On March 28, the U.S. Court of Appeals for the Sixth Circuit ruled that the Environmental Protection Agency (EPA) can challenge power plant construction projects suspected of not fully considering potential air pollution increases. In 2010, the EPA sued DTE Energy for not installing pollution controls during boiler part replacement at their coal-fired power plant. DTE Energy claimed the plant was exempt from regulations because it was routine maintenance. A federal judge previously threw out the suit because the EPA filed the suit too soon after the maintenance.