Today, the Environmental Protection Agency announced that EPA Region 5 Administrator Susan Hedman will resign as of February 1.

Hedman headed up the EPA regional department that oversees the Michigan Department of Environmental Quality. She was appointed to lead the EPA’s Region 5 office in 2010, where she oversaw EPA operations in six states. Before that, she was an environmental attorney with the Illinois Attorney General’s office.

Back in early 2015, emails from concerned EPA officials asked Michigan regulators whether Flint was treating to control corrosion. State officials said yes. When the EPA asked what kind of treatment, there seemed to be a reversal. One email says plainly: “Flint is currently not practicing corrosion control treatment.”

But that admission appeared to yield little consequence from the EPA.

When Michigan Radio asked in November if Flint broke federal rules by not having a corrosion control treatment plan, the U.S. EPA said the question was “relatively complex.”

Emails show at least one EPA employee believes Flint was required to treat the water to help prevent lead corrosion.

And although Hedman announced in November that the agency would review how Michigan monitors local drinking water, the EPA has not yet said, plainly, that Flint broke federal rules.

More from the EPA's press release:

EPA Region 5 Administrator Susan Hedman has offered her resignation effective February 1, and EPA Administrator Gina McCarthy has accepted given Susan’s strong interest in ensuring that EPA Region 5’s focus remains solely on the restoration of Flint’s drinking water.

In the release, McCarthy calls for a culture change in which all staff bring problems to light:

EPA Administrator Gina McCarthy sent a memo to all staff instating a formal policy, effective immediately, on elevation of critical public health issues. It includes specific parameters for staff to elevate critical public health and/or environmental issues so that the agency can properly assess them and respond at appropriate policy and governmental levels.

McCarthy requested that the EPA’s Office of Inspector General conduct an evaluation of Region 5's public water system supervision program.

The EPA says it is "working to understand what it could have done to prevent this crisis in the City of Flint."

The U.S. Department of Health and Human Services has been designated as the lead agency overseeing its response to the crisis in Flint. The Department will coordinate its response with the Federal Emergency Management Agency.