Tap water can meet legal limits and still pose risks

The tap water you drink may be within the legal limit for several contaminants but still pose a significant health risk, The New York Times reports in the latest in the paper's series on water quality.

After reviewing records from the Environmental Protection Agency and the U.S. Geological Survey, Charles Duhigg reports government scientists have evaluated 830 of the contaminants most often found in water supplies and have determined that many of them are associated with cancer or other diseases, even at small concentrations, but almost none of the chemicals have been incorporated into water-protection laws. (Read more)

One example: the legal level of arsenic in drinking water. A community could drink perfectly legal water and one in every 600 residents would likely develop bladder cancer, a risk is roughly equivalent to receiving 1,664 X-rays, Duhigg reports. You can see The Times map of the 25 water systems with the highest arsenic levels below.