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Air Quality

Regulation and SIP Management

State Implementation Plan

The State Implementation Plan (SIP) is developed to show how a state will meet the National Ambient Air Quality Standards (NAAQS) for six common pollutants, called "criteria pollutants," as set forth by the Clean Air Act.

A SIP is the accumulated record of many documents that form a blueprint and timeline for the state's plans to assure compliance with the NAAQS for criteria pollutants (carbon monoxide, sulfur dioxide, ozone, nitrogen dioxide, lead, and particulate matter), as outlined in the Clean Air Act. SIPs include, among other things, control plans, regulations, inventories of emissions within the state, and transcripts of public involvement in the SIP-development process. Once approved, the SIP is enforceable by the state and EPA. Elements of South Carolina's SIP have been in place since 1972. Though there have been many amendments, there is only one South Carolina SIP. For more information, see EPA's SIP webpage.

Nonattainment SIP elements

A nonattainment plan is the specific SIP plan element designed to address a particular area in the state that has been designated as nonattainment for a standard. Once nonattainment designations take effect, the state has three years to develop a nonattainment SIP revision outlining how a particular area will attain and maintain the standards by reducing air pollutant emissions in that area.

The only nonattainment plans in South Carolina are for the York County part of the Charlotte-Gastonia-Rock Hill NC-SC nonattainment area for the 1997 Ozone NAAQS. For more information, see our Ozone SIP-Nonattainment Plan webpages.

The Clean Air Act also requires states with areas designated as nonattainment areas for Ozone(O3), carbon monoxide (CO), particulate matter (PM10 and PM2.5), or nitrogen dioxide (NO2) to demonstrate that any transportation plans, programs, and projects planned for the area are consistent with the state's air quality goals - attaining and maintaining the standards. South Carolina incorporated a Memorandum of Agreement into the SIP to satisfy the Interagency Consultation Requirements of the Federal Transportation Conformity Rule.

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