2020-12691. Air Plan Approval; GA: Non-Interference Demonstration and Maintenance Plan Revision for the Removal of Transportation Control Measures in the Atlanta Area

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Proposed rule.

SUMMARY:

The Environmental Protection Agency (EPA) is proposing to approve a State Implementation Plan (SIP) revision submitted by Georgia, through the Georgia Environmental Protection Division (GA EPD), on September 16, 2019, for the purpose of removing certain transportation control measures (TCMs) from thirteen counties in the Atlanta, Georgia area. EPA is also proposing to approve Georgia's update to the 2008 8-hour ozone maintenance plan that was submitted in the September 16, 2019, SIP revision. Specifically, EPA is proposing to approve updates to the mobile emissions inventory, the associated 2030 motor vehicle emissions budgets (MVEBs), and measures offsetting the potential emissions increases due to removal of the TCMs from the Georgia SIP. EPA's preliminary analysis indicates that this SIP revision would not interfere with attainment or maintenance of any national ambient air quality standards (NAAQS or standards) or any other Clean Air Act (CAA or Act) requirements.

DATES:

Comments must be received on or before July 30, 2020.

ADDRESSES:

Submit your comments, identified by Docket ID No. EPA-R04-OAR-2019-0661 at 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 www2.epa.gov/​dockets/​commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT:

Dianna Myers, 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. The telephone number is [phone]. Ms. Myers can also be reached via electronic mail at [e-mail].

SUPPLEMENTARY INFORMATION:

I. EPA's Proposed Action

A. What action is EPA proposing?

EPA is proposing to approve the removal of certain TCMs ^[1] applicable in thirteen counties within the Atlanta Area ^[2] from Georgia's SIP. EPA is also proposing to approve Georgia's update to the 2008 8-hour ozone maintenance plan that was submitted in the September 16, 2019, SIP revision. Specifically, EPA is proposing to approve updates to the mobile emissions inventory and the associated MVEBs in the 2008 8-hour ozone Maintenance Plan, and measures offsetting the potential emissions increases due to removal of the TCMs from the Georgia SIP. In addition, EPA is proposing to find that removing the TCMs from the Atlanta Area would not interfere with attainment or maintenance of any NAAQS, reasonable further progress (RFP), or with any other applicable requirement of the CAA.

B. What is the background of the Atlanta area?

On November 6, 1991 (56 FR 56694), EPA designated and classified the following counties in the Atlanta Area as a serious ozone nonattainment area for the 1-hour ozone NAAQS: Cherokee, Clayton, Cobb, Coweta, DeKalb, Douglas, Fayette, Forsyth, Fulton, Gwinnett, Henry, Paulding, and Rockdale (the Atlanta 1979 1-hour ozone Area). TCMs were implemented in the 13-counties comprising the Atlanta 1979 1-hour ozone Area. See Table 2-1 in the September 16, 2019, SIP revision. Because the Atlanta 1979 1-hour ozone Area failed to attain the 1-hour ozone NAAQS by November 15, 1999, EPA issued a final rulemaking action on September 26, 2003, to reclassify or “bump up,” the area to a severe ozone nonattainment area. See 68 FR 55469. Subsequently, the Atlanta 1979 1-hour ozone Area attained the 1-hour ozone NAAQS, and thus EPA redesignated the nonattainment area to attainment for the 1-hour ozone NAAQS. See 70 FR 34660 (June 15, 2005). The 1979 1-hour ozone NAAQS was revoked, effective June 15, 2005. See 69 FR 23951 (April 30, 2004).

On April 30, 2004 (69 FR 23858), EPA designated the following 20 counties in the Atlanta Area as a marginal nonattainment area for the 1997 8-hour ozone NAAQS: Barrow, Bartow, Carroll, Cherokee, Clayton, Cobb, Coweta, DeKalb, Douglas, Fayette, Forsyth, Fulton, Gwinnett, Hall, Henry, Newton, Paulding, Rockdale, Spalding, and Walton (Atlanta 1997 8-hour ozone Area). The Atlanta 1979 1-hour ozone Area is a sub-set of this 20-county area. EPA reclassified the Atlanta 1997 8-hour ozone Area as a moderate nonattainment area on March 6, 2008, because the area failed to attain the 1997 8-hour ozone NAAQS by the required attainment date of June 15, 2007. See 73 FR 12013. Subsequently, the Atlanta 1997 8-hour ozone Area attained the 1997 8-hour ozone standard, and on December 2, 2013, EPA redesignated the Atlanta 1997 8-hour ozone Area to attainment for the 1997 8-hour ozone NAAQS. See 78 FR 72040. The 1997 8-hour ozone NAAQS was revoked, effective April 6, 2015. See 80 FR 12264 (March 6, 2015).

On May 21, 2012 (77 FR 30088), EPA designated the following 15-counties as marginal nonattainment for the 2008 8-hour ozone NAAQS: Bartow, Cherokee, Clayton, Cobb, Coweta, DeKalb, Douglas, Fayette, Forsyth, Fulton, Gwinnett, Henry, Newton, Paulding, and Rockdale (Atlanta 2008 8-hour ozone Area). The Atlanta 1979 1-hour ozone Area is sub-set of the Atlanta 2008 8-hour ozone Area. The Atlanta 2008 8-hour ozone Area did not attain the 2008 8-hour ozone NAAQS by the attainment date of July 20, 2015, and therefore on May 4, 2016, EPA reclassified the area from a marginal nonattainment area to a moderate nonattainment area for the 2008 8-hour ozone standard. See 81 FR 26697. Subsequently, on July 14, 2016, the Atlanta 2008 8-hour ozone Area attained the 2008 8-hour ozone standard. See 81 FR 45419. EPA redesignated the Atlanta 2008 8-hour ozone Area to attainment for the 2008 8-hour ozone NAAQS. See 82 FR 25523.

On October 26, 2015, EPA revised the 8-hour ozone standard from 0.075 parts per million (ppm) to 0.070 ppm. See 80 FR 65292. Subsequently, on June 4, 2018 (83 FR 25776), EPA designated the following seven Atlanta counties as marginal nonattainment for the 2015 8-hour ozone NAAQS: Bartow, Clayton, Cobb, Dekalb, Fulton, Gwinnett and Henry (Atlanta 2015 8-hour ozone Area). The seven counties comprising the Atlanta 2015 8-hour ozone Area were also part of the 13-county Atlanta 1979 1-hour ozone Area. Areas designated as marginal nonattainment must attain the standard by August 3, 2021. Although the attainment date is August 3, 2021, marginal areas must show attainment using air quality data for years 2018 through 2020.

