The Environmental Protection Agency director overseeing a region that includes Flint, Michigan, is stepping down after contaminated water in that city exposed residents to lead poisoning.
EPA Region 5 Administrator Susan Hedman offered her resignation effective Feb. 1, and the offer was accepted, the EPA said in a statement Thursday.
The EPA also announced an emergency order requiring that the state and city "take a series of immediate steps to address the drinking water contamination in Flint."
The EPA has blamed resistance on the state and local level to its recommendations that the water be properly treated.
Residents in the town of nearly 100,000 have been warned not to drink unfiltered tap water and the National Guard has been distributing bottled water in Flint.
Flint in 2014 stopped using Detroit's water in a bid to save money, but the Flint River water it used wasn't properly treated and corroded pipes, allowing lead to leach into drinking water, officials said.
State health officials denied there was a problem until a Virginia Tech professor in August found that tests showed elevated levels of lead in Flint's water, and a pediatrician in September reported that a comparison of blood tests showed lead poisoning in children.
Michigan Gov. Rick Snyder declared a state of emergency in January. He has apologized to the people of Flint and has vowed to fix the problem and support those affected.
President Barack Obama on Sunday signed an emergency declaration ordering federal assistance.