(Bloomberg) — EPA Administrator Andrew Wheeler’s chief of staff is leaving the agency to work for the nation’s top coal mining trade group.Ryan Jackson is stepping down after three years at the Environmental Protection Agency to become the National Mining Association’s senior vice president of government affairs, the trade group said on Thursday night.“Mr. Jackson’s in-depth knowledge of the issues and nearly 20 years of working in the U.S. Senate demonstrate a reputation for persistence, integrity, working in a bipartisan fashion,” said Ashley Burke, a spokeswoman for the association, which represents companies such as Peabody Energy Corp. and Alliance Coal LLC.The EPA has oversight over many issues tied to mining, including the cleanup of old sites and water impacts tied to extracting coal and other minerals. The agency also regulates air pollution from power plants burning coal, and under President Donald Trump it has sought to ease mandates blamed for discouraging electric sector reliance on the fossil fuel.Because of Jackson’s government post, he will be restricted from lobbying the administration for five years and will focus solely on congressional advocacy, Burke said.Jackson joined the EPA after working for Senator Jim Inhofe, an Oklahoma Republican, and was counsel to the Senate Environment and Public Works Committee. His tenure as chief of staff began under the former EPA administrator, Scott Pruitt.His departure was reported earlier by Politico.Most recently, Jackson drew attention because of a dispute with the agency’s independent watchdog. For months, the office of the inspector general complained that Jackson was not fully cooperating with some of its investigations and openly defying efforts to get more information. The office last year went so far as to issue a rarely used “seven-day letter” formally admonishing Jackson.The dispute was deemed resolved after Jackson sat down for an interview with the watchdog’s investigators in December. On Jan. 16, the EPA’s acting inspector general said in a letter to lawmakers that Jackson’s cooperation with ongoing investigations was now complete and the matter “resolved,” though hardly “timely.”(Updates with details on EPA mining oversight, IG dispute starting in fourth paragraph.)To contact the reporters on this story: Ari Natter in Washington at [email protected];Jennifer A. Dlouhy in Washington at [email protected] contact the editors responsible for this story: Jon Morgan at [email protected], Steve GeimannFor more articles like this, please visit us at bloomberg.comSubscribe now to stay ahead with the most trusted business news source.©2020 Bloomberg L.P.