2019-02536. Air Plan Approval and Designation of Areas; FL; Redesignation of the Nassau County 2010 1-Hour Sulfur Dioxide Nonattainment Area to Attainment

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Proposed rule.

SUMMARY:

In a letter dated June 7, 2018, the State of Florida, through the Florida Department of Environmental Protection (FDEP), submitted a request for the Environmental Protection Agency (EPA) to redesignate the Nassau County sulfur dioxide (SO₂) nonattainment area (hereinafter referred to as the “Nassau County Area” or “Area”) to attainment for the 2010 1-hour SO₂ primary national ambient air quality standard (NAAQS) and to approve an accompanying state implementation plan (SIP) revision containing a maintenance plan for the Area. The submittal was received by EPA on June 12, 2018. EPA is proposing to determine that the Nassau County Area attained the 2010 1-hour SO₂ NAAQS by its applicable attainment date of October 4, 2018; to approve the SIP revision containing the State's plan for maintaining attainment of the 2010 1-hour SO₂ standard and to incorporate the maintenance plan into the SIP; and to redesignate the Nassau County Area to attainment for the 2010 1-hour SO₂ NAAQS.

DATES:

Comments must be received on or before March 18, 2019.

ADDRESSES:

Submit your comments, identified by Docket ID No. EPA-R04-OAR-2018-0523 at https://www.regulations.gov. Follow the online instructions for submitting comments. Once submitted, comments cannot be edited or removed from Regulations.gov. EPA may publish any comment received to its public docket. Do not submit electronically any information you consider to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Multimedia submissions (audio, video, etc.) must be accompanied by a written comment. The written comment is considered the official comment and should include discussion of all points you wish to make. EPA will generally not consider comments or comment contents located outside of the primary submission (i.e., on the web, cloud, or other file sharing system). For additional submission methods, the full EPA public comment policy, information about CBI or multimedia submissions, and general guidance on making effective comments, please visit https://www2.epa.gov/​dockets/​commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT:

Madolyn Sanchez, Air Regulatory Management Section, Air Planning and Implementation Branch, Air, Pesticides and Toxics Management Division, U.S. Environmental Protection Agency, Region 4, 61 Forsyth Street SW, Atlanta, Georgia 30303-8960. Ms. Sanchez may be reached by phone at [phone] or via electronic mail at [e-mail].

SUPPLEMENTARY INFORMATION:

I. What are the actions EPA is proposing to take?

EPA is proposing to take the following three separate but related actions: (1) To determine that the Nassau County Area attained the 2010 SO₂ NAAQS by its applicable attainment date of October 4, 2018; (2) to approve Florida's maintenance plan for maintaining the 2010 1-hour SO₂ NAAQS in the Area and incorporate it into the SIP; and (3) to redesignate the Nassau County Area to attainment for the 2010 1-hour SO₂ NAAQS. The Nassau County Area is comprised of the portion of Nassau County encompassing the circular boundary with the center being Universal Transverse Mercator (UTM) Easting 455530 meters, UTM Northing 3391737 meters, UTM zone 17, using the NAD83 datum (the location of the ambient SO₂ monitor in the Area) and the radius being 2.4 kilometers (km). The only point source of SO₂ emissions within the Nassau County Area is a pulp and paper mill—Rayonier Performance Fibers, LLC Fernandina Beach Sulfite Pulp Mill (Rayonier). An additional pulp and paper mill—WestRock CP, LLC Fernandina Beach Mill (WestRock)—is located immediately adjacent to the Area and is the largest source of SO₂ within 25 km outside of the nonattainment area.

EPA is proposing to determine that the Nassau County Area attained the 2010 SO₂ NAAQS by its applicable attainment date of October 4, 2018. EPA is also proposing to approve Florida's SIP revision containing the maintenance plan for the Nassau County Area in accordance with the requirements of section 175A of the Clean Air Act (CAA or Act). The maintenance plan submitted with Florida's request for redesignation is intended to help keep the Nassau County Area in attainment of the 2010 1-hour SO₂ NAAQS through the year 2032.

EPA is also proposing to determine that the Nassau County Area has met the requirements for redesignation under section 107(d)(3)(E) of the CAA. Accordingly, EPA is proposing to approve a request to change the legal designation of the portion of Nassau County that is designated nonattainment to attainment for the 2010 1-hour SO₂ NAAQS.

II. Background

On June 2, 2010, EPA revised the primary SO₂ NAAQS, establishing a new 1-hour SO₂ standard of 75 parts per billion (ppb). See 75 FR 35520 (June 22, 2010). Under EPA's regulations at 40 CFR part 50, the 2010 1-hour SO₂ NAAQS is met at a monitoring site when the 3-year average of the annual 99th percentile of daily maximum 1-hour average concentrations is less than or equal to 75 ppb (based on the rounding convention in 40 CFR part 50, appendix T). See 40 CFR 50.17. Ambient air quality monitoring data for the 3-year period must meet a data completeness requirement. A year meets data completeness requirements when all four quarters are complete, and a quarter is complete when at least 75 percent of the sampling days for each quarter have complete data. A sampling day has complete data if 75 percent of the hourly concentration values, including state-flagged data affected by exceptional events which have been approved for exclusion by the Administrator, are reported.^[1]

Upon promulgation of a new or revised NAAQS, the CAA requires EPA to designate as nonattainment any area that does not meet (or that contributes to ambient air quality in a nearby area that does not meet) the NAAQS. EPA designated the Area as nonattainment for the 2010 1-hour SO₂ NAAQS, effective on October 4, 2013, using 2009-2011 complete, quality assured, and certified ambient air quality data. See 78 FR 47191 (August 5, 2013). Under the CAA, nonattainment areas must attain the NAAQS as expeditiously as practicable but not later than five years after the October 4, 2013, effective date of the designation. See CAA section 192(a). Therefore, the Nassau County Area's applicable attainment date was no later than October 4, 2018.

EPA's 2010 SO₂ nonattainment designation for the Area triggered an obligation for Florida to develop a nonattainment SIP revision addressing certain requirements under title I, part D, subpart 1 (hereinafter “Subpart 1”), and to submit that SIP revision to EPA in accordance with the deadlines in title I, part D, subpart 5 (hereinafter “Subpart 5”). Subpart 1 contains the general requirements for nonattainment areas for criteria pollutants, including requirements to develop a SIP that provides for the implementation of reasonably available control measures (RACM), requires reasonable further progress (RFP), includes base-year and attainment-year emissions inventories, a SIP-approved nonattainment new source review (NNSR) permitting program that accounts for growth in the area, enforceable emission limitations and other such control measures, and provides for the implementation of contingency measures. This SIP revision was due within 18 months following the October 4, 2013, effective date of designation (i.e., April 4, 2015). See CAA section 191(a). Florida submitted a nonattainment SIP revision to EPA on April 3, 2015.

On July 3, 2017 (82 FR 30749), EPA approved Florida's April 3, 2015, SO₂ nonattainment SIP revision. This SIP revision provided a modeled attainment demonstration and satisfied the required nonattainment planning requirements mentioned above for the Nassau County Area. The revision included a base year emissions inventory, a modeling demonstration of attainment for the 2010 SO₂ NAAQS, RACM/Reasonably Available Control Technology (RACT), a RFP plan, NNSR permitting program, and contingency measures for the Nassau County Area. As discussed in Section V, below, the nonattainment SIP revision included permit conditions to reduce SO₂ emissions at the Rayonier and WestRock facilities.

III. What are the criteria for redesignation?

The CAA provides the requirements for redesignating a nonattainment area to attainment. Specifically, section 107(d)(3)(E) of the CAA allows for redesignation provided that the following criteria are met: (1) The Administrator determines that the area has attained the applicable NAAQS; (2) the Administrator has fully approved the applicable implementation plan for the area under section 110(k); (3) the Administrator determines that the improvement in air quality is due to permanent and enforceable reductions in emissions resulting from implementation of the applicable SIP and applicable federal air pollutant control regulations, and other permanent and enforceable reductions; (4) the Administrator has fully approved a maintenance plan for the area as meeting the requirements of section 175A; and (5) the state containing such area has met all requirements applicable to the area for purposes of redesignation under section 110 and part D of the CAA.

