On February 17, 2010, the EPA issued a final rule under the Clean Air Act intended to reduce emissions of toxic pollutants from existing diesel powered stationary reciprocating internal combustion engines (RICE), also known as compression ignition (CI) engines. The new rules are important because they will affect operations at many facilities throughout the country that need to generate electricity for certain applications. RICE engines are typically used in industrial facilities such as power plants, chemical and manufacturing plants to generate electricity for compressors and pumps. The engines can also serve in emergency situations to produce electricity to pump water for flood and fire control. In general, the rules will require installation of pollution control equipment, performance of emissions tests and the burning of ultra-low sulfur fuel. This article, in combination with the EPA fact sheet, summarizes the key aspects of the rule.