[Federal Register Volume 89, Number 158 (Thursday, August 15, 2024)]
[Proposed Rules]
[Pages 66295-66305]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-18173]


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ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52

[EPA-R03-OAR-2024-0016; FRL-12094-01-R3]


Air Plan Approval; Delaware; Motor Vehicle Inspection and 
Maintenance Program

AGENCY: Environmental Protection Agency (EPA).

ACTION: Proposed rule.

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SUMMARY: The Environmental Protection Agency (EPA) is proposing to 
approve three State implementation plan (SIP) revisions submitted by 
the State of Delaware to amend Delaware's motor vehicle emissions 
inspection and maintenance (I/M) programs, Statewide. Delaware has made 
several State regulatory amendments to its prior SIP-approved I/M 
program regulations, to both improve the program and to harmonize its 
two State I/M program regulations so that the entire State is subject 
to similar I/M requirements. These SIP revisions apply to both the 
federally mandated enhanced I/M program applicable to Kent and New 
Castle Counties that comprise Delaware's portion of the Philadelphia-
Wilmington-Atlantic City, PA-NJ-MD-DE ozone nonattainment area, and 
also to the Sussex County program, where I/M is not federally required 
but where Delaware has a prior approved, SIP strengthening I/M program 
(similar in design to a basic I/M program). The amendments to 
Delaware's I/M programs include: a change in program coverage to expand 
exemptions for new vehicles to seven years; addition of vehicle on-
board diagnostic (OBD) testing requirements in the Sussex County 
program; expanded vehicle coverage to include vehicles weighing between 
8,501 to 14,000 pounds gross vehicle weight rating (GVWR), for those 
vehicles model year 2008-and-newer; harmonization of I/M test 
requirements applicable to older vehicles to include curb idle exhaust 
and gas cap pressure tests for vehicles 1995-and-older (replacing 
existing two-speed idle tests on those vehicles previously performed in 
Kent and New Castle Counties); phase-in of increased minimum repair 
cost thresholds for obtaining a repair waiver in Sussex County; and the

[[Page 66296]]

addition of a Statewide prohibition on tampering-related repairs in 
qualifying for an emissions repair waiver. EPA's proposed action is in 
compliance with the Clean Air Act (CAA) because these SIP revisions 
comply with applicable requirements of the CAA and EPA regulations, and 
because this proposed revision of the SIP will not interfere with 
attainment or maintenance of any national ambient air quality standards 
(NAAQS). The intended effect of this action is to update the approved 
Delaware SIP to maintain consistency between the State-adopted I/M 
program rules and the federally approved SIP.

DATES: Written comments must be received on or before September 16, 
2024.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-R03-
OAR-2024-0016 at www.regulations.gov, or via email to 
[email protected]. For comments submitted at Regulations.gov, follow 
the online instructions for submitting comments. Once submitted, 
comments cannot be edited or removed from Regulations.gov. For either 
manner of submission, 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, please contact the person 
identified in the FOR FURTHER INFORMATION CONTACT section. For the full 
EPA public comment policy, information about CBI or multimedia 
submissions, and general guidance on making effective comments, please 
visit www.epa.gov/dockets/commenting-epa-dockets.

FOR FURTHER INFORMATION CONTACT: Brian Rehn, Planning & Implementation 
Branch (3AD30), Air & Radiation Division, U.S. Environmental Protection 
Agency, Region III, 1600 John F. Kennedy Boulevard, Philadelphia, 
Pennsylvania 19103. The telephone number is (215) 814-2176. Mr. Rehn 
can also be reached via electronic mail at [email protected].

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Background
    A. Clean Air Act Requirements for I/M Programs
    B. Background on the History of the Ozone NAAQS and Resulting 
Delaware Area Ozone Nonattainment Designations and I/M Program 
Requirements
    1. Delaware Nonattainment Area Designations and I/M Program 
Requirements Under the 1979 1-Hour Ozone NAAQS
    2. Delaware Nonattainment Area Designations and I/M Program 
Requirements Under the 1997 8-Hour Ozone NAAQS
    3. Delaware Nonattainment Area Designations and I/M Program 
Requirements Under the 2008 8-Hour Ozone NAAQS
    4. Delaware Nonattainment Area Designations and I/M Program 
Requirements Under the 2015 8-Hour Ozone NAAQS
II. Summary of Delaware's March 2023 I/M SIP Revisions and EPA's 
Analysis
    A. Overview of Delaware's March 13, 2023 SIP Submissions
    B. Review of Delaware's March 2023 SIP Revisions for Compliance 
With EPA Requirements
    1. Compliance With EPA's Enhanced I/M Performance Standard 
Requirements
    2. Demonstrating Noninterference of the Revised SIP Under CAA 
Section 110(l) With Attainment, Reasonable Further Progress, or Any 
Other CAA Applicable Requirement
    C. EPA's Evaluation of Delaware's SIP Revisions
III. Proposed Action
IV. Incorporation by Reference
V. Statutory and Executive Order Reviews

SUPPLEMENTARY INFORMATION: On March 13, 2023, the Delaware Department 
of Natural Resources and Environmental Control (DNREC) submitted three 
SIP revisions to EPA to amend its prior SIP-approved motor vehicle 
inspection and maintenance (I/M) programs applicable to all counties in 
Delaware.

I. Background

    This section provides background for EPA's proposed actions on 
Delaware's three March 2023 I/M program-related SIP revisions. To 
provide context, herein we also provide background on the ozone 
national ambient air quality standard (NAAQS, or ``standard'') and on 
Delaware area designations under the ozone NAAQS, which are the pretext 
for the Federal mandate for CAA I/M program requirements. Finally, we 
discuss herein EPA requirements for I/M programs for affected ozone 
nonattainment areas.

A. Clean Air Act Requirements for I/M Programs

    As a control measure to reduce air pollutant emissions from in-use 
motor vehicles, the CAA requires states with areas designated as 
moderate, serious, severe, or extreme ozone nonattainment areas, or 
those lying within an ozone transport region (OTR) (and having a 
population exceeding designated population thresholds), to establish a 
motor vehicle I/M program, to inspect motor vehicles' emissions and, if 
necessary, to require maintenance or repairs to reduce in-use emissions 
from vehicles that fail such testing.\1\ This emissions testing ensures 
that vehicles are well-maintained and operate as designed and that they 
do not exceed established vehicle pollutant limits.
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    \1\ See CAA sections 182(b)(4), (c)(3).
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    Under the CAA, a ``basic'' I/M program is required for any area 
classified as a moderate ozone nonattainment area and having a 1990 
Census-defined urbanized area with a population exceeding 200,000 
persons.\2\ A more stringent, ``enhanced'' I/M program is required in 
the Census-defined urbanized area of any ozone nonattainment area 
classified as serious or worse, where the 1980 Census-defined urbanized 
area population exceeds 200,000.\3\ Additionally, in order to prevent 
transport of air pollution, states or areas within a CAA-defined OTR 
shall implement ``enhanced'' I/M within any metropolitan statistical 
area (MSA) where the 1990 population exceeds 100,000 persons--
regardless of the area's nonattainment designation or 
classification.\4\
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    \2\ See CAA 182(b)(4) and 40 CFR 51.350(a)(4) and (6).
    \3\ See CAA 182(c)(3) and 40 CFR 51.350(a)(2) and (7).
    \4\ See CAA 184(b)(1) and 40 CFR 51.350(a)(1).
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B. Background on the History of the Ozone NAAQS and Resulting Delaware 
Area Ozone Nonattainment Designations and I/M Program Requirements

