Approval and Promulgation of State Implementation Plans and Designation of Areas for Air Quality Planning Purposes; California-South Coast

AGENCY:

Environmental Protection Agency (EPA).

ACTION:

Proposed rule.

SUMMARY:

EPA is proposing to approve state implementation plan (SIP) revisions submitted by the State of California to provide for attainment of the particulate matter (PM-10) national ambient air quality standards (NAAQS) in the Los Angeles-South Coast Air Basin Area and to establish emissions budgets for purposes of transportation conformity. EPA is also proposing to grant the State's request for an extension of the PM-10 attainment deadline to December 31, 2006. EPA is proposing to approve the SIP revisions under provisions of the Clean Air Act (CAA) regarding EPA action on SIP submittals, SIPs for national primary and secondary ambient air quality standards, and plan requirements for nonattainment areas.

DATES:

Written comments on this proposal must be received by January 16, 2003.

ADDRESSES:

Please mail comments to: Dave Jesson (AIR-2), EPA Region IX, 75 Hawthorne Street, San Francisco, CA 94105-3901. The rulemaking docket for this notice is available for public inspection during normal business hours at EPA's Region IX office. A reasonable fee may be charged for copying parts of the docket.

Copies of the SIP materials are also available for inspection at the following locations:

California Air Resources Board, 1001 I Street, Sacramento, California, 95812

South Coast Air Quality Management District, 21865 E. Copley Drive Diamond Bar, California, 91765-0932

Most of the plan materials are also electronically available at: http://www.aqmd.gov/aqmp.

FOR FURTHER INFORMATION CONTACT:

Dave Jesson, EPA Region IX, (415) 972-3957, or jesson.david@epa.gov.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Background

A. Summary

B. PM-10 Problem in the South Coast

C. CAA Provisions

D. Designation and Classification

E. Adoption and Submittal

II. Evaluation of the SIP Submittals

A. Emission Inventories

B. Control Measures

1. Applicable Requirements

2. Description of Control Measures

3. Proposed Action on Control Measures

C. Contingency Measures

D. Reasonable Further Progress (RFP) and Milestones

E. Attainment Demonstration

F. Extension of the Attainment Deadline

G. Motor Vehicle Emission Budgets

III. Summary of the Proposed Action

IV. Administrative Requirements

I. Background

A. Summary

We are proposing to approve portions of the 1994 and 1997 plans, the 1998 and 1999 plan amendments, and the 2002 status report for the South Coast Air Basin (or “South Coast”), as these SIP submittals pertain to PM-10, and to grant the State's request that the attainment date for the 24-hour and annual PM-10 NAAQS be extended from December 31, 2001, to December 31, 2006. We are also proposing to approve emissions budgets for purposes of transportation conformity.

B. PM-10 Problem in the South Coast Air Basin

Although great progress has been made in reducing PM-10 concentrations, the South Coast continues to violate both the 24-hour and annual PM-10 NAAQS, and the State must therefore submit measures and other provisions sufficient to make expeditious progress and attain the NAAQS. The South Coast PM-10 plans were prepared to meet applicable CAA provisions, including attainment of the PM-10 NAAQS throughout the basin. Preparation of these plans was particularly challenging because PM-10 concentrations in the South Coast consist of both primary particulate (such as road dust and diesel soot, emitted directly into the atmosphere) and secondary particulate (particles formed through atmospheric chemical reactions from precursor gases, notably oxides of nitrogen, oxides of sulfur, and ammonia), and the principal causes of PM-10 violations show a strong spatial variation within the South Coast.

The health effects from elevated PM-10 concentrations include lung damage, increased respiratory disease, and premature death. Children, the elderly, and people suffering from heart and lung disease, such as asthma, are especially at risk.

C. CAA Provisions

Title I of the Federal CAA was substantially amended in 1990 to establish new planning requirements and attainment deadlines for the NAAQS. The nonattainment area plan provisions for PM-10 areas appear in CAA section 189. The most fundamental of these provisions is the requirement that the State submit a SIP demonstrating attainment of the PM-10 NAAQS. CAA section 189(a)(1)(B) and 189(b)(1)(A). This demonstration must be based upon enforceable measures to achieve emission reductions leading to emissions at or below the level predicted to result in attainment of the NAAQS throughout the nonattainment area. For areas classified as serious, such as the South Coast, the measures must meet the standard for Best Available Control Measures (BACM), and the measures must be implemented expeditiously and ensure attainment no later than the applicable CAA deadline. Because the State requests an extension of the attainment date beyond the applicable deadline of December 31, 2001, CAA section 188(e) provides that the State must demonstrate that the plan includes the most stringent measures (MSM) that are included in any implementation plan or are achieved in practice, and can feasibly be implemented in the area.

