Quiero saber acerca de...

45872

Federal Register / Vol. 86, No. 156 / Tuesday, August 17, 2021 / Rules and Regulations
khammond on DSKJM1Z7X2PROD with RULES

inspection and maintenance program shall be employed in this state on or after the effective date of this act. See Tenn. Code Ann. section 68201119.
The Tennessee law states that it shall take effect 120 calendar days following the date on which the EPA approves a revised state implementation plan. . . . See Motor Vehicles Inspection and InspectorsAir Pollution, 2018 Tennessee Laws Pub.
Ch. 953 H.B. 1782. Accordingly, Tennessee submitted the February 26, 2020, SIP revisions requesting that EPA
remove the provisions that implement an I/M program for the Middle Tennessee Area and for Hamilton County from the Tennessee SIP.5
EPA published notices of proposed rulemaking NPRMs on June 8, 2020, and June 11, 2020, responding to Tennessees February 26, 2020, SIP
revisions requesting that EPA approve removal of the I/M program from the Tennessee SIP for the Middle Tennessee Area and for Hamilton County, respectively. See 85 FR 35037 and 85 FR
35607. The June 8, 2020, and June 11, 2020, NPRMs hereinafter referred to as the June 2020 NPRMs were based on EPAs proposed findings that the removal of the I/M program from the Tennessee SIP for the Middle Tennessee Area and for Hamilton County will not interfere with attainment or maintenance of any national ambient air quality standards NAAQS or standards or with any applicable requirements of the CAA. See EPAs June 2020 NPRMs.
Comments were due on July 8, 2020, and July 13, 2020, respectively. Adverse comments were received on the June 2020 NPRMs and are addressed in Section IV of this final rulemaking.
On April 22, 2021, EPA published a supplemental notice of proposed rulemaking hereinafter referred to as the April 2021 SNPRM to seek public comment on the Agencys additional and clarified technical rationale related to the proposed approval of Tennessees February 26, 2020, SIP revisions. See 86
FR 21248. The April 2021 SNPRM
proposed to affirm that the Hamilton County and Middle Tennessee areas would continue to attain and maintain the NAAQS after removal of the I/M
program, and to rely on an emissions inventory comparison to inform its determination that both areas would 5 Tenn. Code Ann. section 68201119c allows Tennessee counties to retain local I/M programs under certain conditions. As Tennessee is requesting removal of the I/M program from the SIP, EPAs analysis in this final rule assumes that no I/
M program will be implemented in Hamilton County or the Middle Tennessee Area. However, this final action does not preclude local I/M
programs from being retained at a local level outside of the SIP.

VerDate Sep<11>2014

16:18 Aug 16, 2021

Jkt 253001

continue to attain and maintain the ozone and carbon monoxide CO
NAAQS. See 86 FR 21248. In the April 2021 SNPRM, EPA further proposed to conclude that the removal of the I/M
program will not interfere with the ability of other states to attain and maintain the 2008 ozone NAAQS under the good neighbor provision of the CAA
and provided additional information related to that conclusion. See 86 FR
21248. Comments on the April 2021
SNPRM were due May 24, 2021.
Adverse comments were also received on the April 2021 SNPRM and are addressed in Section IV of this final rulemaking.
As mentioned above, in this action, EPA is responding to adverse comments received of the June 2020 NPRMs. See Section IV of this final rule. Further, as relevant, EPA is responding to additional comments received on the April 2021 SNPRM and is finalizing the removal of the I/M program from Tennessees SIP for the Middle Tennessee Area and for Hamilton County. EPA chose to issue one final rulemaking for all three proposals. See Section IV of this final rule.
III. Summary of EPAs Analysis EPAs CAA section 110l noninterference demonstration supporting approval of Tennessees SIP revisions seeking removal of the I/M program in Hamilton County and the Middle Tennessee Area focuses on ozone through its precursors nitrogen oxides NOX and volatile organic compounds VOC and carbon monoxide CO, the criteria pollutants addressed by I/M
programs.6 I/M programs are not designed to address lead and sulfur dioxide SO2 emissions, and nitrogen dioxide NO2 is captured generally through consideration of NOX impacts.
While EPA considers NOX, VOCs, ammonia, and SO2 as precursors for particulate matter PM, PM formation in Tennessee is dominated by emissions of SO2, reacting in the atmosphere to form sulfates, and not by emissions of NOX, VOCs, or ammonia. However, NOX
and VOC increases are considered through the analysis for ozone.
Although Tennessee is NOX-limited 7 for 6 The total suite of CAA criteria pollutants are ozone through the precursors NOX and VOCs, CO, PM and its precursorsNOX, VOCs, ammonia, and SO2, lead, SO2, and NO2.
7 The term NO limited means that changes in X
anthropogenic VOC emissions have little effect on ozone formation. Control of NOX and VOC are generally considered the most important components of an ozone control strategy, and NOX
and VOC make up the largest controllable contribution to ambient ozone formation. However, Tennessee has shown a greater sensitivity of ground-level ozone to NOX controls rather than
PO 00000

Frm 00018

Fmt 4700

Sfmt 4700

ozone formation, EPA also evaluated VOC emissions to be environmentally conservative in its action.
EPA used an emissions inventory comparison to inform its determination of whether Hamilton County and the Middle Tennessee Area would continue to attain and maintain the ozone and CO
NAAQS after removal of the I/M
program. As explained in the April 2021
SNPRM, Tennessee chose 2022 as the future year for the States noninterference demonstrations.8
Tennessees non-interference demonstration utilized EPAs Motor Vehicle Emission Simulator MOVES
modeling system, specifically MOVES2014b, to estimate ozone precursor emissions for mobile sourcesboth on-road and non-road. In general, an emissions comparison approach is a reasonable and valid approach to determining whether an area removing an I/M program can maintain the NAAQS and is very similar to the maintenance demonstrations that support the redesignations of areas from nonattainment to attainment and 10year maintenance plans that are required for redesignated areas. EPA
compared future year emissions following the removal of the I/M
program to emissions in a base year with an attaining design value.9 If the total future year emissions for the relevant pollutants/precursors are less than the total base year emissions, EPA considers that to be a sufficient and reasonable demonstration that the area will maintain the NAAQS where the base year emissions are at a level sufficient to achieve the NAAQS. EPA is concluding that these analyses, as described greater in EPAs April 2021
SNPRM, provide adequate support for the conclusion that the removal of the I/M program from Hamilton County and the Middle Tennessee Area is consistent with CAA section 110l. CAA section 110l demonstrations are case-specific, and modeling is not required to VOC controls. This is due to high biogenic VOC
emissions compared to anthropogenic VOC
emissions in Tennessee. Therefore, implemented control measures have focused on the control of NOX emissions.
8 EPA notes that Tennessee did an analysis of emissions between 2022 and 2030 without I/M to determine the potential impact of mobile emissions.
Tennessees analysis shows that in the Middle Tennessee Area emissions decrease by 35 percent for NOX, 24 percent for VOC, and 30 percent for CO;
and that in Hamilton County emissions decrease by 45 percent for NOX, 33 percent for VOC, and 40
percent for CO. This analysis is provided in the dockets for this final rulemaking as weight of evidence.
9 Design values are how EPA measures compliance with the NAAQS.

E:FRFM17AUR1.SGM

17AUR1