinking water treatment technologies. Once opened, bottled water is susceptible to bacterial contamination.
Another difference among tap, bottled, and well water is whether fluoride ions have been added to the water. Tap water is often fluoridated at the municipal drinking water plant; most varieties of bottled water do not have added fluoride; and private well water will not have added fluoride. The natural (background) level of fluoride will vary geographically depending on the source of water. The U.S. FDA has a page about Health Claim Notification for Fluoridated Water and Reduced Risk of Dental Caries.
Current Trends and Environmental Issues
Sales of bottled water have increased dramatically in the last few years despite the similar safety and much lower cost of tap water. There is a great deal of debate about whether this is due to misinformation about tap water safety, the effects of advertising, or simply consumer preferences based on taste or convenience. Bottled water is advertised as being very "convenient" but most people already have tap water delivered around the clock to their homes and workplaces, which is another form of convenience. Much attention is being paid in the recent news to the economic, energy, and environmental costs of making bottles, withdrawing water from the environment, bottling the water, transporting it, advertising it, and recycling or disposing of bottles.
Comparison of Drinking Water Standards
Appendix II: FDA and IBWA Standards of Quality and Selected EPA Drinking Water Standards(GAO Report, 2009, see Appendix II)
Maximum Contaminant Levels for Public Water Supplies (NYS Dept. of Health)
Bottled Water: Basic Information and Regulation
Bottled Water (CCE Water Treatment Notes #11, 1999)
FDA bottled water regulations page (U.S. FDA, updated 2009)
Bottled Water Regulation and the FDA (U.S. FDA, 2002; includes FAQ section)
Water Health Series: Bottled Water Basics (U.S. EPA, 2005)
Bottled Water FAQ (NYS Dept. of Health)
Questions and Answers on Bottled Water (Health Canada)
Bottled Drinking Water (World Health Organization)
Bottled Water Types and Treatment (NSF International)
Bottled Water FAQ version 1 (NSF International)
Bottled Water FAQ version 2 (NSF International)
Bottled Water: Questions and Answers (Minnesota Dept. of Health, 2005)
Articles about Bottled Water vs. Tap Water
Bottled Water Blues and Fighting Back - Alternatives to Bottled Water (Legislative Commission on Water Resources Needs of NYS and Long Island, 2008)
Tap Water vs. Bottled Water (EPA webcast, audio or video with closed captioning available at the link, 10/27/08)
Bottled Water - Better than Tap? and To Filter or Not to Filter? (U.S. FDA, 2002)
Can Public Water Utilities Compete with Bottled Water? (National Environmental Services Center, 2003)
Forego bottled water -- and soda -- to save the planet (Cornell Chronicle, 2007)
Perception, Status and Bottled Water (University of Arkansas, College of Business, 2007)
Bottled or Tap? (Univ. of Nebraska Lincoln Extension, 2002)
Is Bottled Water Just Water in a Bottle? (American Ground Water Trust)
Bottled Water - What You Need to Know (National Ground Water Association)
Recent press articles
Bottled Water Vs. Tap Water (Reader's Digest, Feb 2008)
The battle over bottled vs. tap water (Christian Science Monitor, 1/17/08)
A Battle Between the Bottle and the Faucet (NY Times, 7/15/07)
Bottled Water - Pure Drink or Pure Hype? (Natural Resources Defense Council (NRDC), 1999)
Message in a Bottle: Despite the Hype, Bottled Water is Neither Cleaner nor Greener Than Tap Water (E The Environmental Magazine, 2003)
Product Report - Bottled Water (The Green Guide, 2003)
Consumer Reports Product Reviews (some articles require a home or university subscription)
Clear choices for clean drinking water - helpful article compares refrigerator, faucet, under-sink, reverse osmosis, whole house (point-of-entry), and bottled water (Jan. 2003)
Complete article (subscribers & Cornell users)
Which Water Choice is Right for You? - summary of results table in the full article
Printer-friendly version of article overview (easier to read)
Interactive version of article overview (with pop-up photos)
What's in that bottle? - describes regulations, test results, cost, and types of plastic bottles (Jan 2003)
Fortified Water May Be Too Much of a Good Thing (Oct. 2003, subscribers & Cornell users)
Frequently Asked Questions
Why is there an expiration date on bottled water?
As long as properly bottled water stays unopened, it should remain safe to drink. Many water bottlers suggest a 2-year shelf life for their products. Bottled water falls under the same regulations as other food and drink products. Some states require every food item to have an expiration date.
The taste of bottled water can change over time, particularly if the bottle is exposed to sunlight or heat. The plastic in the bottle itself can alter the taste over time. Also, many gases are able to pass through plastics, which can affect the taste of bottled water. For those reasons, always store plastic bottles in a dry, dark place away from household cleaners, gasoline, and other chemicals.
Bottled water is tested for coliform bacteria, which are associated with disease-causing bacteria and other organisms. Unopened water should be safe to drink, but is not necessarily "sterile" (free of all organisms). After a bottle of water is opened, it should be refrigerated and used within two weeks to avoid contamination with harmful bacteria and other organisms. For more information see the publications below.
Other Beverages and Plastic Bottles
Too Many Bottles - It's a Waste (NYS DEC 2009)
Survey of Bisphenol A in Bottled Water Products (Health Canada, 2009)
Study Shows Drinking Water Contaminated With Potent Estrogen (Water Online summary of German study, 2009)
Bottled Water and Infant Formula (U.S. FDA)
Benzene in Beverages (U.S. FDA, 2006)
Since You Asked - Bisphenol A (FAQ on a compound associated with some plastics, and tips to reduce exposure, from NIEHS - NIH, 2008)
FAQ on the Occurrence of Benzene in Soft Drinks and Other Beverages (U.S. FDA, 2006)
Researcher Dispels Myth of Dioxins and Plastic Water Bottles (Johns Hopkins School of Public Health)
Plastic Water Bottles (The Green Guide, 2004)
The (Possible) Perils of Being Thirsty While Being Green (essay in NY Times, 1/5/08, discusses types of plastic and other containers, and various chemicals currently under scientific and regulatory review)
NYS Bottled and Bulk Water Standards (Title 10, Part 5, Subpart 5-6)
NSF International Consumer Page - non-profit third-party testing and certification organization
Bottled Water - information and a search function for NSF certified bottlers
Bottled Water Web - commercial database of water bottlers - includes some information about actual water sources, water quality data, bottler website links, and contact information for bottlers.