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Adequacy Status of the Hickory-Morganton-Lenoir, North Carolina 1997 Annual PM2.5

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Environmental Protection Agency (EPA).


Notice of Adequacy.


In this notice, EPA is notifying the public of its finding that the nitrogen oxides (NOX) motor vehicle emissions budgets (MVEBs) in the Hickory-Morganton-Lenoir, North Carolina area (hereafter referred to as the “Hickory Area”) maintenance plan for the 1997 annual PM2.5 standard, submitted on December 18, 2009, and supplemented on December 22, 2010, by the North Carolina Department of Environment and Natural Resources (NCDENR) are adequate for transportation conformity purposes. EPA is also making an insignificance finding for direct fine particulate (PM2.5) through the transportation conformity adequacy process for the Hickory Area. The Hickory Area is comprised of the entire county of Catawba in North Carolina. On March 2, 1999, the District of Columbia Circuit Court ruled that submitted state implementation plans (SIPs) cannot be used for transportation conformity determinations until EPA has affirmatively found them adequate. As a result of EPA's finding, the Hickory Area must use the NOX MVEBs from the submitted maintenance plan and supplement for the Hickory Area for future conformity determinations. Additionally, as a result of this finding, the Hickory Area is not required to perform a regional emissions analysis for direct PM2.5 in future PM2.5 transportation conformity determinations for the 1997 annual PM2.5 standard.


The adequacy finding for the NOX MVEBs and the insignificance finding for direct PM2.5 are effective May 17, 2011.

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Dianna B. Smith, Environmental Scientist, U.S. Environmental Protection Agency, Region 4, Air Planning Branch, Air Quality Modeling and Transportation Section, 61 Forsyth Street, SW., Atlanta, Georgia 30303. Ms. Smith can also be reached by telephone at (404) 562-9207, or via electronic mail at The finding is available at EPA's conformity Web site:​otaq/​transp.htm (once there, click on the “Transportation Conformity” text icon, then look for “Adequacy Review of SIP Submissions”).

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Today's notice is simply an announcement of findings that EPA has already made. EPA Region 4 sent a letter to NCDENR on February 3, 2011, stating that the 2011 and 2021 NOX MVEBs in the 1997 PM2.5 maintenance plan for Hickory, dated December 18, 2009, and supplemented on December 22, 2010, are adequate. The letter also states that direct PM2.5 is insignificant for the Hickory Area, therefore no regional emissions analysis is required. EPA posted the availability of the Hickory Area NOX MVEBs and insignificance demonstration on EPA's Web site on November 23, 2010, as part of the adequacy process, for the purpose of soliciting comments. The comment period ran from November 23, through December 23, 2010. EPA's findings have also been announced on EPA's conformity Web site:​otaq/​stateresources/​index.htm, (once there, click “Transportation Conformity” text icon, then look for “Adequacy Review of SIP Submissions”). The adequate NOX MVEBs are provided in the following table:

Hickory Area NOX MVEB


Catawba County3,996,6012,236,028

Transportation conformity is required by section 176(c) of the Clean Air Act, as amended in 1990. EPA's conformity rule, 40 Code of Federal Regulations (CFR) Part 93, requires that transportation plans, programs and projects conform to state air quality implementation plans and establishes the criteria and procedures for determining whether or not they do. Conformity to a SIP means that transportation activities will not produce new air quality violations, worsen existing violations, or delay timely attainment of the national ambient air quality standards (NAAQS).

The criteria by which EPA determines whether a SIP's MVEB is adequate for transportation conformity purposes are outlined in 40 CFR 93.118(e)(4). Additionally, the criteria by which EPA determines whether a particular pollutant/precursor is an insignificant contributor to the air quality problem in an area can be found at 40 CFR 93.109(m). Insignificance findings are based on a number of factors, including the percentage of motor vehicle emissions in context of the total SIP inventory, the current state of air quality as determined by monitoring data for that NAAQS, the absence of SIP motor vehicle control measures, and historical trends and future projections of the growth of motor vehicle emissions. EPA's rationale for the allowance of insignificance findings can be found in the July 1, 2004, revision to the transportation conformity rule at 69 FR 40004. Specifically, the rationale is explained on page 40061 under the subsection entitled “B. Areas With Insignificant Motor Vehicle Emissions.” Please note that an adequacy review is separate from EPA's completeness review, and it also should not be used to prejudge EPA's ultimate approval of the SIP. Even if EPA finds the MVEB adequate or makes an insignificance finding through the adequacy process, the Agency may later disapprove the SIP.

Transportation partners should note this insignificance finding in future transportation conformity determinations. While this insignificance finding waives the requirements for regional emissions analyses for direct PM2.5 for the Hickory Area for the 1997 PM2.5 NAAQS, as mentioned above, it does not waive other conformity requirements for the 1997 PM2.5 NAAQS for the Hickory Area, nor does it waive transportation conformity requirements for other pollutants/precursors for which the Area may be designated nonattainment or redesignated to attainment with a maintenance plan.

EPA has described the process for determining the adequacy of submitted SIP MVEBs in a May 14, 1999, memorandum entitled “Conformity Guidance on Implementation of March 2, 1999 Conformity Court Decision.” EPA has followed this guidance in making this adequacy determination. This guidance is incorporated into EPA's July 1, 2004, final rulemaking entitled “Transportation Conformity Rule Amendments for the New 8-hour Start Printed Page 24476Ozone and PM2.5 National Ambient Air Quality Standards and Miscellaneous Revisions for Existing Areas; Transportation Conformity Rule Amendments: Response to Court Decision and Additional Rule Changes” (69 FR 40004).

Within 24 months from the effective date of this notice, the transportation partners will need to demonstrate conformity to the new NOX MVEBs if the demonstration has not already been made, pursuant to 40 CFR 93.104(e). See 73 FR 4419 (January 24, 2008).

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

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Dated: April 18, 2011.

A. Stanley Meiburg,

Acting Regional Administrator, Region 4.

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[FR Doc. 2011-10570 Filed 4-29-11; 8:45 am]