Daily Rules, Proposed Rules, and Notices of the Federal Government
EPA is taking these actions consistent with provisions in the Clean Air Act that obligate the Agency to approve or disapprove submittals of revisions to state implementation plans and requests for redesignation. The intended effect is to redesignate the Miami, Arizona sulfur dioxide nonattainment area to attainment, provide for maintenance of the standard for the ten-year period following redesignation, and correct long-standing errors in the codified description of the area.
Elsewhere in this
On June 26, 2002, the Arizona Department of Environmental Quality (``ADEQ'' or ``State'') submitted to EPA Region IX its Miami Sulfur Dioxide State Implementation and Maintenance Plan and its request for redesignation to attainment (``Miami SO
In today's direct final action, because we find that the Miami SO
The following section discusses the NAAQS for SO
The NAAQS for SO
The CAA requires states to implement, maintain, and enforce ambient air quality equal to or better than the NAAQS. A state's strategies for implementing, maintaining, and enforcing the NAAQS are submitted to EPA for approval, and, once approved, become part of the State Implementation Plan (or SIP) for that State. SIPs are compilations of regulatory and non-regulatory elements adopted, submitted, and approved at different times to address various types of changes in circumstances, such as new or revised NAAQS or amendments to the CAA. SIPs include, among other things, the following: (1) An inventory of emission sources; (2) statutes and regulations adopted by the state legislature and executive agencies; (3) air quality analyses that include demonstrations that adequate controls are in place to meet the NAAQS; and (4) contingency measures to be undertaken if an area fails to attain the standard or make reasonable progress toward attainment by the required date. The state must make proposed changes to the SIP available for public review and comment through a public hearing, and must formally adopt the changes before submitting them to EPA for approval. Upon our approval, a SIP revision becomes federally enforceable.
In the early 1970's, soon after the Clean Air Amendments of 1970 were passed, Arizona began developing air quality regulations that applied to all Arizona primary copper smelters, including the one operating in the Miami area. These regulations focused on establishing an air quality monitoring network in the areas surrounding the smelters and determining the allowable emission rates from the smelters so that the SO
On November 1, 2004, EPA approved several revisions to the SO
Originally, the air quality planning area we refer to as the Miami SO
The dominant source of SO
As stated in the summary section of this rule, Arizona has requested that we redesignate the Miami SO
To evaluate the State's redesignation request for the Miami area, we relied upon the Clean Air Act itself, particularly section 110 and part D (of title I), EPA's NAAQS and SIP regulations in 40 CFR parts 50 and 51, and guidance set forth in “General Preamble for the Implementation of Title I of the Clean Air Act Amendments of 1990” (57 FR 13498, April 16, 1992), and in the following EPA guidance documents: “Procedures for Processing Requests to Redesignate Areas to Attainment,” dated September 4, 1992, from John Calcagni, (“Calcagni Memo”), “Attainment Determination Policy for Sulfur Dioxide Nonattainment Areas,” dated January 26, 1995, from Sally L. Shaver, (“Shaver Memo”), and “Part D New Source Review (part D NSR) Requirements for Areas Requesting Redesignation to Attainment,” dated October 14, 1994, from Mary D. Nichols (“Nichols Memo”).
Under CAA section 107(d)(3)(E)(i), in order for an area to be redesignated, we must determine that the area has attained the applicable NAAQS. The air quality data should be representative of the area of highest concentration and should be measured by monitors that remain at the same location for the duration of the monitoring period required for demonstrating attainment. The data should be collected and quality-assured in accordance with 40 CFR part 58 and recorded in EPA's Air Quality System database (AQS) to be available for public review. Under 40 CFR part 58, States certify data that is entered into AQS on an annual basis.
For the purposes of determining whether an area has attained the SO
The State of Arizona initiated ambient monitoring of SO
Following the Miami smelter's compliance with stack emissions limits (using continuous control technology) as required under Arizona Administrative Code (AAC) R9-3-515, which was submitted and approved by EPA as a revision to the Arizona SIP in the 1980's (but since amended and re-codified as R18-2-7-715), the number of SO
All three presently-operating monitors are located south of the smelter, but vary in distance and elevation relative to smelter sources. The Townsite monitor lies closest to the smelter and at the lowest elevation among the three sites while the Jones Ranch monitor lies furthest from the smelter but at the highest elevation. The Jones Ranch and Townsite monitors are operated by Phelps Dodge using Thermal Electron pulsed fluorescent (TECO) samplers, and the Ridgeline monitor is operated by ADEQ using a Thermo pulse fluorescence analyzer.
Table 2 below summarizes the SO
Review of historic data supports identification of the Jones Ranch monitor as the monitoring location where the highest concentrations are recorded among the network of monitoring locations selected to measure the impact of smelter-related emissions on ambient air quality. We note that the Jones Ranch monitoring site was determined to be the “limiting site” for the purposes of establishing emissions limits for the smelter. ADEQ closed its monitoring site at Jones Ranch in 1994, and while Phelps-Dodge continues to operate an SO
Based on a review of the data from the Miami SO
• Ambient SO
• The monitor at the Jones Ranch site records SO
• There are two consecutive and complete years of “clean” data from the Jones Ranch monitor, i.e., the limiting site, as recorded in AQS (1988 and 1989);
• During the 1988-1989 period, maximum concentrations were approximately 60% of the 3-hour-average secondary NAAQS and approximately 50% of the 24-hour-average primary NAAQS, and the highest of the annual-average concentrations measured in the area during this period was approximately 30% of the corresponding primary NAAQS;
• While annual emissions from the smelter have varied from year to year, they have generally been no higher than 50% above those that occurred during the 1988-1989 period; and
• No SO
Under CAA section 107(d)(3)(E)(ii), the SIP for the Miami area must be fully approved under CAA section 110(k) of the Act. We examined the applicable SIP for Arizona and also looked at the disapprovals listed in 40 CFR 52.125 and have determined that no disapprovals listed remain relevant to the applicable SIP. Arizona has a fully approved SIP with respect to SO
CAA section 107(d)(3)(E)(iii) requires that EPA determine that the improvement in air quality is due to permanent and enforceable reductions in emissions resulting from implementation of the SIP and/or applicable federal measures. Figure 6.1 of the Miami SO
Control over the smelter's SO
Under CAA section 107(d)(3)(E)(v), we must determine whether the State of Arizona has met all requirements under section 110 and under part D (of title I) of the CAA applicable to the Miami SO
CAA section 110 contains the general requirements for SIPs (enforceable emissions limits, ambient monitoring, permitting of new sources, adequate funding, etc.). EPA's guidance for implementing section 110 of the Act is discussed in the General Preamble to Title I (57 FR 13498, April 16, 1992). Over the years, we have approved Arizona's SIP as meeting these basic requirements. The SIP includes enforceable emission limitations; requires monitoring, compiling, and analyzing of ambient air quality data; requires preconstruction review of new
Before an area can be redesignated to attainment, it must have fulfilled the applicable requirements under part D (of title I). For this area, the relevant requirements are found in subparts 1 and 5 of part D. Subpart 1 of part D specifies the basic requirements applicable to all nonattainment areas. Subpart 5 sets out additional provisions for areas designated nonattainment for SO
CAA section 172 contains the general requirements for nonattainment SIPs. A thorough discussion of the requirements of 172(c) can be found in the General Preamble for the implementation of title I (57 FR 13498, April 16, 1992). Additional guidance can be found in the Calcagni memo.
EPA has interpreted the requirements of CAA sections 172(c)(2) (reasonable further progress—RFP), 172(c)(6) (other measures), and 172(c)(9) (contingency measures) as not relevant to a redesignation request because they only have meaning for an area that is not attaining the standard (see the General Preamble and the Calcagni Memo), and as discussed above in section IV.A. of this notice, we find that the Miami area is attaining the SO
In 1998, 2003, and 2006, the State submitted amended rules (AAC R18-2-715 (sections F, G, and H), R18-2-715.01, R18-2-715.02, and R18-2-Appendix 8).
We have not yet fully approved the ADEQ NSR rules.
Prevention of significant deterioration (PSD) is the permitting program that applies in attainment areas. PSD was established to preserve air quality in areas that are meeting the NAAQS. The PSD program requires new, modified, or reconstructed stationary sources to undergo preconstruction review and to apply best available control technology. In addition, sources are required to review PSD increment consumption and undertake preconstruction modeling. ADEQ has an EPA-approved PSD permitting program (Arizona Air Pollution Rule R9-3-304) for all criteria pollutants except respirable particulate matter (PM
Section 176(c) of the CAA requires states to establish criteria and procedures to ensure that federally supported or funded projects conform to the air quality planning goals in the applicable SIP. The requirement to determine conformity applies to transportation plans, programs, and projects developed, funded or approved
Subpart 5 of part D contains additional provisions for areas designated nonattainment for SO
Section 107(d)(3)(E)(iv) of the Act makes EPA approval of a maintenance plan meeting the requirements of section 175A another prerequisite to redesignation. Under section 175A, a maintenance plan must provide for maintenance of the NAAQS for at least 10 years after redesignation, and include any additional control measures as may be necessary to ensure such maintenance. In addition, maintenance plans are to contain such contingency provisions as EPA deems necessary to assure the prompt correction of a violation of the NAAQS that occurs after redesignation. The contingency measures must include, at a minimum, a requirement that the state will implement all control measures contained in the nonattainment SIP prior to redesignation.
The Calcagni Memo contains EPA guidance on the contents of maintenance plans submitted for the purposes of meeting section 175A. Generally, such plans should address the following five topics: the attainment emissions inventory, maintenance demonstration, monitoring network, verification of continued attainment, and a contingency plan.
Lastly, under CAA section 175A(b), states are required to submit a subsequent maintenance plan eight years after redesignation providing for maintenance of the NAAQS for an additional 10-year period beyond the initial 10-year maintenance period.
The Miami SO
ADEQ developed the area and mobile source estimates shown in table 4 based on EPA's AIRData for Gila County. Point source estimates are based on ADEQ annual emissions inventory data. See section 4.0 and appendix B of the Miami SO
Based on our review of the submitted plan, we conclude that the emissions inventory is based on reasonable methods and assumptions and is comprehensive and accurate.
EPA allows states to demonstrate maintenance of the NAAQS by either showing that future emissions of a pollutant or its precursors will not exceed the level of the attainment inventory, or by modeling to show that the future mix of sources and emission rates will not cause a violation of the NAAQS.
The inventory from the Miami SO
The emissions projections for the smelter (from 7,819 tpy) in 1999 to 8,000 tpy in 2005 and beyond are based on the expectation that, through 2015, the copper industry will not expand. While the expectation of continued low price pressures on copper may well have been reasonable in 2002 when the maintenance plan was adopted, changes in the copper market in fact have occurred over the past several years raising the price for copper thereby leading to a reasonable expectation of higher production levels at the Miami smelter than anticipated in the Miami SO
Nonetheless, the demonstration of maintenance of the SO
As explained below, ADEQ has demonstrated that the new limits are protective of the SO
Given the link then between the SO