How Clean is Your Drinking Water?

A recent analysis of the nation's water supplies reveals some dirty little secrets. Is your city on the Worst Water list?

By Emily Main


How clean is your drinking water?Ever wonder what's in your glass of water—besides water? Unfortunately, the answer may be "plenty." The laws designed to guarantee clean drinking water are getting weaker by the day, and a new report from the advocacy-oriented nonprofit Environmental Working Group (EWG) reveals just how much contaminated drinking water is pumping through our nation's municipal water pipes.

The EWG reviewed 20 million water-quality tests from the past five years, and found that the water flowing to about 85 percent of the population contains 316 contaminants. Of those, 202 chemical contaminants are not regulated by the Environmental Protection Agency, meaning that any water supply can have any level of the pollutants and a municipality doesn't need to take action to remove them. In some cases, those pollutants are at low levels and don't cause harm to human health. In others, however, the problems could be serious. For example, perchlorate, a component of rocket fuel that was recently detected by the Centers for Disease Control and Prevention in nearly all Americans tested, is one of those unregulated chemicals, and it can interfere with the body's thyroid-hormone production, which could lead to metabolic disorders and diabetes.

EWG also used its data to rank cities with the best and worst water supplies, based on the number and concentrations of hazardous chemicals found. At the top of the list were Arlington, Texas; Providence, Rhode Island; Fort Worth, Texas; Charleston, South Carolina; and Boston, Massachusetts. The five worst? Reno, Nevada; Riverside County, California; Las Vegas, Nevada; Riverside (city water supply), California; and Pensacola, Florida.

As growing populations and climate change threaten the availability of clean drinking water, it's important to make sure the water we do have is clean and reliable. Unfortunately, the law that regulates our water, the Safe Drinking Water Act, is decidedly outdated: A recent analysis of drinking-water laws by The New York Times found that not a single contaminant has been added to the act's list of regulated chemicals since 2000. In some cases, where research has found that chemicals can be harmful at lower doses than previously believed, the standards for regulating those chemicals have remained unchanged since 1974 when the law went into affect. And new threats like hydraulic fracturing used in natural-gas drilling use chemicals exempt from regulation and could further pollute our drinking water.