EarthTalk: Is Tap Water Safe to Drink?

Dear EarthTalk: Bottled water companies would have us all believe that tap water is unsafe to drink. But I've heard that most tap water is actually pretty safe. Is this true? -- Sam Tsiryulnikov, Los Angeles, CA

Tap water is not without its problems. The nonprofit Environmental Working Group (EWG) in 2005 tested municipal water in 42 states and detected some 260 contaminants in public water supplies, 140 of which were unregulated chemicals, that is, chemicals for which public health officials have no safety standards for, much less methods for removing them.

EWG did find over 90 percent compliance on the part of water utilities in applying and enforcing standards that exist, but faults the U.S. Environmental Protection Agency (EPA) for failing to establish standards on so many of the contaminants-from industry, agriculture and urban runoff-that do end up in our water.

Despite these seemingly alarming stats, the Natural Resources Defense Council (NRDC), which has also conducted extensive municipal as well as bottled water tests, says: "In the short term, if you are an adult with no special health conditions, and you are not pregnant, then you can drink most cities' tap water without having to worry." This is because most of the contaminants in public water supplies exist at such small concentrations that very large quantities would need to be ingested for health problems to occur.

NRDC does caution, however, that pregnant women, young children, the elderly, people with chronic illnesses and those with weakened immune systems can be especially vulnerable to the risks posed by contaminated water." The group suggests that anyone at risk obtain a copy of their city's annual water quality report (they are mandated by law) and review it with their physician.

As for bottled water, it is first important to know that 25 to 30 percent of it comes straight from municipal tap water systems, despite the pretty nature scenes on the bottles that imply otherwise. Some of that water goes through additional filtering, but some does not. NRDC has researched bottled water extensively and has found that it is "subject to less rigorous testing and purity standards than those which apply to city tap water." Bottled water is required to be tested less frequently than tap water for bacteria and chemical contaminants, and U.S. Food and Drug Administration bottled water rules allow for some contamination by E. coli or fecal coliform, contrary to EPA tap water rules which prohibit any such contamination.

Similarly, NRDC found that there are no requirements for bottled water to be disinfected or tested for parasites such as cryptosporidium or giardia, unlike more stringent EPA rules regulating tap water. This leaves open the possibility, says NRDC, that some bottled water may present similar health threats to those with weakened immune systems, the elderly and others they caution about drinking tap water.

The bottom line is that we have invested considerably in highly-efficient municipal water delivery systems that bring this precious liquid straight to our kitchen faucets anytime we need it. Instead of taking that for granted and relying on bottled water instead, we need to make sure our tap water is clean and safe for all.

CONTACTS: Environmental Working Group, www.ewg.org/tapwater/findings.php; EPA Local Drinking Water Information, www.epa.gov/safewater/dwinfo.htm; NRDC, www.nrdc.org/water.

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