2013-01205. Approval and Promulgation of Implementation Plans; South Carolina: New Source Review-Prevention of Significant Deterioration

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Proposed rule.

SUMMARY:

EPA is proposing to approve changes to the South Carolina State Implementation Plan (SIP) submitted by the South Carolina Department of Health and Environmental Control (SC DHEC) to EPA in five separate SIP submittals dated May 1, 2012, July 18, 2011, February 16, 2011, December 23, 2009, and December 4, 2008. The SIP revisions make changes to South Carolina's New Source Review (NSR) Prevention of Significant Deterioration (PSD) program to adopt federal PSD requirements regarding fine particulate matter (PM_2.5) and changes to the State's provisions related to the national ambient air quality standards (NAAQS) and volatile organic compounds (VOC). EPA is proposing to approve portions of the submittals as revisions to South Carolina's SIP because the Agency has preliminarily determined that they are consistent with section 110 of the Clean Air Act (CAA or Act) and EPA regulations regarding NSR permitting.

DATES:

Comments must be received on or before February 22, 2013.

ADDRESSES:

Submit your comments, identified by Docket ID No. EPA-R04-OAR-2012-0837 by one of the following methods:

1. www.regulations.gov: Follow the on-line instructions for submitting comments.

2. Email: [e-mail].

3. Fax: [phone].

4. Mail: EPA-R04-OAR-2012-0837, Regulatory Development Section, Air Planning Branch, Air, Pesticides and Toxics Management Division, U.S. Environmental Protection Agency, Region 4, 61 Forsyth Street SW., Atlanta, Georgia 30303-8960.

5. Hand Delivery or Courier: Ms. Lynorae Benjamin, Chief, Regulatory Development Section, Air Planning Branch, Air, Pesticides and Toxics Management Division, U.S. Environmental Protection Agency, Region 4, 61 Forsyth Street SW., Atlanta, Georgia 30303-8960. Such deliveries are only accepted during the Regional Office's normal hours of operation. The Regional Office's official hours of business are Monday through Friday, 8:30 to 4:30, excluding federal holidays.

Instructions: Direct your comments to Docket ID No. “EPA-R04-OAR-2012-0837.” EPA's policy is that all comments received will be included in the public docket without change and may be made available online at www.regulations.gov,, including any personal information provided, unless the comment includes information claimed to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Do not submit through www.regulations.gov or email, information that you consider to be CBI or otherwise protected. The www.regulations.gov Web site is an “anonymous access” system, which means EPA will not know your identity or contact information unless you provide it in the body of your comment. If you send an email comment directly to EPA without going through www.regulations.gov,, your email address will be automatically captured and included as part of the comment that is placed in the public docket and made available on the Internet. If you submit an electronic comment, EPA recommends that you include your name and other contact information in the body of your comment and with any disk or CD-ROM you submit. If EPA cannot read your comment due to technical difficulties and cannot contact you for clarification, EPA may not be able to consider your comment. Electronic files should avoid the use of special characters, any form of encryption, and be free of any defects or viruses. For additional information about EPA's public docket visit the EPA Docket Center homepage at http://www.epa.gov/​epahome/​dockets.htm.

Docket: All documents in the electronic docket are listed in the www.regulations.gov index. Although listed in the index, some information is not publicly available, i.e., CBI or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the Internet and will be publicly available only in hard copy form. Publicly available docket materials are available either electronically in www.regulations.gov or in hard copy at the Regulatory Development Section, Air Planning Branch, Air, Pesticides and Toxics Management Division, U.S. Environmental Protection Agency, Region 4, 61 Forsyth Street SW., Atlanta, Georgia 30303-8960. EPA requests that if at all possible, you contact the person listed in the FOR FURTHER INFORMATION CONTACT section to schedule your inspection. The Regional Office's official hours of business are Monday through Friday, 8:30 to 4:30, excluding federal holidays.

FOR FURTHER INFORMATION CONTACT:

For information regarding the South Carolina SIP, contact Ms. Twunjala Bradley, Regulatory Development Section, Air Planning Branch, Air, Pesticides and Toxics Management Division, U.S. Environmental Protection Agency, Region 4, 61 Forsyth Street SW., Atlanta, Georgia 30303-8960. Ms. Bradley's telephone number is [phone]; email address: [e-mail]. For information regarding NSR or PSD, contact Ms. Yolanda Adams, Air Permits Section, at the same address above. Ms. Adams' telephone number is [phone]; email address: [e-mail]. For information regarding the PM_2.5 NAAQS, contact Mr. Joel Huey, Regulatory Development Section, at the same address above. Mr. Huey's telephone number is [phone]; email address: [e-mail].

SUPPLEMENTARY INFORMATION:

Table of Contents

I. What action is EPA proposing?

II. What is the background for EPA's proposed action?

III. What is EPA's analysis of South Carolina's SIP submittals?

IV. Proposed Actions

V. Statutory and Executive Order Reviews

I. What action is EPA proposing?

EPA is proposing to approve portions of SIP submittals provided by SC DHEC to EPA on May 1, 2012,^[1] July 18, 2011, February 16, 2011, December 23, 2009, and December 4, 2008, to adopt NSR permitting requirements for implementing the PM_2.5 NAAQS, federal changes to the NAAQS, an update to the federal definition for VOC, and an administrative correction to the State's VOC rule. South Carolina's May 1, 2012, SIP submittal amends the State's PSD regulations at Regulation 61-62.5, Standard No. 7—Prevention of Significant Deterioration to adopt the PM_2.5 PSD increments promulgated in the rule entitled “Prevention of Significant Deterioration (PSD) for Particulate Matter Less Than 2.5 Micrometers (PM_2.5)—Increments, Significant Impact Levels (SILs) and Significant Monitoring Concentration (SMC),” Final Rule, 75 FR 64864, (October 20, 2010) (hereafter referred to as “PM_2.5 PSD Increments-SILs-SMC Rule”).^[2] The December 4, 2008, December 23, 2009, and July 18, 2011, SIP submissions, as well as the May 1, 2012, submission, all update South Carolina's ambient air quality standards table at 61-62.5, Standard No. 2—Ambient Air Quality Standards to be consistent with EPA's NAAQS at 40 CFR part 50 and table at http://www.epa.gov/​air/​criteria.html. Also, South Carolina's December 4, 2008, and February 16, 2011, SIP submittals amend the State's definition for VOC to be consistent with the federal definition at 40 CFR 51.100(s). Lastly, the December 4, 2008, submittal makes an administrative correction to Regulation 61-62.5, Standard 5—Volatile Organic Compounds. Details concerning each SIP submittal are summarized below.

II. What is the background for EPA's proposed action?

Today's proposed action regarding the PSD provisions relate to EPA's PM_2.5 PSD Increments-SILs-SMC Rule. Today's proposed actions on administrative changes to South Carolina's ambient air quality standards and to South Carolina's definition for VOC relate to other federal rule changes including the federal VOC definition at 40 CFR 51.100(s). More detail on the PM_2.5 PSD Increments-SILs-SMC Rule can be found in EPA's October 20, 2010, final rule and is summarized below. See 75 FR 64864.

A. PM _2.5 PSD Increments-SILs-SMC-Rule

On October 20, 2010, EPA finalized the PM_2.5 PSD Increments-SILs-SMC Rule to provide additional regulatory requirements under the PSD program regarding the implementation of the PM_2.5 NAAQS for NSR.^[3] Specifically, the rule establishes: (1) PM_2.5 increments pursuant to section 166(a) of the CAA to prevent significant deterioration of air quality in areas meeting the NAAQS; (2) SILs used as a screening tool (by a major source subject to PSD) to evaluate the impact a proposed major source or modification may have on the NAAQS or PSD increment; and (3) a SMC (also a screening tool) used by a major source subject to PSD to determine if a source must submit to the permitting authority one year of pre-construction air quality monitoring data prior to constructing or modifying a facility. South Carolina's May 1, 2012, SIP submittal adopts the PM_2.5 increments portion of the PM_2.5 PSD Increments-SILs-SMC Rule to be consistent with the federal NSR regulations and to appropriately implement the State's NSR program for the PM_2.5 NAAQS. South Carolina's May 1, 2012, SIP submittal did not adopt the SILs and SMC screening tools also promulgated in the October 20, 2010, rule as the screening tools are not required by the Act as part of an approvable SIP program.^[4] EPA's authority to implement the SILs and SMC for PSD purposes has been challenged by the Sierra Club. Sierra Club v. EPA, Case No 10-1413 (D.C. Circuit Court).^[5]

1. What are PSD increments?

As established in part C of title I of the CAA, EPA's PSD program protects public health from adverse effects of air pollution by ensuring that construction of new or modified sources in attainment or unclassifiable areas does not lead to significant deterioration of air quality while simultaneously ensuring that economic growth will occur in a manner consistent with preservation of clean air resources. Under section 165(a)(3) of the CAA, a PSD permit applicant must demonstrate that emissions from the proposed construction and operation of a facility “will not cause, or contribute to, air pollution in excess of any maximum allowable increase or allowable concentration for any pollutant.” In other words, when a source applies for a permit to emit a regulated pollutant in an area that meets the NAAQS, the state and EPA must determine if emissions of the regulated pollutant from the source will cause significant deterioration in air quality. Significant deterioration occurs when the amount of the new pollution exceeds the applicable PSD increment, which is the “maximum allowable increase” of an air pollutant allowed to occur above the applicable baseline concentration ^[6] for that pollutant. PSD increments prevent air quality in clean areas from deteriorating to the level set by the NAAQS. Therefore, an increment is the mechanism used to estimate “significant deterioration” of air quality for a pollutant in an area.

For PSD baseline purposes, a baseline area for a particular pollutant emitted from a source includes the attainment or unclassifiable area in which the source is located as well as any other attainment or unclassifiable area in which the source's emissions of that pollutant are projected (by air quality modeling) to result in an ambient pollutant increase of at least 1 microgram per meter cubed (μg/m^[3] ) (annual average). See 40 CFR 52.21(b)(15)(i). Under EPA's existing regulations, the establishment of a baseline area for any PSD increment results from the submission of the first complete PSD permit application and is based on the location of the proposed source and its emissions impact on the area. Once the baseline area is established, subsequent PSD sources locating in that area need to consider that a portion of the available increment may have already been consumed by previous emissions increases. In general, the submittal date of the first complete PSD permit application in a particular area is the operative “baseline date” after which new sources must evaluate increment consumption.^[7] On or before the date of the first complete PSD application, emissions generally are considered to be part of the baseline concentration, except for certain emissions from major stationary sources. Most emissions increases that occur after the baseline date will be counted toward the amount of increment consumed. Similarly, emissions decreases after the baseline date restore or expand the amount of increment that is available. See 75 FR 64864. As described in the PM_2.5 PSD Increments-SILs-SMC Rule, and pursuant to the authority under section 166(a) of the CAA, EPA promulgated numerical increments for PM_2.5 as a new pollutant ^[8] for which NAAQS were established after August 7, 1977,^[9] and derived 24-hour and annual PM_2.5 increments for the three area classifications (Class I, II and III) using the “contingent safe harbor” approach. See 75 FR 64864 at 64869 and ambient air increment table at 40 CFR 51.166(c)(1) and 52.21(c).

