Document headings vary by document type but may contain the following:
See the Document Drafting Handbook for more details.
AGENCY:
Environmental Protection Agency (EPA).
ACTION:
Proposed rule.
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 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 goold.megan@epa.gov. 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 rehn.brian@epa.gov.
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. This emissions testing ensures that vehicles are well-maintained and operate as designed and that they do not exceed established vehicle pollutant limits.
See CAA sections 182(b)(4), (c)(3).
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. 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. 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.
See CAA 182(b)(4) and 40 CFR 51.350(a)(4) and (6).
See CAA 182(c)(3) and 40 CFR 51.350(a)(2) and (7).
See CAA 184(b)(1) and 40 CFR 51.350(a)(1).
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.
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,
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. 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.
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.
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. 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.
See 40 CFR 51.351(g).
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. 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.
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.
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. 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.
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.
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. 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. 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. Rather than be subject to basic I/M, the remainder of the Philadelphia- 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).
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.
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.
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.
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. 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.
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.
EPA revoked the 1997 ozone NAAQS (March 6, 2015; 80 FR12264), following promulgation of a more stringent 2008 ozone NAAQS on March 12, 2008.
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. 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). 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.
73 FR 16436 (March 27, 2008).
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.
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. On November 2, 2017, EPA determined that the Philadelphia-Wilmington-Atlantic City area attained the 2008 NAAQS by the July 2016 attainment date. 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.
81 FR 26697.
82 FR 50814.
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. 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). 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.
See80 FR 65292 (October 26, 2015).
See83 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.
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. 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. 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.
See87 FR 60897 (October 7, 2022).
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).
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 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.
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. 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.
See75 FR 48566.
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
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. 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.
See40 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. However, on September 18, 1995, EPA promulgated the “low enhanced” performance standard described in the Background portion of this action. 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.
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).
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.
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.
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)
See40 CFR 51.351(g) for the Alternate Low Enhanced Performance Standard.
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.
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).
See appendix B to 40 CFR part 51, subpart S.
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.
Delaware is newly extending applicability to include MDVs (up to 14,000 lbs GVWR), subject to OBD testing.
Excluding exempted new vehicles, up to 7 model years old.
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.
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.
See40 CFR 51.351(g) for the Alternate Low Enhanced Performance Standard.
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.
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).
See appendix B to 40 CFR part 51, subpart S.
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.
Delaware is newly extending applicability to include MDVs (up to 14,000 lbs GVWR), subject to OBD testing.
Excluding exempted new vehicles, up to 7 model years old.
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.
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
See40 CFR 51.352 Basic I/M Performance Standard.
Delaware exempts all pre-1996 model year, diesel-powered vehicles from the I/M program.
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).
See appendix B to 40 CFR part 51, subpart S.
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.
Delaware is newly extending applicability to include MDVs (up to 14,000 lbs GVWR), subject to OBD testing.
Excludes exempted new vehicles, up to 7 model years old.
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.
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.
See40 CFR 51.352 Basic I/M Performance Standard.
Delaware exempts all pre-1996 model year, diesel-powered vehicles from the I/M program.
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).
See appendix B to 40 CFR part 51, subpart S.
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.
Delaware is newly extending applicability to include MDVs (up to 14,000 lbs GVWR), subject to OBD testing.
Excludes exempted new vehicles, up to 7 model years old.
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.
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 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)
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.
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).
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.
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).
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)
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.
| County | Program description | Difference from baseline SIP in carbon monoxide (CO) (tons per year) | Difference from baseline SIP in VOC (tons per year) | Difference from baseline SIP in NO X (tons per year) |
|---|---|---|---|---|
| Kent | Baseline SIP Program | |||
| 2023 Revised I/M Program | +17.1 | +0.3 | +0.7 | |
| New Castle | Baseline SIP Program | |||
| 2023 Revised I/M Program | +184.0 | +10.1 | +7.8 | |
| Sussex | Baseline SIP Program | |||
| 2023 Revised I/M Program | −594.2 | −112.0 | −54.1 | |
| Net Change (Statewide) | 2023 Revised I/M Program | −393.1 | −101.6 | −45.6 |
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.