A closer look at what caused the Flint water crisis

Flint, Michigan, continues to grapple with the public health crisis that unfolded as lead levels in its tap water spiked to alarming levels. Now the scientists who helped uncover the crisis have tested galvanized iron pipes extracted from the “ground zero” house. They confirm in the ACS journal Environmental Science & Technology that the lead that had accumulated on the interior surface of the pipes was the most likely source of the lead contamination. Flint’s tap water became contaminated with high lead levels after the city turned to the Flint River to supply its water in April 2014. When they switched, officials didn’t use a corrosion-control treatment to maintain the stability of rust layers (containing lead) inside service lines. Within a month of the switch, residents started to report smell and color changes to their water. After her family started getting sick, Flint resident LeeAnne Walters contacted Virginia Tech engineer Marc Edwards and asked him to test her water. All 32 samples from the Walters’ home contained lead concentrations above the U.S. Environmental Protection Agency action level of 15 micrograms per liter. Four samples were above 5,000 micrograms per liter, the threshold for hazardous waste. And one sample contained 13,200 micrograms per liter. -- More...