Satisfying water quality standards is not a guarantee that your tap water is safe for drinking.

A recent study published in Heliyon links more than 100,000 future cancer cases in the U.S. to chemical pollutants in thousands of community water systems. The concentration of these pollutants in water systems is in the range considered legal, according to researchers from the Environmental Working Group (EWG), a non-profit research and advocacy organization based in Washington.

"The vast majority of community water systems meet legal standards," said co-author Olga Naidenko, EWG's vice president for science investigations. "Yet the latest research shows that contaminants present in the water at those concentrations – perfectly legal – can still harm human health."

Toxic cocktail of pollutants pose cancer risk