On April 16, 1992 (57 FR 13498), EPA provided guidance on redesignations in the General Preamble for the Implementation of title I of the CAA Amendments of 1990 and supplemented this guidance on April 28, 1992 (57 FR 18070). EPA has provided further guidance on processing redesignation requests in the following documents:

1. “Procedures for Processing Requests to Redesignate Areas to Attainment,” Memorandum from John Calcagni, Director, Air Quality Management Division, September 4, 1992 (hereinafter referred to as the “Calcagni Memorandum”);

2. “State Implementation Plan (SIP) Actions Submitted in Response to Clean Air Act (CAA) Deadlines,” Memorandum from John Calcagni, Director, Air Quality Management Division, October 28, 1992;

3. “Part D New Source Review (Part D NSR) Requirements for Areas Requesting Redesignation to Attainment,” Memorandum from Mary D. Nichols, Assistant Administrator for Air and Radiation, October 14, 1994; and

4. “Guidance for 1-Hour SO₂ Nonattainment Area SIP Submissions,” Memorandum from Stephen D. Page, April 23, 2014 (hereinafter referred to as the “SO₂ Nonattainment Area Guidance”).

EPA's SO₂ Nonattainment Area Guidance discusses the CAA requirements that air agencies need to address when implementing the 2010 SO₂ NAAQS in areas designated as nonattainment for the standard. The guidance includes recommendations for air agencies to consider as they develop SIPs to satisfy the requirements of sections 110, 172, 175A, 191, and 192 of the CAA to show future attainment and maintenance of the 2010 SO₂ NAAQS. Additionally, the SO₂ nonattainment guidance provides recommendations for air agencies to consider as they develop redesignation requests and maintenance plans to satisfy the requirements of sections 107(d)(3)(E) and 175A.

IV. Why is EPA proposing these actions?

Through a letter dated June 7, 2018, FDEP submitted a request for EPA to redesignate the Nassau County Area to attainment for the 2010 1-hour SO₂ NAAQS and submitted an associated SIP revision containing a maintenance plan. EPA's evaluation indicates that the Nassau County Area meets the requirements for redesignation as set forth in section 107(d)(3)(E), including the maintenance plan requirements under section 175A of the CAA. As a result of this evaluation, EPA is proposing to determine that the Area has attained the 2010 1-hour SO₂ NAAQS by its attainment date of October 4, 2018, in accordance with section 179(c)(1) of the CAA based upon air monitoring data for 2015-2017 and air quality dispersion modeling analyses.^[2] EPA is also proposing to approve Florida's maintenance plan for maintaining the 2010 1-hour SO₂ NAAQS in the Area and incorporate it into the SIP and to redesignate the Nassau County Area to attainment for the 2010 1-hour SO₂ NAAQS.

V. What is EPA's analysis of the redesignation request and SIP revision?

As stated above, in accordance with the CAA, EPA proposes to: (1) To determine that the Nassau County Area attained the 2010 1-hour SO₂ NAAQS by its attainment date of October 4, 2018; (2) to approve Florida's maintenance plan for maintaining the 2010 1-hour SO₂ NAAQS in the Area and incorporate it into the SIP; and (3) to redesignate the Nassau County Area to attainment for the 2010 1-hour SO₂ NAAQS.

The five redesignation criteria provided under CAA section 107(d)(3)(E) are discussed in greater detail for the Nassau County Area in the following paragraphs.

Criterion (1)—The Administrator Determines That the Area Has Attained the NAAQS

For redesignating a nonattainment area to attainment, the CAA requires EPA to determine that the area has attained the applicable NAAQS (CAA section 107(d)(3)(E)(i)). As discussed in section VIII.A of the SO₂ Nonattainment Area Guidance, there are generally two components needed to support an attainment determination for SO₂, which should be considered interdependently.^[3] The first component relies on air quality monitoring data. For SO₂, any available monitoring data would need to indicate that all monitors in the affected area are meeting the standard as stated in 40 CFR 50.17 using data analysis procedures specified in 40 CFR part 50, Appendix T. The second component relies on air quality modeling data. If there are no air quality monitors located in the affected area, or there are air quality monitors located in the area, but analyses show that none of the monitors are located in the area of maximum concentration,^[4] then air quality dispersion modeling will generally be needed to estimate SO₂ concentrations in the area. Such dispersion modeling should be conducted to estimate SO₂ concentrations throughout the nonattainment area using actual emissions and meteorological information for the most recent three calendar years. However, EPA may also make determinations of attainment based on the modeling from the attainment demonstration for the applicable SIP for the affected area, eliminating the need for separate actuals-based modeling to support the determination that an area is currently attaining. If the air agency has previously submitted a modeled attainment demonstration using allowable emissions, no further modeling is needed as long as the source characteristics are still reasonably represented.

Florida's pre- and post-modification attainment demonstration modeling indicates that the Fernandina Beach monitor is not sited in the area of maximum concentration for both the Rayonier and West Rock SO₂ sources, and therefore the clean monitoring data at the Fernandina Beach monitor does not on its own demonstrate that the Area is currently attaining the 1-hour SO₂ NAAQS. EPA's proposed approval of Florida's redesignation and maintenance plan SIP for the Nassau County Area is also based on the modeled attainment demonstration that includes permanent and enforceable SO₂ controls and emissions limits at Rayonier and WestRock showing attainment of the 2010 SO₂ standard by the statutory deadline. EPA approved the attainment demonstration for the Nassau Area on July 3, 2017, and incorporated the new allowable emission rates and control measures into the SIP, making them permanent and enforceable. See 82 FR 30749. These permanent and enforceable measures were fully implemented at Rayonier during the second quarter of 2014 and at WestRock in December 2017.

For SO₂, a location may be considered to be attaining the 2010 1-hour SO₂ NAAQS if it meets the NAAQS as determined in accordance with 40 CFR 50.17 and Appendix T of part 50, based on three complete, consecutive calendar years of quality-assured air quality monitoring data. Specifically, to attain the NAAQS at each monitoring site, the 3-year average of the annual 99th percentile (fourth highest value) of 1-hour daily maximum concentrations measured at each monitor within an area must be less than or equal to 75 ppb. The data must be collected and quality-assured in accordance with 40 CFR part 58 and recorded in the EPA Air Quality System (AQS). The monitors should have remained at the same location for the duration of the monitoring period required for demonstrating attainment.

FDEP currently operates one ambient SO₂ monitor in the Area, the Fernandina Beach SO₂ monitor (AQS ID: 12-089-0005). This monitor is located approximately 0.9 km southeast of Rayonier and 2.5 km south of WestRock. The original nonattainment designation was based on the 2009-2011 design value of 129 ppb at this monitor. As shown in Table 1, the design values at this monitor have decreased since 2011, and the quality-assured, complete, and certified 2015-2017 3-year design value is 43 ppb, well below the 2010 1-hour SO₂ standard of 75 ppb. Since 2011, the annual fourth high value has remained below the standard and there have been no 1-hour values recorded above the standard since late 2014. The significant decrease in SO₂ concentrations is due to the implementation of the permanent and enforceable control measures at Rayonier and WestRock.

Table 1—Nassau County Area SO₂ Monitored Design Values

[ppb]

Monitoring station (AQS Site ID)	2011-2013 Design value	2012-2014 Design value	2013-2015 Design value	2014-2016 Design value	2015-2017 Design value 5
Fernandina Beach (12-089-0005)	70 ppb	57 ppb	58 ppb	51 ppb	43 ppb

Preliminary monitoring data from the Fernandina Beach monitor for 2018 indicates that it continues to not record a violation of the standard.^[6] EPA is proposing to determine that the Nassau County Area has attained the 2010 1-hour SO₂ NAAQS based primarily on the modeling analysis discussed below, which is not contradicted by the quality-assured, complete, and certified ambient air monitoring data for the 2015-2017 period that does not indicate a NAAQS violation. If, before EPA takes final action, monitoring data or other evidence causes EPA to conclude that the Area is not continuing to meet the standard, EPA will not go forward with the redesignation. As discussed in more detail below, Florida has committed to continue monitoring ambient SO₂ concentrations in this Area in accordance with 40 CFR part 58. Any future changes to the state or local air monitoring station (SLAMS) network in the Area will be submitted to EPA for approval in Florida's annual ambient air monitoring network plan, as required by 40 CFR 58.10.