EPA has issued a “General Preamble” describing the Agency's preliminary views on how EPA intends to act on SIPs submitted under Title I of the Act. See 57 FR 13498 (April 16, 1992), 57 FR 18070 (April 28, 1992). EPA later issued an Addendum to the General Preamble providing guidance on SIP requirements for serious PM-10 areas. 59 FR 41998 (August 16, 1994). The reader should refer to these documents for a more detailed discussion of EPA's preliminary interpretations of Title I requirements. In this proposed rulemaking action, EPA applies these policies to the South Coast PM-10 SIP submittals, taking into consideration the specific factual issues presented.

D. Designation and Classification

On the date of enactment of the 1990 CAA Amendments, PM-10 areas, including the South Coast Air Basin, meeting the qualifications of section 107(d)(4)(B) of the amended Act, were designated nonattainment by operation of law. See 56 FR 11101 (March 15, 1991).

Once an area is designated nonattainment, section 188 of the CAA outlines the process for classification of the area and establishes the area's attainment date. In accordance with section 188(a), at the time of designation, all PM-10 nonattainment areas, including the South Coast Air Basin, were initially classified as moderate by operation of law. Section 188(b)(1) of the Act further provides that moderate areas can subsequently be reclassified as serious before the applicable moderate area attainment date if at any time EPA determines that the area cannot “practicably” attain the PM-10 NAAQS by this attainment date.

EPA determined on January 8, 1993, that the South Coast could not practicably attain the PM-10 NAAQS by the applicable attainment deadline for moderate areas (December 31, 1994, per section 188(c)(1) of the Act), and reclassified the area as serious (58 FR 3334). In accordance with section 189(b)(2) of the Act, the applicable deadline for submittal of SIPs for the South Coast addressing the requirements for serious PM-10 nonattainment areas in section 189(b) and (c) of the Act were:

(1) August 8, 1994 (18 months after the effective date of the reclassification)—SIP to ensure the implementation of BACM no later than 4 years after reclassification;

(2) February 8, 1997 (4 years after the effective date of the reclassification)—SIP to provide for progress and expeditious attainment.

The 1994 PM10 plan addresses the first requirement and the 1997 plan addresses the second requirement.

E. Adoption and Submittal

The South Coast Air Quality Management District (SCAQMD) adopted the 1994 Air Quality Management Plan (AQMP) on September 9, 1994, and the California Air Resources Board (CARB) submitted the plan to us on November 15, 1994. This plan addresses the BACM provisions of CAA section 189(b)(1)(B).

The SCAQMD adopted the 1997 AQMP on November 15, 1996, and CARB submitted the plan on February 5, 1997. This plan addresses the remaining plan provisions for serious PM-10 nonattainment areas, as specified in CAA sections 188 and 189.

In addition to PM-10, these two AQMPs address carbon monoxide (CO), ozone, and nitrogen dioxide (NO2). By operation of law pursuant to CAA section 110(k)(1)(B), the PM-10 portions of the 1994 and 1997 plan submittals became complete 6 months after submittal by the State—i.e., on May 15, 1995, and August 5, 1997, respectively.

On April 10, 1998, the SCAQMD adopted a 1998 amendment to the 1997 plan, establishing 2010 and 2020 PM-10 motor vehicle emission budgets. The State submitted these budgets to us as a SIP revision on April 22, 1998, and this submittal became complete by operation of law on October 22, 1998.

On December 10, 1999, the SCAQMD adopted a 1999 amendment to the 1997 plan, primarily addressing the ozone elements of the plan but also affecting some control measures relating to PM-10. CARB submitted the 1999 amendment on February 4, 2000. On March 15, 2000, we found that the 1999 amendment met the completeness criteria in 40 CFR part 51, appendix V.

