AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Proposed rule.

SUMMARY:

The Environmental Protection Agency (EPA) is proposing to approve Georgia's January 9, 2019, 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 will contribute significantly to nonattainment, or interfere with maintenance, of a NAAQS in any other state. In this action, EPA is proposing to determine that Georgia will not contribute significantly to nonattainment or interfere with maintenance of the 2010 1-hour SO₂ NAAQS in any other state. Therefore, EPA is proposing to approve the January 9, 2019, SIP revision as meeting the requirements of the good neighbor provision for the 2010 1-hour SO₂ NAAQS.

DATES:

Written comments must be received on or before January 3, 2020.

ADDRESSES:

Submit your comments, identified by Docket ID No. EPA-R04-OAR-2019-0329 at http://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 http://www.epa.gov/​dockets/​commenting-epa-dockets.

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

A. Infrastructure SIPs

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). Whenever EPA promulgates a new or revised NAAQS, CAA section 110(a)(1) requires states to make SIP submissions to provide for the implementation, maintenance, and enforcement of the NAAQS. This particular type of SIP submission is commonly referred to as an “infrastructure SIP.” These submissions must meet the various requirements of CAA section 110(a)(2), as applicable.

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 January 9, 2019, the Georgia Department of Natural Resources, through the Georgia Environmental Protection Division (GA EPD), submitted a revision to the Georgia SIP addressing only prongs 1 and 2 of CAA section 110(a)(2)(D)(i)(I) for the 2010 1-hour SO₂ NAAQS.^[1] EPA is proposing to approve GA EPD's January 9, 2019, SIP submission because the State demonstrated that Georgia 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 Georgia were addressed in separate rulemakings.^[2]

B. 2010 1-Hour SO ₂ NAAQS Designations Background

In this action, EPA has considered information from the 2010 1-hour SO₂ NAAQS designations process, as discussed in more detail in section III.C of this notice. For this reason, a brief summary of EPA's designations process for the 2010 1-hour SO₂ NAAQS is included here.^[3]

After the promulgation of a new or revised NAAQS, EPA is required to designate areas as “nonattainment,” “attainment,” or “unclassifiable,” pursuant to section 107(d)(1) of the CAA. The process for designating areas following promulgation of a new or revised NAAQS is contained in section 107(d) of the CAA. The CAA requires EPA to complete the initial designations process within two years of promulgating a new or revised standard. If the Administrator has insufficient information to make these designations by that deadline, EPA has the authority to extend the deadline for completing designations by up to one year.

EPA promulgated the 2010 1-hour SO₂ NAAQS on June 2, 2010. See 75 FR 35520 (June 22, 2010). EPA completed the first round of designations (“round 1”) ^[4] for the 2010 1-hour SO₂ NAAQS on July 25, 2013, designating 29 areas in 16 states as nonattainment for the 2010 1-hour SO₂ NAAQS. See 78 FR 47191 (August 5, 2013).

On August 21, 2015 (80 FR 51052), EPA separately promulgated air quality characterization requirements for the 2010 1-hour SO₂ NAAQS in the Data Requirements Rule (DRR). The DRR required state air agencies to characterize air quality, through air dispersion modeling or monitoring, in areas associated with sources that emitted 2,000 tons per year (tpy) or more of SO₂, or that have otherwise been listed under the DRR by EPA or state air agencies. In lieu of modeling or monitoring, state air agencies, by specified dates, could elect to impose federally-enforceable emissions limitations on those sources restricting their annual SO₂ emissions to less than 2,000 tpy, or provide documentation that the sources have been shut down. EPA expected that the information generated by implementation of the DRR would help inform designations for the 2010 1-hour SO₂ NAAQS that must be completed by December 31, 2020 (“round 4”).^[5] EPA signed Federal Register notices of promulgation for round 2 designations ^[6] on June 30, 2016 (81 FR 45039 (July 12, 2016)), and on November 29, 2016 (81 FR 89870 (December 13, 2016)), and round 3 designations ^[7] on December 21, 2017 (83 FR 1098 (January 9, 2018)).

Currently, there are no nonattainment areas for the 2010 1-hour SO₂ NAAQS in Georgia. One area in Floyd County, Georgia, will be designated in round 4.^[8] The remaining counties in Georgia were designated as attainment/unclassifiable in rounds 2 and round 3.