    In 1970, Congress enacted the CAA and authorized the EPA to 
establish NAAQS for criteria pollutants shown to threaten human health, 
welfare, and the environment--including ozone. In January 1983, 
Delaware implemented its first I/M program under Title 7 Natural 
Resources & Environmental Control of the Delaware Administrative Code, 
Regulation 26 (7 DE Admin. Code 26) applicable to New Castle County, as 
a control measure in its SIP. Delaware later recodified this regulatory 
chapter to Regulation 1126.\5\
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    \5\ Delaware's Regulation 1126 applies to the Sussex County SIP-
strengthening I/M program, which is not required by the CAA, but is 
substantially similar to an EPA-defined basic I/M program--
strengthening the SIP and harmonizing I/M testing across Delaware. 
Regulation 1131 (then Regulation 31) is a CAA-required, low-enhanced 
I/M program applicable to the New Castle and Kent Counties,

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[[Page 66297]]

1. Delaware Nonattainment Area Designation and I/M Program Requirements 
Under the 1979 1-Hour Ozone NAAQS
    In 1990, Congress amended the CAA, by adding specific requirements 
for areas in nonattainment of a NAAQS. In 1991, EPA classified the 
Philadelphia-Wilmington-Trenton, PA-DE-NJ area as severe ozone 
nonattainment for the 1979 1-hour ozone NAAQS, triggering a requirement 
for Delaware to establish an enhanced I/M program (as discussed in the 
section below summarizing I/M requirements) for its portion of that 
multi-State nonattainment area--comprised of Kent and New Castle 
Counties.\6\ As the Wilmington, Delaware, area also lies in the 
Northeast OTR, as defined under CAA section 184, Delaware's portion of 
the Census-defined Philadelphia-Wilmington-Trenton metropolitan 
statistical area (MSA) having population exceeding 100,000 persons is 
also subject to enhanced I/M (i.e., Kent and New Castle Counties). 
Sussex County, Delaware, was not part of the Philadelphia-Wilmington-
Trenton nonattainment area (and thus not subject to enhanced I/M), and 
neither did it meet the MSA/population threshold criteria to subject 
the area to enhanced I/M under CAA section 184 requirements applicable 
to ozone transport areas.
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    \6\ On November 6, 1991 (56 FR 56994), EPA designated and 
classified the Philadelphia-Wilmington-Atlantic City consolidated 
metropolitan area (CMSA) as Severe-15 ozone nonattainment. This 
includes Kent and New Castle Counties in the Wilmington, Delaware, 
portion of that CMSA. CAA section 107(d)(1)(C) provides that each 
area designated nonattainment, attainment, or unclassifiable for the 
ozone NAAQS immediately before the date of enactment of the CAA ``is 
designated, by operation of law,'' as a nonattainment, attainment, 
or unclassifiable area, respectively, and CAA section 107(d)(2)(A) 
required EPA to publish a Federal Register notification with respect 
to this designation, which EPA did with the November 6, 1991 
document effective November 15, 1990.
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    In 1995 and 1998, Delaware submitted several SIP revisions to EPA, 
requesting approval of its enhanced I/M SIP revision to satisfy the 
1990 CAA requirements for an enhanced I/M program for the Delaware 
portion of the Philadelphia-Wilmington-Trenton severe 1-hour ozone 
nonattainment area. Delaware availed itself of flexibility in EPA's I/M 
rule at 40 Code of Federal Regulations (CFR) part 51, subpart S, that 
allows an enhanced I/M subject area to adopt an enhanced I/M program 
that meets an alternate ``low enhanced'' I/M performance standard if 
the area: (1) has an approved SIP pursuant to CAA requirements for 
Reasonable Further Progress (for the period from 1990-1996); (2) does 
not have a disapproved plan for Reasonable Further Progress for the 
period after 1996; and (3) does not have a disapproved plan for 
attainment of the air quality standards for ozone.\7\ EPA refers to 
this program hereafter as the ``low enhanced'' I/M program. Delaware's 
low enhanced I/M program (applicable to the Kent and New Castle 
Counties of the Wilmington area) was codified at Delaware Code Title 7, 
Regulation 31.
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    \7\ See 40 CFR 51.351(g).
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    I/M was not required by the 1990 CAA amendments in Sussex County, 
as it was designated marginal nonattainment and the Seaford area was 
not large enough to trigger the MSA-based CAA population threshold for 
OTR areas or ozone nonattainment-related CAA I/M applicability 
requirements.\8\ However, Delaware opted to enact I/M in the Sussex 
County area and submitted to EPA a SIP-strengthening I/M program for 
Sussex County as part of its 1995 and 1998 I/M SIP submissions to EPA. 
This SIP-strengthening program, similar in design to a basic I/M 
program, was codified under Title 7, Regulation 26 of the Delaware 
Code. The purpose of this Sussex County program was to maintain a 
Statewide I/M program and to provide additional emission benefits for 
the neighboring Philadelphia-Wilmington-Trenton 1-hour ozone 
nonattainment area.
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    \8\ Section 107(d)(1)(C) provides that each ozone and CO area 
designated nonattainment, attainment, or unclassifiable immediately 
before the date of enactment of the CAAA was ``designated, by 
operation of law,'' as a nonattainment, attainment, or 
unclassifiable area, respectively. Section 107(d)(2)(A) requires EPA 
to publish a Federal Register notification with respect to this 
designation, as well as the area's classification and boundary. EPA 
published these designations for the 1979 1-hr ozone NAAQS in the 
November 6, 1991 (56 FR 56694) Federal Register--listing Sussex 
County, Delaware as a marginal nonattainment area.
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    Through a series of actions culminating in a final approval on 
September 30, 1999, EPA approved several 1995 and 1998 Delaware SIP 
revisions submitted to satisfy applicable 1990 CAA I/M requirements.\9\ 
EPA's September 1999 final rule approved Delaware's new Regulation 31 
``low enhanced'' I/M program applicable to Kent and New Castle 
Counties, while retaining Regulation 26 to apply a ``SIP 
strengthening'' I/M program (akin to ``basic'' I/M) in Sussex County. 
Additional information on EPA's prior approval of Delaware's enhanced 
I/M program in the Delaware portion of the Philadelphia-Wilmington-
Trenton ozone nonattainment area (as well as the SIP-strengthening I/M 
program for Sussex County) can be found in EPA's final approval actions 
taken upon those SIP revisions, as referenced in footnote 7 of this 
action.
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    \9\ On May 19, 1997 (62 FR 27195), EPA conditionally approved 
Delaware's ``low enhanced'' inspection and maintenance program, 
submitted by DNREC on February 17, 1995 and supplemented on November 
30, 1995. On September 30, 1999 (64 FR 52657), EPA converted its 
conditional approval of 1995 and 1998 Delaware's I/M SIP to full 
approval, on the basis of supplemental SIP revisions submitted by 
DNREC on June 16, 1998 and May 24, 1999. In an August 10, 2010 final 
rule (75 FR 48566), EPA approved administrative, non-substantive 
edits made by Delaware to some of rules codified under title 7, 
resulting in recodification of the Sussex County I/M Regulation 26 
and its retitling to Regulation 1126.
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2. Delaware Nonattainment Area Designations and I/M Program 
Requirements Under the 1997 8-Hour Ozone NAAQS
    In July 1997, EPA revised the ozone NAAQS, replacing the 1979 1-
hour primary standard with a more stringent, 8-hour standard.\10\ EPA 
designated the entirety of Delaware as Moderate nonattainment under the 
1997 8-hour ozone NAAQS as part of the Philadelphia-Wilmington-Atlantic 
City, PA-NJ-MD-DE area.\11\ This 1997 Moderate ozone NAAQS 
classification subjected the area to basic I/M, for those areas also 
meeting the CAA urbanized area population threshold. The inclusion of 
Sussex County in the expanded nonattainment area boundary did not 
result in the expansion of the I/M program for the Philadelphia-
Wilmington-Atlantic City nonattainment area, as Sussex County was not 
part of the census defined urbanized area in 1990 and thus did not 
trigger the requirement for a basic I/M program in Sussex County under 
the applicability thresholds under EPA's I/M rule.\12\ Rather than be 
subject to basic I/M, the remainder of the Philadelphia-

[[Page 66298]]

Wilmington-Atlantic City 1997 ozone NAAQS nonattainment area (including 
Kent and New Castle Counties in Delaware) remained subject to more 
stringent enhanced I/M requirements (under the CAA section 184 OTR I/M 
provision and the area's continued Severe nonattainment classification 
under the 1979 1-hour ozone NAAQS).
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    \10\ On July 18, 1997 (62 FR 38856), EPA revised the ozone 
NAAQS, replacing the 1979 primary 1-hour primary standard with an 8-
hour standard, based on an ambient air monitoring site's 3-year 
average of the annual third-highest daily maximum 8-hour average 
ozone concentration is less than or equal to 0.08 ppm.
    \11\ Original 8-Hour Ozone (1997) areas were designated July 15, 
2004. On June 8, 2007, the United States Court of Appeals vacated 
the subpart 1 portion of the Phase 1 Rule. The Former subpart 1 
nonattainment areas were classified under subpart 2 on May 14, 2012 
(77 FR 28424), effective June 13, 2012.
    \12\ See 40 CFR 51.350(a)(4) and (6). Any area classified as 
moderate ozone nonattainment, and not required to implement enhanced 
I/M under paragraph (a)(1) of the section, shall implement basic I/M 
in any 1990 Census-defined urbanized area with a population of 
200,000 or more. Sussex County's population did not exceed the 
urbanized area population threshold for a basic I/M program, the 
county continued not to be subject to I/M and instead remained an 
optional, SIP-strengthening program, not bound by CAA I/M 
requirements.
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    The Philadelphia-Wilmington-Atlantic City 1997 ozone nonattainment 
area was eventually granted an attainment date extension and later 
determined to have attained the 1997 standard by its statutory 
attainment date.\13\ However, the Philadelphia-Wilmington-Atlantic City 
area was never redesignated to attainment of the 1997 NAAQS, and as 
such remained subject to I/M requirements under that NAAQS. In March 
2015, EPA revoked the 1997 ozone NAAQS in favor of a more stringent 
ozone NAAQS issued in March 2008. However, due to anti-backsliding 
requirements, the enhanced I/M program requirement in Kent and New 
Castle Counties remained in place for the revoked NAAQS.\14\
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    \13\ On January 21, 2011 (76 FR 3840), EPA granted the 
Philadelphia-Wilmington-Atlantic City area a 1-year extension of its 
1997 ozone attainment date (to June 2011). On March 26, 2012 (77 FR 
17341), EPA determined that the Philadelphia-Wilmington-Atlantic 
City area attained the 1997 ozone NAAQS by the applicable attainment 
date.
    \14\ EPA revoked the 1997 ozone NAAQS (March 6, 2015; 80 
FR12264), following promulgation of a more stringent 2008 ozone 
NAAQS on March 12, 2008.
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3. Delaware Nonattainment Area Designations and I/M Program 
Requirements Under the 2008 8-Hour Ozone NAAQS
    On March 12, 2008, EPA revised the 8-hour ozone NAAQS.\15\ EPA 
designated the Philadelphia-Wilmington-Atlantic City, PA-NJ-MD-DE (with 
Delaware's portion of the nonattainment area limited to New Castle 
County) and Seaford, Delaware as two, separate marginal ozone 
nonattainment areas for the 2008 8-hour ozone NAAQS on April 30, 2012 
(effective July 20, 2012).\16\ This marginal designation did not add 
new I/M applicability requirements, allowing the existing SIP-approved 
I/M program to remain in place unchanged. The Delaware portion of the 
Philadelphia-Wilmington-Atlantic City area (New Castle and Kent 
Counties) continued to be subject to enhanced I/M requirements under 
anti-backsliding provisions applicable to the prior 1979 ozone NAAQS 
and under the OTR requirements of CAA section 184.
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    \15\ 73 FR 16436 (March 27, 2008).
    \16\ 77 FR 30088 (May 21, 2021). Note that Kent County, Delaware 
was not included in either the Philadelphia-Wilmington-Atlantic City 
or the Seaford ozone nonattainment areas for the 2008 ozone NAAQS, 
but Kent County was instead designated by EPA as unclassifiable/
attainment. Under EPA's anti-backsliding rules, Kent and New Castle 
County continued to remain subject to enhanced I/M under prior NAAQS 
and under CAA section 184 OTR I/M program requirements.
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    On May 4, 2016, EPA issued the Philadelphia-Wilmington-Atlantic 
City area a 1-year attainment date extension to July 20, 2016, and 
determined that the Seaford nonattainment area attained the 2008 ozone 
NAAQS by the attainment date.\17\ On November 2, 2017, EPA determined 
that the Philadelphia-Wilmington-Atlantic City area attained the 2008 
NAAQS by the July 2016 attainment date.\18\ Neither area has been 
subsequently redesignated to attainment for the 2008 ozone NAAQS under 
section 107(d)(3) of the CAA. While the Seaford area did not exceed the 
classification/population thresholds to be subject to I/M, the area 
continued to operate the prior SIP-approved program for anti-
backsliding purposes.
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    \17\ 81 FR 26697.
    \18\ 82 FR 50814.
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4. Delaware Nonattainment Area Designations and I/M Program 
Requirements Under the 2015 8-Hour Ozone NAAQS
    On October 1, 2015, EPA again revised the 8-hour ozone NAAQS.\19\ 
EPA designated the Philadelphia-Wilmington-Atlantic City, PA-NJ-MD-DE 
area (with Delaware's portion of the nonattainment area limited to New 
Castle County) as a marginal ozone nonattainment area for the 2015 8-
hour ozone NAAQS on April 30, 2018 (effective August 3, 2018).\20\ As a 
result, under EPA's initial designations for the 2015 NAAQS, Delaware 
faced no new I/M obligation, but Kent and New Castle Counties continued 
to be subject to enhanced I/M requirements under the anti-backsliding 
requirements of the prior 1979 ozone NAAQS and under the OTR 
requirements of CAA section 184.
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    \19\ See 80 FR 65292 (October 26, 2015).
    \20\ See 83 FR 25776 (June 4, 2018). For the 2015 ozone NAAQS, 
the Delaware portion of the Philadelphia-Wilmington-Atlantic City 
2015 ozone nonattainment area includes Kent and New Castle Counties 
in Delaware. In the same action, EPA designated the Seaford area 
(Sussex County) as attainment for the 2015 ozone NAAQS.
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    In October 2022, EPA determined that the Philadelphia-Wilmington-
Atlantic City 2015 ozone nonattainment area failed to attain by its 
attainment date (August 3, 2021) and reclassified the area from 
marginal to moderate nonattainment.\21\ EPA established in that failure 
to attain/reclassification determination, that a basic vehicle I/M SIP 
is required (due by January 1, 2023) for urbanized Moderate areas under 
the 2015 ozone NAAQS. Existing I/M program areas classified as moderate 
or worse nonattainment (including areas with a basic or enhanced I/M 
program implemented under a prior NAAQS) were required to submit a 
certification SIP demonstrating that the existing program continues to 
meet applicable CAA requirements for the new ozone NAAQS 
classification.\22\ Delaware submitted a SIP revision on March 4, 2024, 
for the purpose of demonstrating that the existing enhanced I/M SIP for 
the Delaware portion of the Philadelphia-Wilmington-Atlantic City area 
meets all applicable requirements for a basic I/M program required by 
the 2015 ozone NAAQS. However, that SIP revision relies upon updates to 
the enhanced I/M SIP submitted to EPA as SIP revisions in March 2023 
(that we propose to approve as part of this action). So, EPA intends to 
defer action on the March 4, 2024 I/M certification SIP submission 
until after we finalize the pre-requisite action on Delaware's March 
2023 enhanced I/M update SIP submissions.
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    \21\ See 87 FR 60897 (October 7, 2022).
    \22\ Id. See Section II.E of the October 7, 2022 final rule (87 
FR 60897, 60906) and the April 13, 2022 proposal (87 FR 21842).
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II. Summary of Delaware's March 2023 I/M SIP Revisions and EPA's 
Analysis