C. What is the background of the TCMs?

CAA section 108(f) contains information related to processes, procedures, and methods that can be used by states and transportation planning agencies to reduce or control transportation and mobile source related pollutants and includes a non-comprehensive list of transportation control measures.

Section 93.101 of the transportation conformity rule at 40 CFR part 93 defines a TCM as: Any measure that is specifically identified and committed to in the applicable implementation plan, including a substitute or additional TCM that is incorporated into the applicable SIP through the process established in CAA section 176(c)(8), that is either one of the types listed in CAA section 108(f), or any other measure for the purpose of reducing emissions or concentrations of air pollutants from transportation sources by reducing vehicle use or changing traffic flow or congestion conditions. Notwithstanding the first sentence of this definition, vehicle technology-based, fuel-based, and maintenance-based measures which control the emissions from vehicles under fixed traffic conditions are not TCMs for the purposes of this subpart.

D. Why is EPA proposing this action?

On September 16, 2019, Georgia submitted a SIP revision, requesting removal of certain TCMs from the Georgia SIP. The following TCMs have been approved into the Georgia SIP: High Occupancy Vehicle (HOV) Lanes; High Occupancy Toll (HOT) Lanes; Atlantic Station; Express Bus Routes; Improvements/Expansion of Bus Service; Park and Ride Lots; Transit Signal Preemption; Clean Fuel Buses; Clean Fuels Revolving Loan Program; Intersection Upgrade, Coordination and Computerization; ATMS/Incident Management; Regional Commute Options & HOV Marketing; Transportation Management Associations (TMAs); Transit Incentives; and University Rideshare Programs. See 63 FR 23387 (April 29, 1998), 63 FR 34300 (June 24, 1998), 64 FR 13348 (March 18, 1999), 64 FR 20186 (April 26, 1999), 65 FR 52028 (August 28, 2000), 77 FR 24397 (April 24, 2012), and Table 1, Appendix A, Table 2-1 and Table 2-2 of Georgia's September 16, 2019 SIP Revision. Georgia is requesting removal of all the TCMs that are approved into the SIP except for Intersection Upgrade, Coordination and Computerization. See September 16, 2019, SIP Revision.

Georgia's September 16, 2019, SIP revision also includes a non-interference demonstration to support the State's request to remove TCMs implemented in the Atlanta Area from Georgia's SIP. Georgia's September 16, 2019, SIP revision evaluates the Atlanta 2008 8-hour ozone Area, which encompasses the smaller Atlanta 1979 1-hour ozone and Atlanta 2015 8-hour ozone Areas. Georgia's demonstration also includes an evaluation of the impact that removing the TCMs would have on the Atlanta Area's ability to maintain the ozone NAAQS. Additionally, Georgia's demonstration also evaluates whether the removal of the TCMs would interfere with the ability of the Atlanta 2015 8-hour ozone Area to attain the ozone NAAQS by August 3, 2021, which is the attainment date for areas classified as marginal, or any of the other applicable NAAQS.

Georgia's SIP revision updates the 2008 8-hour ozone maintenance plan ^[3] to support the State's request for removal of most of the TCMs for the Georgia SIP.^[4] To revise the SIP and make the demonstration of non-interference, Georgia completed a technical analysis, including using EPA's Motor Vehicle Emissions Simulator (MOVES2014a) to project the change in emissions that would result from removing the TCMs from the Atlanta Area. The 2014 attainment base year mobile emissions were taken directly from the 2008 maintenance SIP, and future-year on-road mobile source emissions estimates for 2020, 2030, and 2040 were modeled with and without the TCMs. Georgia interpolated years 2025 and 2035 to further illustrate the downward trend in emissions. Georgia selected years 2020, 2030, and 2040 because these years are used by the Atlanta Regional Commission (ARC) in Atlanta's transportation conformity determinations. The July 18, 2016, maintenance plan and the subsequent August 15, 2018, revision showed compliance with and maintenance of the 2008 8-hour ozone NAAQS until the 2030 outyear by providing information to support the demonstration that current and future emissions of nitrogen oxides (NO_X) and volatile organic compounds (VOC) remained at or below the 2014 base year emissions inventory. Further discussions on the demonstration of non-interference for the 2015 8-hour ozone NAAQS and the other pollutants are provided later in the proposal.

EPA has evaluated Georgia's September 16, 2019, SIP revision and is proposing to approve the SIP revision removing the TCMs from the SIP and revising the maintenance plan for the Atlanta 2008 8-hour ozone Area. The Agency is also making the preliminary determination that removing the TCMs from the Georgia SIP would not interfere with attainment or maintenance of any NAAQS or with any other applicable requirement of the CAA in the Atlanta, Area. EPA's section 110(l) analysis of the non-interference demonstration included as a part of Georgia's September 16, 2019, SIP revision is provided below.

E. What are the Section 110(l) requirements?

Section 110(l) requires that a revision to the SIP not interfere with any applicable requirement concerning attainment and RFP (as defined in section 171), or any other applicable requirement of the Act. The mobile emissions modeling associated with Georgia's maintenance plan for the 2008 8-hour ozone NAAQS was premised upon the future-year emissions estimates for 2020 ^[5] which includes the emission reductions from the various TCMs in the Georgia SIP for the Atlanta Area. To approve Georgia's request to remove the TCMs in the Atlanta Area, EPA must conclude that requested change will satisfy section 110(l) of the CAA. In Georgia's September 16, 2019, SIP revision, the State's modeling includes the same future years as the original 2008 8-hour ozone maintenance plan but is now based on the federal 9.0 psi RVP limit and removal of the TCMs.

In the absence of an attainment demonstration, to demonstrate no interference with any applicable NAAQS or requirement of the CAA under section 110(l), EPA believes it is appropriate to allow states to substitute equivalent emissions reductions to compensate for any change to a SIP-approved program, if actual emissions in the air are not increased. “Equivalent” emissions reductions are reductions that are equal to or greater than those reductions achieved by the control measure approved in the SIP. To show that compensating emissions reductions are equivalent, adequate justification must be provided. The compensating, equivalent reductions should represent actual emissions reductions achieved in a contemporaneous time frame to the change of the existing SIP control measure in order to preserve the status quo level of emission in the air. If the status quo is preserved, non-interference is demonstrated. In addition to being contemporaneous, the equivalent emissions reductions should also be permanent, enforceable, quantifiable, and surplus. The offset measures are described in Section I.M. of this notice.

EPA evaluates each section 110(l) non-interference demonstration on a case-by-case basis considering the circumstances of each SIP revision. EPA interprets 110(l) as applying to all NAAQS that are in effect, including those for which SIP submissions have not been made. The degree of analysis focused on any NAAQS in a non-interference demonstration varies depending on a number of relevant factors, including the nature of the emissions associated with the proposed SIP revision. EPA's section 110(l) analysis of the non-interference demonstration included as part of Georgia's September 16, 2019, SIP revision is provided below.

F. Proposed Analysis of Georgia's Non-Interference Demonstration

As mentioned above, on September 16, 2019, Georgia submitted a non-interference demonstration to support the State's request to remove several TCMs implemented in the Atlanta Area from the Georgia SIP. Georgia is currently in attainment for all particulate matter (PM), sulfur dioxide (SO₂), nitrogen dioxide (NO₂), carbon monoxide (CO), and lead (Pb) NAAQS.

GA EPD focused its analysis on the impact that removing the TCMs would have on attainment and maintenance of the ozone standards and ozone precursors (NO_X and VOC). Specifically, Georgia's non-interference demonstration evaluates the Atlanta 2008 8-hour ozone Area, which encompasses the smaller Atlanta 1979 1-hour ozone Area and the Atlanta 2015 8-hour ozone Area. This demonstration includes an evaluation of the impact that removing the TCMs would have on Atlanta's ability to maintain the 1997 and 2008 ozone standards. It also evaluates whether removing the TCMs would interfere with the ability of the Atlanta 2015 8-hour ozone Area to attain the ozone standard by August 3, 2021, which is the attainment date for areas classified as marginal, or with any of the other applicable NAAQS. Although the attainment date is August 3, 2021, marginal areas must show attainment using air quality data for years 2018 through 2020.

Additional discussion regarding VOCs, NO_X, and PM is included later in this section because VOC and NO_X emissions are also precursors for PM, and NO_X is also a precursor for NO₂.

G. Non-Interference Analysis for the Ozone NAAQS

In its non-interference demonstration, Georgia used EPA's MOVES2014a model to develop its projected mobile emissions inventory according to EPA's guidance for on-road mobile sources. As mentioned in Section I.D, the on-road mobile source emissions calculations for 2020, 2025 and 2030, 2035, and 2040 were generated with MOVES2014a with and without the TCMs.^[6] Georgia used two categories of methodologies to calculate emissions from the TCMs: An activity-based model (ABM) and an off-model method. The emissions from the TCM projects calculated with the ABM were coded directly into the ARC's travel demand model then ran through MOVES2014a. The emissions from the TCM projects using the off-model method were added to the MOVES2014a output. See Appendix B of the submittal for more details on the methodologies and the projects identified in each category.

The information provided by Georgia indicates that that current and future emissions of NO_X and VOC remained at or below the 2008 8-hour ozone NAAQS attainment base year (2014) emissions inventory, thus showing compliance with the 2008 8-hour ozone NAAQS.^[7] The analysis in this proposal will primarily refer to the year 2020 because that is the first year Georgia anticipated it would be able to remove the TCMs, and 2030 because it is the maintenance year in the Atlanta 2008 8-hour ozone Area maintenance plan. In addition, the emissions trend for year 2020 will be discussed later in the notice because attainment for the 2015 8-hour ozone NAAQS will be based on years 2018 through 2020.

Tables 1 and 2, below, show the direct impact on the on-road mobile source emissions from removing the TCMs in the Atlanta Area. As summarized below, on-road NO_X and VOC emissions increase when the TCMs are removed. NO_X emissions increased by 0.32 and 0.09 tons per day (tpd) in 2020 and 2030, respectively in the Atlanta 2008 8-hour ozone Area. VOC emissions also increased by 0.49 and 0.27 tpd in 2020 and 2030, respectively in the same area. As discussed in section I.L. of this proposal, Georgia has also requested EPA approve measures to offset these small increases.

Table 1—On-Road NO_X Emissions With and Without TCMs ⁸

Pollutant and region	Year	On-road emissions with TCMs (tpd)	On-road emissions without TCMs (tpd)	Emissions increase with TCM removal (tpd)	Emissions increase with TCM removal as percentage
13-county area	2020 2025	76.70 55.74	77.01 55.94	0.31 0.20	0.41 0.35
	2030	34.78	34.86	0.08	0.23
	2035	29.10	29.14	0.04	0.14
	2040	23.42	23.42	0.00	0.00
2-county area	2020 2025	9.49 7.16	9.50 7.17	0.01 0.01	0.11 0.14
	2030	4.82	4.83	0.01	0.21
	2035	4.36	4.37	0.01	0.12
	2040	3.90	3.90	0.00	0.00
15-county 9 area	2020 2025	86.19 62.89	86.51 63.10	0.32 0.21	0.37 0.33
	2030	39.46	39.51	0.09	0.23
	2035	33.46	33.51	0.05	0.13
	2040	27.32	27.32	0.00	0.00

 

Table 2—On-Road VOC Emissions With and Without TCMs ¹⁰

Pollutant and region	Year	On-road emissions with TCMs (tpd)	On-road emissions without TCMs (tpd)	Emissions increase with TCM removal (tpd)	Emissions increase with TCM removal as percentage
13-county area	2020 2025	54.14 43.59	54.63 43.96	0.49 0.37	0.90 0.86
	2030	33.03	33.30	0.27	0.81
	2035	28.69	28.93	0.24	0.83
	2040	24.36	24.56	0.20	0.86
2-county area	2020 2025	4.72 3.83	4.73 3.83	0.01 0.01	0.21 0.08
	2030	2.93	2.93	0.00	0.00
	2035	2.59	2.59	0.00	0.00
	2040	2.26	2.26	0.00	0.00
15-county 11 area	2020 2025	58.86 47.41	59.35 47.79	0.49 0.38	0.83 0.80
	2030	35.96	36.23	0.27	0.75
	2035	31.29	31.53	0.24	0.77
	2040	26.62	26.83	0.21	0.79

Although removal of the TCMs from the Georgia SIP is projected to cause small increases in ozone precursor emissions in the Atlanta 2008 8-hour ozone Area, the volume of those increases decreases over time. For instance, emissions of both precursors increase with removal of the TCMs; however, the increases decrease over time from a 0.37 percent increase in 2020 to a 0.23 percent increase in 2030 for NO_X emissions, and from a 0.83 percent increase in 2020 down to a 0.75 percent increase in 2030 for VOC emissions in the 15-county Atlanta 2008 8-hour ozone Area. The overall on-road emissions for NO_X decrease from 86.51 tpd in 2020 to 39.51 tpd in 2030. Similarly, the overall on-road emissions for VOC decrease from 59.35 tpd in 2020 to 36.23 tpd in 2030 in the Atlanta 2008 8-hour ozone Area. This indicates that changes in on-road emissions from removing the TCMs from the SIP would not interfere with continued maintenance of the 2008 8-hour ozone NAAQS in the Atlanta 2008 8-hour ozone Area.

Tables 3 and 4, below, show the impact of TCM removal on NO_X and VOC emissions from all sectors (point, area, nonroad, and on-road) compared to the 2014 attainment inventory. Georgia calculated the change in emissions from attainment levels with and without the TCMs and used the term “margin” to indicate the amount of the decrease in tpd from attainment (2014) to the maintenance (2030) and beyond (2040). The amount of margin “allotted” to TCM removal is the difference in emissions with and without the TCMs. Georgia also shows the allotted difference as a percent.

Table 3—2014 NO_X Attainment Inventory Comparison With and Without TCMs

Year	Total 2014 NOX attainment inventory (Tpd)	Total NOX emissions inventory with TCMs (tpd)	Total NOX emissions inventory without TCMs (tpd)	Current margin with TCMs (NOX) (tpd)	Margin without TCMs (NOX) (tpd)	Amount of margin allotted to TCM removal (tpd)	Percent of margin allotted to removal of TCMs
2014	283.09	283.09	283.09	0	N/A	N/A	N/A
2020	283.09	181.44	181.76	101.65	101.33	0.32	0.31
2025	283.09	153.29	153.49	129.80	129.60	0.21	0.16
2030	283.09	125.14	125.23	157.95	157.86	0.09	0.06
2035	283.09	118.69	118.74	164.40	164.35	0.05	0.03
2040	283.09	112.24	112.24	170.85	170.85	0.00	0.00

Table 4—2014 VOC Attainment Inventory Comparison With and Without TCMs

Year	Total 2014 VOC attainment inventory (tpd)	Total VOC emissions inventory with TCMs (tpd)	Total VOC emissions inventory without TCMs (tpd)	Current margin with TCMs (VOC) (Tpd)	Margin without TCMs (VOC) (tpd)	Amount of margin allotted to TCM removal (tpd)	Percent of margin allotted to removal of TCMs
2014	266.25	266.25	N/A	0	N/A	N/A	N/A
2020	266.25	237.67	238.16	28.58	28.09	0.49	1.71
2025	266.25	226.36	226.74	39.89	39.51	0.38	0.95
2030	266.25	215.06	215.33	51.19	50.92	0.27	0.53
2035	266.25	211.77	212.01	54.48	54.24	0.24	0.44
2040	266.25	208.48	208.69	57.77	57.56	0.21	0.36

As shown in Table 3, when the TCMs are removed, the total NO_X emissions increase the most in 2020 by 0.32 tpd, from 181.44 tpd to 181.76 tpd. In 2030, NO_X emissions increase slightly by 0.09 tpd, from 125.14 tpd to 125.23 tpd when the TCMs are removed. Although the removal of TCMs results in small increases in NO_X emissions initially, overall, total NO_X emissions decrease by 170.85 tpd from the attainment year 2014 to 2040. With respect to years 2020 through 2040, total NO_X emissions are less than the attainment year of 2014.

Table 4 shows that the total VOC emissions increase in 2020 by 0.49 tpd, from 237.67 tpd to 238.16 tpd. In 2030, VOC emissions increase by 0.27 tpd, from 215.06 tpd to 215.33 tpd. Although there are emissions increases in VOC when the TCMs are removed, there is an overall downward trend in emissions from the 2014 attainment year to the 2030 maintenance year. VOC emissions decrease from 266.25 tpd in 2014 down to 208.69 tpd in 2040 an overall decrease of 57.56 tpd. With respect to years 2020 through 2040, total VOC emissions are less than the attainment year of 2014.

Based on Tables 3 and 4, total NO_X emissions trend downward from 283.09 tpd in 2014 to 125.23 tpd in 2030 with the TCMs removed. This gives a safety margin of 157.86 tpd. The VOC safety margin is 50.92 tpd because of the downward trend from the 2014 attainment level of 266.25 tpd to 215.33 tpd in 2030 with the TCMs removed. A safety margin is the difference between the attainment level of emissions (from all sources) and the projected level of emissions (from all sources) in the maintenance plan. The decline in total emissions, including the safety margin, indicate that changes in on-road emissions from removing the TCMs from the SIP would not interfere with continued maintenance of the 2008 8-hour ozone NAAQS in the Atlanta 2008 8-hour ozone Area.

H. Non-Interference Analysis for the 2015 Ozone NAAQS

The current 3-year design value for 2016-2018 for the Atlanta 2015 8-hour ozone Area is 0.073 ppm.^[12] The 2015 8-hour ozone NAAQS is 0.070 ppm and this area is currently designated as marginal nonattainment for this NAAQS. Table 5, below, shows the ozone monitoring data from monitoring stations in Atlanta.

Table 5—2016-2018 Design Value Concentrations for Atlanta (ppm) ¹³

Location (county)	Monitoring station	4th Highest 8-hour ozone value			3-Year design values
		2016	2017	2018	2016-2018
Cobb	GA National Guard, McCollum Pkwy. (13-067-0003)	0.070	0.065	0.065	0.066
Coweta	University of W Georgia at Newnan (13-077-0002)	0.066	0.057		(14)
DeKalb	2390-B Wildcat Road Decatur (13-089-0002)	0.074	0.068	0.067	0.069
Douglas	Douglas Co. Water Auth. W Strickland St. (13-097-0004)	0.071	0.066	0.064	0.067
Gwinnett	Gwinnett Tech, 5150 Sugarloaf Pkwy. (13-135-0002)	0.078	0.065	0.065	0.069
Henry	Henry County Extension Office (13-151-0002)	0.078	0.067	0.069	0.071
Paulding	Yorkville, King Farm (13-223-0003)	0.067			(15)
Rockdale	Conyers Monastery, 2625 GA Hwy. 212 (13-247-0001)	0.076	0.065	0.069	0.070
Fulton	Confederate Ave., Atlanta (13-121-0055)	0.075	0.074	0.072	0.073

As previously mentioned, the Atlanta 2015 8-hour ozone Area must attain the 2015 8-hour ozone NAAQS by August 3, 2021, with air quality data for years 2018 through 2020.

Marginal areas are not required to provide attainment demonstrations because these areas are expected to attain the standard three years after being designated nonattainment. As such, Georgia has decided to demonstrate non-interference for removal of the TCMs for the 2015 8-hour ozone standard by securing offsetting, contemporaneous, compensating, equivalent, emissions reductions. These emission reductions are associated with measures that Georgia has proposed for incorporation into the SIP through its September 16, 2019, SIP revision and that were obtained for the Atlanta 2015 8-hour ozone Area to account for the small increases due to a removal of the TCMs. With offsets, EPA believes that removing the TCMs would not affect Atlanta's ability to attain the 2015 8-hour ozone NAAQS. A more detailed discussion regarding Georgia's ozone sensitivities and offset calculations for the Atlanta Area is provided below.

I. Sensitivity of Ozone in the Atlanta Area to NO _X and VOC Emissions

Control of NO_X and VOC are generally considered the most important components of an ozone control strategy, and NO_X and VOC make up the largest controllable contribution to ambient ozone formation. However, the Atlanta Area has shown a greater sensitivity of ground-level ozone to NO_X controls rather than VOC controls. This is due to high biogenic VOC emissions compared to anthropogenic VOC emissions in Georgia. Therefore, implemented control measures have focused on the control of NO_X emissions. The Atlanta Area is NO_X limited in such a way that changes in anthropogenic VOC emissions have little effect on ozone formation.

The Southeastern Modeling Analysis and Planning (SEMAP) project modeled sensitivities relative to 2018 emissions to evaluate the impact of NO_X and VOC reductions on daily 8-hour maximum ozone concentrations.^[16] Each emissions sensitivity run reduced the 2018 anthropogenic NO_X or VOC emissions (point, area, mobile, nonroad, marine/aircraft/rail) within a specific geographic region by 30 percent. GA EPD used the SEMAP project to examine the normalized sensitivities of NO_X and VOC emissions on 8-hour daily maximum ozone concentrations (parts per billion (ppb) ozone/tpd) at nine ozone monitors in the Atlanta Area.^[17] In order to look at the impact of removing the TCMs, Georgia averaged the normalized sensitivities from the nine site-specific Atlanta ozone monitors. The average normalized sensitivities for NO_X and VOC were −0.0768 and −0.0042 ppb/tpd, respectively.^[18] The site-specific normalized NO_X and VOC sensitivities were applied to the expected emissions increases due to removing the TCMs. The emissions increases are based on 2018 values and represent the largest impact as the emissions increase will decrease each successive year. A removal of the TCMs results in an increase of VOC emissions of 0.49 tpd in 2020. See Table 3. The TCM removal also results in an increase of 0.32 tpd of NO_X in 2020 in the Atlanta Area decreasing over time to near zero by 2040. See Table 4. The corresponding NO_X and VOC emissions increases at the site-specific ozone monitors, due to the TCM removal, are found in Table 6 below. The results of the combined NO_X and VOC emissions increases from removing the TCMs demonstrate there are minimal increases in ozone concentrations at the monitors. The calculated changes in ozone levels are well below the level of precision of the ambient ozone monitors (1 ppb or 0.001 ppm).^[19] Since the corresponding ozone increase at all nine monitors would only be seen at the fifth decimal place,^[20] these small increases could not impact maintenance or attainment of any ozone NAAQS.

Table 6—Emissions Increases Due to Removal of TCMs and Effects on Ozone Formation

Monitor	Removal of TCMs			Combined
	2020 NOX emissions increase (tpd)	Corresponding ozone increase at monitor due to NOX increase 21 (ppb)	2020 VOC emissions increase (tpd)	Corresponding ozone increase at Monitor due to VOC increase (ppb)	Corresponding ozone increase at monitor (ppb)
Kennesaw	0.32	0.02378	0.49	0.00221	0.0260
Newnan	0.32	0.02579	0.49	0.00089	0.0267
Dawsonville	0.32	0.01991	0.49	0.00034	0.0203
South Dekalb	0.32	0.02467	0.49	0.00285	0.0275
Douglasville	0.32	0.02550	0.49	0.00205	0.0276
United Ave	0.32	0.01959	0.49	0.00377	0.0234
Gwinnett	0.32	0.02442	0.49	0.00127	0.0257
McDonough	0.32	0.02781	0.49	0.00167	0.0295
Dallas/Yorkville	0.32	0.02218	0.49	0.00054	0.0227
Conyers	0.32	0.02873	0.49	0.00152	0.0303

J. Non-Interference Analysis for the PM_2.5 NAAQS

Over the course of several years, EPA has reviewed and revised the PM_2.5 NAAQS several times. On July 18, 1997, EPA established an annual PM_2.5 NAAQS of 15.0 micrograms per cubic meter (μg/m³), and on April 14, 2005 (70 FR 19844) designated certain counties in the Atlanta Area as nonattainment for the 1997 annual PM_2.5 NAAQS. These counties attained the 1997 annual NAAQS and were redesignated to attainment on February 24, 2016. See 81 FR 9114. On August 24, 2016, EPA took final action to revoke the 1997 PM_2.5 NAAQS for areas designated attainment or in maintenance for the standard. See 81 FR 58010.

On September 21, 2006 (71 FR 61144), EPA retained the 1997 annual PM_2.5 NAAQS of 15.0 μg/m³ but revised the 24-hour PM_2.5 NAAQS from 65.0 μg/m³ to 35.0 μg/m³. On November 13, 2009, EPA designated most of the state of Georgia—including the Atlanta Area—as unclassifiable/attainment for the 24-hour PM_2.5 NAAQS. See 74 FR 58688.

On December 14, 2012, EPA strengthened the annual primary PM_2.5 NAAQS from 15.0 μg/m³ to 12.0 μg/m.³ See 78 FR 3086. EPA designated the state of Georgia—including the Atlanta Area—as unclassifiable/attainment for the 2012 annual PM_2.5 NAAQS. See 80 FR 2206 (January 15, 2015), 81 FR 61136 (September 6, 2016). The current 2016-2018 design value for the annual and 24-hour PM_2.5 NAAQS are 10.1 and 21.0 μg/m³, respectively.

The recognized precursor pollutants for PM_2.5 are NO_X, SO₂, VOC, and ammonia. As mentioned above, removing the TCMs only results in small emissions increases of VOC and NO_X. Moreover, there have been several studies which have indicated that SO₂ is the primary driver of PM_2.5 formation in the Southeast.^[22]

As previously stated, removing the TCMs does not affect the most significant PM_2.5 precursor (SO₂). In addition, the increases to other PM_2.5 precursors—NO_X and VOCs—are negligible. See Section I.G., above. Based on this and the fact that the current PM_2.5 design values for the Atlanta Area are below the level of the 2012 annual primary and 2006 24-hour PM_2.5 NAAQS, EPA is proposing to determine that removing the TCMs for the affected counties would not interfere with the Atlanta Area's attainment or maintenance of the PM_2.5 NAAQS.

