Acid Rain Program

The Acid Rain Program is a market-based initiative taken by the United States Environmental Protection Agency in an effort to reduce overall atmospheric levels of sulfur dioxide and nitrogen oxides, which cause acid rain. The program is an implementation of emissions trading that primarily targets coal-burning power plants, allowing them to buy and sell emission permits (called "allowances") according to individual needs and costs. Allowance trading essentially ended in 2010 when EPA issued the Transport Rule. In 2011, the trading program that existed since 1995 was replaced by four separate trading programs under the Cross-State Air Pollution Rule (CSAPR). On August 21, 2012, the United States Court of Appeals for the District of Columbia issued its Opinion and Order in the appeal of the Cross State Air Pollution Rule (CSAPR). In deciding, EME Homer City Generation L.P. v. EPA, the Court vacated CSAPR for two independent legal reasons and has remanded the rule back to the Environmental Protection Agency (EPA) for further consideration.