As discussed in Section VIII.A. of the SO₂ Nonattainment Area Guidance, air quality dispersion modeling will generally be needed to demonstrate attainment in addition to attaining air quality monitoring data (in accordance with 40 CFR 50.17 and Appendix T of part 50) if the existing monitor is not located in the area of maximum concentration. The SO₂ attainment demonstration submitted by Florida on April 3, 2015, provided an air quality dispersion modeling analysis demonstrating that the control strategies chosen by the State to reduce SO₂ emissions at Rayonier and WestRock would bring the Area into attainment of the standard by the applicable attainment date of October 4, 2018. On July 3, 2017 (82 FR 30749), EPA approved this attainment demonstration along with Florida's control strategies at these facilities. In its June 7, 2018, redesignation request and maintenance plan, FDEP included the modeling analysis from its attainment demonstration that demonstrates modeled attainment within the Nassau County Area. Florida's redesignation request states that the control strategies were fully implemented at Rayonier during the second quarter of 2014 and at WestRock in December 2017. Details regarding the control strategies and emissions reductions are provided in the Criterion (3) Section of this document. Details regarding the modeling analysis are discussed in the following paragraphs.

FDEP's modeling analysis was developed in accordance with EPA's Guideline on Air Quality Models (Modeling Guideline) ^[7] and the SO₂ Nonattainment Area Guidance, and was prepared using EPA's preferred dispersion modeling system, the American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD) consisting of the AERMOD (version 14134) ^[8] model and multiple data input preprocessors as described below. FDEP used regulatory default options and the rural land use designation in the AERMOD modeling.

The pre-processors AERMET (version 14134) and AERMINUTE were used to process five years (i.e., 2008-2012) of 1-minute meteorological data from the Jacksonville National Weather Service Office (NWS) at the Jacksonville International Airport, Jacksonville, Florida, surface level site, based on FDEP's land use classifications, in combination with twice daily upper-air meteorological information from the same site. The Jacksonville International Airport is located approximately 28 km southeast from the Nassau County Area.

The AERMOD pre-processor AERMAP (version 11103) was used to generate terrain inputs for the receptors, based on a digital elevation mapping database from the National Elevation Dataset developed by the U.S. Geological Survey. FDEP used AERSURFACE to generate direction-specific land-use surface characteristics for the modeling.

The stack heights used in the modeling meet the Good Engineering Practice stack height criteria, and the Building Profile Input Program for Plume Rise Model Enhancements preprocessor was used to generate direction-specific building downwash parameters. FDEP developed a Cartesian receptor grid across the nonattainment boundary (approximately 2.4 km around the monitor), with 100-meter spacing in ambient air to ensure maximum concentrations are captured in the analysis.

FDEP selected a background SO₂ concentration based on local SO₂ monitoring data from the Fernandina Beach monitor, located within the nonattainment area, for the period January 2012 to December 2013. This background concentration from the nearby ambient air monitor is used to account for SO₂ impacts from all sources that are not specifically included in the AERMOD modeling analysis. The ambient monitoring data was obtained from the Florida Air Monitoring and Assessment System. Due to its close proximity to the Rayonier facility, monitored concentrations at this station are strongly influenced by emissions from both facilities. As a result, and as allowed by EPA's Modeling Guideline, the data was filtered to remove measurements where the wind direction could transport pollutants from Rayonier and WestRock to the monitor. More specifically, the data was filtered to remove measurements where hourly wind directions were between 263° to 61°.

EPA's SO₂ nonattainment guidance provides a procedure for establishing longer-term averaging times for SO₂ emission limits (up to a 30-day rolling averaging time).^[9] In approving Florida's 2015 attainment demonstration, EPA concluded that FDEP completed this analysis for the Rayonier and WestRock facilities to derive SIP emission limits with a 3-hour longer-term averaging time that are comparatively stringent to the modeled attaining 1-hour level. For more details, see Florida's April 3, 2015, nonattainment SIP submittal and EPA's final approval. See 82 FR 30749 (July 3, 2017).

The results of Florida's attainment modeling are summarized in Table 2. The table presents the results from the four sets of AERMOD modeling runs that were performed. The four modeling runs were the result of using an uncontrolled, or pre-modification, scenario and three different controlled, or post-modification, scenarios. The State used maximum allowable permitted emissions limits for each of the SO₂ emissions units at the Rayonier and WestRock facilities in the modeling demonstration. These emissions limits and other control measures were established in construction permits issued by FDEP. The conditions have been incorporated into the Florida SIP via the approved attainment plan, making them permanent and enforceable, and the Title V operating permits for the Rayonier ^[10] and WestRock ^[11] facilities. Two of the units at the WestRock facility, emissions unit (EU) 007 and 011 (recovery boilers), have a combined SO₂ emissions limit cap of 300 pounds per hour (lb/hr). Therefore, the State performed three post-control runs to identify the worst-case scenario of emissions distributions. For each of the three modeling runs, all other emissions units at both the Rayonier and WestRock facilities were modeled at their individual permitted allowable SO₂ emissions rates. Under one modeling scenario, the SO₂ emissions cap of 300 pounds per hour (lb/hr) for WestRock EUs 007 and 011 was allotted equally between the recovery boilers. For the two remaining scenarios, the entire 300 lb/hr cap was allotted totally to EU 007 or EU 011, assuming only one recovery boiler was operating at any given time. Table 2 shows that the maximum 1-hour average across all five years of meteorological data (2008-2012) is less than or equal to the 2010 1-hour SO₂ NAAQS of 75 ppb for all three sets of AERMOD modeling runs. For more details, see Florida's April 3, 2015, SIP submittal.

Table 2—Maximum Modeled SO₂ Impacts in the Nassau County Area, Micrograms per Cubic Meter

[ppb] ¹²

Model scenario	Averaging time	Maximum predicted impact		Background	Total	SO2 NAAQS
		Rayonier	WestRock
Pre-modification	1-hour	13 0.0	2,957.80 (1,128)	4.19 (1.6)	2,961.99 (1,130)	196.4 (75)
Equal Cap Distribution	1-hour	1,14.45 (43.7)	67.69 (25.8)	10.72 (4.09)	192.87 (73.6)
Entire Cap—EU 007	1-hour	110.93 (42.3)	71.56 (27.3)	9.16 (3.5)	191.65 (73.1)
Entire Cap—EU 011	1-hour	117.51 (44.8)	63.79 (24.3)	12.82 (4.9)	194.11 (74.0)

The pre-control analysis resulted in a predicted impact of 1,130 ppb. The post-control analysis resulted in a worst-case predicted impact of 74.0 ppb. EPA has determined that the modeling results indicate sufficient reductions in air quality impact with the implementation of the post-construction control plan for the Rayonier and WestRock facilities. The control measures that have been implemented at the Rayonier and West Rock facilities are outlined in the Criterion (3) Section of this document. The modeling results included in Table 2 show that WestRock should be included in the consideration of controls for the following reasons: (1) If both facilities were left uncontrolled, as presented in the first modeled scenario, WestRock would have the greater impact on the area of maximum concentration within the Nassau County Area; and (2) with the worst possible post-control modeling scenario, 35 percent of the total predicted impact on the Nassau County Area would stem from WestRock. Therefore, if no controls were implemented at WestRock, the Area would not likely attain and maintain the 2010 1-hour SO₂ NAAQS. All emissions limits and related compliance parameters have been incorporated into Florida's SIP, making these changes permanent and federally enforceable. More details on the pre-construction and post-construction operations at the facilities are included in Florida's April 3, 2015, nonattainment SIP submission and in EPA's rulemaking on that submittal.^[14]

On July 3, 2017, EPA approved the modeled attainment demonstration described above and concluded that it is consistent with CAA requirements, EPA's Modeling Guideline, and EPA's guidance for SO₂ attainment demonstration modeling. The modeled controls and emissions limits have been fully implemented as of December 1, 2017. Therefore, EPA proposes to find that the Area has attained the 2010 1-hour SO₂ NAAQS and attained the standard by its applicable attainment date based on this modeling analysis and on quality-assured, complete, and certified 2015-2017 ambient air monitoring data at the Fernandina Beach monitor.

