Andrew Wheeler during his confirmation hearing to be Deputy Administrator of the Environmental Protection Agency before the United States Senate Committee on the Environment and Public Works on Capitol Hill in Washington, D.C. on November 8th, 2017. Alex Edelman | picture-alliance/dpa | AP

Scott Pruitt resigned as administrator of the Environmental Protection Agency on Thursday after a series of ethics scandals that exposed, among other things, questionable relationships with some of Washington’s elite energy lobbyists and powerful tycoons. Pruitt’s interim replacement, deputy EPA administrator and former coal lobbyist Andrew Wheeler, meanwhile, steps into his new role with long and lucrative ties to the energy and chemical industries. The appointment indicates that President Donald Trump’s EPA will maintain its cozy relationship with same corporations it is charged with regulating. The EPA has argued that there is distance between Wheeler and his ex-clients. Regarding Wheeler’s past lobbying work, agency spokeswoman Kelsi Daniels said in a statement "as stated in his May 24, 2018 recusal statement, the Deputy Administrator is recused from specific party matters involving former clients until April 28, 2020."

Murray Energy

As a lobbyist for Faegre Baker Daniels, Wheeler’s most lucrative client was Murray Energy Corporation, one of the largest coal companies in the U.S. It is run by CEO Robert Murray, who has ties to the president -- including donations to Trump’s 2016 campaign. In 2013, Murray Energy paid Faegre Baker Daniels $300,000 after Wheeler and his team lobbied members of Congress for what’s described in their quarterly disclosure forms as “general energy and environmental issues," according to disclosure forms reviewed by CNBC.

Murray has called on Trump to arrange an emergency bailout to keep open unprofitable coal plants. In March 2017, he met with Energy Secretary Rick Perry to propose regulatory changes to the coal industry. Murray’s connections to the Trump administration are also clear through his campaign contributions during the 2016 presidential election. He gave $10,000 to the Trump Victory committee, a joint fundraising group for the campaign and the Republican National Committee. He also shelled out $2,700 directly to Trump’s campaign. He has yet to donate Trump’s re-election efforts. Murray, in a statement first given to CNBC, praised Pruitt as "very qualified" and said that he "worked diligently to protect our environment, while concomitantly providing regulatory certainty for our Nation’s economy." As for Wheeler, though, the coal baron said he hasn’t had any contact with the official since he became Pruitt's deputy. Murray declined to comment further on Wheeler’s appointment.

Celanese Corp.

Wheeler also lobbied for Celanese Corporation, a chemical industry giant. Ranked in 2012 as a Fortune 500 company, Celanese paid approximately $241,000 from 2011 through 2012 for Wheeler’s services, according to lobbying disclosure forms. The reports show that Wheeler, similar to his work with Murray Energy, lobbied members of Congress, only this time for “chemical issues.” Celanese CEO Mark Rohr gave $2,700 to Hillary Clinton’s campaign in 2016, but this year he has contributed $5,000 to the McConnell for Majority Leader Committee, a joint fundraising organization that supports Republican Senate Majority Leader Mitch McConnell and the Kentucky Republican Party, Federal Election Commission records show. Rohr backed McConnell’s campaign directly through the McConnell Senate Committee.

Energy Fuels Resources Inc.

Wheeler also worked with Energy Fuels Resources Inc., a leading U.S. based uranium producer. In 2016 it was considered the second largest supplier of uranium in the country and was moving up the ranks to become number one throughout the following year. Starting in April 2017, Wheeler’s firm was paid $20,000 for two quarters of work. Each time they met with congressional lawmakers they discussed “general energy issues related to uranium mining and milling.”

Environmentalists are worried