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Clean Air Act Reclassification; Arizona-Phoenix Nonattainment Area; PM<INF>10
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[Federal Register: May 10, 1996 (Volume 61, Number 92)] [Rules and Regulations] [Page 21372-21378] From the Federal Register Online via GPO Access [wais.access.gpo.gov]
ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 81 [AZR91-0003; FRL-5503-7] Clean Air Act Reclassification; Arizona-Phoenix Nonattainment Area; PM<INF>10 AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule.
[[Page 21373]] SUMMARY: In this document EPA is making a final finding that the Phoenix Planning Area (PPA) has not attained the PM<INF>10 (particulate matter 10 microns or less in aerodynamic diameter) national ambient air quality standards (NAAQS) by the applicable attainment date in the Clean Air Act (CAA) for moderate PM<INF>10 nonattainment areas, December 31, 1994. This finding is based on EPA's review of PM<INF>10 ambient air quality data. As a result of this finding, the PPA is reclassified as a serious PM<INF>10 nonattainment area by operation of law. The intended effect of the reclassification is to allow the State 18 months from the effective date of this action to submit a new State Implementation Plan (SIP) demonstrating attainment of the PM<INF>10 NAAQS by December 31, 2001, the CAA attainment date for serious areas. EFFECTIVE DATE: This action is effective on June 10, 1996. FOR FURTHER INFORMATION CONTACT: Wallace Woo, Chief, Plans Development Section (A-2-2), Air Planning Branch, Air and Toxics Division, U.S. Environmental Protection Agency, Region 9, 75 Hawthorne Street, San Francisco, California 94105, (415) 744-1207. SUPPLEMENTARY INFORMATION: I. Background A. CAA Requirements and EPA Actions Concerning Designation and Classification On November 15, 1990, the date of enactment of the 1990 Clean Air Act Amendments (CAA), PM<INF>10 areas meeting the qualifications of section 107(d)(4)(B) of the Act were designated nonattainment by operation of law. Once an area is designated nonattainment, section 188 of the Act outlines the process for classification of the area and establishes the area's attainment date. Pursuant to section 188(a), all PM<INF>10 nonattainment areas were initially classified as moderate by operation of law upon designation as nonattainment. These nonattainment designations and moderate area classifications were codified in 40 CFR part 81 in a Federal Register notice published on November 6, 1991 (56 FR 56694).
Under section 188(c)(1) of the CAA, the attainment deadline for all PM<INF>10 nonattainment areas originally classified as moderate was no later than December 31, 1994. Under section 188(d), EPA may, upon application by a state, extend the attainment deadline if the state has complied with all requirements and commitments pertaining to the area in the applicable implementation plan. In addition, in order to qualify for an extension there must have been no more than one exceedance of the 24 hour national ambient air quality standard (NAAQS) in the area in the year preceding the extension year, and the annual mean concentration of PM<INF>10 in the area for such year must be less than or equal to the standard. Under this provision, EPA may grant up to two one year extensions if these conditions have been met. B. Reclassification as Serious Nonattainment EPA has the responsibility, pursuant to sections 179(c) and 188(b)(2) of the CAA, of determining within six months of the applicable attainment date, whether PM<INF>10 nonattainment areas have attained the NAAQS. Section 179(c)(1) of the Act provides that these determinations are to be based upon an area's air quality as of the attainment date, and section 188(b)(2) is consistent with this requirement. EPA makes the determinations of whether an area's air quality is meeting the PM<INF>10 NAAQS based upon air quality data gathered at monitoring sites in the nonattainment area and entered into the Aerometric Information Retrieval System (AIRS). These data are reviewed to determine the area's air quality status in accordance with EPA guidance at 40 CFR part 50, Appendix K. Pursuant to Appendix K, attainment of the annual PM<INF>10 standard is achieved when the annual arithmetic mean PM<INF>10 concentration is equal to or less than 50 <greek-m>g/m\3\. The annual average is determined by first calculating the average PM<INF>10 concentration for each calendar quarter. The annual average is then calculated by averaging the four calendar quarter averages. Attainment of the 24 hour standard is determined by calculating the expected number of exceedances of the 150 <greek-m>g/m\3\ limit per year. The 24 hour standard is attained when the expected number of exceedances is 1.0 or less. A total of three consecutive years of clean air quality data is generally necessary to show attainment of the 24 hour and annual standards for PM<INF>10. A complete year of air quality data, as referred to in 40 CFR part 50, Appendix K, is comprised of all four calendar quarters with each quarter containing data from at least 75 percent of the scheduled sampling days. Under section 188(b)(2)(A) of the CAA, a moderate PM<INF>10 nonattainment area must be reclassified as serious by operation of law after the statutory attainment date if the Administrator finds that the area has failed to attain the NAAQS. Pursuant to section 188(b)(2)(B), EPA must publish a notice in the Federal Register identifying those areas that failed to attain the standard and the resulting reclassification. C. Effect of Reclassification PM<INF>10 nonattainment areas reclassified as serious under section 188(b)(2) of the CAA are required to submit, within 18 months of the area's reclassification, SIP revisions providing for the implementation of best available control measures (BACM) no later than four years from the date of reclassification. The SIP also must contain a demonstration that the implementation of BACM will provide for attainment of the PM<INF>10 NAAQS no later than December 31, 2001. EPA has provided specific guidance on developing serious area PM<INF>10 SIP revisions in an addendum to the General Preamble to Title I of the Clean Air Act. See 59 FR 41998 (August 16, 1994). D. Proposed Finding of Failure to Attain On June 7, 1995 EPA proposed to find that the Phoenix Planning Area (PPA) had failed to attain the PM<INF>10 NAAQS by the applicable attainment date. 60 FR 30046. This proposed finding was based on PM<INF>10 monitoring data collected by Maricopa County during the years 1992 through 1994. The air quality monitoring data for the PPA showed three violations of the 24 hour PM<INF>10 NAAQS in 1992 and violations of the annual PM<INF>10 NAAQS in 1992 and 1993. The air quality monitoring data are discussed in detail in the Notice of Proposed Rulemaking (NPRM). 60 FR 30046, 30047. The following table summarizes the data on which EPA has based its finding of failure to attain:
24 hour exceedances Annual exceedances Conc. Date 1992 1993 158 <greek-m>g/m\3\ 12/2/92 .................... .................... Arizona--PM-10 Designation Classification Date Type Date Type Cochise County: area. Township 23 South, Range 25 East (T23S, R25E): T23S,R26E T23S, R27E T23S, R28E T24S, R25E T24S, R26E T24S, R27E T24S, R28E Santa Cruz County: The portions of the following Townships which are within the State of Arizona and lie east of 111 deg. longitude: T23S, R13E T23S, R14E T24S, R13E T24S, R14E Townships: T11S, R9E T11S, R10E T11S, R11E T11S, R12E T12S, R8E T12S, R9E T12S, R10E T12S, R11E T12S, R12E Pima County Township T12S, R6W, and the following sections of Township T12S, R5W: a. Sections 6-8 b. Sections 17-20, and c. Sections 29-32 Maricopa and Pinal Counties The rectangle determined by, and including-- T6N, R3W T6N, R7E T2S, R3W T2S, R7E T1N, R8E Yuma County: Townships: T7S-R21W, R22W; T8S-R21W, R22W, R23W, R24W T9S-R21W, R22W, R23W, R24W, R25W; T10S-R21W, R22W, R23W, R24W, R25W Pinal and Gila Counties: Townships: T4S, R16E T5S, R16E T6S, R16E plus the portion of Township T3S, R16E that does not lie on the San Carlos Indian Reservation, and the rectangle formed by, and including, Townships T1N, R13E T1N, R15E T6S, R13E T6S, R15E Gila County (part): 10-15, 22-27, and 34-36 of R9E; T11N, Sections 1-3, 10- 15, 22- 27, and 34-36 of R9E; T10-11N, R10E; T10N, Sections 4-9, 16-21, and 28- 33 of R11E; T11N, Sections 4- 9, 16-21, and 28-33 of R11E.. Mohave County (part): excluding Lake Mead National Recreation Area; T20N, R20- 22W; T19N, R21-22W excluding Fort Mohave Indian Reservation.. Rest of State................ 11/15/90 Unclassifiable..............