The EPA Acting Regional Administrator, Keith Takata , signed the following proposed rule on 03/30/2012, and EPA

is submitting it for publication in the Federal Register (FR). While we have taken steps to ensure the accur acy of this Internet version of the rule, it is not the of ficial version of the rule for purposes of public c omment. Please refer to the official version in a forthcoming FR publica tion, which will appear on the Government Printing Office's FDsys website ( http://fdsys.gpo.gov/fdsys/search/home.action ) and on Regulations.gov ( http://www.regulations.gov ) in Docket No. EPA-R09-OAR-2012-0253. Once the off icial version of this document is published in the FR, this version will be remove d from the Internet and replaced with a link to the official version. 6560-50-P
ENVIRONMENTAL PROTECTION AGENCY

40 CFR Part 52 [EPA-R09-OAR-2012-0253; FRL-] Approval and Promulgation of Air Quality Implementa tion Plan for

1997 8-hour Ozone Standard; Arizona
AGENCY: U.S. Environmental Protection Agency (EPA).
ACTION: Proposed rule.
SUMMARY: EPA is proposing to approve revisions to the Arizon a state implementation plan (SIP) that demonstrate at tainment of the 1997 8-hour ozone national ambient air quality standards in the Phoenix-Mesa nonattainment area by June 15, 200 9. These SIP revisions are the 2007 Ozone Plan developed by the Maricopa Association of Governments and adopted and submitte d to EPA by the Arizona Department of Environmental Quality on June 13, 2007. EPA is proposing to approve the 2007 Ozone Pl an based on our determination that the plan contains all the pr ovisions required for areas classified as nonattainment unde r Part D, Subpart 1 of the Clean Air Act, including the demon stration of reasonably available control measures (RACM), reaso nable further progress (RFP), emission inventories, transportatio n conformity motor vehicle emission budgets for 2008, and contin gencyThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

2 measures to be implemented if the Phoenix-Mesa nona ttainment area fails to attain by June 15, 2009.

DATE: Written comments must be received on or before [ Insert date 30 days from the date of publication in the Fe deral Register ].

ADDRESSES : Submit comments, identified by docket number EPA- R09- OAR-2012-0253 , by one of the following methods:

• Federal e-Rulemaking Portal: www.regulations.gov. F ollow the on-line instructions.

• E-mail: lee.anita@epa.gov.

• Mail or deliver: Marty Robin, Office of Air Plannin g (AIR2), U.S. Environmental Protection Agency Region IX, 75 Hawthorne Street, San Francisco, CA 94105. Instructions : All comments will be included in the public docket without change and may be made available online at www.regulations.gov, including any personal informa tion provided, unless the comment includes Confidential Business Information (CBI) or other information whose disclo sure is restricted by statute. Information that you conside r CBI or otherwise protected should be clearly identified as such and should not be submitted through www.regulations.gov or e-mail. The www.regulations.gov website is an “anonymous ac cess” system, and EPA will not know your identity or contact info rmation unless you provide it in the body of your comment. If you sendThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

3 e-mail directly to EPA, your e-mail address will be automatically captured and included as part of the public comment. If EPA cannot read your comments due to te chnical difficulties and cannot contact you for clarificati on, EPA may not be able to consider your comment. Docket : The index to the docket for this action is availabl e electronically on the www.regulations.gov website a nd in hard copy at EPA Region IX, 75 Hawthorne Street, San Fra ncisco, California, 94105. While all documents in the docke t are listed in the index, some documents may be publicly availa ble only at the hard copy location (e.g., copyrighted material) , and some may not be publicly available at either location (e .g., CBI). To inspect the hard copy materials, please schedule an appointment during normal business hours with the contact liste d in the FOR
FURTHER INFORMATION CONTACT section below. Copies of the SIP materials are also available for inspection at the following location:

• Arizona Department of Environmental Quality, 1110 W

. Washington Street, First Floor, Phoenix, AZ 85007, Phone: (602) 771-2217. The SIP materials are also electronically available at: http://www.azmag.gov/Projects/Project.asp?CMSID2=11 20.This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

4 FOR FURTHER INFORMATION CONTACT: Anita Lee, Air Planning Office (AIR-2), U.S. Environmental Protection Agency, Regi on IX, (415) 972-3958, lee.anita@epa.gov.
SUPPLEMENTARY INFORMATION: Table of Contents I. The 1997 8-Hour Ozone Standard and the Phoenix-M esa Ozone Nonattainment Area A. Background on the 1997 8-Hour Ozone NAAQS B. The Phoenix-Mesa 8-Hour Ozone Nonattainment Area II. CAA and Regulatory Requirements for 1997 8-Hour Ozone Nonattainment Area SIPs III. Arizona’s State Implementation Plan Submittal to Address Ozone Attainment in the Phoenix-Mesa Nonattainment Area A. Arizona’s SIP Submittal B. CAA Procedural and Administrative Requirements f or SIP Submissions IV. Review of the 2007 Ozone Plan for Phoenix-Mesa A. Emission Inventories B. Reasonably Available Control Measures Demonstrat ion and Control Strategy C. Attainment Demonstration D. Reasonable Further Progress Demonstration E. Contingency MeasuresThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

5 F. Motor Vehicle Emissions Budgets for Transportati on Conformity V. EPA’s Proposed Action VI. Statutory and Executive Order Reviews Throughout this document, “we”, “us” and “our” refe r to EPA. I. The 1997 8-Hour Ozone Standard and the Phoenix-M esa Ozone Nonattainment Area A. Background on the 1997 8-Hour Ozone NAAQS Ground-level ozone pollution is formed in the atmos phere from the reaction of volatile organic compounds (VO C) and oxides of nitrogen (NO x ) in the presence of sunlight. These two pollutants, referred to as ozone precursors, are em itted by many types of pollution sources including on- and off-ro ad motor vehicles and engines, power plants and industrial f acilities, and smaller area sources such as lawn and garden eq uipment and paints. Scientific evidence indicates that adverse public h ealth effects occur following exposure to ozone, particul arly in children and adults with lung disease. Breathing ai r containing ozone can reduce lung function and inflame airways, which can increase respiratory symptoms and aggravate asthma or other lung diseases. Ozone exposure also has been associated w ith increased susceptibility to respiratory infections, medicatio n use, doctor visits, and emergency department visits and hospita l admissionsThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

6 for individuals with lung disease. Ozone exposure a lso increases the risk of premature death from heart or lung dise ase. Children are at increased risk from exposure to ozone becaus e their lungs are still developing and they are more likely to be active outdoors, which increases exposure. See “Fact Sheet , Proposal to Revise the National Ambient Air Quality Standards f or Ozone”, January 6, 2010 and 75 FR 2938 (January 19, 2010). On July 18, 1997, EPA revised the primary and secon dary national ambient air quality standards (NAAQS or st andard) for ozone to replace the existing 1-hour ozone standard of 0.12 parts per million (ppm) with an 8-hour standard of 0.08 ppm 1 . 62 FR 33856. EPA revised the ozone standard after cons idering substantial evidence from numerous health studies d emonstrating that serious health effects are associated with exp osures to ozone concentrations above the levels of these revi sed standards. B. The Phoenix-Mesa 8-Hour Ozone Nonattainment Area Following promulgation of a new or revised NAAQS, E PA is required by Clean Air Act (CAA) section 107(d) to d esignate areas throughout the nation as attaining or not att aining the NAAQS. Under the implementation rule for the 1997 8 -hour ozone standard, EPA designated certain areas as nonattain ment under

1 In March 2008, EPA completed another review of the primary and secondary ozone standards and further tightened the standards by lowering the level for both to 0.075 ppm. 73 FR 16436 (March 27, 2008).This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

7 title I, part D, subpart 1 of the CAA (subpart 1) i f the area’s 1-hour ozone design value was above the level of th e standard but below 0.121 ppm. On April 15, 2004, EPA designa ted PhoenixMesa as “Subpart 1” nonattainment for the 1997 8-ho ur ozone standard u nder CAA section 172. See 69 FR 23858 (April 30, 20 04) and 40 CFR 81.303. The designation became effective on June 15, 2004. Under part D, subpart 1 of the Act, states mu st submit plans to come into attainment within 3 years of the effective date of the nonattainment designation, and must att ain the standard as expeditiously as practicable, but no la ter than 5 years after the effective date of the designation. Arizona Department of Environmental Quality (ADEQ) submitte d the 2007 Attainment Plan to EPA on June 13, 2007 2 to attain the 1997 8- hour ozone standard by the attainment date of June 15, 2009, which is 5 years after the effective date of the ar ea’s designation as nonattainment. 3 In June 2007, the United States Court of Appeals fo r the District of Columbia Circuit (D.C. Circuit Court) v acated the

