Regulations and SIPs

When the U.S. Environmental Protection Agency (EPA) establishes a new National Ambient Air Quality Standard (NAAQS) or revises an existing standard, it sets in motion a series of actions aimed at ensuring that air quality throughout the country meets those standards. State Implementation Plans (SIPs) are plans put together by states to help them meet the new or revised NAAQS.

The EPA designates areas as meeting ("attainment") or not meeting ("non-attainment") the new NAAQS. If an area meets attainment, states are required to develop a general plan to maintain the NAAQS. If an area is classified as non-attainment, states must formulate a specific plan to meet the new NAAQS. These plans are known as SIPs and are developed by state and local air quality management agencies and submitted to EPA for approval. Find more information about SIPs.