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Approval and Promulgation of Implementation Plans; New Mexico; Revision to Motor Vehicle Emission Budgets in Bernalillo County, New Mexico Carbon Monoxide Air Quality Maintenance Plan Using MOBILE6
[Federal Register: October 9, 2003 (Volume 68, Number 196)] [Rules and Regulations] [Page 58276-58281] From the Federal Register Online via GPO Access [wais.access.gpo.gov] [DOCID:fr09oc03-8] ======================================================================= ----------------------------------------------------------------------- ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 [NM-46-1-7615a; FRL-7571-1] Approval and Promulgation of Implementation Plans; New Mexico; Revision to Motor Vehicle Emission Budgets in Bernalillo County, New Mexico Carbon Monoxide Air Quality Maintenance Plan Using MOBILE6 AGENCY: Environmental Protection Agency (EPA). ACTION: Direct final rule. ----------------------------------------------------------------------- SUMMARY: The EPA is taking direct final action approving the State Implementation Plan (SIP) revisions for Bernalillo County, New Mexico, which is a carbon monoxide maintenance area. This SIP revision was submitted to EPA by the Governor of New Mexico on May 15, 2003. More specifically, EPA is approving the county's revised Motor Vehicle Emissions Budget (MVEB) for carbon monoxide (CO) for 1996, 1999, 2002, 2005 and 2006. This budget was developed using EPA's latest emissions [[Page 58277]] modeling program, MOBILE6. This submittal updates the maintenance plan by establishing new transportation conformity MVEBs for use by the Mid- Region Council of Governments, the area's Metropolitan Planning Organization (MPO). These budgets will continue to maintain the total on-road mobile source emissions for the area at or below the attainment level for the CO National Ambient Air Quality Standard (NAAQS). DATES: This rule is effective on November 24, 2003 without further notice, unless EPA receives adverse comment by November 10, 2003. If EPA receives such comment, EPA will publish a timely withdrawal in the Federal Register informing the public that this rule will not take effect. ADDRESSES: Written comments on this action should be addressed to Mr. Thomas H. Diggs, Chief, Air Planning Section (6PD-L), at the EPA Region 6 office listed below. Electronic comments should be sent either to Diggs.Thomas@epa.gov or to http://www.regulations.gov,which is an alternative method for submitting electronic comments to EPA. To submit comments, please follow the detailed instructions described in the Final Action part of this document. Copies of the State's submittal and other documents relevant to this action are available for public inspection during normal business hours at the following locations. Anyone wanting to examine these documents should make an appointment with the appropriate office at least two working days in advance. Environmental Protection Agency, Region 6, Air Planning Section (6PD-L), 1445 Ross Avenue, Dallas, Texas, 75202-2733. City of Albuquerque Environmental Health Department, 1 Civic Plaza, Albuquerque, New Mexico 87103. Telephone 505-768-2600. FOR FURTHER INFORMATION CONTACT: Ms. Peggy Wade, Air Planning Section (6PD-L), Environmental Protection Agency, Region 6, 1445 Ross Avenue, Dallas, Texas, 75202-2733, telephone (214) 665-7247 or Wade.Peggy@epa.gov. SUPPLEMENTARY INFORMATION: Throughout this document whenever ``we'', ``us'', or ``our'' is used, we mean the EPA. Outline I. Background II. What Is MOBILE6? III. Analysis of the State's Submittal A. Why Were Updated Carbon Monoxide Budgets Established? B. Recalculating the Motor Vehicle Emissions Budget with MOBILE6 IV. Final Action A. How Can I Get Copies of This Document and Other Related Information? B. How and To Whom Do I Submit Comments? V. Statutory and Executive Order Reviews I. Background In 1990, the City of Albuquerque/Bernalillo County (Albuquerque) in New Mexico had a CO design value of 11.1 parts per million, exceeding the National Ambient Air Quality Standard (NAAQS) of 9 parts per million (8-hour average basis). Consequently, Albuquerque was classified as a moderate nonattainment area for CO under the Clean Air Act (the Act). As required by the Act, on November 5, 1992, New Mexico submitted for EPA approval a revision to the SIP to address Albuquerque's CO nonattainment. Different parts of the November 1992 SIP submittal were approved at different times, with approval of all aspects completed in June of 1996. Air quality data in the Albuquerque area showed no violations of the CO NAAQS between 1992 and 1995, meeting the first criterion for redesignation. On April 14, 1995, New Mexico submitted a request that Albuquerque be redesignated to attainment for