Proposed approval of the Michigan 2015 Ozone Moderate SIP Elements for the Allegany, Berrien, and Muskegon County areas

Air Plan Approval; Michigan; Moderate Attainment Plan Elements for the Allegan County, Berrien County, and Muskegon County Areas for the 2015 Ozone Standard

SUPPLEMENTARY INFORMATION:

Throughout this document whenever "we," "us," or "our" is used, we mean EPA.

I. Background

On December 28, 2015, EPA promulgated a revised 8-hour ozone NAAQS of 0.070 parts per million (ppm). ⁽¹⁾ Promulgation of a revised NAAQS triggers a requirement for EPA to designate all areas of the country as nonattainment, attainment, or unclassifiable for the NAAQS. For the ozone NAAQS, this also involves classifying any nonattainment areas at the time of designation. ⁽²⁾ Ozone nonattainment areas are classified based on the severity of their ozone levels as determined based on the area's "design value," which represents air quality in the area for the most recent 3 years. The classifications for ozone nonattainment areas are Marginal, Moderate, Serious, Severe, and Extreme. ⁽³⁾

Areas that EPA designates nonattainment for the ozone NAAQS are subject to the general nonattainment area planning requirements of CAA section 172 and the ozone-specific planning requirements of CAA section 182. Ozone nonattainment areas in the lower classification levels have fewer and/or less stringent mandatory air quality planning and control requirements than those in higher classifications. In EPA's December 6, 2018 (83 FR 62998), rule, "Implementation of the 2015 National Ambient Air Quality Standards for Ozone: Nonattainment Area State Implementation Plan Requirements," known as the "SIP Requirements Rule," EPA set forth nonattainment area requirements for the 2015 ozone NAAQS. These requirements are codified at 40 CFR part 51 subpart CC. For Marginal areas, a State is required to submit a baseline emissions inventory, adopt provisions into the SIP requiring emissions statements from stationary sources, and implement a nonattainment new source review program for the relevant ozone NAAQS. ⁽⁴⁾ For Moderate areas, a State needs to comply with the Marginal area requirements, plus additional Moderate area requirements, including the requirement to submit a modeled demonstration that the area will attain the NAAQS as expeditiously as practicable but no later than 6 years after designation, the requirement to submit an RFP plan, the requirement to adopt and implement certain emissions controls, such as Reasonably Available Control Technology (RACT) and motor vehicle inspection and maintenance programs, and the requirement for greater emissions offsets for new or modified major stationary sources under the State's nonattainment new source review program. ⁽⁵⁾

Effective August 3, 2018, EPA designated the Allegan County (partial county), Berrien County, and Muskegon County (partial county) areas as Marginal nonattainment areas for the 2015 ozone NAAQS. ⁽⁶⁾ The Allegan County area includes Casco Township, Cheshire Township, the City of Douglas, the City of Holland, the City of Saugatuck, Clyde Township, Fillmore Township, Ganges Township, Heath Township, Laketown Township, Lee Township, Manilus Township, Overisel Township, Saugatuck Township, and Valley Township. The Muskegon County area includes Blue Lake Township, the City of Montague, the City of Muskegon, the City of Muskegon Heights, the City of North Muskegon, the City of Roosevelt Park, the City of Whitehall, Dalton Township, (incl. the Village of Lakewood Club), Fruitland Township, Fruitport Township (incl. the Village of Fruitport), Laketon Township, Montague Township, Muskegon Township, Norton Shores Township, White River Township, and Whitehall Township.

On October 7, 2022 (87 FR 60897), pursuant to section 181(b)(2) of the CAA, EPA determined that the Allegan County, Berrien County and Muskegon County areas failed to attain the 2015 ozone NAAQS by the August 3, 2021, Marginal area attainment deadline and thus reclassified the areas from Marginal to Moderate nonattainment. In that action, EPA established January 1, 2023, as the due date for the State to submit all Moderate area nonattainment plan SIP requirements applicable to newly reclassified areas.

II. Evaluation of Michigan's Submittal

The Michigan Department of Environment, Great Lakes, and Energy (EGLE) submitted a SIP revision on October 16, 2023, to address Moderate area requirements for the Allegan County, Berrien County and Muskegon County areas under the 2015 ozone NAAQS. The submittal contained a number of nonattainment plan elements, including an updated 2017 base year emissions inventory for volatile organic compounds (VOC) and oxides of nitrogen (NO _X ) and a 15% RFP plan with 2023 VOC and NO _X motor vehicle emissions budgets. The submission also included an attainment demonstration, a reasonably available control measures demonstration, and contingency measures, which are not being addressed in this action.

A. 2017 Base Year Emissions Inventory

1. Background

CAA sections 172(c)(3) and 182(a)(1), 42 U.S.C. 7502(c)(3) and 7511a(a)(1), require States to develop and submit, as SIP revisions, comprehensive, accurate, and complete emissions inventories for all areas designated as nonattainment for the ozone NAAQS. This requirement is codified at 40 CFR 51.1315, and the term "base year inventory" is defined at 51.1300(p). For ozone, the base year inventory is an estimation of actual emissions of VOC and NO _X from all sources within the boundaries of the nonattainment area.

The regulation at 40 CFR 51.1315(a) requires that the inventory year be selected consistent with the baseline year for the RFP plan as required by 40 CFR 51.1310(b), which states that the baseline emissions inventory shall be the emissions inventory for the most recent calendar year for which a complete triennial inventory is required to be submitted to EPA under the provisions of subpart A of 40 CFR part 51, Air Emissions Reporting Requirements, 40 CFR 51.1 through 50. For areas designated as nonattainment in 2018, the most recent triennial inventory year conducted for the National Emissions Inventory (NEI) pursuant to the Air Emissions Reporting Requirements (AERR) rule is 2017. ⁽⁷⁾

Further, 40 CFR 51.1315(c) requires emissions values included in the base year inventory to be actual ozone season day emissions as defined by 40 CFR 51.1300(q), which states: Ozone season day emissions means an average day's emissions for a typical ozone season work weekday. The State shall select, subject to EPA approval, the particular month(s) in the ozone season and the day(s) in the work week to be represented, considering the conditions assumed in the development of RFP plans and/or emissions budgets for transportation conformity.

On December 18, 2020, EGLE submitted a SIP revision addressing the emissions inventory requirement of CAA section 182(a)(1). EPA approved Michigan's 2017 base year emissions inventories for the Allegan County, Berrien County, and Muskegon County areas on January 18, 2023 (88 FR 2834).

2. Michigan's Emission Inventory Submittal

As part of Michigan's Moderate SIP submission, EGLE updated the 2017 base year emissions inventories to incorporate improved emissions estimates where available. In Michigan's original base year emissions inventory submittal, EGLE used the 2016v1 modeling platform to generate emissions data for the point and nonpoint sectors and MOVES2014 to generate emissions data for the onroad and nonroad sectors. EGLE updated the 2017 base year emissions inventories for the Allegan County, Berrien County, and Muskegon County areas using the 2016v2 modeling platform for point and nonpoint sectors and MOVES3  ⁽⁸⁾ for nonroad and on-road sectors. EGLE did not update biogenic emissions estimates.

EGLE converted annual point and nonpoint values to tons/day following the same procedure as was used when preparing the original 2017 base year emissions inventories. EGLE extracted data from the 2016v2 modeling platform to calculate the ratio of July emissions to total annual emissions for each county by sector. These conversion factors were then divided by 31 days in July to create final daily scaling factors that were applied to the updated annual emissions estimates. ⁽⁹⁾ The Michigan Department of Transportation (MDOT) used MOVES3 to generate nonroad and on-road July weekday emissions. Non-point and nonroad emissions for Allegan County and Muskegon County were scaled down based on geographic area. Allegan County is 50 percent of full county; Muskegon is 58 percent of full county. On-road data for Allegan County and Muskegon County was apportioned using vehicle miles traveled and vehicle hours traveled ratios.

