The U.S. Environmental Protection Agency (EPA) is a department specific to the Clean Air Act. Its purpose is to make sure the amount of air pollution emitted stays inside the standards set by the U.S. Each state is required to have a state implementation plan (SIPs) that clearly indicates how it will enforce the regulations of the Clean Air Act. The states have to create regulations of their own that also adhere to the guidelines of the U.S. regulations; in order to do so, they must hold hearings so the public can contribute ideas and provide feedback.