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Air Quality

Regulation and SIP Management

New Source Review (NSR)

New Source Review (NSR) is a preconstruction permitting program that started with the Clean Air Act Amendments of 1977. The goal of NSR is to ensure that new facilities do not significantly degrade existing air quality in areas that attain the National Ambient Air Quality Standards (NAAQS), or prevent areas that are in nonattainment with the NAAQS from slowing progress towards improving their air quality. NSR also ensures that new facilities use the most current emissions control technology. The Environmental Protection Agency (EPA) significantly amended the NSR program in 2002, and DHEC incorporated those changes in 2005. DHEC incorporated further changes in 2009 and 2011, and EPA granted full approval to all three of these NSR revisions in 2011. Please see EPA's NSR webpage for more information.

On June 2, 2008, EPA acted on DHEC's July 1, 2005, amendments to S.C. Regulation 61-62.5, Standard No. 7, Prevention of Significant Deterioration; S.C. Regulation 61-62.5, Standard No. 7.1, Nonattainment New Source Review (NSR); and the State Implementation Plan (SIP) to incorporate provisions of the following federal rules:

  • "Prevention of Significant Deterioration (PSD) and Nonattainment New Source Review (NSR): Baseline Emissions Determination, Actual-to-Future-Actual Methodology, Plantwide Applicability Limitations, Clean Units, Pollution Control Projects" (62 FR 80186, December 31, 2002)
  • "Prevention of Significant Deterioration (PSD) and Nonattainment New Source Review (NSR): Equipment Replacement Provision of the Routine Maintenance, Repair and Replacement Exclusion)" (68 FR 61248, October 27, 2003).

EPA's June 2, 2008, action included a partial approval, a disapproval, and a conditional approval of DHEC's July 1, 2005 amendments. The disapproval was a result of the vacatur by the Court of Appeals for the DC Circuit of two parts of the 2002 federal rule above. The two vacated parts governed clean units and pollution-control projects. Following EPA's removal of these provisions from federal regulations in 2007, DHEC needed to remove them from state regulations. DHEC made that change in the 2009 NSR revisions. The conditional approval part of EPA's action required changes to emissions offset credits, which DHEC also did in the 2009 NSR revisions.

The EPA acted on its June 2, 2008, conditional and partial approval, disapproval, and conditional approval of R. 61-62.5, Standard No. 7, Prevention of Significant Deterioration; S.C. Regulation 61-62.5, Standard No. 7.1, Nonattainment New Source Review (NSR), in its June 23, 2011, final rule approving DHEC's 2009 and 2011 NSR revisions.

New Source Review Revision Documents

Federal Register Publications

  • "Approval and Promulgation of Implementation Plans; South Carolina; Prevention of Significant Deterioration and Nonattainment New Source Review Rules" (73 FR 31368, June 2, 2008)
  • "Prevention of Significant Deterioration (PSD) and Nonattainment New Source Review (NSR): Baseline Emissions Determination, Actual-to-Future-Actual Methodology, Plantwide Applicability Limitations, Clean Units, Pollution Control Projects" (62 FR 80186, December 31, 2002)
  • "Prevention of Significant Deterioration (PSD) and Nonattainment New Source Review (NSR): Equipment Replacement Provision of the Routine Maintenance, Repair and Replacement Exclusion)" (68 FR 61248, October 27, 2003)

If you have any questions, please contact Maeve Mason by phone at (803) 898-2230 or by email


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