II. Relevant Factors Used To Evaluate 2010 1-Hour SO₂ Interstate Transport SIPs

Although SO₂ is emitted from a similar universe of point and nonpoint sources as is directly emitted fine particulate matter (PM_2.5) and the precursors to ozone and PM_2.5, interstate transport of SO₂ is unlike the transport of PM_2.5 or ozone because SO₂ emissions sources usually do not have long range SO₂ impacts. The transport of SO₂ relative to the 2010 1-hour SO₂ NAAQS is more analogous to the transport of lead (Pb) relative to the Pb NAAQS in that emissions of SO₂ typically result in 1-hour pollutant impacts of possible concern only near the emissions source. However, ambient 1-hour concentrations of SO₂ do not decrease as quickly with distance from the source as do 3-month average concentrations of Pb, because SO₂ gas is not removed by deposition as rapidly as are Pb particles and because SO₂ typically has a higher emissions release height than Pb. Emitted SO₂ has wider ranging impacts than emitted Pb, but it does not have such wide-ranging impacts that treatment in a manner similar to ozone or PM_2.5 would be appropriate. Accordingly, while the approaches that EPA has adopted for ozone or PM_2.5 transport are too regionally focused, the approach for Pb transport is too tightly circumscribed to the source. SO₂ transport is therefore a unique case and requires a different approach. In SO₂ transport analyses, EPA focuses on a 50 kilometer (km)-wide zone because the physical properties of SO₂ result in relatively localized pollutant impacts near an emissions source that drop off with distance.

In its July 31, 2019, SIP submission, GA EPD identified a distance threshold to reflect the transport properties of SO₂. GA EPD selected a spatial scale with dimensions from four to 50 km from point sources—the “urban scale”—as appropriate in assessing trends in both area-wide air quality and the effectiveness of large-scale pollution control strategies at such point sources. GA EPD supported this choice of transport distance threshold with references to the March 1, 2011, EPA memorandum titled “Additional Clarification Regarding Application of Appendix W Modeling Guidance for the 1-hour NO₂ National Ambient Air Quality Standard,” and noted that GA EPD believes that this guidance memorandum can be applied to 1-hour SO₂ analyses.^[9] In its January 9, 2019, SIP submission, GA EPD included a quote from page 16 of this March 1, 2011, EPA memorandum: “Even accounting for some terrain influences on the location and gradients of maximum 1-hour concentrations, these considerations suggest that the emphasis on determining which nearby sources to include in the modeling analysis should focus on the area within about 10 kilometers of the project location in most cases. The routine inclusion of all sources within 50 kilometers of the project location, the nominal distance for which the American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD) is applicable, is likely to produce an overly conservative result in most cases.” In addition, the State indicated that GA EPD conducted modeling for the DRR which showed that the highest impacts from sources are typically within 2-5 km from the source and that the impacts past 10 km are “insignificant.” GA EPD believes that based on EPA's March 11, 2011, guidance memorandum and GA EPD's SO₂ modeling, an appropriate transport distance for SO₂ from Georgia to neighboring states is 10 km. However, GA EPD stated that Georgia “will use an extremely conservative transport distance of 50 km in this demonstration to match the distance for which AERMOD is applicable.” ^[10]

Given the properties of SO₂, EPA preliminarily agrees with Georgia's selection of the urban scale to assess trends in area-wide air quality that might impact downwind states.^[11] As discussed further in section III.B, EPA believes that Georgia's selection of the urban scale is appropriate for assessing trends in both area-wide air quality and the effectiveness of large-scale pollution control strategies at SO₂ point sources. EPA's notes that Georgia's selection of this transport distance for SO₂ is consistent with 40 CFR 58, Appendix D, Section 4.4.4(4) “Urban scale,” which states that measurements in this scale would be used to estimate SO₂ concentrations over large portions of an urban area with dimensions from four to 50 km. AERMOD is EPA's preferred modeling platform for regulatory purposes for near-field dispersion of emissions for distances up to 50 km. See Appendix W of 40 CFR part 51. Thus, EPA is proposing to concur with Georgia's application of the 50-km threshold to evaluate emission source impacts into neighboring states and to assess air quality monitors within 50 km of the State's border, which is discussed further in section III.C.^[12]

As discussed in sections III.C and III.D, EPA first reviewed Georgia's analysis to assess how the State evaluated the transport of SO₂ to other states, the types of information used in the analysis, and the conclusions drawn by the State. EPA then conducted a weight of evidence analysis based on a review of the State's submission and other available information, including SO₂ air quality and available source modeling for monitors and sources in Georgia and in neighboring states within 50 km of the Georgia border.^[13]

III. Georgia's SIP Submission and EPA's Analysis

A. State Submission

On January 9, 2019, GA EPD submitted a revision to the Georgia SIP addressing prongs 1 and 2 of CAA section 110(a)(2)(D)(i)(I) for the 2010 1-hour SO₂ NAAQS. Georgia conducted a weight of evidence analysis to examine whether SO₂ emissions from the State adversely affect attainment or maintenance of the 2010 1-hour SO₂ NAAQS in downwind states.

