ENVIRONMENTAL PROTECTION AGENCY 

[EPA-R04-OAR-2010-0260-201019 ; FRLAdequacy Status of the Alabama Portion (Jackson County) of the Chattanooga, Tennessee TriState Area 1997 Annual PM2.5 Attainment Demonstration Insignificance Finding for 

Transportation Conformity Purposes 

AGENCY: Environmental Protection Agency (EPA). 

ACTION: Notice of Adequacy. 

SUNEVIARY: In this notice, EPA is notifying the public that EPA has made an insignificance 

finding through the transportation conformity adequacy process for directly emitted fine 

particulate matter (PM2,5) and nitrogen oxides (NOx) emissions as contained in the 1997 PM2.5 

attainment demonstration for the Alabama portion of the tri-state Chattanooga, Tennessee 

nonattainment area (hereafter referred to as the "Jackson County Area") . On October 14, 2009, 

the State of Alabama, through the Alabama Department of Environmental Management 

(ADEM), submitted an attainment demonstration plan for the 1997 annual PM2.5 standard for 

Jackson County, Alabama as part of the tri-state Chattanooga 1997 PM2.5 nonattainment area. 

The tri-state Chattanooga 1997 annual PM2.5 nonattainment area is comprised of a portion of 

Jackson County, Alabama; Catoosa and Walker Counties, Georgia; and Hamilton County, 

Tennessee. As a result of EPA's finding, the portion of Jackson County within the tri-state 

Chattanooga 1997 PM2.5 nonattainment area is no longer required to perform a regional 

emissions analysis for either directly emitted PM2.5 or NOx as part of future PM2.5 conformity 

determinations for the 1997 annual PM2.5 standard . This finding only relates to the Alabama 

portion of this Area, and does not relieve the Georgia or Tennessee portions of the tri-state 1997 
PM2,5 nonattainment area from the requirement of performing the regional emissions analyses for 

direct PM2.5 and NOx. EPA will review the adequacy of the Georgia and Tennessee submittals 

with regard to the motor vehicle emission budgets or insignificance findings (if any and if 

appropriate) in separate actions. 

DATES: This insignificance finding for direct PM2.5 and NOx is effective [insert date 15 days 

after date of publication in the Federal Register . 

FOR FURTHER INFORMATION CONTACT: Dianna 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 smith.dianna@epa. o~-v . The 

finding is available at EPA's conformity website: 

httn://www.epa. ,-ov/otaa/.vtateresources/transconf/adequacy.htm 

SUPPLEMENTARY INFORMATION: 

This notice is simply an announcement of a finding that EPA has already made. EPA 

Region 4 sent a letter to ADEM on March 25, 2010, stating that regional mobile source 

emissions of direct PM2,5 and NOx emissions are insignificant as provided in the Alabama 

portion of the 1997 annual PM2.5 attainment demonstration for the Jackson County Area 

submitted on October 14, 2009. EPA posted the availability of the insignificance finding on 

EPA's website on February 16, 2010, as part of the adequacy process, for the purpose of 

soliciting comments . The comment period ran from February 16, 2010, through March 18, 2010. 
During EPA's adequacy comment period, no comments were received on the insignificance 

finding for the Jackson County Area. Through this notice, EPA is informing the public of the 

insignificance finding for direct PM2,5 and NOx for the purpose of implementing transportation 

conformity in the Jackson County Area for the 1997 PM2,5 standard . EPA's findings have also 

been announced on EPA's conformity website: 

http : //www. epa. gov/otaa/stateresources/transconf/adequacy . htm. 

Transportation conformity is required by section 176(c) of the Clean Air Act, as amended 

in 1990. EPA's conformity rule requires that transportation plans, programs and projects -

conform to state air quality implementation plans and establishes the criteria and procedures fot 

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. 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. 

The criteria by which EPA determines whether a S1P's motor vehicle emissions budget is 

adequate for transportation conformity purposes are outlined in 40 Code of Federal Regulations 

(CFR) 93.118(e)(4) : The Transportation Conformity Rule in 40 CFR 93,109(k) states that a 

regional emissions analysis is no longer necessary if EPA finds through the adequacy or approval 

process that a SIP demonstrates that regional motor vehicle emissions are an insignificant 

contributor to the air quality problem for that pollutant/precursor. A finding of insignificance 

does not change the requirement for a regional analysis for other pollutants/precursors and does 

not change the requirement for hot-spot analysis . (See 73 FR 4419, January 24, 2008.) 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 attainment demonstration plan for the 

Jackson County Area. Even if EPA finds the insignificance determination adequate, the 

attainment demonstration plan could later be disapproved. 

Transportation partners should note this insignificance finding in future transportation 

conformity determinations. Additionally, while this insignificance finding waives the 

requirements for regional emissions analyses for direct PM2.5 and NOx for the Jackson County 

Area for the 1997 PM2,5 standard, as mentioned above, it does not waive other conformity 

requirements for the 1997 PM2.5 standard for the Jackson County 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 budgets 

(which also applies to insignificance determinations) 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 Ozone 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). 
Authority: 42 U.S.C. 7401 et sea. 

Dated: JUN - 8 2010 

Jun 8, 2010 

Acting Regional Administrator, 

Region 4.