On March 29, the Environmental Protection Agency (EPA) filed a petition with the Supreme Court to consider a ruling by the U.S. Court of Appeals for the District of Columbia Circuit on the Cross-State Air Pollution Rule. The rule was published in August 2011 and was designed to help downwind states meet clean air standards by reducing power plant emissions. The Circuit Court ruled that the agency should have allowed states to issue implementation plans rather than creating federal plans. The EPA said the ruling will prevent the agency from addressing a serious public health problem.