Table 1, below, shows the updated 2017 ozone season day emissions in tons per ozone season day of NO _X and VOC for the Allegan County, Berrien County, and Muskegon County areas.

3. Evaluation of Michigan's 2017 Base Year Emission Inventory

EPA has reviewed Michigan's 2017 base year emissions inventory for consistency with sections 172(c)(3) and 182(a)(1) of the CAA, and EPA's emission inventory requirements. The selection of 2017 as the base year comports with the RFP baseline year requirements set forth in the SIP Requirements Rule and codified at 40 CFR 51.1310(b).

EGLE documented the procedures used to estimate the emissions for each of the major source types. The documentation of the emission estimation procedures is adequate to determine that Michigan followed acceptable procedures to estimate the emissions. Accordingly, EPA concludes that Michigan has developed inventories of NO _X and VOC emissions that are comprehensive and complete.

B. 15% RFP Plan

1. Background

The CAA requires that States with areas designated as nonattainment for ozone achieve RFP toward attainment of the ozone NAAQS. CAA section 172(c)(2) contains a general requirement that nonattainment plans must provide for emissions reductions that meet RFP. For areas classified Moderate and above, section 182(b)(1) imposes a more specific RFP requirement that a State was required to meet through a 15% reduction in VOC emissions from the baseline anthropogenic emissions within 6 years after November 15, 1990.

The SIP Requirements Rule addressed, among other things, RFP requirements as they apply to areas designated nonattainment and classified as Moderate for the 2015 ozone NAAQS. ⁽¹⁰⁾ RFP requirements under the 2015 ozone NAAQS are codified at 40 CFR 51.1310. EPA interprets the 15% VOC emission reduction requirement in CAA section 182(b)(1) such that a State that has already met the 15% requirement for VOC for an area under either the 1-hour ozone NAAQS or a prior 8-hour ozone NAAQS would not have to fulfill that requirement through reductions of VOC again. Instead, EPA interprets CAA section 172(c)(2) to require States with such areas to obtain 15% ozone precursor emission reductions from VOC and/or NO _X over the first 6 years after the baseline year for the 2015 ozone NAAQS. Michigan has not met the 15% VOC reduction requirement of CAA section 182(b)(1) for the Allegan County, Berrien County, or Muskegon County areas under previous ozone NAAQS. ⁽¹¹⁾ Therefore, the State must rely upon VOC emissions reductions to meet the RFP requirement for the 2008 ozone NAAQS.

The SIP Requirements Rule specifies that the baseline emissions inventory for RFP plans shall be the most recent calendar year prior to designation for which a complete triennial inventory is required to be submitted to EPA under the provisions of subpart A of 40 CFR part 51, Air Emissions Reporting Requirements, 40 CFR 51.1 through 50. For areas designated as nonattainment in 2018, the most recent triennial inventory year conducted for the NEI pursuant to the AERR rule is 2017. The rule also allows the use of an alternative RFP baseline year that corresponds with the year of the effective date of an area's designation, i.e., 2018 for areas designated nonattainment in 2018. ⁽¹²⁾

States may not take credit for VOC or NO _X reductions occurring from sources outside the nonattainment area for purposes of meeting the 15% RFP requirements of CAA sections 172(c)(2), 182(b)(1) and 182(c)(2)(B). ⁽¹³⁾

Except as specifically provided in CAA section 182(b)(1)(C) and (D) and CAA section 182(c)(2)(B), all emission reductions from SIP-approved or federally promulgated measures that occur after the baseline emissions inventory year are creditable for purposes of the RFP requirements in this section, provided the reductions meet the requirements for creditability, including the need to be enforceable, permanent, quantifiable, and surplus. ⁽¹⁴⁾ Further, the Administrator has determined that the four categories of control measures listed in CAA section 182(b)(1)(D) are no longer required to be calculated for exclusion in RFP analyses because due to the passage of time the effect of these exclusions would be de minimis. ⁽¹⁵⁾

