It’s no secret we need to drink water. In fact, drinking water aids digestion, circulation, nutrient transportation, weight loss, muscle energy, skin hydration, and toxin excretion (Zelman 2008). But where should we get our water?

Water’s origin often depends on our location. Americans drink more tap water when they are at home (two-thirds of the water they consume) than when they are away (one-half of the water they consume) (Sebastian, Enns, and Goldman 2011). And bottled water sales continue to increase. In 2011, Americans consumed 9.1 billion gallons of bottled water (IBWA 2012b).

The Environmental Protection Agency (EPA) regulates tap water, and the U.S. Food and Drug Administration (FDA) regulates bottled water. (Note: Carbonated, soda, seltzer, sparkling, and tonic waters are not regulated as bottled water [EPA 2005; FDA 2010].) But apart from the regulators and source, the main differences between tap and bottled water are the taste, fluoride concentration, and standards.

Some people prefer how bottled water tastes, a result of its treatment. Others don’t like the negative environmental impact associated with the disposal of plastic bottles, or simply prefer the lower price of tap water.

Most public water systems add fluoride to water, but not all bottled water companies do. The FDA sets limits for acceptable amounts of fluoride, but some bottled water treatment methods remove this fluoride (McCowan and Silitonga 2005; FDA 2010).

Standards can also differ. For example, tap water can absorb lead as it travels from water utilities to home faucets. For this reason, the EPA has higher lead limits for tap water (15 parts per billion [ppb]) than the FDA does for bottled water (5 ppb) (IBWA 2012a).

Among tap water drinkers, about 32% of communities who receive their water from public water systems drink groundwater. This water typically originates in wells 15 to 305 m (50 to 1,000 ft.) deep. Other communities receive surface water, which originates in rivers, lakes, and reservoirs (EPA 2009).

Many groundwater systems don’t require treatment to meet federal requirements. On the other hand, weather runoff and the atmosphere can more easily contaminate surface water, so it requires treatment (EPA 2009). Some treatment methods (i.e., chlorine, chloramine) continue to disinfect tap water as it travels through pipes to homes and businesses, but they can affect water’s taste and smell (EPA 2009).

At-home purification systems, such as carbon filters, can adjust tap water’s taste, odor, and organic contaminants, but do not affect hardness, bacteria, or nitrate.

Some bottled waters are named after their source, such as spring, artesian, well, and ground. Spring water comes from an underground formation where water flows naturally to the surface. It is collected at the spring or through a borehole that taps the underground formation (FDA 2010; IBWA 2012a; EPA 2005). Artesian and well water are tapped through a well. Ground water collects in spaces around rocks and soil beneath Earth’s surface.

Purified water can originate at any source (e.g., the tap). It receives treatment and does not typically contain any microbes or pathogens (IBWA 2012a; FDA 2010; EPA 2005).

Both bottled water and tap water are safe to drink if they meet government standards, unless you have a severely weakened immune system or other specific health condition (EPA 2005).

But regardless of whether you choose tap or bottled water, the EPA (2005) recommends that you educate yourself about what you’re drinking. Research your local water source on the EPA’s website ( www.epa.gov ), or read the label on your bottle to inform yourself about what you’re drinking. And remember, stay hydrated!

Do you have a question for the Health Wise column to answer? Send an e-mail to streker@nsta.org.

Acknowledgment

Sincere thanks to Russ Hauser, the Frederick Lee Hisaw professor of reproductive physiology at the Harvard School of Public Health, for reviewing this column.

References

Environmental Protection Agency (EPA). 2005. Bottled water basics. Washington, DC: EPA.

EPA. 2009. Drinking water treatment.

International Bottled Water Association (IBWA). 2012a. Types of water—Bottled.

IBWA. 2012b. U.S. consumption of bottled water shows significant growth, Increasing 4.1 percent in 2011.

McCowan, L., and M. Silitonga. 2005. Bottled water vs. tap water: Which is better? Paper presented at the Southern Region Water Quality Conference, Lexington, Kentucky.

Sebastian, R.S., C.W. Enns, and J.D. Goldman. 2011. Drinking water intake in the U.S.: What we eat in America, NHANES 2005–2008. Washington, DC: U.S. Department of Agriculture.

U.S. Food and Drug Administration (FDA). 2010. Bottled water everywhere: Keeping it safe.

Zelman, K.M. 2008. WebMD. 6 reasons to drink water.