GA EPD reviewed the following information to support its conclusion that Georgia does not significantly contribute to nonattainment or interfere with maintenance of the 2010 1-hour SO₂ NAAQS in downwind states: Annual SO₂ 99th percentile values (2015, 2016, and 2017) and 2017 design values (DVs) ^[14] at monitors in Georgia and adjacent states within 50 km of Georgia's border; SO₂ emissions trends in Georgia and adjacent states from 1990 to 2017; the fact that EPA designated all counties within 50 km of Georgia's border as attainment/unclassifiable with the exception of Haywood County in North Carolina and a portion of Nassau County in Florida ^[15] (GA EPD's analysis of Haywood County, North Carolina, and Nassau County, Florida, is described in section III.C.3.a of this notice); and established federal and State control measures which reduce SO₂ emissions in the present and future. Based on this weight of evidence analysis, the State concluded that emissions within Georgia will not contribute significantly to nonattainment or interfere with maintenance of the 2010 1-hour SO₂ NAAQS in any other state. EPA's evaluation of Georgia's submission is detailed in sections III.B, C, and D.

B. EPA's Evaluation Methodology

EPA believes that a reasonable starting point for determining which sources and emissions activities in Georgia are likely to impact downwind air quality in other states with respect to the 2010 1-hour SO₂ NAAQS is by using information in EPA's National Emissions Inventory (NEI).^[16] The NEI is a comprehensive and detailed estimate of air emissions for criteria pollutants, criteria pollutant precursors, and hazardous air pollutants from air emissions sources that is updated every three years using information provided by the states and other information available to EPA.

EPA evaluated data from the 2014 NEI (version 2), the most recently available, complete, and quality assured dataset of the NEI. As shown in Table 1, the majority of SO₂ emissions in Georgia originate from fuel combustion at point sources.^[17] In 2014, SO₂ emissions from point sources ^[18] in Georgia comprised approximately 91 percent of the total SO₂ emissions in the State, with 81 percent of the State's total SO₂ emissions coming from fuel combustion point sources. Because emissions from the other listed source categories are more dispersed throughout the State, those categories are less likely to cause high ambient concentrations when compared to a point source on a ton-for-ton basis. In addition, EPA considered 2017 statewide SO₂ emissions data in Georgia's SIP submission, which showed that fuel combustion by electric generating units (EGUs) and industrial processes comprised approximately 57 percent of the State's SO₂ emissions in 2017.^[19] Based on EPA's analysis of the 2014 NEI and GA EPD's evaluation of 2017 statewide SO₂ emissions data by certain source categories, EPA believes that it is appropriate to focus the analysis on SO₂ emissions from Georgia's larger point sources (i.e., emitting over 100 tpy of SO₂ in 2017), including fuel combustion point sources, which are located within the “urban scale,” i.e., within 50 km of one or more state borders.

As explained in Section II, because the physical properties of SO₂ result in relatively localized pollutant impacts near an emissions source that drop off with distance, in SO₂ transport analyses, EPA focuses on a 50 km-wide zone. Thus, EPA focused its evaluation on Georgia's point sources of SO₂ emissions located within approximately 50 km of another state and their potential impact on neighboring states.

As discussed in section I.B., EPA's current implementation strategy for the 2010 1-hour SO₂ NAAQS includes the flexibility to characterize air quality for stationary sources subject to the DRR via either data collected at ambient air quality monitors sited to capture the points of maximum concentration, or air dispersion modeling (hereinafter referred to as the “DRR monitor”). EPA's assessment of SO₂ emissions from Georgia's point sources located within approximately 50 km of another state and their potential impacts on neighboring states (section III.C.1. of this notice) and SO₂ air quality data at monitors within 50 km of the Georgia border (section III.C.3. of this notice) is informed by all available data at the time of this rulemaking.^[20]

As described in Section III, EPA proposes to conclude that an assessment of Georgia's satisfaction of the prong 1 and 2 requirements under section 110(a)(2)(D)(i)(I) of the CAA for the 2010 1-hour SO₂ NAAQS may be reasonably based upon evaluating the downwind impacts of SO₂ emissions from Georgia's point sources, including fuel combustion sources, located within approximately 50 km of another state and upon any regulations intended to address Georgia's point sources.

C. EPA's Prong 1 Evaluation—Significant Contribution to Nonattainment

Prong 1 of the good neighbor provision requires states' plans to prohibit emissions that will significantly contribute to nonattainment of a NAAQS in another state. GA EPD confirms in its submission that Georgia sources will not contribute significantly to nonattainment in any other state with respect to the 2010 1-hour SO₂ standard. To evaluate Georgia's satisfaction of prong 1, EPA assessed the State's implementation plan with respect to the following factors: (1) Potential ambient impacts of SO₂ emissions from certain facilities in Georgia on neighboring states based on available air dispersion modeling results; (2) SO₂ ambient air quality and emissions trends for Georgia and neighboring states; (3) SIP-approved regulations that address SO₂ emissions; and (4) federal regulations that reduce SO₂ emissions. A detailed discussion of Georgia's SIP submission with respect to each of these factors follows.^[21] EPA proposes that these factors, taken together, support the Agency's proposed determination that Georgia will not significantly contribute to nonattainment of the 2010 1-hour SO₂ NAAQS in another state. EPA also notes that the Agency does not have information indicating that there are violations of the 2010 1-hour SO₂ NAAQS in the surrounding states. Also, 2017 SO₂ emissions for Georgia's non-DRR sources emitting over 100 tons of SO₂ within 50 km of another state are at distances or emit levels of SO₂ that make it unlikely that these SO₂ emissions could interact with SO₂ emissions from the neighboring states' sources in such a way as to contribute significantly to nonattainment in these states. In addition, the downward trends in SO₂ emissions and DVs for air quality monitors in the State, the fact that the highest annual 99th percentile daily maximum 1-hour SO₂ concentration values observed at the only DRR monitor within 50 km of the Georgia border were well below the 2010 1-hour SO₂ NAAQS in 2017 and 2018, combined with federal and State SIP-approved regulations affecting SO₂ emissions of Georgia's sources, further support EPA's proposed conclusion.

1. SO₂ Designations Air Dispersion Modeling

a. State Submission

In its SIP revision, GA EPD references modeling done by the State for the DRR when discussing SO₂ transport. Regarding source-specific modeling under the DRR, EPA evaluated and summarized the modeling results for Georgia's DRR sources within 50 km of the State's border in Table 2 of section III.C.1.b.

b. EPA Analysis

EPA evaluated available DRR modeling results for sources in Georgia and in the adjacent states that are within 50 km of the Georgia border.^[22] The purpose of evaluating modeling results in adjacent states within 50 km of the Georgia border is to ascertain whether any nearby sources in Georgia are impacting a violation of the 2010 1-hour SO₂ NAAQS in another state.^[23]

Table 2 provides a summary of the modeling results for the modeled DRR sources ^[24] in Georgia which are located within 50 km of another state: Georgia-Pacific Consumer Products—Savannah River Mill (Savannah River Mill); Georgia Power Company—Plant Bowen (Plant Bowen); Georgia Power Company—Plant McIntosh (Plant McIntosh); Georgia Power Company—Plant Wansley (Plant Wansley); and International Paper—Savannah. The modeling analysis resulted in no modeled violations of the 2010 1-hour SO₂ NAAQS within the modeling domain for each facility.

Table 3 provides a summary of the modeling results for the modeled DRR sources in neighboring states which are located within 50 km of Georgia: ^[25] Continental Carbon Company—Phenix City Plant (Continental Carbon) in Alabama and JEA—Northside/St. Johns River Power Park (SJRPP); ^[26] WestRock CP, LLC—Fernandina Beach Mill (WestRock); and White Springs Agricultural Chemical—Swift Creek Chemical Complex (White Springs) in Florida.

EPA believes that the modeling results summarized in Tables 2 and 3, weighed along with the other factors in this notice, support EPA's proposed conclusion that sources in Georgia will not significantly contribute to nonattainment of the 2010 1-hour SO₂ NAAQS in any other state. Furthermore, EPA does not have any evidence of any modeled 2010 1-hour SO₂ violations in the neighboring states due to SO₂ emissions from Georgia.

2. SO₂ Emissions Analysis

a. State Submission

As discussed above, GA EPD provided 2017 statewide SO₂ emissions data by certain source categories, which showed that fuel combustion by EGUs and industrial processes comprised approximately 57 percent of the State's SO₂ emissions in 2017. In addition, GA EPD provided in Georgia's January 9, 2019, submission in Appendix A and displayed in a figure SO₂ emission trends in Georgia from 1990 to 2017 and notes that SO₂ emissions decreased by 95 percent during that time period.^[28] GA EPD also analyzed and displayed in a figure in Georgia's January 9, 2019, submission SO₂ emission trends in the adjacent states of Alabama, Florida, North Carolina, South Carolina, and Tennessee from 1990 to 2017.^[29] From the State's analysis of these emissions data, GA EPD concludes that there has been a significant reduction in SO₂ emissions in Georgia and its neighboring states from 2007 to 2017.

b. EPA Analysis

EPA reviewed the SO₂ emissions data from 1990 to 2017 for Georgia and the adjacent states of Alabama, Florida, North Carolina, South Carolina, and Tennessee.^[30] Georgia's statewide SO₂ emissions decreased from 985,445 tons in 1990 to 50,606 tons in 2017. EPA agrees that statewide SO₂ emissions for these six states, including Georgia, have decreased significantly over this time period and notes that these reductions show a similar downward trend.^[31] EPA also notes that SO₂ emissions from fuel combustion at Georgia EGUs decreased from 875,451 tons in 1990 to 13,794 tons in 2017 and that SO₂ emissions from fuel combustion due to industrial processes in Georgia declined from 54,570 tons in 1990 to 14,706 tons in 2017.^[32]

As discussed in section III.B, EPA finds that it is appropriate to examine the impacts of SO₂ emissions from stationary sources emitting greater than 100 tons of SO₂ in Georgia in distances ranging from zero km to 50 km from the sources. Therefore, in addition to the sources addressed in section III.C.1.b of this notice, EPA also assessed the potential impacts of SO₂ emissions from stationary sources not subject to the DRR and located up to 50 km from Georgia's borders using 2017 emissions data and to evaluate whether the SO₂ emissions from these sources could interact with SO₂ emissions from the nearest source in a neighboring state in such a way as to impact a violation of the 2010 1-hour SO₂ NAAQS in that state. Table 4 lists sources in Georgia not subject to the DRR that emitted greater than 100 tpy of SO₂ in 2017 and are located within 50 km of the State's border.

Currently, EPA does not have monitoring or modeling data suggesting that the states of Alabama, Florida, and South Carolina are impacted by SO₂ emissions from the nine Georgia sources listed in Table 4. All 10 Georgia sources are located over 50 km from the nearest non-DRR sources in another state emitting over 100 tons of SO_2. EPA believes that the distances greater than 50 km between sources make it unlikely that SO₂ emissions from the 10 Georgia sources could interact with SO₂ emissions from these out-of-state sources in such a way as to contribute significantly to nonattainment in Alabama, Florida, or South Carolina.

Based on the declining SO₂ emissions trends statewide in Georgia and the adjacent states of Alabama, Florida, North Carolina, South Carolina, and Tennessee, and the Agency's analysis of the Georgia sources in Table 4, EPA believes that Georgia's potential for contributing significantly to nonattainment of the 2010 1-hour SO₂ NAAQS in a nearby state is reduced substantially.

3. SO₂ Ambient Air Quality

a. State Submission

In its SIP submission, GA EPD included a table showing that the six SO₂ monitors in Georgia and six monitors in the adjacent states of Florida and South Carolina within 50 km of Georgia's border with complete, valid DVs for the 2015-2017 time period have 2017 DVs of 52 ppb or less, well below the 2010 1-hour SO₂ NAAQS.^[33] GA EPD also summarized EPA's round 3 designations for the 2010 1-hour SO₂ NAAQS for Georgia and adjacent states. GA EPD notes that EPA designated all counties within 50 km of Georgia's border as attainment/unclassifiable in round 3 with the exception of Haywood County in North Carolina and a small portion of Nassau County in Florida.

With respect to Haywood County, North Carolina, GA EPD explains that Haywood County will be designated in round 4. The only SO₂ source in Georgia within 50 km ^[34] of Haywood County, North Carolina, is Multitrade Rabun Gap. According to the State, the 2014 SO₂ emissions from this facility were 25.1 tpy.^[35] In the January 9, 2019, SIP submission, GA EPD concluded that Multitrade Rabun Gap will not contribute significantly to nonattainment of the 2010 1-hour SO₂ NAAQS in Haywood County, North Carolina, due to the amount of these emissions and the distance from Haywood County.

With respect to Nassau County, Florida, GA EPD summarized the status of this area as follows. On August 5, 2013,^[36] EPA designated an area in Nassau County, Florida, as nonattainment for the 2010 1-hour SO₂ NAAQS based on ambient SO₂ monitoring data in the area over the three-year period 2009-2011. Florida submitted an attainment demonstration for Nassau County on April 3, 2015, and EPA fully approved this demonstration on July 3, 2017. GA EPD notes that the SO₂ monitor in Nassau County has a 2017 SO₂ DV of 43 ppb. Florida submitted a redesignation request and maintenance plan for the Nassau County SO₂ nonattainment area on June 7, 2018. Thus, GA EPD concluded that because Nassau County currently has a 3-year DV well below the 2010 1-hour SO₂ NAAQS and, at the time of Georgia's SIP development, was in the process of being redesignated to attainment for the 2010 1-hour SO₂ NAAQS, SO₂ emission sources in Georgia do not contribute significantly to nonattainment of the 2010 1-hour SO₂ NAAQS in Nassau County, Florida.^[37]

b. EPA Analysis

Since the time of development of Georgia's SIP submission, certified monitoring data from EPA's Air Quality System (AQS) ^[38] (“AQS monitors”) have become available for Georgia and the surrounding states. EPA has summarized the DVs from 2013 to 2018 for AQS monitors in Georgia within 50 km of another state in Table 5 and AQS monitors in neighboring states within 50 km of Georgia in Table 6 using relevant data from EPA's AQS DV reports for recent and complete 3-year periods. The 2010 1-hour SO₂ standard is violated at an ambient air quality monitoring site (or in the case of dispersion modeling, at an ambient air quality receptor location) when the 3-year average of the annual 99th percentile of the daily maximum 1-hour average concentrations exceeds 75 ppb, as determined in accordance with Appendix T of 40 CFR part 50.