A. Overview of Delaware's March 13, 2023 SIP Submissions

    Delaware submitted three SIP revisions on March 13, 2023, serving 
to update the State's existing, SIP-approved I/M programs. These March 
2023 SIP revisions pertain to both of Delaware's two I/M programs--the 
enhanced I/M program applicable to Kent and New Castle Counties and the 
SIP-strengthening (akin to basic) I/M program in Sussex County. The 
first of these SIP revisions is an amendment to 7 DE Admin. Code 1131, 
pertaining to the low enhanced I/M program operated in Kent and New 
Castle Counties (referred to hereafter as the ``Wilmington I/M 
program,'' the ``low enhanced I/M program,'' or the ``Regulation 1131'' 
I/M program).
    The second of the March 2023 SIP submittals amends 7 DE Admin. Code 
1126 pertaining to the SIP-strengthening I/M program applicable to 
Sussex County (referred to as the ``Sussex County'' or ``Regulation 
1126'' program). DNREC revised Regulations 1126 and 1131 to optimize 
the I/M program and to harmonize the requirements of the two programs, 
as well as to align Delaware's regulations with a change in State law 
(i.e., House Bill 246 of the

[[Page 66299]]

2017 Delaware General Assembly legislative session), which altered 
subject vehicle applicability of the program by changing the exemption 
for new vehicles from five to seven years.\23\
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    \23\ See 21 Delaware Code 2143.
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    Delaware's third SIP submittal of March 2023 serves to correct an 
error made by the State in a 2012 State regulatory action, which 
inadvertently incorporated Delaware's Plan for Implementation (PFI) for 
7 DE Admin Code 1126 and 7 DE Admin. Code 1131 into Regulation 31. 
Delaware never requested that EPA incorporate the 2012 version of 
Regulation 1131 into the SIP, so that error did not translate to the 
SIP. However, Delaware's March 2023 SIP revision requests that EPA 
incorporate the now non-regulatory Plan for Implementation as 
additional supporting materials for inclusion into the SIP, for the 
purpose of meeting Federal I/M requirements at 40 CFR part 51, subpart 
S, not addressed by the revised Regulations 1126 and 1131.
    These regulatory updates to Regulation 1131 serve to update the 
rules to reflect changes made by Delaware to revise its low-enhanced I/
M program as described (i.e., to increase new vehicle I/M program 
exemptions to seven years, to expand vehicle coverage to include 
medium-duty vehicles; to change idle testing requirements to curb idle 
testing, etc.). Additionally, the version of Regulation 1131 being 
incorporated by reference updates the prior SIP-approved Regulation 31 
program to reflect a State regulatory format change made since EPA last 
approved the SIP, essentially recodifying that program. The proposed 
revised Regulation 1131 being incorporated by reference includes the 
State-adopted January 1, 2023 revised Regulation 1131 (State effective 
January 11, 2023). The January 1, 2023 sections of Regulation 1131 
being adopted include sections 1.0, 2.0 (including 2.1 through 2.6), 
3.0 (including revised definitions), 4.0 (including 4.1 through 4.5), 
5.0 (including 5.1 through 5.4), 6.0 (including 6.1), 7.0 (including 
7.1 and 7.2), 8.0 (including 8.1 through 8.4), and 9.0 (including 9.1 
through 9.3). Sections 10 through 13 of Regulation 31 are being removed 
from the SIP, as are Appendices 1(d), 3(a)(7), 3(c)(2), 4(a), 5(a), 
5(f), 6(a), 6(a)(5), 6(a)(8), 6(a)(9), 7(a), 8(a), and 9(a)--as revised 
by the State on May 15, 2012 (with the State effective date of June 11, 
2012).
    In accordance with requirements of 1 CFR 51.5, EPA is proposing to 
incorporate by reference Delaware's revised Title 7, Regulation 1126 
entitled ``Motor Vehicle Emissions Inspection Program--Sussex County,'' 
as published as a final rule in the Delaware Register on January 1, 
2023 (effective January 11, 2023). The amended sections of Regulation 
1126 being incorporated by reference include Sections 1.0 (including 
1.1 through 1.6), 2.0 (including revised definitions), 4.0 (including 
4.1 through 4.5), 5.0 (including 5.1 through 5.4), 6.0 (including 6.1), 
7.0 (including 7.1 and 7.2), 8.0 (including 8.1 through 8.4), and 9.0 
(including 9.1 through 9.3). Section 3.0 of Regulation 1126 and 
Technical Memorandum 1 and 2 to Regulation 1126 are removed and 
reserved, based on the January 1, 2023 State rule revisions.
    In an August 11, 2010 action, EPA approved into the SIP Delaware's 
administrative recodification of 7 DE Code 1126.\24\ Delaware 
subsequently finalized a State administrative recodification of 7 DE 
Admin Code 1131 but did not then submit that administrative change as a 
SIP revision to EPA. As a result, EPA did not at that time approve into 
the SIP the State's recodification of Regulation 1131. Delaware's March 
2023 SIP revision contains a January 2023 State regulation amendment to 
Regulation 1131, which is based on a prior 2012 revision of that rule 
that Delaware had not previously requested be approved as part of the 
SIP. The relevant regulation in the SIP was most recently approved by 
EPA in October 2001, when it was still Regulation 31 in the Delaware 
Code. The 2023 SIP revision serves to incorporate by reference the 2023 
version of the State rule revision into the Delaware SIP. The effect of 
doing so will be to incorporate the latest 2023 State rule amendments, 
as well as the 2012 State amendments. The effect of approving the PFI 
SIP would be to remove from Regulations 1126 and 1131 some oversight 
and administrative provisions formerly contained in regulatory 
addendums and appendices to Regulation 1126 and 1131 and instead to 
include them in the SIP as additional State supporting materials.
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    \24\ See 75 FR 48566.
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B. Review of Delaware's March 2023 SIP Revisions for Compliance With 
EPA Requirements

1. Compliance With EPA's Enhanced I/M Performance Standard Requirements

[[Page 66300]]

    As part of its rule specifying I/M requirements, codified at 40 CFR 
part 51, subpart S, EPA established a ``model'' program for areas 
required to implement either basic or enhanced I/M programs.\25\ A 
state compares its own I/M program design choice with EPA's applicable 
model program design. The EPA model program serves as a benchmark, or 
``performance standard,'' the emissions results of which serve as means 
to compare the resultant emission benefits. The performance standard 
provides a gauge by which the state and EPA can evaluate the 
effectiveness of each state's basic or enhanced I/M program, from the 
perspective of ozone precursor emissions reductions. As such, states 
are required to demonstrate that their enhanced or basic I/M programs 
achieve applicable areawide emission levels that are equal to, or lower 
than, those which would be realized by the implementation of EPA's 
respective model I/M program.
---------------------------------------------------------------------------

    \25\ See 40 CFR 51.351 and 51.352.
---------------------------------------------------------------------------

    With respect to the enhanced I/M performance standard, EPA 
originally designed a single enhanced performance standard option under 
the 1992 version of its I/M requirements rule.\26\ However, on 
September 18, 1995, EPA promulgated the ``low enhanced'' performance 
standard described in the Background portion of this action.\27\ The 
low enhanced performance standard is a less stringent enhanced I/M 
performance standard established to avail areas having an approved SIP 
for Reasonable Further Progress (RFP) for 1996, and that do not have a 
disapproved post-1996 RFP plan, or a disapproved plan for attainment of 
the ozone NAAQS. Delaware has demonstrated compliance with CAA 
requirements for RFP and attainment planning for the Delaware portion 
of the Philadelphia-Wilmington-Atlantic City area--and thus has used 
the ``low enhanced'' performance standard in its prior approved I/M SIP 
and can continue to do so for updates to its currently approved I/M 
SIP. The revised performance standard modeling included as part of 
Delaware's 2023 SIP submittal is designed to demonstrate compliance 
with this ``low enhanced'' performance standard.
---------------------------------------------------------------------------

