2020-12044. Air Plan Approval; Texas; Beaumont-Port Arthur Area Second Maintenance Plan for 1997 Ozone National Ambient Air Quality Standards

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Proposed rule.

SUMMARY:

Pursuant to the Federal Clean Air Act (CAA or the Act), the Environmental Protection Agency (EPA) is proposing to approve a revision to the Texas State Implementation Plan (SIP). The EPA is proposing to approve the plan for maintaining the 1997 8-hour ozone National Ambient Air Quality Standards (NAAQS or standard) through 2032 in the Beaumont-Port Arthur (BPA) area.

DATES:

Written comments must be received on or before July 8, 2020.

ADDRESSES:

Submit your comments, identified by Docket No. EPA-R06-OAR-2018-0716, at https://www.regulations.gov or via email to [e-mail]. Follow the online instructions for submitting comments. Once submitted, comments cannot be edited or removed from Regulations.gov. The 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. The 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 Jeff Riley, 214-665-8542, [e-mail]. For the full EPA public comment policy, information about CBI or multimedia submissions, and general guidance on making effective comments, please visit https://www.epa.gov/​dockets/​commenting-epa-dockets.

Docket: The index to the docket for this action is available electronically at www.regulations.gov. While all documents in the docket are listed in the index, some information may not be publicly available due to docket file size restrictions or content (e.g., CBI).

FOR FURTHER INFORMATION CONTACT:

Jeff Riley, EPA Region 6 Office, Infrastructure and Ozone Section, 214-665-8542, [e-mail]. Out of an abundance of caution for members of the public and our staff, the EPA Region 6 office will be closed to the public to reduce the risk of transmitting COVID-19. We encourage the public to submit comments via https://www.regulations.gov,, as there will be a delay in processing mail and no courier or hand deliveries will be accepted. Please call or email the contact listed above if you need alternative access to material indexed but not provided in the docket.

SUPPLEMENTARY INFORMATION:

Throughout this document wherever “we,” “us,” or “our” is used, we mean the EPA.

Table of Contents

I. Summary of EPA's Proposed Action

II. Background

III. The EPA's Evaluation

A. Second Maintenance Plan

B. Transportation Conformity

IV. Proposed Action

V. Statutory and Executive Order Reviews

I. Summary of EPA's Proposed Action

EPA is proposing to approve, as a revision to the Texas SIP, an updated 1997 ozone NAAQS maintenance plan for the Beaumont-Port Arthur area. The maintenance plan is designed to keep the area in attainment of the 1997 ozone NAAQS through the end of the second 10-year maintenance period.

II. Background

Ground-level ozone is formed when oxides of nitrogen (NO_X) and volatile organic compounds (VOC) react in the presence of sunlight. These two pollutants are referred to as ozone precursors. Scientific evidence indicates that adverse public health effects occur following exposure to ozone.

In 1979, under section 109 of the Clean Air Act (CAA), EPA established primary and secondary NAAQS for ozone at 0.12 parts per million (ppm), averaged over a 1-hour period. 44 FR 8202 (February 8, 1979). On July 18, 1997, EPA revised the primary and secondary NAAQS for ozone to set the acceptable level of ozone in the ambient air at 0.08 ppm, averaged over an 8-hour period. 62 FR 38856 (July 18, 1997).^[1] EPA set the 8-hour ozone NAAQS based on scientific evidence demonstrating that ozone causes adverse health effects at lower concentrations and over longer periods of time than was understood when the pre-existing 1-hour ozone NAAQS was set.

Following promulgation of a new or revised NAAQS, EPA is required by the CAA to designate areas throughout the nation as attaining or not attaining the NAAQS. On April 15, 2004 (69 FR 23857), EPA designated certain areas for the 1997 ozone NAAQS, including the Beaumont-Port Arthur area, consisting of Hardin, Jefferson and Orange Counties as nonattainment. These designations became effective on June 15, 2004. Under the CAA, states are also required to adopt and submit SIPs to implement, maintain, and enforce the NAAQS in designated nonattainment areas and throughout the state.

When a nonattainment area has three years of complete, certified air quality data that has been determined to attain the 1997 ozone NAAQS, and the area has met other required criteria described in section 107(d)(3)(E) of the CAA, the state can submit to EPA a request to be redesignated to attainment, and if approved, would then be referred to as a “maintenance area”.^[2]

One of the criteria for redesignation is to have an approved maintenance plan under CAA section 175A. The maintenance plan must demonstrate that the area will continue to maintain the standard for the period extending 10 years after redesignation, and it must contain such additional measures as necessary to ensure maintenance and such contingency provisions as necessary to assure that violations of the standard will be promptly corrected. At the end of the eighth year after the effective date of the redesignation, the state must also submit a second maintenance plan to ensure ongoing maintenance of the standard for an additional 10 years. CAA section 175A.

EPA has long-standing guidance for states on developing maintenance plans. This includes “Procedures for Processing Requests to Redesignate Areas to Attainment,” Memorandum from John Calcagni, Director, Air Quality Management Division, September 4, 1992 (the “Calcagni Memorandum”).^[3] The Calcagni Memorandum provides that states may generally demonstrate maintenance by either performing air quality modeling to show that the future mix of sources and emission rates will not cause a violation of the NAAQS or by showing that future emissions of a pollutant and its precursors will not exceed the level of emissions during a year when the area was attaining the NAAQS (i.e., attainment year inventory). See Calcagni Memorandum at 3.

On December 16, 2008, the Texas Commission on Environmental Quality (TCEQ) submitted a request to EPA to redesignate the Beaumont-Port Arthur area to attainment for the 1997 ozone NAAQS. This submittal included a plan to maintain the 1997 ozone NAAQS in the BPA area through 2021 as a revision to the Texas SIP. EPA approved the maintenance plan for the BPA area and redesignated the area to attainment of the 1997 ozone NAAQS effective November 19, 2010 (75 FR 64675). The Beaumont-Port Arthur area continues to meet the 1997 standard. In fact, air quality has continued to improve. The area's preliminary design value for 2017-2019 is 70 ppb which not only complies with the 1997 standard but also the more stringent 2008 and 2015 ozone standards.

Under CAA section 175A(b), states must submit a revision to the first maintenance plan eight years after redesignation to provide for maintenance of the NAAQS for ten additional years following the end of the first 10-year period. EPA's final implementation rule for the 2008 ozone NAAQS revoked the 1997 ozone NAAQS and provided that one consequence of revocation was that areas that had been redesignated to attainment (i.e., maintenance areas) for the 1997 standard no longer needed to submit second 10-year maintenance plans under CAA section 175A(b).^[4] However, in South Coast Air Quality Management District v. EPA ^[5] (South Coast II), the D.C. Circuit vacated EPA's interpretation that, because of the revocation of the 1997 ozone standard, second maintenance plans were not required for “orphan maintenance areas,” i.e., areas that had been redesignated to attainment for the 1997 NAAQS and were designated attainment for the 2008 ozone NAAQS. Thus, states with these “orphan maintenance areas” under the 1997 ozone NAAQS must submit maintenance plans for the second maintenance period. Accordingly, on February 5, 2019, the Texas Commission on Environmental Quality (TCEQ) submitted the second maintenance plan for the Beaumont-Port Arthur area. The maintenance plan shows that the area is expected to remain in attainment of the 1997 ozone NAAQS through the end of the full 20-year maintenance period. The State's submittal also included a request to EPA to redesignate the BPA area to attainment for the revoked 1979 1-hour ozone NAAQS ^[6] and a plan to provide for maintenance of the 1-hour ozone standard in the BPA area through 2032. EPA is not addressing the 1-hour ozone standard portion of the State's submission at this time.

III. The EPA's Evaluation

A. Second Maintenance Plan

Section 175A of the CAA sets forth the elements of a maintenance plan for areas seeking redesignation from nonattainment to attainment. Under section 175A, the maintenance plan must demonstrate continued attainment of the NAAQS for at least 10 years after the Administrator approves a redesignation to attainment. Eight years after the redesignation, the state must submit a revised maintenance plan which demonstrates that attainment of the NAAQS will continue for an additional 10 years beyond the initial 10-year maintenance period. To address the possibility of future NAAQS violations, the maintenance plan must contain contingency measures, as EPA deems necessary, to assure prompt correction of the future NAAQS violation.

The Calcagni Memorandum provides further guidance on the content of a maintenance plan, explaining that a maintenance plan should address five elements: (1) An attainment emission inventory; (2) a maintenance demonstration; (3) a commitment for continued air quality monitoring; (4) a process for verification of continued attainment; and (5) a contingency plan.

On February 5, 2019, TCEQ submitted, as a SIP revision, a plan to provide for maintenance of the 1997 ozone standard in the Beaumont-Port Arthur area through 2032, more than 20 years after the effective date of redesignation to attainment. As discussed below, EPA finds that Texas' second maintenance plan includes the necessary components and proposes to approve the maintenance plan as a revision to the Texas SIP.

1. Attainment Inventory

For maintenance plans, a state should develop a comprehensive, accurate inventory of actual emissions for an attainment year to identify the level of emissions which is sufficient to maintain the NAAQS. A state should develop this inventory consistent with EPA's most recent guidance on emissions inventory development. For ozone, the inventory should be based on typical summer day VOC and NO_X emissions, as these pollutants are precursors to ozone formation.

The CAA section 175A maintenance plan approved by EPA for the first 10-year period included an attainment inventory that reflects typical summer day VOC and NO_X emissions for the 2005 attainment year. In addition, because the BPA maintenance area continued to monitor attainment of the 1997 ozone NAAQS in 2014, this is also an appropriate year to use for an attainment year inventory. As such, the TCEQ has developed a 2014 attainment year inventory for the BPA area, presented in Table 1 below, to represent the VOC and NO_X emissions that occur on a typical summer weekday. The 2014 attainment year inventory was developed from the 2014 periodic emissions inventory (PEI), in accordance with the Air Emissions Reporting Requirements. See 80 FR 8787 (February 19, 2015). For some source categories, the TCEQ developed state-specific emissions estimates by acquiring state-specific activity data and applying appropriate emissions factors in developing the 2014 attainment year inventory, as well as projections for the 2032 maintenance year inventory presented in Table 2 below. These source categories include but are not limited to: Storage tanks, structural fires, dry cleaners, and automobile fires. In particular, the TCEQ focused on refining the oil and gas area source inventory production categories. These inventories also include descriptions of the methods used to estimate emissions.^[7] Table 1 shows 2014 attainment year VOC and NO_X emission totals for all sectors for the BPA maintenance area.

Table 1—Beaumont-Port Arthur Area Typical Summer Day VOC and NO_X Emissions for Attainment year 2014 in Tons per Day (tpd)

Source category	VOC	NOX
Nonroad	2.67	16.66
Onroad	6.27	18.49
Point	32.20	62.25
Area	54.99	3.89
Total	96.13	101.29

2. Maintenance Demonstration

TCEQ is demonstrating maintenance through 2032 by showing that future emissions of VOC and NO_X for the Beaumont-Port Arthur area remain at or below attainment year emission levels. 2032 is an appropriate maintenance year for the BPA area because it is more than 10 years beyond the first 10-year maintenance period. The 2032 emissions inventory is projected from the 2014 PEI, which was the most recent available inventory at the time the TCEQ was preparing the maintenance plan submittal for the BPA area. The 2032 summer day emissions inventory for the Beaumont-Port Arthur area is summarized in Table 2 below.

Table 2—Beaumont-Port Arthur Area Typical Summer Day VOC and NO_X Emissions for Maintenance Year 2032

[tpd]

Source category	VOC	NOX
Nonroad	2.29	7.64
Onroad	2.21	4.76
Point	32.73	62.32
Area	43.65	3.95
Total	80.88	78.67

Table 3 below shows the changes in VOC and NO_X emissions between the attainment year (2014) and maintenance year (2032) for the BPA maintenance area.

Table 3—Change in Typical Summer Day VOC and NO_X Emissions in the Beaumont-Port Arthur Area Between 2014 and 2032

[tpd]

Source category	VOC			NOX
	2014	2032	Net change (2014-2032)	2014	2032	Net change (2014-2032)
Nonroad	2.67	2.29	−0.38	16.66	7.64	−9.02
Onroad	6.27	2.21	−4.06	18.49	4.76	−13.73
Point	32.20	32.73	+0.53	62.25	62.32	+0.07
Area	54.99	43.65	−11.34	3.89	3.95	+0.06
Total	96.13	80.88	−15.25	101.29	78.67	−22.62

We note the slight increase in point source VOC emissions, which is offset by the decreases in area and mobile source VOC emissions. Additionally, the slight increases in stationary source NO_X emissions are offset by decreases in mobile source NO_X emissions. We also note that the projections for the on-road mobile source inventory for 2032, which TCEQ submitted as motor vehicle emissions budgets, are consistent with maintenance of the 1997 ozone NAAQS. The maintenance demonstration for the BPA area shows maintenance of the 1997 ozone NAAQS by providing emissions information to support the demonstration that future emissions of NO_X and VOC will remain at or below 2014 emission levels when considering both future source growth and implementation of future controls. We are proposing that TCEQ has met the maintenance demonstration requirements on the basis that the approach and methods of calculating the attainment year and future year emission inventories that were used are consistent with EPA guidance.^[8]

3. Continued Air Quality Monitoring

TCEQ has committed to continue to operate an approved ozone monitoring network in the Beaumont-Port Arthur area. TCEQ has committed to consult with EPA prior to making changes to the existing monitoring network should changes become necessary in the future. TCEQ remains obligated to meet monitoring requirements and continue to quality assure monitoring data in accordance with 40 CFR part 58, and to enter all data into the Air Quality System in accordance with Federal guidelines.

4. Verification of Continued Attainment

The State of Texas has confirmed that it has the legal authority to enforce and implement the requirements of the maintenance plans for the areas addressed in this action. This includes the authority to adopt, implement, and enforce any subsequent emission control measures determined to be necessary to correct future ozone attainment problems.

Verification of continued attainment is accomplished through operation of the ambient ozone monitoring network and the periodic update of the area's emissions inventory. TCEQ has committed to continue to operate an approved ozone monitoring network in the Beaumont-Port Arthur maintenance area. TCEQ will not discontinue operation, relocate, or otherwise change the existing ozone monitoring network other than through revisions in the network approved by EPA.

In addition, to track future levels of emissions, TCEQ has committed to continue to develop and submit to EPA updated emission inventories for all source categories at least once every three years, consistent with the requirements of 40 CFR part 51, subpart A, and in 40 CFR 51.122. The Consolidated Emissions Reporting Rule (CERR) was promulgated by EPA on June 10, 2002 (67 FR 39602). The CERR was replaced by the Annual Emissions Reporting Requirements on December 17, 2008 (73 FR 76539).

5. Contingency Plan

Section 175A of the CAA requires that the state must adopt a maintenance plan, as a SIP revision, that includes such contingency measures as EPA deems necessary to assure that the state will promptly correct a violation of the NAAQS that occurs after redesignation of the area to attainment of the NAAQS. The maintenance plan must identify: The contingency measures to be considered and, if needed for maintenance, adopted and implemented; a schedule and procedure for adoption and implementation; and, a time limit for action by the state. The state should also identify specific indicators to be used to determine when the contingency measures need to be considered, adopted, and implemented. The maintenance plan must include a commitment that the state will implement all measures with respect to the control of the pollutant that were contained in the SIP before redesignation of the area to attainment in accordance with section 175A(d) of the CAA.

As required by section 175A of the CAA, Texas has adopted a contingency plan for the Beaumont-Port Arthur maintenance area to address possible future ozone air quality problems. The adopted contingency plan maintains the same contingency measures included in the BPA area's first 1997 ozone NAAQS 10-year maintenance plan, approved by EPA on October 20, 2010 (75 FR 64675). The potential contingency measures identified by the TCEQ include, but are not limited to the following:

• Revision to Title 30 of the Texas Administrative Code (TAC) Chapter 117, Subchapter B, Division 1 or Subchapter E, Division 4, to control rich-burn, gas-fired, reciprocating internal combustion engines located in the BPA area.
• Inclusion of one or more counties in the BPA area in 30 TAC Chapter 115 VOC rules for the control of crude and condensate storage tanks at upstream oil and gas exploration and production sites or midstream pipeline breakout stations with uncontrolled flash emissions greater than 25 tons per year.
• Inclusion of one or more counties in the BPA area in 30 TAC Chapter 115 VOC rules for more stringent controls for tank fittings on floating roof tanks, such as slotted guidepoles and other openings on internal and external floating roofs.
• Inclusion of one or more counties in the BPA area in 30 TAC Chapter 115 VOC rules limiting emissions from landings of floating roofs in floating roof tanks.
• Inclusion of one or more counties in the BPA area in 30 TAC Chapter 115 VOC rules for control of VOC emissions from degassing operations for storage tanks with a nominal capacity of 75,000 gallons or more storing materials with a true vapor pressure greater than 2.6 pounds per square inch absolute (psia), or with a nominal capacity of 250,000 gallons or more storing materials with a true vapor pressure of 0.5 psia or greater. Degassing vapors from storage vessels, transport vessels, and marine vessels would be required to vent to a control device until the VOC concentration of the vapors is reduced to less than 34,000 parts per million by volume as methane.
• Expand the Texas Low Emission Diesel marine diesel requirements in 30 TAC § 114.319(c) to include one or more counties in the BPA area.

To qualify as a contingency measure, emissions reductions from that measure must not be factored into the emissions projections used in the maintenance plan. The maintenance plan provides that a monitored and certified violation of the NAAQS triggers the requirement to consider, adopt, and implement the plan's contingency measures. The schedule and procedure for adoption and implementation by the State is no longer than 18 months following a monitored and certified violation of the NAAQS.^[9] Given the estimated emissions in the Beaumont nonattainment area, we believe the proposed contingency measures are sufficient to address any potential future violations.

TCEQ's maintenance plan adequately addresses the five basic components of a maintenance plan: attainment inventory, maintenance demonstration, monitoring network, verification of continued attainment, and a contingency plan. As such, EPA is proposing to approve the maintenance plan SIP revision submitted by the TCEQ on the basis that it meets the requirements of CAA section 175A.

B. Transportation Conformity

Transportation conformity is required by section 176(c) of the CAA. Conformity to a SIP means that transportation activities will not cause or contribute to new air quality violations, worsen existing violations, or delay timely attainment of the relevant NAAQS or interim milestones (CAA 176(c)(1)). EPA's conformity rule at 40 CFR part 93 establishes the criteria and procedures for determining whether transportation plans, transportation improvement programs (TIPs), and federally supported highway and transit projects conform to the SIP. EPA's regulation at 40 CFR 93.109 specifies the conformity criteria for each transportation action. See Table 1, 40 CFR 93.109.

The BPA maintenance plan submission includes motor vehicle emissions budgets (MVEBs) for the last year of the maintenance plan (in this case 2032). MVEBs are used to conduct regional emissions analyses for transportation conformity purposes. See 40 CFR 93.118. The MVEB is the portion of the total allowable emissions in the maintenance demonstration that is allocated to highway and transit vehicle use and emissions. See 40 CFR 93.101. The South Coast II court decision upheld EPA's revocation of the 1997 ozone NAAQS, which was effective on April 6, 2015. EPA's current transportation conformity regulation requires a regional emissions analysis only during the time period beginning one year after a nonattainment designation for a particular NAAQS until the effective date of revocation of that NAAQS (40 CFR 93.109(c)). Therefore, pursuant to the conformity regulation, a regional emissions analysis using MVEBs is not required for conformity determinations for the 1997 ozone NAAQS because that NAAQS has been revoked (80 FR 12264). As no regional emissions analysis is required for the BPA maintenance area, transportation conformity for the 1997 ozone NAAQS can be demonstrated for transportation plans and TIPs by showing that the remaining criteria contained in Table 1 in 40 CFR 93.109, and 40 CFR 93.108 have been met. Therefore, EPA is not taking any action on the submitted 2032 NO_X and VOC MVEBs for transportation conformity purposes. As noted previously, EPA is proposing to find that the projected emissions inventory which reflects these budgets are consistent with maintenance of the 1997 8-hour ozone standard.

IV. Proposed Action

Under section 175A of the CAA and for the reasons set forth above, based on Texas' representations and commitments set forth above, EPA is proposing to approve the second maintenance plan for the 1997 ozone NAAQS for the Beaumont-Port Arthur area, submitted by TCEQ on February 5, 2019, as a revision to the Texas SIP. This maintenance plan is designed to keep the area in attainment of the 1997 ozone NAAQS through the second 10-year maintenance period.