CO. EPA proposed approval of this request on February 16, 1996. This approval was made effective on July 15, 1996. The Act also requires a periodic inventory of all emissions from area, mobile, and stationary sources. The 1993 emission inventory found the following CO emissions levels, in tons per day: Stationary sources, 3.18; area sources, 111.60; On-road mobile sources, 274.16; and nonroad mobile sources, 45.74. Total CO emissions were 434.69 tons per day. This inventory was further updated in 1996. This updated inventory reflected the following CO emissions levels, in tons per day: On-road mobile sources, 266.99; nonroad mobile sources, 50.90; area sources, 67.19; and stationary sources, 3.92. Total CO emissions were inventoried at 389.0 tons per day. The Albuquerque/Bernalillo County area submitted further revisions to its maintenance plan emissions budgets on February 4, 1999, using the MOBILE5 emission factor modeling program. These revisions, for years 1996-2006, increased the budgets for mobile and stationary source emissions but decreased the budget for area source emissions, resulting in an overall decrease in budgeted emissions. These revisions also established a 2010 emissions budget. A direct final rule approving these revisions was published December 20, 1999. However, adverse comments were received and the direct final approval was withdrawn. After addressing the comments received, the EPA gave final approval to the budget revisions for 1996-2010 on May 24, 2000 (65 FR 33455). The revised MVEBs are as follows, in tons of CO emissions per day: 1996, 266.99; 1999, 229.09; 2002, 209.1; 2005, 205.67; 2006, 205.86; and 2010, 222.46. II. What Is MOBILE6? MOBILE6 is the latest in a series of EPA emissions factor models for estimating pollution from on-road motor vehicles in states outside of California and represents the first major update of the preexisting MOBILE model since 1993. The release of this model was announced in a Federal Register notice published on January 29, 2002 (67 FR 4254). This date marks the beginning of the two-year grace period, after which all areas must use MOBILE6 for emissions factor modeling for transportation conformity purposes. MOBILE6 calculates emissions of carbon monoxide and other pollutants from passenger cars, motorcycles, buses, and light-duty and heavy-duty trucks. The model accounts for the emission impacts of factors such as changes in vehicle emissions standards, changes in vehicle populations, and variation in local conditions such as temperature, humidity, fuel quality, and air quality programs. MOBILE6 is used to calculate current and future inventories of motor vehicle emissions at the national and local level. These inventories are used to make decisions about air pollution policies and programs at the local, state and national level. Inventories based on MOBILE6 are also used to meet the federal Clean Air Act's SIP and transportation conformity requirements. The MOBILE model was first developed in 1978 and MOBILE6 is the first major update of the model since 1993. It has been updated many times to reflect changes in vehicle fleet composition and fuels, to incorporate EPA's growing understanding of vehicle emissions, and to cover new emissions regulations and modeling needs. III. Analysis of the State's Submittal A. Why Were Updated Carbon Monoxide Budgets Established? The existing MVEBs for CO were last modified through a SIP revision approved and made effective by EPA on May 24, 2000 (65 FR 33455). To address and accommodate the release of MOBILE6 as the latest EPA-approved emissions factor model, the [[Page 58278]] governor of New Mexico submitted a SIP revision to EPA on May 15, 2003. The MVEBs contained in the current CO maintenance plan were calculated with a previous emissions factor model, MOBILE5a. This submittal revises the Motor Vehicle Emissions Budgets for the years 1996, 1999, 2002, 2005 and 2006 using MOBILE6. Note that only the MVEBs are being revised using the MOBILE6 model; budgets for the other source categories will remain unchanged as the MOBILE6 model does not affect these categories. However, changes in the estimated amount of CO produced by the on-road mobile source category will affect the CO baseline level and the CO totals by year. Therefore, the baseline level and amounts of total CO by year will be revised in response to the MOBILE6 analysis. The EPA guidance document, Policy Guidance on the Use of MOBILE6 for SIP Development and Transportation Conformity, issued by John Seitz on January 18, 2002 (``MOBILE6 Guidance''), states that nonattainment and maintenance areas may forgo the requirement to update all planning assumptions when updating the MVEBs with MOBILE6, if the area can demonstrate that these assumptions have not changed since the last budget revision. For CO, population is the most important assumption underlying the CO forecasts as it has a direct impact on the number of miles driven. Comparing the Albuquerque/Bernalillo County population figure for the year 2000 used in the last SIP revision (556,248) to the population for the same area recorded in the 2000 Census (556,678) results in a difference of 0.077%, less than 1%. Because the estimated figure matches so closely with the actual census count, the requirement that the latest planning assumptions continue to be valid is met and this SIP revision continues to use these estimates. Additionally, work has already begun on the required second ten-year maintenance plan, due to EPA in June of 2004. With this expected submission, the MPO will update the emissions inventory in its entirety with the latest planning assumptions and demographic data. B. Recalculating the Motor Vehicle Emissions Budget With MOBILE6 Because of the significant difference in modeling results between the previous version of the emissions factor model, MOBILE5a, and the updated version, MOBILE6, the on-road mobile source category in the emissions inventory was recalculated for all years represented in the ten-year maintenance time frame of the SIP using MOBILE6. This inventory provides the basis for determining the MVEBs for CO. The MVEBs are the same as the total estimated CO, in tons per day, for the on-road mobile source category in the emissions inventory. For all years beyond 2006 (the last modeled year), the MVEB will be held at the 2006 level. The table below compares the existing MVEBs with the revised MVEBs submitted with this SIP revision. Motor Vehicle Emission Budgets ------------------------------------------------------------------------ Existing Proposed Year (CO in (CO in Change tpd) tpd) ------------------------------------------------------------------------ 1996................................... 266.90 416.31 149.32 1999................................... 229.09 373.05 143.96 2002................................... 209.01 369.53 160.52 2005................................... 205.67 367.28 161.61 2006................................... 205.86 312.65 106.79 ------------------------------------------------------------------------ For all budget years, MOBILE6 estimates a greater production of CO than MOBILE5a. Although the MOBILE6 emissions are estimated to be higher than that previously predicted by MOBILE5a, the model still demonstrates greater relative emissions reductions benefits. Recall that only the budget estimates for on-road mobile source emissions (the MVEBs) are being revised with the MOBILE6 model. Changes in the MVEBs will, however, affect the overall CO budgets and CO baseline level even though the amount of CO in the other source categories (nonroad mobile, area, and stationary) will remain unchanged. The MOBILE6 Guidance provides that nonattainment and maintenance areas may revise the on- road mobile emissions inventory and MVEBs without revising the entire SIP and other emission inventory categories, if the SIP continues to demonstrate maintenance of the standard when the MOBILE5a-based on-road mobile source inventories are replaced with MOBILE6 inventories. To demonstrate this, the following table shows the entire emission inventory, with the on-road mobile source category replaced with the resultant MOBILE6-derived estimates. The revised MVEBs are shown, along with the currently approved inventories from the other source categories. These inventories were approved in a revision to the CO maintenance plan on May 24, 2000 (65 FR 33455). Inventory Source Category [CO in tpd] ---------------------------------------------------------------------------------------------------------------- Proposed Off-road Revised Year MOBILE6 mobile Area Stationary total MVEBs sources sources sources inventory ---------------------------------------------------------------------------------------------------------------- 1996........................................... 416.31 50.90 67.19 3.92 538.32 1999........................................... 373.05 52.68 69.87 27.40 523.00 2002........................................... 369.53 54.46 72.60 27.54 524.13 2005........................................... 367.28 56.25 75.25 27.68 526.46 2006........................................... 312.65 56.84 76.09 27.72 473.30 ---------------------------------------------------------------------------------------------------------------- The 1996 figure found in the revised total column, 538.32 tpd, is the new CO baseline level as calculated with MOBILE6. The original baseline level, as approved on May 24, 2000, was 389.0 tpd. This level represents the amount of CO, in tons per day, which may be emitted by all sources and still allow the Albuquerque/Bernalillo County area to be in attainment of the NAAQS. Essentially, this baseline represents the ``cap'' of emissions from all sources. The results of MOBILE6 modeling, which raises the baseline level, indicates that the initial CO baseline, as determined using MOBILE5a, was set too low. This new analysis indicates that the Albuquerque/Bernalillo County area actually had a larger amount of CO in the airshed in 1996, yet still met the NAAQS. The following table illustrates the relative gain in emissions reductions when comparing the MOBILE5a-derived estimates with those of MOBILE6. [[Page 58279]] ------------------------------------------------------------------------ Cap under Cap under Year MOBILE5a MOBILE6 (in Difference (in tpd) tpd) (in tpd) ------------------------------------------------------------------------ 1996.......................... 389.0 538.32 164 2006.......................... 366.51 473.30 106.79 Decrease in CO Emissions (in -22.49 -65.02 tpd)......................... Percent Reduction............. 5.78 12.08 ------------------------------------------------------------------------ The greater decline in emissions seen with MOBILE6 between 1996 and 2006 can be attributed to the sensitivity of the model to local parameters incorporated into MOBILE6 and the control programs in place in Albuquerque/Bernalillo County. So, although the emissions cap is higher with MOBILE6, that difference is due to the sensitivity of the newer model. MOBILE6 offers a more robust and accurate estimate of emissions than prior versions of the model. Comparing just the MOBILE5a and MOBILE6 on-road mobile source estimates indicates that MOBILE6 shows a relative reduction in CO emissions that is approximately twice as much as that seen with MOBILE5a. IV. Final Action We have evaluated the State's submittal and have determined that it meets the applicable requirements of the Act and EPA regulations, and is consistent with EPA policy. Therefore, we are approving Albuquerque's request to revise the MVEBs in its carbon monoxide maintenance SIP using MOBILE6, EPA's latest emission factor modeling program. The EPA is publishing this rule without prior proposal because we view this as a noncontroversial amendment and anticipate no adverse comments. However, in the proposed rules section of this Federal Register publication, we are publishing a separate document that will serve as the proposal to approve the SIP revision if adverse comments are received. This rule will be effective on November 24, 2003 without further notice unless we receive adverse comment by November 10, 2003. If we receive adverse comments, we will publish a timely withdrawal in the Federal Register informing the public that the rule will not take effect. We will address all public comments in a subsequent final rule based on the proposed rule. We will not institute a second comment period on this action. Any parties interested in commenting must do so at this time. Please note that if we receive adverse comment on an amendment, paragraph, or section of this rule and if that provision may be severed from the remainder of the rule, we may adopt as final those provisions of the rule that are not the subject of an adverse comment. A. How Can I Get Copies of This Document and Other Related Information? 1. The Regional Office has established an official public rulemaking file available for inspection at the Regional Office. The EPA has established an official public rulemaking file for this action under NM-46-1-7615. The official public file consists of the documents specifically referenced in this action, any public comments received, and other information related to this action. Although a part of the official record, the public rulemaking file does not include Confidential Business Information (CBI) or other information whose disclosure is restricted by statute. The official public rulemaking file is the collection of materials that is available for public viewing at the Air Planning Section, EPA Region 6, 1445 Ross Avenue, Dallas, Texas, 75202. The EPA requests that, if at all possible, you contact the rulemaking contact listed as the Further Information Contact to schedule your inspection. The Regional Office's official hours of business are Monday through Friday, 8:30 to 4:30 excluding Federal holidays. 2. Copies of the State submittal are also available for public inspection during official business hours, by appointment at the local air agency. City of Albuquerque Environmental Health Department, 1 Civic Plaza, Albuquerque, New Mexico 87103. Telephone 505-768-2600. 3. Electronic Access. You may access this Federal Register document electronically through the Regulations.gov Web site located at http:// www.regulations.gov