Trump tweeted that he has "no doubt that Andy will continue on with our great and lasting EPA agenda".
"With Scott Pruitt in charge, we can finally unravel the mess of the EPA, and begin developing and implementing thoughtful policies that will make measurable improvements to our natural resources and unleash an energy revolution that will bring jobs and higher wages to Americans".
The New York Times and CNN, quoting former EPA staff, reported on Thursday Mr Pruitt's aides retroactively deleted meetings from his public schedule in what could be potential violations of the US Federal Records Act. While Pruitt was sidetracked by scandal - such as claims of fiscal mismanagement - Wheeler is a nose-to-the-grindstone workaholic and will be able to achieve the agency's updated mission with little fanfare.
Wheeler was only marginally approved as EPA deputy in April.
Wheeler worked at FaegreBD Consulting and Faegre Baker Daniels law firm before going to the EPA. Trump needs to nominate a new agency chief, and his choice would then have to be confirmed by the Senate, which may not happen by mid-term elections in November.
Trump tweets that Deputy Administrator Andrew Wheeler will assume the acting administrator position Monday.
"I could have put my hat in the ring for the administrator".
At the EPA, staffers expect Wheeler to stick to the agenda set by Pruitt and Trump: Cutting environmental regulations that the Trump administration and industries see as unnecessarily burdensome to business, Southerland, the former water official, said. Mink said that when she first approached Pruitt, he "was all smiles", but as their conversation progressed, that smile quickly faded and the former EPA administrator got increasingly defensive and uncomfortable. Where Pruitt's somewhat sloppy policymaking means that some of his rulings can be challenged in court, Wheeler is known to be meticulous and may ultimately end up causing even more damage to environmental protection than his predecessor.
When it comes to substance, Wheeler has eschewed hardline political statements on environmental issues - but the public comments he has made show him in line with Trump administration policies.