2015-12347. Approval and Promulgation of Implementation Plans and Designation of Areas for Air Quality Planning Purposes; Tennessee; Redesignation of the Knoxville 2008 8-Hour Ozone Nonattainment Area to Attainment

AGENCY:

Environmental Protection Agency.

ACTION:

Proposed rule.

SUMMARY:

On November 14, 2014, the State of Tennessee, through the Tennessee Department of Environment and Conservation (TDEC), Air Pollution Control Division, submitted a request for the Environmental Protection Agency (EPA) to redesignate the Knoxville, Tennessee 8-hour ozone nonattainment area (hereafter referred to as the “Knoxville Area” or “Area”) to attainment for the 2008 8-hour ozone National Ambient Air Quality Standards (NAAQS) and to approve a State Implementation Plan (SIP) revision containing a maintenance plan and a base year emissions inventory for the Area. The Knoxville Area includes a portion of Anderson County as well as Blount and Knox Counties in their entireties. EPA is proposing to approve the base year emissions inventory for the 2008 8-hour ozone NAAQS for the Knoxville Area; to determine that the Knoxville Area is attaining the 2008 8-hour ozone NAAQS; to approve the State's plan for maintaining attainment of the 2008 8-hour ozone standard in the Area, including the motor vehicle emission budgets (MVEBs) for nitrogen oxides (NO_X) and volatile organic compounds (VOC) for the years 2011 and 2026 for the Area, into the SIP; and to redesignate the Area to attainment for the 2008 8-hour ozone NAAQS. EPA is also notifying the public of the status of EPA's adequacy determination for the Knoxville Area MVEBs.

DATES:

Comments must be received on or before June 22, 2015.

ADDRESSES:

Submit your comments, identified by Docket ID No. EPA-R04-OAR-2014-0870, by one of the following methods:

1. www.regulations.gov: Follow the on-line instructions for submitting comments.

2. Email: [e-mail].

3. Fax: [phone].

4. Mail: “EPA-R04-OAR-2014-0870,” Air Regulatory Management Section (formerly the Regulatory Development Section), Air Planning and Implementation Branch (formerly the Air Planning Branch), Air, Pesticides and Toxics Management Division, U.S. Environmental Protection Agency, Region 4, 61 Forsyth Street SW., Atlanta, Georgia 30303-8960.

5. Hand Delivery or Courier: Ms. Lynorae Benjamin, Chief, Air Regulatory Management Section, Air Planning and Implementation Branch, Air, Pesticides and Toxics Management Division, U.S. Environmental Protection Agency, Region 4, 61 Forsyth Street SW., Atlanta, Georgia 30303-8960. Such deliveries are only accepted during the Regional Office's normal hours of operation. The Regional Office's official hours of business are Monday through Friday, 8:30 a.m. to 4:30 p.m., excluding Federal holidays.

Instructions: Direct your comments to Docket ID No. EPA-R04-OAR-2014-0870. EPA's policy is that all comments received will be included in the public docket without change and may be made available online at www.regulations.gov,, including any personal information provided, unless the comment includes information claimed to be Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. Do not submit through www.regulations.gov or email, information that you consider to be CBI or otherwise protected. The www.regulations.gov Web site is an “anonymous access” system, which means EPA will not know your identity or contact information unless you provide it in the body of your comment. If you send an email comment directly to EPA without going through www.regulations.gov,, your email address will be automatically captured and included as part of the comment that is placed in the public docket and made available on the Internet. If you submit an electronic comment, EPA recommends that you include your name and other contact information in the body of your comment and with any disk or CD-ROM you submit. If EPA cannot read your comment due to technical difficulties and cannot contact you for clarification, EPA may not be able to consider your comment. Electronic files should avoid the use of special characters, any form of encryption, and be free of any defects or viruses. For additional information about EPA's public docket visit the EPA Docket Center homepage at http://www.epa.gov/​epahome/​dockets.htm.

Docket: All documents in the electronic docket are listed in the www.regulations.gov index. Although listed in the index, some information is not publicly available, i.e., CBI or other information whose disclosure is restricted by statute. Certain other material, such as copyrighted material, is not placed on the Internet and will be publicly available only in hard copy form. Publicly available docket materials are available either electronically in www.regulations.gov or in hard copy at the Air Regulatory Management Section, Air Planning and Implementation Branch, Air, Pesticides and Toxics Management Division, U.S. Environmental Protection Agency, Region 4, 61 Forsyth Street SW., Atlanta, Georgia 30303-8960. EPA requests that if at all possible, you contact the person listed in the FOR FURTHER INFORMATION CONTACT section to schedule your inspection. The Regional Office's official hours of business are Monday through Friday, 8:30 to 4:30, excluding Federal holidays.

FOR FURTHER INFORMATION CONTACT:

Jane Spann or Tiereny Bell of the Air Regulatory Management Section, in the Air Planning and Implementation Branch, Air, Pesticides and Toxics Management Division, U.S. Environmental Protection Agency, Region 4, 61 Forsyth Street SW., Atlanta, Georgia 30303-8960. Ms. Spann may be reached by phone at [phone] or via electronic mail at [e-mail]. Ms. Bell may be reached by phone at [phone] or via electronic mail at [e-mail].

SUPPLEMENTARY INFORMATION:

Table of Contents

I. What are the actions EPA is proposing to take?

II. What is the background for EPA's proposed actions?

III. What are the criteria for redesignation?

IV. Why is EPA proposing these actions?

V. What is EPA's analysis of the redesignation request and November 14, 2014, SIP submission?

VI. What is EPA's analysis of Tennessee's proposed NO_X and VOC MVEBs for the Knoxville area?

VII. What is the status of EPA's adequacy determination for the proposed NO_X and VOC MVEBs for the Knoxville area?

VIII. What is the effect of EPA's proposed actions?

IX. Proposed Actions

X. Statutory and Executive Order Reviews

I. What are the actions EPA is proposing to take?

EPA is proposing to take four separate but related actions, one of which involves multiple elements: (1) To approve the base year inventory for the 2008 8-hour ozone NAAQS for the Knoxville Area into the Tennessee SIP; (2) to determine that the Knoxville Area is attaining the 2008 8-hour ozone NAAQS; (3) to approve Tennessee's plan for maintaining the 2008 8-hour ozone NAAQS (maintenance plan), including the associated MVEBs, into the SIP; and (4) to redesignate the Knoxville Area to attainment for the 2008 8-hour ozone NAAQS. EPA is also notifying the public of the status of EPA's adequacy determination for the Knoxville Area MVEBs. These actions are summarized below and described in greater detail throughout this notice of proposed rulemaking.

Based on the 2008 8-hour ozone nonattainment designation for the Knoxville Area, Tennessee was required to develop a nonattainment SIP revision addressing certain CAA requirements. Specifically, pursuant to CAA section 182(a)(3)(B) and section 182(a)(1), the Knoxville Area was required to submit a SIP revision addressing emissions statements and emissions inventory requirements, respectively. EPA approved the emissions statements requirements for the Area into the SIP in a separate action. See 80 FR 11974 (March 5, 2015). Today, EPA is proposing to determine that the base year emissions inventory, as submitted in the State's November 14, 2014, SIP revision, meets the requirements of sections 110 and 182(a)(1) of the CAA and proposing to approve this emissions inventory into the SIP.

EPA is also making the preliminarily determination that the Knoxville Area is attaining the 2008 8-hour ozone NAAQS based on recent air quality data and proposing to approve Tennessee's 2008 ozone NAAQS maintenance plan for the Knoxville Area as meeting the requirements of section 175A of the CAA (such approval being one of the CAA criteria for redesignation to attainment status). The maintenance plan is designed to keep the Knoxville Area in attainment of the 2008 8-hour ozone NAAQS through 2026. Additionally, EPA is proposing to approve the 2011 and 2026 NO_X and VOC MVEBs that are included as part of Tennessee's 2008 ozone NAAQS maintenance plan for the Knoxville Area.

EPA is also notifying the public of the status of EPA's adequacy process for the NO_X and VOC MVEBs for the years 2011 and 2026 for the Knoxville Area. The public comment period for Adequacy began on December 4, 2014, with EPA's posting of the availability of this submittal on EPA's Adequacy Web site (http://www.tn.gov/​environment/​ppo/​docs/​air/​knoxville-redesignation-request-2014.pdf). The Adequacy comment period for these MVEBs closed on January 5, 2015. No comments, adverse or otherwise, were received during EPA's adequacy process for the MVEBs associated with Tennessee's 2008 8-hour ozone maintenance plan. Please see section VII of this proposed rulemaking for further explanation of this process and for more details on the MVEBs.

In summary, today's notice of proposed rulemaking is in response to Tennessee's November 14, 2014, redesignation request and associated SIP submittal that address the specific issues summarized above and the necessary elements described in section 107(d)(3)(E) of the CAA for redesignation of the Knoxville Area to attainment for the 2008 8-hour ozone NAAQS. More detail regarding the rationale for EPA's proposed actions is discussed below.

II. What is the background for EPA's proposed actions?

On March 12, 2008, EPA promulgated a revised 8-hour ozone NAAQS of 0.075 parts per million (ppm). See 73 FR 16436 (March 27, 2008). Under EPA's regulations at 40 CFR part 50, the 2008 8-hour ozone NAAQS is attained when the 3-year average of the annual fourth highest daily maximum 8-hour average ambient air quality ozone concentrations is less than or equal to 0.075 ppm. See 40 CFR 50.15. Ambient air quality monitoring data for the 3-year period must meet a data completeness requirement. The ambient air quality monitoring data completeness requirement is met when the average percent of days with valid ambient monitoring data is greater than 90 percent, and no single year has less than 75 percent data completeness as determined in Appendix I of part 50.

Upon promulgation of a new or revised NAAQS, the CAA requires EPA to designate as nonattainment any area that is violating the NAAQS, based on the three most recent years of ambient air quality data at the conclusion of the designation process. The Knoxville Area was designated nonattainment for the 2008 8-hour ozone NAAQS on May 21, 2012 (effective July 20, 2012) using 2009-2011 ambient air quality data. See 77 FR 30088 (May 21, 2012). At the time of designation, the Knoxville Area was classified as a marginal nonattainment area for the 2008 8-hour ozone NAAQS. In the final implementation rule for the 2008 8-hour ozone NAAQS (SIP Implementation Rule),^[1] EPA established ozone nonattainment area attainment dates based on Table 1 of section 181(a) of the CAA. This established an attainment date three years after the July 20, 2012, effective date for areas classified as marginal areas for the 2008 8-hour ozone nonattainment designations. Therefore, the Knoxville Area's attainment date is July 20, 2015.

III. What are the criteria for redesignation?

The CAA provides the requirements for redesignating a nonattainment area to attainment. Specifically, section 107(d)(3)(E) of the CAA allows for redesignation providing that: (1) The Administrator determines that the area has attained the applicable NAAQS; (2) the Administrator has fully approved the applicable implementation plan for the area under section 110(k); (3) the Administrator determines that the improvement in air quality is due to permanent and enforceable reductions in emissions resulting from implementation of the applicable SIP and applicable federal air pollutant control regulations and other permanent and enforceable reductions; (4) the Administrator has fully approved a maintenance plan for the area as meeting the requirements of section 175A; and (5) the state containing such area has met all requirements applicable to the area for purposes of redesignation under section 110 and part D of the CAA.

On April 16, 1992, EPA provided guidance on redesignation in the General Preamble for the Implementation of title I of the CAA Amendments of 1990 (57 FR 13498), and supplemented this guidance on April 28, 1992 (57 FR 18070). EPA has provided further guidance on processing redesignation requests in the following documents:

1. “Ozone and Carbon Monoxide Design Value Calculations,” Memorandum from Bill Laxton, Director, Technical Support Division, June 18, 1990;

2. “Maintenance Plans for Redesignation of Ozone and Carbon Monoxide Nonattainment Areas,” Memorandum from G.T. Helms, Chief, Ozone/Carbon Monoxide Programs Branch, April 30, 1992;

3. “Contingency Measures for Ozone and Carbon Monoxide (CO) Redesignations,” Memorandum from G.T. Helms, Chief, Ozone/Carbon Monoxide Programs Branch, June 1, 1992;

4. “Procedures for Processing Requests to Redesignate Areas to Attainment,” Memorandum from John Calcagni, Director, Air Quality Management Division, September 4, 1992 (hereafter referred to as the “Calcagni Memorandum”);

5. “State Implementation Plan (SIP) Actions Submitted in Response to Clean Air Act (CAA) Deadlines,” Memorandum from John Calcagni, Director, Air Quality Management Division, October 28, 1992;

6. “Technical Support Documents (TSDs) for Redesignation of Ozone and Carbon Monoxide (CO) Nonattainment Areas,” Memorandum from G.T. Helms, Chief, Ozone/Carbon Monoxide Programs Branch, August 17, 1993;

7. “State Implementation Plan (SIP) Requirements for Areas Submitting Requests for Redesignation to Attainment of the Ozone and Carbon Monoxide (CO) National Ambient Air Quality Standards (NAAQS) On or After November 15, 1992,” Memorandum from Michael H. Shapiro, Acting Assistant Administrator for Air and Radiation, September 17, 1993;

8. “Use of Actual Emissions in Maintenance Demonstrations for Ozone and CO Nonattainment Areas,” Memorandum from D. Kent Berry, Acting Director, Air Quality Management Division, November 30, 1993;

9. “Part D New Source Review (Part D NSR) Requirements for Areas Requesting Redesignation to Attainment,” Memorandum from Mary D. Nichols, Assistant Administrator for Air and Radiation, October 14, 1994; and

10. “Reasonable Further Progress, Attainment Demonstration, and Related Requirements for Ozone Nonattainment Areas Meeting the Ozone National Ambient Air Quality Standard,” Memorandum from John S. Seitz, Director, Office of Air Quality Planning and Standards, May 10, 1995.

IV. Why is EPA proposing these actions?

On November 14, 2014, the State of Tennessee, through TDEC, requested that EPA redesignate the Knoxville Area to attainment for the 2008 8-hour ozone NAAQS. EPA's evaluation indicates that the Knoxville Area has attained the 2008 8-hour ozone NAAQS and that the Knoxville Area meets the requirements for redesignation set forth in section 107(d)(3)(E), including the maintenance plan requirements under section 175A of the CAA and associated MVEBs. Also, based on Tennessee's November 14, 2014, submittal, EPA is also proposing to approve the base year emissions inventory, included in Tennessee's November 14, 2014, submittal, into the SIP. Approval of the base year inventory is a prerequisite to redesignating an ozone nonattainment area to attainment.

V. What is EPA's analysis of the redesignation request and November 14, 2014, sip submission?

As stated above, in accordance with the CAA, EPA proposes in today's action to: (1) Approve the 2008 8-hour ozone base year emissions inventory for the Knoxville Area into the Tennessee SIP; (2) determine that the Knoxville Area is attaining the 2008 8-hour ozone NAAQS; (3) approve the Knoxville Area's 2008 8-hour ozone NAAQS maintenance plan, including the associated sub-area MVEBs, into the Tennessee SIP; and (4) redesignate the Knoxville Area to attainment for the 2008 8-hour ozone NAAQS. Approval of the 2008 8-hour ozone base year inventory is a required prerequisite action before the Area can be redesignated to attainment. The five redesignation criteria provided under CAA section 107(d)(3)(E) are discussed in greater detail for the Area following the discussion below on the Knoxville emissions inventory.

A. Emission Inventory

Section 182(a)(1) of the CAA requires states to submit a comprehensive, accurate, and current inventory of actual emissions from all sources of the relevant pollutant or pollutants in each ozone nonattainment area. The section 182(a)(1) base year inventory is defined in the SIP Requirements Rule as “a comprehensive, accurate, current inventory of actual emissions from sources of VOC and NO_X emitted within the boundaries of the nonattainment area as required by CAA section 182(a)(1).” See 40 CFR 51.1100(bb). The inventory year must be selected consistent with the baseline year for the RFP plan as required by 40 CFR 51.1110(b),^[2] and the inventory must include actual ozone season day emissions as defined in 40 CFR 51.1100(cc) ^[3] and contain data elements consistent with the detail required by 40 CFR part 51, subpart A. See 40 CFR 51.1115(a), (c), (e). In addition, the point source emissions included in the inventory must be reported according to the point source emissions thresholds of the Air Emissions Reporting Requirements (AERR) in 40 CFR part 51, subpart A. 40 CFR 51.1115(d).

Knoxville selected 2011 as the base year for the section 182(a)(1) emissions inventory which is the year corresponding with the first triennial inventory under 40 CFR part 51, subpart A. This base year is one of the three years of ambient data used to determine attainment and therefore represents emissions associated with attainment conditions. The emissions inventory is based on data developed and submitted by TDEC and Knox County Division of Air Quality Management to TDEC to EPA's 2011 National Emissions Inventory (NEI), and it contains data elements consistent with the detail required by 40 CFR part 51, subpart A.^[4]

Knoxville's emissions inventory for its portion of the Area provides 2011 emissions data for NO_X and VOCs for the following general source categories: Stationary point, area, non-road mobile, and on-road mobile. A detailed discussion of the inventory development is located in Attachment A, Emission Inventory, in Tennessee's November 14, 2014, SIP submittal which is provided in the docket for this action. The table below provides a summary of the emissions inventory.

Table 1—2011 Point, Area, Non-Road Mobile, and On-Road Mobile Sources Emissions for the Knoxville Area

[Tons per typical summer day]

County	Point		Area		Non-road mobile		On-road mobile
	NOX	VOC	NOX	VOC	NOX	VOC	NOX	VOC
Anderson (partial)	6.15	0.2	0.93	5.56	0.23	0.31	1.05	0.70
Blount	0.53	3.67	2.38	41.16	1.53	2.15	6.65	4.60
Knox	3.29	1.11	3.26	40.12	6.61	5.02	33.92	14.42
Total Emissions	9.97	4.98	6.57	86.93	8.37	7.47	41.62	19.71

The emissions inventory includes all anthropogenic VOC and NO_X sources for all of Blount and Knox Counties, as well as the portion of Anderson County included in the Area. NO_X and VOC emissions were calculated for a typical summer July day, taking into account the seasonal adjustment factor for summer operations. The inventory contains point source emissions data for facilities located within the Blount and Knox Counties as well as the portion of Anderson County included in the Area based on Geographic Information Systems (GIS) mapping. For Blount and Knox County, the emissions for the entire county are provided. More detail on the inventory emissions for individual sources categories is provided below and in the Attachment A to Tennessee's November 14, 2014, SIP submittal.

Point sources are large, stationary, identifiable sources of emissions that release pollutants into the atmosphere. The inventory contains point source emissions data for facilities located within the Blount and Knox Counties as well as the portion of Anderson County included in the Area based on GIS mapping. Each facility was required to update the previous Emission Database Layout (EDL) file with information for the requested year and return the updated EDL to the TDEC emission inventory mailbox. For this submittal, point source emissions were obtained from EDL for facilities in the nonattainment counties. The point source emissions inventory for Blount and Knox County as well as the portion of Anderson County included in the Area is located in the docket for today's action.

Area sources are small emission stationary sources which, due to their large number, collectively have significant emissions (e.g., dry cleaners, service stations). Emissions for these sources were estimated by multiplying an emission factor by such indicators of collective emissions activity as production, number of employees, or population. These emissions were estimated at the county level. Tennessee developed its inventory using EPA Nonpoint files located on EPA's CHIEF Emission Inventory Web site for the 2011 NEI and subtracted available activity data for area sources that may have a point source contribution to eliminate double counting. Tennessee developed its inventory according to the current EPA emissions inventory guidance for area sources.^[5]

On-road mobile sources include vehicles used on roads for transportation of passengers or freight. Tennessee developed its on-road emissions inventory using EPA's Motor Vehicle Emissions Simulator (MOVES) model for each ozone nonattainment county.^[6] County level on-road modeling was conducted using county-specific vehicle population and other local data. Tennessee developed its inventory according to the current EPA emissions inventory guidance for on-road mobile sources using MOVES version 2014.^[7]

Non-road mobile sources include vehicles, engines, and equipment used for construction, agriculture, recreation, and other purposes that do not use roadways (e.g., lawn mowers, construction equipment, railroad locomotives, and aircraft). Tennessee calculated emissions for most of the non-road mobile sources using EPA's NONROAD2008a model ^[8] and developed its non-road mobile source inventory according to the current EPA emissions inventory guidance for non-road mobile sources.^[9]

For the reasons discussed above, EPA has preliminarily determined that Tennessee's emissions inventory meets the requirements under CAA section 182(a)(1) and the SIP Requirements Rule for the 2008 8-hour ozone NAAQS. Approval of Tennessee's redesignation request and associated maintenance plan is contingent upon EPA's final approval of the base year emission inventory for the 2008 8-hour ozone NAAQS.

B. Redesignation Request and Maintenance Demonstration

The five redesignation criteria provided under CAA section 107(d)(3)(E) are discussed in greater detail for the Knoxville Area in the following paragraphs of this section.

Criteria (1)—The Knoxville Area has Attained the 2008 8-Hour Ozone NAAQS

For redesignating a nonattainment area to attainment, the CAA requires EPA to determine that the area has attained the applicable NAAQS (CAA section 107(d)(3)(E)(i)). For ozone, an area may be considered to be attaining the 2008 8-hour ozone NAAQS if it meets the 2008 8-hour ozone NAAQS, as determined in accordance with 40 CFR 50.15 and Appendix I of part 50, based on three complete, consecutive calendar years of quality-assured air quality monitoring data. To attain the NAAQS, the 3-year average of the fourth-highest daily maximum 8-hour average ozone concentrations measured at each monitor within an area over each year must not exceed 0.075 ppm. Based on the data handling and reporting convention described in 40 CFR part 50, Appendix I, the NAAQS are attained if the design value is 0.075 ppm or below. The data must be collected and quality-assured in accordance with 40 CFR part 58 and recorded in the EPA Air Quality System (AQS). The monitors generally should have remained at the same location for the duration of the monitoring period required for demonstrating attainment.

In this action, EPA is preliminarily determining that the Knoxville Area is attaining the 2008 8-hour ozone NAAQS. EPA reviewed the available ozone monitoring data from monitoring stations in the Knoxville Area for the 2008 8-hour ozone NAAQS for 2011-2013. These data have been quality-assured, are recorded in Aerometric Information Retrieval System (AIRS-AQS), and indicate that the Area is attaining the 2008 8-hour ozone NAAQS. The fourth-highest 8-hour ozone values at each monitor for 2011, 2012, and 2013, and the 3-year averages for 2011-2013 (i.e., design values), are summarized in Table 1, below.

Table 2—Design Value Concentrations for the Knoxville Area

Location	County	Monitor ID	4th Highest values (ppm)			3-Year design values (ppm)
			2011	2012	2013	2011-2013
Freels Bend Study Area	Anderson	470010101-1	0.074	0.073	0.060	0.069
Look Rock GSMNP	Blount	470090101-1	0.083	0.075	0.064	0.074
Cades Cove GSMNP		470090102-1	0.068	0.064	0.059	0.063
9315 Rutledge Pike	Knox	470930021-1	0.071	0.073	0.057	0.067
4625 Mildred Drive		470931020-1	0.072	0.078	0.061	0.070

The 3-year design value for 2011-2013 is 0.074 ppm,^[10] which meets the NAAQS. This data has been certified and quality-assured. In today's action, EPA is proposing to determine that the Area is attaining the 2008 8-hour ozone NAAQS. EPA will not take final action to approve the redesignation if the 3-year design value exceeds the NAAQS after proposal. Preliminary 2014 data indicates that this Area will continue to attain the 2008 8-hour ozone NAAQS.^[11] As discussed in more detail below, the State of Tennessee has committed to continue monitoring in this Area in accordance with 40 CFR part 58.

Criteria (2)—Tennessee has a Fully Approved SIP Under Section 110(k) for the Knoxville Area; and Criteria (5)—Tennessee has met all Applicable Requirements Under Section 110 and Part D of Title I of the CAA

For redesignating a nonattainment area to attainment, the CAA requires EPA to determine that the state has met all applicable requirements under section 110 and part D of title I of the CAA (CAA section 107(d)(3)(E)(v)) and that the state has a fully approved SIP under section 110(k) for the area (CAA section 107(d)(3)(E)(ii)). EPA proposes to find that Tennessee has met all applicable SIP requirements for the Knoxville Area under section 110 of the CAA (general SIP requirements) for purposes of redesignation. Additionally, EPA proposes to find that the Tennessee SIP satisfies the criterion that it meets applicable SIP requirements for purposes of redesignation under part D of title I of the CAA (requirements specific to 2008 8-hour ozone nonattainment areas) in accordance with section 107(d)(3)(E)(v). Further, EPA proposes to determine that the SIP is fully approved with respect to all requirements applicable for purposes of redesignation in accordance with section 107(d)(3)(E)(ii). In making these proposed determinations, EPA ascertained which requirements are applicable to the Area and, if applicable, that they are fully approved under section 110(k). SIPs must be fully approved only with respect to requirements that were applicable prior to submittal of the complete redesignation request.

a. The Knoxville Area Has Met All Applicable Requirements Under Section 110 and Part D of the CAA

General SIP requirements. Section 110(a)(2) of title I of the CAA delineates the general requirements for a SIP, which include enforceable emissions limitations and other control measures, means, or techniques; provisions for the establishment and operation of appropriate devices necessary to collect data on ambient air quality; and programs to enforce the limitations. General SIP elements and requirements are delineated in section 110(a)(2) of title I, part A of the CAA. These requirements include, but are not limited to, the following: submittal of a SIP that has been adopted by the state after reasonable public notice and hearing; provisions for establishment and operation of appropriate procedures needed to monitor ambient air quality; implementation of a source permit program; provisions for the implementation of part C requirements (Prevention of Significant Deterioration (PSD)) and provisions for the implementation of part D requirements (NSR permit programs); provisions for air pollution modeling; and provisions for public and local agency participation in planning and emission control rule development.

Section 110(a)(2)(D) requires that SIPs contain certain measures to prevent sources in a state from significantly contributing to air quality problems in another state. To implement this provision, EPA has required certain states to establish programs to address the interstate transport of air pollutants. The section 110(a)(2)(D) requirements for a state are not linked with a particular nonattainment area's designation and classification in that state. EPA believes that the requirements linked with a particular nonattainment area's designation and classifications are the relevant measures to evaluate in reviewing a redesignation request. The transport SIP submittal requirements, where applicable, continue to apply to a state regardless of the designation of any one particular area in the state. Thus, EPA does not believe that the CAA's interstate transport requirements should be construed to be applicable requirements for purposes of redesignation.

In addition, EPA believes other section 110 elements that are neither connected with nonattainment plan submissions nor linked with an area's attainment status are applicable requirements for purposes of redesignation. The area will still be subject to these requirements after the area is redesignated. The section 110 and part D requirements which are linked with a particular area's designation and classification are the relevant measures to evaluate in reviewing a redesignation request. This approach is consistent with EPA's existing policy on applicability (i.e., for redesignations) of conformity and oxygenated fuels requirements, as well as with section 184 ozone transport requirements. See Reading, Pennsylvania, proposed and final rulemakings (61 FR 53174-53176, October 10, 1996), (62 FR 24826, May 7, 2008); Cleveland-Akron-Loraine, Ohio, final rulemaking (61 FR 20458, May 7, 1996); and Tampa, Florida, final rulemaking at (60 FR 62748, December 7, 1995). See also the discussion on this issue in the Cincinnati, Ohio, redesignation (65 FR 37890, June 19, 2000), and in the Pittsburgh, Pennsylvania, redesignation (66 FR 50399, October 19, 2001).

Title I, Part D, applicable SIP requirements. Section 172(c) of the CAA sets forth the basic requirements of attainment plans for nonattainment areas that are required to submit them pursuant to section 172(b). Subpart 2 of part D, which includes section 182 of the CAA, establishes specific requirements for ozone nonattainment areas depending on the area's nonattainment classification. As provided in Subpart 2, a marginal ozone nonattainment area, such as the Knoxville Area, must submit an emissions inventory that complies with section 172(c)(3), but the specific requirements of section 182(a) apply in lieu of the demonstration of attainment (and contingency measures) required by section 172(c). See 42 U.S.C. 7511a(a). A thorough discussion of the requirements contained in sections 172(c) and 182 can be found in the General Preamble for Implementation of Title I (57 FR 13498).

Section 182(a) Requirements. Section 182(a)(1) requires states to submit a comprehensive, accurate, and current inventory of actual emissions from sources of VOC and NOx emitted within the boundaries of the ozone nonattainment area. Tennessee provided an emissions inventory for the Knoxville Area to EPA in a November 14, 2014 SIP submission. Specifically, Tennessee addressed this requirement by submitting a 2011 base year emissions inventory for the Knoxville Area. EPA is proposing approval of Tennessee's 2011 base year inventory in this action (see Section V.A. above). Tennessee's section 182(a)(1) inventory must be incorporated into the SIP before EPA can take final action to approve the State's redesignation request for the Knoxville Area.

Under section 182(a)(2)(A), states with ozone nonattainment areas that were designated prior to the enactment of the 1990 CAA amendments were required to submit, within six months of classification, all rules and corrections to existing VOC RACT rules that were required under section 172(b)(3) of the CAA (and related guidance) prior to the 1990 CAA amendments. The Knoxville Area is not subject to the section 182(a)(2) RACT “fix up” because it was designated as nonattainment after the enactment of the 1990 CAA amendments.

Section 182(a)(2)(B) requires each state with a marginal ozone nonattainment area that implemented, or was required to implement, an inspection and maintenance (I/M) program prior to the 1990 CAA amendments to submit a SIP revision providing for an I/M program no less stringent than that required prior to the 1990 amendments or already in the SIP at the time of the amendments, whichever is more stringent. The Knoxville Area is not subject to the section 182(a)(2)(B) because it was designated as nonattainment after the enactment of the 1990 CAA amendments and did not have an I/M program in place prior to those amendments.

Regarding the permitting and offset requirements of section 182(a)(2)(C) and section 182(a)(4), Tennessee currently has a fully-approved part D NSR program in place. However, EPA has determined that areas being redesignated need not comply with the requirement that a NSR program be approved prior to redesignation, provided that the area demonstrates maintenance of the NAAQS without part D NSR, because PSD requirements will apply after redesignation. A more detailed rationale for this view is described in a memorandum from Mary Nichols, Assistant Administrator for Air and Radiation, dated October 14, 1994, entitled, “Part D New Source Review Requirements for Areas Requesting Redesignation to Attainment.” Tennessee's PSD program will become applicable in the Knoxville Area upon redesignation to attainment.

Section 182(a)(3) requires states to submit periodic inventories and emissions statements. Section 182(a)(3)(A) requires states to submit a periodic inventory every three years. As discussed below in the section of this notice titled Criteria (4)(e), Verification of Continued Attainment, the State will continue to update its emissions inventory at least once every three years. Under section 182(a)(3)(B), each state with an ozone nonattainment area must submit a SIP revision requiring emissions statements to be submitted to the state by sources within that nonattainment area. EPA approved Tennessee's emissions statements requirement on March 5, 2015 (80 FR 11887).

Section 176 Conformity Requirements: Section 176(c) of the CAA requires states to establish criteria and procedures to ensure that federally supported or funded projects conform to the air quality planning goals in the applicable SIP. The requirement to determine conformity applies to transportation plans, programs and projects that are developed, funded or approved under title 23 of the United States Code (U.S.C.) and the Federal Transit Act (transportation conformity) as well as to all other federally supported or funded projects (general conformity). State transportation conformity SIP revisions must be consistent with federal conformity regulations relating to consultation, enforcement and enforceability that EPA promulgated pursuant to its authority under the CAA.

EPA interprets the conformity SIP requirements ^[12] as not applying for purposes of evaluating a redesignation request under section 107(d) because state conformity rules are still required after redesignation and federal conformity rules apply where state rules have not been approved. See Wall v. EPA, 265 F.3d 426 (6th Cir. 2001) (upholding this interpretation); see also 60 FR 62748 (December 7, 1995) (redesignation of Tampa, Florida). Nonetheless, Tennessee has an approved conformity SIP for the Knoxville Area. See 78 FR 29027 (May 17, 2013). Thus, the Knoxville Area has satisfied all applicable requirements for purposes of redesignation under section 110 and part D of title I of the CAA.

b. The Knoxville Area Has a Fully Approved Applicable SIP Under Section 110(k) of the CAA

EPA has fully approved the applicable Tennessee SIP for the Knoxville Area under section 110(k) of the CAA for all requirements applicable for purposes of redesignation. EPA may rely on prior SIP approvals in approving a redesignation request (see Calcagni Memorandum at p. 3; Southwestern Pennsylvania Growth Alliance v. Browner, 144 F.3d 984, 989-90 (6th Cir. 1998); Wall, 265 F.3d 426) plus any additional measures it may approve in conjunction with a redesignation action (see 68 FR 25426 (May 12, 2003) and citations therein). Tennessee has adopted and submitted, and EPA has approved at various times, provisions addressing the various SIP elements applicable for the ozone NAAQS. See 78 FR 14450 (March 16, 2013).

As indicated above, EPA believes that the section 110 elements that are neither connected with nonattainment plan submissions nor linked to an area's nonattainment status are not applicable requirements for purposes of redesignation. With the exception of the emissions inventory requirement, which is addressed in this action, EPA has approved all part D requirements applicable for purposes of this redesignation.

Criteria (3)—The Air Quality Improvement in the Knoxville Area Is Due to Permanent and Enforceable Reductions in Emissions Resulting From Implementation of the Sip and Applicable Federal Air Pollution Control Regulations and Other Permanent and Enforceable Reductions

For redesignating a nonattainment area to attainment, the CAA requires EPA to determine that the air quality improvement in the area is due to permanent and enforceable reductions in emissions resulting from implementation of the SIP and applicable federal air pollution control regulations and other permanent and enforceable reductions (CAA section 107(d)(3)(E)(iii)). EPA has preliminarily determined that Tennessee has demonstrated that the observed air quality improvement in its portion of the Knoxville Area is due to permanent and enforceable reductions in emissions resulting from federal measures and from state measures adopted into the SIP. EPA does not have any information to suggest that the decrease in ozone concentrations in the Knoxville Area is due to unusually favorable meteorological conditions.

State and Federal measures enacted in recent years have resulted in permanent emission reductions. Most of these emission reductions are enforceable through regulations. A few non-regulatory measures also result in emission reductions. The state and local measures that have been implemented to date and relied upon by Tennessee to demonstrate attainment and/or maintenance in the Knoxville Area include the Statewide Motor Vehicle Anti-Tampering Rule and Stage I Gasoline Vapor Recovery. These measures are approved in the federally-approved SIP and thus are permanent and enforceable. The Federal measures that have been implemented include the following:

Tier 2 Vehicle Standards. Implementation began in 2004 and requires all passenger vehicles in any manufacturer's fleet to meet an average standard of 0.07 grams of NO_X per mile. Additionally, in January 2006 the sulfur content of gasoline was required to be on average 30 ppm which assists in lowering the NO_X emissions.^[13]

Heavy-duty gasoline and diesel highway vehicle standards and Ultra Low-Sulfur Diesel Rule. EPA issued this rule on January 18, 2001 (66 FR 5002). This rule includes standards limiting the sulfur content of diesel fuel, which began to take effect in 2004. A second phase took effect in 2007, which further reduced the highway diesel fuel sulfur content to 15 ppm, leading to additional reductions in combustion NO_X and VOC emissions. This rule is expected to achieve a 95 percent reduction in NO_X emissions from diesel trucks and buses.

Nonroad spark-ignition engines and recreational engines standards. The nonroad spark-ignition and recreational engine standards, effective in July 2003, regulate NO_X, hydrocarbons, and carbon monoxide from groups of previously unregulated nonroad engines. These engine standards apply to large spark-ignition engines (e.g., forklifts and airport ground service equipment), recreational vehicles (e.g., off-highway motorcycles and all-terrain-vehicles), and recreational marine diesel engines sold in the United States and imported after the effective date of these standards. When all of the nonroad spark-ignition and recreational engine standards are fully implemented, an overall 72 percent reduction in hydrocarbons, 80 percent reduction in NO_X, and 56 percent reduction in carbon monoxide emissions are expected by 2020. These controls reduce ambient concentrations of ozone, carbon monoxide, and fine particulate matter.

Mercury and Air Toxics Standards (MATS). On February 16, 2012, EPA promulgated maximum achievable control technology regulations for coal-and oil-fired EGUs, intended to reduce hazardous air pollutants emissions from EGUs. Although the MATS rule is not targeted at NO_X emissions, it is expected to result in additional NO_X reductions due to the retirement of older coal-fired units.

Tennessee Valley Authority (TVA) Consent Decree/Federal Facilities Compliance Agreement. On April 14, 2011, TVA entered into a consent decree with Tennessee, Alabama, Kentucky, and North Carolina to resolve allegations of CAA violations at TVA's coal-fired power plants. The relief obtained in this consent decree was also secured in a Federal Facilities Compliance Agreement (FFCA) between EPA and TVA. The consent decree and FFCA establish system-wide caps on NO_X and SO₂ emissions at TVA's coal-fired facilities, declining to permanent levels of 52,000 tons of NO_X in 2018 and 110,000 tons of SO₂ in 2019, and require TVA to meet specific control requirements.^[14]

NO_XSIP Call. On October 27, 1998 (63 FR 57356), EPA issued the NO_X SIP Call requiring the District of Columbia and 22 states to reduce emissions of NO_X, a precursor to ozone pollution, and providing a mechanism (the NO_X Budget Trading Program) that states could use to achieve those reductions. Affected states were required to comply with Phase I of the SIP Call beginning in 2004 and Phase II beginning in 2007. By the end of 2008, ozone season emissions from sources subject to the NO_X SIP Call dropped by 62 percent from 2000 emissions levels. All NO_X SIP Call states have SIPs that currently satisfy their obligations under the NO_X SIP Call; the NO_X SIP Call reduction requirements are being met; and EPA will continue to enforce the requirements of the NO_X SIP Call. Emission reductions resulting from regulations developed in response to the NO_X SIP Call are therefore permanent and enforceable for the purposes of today's action.

CAIR/CSAPR. CAIR created regional cap-and-trade programs to reduce SO₂ and NO_X emissions in 27 eastern states, including Tennessee. See 70 FR 25162 (May 12, 2005). EPA approved Tennessee's CAIR regulations into the Tennessee SIP on November 25, 2009. See 74 FR 61535. In 2009, the CAIR ozone season NO_X trading program superseded the NO_X Budget Trading Program, although the emission reduction obligations of the NO_X SIP Call were not rescinded. See 40 CFR 51.121(r) and 51.123(aa). In 2008, the United States Court of Appeals for the District of Columbia Circuit (D.C. Circuit) initially vacated CAIR, North Carolina v. EPA, 531 F.3d 896 (D.C. Cir. 2008), but ultimately remanded the rule to EPA without vacatur to preserve the environmental benefits provided by CAIR, North Carolina v. EPA, 550 F.3d 1176, 1178 (D.C. Cir. 2008). On August 8, 2011 (76 FR 48208), acting on the D.C. Circuit's remand, EPA promulgated CSAPR to address interstate transport of emissions and resulting secondary air pollutants and to replace CAIR. CSAPR requires substantial reductions of SO₂ and NO_X emissions from electric generating units (EGUs) in 28 states in the Eastern United States.

Implementation of CSAPR was scheduled to begin on January 1, 2012, when CSAPR's cap-and-trade programs would have superseded the CAIR cap and trade programs. Numerous parties filed petitions for review of CSAPR, and on December 30, 2011, the D.C. Circuit issued an order staying CSAPR pending resolution of the petitions and directing EPA to continue to administer CAIR. EME Homer City Generation, L.P. v. EPA, No. 11-1302 (D.C. Cir. Dec. 30, 2011), Order at 2.

On August 21, 2012, the D.C. Circuit issued its ruling, vacating and remanding CSAPR to EPA and once again ordering continued implementation of CAIR. EME Homer City Generation, L.P. v. EPA, 696 F.3d 7, 38 (D.C. Cir. 2012). The D.C. Circuit subsequently denied EPA's petition for rehearing en banc. EME Homer City Generation, L.P. v. EPA, No. 11-1302, 2013 WL 656247 (D.C. Cir. Jan. 24, 2013), at *1. EPA and other parties then petitioned the Supreme Court for a writ of certiorari, and the Supreme Court granted the petitions on June 24, 2013. EPA v. EME Homer City Generation, L.P., 133 S. Ct. 2857 (2013).

On April 29, 2014, the Supreme Court vacated and reversed the D.C. Circuit Court's decision regarding CSAPR, and remanded that decision to the D.C. Circuit Court to resolve remaining issues in accordance with its ruling. EPA v. EME Homer City Generation, L.P., 134 S. Ct. 1584 (2014). EPA moved to have the stay of CSAPR lifted in light of the Supreme Court decision. EME Homer City Generation, L.P. v. EPA, Case No. 11-1302, Document No. 1499505 (D.C. Cir. filed June 26, 2014). In its motion, EPA asked the D.C. Circuit to toll CSAPR's compliance deadlines by three years so that the Phase 1 emissions budgets apply in 2015 and 2016 (instead of 2012 and 2013), and the Phase 2 emissions budgets apply in 2017 and beyond (instead of 2014 and beyond). On October 23, 2014, the D.C. Circuit granted EPA's motion and lifted the stay of CSAPR which was imposed on December 30, 2011. EME Homer City Generation, L.P. v. EPA, No. 11-1302 (D.C. Cir. Oct. 23, 2014), Order at 3. On December 3, 2014, EPA issued an interim final rule to clarify how EPA will implement CSAPR consistent with the D.C. Circuit Court's order granting EPA's motion requesting lifting the stay and tolling the rule's deadlines. See 79 FR 71663 (December 3, 2014) (interim final rulemaking). Consistent with that rule, EPA began implementing CSAPR on January 1, 2015. EPA expects that the implementation of CSAPR will preserve the reductions achieved by CAIR and result in additional SO₂ and NO_X emission reductions throughout the maintenance period.

As mentioned above, the State measures that have been implemented include the following:

Statewide Motor Vehicle Anti-Tampering Rule. Tennessee promulgated a statewide motor vehicle anti-tampering rule in 2005 to reduce air pollution caused by tampering with a motor vehicle's emissions control system. The rule defines tampering as modifying, removing, or rendering inoperative any air pollution emission control device which results in an increase in emissions beyond established federal motor vehicle standards. EPA approved this rule into the Tennessee SIP on August 26, 2005 (70 FR 50199); therefore it is both state and federally enforceable.

Stage I Gasoline Vapor Recovery. Tennessee promulgated rules for Stage I Gasoline Vapor Recovery for several counties throughout Tennessee, including Anderson, Blount, Jefferson, Knox, Loudon Counties in the Knoxville Area. Gasoline dispensing stations in these counties that were contributing sources on December 29, 2004, were required to comply by March 1, 2006. EPA approved these rules into the Tennessee SIP on August 26, 2005 (70 FR 50199).

Criteria (4)—The Knoxville Area Has a Fully Approved Maintenance Plan Pursuant to Section 175A of the CAA

For redesignating a nonattainment area to attainment, the CAA requires EPA to determine that the area has a fully approved maintenance plan pursuant to section 175A of the CAA (CAA section 107(d)(3)(E)(iv)). In conjunction with its request to redesignate the Knoxville Area to attainment for the 2008 8-hour ozone NAAQS, TDEC submitted a SIP revision to provide for the maintenance of the 2008 8-hour ozone NAAQS for at least 10 years after the effective date of redesignation to attainment. EPA has made the preliminary determination that this maintenance plan meets the requirements for approval under section 175A of the CAA.

a. What is required in a 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 plan must demonstrate continued attainment of the applicable 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 will continue to be maintained for the remainder of the 20-year period following the initial 10-year 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 any future 2008 8-hour ozone violations. The Calcagni Memorandum provides further guidance on the content of a maintenance plan, explaining that a maintenance plan should address five requirements: The attainment emissions inventory, maintenance demonstration, monitoring, verification of continued attainment, and a contingency plan. As is discussed more fully below, EPA proposes to find that Tennessee's maintenance plan includes all the necessary components and is thus proposing to approve it as a revision to the Tennessee SIP.

b. Attainment Emissions Inventory

EPA is proposing to determine that the Knoxville Area has attained the 2008 8-hour ozone NAAQS based on monitoring data for the 3-year period from 2011-2013. Tennessee selected 2011 as the base year (i.e., attainment emissions inventory year) for developing a comprehensive emissions inventory for NO_X and VOC, for which projected emissions could be developed for 2014, 2017, 2020, 2023 and 2026. The attainment inventory identifies a level of emissions in the Area that is sufficient to attain the 2008 8-hour ozone NAAQS. Tennessee began development of the attainment inventory by first generating a baseline emissions inventory for the Knoxville Area.

The attainment year emissions were projected to future years separately using different methods by source categories, including: Point sources; area sources; on-road mobile sources; non-road mobile sources including commercial marine vessels, locomotives and air craft (MLA); and non-road mobile sources excluding MLA. The emissions were projected for 2014, 2017, 2020, 2023 and 2026 using 2011 emissions and growth factors developed from the methodology from SESARM Metro4, Inc. Growth factors were developed using the U.S. Energy Information Administration's 2014 Annual Energy Outlook (AEO2014) energy consumption and production forecasts.

Tennessee's 2011 emissions inventory, prepared by TDEC, was used as a source of base year emissions for Blount and Knox Counties, as well as the part of Anderson County included in the Area. NO_X and VOC emissions were calculated for a typical summer July day, taking in to account the seasonal adjustment factor for summer operations of facilities. Future-year emissions were projected for 2014, 2017, 2020, 2023, and 2026. Growth factors were developed using the methodology in the SESARM Metro4, Inc. document prepared by AMEC Environment & Infrastructure, Inc., titled “Development of the 2018 Projection Point Source Emission Inventory for the SESARM Region,” February 11, 2014. Point source units were categorized as electric generating units (EGU) or non-EGU sources. Data obtained from the U.S. Energy Information Administration on either fuel use projections or industrial output projections were used to develop the growth factors used to generate the emissions inventory.

Nonpoint sources captured in the inventory include stationary sources whose emissions levels of NO_X, SO₂, and particulate matter are each less than 25 tons per year. Emissions from nonpoint sources in 2011 were obtained from NEI2011 ozone season daily emissions for area sources were calculated using the SMOKE temporal profiles as described for non-EGU point sources.

The 2011 NO_X and VOC emissions for the Knoxville Area, as well as the emissions for other years, were developed consistent with EPA guidance and are summarized in Tables 3 through 5 of the following subsection discussing the maintenance demonstration.

c. Maintenance Demonstration

The November 14, 2014, final SIP revision includes a maintenance plan for the Knoxville Area. The maintenance plan:

(i). Shows compliance with and maintenance of the 8-hour ozone standard by providing information to support the demonstration that current and future emissions of NO_X and VOC remain at or below 2011 emissions levels.

(ii). Uses 2011 as the attainment year and includes future emissions inventory projections and national growth factors for 2014, 2017, 2020, 2023, and 2026.

(iii). Identifies an “out year” at least 10 years after the time necessary for EPA to review and approve the maintenance plan. Per 40 CFR part 93, NO_X and VOC MVEBs were established for the last year (2026) of the maintenance plan (see section VI below). Through the interagency consultation process, it was also decided that MVEBs would be adopted for the year 2011.

(iv). Provides actual (2011) and projected emissions inventories, in tons per day (tpd), for the Knoxville Area, as shown in Tables 3 and 4, below.

Table 3—Actual and Projected Annual NO_X Emissions (tpd) for the Knoxville Area

Sector	2011	2014	2017	2020	2023	2026
Point	9.97	10.55	11.05	11.70	12.28	12.90
Area	6.56	6.67	6.53	6.53	6.65	6.72
On-road	41.62	35.13	28.63	22.14	15.65	9.15
Non-road (excluding MLA)	8.37	5.43	4.43	3.78	3.38	3.15
Non-road (MLA)	4.06	3.79	3.70	3.81	4.19	4.92
Total	70.6	61.6	54.3	48.0	42.2	36.8
Note: Emissions are provided for Blount and Knox Counties and a portion of Anderson County MLA—Commercial Marine Vessels, Locomotive, and Aircraft.

Table 4—Actual and Projected Annual VOC Emissions (tpd) for the Knoxville Area

Sector	2011	2014	2017	2020	2023	2026
Point	4.98	5.42	6.09	6.48	7.14	7.75
Area	86.93	84.81	84.61	84.94	85.28	85.64
On-road	19.71	17.17	14.63	12.08	9.54	7.00
Non-road (excluding MLA)	7.47	5.33	4.64	4.26	4.19	4.19
Non-road (MLA)	0.31	0.32	0.36	0.44	0.55	0.74
Total	119.40	113.05	110.33	108.20	106.70	105.32
Note: Emissions are provided for Blount and Knox Counties and a portion of Anderson County MLA—Commercial Marine Vessels, Locomotives, and Aircraft.

In situations where local emissions are the primary contributor to nonattainment, such as the Knoxville Area, if the future projected emissions in the nonattainment area remain at or below the baseline emissions in the nonattainment area, then the ambient air quality standard should not be exceeded in the future. Tennessee has projected emissions as described previously and determined that emissions in the Knoxville Area will remain below those in the attainment year inventory for the duration of the maintenance plan.

As discussed in section VI of this proposed rulemaking, a safety margin is the difference between the attainment level of emissions (from all sources) and the projected level of emissions (from all sources) in the maintenance plan. The attainment level of emissions is the level of emissions during one of the years in which the area met the NAAQS. Tennessee selected 2011 as the attainment emissions inventory year for the Knoxville Area and calculated a safety margin for 2026. The State has decided to allocate a portion of this 2026 safety margin to the 2026 MVEB for the Knoxville Area. Specifically, Tennessee has decided to allocate 8.53 tpd to the 2026 NO_X MVEB and 3.49 tpd to the 2026 VOC MVEB. After allocation of the available safety margin, the remaining safety margin was calculated as 25.30 tpd for NO_X and 10.59 tpd for VOC. The MVEB to be used for transportation conformity proposes is discussed in section VI. This allocation and the resulting available safety margin for the Knoxville Area are discussed further in section VI of this proposed rulemaking.

d. Monitoring Network

There are currently three monitors measuring ozone in the Knoxville Area. The State of Tennessee, through TDEC, has committed to continue operation of the monitors in Knoxville Area in compliance with 40 CFR part 58 and have thus addressed the requirement for monitoring. EPA approved the ozone portion of Tennessee's 2012 annual ambient air monitoring network plan on June 15, 2012.

e. Verification of Continued Attainment

The State of Tennessee, through TDEC, has the legal authority to enforce and implement the requirements of the maintenance plan for the Knoxville Area. This includes the authority to adopt, implement, and enforce any subsequent emissions control contingency 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 updates of the Area's emissions inventory. As discussed above, TDEC will continue to operate the current monitors located in the Knoxville Area. There are no plans to discontinue operation, relocate, or otherwise change the existing ambient monitoring network. Tennessee will continue to update its emissions inventory at least once every three years.

The Consolidated Emissions Reporting Rule (CERR) was promulgated by EPA on June 10, 2002. The CERR was replaced by the Annual Emissions Reporting Requirements (AERR) rule on December 17, 2008. The most recent triennial inventory for Tennessee was compiled for 2011. The larger point sources of air pollution will continue to submit data on their emissions on an annual basis as required by the AERR. Emissions from the rest of the point sources, the nonpoint source portion, and the on-road and nonroad mobile sources continue to be quantified on a three-year cycle. The inventory will be updated and maintained on a three-year cycle. As required by the AERR, the next overall emissions inventory will be compiled for 2014.

f. Contingency Measures in the Maintenance Plan

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

The contingency plan included in Tennessee's SIP revision includes a triggering mechanism to determine when contingency measures are needed and a process of developing and implementing appropriate control measures. The State of Tennessee will use actual ambient monitoring data and emissions inventory data as the indicators to determine whether a trigger has been activated and whether contingency measures should be implemented.

Tennessee has identified a primary trigger (Tier I) that will be activated when any quality-assured/quality controlled 8-hour ozone monitoring reading exceeds 0.075 ppm at an ambient monitoring station located in the Knoxville Area or if the periodic emission inventory updates reveal excessive or unanticipated growth greater than 10 percent in emissions of NO_X or VOC over the attainment or intermediate emissions inventories for the Knoxville Area (as determined by the triennial emission reporting required by AERR). The State of Tennessee, in conjunction with the Knox County Department of Air Quality Management (DAQM), will conduct an evaluation as expeditiously as practicable to determine what additional measures will be necessary to attain or maintain the 8-hour ozone standard. If it is determined that additional emission reductions are necessary, Tennessee and Knox County DAQM, will adopt and implement any required measures in accordance with the schedule and procedure for adoption and implementation of contingency measures.

The ozone trigger concentrations described above apply to each monitor in the maintenance area. TDEC will evaluate a Tier I condition, if it occurs, as expeditiously as practicable to determine the cause(s) of the ambient ozone or emissions inventory increase and to determine if a Tier II condition (see below) is likely to occur.

A secondary trigger (Tier II) is activated when any violation of the 2008 8-hour ozone NAAQS at any of the ambient monitoring stations in the Knoxville Area is recorded, based on quality-assured monitoring data. In the event that a Tier II trigger is activated, Tennessee and Knox County DAQM will conduct a comprehensive study to determine the cause(s) of the ambient ozone increase and will implement any required measures as expeditiously as practicable, taking into consideration the ease of implementation and the technical and economic feasibility of selected measures.

Tennessee and Knox County DAQM will, in the event of: (1) A Tier II trigger condition, or (2) a Tier I condition in which Tennessee has determined that a Tier II condition is likely to occur, conduct a comprehensive study to determine what contingency measure(s) are required for the maintenance of the ozone standard. Since the Knoxville Area may be influenced by emissions from outside the maintenance area, the study will attempt to determine whether the trigger condition is due to local emissions, emissions from elsewhere, or a combination of the previous. Selected emission control measures will be subject to public review and the State will seek public input prior to selecting new emission control measures.

The comprehensive study will be completed and submitted to EPA for review as expeditiously as practical, but no later than nine months after the Tier I or Tier II trigger is activated. When Tennessee and Knox County DAQM determines, through the comprehensive study, what contingency measure(s) are required for the maintenance of the ozone standard, appropriate corrective measures will be adopted and implemented within 18 to 24 months after the Tier I or II trigger occurs. The proposed schedule for these actions include:

• Six months to identify appropriate contingency measures;
• Three to six months to initiate stakeholder process; and
• Nine to twelve months to implement the contingency measures.

Section 175A(d) requires that state maintenance plans shall include a requirement that the state will implement all measures with respect to the control of the air pollutant concerned which were contained in the SIP for the area before redesignation of the area to attainment. Currently all such measures are in effect for the Knoxville Area. Contingency measure(s) will be selected from the following types of measures or from any other measure deemed appropriate and effective at the time the selection is made:

• Implementation of diesel retrofit programs, including incentives for performing retrofits.
• Reasonable Available Control Technology (RACT) for NO_X sources in nonattainment counties.
• Programs or incentives to decrease motor vehicle use, including employer-based programs, additional park and ride services, enhanced transit service and encouragement of flexible work hours/compressed work week/telecommuting.
• Trip reduction ordinances.
• Additional emissions reductions on stationary sources.
• Enhanced stationary source inspection to ensure that emissions control equipment is functioning properly.
• Voluntary fuel programs including incentives for alternative fuels.
• Construction of high-occupancy vehicle (HOV) lanes, or restriction of certain roads or lanes for HOV.
• Programs for new construction and major reconstruction of bicycle and pedestrian facilities, including shared use paths, sidewalks and bicycle lanes.
• Expand Air Quality Action Day activities/Clean Air Partners public education outreach.
• Expansion of E-Government services at State and local level.
• Additional Enforcement or outreach on driver observance of reduce speed limits.
• Land use/transportation policies.
• Promotion of non-motorized transportation.
• Promotion or tree-planting standards that favor trees with low VOC biogenic emissions.
• Promotion if energy saving plans for local government.
• Gas can and lawnmower replacement programs.
• Seasonal open burning ban in nonattainment counties.
• Evaluation of anti-idling rules and/or policy.
• Additional controls in upwind areas, if necessary.

EPA has preliminarily concluded that the maintenance plan adequately addresses the five basic components of a maintenance plan: The attainment emissions inventory, maintenance demonstration, monitoring, verification of continued attainment, and a contingency plan. Therefore, the maintenance plan for the Knoxville Area meets the requirements of section 175A of the CAA and is approvable.

VI. What is EPA's analysis of Tennessee's proposed NO_X and VOC MVEBs for the Knoxville Area?

Under section 176(c) of the CAA, new transportation plans, programs, and projects, such as the construction of new highways, must “conform” to (i.e., be consistent with) the part of the state's air quality plan that addresses pollution from cars and trucks. Conformity to the SIP means that transportation activities will not cause new air quality violations, worsen existing violations, or delay timely attainment of the NAAQS or any interim milestones. If a transportation plan does not conform, most new projects that would expand the capacity of roadways cannot go forward. Regulations at 40 CFR part 93 set forth EPA policy, criteria, and procedures for demonstrating and assuring conformity of such transportation activities to a SIP. The regional emissions analysis is one, but not the only, requirement for implementing transportation conformity. Transportation conformity is a requirement for nonattainment and maintenance areas. Maintenance areas are areas that were previously nonattainment for a particular NAAQS but have since been redesignated to attainment with an approved maintenance plan for that NAAQS.

Under the CAA, states are required to submit, at various times, control strategy SIPs and maintenance plans for nonattainment areas. These control strategy SIPs (including RFP and attainment demonstration requirements) and maintenance plans create MVEBs for criteria pollutants and/or their precursors to address pollution from cars and trucks. Per 40 CFR part 93, a MVEB must be established for the last year of the maintenance plan. A state may adopt MVEBs for other years as well. 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 MVEB serves as a ceiling on emissions from an area's planned transportation system. The MVEB concept is further explained in the preamble to the November 24, 1993, Transportation Conformity Rule (58 FR 62188). The preamble also describes how to establish the MVEB in the SIP and how to revise the MVEB.

After interagency consultation with the transportation partners for the Knoxville Area, Tennessee has developed MVEBs for NO_X and VOC for the Knoxville Area. Tennessee is developing these MVEBs, as required, for the last year of its maintenance plan, 2026. Additionally, Tennessee is establishing MVEBs for the year 2011. The 2011 MVEBs reflect the total on-road emissions for 2011. The 2026 MVEBs reflect the total on-road emissions 2026, plus an allocation from the available NO_X and VOC safety margins. Under 40 CFR 93.101, the term “safety margin” is the difference between the attainment level (from all sources) and the projected level of emissions (from all sources) in the maintenance plan. The safety margin can be allocated to the transportation sector; however, the total emissions must remain below the attainment level. The NO_X and VOC MVEBs and allocation from the safety margin were developed in consultation with the transportation partners and were added to account for uncertainties in population growth, changes in model vehicle miles traveled and new emission factor models. The NO_X and VOC MVEBs for the Knoxville Area are defined in Table 5 below.

Table 5—Knoxville Area NO_X and VOC MVEBs (tpd)

	2011	2026
NOXEmissions:
Base Emissions	41.62	9.15
Safety Margin Allocated to MVEB	n/a	8.53
NOX Conformity MVEBs	41.62	* 17.69
VOC Emissions:
Base Emissions	19.71	7.00
Safety Margin Allocated to MVEB	n/a	3.49
VOC Conformity MVEBs	19.71	10.49
* Due to rounding convention.

As mentioned above, Tennessee has chosen to allocate a portion of the available safety margin to the NO_X and VOC MVEBs for the Knoxville Area. This allocation is 8.53 tpd and 3.49 tpd for NO_X and VOC, respectively. Thus, the remaining safety margins for 2026 are 25.30 tpd and 10.59 tpd NO_X and VOC, respectively.

Through this rulemaking, EPA is proposing to approve the MVEBs for NO_X and VOC for 2011 and 2026 for the Knoxville Area because EPA has preliminarily determined that the Area maintains the 2008 8-hour ozone NAAQS with the emissions at the levels of the budgets. Once the MVEBs for the Knoxville Area are approved or found adequate (whichever is completed first), they must be used for future conformity determinations. After thorough review, EPA has preliminarily determined that the budgets meet the adequacy criteria, as outlined in 40 CFR 93.118(e)(4), and is proposing to approve the budgets because they are consistent with maintenance of the 2008 8-hour ozone NAAQS through 2026.

VII. What is the status of EPA's adequacy determination for the proposed NO_X and VOC MVEBs for the Knoxville Area?

When reviewing submitted “control strategy” SIPs or maintenance plans containing MVEBs, EPA may affirmatively find the MVEB contained therein adequate for use in determining transportation conformity. Once EPA affirmatively finds the submitted MVEB is adequate for transportation conformity purposes, that MVEB 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 MVEB are set out in 40 CFR 93.118(e)(4). The process for determining adequacy consists of three basic steps: Public notification of a SIP submission, a public comment period, and EPA's adequacy determination. This process for determining the adequacy of submitted MVEBs for transportation conformity purposes was initially outlined in EPA's May 14, 1999, guidance, “Conformity Guidance on Implementation of March 2, 1999, Conformity Court Decision.” EPA adopted regulations to codify the adequacy process in the Transportation Conformity Rule Amendments for the “New 8-Hour Ozone and PM_2.5 National Ambient Air Quality Standards and Miscellaneous Revisions for Existing Areas; Transportation Conformity Rule Amendments—Response to Court Decision and Additional Rule Change,” on July 1, 2004 (69 FR 40004). Additional information on the adequacy process for transportation conformity purposes is available in the proposed rule entitled, “Transportation Conformity Rule Amendments: Response to Court Decision and Additional Rule Changes,” 68 FR 38974, 38984 (June 30, 2003).

As discussed earlier, Tennessee's maintenance plan includes NO_X and VOC MVEBs for the Knoxville Area for 2026, the last year of the maintenance plan, and for 2011. EPA reviewed the NO_X and VOC MVEBs through the adequacy process. Tennessee's November 14, 2015, SIP submission, including the Knoxville Area NO_X and VOC MVEBs, was open for public comment on EPA's adequacy Web site on December 4, 2014, found at: http://www.epa.gov/​otaq/​stateresources/​transconf/​currsips.htm#knx-tn. The EPA public comment period on adequacy for the MVEBs for 2011 and 2026 for the Knoxville Area closed on January 5, 2015. No comments, adverse or otherwise, were received during EPA's adequacy process for the MVEBs associated with Tennessee's maintenance plan.

EPA intends to make its determination on the adequacy of the 2011 and 2026 MVEBs for the Knoxville Area for transportation conformity purposes in the near future by completing the adequacy process that was started on December 4, 2014. After EPA finds the 2011 and 2026 MVEBs adequate or approves them, the new MVEBs for NO_X and VOC must be used for future transportation conformity determinations. For required regional emissions analysis years for 2026 and beyond, the applicable budgets will be the new 2026 MVEBs established in the maintenance plan, as defined in section VI of this proposed rulemaking. The 2011 MVEBs will be used for any analysis year prior to 2026.

VIII. What is the effect of EPA's proposed actions?

EPA's proposed actions establish the basis upon which EPA may take final action on the issues being proposed for approval today. Approval of Tennessee's redesignation request would change the legal designation of Blount and Knox Counties and the portion of Anderson County included in the Knoxville Area, found at 40 CFR part 81, from nonattainment to attainment for the 2008 8-hour ozone NAAQS. Approval of Tennessee's associated SIP revision would also incorporate a plan for maintaining the 2008 8-hour ozone NAAQS in the Knoxville Area through 2026 and a section 182(a)(1) base year emissions inventory into the Tennessee SIP. The maintenance plan establishes NO_X and VOC MVEBs for 2011 and 2026 for the Knoxville Area and includes contingency measures to remedy any future violations of the 2008 8-hour ozone NAAQS and procedures for evaluation of potential violations. The NO_X MVEB for 2011 is 41.62 tpd, and for 2026 is 17.69 tpd. The VOC MVEB is 19.71 for 2011 and 10.49 tpd for 2026. Additionally, EPA is notifying the public of the status of EPA's adequacy determination for the newly-established NO_X and VOC MVEBs for 2026 for the Knoxville Area.

IX. Proposed Actions

EPA is now proposing to take four separate but related actions regarding the Knoxville Area's redesignation and maintenance of the 2008 8-hour ozone NAAQS. First, EPA is proposing to approve Tennessee's section 182(a)(1) base year emissions inventory for the 2008 8-hour ozone standard for the Knoxville Area into the SIP. Approval of the base year inventory is a prerequisite for EPA to redesignate the Area from nonattainment to attainment.

Second, EPA is proposing to determine that the Knoxville Area is attaining the 2008 8-hour ozone NAAQS based on complete, quality-assured and certified monitoring data for the 2011-2013 monitoring period. Preliminary 2012-2014 data in AQS indicates that the Area is continuing to attain the 2008 8-hour ozone NAAQS.

Third, EPA is proposing to approve the maintenance plan for the Knoxville Area, including the NO_X and VOC MVEBs for 2011 and 2026, into the Tennessee SIP (under CAA section 175A). The maintenance plan demonstrates that the Area will continue to maintain the 2008 8-hour ozone NAAQS, and the budgets meet all of the adequacy criteria contained in 40 CFR 93.118(e)(4) and (5). Further, as part of today's action, EPA is describing the status of its adequacy determination for the NO_X and VOC MVEBs for 2011 and 2026 in accordance with 40 CFR 93.118(f)(1). Within 24 months from the publication date of EPA's adequacy determination for the MVEBs or the effective date for the final rule for this action, whichever is earlier, the transportation partners will need to demonstrate conformity to the new NO_X and VOC MVEBs pursuant to 40 CFR 93.104(e).

Finally, EPA is proposing to determine that Tennessee has met the criteria under CAA section 107(d)(3)(E) for the Knoxville Area for redesignation from nonattainment to attainment for the 2008 8-hour ozone NAAQS. On this basis, EPA is proposing to approve Tennessee's redesignation request for the 2008 8-hour ozone NAAQS for the Knoxville Area. If finalized, approval of the redesignation request would change the official designation of Blount and Knox Counties and the portion of Anderson County in the Knoxville Area for the 2008 8-hour ozone NAAQS from nonattainment to attainment, as found at 40 CFR part 81.

X. Statutory and Executive Order Reviews

Under the CAA, redesignation of an area to attainment and the accompanying approval of a maintenance plan under section 107(d)(3)(E) are actions that affect the status of a geographical area and do not impose any additional regulatory requirements on sources beyond those imposed by state law. A redesignation to attainment does not in and of itself create any new requirements, but rather results in the applicability of requirements contained in the CAA for areas that have been redesignated to attainment. Moreover, the Administrator is required to approve a SIP submission that complies with the provisions of the Act and applicable Federal regulations. See 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, these proposed actions merely propose to approve state law as meeting federal requirements and do not impose additional requirements beyond those imposed by state law. For that reason, these proposed actions:

• Are not a significant regulatory actions 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);
• do not impose an information collection burden under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.);
• are 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.);
• do 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);
• do not have Federalism implications as specified in Executive Order 13132 (64 FR 43255, August 10, 1999);
• are not economically significant regulatory actions based on health or safety risks subject to Executive Order 13045 (62 FR 19885, April 23, 1997);
• are not a significant regulatory action subject to Executive Order 13211 (66 FR 28355, May 22, 2001);
• are 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
• do 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).

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 rule does not have tribal implications as specified by Executive Order 13175 (65 FR 67249, November 9, 2000), nor will it impose substantial direct costs on tribal governments or preempt tribal law.

List of Subjects

40 CFR Part 52

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

40 CFR Part 81

• Environmental protection
• Air pollution control

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

Dated: May 13, 2015.

Heather McTeer Toney,

Regional Administrator, Region 4.

Footnotes

1.  This rule, entitled Implementation of the 2008 National Ambient Air Quality Standards for Ozone: State Implementation Plan Requirements and published at 80 FR 12264 (March 6, 2015), addresses a range of nonattainment area SIP requirements for the 2008 ozone NAAQS, including requirements pertaining to attainment demonstrations, reasonable further progress (RFP), reasonably available control technology (RACT), reasonably available control measures (RACM), major new source review (NSR), emission inventories, and the timing of SIP submissions and of compliance with emission control measures in the SIP. This rule also addresses the revocation of the 1997 ozone NAAQS and the anti-backsliding requirements that apply when the 1997 ozone NAAQS are revoked.

2.  40 CFR 51.1110(b) states that “at the time of designation for the 2008 ozone NAAQS 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 this part. States may use an alternative baseline emissions inventory provided the state demonstrates why it is appropriate to use the alternative baseline year, and provided that the year selected is between the years 2008 to 2012.”

3.  “Ozone season day emissions” is defined as “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.” See 40 CFR 51.1100(cc).

4.  Data downloaded from the EPA EIS from the 2011 NEI was subjected to quality assurance procedures described under quality assurance details under 2011 NEI Version 1 Documentation located at http://www.epa.gov/​ttn/​chief/​net/​2011inventory.html#inventorydoc. The quality assurance and quality control procedures and measures associated with this data are outlined in the State's EPA-approved Emission Inventory Quality Assurance Project Plan.

5.  This guidance includes: Procedures for the Preparation of Emission Inventories of Carbon Monoxide and Precursors of Ozone, Vol. 1, EPA-450/4-91-016 (May 1991) and Emissions Inventory Improvement Program (EIIP) Technical Report, Vol. 3, Area Sources (Revised January 2001, updated April 2001).

6.  Tennessee used MOVES to Prepare Emission Inventories in State Implementation Plans and Transportation Conformity: Technical Guidance for MOVES2010, 2010a and 2010b, EPA-420-12-028 (April 2012).

7.  This guidance includes: Emissions Inventory Guidance for Implementation of Ozone and Particulate Matter National Ambient Air Quality Standards (NAAQS) and Regional Haze Regulations, EPA-454/R-05-001 (August 2005, updated November 2005); Policy Guidance on the Use of MOVES2010 for State Implementation Plan Development, Transportation Conformity, and Other Purposes, EPA-420-B-09-046 (December 2009); and Technical Guidance on the Use of MOVES2010 for Emission Inventory Preparation in State Implementation Plans and Transportation Conformity, EPA-420-B-10-023 (April 2010).

8.  For consistency with the National Emissions Inventory (NEI), Tennessee included emissions data for locomotive, and aircraft by county. ALM emissions for 2011 were primarily based on EPA's 2011 NEI.

9.  This guidance includes: Procedures for Emission Inventory Preparation, Volume IV: Mobile Sources, EPA-450/4-81-026d (July 1991).

10.  The monitor with the highest 3-year design value is considered the design value for the Area.

11.  Preliminary 2014 data for the Knoxville Area is available at www.epa.gov/​airdata.

12.  CAA section 176(c)(4)(E) requires states to submit revisions to their SIPs to reflect certain federal criteria and procedures for determining transportation conformity. Transportation conformity SIPs are different from the MVEBs that are established in control strategy SIPs and maintenance plans.

13.  Tennessee also identified Tier 3 Motor Vehicle Emissions and Fuel Standards as a federal measure. EPA issued this rule in April 28, 2014 (79 FR 23414), which applies to light duty passengers cars and trucks. EPA promulgated this rule to reduce air pollution from new passenger cars and trucks beginning in 2017. Tier 3 emission standards will lower sulfur content of gasoline and lower the emissions standards.

14.  The Bull Run facility in Anderson County is the only source in the Knoxville Area that is covered by the consent decree/FFCA. While Tennessee notes in its submission that selective catalytic reduction (SCR) was required per the consent decree/FFCA to be operational at unit 1 for Bull Run in 2011, EPA has reviewed data for this unit and it appears that controls were put in place on the Bull Run facility prior to the nonattainment designation for the Knoxville Area for the 2008 8-hour ozone NAAQS. These controls continue to operate. Specifically, according to the data reported to EPA's Clean Air Markets Division, the SCR was installed and began operating on May 12, 2004. It appears that the SCR was only used during the ozone season between 2004 and 2008, and from 2009 to the present, began operating the full year.