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BOSTON, Dec 23 (Reuters) - Three U.S. Democratic senators have asked the investigative arm of Congress to evaluate a $1 billion-a-year subsidy for burning chemically treated refined coal, after research has shown that some power plants using the fuel produced surging amounts of mercury and smog instead of cutting pollution.
Senator Sheldon Whitehouse of Rhode Island, as well as Senators Elizabeth Warren of Massachusetts and Sherrod Brown of Ohio, on Friday requested the Government Accountability Office investigate the tax credit program for refined coal, according to a letter viewed by Reuters.
The request for an investigation comes after a Reuters Special Report in December 2018 revealed that many power plants burning refined coal pumped out more smog, not less.
After the Reuters report, a study by independent nonprofit Resources for the Future found that power plants using refined coal were not reducing mercury, nitrogen oxide and sulfur dioxide pollution to levels required by the tax credit program.
Those pollutants rose sharply at some power plants after they began burning refined coal, the study said. Others showed reductions, but not enough to meet the requirements for taxpayer subsidies, according to the study by the Washington, D.C., research institution.
"(This) raises questions about the extent to which the use of refined coal is actually achieving the emissions reductions required to claim the refined coal production tax credit," the senators wrote in their letter to the GAO.
(Reporting by Tim McLaughlin in Boston Editing by Leslie Adler and Matthew Lewis)