Criterion (2)—The Administrator Fully Approves the Applicable Implementation Plan for the Area Under Section 110(k); and Criterion (5)—Florida Has Met All Applicable Requirements Under Section 110 and Part D of Title I of the CAA

For redesignating a nonattainment area to attainment, the CAA requires EPA to determine that the state has met all applicable requirements under section 110 and part D of title I of the CAA (CAA section 107(d)(3)(E)(v)) and that the state has a fully approved SIP under section 110(k) for the area (CAA section 107(d)(3)(E)(ii)). EPA proposes to find that Florida has met all applicable SIP requirements for the Nassau County Area under section 110 of the CAA (general SIP requirements) for purposes of redesignation. Additionally, EPA proposes to find that the Florida SIP satisfies the criterion that it meets applicable SIP requirements for purposes of redesignation under part D of title I of the CAA in accordance with section 107(d)(3)(E)(v). Further, EPA proposes to determine that the SIP is fully approved with respect to all requirements applicable for purposes of redesignation in accordance with section 107(d)(3)(E)(ii). In making these proposed determinations, EPA ascertained which requirements are applicable to the Area and, if applicable, that they are fully approved under section 110(k). SIPs must be fully approved only with respect to requirements that were applicable prior to submittal of the complete redesignation request.

A. The Nassau County Area Has Met All Applicable Requirements Under Section 110 and Part D of the CAA

1. General SIP Requirements

General SIP elements and requirements are delineated in section 110(a)(2) of title I, part A of the CAA. These requirements include, but are not limited to, the following: Submittal of a SIP that has been adopted by the state after reasonable public notice and hearing; provisions for establishment and operation of appropriate procedures needed to monitor ambient air quality; implementation of a source permit program; provisions for the implementation of part C requirements (Prevention of Significant Deterioration (PSD)) and provisions for the implementation of part D requirements (NNSR permit programs); provisions for air pollution modeling; and provisions for public and local agency participation in planning and emission control rule development.

Section 110(a)(2)(D) requires that SIPs contain certain measures to prevent sources in a state from significantly contributing to air quality problems in another state. To implement this provision, EPA has required certain states to establish programs to address the interstate transport of air pollutants. The section 110(a)(2)(D) requirements for a state are not linked with a particular nonattainment area's designation and classification in that state. EPA believes that the requirements linked with a particular nonattainment area's designation and classifications are the relevant measures to evaluate in reviewing a redesignation request. The transport SIP submittal requirements, where applicable, continue to apply to a state regardless of the designation of any one particular area in the state. Thus, EPA does not believe that the CAA's interstate transport requirements should be construed to be applicable requirements for purposes of redesignation.

In addition, EPA believes that other section 110(a)(2) elements that are neither connected with nonattainment plan submissions nor linked with an area's attainment status are not applicable requirements for purposes of redesignation. The area will still be subject to these requirements after the area is redesignated. The section 110(a)(2) and part D requirements which are linked with a particular area's designation and classification are the relevant measures to evaluate in reviewing a redesignation request. This approach is consistent with EPA's existing policy on applicability (i.e., for redesignations) of conformity and oxygenated fuels requirements, as well as with section 184 ozone transport requirements. See Reading, Pennsylvania, proposed and final rules (61 FR 53174-53176, October 10, 1996), (62 FR 24826, May 7, 2008); Cleveland-Akron-Loraine, Ohio, final rule (61 FR 20458, May 7, 1996); and Tampa, Florida, final rule at (60 FR 62748, December 7, 1995). See also the discussion on this issue in the Cincinnati, Ohio, redesignation (65 FR 37890, June 19, 2000), and in the Pittsburgh, Pennsylvania, redesignation (66 FR 50399, October 19, 2001). Nonetheless, EPA has approved Florida's SIP revisions related to the section 110 requirements for the 2010 SO₂ NAAQS, with the exception of the interstate transport elements at section 110(a)(2)(D)(i)(I). See 81 FR 67179 (September 30, 2016).

2. Title I, Part D, Applicable SIP Requirements

Subpart 1 of part D, comprised of CAA sections 171-179B, sets forth the basic nonattainment requirements applicable to all nonattainment areas. All areas that were designated nonattainment for the SO₂ NAAQS were designated under Subpart 1 of the CAA in accordance with the deadlines in Subpart 5. For purposes of evaluating this redesignation request, the applicable Subpart 1 SIP requirements are contained in section 172(c)(1)-(9), section 176, and sections 191 and 192. A thorough discussion of the requirements contained in sections 172(c) can be found in the General Preamble for Implementation of Title I. See 57 FR 13498 (April 16, 1992).

a. Subpart 1 Section 172 Requirements

Section 172 requires states with nonattainment areas to submit plans providing for timely attainment and meeting a variety of other requirements. As discussed in section V.A, above, EPA's longstanding interpretation of the attainment-related nonattainment planning requirements of section 172 is that once an area is attaining the NAAQS, those requirements are not “applicable” for purposes of CAA section 107(d)(3)(E)(ii) and therefore need not be approved into the SIP before EPA can redesignate the area. In the 1992 General Preamble for Implementation of Title I, EPA set forth its interpretation of applicable requirements for purposes of evaluating redesignation requests when an area is attaining a standard. See 57 FR 13498, 13564 (April 16, 1992). EPA noted that the requirements for RFP and other measures designed to provide for attainment do not apply in evaluating redesignation requests because those nonattainment planning requirements “have no meaning” for an area that has already attained the standard. Id. This interpretation was also set forth in the Calcagni Memo. EPA's understanding of section 172 also forms the basis of its Clean Data Policy, articulated with regard to the 2010 1-hour SO₂ NAAQS in the SO₂ Nonattainment Area Guidance, which suspends a state's obligation to submit most of the attainment planning requirements that would otherwise apply, including an attainment demonstration and planning SIPs to provide for RFP, RACT/RACM, NNSR, and contingency measures under section 172(c)(9).

As discussed above, EPA previously approved Florida's nonattainment SIP for the Nassau County Area. See 82 FR 30749 (July 3, 2017). Among other things, the nonattainment SIP for the Area satisfied the section 172(c)(1) requirements for RACT/RACM; 172(c)(2) requirements related to RFP; 172(c)(3) requirements for a comprehensive and accurate emissions inventory; 172(c)(4) and (5) for NNSR; 172(c)(6) requirements for permanent and enforceable control measures necessary to provide attainment of the NAAQS by the attainment date; and section 172(c)(9) requirements for contingency measures.

Section 172(c)(4) requires the identification and quantification of allowable emissions for major new and modified stationary sources to be allowed in an area, and section 172(c)(5) requires source permits for the construction and operation of new and modified major stationary sources anywhere in the nonattainment area. EPA has a longstanding interpretation that because NNSR is replaced by PSD upon redesignation, nonattainment areas seeking redesignation to attainment need not have a fully approved part D NNSR program in order to be redesignated. See memorandum from Mary Nichols, Assistant Administrator for Air and Radiation, dated October 14, 1994, entitled “Part D New Source Review Requirements for Areas Requesting Redesignation to Attainment.” Florida currently has a fully-approved PSD and part D NNSR program in place in Chapters 62-204, 62-210, and 62-212 of the Florida Administrative Code. Florida's PSD program will become effective in the Area upon redesignation to attainment.

Section 172(c)(7) requires the SIP to meet the applicable provisions of section 110(a)(2). As noted above, EPA believes that Florida's SIP meets the requirements of section 110(a)(2) applicable for purposes of redesignation.

Finally, section 172(c)(8) allows a state to use equivalent modeling, emission inventory, and planning procedures if such use is requested by the state and approved by EPA. Florida has not requested the use of equivalent techniques under section 172(c)(8).

As mentioned above, EPA fully approved Florida's April 3, 2015, nonattainment SIP for the Nassau County Area, including the modeled attainment demonstration, and determined that the SIP submission met the applicable nonattainment planning requirements of sections 172 and 191-192 of the CAA demonstrating attainment of the SO₂ standard by the statutory deadline. This approval included the specific SO₂ emission limits and compliance parameters established for the two SO₂ point sources impacting the Nassau Area (Rayonier and WestRock).

b. Subpart 1 Section 176—Conformity Requirements

Section 176(c) of the CAA requires states to establish criteria and procedures to ensure that federally supported or funded projects conform to the air quality planning goals in the applicable SIP. The requirement to determine conformity applies to transportation plans, programs, and projects that are developed, funded, or approved under title 23 of the United States Code (U.S.C.) and the Federal Transit Act (transportation conformity) as well as to all other federally supported or funded projects (general conformity). State transportation conformity SIP revisions must be consistent with federal conformity regulations relating to consultation, enforcement, and enforceability that EPA promulgated pursuant to its authority under the CAA.

EPA believes that it is reasonable to interpret the conformity SIP requirements ^[15] as not applying for purposes of evaluating the redesignation request under section 107(d) because state conformity rules are still required after redesignation and federal conformity rules apply where state rules have not been approved. See Wall v. EPA, 265 F.3d 426 (upholding this interpretation) (6th Cir. 2001); See 60 FR 62748 (December 7, 1995). Furthermore, due to the relatively small, and decreasing, amounts of sulfur in gasoline and on-road diesel fuel, the EPA's transportation conformity rules provide that they do not apply to SO₂ unless either the EPA Regional Administrator or the director of the state air agency has found that transportation-related emissions of SO₂ as a precursor are a significant contributor to a SO₂ or fine particulate matter (PM_2.5) nonattainment problem, or if the SIP has established an approved or adequate budget for such emissions as part of the RFP, attainment, or maintenance strategy. See 40 CFR 93.102(b)(1), (2)(v); SO₂ Nonattainment Area Guidance. Neither of these conditions have been met; therefore, EPA's transportation conformity rules do not apply to SO₂ for the Area. For these reasons, EPA proposes to find that Florida has satisfied all applicable requirements for purposes of redesignation of the Nassau County Area under section 110 and part D of title I of the CAA.

B. The Nassau County Area Has a Fully Approved Applicable SIP Under Section 110(k) of the CAA

EPA has fully approved the applicable Florida SIP for the Nassau County Area under section 110(k) of the CAA for purposes of redesignation. EPA may rely on prior SIP approvals in approving a redesignation request (see Calcagni Memorandum at p. 3, Southwestern Pennsylvania Growth Alliance v. Browner, 144 F.3D 984, 989-90 (6th Cir. 1998); Wall, 265 F.3d 426) plus any additional measures it may approve in conjunction with a redesignation action. See 68 FR 25426 (May 12, 2003) and citations therein. As mentioned above, EPA fully approved the State's nonattainment SIP and approved Florida's SIP revisions related to the section 110 requirements for the 2010 SO₂ NAAQS, with the exception of the interstate transport elements at section 110(a)(2)(D)(i)(I). See 82 FR 30749 (July 3, 2017) and 81 FR 67179 (September 30, 2016), respectively.

As discussed above, EPA believes that the section 110 elements that are neither connected with nonattainment plan submissions nor linked to an area's nonattainment status are not applicable requirements for purposes of redesignation.

Criterion (3)—The Air Quality Improvement in the Nassau County Area Is Due to Permanent and Enforceable Reductions in Emissions Resulting From Implementation of the SIP and Applicable Federal Air Pollution Control Regulations and Other Permanent and Enforceable Reductions

For redesignating a nonattainment area to attainment, the CAA requires EPA to determine that the air quality improvement in the area is due to permanent and enforceable reductions in emissions resulting from implementation of the SIP, applicable Federal air pollution control regulations, and other permanent and enforceable reductions (CAA section 107(d)(3)(E)(iii)). EPA proposes to determine that Florida has demonstrated that the observed air quality improvement in the Nassau County Area is due to permanent and enforceable reductions in SO₂ emissions resulting from implementation of the SIP, including SO₂ control measures at the Rayonier and WestRock facilities since the nonattainment designation.

When EPA designated the Nassau County Area as a nonattainment area for the 2010 1-hour SO₂ NAAQS, EPA determined that operations at Rayonier were the primary cause of the 2010 1-hour SO₂ NAAQS violations in the Area. See 78 FR 47191.^[16] However, Florida included the nearby WestRock facility in its modeled attainment demonstration because it determined that WestRock was also a significant contributor to elevated concentrations within the defined nonattainment area.^[17] The April 3, 2015, Nassau County Area nonattainment SIP revision was based on this determination and successfully reduced ambient concentrations below the 1-hour SO₂ NAAQS by only requiring emissions reductions at Rayonier and WestRock.

Rayonier received an air construction permit ^[18] on April 12, 2012, from FDEP to lower SO₂ maximum allowable emission rates on all three of its SO₂ emitting units—EU 005, EU 006, and EU 022—based on a 3-hour rolling average. The construction permit authorized a stack height increase for the vent gas scrubbing system (EU 005) from 110 feet (ft.) to at least 165 ft. to improve dispersion (the final as-built height is 180 feet) and lowered the allowable SO₂ emission limit to 100 ppm (25.3 lb/hr). The permit also lowered the allowable SO₂ emission limit for the Recovery Boiler (EU 006) to 250 parts per million (volumetric dry (297 lb/hr)) and lowered the allowable SO₂ emission limit for the No. 6 Power Boiler (EU 022) from 420 lb/hr to 180 lb/hr.^[19] All three SO₂ units have in-stack continuous emission monitoring systems (CEMS) for SO₂ to ensure compliance with their SO₂ emission limits. FDEP estimated that Rayonier's allowable SO₂ emissions (total from sum of all three controlled units) were reduced from 836.5 lb/hr to 502.3 lb/hr, representing a 40 percent decrease. The construction project was completed in the second quarter of 2014, and the emission limitations for all three controlled units were established in air construction permit (Permit No. 0890004-036-AC) on April 12, 2012, and incorporated into the source's Title V operating permit (Permit No. 0890004-042-AV) ^[20] on May 6, 2014. The limitations became effective the date that the Title V permit revision was issued. EPA incorporated these new SO₂ emissions limits, operating parameters, and compliance monitoring, recordkeeping, and reporting requirements from the air construction permit into the Florida SIP on July 3, 2017, making these controls permanent and enforceable. See 82 FR 30749 (July 3, 2017). Table 3 summarizes the changes at the Rayonier facility.

Table 3—Rayonier Facility SO₂ Source Changes

Source	SO2 Emission limit *		Stack height
	Previous	Current	Previous	Current
EU 005-Vent Gas Scrubber	250 ppm (63.2 lb/hr)	100 ppm (25.3 lb/hr)	110 ft	180 ft
EU 006—Recovery Boiler	300 ppm (353.3 lb/hr)	250 ppm (297 lb/hr)	No change
EU 022—No. 6 Power Boiler	420 lb/hr	180 lb/hr	No change
* All previous and new SO2 emission limits are 3-hour rolling averages.

