U.S. environmental chief Scott Pruitt has unveiled plans to roll back at least three Obama-era rules at the EPA while vowing to give businesses “regulatory certainty.”

Those policy reversals, set to start this week, will empower the Environmental Protection Agency to focus on its core mission of protecting the air and water, Pruitt said Saturday in a speech and question-and-answer session on the final day of the Conservative Political Action Conference in Maryland.

“The previous administration was so focused on climate change and so focused on CO2, some of those other priorities were left behind,” Pruitt said in his first detailed remarks since being sworn in to lead the EPA on Feb. 17. “I really believe that at the end of eight years, we’re going to have better air quality, we’re going to have better water quality because it’s going to be vested in a partnership” with states.

As soon as Monday, President Donald Trump is slated to sign documents compelling the EPA to begin undoing recent regulations, including the Clean Power Plan that slashes greenhouse gas emissions from electricity generation and the Waters of the U.S. rule that defined which waterways are subject to pollution regulation.

Documents drafted by the Trump administration would direct Pruitt to begin dismantling those measures, helping fulfill the president’s pledge to eviscerate rules he describes as hampering U.S. energy ­development.

“There are some regulations that in the near term need to be rolled back in a very aggressive way,” Pruitt said. “In the next week, you may be hearing about some of those.”

“We know what those are: The previous administration took the Waters of the United States rule and transformed the Clean Water Act and made puddles and dry creek beds across this country subject to the jurisdiction of Washington, D.C.,” Pruitt said. “That’s going to change.”

Pruitt described another high-priority target: an EPA rule imposed last year that limits methane gas emissions from oil and gas wells. He took aim at the measure while he was Oklahoma’s attorney general, with the urging of oil and gas producer Devon Energy Corp., according to recently disclosed e-mails.

Pruitt built his political career fighting federal regulations he said usurped states’ power, joining more than a dozen lawsuits challenging EPA actions.