On June 7, 2002, the SCAQMD adopted and on November 18, 2002, CARB submitted a status report, including motor vehicle emissions budgets for purposes of transportation conformity under CAA section 176(c), based on the motor vehicle emissions in the 1997 PM-10 plan. On November 20, 2002, we found that this submittal met the completeness criteria in 40 CFR part 51, appendix V.

In this document, we refer to the PM-10 portion of the 1994 and 1997 Air Quality Management Plans as “the 1994 plan” and “1997 plan.” We refer to the 1998 and 1999 amendments to the 1997 plan as the “1998 amendments,” and “1999 amendments,” respectively, and we refer to the 2002 submittal as the “2002 status report.”

Both the District and CARB satisfied applicable statutory and regulatory requirements for reasonable public notice and hearing prior to adoption of the plans and the motor vehicle emissions budgets. The District conducted numerous public workshops, and properly noticed the public hearing at which the plans were adopted. The SIP submittals include proof of publication for notices of the public hearings. Therefore, we conclude that the 1994 and 1997 plans, the 1998 and 1999 amendments, and the 2002 status report met the public notice and involvement requirements of section 110(a)(1) of the CAA.

II. Evaluation of the SIP Submittals

A. Emission Inventories

The emission inventories in the 1997 plan supersede those in the 1994 plan. The 1997 plan includes summary emission inventories for major source categories in tons per annual average day for VOC, NO_X, CO, SOx, and PM-10 for the 1993 base year (Table 3-3A) and for 2000 (Table 3-5A) and 2006 (Table 3-6A). Appendix III (Base and Future Year Emission Inventories) to the 1997 plan provides more detailed emissions inventories for 1987, 1990, 1993, 1997, 2000, 2002, 2003, 2005, and 2006. Appendix III also includes additional emissions data, including planning inventories for summer and winter days, and estimates of emission reductions from each of the 1997 plan control measures for 2000, 2006, and subsequent years. Finally, Appendix III documents the source of the data and references SCAQMD and ARB reports that provide detailed information on the methodologies used to estimate emissions from area sources.

Appendix V (Modeling and Attainment Demonstrations) includes estimated emission reductions by control measure for PM-10 milestone years (1997, 2000, 2003, and 2006) and the detailed emission inventories used in the modeling analyses.

The 1997 plan's emission inventories employ activity levels, emission factors, and growth projections that were the most current and accurate available when the plan was required to be submitted and when the plan was, in fact, submitted: February 1997. The emission inventories are complete with respect to sources that have been found to contribute to PM-10 violations. We therefore propose to approve the emission inventories in Chapter 3, Appendix III, and Appendix V of the 1997 plan as meeting the provisions of CAA section 172(c)(3).

In the years since development, adoption, and submittal of the 1997 plan, CARB has prepared draft revisions to the mobile source component of the emissions inventories, including the model used to calculate exhaust and evaporative emissions from motor vehicles. This California-specific motor vehicle emissions model is known as EMFAC. The version of the model available for development of the 1997 PM-10 plan is known as EMFAC 7G, adopted by CARB in 1996 (CARB, Methodology for Estimating Emissions from On-Road Motor Vehicles, 1996).

CARB and SCAQMD have formally committed to adopt and submit a revised PM-10 plan and revised motor vehicle emissions budgets by Spring 2003, and to base the new plan and budgets on use of the most current and accurate emissions data, including the latest available version of the EMFAC model for motor vehicle emissions, incorporating the latest planning assumptions on vehicle fleet and age distribution, and incorporating the latest activity levels. This revised plan will also update the ozone and CO SIPs and budgets for the South Coast, which are similarly based on motor vehicle emissions calculated using EMFAC 7G and planning assumptions available in 1996.

We believe that approval of the 1997 plan's emissions inventories and the motor vehicle emissions budgets derived from the 1997 plan's emissions inventories is warranted at this time, since the inventories and budgets reflect the best available information at the time of the plan's preparation. Moreover, both SCAQMD and CARB have committed to submit, within a short period of time, a revised plan with updated emissions inventories and budgets. The transportation conformity implications of our proposed approval are discussed later in this document, in section II.G., Motor Vehicle Emissions Budgets.

B. Control Measures

1. Applicable Requirements

Because the South Coast is classified as serious for PM-10, the nonattainment plan for the area must include control measures that reflect a BACM level of control for each source category that contributes significantly to a violation of the 24-hour or annual PM-10 NAAQS.

