Washington (CNN) A top aide to Environmental Protection Agency Administrator Scott Pruitt is resigning.

Samantha Dravis, the associate administrator of the EPA's office of policy, is considered to be one of the aides closest to Pruitt and has been responsible in the last year for carrying out much of the agency's deregulation agenda that has been so controversial.

"It has been an honor to serve in this role at EPA, and I am enormously grateful for the opportunity," Dravis said in a statement to CNN. "I wish Administrator Pruitt and all of the public servants at EPA the very best."

The resignation news comes during a tough week for Pruitt in the wake of recent reports that he rented a $50-a-night room from a lobbyist who was actively lobbying the EPA.

A source familiar with the decision said Dravis resigned because she wanted to work in the private sector. She formally gave verbal notice last Tuesday, and sent her written notice last Thursday, the source said.

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