In Sebring, Ohio, routine laboratory tests last August found unsafe lead levels in the town’s drinking water after workers stopped adding a chemical to keep lead water pipes from corroding. Five months passed before the city told pregnant women and children not to drink the water, and shut down taps and fountains in schools.

In 2001, after Washington, D.C., changed how it disinfected drinking water, lead in tap water at thousands of homes spiked as much as 20 times the federally approved level. Residents did not find out for three years. When they did, officials ripped out lead water pipes feeding 17,600 homes — and discovered three years later that many of the repairs had only prolonged the contamination.  [Read more…]