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Air Quality

Air Pollutants - Particulate Matter (PM) - Standards & Requirements

State Implementation Plan (SIP)

The Clean Air Act requires each state to develop a State Implementation Plan (SIP) that outlines the state's strategy for controlling air pollution for each of the National Ambient Air Quality Standards (standard). A SIP is a plan that can include a narrative, models, regulations, programs, and other technical documentation that a state presents as evidence of its efforts to address air pollution and maintain good air quality.

The Clean Air Act requires states to involve the general public and industry through public hearings and opportunities to comment on the development of each state plan. States then submit the initial SIP or SIP revision to the U.S. Environmental Protection Agency (EPA) for approval. Once approved, the SIP is enforceable by the state and EPA.

Infrastructure Certification SIPs are the general plans that each state must submit for implementing, maintaining, and enforcing any new or revised primary and secondary standard. These plans are due three years from the promulgation date of a new or revised standard regardless of the designations process. These are detailed in sections 110(a)(1) and (2) of the Clean Air Act.

On August 1, 2012, EPA approved both the 1997 and 2006 infrastructure SIPs for PM2.5, for all elements of the plan but interstate transport of air pollution (77 FR 45492). EPA partially disapproved the transport elements of the 2006 plan on October 11, 2012 (77 FR 61724). EPA action on transport elements for the 1997 PM2.5 NAAQS is pending and related to the outcome of the EPA's Cross State Air Pollution Rule.

Additional Resources

For more information please contact the Bureau of Air Quality at (803) 898-4123 or by email.