K. Non-Interference Analysis for the 2010 NO₂ NAAQS

On February 9, 2010 (75 FR 6474), EPA established a 1-hour NO₂ standard set at 100 ppb. In 1971, an annual standard was set at a level of 53 ppb and has remained unchanged. EPA designated all counties in Georgia as unclassifiable/attainment for the 2010 NO₂ NAAQS on February 17, 2012. See 77 FR 95320. Currently, the 2016-2018 design values for the 2010 1-hour and annual NO₂ NAAQS are 53.0 and 16.3 ppb, respectively, in the Atlanta Area. Given that the area is well below the level of the NAAQS, the small NO₂ emissions increase from the TCM removal would not interfere with the area's ability to continue to attain the NAAQS. EPA is proposing to determine that removing the TCMs from the area would not interfere with attainment or maintenance of the 1-hour or annual NO₂ NAAQS.

L. Emissions Increase and Available Offsets and Measures

As shown in Section 1, Tables 3 and 4, removing the TCMs results in an increase in NO_X emissions in 2020 of 0.32 tpd and 0.49 tpd of VOC. The ozone season for the Atlanta ozone Area consists of 245 days per calendar year. This results in equivalent emissions increases of 79.06 tons per year (tpy) of NO_X and 121.01 tpy of VOC as shown below.

0.32 tpd NO_X * 245 days/year = 79.06 tpy of NO_X

0.49 tpd VOC * 245 days/year = 121.01 tpy of VOC

As discussed above, Table 6, shows ozone formation in the Atlanta 2008 8-hour ozone Area and the sensitivity to reductions of NO_X and VOC emissions. The Atlanta Area is a NO_X limited area; therefore, the control of NO_X emissions result in greater reductions of ozone compared to control of VOC emissions. The maximum VOC emissions increase resulting from removing the TCMs results in 0.49 tpd (121.01 tpy). This increase in VOC emissions can be converted to an equivalent increase in NO_X emissions. GA EPD multiplied the VOC emissions increase during ozone season by the ratio of the average VOC to NO_X normalized ozone sensitivities at the nine site-specific monitors, as discussed in Section I.I., to get the equivalent NO_X emissions increase. See the calculation below.

121.01 tpy VOC * (-0.00427ppb/tpd VOC)/(-0.07680 ppb/tpd NO_X) = 6.62 (VOC equivalent reduction) tpy NO_X

By adding the actual NO_X emissions increase during ozone season to the equivalent NO_X emissions increase from VOC emissions (VOC equivalent) using the sensitivity calculation, GA calculated the amount of NO_X offsets needed to remove the TCMs. See the calculation below.

79.06 tpy of NO_X + 6.62 tpy of NO_X (VOC equivalent reduction) = 85.68 tpy NO_X offsets required ^[23]

As mentioned earlier, Georgia is requesting the removal of all but one TCM from the SIP (i.e., the Intersection Upgrade TCM), and therefore does not need to acquire the entire 85.68 tpy of NO_X offsets. Georgia used the same sensitivity calculations and ABM and off-model calculations mentioned in Section F to show the NO_X and VOC emissions increase associated with the removal of the TCMs and excluding the Intersection Upgrade TCM ^[24] as seen below.

0.11 tpd NO_X * 245 days/year = 27.93 tpy of NO_X

0.30 tpd VOC * 245 days/year = 74.30 tpy of VOC

74.30 tpy VOC * (−0.0042 ppb/tpd VOC)/(−0.0768 ppb/tpd NO_X) = 4.06 tpy NO_X

27.93 tpy of NO_X + 4.06 tpy of NO_X (VOC equivalent reduction) = 31.99 tpy of NO_X offsets needed.

Georgia's SIP revision includes two offset measures—school bus replacements and rail locomotive conversions—to obtain the necessary emissions reductions.^[25] GA EPD has a school bus early replacement program. School bus replacement projects that were completed in 2018 using Diesel Emissions Reduction Act funding have resulted in NO_X emissions reductions of 12.86 tpy in the Atlanta 2008 8-hour ozone maintenance Area. Specifically, eighty-five old school buses (built in 1999-2005) in Fulton County were replaced with 2018 school buses. The replacements took place in September 2018. Georgia has not previously relied on these emissions reductions to satisfy any CAA requirement.

The Locomotive Conversion Program consists of two components in the Atlanta Area: (1) The conversion of three older traditional switcher locomotives into newly-available low emissions engine technology from Norfolk Southern Railway, Inc., and (2) Norfolk Southern Railway, Inc.'s conversion of two switchers into “slugs” which are driven by electrical motors whose electricity is received from companion “mother” locomotives. This configuration is referred to as mother-slug locomotives. Slugs do not have any direct emissions. The conversion took place in December 2018, which also falls within the contemporaneous timeframe and generated 25.99 tpy of NO_X reductions. Georgia has not previously relied on the emissions reductions from the Locomotive Conversion Program to satisfy any CAA requirement. See Table 8 below for a summary of the offsets.

Table 7—Offsets Available for TCM Removal in 2020

	Locomotive conversions (tpy)	School bus replacements (tpy)	Total offsets (tpy)
Available NOX Offsets	25.99	12.86	38.85

Based on the available offsets from the locomotive conversion projects and school bus early replacement projects, GA EPD has offsets in excess of the increase in emissions associated with removing the TCMs.

Table 8—NO_X Emissions Increase Compared to Available Emissions Offsets

Emissions increases due to removing the TCMs (tpy)	Total offsets available (tpy)	Excess offsets (tpy)
31.99	38.85	6.86

The offsets available from both bus replacements and locomotive conversions total 38.85 tpy of NO_X as shown in Table 7 above. The annual NO_X decrease from the locomotive conversions and school bus replacements are more than adequate to offset the maximum NO_X and VOC emissions increases (31.99 tpy of equivalent NO_X) associated with removing the TCMs. There is a 6.86 tpy excess NO_X emissions offset that will remain available. See Table 8.