For WestRock, FDEP issued an air construction permit (Permit No. 0890003-046-AC) ^[21] on January 9, 2015, authorizing two phases of physical and operational changes to the four largest SO₂ emitting units—No. 5 Power Boiler (EU 006), No. 4 Recovery Boiler (EU 007), No. 5 Recovery Boiler (EU 011), and No. 7 Recovery Boiler (EU 015). WestRock implemented physical upgrades to the No. 4 and No. 5 recovery boilers to achieve a more stable and consistent combustion and chemical recovery process. These physical improvements resulted in an individual permitted allowable emission rate of 150 lb/hr for each recovery boiler or a combined 300.0 lb/hr SO₂ emission cap for both units on a 3-hour block average. These individual and combined emission limits were effective January 1, 2018. For the two power boilers, a pipeline was constructed to reroute low volume, high concentration non-condensable gas (NCGs) to the No. 7 power boiler, and a white liquor scrubber system was installed upstream of the NCGs to remove total reduced sulfur before combustion. These NCGs were previously collected and burned in the No. 5 power boiler completed in December, but the rerouting and scrubbing of NCGs allowed for a significant reduction in SO₂ emissions from the No. 5 Power Boiler lowering the allowable SO₂ emissions from 550 lb/hr to 15.0 lb/hr based on a 3-hour block average and representing a 97 percent decrease in SO₂ emissions (without any increase in the emission limit of the No. 7 Power Boiler). The 15.0 lb/hr limit was effective beginning

January 31, 2016 (except when the boiler was used as a control device for NCG through November 30, 2017). In addition, effective January 31, 2016, the No. 5 Power boiler ceased burning of No. 6 fuel oil. Effective December 1, 2017, after the rerouting and scrubbing of NCGs was complete, the No. 5 power boiler was no longer used as a backup NCG control device.

The new emission limits for three of the four controlled units were established in an air construction permit (Permit No. 0890004-046-AC) on January 9, 2015, and incorporated into the source's Title V operating permit (Permit No. 0890003-055-AV) ^[22] on November 14, 2017. All four SO₂ units have in-stack CEMS for SO₂ to ensure compliance with their SO₂ emission limits in accordance with section 113(a)(1) of the CAA.^[23] EPA incorporated these new SO₂ emissions limits for three of the four controlled emission units, operating parameters, and compliance monitoring, recordkeeping and reporting requirements from the air construction permit into the Florida SIP on July 3, 2017, making these controls permanent and enforceable. See 82 FR 30749 (July 3, 2017). Table 4 summarizes each of the source changes at the WestRock facility.

Table 4—WestRock Facility SO₂ Source Changes

Source	SO2 Emission limit		Other changes
	Previous	Current *
EU 006—No. 5 Power Boiler	550 lb/hr **	15.0 lb/hr	Removal of NCGs.
EU 007—No. 4 Recovery Boiler ***	None	300.0 lb/hr cap	Improvements made to combustion air system.
EU 011—No. 5 Recovery Boiler ***	None		Improvements made to combustion air system.
EU 015—No. 7 Power Boiler	No Change		Addition of NCG pipeline for backup combustion (white liquor scrubber added upstream).
* All new SO2 emission limits are 3-hour block averages.
** 24-hour average.
*** SO2 emissions from each recovery boiler shall not exceed 150.0 lb/hour based on 3-hour block average.

Rayonier's previous allowable SO₂ limit was 3,663.87 tons per year (tpy), and WestRock's previous allowable SO₂ limit was 12,286.69 tpy. The new maximum allowable emissions are 2,200.07 and 6,746.08 tpy for Rayonier and WestRock, respectively, corresponding to a combined reduction of approximately 44 percent in allowable SO₂ emissions. The air quality improvement in the Nassau County Area is due to permanent and enforceable reductions in SO₂ emissions resulting from the control measures identified above and incorporated into the SIP.

Criterion (4)—The Nassau County Area Has a Fully Approved Maintenance Plan Pursuant to Section 175A of the CAA

For redesignating a nonattainment area to attainment, the CAA requires EPA to determine that the area has a fully approved maintenance plan pursuant to section 175A of the CAA. See CAA section 107(d)(3)(E)(iv). In conjunction with its request to redesignate the Nassau County Area to attainment for the 2010 1-hour SO₂ NAAQS, Florida submitted a SIP revision to provide for the maintenance of the 2010 1-hour SO₂ NAAQS for at least 10 years after the effective date of redesignation to attainment. EPA is proposing to determine that this maintenance plan meets the requirements for approval under section 175A of the CAA.

a. What is required in a maintenance plan?

Section 175A of the CAA sets forth the elements of a maintenance plan for areas seeking redesignation from nonattainment to attainment. Under section 175A, the plan must demonstrate continued attainment of the applicable NAAQS for at least 10 years after the Administrator approves a redesignation to attainment. Eight years after the redesignation, the state must submit a revised maintenance plan demonstrating that attainment will continue to be maintained for the 10 years following the initial 10-year period. To address the possibility of future NAAQS violations, the maintenance plan must contain contingency measures as EPA deems necessary to assure prompt correction of any future 2010 1-hour SO₂ violations. The Calcagni Memorandum provides further guidance on the content of a maintenance plan, explaining that a maintenance plan should address five requirements: The attainment emissions inventory; maintenance demonstration; monitoring; verification of continued attainment; and a contingency plan. As is discussed more fully below, EPA is proposing to determine that Florida's maintenance plan includes all the necessary components and is thus proposing to approve it as a revision to the Florida SIP.

b. Attainment Emissions Inventory

An attainment inventory identifies a level of emissions in the Area that is sufficient to attain the NAAQS. In its maintenance plan, Florida used 2013 actual emissions data to represent the attainment emissions inventory. As identified above, the 2011-2013 design value at the Fernandina Beach monitor was below the NAAQS. SO₂ emissions data from Rayonier and WestRock facilities, as included in the 2013 annual operating reports for all sources, is presented in Table 5. Although WestRock is located outside of the Area, Florida included the nearby WestRock facility in its modeled attainment demonstration because it determined that WestRock was also a significant contributor to elevated concentrations within the defined nonattainment area. The complete attainment emissions inventory is presented in Table 6. Florida interpolated area and non-road emissions for the Area for 2013 from the 2011 and 2014 National Emissions Inventory (NEI) data for Nassau County because the State is only required to develop these inventories on a triennial period in accordance with the NEI and subpart A to 40 CFR part 51. The 2013 estimated emissions were then allocated to the Area based on the Area's fraction of land area within the county. The State estimated on-road emissions for the Area with MOVES2014a, and then allocated them to the Area based on the Area's fraction of land area within the county.

Table 5—2013 SO₂ Emissions Inventory for Rayonier and WestRock Facilities

EU ID	Unit description	2013 SO2 Emissions (tons)
Rayonier Facility SO 2 Emissions
005	Vent Gas Scrubber	14.84
006	Recovery Boiler	470.56
022	No. 6 Power Boiler	6.30
Total		491.70
WestRock Facility SO 2 Emissions
006	No. 5 Power Boiler	60.29
007	No. 4 Recovery Boiler	134.32
011	No. 5 Recovery Boiler	128.91
013	No. 4 Smelt Dissolving Tank	1.45
014	No. 5 Smelt Dissolving Tank	1.37
015	No. 7 Power Boiler	2,793.45
021	No. 4 Lime Kiln	26.70
Total		3,146.49
Total All Point Sources		3,638.19

Table 6—2013 Attainment Emissions Inventory for the Nassau County Area

Source type	Point	Area	Non-road	On-road	Total
2013 SO2 Emissions (tons)	3,638.19	0.72	0.01	0.11	3,639.03

For additional information regarding the development of the attainment year inventory, please see Appendix D to Florida's June 7, 2018, SIP submittal.

c. Maintenance Demonstration

Maintenance of the SO₂ standard is demonstrated either by showing that future emissions will not exceed the level of the attainment emissions inventory year or by modeling to show that the future mix of sources and emission rates will not cause a violation of the NAAQS.

To evaluate maintenance through 2032 and satisfy the 10-year interval required in CAA section 175A, Florida prepared projected emissions inventories for 2020-2032. The emissions inventories are composed of the following general source categories: Point, area, non-road mobile, and on-road mobile. The emissions inventories were developed consistent with EPA guidance and are summarized in Table 7. Florida compared projected emissions for the final year of the maintenance plan (2032) to the attainment emissions inventory year (2013) and compared interim years to the attainment emissions inventory year to demonstrate continued maintenance of the 2010 1-hour SO₂ standard. For additional information regarding the development of the projected inventories, please see Appendix D to Florida's June 7, 2018, SIP submittal.

