Tap water from public water systems is regulated by the Environmental Protection Agency (EPA). Routine testing of public water is required, and test results must be made available to the public. If your water comes from a well, the Centers for Disease Control and Prevention recommends having it tested once a year. Although U.S. drinking water is among the safest and most reliable in the world, it is not without controversy. Many people choose to use a whole house, under-sink, refrigerator, or pitcher-based filter system at home.
Spring water, according to the U.S. Food and Drug Administration (FDA), must be “derived from an underground formation from which water flows naturally to the surface” and cannot be altered. (Complaints have been raised against some manufacturers claiming fraudulent labelling.) “Glacier water” is typically runoff from a melting glacier (or glacier ice melted at a processing facility), but this is largely an unregulated term.
Mineral water, like spring water, originates from a protected underground water source that rises to the surface. According to the FDA, mineral water must contain at least 250 parts-per-million total dissolved solids, such as calcium, magnesium, zinc, and sodium. Flavor profile varies with the mineral make-up, and some mineral waters are effervescent from naturally occurring gases.
Purified water may come from any source (including a tap). It is purified by methods such as carbon filtration or reverse osmosis. Be aware that much of the water we buy in plastic bottles is simply tap water that has been filtered—often in ways similar to what can be accomplished more cheaply with a home filter.
Distilled water is a type of purified water from which all natural components have been removed. Distilled water prevents mineral buildup in appliances, for example, but it lacks beneficial nutrients and is not the best choice for human consumption.
Alkaline water has been treated to have a higher pH level than most tap or bottled waters. Proponents claim it helps keep the body “in balance” and provides health benefits, but there is very limited research to support these claims. The kidneys naturally keep the body’s acid/base ratio in balance. Eating more plant foods and less animal protein is a science-backed way of making the kidneys’ job easier.
Electrolyte waters have added minerals, such as sodium, potassium, and magnesium. This category can include sports drinks (which generally contain added sugars in addition to minerals) and preparations specifically marketed for hydration during illness, such as Pedialyte®. All waters (except distilled) contain some electrolytes. The concentrations of minerals in so-called “electrolyte water” vary by brand. While these products may be useful to athletes who are sweating profusely or people with stomach viruses, they are not necessary for normal hydration.
Flavored waters typically use natural or artificial fruit flavors for a change of pace from “plain” water. Look for brands without added sweeteners, or, better yet, make them at home (see recipe, below).
Sparkling waters are a better choice than carbonated sugar-sweetened beverages when you’re in the mood for a fizzy drink. The bubbles in these drinks come from the addition of carbon dioxide. This category includes club soda (which is infused with minerals, including sodium), tonic water (with added minerals and quinine, which imparts a bitter taste), and seltzers. Seltzers are often enhanced with natural fruit flavorings, artificial flavorings, or sometimes a small amount of fruit juice. They are generally unsweetened, but always scan the label to be sure there are no added sugars.
Costs and Concerns: Bottled water is much more expensive than tap water, and the costs don’t begin at the cash register. There is a steep environmental cost to using fossil fuels to make plastic water bottles, and a reported 86 percent of them end up as garbage or litter. Research into possible health impacts of the chemicals that leach from plastic bottles into beverages is ongoing. Municipal drinking water is required to undergo more rigorous and frequent safety testing and monitoring than bottled water (although we must acknowledge notable lapses in safety, such as Flint, Michigan).
Homemade flavored water or plain seltzer with a splash of fruit juice are a great choice for a change of pace. If you do choose bottled or canned varieties, be sure to recycle the containers. All in all, filtering tap water at home and carrying a reusable water bottle is a better choice for the environment—and all that’s necessary for healthy hydration.
- Aim For around eight (Eight-Ounce) cups of water each day to stay hydrated, more during a heat wave and when unusually physically active in hot weather
- Carry a reusable water bottle
- Invest in a water filter (whole house, under-sink, refrigerator, or pitcher) if you have concerns about your municipal or well water supply, and replace all filters as recommended
- Be aware that many bottled drinking waters come from a municipal source, just like tap water
- Read labels on flavored waters, as some have added sugars
- Don’t believe unverified health claims about specialty waters like alkaline and electrolyte products