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 Act and applicable Federal regulations. 42 U.S.C. 7410(k); 40 CFR 52.02(a). Thus, in reviewing SIP submissions, the EPA's role is to approve state choices, provided that they meet the criteria of the CAA. Accordingly, this action merely proposes to approve state law as meeting Federal requirements and does not impose additional requirements beyond those imposed by state law. For that reason, this action:

• Is not a “significant regulatory action” subject to review by the Office of Management and Budget under Executive Orders 12866 (58 FR 51735, October 4, 1993) and 13563 (76 FR 3821, January 21, 2011);
• Is not an Executive Order 13771 (82 FR 9339, February 2, 2017) regulatory action because SIP approvals are exempted under Executive Order 12866;
• Does not impose an information collection burden under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
• Is certified as not having a significant economic impact on a substantial number of small entities under the Regulatory Flexibility Act (5 U.S.C. 601 et seq.);
• Does not contain any unfunded mandate or significantly or uniquely affect small governments, as described in the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4);
• Does not have federalism implications as specified in Executive Order 13132 (64 FR 43255, August 10, 1999);
• Is not an economically significant regulatory action based on health or safety risks subject to Executive Order 13045 (62 FR 19885, April 23, 1997);
• Is not a significant regulatory action subject to Executive Order 13211 (66 FR 28355, May 22, 2001);
• Is not subject to requirements of section 12(d) of the National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) because application of those requirements would be inconsistent with the CAA; and
• Does not provide EPA with the discretionary authority to address, as appropriate, disproportionate human health or environmental effects, using practicable and legally permissible methods, under Executive Order 12898 (59 FR 7629, February 16, 1994).

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 proposed rule 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).

List of Subjects in 40 CFR Part 52

• Environmental protection
• Air pollution control
• Incorporation by reference
• Intergovernmental relations
• Nitrogen dioxide
• Ozone
• Reporting and recordkeeping requirements
• Volatile organic compounds

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

Dated: May 29, 2020.

Kenley McQueen,

Regional Administrator, Region 6.

Footnotes

1.  In March 2008, EPA completed another review of the primary and secondary ozone standards and tightened them further by lowering the level for both to 0.075 ppm. 73 FR 16436 (March 27, 2008). Additionally, in October 2015, EPA completed a review of the primary and secondary ozone standards and tightened them by lowering the level for both to 0.70 ppm. 80 FR 65292 (October 26, 2015).

2.  Section 107(d)(3)(E) of the CAA sets out the requirements for redesignation. They include attainment of the NAAQS, full approval under section 110(k) of the applicable SIP, determination that improvement in air quality is a result of permanent and enforceable reductions in emissions, demonstration that the state has met all applicable section 110 and part D requirements, and a fully approved maintenance plan under CAA section 175A.

3.  “Procedures for Processing Requests to Redesignate Areas to Attainment,” Memorandum from John Calcagni, Director, Air Quality Management Division, September 4, 1992. To view the memo, please visit https://www.epa.gov/​sites/​production/​files/​2016-03/​documents/​calcagni_​memo_​-_​procedures_​for_​processing_​requests_​to_​redesignate_​areas_​to_​attainment_​090492.pdf.

4.  See 80 FR 12315 (March 6, 2015).

5.  882 F.3d 1138 (D.C. Cir. 2018).

6.  In April 2004, EPA published a rule governing implementation of the 1997 ozone NAAQS (Phase 1 Rule). 69 FR 23951 (April 30, 2004). The Phase 1 Rule revoked the 1-hour ozone NAAQS along with designations and classifications for that standard.

7.  For more information on EIs, including guidance, reports, and resources, see EPA's website at https://www.epa.gov/​air-emissions-inventories.

8.  See EPA's web page for Emission Models and Other Methods to Produce Emission Inventories. The web page includes general guidance for preparing inventories; estimating commercial marine emission inventories and port emissions; estimating emissions from locomotives; and estimating emissions from aircraft: https://www.epa.gov/​moves/​emissions-models-and-other-methods-produce-emission-inventories.

9.  The 1997 eight-hour ozone NAAQS is violated by any consecutive three-year average of each annual fourth-highest daily maximum eight-hour ozone average at or above 85 ppb.