IV. Why Is EPA Taking These Actions?

On September 28, 2006, PADEP requested redesignation of the Tioga Area to attainment for the 8hour ozone standard. On September 28, 2006, PADEP submitted a maintenance plan for the Tioga Area as a SIP revision to assure continued attainment at least 10 years after redesignation. EPA has determined that the Tioga Area has attained the standard and has met the requirements for redesignation set forth in section 107(d)(3)(E). PADEP also submitted a 2002 base year inventory concurrently with its maintenance plan as a SIP revision and supplemented on November 14, 2006.

V. What Would Be the Effect of These Actions?

Approval of the redesignation request would change the designation of the Tioga Area from nonattainment to attainment for the 8hour ozone NAAQS found at 40 CFR part 81. It would also incorporate into the Pennsylvania SIP a 2002 base year inventory and a maintenance plan ensuring continued attainment of the 8hour ozone NAAQS in the Tioga Area for the next 10 years. The maintenance plan includes contingency measures to remedy any future violations of the 8hour NAAQS (should they occur), and identifies the MVEBs for NOX and VOC for transportation conformity purposes for the years 2004, 2009 and 2018. These motor vehicle emissions (2004) and MVEBs (2009 and 2018) are displayed in the following table:
Table 1.Motor Vehicle Emissions Budgets in Tons Per Day (tpd) Year NOX VOC 2004.................................................. 4.8 3.0 2009.................................................. 3.4 2.2 2018.................................................. 1.6 1.3 VI. What is EPA's Analysis of the State's Request?

EPA is proposing to determine that Tioga Area has attained the 8 hour ozone standard and that all other redesignation criteria have been met. The following is a description of how PADEP's September 28, 2006 submittal satisfies the requirements of section 107(d)(3)(E) of the CAA.

A. The Tioga Area Has Attained the 8Hour Ozone NAAQS

EPA is proposing to determine that the Tioga Area has attained the 8hour ozone NAAQS. For ozone, an area may be considered to be attaining the 8hour ozone NAAQS if there are no violations, as determined in accordance with 40 CFR 50.10 and Appendix I of part 50, based on three complete and consecutive calendar years of quality assured air quality monitoring data. To attain this standard, the design value, which is the 3year average of the fourthhighest daily maximum 8hour average ozone concentrations, measured at each monitor within the area over each year must not exceed the ozone standard of 0.08 ppm. Based on the rounding convention described in 40 CFR part 50, Appendix I, the standard is attained if the design value is 0.084 ppm or below. The data must be collected and qualityassured in accordance with 40 CFR part 58, and recorded in the Air Quality System (AQS). The monitors generally should have remained at the same location for the duration of the monitoring period required for demonstrating attainment.

In the Tioga Area, there is one monitor that measures air quality with respect to ozone. As part of its redesignation request, Pennsylvania submitted ozone monitoring data for the years 20032005 (the most recent three years of data available as of the time of the redesignation request) for the Tioga Area. This data has been quality assured and is recorded in AQS. The fourthhigh 8hour daily maximum concentrations, along with the threeyear average, are summarized in Table 2.
Table 2.Tioga County Nonattainment Area Fourth Highest 8Hour Average Values; Tioga County Monitor, AQS ID 421174000
Annual 4th High Reading Year (ppm) 2003...................................... 0.084
2004...................................... 0.079

2005...................................... 0.080

The average for the 3year period 2003 through 2005 is 0.081 ppm

The air quality data for 20032005 show that the Tioga Area has attained the standard with a design value of 0.081 ppm. The data collected at the Tioga Area monitor satisfies the CAA requirement that the 3year average of the annual fourthhighest daily maximum 8hour average ozone concentration is less than or equal to 0.08 ppm. PADEP's request for redesignation for the Tioga Area indicates that the data was quality assured in accordance with 40 CFR part 58. PADEP uses the AQS as the permanent database to maintain its data and quality assures the data transfers and content for accuracy. In addition, as discussed below with respect to the maintenance plan, PADEP has committed to continue monitoring in accordance with 40 CFR part 58. In summary, EPA has determined that the data submitted by Pennsylvania and taken from AQS indicates that Tioga Area has attained the 8hour ozone NAAQS. [[Page 26050]]
B. The Tioga Area Has Met All Applicable Requirements Under Section 110 and Part D of the CAA and Has a Fully Approved SIP Under Section 110(k) of the CAA

EPA has determined that the Tioga Area has met all SIP requirements applicable for purposes of this redesignation under section 110 of the CAA (General SIP Requirements) and that it meets all applicable SIP requirements under Part D of Title I of the CAA, in accordance with section 107(d)(3)(E)(v). In addition, EPA has determined that the SIP is fully approved with respect to all requirements applicable for purposes of redesignation in accordance with section 107(d)(3)(E)(ii). In making these proposed determinations, EPA ascertained what requirements are applicable to the area and determined that the applicable portions of the SIP meeting these requirements are fully approved under section 110(k) of the CAA. We note that SIPs must be fully approved only with respect to applicable requirements.