    \26\ See original version of EPA's I/M Requirements Rule (note 
this version has since been superseded by multiple rule updates), at 
57 FR 52950 (November 5, 1992). The enhanced performance standard is 
specified at 40 CFR 51.351 (57 FR 52950, 52988).
    \27\ See ``EPA's Inspection and Maintenance Flexibility 
Amendments'' Final Rule, at 60 FR 48029 (September 18, 1995).
---------------------------------------------------------------------------

    States seeking to amend an I/M program for an area with an existing 
CAA-mandated, SIP-approved I/M program (e.g., exemption of additional 
model years of vehicles from their program) must demonstrate that that 
the program continues to meet the applicable performance standard. This 
might entail upgrading the program in some other way (e.g., by 
increasing vehicle type or weight class coverage subject to the 
program) in order to demonstrate the applicable performance standard is 
still being met. In addition to the performance standard, per CAA 
section 110(l) the revised program must be shown not to interfere with 
an area's ability to attain the NAAQS in a timely manner.\28\
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    \28\ See EPA's Performance Standard Modeling for New and 
Existing Vehicle Inspection and Maintenance (I/M) Programs Using the 
MOVES Mobile Source Emissions Model [EPA-420-B-22-034 October 2022], 
p. 4.
---------------------------------------------------------------------------

    Table 1, in this document, compares EPA's low enhanced I/M 
performance standard with Delaware's latest program for the March 2023 
SIP revisions amending the Wilmington area low enhanced I/M program 
SIP.
---------------------------------------------------------------------------

    \29\ See 40 CFR 51.351(g) for the Alternate Low Enhanced 
Performance Standard.
    \30\ Delaware is newly extending applicability to include 1996 
MDVs (up to 14,000 lbs GVWR), subject to OBD testing, with 1970 and 
newer MDVs subject to curb idle tailpipe testing. Delaware exempts 
all pre-1996 model year, diesel-powered vehicles from the I/M 
program.
    \31\ Except for OBDII equipped vehicles, which instead receive 
an OBDII check in lieu of idle testing. EPA's position on the use of 
OBD testing, in lieu of idle tailpipe testing, is detailed in EPA's 
Amendments to I/M Program Requirements Incorporating OBD Checks 
final rule (66 FR 18156; April 5, 2001).
    \32\ See appendix B to 40 CFR part 51, subpart S.
    \33\ EPA's MOVES model no longer models the impacts of all 
enhanced I/M performance standard parameters listed under EPA's I/M 
requirements rule, at 40 CFR 51.351, including certain emission 
control device inspections and pre-1981 test stringency rate.
    \34\ Delaware is newly extending applicability to include MDVs 
(up to 14,000 lbs GVWR), subject to OBD testing.
    \35\ Excluding exempted new vehicles, up to 7 model years old.
    \36\ EPA's enhanced performance standard requirements at 40 CFR 
51.351(g) require that the state's program be shown to obtain the 
same or lower emission levels (relevant to the subject NAAQS) as the 
model program by January 1, 2002, to within 0.02 gpm, 
through their attainment deadline for the applicable NAAQS.
    \37\ For revisions to a SIP-approved I/M program, the 
performance standard modeling analysis year is the evaluation date 
is the date of implementation of the revised I/M program. See EPA's 
Performance Standard Modeling for New and Existing Vehicle 
Inspection and Maintenance (I/M) Programs Using the MOVES Mobile 
Source Emissions Model [EPA-420-B-22-034 October 2022], p. 10. For 
revisions to an I/M program currently approved into the SIP, the PSM 
analysis year would be the evaluation date used in the approved SIP 
or the date of implementation of the revised I/M program, whichever 
is later.

 Table 1--Low Enhanced Performance Standard Comparison for the Delaware portion of the Philadelphia-Wilmington-
                   Atlantic City Ozone Nonattainment Area (Kent and New Castle Counties) \29\
----------------------------------------------------------------------------------------------------------------
     I/M program element        EPA low enhanced performance standard      Delaware's low enhanced I/M program
----------------------------------------------------------------------------------------------------------------
Network Type................  Centralized.............................  Centralized.
Program Start Date..........  Existing programs--1983; Newly subject    New Castle County--1995; Kent County--
                               areas--1995.                              1991.
Test Frequency..............  Annual..................................  Biennial.
Model Year Coverage.........  1968 and newer..........................  1968 and newer (7 newest model years
                                                                         exempt).
Vehicle Type Coverage.......  Light-duty gasoline vehicles (LDGVs) and  1968 and newer LDGVs and LDGTs, up to
                               light-duty gasoline trucks (LDGTs), up    8,500 lbs GVWR; and 1970 and newer
                               to 8,500 lbs gross vehicle weight         Medium Duty Gasoline Vehicles (MDVs),
                               rating (GVWR).                            up to 14,000 lbs GVWR. \30\
Exhaust Emission Test \31\..  Idle Test, (1968-1995 model years) \32\.  Curb Idle test (1968-1995 LDVs and LDTs;
                                                                         and 1970-1995).
Emission Standards..........  1981 and newer--1.2% CO. 1981 and newer-- 1981 and newer--1.2% CO. 1981 and newer--
                               220 ppm HC.                               220 ppm HC.
Emission Control Device       1968-71 PCV valve; 1972 and newer EGR     1981 and newer Catalytic converter.
 Visual Inspection\33\.        valve.
On-board Diagnostics II       1996 and newer LDGVs and LDGTs..........  1996 and newer LDGVs and LDGTs, up to
 (OBDII) Inspection.                                                     8,500 lbs GVWR; and 1997 and later
                                                                         LDDVs (light-duty diesel vehicles), up
                                                                         to 8,500 lbs GVWR; and 2008 and newer
                                                                         MDVs (gasoline or diesel), up to 14,000
                                                                         lbs GVWR.\34\ \35\

[[Page 66301]]

 
Evaporative system function   None....................................  Gas Cap Pressure Test, for 1975-1995
 check.                                                                  vehicles.
Waiver Rate (for cost-        3%......................................  3%.
 limited I/M repair
 expenditures).
Motorist Compliance Rate....  96%.....................................  See Delaware SIP Appendix A of the
                                                                         Delaware Plan for Implementation for
                                                                         program compliance rate.
Evaluation Date \36\ \37\...  January 2002............................  January 2023.
----------------------------------------------------------------------------------------------------------------

    Though Delaware is not required to demonstrate compliance with a 
performance standard in the Sussex County area, as I/M there was 
adopted as a SIP strengthening program (as described in section I. of 
this action), the State elected to demonstrate that the Sussex County 
program meets EPA's basic I/M performance standard in order to rely 
upon the benefits from this program to meet CAA noninterference 
requirements under section 110(l). Additionally, the Sussex County 
program provides additional reductions to offset impacts to the 
Wilmington area program from the changes to that program. Table 2, in 
this document, shows the I/M program parameters of the Sussex County 
program compared to those of EPA's basic I/M performance standard, to 
show the assumptions used to model the benefits of the Sussex County 
program and to demonstrate that the revised program does not backslide 
from that in the approved SIP.
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    \38\ See 40 CFR 51.352 Basic I/M Performance Standard.
    \39\ Delaware exempts all pre-1996 model year, diesel-powered 
vehicles from the I/M program.
    \40\ Except for OBDII equipped vehicles, which instead receive 
an OBDII check in lieu of idle testing. EPA's position on the use of 
OBD testing, in lieu of idle tailpipe testing, is detailed in EPA's 
Amendments to I/M Program Requirements Incorporating OBD Checks 
final rule (66 FR 18156; April 5, 2001).
    \41\ See appendix B to 40 CFR part 51, subpart S.
    \42\ EPA's MOVES model no longer models the impacts of all 
enhanced I/M performance standard parameters listed under EPA's I/M 
requirements rule, at 40 CFR 51.351, including certain emission 
control device inspections and pre-1981 test stringency rate.
    \43\ Delaware is newly extending applicability to include MDVs 
(up to 14,000 lbs GVWR), subject to OBD testing.
    \44\ Excludes exempted new vehicles, up to 7 model years old.
    \45\ EPA's basic I/M performance standard at 40 CFR 51.352 
requires that the state's program be shown to obtain the same or 
lower emission levels as the model program by 1997 for the ozone 
NAAQS.
    \46\ For revisions to a SIP-approved I/M program, the 
performance standard modeling analysis year is the evaluation date 
is the date of implementation of the revised I/M program. See EPA's 
``Performance Standard Modeling for New and Existing Vehicle 
Inspection and Maintenance (I/M) Programs Using the MOVES Mobile 
Source Emissions Model'' [EPA-420-B-22-034 October 2022], p. 10. For 
revisions to an I/M program currently approved into the SIP, the PSM 
analysis year would be the evaluation date used in the approved SIP 
or the date of implementation of the revised I/M program, whichever 
is later.

       Table 2--Basic I/M Performance Standard Comparison for Sussex County SIP Strengthening Program \38\
----------------------------------------------------------------------------------------------------------------
     I/M program element           EPA basic performance standard       Delaware's SIP-strengthening I/M program
----------------------------------------------------------------------------------------------------------------
Network Type................  Centralized.............................  Centralized.
Program Start Date..........  Existing programs--1983; Newly subject    Sussex County--1983.
                               areas--1994.
Test Frequency..............  Annual..................................  Biennial.
Model Year Coverage.........  1968 and newer..........................  1968 and newer (7 newest model years
                                                                         exempt).
Vehicle Type Coverage.......  LDGVs...................................  LDVs and LDTs (up to 8,500 lbs GVWR);
                                                                         MDVs, up to 14,000 lbs GVWR. \39\
Exhaust Emission Test \40\..  Idle Test (1968-1995 model years) \41\..  Curb Idle test (1968-1995 model years).
Emission Standards..........  1981 and newer--1.2% CO; 1981 and newer-- 1981 and newer--1.2% CO; 1981 and newer--
                               220 ppm HC.                               220 ppm HC.
Emission Control Device       None....................................  1981 and newer Catalytic converter.
 Visual Inspection \42\.
On-board Diagnostics II       1996 and newer vehicles.................  1996 and newer LDGVs and LDGTs (up to
 (OBDII) Inspection.                                                     8,500 lbs GVWR); and 1997 and later
                                                                         LDDVs (light-duty diesel vehicles), up
                                                                         to 8,500 lbs GVWR; and 2008 and newer
                                                                         MDVs (gasoline or diesel), up to 14,000
                                                                         lbs GVWR. 43 44
Evaporative system function   None....................................  Gas Cap Pressure Test, for 1975-1995
 check.                                                                  vehicles.
Waiver Rate (for repair       0%......................................  3%.
 expenditure limits for I/M
 repairs).
Motorist Compliance Rate....  100%....................................  See Appendix A of the Delaware SIP Plan
                                                                         for Implementation for compliance rate.
Evaluation Date \45\ \46\...  January 2002............................  January 2023.
----------------------------------------------------------------------------------------------------------------

    To demonstrate the applicable performance standard has been met, 
the state must model the emissions benefits of its program against that 
of EPA's model program, comparing the results to show that their 
program is at least as beneficial as the applicable performance 
standard. For an area subject to I/M under the ozone NAAQS, this 
analysis (performed using the latest available version of EPA's Motor 
Vehicle Emissions Simulator Model (MOVES)

[[Page 66302]]

entails the comparison of the resultant levels, expressed as a 
comparison of average grams per mile (gpm), of the ozone precursors 
nitrogen oxides (NOX) and volatile organic compounds (VOCs), 
from highway mobile sources in the I/M area, as derived from MOVES. For 
purposes of this comparison, the state uses the latest available 
meteorological and vehicle composition and usage data, keeping constant 
all other mobile source emission control program assumptions between 
the model program and state program scenarios.\47\ For comparison 
purposes, Delaware also modeled a hypothetical ``no I/M'' scenario to 
show the emissions for the same area with no benefits from an I/M 
program. Delaware used MOVES2014b as the emissions model to generate 
2023 evaluation year emissions scenarios. Though EPA has since released 
newer versions of the MOVES model (i.e., MOVES3 and MOVES4), Delaware 
commenced development of their MOVES SIP analyses prior to the release 
of MOVES 3 in 2020.\48\
---------------------------------------------------------------------------

    \47\ Requirements for conducting a performance standard analysis 
are established by 40 CFR part 51, subpart S, with guidance provided 
by EPA's guidance document ``Performance Standard Modeling for New 
and Existing Vehicle Inspection and Maintenance (I/M) Programs Using 
the MOVES Mobile Source Emissions Model,'' dated October 2022 [EPA-
420-B-22-034].
    \48\ See ``EPA Policy Guidance on the Use of MOVES 2014 for SIP 
Development, Transportation Conformity, and Other Purposes'' (EPA-
420-B-14-008, July 2014), p. 6. Delaware's SIP modeling was 
completed in 2019, to support regulatory adoption of Regulations 
1126 and 1131. However, those rules were delayed during State 
adoption and not finalized until January 2023, delaying submission 
of the SIP until March 2023. This MOVES modeling analysis in support 
of these SIP revisions commenced prior to the subsequent release by 
EPA of MOVES3.
---------------------------------------------------------------------------

    Table 3, in this document, shows the results of Delaware's low 
enhanced I/M performance standard analysis for the Delaware portion of 
the Philadelphia-Wilmington-Atlantic City area. As the modeling 
depicted in Table 3 demonstrates, the NOX and VOC emission 
levels meet EPA's relevant I/M performance standard, as MOVES modeling 
for both Kent and New Castle Counties demonstrate that both county's 
programs are within the regulatory allowance (40 CFR 51.351(g)(13)) of 
0.02 gpm as compared to emission levels resulting from EPA's Low 
Enhanced Performance Standard of 40 CFR 51.351.

    Table 3--Low Enhanced Performance Standard Modeling Results for the Delaware Portion of the Philadelphia-
       Wilmington-Atlantic City I/M Program for a 2023 Evaluation Year (Kent and New Castle Counties) \49\
----------------------------------------------------------------------------------------------------------------
                                                                        NOX (in grams per     VOC (in grams per
                County                       I/M program design               mile)                 mile)
----------------------------------------------------------------------------------------------------------------
Kent.................................  No I/M Program...............                0.5139                0.3171
                                       Low Enhanced Performance                     0.4871                0.2869
                                        Standard.
                                       Delaware 2023 Program........                0.4794                0.2831
                                       Performance Standard Margin..                0.0077                0.0038
New Castle...........................  No I/M Program...............                0.4236                0.2557
                                       Low Enhanced Performance                     0.3988                0.2289
                                        Standard.
                                       Delaware 2023 Program........                0.3950                0.2300
                                       Performance Standard Margin..                0.0038          \50\ -0.0011
----------------------------------------------------------------------------------------------------------------

    As described in the Background section of this action, an I/M 
program is not CAA-required in Sussex County, Delaware--as the Seaford 
area meets neither the minimum MSA population threshold specified under 
CAA section 184, nor the minimum urbanized area population threshold 
for a nonattainment area under CAA section 182. However, Delaware 
elected to voluntarily implement an I/M program in Sussex County as a 
SIP strengthening measure and to provide additional ozone precursor 
emission reductions to benefit the Delaware portion of the 
Philadelphia-Wilmington-Atlantic City ozone nonattainment area. In 
order to quantify the benefits of this program, for the purpose of 
claiming benefits from the program to contribute to attainment of the 
Philadelphia-Wilmington-Atlantic City nonattainment area, Delaware 
elected to institute a program design similar to EPA's basic I/M 
performance standard.\51\ EPA's review of Delaware's updates to the 
Sussex County SIP-strengthening program finds that the revised program 
is substantially similar to CAA requirements for a basic I/M program.
---------------------------------------------------------------------------

    \49\ Delaware's 2023 I/M program amendments expand OBD II 
testing Statewide, including expanding existing OBDII testing 
requirements in Kent and New Castle Counties on MDV's to include 
MDVs up to 14,000 lbs GVWR.
    \50\ Kent County, Delaware's VOC emission factor for the State's 
2023 I/M Program falls within the 0.02 gpm margin of EPA's enhanced 
model enhanced performance standard program, as granted under EPA's 
enhanced I/M performance standard requirements at 40 CFR 
51.351(g)(13).
    \51\ See CAA section 182(b)(4) and 40 CFR 51.352.
---------------------------------------------------------------------------

2. Demonstrating Noninterference of the Revised SIP Under CAA Section 
110(l) With Attainment, Reasonable Further Progress, or Any Other CAA 
Applicable Requirement
    In the case where a state elects to revise its SIP-approved I/M 
program, in addition to meeting the applicable CAA section 182 program 
requirements and applicable performance standard compliance, the state 
must also demonstrate that the revisions to the prior, SIP-approved I/M 
program will not interfere with the area's ability to attain or 
maintain any NAAQS, or with any other applicable CAA requirement. This 
type of demonstration is known as a CAA section 110(l) noninterference 
demonstration.
    In order to offset any potential increase in emissions due to 
expansion of new car I/M exemptions to seven model years (as a result 
of a State law change (HB 246)), DNREC elected to harmonize inspection 
requirements more closely between the low enhanced Regulation 1131 
program in the Wilmington area and the Regulation 1126 SIP 
strengthening I/M program in Sussex County. This includes: (1) the 
addition of OBD II checks to Sussex County; (2) expansion of OBD 
testing in all counties, to include OBD II testing for model year 2008 
and newer medium duty vehicles between 8500-14,000 lbs GVWR; (3) 
elimination of 2-speed idle tailpipe testing in the Wilmington area, 
while retaining curb idle tailpipe testing for pre-1996 LDGVs in all 
areas (including Sussex County); (4) extension of gas cap pressure 
check testing to pre-1996 I/M-subject vehicles; and (5) retention of 
visual inspection for catalytic converters in all counties.
    See Table 4, in this document, for a comparison in the difference 
between emissions under the March 2023 SIP

[[Page 66303]]

revision I/M programs and the prior SIP-approved Delaware I/M program.
---------------------------------------------------------------------------

    \52\ The Baseline SIP program is the I/M program, as of 2017, 
including exemption of vehicles up to 5 years old from testing. The 
2023 Revised I/M program includes the disbenefit of expanding the 
new car exemption from 5 to 7 model years old, but offsets that 
emissions increase through the expansion of OBD testing to the 
Sussex County SIP strengthening program, the expansion of OBD checks 
in all counties to cover MDVs up to 14,000 lbs GVWR, the expansion 
of idle testing to LDVs and LDTs up to 8,500 lbs Statewide (i.e., 
including Sussex County), and a gas cap pressure check for all pre-
1995 I/M-subject vehicles.

 Table 4--CAA 110(l) Noninterference Demonstration--Difference Between Delaware's Baseline (Prior, Approved SIP
                       Program) and the 2023 Revised I/M Program (All Program Areas) \52\
----------------------------------------------------------------------------------------------------------------
                                                          Difference from
                                                          baseline SIP in    Difference from    Difference from
             County                Program description    carbon monoxide    baseline SIP in    baseline SIP in
                                                           (CO) (tons per     VOC (tons per      NOX (tons per
                                                               year)              year)              year)
----------------------------------------------------------------------------------------------------------------
Kent...........................  Baseline SIP Program..  .................  .................  .................
                                 2023 Revised I/M                    +17.1               +0.3               +0.7
                                  Program.
New Castle.....................  Baseline SIP Program..  .................  .................  .................
                                 2023 Revised I/M                   +184.0              +10.1               +7.8
                                  Program.
Sussex.........................  Baseline SIP Program..  .................  .................  .................
                                 2023 Revised I/M                   -594.2             -112.0              -54.1
                                  Program.
                                                        --------------------------------------------------------
    Net Change (Statewide).....  2023 Revised I/M                   -393.1             -101.6              -45.6
                                  Program.
----------------------------------------------------------------------------------------------------------------

    Table 4, in this document, shows that there is a slight increase in 
annual emissions attributed with Delaware's 2023 SIP revision (due 
primarily to expansion of new car exemptions) in the Wilmington area 
counties, as compared to the prior SIP program. However, the small 
increase in emissions (due to revision of Regulation 1131) within the 
Philadelphia-Wilmington-Atlantic City nonattainment area is offset by 
an overall net decrease in emissions from the I/M program Statewide, 
due to program improvements made Statewide and in particular benefits 
(due to upgrade of the Regulation 1126 I/M program) in upwind Sussex 
County.
    The Sussex County, SIP-strengthening program was never a CAA-
required emission control measure, nor were the emissions benefits 
attributed to the Sussex County I/M program part of any reasonable 
further progress demonstration or attainment demonstration for any 
NAAQS, nor any redesignation/maintenance plan for any NAAQS. Therefore, 
the reductions attributed to the Sussex program are ``surplus.'' The 
Regulation 1126 SIP-strengthening program is considered ``permanent'' 
and ``enforceable,'' in that it is required by State regulation 
(without sunset) and has been approved as part of Delaware's SIP for 
several decades. While Delaware could elect to discontinue I/M in 
Sussex County in the future, its removal from the SIP would warrant a 
110(l) demonstration showing that the removal of the program would not 
impact the ability of any area to attain the NAAQS or demonstrate RFP, 
nor interfere with any other applicable CAA requirement. The emissions 
reductions from the Sussex County I/M program occur in a county 
adjacent to the Philadelphia-Wilmington-Atlantic City ozone 
nonattainment area, providing nearby and surplus emission reductions 
directly upwind from the Philadelphia-Wilmington-Atlantic City 
nonattainment area.
    In showing that all ozone and fine particulate matter precursor 
pollutants (NOX and VOC), as well as the pollutant CO, are 
decreased from the 2023 SIP revised program relative to the prior, SIP-
approved program, Delaware has demonstrated that the 2023 SIP revision 
to amend the approved SIP will not interfere with attainment of any 
NAAQS, reasonable further progress, or any other applicable 
requirement.