Table 7—Projected Future Emissions Inventories for the Area

Source type	Projected 2020 SO2 emissions (tons)	Projected 2023 SO2 emissions (tons)	Projected 2026 SO2 emissions (tons)	Projected 2029 SO2 emissions (tons)	Projected 2032 SO2 emissions (tons)
Point	3,638.19	3,638.19	3,638.19	3,638.19	3,638.19
Area	0.93	0.98	1.03	1.08	1.12
Non-road	0.01	0.01	0.01	0.01	0.01
On-road	0.05	0.05	0.05	0.04	0.04
Total	3,639.18	3,639.23	3,639.28	3,639.32	3,639.37

In situations where local emissions are the primary contributor to nonattainment, such as the Nassau County Area, if the future projected emissions in the nonattainment area remain at or below the baseline emissions in the nonattainment area, then the related ambient air quality standards should not be exceeded in the future. Florida has projected emissions as described previously, and these projections indicate that emissions in the Nassau County Area will remain at nearly the same levels as those in the attainment year inventory for the duration of the maintenance plan. While these projections include a very small increase in area source emissions from 2020 to 2032 (0.19 tons), the increase is negligible when compared to the total emissions inventory and EPA does not believe that this projected increase should cause an exceedance of the SO₂ NAAQS through 2032. This belief is supported by the fact and any increases in actual emissions from Rayonier or WestRock must remain below their permitted levels, which were made permanent and enforceable through incorporation into the SIP. Furthermore, any potential future SO₂ emissions sources that may locate in or near the Area would be required to comply with the FDEP's approved NSR permitting programs to ensure that the Area will continue to meet the NAAQS.

As discussed in the SO₂ Nonattainment Area Guidance, an approved attainment plan that relies on air quality dispersion modeling using maximum allowable emissions, such as Florida's attainment plan for the Area, can generally be expected to demonstrate that the standard will be maintained for the requisite 10 years and beyond without regard to any changes in operation rate of the pertinent sources that do not involve increases in maximum allowable emissions.^[24] EPA believes that the Area will continue to maintain the standard at least through the year 2032 because the air quality modeling in the approved attainment plan showed that the Area would attain the standard based on maximum allowable emissions limits at Rayonier and WestRock that are incorporated into the SIP, these sources have fully implemented the permanent and enforceable modeled limits and controls, and the emissions reductions from these measures are reflected in the attaining design values for the Area.

d. Monitoring Network

The Fernandina Beach monitor (12-089-0005) is the only SO₂ monitor located within the Nassau County Area, and the 2010 1-hour SO₂ nonattainment designation was based on data collected from 2009-2011 at this monitor. In its maintenance plan, Florida has committed to continue operating an appropriate SO₂ monitoring network, consult with EPA prior to making any changes to the existing network, and continue to quality assure the monitoring data in accordance with 40 CFR part 58. Therefore, Florida has addressed the requirement for monitoring. FDEP's monitoring network plan was submitted on June 30, 2017, and approved by EPA on October 19, 2017.

e. Verification of Continued Attainment

The State of Florida, through FDEP, has the legal authority to enforce and implement all measures necessary to attain and maintain the NAAQS. Section 403.061(35), Florida Statutes, authorizes the Department to “exercise the duties, powers, and responsibilities required of the state under the federal Clean Air Act.” This includes implementing and enforcing all measures necessary to attain and maintain the NAAQS. In addition, FDEP will use emissions data submitted by Rayonier and WestRock through annual operating reports to verify continued compliance with the permitted emissions rates that were shown through the modeling demonstration in the attainment plan to be sufficient to provide for maintenance of the 2010 1-hour SO₂ NAAQS throughout the Area. Any increases in actual emissions from Rayonier or WestRock must remain below their permitted levels, which were made permanent and enforceable through incorporation into the SIP. Furthermore, any potential future SO₂ emissions sources that may locate in or near the Area would be required to comply with the FDEP's approved NSR permitting programs to ensure that the Area will continue to meet the NAAQS. In addition to assuring continued attainment in this manner, FDEP will verify continued attainment through operation of the monitoring network.

f. Contingency Measures in the Maintenance Plan

Section 175A of the CAA requires that a maintenance plan include such contingency measures as EPA deems necessary to assure that the state will promptly correct a violation of the NAAQS that occurs after redesignation. The maintenance plan should identify the contingency measures to be adopted, a schedule and procedure for adoption and implementation, and a time limit for action by the state. In cases where attainment revolves around compliance of a single source or a small set of sources with emissions limits shown to provide for attainment, the EPA interprets “contingency measures” to mean that the state agency has a comprehensive program to identify sources of violations of the SO₂ NAAQS and to undertake aggressive follow-up for compliance and enforcement, including expedited procedures for establishing enforceable consent agreement pending the adoption of revised SIPs.^[25] A state should also identify specific indicators to be used to determine when the contingency measures need to be implemented. The maintenance plan must include a requirement that a state will implement all measures with respect to control of the pollutant that were contained in the SIP before redesignation of the area to attainment in accordance with section 175A(d).

The contingency plan included in the maintenance plan contains triggers to determine when contingency measures are needed and what kind of measures should be used. Upon notification by the FDEP Office of Air Monitoring that the Fernandina Beach monitor has registered SO₂ levels in excess of the standard for a fourth time during a calendar year, FDEP will notify Rayonier and WestRock of the occurrence of the fourth high exceedance. Upon notification by FDEP of a confirmed fourth high exceedance,^[26] Rayonier and WestRock will, without any further action by FDEP or EPA, undertake a full system audit of all emissions units subject to control under the attainment plan. Within 10 days of notification of the confirmed fourth high exceedance, each source will independently submit a written system audit report to FDEP summarizing all operating parameters of all emissions units for four 10-day periods up to and including the dates of the exceedances together with recommended provisional SO₂ emission control strategies for each affected unit and evidence that these control strategies have been deployed, as appropriate. Upon receipt of the above-mentioned reports, FDEP will then begin a 30-day evaluation of these reports to determine the cause of the exceedances, followed by a 30-day consultation period with the sources to develop and implement appropriate operational changes. At the end of the consultation period, FDEP will mandate operational changes identified by the written system audit to prevent any future violation of the NAAQS. Any necessary changes would be implemented as soon as practicable, with at least one implemented within 18-24 months of the monitored violation, in order to bring the Area into attainment as expeditiously as possible. These changes could include, but would not be limited to:

• Fuel switching to reduce or eliminate the use of sulfur-containing fuels;
• Combustion air system enhancement;
• Vent gas scrubber enhancement;
• White liquor scrubber enhancement; and/or
• Physical or operational reduction of production capacity, as appropriate.

If a permit modification is necessary, the State would issue a final permit in accordance to Sections 120 and 403 of the Florida Statutes. Subsequently, Florida would submit any relevant permit change to EPA as a source-specific SIP revision to make the change permanent and enforceable. In addition to including these contingency measures in the maintenance plan, Florida also stated that all existing control measures will remain in effect after redesignation.

EPA has preliminarily concluded that the maintenance plan adequately addresses the five basic components of a maintenance plan: The attainment emissions inventory; maintenance demonstration; monitoring; verification of continued attainment; and a contingency plan. Therefore, EPA proposes to determine that the maintenance plan for the Area meets the requirements of section 175A of the CAA and proposes to incorporate the maintenance plan into the Florida SIP.

VI. What is the effect of EPA's proposed actions?

Approval of Florida's redesignation request would change the legal designation of the portion of Nassau County that is within the Nassau County Area, as found at 40 CFR part 81, from nonattainment to attainment for the 2010 1-hour SO₂ NAAQS. Approval of Florida's associated SIP revision would also incorporate a plan for maintaining the 2010 1-hour SO₂ NAAQS in the Nassau County Area through 2032 into the SIP.

