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Clean Air Act Approval and Promulgation of Carbon Monoxide Implementation Plan for the State of Washington: Puget Sound Attainment Demonstration
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[Federal Register: July 25, 1996 (Volume 61, Number 144)] [Rules and Regulations] [Page 38597-38600] From the Federal Register Online via GPO Access [wais.access.gpo.gov]
ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 [WA47-7120a; FRL-5538-3] Clean Air Act Approval and Promulgation of Carbon Monoxide Implementation Plan for the State of Washington: Puget Sound Attainment Demonstration AGENCY: Environmental Protection Agency (EPA). ACTION: Direct final rule.
SUMMARY: EPA is approving the attainment demonstration portion of the Puget Sound carbon monoxide (CO) State implementation plan (SIP) revision submitted on September 30, 1994, by the State of Washington Department of Ecology (Washington) for the purpose of documenting attainment of the national ambient air quality standards (NAAQS) for CO. The implementation plan revision was submitted by the State to satisfy certain federal requirements for an approvable nonattainment area CO SIP for the Puget Sound nonattainment area in the State of Washington. The rationale for the approval is set forth in this notice. Additional information is available at the address indicated below. Under the Clean Air Act (CAA), EPA must approve or disapprove SIPs or portions of SIPs within time frames specified in the CAA; failure to do so would render EPA liable to citizen suits to conduct rulemaking on those SIPs and would delay making approvable rules federally enforceable. DATES: This action is effective on September 23, 1996 unless adverse or critical comments are received by August 26, 1996. If the effective date is delayed, timely notice will be published in the Federal Register. ADDRESSES: Written comments should be addressed to: Montel Livingston, SIP Manager, Office of Air Quality (OAQ-107), EPA, 1200 Sixth Avenue, Seattle, Washington 98101.
Documents which are incorporated by reference are available for public inspection at the Air and Radiation Docket and Information Center, Environmental Protection Agency, 401 M Street SW., Washington, D.C. 20460. [[Page 38598]] Copies of material submitted to EPA may be examined during normal business hours at the following locations: EPA Region 10, Office of Air Quality, 1200 Sixth Avenue (OAQ-107), Seattle, Washington 98101; Washington Department of Ecology, Attention Tami Dahlgren, Olympia, Washington 98504-7600, telephone (360) 407-6830; and the Puget Sound Air Pollution Control Authority, 110 Union Street, Suite 500, Seattle, Washington 98101-2038. FOR FURTHER INFORMATION CONTACT: William M. Hedgebeth, EPA Region 10, Office of Air Quality, 1200 Sixth Avenue, M/S OAQ-107, Seattle, Washington 98101, (206) 553-7369. SUPPLEMENTARY INFORMATION: I. Background The air quality planning requirements for moderate CO nonattainment areas are set out in sections 186-187 of the CAA Amendments of 1990 (CAAA) which pertain to the classification of CO nonattainment areas and to the submission requirements of the SIPs for these areas, respectively. The EPA has issued a ``General Preamble'' describing EPA's preliminary views on how EPA intends to review SIPs and SIP revisions submitted under Title I of the CAA, [see generally 57 FR 13498 (April 16, 1992) and 57 FR 18070 (April 28, 1992)]. Because EPA is describing its interpretations here only in broad terms, the reader should refer to the General Preamble for a more detailed discussion of the interpretations of Title I advanced in today's proposal and the supporting rationale.
Those States containing CO nonattainment areas with design values greater than (>) 12.7 parts per million (ppm) were required to submit, among other things, an attainment demonstration by November 15, 1992, showing that the plan will provide for attainment by December 31, 1995, for moderate CO nonattainment areas. The Puget Sound area, which includes lands within the Puyallup, Tulalip, and Muckleshoot Indian Reservations, had a design value of 14.8 ppm based on 1987 data, and was classified as ``moderate > 12.7 ppm,'' under the provisions of section 186 of the CAA (see 56 FR 56694, November 6, 1991, 40 CFR Sec. 81.348).
The CO NAAQS are for 1-hour and 8-hour periods and are not to be exceeded more than once per year. The 1-hour CO NAAQS is 35 ppm (40 mg/ m<SUP>3) and the 8-hour CO NAAQS is 9 ppm (10 mg/m<SUP>3). Washington's attainment demonstration predicted that the highest 8-hour design concentration as of the attainment date would be 9 ppm, thus demonstrating attainment of the 8-hour CO NAAQS. No demonstration was required to be carried out for the 1-hour NAAQS, as the Puget Sound area has not violated this NAAQS since before the 1990 CAAA were enacted. The same strategies which bring the area into attainment with the 8-hour NAAQS will also contribute to reduced 1-hour concentrations. The modeled attainment demonstration is discussed in greater detail below. II. Review of State Submittal Section 110(k) of the CAA sets out provisions governing EPA's review of SIP submittals (see 57 FR 13565-66). In this action, EPA is granting approval of the attainment demonstration portion of the plan revision submitted to EPA on September 30, 1994, because it meets all of the applicable requirements of the CAA.
- Procedural Background The CAA requires States to observe certain procedural requirements in developing implementation plans and plan revisions for submission to EPA. Section 110(a)(2) of the CAA provides that each implementation plan submitted by a State must be adopted after reasonable notice and public hearing.<SUP>1 Section 110(l) of the CAA similarly provides that each revision to an implementation plan submitted by a State under the CAA must be adopted by such State after reasonable notice and public hearing.
\1\ Also Section 172(c)(7) of the Act requires that plan provisions for nonattainment areas meet the applicable provisions of section 110(a)(2).
The EPA also must determine whether a submittal is complete and therefore warrants further EPA review and action [see section 110(k)(1) and 57 FR 13565]. The EPA's completeness criteria for SIP submittals are set out at 40 CFR Part 51, Appendix V (1991), as amended by 57 FR 42216 (August 26, 1991). The EPA attempts to make completeness determinations within 60 days of receiving a submission. However, a submittal is deemed complete by operation of law if a completeness determination is not made by EPA six months after receipt of the submission. In this instance, a completeness determination was made by operation of law.
The State of Washington Department of Ecology held a public hearing in Bellevue, Washington on September 8, 1994, to entertain public comment on the implementation plan for the Puget Sound CO nonattainment area. Following the public hearing the plan was adopted by the State and submitted to EPA on September 30, 1994, as a proposed revision to the SIP.
With respect to the portions of the tribal lands which lie within the CO nonattainment area, EPA contacted the chairpersons of the Puyallup and Muckleshoot Tribal Councils and the Chairman of the Tulalip Board of Directors of the Tulalip Tribes of Washington to provide them with the information EPA has regarding the CO levels in the ambient air within the entire nonattainment area and to identify the effects that redesignating the entire area as attainment would have on those tribal lands. Mobile sources of CO are the primary sources of concern on the tribal lands within the nonattainment area. No CO ``hot spot'' problems have been identified on the tribal lands by EPA, Washington, or PSAPCA, nor have any stationary CO sources of concern been identified. EPA provided the three tribes the opportunity to discuss any concerns that they had regarding the pending redesignation; no concerns were identified.
In today's action EPA is approving the attainment demonstration portion of Washington's CO SIP submittal for the Puget Sound area and invites public comment on the action. EPA also finds that information and requirements provided in the attainment demonstration portion of the Department of Ecology SIP revision request for the Puget Sound nonattainment area demonstrate that the section 187(a)(7) requirements have been met for the entire Puget Sound area, including portions of the Tulalip, Puyallup, and Muckleshoot Indian Reservations. 2. Attainment Demonstration As noted, CO moderate nonattainment areas with design values greater than 12.7 parts per million (ppm) were required to submit a demonstration by November 15, 1992, showing that the plan will provide for attainment by December 31, 1995. Washington conducted an attainment demonstration using a ``rollback'' modeling approach for the Puget Sound CO nonattainment area to show that emission reductions resulting from implementation of control measures were sufficient to ``roll back'' the design value to a concentration at or below the NAAQS for CO of 9 ppm.
The CO NAAQS are for 1-hour and 8-hour periods and are not to be exceeded more than once per year. The 8-hour CO NAAQS is 9 ppm (10 mg/ m\3\). As noted, no demonstration was required to be carried out for the 1-hour NAAQS, as the Puget Sound nonattainment area has [[Page 38599]] not violated the 1-hour NAAQS since before the CAAA were enacted. In the attainment demonstration portion of the SIP submittal, Washington showed that the 8-hour design value concentration of 9.0, predicted for 1995, the attainment year, documents attainment of the 8-hour CO NAAQS by the required date, December 31, 1995. The rollback modelling used in the 1994 SIP submittal incorporated the use of a 90/10 split for emission sources, specifically attributing 9012f the CO emissions to local traffic and 10267f the CO emissions to regional CO sources. Because of questions about whether the use of this split was adequately justified, Washington submitted additional information on May 10, 1996, documenting that the Puget Sound Air Pollution Control Agency (PSAPCA) had conducted additional rollback modelling using a 75/25 split, specifically attributing 7512f the CO emission sources to local traffic and 25to regional CO sources. This general approach had been approved by EPA in a letter dated October 16, 1992. Conservative assumptions used in the 1994 modelling were: (1) all sources included in the regional emission inventory contribute to ambient concentrations at monitoring sites uniformly (i.e., distant point sources contribute just as much as motor vehicles two blocks away); (2) the attainment demonstration for Tacoma (the site of the highest design value in the nonattainment area) uses 1987 data, when the CAA calls for the most recent two years of data (1988 and 1989) and base year air quality data for all other monitoring sites are from 1988 and 1989; and (3) the rollback analysis is based on 1987, 1988, and 1989 air quality and a 1990 base year for emissions. A fundamental assumption of the rollback approach is that there is a proportional relationship between emissions and air quality during a base year and emissions and air quality in a future year. Use of the same base year for air quality and emissions is the norm. Changes made by PSAPCA in the additional rollback modelling included the following four factors. First, the additional modeling used the same base year for emissions and air quality in Tacoma. Second, it conservatively assumed that all emissions other than local traffic emissions were the same in 1987 as in 1990, when in all likelihood, these emissions were higher in 1987. Third, the MOBILE5a model was run for 1987 and 1990 and, using the fleet average emission factors for CO from these runs, developed a factor by which to multiply the 1990 mobile source emissions to produce a reasonable approximation of 1987 mobile source emissions. (No adjustment was made for traffic volumes, which may have been lower in 1987). And fourth, as noted, the estimated 1987 mobile source emissions were input into the rollback model using a 75/25 split. Separate design values were calculated for cold and warm weather since both cold and warm weather exceedances had been recorded. The recalculation of the rollback modelling predicted attainment for both cold and warm weather in 1995, with a predicted cold weather design value of 8.6 ppm and a predicted warm weather design value of 8.4 ppm, both in Tacoma, the site of the monitor with the highest recorded CO measurements.
A review of 1995 air quality data entered into the Aerometric Information Retrieval System (AIRS) data base indicated that the actual 1995 design value for the Tacoma CO monitor was 6.3. The 1995 design value for the entire nonattainment area was 6.5, significantly below the modeled 1995 design value of 9.0 using the 90/10 split or the cold and warm weather predicted design values using the 75/25 split in the modeling developed by PSAPCA in 1996.
Major control measures used by Washington during the winter season to effect annual emission reductions were the State's Emission Check Program, the expansion of the Program into new areas, and oxygenated fuel. During the ``warm season,'' there was no oxygenated fuel. The following summarizes the 1990 to 1995 emission inventory reductions. 1990 to 1995 Emission Inventory Reductions
Percent reduction ------------------- Category Cold Warm weather weather King County: Pierce County: Snohomish County: