Air Plan Approval; SC; 2010 1-Hour SO2

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Final rule.

SUMMARY:

The Environmental Protection Agency (EPA) is approving South Carolina's June 25, 2018, State Implementation Plan (SIP) submission pertaining to the “good neighbor” provision of the Clean Air Act (CAA or Act) for the 2010 1-hour sulfur dioxide (SO₂) National Ambient Air Quality Standard (NAAQS). The good neighbor provision requires each state's implementation plan to address the interstate transport of air pollution in amounts that contribute significantly to nonattainment, or interfere with maintenance, of a NAAQS in any other state. In this action, EPA has determined that South Carolina's SIP contains adequate provisions to prohibit emissions within the State from contributing significantly to nonattainment or interfering with maintenance of the 2010 1-hour SO₂ NAAQS in any other state.

DATES:

This rule will be effective November 12, 2019.

ADDRESSES:

EPA has established a docket for this action under Docket Identification No. EPA-R04-OAR-2018-0665. All documents in the docket are listed on the www.regulations.gov website. Although listed in the index, some information may not be publicly available, i.e., Confidential Business Information 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 through www.regulations.gov or in hard copy at the Air Regulatory Management Section, Air Planning and Implementation Branch, Air and Radiation 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 a.m. to 4:30 p.m., excluding Federal holidays.

FOR FURTHER INFORMATION CONTACT:

Michele Notarianni, Air Regulatory Management Section, Air Planning and Implementation Branch, Air and Radiation Division, U.S. Environmental Protection Agency, Region 4, 61 Forsyth Street SW, Atlanta, Georgia 30303-8960. Ms. Notarianni can be reached via phone number (404) 562-9031 or via electronic mail at notarianni.michele@epa.gov.

SUPPLEMENTARY INFORMATION:

I. Background

On June 2, 2010, EPA promulgated a revised primary SO₂ NAAQS with a level of 75 parts per billion (ppb), based on a 3-year average of the annual 99th percentile of 1-hour daily maximum concentrations. See 75 FR 35520 (June 22, 2010). Pursuant to section 110(a)(1) of the CAA, states are required to submit SIPs meeting the applicable requirements of section 110(a)(2) within three years after promulgation of a new or revised NAAQS or within such shorter period as EPA may prescribe. These SIPs, which EPA has historically referred to as “infrastructure SIPs,” are to provide for the “implementation, maintenance, and enforcement” of such NAAQS, and the requirements are designed to ensure that the structural components of each state's air quality management program are adequate to meet the state's responsibility under the CAA. Section 110(a) of the CAA requires states to make a SIP submission to EPA for a new or revised NAAQS, but the contents of individual state submissions may vary depending upon the facts and circumstances. The content of the changes in such SIP submissions may also vary depending upon what provisions the state's approved SIP already contains. Section 110(a)(2) requires states to address basic SIP elements such as requirements for monitoring, basic program requirements, and legal authority that are designed to assure attainment and maintenance of the NAAQS.

Section 110(a)(2)(D)(i)(I) of the CAA requires SIPs to include provisions prohibiting any source or other type of emissions activity in one state from emitting any air pollutant in amounts that will contribute significantly to nonattainment, or interfere with maintenance, of the NAAQS in another state. The two clauses of this section are referred to as prong 1 (significant contribution to nonattainment) and prong 2 (interference with maintenance of the NAAQS).

On June 25, 2018, the South Carolina Department of Health and Environmental Control (SC DHEC) submitted a revision to the South Carolina SIP addressing only prongs 1 and 2 of CAA section 110(a)(2)(D)(i)(I) for the 2010 1-hour SO₂ NAAQS. EPA is approving SC DHEC's June 25, 2018, SIP submission because the State demonstrated that South Carolina will not contribute significantly to nonattainment, or interfere with maintenance, of the 2010 1-hour SO₂ NAAQS in any other state. All other elements related to the infrastructure requirements of section 110(a)(2) for the 2010 1-hour SO₂ NAAQS for South Carolina are addressed in separate rulemakings.

In a notice of proposed rulemaking (NPRM) published on April 23, 2019, EPA proposed to approve South Carolina's June 25, 2018, SIP revision on the basis that the State's implementation plan adequately addresses prong 1 and prong 2 requirements for the 2010 1-hour SO₂ NAAQS. See 84 FR 16799. The details of the SIP revision and the rationale for EPA's action is explained in the NPRM. Comments on the proposed rulemaking were due on or before May 23, 2019. EPA received three sets of adverse comments from anonymous commenters. These comments are included in the docket for this final action. EPA has summarized the comments and provided responses below.

II. Response to Comments

Comment 1: A commenter expresses concern about EPA's statement that the Agency does not have monitoring or modeling data suggesting that North Carolina is impacted by SO₂ emissions from the Milliken & Co. Magnolia Plant (Magnolia) or WestRock CP LLC (WestRock). The commenter questions why EPA did not model these facilities and states that EPA must have monitoring data to “definitively conclude anything about these sources.”

Response 1: EPA disagrees with the commenter's assertion that monitoring and dispersion modeling are needed for these two sources before EPA can approve South Carolina's SIP submittal as meeting the interstate transport requirements in CAA section 110(a)(2)(D). There is nothing in this section of the CAA suggesting that monitoring or dispersion modeling is legally required to evaluate good neighbor SIPs, and EPA has previously found that a weight of evidence (WOE) approach is sufficient to determine whether or not a state satisfies the good neighbor provision.

EPA continues to believe that the WOE analysis provided in the NPRM is adequate to determine the potential downwind impact from South Carolina to neighboring states. EPA's analysis includes the following factors: (1) SO₂ air dispersion modeling results for sources within 50 kilometers (km) of South Carolina's border both within the State and in neighboring states, (2) SO₂ emissions trends for sources in South Carolina, (3) SO₂ ambient air quality for monitors for sources within 50 km of South Carolina's border both within the State and in neighboring states; and (4) South Carolina's statutes and SIP-approved regulations and federal regulations that address SO₂ emissions. As part of its WOE analysis, EPA performed a qualitative evaluation to assess whether SO₂ emissions from Magnolia and WestRock are impacting North Carolina, the only neighboring state within 50 km of these sources. Because EPA does not have monitoring or modeling data for these two sources, EPA evaluated their 2017 SO₂ emissions, distances from the South Carolina border, and distances from sources in North Carolina with SO₂ emissions greater than 100 tons per year (tpy) in 2017 and not subject to EPA's Data Requirements Rule (DRR) as summarized in Table 5 of the NPRM and found that this information supports EPA's proposed determination that South Carolina has met the good neighbor provision for the 2010 1-hour SO₂ NAAQS. The commenter did not provide a technical analysis that contradicts EPA's proposed determination that sources in South Carolina such as Magnolia or Westrock will not significantly contribute to nonattainment or interfere with maintenance in another state. Therefore, EPA continues to believe that the Agency's analysis of these and other South Carolina sources in the NPRM, weighed along with other WOE factors described in the NPRM, support EPA's conclusion that South Carolina has satisfied the good neighbor provision for the 2010 1-hour SO₂ NAAQS.

Comment 2: Two commenters expressed concerns regarding the modeling analysis for Resolute FP US Inc.—Catawba Mill (Resolute). One commenter questions the use of 2012-2014 actual emissions in the modeling of Resolute. The commenter states that “EPA is hiding behind 5-7 year old data” and that EPA should perform the modeling using maximum allowable potential emissions before concluding that the source, located 7 km from the North Carolina border, “does not contribute to violations in the neighboring state.” Another commenter questions the use of a modeling domain for Resolute that extends 4 km into North Carolina and mentions that EPA should perform “additional modeling to confirm that an extended modeling domain would not show an even higher modeled concentration farther into the state of North Carolina.”

Response 2: As discussed above, the good neighbor provision does not require modeling to determine whether a state contributes significantly to nonattainment or interferes with maintenance of a specific NAAQS in another state. EPA used a WOE analysis to evaluate South Carolina's SIP revision under the good neighbor provision and evaluated all available data, including the modeling submitted by South Carolina during the DRR process for Resolute.

As stated in the NPRM, the modeling for Resolute predicts no violations of the 2010 1-hour SO₂ NAAQS within 50 km of the South Carolina border. The modeling results show that SO₂ concentrations drop off rapidly with a predicted maximum modeled concentration of approximately 69 ppb just north of the facility and concentrations in North Carolina below approximately 18 ppb. EPA continues to believe that these results, weighed along with the other WOE factors discussed in the NPRM, support EPA's proposed conclusion that sources in South Carolina do not significantly contribute to nonattainment or interfere with maintenance of the 2010 1-hour SO₂ NAAQS in any other state.

In response to the comment regarding the use of modeling with “5-7 year old data” to evaluate South Carolina's June 25, 2018, SIP submission, EPA has evaluated more recent actual SO₂ emissions data for Resolute for the years 2015-2017. Resolute's 2015-2017 SO₂ emissions (2,386 tpy, 2,391 tpy, and 2,211 tpy in 2015, 2016, and 2017, respectively) are lower than the modeled 2012-2014 SO₂ emissions (4,562 tpy, 4,491 tpy, and 4,780 tpy in 2012, 2013, and 2014, respectively). Because emissions have decreased from 2012-2014 to 2015-2017, the model results may overpredict current SO₂ concentrations and therefore continue to support the Agency's conclusion that South Carolina has satisfied the good neighbor provision with respect to the 2010 1-hour SO₂ NAAQS. EPA also notes that the commenters did not provide any technical analysis contradicting EPA's proposed determination that Resolute will not significantly contribute to nonattainment or interfere with maintenance in another state.

Comment 3: A commenter notes that EPA analyzed sources that emitted more than 100 tpy of SO₂ within 50 km of the South Carolina border. The commenter states that EPA should have considered and modeled sources that emitted less SO₂ and are closer to the border and that EPA evaluated sources emitting 1 tpy when acting on good neighbor SIP revisions for Delaware and the District of Columbia.

Response 3: EPA assessed annual emissions data for non-DRR sources emitting over 100 tons of SO₂ in 2017 in South Carolina and existing dispersion modeling for DRR sources to identify the universe of sources in the State likely to be responsible for SO₂ emissions potentially contributing to interstate transport. After determining that 89 percent of South Carolina's statewide SO₂ emissions are from point sources based on 2014 emissions, EPA next focused on individual facilities which emitted above 100 tpy using the most recent year for which point source emission data was available, i.e., 2017. EPA assessed, using its best judgment, which sources could have the most serious impact on downwind states. EPA chose 100 tpy as the emissions threshold for consideration for interstate transport because South Carolina's universe of point sources was too large to evaluate every source at a lower threshold like that used in the Delaware and District of Columbia analyses. South Carolina's point sources of SO₂ emitting 100 tons or less in 2017 comprise only seven percent of the State's total SO₂ point source inventory in 2017. EPA is not precluded from choosing different thresholds for evaluating interstate transport in different states because the factual circumstances vary from state to state. Furthermore, EPA notes that small sources, in particular those emitting less than 100 tpy of SO₂, usually cannot be characterized accurately because the level of detail about the source and the data needed for such an analysis is not as often readily available as for the larger sources.

Regarding the statement about modeling, EPA notes that it did not independently model any sources as part of its evaluation of South Carolina's good neighbor SIP submission, including sources emitting more than 100 tpy of SO₂ within 50 km from the South Carolina border. EPA did, however, evaluate all available information for sources that emitted more than 100 tpy of SO₂ within 50 km of the border, including any available air dispersion modeling, and continues to believe that its WOE analysis demonstrates that South Carolina has satisfied the good neighbor provision for the 2010 1-hour SO₂ NAAQS. The commenter did not provide a technical analysis indicating that sources emitting less than or equal to 100 tpy within 50 km of the border may have downwind impacts that violate the good neighbor provision.

Comment 4: A commenter states that three sources in South Carolina (i.e., W.S. Lee Station, McMeekin Station, and WestRock) were “able to escape nonattainment designation status” by accepting federally-enforceable permit limits “to exempt them from complying with the DRR.” The commenter states that accepting these limits does not mean that these sources are not “causing or contributing to nonattainment or maintenance” in another state and questions why EPA did not perform modeling to determine if these sources are impacting neighboring states for the 2010 1-hour SO₂ NAAQS.