In addition, Georgia provided information designed to show that the substitute measures are quantifiable, permanent, surplus, enforceable, and contemporaneous. The locomotive conversions and school bus replacements occurring in 2018 are surplus since they have not been relied upon by any attainment plan or demonstration or credited in any RFP demonstration. The converted locomotives must remain operational for a period of ten years from the date placed into revenue service (December 2028). The school buses replaced must be scrapped or rendered permanently disabled or remanufactured to a cleaner emissions standard within 90 days of replacement. Therefore, the emissions reductions obtained are considered permanent. The emissions reductions have been quantified, as shown in Table 7. Fulton County Schools has grant commitments with EPA to replace school buses, while GA EPD and Norfolk Southern Railway, Inc., have a contract that requires locomotive conversions. The locomotive and school replacements occurred within one year of this submittal. EPA is proposing to conclude that the substitute measures are quantifiable, permanent, surplus, enforceable, and contemporaneous as described above to achieve equivalent emissions reductions to offset the potential emission increases related to removing the TCMs.

M. Conclusion Regarding the Non-Interference Analysis

With respect to ozone, EPA is proposing to conclude that the emissions reductions from the offset measures included in the SIP revision are greater than those needed to maintain the status quo in air quality and are permanent, enforceable, quantifiable, surplus, contemporaneous and equivalent. Removing the identified TCMs from the SIP would not worsen ozone air quality because Georgia has provided offsets as compensating, equivalent emissions reductions to negate the predicted increases in emissions from NO_X and VOCs in the Atlanta 2015 8-hour ozone Area. The amount of NO_X reductions obtained from the school bus and locomotive retrofits are more than what is needed to compensate for the small amount of NO_X and VOC increases due to removing the TCMs from the Georgia SIP in the Atlanta Area. In addition, the downward trend in emissions in the Atlanta 2008 8-hour ozone Area are reflected in the NO_X and VOC attainment inventories summarized in Tables 3 and 4. The emissions trend show there are safety margins in the maintenance year 2030 of 157.86 tpd for NO_X and 50.92 tpd for VOC. EPA has preliminarily determined that the SIP revision adequately demonstrates that removing the TCMs from the Georgia SIP for the Atlanta Area would not interfere with Atlanta Area's ability to attain the 2015 8-hour ozone NAAQS or maintain the 1997 and 2008 8-hour ozone NAAQS, or with any other applicable requirement of the CAA.

With respect to NO₂ and PM_2.5, EPA is proposing to find that the minimal increases in emissions of NO₂, PM_2.5 and PM_2.5 precursors would not interfere with attainment or maintenance of the NO₂ or PM_2.5 NAAQS. In addition, with respect to lead,^[26] CO,^[27] coarse particulate matter (PM₁₀),^[28] and SO₂,^[29] EPA is proposing to find that removal of the TCMs from Georgia's SIP would not interfere with attainment or maintenance of the NAAQs.

Therefore, EPA is proposing to find that removal of the TCMs from the Georgia SIP meets the requirements of CAA section 110(l) and would not interfere with attainment or maintenance of any NAAQS, or any other requirement of the CAA.

N. Analysis of Updated 2030 MVEBs

This SIP revision includes an update the 2008 8-hour ozone Maintenance Plan to update the mobile emissions inventory and associated 2030 MVEBs due to removing the TCMs. Georgia used the same approach as outlined in the 2008 8-hour ozone Maintenance Plan and redesignation request to determine the portion of the safety margin allocated to the MVEBs for this SIP revision. The on-road emissions inventory and safety margin allocation for the year 2030 were updated, but the MVEB totals remain unchanged. See Table 9 below. EPA has evaluated Georgia's revision to the MVEBs and notes that the State went through the appropriate interagency consultation process (of which EPA was a part) to establish these updated budgets per 40 CFR 93.105. As a result, EPA is proposing to approve the updated on-road emissions inventory, safety margins and MVEBs into the Atlanta 2008 8-hour ozone Maintenance Plan.

Table 9—Updated MVEBs for the Atlanta 2008 8-Hour Ozone Area (tpd)

	2014 30		2030
	NOX	VOC	NOX	VOC
On-Road Emissions	170.15	81.76	39.63	36.01
Safety Margin Allocation			18.37	15.99
MVEBs with Safety Margin	170.15	81.76	58	52

II. Proposed Action

EPA is proposing to approve Georgia's September 16, 2019, SIP revision requesting removal of certain TCMs from the Georgia SIP applicable within the Atlanta Area. This SIP revision includes updates to the 2008 8-hour ozone standard Maintenance Plan, specifically the on-road emissions inventory and the associated 2030 MVEBs, and measures offsetting the emissions increases due to removal of the TCMs. EPA is proposing to find that removing the TCMs would not interfere with attainment or maintenance of any NAAQS or with any other applicable requirement of the CAA.

III. 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 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
• Carbon monoxide
• Incorporation by reference
• Intergovernmental relations
• Lead
• Nitrogen dioxide
• Ozone
• Particulate matter
• Reporting and recordkeeping requirements
• Sulfur oxides
• Volatile organic compounds

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

Dated: June 4, 2020.

Mary Walker,

Regional Administrator, Region 4.

Footnotes

1.  See section I.D. for a discussion of the TCMs for which Georgia has requested removal. Georgia is removing all TCMs except for the Intersection Upgrade TCM, which will remain in the Georgia SIP. However, for this SIP revision and non-interference demonstration, Georgia was conservative by modeling removal of all the TCMs.

2.  The Atlanta Area consists of the following 20 counties: Barrow, Bartow, Carroll, Cherokee, Clayton, Cobb, Coweta, DeKalb, Douglas, Fayette, Forsyth, Fulton, Gwinnett, Hall, Henry, Newton, Paulding, Rockdale, Spalding, and Walton. As discussed further in section I.B., this area encompasses the 13-county 1-hour Atlanta Area for the 1979 ozone NAAQS, the 20-county 8-hour Atlanta Area for the 1997 ozone NAAQS, the 15-county 8-hour Atlanta Area for the 2008 ozone NAAQS, and the 7-county 8-hour Atlanta Area for the 2015 ozone NAAQS.

3.  On August 15, 2018, Georgia submitted a request to revise and update the 2008 8-hour ozone maintenance plan to relax the federal Reid Vapor Pressure (RVP) requirements from 7.8 to 9.0 pounds per square inch (psi) RVP. On September 20, 2019, EPA published final approval allowing for a change for the federal RVP requirements. See 84 FR 49470. The approval of the August 15, 2018 SIP revision and change to the federal RVP requirements updated Georgia's mobile emissions inventory and MVEBs which are the basis for Georgia's September 16, 2019 submittal.

4.  For more detailed information on the current approved maintenance plan and revisions, see EPA's December 23, 2016 (81 FR 94283) proposed approval of Georgia's maintenance plan and EPA's February 12, 2019 (84 FR 3358) proposed approval of the relaxation of the federal RVP requirements. On April 23, 2019 (84 FR 16786), EPA approved the revision to the 2008 8-hour ozone maintenance plan.