VII. Proposed Actions

EPA is proposing to take three separate but related actions regarding the redesignation request and associated SIP revision for the Nassau County Area.

First, EPA is proposing to determine that the Area attained the 2010 1-hour SO₂ NAAQS by its attainment date of October 4, 2018. This determination is being proposed in accordance with section 179(c)(1) of the CAA.

Second, EPA is proposing to approve the maintenance plan for the Area and to incorporate it into the SIP. As described above, the maintenance plan demonstrates that the Area will continue to maintain the 2010 1-hour SO₂ NAAQS through 2032.

Third, EPA is proposing to approve Florida's request for redesignation of the Area from nonattainment to attainment for the 2010 1-hour SO₂ NAAQS. If finalized, approval of the redesignation request for the Nassau County Area would change the official designation of the portion of Nassau County, Florida, encompassing the circular boundary with the center being UTM Easting 455530 meters, UTM Northing 3391737 meters, UTM zone 17, using the NAD83 datum (the location of the ambient monitor in the Area) and the radius being 2.4 kilometers, as found at 40 CFR part 81, from nonattainment to attainment for the 2010 1-hour SO₂ NAAQS.

VIII. Statutory and Executive Order Reviews

Under the CAA, redesignation of an area to attainment and the accompanying approval of a maintenance plan under section 107(d)(3)(E) are actions that affect the status of a geographical area and do not impose any additional regulatory requirements on sources beyond those imposed by state law. A redesignation to attainment does not in and of itself create any new requirements, but rather results in the applicability of requirements contained in the CAA for areas that have been redesignated to attainment. Moreover, 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. Accordingly, these proposed actions merely propose to approve state law as meeting Federal requirements and do not impose additional requirements beyond those imposed by state law. For this reason, these proposed actions:

• Are not significant regulatory actions 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);
• Are not Executive Order 13771 (82 FR 9339, February 2, 2017) regulatory actions because redesignations and SIP approvals are exempted under Executive Order 12866;
• Do not impose information collection burdens under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
• Are 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.);
• Do not contain any unfunded mandates or significantly or uniquely affect small governments, as described in the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4);
• Do not have Federalism implications as specified in Executive Order 13132 (64 FR 43255, August 10, 1999);
• Are not economically significant regulatory actions based on health or safety risks subject to Executive Order 13045 (62 FR 19885, April 23, 1997);
• Are not significant regulatory actions subject to Executive Order 13211 (66 FR 28355, May 22, 2001);
• Are 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
• Will not have disproportionate human health or environmental effects under Executive Order 12898 (59 FR 7629, February 16, 1994).

This redesignation action is not approved to apply on any Indian reservation land or in any other area where EPA or an Indian tribe has demonstrated that a tribe has jurisdiction. In those areas of Indian country, the rule does not have tribal implications as specified by Executive Order 13175 (65 FR 67249, November 9, 2000), nor will it impose substantial direct costs on tribal governments or preempt tribal law.

List of Subjects

40 CFR Part 52

• Environmental protection
• Air pollution control
• Incorporation by reference
• Intergovernmental relations
• Reporting and recordkeeping
• Sulfur dioxide

40 CFR Part 81

• Environmental protection
• Air pollution control
• National parks
• Wilderness areas

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

Dated: February 5, 2019.

Mary S. Walker,

Acting Regional Administrator, Region 4.

Footnotes

1.  See 40 CFR part 50, appendix T, section 3(b).

2.  Section 179(c)(1) reads as follows: “As expeditiously as practicable after the applicable attainment date for any nonattainment area, but not later than 6 months after such date, the Administrator shall determine, based on the area's air quality as of the attainment date, whether the area attained the standard by that date.”

3.  SO₂ is primarily a localized, source-specific pollutant, and therefore, SO₂ control measures are, by definition, based on what is directly and quantifiably necessary to attain the NAAQS.

4.  See section VIII.A of the SO₂ Nonattainment Area Guidance.

5.  The 2017 data is available at https://www.epa.gov/​outdoor-air-quality-data/​monitor-values-report.

6.  Preliminary 2018 data is available at https://www.epa.gov/​outdoor-air-quality-data/​monitor-values-report.

7.  See 40 CFR part 51 Appendix W (EPA's Guideline on Air Quality Models) (January 17, 2017) located at https://www3.epa.gov/​ttn/​scram/​appendix_​w/​2016/​AppendixW_​2017.pdf.

8.  Version 14134 of the AERMOD Modeling System was the current EPA-recommended regulatory version at the time the modeling was performed in 2014-2015, and therefore was appropriate for the modeling analysis.

9.  FDEP followed the SO₂ Nonattainment Area Guidance on procedures for establishing emissions limits with averaging periods longer than one hour.

10.  See air construction permit 0890004-036-AC issued by FDEP on April 12, 2012; 82 FR 30749 (July 3, 2017); and 40 CFR 52.520(d). See Title V operating permit 0890004-054-AV issued by FDEP on September 7, 2017.

11.  See air construction permit 0890003-046-AC issued by FDEP on January 9, 2015; 82 FR 30749 (July 3, 2017); and 40 CFR 52.520(d). See Title V operating permit 0890003-055-AV issued by FEDP on November 14, 2017.

12.  The April 3, 2015, final submittal contained typographical errors in its summary modeling table. On April 8, 2016, FDEP provided EPA Region 4 with corrected numbers. FDEP in no way revised the modeling demonstration nor the results inherent in the April 3, 2015, submittal. The correspondence and clarifying information is provided in the Docket for the attainment demonstration (Docket ID: EPA-R04-OAR-2015-0623).

13.  The “0” impact from Rayonier indicates that the worst-case scenario was at a time when WestRock was impacting the area of maximum concentration because the wind was coming from the direction of WestRock. Rayonier impacts other receptors in the nonattainment area and may impact this same receptor at other times, as can be seen with the remainder of the modeling demonstration.

14.  See 82 FR 30749 (July 3, 2017) (final rule), 81 FR 57535 (August 23, 2016) (proposed rule), and Florida's SIP submittal located in Docket EPA-R04-OAR-2015-0623.

15.  CAA section 176(c)(4)(E) requires states to submit revisions to their SIPs to reflect certain federal criteria and procedures for determining transportation conformity. Transportation conformity SIPs are different from the motor vehicle emission budgets that are established in control strategy SIPs and maintenance plans.

16.  See Final Technical Support Document, July 2013, Florida First Round of Nonattainment Area Designations for the 2010 SO₂ Primary NAAQS, Prepared by EPA Region 4. This document is available at Docket ID: EPA-HQ-OAR-2012-0233-0307.

17.  FDEP modeled actual emissions at the time of area designations which revealed contributing impacts throughout the NAA due to emissions from WestRock (formerly RockTenn). See 82 FR 30749 (July 3, 2017) and Docket ID: EPA-R04-OAR-2015-0623.

18.  See air construction permit 0890004-036-AC issued by FDEP on April 12, 2012, located in the docket for this action.

19.  Rayonier considered two emissions limits for EU 022—180 lb/hr SO₂ at the current stack height of 190 ft; or 250 lb/hr SO₂ if the stack height was increased to 210 ft. However, the stack height for EU 022 No.6 power boiler was not increased, and therefore, the final limit emission limit is 180 lb/hr.

20.  See Title V operating permit 0890004-042-AV issued by FDEP on May 6, 2014, located in the docket for this action.

21.  See air construction permit 0890003-046-AC issued by FDEP on January 9, 2015, located in the docket for this action.

22.  See Title V operating permit 0890003-055-AV issued by FDEP on November 14, 2017, located in the docket for this action.

23.  Air construction permit 0890003-046-AC requires that compliance with the combined SO₂ emission cap be demonstrated by certified CEMS data. See Condition 2 in Section 3.C.

24.  See SO₂ Nonattainment Area Guidance at p.67.

25.  See SO₂ Nonattainment Area Guidance at p.69.

26.  Confirmation of a fourth high exceedance over the SO₂ NAAQS would be made after quality assurance activities are completed, but not necessarily with FDEP-certified data.