2. Michigan's 15% RFP Plan

Emission Inventories

To demonstrate that the Allegan County, Berrien County, and Muskegon County areas have achieved 15% RFP over the 6-year attainment planning period, EGLE is using a 2017 base year inventory and a 2023 RFP inventory. The procedures EGLE used to develop the 2017 base year inventory are discussed in section I.A. of this preamble. When developing the 2023 RFP inventory EGLE estimated onroad and nonroad emissions using EPA's MOVES3 model. For the point and nonpoint source categories, EGLE used the 2023v3 modeling inventory.

EGLE converted annual point and nonpoint values to tons/day following the same procedure as was used when preparing the 2017 base year emissions inventories. EGLE extracted data from the 2023v2 modeling platform to calculate the ratio of July emissions to total annual emissions for each county by sector. These conversion factors were then divided by 31 days in July to create final daily scaling factors that were applied to the updated annual emissions estimates. The Michigan Department of Transportation (MDOT) used MOVES3 to generate nonroad and on-road July weekday emissions. Non-point and nonroad emissions for Allegan County and Muskegon County were scaled down based on geographic area. Allegan County is 50 percent of full county; Muskegon is 58 percent of full county. On-road data for Allegan County and Muskegon County was apportioned using vehicle miles traveled and vehicle hours traveled ratios.

2023 ozone season day emissions of NO _X and VOCs for each county by sector are shown in Tables 3 and 4, below.

15% RFP Demonstration

EGLE demonstrated that the Allegan County, Berrien County, and Muskegon County Areas have achieved 15% RFP over the 6-year attainment planning period through VOC emission reductions in the onroad and nonroad sectors attributable to EPA's existing Federal regulations, Michigan's VOC RACT rules, Michigan's architectural and industrial maintenance coating rule, and Michigan's consumer products rule. ⁽¹⁶⁾

EPA onroad mobile source regulations currently being implemented across the country include: passenger vehicle, SUV, and light duty truck emissions and fuel standards; light-duty truck and medium duty passenger vehicle evaporative standards; heavy-duty highway compression engine standards; heavy-duty spark ignition engine standards; motorcycle emission standards; mobile source air toxics fuel formulation standards, passenger vehicle emission standards, and portable container emission standards. ⁽¹⁷⁾ EPA nonroad mobile source regulations currently being implemented across the country include: aircraft, compression ignition, large spark ignition, locomotive engines, marine compression ignition, marine spark ignition, recreational vehicle, and small spark ignition engine emission standards and evaporative standards. ⁽¹⁸⁾

Table 3 shows calculations demonstrating that Michigan's emission reductions meet the 15% RFP requirement for the Allegan County, Berrien County, and Muskegon County areas.

3. Evaluation of Michigan's 15% RFP Plan

EPA has reviewed Michigan's 15% RFP plan for consistency with sections 172(c)(2) and 182(b)(1) of the CAA, and 40 CFR 51.1310. The selection of 2017 as the base year comports with the RFP baseline year requirements set forth in the SIP Requirements Rule and codified at 40 CFR 51.1310(b). EPA has reviewed the techniques used by Michigan to derive and quality assure the 2017 and 2023 emission estimates. EGLE documented the procedures used to estimate the emissions for each of the major source types. The documentation of the emission estimation procedures is thorough and adequate to determine that EGLE followed acceptable procedures to estimate the emissions. Emission reductions attributable to Federal onroad and nonroad regulations, Michigan's VOC RACT rules, Michigan's architectural and industrial maintenance coating rule, and Michigan's consumer products rule are permanent and enforceable and will result in at least 15% RFP in the Allegan County, Berrien County, and Muskegon County areas over the 6-year attainment planning period beginning with the 2017 base year. Thus, EPA is proposing to approve Michigan's 15% RFP plan for the Allegan County, Berrien County, and Muskegon County areas for the 2015 ozone NAAQS.

C. Motor Vehicle Emission Budgets

1. Background

Under section 176(c) of the CAA, transportation plans, programs, or projects that receive Federal funding or support, such as the construction of new highways, must "conform" to ( i.e., be consistent with) the SIP before they receive Federal funding or approval. Conformity to the SIP means that transportation activities will not cause or contribute to any new air quality violations, increase the frequency or severity of any existing air quality problems, or delay timely attainment or any required interim emissions reductions or any other milestones. Regulations at 40 CFR part 93 subpart A set forth EPA policy, criteria, and procedures for demonstrating and ensuring conformity of transportation activities to a SIP.

Transportation conformity is a requirement for nonattainment and maintenance areas, as defined in 40 CFR 93.101. The budget in a State's SIP serves as a ceiling on emissions from an area's planned transportation system (see definition of "motor vehicle emissions budget" in 40 CFR 93.101 and how the term is used in 40 CFR 93.109 and 93.118).

When reviewing submitted SIPs containing budgets, EPA reviews the budgets for adequacy. Once EPA affirmatively finds the submitted budget is adequate for transportation conformity purposes, that budget must be used by State and Federal agencies in determining whether proposed transportation projects conform to the SIP as required by section 176(c) of the CAA.

EPA's substantive criteria for determining adequacy of a budget are set out in 40 CFR 93.118(e)(4). The process for determining adequacy is found in 40 CFR 93.118(f) and consists of three basic steps: public notification of a SIP submission, a public comment period, and EPA's adequacy finding. The regulations that allow EPA to begin an adequacy review through a notice of proposed rulemaking in the Federal Register are found in 40 CFR 93.118(f)(2). This proposal notifies the public that EPA has received a SIP submission with budgets that EPA will review for adequacy and begins the public comment period. Comments must be submitted to the docket for this proposal by the close of the comment period on this proposal.

2. VOC and NO _X Budgets for the Allegan County, Berrien County, and Muskegon County Areas

The RFP plan includes VOC and NO _X budgets for the Allegan County, Berrien County, and Muskegon County areas for 2023, the milestone year for RFP. EPA invites the public to comment on the adequacy of these budgets as well as on its proposed approval of the budgets and on other actions EPA is proposing in this action.

The Michigan Department of Transportation prepared motor vehicle emissions inventories for 2017 and 2023 for the purpose of setting budgets for the year 2023. These inventories were developed using up-to-date assumptions about vehicles mile traveled (VMT), vehicle age distribution, socioeconomic variables, fuels used, weather inputs, other planning assumptions, and the latest approved motor vehicle emissions model at the time EGLE began to prepare the SIP submission, which was MOVES3. Total onroad emissions in the Allegan County, Berrien County, and Muskegon County areas are shown in Table 4.

Table 5 identifies Michigan's 2023 budgets. The budgets, agreed upon as part of the interagency consultation process, include the emission estimates calculated for 2023 with an additional safety margin allocated to those estimates to accommodate future variations in travel demand models and VMT forecast. A State can add a safety margin to a budget based on the transportation conformity regulation at 40 CFR 93.124(a).

3. Evaluation of the VOC and NO _X Budgets for the Allegan County, Berrien County, and Muskegon County Areas

The VOC and NO _X budgets for the Allegan County, Berrien County, and Muskegon County areas were developed as part of an interagency consultation process which includes Federal, State, and local agencies. The budgets were clearly identified and precisely quantified. Michigan has demonstrated that the Allegan County, Berrien County, and Muskegon County areas can meet the 15% RFP requirement with mobile source emissions of 1.15 tpd of NO _X and 0.70 tpd of VOC, 2.98 tpd of NO _X and 1.85 tpd of VOC, and 1.73 tpd of NO _X and 1.74 tpd of VOC, respectively, in 2023 because, as shown in Table 3, despite partial allocation of the RFP plan surplus reductions, emissions will remain under 2023 RFP target levels. EPA is thus proposing to approve the 2023 VOC and NO _X budgets for use in determining transportation conformity in the Allegan County, Berrien County, and Muskegon County areas under the 2015 ozone NAAQS.

III. What action is EPA taking?

EPA is proposing to approve Michigan's updated 2017 base year emissions inventory and 15% RFP demonstration, including the associated motor vehicle emissions budgets, as revisions to Michigan's SIP pursuant to section 110 and part D of the CAA and EPA's regulations because EGLE's October 16, 2023, submission satisfies the base year inventory and RFP requirements of the CAA for the Allegan County, Berrien County and Muskegon County areas under the 2015 ozone NAAQS. EPA is also initiating the adequacy process for the 2023 motor vehicle emissions budgets for the Allegan County, Berrien County and Muskegon County areas included in this SIP submission.

IV. 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 action:

• Is not a significant regulatory action subject to review by the Office of Management and Budget under Executive Order 12866 (58 FR 51735, October 4, 1993);
• Is not subject to Executive Order 14192 (90 FR 9065, February 6, 2025) because SIP actions are exempt from review under Executive Order 12866;

• Does not impose an information collection burden under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq. );

• Is certified as not having a significant economic impact on a substantial number of small entities under the Regulatory Flexibility Act (5 U.S.C. 601 et seq. );

• Does not contain any unfunded mandate or significantly or uniquely affect small governments, as described in the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4);
• Does not have federalism implications as specified in Executive Order 13132 (64 FR 43255, August 10, 1999);
• Is not subject to Executive Order 13045 (62 FR 19885, April 23, 1997) because it approves a State program;
• 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 CAA.

In addition, the SIP is not approved to apply on any Indian reservation land or in any other area where EPA or an Indian Tribe has demonstrated that a Tribe has jurisdiction. In those areas of Indian country, the rulemaking does not have Tribal implications and will not impose substantial direct costs on Tribal governments or preempt Tribal law as specified by Executive Order 13175 (65 FR 67249, November 9, 2000).

[FR Doc. 2025-22607 Filed 12-10-25; 8:45 am]

BILLING CODE 6560-50-P

⁽¹⁾  80 FR 65292, October 26, 2015, codified at 40 CFR 50.19.

⁽²⁾  CAA sections 107(d)(1) and 181(a)(1).

⁽³⁾  CAA section 181(a)(1).

⁽⁴⁾  CAA section 182(a).

⁽⁵⁾  CAA section 182(b).

⁽⁶⁾  83 FR 25776, June 4, 2018.

⁽⁷⁾  December 6, 2018, 83 FR 62998, 63005.

⁽⁸⁾  MOVES3 was the most current mobile model available at the time EGLE was developing Moderate SIPs for the Allegan County, Berrien County, and Muskegon County areas.

⁽⁹⁾  EGLE determined that weekend day emissions have a large impact on individual monitor design values and, therefore, included weekend days in the calculation of typical ozone season day emission values.

⁽¹⁰⁾  83 FR 62998 at 63004, December 6, 2018.

⁽¹¹⁾  74 FR 47414, September 15, 2009.

⁽¹²⁾  83 FR 62998 at 63005, December 6, 2018, codified at 40 CFR 51.1310(b).

⁽¹³⁾  40 CFR 51.1310(a)(6).

⁽¹⁴⁾  40 CFR 51.1310(a)(5).

⁽¹⁵⁾  40 CFR 51.1310(a)(7).

⁽¹⁶⁾  EGLE also documented emission reductions from voluntary programs that EPA is not including in RFP calculations.

⁽¹⁷⁾  40 CFR parts 59, 80, 85, 86, and 600.

⁽¹⁸⁾  40 CFR parts 54, 60, 87, 89, 90, 1033, 1039, 1042, 1045, 1048, 1051, and 1054.