In addition to PSD increments for the PM_2.5 NAAQS, the PM_2.5 PSD Increments-SILs-SMC Rule amended the definition at 40 CFR 51.166 and 52.21 for “major source baseline date” and “minor source baseline date” (including trigger dates) to establish the PM_2.5 NAAQS specific dates associated with the implementation of PM_2.5 PSD increments. See 75 FR 64864. In accordance with section 166(b) of the CAA, EPA required the states to submit revised implementation plans to EPA for approval (to adopt the PM_2.5 PSD increments) within 21 months from promulgation of the final rule (by July 20, 2012). Regardless of when a state submits its revised SIP, the emissions from major sources subject to PSD for PM_2.5 for which construction commenced after October 20, 2010 (major source baseline date), consume PM_2.5 increment and should be included in the increment analyses occurring after the minor source baseline date is established for an area under the state's revised PSD program. See 75 FR 64864. As discussed in detail in Section III, South Carolina's May 1, 2012, SIP submission adopts the PM_2.5 PSD increment permitting requirements promulgated in the PM_2.5 PSD Increments-SILs-SMC Rule.

III. What is EPA's analysis of South Carolina's SIP submittals?

South Carolina currently has a SIP-approved NSR program for new and modified stationary sources. SC DHEC's PSD preconstruction rules are found at Regulation 61-62.5, Standard No. 7- Prevention of Significant Deterioration and apply to major stationary sources or modifications constructed in areas designated attainment or unclassifiable/attainment as required under part C of title I of the CAA with respect to the NAAQS. EPA is proposing to approve changes to South Carolina's SIP to adopt the PM_2.5 PSD increments, administrative updates to the State's NAAQS table at Regulation 61-62.5, Standard No. 2, and a revision to the VOC definition at Regulation 61-62.1—Definitions and General Requirements—VOC. See below for more details on South Carolina's changes to its SIP.

A. Regulation 62-62.5, Standard No. 7—Prevention of Significant Deterioration

South Carolina's May 1, 2012, SIP submittal adopts PM_2.5 PSD increments for the PM_2.5 annual and 24-hour NAAQS (pursuant to section 166(a) of the CAA) into the South Carolina SIP (at Regulation 61-62.5, Standard No. 7) as promulgated in the October 20, 2010, and includes: (1) Addition of PM_2.5 PSD increments at SC DEHC's increments at Regulation 61-62.5, Standard No. 7 (c) and (p)(5) (for Class I variances) (consistent with the tables at 40 CFR 51.166(c)), including replacing the term “particulate matter” with “PM₁₀” in the tables at Regulation 61-62.5, Standard No. 7 paragraphs (c) and (p)(5) (for Class I Variances) and replacing the term “particulate matter” with “PM_2.5, PM₁₀” in the text at Regulation 61-62.5, Standard No. 7 paragraph (p)(5) (for Class I Variances); (2) revision to the definition at Regulation 61-62.5, Standard No. 7, paragraph (b)(31)(i)(a)-(c) for “major source baseline date” (consistent with 40 CFR 51.166(b)(14)(i)(a) and (c)), to establish major source baseline date for PM_2.5 and removing the term “particulate matter” to distinguish between PM₁₀ and PM_2.5; Regulation 61-62.5, Standard No. 7, paragraph (b)(31)(ii)(a)-(c) for “minor source baseline date,” to establish the PM_2.5 “trigger date” (consistent with 40 CFR 51.166(b)(14)(ii)(c)) and remove the term “particulate matter” to distinguish between PM₁₀ and PM_2.5; (3) revisions to Regulation 61-62.5, Standard No. 7, paragraph (5)(i) for “baseline area” (consistent with 40 CFR 51.166(b)(15)(i) and (ii)) to specify pollutant air quality impact annual averages and amend the regulatory reference for section 107(d) of the CAA at paragraph (5)(ii); and (4) amendment to Regulation 61-62.5, Standard No. 7 paragraph (b)(31)(iii)(a) to also amend the regulatory reference for section 107(d) of the CAA and to add a reference to 40 CFR 51.166. These changes provide for the implementation of the PM_2.5 PSD increments for the PM_2.5 NAAQS in South Carolina's PSD program. In today's action, EPA is proposing to approve South Carolina's May 1, 2012, SIP submittal to address PM_2.5 PSD increments. As mentioned above, South Carolina's May 1, 2012, SIP submittal did not propose to adopt the SILs and SMC screening tools also promulgated in the PM_2.5 PSD Increments-SILs-SMC Rule.

