ENVIRONMENTAL PROTECTION AGENCY
 

40 CFR Parts 52 and 81
 

[EPA-R04-0AR-201O-0666-201031; FRL- ]
 

Approval and Promulgation of Implementation Plans and Designation of Areas for Air Quality
 

Planning Purposes; Tennessee; Redesignation of the Knoxville 8-Hour Ozone Nonattainment
 

Area to Attainment for Ozone
 

AGENCY: Environmental Protection Agency (EPA). 

ACTION: Proposed Rule. 

SUMMARY: On July 14,2010, the State of Tennessee, through the Tennessee Department of 

Environment and Conservation (TDEC), Air Pollution Control Division, submitted a request to 

redesignate the Knoxville 8-hour ozone nonattainment area to attainment for the 1997 8-hour 

National Ambient 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 of Anderson, Blount, Jefferson, Knox, 

Loudon, and Sevier Counties in their entireties, and the portion of Cocke County that falls within 

the boundary of the Great Smoky Mountains National Park (hereafter referred to as the 

"Knoxville Area"). In this 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-hour ozone NAAQS maintenance plan for the Knoxville Area, including the 2007 

baseline emission inventory, and the motor vehicle emission budgets (MVEBs) for nitrogen 

oxides (NOx) and volatile organic compounds (VOC) for 2024 for the Knoxville Area. This 

proposed approval of Tennessee's redesignation request is based on EPA's determination that the 
Knoxville Area has 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 of its 

transportation conformity adequacy determination for the new 2024 MVEBs that are contained 

in the 1997-8-hour ozone NAAQS maintenance plan for the Knoxville Area. This action is 

being taken pursuant to the CAA and its implementing regulations. 

DATES: Conunents must be received on or before [insert date 30 days after date of publication 

in the Federal Registerl. 

ADDRESSES: Submit your conunents, identified by Docket ill No. EPA-R04-0AR-2010­

0666, by one of the 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, Air Planning 

Branch, Air, Pesticides and Toxies 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, Regulatory Development 

Section, Air Planning Branch, Air, Pesticides and Toxics Management Division, U.S. 

Environmental Protection Agency, Region 4,61 Forsyth Street, SW, At1anta, 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 

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Friday, 8:30 to 4:30, excluding federal holidays. 

Instructions: Direct your comments to Docket ill No. 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 be Confidential Business Information (CBI) 

or other information whose disclosure is restricted by statute. Do not submit through 

www.regulations.gov or e-mail, information that you consider to be CBI or otherwise protected. 

. The www.regulations.gov website 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 e-mail comment directly to EPA without going through www.regulations.gov, your 

e-mail 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 

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material, 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, 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 Royce Dansby-Sparks of the 

Regulatory Development Section, in 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. Ms. Spann may be reached by phone at (404) 562-9029, or via 

electronic mail at spmID.jane@epa.gov. Mr. Dansby-Sparks may be reached by phone at (404) 

562-9187, or via electronic mail at dansby-sparks.royce@epa.gov. 

SUPPLEMENTARY INFORMATION: 

Table of Contents 

I. What Proposed Actions is EPA Taking? 

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 the Effect of EPA's Proposed Actions? 

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VI. What is EPA's Analysis of the Request? 

VII.	 What is EPA's Analysis of Tennessee's Proposed NOx and VOC MVEBs for the 

Knoxville Area? 

VIII.	 What is the Status of EPA's Adequacy Determination for the Proposed NOx and 

VOC MVEBs for 2024 for the Knoxville Area? 

IX. What is EPA's analysis of the proposed 2007 base year emissions inventory for the 

Knoxville Area? 

X. Proposed Action on the Redesignation Request and Maintenance Plan SIP Revision 

Including Proposed Approval of the 2024 NOx and VOC MVEBs for the Knoxville 

Area. 

XI. Statutory and Executive Order Reviews 

I.	 What Proposed Actions is EPA Taking? 

EPA is proposing several related actions, which are summarized below and described in 

greater detail throughout this notice of rulemaking: (1) to redesignate the Knoxville Area to 

attainment for the 1997 8-hour ozone NAAQS; (2) to approve under section 172(c)(3) the 

emissions inventory submitted with the maintenance plan; and (3) to approve, under section 

175A of the eAA, Knoxville's 1997 8-hour ozone NAAQS maintenance plan into the Tennessee 

SIP, including the associated MVEBs. In addition, and related to today's actions, EPA is also 

notifying the public of the status of EPA's adequacy determination for the Knoxville Area 

MVEBs. 

First, EPA is proposing to determine that the Knoxville Area has attained the 1997 8-hour 

ozone NAAQS. EPA further proposes to determine that, if EPA's proposed approval of the 2007 

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baseline emissions inventory for the Knoxville Area is finalized, the Area has met the 

requirements for redesignation under section 107(d)(3)(E) of the CAA. The Knoxville Area 

1997 8-hour ozone area is composed of Anderson, Blount, Jefferson, Knox, Loudon, and Sevier 

Counties in their entireties, and the portion of Cocke County that falls within the boundary of the 

Great Smoky Mountains National Park. In this action, EPA is now proposing to approve a 

request to change the legal designation of Anderson, Blount, Jefferson, Knox, Loudon, and 

Sevier Counties in their entireties, and the portion of Cocke County that falls within the 

boundary of the Great Smoky Mountains National Park in the Knoxville Area from 

nonattainment to attainment for the 1997 8-hour ozone NAAQS. 

Second, EPA is proposing to approve under the 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 of the CAA criteria for 

redesignation to attainment status). The maintenance plan is designed to help keep the Knoxville 

Area in attainment of the 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 of Tennessee's maintenance plan for the 1997 8-hour ozone NAAQS. 

EPA is also notifying the public of the status of EPA's adequacy process for the newlyestablished 2024 NOx and VOC MVEBs for the Knoxville Area. The Adequacy comment 

period for the Knoxville Area 2024 MVEBs began on June 15,2010, with EPA's posting of the 

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availability of this submittal on EPA's Adequacy website. 