By analogy to Title I Part C of the Clean Air Act relating to Prevention of Significant Deterioration (PSD), EPA interprets BACM for serious PM-10 areas as generally similar to the definition of Best Available Control Technology (BACT) for the PSD program. PM-10 BACM is therefore defined as “the maximum degree of emissions reduction of PM-10 and PM-10 precursors from a source * * * which is determined on a case-by-case basis, taking into account energy, environmental, and economic impacts and other costs, to be achievable for such source through application of production processes and available methods, systems, and techniques for control of each such pollutant.” General Preamble Addendum, 59 FR 42010 (August 16, 1994).

EPA exempts from the BACM requirement de minimis source categories, which do not contribute significantly to nonattainment. By analogy to the new source permit programs (40 CFR 51.165(b)), EPA has presumed that a source category contributes significantly to a violation of the 24-hour PM-10 NAAQS if its impact at the location of expected violation would exceed 5 μg/m3, and would contribute significantly to a violation of the annual PM-10 NAAQS if its impact at the time and location of the expected violation would exceed 1 μg/m3. 59 FR 42011. However, states must also review the potential to attain the PM-10 NAAQS earlier through application of controls on anthropogenic sources below these general levels.

SCAQMD identified significant categories as part of the BACM provisions of the 1994 plan. Appendix I-D (Best Available Control Measures—PM10 SIP for the South Coast Air Basin), Chapter 3, includes a calculation of the ambient impact of source categories at 5 representative sampling sites in the South Coast, which were subject to source apportionment analysis. Table 3-2 shows source contribution to annual average concentrations of ammonium sulfate, ammonium nitrate, secondary carbon, and geological particulate. Table 3-3 shows contributions to 24-hour average concentrations for the same species. The Tables show that the following categories were clearly significant contributors with respect to both of the NAAQS: Paved road dust, unpaved road dust, construction and demolition, and motor vehicles. The SCAQMD noted that 3 other categories are slightly above the de minimis levels but, given emission uncertainties, may not be significant: Non-farm equipment, non-utility internal combustion engines, and refinery boilers and heaters. These 3 source categories and most of the source categories that are below the de minimis levels were subject to stringent SCAQMD or CARB regulations, which helped keep PM-10 impact levels from these categories low, despite the large population and activity levels in the basin.

CAA section 189(b)(1)(B) provides that BACM must be implemented within 4 years after the date the area is reclassified to serious. In the case of the South Coast, reclassification to serious became effective on January 8, 1993, so BACM implementation is required by January 8, 1997.

Because the State has requested an extension of the PM-10 NAAQS attainment deadline pursuant to CAA section 188(e), the plan must include a demonstration that “the plan for the area includes the most stringent measures that are included in the implementation plan of any State or are achieved in practice in any State, and can feasibly be implemented in the area.”

Finally, the control measures in the serious area plan must be sufficient to achieve expeditious attainment by the applicable deadline.

2. Description of Control Measures

The control measures in the 1997 PM-10 plan are described at length in Appendix IV-A (Stationary and Mobile Source Control Measures). To reduce secondary precursor emissions of PM-10 (notably NO_X and, to a lesser extent, SO_x, VOC, and ammonia), the 1997 PM-10 plan relies on a large number of SCAQMD and CARB control measures, either as part of the base line emissions (this is primarily the case for measures which were fully adopted in regulatory form by 1996) or as specific control measure commitments. The majority of these control measures have been approved in prior actions on South Coast ozone plans or on individual SCAQMD regulations submitted over the years.

The 1997 plan also contains SCAQMD control measure commitments to reduce primary PM-10. These control measure commitments have not been previously approved and we are proposing approval of them at this time. Table 1 below, entitled “South Coast PM-10 Control Measure Commitments,” lists for each primary PM-10 control measure the SCAQMD commitments to adopt and implement the measure by specific dates to achieve particular emission reductions. A thorough discussion of each of the measures may be found in Appendix IV-A; the adoption and implementation dates are taken from Table 7-3 in the 1997 plan, Table 2-1 in the 1999 amendments, and Attachment D in the 2002 status report; the emission reduction commitments are taken from the 1997 plan, Appendix V, Attachment A, and from the 2002 status report, Attachment D.

