A registered nurse, Brian Jones, drew a blood sample from a student at Eisenhower Elementary School in Flint, Mich., in 2016 to test for lead after the metal was found in the city’s drinking water.
Credit Carlos Osorio/Associated Press

If you live in the United States, there is a nearly one-in-four chance your tap water is either unsafe to drink or has not been properly monitored for contaminants in accordance with federal law, a new study has found.

In 2015, nearly 77 million Americans lived in places where the water systems were in some violation of safety regulations, including the 1974 Safe Drinking Water Act, according to the report released on Tuesday from the Natural Resources Defense Council, a New York-based environmental advocacy group. (emphasis added)

It’s not only that some tap water has high levels of lead, nitrates, arsenic or other pollutants, said Mae Wu, a senior attorney with the council’s health program. […]