5.  As discussed below, 2020 was chosen because the attainment date for the Atlanta 2015 8-hour ozone Area to attain the ozone standard is August 3, 2021, based on data from 2018 through 2020. Further, Georgia anticipated that 2020 was the first year that it could cease implementation of the TCMs.

6.  For additional information on the methodology used to assess the emissions impacts, see Appendix B of the September 16, 2019 submittal.

7.  The 2014 base year emissions are unchanged from the 2008 8-hour ozone maintenance plan included in Appendix A of the September 16, 2019, SIP revision.

8.  In this table, the 13-county area refers to the Atlanta 1979 1-hour ozone Area and the 15-county area refers to the 2008 8-hour ozone Area. The 2-county area is the difference between the Atlanta 1-hour ozone Area and the Atlanta 2008 8-hour ozone Area. This table reflects how the State references these areas in their submittal.

9.  In final calculations for the Atlanta 2008 8-hour ozone Area, an additional 0.03 tpd is added to these values to account for the Senior Exemption. Senior citizens are exempt from the Inspection and Maintenance (I/M) program testing, and thus 0.03 tpd (based on 2002 emissions comparisons) is used as a conservative estimate of disbenefit.

10.  See footnote 9.

11.  In final calculations for the Atlanta 2008 8-hour ozone Area, an additional 0.05 tpd would be added to these values to account for the Senior Exemption. Senior citizens are exempt from the Inspection and Maintenance (I/M) program testing, and thus 0.05 tpd (based on 2002 emissions comparisons) is used as a conservative estimate of disbenefit.

12.  The design value for an area is the highest 3-year average of the annual fourth-highest daily maximum 8-hour concentration recorded at any monitor in the area.

13.  These monitoring stations are representative of the air quality in the entire 2015 8-hour ozone Area even though not all counties in the area have a monitoring station. In addition, the table includes counties (Coweta, Douglas, Paulding, and Rockdale) that are not located within the Atlanta 2015 8-hour ozone Area but are located within the Atlanta 2008 8-hour ozone Area.

14.  The average of the 2016 and 2017 values for the Coweta Monitor (13-077-0002) is 0.061. The monitor was shut down on November 15, 2017. See GA EPD Addendum to 2018 Ambient Air Monitoring Plan, available at https://airgeorgia.org/​docs/​2018%20Addendum%20to%20Annual%20Plan.pdf.

15.  The value for the Paulding Monitor (13-223-0003) of 0.067 is the value for 2016 only. The monitor was shut down on January 31, 2017. See GA EPD Addendum to 2016 Ambient Air Monitoring Plan, available at https://airgeorgia.org/​docs/​2016%20Addendum%20to%20Annual%20Plan.pdf.

16.  As part of the SEMAP project, Georgia Institute of Technology performed an analysis of the sensitivity of ozone concentrations in the Eastern U.S. to reductions in emissions of both NO_X and VOCs. This analysis was based off the 2007 and 2018 SEMAP modeling which used the Community Multi-scale Air Quality (CMAQ) model, version 5.01 with updates to the vertical mixing coefficients and land-water interface. May 1st through September 30th was modeled using a 12-km modeling grid that covered the Eastern U.S. Details of the modeling platform set-up can be found in Appendix D of the September 16, 2019 SIP submission.

17.  For further details on the approach used to calculate the normalized sensitivities of NO_X and VOC, please see Appendix D of Georgia's submittal.

18.  See Appendix E-2 of the September 16, 2019 SIP submission for the sensitivity calculations.

19.  Ozone concentrations are reported in ppm and to three decimal places (e.g., 0.070 ppm); any additional decimal places are truncated.

20.  Because the increases in Table 7 are reported in ppb, the changes are in the 2nd decimal place.

21.  See Appendix E of the submission.

22.  See, e.g., Quantifying the sources of ozone, fine particulate matter, and regional haze in the Southeastern United States, Journal of Environmental Engineering (June 24, 2009), available at: http://www.sciencedirect.com/​science/​article/​pii/​S0301479709001893?​via%3Dihub.

23.  85.68 tons/year represents the total NO_X offsets required if all of the TCMs are removed.

24.  Tables 2-4 and 2-7 of Georgia's submittal detail the NO_X and VOC emissions associated with the Intersection Upgrade TCM. The method used for the ABM and off-model calculations can be found in Appendix B of Georgia's submittal.

25.  See Appendix F of the September 16, 2019 SIP submittal for additional information related to these programs, including calculations for NO_X emissions reductions.

26.  The entire state of Georgia is designated attainment or unclassifiable/attainment for the lead NAAQS. See 40 CFR 81.311. The TCMs are not designed to reduce emissions of SO₂; therefore, removing the TCMs from the SIP would not have any impact on ambient concentrations of lead. EPA proposes to find that removal of the TCMs from Georgia's SIP would not interfere with continued attainment or maintenance of the lead NAAQS.

27.  The entire state of Georgia is designated as attainment or unclassifiable/attainment for the CO NAAQS. See 40 CFR 81.311. The TCMs are not designed to reduce emissions of CO; therefore, removing the TCMs from the SIP would not have any impact on ambient concentrations of CO. EPA proposes to find that removal of the TCMs from Georgia's SIP would not interfere with continued attainment or maintenance of the CO NAAQS.

28.  The entire state of Georgia is designated attainment for the PM₁₀ NAAQS. The TCMs are not designed to reduce emissions of PM₁₀; therefore, removing the TCMs from the SIP would not have any impact on ambient concentrations of PM₁₀. EPA proposes to find that removal of the TCMs from Georgia's SIP would not interfere with continued attainment or maintenance of the PM₁₀ NAAQS.

29.  On June 22, 2010, EPA revised the 1-hour SO₂ NAAQS to 75 ppb which became effective on August 23, 2010. See 75 FR 35520. On January 9, 2018, EPA designated most of the state of Georgia, including the counties where the TCMs were implemented, as attainment/unclassifiable for the 2010 SO₂ NAAQS. See 83 FR 1098. The TCMs are not designed to reduce emissions of SO₂; therefore, removing the TCMs from the SIP would not have any impact on ambient concentrations of SO₂. EPA proposes to find that removal of the TCMs from Georgia's SIP would not interfere with continued attainment or maintenance of the SO₂ NAAQS.

30.  The 2014 on-road emissions and MVEBs in this chart are shown for illustration purposes only, as no changes were made to the 2014 attainment year emissions inventory due to removing the TCMs.