As shown in Table 5, DVs for the four non-DRR monitoring sites in Georgia within 50 km of another state's border have remained well below the 2010 1-hour SO₂ NAAQS for the 2011-2013 through 2016-2018 time periods.^[39] The monitor located in Floyd County maintained 2010 1-hour SO₂ NAAQS DVs well below the NAAQS for the 2011-2013 through 2014-2016 time periods, and was then relocated to a nearby site in 2016 to characterize the area pursuant to the DRR; therefore, no DVs are available for this monitor after the 2014-2016 time period.^[40]

There is one AQS monitor in South Carolina and six AQS monitors in Florida that are located within 50 km of Georgia. As shown in Table 6, the DVs from 2013 to 2018 for these monitors are generally trending downward, and the 2018 DVs are well below the 2010 1-hour SO₂ NAAQS, with the exception of the Hamilton County, Florida monitor which has no data for the 2016-2018 DV time period. The Hamilton County monitor has 2012 and 2013 DVs of 23 and 25 ppb, respectively, and incomplete data for the remaining DV time periods (2014-2018).

EPA also evaluated monitoring data provided to date for DRR monitors either located in Georgia within 50 km of another state's border or in other states within 50 km of the Georgia border that were established to characterize the air quality around specific sources subject to EPA's DRR to inform the Agency's future round 4 designations for the 2010 1-hour SO₂ NAAQS in lieu of modeling. There are no DRR monitors located in other states within 50 km of the Georgia border. There is one DRR monitor in Georgia which is within 50 km of the border, and it is located approximately 12 km from Alabama in Floyd County, Georgia (AQS ID: 13-115-0006) and is sited in the vicinity of the International Paper—Rome facility, a DRR source. Table 7 lists the 2017 and 2018 99th percentile SO₂ concentration data for this DRR monitor in Floyd County, Georgia.^[41]

Although the annual 99th percentile daily maximum 1-hour SO₂ concentrations shown in Table 7 are not directly comparable to a DV for the 2010 1-hour SO₂ NAAQS, which is in the form of the 3-year average of the 99th percentile of daily maximum 1-hour values, EPA notes that the highest annual 99th percentile daily maximum 1-hour values observed at the Floyd County DRR monitor in 2017 and 2018 were 22 ppb and 15 ppb, respectively, which are well below the 2010 1-hour SO₂ NAAQS. The Floyd County DRR monitor did not measure any daily exceedances of the 2010 1-hour SO₂ NAAQS during 2017 or 2018.

After careful review of the State's assessment and all available monitoring data, EPA believes that the AQS monitoring data and the preliminary data from the Floyd County DRR monitor (AQS ID: 13-115-0006) further support EPA's proposed conclusion that Georgia will not contribute significantly to nonattainment of the 2010 1-hour SO₂ NAAQS in neighboring states.

4. SIP-Approved Regulations Addressing SO₂ Emissions

a. State Submission

Georgia identified the following SIP-approved measures which help ensure that SO₂ emissions in the State do not significantly contribute to nonattainment of the 2010 1-hour SO₂ NAAQS in any other state. Georgia Rules for Air Quality Control 391-3-1-.03.—Permits. Amended, contains provisions addressing construction permits (391-3-1-.03(1)); operating permits (391-3-1-.03(2)); new source review (NSR) (391-3-1-.03(8)(c) and (g)); permit by rule (391-3-1-.03(11)); and generic permits (391-3-1-.03(12)). Georgia Rules for Air Quality Control 391-3-1-.02(7) addresses Prevention of Significant Deterioration (PSD) requirements, which apply to all new major sources and major modifications in attainment, unclassifiable, or undesignated areas.^[42] Georgia Rules for Air Quality Control 391-3-1-.02(2)(g)—Sulfur Dioxide and 391-3-1-.02(13)—Cross State Air Pollution Rule SO₂Annual Trading Program also reduce SO₂ emissions.

In addition, GA EPD listed the following State-enforceable rules not approved into the Georgia SIP which control SO₂ emissions: Georgia Rules for Air Quality Control 391-3-1-.02(2)(sss)—Multipollutant Control for Electric Utility Steam Generating Units and 391-3-1-.02(2)(uuu)—SO₂ Emissions from Electric Utility Steam Generating Units.

b. EPA Analysis

EPA believes that Georgia's SIP-approved measures which establish emission limits, permitting requirements, and other control measures for SO₂ effectively address emissions of SO₂ from sources in the State. For the purposes of ensuring that SO₂ emissions at new major sources or major modifications at existing major sources in Georgia do not contribute significantly to nonattainment of the NAAQS, the State has a SIP-approved major NSR program. Georgia Rules for Air Quality Control 391-3-1-.03.—Permits. Amended, which includes NSR requirements under 391-3-l-.03(8)(c) and (g), regulates the construction of any new major stationary source or any modification at an existing major stationary source in an area designated as nonattainment, attainment, or unclassifiable. The State's SIP-approved PSD regulation, 391-3-1-.02.—Provisions. Amended, which includes PSD requirements under 391-3-1-.02(7), applies to the construction of any new major stationary source or major modification at an existing major stationary source in an area designated as attainment or unclassifiable or not yet designated. SIP-approved Georgia Rules for Air Quality Control 391-3-1-.03(1)—Construction (SIP) Permit governs the preconstruction permitting of minor modifications and the construction of minor stationary sources. These major and minor NSR rules ensure that SO₂ emissions due to major modifications at existing major stationary sources, modifications at minor stationary sources, and the construction of new major and minor sources subject to these rules will not contribute significantly to nonattainment of the 2010 1-hour SO₂ NAAQS in neighboring states.