B. Regulation 61.62.5, Standard No. 2—Ambient Air Quality Standards

Sections 108 and 109 of the CAA govern the establishment, review, and revision, as appropriate, of the NAAQS to protect public health and welfare. The CAA requires periodic review of the air quality criteria—the science upon which the standards are based—and the standards themselves. EPA's regulatory provisions that govern the NAAQS are found at 40 CFR part 50—National Primary and Secondary Ambient Air Quality Standards. In this rulemaking, EPA is proposing to approve portions of multiple South Carolina SIP submissions amending the State's NAAQS table for PM_2.5, PM₁₀, ozone and lead that are found at Regulation 61.62-5, Standard No. 2. The four SIP submittals amending SC DEHC's NAAQS table can be found in the Docket for this proposed rulemaking at www.regulations.gov and are summarized below.

1. South Carolina's December 4, 2008, SIP Submittal ^[10]

On October 17, 2006, EPA revised the 24-hour primary NAAQS for PM_2.5 from a level of 65 micrograms per cubic meter (µg/m³) to 35 µg/m³. See 71 FR 61144. Accordingly, South Carolina's December 4, 2008, SIP submittal amends the State's NAAQS table to address the amendment to the 24-hour primary NAAQS for PM_2.5 from 65 µg/m³ to 35 µg/m³. EPA is proposing to approve this change to South Carolina's NAAQS table at Regulation 61.62-5, Standard No. 2, based on a preliminary determination that this change is consistent with EPA's regulations for the 24-hour primary NAAQS for PM_2.5.

2. South Carolina's December 23, 2009, SIP Submittal ^[11]

On March 27, 2008, EPA revised the primary and secondary NAAQS for the 8-hour ozone to 75 parts per billion (ppb) to provide increased protection of public health and welfare, respectively. See 73 FR 16436. Accordingly, South Carolina's December 23, 2009, SIP submittal amends the State's NAAQS table to: (1) add the 2008 8-hour ozone NAAQS of 75 ppb, and (2) remove the 1-hour ozone NAAQS, which EPA revoked on June 15, 2005, one year after the effective date of the 1997 8-hour ozone designations. See 70 FR 44470 (August 3, 2005), 69 FR 23858 and 69 FR 23951 (April 30, 2004).^[12] Additionally, on November 12, 2008, EPA revised the lead NAAQS from 1.5 µg/m³ to 0.15 µg/m³ based on a rolling 3-month average for both the primary and secondary standards. See 73 FR 66964. South Carolina's December 23, 2009, SIP submittal amends the State's NAAQS table to adopt the 2008 lead NAAQS of 0.15 µg/m³ based on a rolling 3-month average for both the primary and secondary standards.

EPA is proposing to approve these change to South Carolina's NAAQS table at Regulation 61.62-5, Standard No. 2, based on a preliminary determination that these changes are consistent with EPA's regulations for the 2008 8-hour ozone NAAQS and the 2008 lead NAAQS. Further, EPA is proposing to approve South Carolina's removal of the 1-hour ozone NAAQS from its SIP at Regulation 61.62-5, Standard No. 2, because this NAAQS has been revoked by the Agency for South Carolina areas.

3. South Carolina's July 18, 2011, SIP Submittal ^[13]

South Carolina's July 18, 2011, SIP submittal removes the annual total suspended particulate (TSP) standard from South Carolina's NAAQS table.^[14] This SIP submittal also clarifies that the carbon monoxide 1-hour and 8-hour average concentrations are not to be exceeded more than once a year (in accordance with 40 CFR 50.8) and adds a footnote referencing 40 CFR 50.16 for detailed explanation concerning calculation of the rolling 3-month average for the lead NAAQS. However, these two revisions are superseded by SC's DHEC's May 1, 2012, SIP submittal which streamlines and reformats the State's NAAQS table. See discussion below.

