The EPA official who led efforts to weaken Obama-era rules is leaving the agency.

As assistant administrator, Bill Wehrum faced scrutiny from Democratic lawmakers and environmental groups for his past ties to industry.

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A top Environmental Protection Agency who had led the agency's weakening of Obama-era climate change rules is resigning.

EPA Administrator Andrew Wheeler announced Wednesday the departure of Assistant Administrator Bill Wehrum, the chief of the agency's Office of Air and Radiation. Wehrum had been facing scrutiny from Democratic lawmakers and environmental groups for his past ties to industry, considering his role in drafting business-friendly regulations.

"While I have known of Bill's desire to leave at the end of this month for quite sometime, the date has still come too soon," Wheeler said. "I applaud Bill and his team for finalizing the Affordable Clean Energy regulation last week and for the tremendous progress he has made in so many other regulatory initiatives."

Wheeler named Anne Idsal acting assistant administrator. She is currently EPA's principal deputy assistant administrator.

Wehrum spearheaded EPA's rollback of the Obama-era Clean Power Plan that meant to regulate carbon emissions of coal plants. The agency last week finalized its replacement for the plan, called the Affordable Clean Energy, or ACE rule, which would give states latitude to improve the efficiency of coal plants, which critics charge is intended to encourage struggling coal plants to exist longer.

He has also led EPA's work, along with the Transportation Department, to weaken Obama-era fuel-efficiency rules for vehicles, a key initiative intended to reduce carbon emissions from transportation, the highest emitting economic sector.