5. Federal Regulations Addressing SO₂ Emissions in Georgia

a. State Submission

GA EPD did not identify any specific federal regulations that address SO₂ emissions in its SIP submission. Thus, EPA lists in section III.C.5.b several federal regulations which have reduced SO₂ emissions in Georgia and will continue to do so in the future.

b. EPA Analysis

The following federal control measures reduce SO₂ emissions from various sources: 2007 Heavy-Duty Highway Rule; Acid Rain Program; Cross-State Air Pollution Rule; Mercury Air Toxics Rule; National Emission Standards for Hazardous Air Pollutants; New Source Performance Standards; Nonroad Diesel Rule; and Tier 1 and 2 Mobile Source Rules. EPA believes that these federal measures will lower SO₂ emissions, which, in turn, are expected to continue to support EPA's proposed conclusion that SO₂ emissions from Georgia will not significantly contribute to nonattainment of the 2010 1-hour SO₂ NAAQS in another state.

6. Conclusion

EPA proposes to determine that Georgia's January 9, 2019, SIP submission satisfies the requirements of prong 1 of CAA section 110(a)(2)(D)(i)(I). This proposed determination is based on the following considerations: Modeling for the six Georgia DRR sources within 50 km of another state's border shows that the areas around these facilities are not exceeding the level of the 2010 1-hour SO₂ NAAQS; DVs for 2013 through 2018 for the four currently operating non-DRR monitoring sites in Georgia within 50 km of another state's border have remained well below the 2010 1-hour SO₂ NAAQS; 2017 and 2018 99th percentile SO₂ concentrations at the DRR monitor in Floyd County, Georgia, are well below the 2010 1-hour SO₂ NAAQS; the DVs for five of the six non-DRR monitors in Florida ^[43] and the one non-DRR monitor South Carolina that are located within 50 km of Georgia are trending downward overall and have remained below the level of the 2010 1-hour SO₂ NAAQS from the 2011-2013 to 2016-2018 time periods; SO₂ emissions from Georgia sources not subject to the DRR emitting over 100 tons of SO₂ in 2017 are not likely interacting with SO₂ emissions from the nearest out-of-state source in a bordering state in such a way as to contribute significantly to nonattainment in Alabama, Florida, or South Carolina; downward SO₂ emissions trends in Georgia and the Agency's analysis of the non-DRR Georgia sources emitting over 100 tpy in 2017 in Table 4 suggest that Georgia's potential for contributing significantly to nonattainment of the 2010 1-hour SO₂ NAAQS in a nearby state is reduced substantially; and current Georgia SIP-approved measures and federal emissions control programs adequately control SO₂ emissions from sources within Georgia.

Based on the analysis provided by Georgia in its SIP submission and EPA's analysis of factors described in section III.C, EPA proposes to find that sources within Georgia will not contribute significantly to nonattainment of the 2010 1-hour SO₂ NAAQS in any other state.

D. EPA's Prong 2 Evaluation—Interference With Maintenance of the NAAQS

Prong 2 of the good neighbor provision requires state plans to prohibit emissions that will interfere with maintenance of a NAAQS in another state.

1. State Submission

In its January 9, 2019, SIP submission, GA EPD confirms that Georgia will not interfere with maintenance of the 2010 1-hour SO₂ NAAQS in any other state. GA EPD bases its conclusion for prong 2 on the following: Annual SO₂ 99th percentile values (2015, 2016, and 2017) and the 2015-2017 DVs at monitors in Georgia and within 50 km of Georgia's border; SO₂ emissions trends in Georgia and adjacent states from 1990 to 2017; and the SIP-approved measures discussed in sections III.C.4.a of this notice.

2. EPA Analysis

In North Carolina v. EPA, the United States Court of Appeals for the District of Columbia Circuit (D.C. Circuit) explained that the regulating authority must give prong 2 “independent significance” from prong 1 by evaluating the impact of upwind state emissions on downwind areas that, while currently in attainment, are at risk of future nonattainment. North Carolina v. EPA, 531 F.3d 896, 910-11 (D.C. Cir. 2008). EPA interprets prong 2 to require an evaluation of the potential impact of a state's emissions on areas that are currently measuring clean data, but that may have issues maintaining that air quality. Therefore, in addition to the analysis presented by Georgia, EPA has also reviewed additional information on SO₂ air quality and emission trends to evaluate the State's conclusion that Georgia will not interfere with maintenance of the 2010 1-hour SO₂ NAAQS in downwind states. This evaluation builds on the analysis regarding significant contribution to nonattainment (prong 1).