4. South Carolina's May 1, 2012, SIP Submittal ^[15]

South Carolina's May 1, 2012, submittal removes from the State's NAAQS table the PM₁₀ annual standard to be consistent with EPA's October 17, 2006, revocation of the annual PM₁₀ NAAQS. See 71 FR 61144. Additionally, this SIP submittal reformats SC DEHC's NAAQS table in an effort to ensure information found therein is consistent with EPA's NAAQS at 40 CFR 50 and the table at http://www.epa.gov/​air/​criteria.html including (1) removing the table's footnotes and instead adding a column referencing the federal CFR for each NAAQS; (2) streamlining the units column; and (3) updating test method references.

C. Regulation 61-62.1—Definitions and General Requirements

South Carolina's December 4, 2008, and February 16, 2011,^[16] SIP submittals revise the definition for VOC at Regulation 61-62.1—Definitions and General Requirements to include additional compounds 1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-trifluoromethyl-pentane (HFE-7300) (as amended on January 18, 2007 (72 FR 2193)) and propylene carbonate and dimethyl carbonate (amended on January 21, 2009 (74 FR 3437)) respectively to the list of compounds excluded from the definition of VOC on the basis that they have a negligible contribution to tropospheric formation of ozone.^[17] EPA has preliminarily determined that these changes are consistent with EPA's federal regulations at 40 CFR 51.100 and as such is proposing to approve these changes into the South Carolina SIP.

D. Regulation 61-62.5, Standard 5—Volatile Organic Compounds

South Carolina's December 4, 2008, SIP submittal makes an administrative correction to subparagraphs 2.a.(i)(a) and (b) of Regulation 61-62.5, Standard 5, Section II, Part Q (Manufacture of Synthesized Pharmaceutical Products) by adding the term and symbol “minus (−)” to express the outlet gas temperature threshold for surface condensers.

IV. Proposed Action

EPA is proposing to approve multiple submissions revising South Carolina's SIP to adopt the PM_2.5 increments as amended in the October 20, 2010, PM_2.5 PSD Increments-SILs-SMC Rule, to adopt federal NAAQS updates and VOC definition updates, and to make an administrative correction. EPA has made the preliminary determination that these SIP submittals, with regard to the aforementioned proposed actions, are approvable because they are consistent with section 110 of the CAA and EPA regulations regarding NSR permitting.

V. Statutory and Executive Order Reviews

Under the CAA, the Administrator is required to approve a SIP submission that complies with the provisions of the Act and applicable federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in reviewing SIP submissions, EPA's role is to approve state choices, provided that they meet the criteria of the CAA. Accordingly, this proposed action merely approves state law as meeting federal requirements and does not impose additional requirements beyond those imposed by state law. For that reason, this proposed action:

• Is not a “significant regulatory action” subject to review by the Office of Management and Budget under Executive Order 12866 (58 FR 51735, October 4, 1993);
• Does not impose an information collection burden under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
• Is certified as not having a significant economic impact on a substantial number of small entities under the Regulatory Flexibility Act (5 U.S.C. 601 et seq.);
• Does not contain any unfunded mandate or significantly or uniquely affect small governments, as described in the Unfunded Mandates Reform Act of 1995 (Pub. L.104-4);
• Does not have Federalism implications as specified in Executive Order 13132 (64 F43255, August 10, 1999);
• Is not an economically significant regulatory action based on health or safety risks subject to Executive Order 13045 (62 FR 19885, April 23, 1997);
• Is not a significant regulatory action subject to Executive Order 13211 (66 FR 28355, May 22, 2001);
• Is not subject to requirements of Section 12(d) of the National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) because application of those requirements would be inconsistent with the CAA; and
• Does not provide EPA with the discretionary authority to address, as appropriate, disproportionate human health or environmental effects, using practicable and legally permissible methods, under Executive Order 12898 (59 FR 7629, February 16, 1994).

In addition, this proposed rule does have tribal implications as specified by Executive Order 13175 (65 FR 67249, November 9, 2000), because the SIP is being proposed for approval to apply PSD permitting program statewide including the Catawba Indian Nation. Accordingly, EPA and the Catawba Indian Nation discussed South Carolina's SIP submittals prior to today's proposed action. EPA notes that this rulemaking will not impose substantial direct costs on tribal governments or preempt tribal law.

List of Subjects in 40 CFR Part 52

• Environmental protection
• Air pollution control
• Greenhouse gases
• Incorporation by reference
• Intergovernmental relations
• Nitrogen oxides
• Particulate matter
• Reporting and recordkeeping requirements

Authority: 42 U.S.C. 7401 et seq.

Dated: January 7, 2013.

A. Stanley Meiburg,

Acting Regional Administrator, Region 4.

Footnotes

1.  South Carolina's May 1, 2012 submission to EPA also included changes to Regulation 61-62.63—National Emissions Standards for Hazardous Air Pollutants which is not part of the South Carolina federally approved SIP.

2.  South Carolina's May 1, 2012, SIP submittal did not include the SILs-SMC screening tools also promulgated in the PM_2.5 PSD Increments-SILs-SMC Rule. Furthermore, EPA's authority to implement the SILs and SMC for PSD purposes has been challenged by the Sierra Club. Sierra Club v. EPA, Case No 10-1413 (D.C. Circuit Court).

3.  EPA's May 16, 2008, Rule entitled “Implementation of the New Source Review Program for Particulate Matter Less Than 2.5 Micrometers,” Final Rule (73 FR 28321) and the PM_2.5 PSD Increments-SILs-SMC Rule establish the framework for implementing preconstruction permit review for the PM_2.5 NAAQS. EPA approved South Carolina's SIP submittal to adopt the May 16, 2008, PM_2.5 NSR requirements on June 23, 2011. See 76 FR 36875.

4.  As part of the response to comments on the October 20, 2010, final rulemaking, EPA explained that the Agency agrees that the SILs and SMCs used as de minimis thresholds for the various pollutants are useful tools that enable permitting authorities and PSD applicants to screen out “insignificant” activities; however, these values are not required by the Act as part of an approvable SIP program. EPA believes that most states are likely to adopt the SILs and SMCs because of the useful purpose they serve regardless of EPA's position that the values are not mandatory. Alternatively, states may develop more stringent values if they desire to do so. In any case, states are not under any SIP-related deadline for revising their PSD programs to add these screening tools. See 75 FR 64864, 64900.

5.  On April 6, 2012, EPA filed a brief with the D.C. Circuit Court defending the Agency's authority to implement SILs and SMC for PSD purposes.

6.  Section 169(4) of the CAA provides that the baseline concentration of a pollutant for a particular baseline area is generally the air quality at the time of the first application for a PSD permit in the area.

7.  Baseline dates are pollutant specific. That is, a complete PSD application establishes the baseline date only for those regulated NSR pollutants that are projected to be emitted in significant amounts (as defined in the regulations) by the applicant's new source or modification. Thus, an area may have different baseline dates for different pollutants.

8.  EPA generally characterized the PM_2.5 NAAQS as a NAAQS for a new indicator of PM. EPA did not replace the PM₁₀ NAAQS with the NAAQS for PM_2.5 when the PM_2.5 NAAQS were promulgated in 1997. EPA rather retained the annual and 24-hour NAAQS for PM_2.5 as if PM_2.5 was a new pollutant even though EPA had already developed air quality criteria for PM generally. See 75 FR 64864 (October 20, 2010).

