The measures will set in motion Trump's campaign promises to rescind both the Clean Power Plan and the "Waters of the U.S." rule, while signaling the start of a new era at the federal agency that President Barack Obama put on the front lines of his battle against climate change. The directives are set to compel the EPA administrator to take any needed steps to withdraw those regulations, according to the people who described the documents and spoke on condition of anonymity about internal discussions.