For the prong 2 analysis, EPA evaluated the emissions trends provided by Georgia for the State, evaluated air quality data, and assessed how future sources of SO₂ are addressed through existing SIP-approved and federal regulations. Given the continuing trend of decreasing SO₂ emissions from sources within Georgia and the fact that all areas in other states within 50 km of the Georgia border have DVs attaining the 2010 1-hour SO₂ NAAQS (with the exception of Florida's Duval County monitor (AQS ID: 12-031-0080) which does not have a 2018 DV), EPA believes that evaluating whether these decreases in emissions can be maintained over time is a reasonable criterion to ensure that sources within Georgia do not interfere with its neighboring states' ability to maintain the 2010 1-hour SO₂ NAAQS.

With respect to air quality data trends, the 2018 DVs for AQS SO₂ monitors both in Georgia within 50 km of another state's border and in adjacent states within 50 km of Georgia's border are below the 2010 1-hour SO₂ NAAQS. Further, modeling results for DRR sources both within the State and in neighboring states within 50 km of Georgia's border demonstrate attainment of the 2010 1-hour SO₂ NAAQS, and thus, demonstrate that Georgia's largest point sources of SO₂ are not expected to interfere with maintenance of the 2010 1-hour SO₂ NAAQS in another state.

As discussed in sections III.C.4 and III.C.5, EPA believes that federal and SIP-approved State regulations that both directly and indirectly reduce emissions of SO₂ in Georgia help ensure that the State does not interfere with maintenance of the NAAQS in another state. SO₂ emissions from future major modifications and new major sources will be addressed by Georgia's SIP-approved major NSR regulations described in section III.C.4. In addition, Georgia's SIP approved Air Quality Control Rule 391-3-1-.03(1)—Construction (SIP) Permit governs the preconstruction permitting of modifications, construction of minor stationary sources, and minor modifications of major stationary sources. The permitting regulations contained within these programs ensure that emissions from these activities do not interfere with maintenance of the 2010 1-hour SO₂ NAAQS in the State or in any other state.

3. Conclusion

EPA proposes to determine that Georgia's January 9, 2019, SIP submission satisfies the requirements of prong 2 of CAA section 110(a)(2)(D)(i)(I). This determination is based on the following considerations: Modeling for DRR sources within 50 km of Georgia's border both within the State and in neighboring states demonstrate that Georgia's largest point sources of SO₂ are not expected to interfere with maintenance of the 2010 1-hour SO₂ NAAQS in another state; SO₂ emissions statewide from 1990 to 2017 in Georgia have declined significantly and, weighed along with the Agency's analysis of the Georgia non-DRR sources emitting greater than 100 tpy in 2017 listed in Table 4 of this notice, indicate that Georgia's potential for interfering with maintenance of the 2010 1-hour SO₂ NAAQS in a nearby state is reduced substantially; current Georgia SIP-approved measures and federal emissions control programs adequately control SO₂ emissions from sources within Georgia, including Georgia's SIP-approved NSR permit programs which address future large and small SO₂ sources in the State; DVs for the 2011-2013 through 2016-2018 time periods for AQS SO₂ monitors both in Georgia within 50 km of another state's border and in adjacent states within 50 km of Georgia's border are well below the level of the 2010 1-hour SO₂ NAAQS and trending downward; and the relatively low 99th percentile of 1-hour daily maximum SO₂ concentrations for 2017 and 2018 at the Floyd County, Georgia, DRR monitor. Based on the analysis provided by Georgia in its SIP submission and EPA's supplemental analysis of the factors described in section III.C and III.D of this notice, EPA proposes to find that emission sources within Georgia will not interfere with maintenance of the 2010 1-hour SO₂ NAAQS in any other state.

IV. Proposed Action

Based on the above analysis, EPA is proposing to determine that Georgia will not contribute significantly to nonattainment or interfere with maintenance of the 2010 1-hour SO₂ NAAQS in any other state. Therefore, EPA is proposing to approve the January 9, 2019, SIP revision as meeting the requirements of the good neighbor provision for the 2010 1-hour SO₂ NAAQS.

V. Statutory and Executive Order Reviews

Under the CAA, the Administrator is required to approve a SIP submission that complies with the provisions of the Act and applicable Federal regulations. 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 proposes to approve state law as meeting Federal requirements and does not impose additional requirements beyond those imposed by state law. For that reason, this proposed action:

• Is not a significant regulatory action subject to review by the Office of Management and Budget under Executive 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).

The SIP 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 in 40 CFR Part 52

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

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

Footnotes