C. EPA's Evaluation of Delaware's SIP Revisions

    EPA has reviewed Delaware's changes to its enhanced I/M program 
that differ from the previous federally approved program and has 
determined that these changes meet the requirements of CAA sections 182 
and 184, EPA's I/M Requirements Rule at 40 CFR part 51, subpart S, as 
well as all other EPA guidance relevant to I/M programs that are cited 
in this action. EPA finds that Delaware's revised program meets 
applicable I/M performance standards of 40 CFR part 51.351 and has been 
shown to comply with the NAAQS noninterference provisions of CAA 
section 110(l). Delaware's revisions to its SIP-strengthening 1126 
program in Sussex County and the incorporation of the Plan for 
Implementation as additional supporting materials for inclusion into 
the SIP are similarly approvable. EPA therefore proposes to find that 
that Delaware's SIP revisions are approvable into the SIP.
    EPA will continue to evaluate the effectiveness of Delaware's 
enhanced I/M program for the Delaware portion of the Philadelphia-
Wilmington-Atlantic City I/M program through the annual and biennial 
reports submitted by Delaware in accordance with 40 CFR 51.366, ``Data 
analysis and reporting,'' and with the ongoing program evaluation 
requirements set forth at 40 CFR 51.353(c).
    EPA's review of this material indicates that Delaware's requested 
SIP revisions submitted on March 13, 2023, to amend the SIP-approved I/
M program for the Delaware portion of the Philadelphia-Wilmington-
Atlantic City area meets all applicable requirements for an enhanced I/
M program under CAA section 182 and 184. The SIP strengthening program 
in Sussex County meets applicable requirements for a basic I/M program. 
The program enhancements made to both programs have been shown to meet 
the applicable EPA performance standards, as required by 40 CFR part 
51. The improvements made have been shown to offset emission increases 
brought about by expansion of the new vehicle test exemption to seven 
years.

III. Proposed Action

    Pursuant to the analysis above, EPA is proposing to approve the 
relevant revisions to the Delaware I/M rules at 7 DE Admin Code 1126 
(for Sussex

[[Page 66304]]

County) and 7 DE Admin. Code 1131 (for Kent and New Castle County), as 
submitted on March 13, 2023. For Regulation 1126, this involves 
incorporating by reference amendments to sections 1.0 through 9.0 and 
the removal of Technical Memorandum #1 and Technical Memorandum #2. For 
Regulation 1131, this entails incorporation of a State recodification 
of the regulation to reflect a State format change made in 2012, as 
well as incorporation of regulatory amendments made in 2012 and 2023. 
This results in a reformat of the prior SIP-approved Regulation 31, 
replacing sections 1 through 13 with the new format Regulation 1131, 
reflecting sections 1.0 to 9.0 as amended in January 2023, as well as 
removal of prior codified portions of Appendices 1, 3, 4, 5, 6, 7, 8, 
and 9.
    EPA is also proposing to approve a SIP revision dated March 13, 
2023, submitting for inclusion to the SIP Delaware's ``Motor Vehicle 
Emissions Inspection Program; Plan for Implementation for 7 DE Admin 
Code 1126 and 7 DE Admin. Code 1131''. This PFI details the means by 
which the Delaware SIP provides for the implementation, maintenance, 
and enforcement of the ozone NAAQS. Delaware inadvertently added this 
PFI language to their regulation in a State action dated May 15, 2021. 
Delaware mistakenly included what were intended as non-regulatory 
planning provisions to support the I/M regulation as part of a State 
amendment to Regulation 1131--Low Enhanced Inspection and Maintenance 
Program; Plan for Implementation (PFI). In January 2023, Delaware acted 
to remove the PFI from Regulation 1131,\53\ instead making it a 
standalone, non-regulatory document for inclusion in the SIP to support 
both Regulation 1131 and Regulation 1126. Delaware has requested that 
EPA add this PFI document for Regulations 1126 and 1131 as additional 
materials for inclusion in the Delaware SIP, rather than incorporating 
these materials into State regulation for incorporation by reference by 
EPA as part of the SIP.
---------------------------------------------------------------------------

    \53\ Regulation 1131--Low Enhanced Inspection and Maintenance 
Program; Plan for Implementation (PFI) was repealed effective 
January 11, 2023.
---------------------------------------------------------------------------

    EPA proposes to grant Delaware's request to approve the now non-
regulatory PFI documents as additional supporting, non-regulatory State 
materials to the SIP.
    Approval of these three March 13, 2023 proposed SIP revisions will 
enable the Department to formally address EPA's applicable CAA 182 and 
184 I/M requirements, as well as other SIP requirements under CAA 
section 110, and incorporate the same into Delaware's SIP document.
    EPA is proposing to approve three Delaware SIP revisions for their 
I/M programs in the Delaware portion of the Philadelphia-Wilmington-
Atlantic City area and the Sussex Area, as well as their accompanying 
PFI SIP revision, all of which were submitted on March 13, 2023. EPA is 
soliciting public comments on the proposed SIP revisions discussed in 
this document. These comments will be considered before taking final 
action.

IV. Incorporation by Reference

    In this document, EPA is proposing to include in a final EPA rule 
regulatory text that includes incorporation by reference. In accordance 
with requirements of 1 CFR 51.5, EPA is proposing to incorporate by 
reference Delaware's revised Title 7, Regulation 1131 entitled ``Motor 
Vehicle Emissions Inspection Program--Kent and New Castle Counties'', 
as State-adopted on January 1, 2023--including updates to revisions 
made by the State on June 12, 2012, as described in section II.A. of 
the preamble. In accordance with requirements of 1 CFR 51.5, EPA is 
also proposing to incorporate by reference Delaware's revised Title 7, 
Regulation 1126, entitled ``Motor Vehicle Emissions Inspection 
Program--Sussex County'', as published as a final rule in the Delaware 
Register on January 1, 2023 (effective January 11, 2023).
    EPA has made, and will continue to make, these materials generally 
available through www.regulations.gov and at the EPA Region III Office 
(please contact the person identified in the FOR FURTHER INFORMATION 
CONTACT section of this preamble for more information).

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 CAA and applicable 
Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in 
reviewing SIP submissions, EPA's role is to approve state choices, 
provided that they meet the criteria of the CAA. Accordingly, this 
action merely approves state law as meeting Federal requirements and 
does not impose additional requirements beyond those imposed by state 
law. For that reason, this 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);
     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); and
     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 Clean Air Act;
    In addition, this proposed rule, to approve three March 13, 2023 
Delaware SIP revisions related to the vehicle I/M program, does not 
have tribal implications as specified by Executive Order 13175 (65 FR 
67249, November 9, 2000), because the SIP is not approved to apply in 
Indian country located in the State, and EPA notes that it will not 
impose substantial direct costs on tribal governments or preempt tribal 
law.
    Executive Order 12898 (Federal Actions to Address Environmental 
Justice in Minority Populations and Low-Income Populations, 59 FR 7629, 
February 16, 1994) directs Federal agencies to identify and address 
``disproportionately high and adverse human health or environmental 
effects'' of their actions on minority populations and low-income 
populations to the greatest extent practicable and permitted by law. 
EPA defines environmental justice (EJ) as ``the fair treatment and 
meaningful involvement of all people regardless of race, color, 
national origin, or income with respect to the development, 
implementation, and enforcement of environmental laws, regulations, and 
policies.'' EPA further defines the term fair treatment to mean that 
``no group of people should bear a disproportionate burden of 
environmental harms and risks, including those resulting from the 
negative environmental consequences of industrial, governmental, and

[[Page 66305]]

commercial operations or programs and policies.''
    The Delaware Department of Natural Resources and Environmental 
Control did not evaluate environmental justice considerations as part 
of its revised enhanced I/M program SIP submittal; the CAA and 
applicable implementing regulations neither prohibit nor require such 
an evaluation. EPA did not perform an EJ analysis and did not consider 
EJ in this action. Due to the nature of the action being taken here, 
this action is expected to have a neutral to positive impact on the air 
quality of the affected area.
    Consideration of EJ is not required as part of this action 
proposing approval of Delaware's revision of its enhanced I/M program 
SIP revision, and there is no information in the record inconsistent 
with the stated goal of E.O. 12898 of achieving environmental justice 
for people of color, low-income populations, and Indigenous peoples.

List of Subjects in 40 CFR Part 52

    Environmental protection, Air pollution control, Carbon monoxide, 
Incorporation by reference, Intergovernmental relations, Nitrogen 
dioxide, Ozone, Particulate matter, Reporting and recordkeeping 
requirements, Volatile organic compounds.

Adam Ortiz,
Regional Administrator, Region III.
[FR Doc. 2024-18173 Filed 8-14-24; 8:45 am]
 BILLING CODE 6560-50-P