Skip to content
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.

Section 129 Plans

Section 129 of the Clean Air Act regulates solid waste combustion sources, such as incinerators. Section 111 of the CAA requires the U.S. Environmental Protection Agency (EPA) to issue "Standards of Performance for New Stationary Sources" (NSPS). Within one year of when EPA issues NSPS rules for solid waste combustion sources, Section 129 requires plans from states, commonly called "Section 129 plans," that detail how the state will implement and enforce those standards. Section 129 plans consist of regulations, a list of affected sources, and permits and emissions inventories for these sources. DHEC has adopt-by-reference authority to enforce NSPS regulations, which means when DHEC adopts an EPA-issued NSPS rule, DHEC has the authority to enforce it. We adopt these regulations by reference in our End of Year Revisions. CAA Section 129(b)(2) requires that if a state fails to submit an approvable Section 129 plan within two years of the date that EPA issues an NSPS rule for a group of solid waste combustion sources, then the EPA is required to develop a federal plan.

The requirements for these plans are distinct from State Implementation Plan (SIP) revisions that are based on Sections 110, 172, or 175A of the Clean Air Act. Provisions for sanctions, the content of the plans, and timing differ in the various types of plans.

DHEC has submitted 3 Section 129 plans to the EPA for five NSPS rules:

  • CISWI Rule: Commercial and industrial solid waste incineration units
  • HMIWI Rule: Hospital, medical, and infectious waste incinerators
  • LMWC Rule: Large municipal waste combustors
  • OSWI Rule: Other solid waste incineration units
  • SSI Rule: Sewage sludge incineration units

CISWI

CISWI is a federal rule entitled "Standards of Performance for New Stationary Sources and Emission Guidelines for Existing Sources: Commercial and Industrial Solid Waste Incineration Units" (65 FR 75338, December 1, 2000). EPA revised CISWI on October 3, 2003 (68 FR 57518), on March 21, 2011 (76 FR 15704), and on February 7, 2013 (78 FR 9112). DHEC submitted the Section 129 plan for CISWI on April 12, 2002. EPA approved this plan on April 3, 2004 (69 FR 9554).

HMIWI

HMIWI is a federal rule entitled "Standards of Performance for New Stationary Sources and Emission Guidelines for Existing Sources: Hospital/Medical/Infectious Waste Incinerators" (62 FR 48348, September 15, 1997; revised at 74 FR 51368, October 6, 2009). DHEC submitted a negative declaration to EPA for HMIWI on December 14, 2009. This negative declaration certifies that there are no sources in South Carolina subject to the HMIWI rule. EPA approved the negative declaration on April 25, 2011 (76 FR 22822).

LWMC

The LMWC rule is a federal rule entitled "Standards of Performance for New Stationary Sources and Emission Guidelines for Existing Sources Municipal Waste Combustor," (60 FR 65415, December 19, 1995; revised at 71 FR 27324, May 10, 2006). DHEC submitted a negative declaration for the LMWC rule on July 8, 2010. This negative declaration certifies that there are no sources in South Carolina subject to the LWMC rule. EPA approved the negative declaration on April 25, 2011 (76 FR 22822).

OSWI

OSWI is a federal rule entitled "Standards of Performance for New Stationary Sources and Emission Guidelines for Existing Sources: Other Solid Waste Incineration Units" (70 FR 74870, December 16, 2005). The EPA revised OSWI on January 22, 2007 (72 FR 2620). DHEC submitted its Section 129 plan for OSWI on June 25, 2007, and revised it on June 20, 2008. EPA has not taken action on this plan.

SSI

SSI is a federal rule entitled "Standards of Performance for New Stationary Sources and Emission Guidelines for Existing Sources: Sewage Sludge Incineration Units" (76 FR 15372, March 21, 2011). DHEC is currently developing the 129 plan for SSI, which includes adding 40 CFR 60 Subparts LLLL and MMMM to Regulation 61-62.60.


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