9.  EPA interprets 166(a) to authorize EPA to promulgate pollutant-specific PSD regulations meeting the requirements of section 166(c) and 166(d) for any pollutant for which EPA promulgates a NAAQS after 1977.

10.  This SIP submittal also included changes to SC DHEC's Regulation 61.62-96—Nitrogen Oxides (NO_X) and Sulfur Dioxide (SO₂) Budget Trading Program General Provisions. EPA took final action to approve this portion of the December 4, 2008, submittal on October 16, 2009 (74 FR 53167).

11.  This submittal also make changes to South Carolina's State Regulations 61-62.60, 62.61, 62.63 and 62.72 regarding New Source Performance Standards (NSPS), National Emission Standards for Hazardous Air Pollutants (NESHAP) and Acid Rain, respectively. However, these regulations are not part of South Carolina's federally approved SIP; therefore, EPA is not proposing action on these changes.

12.  On June 15, 2005 (one year after the effective date of the 1997 8-hour ozone designations), EPA revoked the 1-hour ozone NAAQS for all areas except the 8-hour ozone nonattainment-deferred Early Action Compact Areas (EAC) areas. The 1-hour ozone NAAQS for the EAC nonattainment-deferred areas including those in South Carolina (Greenville-Spartanburg-Anderson, SC and Central Midlands Columbia Area) was revoked on April 15, 2009 (one year after the effective date of the EAC areas 8-hour ozone designations to attainment). See 64 FR 17897 (April 2, 2008), 69 FR 23858 and 69 23951 (April 30, 2004).

13.  This SIP submittal also make changes to South Carolina's SIP at Regulations 61-62.1—Definitions and General Requirements; 61-62.5, Standard 1—Emissions from Fuel Burning Operations; 61-62.5, Standard No. 4—Emissions from Process Industries; and 61-62.5, Standard 6—Alternative Emission Limitation Options (“Bubble”). EPA will consider action on these changes to South Carolina SIP in a separate rulemaking.

14.  EPA initially established NAAQS for PM in 1971 measured by the TSP indicator. On July 1, 1987, EPA revised the PM NAAQS by changing the indicator to PM₁₀ (establishing an annual and 24-hour standard) and revoking the TSP NAAQS. See 52 FR 24634.

15.  This submittal also make changes to South Carolina's regulations 61-62.63—National Emission Standards for Hazardous Air Pollutants. However, these regulations are not part of South Carolina's federally approved SIP; therefore, EPA is not proposing action on these changes.

16.  This submittal also make changes to South Carolina's State Regulations 61-62.60, 62.61, 62.63 and 62.72 regarding NSPS, NESHAP, NESHAP for Source Categories, and Acid Rain, respectively. However, these regulations are not part of South Carolina's federally approved SIP; therefore, EPA is not proposing action on these changes.

17.  Tropospheric ozone, commonly known as smog, occurs when VOC and nitrogen oxide (NO_X) react in the atmosphere. Because of the harmful health effects of ozone, EPA limits the amount of VOC and NO_X that can be released into the atmosphere. VOC are those compounds of carbon (excluding carbon monoxide, carbon dioxide, carbonic acid, metallic carbides, or carbonates, and ammonium carbonate) which form ozone through atmospheric photochemical reactions. Compounds of carbon (or organic compounds) have different levels of reactivity; they do not react at the same speed, or do not form ozone to the same extent. It has been EPA's policy that compounds of carbon with a negligible level of reactivity need not be regulated to reduce ozone (42 FR 35314, July 8, 1977). EPA determines whether a given carbon compound has “negligible” reactivity by comparing the compound's reactivity to the reactivity of ethane. EPA lists these compounds in its regulations at 40 CFR 51.100(s), and excludes them from the definition of VOC. The chemicals on this list are often called “negligibly reactive.” EPA may periodically revise the list of negligibly reactive compounds to add compounds to or delete them from the list.