2 Letter from Stephen A. Owens, Director, Arizona De partment of Environmental Quality to Wayne Nastri, Regional Administrator, U. S. Environmental Protection Agency, Region IX, dated June 13, 2007, plus three enclosures, including the “Eight-Hour Ozone Plan for the Marico pa Nonattainment Area, dated June 2007” and Appendices Volumes one and two , dated June 2007. 3 On March 23, 2009, ADEQ submitted to EPA a redesig nation request and maintenance plan for Phoenix-Mesa for the 1997 8-ho ur ozone standard based on ambient ozone monitoring data for the 2006 – 2008 p eriod. EPA has not yet acted on this submittal. The maintenance plan and r edesignation request are available from the Maricopa Association of Governme nts at: http://www.azmag.gov/Projects/Project.asp?CMSID2=11 20&MID=Environmental%20Pro gramsThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

8 portion of the 2004 ozone implementation rule that allowed areas to be classified under subpart 1. See South Coast Air Quality Mgmt. Dist. v. EPA , 472 F. 3d 882 (D.C. Cir. 2006), reh’g denied 489 F.3d 1245 ( SCAQMD ) (vacating certain elements of EPA’s Phase 1 ozone implementation rule). On January 16, 2009 ( 74 FR 2936), EPA published a proposed rule to address, among oth er issues, the D.C. Circuit Court vacatur of the classificatio n system that EPA used to designate a subset of initial 1997 8-ho ur ozone nonattainment areas under subpart 1. In that rulema king, EPA proposed that all areas designated nonattainment fo r the 1997 8- hour ozone NAAQS under subpart 1 would be classifie d as subpart 2 areas (hereafter referred to as the Subpart 1/Sub part 2 Rulemaking). The Phoenix-Mesa area is included in t he areas that would be classified under subpart 2 if EPA's propos al is finalized. EPA has not yet taken final action on th e Subpart 1/Subpart 2 Rulemaking. Following completion of the Subpart 1/Subpart 2 Rulemaking, EPA will address in a futur e rulemaking any additional requirements that become applicable to PhoenixMesa, if any, as a result of its classification und er subpart 2. If, after Phoenix-Mesa is classified under subpart 2, EPA determines in a future rulemaking that the area is in attainment with the 1997 8-hour ozone standard, then the oblig ation to submit certain planning SIPs related to attainment of the 1997This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

9 8-hour ozone standard pursuant to its subpart 2 cla ssification would be suspended in accordance with 40 CFR 51.918

. The Phoenix-Mesa nonattainment area is located in t he central portion of Arizona and encompasses 4,880 sq uare miles, including the urban portions of Maricopa and Pinal Counties, the Fort McDowell Yavapai Nation and the Salt River-Pim a Maricopa Indian Community. For a precise description of the geographic boundaries of the Phoenix-Mesa nonattainment area, see 40 CFR 81.303. The Maricopa Association of Governments (MA G) is the agency with primary responsibility for developing t he plan to attain the 1997 8-hour ozone standard for Phoenix-M esa. Ambient 8-hour ozone concentrations in Phoenix-Mesa vary depending on location and season, with the highest values generally occurring in May - September, in north Ph oenix or the air quality monitors located in the mountainous nor theastern region of the Phoenix-Mesa nonattainment area. Ozon e design values 4 from Phoenix-Mesa that exceeded the 1997 8-hour st andard of 0.08 parts per million 5 (ppm) ranged from 0.085 ppm (for the 2000 – 2002, 2001 – 2003, and 2003 – 2005 periods) to 0.088 ppm (for the 1998 – 2000 and 1999 – 2001 periods). The ozone design

4 A design value is an ambient concentration calcula ted using a specific methodology to evaluate monitored air quality data and is used to determine whether an area’s air quality meets a NAAQS. The me thodology for calculating design values for the 8-hour ozone NAAQS is found i n 40 CFR part 50, Appendix I. 5 Based on the rounding conventions described in 40 CFR part 50, Appendix I, a design value of 0.085 ppm is the lowest value that exceeds the 1997 8-hour ozone NAAQS of 0.08 ppm.This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

10 values for the Phoenix-Mesa nonattainment area for the 2004 – 2006 period (highest design value was 0.083 ppm) an d years thereafter were at or below the standard. See EPA A ir Quality System (AQS) data available in the docket for this proposed rulemaking and Table 3 below. II. CAA and Regulatory Requirements for 1997 8-Hour Ozone Nonattainment Area SIPs Each area designated nonattainment for the 1997 8-h our ozone standard is subject to, at minimum, the gener al requirements for nonattainment area plans in subpar t 1 of part D, title I of the CAA. Subpart 2 of part D contains more detailed requirements for ozone nonattainment areas classified under this subpart. The Phoenix-Mesa ozone nonattai nment area is not currently classified under subpart 2. 6 EPA has proposed to classify the Phoenix-Mesa area under subpart 2 as “ marginal” nonattainment for the 1997 8-hour ozone NAAQS (see 74 FR 2936 at 2944, January 16, 2009) but has not yet completed t his rulemaking. Although a future final decision by EPA to classify the Phoenix-Mesa area under subpart 2 may trigger a dditional future requirements for the area, EPA believes that this does not prevent EPA from proposing or ultimately finali zing our action on the 2007 Ozone Plan in accordance with th e subpart 1

6 EPA now refers to these areas as “former subpart 1 ” nonattainment areas in light of the SCAQMD decision.This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

11 requirements that currently apply to the area. 7 Thus, for purposes of evaluating the 2007 Ozone Plan, we are reviewing it for consistency with the applicable requirements of part D, title I of the Act, which are contained in sections 172(c)(1)- (9). 8 In order to assist states in developing effective p lans to attain the ozone standard, EPA issued the 8-hour oz one implementation rule. This rule was finalized in two phases. The first phase of the rule addresses classifications f or the 1997 8-hour ozone standard, applicable attainment dates for the various classifications, and the timing of emission s reductions needed for attainment. See 69 FR 23951 (April 30, 2 004). The second phase addresses SIP submittal dates and the requirements for reasonably available control technology and mea sures (RACT and RACM), reasonable further progress (RFP) demons tration, modeling and attainment demonstrations, contingency measures, and new source review. See 70 FR 71612 (November 29 , 2005). The rule is codified at 40 CFR part 51, subpart X 9 . We discuss each

7 EPA is currently obligated under the terms of a Co nsent Decree to take final action on the 2007 Ozone Plan by May 31, 2012. See WildEarth Guardians v. Jackson , Case No. 4:11-cv-02205-SI (N.D. CA). 8 Although the D.C. Circuit Court in SCAQMD rejected EPA’s rationale for implementing the 1997 8-hour ozone standard in cert ain nonattainment areas solely under subpart 1, EPA does not believe that t he Court’s ruling in this case alters any subpart 1 requirements that current ly apply to the 2007 Ozone Plan. 9 EPA has revised or proposed to revise several elem ents of the 8-hour ozone implementation rule since its initial promulgation in 2004. See, e.g., 74 FR 2936 (January 16, 2009); 75 FR 51960 (August 24, 20 10); and 75 FR 80420 (December 22, 2010). None of these revisions affect any provision of the ruleThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

12 of the applicable CAA and regulatory requirements f or 8-hour ozone nonattainment plans in more detail below. III. Arizona’s State Implementation Plan Submittal to Address Ozone Attainment in the Phoenix-Mesa Nonattainment Area A. Arizona’s SIP Submittal On June 13, 2007, the Arizona Department of Enviro nmental Quality (ADEQ) submitted the “Eight-Hour Ozone Plan for the Maricopa Nonattainment Area” (2007 Ozone Plan) to E PA as a revision to the Arizona SIP. The plan was deemed co mplete by operation of law on December 13, 2007. MAG develope d the 2007 Ozone Plan and the MAG Regional Council Executive C ommittee adopted the plan on June 11, 2007. ADEQ adopted the plan on June 13, 2007 10 . The 2007 Ozone Plan contains complete emission inventories for ozone precursors for 2002 and 2008, photochemical modeling to demonstrate that the stan dard will be attained in 2008 through the continued implementati on of federal, state, and local control measures, motor v ehicle emission budgets (MVEBs) used for transportation co nformity, and descriptions of the State’s compliance with CAA req uirements for “Subpart 1” ozone nonattainment areas. We are propo sing to

that is applicable to our proposed action today on the Phoenix-Mesa 2007 8- hour Ozone SIP. 10 Letter from Stephen A. Owens, Director of Arizona Department of Environmental Quality, to Wayne Nastri, Regional Ad ministrator, U.S. Environmental Protection Agency, Region IX, “Submit tal of the Eight-Hour Ozone Plan for the Maricopa County Nonattainment Ar ea”. June 13, 2007.This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

13 approve the 2007 Ozone Plan for the Phoenix-Mesa no nattainment

area. B. CAA Procedural and Administrative Requirements f or SIP Submittals CAA sections 110(a)(1) and (2) and 110(l) require a state to provide reasonable public notice and opportunity for public hearing prior to the adoption and submittal of a SI P or SIP revision. To meet this requirement, every SIP submi ttal should include evidence that adequate public notice was gi ven and an opportunity for a public hearing was provided consi stent with EPA’s implementing regulations in 40 CFR 51.102. MAG has satisfied the applicable statutory and regu latory requirements for reasonable public notice and heari ng prior to adoption and submittal of the 2007 Ozone Plan. MAG and ADEQ jointly held two public hearings on June 1, 2007 an d June 4, 2007. As evidence of notification of public hearing s consistent with 40 CFR 51.102, the SIP submittal includes proo f of newspaper publication and copies of letters sent to EPA and affected federal, state, and local agencies notifyi ng interested parties of the joint MAG and ADEQ public hearings. We find, therefore, that the 2007 Ozone Plan submittal meets the procedural requirements for public notice and heari ng in sections 110(a) and 110(l) of the CAA.This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

14 CAA section 110(k)(1)(B) requires EPA to determine whether a SIP submittal is complete within 60 days of recei pt. This section also provides that any plan submittal that EPA has not affirmatively determined to be complete or incomple te will be deemed complete by operation of law six months afte r the date of submittal. EPA’s SIP completeness criteria are foun d in 40 CFR part 51, Appendix V. The 2007 Ozone Plan, submitted by ADEQ on June 13, 2007, was deemed complete by operation of law on December 13, 2007. IV. Review of the 2007 Ozone Plan for Phoenix-Mesa EPA evaluated the 2007 Ozone Plan according to the general subpart 1 nonattainment plan requirements contained in section 172(c) of the Act. A. Emission Inventories 1. Requirements for Emissions Inventories CAA section 172(c)(3) requires each state with an ozone nonattainment area to submit plan provisions that i nclude a “comprehensive, accurate, current inventory of actu al emissions from all sources of the relevant pollutant or pollu tants in such area, including such periodic revisions as the Admi nistrator may determine necessary to assure that the requirements of this part are met”. EPA has issued the “Emissions Inventory G uidance for Implementation of Ozone and Particulate Matter Nati onal Ambient Air Quality Standards (NAAQS) and Regional Haze Reg ulations” (EIThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

15 Guidance), 11 which provides guidance on how to develop base yea r and future year baseline emission inventories for 8 -hour ozone,

PM 2.5 , and regional haze SIPs. For areas designated nona ttainment for the 8-hour ozone standard in 2004, EPA recommen ds using calendar year 2002 as the base year for the invento ry. EI Guidance, p. 8. Emissions inventories for ozone should include emi ssions of VOC, NO x and carbon monoxide (CO) and represent an average summer week day during the ozone season. EI Guidance, pp. 14 and 17. States should include documentation in their submit tals explaining how the emissions data were calculated. 70 FR at 71664 and EI Guidance p. 40. In estimating mobile s ource emissions, states should use the latest emissions m odels and planning assumptions available at the time the SIP is developed. 68 FR at 32854 and 70 FR 71666. 2. Emission Inventories in the 2007 8-Hour Ozone Pl an The base year and future year baseline inventories for NO x , CO and VOC for the Phoenix-Mesa nonattainment area, together with additional documentation for the inventories, are found in Volume 1 of the Appendices to the 2007 Ozone Plan 12 . These

11 “Emissions Inventory Guidance for Implementation o f Ozone and Particulate Matter National Ambient Air Quality Standards (NAAQ S) and Regional Haze Regulations”, EPA-454/R-05-001, November 2005. This document is available at: http://www.epa.gov/ttnchie1/eidocs/eiguid/index.htm l. 12 By “future year baseline inventories” or “projecte d baseline inventories”, we mean projected emission inventories for future y ears that account for,This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

16 inventories represent average summer day (ozone sea son) emissions. A base year inventory is provided for 20 02 and the projected baseline inventory is provided for the at tainment year of 2008. 13 All inventories include NO x , CO, and VOC emissions from point, area, nonroad mobile, and onroad mobile sources, except that biogenic emission inventories include o nly NO x and VOC emissions. The 2002 Periodic Emission Inventory (PEI) emission s estimates for Maricopa County and the Phoenix-Mesa nonattainment area, which provided the basis for the 2002 base ye ar inventory, were calculated in terms of annual emissions and oz one seasonday emissions. Emissions from point sources were es timated from each identified facility through permit system data bases and annual emission reports submitted to the facility’s permitting authority. Emissions from area sources were estimat ed by source category using information from permit databases an d previous SIP inventories. Nonroad mobile source emissions we re estimated with the EPA NONROAD 2002 model and onroad mobile s ource emissions were estimated from emission factors for various vehicle classes from MOBILE6.2 combined with estima tes of

among other things, the ongoing effects of economic growth and adopted emission control requirements. 13 EPA’s ozone implementation rule defines “attainmen t year ozone season” as “the ozone season immediately preceding a nonattain ment area’s attainment date.” 40 CFR 51.900(g). Because the attainment dat e for Phoenix-Mesa is June 15, 2009, we refer to 2008 as the attainment year, and the 2008 ozone season as the “attainment year ozone season.”This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

17 vehicle miles traveled (VMT) using data submitted b y the Arizona Department of Transportation to the U.S. Department of Transportation’s Federal Highway Administration for the 2002 Highway Performance and Monitoring System. Biogenic emissions of
NO x and VOC were calculated using MAGBEIS2, a modified version of the UAM-BEIS2 model developed specifically for use in Maricopa County, based on land use information, surface temp erature data, and emission factors for land use categories. See 2 002 Periodic Emissions Inventory for Ozone Precursors, June 2004 in Volume 1 of the Appendices to the 2007 Ozone Plan. Ozone precursor emissions from point, area, onroad, and nonroad sources used in the modeling domain (Table 1) were developed from the Comprehensive Air Quality Model with Extensions (CAMx), version 4.40, and the Emissions Preprocessor System (EPS3.0), based on the 2002 Periodic Emissio n Inventory for the three ozone episodes modeled for 2002. Biog enic VOC emission estimates used for the 2002 modeling domai n (e.g., 451.3 metric tons per day in the June 2002 ozone ep isode) are significantly higher than biogenic VOC emissions es timated in the 2002 PEI (e.g., 41.7 metric tons per ozone seas on day). Section III of Appendix A, Exhibit 2 of the 2007 Oz one Plan describes the method used to estimate biogenic emis sions for the modeling domain. MAG used a model developed in 2005 , called Model of Emissions of Gases and Aerosols from Natur e (MEGAN),This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

18 that was determined to be more reliable and accurat e for Maricopa County because it relies on local field st udies that identified dominant plant species and emission fact ors, as well as locations and biomass densities, to estimate bio genic emissions of ozone precursors. In the 2002 base yea r inventory, biogenic sources contributed 65 percent to total VO C emissions. In contrast, anthropogenic onroad mobile sources do minated the total NO x emissions and accounted for 63 percent of total NO x . See Tables 5-3 and 5-4 of the 2007 Ozone Plan. The 2002 inventory was projected to 2008 by accoun ting for expected growth factors, ongoing control programs, and retirement rates for obsolete sources of emissions. MAG accounted for known projects in 2008 (e.g., the Pho enix Expansion Project of the Transwestern Pipeline Comp any) and additionally applied a five percent increase to onr oad mobile source emissions of NO x and a three percent increase to all other anthropogenic emissions of VOC and NO x . The three percent increase was based on population projections prepar ed by the Arizona Department of Economic Security, based on a 2005 special census in Maricopa County. MAG applied the five per cent increase to onroad mobile source emissions of NO x to create a safety margin for transportation conformity. See 2007 Ozon e Plan, p. 5- 5, and Appendices to Ozone Plan, Volume 1.This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

19 For biogenic emissions, the 2002 inventory was hel d constant for 2008. In additional information provid ed to EPA, MAG explained that no projected land use or land co ver data was available for the 2008 attainment year, therefore b iogenic emissions in the ozone modeling domain were held co nstant 14 . In the approved 1-hour ozone maintenance plan, MAG pro jected an increase in VOC emissions from the Phoenix Metropol itan nonattainment area due to changes in land use, i.e. , increasing urbanization and residential land use and decreasin g use of land for agriculture. See 70 FR at 13437. The 1-hour ozo ne maintenance plan relied on MAGBEIS2 to estimate bio genic emissions from the nonattainment area and modeling domain. 15 As shown in the additional information provided by MAG on February 8, 2012, the MAGBEIS2 VOC emission factor for urban ized land use is greater than the VOC emission factor for agricul tural land use, therefore, based on the projected increased ur banization in the 1-hour ozone nonattainment area, VOC emissions projected by MAGBEIS2 increased from the 1999 base year to the 2 015 maintenance year. In contrast, as described above, the 2007 8- hour ozone plan relied on a new biogenic emissions model (MEGAN) that is more representative of Maricopa County and its desert environment. The additional information provided by MAG shows

14 Email from Cathy Arthur, MAG, to Anita Lee, EPA, r e: “Biogenic VOCs” on February 8, 2012, plus two attachments on land use boundaries and emission factors. 15 Ibid.This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

20 the urbanized land use emission factors from MEGAN are lower than emission factors associated with agriculture o r other undeveloped desert landscapes in Maricopa County. T herefore, using MEGAN, MAG expects that the trend of increasi ng urbanization (as projected in the 1-hour ozone main tenance plan) is expected to decrease VOC emissions from Maricopa County. Because MAG did not have 2008 land use data availab le, it determined that maintaining constant biogenic emiss ions of the ozone precursors would be more conservative than at tempting to estimate the anticipated decrease in biogenic VOC e missions. 16

Table 1: Emission Inventories for the Phoenix-Mesa Modeling Domain for June Ozone Episode (metric tons per day)

NO x VOC 2002 2008 2002 2008 Point 11.15 32.78 11.72 13.55 Area 9.79 13.49 90.56 105.03 Nonroad Mobile 79.97 86.58 50.73 57.55 Onroad Mobile 182.36 145.52 91.84 72.34 Biogenics 8.56 8.56 451.28 451.28 Total 291.82 286.93 696.13 699.75 Source: 2007 Ozone Plan at Tables 5-3 and 5-4.

16 Ibid

.This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

21 3. Proposed Action on the Emission Inventories We have reviewed the 2002 base year inventory and the inventory methodologies used in the 2007 Ozone Plan and believe that the inventory was developed consistent with th e CAA requirements as reflected in the 8-hour ozone imple mentation rule and EPA’s guidance. The 2002 base year invento ry is a comprehensive inventory of actual emissions of ozon e precursors in the Phoenix-Mesa nonattainment area. We therefor e propose to approve the base year inventory as meeting the requ irements of CAA section 172(c)(3) and EPA’s 8-hour ozone implem entation rule. B. Reasonably Available Control Measures Demonstrat ion and Control Strategy 1. Requirements for RACM and Control Strategies CAA Section 172(c)(1) requires that each attainmen t plan “provide for the implementation of all reasonably a vailable control measures as expeditiously as practicable (i ncluding such reductions in emissions from existing sources in th e area as may be obtained through the adoption, at a minimum, of reasonable available control technology), and shall provide fo r attainment of the national primary ambient air quality standar ds.” The 8- hour ozone implementation rule requires that for ea ch nonattainment area that is required to submit an at tainmentThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

22 demonstration, the state must also submit concurren tly a SIP revision demonstrating that it has adopted all RACM necessary to demonstrate attainment as expeditiously as practica ble and to meet any RFP requirements. 40 CFR 51.912(d). EPA has previously provided guidance interpreting the RACM requirement in the General Preamble at 13560 17 and in a memorandum entitled “Guidance on the Reasonably Ava ilable Control Measure Requirement and Attainment Demonstr ation Submissions for Ozone Nonattainment Areas”, John Se itz, Director, OAQPS to Regional Air Directors, November 30, 1999 (Seitz memo). In summary, EPA guidance provides tha t, to address the requirement to adopt all RACM, states should co nsider all potentially reasonable control measures for source categories in the nonattainment area to determine whether they ar e reasonably available for implementation in that area and wheth er they would, if implemented individually or collectively, advance the area’s attainment date by one year or more. See Sei tz memo and General Preamble at 13560 18 . Any measures that are necessary to

17 The “General Preamble for the Implementation of Ti tle I of the Clean Air Act Amendments of 1990”, published at 57 FR 13498 o n April 16, 1992, describes EPA’s preliminary view on how we would in terpret various SIP planning provisions in title I of the CAA as amende d in 1990, including those planning provisions applicable to the 1-hour ozone standard. EPA continues to rely on certain guidance in the General Preamble to implement the 8-hour ozone standard under title I. 18 See also “State Implementation Plans; General Prea mble for Proposed Rulemaking on Approval of Plan Revisions for Nonatt ainment Areas”, 44 FR 20372 (April 4, 1979), and Memorandum dated Decembe r 14, 2000 from John S. Seitz, Director, Office of Air Quality Planning and Standards, “AdditionalThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

23 meet these requirements that are not already either federally promulgated, part of the state’s SIP, or otherwise creditable in SIPs must be submitted in enforceable form as part of a state’s attainment plan for the area. CAA section 172(c)(6) requires nonattainment plans to “include enforceable emission limitation, and such other control measures, means, or techniques (including economic incentives such as fees, marketable permits, and actions of em ission rights), as well as schedules and timetables for co mpliance, as may be necessary or appropriate to provide for atta inment of such standard in such area by the applicable attain ment date * * *.” See also CAA section 110(a)(2)(A). The ozone im plementation rule requires that all control measures needed for attainment be implemented no later than the beginning of the atta inment year ozone season. 40 CFR 51.908(d). The attainment year ozone season is defined as the ozone season immediately precedin g a nonattainment area’s attainment date. 40 CFR 51.900 (g). 2. RACM Demonstration and the Control Strategy in t he 2007 Ozone Plan The attainment demonstration for the Phoenix-Mesa nonattainment area, which we discuss further in sec tion IV.D of this document, shows that implementation of all of the measures

Submission on RACM from States with Severe One-Hour Ozone Nonattainment Area SIPs”.This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

24 identified as RACM for the 1997 8-hour ozone NAAQS would enable the Phoenix-Mesa area to attain the 1997 8-hour ozo ne standard during the 2008 ozone season, preceding the 2009 at tainment date for the area. EPA previously approved all of the ke y NO x and VOC control measures, including several dozen VOC RACT rules, as part of Arizona’s plans for attaining and maintaini ng the 1-hour ozone standard in Phoenix-Mesa. 19 The 2007 Ozone Plan specifically relies on seven of these control measu res to demonstrate attainment of the 1997 8-hour ozone sta ndard by June 15, 2009, and provides for implementation of these measures by the beginning of the attainment year ozone season ( January 2008), consistent with the requirements of 40 CFR 5 1.908(d). See 2007 Ozone Plan at pp. 4-2 through 4-7. 20 We discuss below the seven measures that the attainment demonstration in the 2007 Ozone Plan relied on to reduce emissions of VOC and /or NO x (see Table 2). Emission reductions associated with each measure were estimated for the June 2008 ozone episode modeled f or the attainment demonstration. Of these seven measures, phased-in

19 See, e.g., 2007 Ozone Plan at Table 1-1; 68 FR 291 2 (January 22, 2003); 69 FR 10161 (March 4, 2004); 70 FR 30370 (May 26, 2005 ); 70 FR 13425 (March 21, 2005) (proposed redesignation of Phoenix to attainm ent for the 1-hour standard) and 70 FR 34362 (June 14, 2005) (final re designation). RACT rules for NO x were not required for purposes of attaining and ma intaining the 1-hour ozone NAAQS in Phoenix-Mesa because EPA approved a petition for NO x exemption for this purpose. 60 FR 19510 (April 19, 1995). 20 The 2007 Ozone Plan refers to these seven control measures as “attainment measures,” to be distinguished from “baseline measu res,” which were taken into account in the base year and projection year e mission inventories. See 2007 Ozone Plan at 4-2 and Volume 1 of the Appendic es to the 2007 Ozone Plan at Table III-1.This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

25 emission test cutpoints and the development of inte lligent transportation systems resulted in the greatest red uction in VOC emissions, and the summer fuel reformulation result ed in the greatest reduction in NO x emissions.

Table 2: 2008 Emission Reductions from “Attainment Measures”

VOC NO x Metric

ton/day reduction % change

compared to 2008 base

case Metric

ton/day reduction % change

compared to 2008 base

case Summer Fuel Reformulation (0.1) (increase) < 0.1%

(increase) 10.3 3.5%

Phased-in Emission Test Cutpoints 3.1 1.2% 2.6 0.9%

One Time Waiver from Vehicle Emissions Test 0.1 < 0.1% < 0.1 < 0.1%

Coordinate Traffic Signal Systems < 0.1 < 0.1% < 0.1 < 0.1%

Develop Intelligent Transportation Systems 2.2 0.9% 0.4 0.1%

Tougher Enforcement of Vehicle Registration and Emission Test Compliance 0.2 < 0.1% 0.1 < 0.1%

Rule 358: Polystyrene Foam Operations 0.5 0.2% N/A N/A

Total 6.0 2.4% 13.4 4.6%This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

26 Source: 2007 Ozone Plan at Table 5-2.

a. Summer Fuel Reformulation The 2007 Ozone Plan relies on H.B. 2307, a Cleaner Burning Gasoline (CBG) program passed by the Arizona Legisl ature in 1997. The CBG program contains requirements related to seasonal changes in gasoline formulation related to vapor pr essure and oxygen content. Typically, fuel reformulation measu res are designed to reduce summertime evaporative VOC emiss ions. However, the results of MAG’s emissions modeling an alyses suggest that the summer reformulation measure would increase VOC emissions slightly and significantly reduce emissio ns of NO x . In Volume 2 of the Appendices to the 2007 Ozone Plan, in response to EPA comments, MAG explains that the slight incre ase in projected VOC emissions from the summer fuel reform ulation measure occurred because the MOBILE6.2 input for th e measure specified a Reid vapor pressure (RVP) of 7.0 pounds per square inch (psi). Actual fuel specifications for the 2002 base case used actual fuel specifications from the Arizona De partment of Weights and Measures that were lower than 7.0 psi. The projected decrease in NO x emissions in 2008 from the summer fuel reformulation measure is a result of the removal of the summertime (April 1 through November 1) minimum oxy gen content standard for Type 1 gasoline. Oxygenates in fuel ar e used toThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

27 improve combustion as a control strategy for CO and other products of incomplete combustion, for example unbu rned VOCs; however improved combustion also tends to increase formation of
NO x . Therefore, removal of the minimum summertime oxyg enate standard is projected to reduce formation of NO x . See 2007 Ozone Plan at 4-2, 4-3. b. Phased-in Emission Test Cutpoints The 2007 Ozone Plan describes two measures passed by the Arizona Legislature that comprise this attainment m easure: H.B. 2237, passed in 1997, that appropriates funds from the State General Fund to develop and implement an alternativ e test protocol to reduce false failure rates associated w ith the more stringent standards for the Vehicle Emissions Testi ng Program, and S.B. 1427, which requires vehicles in certain a reas to be emission tested and requires owners of the newest f ive model year vehicles to be exempt from testing but to pay an in lieu fee that is deposited into the Arizona Clean Air Fu nd, effective December 31, 1998. Using MOBILE6.2, MAG estimated t hat this measure reduces NO x emissions by 2.6 metric tons per day in the June 2008 ozone episode and VOC emissions by 3.1 me tric tons per day. See 2007 Ozone Plan at 4-3, 4-4. c. One Time Waiver from Vehicle Emissions Test The Arizona Legislature passed S.B. 1002 which limi ts issuance of a waiver for failure to comply with emi ssion testingThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

28 requirements to one-time only, effective January 1, 1997. MAG modeled this measure in MOBILE6.2 by adjusting the percentage of waivers allowed and estimated that this measure red uces NO x emissions by less than 0.1 metric tons per day in t he June 2008 ozone episode and VOC emissions by 0.1 metric tons per day. See 2007 Ozone Plan at 4-4. d. Coordinate Traffic Signal Systems House Bill 2237 passed by the Arizona Legislature contains appropriations for fiscal years 1997-1998 and 1998- 1999 to Arizona Department of Transportation for distributi on to cities and counties for synchronization of traffic signals within and across jurisdictional boundaries. MAG modeled this measure in MOBILE6.2 by adjusting the input for idling time at traffic signals and estimated that this measure reduces NO x emissions by less than 0.1 metric tons per day in the June 2008 ozone episode and VOC emissions by less than 0.1 metric tons per day. See 2007 Ozone Plan at 4-4, 4-5. e. Develop Intelligent Transportation Systems The 2007 Ozone Plan cites three committed control measures in the 1-hour Ozone Maintenance Plan that serve to reduce traffic congestion: “Coordinate Traffic Signal Syst ems”, “Develop Intelligent Transportation Systems”, and “ Reduce Traffic Congestion at Major Intersections”. The 200 7 Ozone Plan describes these measures as technologies implemente d on theThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

29 local level over fiscal years 2003-2006 that reduce VOC and NO x emissions by reducing congestion. MAG estimated emi ssion reductions from these measures to be 0.4 metric ton s of NO x per day in the June 2008 ozone episode and 2.2 metric t ons of VOC per day. See 2007 Ozone Plan at 4-5. f. Tougher Enforcement of Vehicle Registration and Emission Test Compliance The 2007 Ozone Plan cites two measures from the Ar izona Legislature and a program implemented by the Arizon a Motor Vehicle Division of the Arizona Department of Trans portation that collectively improve enforcement of vehicle re gistration and compliance with vehicle testing requirements: S .B. 1427 passed in 1998 that requires school and special dis tricts in certain areas to prohibit employees who have not co mplied with emission testing requirements from parking in emplo yee parking lots, and H.B. 2254 passed in 1999 that requires ve hicles owned by federal, state, or political state subdivisions in Arizona to comply with A.R.S 49-542. MAG modeled this measu re in MOBILE6.2 by adjusting the weighting between inspec tion and maintenance (I/M) and non-I/M emission factors, and estimated that this measure reduces NO x emissions by 0.1 metric tons per day in the June 2008 ozone episode and VOC emission s by 0.2 metric tons per day. See 2007 Ozone Plan at 4-5, 4- 6. g. Maricopa County Rule 358: Polystyrene Foam Opera tionsThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

30 Rule 358 adopted by Maricopa County on April 20, 2 005 limits VOC emissions from the manufacturing of expa ndedpolystyrene products. MAG relied on information pro vided by the Maricopa County Air Quality Department that Rule 35 8 would result in 80 percent control effectiveness and 80 p ercent rule effectiveness. MAG estimated VOC emission reduction s to be 0.5 metric tons per day in the June 2008 ozone episode, with no effect on emissions of NO x . See 2007 Ozone Plan at 4-6, 4-7. 3. Proposed Actions on the RACM Demonstration and C ontrol Strategy Based on our review of the RACM analysis and Arizo na’s adopted rules, we propose to find that the 2007 Ozo ne Plan provides for implementation of all reasonably avail able control measures necessary to demonstrate expeditious attai nment of the 1997 8-hour ozone standard and to meet any related RFP requirements in the Phoenix-Mesa nonattainment area , consistent with the applicable requirements of CAA section 172 (c)(1) and 40 CFR 51.912. C. Attainment Demonstration 1. Requirements for Attainment Demonstration CAA section 172(c)(1) requires states with ozone nonattainment areas to submit plan provisions that provide for attainment of the national ambient air quality stan dards. See also 40 CFR 51.908. The attainment demonstration sh ould include:This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

31 (1) Technical analyses to locate and identify sourc es of emissions that are causing violations of the 8-hour ozone NAAQS within the nonattainment area; (2) Adopted measures with schedules for implementa tion and other means and techniques necessary and appropriat e for attainment; and (3) Contingency measures required under section 17 2(c)(9) of the CAA. See 70 FR 71612 at 71615. The requirements for the first two items are descr ibed in the sections on emission inventories and RACM/RACT above (sections IV.A and IV.B) and in the sections on air quality modeling and attainment demonstration that follow i mmediately below. Requirements for the third item are describe d in the section on contingency measures (IV.F.). 2. Air Quality Modeling in the Phoenix-Mesa 2007 Oz one Plan Under EPA’s ozone implementation rule, an attainme nt demonstration must meet the air quality modeling an d other requirements of 40 CFR 51.112 and must be supported “by means of a photochemical grid model or any other analytical method determined by [EPA] to be at least as effective.” 4 0 CFR 51.908. Air quality modeling is used to establish attainmen t emissions targets, that is, a combination of ozone precursor emission levels that the area can accommodate without exceed ing theThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

32 NAAQS, and to assess whether the proposed control s trategy will result in attainment of the NAAQS. Air quality modeling is performed for a base year a nd compared to air quality monitoring data from that y ear in order to evaluate model performance. Once the performance is determined to be acceptable, future year changes to the emissions inventory are simulated with the model to determine the effect of emissions reductions on ambient air q uality. The procedures for modeling ozone as part of an attainm ent demonstration are contained in EPA's “Guidance on t he Use of Models and Other Analyses for Demonstrating Attainm ent of Air Quality Goals for the 8-Hour Ozone and PM2.5 NAAQS and Regional Haze” (Guidance). The Guidance also recommends tha t supplemental analyses be performed, and used in com bination with the modeling in a Weight of Evidence determination that the control strategy will result in attainment of the N AAQS. Guidance p. 17. The air quality modeling is described in Chapter 3 of the 2007 Ozone Plan and documented in Volume One of the Appendices to the 2007 Ozone Plan, in Appendix A, Exhibit 2 (“ Modeling TSD”). We provide a brief description of the modeli ng and a summary of our evaluation of it below. MAG performed the air quality modeling for the 2007 Ozone Plan using the Comprehensive Air Quality Model with ExtensionsThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

33 (CAMx) photochemical model, incorporating meteorolo gical fields from the Mesoscale Model version 5 (MM5). These mo dels have been extensively used in developing SIP attainment demonstrations and are identified in EPA Guidance a s candidate models. Guidance pp. 139 & 160. While there was no intensive field study for this modeling effort, 31 ozone stat ions and 56 meteorological stations provided an ample database of routinely collected data for use in model application develop ment and performance evaluation. EPA recommends that States prepare modeling protoco ls as part of their modeled attainment demonstrations. Gu idance, p. 133. The Guidance at pp. 133-134 describes the topi cs to be addressed in this modeling protocol. A modeling pro tocol should detail the procedures for conducting the modeling a nalysis, such as the background and objectives, the schedule and organizational structure, selection of ozone episod es to model, meteorological and emissions input data preparation , model performance evaluation, interpreting modeling resul ts, and procedures for using the model to demonstrate wheth er proposed strategies are sufficient to attain the NAAQS. The 2007 Ozone Plan’s modeling protocol is contained in Volume Two of the Appendices to the 2007 Plan, in Appendix I-i, and c overs all of the topics recommended in the Guidance.This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

34 A key part of the modeling protocol is the selectio n of ozone episodes to be modeled. An attainment demonst ration that is robust despite natural variability should includ e modeling of multiple days with high ozone concentrations, spann ing the range of meteorological conditions that lead to exceedanc es of the NAAQS in the area. Guidance p. 146. Volume two of t he Appendices to the 2007 Ozone Plan, Attachment II, has a thorou gh description of the episode selection process. A cli matology of high ozone days for 1987-2004 was prepared, conside ring synoptic meteorological conditions, temperature, wind speed, wind direction, and frequency of high ozone by month, da y of week, and hour of day. For the more recent 2000-2004 per iod, ozone spatial patterns were examined, and back trajectori es prepared to help assess whether ozone was locally generated or partly due to transport from outside the domain. High tempera ture occurred on summer days whether they exceeded the standard o r not, and so was not useful in selecting episodes. Typical feat ures of episodes are high ozone concentrations northeast of central Phoenix and winds from the east in the morning, shi fting to south at midday, and then southwesterly in the afte rnoon. Based on the analysis, MAG identified three meteorologica l regimes leading to high ozone concentrations, and six candi date recent ozone episodes. On the basis of ozone episode sever ity and duration, MAG chose three of the episodes for model ing. Regime 1This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

35 is characterized by stagnant winds and purely local generation of ozone; it includes some weekend exceedances. It is represented by the July 8-14, 2002 episode with a m aximum ozone concentration of 107 ppb at Maryvale, and eight oth er exceeding sites; this was the episode with the highest ozone concentration during the 2000-2004 period. Regime 2 is characteri zed by light winds, with potential for transport from the south and southwest. It is represented by the June 3-7, 2002 episode with a maximum ozone concentration of 92 ppb at Fountain Hills, and eleven other exceeding sites. Regime 3 is character ized by a non-calm winds from other directions. It is represe nted by the August 5-11, 2001 episode with a maximum ozone conc entration of 99 ppb at Cave Creek, and four other exceeding site s. (Both regimes 2 and 3 occur in this episode.) The regime s had in common low wind speeds, partial cloud cover, and a low pressure system in the southwest of the State and a high pre ssure system in the northeast. EPA finds the selection process t o be welldocumented and well-reasoned, and the selected epis odes to be a good basis for the attainment demonstration. Section IV of the Modeling TSD in Volume one of the Appendices to the 2007 Ozone Plan includes extensiv e statistical and graphical analysis demonstrating adequate overa ll model performance for the June 2002 episode, but also sho ws consistent underprediction for the August 2001 and July 2002 e pisodes.This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

36 Under EPA Guidelines, models are used in a relative sense (see discussion on Relative Response Factors below), so although underpredictions in model performance do not necess arily mean that future design values would be underpredicted, they do suggest that these two episodes may be less reliabl e for predicting the effect of emissions changes. Thus, p rimary weight was given to the June 2002 episode in the attainmen t demonstration. CAMx model diagnostic sensitivity te sts were performed by MAG to provide assurance that the mode l is adequately simulating the physical and chemical pro cesses leading to ozone in the atmosphere and that the mod el responds in a scientifically reasonable way to emissions cha nges. The tests included zeroing out boundary condition conce ntrations, initial condition concentrations, and various categ ories of emissions. The model responded in a physically reas onable way in each of these tests. MAG also undertook sensitivity tests for MM5, which provides meteorological input to the CAM x air quality model. These are described in Appendix III to the M odeling TSD, and included incorporation of alternative observati onal data sets, and an alternative convection scheme to avoid overestimating convective rainfall in this dry sout hwestern area. The meteorological model was found to perform adequately for wind speed, wind direction, temperature, and hu midity. EPA finds the procedures MAG followed to be well-docume nted andThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

37 reasonable, and to be acceptable for supporting the modeled attainment demonstration. For the modeled attainment test, the model is used to predict the air quality effect of changes in emissi ons due to land use changes, growth, and the effect of control measures. Under current EPA Guidance, the model is used to de velop Relative Response Factors (RRFs) that give the mode l’s response to emission changes, and the RRFs are applied to mo nitored design value concentrations to arrive at the predic ted future concentrations. The particulars of the calculation, and which model grid cells and modeled days are to be include d, are specified in the EPA Guidance. Guidance pp. 15, 25, and 155. MAG assessed the 2008 effect of the seven control m easures using the EPA-specified procedure, and found the maximum predicted ozone design value to be 84 ppb, which is in attain ment of the ozone NAAQS. It should be noted that this result in cludes 5 percent additional NO x to create a safety margin for the transportation conformity motor vehicle emissions b udget. EPA agrees that MAG’s modeling demonstrates attainment of the ozone NAAQS by summer 2008. In addition to a modeled attainment demonstration, which focuses on locations with an air quality monitor, E PA generally requires an Unmonitored Area Analysis. This analysi s is intended to ensure that a control strategy leads to reductio ns in ozoneThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

38 at other locations that have no monitor but that mi ght have base year (and/or future year) ambient ozone levels exce eding the NAAQS. The unmonitored area analysis uses a combina tion of model output and ambient data to identify areas that migh t exceed the NAAQS if monitors were located there. In order to e xamine unmonitored areas in all portions of the modeling d omain, EPA recommends use of interpolated spatial fields of am bient data combined with gridded modeled outputs. Guidance, p. 29. MAG used a variation of the EPA-described approach, describe d in section V of the modeling TSD, as a corroboratory screening test. The attainment demonstration passed this corroboratory screening test. EPA notes that concentration gradients in the supplied spatial isopleth maps appear to be weak except in t he downtown area where the monitoring network is fairly dense a nd the RRFs themselves have only weak spatial variation. We bel ieve the plan’s Unmonitored Area Analysis is adequate. Finally, the Weight of Evidence Analysis in Appendi x V of the Modeling TSD, in Volume two of the Appendices t o the 2007 Ozone Plan, includes several supplemental analyses in support of the attainment demonstration. These include ozone a ir quality trends and precursor emission trends, both of which show continued progress and support the conclusion that the attainment demonstration is sound. Appendix G of At tachment II to the modeling protocol, in Volume two of the Appe ndices to theThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

39 2007 Ozone Plan also illustrated the downward ozone trends at all ozone monitors. Other analyses examined the sen sitivity of the model to NO x reductions, the representation of VOC speciation in the model, the VOC:NOx ratio as a photochemical indicator, Process Analysis, and examination of Weekday vs. We ekend effects. These analyses provided observational and modeling evidence that the model is correctly replicating th e ozone photochemistry of the area, and that the Weight of Evidence supports the conclusion that the Phoenix-Mesa will attain the ozone NAAQS in 2008. Additionally, Table 3 below sh ows that design values (DV) in ppm from all monitors in the Phoenix-Mesa nonattainment area, operated by three different age ncies (Pinal County Air Quality Control District (PCAQCD), Maric opa County Air Quality Division (MCAQD), and ADEQ), appear to have been meeting the 1997 ozone NAAQS based on monitored ozo ne concentrations since 2005. EPA proposes to find that the modeling provides an adequate basis for the RACM/RACT, RFP, and attainment demons trations in the Phoenix-Mesa 2007 8-Hour Ozone Plan.

Table 3: Ozone Design Values from 2005 – 2010 Monit oring Data in Phoenix-Mesa Nonattainment Area*

Site Site ID Agency 2005 - 07 2006 - 08 2007 - 09 2008 - 10 Apache Junction 04-013- PCAQCD DV (ppm) 0.076 0.080 0.075 0.073This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

40 3001 % complete 99 99 99 99 Buckeye 04-013-

4011 MCAQD DV (ppm) 0.065 0.066 0.064 0.064 % complete 100 100 100 100 Blue Point 04-013-

9702 MCAQD DV (ppm) 0.067 0.064 0.067 0.070 % complete 100 94 99 99 Cave Creek 04-013-

4008 MCAQD DV (ppm) 0.079 0.078 0.075 0.074 % complete 100 100 100 100 Central Phoenix 04-013-

3002 MCAQD DV (ppm) 0.075 0.074 0.070 0.071 % complete 99 97 100 100 Dysart 04-013-

4010 MCAQD DV (ppm) 0.067 0.067 0.066 0.068 % complete 97 100 100 100 Falcon Field 04-013-

1010 MCAQD DV (ppm) 0.076 0.075 0.071 0.070 % complete 97 98 100 100 Fountain Hill 04-013-

9704 MCAQD DV (ppm) 0.082 0.079 0.074 0.074 % complete 98 100 99 100 Glendale 04-013-

2001 MCAQD DV (ppm) 0.075 0.074 0.071 0.072 % complete 100 100 100 100 Humboldt Mountain 04-013-

9508 MCAQD DV (ppm) 0.081 0.078 0.074 0.071 % complete 100 100 99 100 North Phoenix 04-013-

1004 MCAQD DV (ppm) 0.082 0.081 0.076 0.077 % complete 99 95 100 100 Pinnacle Peak 04-013-

2005 MCAQD DV (ppm) 0.078 0.074 0.072 0.073 % complete 99 99 100 99 Rio Verde 04-013-

9706 MCAQD DV (ppm) 0.083 0.080 0.075 0.072 % complete 99 92 96 100 South Phoenix 04-013-

4003 MCAQD DV (ppm) 0.072 0.072 0.071 0.072 % complete 99 99 99 100 South Scottsdale 04-013-

3003 MCAQD DV (ppm) 0.078 0.077 0.075 0.074 % complete 98 97 99 99

JLG Supersite 04-013- ADEQ DV (ppm) 0.076 0.076 0.075 0.075This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

41 9997 % complete 100 98 100 99 Tempe 04-013-

4005 MCAQD DV (ppm) 0.077 0.077 0.073 0.071 % complete 97 97 100 98

West Chandler 04-013-

4004 MCAQD DV (ppm) 0.076 0.076 0.073 0.073 % complete 100 98 100 100

West Phoenix 04-013-

0019 MCAQD DV (ppm) 0.074 0.078 0.073 0.073 % complete 100 99 99 99 * The data in this table has been certified in EPA’ s Air Quality System (AQS) database in accordance with the requir ements of 40 CFR part 58. We provide these data only to support our evaluation of the modeling and attainment demonstra tion and not to support a determination regarding attainment, wh ich is not part of today’s proposed action.

3. Proposed Action on the Attainment Demonstration In order to approve a SIP’s attainment demonstrati on, EPA must make several findings: First, we must find that the demonstration’s techn ical bases, emission inventories and air quality modelin g, are adequate. As discussed in section IV.A and IV.C.2, we are proposing to approve the base year emission invento ry and to find the air quality modeling adequate to support t he attainment demonstration. Second, we must find that the SIP provides for exp editious attainment through the implementation of all RACM. As discussed above in section III.B, we propose to find that the 2007 Ozone Plan provides for implementation of all reasonably available control measures necessary for expeditious attainme nt of theThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

42 1997 8-hour ozone NAAQS and any related RFP require ments in the Phoenix-Mesa nonattainment area. Third, we must find that the emission reductions t hat are relied on for attainment are creditable and are suf ficient to provide for attainment. All of the key attainment m easures relied on in the 2007 Ozone Plan to attain the 1997 8-hour ozone standard by June 15, 2009 have been adopted and app roved into the SIP. For the foregoing reasons, we propose to approve t he attainment demonstration in the 2007 Ozone Plan for the PhoenixMesa nonattainment area. D. Reasonable Further Progress Demonstration CAA section 172(c)(2) requires that plans for nona ttainment areas provide for reasonable further progress (RFP) . RFP is defined in section 171(1) as “such annual increment al reductions in emissions of the relevant air pollutant as are r equired by [title 1, part D] or may reasonably be required by the Administrator for the purpose of ensuring attainmen t of the applicable [standard] by the applicable date.” The ozone implementation rule interprets the RFP requirements for the purposes of the 1997 ozone standards, establishing requirements for RFP that depend on the area’s classification. F or areas with attainment dates on or before June 15, 2009, RFP wo uld be met by ensuring emissions reductions needed for attainment areThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

43 implemented by the beginning of the ozone season pr ior to the attainment date. 40 CFR 51.910(b) and 70 FR 71612. The attainment date for the Phoenix-Mesa ozone nonattainment area is June 15, 2009, and as discuss ed in the RACM demonstration and control strategy (section IV .B) and the attainment demonstration (section IV.C) sections ab ove, all of the control measures needed for the attainment demo nstration were being implemented prior to the 2008 ozone seas on. We propose, therefore, to approve the RFP demonstratio n in the 2007 Ozone Plan. E. Contingency Measures 1. Requirements for Contingency Measures CAA section 172(c)(9) requires plans to provide fo r the implementation of contingency measures, that achiev e additional emission reductions, to be undertaken if the area f ails to meet RFP milestones or fails to attain by its attainment date. These contingency measures must be rules or measures that are ready for implementation quickly upon failure to meet mil estones or attainment. The SIP should define trigger mechanism s for the contingency measures, specify a schedule for implem entation, and indicate that the measures will be implemented with out significant further action by the State or EPA. See 68 FR 32802, 32837 and 70 FR 71612, 71650.This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

44 Additional guidance on the CAA contingency measure provisions is found in the General Preamble at 1351 0-13512 and 13520. The guidance indicates that states should ad opt and submit contingency measures sufficient to provide a 3 percent emission reduction from the adjusted RFP base year. This level of reduction is generally acceptable to offset emis sion increase while States are correcting their SIPs. These reduc tions would be beyond what is needed to meet the attainment and /or RFP requirement. States may use reductions of either VO C or NO x or a combination of both to meet the contingency measure requirements. General Preamble at 13520, footnote 6 . EPA guidance also provides that contingency measures co uld be implemented early, i.e., prior to the milestone or attainment date 21 . Consistent with this policy, states are allowed t o use excess reductions from already adopted measures to meet the CAA section 172(c)(9) and 182(c)(9) contingency measure requirement. This is because the purpose of contingency measures is to provide extra reductions that are not relied on for RFP or attainment that will provide for continued progress while the plan is being revised to fully address the failure to meet the required milestone. Nothing in the CAA precludes a State from implementing such measures before they are triggere d. This

21 Memorandum, G.T. Helms, Chief, Ozone/Carbon Monoxi de Programs Branch to Air Directors, “Contingency Measures for Ozone and Carb on Monoxide Redesignations”, June 1, 1992.This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

45 approach has been approved in numerous SIPs. See 62 FR 15844(April 3, 1997) (approval of the Indiana porti on of the Chicago area 15 percent Rate of Progress plan); 66 FR 30811 (June 8, 2001) (proposed approval of the Rhode Isla nd post-1996 ROP plan); and 66 FR 586 and 66 FR 634 (January 3, 2001) (approval of the Massachusetts and Connecticut 1-ho ur ozone attainment demonstrations). In the only adjudicated challenge to this approach, the court upheld it. See LEAN v. EPA , 382 F.3d 575 (5 th Cir. 2004). 70 FR 71611, 71651. 2. Contingency Measures in the 2007 Ozone Plan Contingency measure provisions for the Phoenix-Mes a nonattainment area and the methodologies used to es timate the emission reductions from these measures are describ ed in Chapters 4 and 5 of the 2007 Ozone Plan and Section V of Volume 1 of the Appendices to the 2007 Ozone Plan. Table 4 lists the five contingency measures and the estimated reducti ons in VOC and NO x emissions from each measure. All five contingency measures have already been implemented in the Phoen ix-Mesa nonattainment area, but credit for these measures w ere not needed or used to demonstrate attainment. See 2007 Ozone Plan at pp. 4-7 through 4-10 and 5-15 through 5-17.

Table 4: Emission Reductions from Individual Contin gency Measures in the Phoenix-Mesa 8-Hour Ozone Modeling DomainThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

46 VOC NO x Base Case Emissions on June 6, 2002 696.13 metric tons/day 291.82 metric tons/day Contingency Measure Reduction (metric ton/day) Percent

Reduction Reduction

(metric ton/day) Percent

Reduction

Expansion of Area A Boundaries 1.3 0.2% 0.7 0.2%

Gross Polluter Option for I/M Waivers <0.1 <0.1% <0.1 <0.1%

Increased Waiver Repair Limit Options <0.1 <0.1% <0.1 <0.1%

Federal Heavy Duty Diesel Vehicle Standards <0.1 <0.1% 2.5 0.9%

Federal Nonroad Equipment Standards 14.6 2.1% 15.6 5.3%

Total 15.9 2.3% 18.8 6.4% Source: 2007 Ozone Plan at Table 5-6. a. Expansion of Area A Boundaries In 2001, the Arizona legislature passed H.B. 2538 to expand the boundaries of Area A, adding additional portion s of Maricopa County west of Goodyear and Peoria and a small area on the north side of Lake Pleasant. The implementation of air qu ality measures within the new Area A boundaries began on January 1,This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

47 2002, except for public sector alternative fuel req uirements to be phased in over a seven-year period. MAG modeled this contingency measure by increasing the number of reg istered vehicles in Area A that will be required to partici pate in the I/M program. MAG estimated the emission reductions from this contingency measure to be 1.3 metric tons per day o f VOC and 0.7 metric tons per day of NO x , but did not take credit for this measure in the attainment demonstration. See 2007 O zone Plan at 4-7 and 4-8. b. Gross Polluter Option for I/M Waivers The Arizona legislature passed S.B. 1427 in 1998 t o require vehicle owners with vehicles emitting more than twi ce the emission standard to repair the vehicle sufficientl y to reduce the emission levels to less than twice the standard in order to obtain a compliance waiver from the Vehicle Emissio ns Inspection Program. ADEQ modeled the emission reductions for t his measure and estimated the emission reductions from this con tingency measure to be less than 0.1 metric tons per day of VOC and less than 0.1 metric tons per day of NO x . MAG but did not take credit for this measure in its attainment demonstration. S ee 2007 Ozone Plan at 4-9. c. Increased Waiver Repair Limit Options In 1998, the Arizona legislature passed S.B. 1427 to increase the amount a person must spend to repair a failing 1967This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

48 – 1974 vehicle in Area A in order to qualify for a waiver from $100 to $200. MAG modeled this measure using MOBILE 6.2 by reducing the pre-1981 vehicle waiver rate from 4 to 2.6 percent. The emission reductions from this contingency measu re were estimated to be less than 0.1 metric tons per day o f VOC and less than 0.1 metric tons per day of NO x . MAG did not take credit for this measure in its attainment demonstration. S ee 2007 Ozone Plan at 4-9. d. Federal Heavy Duty Diesel Vehicle Standards On January 18, 2001, EPA issued a final rule that set more stringent emission standards for new heavy duty die sel vehicles (66 FR 5001). The rule requires high-efficiency cat alytic convertors or comparable technologies be installed on 2007 and later model year diesel vehicles, and requires ultr a-low sulfur fuel be used in all onroad diesel vehicles beginnin g in 2006. MAG modeled emission reductions from this federal m easure using MOBILE6.2 and estimated VOC reductions of less than 0.1 metric tons of VOC per day and 2.5 metric tons of NO x per day. MAG did not take credit for this measure in its attainment demonstration. See 2007 Ozone Plan at 4-9. e. Federal Nonroad Equipment Standards On October 23, 1998, EPA issued a final rule to se t more stringent Tier 2 and Tier 3 emission standards for new diesel nonroad equipment (63 FR 56967). The Tier 2 program phased inThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

49 more stringent standards for all equipment between 2001 and 2006 and Tier 3 imposed even more stringent standards fo r 50 to 750 horsepower engines in 2006 to 2008. Additionally, o n June 29, 2004, EPA issued the Clean Air Nonroad Diesel – Tie r 4 Final rule to require manufacturers to produce nonroad en gines with emission controls that will reduce emissions by mor e than 90 percent (69 FR 38958). The Tier 4 standards apply t o nonroad engines less than 25 horsepower beginning in 2008 a nd will apply to larger engines over 2011 to 2015. MAG estimated emission reductions from this measure using the EPA NONROAD model and projected VOC emission reductions of 14.6 metric to ns of VOC per day and 15.6 metric tons of NO x per day. MAG did not take credit for this measure in its attainment demonstration. S ee 2007 Ozone Plan at 4-9 and 4-10. 3. Proposed Action on the Contingency Measures We propose to approve the contingency measures in the 2007 Ozone Plan. The contingency measures are consistent with EPA guidance that recommends a 3 percent emission reduc tion. All contingency measures have already been implemented but EPA guidance allows for the early implementation of con tingency

measures. F. Motor Vehicle Emissions Budgets for Transportati on Conformity 1. Requirements for Motor Vehicle Emission BudgetsThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

50 CAA section 176(c) requires federal actions in nonattainment and maintenance areas to conform to t he SIP’s goals of eliminating or reducing the severity and n umber of violations of the NAAQS and achieving expeditious a ttainment of the standards. Conformity to the SIP’s goals means that such actions will not: (1) cause or contribute to violat ions of a NAAQS, (2) worsen the severity of an existing viola tion, or (3) delay timely attainment of any NAAQS or any interim milestone. Actions that involve Federal Highway Administratio n (FHWA) or Federal Transit Administration (FTA) funding or approval are subject to the EPA’s transportation conformity rule , codified in 40 CFR part 93, subpart A. Under this rule, metropo litan planning organizations (MPOs) in nonattainment and maintenance areas coordinate with state and local air quality a nd transportation agencies, EPA, FHWA, and FTA to demo nstrate that an area’s regional transportation plans (RTP) and t ransportation improvement programs (TIP) conform to the applicabl e SIP. This demonstration is typically done by showing that est imated emissions from existing and planned highway and tra nsit systems are less than or equal to the motor vehicle emissio n budgets (budgets) contained in the SIP. An attainment, main tenance, or RFP SIP should establish budgets for the attainment year, each required RFP year, or last year of the maintenance plan, as appropriate. Budgets are generally established for specificThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

51 years and specific pollutants or precursors. Ozone attainment and RFP plans should establish budgets for NO x and VOC. See 40 CFR 93.102(b)(2)(i). Before an MPO may use budgets in a submitted SIP, EPA must first determine that the budgets are adequate or ap prove the budgets. In order for EPA to find the budgets adequ ate and approvable, the submittal must meet the conformity adequacy requirements of 40 CFR 93.118(e)(4) and be approvab le under all pertinent SIP requirements. To meet these requireme nts, the budgets must reflect all of the motor vehicle contr ol measures contained in the attainment and RFP demonstrations. See 40 CFR 93.118(e)(4)(v). 2. Motor Vehicle Emission Budgets in the Phoenix-Me sa 2007 Ozone Plan The 2007 Ozone Plan for Phoenix Mesa included budg ets for VOC and NO x for the 2008 attainment year. On October 4, 2007, we notified ADEQ and MAG that we found the MVEB for th e 2008 attainment year adequate for transportation conform ity purposes. See letter from Deborah Jordan, EPA Region 9, to Na ncy Wrona, ADEQ, and Dennis Smith, MAG, “RE: Adequacy Status o f Motor Vehicle Emissions Budgets in Eight-Hour Ozone Plan for the Maricopa Nonattainment Area (June 2007)”, October 4 , 2007. We published a notice of our findings at 72 FR 60666 ( October 25, 2007). The budget for the 2008 attainment year is r epresented byThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

52 onroad VOC and NO x emissions for the Phoenix-Mesa modeling domain on the peak episode day in June 2008 of 72.3 metric tons per day of VOC and 145.5 metric tons per day of NO x . MAG used geographic information systems (GIS) to separate the onroad mo bile emissions from the Phoenix-Mesa 8-hour ozone nonatt ainment area from the modeling domain, resulting in the estimate d 2008 MVEB of 67.9 metric tons per day of VOC and 138.2 metric tons per day of NO x . 3. Proposed Action on the Motor Vehicle Emission Bu dgets Based on our evaluation of the 2007 Ozone Plan and the budgets contained in it, which reflect all motor ve hicle control measures contained in the attainment and RFP demons tration, we are proposing to approve the 2008 MVEB. V. EPA’s Proposed Action For the reasons discussed above, EPA is proposing to approve Arizona’s submitted SIP for attaining the 1 997 8-Hour Ozone Standard in the Phoenix-Mesa nonattainment ar ea. Specifically, EPA is proposing to approve under CA A section 110(k)(3) the following elements of the 2007 Ozone Plan for Phoenix-Mesa: 1. The 2002 base year emission inventory as meeting the requirements of CAA section 172(c)(3) and 40 CFR 51 .915;This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

53 2. The reasonably available control measures demons tration as meeting the requirements of CAA section 172(c)(1 ) and 40 CFR 51.912(d); 3. The reasonable further progress demonstration as meeting the requirements of CAA section 172(c)(2) and 40 CF R 51.910; 4. The attainment demonstration as meeting the requ irements of CAA section 172(c)(1) and 40 CFR 51.908; 5. The contingency measures for failure to make RFP or to attain as meeting the requirements of CAA section 1 72(c)(9); and 6. The motor vehicle emission budgets for the attai nment year of 2008, which are derived from the attainment demonstration, as meeting the requirements of CAA s ection 176(c) and 40 CFR part 93, subpart A. VI. Statutory and Executive Order Reviews Under the Clean Air Act, the Administrator is requi red to approve a SIP submission that complies with the pro visions 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 mee t the criteria of the Clean Air Act. Accordingly, this ac tion merely proposes to approve state law as meeting Federal re quirements and does not impose additional requirements beyond those imposed by state law. For that reason, this proposed action :This document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

54 • 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.); • is certified as not having a significant economic impact on a substantial number of small entities un der the Regulatory Flexibility Act (5 U.S.C. 601 et seq.); • does not contain any unfunded mandate or signific antly or uniquely affect small governments, as described in the Unfunded Mandates Reform Act of 1995 (Public Law 10 4-4); • does not have Federalism implications as specifie d in Executive Order 13132 (64 FR 43255, August 10, 1999 ); • is not an economically significant regulatory act ion based on health or safety risks subject to Executiv e 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) o f the National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) because application of those requi rements would be inconsistent with the Clean Air Act; andThis document is a prepublication version, signed b y the EPA Acting Regional Administrator, Keith Taka ta, on

3/30/2012. We have taken steps to ensure the accura cy of this version, but it is not the official vers ion.

55 • does not provide EPA with the discretionary autho rity to address, as appropriate, disproportionate human health or environmental effects, using practicable and legall y permissible methods, under Executive Order 12898 (59 FR 7629, F ebruary 16, 1994). In addition, this proposed rule does not have triba l 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 gover nments or preempt tribal law.

List of Subjects in 40 CFR Part 81 Environmental protection, Air pollution contro l, Ozone, Nitrogen Dioxide, Volatile Organic Compounds.

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

_____________ ______________________________ Dated: Jared Blumenfeld Regional Administrator, EPA Region IX

Billing Code: 6560-50-P