In the 1994 and 1997 plans and in the appendices to the plans (e.g., 1994 plan, Appendix I-D), the District has provided extensive documentation on both the control measures included in the plan and those rejected. The documentation quantifies the costs of implementation, discusses the technological feasibility of control options, explains the schedule for expeditious implementation, and examines other factors as part of a comprehensive justification of the measures as reflecting BACM. As discussed above, the plans also include quantitative analyses of the South Coast emissions sources and a determination of which categories have “significant” impacts on PM-10 concentrations.

SCAQMD also reviewed the measures against the MSM criteria, in order to demonstrate that the plan reflects the most stringent measures that were included in the implementation plan of any State or were achieved in practice in any State, and can feasibly be implemented in the area. SCAQMD further analyzed all source categories and control approaches as part of an “all feasible measures” requirement of State law, and assessed on an international scale those potential control measures that could be adopted to attain the ozone NAAQS in the South Coast, the only ozone area in the country classified as extreme.

We agree with the SCAQMD's conclusion that the District's control measures represent the most stringent measures at the time the plans were required to be submitted. The plans therefore demonstrate that BACM and MSM have been adopted for each of the significant source categories.

3. Proposed Action on Control Measures

We conclude that the submittals demonstrate that the control measures for each significant source category, and for de minimis categories as a whole, are consistent with the BACM requirement in terms of the timing, degree, and extent of the control program and reflect MSM at the time the plan was required to be submitted.

We also conclude that the measures are sufficient to meet RFP and expeditious attainment provisions, as discussed below in sections II.D and II.F.

We therefore propose to approve the control measures under CAA section 110(k)(3), as meeting the requirements of CAA sections 110(a), 188(e), and 189(b)(1)(B). We are proposing to approve each of the control measure commitments to adopt and implement rules by specified dates and to achieve particular emission reductions by milestone years. Specifically, we are approving the SCAQMD's enforceable commitments in Table 1, taken from Attachment D to the 2002 status report, and the descriptions of the measures in Appendix IV-A of the 1997 plan, as amended by the 1999 amendments.

C. Contingency Measures

The CAA requires that the SIP include contingency measures to be implemented if the area fails to meet progress requirements or to attain the NAAQS by the applicable deadline. In response to this provision, the 1997 plan includes contingency measures, 3 of which are specifically directed toward increasing reductions of primary PM-10: CTY-12—Emission Reductions from Paved Roads (Curb and Gutter/Chemical Stabilization); CTY-13—Further Emission Reductions from Construction and Demolition Activities; and CTY-14—Emission Reductions from Miscellaneous Sources (Weed Abatement). These measures are discussed at length in Appendix IV, Section 6, pages IV-6-25 through IV-6-33. Each measure has the potential to achieve significant further PM-10 reductions and may be implemented quickly to cure a SIP shortfall.

We conclude that the 1997 plan satisfies the contingency requirements, and propose to approve the SCAQMD's contingency measure commitments under CAA section 110(k)(3) as meeting the contingency provisions of CAA section 172(c)(9). Specifically, we are approving the contingency measure commitments as set forth in Section 6 of Appendix IV-A to the 1997 plan.

D. Reasonable Further Progress (RFP) and Milestones

The plan must also include quantitative milestones which are to be achieved every 3 years until the area is redesignated to attainment, and show RFP toward attainment by the applicable attainment deadline. CAA section 189(c).

The 1997 plan, as modified by the 2002 status report, includes enforceable schedules for implementation of the specified control measures resulting in the emissions levels shown in Table 2—“South Coast PM-10 Reasonable Further Progress Milestones.” Using the approaches discussed in Section II.F. below, the SCAQMD modeled the emissions levels for 2006 to demonstrate attainment of both the 24-hour and annual PM-10 NAAQS.

EPA proposes to approve this annual schedule as meeting the RFP and milestone requirements of CAA section 189(c), since the schedule reflects expeditious implementation of BACM and expeditious attainment of the 24-hour and annual PM-10 NAAQS. We are approving the RFP and milestone provisions in the 1997 plan, Chapters 4 and 6, Appendix III, and Chapter 2 of Appendix V, as modified by the 2002 status report.

E. Attainment Demonstration

The SIP must provide a detailed demonstration (including air quality modeling) that the specified control strategy will reduce PM-10 emissions so that the standards will be attained as soon as practicable but no later than December 31, 2006, assuming final EPA approval of the attainment date extension. CAA section 189(b)(1)(A). EPA considers the area to be in attainment of the NAAQS if 24-hour concentrations are 150 ug/m3 or less and the annual arithmetic mean is 50 ug/m3 or less. In the case of the South Coast, the attainment demonstration in the 1997 PM-10 plan must analyze both the 24-hour and annual NAAQS, since the area has historically violated both NAAQS.

Because of the complexity and diversity of the PM-10 problem in the South Coast, the SCAQMD decided to use a variety of modeling approaches to assess control scenarios and determine attainment of the 24-hour and annual PM-10 NAAQS: (1) Urban Airshed Modeling with Linear Chemistry Module (UAM/LC (Lurmann and Kumar 1996); (2) the Chemical Mass Balance (CMB) receptor model for source apportionment in the Basin; (3) the particle in cell (PIC) model developed by California Institute of Technology for determining sulfate and nitrate formation; and (4) UAM-Aero (Kumar and Lurmann, 1996) for evaluating interactions of emissions, meteorology, and aerosol chemistry. The inputs and applications of each of these models are described in Chapter 2 of Appendix V (Modeling and Attainment Demonstrations) of the 1997 plan.

The modeling results for 2000, 2006, and 2010 are presented in the 1997 AQMP, Chapter 5 (Figures 5-3, 5-4, and 5-5), and on pages V-2-58 to V-2-67 of Appendix V. The UAM/LC and CMB modeling predicts that the peak annual concentration in 2006 with implementation of controls will be 48.10 ug/m3, compared to the 50 ug/m3 annual PM-10 NAAQS. The speciated rollback analysis predicts peak concentrations of 47.10 ug/m3 for 2006 with controls. The UAM/LC and CMB modeling predicts that the peak 24-hour concentration in 2006 with controls will be 142.9 ug/m3, while the speciated rollback analysis predicts 136.26 ug/m3, compared to the 150 ug/m3 24-hour PM-10 NAAQS.

In contrast to other pollutants, we have not issued detailed modeling guidelines for PM-10, nor have we established minimum performance requirements for PM-10 modeling. We have reviewed the SCAQMD's modeling approaches for both primary PM-10 and secondary PM-10, using both receptor modeling and dispersion modeling. We believe that the modeling in the 1997 plan provides a reasonable basis for linking emissions with air quality, for identifying an appropriate control strategy, and for determining whether the strategy delivers attainment for both the 24-hour and annual PM-10 NAAQS.

The SCAQMD's modeling shows that the level of emissions after implementation of the proposed set of control strategies would result in ambient concentrations within the South Coast in 2006 consistent with attainment of both the 24-hour and annual PM-10 NAAQS. We therefore conclude that the air quality modeling and attainment demonstration contained in the 1997 plan, Chapter 5 and Appendix V, Chapter 2, are consistent with existing EPA guidance, and we propose to approve the attainment demonstration under CAA section 189(b)(1)(A).

F. Extension of the Attainment Deadline

CAA section 188(e) allows states to apply for up to a 5-year extension of the serious area attainment deadline of December 31, 2001. In order to obtain the extension, there must be a showing that: (1) The plan for the area includes the most stringent measures that are included in the SIP of any state or are achieved in practice in any state, and can feasibly be implemented in the area, (2) the state complied with all requirements and commitments pertaining to the area in the implementation plan for the area, and (3) attainment by 2001 would be impracticable.

As discussed in section II.B. above, we propose to conclude that the South Coast PM-10 plans include BACM and MSM for each significant source category, and that the implementation schedule for each control measure is as expeditious as practicable. Attachment B to the 2002 status report shows that the responsible agencies have generally met the SIP requirements and commitments. Although the adoption and implementation dates of some of the 1997 plan's scheduled measures have been revised, EPA agrees with the SCAQMD that SIP implementation has been satisfactory and changes in the schedule should not adversely affect air quality at the 2003 milestone or at the 2006 attainment date.

Using UAM/LC and chemical mass balance modeling techniques discussed below in section II.E., the SCAQMD calculated 24-hour and annual PM10 concentrations in the year 2000 for the 5 representative sampling sites in the basin, with and without the plan control measures (1997 plan, Tables 2-17 and 2-19). The results show attainment at 4 of the sites but not at the Rubidoux site in northwestern Riverside County, where continued violations of both the 24-hour and annual NAAQS were predicted, despite aggressive implementation of BACM and MSM. Similar modeling analyses for 2006 show that additional emissions reductions from BACM and MSM, along with further emissions reductions from de minimis source categories, reduced ambient PM-10 concentrations further, bringing Rubidoux values slightly below both the 24-hour and annual PM-10 NAAQS. Based on this analysis, the SCAQMD determined that attainment could not feasibly be achieved before 2006.

We find that the SCAQMD has met the CAA provisions relating to attainment date extensions, and we propose to grant, under CAA section 188(e), a 5-year attainment date extension to December 31, 2006, for attainment of both the 24-hour and annual PM-10 NAAQS, based on the demonstration provided in the 1997 plan in Chapters 5 and 6 and in Appendix V, Chapter 2.

G. Motor Vehicle Emission Budgets

Rate of progress and attainment demonstration submittals must specify the maximum emissions of transportation-related precursors of PM-10 allowed in each milestone year and the attainment year. The submittals must also demonstrate that these emissions levels, when considered with emissions from all other sources, are consistent with RFP and attainment. In order for us to find these emissions levels or “budgets” adequate and approvable, the submittal must meet the conformity adequacy provisions of 40 CFR 93.118(e)(4) and be approvable under all pertinent SIP requirements.

The budgets defined by this and other plans when they are approved into the SIP or, in some cases, when the budgets are found to be adequate, are then used to determine the conformity of transportation plans, programs, and projects to the SIP, as described by CAA section 176(c)(3)(A). For more detail on this part of the conformity requirements, see 40 CFR 93.118. For transportation conformity purposes, the cap on emissions of transportation-related PM-10 precursors is known as the motor vehicle emissions budget. The budget must reflect all of the motor vehicle control measures contained in the attainment demonstration (40 CFR 93.118(e)(4)(v)), and must include PM-10 and PM-10 precursor emissions from the following sources: motor vehicles, reentrained dust from traffic on paved and unpaved roads, and emissions during construction of highway and rail projects.

The motor vehicle emissions budgets are presented in Table 3 below, entitled “South Coast PM-10 Plan Motor Vehicle Emissions Budgets,” which is taken from Attachment C to the 2002 status report. Emission reductions attributed to transportation control measures (TCMs) in the SIP are shown as positive numbers, and emission increases associated with the TCMs are shown as negative numbers in Table 3; however, as noted, the TCM emissions impacts are incorporated in the motor vehicle emissions lines in the budgets.

As discussed above in section II.A., Emission Inventories, the motor vehicle emissions portion of these budgets (i.e., the evaporative and tailpipe emissions) was developed using the EMFAC 7G motor vehicle emissions factors.

When the 2010 and 2020 budgets were adopted on April 10, 1998, SCAQMD submitted with the 1998 amendments a modeled demonstration that the emissions levels for motor vehicles reflected in the budgets, combined with emissions levels from all other PM-10 and PM-10 precursor emissions sources in the South Coast, would be consistent with maintenance of the 24-hour and annual PM-10 NAAQS. This demonstration was required in order to allow for approval of the budgets, since the budgets show a slight increase in emissions of primary PM-10 over the 2006 attainment levels (an increase of 2 percent in 2010 and 6 percent in 2020). The demonstration showed that the increase in primary PM-10 associated with motor vehicles is more than offset by decreases in emissions of secondary PM-10 precursors, resulting in projected 24-hour and annual concentrations below the predicted 2006 levels, which are below the NAAQS.

We propose to approve the motor vehicle emission budgets as consistent with the adequacy criteria of 40 CFR 93.118(e)(4), including consistency with the baseline emissions inventories, the motor vehicle control measure emission reductions used in the progress and attainment demonstration, and the reductions needed for continued attainment of the standard after the attainment deadline. Specifically, we are approving the budgets in the 2002 status report, which are based on, and consistent with, the 1997 plan and the 1998 amendment.

As discussed in section II.A., CARB is finalizing a revised version of EMFAC, and both CARB and SCAQMD have committed to adopt and submit a comprehensive revision to the PM-10 plan in Spring 2003, using the new EMFAC, incorporating the latest planning assumptions on vehicle fleet and age distribution, and incorporating the latest activity levels. This revised plan will include revised budgets, based on the new inventory and attainment demonstration. Assuming that these new budgets are adequate and approvable, the new budgets will soon replace the budgets in the current submittal.

Since these revised budgets will be based on the most current and accurate motor vehicle emissions data, we intend to allow for expedited use of the updated budgets in transportation conformity determinations. Therefore, we propose to limit our proposed approval of the budgets in the current submittal to last only until we find adequate the new budgets that are expected to be adopted in Spring 2003 as part of the revised PM-10 plan for the South Coast. On the effective date of our adequacy finding for the new budgets, our approval of the budgets in the current submittal would terminate and thus the new adequate budget would apply for purposes of transportation conformity. We have separately promulgated a similar limitation on the approval of the existing South Coast ozone and nitrogen dioxide (NO₂) budgets, in order to expedite use of new budgets associated with these pollutants in the 2003 plan revision for the South Coast. 67 FR 69139 (November 15, 2002).

III. Summary of EPA's Proposed Action

We are proposing to approve the serious area PM-10 SIP submitted by the State of California for the South Coast. Specifically, we are proposing to approve the 1994 and 1997 PM-10 plans, the 1998 and 1999 amendments, and the 2002 status report with respect to the CAA requirements for emissions inventories under section 172(c)(3); control measures under section 110(k)(3), as meeting the requirements of sections 110(a), 188(e), and 189(b)(1)(B); RFP under section 189(c); contingency measures under section 172(c)(9); demonstration of attainment under section 189(b)(1)(A); and motor vehicle emissions budgets under section 176(c)(2)(A). We are proposing to limit our approval of the motor vehicle emissions budgets to last only until the effective date of our adequacy findings for new replacement budgets. We are also proposing to approve the State's request for an extension of the attainment date from December 31, 2001 to December 31, 2006, under CAA section 188(e). We show the proposed approvals in Table 4—“Proposed Approvals of South Coast PM-10 Submittals.”

IV. Administrative Requirements

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 proposed 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 proposed action merely approves state law as meeting Federal requirements and imposes no additional requirements beyond those imposed by state law. Accordingly, the Administrator certifies that this proposed rule will not have a significant economic impact on a substantial number of small entities under the Regulatory Flexibility Act (5 U.S.C. 601 et seq.). Because this rule proposes to approve pre-existing requirements under state law and does not impose any additional enforceable duty beyond that required by state law, it does not contain any unfunded mandate or significantly or uniquely affect small governments, as described in the Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4).

This rule also does not have tribal implications because it will not have a substantial direct effect on one or more Indian tribes, on the relationship between the Federal Government and Indian tribes, or on the distribution of power and responsibilities between the Federal Government and Indian tribes, as specified by Executive Order 13175 (65 FR 67249, November 9, 2000). This action also does not have Federalism implications because it does not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government, as specified in Executive Order 13132 (64 FR 43255, August 10, 1999). This action merely proposes to approve a state plan implementing a Federal standard, and does not alter the relationship or the distribution of power and responsibilities established in the Clean Air Act. This proposed rule also is not subject to Executive Order 13045, “Protection of Children from Environmental Health Risks and Safety Risks” (62 FR 19885, April 23, 1997), because it is not economically significant.

In reviewing SIP submissions, EPA's role is to approve state choices, provided that they meet the criteria of the Clean Air Act. In this context, in the absence of a prior existing requirement for the State to use voluntary consensus standards (VCS), EPA has no authority to disapprove a SIP submission for failure to use VCS. It would thus be inconsistent with applicable law for EPA, when it reviews a SIP submission, to use VCS in place of a SIP submission that otherwise satisfies the provisions of the Clean Air Act. Thus, the requirements of section 12(d) of the National Technology Transfer and Advancement Act of 1995 (15 U.S.C. 272 note) do not apply. This proposed rule does not impose an information collection burden under the provisions of the Paperwork Reduction Act of 1995 (44 U.S.C. 3501 et seq.).

List of Subjects

40 CFR Part 52

• Environmental protection
• Air pollution control
• Incorporation by reference
• Intergovernmental relations
• Particulate matter
• Reporting and recordkeeping requirements

40 CFR Part 81

• Environmental protection
• Air pollution control
• National parks
• Wilderness areas