The September 4, 1992 Calcagni memorandum (``Procedures for Processing Requests to Redesignate Areas to Attainment,'' Memorandum from John Calcagni, Director, Air Quality Management Division, September 4, 1992) describes EPA's interpretation of section 107(d)(3)(E) with respect to the timing of applicable requirements. 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, September 17, 1993, and 60 FR 12459, 1246566, (March 7, 1995) (redesignation of DetroitAnn Arbor). 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, but are not required as a prerequisite to redesignation. Section 175A(c) of the CAA. Sierra Club v. EPA, 375 F.3d 537 (7th Cir. 2004). See also, 68 FR 25424, 25427 (May 12, 2003) (redesignation of St. Louis).

This action also sets forth EPA's views on the potential effect of the Court's ruling in South Coast on this redesignation action. For the reasons set forth below, EPA does not believe that the Court's ruling alters any requirements relevant to this redesignation action so as to preclude redesignation, and does not prevent EPA from finalizing this redesignation. EPA believes that the Court's decision, as it currently stands or as it may be modified based upon any petition for rehearing that has been filed, imposes no impediment to moving forward with redesignation of this area to attainment, because in either circumstance redesignation is appropriate under the relevant redesignation provisions of the Act and longstanding policies regarding redesignation requests.

1. Section 110 General SIP Requirements

Section 110(a)(2) of Title I of the CAA delineates the general requirements for a SIP, which include enforceable emissions limitations and other control measures, means, or techniques, provisions for the establishment and operation of appropriate devices necessary to collect data on ambient air quality, and programs to enforce the limitations. The general SIP elements and requirements set forth in section 110(a)(2) include, but are not limited to, the following:

Section 110(a)(2)(D) requires that SIPs contain certain measures to prevent sources in a State from significantly contributing to air quality problems in another State. To implement this provision, EPA has required certain States to establish programs to address transport of air pollutants in accordance with the NOX SIP Call, October 27, 1998 (63 FR 57356), amendments to the NOX SIP Call, May 14, 1999 (64 FR 26298) and March 2, 2000 (65 FR 11222), and the Clean Air Interstate Rule (CAIR), May 12, 2005 (70 FR 25162). However, the section 110(a)(2)(D) requirements for a State are not linked with a particular nonattainment area's designation and classification in that State. EPA believes that the requirements linked with a particular nonattainment area's designation and classifications are the relevant measures to evaluate in reviewing a redesignation request. The transport SIP submittal requirements, where applicable, continue to apply to a State regardless of the designation of any one particular area in the State.

Thus, we do not believe that these requirements are 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 Tioga Area will still be subject to these requirements after it 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 policy is consistent with EPA's existing policy on applicability of conformity (i.e., for redesignations) and oxygenated fuels requirement. See, Reading, Pennsylvania, proposed and final rulemakings (61 FR 5317453176, October 10, 1996), (62 FR 24816, May 7, 1997); ClevelandAkronLorain, Ohio, final rulemaking (61 FR 20458, May 7, 1996); and Tampa, Florida, final rulemaking (60 FR 62748, December 7, 1995). See also, the discussion on this issue in the Cincinnati redesignation (65 FR at 37890, June 19, 2000), and in the Pittsburgh redesignation (66 FR at 50399, October 19, 2001). Similarly, with respect to the NOX SIP Call rules, EPA noted in its Phase 1 Final Rule to Implement the 8hour Ozone NAAQS, that the NOX SIP Call rules are not ``an `applicable requirement' for purposes of section 110(l) because the NOX rules apply regardless of an area's attainment or nonattainment status for the 8hour (or the 1 hour) NAAQS.'' 69 FR 23951, 23983 (April 30, 2004).

EPA believes that section 110 elements not linked to the area's nonattainment status are not applicable for purposes of redesignation. Any section 110 requirements that are linked to the Part D requirements for 8hour ozone nonattainment areas are not yet due, because, as we explain later in this notice, no Part D requirements applicable for purposes of redesignation under the 8hour standard became due prior to submission of the redesignation request.

Because the Pennsylvania SIP satisfies all of the applicable general SIP elements and requirements set forth in section 110(a)(2), EPA concludes that Pennsylvania has satisfied the criterion of section 107(d)(3)(E) regarding section 110 of the Act.
[[Page 26051]]
2. Part D Nonattainment Area Requirements Under the 1Hour and 8Hour Standards

The Tioga Area was designated a basic nonattainment area for the 8 hour ozone standard. Sections 172176 of the CAA, found in subpart 1 of Part D, set forth the basic nonattainment requirements for all nonattainment areas. As discussed previously, because the Tioga Area was designated unclassifiable/attainment under the 1hour standard, and was never designated nonattainment for the 1hour standard, there are no outstanding 1hour nonattainment area requirements it would be required to meet. Thus, we find that the Court's ruling does not result in any additional 1hour requirements for purposes of redesignation.

With respect to the 8hour standard, EPA notes that the Court's ruling rejected EPA's reasons for classifying areas under subpart 1 for the 8hour standard, and remanded that matter to the Agency. Consequently, it is possible that this area could, during a remand to EPA, be reclassified under subpart 2. Although any future decision by EPA to classify this under subpart 2 might trigger additional future requirements for the area, EPA believes that this does not mean that redesignation of the area cannot now go forward. This belief is based upon (1) EPA's longstanding policy of evaluating requirements in accordance with the requirements due at the time the request is submitted; and (2) consideration of the inequity of applying retroactively any requirements that might in the future be applied.

At the time the redesignation request was submitted, the Tioga Area was classified under subpart 1 and was obligated to meet subpart 1 requirements. Under EPA's longstanding interpretation of section 107(d)(3)(E) of the Clean Air Act, 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, Michael Shapiro Memorandum, September 17, 1993, and 60 FR 12459, 1246566 (March 7, 1995) (Redesignation of DetroitAnn Arbor); Sierra Club v. EPA, 375 F.3d 537 (7th Cir. 2004) (which upheld this interpretation); 68 FR 25418, 25424, 25427 (May 12, 2003) (redesignation of St. Louis).

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 recognized the inequity in such retroactive rulemaking. See, Sierra Club v. Whitman, 285 F. 3d 63 (D.C. Cir. 2002), in which the D.C. Circuit upheld a District Court's ruling refusing to make retroactive an EPA determination that was past the statutory due date. Such a determination would have resulted in the imposition of additional requirements on the area. The Court stated: ``Although EPA failed to make the nonattainment determination within the statutory time frame, Sierra Club's proposed solution only makes the situation worse. Retroactive relief would likely impose large costs on the States, which would face fines and suits for not implementing air pollution prevention plan in 1997, even though they were not on notice at the time.'' Id. at 68. Similarly, here it would be unfair to penalize the area by applying to it for purposes of resedignation additional SIP requirements under subpart 2 that were not in effect at the time it submitted its redesignation request.

With respect to the 8hour standard, EPA proposes to determine that Pennsylvania's SIP meets all applicable SIP requirements under Part D of the CAA, because no 8hour ozone standard Part D requirements applicable for purposes of redesignation became due prior to submission of the redesignation request for the Tioga Area. Because the Commonwealth submitted a complete redesignation request for the Tioga Area prior to the deadline for any submissions required under the 8 hour standard, we have determined that the Part D requirements do not apply to the Tioga Area for the purposes of redesignation.

In addition to the fact that no Part D requirements applicable under the 8hour standard became due prior to submission of the redesignation request, EPA believes it is reasonable to interpret the general conformity and NSR requirements of Part D as not requiring approval prior to redesignation.

With respect to 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 U.S.C. and the Federal Transit Act (``transportation conformity'') as well as to all other Federally supported or funded projects (``general conformity''). State conformity revisions must be consistent with Federal conformity regulations relating to consultation, enforcement and enforceability that the CAA required EPA to promulgate.

EPA believes it is reasonable to interpret the conformity SIP requirements as not applying for purposes of evaluating the redesignation request under section 107(d) since State conformity rules are still required after redesignation and Federal conformity rules apply where State rules have not been approved. See, Wall v. EPA, 265 F. 3d 426, 438440 (6th Cir. 2001), upholding this interpretation. See also, 60 FR 62748 (December 7, 1995).

In the case of the Tioga Area, EPA has also determined that before being redesignated, the Tioga Area need not comply with the requirement that a NSR program be approved prior to redesignation. The Part D NSR SIP revision does not come due until June 15, 2007, see, 70 FR 71683, November 29, 2005, and thus is not an applicable requirement with respect to redesignation. Additionally, Pennsylvania's preconstruction permitting program regulations in Chapter 127.200217 of the Pennsylvania Code (approved into the SIP at 40 CFR 52.2020(c)), apply only to ozone nonattainment area sources that are located in areas classified as marginal or worse, i.e., to subpart 2 nonattainment areas. Pennsylvania's NSR regulations do not apply to sources in nonattainment areas classified as basic nonattainment under subpart 1. Consequently, sources in the Tioga Area are subject to Part D NSR requirements of Appendix S to 40 CFR part 51, pursuant to 40 CFR 52.24(k). Appendix S of 40 CFR part 51 contains the preconstruction permitting program that applies to major stationary sources in nonattainment areas lacking an approved Part D NSR program. Appendix S applies during the interim period after EPA designates an area as nonattainment, but before EPA approves revisions to a SIP to implement the Part D NSR requirements for that pollutant. See, 70 FR 71618 (November 29, 2005). The Chapter 127 Part D NSR regulations in the Pennsylvania SIP explicitly apply to attainment areas within the Ozone Transport Region (OTR). See, Chapter 127 in 40 CFR 52.2020(c)(1); See, 66 FR 53094, October 19, 2001. Therefore, after the Tioga Area is redesignated to attainment, sources in the Tioga Area will be subject to Part D NSR applicable under the permitting regulations in [[Page 26052]]

Chapter 127, because the Tioga Area is located in the OTR.

All areas in the OTR, both attainment and nonattainment, are subject to additional control requirements under section 184 for the purpose of reducing interstate transport of emissions that may contribute to downwind ozone nonattainment. The section 184 requirements include reasonably available control technology (RACT), NSR, enhanced vehicle inspection and maintenance, and Stage II vapor recovery or a comparable measure.

In the case of Tioga Area, which is located in the OTR, nonattainment NSR will continue to be applicable after redesignation. On October 19, 2001 (66 FR 53094), EPA fully approved the 1hour Pennsylvania's NSR SIP revision consisting of Pennsylvania's Chapter 127 Part D NSR regulations that cover the Tioga Area. The Chapter 127 Part D NSR regulations in the Pennsylvania SIP explicitly apply the requirements for NSR of section 184 of the CAA to attainment areas within the OTR.

EPA has also interpreted the section 184 OTR requirements, including the NSR program, as not being applicable for purposes of redesignation. The rationale for this is based on two factors. First, the requirement to submit SIP revisions for the section 184 requirements continues to apply to areas in the OTR after redesignation to attainment. Therefore, the State remains obligated to have NSR, as well as RACT, even after redesignation. Second, the section 184 control measures are regionwide requirements and do not apply to the Tioga Area by virtue of the area's designation and classification. Rather, section 184 measures are required in the Tioga Area because it is located in the OTR. See, 61 FR 53174, 5317553176 (October 10, 1996) and 62 FR 24826, 2483032 (May 7, 1997).
3. The Tioga Area Has a Fully Approved SIP for the Purposes of Redesignation

EPA has fully approved the Pennsylvania SIP for the purposes of redesignation. EPA may rely on prior SIP approvals in approving a redesignation request. Calcagni Memo, p. 3; Southwestern Pennsylvania Growth Alliance v. Browner, 144 F. 3d 984, 98990 (6th Cir. 1998),; Wall v. EPA, 265 F.3d 426 (6th Cir. 2001), plus any additional measures it may approve in conjunction with a redesignation action. See also, 68 FR at 25425 (May 12, 2003) and citations therein.

The Tioga Area was a 1hour attainment/unclassifiable area at the time of its designation as a basic 8hour ozone nonattainment area on April 30, 2004 (69 FR 23857). Because the Tioga Area was a 1hour attainment/unclassifiable area, there are no previous Part D SIP submittal requirements. Also, no Part D submittal requirements have come due prior to the submittal of the 8hour maintenance plan for the area. Therefore, all Part D submittal requirements have been fulfilled. Because there are no outstanding SIP submission requirements applicable for the purposes of redesignation of the Tioga Area, the applicable implementation plan satisfies all pertinent SIP requirements. As indicated previously, EPA believes that the section 110 elements not connected with Part D nonattainment plan submissions and not linked to the area's nonattainment status are not applicable requirements for purposes of redesignation. EPA also believes that no 8hour Part D requirements applicable for purposes of redesignation have yet become due for the Tioga Area, and therefore they need not be approved into the SIP prior to redesignation.
C. The Air Quality Improvement in the Tioga Area Is Due to Permanent and Enforceable Reductions in Emissions Resulting From Implementation of the SIP and Applicable Federal Air Pollution Control Regulations and Other Permanent and Enforceable Reductions

EPA believes that the Commonwealth has demonstrated that the observed air quality improvement in the Tioga Area is due to permanent and enforceable reductions in emissions resulting from implementation of the SIP, Federal measures, and other Stateadopted measures. Emissions reductions attributable to these rules are shown in Table 3. Table 3.Total VOC and NOX Emissions for 2002 and 2004 in Tons Per Day (tpd) Year Point Area Nonroad Mobile Total Volatile Organic Compounds (VOC) Year 2002................................................ 0.6 2.7 2.1 3.4 8.8 Year 2004................................................ 0.6 2.7 2.2 3.0 8.5 Diff. (0204)............................................ 0.0 0.0 0.1 0.4 0.3 Nitrogen Oxides (NOX) Year 2002................................................ 1.9 0.3 1.5 5.4 9.1 Year 2004................................................ 2.0 0.3 1.5 4.8 8.6 Diff. (0204)............................................ 0.1 0.0 0.0 0.6 0.5

Between 2002 and 2004, VOC emissions were reduced by 0.3 tpd, and NOX emissions were reduced by 0.5 tpd. These reductions and anticipated future reductions are due to the following permanent and enforceable measures implemented or in the process of being implemented in the Tioga Area:

1. Stationary Point Sources

Federal NOX SIP Call (66 FR 43795, August 21, 2001) 2. Stationary Area Sources

Solvent Cleaning (68 FR 2206, January 16, 2003)

Portable Fuel Containers (69 FR 70893, December 8, 2004) 3. Highway Vehicle Sources

Federal Motor Vehicle Control Programs (FMVCP)

Tier 1 (56 FR 25724, June 5, 1991)

Tier 2 (65 FR 6698, February 10, 2000)

Heavy Duty Engines and Vehicles Standards (62 FR 54694, October 21, 1997 and 65 FR 59896, October 6, 2000)

National Low Emission Vehicle (NLEV) (64 FR 72564, December 28, 1999)

Vehicle Safety Inspection Program (70 FR 58313, October 6, 2005) 4. Nonroad Sources

Nonroad Diesel Engine and Fuel (69 FR 38958, June 29, 2004)

EPA believes that permanent and enforceable emissions reductions are the cause of the longterm improvement in ozone levels and are the cause of the area achieving attainment of the 8hour ozone standard. [[Page 26053]]
D. The Tioga Area Has a Fully Approved Maintenance Plan Pursuant to Section 175A of the CAA

In conjunction with its request to redesignate the Tioga Area to attainment status, Pennsylvania submitted a SIP revision to provide for maintenance of the 8hour ozone NAAQS in the Tioga Area for at least 10 years after redesignation. Pennsylvania is requesting that EPA approve this SIP revision as meeting the requirement of section 175A of the CAA. Once approved, the maintenance plan for the 8hour ozone NAAQS will ensure that the SIP for the Tioga Area meets the requirements of the CAA regarding maintenance of the applicable 8hour ozone standard. 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 approval of a redesignation of an area to attainment. Eight years after the redesignation, the State must submit a revised maintenance plan demonstrating that attainment will continue to be maintained for the next 10year period following the initial 10year 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 8hour ozone violations. Section 175A of the CAA sets forth the elements of a maintenance plan for areas seeking redesignation from nonattainment to attainment. The Calcagni memo provides additional guidance on the content of a maintenance plan. An ozone maintenance plan should address the following provisions:
(1) An attainment emissions inventory;
(2) A maintenance demonstration;
(3) A monitoring network;
(4) Verification of continued attainment; and
(5) A contingency plan.
Analysis of the Tioga Area Maintenance Plan
(a) Attainment InventoryAn attainment inventory includes the emissions during the time period associated with the monitoring data showing attainment. An attainment year of 2004 was used for the Tioga Area since it is a reasonable year within the 3year block of 20022004 and accounts for reductions attributable to implementation of the CAA requirements to date. The 2004 inventory is consistent with EPA guidance and is based on actual ``typical summer day'' emissions of VOC and NOX during 2004 and consists of a list of sources and their associated emissions.

PADEP prepared comprehensive VOC and NOX emissions inventories for the Tioga Area, including point, area, mobile onroad, and mobile nonroad sources for a base year of 2002.

To develop the NOX and VOC base year emissions inventories, PADEP used the following approaches and sources of data: (i) Point source emissionsPennsylvania requires owners and operators of larger facilities to submit annual production figures and emission calculations each year. Throughput data are multiplied by emission factors from Factor Information Retrieval (FIRE) Data System and EPA's publication series AP42 and are based on Source
Classification Code (SCC). Each process has at least one SCC assigned to it. If the owners and operators of facilities provide more accurate emission data based upon other factors, these emission estimates supersede those calculated using SCC codes.
(ii) Area source emissionsArea source emissions are generally estimated by multiplying an emission factor by some known indicator or collective activity for each area source category at the county level. Pennsylvania estimates emissions from area sources using emission factors and SCC codes in a method similar to that used for stationary point sources. Emission factors may also be derived from research and guidance documents if those documents are more accurate than FIRE and AP42 factors. Throughput estimates are derived from countylevel activity data, by apportioning national and statewide activity data to counties, from census numbers, and from county employee numbers. County employee numbers are based upon North American Industry Classification System (NAICS) codes to establish that those numbers are specific to the industry covered.
(iii) Onroad mobile sourcesPADEP employs an emissions estimation methodology that uses current EPAapproved highway vehicle emission model, MOBILE 6.2, to estimate highway vehicle emissions. The Tioga Area highway vehicle emissions in 2004 were estimated using MOBILE 6.2 and PENNDOT estimates of vehicles miles traveled (VMT) by vehicle type and roadway type.
(iv) Mobile nonroad emissionsThe 2002 emissions for the majority of nonroad emission source categories were estimated using the EPA NONROAD 2005 model. The NONROAD model estimates emissions for diesel, gasoline, liquefied petroleum gasoline, and compressed natural gas fueled nonroad equipment types and includes growth factors. The NONROAD model does not estimate emissions from aircraft or locomotives. For 2002 locomotive emissions, PADEP projected emissions from a 1999 survey using national fuel information and EPA emission and conversion factors. There are no commercial aircraft operations in the Tioga Area. For 2002 aircraft emissions, PADEP estimated emissions using small aircraft operation statistics from http://www.airnav.com, and emission factors and operational characteristics in the EPAapproved model, Emissions and Dispersion Modeling System (EDMS).

The 2004 attainment year VOC and NOX emissions for the Tioga Area are summarized along with the 2009 and 2018 projected emissions for this area in Tables 4 and 5, which cover the demonstration of maintenance for this area. EPA has concluded that Pennsylvania has adequately derived and documented the 2004 attainment year VOC and NOX emissions for this area.
(b) Maintenance DemonstrationOn September 28, 2006, PADEP submitted a SIP revision to supplement its September 28, 2006 redesignation request. The submittal by PADEP consists of the maintenance plan as required by section 175A of the CAA. The Tioga Area plan shows maintenance of the 8hour ozone NAAQS by demonstrating that current and future emissions of VOC and NOX remain at or below the attainment year 2004 emissions levels throughout the Tioga Area through the year 2018. A maintenance demonstration need not be based on modeling. See, Wall v. EPA, supra; Sierra Club v. EPA, supra. See also, 66 FR at 5309953100; 68 FR at 2543032.

Tables 4 and 5 specify the VOC and NOX emissions for the Tioga Area for 2004, 2009, and 2018. PADEP chose 2009 as an interim year in the 10year maintenance demonstration period to demonstrate that the VOC and NOX emissions are not projected to increase above the 2004 attainment level during the time of the 10year maintenance period.
[[Page 26054]]
Table 4.Total VOC Emissions for 20042018 (tpd) 2004 VOC 2009 VOC 2018 VOC Source category emissions emissions emissions Mobile*................................................... 3.0 2.2 1.3 Nonroad................................................... 1.5 1.36 1.0 Area...................................................... 2.7 2.4 2.6 Point..................................................... 0.6 0.5 0.6 Total..................................................... 8.4 7.1 6.0 *Includes safety margin identified in the motor vehicle emission budgets for transportation conformity. Table 5.Total NOX Emissions 20042018 (tpd) 2004 NOX 2009 NOX 2018 NOX Source category emissions emissions emissions Mobile*................................................... 4.8 1.3 1.6 Nonroad................................................... 1.5 1.3 0.8 Area...................................................... 0.3 0.3 0.3 Point..................................................... 2.0 2.1 2.6 Total..................................................... 8.5 7.1 5.3 *Includes safety margin identified in the motor vehicle emission budgets for transportation conformity.

The following programs are either effective or due to become effective and will further contribute to the maintenance demonstration of the 8hour ozone NAAQS:

1. Pennsylvania's Portable Fuel Containers (69 FR 70893, December 8, 2004)

2. Pennsylvania's Consumer Products (69 FR 70895, December 8, 2004)

3. Pennsylvania's Architectural and Industrial Maintenance (AIM) Coatings (69 FR 68080, November 23, 2004)

4. Federal NOX SIP Call (66 FR 43795, August 21, 2001)

5. Federal Clean Air Interstate Rule (71 FR 25328, April 28, 2006)

6. FMVCP for passenger vehicles and lightduty trucks and cleaner gasoline (2009 and 2018 fleet)Tier 1 and Tier 2 (56 FR 25724, June 5, 1991 and 65 FR 6698, February 10, 2000)

7. NLEV Program, which includes the Pennsylvania's Clean Vehicle Program for passenger vehicles and lightduty trucks (69 FR 72564, December 28, 1999)proposed amendments to move the implementation to model year (MY) 2008

8. Heavy duty diesel onroad (2004/2007) and lowsulfur onroad (2006) (66 FR 5002, January 18, 2001)

9. Nonroad emissions standards (2008) and offroad diesel fuel (2007/2010) (69 FR 38958, June 29, 2004)

Based upon the comparison of the projected emissions and the attainment year emissions along with the additional measures, EPA concludes that PADEP has successfully demonstrated that the 8hour ozone standard should be maintained in the Tioga Area.
(c) Monitoring NetworkThere is currently one monitor measuring ozone in the Tioga Area. Pennsylvania will continue to operate its current air quality monitor in accordance with 40 CFR part 58. (d) Verification of Continued AttainmentThe Commonwealth will track the attainment status of the ozone NAAQS in the Tioga Area by reviewing air quality and emissions during the maintenance period. The Commonwealth will perform an annual evaluation of two key factors, vehicle miles traveled (VMT) data and emissions reported from stationary sources, and compare them to the assumptions about these factors used in the maintenance plan. The Commonwealth will also evaluate the periodic (every three years) emission inventories prepared under EPA's Consolidated Emission Reporting Regulation (40 CFR part 51, subpart A) to see if the area exceeds the attainment year inventory (2004) by more than 10 percent. Based on these evaluations, the Commonwealth will consider whether any further emission control measures should be implemented.
(e) The Maintenance Plan's Contingency MeasuresThe 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 plan include such contingency measures as EPA deems necessary to ensure that the State will promptly correct a violation of the NAAQS that occurs after redesignation. The maintenance plan should identify the events that would ``trigger'' the adoption and implementation of a contingency measure(s), the contingency measure(s) that would be adopted and implemented, and the schedule indicating the time frame by which the state would adopt and implement the measure(s).

The ability of the Tioga Area to stay in compliance with the 8hour ozone standard after redesignation depends upon VOC and NOX emissions in the area remaining at or below 2004 levels. The Commonwealth's maintenance plan projects VOC and NOX emissions to decrease and stay below 2004 levels through the year 2018. The Commonwealth's maintenance plan outlines the procedures for the adoption and implementation of contingency measures to further reduce emissions should a violation occur.

Contingency measures will be considered if for two consecutive years the fourth highest eighthour ozone concentrations at the Tioga Area monitor are above 84 ppb. If this trigger point occurs, the Commonwealth will evaluate whether additional local emission control measures should be implemented in order to prevent a violation of the air quality standard. PADEP will analyze the conditions leading to the excessive ozone levels and evaluate what measures might be most effective in correcting the excessive ozone levels. PADEP will also analyze the potential emissions effect of Federal, state and local measure that have been adopted but not yet implemented at the time of excessive ozone levels occurred. PADEP will then begin the process of implementing any selected measures.

Contingency measures will be considered in the event that a violation of the 8hour ozone standard occurs at the Tioga County, Pennsylvania
[[Page 26055]]
monitor. In the event of a violation of the 8hour ozone standard, contingency measures will be adopted in order to return the area to attainment with the standard. Contingency measures to be considered for the Tioga Area will include, but not limited to the following: NonRegulatory Measures
Voluntary diesel engine ``chip reflash''installation software to correct the defeat device option on certain heavy duty diesel engines Diesel retrofit, including replacement, repowering or alternative fuel use, for public or private local onroad or offroad fleets Idling reduction technology for Class 2 yard locomotives
Idling reduction technologies or strategies for truck stops, warehouses and other freighthandling facilities
Accelerated turnover of lawn and garden equipment, especially commercial equipment, including promotion of electric equipment Additional promotion of alternative fuel (e.g., biodiesel) for home heating and agricultural use
Regulatory Measures
Additional controls on consumer products

Additional control on portable fuel containers

The plan lays out a process to have any regulatory contingency measures in effect within 19 months of the trigger. The plan also lays out a process to implement the nonregulatory contingency measures within 1224 months of the trigger.
VII. Are the Motor Vehicle Emissions Budgets Established and Identified in the Maintenance Plan for the Tioga Area Adequate and Approvable? A. What Are the Motor Vehicle Emissions Budgets?

Under the CAA, States are required to submit, at various times, control strategy SIPs and maintenance plans in ozone areas. These control strategy SIPs (i.e. RFP SIPs and attainment demonstration SIPs) and maintenance plans identify and establish MVEBs for certain criteria pollutants and/or their precursors to address pollution from onroad mobile sources. Pursuant to 40 CFR part 93 and Sec. 51.112, MVEBs must be established in an ozone maintenance plan. A MVEB is the portion of the total allowable emissions that is allocated to highway and transit vehicle use and emissions. A MVEB serves as a ceiling on emissions from an area's planned transportation system. The MVEB concept is further explained in the preamble to the November 24, 1993, transportation conformity rule (58 FR 62188). The preamble also describes how to establish and revise the MVEBs in control strategy SIPs and maintenance plans.

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 or reasonable progress towards 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 CFR part 93 set forth EPA policy, criteria, and procedures for demonstrating and ensuring conformity of such transportation activities to a SIP.

When reviewing submitted ``control strategy'' SIPs or maintenance plans containing MVEBs, EPA must affirmatively find the MVEB budget contained therein ``adequate'' for use in determining transportation conformity. After EPA affirmatively finds the submitted MVEB is adequate for transportation conformity purposes, that MVEB can be used by State and Federal agencies in determining whether proposed transportation projects ``conform'' to the SIP as required by section 176(c) of the CAA. EPA's substantive criteria for determining ``adequacy'' of a MVEB are set out in 40 CFR 93.118(e)(4).

EPA's process for determining ``adequacy'' consists of three basic steps: public notification of a SIP submission, a public comment period, and EPA's adequacy finding. 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, Conformity Court Decision.'' This guidance was finalized in the Transportation Conformity Rule Amendments for the ``New 8Hour Ozone and PM2.5 National Ambient Air Quality Standards and Miscellaneous Revisions for Existing Areas; Transportation Conformity Rule AmendmentsResponse to Court Decision and Additional Rule Change'' on July 1, 2004 (69 FR 40004). EPA consults this guidance and follows this rulemaking in making its adequacy determinations.

The MVEBs for the Tioga Area are listed in Table 1 of this document for the 2004, 2009, and 2018 years and are the projected emissions for the onroad mobile sources plus any portion of the safety margin allocated to the MVEBs. These emission budgets, when approved by EPA, must be used for transportation conformity determinations.

B. What Is a Safety Margin?

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. The following example is for the 2018 safety margin: The Tioga Area first attained the 8hour ozone NAAQS during the 2002 to 2004 time period. The Commonwealth used 2004 as the year to determine attainment levels of emissions for the Tioga Area.

The total emissions from point, area, mobile onroad, and mobile nonroad sources in 2004 equaled 7.7 tpd of VOC and 8.0 tpd of NOX. PADEP projected emissions out to the year 2018 and projected a total of 5.5 tpd of VOC and 4.1 tpd of NOX from all sources in the Tioga Area. The safety margin for Tioga for 2018 would be the difference between these amounts, or 2.2 tpd of VOC and 3.9 tpd of NOX. The emissions up to the level of the attainment year including the safety margins are projected to maintain the area's air quality consistent with the 8hour ozone NAAQS. The safety margin is the extra emissions reduction below the attainment levels that can be allocated for emissions by various sources as long as the total emission levels are maintained at or below the attainment levels. Table 6 shows the safety margins for the 2009 and 2018 years. Table 6.2009 and 2018 Safety Margins for the Tioga Area VOC emissions NOX emissions Inventory year (tpd) (tpd) 2004 Attainment..................... 7.7 8.0 [[Page 26056]]
2009 Interim........................ 6.7 6.2 2009 Safety Margin.................. 1.0 1.8 2004 Attainment..................... 7.7 8.0 2018 Final.......................... 5.5 4.1 2018 Safety Margin.................. 2.2 3.9

PADEP allocated 0.2 tpd NOX and 0.1 tpd VOC to the 2009 interim VOC projected onroad mobile source emissions projection and the 2009 interim NOX projected onroad mobile source emissions projection to arrive at the 2009 MVEBs. For the 2018 MVEBs the PADEP allocated 0.2 tpd NOX and 0.2 tpd VOC from the 2018 safety margins to arrive at the 2018 MVEBs. Once allocated to the mobile source budgets these portions of the safety margins are no longer available, and may no longer be allocated to any other source category. Table 7 shows the final 2009 and 2018 MVEBs for the Tioga Area.
Table 7.2009 and 2018 Final MVEBs for the Tioga Area VOC emissions NOX emissions Inventory year (tpd) (tpd) 2009 projected onroad mobile source 2.1 3.2 projected emissions................
2009 Safety Margin Allocated to 0.1 0.2 MVEBs..............................
2009 MVEBs.......................... 2.2 3.4 2018 projected onroad mobile source 1.1 1.4 projected emissions................
2018 Safety Margin Allocated to 0.2 0.2 MVEBs..............................
2018 MVEBs.......................... 1.3 1.6 C. Why Are the MVEBs Approvable?

The 2004, 2009 and 2018 MVEBs for the Tioga Area are approvable because the MVEBs for NOX and VOC, including the allocated safety margins, continue to maintain the total emissions at or below the attainment year inventory levels as required by the transportation conformity regulations.
D. What Is the Adequacy and Approval Process for the MVEBs in the Tioga Area Maintenance Plan?

The MVEBs for the Tioga Area maintenance plan are being posted to EPA's conformity Web site concurrent with this proposal. The public comment period will end at the same time as the public comment period for this proposed rule. In this case, EPA is concurrently processing the action on the maintenance plan and the adequacy process for the MVEBs contained therein. In this proposed rule, EPA is proposing to find the MVEBs adequate and also proposing to approve the MVEBs as part of the maintenance plan. The MVEBs cannot be used for transportation conformity until the maintenance plan update and associated MVEBs are approved in a final Federal Register notice, or EPA otherwise finds the budgets adequate in a separate action following the comment period.

If EPA receives adverse written comments with respect to the proposed approval of the Tioga Area MVEBs, or any other aspect of our proposed approval of this updated maintenance plan, we will respond to the comments on the MVEBs in our final action or proceed with the adequacy process as a separate action. Our action on the Tioga Area MVEBs will also be announced on EPA's conformity Web site: http://www.epa.gov.otaq/stateresources/transconf/index.htm (once there, click
on ``Adequacy Review of SIP Submissions'').

VIII. Proposed Actions

EPA is proposing to determine that the Tioga Area has attained the 8hour ozone NAAQS. EPA is also proposing to approve the Commonwealth's September 28, 2006 request for the Tioga Area to be redesignated to attainment of the 8hour NAAQS for ozone. EPA has evaluated Pennsylvania's redesignation request and determined that it meets the redesignation criteria set forth in section 107(d)(3)(E) of the CAA. EPA believes that the redesignation request and monitoring data demonstrate that the area has attained the 8hour ozone standard. The final approval of this redesignation request would change the designation of the Tioga Area from nonattainment to attainment for the 8hour ozone standard. EPA is also proposing to approve the associated maintenance plan and the 2002 base year inventory for Tioga Area, submitted on September 28, 2006 and supplemented on November 14, 2006, as revisions to the Pennsylvania SIP. EPA is proposing to approve the maintenance plan for the Tioga Area because it meets the requirements of section 175A as described previously in this notice. EPA is also proposing to approve the MVEBs submitted by Pennsylvania for the Tioga Area in conjunction with its redesignation request. EPA is soliciting public comments on the issues discussed in this document. These comments will be considered before taking final action.

IX. Statutory and Executive Order Reviews

Under Executive Order 12866 (58 FR 51735, October 4, 1993), this proposed action is not a ``significant regulatory action'' and therefore is not subject to review by the Office of Management and Budget. For this reason, this action is also not subject to Executive Order 13211, ``Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use'' (66 FR 28355 (May 22, 2001)). This action merely proposes to approve state law as meeting Federal requirements and imposes no additional requirements beyond those imposed by state law. Redesignation of an area to attainment under section 107(d)(3)(e) of the Clean Air Act does not impose any new requirements on small entities. Redesignation is an action that affects the status of a geographical area and does not impose any new regulatory requirements on sources. Redesignation
[[Page 26057]]
of an area to attainment under section 107(d)(3)(E) of the Clea

FOR FURTHER INFORMATION CONTACT Rose Quinto, (215) 814-2182, or by e- mail at quinto.rose@epa.gov.