Response 4: Regarding the commenter's reference to the SO₂ designations signed on December 21, 2017 (83 FR 1098), to the extent commenter is taking issue with those designations, those designations and the federally-enforceable emission limits taken to comply with the DRR are outside the scope of this action to approve South Carolina's SIP revision to address interstate transport for the 2010 1-hour SO₂ NAAQS. Regarding the comment concerning modeling, EPA does not agree that modeling is necessary to demonstrate that these sources do not significantly contribute to nonattainment or interfere with maintenance of the 2010 1-hour SO₂ NAAQS in another state. As discussed above, there is nothing in the interstate transport requirements of CAA section 110(a)(2)(D) suggesting that dispersion modeling is legally required to evaluate good neighbor SIPs, and EPA used its long-standing WOE approach to evaluate South Carolina's SIP revision under the good neighbor provision. EPA also notes that the commenter did not provide a technical analysis that contradicts EPA's proposed determination that W.S. Lee Station, McMeekin Station, and WestRock will not significantly contribute to nonattainment or interfere with maintenance in another state.

III. Final Action

EPA is approving South Carolina's June 25, 2018, SIP submission as demonstrating that South Carolina's SIP has adequate provisions prohibiting any source or other type of emissions activity in the State from emitting any air pollutant in amounts that will contribute significantly to nonattainment or interfere with maintenance of the 2010 1-hour SO₂ NAAQS in another state.

IV. 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. See 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. This 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 action:

• Is not a significant regulatory action subject to review by the Office of Management and Budget under Executive Orders 12866 (58 FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 2011);
• Is not an Executive Order 13771 (82 FR 9339, February 2, 2017) regulatory action because SIP approvals are exempted under Executive Order 12866;
• 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 FR 43255, 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 action for South Carolina does not have Tribal implications as specified by Executive Order 13175 (65 FR 67249, November 9, 2000) because it does not have substantial direct effects on an Indian Tribe. The Catawba Indian Nation Reservation is located within the boundary of York County, South Carolina. Pursuant to the Catawba Indian Claims Settlement Act, S.C. Code Ann. 27-16-120, “all state and local environmental laws and regulations apply to the Catawba Indian Nation and Reservation and are fully enforceable by all relevant state and local agencies and authorities.” However, EPA has determined that this rule does not have substantial direct effects on an Indian Tribe because this action is not approving any specific rule, but rather has determined that South Carolina's already approved SIP meets certain CAA requirements. EPA notes that this action will not impose substantial direct costs on Tribal governments or preempt Tribal law.

The Congressional Review Act, 5 U.S.C. 801 et seq., as added by the Small Business Regulatory Enforcement Fairness Act of 1996, generally provides that before a rule may take effect, the agency promulgating the rule must submit a rule report, which includes a copy of the rule, to each House of the Congress and to the Comptroller General of the United States. EPA will submit a report containing this action and other required information to the U.S. Senate, the U.S. House of Representatives, and the Comptroller General of the United States prior to publication of the rule in the Federal Register. A major rule cannot take effect until 60 days after it is published in the Federal Register. This action is not a “major rule” as defined by 5 U.S.C. 804(2).

Under section 307(b)(1) of the CAA, petitions for judicial review of this action must be filed in the United States Court of Appeals for the appropriate circuit by December 9, 2019. Filing a petition for reconsideration by the Administrator of this final rule does not affect the finality of this action for the purposes of judicial review nor does it extend the time within which a petition for judicial review may be filed, and shall not postpone the effectiveness of such rule or action. This action may not be challenged later in proceedings to enforce its requirements. See section 307(b)(2).

List of Subjects in 40 CFR Part 52

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

40 CFR part 52 is amended as follows:

PART 52—APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS

1. The authority citation for part 52 continues to read as follows:

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

Subpart PP-South Carolina

2. In § 52.2120, the table in paragraph (e) is amended by adding the entry “110(a)(1) and (2) Infrastructure Requirements for the 2010 1-hour SO ₂ NAAQS” at the end of the table to read as follows: