ENVIRONMENTAL PROTECTION AGENCY 40 CFR Parts52 and 81 [EPA-R04-0AR-201O-0666-201031; FRL- ] Approval and Promulgation ofImplementation Plans and Designation ofAreas for Air Quality Planning Purposes; Tennessee; Redesignation ofthe Knoxville 8-Hour Ozone Nonattainment Area to Attainment for Ozone

AGENCY: Environmental ProtectionAgency (EPA). ACTION: Proposed Rule. SUMMARY: On July 14,2010, the State ofTennessee, through the Tennessee Department of Environment and Conservation (TDEC), Air Pollution Control Division, submitted a requestto redesignate the Knoxville 8-hour ozonenonattainment area to attainment for the 1997 8-hour NationalAmbient Air Quality Standards (NAAQS); and to approve a State Implementation Plan (SIP) revision containing a maintenance plan for the Knoxville, Tennessee Area. The Knoxville 1997 8-hour ozone nonattainment area is comprised ofAnderson, Blount, Jefferson, Knox, Loudon, and SevierCounties in their entireties, and the portion ofCocke Countythat falls within the boundary ofthe Great SmokyMountains National Park (hereafterreferred to as the "Knoxville Area"). Inthis action, EPA is proposing to approve the July 14,2010, 8-hour ozone redesignation request for the Knoxville Area. Additionally, EPA is proposing to approve the 1997 8-hourozone NAAQS maintenance plan for the Knoxville Area, including the 2007 baseline emission inventory, and the motor vehicle emissionbudgets (MVEBs) for nitrogen oxides (NOx) and volatile organic compounds (VOC) for 2024 for the Knoxville Area. This proposed approval ofTennessee's redesignation request is based onEPA's determination that theKnoxvilleAreahas met the criteria for redesignation to attainment specified in the Clean Air Act (CAA), including the determination that the Knoxville 8-hour ozone nonattainment area has attained the 1997 8-hour ozone NAAQS. In this action, EPA is also describing the status ofits transportation conformity adequacy determination for the new 2024 MVEBs that are contained in the 1997-8-hourozone NAAQS maintenance planfor the Knoxville Area. This action is being taken pursuant to the CAA and its implementing regulations.

DATES: Conunents must bereceived onorbefore [insert date 30 days after date ofpublication in the Federal Registerl.

ADDRESSES: Submityour conunents, identified by Docket illNo. EPA-R04-0AR-2010­ 0666, by one ofthe following methods: 1. www.regulations.gov: Follow the on-line instructions for submitting conunents. 2. E-mail: benjamin.lynorae@epa.gov. 3. Fax: (404) 562-9019. 4. Mail: EPA-R04-0AR-2010-0666, Regulatory Development Section, AirPlanning Branch, Air, Pesticides and Toxies Management Division, U.S. Environmental Protection Agency, Region4,61 Forsyth Street, SW, Atlanta, Georgia 30303-8960. 5. Hand Delivery or Courier: Ms. Lynorae Benjamin, Chief, Regulatory Development Section, AirPlanning Branch, Air, Pesticides and Toxics ManagementDivision, U.S. Environmental Protection Agency, Region4,61 Forsyth Street, SW, At1anta, Georgia 30303-8960. Such deliveries are only accepted during the Regional Office's normal hours ofoperation. The Regional Office's official hours ofbusiness are Monday through 2Friday, 8:30 to 4:30, excluding federal holidays.

Instructions: Direct your comments to Docket illNo. EPA-R04-0AR-2010-0666. 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 beConfidential Business Information (CBI)
orother information whose disclosure is restricted by statute. Do not submit through www.regulations.gov ore-mail, informationthat you consider to be CBI orotherwiseprotected
.

.Thewww.regulations.gov website is an "anonymous access" system, which means EPA will not

know your identity orcontact informationunless you provide it in the body ofyour comment. 

### If you send an e-mail comment directly to EPA without going through www.regulations.gov, your e-mail address will be automatically captured and included as part ofthe commentthat is placed in the public docket and made available onthe Internet. 

### Ifyou submit an electronic comment, EPArecommends that you include your name and other contact information in the body ofyour comment and with any disk or CD-ROM you submit. 

### IfEPAcannot read your comment due to technical difficulties and cannot contact you for clarification, EPA may notbe able to consider your comment. Electronic files should avoid the use ofspecial characters, any form of encryption, and be free ofany defects orviruses. For additional information about EPA's public docket visit the EPADocket Centerhomepage 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., CBIorother information whose disclosure is restricted by statute. Certain other material, such as copyrighted 

### 3material, is not placed on the Internet and will be publicly available only in hard copy fonn. Publicly available docket materials are available either electronically in www.regulations.gov or in hard copy at the Regulatory Development Section, Air Planning Branch, Air, Pesticides and Toxics Management Division, U.S. Environmental Protection Agency,Region4,61 Forsyth

. Street, SW, Atlanta, Georgia 30303-8960. EPA requests that ifat all possible, you contact the

person listed in the 

### FORFURTHERINFORMATION CONTACT section to schedule your inspection. The Regional Office's official hours ofbusiness are Monday through Friday, 8:30 to 4:30, excluding federal holidays.



### FORFURTHERINFORMATION CONTACT: Jane Spann orRoyce Dansby-Sparks ofthe Regulatory Development Section, in the Air Planning Branch, Air, Pesticides and Toxics Management Division, U.S. Environmental ProtectionAgency, Region 4,61 Forsyth Street, SW, Atlanta, Georgia 30303-8960. Ms. Spann maybe reached byphone at (404) 562-9029, orvia electronic mail at spmID.jane@epa.gov. Mr. Dansby-Sparks maybe reached byphone at (404) 562-9187, orviaelectronic mail at dansby-sparks.royce@epa.gov.



### SUPPLEMENTARYINFORMATION: Table ofContents I. WhatProposed Actions is EPATaking? II. Whatis the BackgroundforEPA's Proposed Actions? III. What are the Criteriafor Redesignation? IV. Why is EPAProposingThese Actions? V. Whatis the Effect ofEPA'sProposed Actions? 4

### VI. Whatis EPA'sAnalysis ofthe Request? VII. Whatis EPA's Analysis ofTennessee's ProposedNOx and VOC MVEBs for the Knoxville Area? VIII. Whatis the Status ofEPA's Adequacy Determinationfor the ProposedNOx and VOC MVEBs for 2024 for the Knoxville Area? IX. Whatis EPA's analysis ofthe proposed 2007 base year emissions inventory for the Knoxville Area? X. Proposed Action on the Redesignation Request andMaintenancePlan SIPRevision Including Proposed Approval ofthe 2024 NOx andVOC MVEBs for the Knoxville Area. XI. StatutoryandExecutive OrderReviews

I. WhatProposed Actions is EPATaking? EPA is proposing several related actions, which are summarizedbelow and described in greater detail throughout this notice ofrulemaking: (1) to redesignate the KnoxvilleArea to attainmentforthe 1997 8-hourozoneNAAQS; (2) to approve under section 172(c)(3) the emissions inventory submitted with the maintenanceplan; and (3) to approve, under section 175A ofthe eAA, Knoxville's 1997 8-hour ozone NAAQS maintenanceplan into the Tennessee SIP, including the associated MVEBs. In addition, andrelated to today's actions, EPA is also notifying the public ofthe status ofEPA's adequacy determination for the Knoxville Area MVEBs. First, EPA is proposing to determine that the Knoxville Areahas attained the 1997 8-hour
ozone NAAQS. EPA further proposes to determine that, ifEPA's proposed approval ofthe 2007 5baseline emissions inventory for the Knoxville Area is finalized, the Area has met the requirements for redesignation under section 107(d)(3)(E) ofthe CAA. The Knoxville Area 1997 8-hour ozone area is composed ofAnderson, Blount,Jefferson, Knox, Loudon, and Sevier Counties intheir entireties, and the portion ofCocke County that falls within the boundary ofthe Great SmokyMountains National Park. In this action, EPA is now proposing to approve a request to change the legal designation ofAnderson, Blount, Jefferson, Knox, Loudon, and SevierCounties in their entireties, and the portion ofCocke County that falls within the boundary ofthe Great SmokyMountains National Park in the Knoxville Area from nonattainment to attainment for the 1997 8-hour ozone NAAQS. Second, EPA is proposing to approve underthe CAA, Tennessee's 2007 inventory for the Knoxville Area (under section 172(c)(3)). Tennessee selected 2007 as the attainment emissions inventory year for the Knoxville Area. This attainment inventory identifies the level of emissions in the Area, which is sufficient to attain the 1997 8-hour ozone NAAQS. Third, EPA is proposing to approve Tennessee's 1997 8-hour ozone NAAQS maintenance plan for the Knoxville Area (such approval being one ofthe CAA criteria for redesignation to attainment status). The maintenance plan is designed to help keep the Knoxville Area in attainment ofthe 1997 8-hour ozone NAAQS through 2024. Consistent with the CAA, the maintenance plan that EPA is proposing to approve today also includes 2024 NOx and VOC MVEBs. EPA is proposing to approve (into the Tennessee SIP) the 2024 MVEBs that are included as part ofTennessee's maintenance plan for the 1997 8-hour ozone NAAQS. EPA is also notifying the public ofthe status ofEPA's adequacyprocess for the newlyestablished 2024 NOx and VOC MVEBs for the Knoxville Area. The Adequacy comment periodfor the Knoxville Area 2024 MVEBs began onJune 15,2010, with EPA's posting ofthe 6availability ofthis submittal onEPA's Adequacy website. (http://www.epa.gov/otaq/stateresources/transconf/currsips.htm). The Adequacy comment period for these MVEBs closed onJuly 15,2010. No adverse comments were received during the Adequacy public commentperiod. On September 15,2010,EPA published its adequacy notice for the 2024 MVEB's for the Knoxville Area (75 FR 55977). Please see section VIII of this proposed rulemaking for further explanation ofthis process, and for more details on the MVEBs determination. Today's notice ofproposed rulemaking is in response to Tennessee's July 14,2010, SIP submittal requesting the redesignation ofthe Knoxville 1997 8-hour ozone area, and includes a SIPrevision addressing the specific issues summarized above and the necessary elements for redesignation described in section 107(d)(3)(E) ofthe CAA.



### II. Whatis the BackgroundforEPA'sProposed Actions? The CAA establishes a process for air quality management through the NAAQS. Ozone is a criteriapollutant for which NAAQS are established. OnJuly 18, 1997, EPA promulgated a revised 8-hour ozone NAAQS of0.08 parts per million (ppm). I These NAAQSaremore stringent thanthe previous I-hour ozone NAAQS. UnderEPA regulations found at 40 CFR part 50, the 1997 8-hour ozone NAAQS are attained when the 3-year average ofthe annual fourthhighest daily maximum 8-hour average ambient air quality ozone concentrations is less than or equal to 0.08 ppm (Le., 0.084 ppm when rounding is considered). (See 69 FR 23857 (April 30, 2004) for further information.) Ambient air quality monitoring datafor the 3-yearperiod must meet a data completeness requirement. The ambient air quality monitoring data completeness

7**requireme~t** 

### is met when the percent ofdays with valid ambient monitoring data is greater than 90 percent, on average, and no single year has less than 75 percent data completeness as determined in Appendix Iofpart 50. Specifically, section 2.3 of40 CFR part 50, Appendix I, "Comparisons with the Primary andSecondary Ozone Standards" 

### states: The primary and secondary ozone ambient air quality standards are met at an ambient air quality monitoring site when the 3-year average ofthe annual fourthhighest daily maximum 8-hour average ozone concentration is less than or equal to 0.08 ppm. The number of significant figures in the level of the standard dictates the rounding convention for comparing the computed 3-year average annual fourth-highest daily maximum 8-hour average ozone concentration with the level of the standard. The third decimal place of the computed value is rounded, with values equal to or greater than 5 rounding up. Thus, a computed 3­ year average ozone concentration of 0.085 ppm is the smallest value that is greaterthan 0.08 ppm.

The CAA required EPA to designate as nonattainment any area that was violating the 1997 8-hourozone NAAQS based on the three most recent years ofambient air quality data. The Knoxville Area was initiallydesignated nonattainment for the 1997 8-hourozone NAAQS using 2001-2003 ambient air quality data. The Federal Register document making these designations was published on April 30, 2004 (69 FR 23857). The CAA contains two sets ofprovisions

- subpart 1 and subpart 2 - that address planning and control requirements for ozone nonattainment areas. (Both are found in title I, part

I Ground-level ozone is not emitted directly by sources. Rather, emissions ofNOx and VOC react in the presence of 

### 8D.) Subpart 1 (which EPA refers to as "basic" nonattainment) contains general, less prescriptive, requirements for nonattainment areas for any pollutant

- including ozone- governed by a NAAQS. Subpart 2 (which EPArefers to as "classified" nonattainment) provides more specific requirements for certain ozone nonattainment areas. UnderEPA's Phase I 1997 8-Hour Ozone Implementation Rule (69 FR 23857) (Phase I Rule), published April 30, 2004, an area was classifiedunder subpart 2 based on its 1997 8-hour ozone design value (i.e., the 3-year average ofthe annual fourth-highest daily maximum 8-hour average ozone concentrations), ifit had a 1­ hour design value at or above 0.121 ppm (the lowest I-hour design value in Table 1ofsubpart 2). All other areas were covered under subpart 1, based upon their 8-hour ambient air quality design values. Knox County (which is a part ofthe Knoxville Area) was originally designated as marginal nonattainment for the I-hour ozone NAAQS on November 6, 1991 (56 FR 56694). Knox County was redesignated as attainment for the I-hour ozone NAAQS on September 27, 1993 (58 FR 50271). At that same time, Anderson, Blount, Cocke, Jefferson, Loudon and Sevier Counties in their entireties were designated attainmentlunclassifiable for the I-hour ozone· NAAQS. OnApril 30, 2004, EPA designated the Knoxville Area (ofwhich Knox County is a part) as a "basic" (subpart 1) 8-hour ozone nonattainment area (69 FR 23857, April 30, 2004). When Tennessee submitted its fmal redesignation request on July 14,2010, the Knoxville Area
was classified under subpart 1ofthe CAA, and was obligated to meet only the subpart 1 requirements. EPA promulgated implementationrules for the 1997 8-hour ozone NAAQS. These rules
were published in 2 phases. The Phase I Implementation Rule (69 FR 23951, April 30, 2004)
sunlight to form ground-level ozone. As a result, NOx and

### voe are referred to as precursors ofozone. 

### 9was published at the same time as the ozone designations and addresses such topics as classifications, revocation ofthe I-hourNAAQS, anti-backsliding principles, and timing for emission reductions. The Phase II Rule was published November 29, 2005, (72 FR 31727) and addressed remaining implementation issues not coveredby the Phase 1Rule. Various aspects of EPA's Phase 1Rule were challenged in court. OnDecember22,2006, the U.S. Court of Appeals for the District ofColumbia Circuit (D.C. Circuit Court) vacated EPA'sPhase 1Rule (69 FR 23951, April 30, 2004). South CoastAirQualityManagementDist. (SCAQMD) v. EPA, 472 F.3d 882 (D.C. Cir. 2006). On June 8, 2007, in response to several petitions for rehearing, the D.C. CircuitCourt clarified that the Phase IRule was vacated only with regard to those parts ofthe Rule thathad been successfully challenged. Therefore, the Phase I Rule provisions related to classifications for areas currently classified under subpart 2 of title I, part D ofthe CAA as 1997 8-hour ozone NAAQS nonattainment areas, the 1997 8-hour ozone NAAQS attainment dates and the timing for emissions reductions needed for attainment ofthe 1997 8-hour ozone NAAQS remain effective. The June 8th decision left intact the court's rejection ofEPA's reasons for implementing the 1997 8-hour NAAQS in certain nonattainment areas under subpart 1in lieu ofsubpart 2, i.e., the court's rejection ofthe subpart 1classification. By limiting the vacatur, the court let stand EPA's revocation ofthe I-hourNAAQS and those anti-backsliding provisions of the Phase IRule that had not been successfully challenged. The June 8th decision reaffirmed the December 22, 2006, decision that EPA had improperly failed to retain measures required for 1­ hournonattainment areas under the anti-backsliding provisions ofthe regulations: (1) nonattainment area New Source Review (NSR) requirements based onan area's I-hour nonattainment classification; (2) Section 185 penalty fees for I-hour severe orextreme nonattainment areas; and (3) measures to be implemented pursuantto section 172(c)(9) or 

### 10182(c)(9) ofthe CAA, on the contingency ofan area not making reasonable further progress (RFP) toward attainment ofthe I-hour NAAQS, orfor failure to attain that NAAQS. The June 8th decision clarified that the court's reference to conformityrequirements for anti-backsliding purposes was limited to requiring the continued use ofI-hourMVEBs until 1997 8-hour ozone NAAQS budgets were available for 8-hour ozone conformity determinations, which is already required underEPA's conformityregulations. The court thus clarified that I-hour ozone conformity determinations are notrequired for anti-backsliding purposes. This section sets forth EPA's views onthe potential effect ofthe court's rulings onthis proposed redesignation action. Forthe reasons set forth below, EPA does notbelieve that the court's rulings alter any requirements relevant to this redesignation action so as to preclude redesignation, nor does EPAbelieve the court's ruling prevents EPA from proposing or ultimately finalizing this redesignation. EPA believes that the court's December 22,2006, and June 8, 2007, decisions impose no impediment to moving forward with redesignation ofthe Knoxville Area to attainment. Withrespect to the 1997 8-hour ozone NAAQS, the court's ruling rejected EPA's reasons for classifying areas under subpart 1for the 1997 8-hour ozone NAAQS, and remanded that matterbackto the Agency. In its January 16,2009,proposed rulemaking inresponse to the SCAQMD decision, EPAhas proposed to classify the Knoxville Area under subpart 2 as a moderate area (74 FR 2936). IfEPA finalizes the reclassification ofthe Knoxville Areabefore the July 14, 2010, redesignationrequest is approved, the requirements under subpart 2 will become applicable when they are due. EPAproposed a deadline for submission ofthese requirements ofone year after the effective date ofthe final rulemaking classifying this and other
areas (74 FR 2940-2941). However, EPAbelieves that this does not preclude this redesignation 11from being approved. This beliefis basedupon: (1) EPA's longstanding policy ofevaluating requirements in accordance with the requirements due at the time redesignation request is submitted; and (2) consideration ofthe inequity ofapplying retroactively any requirements that might in the future be applied. First, at the time the redesignation request was submitted, the Knoxville Area was not classified under subpart 2, nor were subpart 2 requirements yet due for this Area. UnderEPA's longstanding interpretation ofsection 107(d)(3)(E) ofthe CAA, to qualify for redesignation, states requesting redesignation to attainment must meet only the relevant SIPrequirements that
came due priorto the submittal ofa complete redesignation request. September4, 1992, Calcagni Memorandum ("Procedures for Processing Requests to Redesignate Areas to Attainment," Memorandum from John Calcagni, Director, Air Quality Management Division). See also the September 17, 1993, Michael Shapiro Memorandum ("State Implementation Plan (SIP) Requirements for Areas SubmittingRequests for Redesignation to Attainment of the Ozone and CarbonMonoxide (CO) National Ambient Air Quality Standards (NAAQS) on or after November 15, 1992," Memorandum from Michael Shapiro, Acting Assistant Administrator for Air and Radiation), and 60 FR 12459, 12465-66 (March 7,1995) (Redesignation ofDetroitAnnArbor, Michigan); 

### Sierra Club v

### EPA, 375 F.3d 537 (7th Cir. 2004) (upholding this interpretation); 68 FR 25418,25424,25427 (May 12,2003) (redesignation ofSt. Louis, Missouri). Moreover, it would be inequitable to retroactively apply any new SIPrequirements that
were not applicable at the time the request was submitted. The D.C. Circuit Courthas recognized the inequity in such retroactive rulemaking (see 

### Sierra Club v. 

### Whitman285 F. 3d 63 (D.C. Cir. 2002)), in which the courtupheld a district court's ruling refusing to make retroactive 12an EPA detennination ofnonattainment that was past the statutory due date. Such a detennination wouldhave resulted in the imposition ofadditional requirements onthe area., The court stated, "[a]lthough EPAfailed to make the nonattainment detennination within the statutory frame, Sierra Club's proposed solution only makes the situation worse. Retroactive reliefwould likely impose large costs onthe states, which would face fmes and suits for not implementing air pollutionprevention plans in 1997, even though they were not onnotice at the time." [d. at 68. Similarlyhere, it would beunfair to penalize the Knoxville Areaby applying to it, for purposes ofredesignation, additional SIP requirements under subpart 2 that were not in effect or yet due at the time it submitted its redesignation request, orthe time that the Knoxville Area attained the NAAQS. With respect to the requirements under the I-hour ozone NAAQS, only the Knox County portion ofthe Knoxville Area was originally designated as a marginal nonattainmentfor the 1­ hour ozone NAAQS in November 6, 1991 (56 FR 56694); the remainder ofthe Knoxville Area
was designated as attainment. Knox Countywas redesignated as attainment for the I-hour ozone NAAQS on September 27, 1993 (58 FR50271). Therefore, Knox County was redesignated to attainment ofthe I-hoUr ozone NAAQS prior to its nonattainment designationfor the 1997 8­ hourozone NAAQS. As a result, Knox County (as part ofthe Knoxville Area) is considered to be a I-hour attainment area subject to a CAA section 175A maintenance plan for the I-hour
ozone NAAQS. The D.C. Circuit Court's decisions do not impact redesignation requests for these types ofareas, except to the extent that the court, in its June 8th decision, clarified that for those areas with I-hour MVEBs in their maintenance plans, anti-backsliding requires that those. I-hourbudgets must be used for 8-hour confonnity detenninations until they are replaced by

131997 8-hourbudgets. To meetthis requirement, conformity determinations in such areas must comply with the applicable requirements ofEPA's conformity regulations at 40 CFR part 93. First, there are no conformityrequirements relevant for evaluating the Knoxville Area redesignation request, such as a transportation conformity SIP.2 Itis EPA's longstandingpolicy that it is reasonable to interpret the conformity SIPrequirements as not applying for purposes of evaluating a redesignation request under section 107(d) because state conformityrules are still required after redesignation and Federal conformityrules apply where state rules have not been approved. See40 CFR 51.390; see also Wall v. EPA, 265 F.3d 426 (6th Cir. 2001) (upholding EPA's interpretation); 60 FR 62748 (Dec. 7, 1995) (redesignation ofTampa, Florida). Tennessee currentlyhas a fully approved I-hourozone transportation conformity SIP, which was approved onMay 16,2003 (68 FR 26492). Second, withregard to the three other anti-backsliding provisions for the I-hour standard thatthe D.C. Circuit Courtfound were notproperlyretained, Knox County, Tennessee is an attainment area subject to a maintenance plan for the I-hour standard, and the NSR requirement
no longer applies to this area because it was redesignated to attainment ofthe I-hour standard. Because Knox County was redesignated as a I-hour attainment area, the contingency measure (pursuant to section 172(c)(9) or 182(c)(9» and fee provision requirements no longer apply to the Knoxville Area. As a result, the decisions in SCAQMD should not alter anyrequirements that would preclude EPA from fmalizing the redesignation ofthe Knoxville Area to attainment for the 1997 8-hour ozone NAAQS.

2 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. Transportationconformity SIPs are different from the motor vehicle emission budgets that are established incontrol strategy SIPs and maintenance plans. 14As was noted earlier, in 2009, the ambient ozone data for the Knoxville Area indicated no further violations ofthe 1997 8-hour ozone NAAQS, using data from the 3-yearperiod of2007­ 2009 to demonstrate attainment. As a result, onJuly 14,2010,Tennessee requested redesignation ofthe Knoxville Area to attainment for the 1997 8-hour ozone NAAQS. The redesignation request included three years ofcomplete, quality-assured ambient air quality data for the ozone seasons (March 1st through October 31 st) of2007-2009, indicating that the 1997 8­ hour ozone NAAQS has been achieved for the entire Knoxville Area. Underthe CAA, nonattainment areas may beredesignated to attainment ifsufficient, complete, quality-assured data is available for the Administrator to determine that the areahas attained the standard and the
area meets the other CAA redesignationrequirements in section 107(d)(3)(E). The 1997 8-hour
ozone design values for the Knoxville Area indicate thatbetween 1999 and 2009, ozone concentrations declined noticeably atboth high and low evaluations. While ozone concentrations are dependent on a variety ofconditions, the likelyreason for the overall downtrend in ozone concentrations in the Knoxville Area is most likely due to the reduction of NOx emissions thathave occurred since 2004.



### III. What are the Criteriafor Redesignation? The CAAprovides the requirements for redesignating a nonattainment area to attainment. Specifically, section 107(d)(3)(E) ofthe CAA allows for redesignation providing that: (1) the Administratordetermines that the areahas attained the applicable NAAQS; (2) the Administrator has fully approved the applicable implementation plan for the area under section 11O(k); (3) the Administratordetermines that the improvement in air quality is due to permanent and enforceable reductions in emissions resulting from implementation ofthe applicable SIP and 15applicable Federal air pollutant control regulations and otherpennanent and enforceable reductions; (4) the Administratorhas fully approved a maiJ)tenance planfor the area as meeting the requirements ofsection 175A; and, (5) the state containing such areahas met all requirements applicable to the area for purposes ofredesignation under section 110 and part D of theCAA. OnApril 16, 1992, EPA provided guidance on redesignation in the General Preamble for the Implementation oftitle I ofthe CAAAmendments of 1990 (57 FR 13498), and supplemented this guidance onApril 28, 1992 (57 FR 18070). EPAhas provided further guidance on processing redesignationrequests in the following documents:

1. "Ozone and Carbon Monoxide DesignValue Calculations," Memorandum from Bill Laxton, Director, Technical SupportDivision, June 18, 1990;

2. "MaintenancePlans for Redesignation ofOzone and CarbonMonoxide Nonattainment Areas," Memorandum from G. T. Helms, Chief, Ozone/Carbon Monoxide Programs Branch, April 30, 1992;

3. "ContingencyMeasures for Ozone and Carbon Monoxide (CO) Redesignations," Memorandum from G. T. Helms, Chief, Ozone/CarbonMonoxide Programs Branch, June 1, 1992;

16

### 4. "Procedures for Processing Requests to Redesignate Areas to Attainment," Memorandum from John Calcagni, Director, Air Quality Management Division, September4, 1992 (hereafterreferred 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 ofOzone and Carbon Monoxide (CO) NonattainmentAreas," Memorandum from G. T. Helms, Chief, Ozone/Carbon Monoxide Programs Branch, August 17, 1993;

7. "State ImplementationPlan (SIP) Requirements for Areas Submitting Requests for Redesignation to Attainment ofthe Ozone and Carbon Monoxide (CO) National Ambient Air Quality Standards (NAAQS) Onor After November 15, 1992," Memorandum from Michael H. Shapiro, Acting AssistantAdministrator for Air and Radiation, September 17, 1993;

8. "Use ofActual Emissions in Maintenance Demonstrations for Ozone and CO NonattainmentAreas," Memorandum from D. Kent Berry, Acting Director, Air Quality Management Division, November 30, 1993;

179. "PartD 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 ofAir Quality Planning and Standards, May 10, 1995.



### IV. Why is EPA ProposingThese Actions? On July 14, 2010, Tennessee, through TDEC, requested redesignation ofthe Knoxville Area to attainment for the 1997 8-hour ozone NAAQS. EPA's evaluation indicates that the Knoxville Areahas attainedthe 1997 8-hour ozone NAAQS and has met the requirements for redesignation set forth in section 107(d)(3)(E), including the maintenance planrequirements under section 175A ofthe CAA. EPA is also proposing to approve the 2007 baseline emission inventory under section 172(c)(3) because Tennessee has used methodology consistent with EPA guidance and implementing regulations to develop this inv€?ntory. EPA is also announcing the status ofits adequacy determination ofthe 2024 NOx and VOC MVEBs which are relevant to the requested redesignation.



### V. Whatis the Effect ofEPA'sProposed Actions? EPA's proposed actions establish the basis upon which EPAmay take fmal action onthe issues beingproposed for approval today. Approval ofTennessee's redesignation request would 18change the legal designation ofthe Anderson, Blount, Jefferson, Knox, Loudon, and Sevier Counties in their entireties, and the portion ofCocke County thatfalls within the boundary ofthe Great Smoky Mountains National Parkfor the 1997 8-hour ozone NAAQS found at 40 CPRpart 81 from nonattainmentto attainment. Approval ofTennessee's request would also incorporate into the Tennessee SIP, a planfor maintaining the 1997 8-hour ozone NAAQS in the Knoxville Area through 2024. This maintenance plan includes contingency measures to remedy future violations ofthe 1997 8-hourozone NAAQS. The maintenance plan also establishes NOx and VOC MVEBs for the Knoxville Area. The NOx and VOC MVEBs for 2024 for the Knoxville Area are 36.32 tons per day (tpd) and 25.19 tpd, respectively. Final action would also approve the Area's emissions inventory under section 172(c)(3). Approval ofTennessee's maintenance plan would also result in approval ofthe NOx and VOC MVEBs. Additionally, EPA is notifying the public ofthe status ofits adequacy determination for the 2024 NOx and VOC MVEBs pursuantto 40 CPR 93. 118(f)(1).



### VI. Whatis EPA's Analysis ofthe Request? EPA is proposing to make the determination that the Knoxville 1997 8-hour ozone nonattainment areahas attained the 1997 8-hour ozone NAAQS, and that all otherredesignation criteria have beenmet for the Knoxville Area. Thebasis for EPA's determinationfor the Area is discussed in greater detail below.



### Criteria (1)

- The KnoxvilleAreahasattainedthe 

### 19978-hourozoneNAAQS. EPA is proposing to determine that the Knoxville Area has attained the 1997 8-hour
ozone NAAQS. For ozone, an area may be considered to be attaining the 1997 8-hour ozone 19NAAQS ifit meets the 1997 8-hour ozone standard, as detennined in accordance with 40 CFR 50.10 and Appendix I ofpart 50, based onthree complete, consecutive calendaryears ofqualityassured air quality monitoring data. To attain these NAAQS, the 3-year average ofthe fourthhighest daily maximum 8-houraverage ozone concentrations measured at each monitor within an
area overeach yearmust not exceed 0.08 ppm. Based on the data handling and reporting convention described in 40 CFRpart 50, Appendix I, the NAAQS are attained ifthe design value is 0.084 ppmorbelow. The data mustbe collected and quality-assured in accordance with 40 CFR part 58, and recorded in the EPAAir Quality System (AQS). The monitors generally should have remained at the same location for the duration ofthe monitoring periodrequired for demonstrating attainment. EPAreviewed ozone monitoring data from ambient ozone monitoring stations in the Knoxville Area for the ozone seasonfrom 2007-2009. These datahave been quality-assured and
are recorded inAQS. The fourth-highest 8-hour ozone average for 2007, 2008 and 2009, and the 3-year average ofthese values (Le., design values), are summarized in the following Table 1of this proposed rulemaking.

Table 1. Design Value Concentrationsfor the Knoxville 8-Hour Ozone Area (ppm) County SiteName MonitorID Eil!ht-HourDesilm Values (oom) 2005-2007 2006-2008 2007-2009 Anderson Freels Bend Study Area 470010101-1 0.080 0.077 0.072
Blount Look Rock, GSMNP 470090101-1 0.086 0.085 0.079 Cades Cove, GSMNP 470090102-1 0.070 0.072 0.069 Jefferson 1188 Lost Creek Road 470890002-1 0.084 0.081 0.076 20Knox 9315 Rutledge Pike 470930021-1 0.081 0.081 0.077 4625 Mildred Drive 470931020-1 0.088 0.088 0.082
Loudon 1703 Roberts Road 47105109-1 0.085 0.082 0.077 Sevier Cove Mountain, GSMNP 47155101-1 0.082 0.082 0.079

As discussed above, the design value for an area is thehighest 3-year average ofthe annual fourth-highest 8-hour ozone value record,ed at any monitor inthe area. Therefore, the mostrecent 3-yeardesign value (2007-2009) for the Knoxville Area is 0.082 ppm, which meets the NAAQS as described above. Current air quality data show thatthe Area continues to attain the NAAQS. Ifthe Area does not continue to attainuntil EPA fmalizes the redesignation, EPA will not go forward with the redesignation. As discussed in more detail below, the State of Tennessee has committedto continue monitoring inthis Area in accordance with 40 CFR part 58. EPAproposes to find that the Knoxville Areahas attained the 1997 8-hourozone NAAQS.



### Criteria (2)

- Tennessee hasa/ullyapprovedSIP undersection 110(k)/ortheKnoxvilleArea and

### Criteria(5)

- Tennessee hasmetallapplicable requirements undersection 110andpart Do/the CAA. Below is a summary ofhow these two criteria were met. EPA proposes to find that Tennessee has met all applicable SIPrequirements for the Knoxville Area under section 110 ofthe CAA (general SIP requirements) for purposes of redesignation. EPA also proposes to find thatthe Tennessee SIP satisfies the criterionthat it 21meet applicable SIP requirements for purposes ofredesignationunderpartD oftitle I ofthe CAA (requirements specific to subpart 1basic 1997 8-hour ozonenonattainment areas) in accordance with section 107(d)(3)(E)(v). 

### In addition, EPA proposes to determine that the SIP is fully approved with respect to all requirements applicable for purposes ofredesignation in accordance with section 107(d)(3)(E)(ii). 

### In making these determinations, EPA ascertained which requirements are applicable to the Area and that ifapplicable, they are fully approved under section 11O(k). SIPs must be fully approved only with respect to applicable requirements.


### a. KnoxvilleAreahas metallapplicable requirements undersection 110 andpart D ofthe CAA. The September4, 1992, Calcagni Memorandum describes EPA's interpretation ofsection 107(d)(3)(E). Under this interpretation, to qualify for redesignation, states requesting redesignation to attainment must meet only therelevant CAA requirements that come due prior to the submittal ofa completeredesignation request. See also Michael Shapiro Memorandum, ("SIP Requirements for Areas Submitting Requests for Redesignation to Attainment ofthe Ozone and Carbon Monoxide NAAQS OnorAfter November 15, 1992," September 17, 1993); 60 FR 12459, 12465-66 (March 7, 1995) (redesignation ofDetroit-Ann Arbor, Michigan). Applicable requirements ofthe CAA that comedue subsequent to the area's submittal ofa complete redesignation request remain applicable until a redesignation is approved, bnt are not required as a prerequisite to redesignation. See section 175A(c) ofthe CAA; Sierra Club, 375 F.3d 537; see also 68 FR 25424, 25427 (May 12, 2003) (redesignation ofSt. Louis, Missouri). General SIP requirements. Section 1l0(a)(2) oftitle I ofthe 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 ofappropriate devices necessaryto collect data on ambient air quality, and programs to enforce the limitations. 22General SIP elements and requirements are delineated in section 11O(a)(2) oftitle I, partA ofthe CAA. These requirements include, but are notlimited to, the following: submittal ofa SIPthat has beenadopted bythe state afterreasonable public notice and hearing; provisions for establishment and operation ofappropriate procedures needed to monitor ambient air quality; implementation ofa source permitprogram; provisions for the implementation ofpart C requirements (Prevention ofSignificantDeterioration (PSD» and provisions for the implementation ofpart D requirements (NSR permitprograms); provisions for air pollution modeling; and provisions for public and local agency participation in planning and emission control rule development. Section 11O(a)(2)(D) requires that SIPs contain certain measures toprevent sources in a state from significantlycontributingto air quality problems in another state. To implementthis provision, EPAhas required certain states to establishprograms to address the transport ofair pollutants (NOxSIPCa1l3 and CleanAir Interstate Rule (CAIR4». The section 11O(a)(2)(D) requirements for a state are not linked with a particular nonattainment area's designation and classification in that state. EPAbelieves that the requirements linked with a particular

3 OnOctober 27, 1998 (63 FR57356), EPA issued a NOx SIPCall requiring the DistrictofColumbia and 22 states to reduce emissionsofNOx in order to reduce the transport ofozone and ozone precursors. Incompliance with EPA's NOx SIP Call, Tennessee developed rules governing the control ofNOx emissions from Electric Generating Units (EGUs), major non-EGU industrial boilers, majorcementkilns, and internalcombustion engines. OnJanuary 22,2004, EPA approved Tennessee's rules as fulfilling Phase I (69FR 3015) and Phase IIonDecember 27, 2005 (70FR76408).

4 OnMay 12,2005 (70FR25162), EPA promulgated CAIR which required 28 upwind States and the District of Columbia to revise their SIPs to include control measures that would reduce emissions ofsulfur dioxide and NOx. Various aspects ofCAIRrule were petitioned in court and onDecember 23, 2008, the U.S. Court ofAppeals for the DistrictofColumbia Circuit remanded CAIRtoEPA (seeNorth Carolina v. EPA, 550F.3d 1176 (D.C. Cir., 2008)) which left CAIR in place to "temporarilypreserve the environmental values covered by CAIR" until EPAreplaces it with a rule consistent with the court's decision. The court directed EPA to remedy various areas ofthe rule that were petitioned consistent with its July 11, 2008, opinion (see, North Carolina v. EPA, 531 F.3d 836 (D.C. Cir., 2008)), but declined to impose a schedule onEPA for completing that action. Id. Therefore, CAIRis currently in effect in Tennessee. 23nonattainment area's designation and classifications are the relevant measures to evaluate in reviewing a redesignation request. The transportSIP submittal requirements, where applicable, continue to apply to a stateregardless ofthe designation ofanyoneparticular area in the state. Thus, we do notbelieve that the CAA's interstate transport requirements shouldbe construed to be applicable requirements for purposes ofredesignation. In addition, EPAbelieves that the other section 110elements not connected with nonattainment plan submissions and not linked with an area's attainment status are not applicable requirements for purposes ofredesignation. 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 policyon applicability (i.e., for redesignations) ofconformity and oxygenated fuels requirements, as well as with section 184 ozonetransport requirements. SeeReading, Pennsylvania, proposed and final rulemakings (61 FR 53174-53176, October 10,1996), (62 FR 24826, May7, 1997); Cleveland-Aleron-Loraine, Ohio, final rulemaking (61 FR 20458, May7, 1996); and Tampa, Florida, fmal rulemaking at (60 FR 62748, December7, 1995). See also the discussion onthis issue in the Cincinnati, Ohio redesignation (65 FR 37890, June 19,2000), and inthe Pittsburgh, Pennsylvaniaredesignation (66 FR 50399, October 19,2001). EPAbelieves that section

# no elements not linked to the area's nonattainment status are not applicable for purposes ofredesignation. Therefore, as was discussed above, for purposes of redesignation, they are not considered applicable requirements. Nonetheless, EPAnotes it has previously approved provisions inthe Tennessee SIP addressing section 110 elements under the I-hour ozone NAAQS (45 FR 53809, August 13, 1980). The Statebelieves that the section 110 24SIP approved for the I-hourozone NAAQS are sufficient to meet the requirements under the 1997 8-hour ozone NAAQS. Tennessee submitted a letter dated December 14,2007, setting· forth its beliefthat the section 110 SIP approved for the I-hourozone NAAQS is also sufficient to meet the requirements under the 1997 8-hourozone NAAQS. EPAhas not yet approved this submission, but such approval is not necessary for purposes ofredesignation. PartD requirements. EPA proposes that ifEPA approves Tennessee's base year emissions inventory, which is part ofthe maintenance plan submittal, the Tennessee SIP will meet applicable SIP requirements under partD ofthe CAA. Webelieve the emissions inventory is approvablebecause the 2007 VOC and NOx emissions for Tennessee were developed consistent with EPA guidance for emission inventories, and the choice ofthe 2007 base year is appropriate because it represents the 2007-2009 period when the 1997 8-hourozone NAAQS
were not violated. PartD, subpart 1 applicable SIP requirements. EPAhas determined that, ifEPA finalizes the approval ofthe base year emissions inventories discussed in section IX. ofthis rulemaking, the Tennessee SIP will meet the applicable SIP requirements for the Knoxville Area applicable for purposes ofredesignationunderpartD ofthe CAA. Subpart 1ofpartD, found in sections 172-176 ofthe CAA, sets for the basic nonattainment requirements applicable to all nonattainment areas. Subpart 2 ofpart D, which includes section 182 ofthe CAA, establishes additional specific requirements depending onthe area's nonattainment classification. Sincethe Knoxville Area was not classified under subpart 2 atthe time the redesignationrequest was submitted, the subpart 2 requirements do not apply for purposes ofevaluating the Tennessee's redesignation request. The applicable subpart 1 requirements are contained in sections

25172(c)(l)-(9) and in section 176. A thorough discussion ofthe requirements contained in section 172 canbe found in the General Preamble for Implementation oftitle I (57 FR 13498). Subpart 1 Section 172 Requirements. 5 Forpurposes ofevaluating this redesignation request, the applicable section 172 SIP requirements for the Knoxville Area are contained in sections 172(c)(l)-(9). A thorough discussion ofthe requirements contained in section 172 can be found in the General Preamble for Implementation ofTitle I (57 FR 13498, April 16, 1992). Section 172(c)(l)requires the plans for all nonattainment areas to provide for the implementation ofall reasonably available control measures (RACM) as expeditiously as practicable and to provide for attainment ofthe national primary ambient air quality standards. EPA interprets this requirement to impose a duty on all nonattainment areas to consider all available control measures and to adopt and implement such measures as are reasonably available for implementation in each area as components ofthe area's attainment demonstration. TheRFPplanrequirement under section 172(c)(2) is defined as progress that must be made toward attainment. This requirement is notrelevant for purposes ofredesignationbecause the Knoxville Areahas monitored attainment ofthe ozone NAAQS. (General Preamble, 57 FR 13564). See also 40 CFR 51.918. In addition, because the Knoxville Area has attained the
ozone NAAQS and is no longer subject to an RFP requirement, the requirement to submit the section 172(c)(9) contingency measures is not applicable for purposes ofredesignation. [d. Section 172(c)(3)requires submission and approval ofa comprehensive, accurate, and current inventory ofactual emissions. As part ofTennessee's redesignation request for the

5 On August 3, 2010, EPA proposed to approve a clean data determination for the Knoxville Area for the 19978­ hour ozone NAAQS (75 FR45568). IfEPA takes final actiononthis determination, under the provisions ofEPA's ozone implementation rule (see 40 CFRSection51.918), the requirements for the State ofTennessee to submit an attainment demonstration and associated reasonably available control measures plan, RFP plan, contingency 26Knoxville Area,Tennessee submitted a 2007 base year emissions inventory. As discussed below in section IX, EPA is proposing to approve the 2007 base year inventory that Tennessee submitted with the redesignation request as meeting the section 172(c)(3) emissions inventory requirement. Section 172(c)(4) requires the identification and quantification ofallowable emissions for majornew and modified stationary sources to be allowed in an area, and section 172(c)(5) requires source permits for the construction and operation ofnew and modified major stationary
sources anywhere in the nonattainment area. EPA has determined that, since PSD requirements will apply afterredesignation, areas beingredesignated need not comply with the requirement that a NSR programbe approved priorto redesignation, provided that the area demonstrates maintenance ofthe NAAQSwithout part D NSR. A more detailed rationale for this view is described in a memorandum from Mary Nichols, Assistant Administratorfor Air and Radiation, dated October 14, 1994, entitled, "PartD New Source Review Requirements for Areas Requesting Redesignationto Attainment. " Tennessee has demonstrated that the Knoxville Area will be able to maintain the NAAQS without part D NSR in effect; therefore, EPA concludes that Tennesseeneed nothave fully approved part D NSR programs prior to approval ofthe redesignationrequest. Tennessee's PSD programs will become effective in the Knoxville Area upon redesignation to attainment. See rulemakings for Detroit, Michigan (60 FR 12467-12468, March 7, 1995); Cleveland-Akron-Lorain, Ohio (61 FR 20458, 20469-20470, May 7, 1996); Louisville, Kentucky (66 FR 53665, October 23,2001); and Grand Rapids, Michigan (61 FR 31834-31837,June 21, 1996).

measures. and any other planning SIPs related to attainment ofthe 1997 8-hour ozone NAAQS for the Knoxville Area, shall be suspended for as long as the Area continues to meet the 1997 8-hourozone NAAQS. 27Section 172(c)(6) requires the SIP to contain control measures necessary to provide for attainment ofthe NAAQS. Because attainmenthas beenreached, no additional measures are needed to provide for attainment. Section 172(c)(7) requires the SIP to meet the applicable provisions ofsection 11O(a)(2). As noted above, we believe the Tennessee SIP meets the requirements ofsection 11O(a)(2) applicable for purposes ofredesignation. Section 176 ConformityRequirements. Section 176(c) ofthe CAA requires states to establish criteria and procedures to ensure that federally-supported orfunded projects conform to the air quality planning goals in the applicable SIP. Therequirement to determine conformity. applies to transportation plans, programs and projects developed, funded or approved under title 23 oftheUnited States Code (U.S.C.) and the Federal Transit Act (transportation conformity) as well as to all otherfederally-supported or funded projects (general conformity). State transportation conformity SIPrevisions mustbe consistent with federal conformityregulations relating to consultation, enforcement and enforceabilitythat EPA promulgated pursuant to its authority under the CAA. EPAbelieves it is reasonable to interpret the conformity SIP requirements6 as not applying for purposes ofevaluating the redesignation requestunder 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, 265 F.3d 426 (upholding this interpretation); see also 60 FR 62748 (December 7, 1995, Tampa, Florida). Tennessee submitted its transportation

6 eAA section l76(c)(4)(E) requires states to submitrevisions to their SIPs to reflect certain federal criteria and procedures for determining transportationconformity. Transportation conformity SIPs are different from the motor vehicle emission budgets that are established in control strategy SIPs and maintenance plans. 28conformity SIP for I-hourozone on March 19,2002. EPA issued a direct final rule approving Tennessee's Transportation Conformity SIP on May 16,2003 (68 FR 26492). 

### NSR Requirements. EPAhas also determined that areas being redesignated need not comply with the requirement that a NSR programbe approved priorto redesignation, provided that the area demonstrates maintenance ofthe NAAQS without a part D NSR program in effect since PSD requirements will apply afterredesignation. The rationale for this view is described in
a memorandum from Mary Nichols, Assistant Administratorfor Air and Radiation, dated October 14, 1994, entitled "Part D New Source Review (Part D NSR) Requirements for Areas Requesting Redesignationto Attainment." Tennessee has demonstrated that the Knoxville Area will be able to maintain the NAAQS without a part D NSR program in effect, and therefore, Tennessee need not have a fully-approved part D NSR program priorto approval ofthe redesignation request. However, Tennessee currently has a fully-approved part D NSR program in place. Tennessee's PSD program will become effective in the Knoxville Area upon redesignationto attainment. Seerulemakings for Detroit, Michigan (60 FR 12467-12468, March 7, 1995); Cleveland-Akron-Lorraine, Ohio (61 FR 20458, 20469-70, May 7, 1996); Louisville, Kentucky (66 FR 53665, October 23, 2001); and Grand Rapids; Michigan (61 FR 31834-31837, June 21, 1996). Thus, the Knoxville Area has satisfied all applicable requirements for purposes ofredesignation under section 110 and partD ofthe CAA.



### b. The KnoxvilleArea has a fully

### approvedapplicable SIP undersection 110(k) ofthe eAA. IfEPA issues a final approval ofthe base year emissions inventories, EPA will have fully approved the applicable Tennessee SIP for the Knoxville 8-hour ozone nonattainment area, under section 11O(k) ofthe CAAfor all requirements applicable for purposes ofredesignation. 29EPA mayrely on prior SIP approvals in approving a redesignation request, see Calcagni Memorandum at p. 3; Southwestern Pennsylvania GrowthAlliance v. Browner, 144 F.3d 984, 989-90 (6th Cir. 1998); 

### Wall, 265 F.3d426, plus any additional measures it may approve in conjunction with aredesignation action. See 68 FR 25426 (May 12, 2003) and citations therein. Following passage ofthe CAAof 1970, Tennessee has adopted and submitted, and EPAhas fully approved at various times, provisions addressing the various I-hour ozone NAAQS SIP elements applicable in Knox County, Tennessee (58 FR 50271, September 27, 1993; and 69 FR 4852, February 2, 2004). As indicated above, EPAbelieves that the section 110 elements not connected with nonattainmentplan submissions and not linked to the area's nonattainment status are not applicable requirements for purposes ofredesignation. EPA also believes that since the part D subpart 1requirements did not become due priorto submission ofthe redesignation request, they also are therefore not applicable requirements for purposes ofredesignation. Sierra Club v. EPA, 375 F.3d 537 (7th Cir. 2004); 68 FR 25424, 25427 (May 12,2003) (redesignation ofthe St. Louis-East St. Louis Area to attainment ofthe I-hour ozone NAAQS). With the approval ofthe emissions inventory, EPA will have approved all Part D subpart 1requirements applicable for purposes ofredesignation.



### Criteria (3)

- 

### The airquality improvement in the KnoxvilleArea 1997

### 8-Hour OzoneNAAQS NonattainmentAreaisdue topermanentandenforceable reductions in emissionsresulting from implementation of theSIPandapplicable federal airpollution control regulationsand otherpermanentandenforceable reductions.

30EPA believes that Tennessee has demonstrated that the observed air quality improvement in the KnoxvilleArea is due to permanent and enforceable reductions in emissions resulting from implementation ofthe SIP, federal measures, and other state adopted measures. Additionally,
new emissions control programs for fuels and motor vehicles will help ensure a continued decrease in emissions throughout the region. Measured reductions in ozone concentrations in and around the Knoxville Area are largely attributable to reductions from emission sources ofVOC and NOx, which are precursors in the formation ofozone. Table 2 summarizes several ofthe measures adopted that contributed to reductions ofemissions. The majority ofthese reductions have beenrealized from federal
measures related to mobile sources and electrical power generation.
Table 2. Federal and State Measures Contributing to Emissions Reductions Federal Measures: NOx BudgetTrading Program NOx SIP call National Low Emission Vehicles Tier 2 Vehicle Standards Tier 1, Tier 2 and Tier 3 (non-road) Sources-Spark Ignition Engines (non-road) State and Local Measures: Stage I VaporRecovery Motor Vehicle Anti-tampering Rule Air Quality AlertPrograms SmartTrips Pro,gram
Onekeyprogram, the NOx SIP, required states to make significant, specific emissions reductions (63 FR 57356). It also provided a mechanism, the NOx Budget TradingProgram, which states could use to achieve those reductions. WhenEPApromulgated CAIR, it discontinued (starting in 2009) the NOx BudgetTrading Program, 40 CPR 51.121(r), but created 31another mechanism

- the CAIR ozone season trading program- which states could use to meet their SIP Call obligations, 70 FR 25289-90. All NOx SIP Call states have SIPs that currently satisfy their obligations under the SIP Call, the SIP Call reduction requirements are being met, and EPA will continue to enforce the requirements ofthe NOx SIP Call even after any response to the CAIR remand. Notably, the anti-backsliding provisions of40 CFR 51.905(f) specifically provide that the provisions ofthe NOx SIP Call, including the statewide NOx emissionbudgets, continue to apply after revocation ofthe I-hour standard. Regarding point source emissions, the Tennessee Valley Authority's (TVA's) Bull Run SteamPlant located in Anderson County and Kingston SteamPlant located in Roane County include a total of 10 coal-fired boiiers. As a result ofEPA's "Finding ofSignificant Contribution and Rulemaking for Certain States in the OzoneTransportAssessment Group Region for Purposes ofReducing Region Transport ofOzone" (NOx SIP Call), TVA began operation of selective catalytic reduction (SCR) systems in 2004 at Bull Run's unit and oneight ofthe nine units at Kingston. TVA began operation ofa SCR for the ninth unit at Kingston in 2006. There
was an 85 percent and 90 percent reduction in NOx emissions from the Bull Run and Kingston facilities, respectively from 2003 to 2008 as a result ofthese controls. Furthermore, NOx emissions from all categories are projected to decrease in the Knoxville Area by 56.1 tpd between 2007 and 2024 (41.5 percentreduction). Total point source NOx emissions are projected to increase slightly (2.42 tpd), while EGU NOx emissions are projected to remain unchanged between 2007 and 2024. Forthese reasons, EPA believes that regardless ofthe status ofthe CAIR program, the NOx SIP call requirements canberelied upon in demonstrating maintenance. Here, Tennessee has demonstrated maintenance based in part onthose requirements. 32In addition, EPA undertook an analysis ofthe changes in NOx expected across a broader region. Inparticular, EPA reviewed available projections ofNOx emissions from nearby states from 2002 to 2018. Table3. 2002 Base AnnualEmission Inventory Summaryfor NOx

# * (tons peryear) States EGU Point Non-EGU Point NonRoad Area Mobile Fires Total AR 24,722 47,698 62,472 21,700 141,894 5,492 303,978 

## KY 201,928 38,434 104,571 39,507 156,417 534 541,391 LA 111,703 199,218 114,711 93,069 180,664 6,942 706,307 

### MS 40,433 61,533 88,787 4,200 111,914 308 307,175 MO 145,438 36,144 99,306 32,435 189,852 2,442 505,617 TN 152,137 64,344 96,827 17,844 238,577 217 569,946 Total 676,361 447,371 566,674 208,755 1,019,318 15,935 2,934,414

33Table4. 2018 BaseAnnualEmission Inventory Summary for NOx* (tons peryear) States EGU Point Non-EGU Point NonRoad Area Mobile Fires Total AR 34,938 36,169 34,305 25,672 33,640 5,600 170,324 

### KY 64,378 41,034 79,392 44,346 52,263 714 282,127 LA 44,485 225,748 106,685 114,374 44,806 6,969 543,067 

### MS 21,535 61,252 68,252 4,483 30,619 1,073 187,214 MO 83,181 51,489 59,625 35,213 50,861 2,442 282,811 TN 31,715 62,519 70,226 19,597 69,385 405 253,847 Total 280,232 478,211 418,485 243,685 281,574 17,203 1,708,390 *Fromthe Tennessee Regional Haze SIP, Appendix D, page D.3-5 and support table for Technical SupportDocumentfor CENRAPEmissions and Air Quality Modeling to SupportRegional Haze StateImplementationPlans, page 2-40, figure 2-4
From 2002 to 2018 NOx emissions are projected to decrease inthe region by 1,215,024 tpy or41.4 percent in all. EGU NOx anticipated decreases due to CAIR and the NOx SIP Call
are projected to be 198,150 tpy. However the largest source in this region remains the motor vehicle sector, which is projected to decrease 737,744 tpy. Even without EGU controls onNOx emissions, total NOx emissions are projected to continuallydecrease throughout the maintenance period. OnIuly6,2010,EPA proposed the TransportRule, which will require significant reductions in sulfur dioxide and NOx emissions that cross state boundaries. This proposed rule will potentially form the basis for a final rule which replaces EPA's 2005 CAIR (North Carolina
v. EPA, 550 F.3d 1176 (D.C. Cir., 2008». These regional projections ofemissions datahave beenprepared through 2018. However, since motor vehicle and non-road emissions continue to decrease long after a rule is adopted as the engine population is graduallyreplaced bynewer engines, it is reasonable to expect that this projected decrease in regional NOx emissions from mobile and non-road sources 34should continue through 2024 and assure that ozone in the Knoxville Area will continue to decline throughout the lO-year maintenance period. Hence, we believe the projected regional NOx reductions are adequate to assure that the Knoxville Area will continue demonstrating maintenance throughout the 10-year maintenance period.



### Criteria (4)· The KnoxvilleAreahasafully approvedmaintenanceplanpursuantto section 175A of the 

## eAA. Inconjunction with its request to redesignate the Knoxville Area to attainment for the 1997 8-hourozone NAAQS, TDEC submitted a SIPrevision to provide for the maintenance of the 1997 8-hour ozone NAAQS for at least 10 years after the effective date ofredesignation to attainment.

a. What is required in a maintenanceplan? Section 175A ofthe CAA sets forth the elements ofa maintenance plan for areas seeking redesignation from nonattainment to attainment. Under section 175A, the plan must demonstrate continued attainment ofthe applicable NAAQS for at least 10 years afterthe Administrator approves a redesignation to attainment. Eight years after the redesignation, the State of Tennessee must submit a revised maintenance plan, which demonstrates that attainment will continue to be maintained for the 10 years following the initial lO-year period. To address the possibilityoffuture NAAQS violations, the maintenance plan must contain such contingency measures, with a schedule for implementation as EPAdeems necessary to assure prompt correction ofany future 1997 8-hour ozone violations. Section 175A ofthe CAA sets forth the elements ofa maintenance plan for areas seekingredesignation from nonattainment to 35attainment. The Calcagni Memorandumprovides additional guidance on the content ofa maintenance plan. The Calcagni Memorandum explains that an ozone maintenance plan should address five requirements: the attainment emissions inventory, maintenance demonstration, monitoring, verification ofcontinued attainment, and a contingencyplan. As is discussed more fully below, Tennessee's maintenance plan includes all the necessary components and is approvable as part ofthe redesignation request.

b. AttainmentEmissions Inventory The Knoxville Area attained the 1997 8-hour NAAQS with monitoring data from 2007, 2008, and 2009, therefore Tennessee selected 2007 as the attainment emission inventory year. The attainment inventory identifies the level ofemissions in the Area, which is sufficient to attain the 1997 8-hour ozone NAAQS. Tennesseebegan development ofthe attainment inventory byfirst developing abaseline emissions inventory for the Knoxville Area. The year 2007 was chosen as the base year for developing a comprehensive ozone precursor emissions inventory for which projected emissions couldbe developed for 2010,2013,2016,2020, and 2024. The projected inventory estimates emissions forward to 2024, which is beyond the 10­ year interval required in section 175(A) ofthe CAA. Non-road mobile emissions estimates were based onEPA's NONROAD2008 model. On-road mobile source emissions were calculated using EPA'sMOBILE6.2 emission factors model. The 2007 VOC and NOx emissions, as well
as the emissions for other years, for the KnoxvilleArea were developed consistent with EPA guidance, and are summarized in Tables 5 and 6 in the following subsection.

c. Maintenance Demonstration 36The July 14, 2010, final submittal includes a maintenance planfor the Knoxville Area. This demonstration: (i) Shows compliance and maintenance ofthe 1997 8-hour ozone NAAQS by providing informationto support the demonstration that current and future emissions ofVOC and NOx remain at orbelow attainment inventory year 2007 emissions levels. The year 2007
was chosen as the attainment inventory yearbecause it is one ofthe mostrecent three years (i.e., 2007, 2008, and 2009) for which the Knoxville Areahas clean air quality data for the 1997 8-hour ozone NAAQS. (ii) Uses 2007 as the attainment inventory year and includes future emission inventory projections for 2010,2013,2016,2020, and 2024. (iii) Identifies an "outyear," at least 10 years (and beyond) after the time necessary for EPAto review and approve the maintenance plan. Per40 CFRpart 93, NOx and VOC MVEBs were established for the last year (2024) ofthe maintenance plan. (iv) Provides the following actual and projected emissions inventories, in tpd for the Knoxville Area. See Tables 5 and 6.
Table 5. Knoxville AreaVOCEmissions (Summer season in tpd) SummaryofVOCEmissions (tDd) Year Point Area Onroad Nonroad (excluding

MLA) Nonroad (MLA) Total Safety Margin Change from 2007 2007 7.32 33.25 36.77 34.26 0.68 112.28 2010 7.17 34.21 33.53 31.05 0.62 106.58 5.70 -5.1% 2013 7.37 35.23 30.29 26.47 0.52 99.88 12.40 -11.0% 2016 7.88 36.64 27.05 22.07 0.44 94.08 18.20 -16.2% 2020 8.64 38.40 22.72 18.04 0.35 88.15 24.13 -21.5% 2024 9.53 40.24 18.39 16.62 0.33 85.11 27.17 -24.2% Note: Emissions are for Anderson, Blount, Jefferson, Knox, Loudon, Sevierand onroad emissions for Cocke County. MLA =Commercial Marine Vessels, Locomotives and Aircraft. 37

### Table 6. Knoxville AreaNOx Emissions (Summer season tpd) Summan ofNOx 

### Emissions (tpd) Year Point Area Onroad Nonroad (excluding MLA) Nonroad (MLA) Total Safety Margin Change from 2007 2007 42.69 2.07 71.83 13.16 5.44 135.19 2010 42.65 2.15 63.10 12.17 5.03 125.10 10.09 -7.5% 2013 42.94 2.29 54.36 10.51 4.34 114.44 20.75 -15.3% 2016 43.56 2.50 45.62 8.74 3.61 104.03 31.18 -23.0% 2020 44.30 2.60 33.96 7.21 2.98 91.05 44.14 -32.7% 2024 45.11 2.68 22.29 6.37 2.63 79.08 56.11 -41.5% Note: Emissions are for Anderson. Blount, Jefferson, Knox, Loudon, Sevier and onroademissions for Cocke County. MLA =Commercial Marine Vessels, Locomotives and Aircraft.
A safety margin is the difference betweenthe attainment level ofemissions (from all sources) and the projected level ofemissions (from all sources) in the maintenance plan. The attainment level ofemissions is the level ofemissions during one ofthe years in which the area met the NAAQS. Tennessee has decided to allocate a portion ofthe available safety margin to the Area's VOC and NOx MVEBs for 2024 for the Knoxville Area andhas calculated the safety margin in its submittal. Specifically, 14.03 tpd ofthe available NOx safety margin is allocated to the 2024 MVEB, the remaining safety margin for NOx for 2024 is 42.08 tpd. Also, 6.8 tpd of the available VOC safety margin is allocated to the 2024 MVEB, the remaining safety margin for VOC for 2024 is 20.37 tpd. See Tables 5 and 6, above. This allocation and the resulting available safetymargin for the Knoxville Area are discussed further in section VII ofthis proposed rulemaking. 

### d. Monitoring Network

38There are currentlynine monitors measuring ozone inthe Knoxville Area (see Table 1).7 TDEC and the Knox County Department ofAir Quality Management (DAQM) have committed, in the maintenance plan, to continue operation ofmonitors in the Knoxville Area in compliance with 40 CPRpart 58, and have addressed the requirement for monitoring.

e. Verification ofContinuedAttainment The State ofTennessee, through TDEC, and the Knox County DAQM have the legal authority to enforce and implementthe requirements ofthe Knoxville Area 1997 8-Hour Ozone Maintenance plan. 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. Both agencies will track the progress ofthe maintenance planby performing future reviews oftriennial emission inventories for the Knoxville Area using the latest emissions factors, models and methodologies. Forthese periodic inventories, TDEC and Knox County DAQM will review the assumptions made for the purpose ofthe maintenance demonstration concerning projected growth ofactivity levels. Ifany ofthese assumptions appear to have changed substantially, the Knoxville Area will re-project emissions.


### J. Contingency Plan. The contingency planprovisions are designed to promptly correct a violation ofthe NAAQS that occurs after redesignation. Section 175A ofthe CAA requires that a maintenance

7 Ofthe nine air quality ozone monitors in the Knoxville Area. the Clingman's Dome ozone monitoring site in SevierCounty does not meet siting criteria listing in 40CFR58. and thus is not appropriate to be used for the determination ofattainment ornonattainment for the ozone NAAQS. 39plan include such contingency measures as EPA deems necessary to assure that the state will promptly correct a violation ofthe 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 tobe 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 ofthe pollutant that were contained in the SIPbefore redesignation ofthe area to attainment in accordance with section 175A(d). Inthe July 14,2010, submittal, Tennessee affirms that all programs instituted by the State and EPA will remain enforceable, and that sources are prohibited from reducing emissions controls following the redesignation ofthe Area. The contingency plan included in the submittal includes a triggering mechanism to determine when contingency measures are needed and a process ofdeveloping and implementing appropriate control measures. The primary trigger will be a quality assured/quality controlled (QNQC) violating design value ofthe 1997 8-hour ozone NAAQS. Inaddition to the primary trigger indicated above, Tennessee and the Knox County DAQM will monitor regional emissions through the ConsolidatedEmissions Reporting Rule (CERR). Ifthe CERR results indicate that the projected emissions in this maintenance plan are significantly less than the CERR reveals (greater than ten percent), TDEC and Knox County DAQM will investigate the differences and develop an appropriate strategy for addressing the differences. In addition, ifambient monitoring data indicates that a violation ofthe three-year design value may be imminent, TDEC and Knox County DAQM will evaluate existing control
measures to determine whether further emissionreduction measures should be implemented. If QNQC data indicates a violating design value for the 1997 8-hourozone NAAQS, then the 40triggering event will be the date ofthe design value violation, and not the fmal QNQC date. However, ifinitial monitoring data indicates a possible violationbut later QNQC data indicates that the NAAQS was not violated, then a triggering event will not have occurred, and contingency measures will notberequired. The contingency plan states that upon a measured violation ofthe 1997 8-hour ozone NAAQS in the Knoxville Area, TDEC and the Knox CountyDAQM will complete sufficient analyses and provide those to the EPA. Ifdeemed necessary, contingency measures would be adopted and implemented as expeditiously as possible, butno later than eighteen to twenty-four months after a triggering event. Theproposed schedule for these actions would be as follows:
• Six months to identify appropriate contingency measures, including identification of emission sources and appropriate control technologies;
• Between three and six months to initiate a stakeholderprocess; and
• Between nine and twelve months to implement the contingency measures. This step would include the time required to draft rules or SIP amendments, complete the rulemaking process, and submit the final plans to EPA. Tennessee will consider one ormore ofthe following contingency measures to re-attain the NAAQS:
• Implementation ofdiesel retrofit programs, including incentives for perfonning retrofits
• Reasonable Available Control Technology for NOx sources in nonattainment counties



### 41• Programs or incentives to decrease motor vehicle use, including employer-based programs, additional park and ride services, enhancedtransit service and encouragement offlexible 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 ofhigh-occupancy vehicle (HOV) lanes, orrestriction ofcertainroads
or lanes for HOV
• Programs for new construction and majorreconstruction ofbicycle and pedestrian facilities including shared use paths, sidewalks, and bicycle lanes
• Expand Air QualityAction Day activities/Clean AirPartners public education outreach
• Expansion ofE-government services at State and local levels
• Additional enforcement oroutreach on driver observance ofreduced speed limits
• Land use/transportation polices
• Promote non-motorized transportation
• Promote tree-planting standards that favor trees with low VOC biogenic emissions
• Promote energy savings plans for local government
• Gas can and lawnmowerreplacement programs
• Seasonal openburning ban in nonattainment counties
42• Evaluate anti-idling rules and/or policy
• Additional controls in upwind areas, ifnecessary Othercontrol measures, not included in the above list, will be consideredifnew control programs are deemed more advantageous for this Area. EPAhas concluded that the maintenance plan adequately addresses the five basic components ofa maintenance plan: attainment inventory, maintenance demonstration, monitoring network, verification ofcontinued attainment, and a contingency plan. The maintenance plan SIPrevision submittedbythe State ofTennessee for the Knoxville Area meets the requirements ofsection 175Aofthe CAA and is approvable.



### VII. Whatis EPA'sAnalysis ofTennessee'sProposed NOx and VOCMVEBs for the Knoxville Area? Underthe CAA, states are required to submit, at various times, control strategy SIPs and maintenance plans in ozone areas. These control strategy SIPs (reasonable further progress and attainment demonstration) and maintenanceplans create MVEBs for criteria pollutants and/or theirprecursors to address pollution from cars and trucks. Per40 CFR part 93, an MVEB is established for the last year ofthe maintenance plan. A state may adopt MVEBs for otheryears
as well. The MVEB is the portion ofthe 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 onemissions from an area's planned transportation system. The MVEB concept is further explained in the preamble to the November 24, 1993, transportation confonnityrule (58 FR 62188). The preamble also describes how to establish the MVEB in the SIP and how to revise the MVEB. 43After interagency consultation with the transportation partners for the Knoxville Area, Tennessee has elected to develop MVEBs for

## voe and NOx for the entire Area. Tennessee is developing these MVEBs, as required, for the last year ofits maintenance plan, 2024. The MVEBs reflect the total on-road emissions for 2024, plus an allocation from the available 

## voe and NOx safety margin. Under40

### eFR 93.101, the term safety margin is the difference between the attainment level (from all sources) and the projected level ofemissions (from all sources) in the maintenance plan. The safety margin canbe allocated to the transportation sector; however, the total emissions must remain below the attainment level. These MVEBs and allocation from the safety margin were developed in consultation with the transportation partners and were added to account for uncertainties inpopulation growth, changes in model vehicle miles traveled and
new emission factor models. The NOx and

## voe MVEBs for the Knoxville Area are defined in Table 7 below.

Table 7. Knoxville Area VOC AND NOlI MVEBs (Summer season tpd)
2024 NOx 36.32 VOC 25.19 As mentioned above, the Knoxville Area has chosen to allocate a portion ofthe available safety margin to the 2024 NOx and

## voe MVEBs. This allocation is 14.03 tpd for NOx and 6.80 tpd for

## voe. Thus, the remaining safety margin in 2024 is 42.08 tpd for NOx and 20.37 tpd for 

## voe. Through this rulemaking, EPA is proposing to approve the 2024 MVEBs for

## voe and NOxfor the Knoxville Area because EPA has determined that the Area maintains the 1997 8­ 44hourozone NAAQS with the emissions at the levels ofthe budgets. Once the MVEBs for the Knoxville Area (the subject ofthis rulemaking) are approved orfound adequate (whichever is done first), they mustbeused for future conformity determinations.



### VIII. WhatIs the Status ofEPA's Adequacy Determination for the Proposed NOx and VOC MVEBs for 2024 for the Knoxville Area? Under section 176(c) ofthe CAA, new transportation projects, such as the construction of
new highways, must "conform" to (i.e., be consistent with) the part ofthe state's air quality plan that addresses pollutionfrom cars and trucks. "Conformity" to the SIP means that transportation activities will not cause new air quality violations, worsen existing violations, ordelay timely attainment ofthe NAAQS. Ifa transportation plan does not "conform," most new projects that would expand the capacity ofroadways cannot go forward. Regulations at40 CPR part 93 set forth EPA policy, criteria, and procedures for demonstrating and assuring conformity ofsuch transportation activities to a SIP. The regional emissions analysis is one, butnot 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 buthave since beenredesignated to attainment with a maintenance plan for that NAAQS. When reviewing submitted "control strategy" SIPs ormaintenance 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 mustbe used by state and Federal

45agencies in detennining whetherproposed transportation projects "confonn" to the SIP as required by section 176(c) ofthe CAA. EPA's substantive criteria for detennining "adequacy" ofan MVEB are set out in 40 CFR 93. 118(e)(4). Theprocess for detennining "adequacy" consists ofthree basic steps: public notification ofa SIP submission, a public commentperiod, and EPA's adequacy fmding. This process for determining the adequacy ofsubmitted SIP MVEBs was initially outlined in EPA's May 14, 1999, guidance, "Conformity Guidance on Implementation ofMarch 2, 1999, Confonnity Court Decision." This guidance was finalized in the Transportation Confonnity Rule Amendments for the "New 8-Hour Ozone and PM2.5 National Ambient Air Quality Standards and Miscellaneous Revisions for Existing Areas; Transportation Confonnity Rule Amendments

- Response to CourtDecision and Additional Rule Change," on July 1, 2004 (69 FR40004). Additional infonnation onthe adequacy process for MVEBs is available in the proposed rule entitled, "TransportationConfonnity Rule Amendments: Response to Court Decision and Additional Rule Changes," 68 FR 38974, 38984 (June 30, 2(03). As discussed earlier, Tennessee's maintenance plan submission includes VOC and NOx MVEBs for the Knoxville Area for 2024. EPA reviewed both the VOCs and NOx MVEBs through the adequacy process. TheTennessee SIP submission, including the Knoxville Area VOC and NOx MVEBs was open for public comment onEPA's adequacy Web site onJune 15, 2010, found athttp://www.epa.gov/otaq!stateresources/transconf!currsips.htm. Thepublic comment period on adequacy ofthe 2024 VOC and NOx MVEBs for Knoxville Area closed on July 15, 2010. EPA did notreceive any comments onthe adequacy ofthe MVEBs, nor did EPA receive any requests for the SIP submittal.

46EPA intends to make its detennination on the adequacy ofthe 2024 MVEBs for the Knoxville Area for transportation confonnitypurposes in the near future by completing the adequacy process that was started onJune 15,2010. After EPAfinds the 2024 MVEBs adequate
or approves them, the new MVEBs for VOC and NOxmust be used, for future transportation confonnity detenninations. Forrequired regional emissions analysis years prior to 2024, the**co~onnity** test will be the applicable interim emissions test applicable for the Area per40 CPR Part 93 (the transportation confonnity rule). Forrequired regional emissions analysis years that involve 2024 orbeyond, the applicable budgets will be the new 2024 MVEBs. The 2024 MVEBs are defined in section VII ofthis proposedrulemaking.



### IX. Whatis EPA's analysis oftheproposed 2007 baseyearemissions inventory for the Knoxville Area? As discussed above, section 172(c)(3) ofthe CAA requires areas to submit a base year emissions inventory. As part ofTennessee's request to redesignate the Knoxville Area, the state submitted 2007 base year emissions inventory to meet this requirement. Emissions contained in the submittal cover the general source categories ofpoint sources, area sources, on-road mobile sources, and non-road mobile sources. All emission summaries were accompanied by sourcespecific descriptions ofemission calculation procedures and sources ofinput data. On-road mobile emissions were prepared using the MOBILE6.2 emissions model. Tennessee's submittal documents 2007 emissions in the Knoxville Area in units oftons per summer day. Table 8 below provides a summary ofthe 2007 summerday emissions ofVOC and NOx for the Knoxville Area.

47Table 8. Knoxville Area2007 SummerDayEmissions for VOC and NOx (Summer season tpd) Source NOx VOC Point Source Total 42.69 7.32 Area Source Total 2.07 33.25 On-Road Mobile Source Total 71.83 36.77 Non-Road Mobile Source Total 13.16 34.26 Non-Road Mobile Source Total 5.44 0.68 Totalfor all Sources 135.19 112.28

EPA is proposing to approve this 2007 base year inventory as meeting the section 172(c)(3) emissions inventory requirement.



# x. ProposedAction onthe Redesignation Request andMaintenancePlan SIPRevision IncludingApproval ofthe 2024 NOx and VOCMVEBsfor the Knoxville Area.
EPA is proposing to make the determination that the Knoxville Areahas met the criteria for redesignation from nonattainment to attainment for the 1997 8-hour ozone NAAQS. Further, EPA is proposing to approve Tennessee's July 14, 2010, SIP submittal including the redesignation request for the Knoxville Area. Additionally, EPA is proposing to approve the baseline emissions inventory for the Knoxville Area for the 1997 8-hour ozone NAAQS. EPA believes that the redesignationrequest and monitoring data demonstrate that the Knoxville Area has attained the 1997 8-hour ozone NAAQS. EPA is also proposing to approve the maintenance plan for the Knoxville Area included
as part ofthe July 14,2010, SIPrevision as meeting the requirements ofsection 175A ofthe 48CAA. The maintenance plan includes NOx and VOC MVEBs for 2024. EPA is proposing to approve the 2024 NOx and VOC MVEBs for the Knoxville Area because the maintenance plan demonstrates that, in light ofexpected emissions for all source categories, the Area will continue to maintain the 1997 8-hourozone NAAQS. Further as part oftoday's action, EPA is describing the status ofits adequacy determination for the 2024 NOx and VOC MVEBs, in accordance with 40 CFR 93. 118(f)(1). Within 24 months from the effective date ofEPA's adequacy finding 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 NOx and VOC MVEBs pursuant to 40 CFR 93.104(e).



### XI. Statutory and Executive Order Reviews
Under the CAA, the Administrator is required to approve a SIP submission that complies with the provisions ofthe Act and applicable Federal regulations. 42 U.S.c. 7410(k); 40 CFR 52.02(a). Thus, inreviewing SIP submissions, EPA's role is to approve state choices, provided that they meet the criteria ofthe CAA. Accordingly, this proposed action merely approves state law as meetingFederal requirements and does not impose additional requirements beyond those imposed by state law. Forthat reason, this proposed action:
• is not a "significantregulatory action" subject to review by the Office ofManagement and BudgetunderExecutive Order 12866 (58 FR 51735, October4, 1993);
• does not impose an information collectionburden under the provisions ofthe Paperwork Reduction Act (44 U.S.c. 3501 etseq.);
49• is certified as nothaving a significant economic impact on a substantial number ofsmall entities under the Regulatory Flexibility Act (5 U.S.C. 601 etseq.);
• does not contain any unfunded mandate or significantly oruniquely affect small governments, as described in the Unfunded Mandates Refonn Act of 1995 (Public Law 104-4);
• does nothave Federalism implications as specified inExecutive Order 13132 (64 FR 43255, August 10, 1999);
• is not aneconomically significantregulatory action based onhealth or safety risks subject to Executive Order 13045 (62 FR 19885, April 23, 1997);
• is not a significantregulatory action subject to Executive Order 13211 (66 FR 28355, May 22, 2001);
• is not subject to requirements ofSection 12(d) ofthe National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) because application ofthose requirements would be inconsistent with the CAA; and
• does notprovide EPA with the discretionary authority to address, as appropriate, disproportionate humanhealth or environmental effects, using practicable and legally pennissible methods, underExecutive Order 12898 (59 FR 7629, February 16, 1994).

In addition, this proposed rule does nothave tribal implications as specified byExecutive Order 13175 (65 FR 67249, November9,2000), because the SIP is not approved to apply in Indian country located in the State, and EPA notes that it will not impose substantial direct costs on tribal governments orpreempt tribal law.

50List ofSubjects: 40 CFRPart52 Environmental protection, Air pollution control, Intergovernmental relations, Nitrogen oxides, Ozone, Reporting and recordkeeping requirements, and Volatile organic compounds.

40 CFR Part 81 Environmental protection, Airpollution control, National parks, Wilderness areas.
Authority: 42 U.S.C. 7401 et seq.

Dated:

__

# tt*-~~2s-+I-=--IO _

# Sep~mbe~28. 2010 Regional Administrator, Region 4.



### 51