(http://www.epa.gov/otaq/stateresources/transconf/currsips.htm). The Adequacy comment 

period for these MVEBs closed on July 15,2010. No adverse comments were received during 

the Adequacy public comment period. 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 of this process, and for more details on the 

MVEBs determination. 

Today's notice of proposed rulemaking is in response to Tennessee's July 14,2010, SIP 

submittal requesting the redesignation of the Knoxville 1997 8-hour ozone area, and includes a 

SIP revision addressing the specific issues summarized above and the necessary elements for 

redesignation described in section 107(d)(3)(E) of the CAA. 

II. What is the Background for EPA's Proposed Actions? 

The CAA establishes a process for air quality management through the NAAQS. Ozone 

is a criteria pollutant for which NAAQS are established. On July 18, 1997, EPA promulgated a 

revised 8-hour ozone NAAQS of 0.08 parts per million (ppm). I These NAAQSare more 

stringent than the previous I-hour ozone NAAQS. Under EPA regulations found at 40 CFR part 

50, the 1997 8-hour ozone NAAQS are attained when the 3-year average of the 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 data for the 3-year period must 

meet a data completeness requirement. The ambient air quality monitoring data completeness 

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requireme~t is met when the percent of days 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 I of part 50. Specifically, section 2.3 of 40 CFR part 50, Appendix I, 

"Comparisons with the Primary and Secondary 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 of the 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 

greater than 0.08 ppm. 

The CAA required EPA to designate as nonattainment any area that was violating the 

1997 8-hour ozone NAAQS based on the three most recent years of ambient air quality data. 

The Knoxville Area was initially designated nonattainment for the 1997 8-hour ozone 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 of provisions - 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 of NOx and VOC react in the presence of 

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D.) 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 EPA refers to as "classified" nonattainment) provides more specific 

requirements for certain ozone nonattainment areas. Under EPA's Phase I 1997 8-Hour Ozone 

Implementation Rule (69 FR 23857) (Phase I Rule), published April 30, 2004, an area was 

classified under subpart 2 based on its 1997 8-hour ozone design value (i.e., the 3-year average 

of the annual fourth-highest daily maximum 8-hour average ozone concentrations), if it had a 1­

hour design value at or above 0.121 ppm (the lowest I-hour design value in Table 1 of subpart 

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 of the 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. On April 30, 2004, EPA designated the Knoxville Area (of which 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 1 of the CAA, and was obligated to meet only the subpart 1 

requirements. 

EPA promulgated implementation rules 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 of ozone. 

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was published at the same time as the ozone designations and addresses such topics as 

classifications, revocation of the I-hour NAAQS, 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 covered by the Phase 1 Rule. Various aspects of 

EPA's Phase 1 Rule were challenged in court. On December 22,2006, the U.S. Court of 

Appeals for the District of Columbia Circuit (D.C. Circuit Court) vacated EPA's Phase 1 Rule 

(69 FR 23951, April 30, 2004). South Coast Air Quality Management Dist. (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. Circuit Court clarified that the Phase I Rule was vacated only with regard to those parts 

of the Rule that had been successfully challenged. Therefore, the Phase I Rule provisions related 

to classifications for areas currently classified under subpart 2 of title I, part D of the 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 of the 1997 8-hour ozone 

NAAQS remain effective. The June 8th decision left intact the court's rejection of EPA's reasons 

for implementing the 1997 8-hour NAAQS in certain nonattainment areas under subpart 1 in lieu 

of subpart 2, i.e., the court's rejection of the subpart 1 classification. By limiting the vacatur, the 

court let stand EPA's revocation of the I-hour NAAQS and those anti-backsliding provisions of 

the Phase I Rule 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

hour nonattainment areas under the anti-backsliding provisions of the regulations: (1) 

nonattainment area New Source Review (NSR) requirements based on an area's I-hour 

nonattainment classification; (2) Section 185 penalty fees for I-hour severe or extreme 

nonattainment areas; and (3) measures to be implemented pursuant to section 172(c)(9) or 

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182(c)(9) of the CAA, on the contingency of an area not making reasonable further progress 

(RFP) toward attainment of the I-hour NAAQS, or for failure to attain that NAAQS. The June 

8th decision clarified that the court's reference to conformity requirements for anti-backsliding 

purposes was limited to requiring the continued use of I-hour MVEBs until 1997 8-hour ozone 

NAAQS budgets were available for 8-hour ozone conformity determinations, which is already 

required under EPA's conformity regulations. The court thus clarified that I-hour ozone 

conformity determinations are not required for anti-backsliding purposes. 

This section sets forth EPA's views on the potential effect of the court's rulings on this 

proposed redesignation action. For the reasons set forth below, EPA does not believe that the 

court's rulings alter any requirements relevant to this redesignation action so as to preclude 

redesignation, nor does EPA believe 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 of the 

Knoxville Area to attainment. 

With respect to the 1997 8-hour ozone NAAQS, the court's ruling rejected EPA's reasons 

for classifying areas under subpart 1 for the 1997 8-hour ozone NAAQS, and remanded that 

matter back to the Agency. In its January 16,2009, proposed rulemaking in response to the 

SCAQMD decision, EPA has proposed to classify the Knoxville Area under subpart 2 as a 

moderate area (74 FR 2936). If EPA finalizes the reclassification of the Knoxville Area before 

the July 14, 2010, redesignation request is approved, the requirements under subpart 2 will 

become applicable when they are due. EPA proposed a deadline for submission of these 

requirements of one year after the effective date of the final rulemaking classifying this and other 

areas (74 FR 2940-2941). However, EPA believes that this does not preclude this redesignation 

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from being approved. This belief is based upon: (1) EPA's longstanding policy of evaluating 

requirements in accordance with the requirements due at the time redesignation request is 

submitted; and (2) consideration of the inequity of applying 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. Under EPA's 

longstanding interpretation of section 107(d)(3)(E) of the CAA, to qualify for redesignation, 

states requesting redesignation to attainment must meet only the relevant SIP requirements that 

came due prior to the submittal of a complete redesignation request. September 4, 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 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 Shapiro, Acting Assistant Administrator 

for Air and Radiation), and 60 FR 12459, 12465-66 (March 7,1995) (Redesignation of DetroitAnn Arbor, Michigan); Sierra Club v EPA, 375 F.3d 537 (7th Cir. 2004) (upholding this 

interpretation); 68 FR 25418,25424,25427 (May 12,2003) (redesignation of St. Louis, 

Missouri). 

Moreover, it would be inequitable to retroactively apply any new SIP requirements that 

were not applicable at the time the request was submitted. The D.C. Circuit Court has 

recognized the inequity in such retroactive rulemaking (see Sierra Club v. Whitman285 F. 3d 63 

(D.C. Cir. 2002)), in which the court upheld a district court's ruling refusing to make retroactive 

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an EPA detennination of nonattainment that was past the statutory due date. Such a 

detennination would have resulted in the imposition of additional requirements on the area., The 

court stated, "[a]lthough EPA failed to make the nonattainment detennination within the 

statutory frame, Sierra Club's proposed solution only makes the situation worse. Retroactive 

relief would likely impose large costs on the states, which would face fmes and suits for not 

implementing air pollution prevention plans in 1997, even though they were not on notice at the 

time." [d. at 68. Similarly here, it would be unfair to penalize the Knoxville Area by applying to 

it, for purposes of redesignation, additional SIP requirements under subpart 2 that were not in 

effect or yet due at the time it submitted its redesignation request, or the time that the Knoxville 

Area attained the NAAQS. 

With respect to the requirements under the I-hour ozone NAAQS, only the Knox County 

portion of the Knoxville Area was originally designated as a marginal nonattainment for the 1­

hour ozone NAAQS in November 6, 1991 (56 FR 56694); the remainder of the Knoxville Area 

was designated as attainment. Knox County was redesignated as attainment for the I-hour ozone 

NAAQS on September 27, 1993 (58 FR 50271). Therefore, Knox County was redesignated to 

attainment of the I-hoUr ozone NAAQS prior to its nonattainment designation for the 1997 8­

hour ozone NAAQS. As a result, Knox County (as part of the 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 of areas, 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-hour budgets must be used for 8-hour confonnity detenninations until they are replaced by 

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1997 8-hour budgets. To meet this requirement, conformity determinations in such areas must 

comply with the applicable requirements of EPA's conformity regulations at 40 CFR part 93. 

First, there are no conformity requirements relevant for evaluating the Knoxville Area 

redesignation request, such as a transportation conformity SIP.2 It is EPA's longstanding policy 

that it is reasonable to interpret the conformity SIP requirements 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 40 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 of Tampa, Florida). 

Tennessee currently has a fully approved I-hour ozone transportation conformity SIP, which was 

approved on May 16,2003 (68 FR 26492). 

Second, with regard to the three other anti-backsliding provisions for the I-hour standard 

that the D.C. Circuit Court found were not properly retained, 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 of the 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 any requirements 

that would preclude EPA from fmalizing the redesignation of the 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. Transportation conformity SIPs are different from the motor 

vehicle emission budgets that are established in control strategy SIPs and maintenance plans. 

14 
As was noted earlier, in 2009, the ambient ozone data for the Knoxville Area indicated no 

further violations of the 1997 8-hour ozone NAAQS, using data from the 3-year period of 2007­

2009 to demonstrate attainment. As a result, on July 14,2010, Tennessee requested 

redesignation of the Knoxville Area to attainment for the 1997 8-hour ozone NAAQS. The 

redesignation request included three years of complete, quality-assured ambient air quality data 

for the ozone seasons (March 1st through October 31st) of 2007-2009, indicating that the 1997 8­

hour ozone NAAQS has been achieved for the entire Knoxville Area. Under the CAA, 

nonattainment areas may be redesignated to attainment if sufficient, complete, quality-assured 

data is available for the Administrator to determine that the area has attained the standard and the 

area meets the other CAA redesignation requirements in section 107(d)(3)(E). The 1997 8-hour 

ozone design values for the Knoxville Area indicate that between 1999 and 2009, ozone 

concentrations declined noticeably at both high and low evaluations. While ozone 

concentrations are dependent on a variety of conditions, the likely reason for the overall 

downtrend in ozone concentrations in the Knoxville Area is most likely due to the reduction of 

NOx emissions that have occurred since 2004. 

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 11O(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 

15
 
applicable Federal air pollutant control regulations and other pennanent and enforceable 

reductions; (4) the Administrator has fully approved a maiJ)tenance 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 

theCAA. 

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; 

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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; 

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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 July 14, 2010, Tennessee, through TDEC, requested redesignation of the Knoxville 

Area to attainment for the 1997 8-hour ozone NAAQS. EPA's evaluation indicates that the 

Knoxville Area has attained the 1997 8-hour ozone NAAQS and has met the requirements for 

redesignation set forth in section 107(d)(3)(E), including the maintenance plan requirements 

under section 175A of the 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 of its adequacy determination of the 2024 NOx and VOC MVEBs which are relevant to 

the requested redesignation. 

V.	 What is the Effect of EPA's Proposed Actions? 

EPA's proposed actions establish the basis upon which EPA may take fmal action on the 

issues being proposed for approval today. Approval of Tennessee's redesignation request would 

18
 
change the legal designation of the Anderson, Blount, Jefferson, Knox, Loudon, and Sevier 

Counties in their entireties, and the portion of Cocke County that falls within the boundary of the 

Great Smoky Mountains National Park for the 1997 8-hour ozone NAAQS found at 40 CPR part 

81 from nonattainment to attainment. Approval of Tennessee's request would also incorporate 

into the Tennessee SIP, a plan for maintaining the 1997 8-hour ozone NAAQS in the Knoxville 

Area through 2024. This maintenance plan includes contingency measures to remedy future 

violations of the 1997 8-hour ozone 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 of Tennessee's maintenance 

plan would also result in approval of the NOx and VOC MVEBs. Additionally, EPA is notifying 

the public of the status of its adequacy determination for the 2024 NOx and VOC MVEBs 

pursuant to 40 CPR 93.118(f)(1). 

VI. What is EPA's Analysis of the Request? 

EPA is proposing to make the determination that the Knoxville 1997 8-hour ozone 

nonattainment area has attained the 1997 8-hour ozone NAAQS, and that all other redesignation 

criteria have been met for the Knoxville Area. The basis for EPA's determination for the Area is 

discussed in greater detail below. 

Criteria (1) - The Knoxville Area has attained the 1997 8-hour ozone NAAQS. 

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 

19
 
NAAQS if it meets the 1997 8-hour ozone standard, as detennined in accordance with 40 CFR 

50.10 and Appendix I of part 50, based on three complete, consecutive calendar years of qualityassured air quality monitoring data. To attain these NAAQS, the 3-year average of the fourthhighest daily maximum 8-hour average ozone concentrations measured at each monitor within an 

area over each year must not exceed 0.08 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 0.084 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. 

EPA reviewed ozone monitoring data from ambient ozone monitoring stations in the 

Knoxville Area for the ozone season from 2007-2009. These data have been quality-assured and 

are recorded in AQS. The fourth-highest 8-hour ozone average for 2007, 2008 and 2009, and the 

3-year average of these values (Le., design values), are summarized in the following Table 1 of 

this proposed rulemaking. 

Table 1. Design Value Concentrations for the Knoxville 8-Hour Ozone Area (ppm) 

County Site Name MonitorID Eil!ht-Hour Desilm 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 

20
 
Knox 

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 the highest 3-year average of the 

annual fourth-highest 8-hour ozone value record,ed at any monitor in the area. Therefore, the 

most recent 3-year design value (2007-2009) for the Knoxville Area is 0.082 ppm, which meets 

the NAAQS as described above. Current air quality data show that the Area continues to attain 

the NAAQS. Ifthe Area does not continue to attain until EPA fmalizes the redesignation, EPA 

will not go forward with the redesignation. 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. EPA proposes to find that the Knoxville Area has attained the 1997 8-hour ozone NAAQS. 

Criteria (2) - Tennessee has a/ully approved SIP under section 110(k)/or the Knoxville Area 

and Criteria (5) - Tennessee has met all applicable requirements under section 110 and part 

Do/the CAA. 

Below is a summary of how these two criteria were met. 

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. EPA also proposes to find that the Tennessee SIP satisfies the criterion that it 

21 
meet applicable SIP requirements for purposes of redesignation under part D of title I of the 

CAA (requirements specific to subpart 1 basic 1997 8-hour ozone nonattainment 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 of redesignation in 

accordance with section 107(d)(3)(E)(ii). In making these determinations, EPA ascertained 

which requirements are applicable to the Area and that if applicable, they are fully approved 

under section 11O(k). SIPs must be fully approved only with respect to applicable requirements. 

a. Knoxville Area has met all applicable requirements under section 110 and part D of the CAA. 

The September 4, 1992, Calcagni Memorandum describes EPA's interpretation of section 

107(d)(3)(E). Under this interpretation, to qualify for redesignation, states requesting 

redesignation to attainment must meet only the relevant CAA requirements that come due prior 

to the submittal of a complete redesignation request. See also Michael Shapiro Memorandum, 

("SIP Requirements for Areas Submitting Requests for Redesignation to Attainment of the 

Ozone and Carbon Monoxide NAAQS On or After November 15, 1992," September 17, 1993); 

60 FR 12459, 12465-66 (March 7, 1995) (redesignation of Detroit-Ann Arbor, Michigan). 

Applicable requirements of the CAA that come due subsequent to the area's submittal of a 

complete redesignation request remain applicable until a redesignation is approved, bnt are not 

required as a prerequisite to redesignation. See section 175A(c) of the CAA; Sierra Club, 375 

F.3d 537; see also 68 FR 25424, 25427 (May 12, 2003) (redesignation of St. Louis, Missouri). 

General SIP requirements. Section 1l0(a)(2) oftitle 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. 

22
 
General SIP elements and requirements are delineated in section 11O(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 11O(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 transport of air 

pollutants (NOx SIP Ca1l3 and Clean Air 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. EPA believes that the requirements linked with a particular 

3 On October 27, 1998 (63 FR 57356), EPA issued a NOx SIP Call requiring the District of Columbia and 22 states 

to reduce emissions of NOx in order to reduce the transport of ozone and ozone precursors. In compliance with 

EPA's NOx SIP Call, Tennessee developed rules governing the control of NOx emissions from Electric Generating 

Units (EGUs), major non-EGU industrial boilers, major cement kilns, and internal combustion engines. On January 

22,2004, EPA approved Tennessee's rules as fulfilling Phase I (69 FR 3015) and Phase II on December 27, 2005 

(70 FR 76408). 

4 On May 12,2005 (70 FR 25162), 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 of sulfur dioxide and NOx. 

Various aspects ofCAIR rule were petitioned in court and on December 23, 2008, the U.S. Court of Appeals for the 

District of Columbia Circuit remanded CAIR to EPA (see North Carolina v. EPA, 550 F.3d 1176 (D.C. Cir., 2008)) 

which left CAIR in place to "temporarily preserve the environmental values covered by CAIR" until EPA replaces 

it with a rule consistent with the court's decision. The court directed EPA to remedy various areas of the 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 on EPA for completing that action. Id. Therefore, CAIR is currently in 

effect in Tennessee. 

23 
nonattainment 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 state regardless of the designation of anyone particular area in the state. 

Thus, we do not believe that the CAA's interstate transport requirements should be construed to 

be applicable requirements for purposes of redesignation. 

In addition, EPA believes that the other section 110 elements not connected with 

nonattainment plan submissions and not linked with an area's attainment status are not 

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, 1997); Cleveland-Aleron-Loraine, Ohio, final rulemaking (61 FR 20458, May 7, 

1996); and Tampa, Florida, fmal 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). 

EPA believes that section no elements not linked to the area's nonattainment status are 

not applicable for purposes of redesignation. Therefore, as was discussed above, for purposes of 

redesignation, they are not considered applicable requirements. Nonetheless, EPA notes it has 

previously approved provisions in the Tennessee SIP addressing section 110 elements under the 

I-hour ozone NAAQS (45 FR 53809, August 13, 1980). The State believes that the section 110 

24
 
SIP approved for the I-hour ozone 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 belief that the section 110 SIP approved for the I-hour ozone NAAQS is also sufficient 

to meet the requirements under the 1997 8-hour ozone NAAQS. EPA has not yet approved this 

submission, but such approval is not necessary for purposes of redesignation. 

Part D requirements. EPA proposes that if EPA approves Tennessee's base year 

emissions inventory, which is part of the maintenance plan submittal, the Tennessee SIP will 

meet applicable SIP requirements under part D of the CAA. We believe the emissions inventory 

is approvable because the 2007 VOC and NOx emissions for Tennessee were developed 

consistent with EPA guidance for emission inventories, and the choice of the 2007 base year is 

appropriate because it represents the 2007-2009 period when the 1997 8-hour ozone NAAQS 

were not violated. 

Part D, subpart 1 applicable SIP requirements. EPA has determined that, if EPA 

finalizes the approval of the base year emissions inventories discussed in section IX. of this 

rulemaking, the Tennessee SIP will meet the applicable SIP requirements for the Knoxville Area 

applicable for purposes of redesignation under part D of the CAA. Subpart 1 of part D, found in 

sections 172-176 of the CAA, sets for the basic nonattainment requirements applicable to all 

nonattainment areas. Subpart 2 of part D, which includes section 182 of the CAA, establishes 

additional specific requirements depending on the area's nonattainment classification. Since the 

Knoxville Area was not classified under subpart 2 at the time the redesignation request was 

submitted, the subpart 2 requirements do not apply for purposes of evaluating the Tennessee's 

redesignation request. The applicable subpart 1 requirements are contained in sections 

25 
172(c)(l)-(9) and in section 176. A thorough discussion of the requirements contained in section 

172 can be found in the General Preamble for Implementation of title I (57 FR 13498). 

Subpart 1 Section 172 Requirements. 5 For purposes of evaluating this redesignation 

request, the applicable section 172 SIP requirements for the Knoxville Area are contained in 

sections 172(c)(l)-(9). A thorough discussion of the requirements contained in section 172 can 

be found in the General Preamble for Implementation of Title I (57 FR 13498, April 16, 1992). 

Section 172(c)(l) requires the plans for all nonattainment areas to provide for the 

implementation of all reasonably available control measures (RACM) as expeditiously as 

practicable and to provide for attainment of the 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 of the area's attainment demonstration. 

The RFP plan requirement under section 172(c)(2) is defined as progress that must be 

made toward attainment. This requirement is not relevant for purposes of redesignation because 

the Knoxville Area has monitored attainment of the 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 of redesignation. [d. 

Section 172(c)(3) requires submission and approval of a comprehensive, accurate, and 

current inventory of actual emissions. As part of Tennessee'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 FR 45568). IfEPA takes final action on this determination, under the provisions of EPA's 

ozone implementation rule (see 40 CFR Section 51.918), the requirements for the State of Tennessee to submit an 

attainment demonstration and associated reasonably available control measures plan, RFP plan, contingency 

26 
Knoxville 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 of allowable emissions for 

major new and modified stationary sources to be allowed in an area, and section 172(c)(5) 

requires source permits for the construction and operation of new and modified major stationary 

sources anywhere in the nonattainment area. EPA has determined that, since PSD requirements 

will apply after redesignation, 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. 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 has demonstrated that the Knoxville Area 

will be able to maintain the NAAQS without part D NSR in effect; therefore, EPA concludes that 

Tennessee need not have fully approved part D NSR programs prior to approval of the 

redesignation request. 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 of the 1997 8-hour ozone NAAQS for the Knoxville 

Area, shall be suspended for as long as the Area continues to meet the 1997 8-hour ozone NAAQS. 

27 
Section 172(c)(6) requires the SIP to contain control measures necessary to provide for 

attainment of the NAAQS. Because attainment has been reached, no additional measures are 

needed to provide for attainment. 

Section 172(c)(7) requires the SIP to meet the applicable provisions of section 11O(a)(2). 

As noted above, we believe the Tennessee SIP meets the requirements of section 11O(a)(2) 

applicable for purposes of redesignation. 

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 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 believes it is reasonable to interpret the conformity SIP requirements6 as not 

applying for purposes of evaluating the 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, 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 submit revisions to their SIPs to reflect certain federal criteria and 

procedures for determining transportation conformity. Transportation conformity SIPs are different from the motor 

vehicle emission budgets that are established in control strategy SIPs and maintenance plans. 

28 
conformity SIP for I-hour ozone 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. EPA has also 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 a part D NSR program in effect 

since PSD requirements will apply after redesignation. The 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 (Part D NSR) Requirements for Areas 

Requesting Redesignation to 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 prior to approval of the 

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 

redesignation to attainment. See rulemakings 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 

of redesignation under section 110 and part D of the CAA. 

b. The Knoxville Area has a fully approved applicable SIP under section 110(k) ofthe eAA. 

IfEPA issues a final approval of the 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) of the CAA for all requirements applicable for purposes of redesignation. 

29
 
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. 

Following passage of the CAA of 1970, Tennessee has adopted and submitted, and EPA has 

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, EPA believes that the section 110 elements not connected with 

nonattainment plan submissions and not linked to the area's nonattainment status are not 

applicable requirements for purposes of redesignation. EPA also believes that since the part D 

subpart 1 requirements did not become due prior to submission of the redesignation request, they 

also are therefore not applicable requirements for purposes of redesignation. Sierra Club v. EPA, 

375 F.3d 537 (7th Cir. 2004); 68 FR 25424, 25427 (May 12,2003) (redesignation of the St. 

Louis-East St. Louis Area to attainment of the I-hour ozone NAAQS). With the approval of the 

emissions inventory, EPA will have approved all Part D subpart 1 requirements applicable for 

purposes of redesignation. 

Criteria (3) - The air quality improvement in the Knoxville Area 1997 8-Hour Ozone NAAQS 

Nonattainment Area is due to permanent and enforceable reductions in emissions resulting 

from implementation ofthe SIP and applicable federal air pollution control regulations and 

other permanent and enforceable reductions. 

30 
EPA believes that Tennessee has demonstrated that the observed air quality improvement 

in the Knoxville Area is due to permanent and enforceable reductions in emissions resulting from 

implementation of the 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 of VOC and NOx, which are precursors 

in the formation of ozone. Table 2 summarizes several of the measures adopted that contributed 

to reductions of emissions. The majority of these reductions have been realized from federal 

measures related to mobile sources and electrical power generation. 

Table 2. Federal and State Measures Contributing to Emissions Reductions 

Federal Measures: 

NOx Budget Trading 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 Vapor Recovery
 

Motor Vehicle Anti-tampering Rule
 

Air Quality Alert Programs
 

Smart Trips Pro,gram
 

One key program, the NOx SIP, required states to make significant, specific emissions 

reductions (63 FR 57356). It also provided a mechanism, the NOx Budget Trading Program, 

which states could use to achieve those reductions. When EPA promulgated CAIR, it 

discontinued (starting in 2009) the NOx Budget Trading Program, 40 CPR 51.121(r), but created 

31
 
another 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 of the NOx SIP Call even after any response 

to the CAIR remand. Notably, the anti-backsliding provisions of 40 CFR 51.905(f) specifically 

provide that the provisions of the NOx SIP Call, including the statewide NOx emission budgets, 

continue to apply after revocation of the I-hour standard. 

Regarding point source emissions, the Tennessee Valley Authority's (TVA's) Bull Run 

Steam Plant located in Anderson County and Kingston Steam Plant located in Roane County 

include a total of 10 coal-fired boiiers. As a result of EPA's "Finding of Significant Contribution 

and Rulemaking for Certain States in the Ozone Transport Assessment Group Region for 

Purposes of Reducing Region Transport of Ozone" (NOx SIP Call), TVA began operation of 

selective catalytic reduction (SCR) systems in 2004 at Bull Run's unit and on eight of the nine 

units at Kingston. TVA began operation of a 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 of these 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 percent reduction). 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. For these reasons, EPA believes that regardless of the status 

of the CAIR program, the NOx SIP call requirements can be relied upon in demonstrating 

maintenance. Here, Tennessee has demonstrated maintenance based in part on those 

requirements. 

32 
In addition, EPA undertook an analysis of the changes in NOx expected across a broader 

region. In particular, EPA reviewed available projections of NOx emissions from nearby states 

from 2002 to 2018. 

Table 3. 2002 Base Annual Emission Inventory Summary for NOx * 

(tons per year) 

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 

33
 
Table 4. 2018 Base Annual Emission Inventory Summary for NOx* 

(tons per year) 

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 

*From the Tennessee Regional Haze SIP, Appendix D, page D.3-5 and support table for 

Technical Support Document for CENRAP Emissions and Air Quality Modeling to 

Support Regional Haze State Implementation Plans, page 2-40, figure 2-4 

From 2002 to 2018 NOx emissions are projected to decrease in the region by 1,215,024 

tpy or 41.4 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 on NOx 

emissions, total NOx emissions are projected to continually decrease throughout the maintenance 

period. 

OnIuly 6,2010, EPA proposed the Transport Rule, 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 of emissions data have been prepared through 2018. 

However, since motor vehicle and non-road emissions continue to decrease long after a rule is 

adopted as the engine population is gradually replaced by newer engines, it is reasonable to 

expect that this projected decrease in regional NOx emissions from mobile and non-road sources 

34
 
should 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 Knoxville Area has a fully approved maintenance plan pursuant to section 

175A ofthe eAA. 

In conjunction with its request to redesignate the Knoxville Area to attainment for the 

1997 8-hour ozone NAAQS, TDEC submitted a SIP revision to provide for the maintenance of 

the 1997 8-hour ozone NAAQS for at least 10 years after the effective date of redesignation to 

attainment. 

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 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 

possibility of future NAAQS violations, the maintenance plan must contain such contingency 

measures, with a schedule for implementation as EPA deems necessary to assure prompt 

correction of any future 1997 8-hour ozone violations. Section 175A of the CAA sets forth the 

elements of a maintenance plan for areas seeking redesignation from nonattainment to 

35 
attainment. The Calcagni Memorandum provides additional guidance on the content of a 

maintenance plan. The Calcagni Memorandum explains that an ozone 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, Tennessee's maintenance plan includes all the necessary components and is 

approvable as part of the redesignation request. 

b. Attainment Emissions 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 of emissions in the Area, which is sufficient to 

attain the 1997 8-hour ozone NAAQS. Tennessee began development of the attainment 

inventory by first developing a baseline 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 could be 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) of the CAA. Non-road mobile emissions estimates were 

based on EPA's NONROAD2008 model. On-road mobile source emissions were calculated 

using EPA's MOBILE6.2 emission factors model. The 2007 VOC and NOx emissions, as well 

as the emissions for other years, for the Knoxville Area were developed consistent with EPA 

guidance, and are summarized in Tables 5 and 6 in the following subsection. 

c. Maintenance Demonstration 

36 
The July 14, 2010, final submittal includes a maintenance plan for the Knoxville Area. 

This demonstration: 

(i) Shows compliance and maintenance of the 1997 8-hour ozone NAAQS by providing 

information to support the demonstration that current and future emissions of VOC and 

NOx remain at or below attainment inventory year 2007 emissions levels. The year 2007 

was chosen as the attainment inventory year because it is one of the most recent three 

years (i.e., 2007, 2008, and 2009) for which the Knoxville Area has 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 "out year," at least 10 years (and beyond) after the time necessary for 

EPA to review and approve the maintenance plan. Per 40 CFR part 93, NOx and VOC 

MVEBs were established for the last year (2024) of the 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 Area VOC Emissions 

(Summer season in tpd) 

Summary of VOC Emissions (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, Sevier and onroad emissions for Cocke County. 

MLA = Commercial Marine Vessels, Locomotives and Aircraft. 

37
 
Table 6. Knoxville Area NOx Emissions 

(Summer season tpd) 

Summan of NOx 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 onroad emissions for Cocke County. 

MLA = Commercial Marine Vessels, Locomotives and Aircraft. 

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 has decided to allocate a portion of the available safety margin to 

the Area's VOC and NOx MVEBs for 2024 for the Knoxville Area and has calculated the safety 

margin in its submittal. Specifically, 14.03 tpd of the 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 safety margin for the Knoxville Area are discussed further in section VII of this 

proposed rulemaking. 

d. Monitoring Network 

38
 
There are currently nine monitors measuring ozone in the Knoxville Area (see Table 1).7 

TDEC and the Knox County Department of Air Quality Management (DAQM) have committed, 

in the maintenance plan, to continue operation of monitors in the Knoxville Area in compliance 

with 40 CPR part 58, and have addressed the requirement for monitoring. 

e. Verification ofContinued Attainment 

The State of Tennessee, through TDEC, and the Knox County DAQM have the legal 

authority to enforce and implement the requirements of the 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 of the maintenance plan by performing future 

reviews of triennial emission inventories for the Knoxville Area using the latest emissions 

factors, models and methodologies. For these periodic inventories, TDEC and Knox County 

DAQM will review the assumptions made for the purpose of the maintenance demonstration 

concerning projected growth of activity levels. If any of these assumptions appear to have 

changed substantially, the Knoxville Area will re-project emissions. 

J. Contingency Plan. 

The contingency plan provisions are designed to promptly correct a violation of the 

NAAQS that occurs after redesignation. Section 175A of the CAA requires that a maintenance 

7 Of the nine air quality ozone monitors in the Knoxville Area. the Clingman's Dome ozone monitoring site in 

Sevier County does not meet siting criteria listing in 40 CFR 58. and thus is not appropriate to be used for the 

determination of attainment or nonattainment for the ozone NAAQS. 

39 
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). 

In the 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 of the Area. The contingency plan included in the submittal 

includes a triggering mechanism to determine when contingency measures are needed and a 

process of developing and implementing appropriate control measures. The primary trigger will 

be a quality assured/quality controlled (QNQC) violating design value of the 1997 8-hour ozone 

NAAQS. In addition to the primary trigger indicated above, Tennessee and the Knox County 

DAQM will monitor regional emissions through the Consolidated Emissions Reporting Rule 

(CERR). If the 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, if ambient monitoring data indicates that a violation of the three-year 

design value may be imminent, TDEC and Knox County DAQM will evaluate existing control 

measures to determine whether further emission reduction measures should be implemented. If 

QNQC data indicates a violating design value for the 1997 8-hour ozone NAAQS, then the 

40
 
triggering event will be the date of the design value violation, and not the fmal QNQC date. 

However, if initial monitoring data indicates a possible violation but later QNQC data indicates 

that the NAAQS was not violated, then a triggering event will not have occurred, and 

contingency measures will not be required. 

The contingency plan states that upon a measured violation of the 1997 8-hour ozone 

NAAQS in the Knoxville Area, TDEC and the Knox County DAQM will complete sufficient 

analyses and provide those to the EPA. If deemed necessary, contingency measures would be 

adopted and implemented as expeditiously as possible, but no later than eighteen to twenty-four 

months after a triggering event. The proposed 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 stakeholder process; 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 or more of the following contingency measures to re-attain the 

NAAQS: 

•	 Implementation of diesel 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, 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 levels 

•	 Additional enforcement or outreach on driver observance of reduced 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 lawnmower replacement programs 

•	 Seasonal open burning ban in nonattainment counties 

42 
• Evaluate anti-idling rules and/or policy 

• Additional controls in upwind areas, if necessary 

Other control measures, not included in the above list, will be considered if new control 

programs are deemed more advantageous for this Area. 

EPA has concluded that the maintenance plan adequately addresses the five basic 

components of a maintenance plan: attainment inventory, maintenance demonstration, 

monitoring network, verification of continued attainment, and a contingency plan. The 

maintenance plan SIP revision submitted by the State of Tennessee for the Knoxville Area meets 

the requirements of section 175A of the CAA and is approvable. 

VII.	 What is EPA's Analysis of Tennessee's Proposed NOx and VOC MVEBs for the 

Knoxville Area? 

Under the 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 maintenance plans create MVEBs for criteria pollutants and/or 

their precursors to address pollution from cars and trucks. Per 40 CFR part 93, an MVEB is 

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 confonnity rule (58 FR 62188). The preamble also describes how to establish the 

MVEB in the SIP and how to revise the MVEB. 

43 
After 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 of its maintenance plan, 2024. The 

MVEBs reflect the total on-road emissions for 2024, plus an allocation from the available voe 

and NOx safety margin. Under 40 eFR 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. These 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 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 of the 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 

NOx for the Knoxville Area because EPA has determined that the Area maintains the 1997 8­

44 
hour ozone NAAQS with the emissions at the levels of the budgets. Once the MVEBs for the 

Knoxville Area (the subject of this rulemaking) are approved or found adequate (whichever is 

done first), they must be used for future conformity determinations. 

VIII.	 What Is the Status of EPA's Adequacy Determination for the Proposed NOx and 

VOC MVEBs for 2024 for the Knoxville Area? 

Under section 176(c) of the CAA, new transportation 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. If a transportation plan does not "conform," most new projects that 

would expand the capacity of roadways cannot go forward. Regulations at 40 CPR 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 a maintenance plan for that NAAQS. 

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 

45
 
agencies in detennining whether proposed transportation projects "confonn" to the SIP as 

required by section 176(c) of the CAA. 

EPA's substantive criteria for detennining "adequacy" of an MVEB are set out in 40 

CFR 93.118(e)(4). The process for detennining "adequacy" consists of three basic steps: public 

notification of a SIP submission, a public comment period, and EPA's adequacy fmding. This 

process for determining the adequacy of submitted SIP MVEBs was initially outlined in EPA's 

May 14, 1999, guidance, "Conformity Guidance on Implementation of March 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 Court Decision and Additional Rule Change," on July 1, 2004 (69 

FR 40004). Additional infonnation on the adequacy process for MVEBs is available in the 

proposed rule entitled, "Transportation Confonnity 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. The Tennessee SIP submission, including the Knoxville Area 

VOC and NOx MVEBs was open for public comment on EPA's adequacy Web site on June 15, 

2010, found athttp://www.epa.gov/otaq!stateresources/transconf!currsips.htm. The public 

comment period on adequacy of the 2024 VOC and NOx MVEBs for Knoxville Area closed on 

July 15, 2010. EPA did not receive any comments on the adequacy of the MVEBs, nor did EPA 

receive any requests for the SIP submittal. 

46 
EPA intends to make its detennination on the adequacy of the 2024 MVEBs for the 

Knoxville Area for transportation confonnity purposes in the near future by completing the 

adequacy process that was started on June 15,2010. After EPA finds the 2024 MVEBs adequate 

or approves them, the new MVEBs for VOC and NOx must be used, for future transportation 

confonnity detenninations. For required regional emissions analysis years prior to 2024, the 

co~onnity test will be the applicable interim emissions test applicable for the Area per 40 CPR 

Part 93 (the transportation confonnity rule). For required regional emissions analysis years that 

involve 2024 or beyond, the applicable budgets will be the new 2024 MVEBs. The 2024 

MVEBs are defined in section VII of this proposed rulemaking. 

IX. What is EPA's analysis of the proposed 2007 base year emissions inventory for the 

Knoxville Area? 

As discussed above, section 172(c)(3) of the CAA requires areas to submit a base year 

emissions inventory. As part of Tennessee'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 of point sources, area sources, on-road mobile 

sources, and non-road mobile sources. All emission summaries were accompanied by sourcespecific descriptions of emission calculation procedures and sources of input 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 of the 2007 summer day emissions of VOC and NOx for the 

Knoxville Area. 

47 
Table 8. Knoxville Area 2007 Summer Day Emissions 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 

Total for 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.	 Proposed Action on the Redesignation Request and Maintenance Plan SIP Revision 

Including Approval of the 2024 NOx and VOC MVEBs for the Knoxville Area. 

EPA is proposing to make the determination that the Knoxville Area has 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 redesignation request 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 of the July 14,2010, SIP revision as meeting the requirements of section 175A of the 

48 
CAA. 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 of expected emissions for all source categories, the Area will continue 

to maintain the 1997 8-hour ozone NAAQS. 

Further as part of today' s action, EPA is describing the status of its 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 of EPA'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 of the Act and applicable Federal regulations. 42 U.S.c. 7410(k); 40 CFR 

52.02(a). Thus, in reviewing SIP submissions, EPA's role is to approve state choices, provided 

that they meet the criteria of the CAA. Accordingly, this proposed action merely approves state 

law as meeting Federal requirements and does not impose additional requirements beyond those 

imposed by state law. For that reason, this proposed action: 

•	 is not a "significant regulatory action" subject to review by the Office of Management 

and Budget under Executive Order 12866 (58 FR 51735, October 4, 1993); 

•	 does not impose an information collection burden under the provisions of the Paperwork 

Reduction Act (44 U.S.c. 3501 et seq.); 

49 
•	 is certified as not having a significant economic impact on a substantial number of small 

entities under the Regulatory Flexibility Act (5 U.S.C. 601 et seq.); 

•	 does not contain any unfunded mandate or significantly or uniquely affect small 

governments, as described in the Unfunded Mandates Refonn Act of 1995 (Public Law 

104-4); 

•	 does not have Federalism implications as specified in Executive Order 13132 (64 FR 

43255, August 10, 1999); 

•	 is not an economically significant regulatory action based on health or safety risks subject 

to Executive Order 13045 (62 FR 19885, April 23, 1997); 

•	 is not a significant regulatory action subject to Executive Order 13211 (66 FR 28355, 

May 22, 2001); 

•	 is not subject to requirements of Section 12(d) of the National Technology Transfer and 

Advancement Act of 1995 (15 U.S.C. 272 note) because application of those 

requirements would be inconsistent with the CAA; and 

•	 does not provide EPA with the discretionary authority to address, as appropriate, 

disproportionate human health or environmental effects, using practicable and legally 

pennissible methods, under Executive Order 12898 (59 FR 7629, February 16, 1994). 

In addition, this proposed rule does not have tribal implications as specified by Executive Order 

13175 (65 FR 67249, November 9,2000), 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 or preempt tribal law. 

50 
List of Subjects: 

40 CFR Part 52 

Environmental protection, Air pollution control, Intergovernmental relations, Nitrogen oxides, 

Ozone, Reporting and recordkeeping requirements, and Volatile organic compounds. 

40 CFR Part 81 

Environmental protection, Air pollution 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