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FINAL

HAYDEN SULFUR DIOXIDE NONATTAINMENT AREA STATE IMPLEMENTATION AND MAINTENANCE PLAN

AIR QUALITY DIVISION

ARIZONA DEPARTMENT OF ENVIRONMENTAL QUALITY

June 2002 TABLE OF CONTENTS

1.0

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Executive Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Regulatory Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.3 Physical, Demographic, and Economic Description of the Hayden Area . . . . . . . 6 1.3.1 Climate and Physiography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.3.2 Population . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.3.3 Economy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 1.4 General SIP Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 1.4.1 CAA Section 172(c), Nonattainment Plan Provisions . . . . . . . . . . . . . . 10 1.4.2 CAA Section 175(A) - Maintenance Plans . . . . . . . . . . . . . . . . . . . . . . . 14 1.4.3 CAA Section 191 and 192 - Plan Submission and Attainment Dates . . 14 1.4.4 Conformity Provisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 COMPLIANCE WITH OTHER FEDERAL REGULATIONS . . . . . . . . . . . . . . . . . . . 16 SO2 MONITORING NETWORK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.1 Current Sampler Type and Siting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.2 Ambient Data Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 SO2 EMISSIONS INVENTORY FOR POINT, AREA AND MOBILE SOURCES . . . 28 4.1 SO2 Point Sources within the Hayden Nonattainment Area . . . . . . . . . . . . . . . . 28 4.1.1 ASARCO Hayden Smelter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 4.2 Major Point Sources within the 50 km Buffer Area . . . . . . . . . . . . . . . . . . . . . . 30 4.2.1 Arizona Public Service (APS) - Red Rock . . . . . . . . . . . . . . . . . . . . . . . 30 4.2.2 BHP Copper San Manuel Smelter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 4.2.3 Phelps-Dodge Miami Smelting Operations . . . . . . . . . . . . . . . . . . . . . . 31 4.3 Area and Mobile Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 4.4 Emissions Projections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 4.4.1 Point Source Projections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 4.4.2 Area, Mobile, and Total Source Projections . . . . . . . . . . . . . . . . . . . . . . 33 MODELING DEMONSTRATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 5.1 Derivation of New Emissions Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 5.1.1 Stack Emissions Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 5.1.2 Fugitive Emissions Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 5.1.3 Total Stack and Fugitive Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 5.2 Smelter Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 5.2.1 Good Engineering Practice Stack Height . . . . . . . . . . . . . . . . . . . . . . . . 43

2.0 3.0

4.0

5.0

6.0 CONTROL MEASURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 6.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 ii

6.2

Emissions Limitations for ASARCO Hayden Smelter . . . . . . . . . . . . . . . . . . . . 50 6.2.1 AAC Rule R18-2-715(F), R18-2-715(G) and R18-2-715.01 - Standards of Performance for Existing Primary Copper Smelters: Site specific requirements; Compliance and Monitoring . . . . . . . . . . . . . . . . . . . . . . . 50 6.2.2 AAC Rule R18-2-715.02 Standards of Performance for Existing Primary Copper Smelters; Fugitive Emissions . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 6.2.3 ASARCO Permit Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

7.0

MAINTENANCE PLAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 7.1 Maintenance Demonstration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 7.2 Ambient Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 7.3 Verification of Continued Attainment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 7.4 Contingency Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 7.4.1 Notification Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 7.4.2 First Action Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 7.4.2(a) Analysis of Gas Handling Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . 59 7.4.3 Second Action Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 7.4.4 Special Measure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

8.0

iii

LIST OF FIGURES Figure 1.1 Figure 3.1 Figure 3.2 Figure 4.1 Figure 5.1 Figure 6.1 Figure 6.2 Figure 7.1 Hayden SO2 Nonattainment Area Hayden SO2 Nonattainment Area Monitor Locations Hayden SO2 Nonattainment Area Magnification of Monitor Locations Hayden SO2 Nonattainment Area 50 Kilometer Buffer Comparison of 1979 and 2002 MPR Limits Hayden Smelter SO2 Emissions and Percent Control 1972-2001 Hayden Smelter SO2 Emissions 1996-2001 Hayden Nonattainment Area SO2 Emissions Projections

LIST OF TABLES Table 1.1 Table 1.2 Table 1.3 Table 1.4 Table 1.5 Table 1.6 Table 3.1 Table 3.2 Table 3.3 Table 4.1 Table 4.2 Table 4.3 Table 4.4 Table 4.5 Table 4.6 Table 5.1 Table 5.2 Table 5.3 Table 6.1 Table 6.2 Current Study Area Definition Decennial Census Population of Hayden area and Gila and Pinal County: 1970-2000 Population Projections for Hayden area and Gila and Pinal County: 2000-2015 Economic Activity in Pinal County by Number of Employees: 1994, 1997, 2000 Economic Activity in Gila County by Number of Employees: 1994, 1997, 2000 Civilian Labor Force Data for Hayden Nonattainment Area Ambient Monitoring Network Current Monitoring Network SO2 Ambient Air Quality Monitoring Data SO2 Emissions for Hayden Nonattainment Area - Point Sources SO2 Emissions within 50km of the Hayden Nonattainment Area - Point Sources SO2 Emissions for Hayden Nonattainment Area - All Sources SO2 Emissions Projections for Hayden Nonattainment Area - Point Sources SO2 Projected Emissions within 50km of the Hayden Nonattainment Area - Point Sources SO2 Emissions Projections for Hayden Nonattainment Area - All Sources Hayden Smelter 3-hour MPR Stack Emissions Curve Based on Attainment Period Hayden Smelter MPR Stack Emissions Limits Hayden Smelter Configuration 1976 to Present Implementation of SO2 Process and Control Technology Permit Conditions

1.0 1.1

INTRODUCTION Executive Summary

This document includes an attainment demonstration and formal request to the United States Environmental Protection Agency (EPA) to redesignate the Hayden, Arizona Sulfur Dioxide (SO2) Nonattainment Area to attainment for the health-based 24-hour average and annual average SO2 National Ambient Air Quality Standards (NAAQS). It summarizes the progress of the area in attaining the SO2 standards, demonstrates that all Clean Air Act (CAA) requirements for attainment have been adopted, and includes a maintenance plan to assure continued attainment after redesignation. The air quality record included in Chapter 2 of this document shows that ambient air quality monitors located in the Hayden nonattainment area have recorded no violations of the primary or secondary SO2 NAAQS since 1989. This meets the EPA requirement to demonstrate eight consecutive quarters of ambient air quality measurements below the SO2 NAAQS. This document also demonstrates that the emission reduction control measures responsible for the air quality improvement are both permanent and enforceable. Based on state point source and EPA National Emissions Trends (NET) mobile and area source emissions inventories, the primary source of SO2 in the nonattainment area is the copper smelter located near Hayden, Arizona. The 2000 base-year Hayden nonattainment area emissions inventory, presented in Chapter 4, lists the sources in the nonattainment area and their SO2 emissions. Chapter 5 contains a modeling demonstration, and Chapter 6 describes the primary control measures implemented to achieve attainment. These measures include implementation of reasonably available control measures (RACM) to reduce emissions from the smelter near Hayden. Chapter 7 describes in detail measures designed to ensure continued maintenance of the SO2 NAAQS for at least 10 years after redesignation of the area to attainment. The clean air quality record, enforceable control measures, and projections of future emissions presented in this document, all demonstrate that the area has attained and will continue to maintain the SO2 air quality standards. With this submittal, ADEQ requests that EPA approve this attainment demonstration and maintenance plan for the Hayden SO2 nonattainment area and redesignate the area to attainment for the 24-hour and annual NAAQS. 1.2 Regulatory Background

The federal air quality standards for SO2 were established to identify maximum ambient concentrations above which adverse effects on human health and welfare may occur. Accordingly, the SO2 standards are divided into two types: primary and secondary. The primary standards are based on the protection of public health and the secondary standard is based on protection of the environment, including protection against damage to animals, vegetation, buildings, and decreased visibility. The original national primary and secondary NAAQS for SO2 were codified in Volume 42 of the Code of Federal Regulations, Part 410 (42 CFR 410) on April 30, 1971, (36 FR 81875) and recodified to 40 CFR 50.4 and 50.5 on November 25, 1971 (36 FR 22384). On May 22, 1996, the

EPA promulgated the current primary and secondary NAAQS for SO2 (61 FR 25566) as follows:1 Standard 2 Primary Secondary Annual 0.030 ppm (80 Fg/m3) 24-hour 0.14 ppm (365 Fg/m3) 0.5 ppm (1300 Fg/m3) 3-hour

Areas that do not meet the NAAQS may be designated nonattainment for the respective standard. The Hayden SO2 nonattainment area comprises nine townships in southern Gila County and northeastern Pinal County. In addition, six adjacent townships are designated as unclassified (See Figure 1.1 for location map). The current boundaries of the nonattainment and unclassified areas are codified at 40 CFR 81.303 and are defined by the complete townships on the following pages.

Table 1.1 - Study Area Definition Hayden Area Description T4S, R14E T4S, R15E T4S, R16E T5S, R14E T5S, R15E T5S, R16E T6S, R14E T6S, R15E T6S, R16E T4S, R13E T4S, R17E T5S, R13E T5S, R17E Does Not Meet Primary Standards X X X X X X X X X X X X X Cannot Be Classified

Several technical changes were made at this time including stating the standards in parts per million (ppm) to make the SO2 NAAQS consistent with those for other pollutants. The former standards, stated in micrograms per cubic meter (ug/m3), are in parentheses. Violations of the primary and secondary standards are determined as follows. The annual arithmetic mean of measured hourly ambient SO2 concentrations must not exceed the level of the annual standard in a calendar year. The 24-hour and 3-hour averages of measured concentrations must not exceed the level of the respective standard more than once per calendar year.

Table 1.1 - Study Area Definition Hayden Area Description T6S, R13E T6S, R17E Does Not Meet Primary Standards Cannot Be Classified X X

The relationship of major SO2 point sources and ambient air quality is relatively well-defined. Emissions inventories demonstrate that the smelter, owned and operated by ASARCO, comprises 99 percent of total SO2 emissions in the nonattainment area (See Chapter 4). The primary copper smelter is located near the town of Hayden, Gila County, Arizona; at latitude 33E 00' 29" N and longitude 110E 47' 17" W, at an elevation of 2,050 feet above mean sea level (See Figure 1.1). As required by the Clean Air Act (CAA), Arizona submitted a State Implementation Plan (SIP) for all major sources in the state in 1972. The portion of the SIP pertaining to attainment and maintenance of the NAAQS for SO2 did not sufficiently define emissions limitations or require permanent control of emissions for existing copper smelters and was, therefore, disapproved on July 27, 1972 (37 FR 15081). On the same date, EPA proposed revised regulations for control of sulfur oxides emitted by all existing smelters in Arizona (37 FR 15096). These regulations were never finalized due to issues regarding the adequacy of the air quality data used to develop the limits. EPA subsequently established an SO2 monitoring network around each smelter (June 1973 - October 1974) to gather air quality data upon which to base emissions limitations. EPA and State efforts to develop comprehensive emissions limits continued through the 1970s. In 1977, the State developed rules for the use of Supplementary Control Systems (SCS), whereby, based on ambient monitoring data, the smelters could intermittently curtail emissions to meet the SO2 NAAQS. EPA disapproved this approach and required installation of continuous SO2 emissions controls adequate to meet the NAAQS. Consequently, on January 4, 1978, EPA published final emissions limits for the Arizona smelters based on the 1973-1974 air quality data and the use of a proportional rollback model (43 FR 755). These regulations specified an emission rate and compliance test methods for each smelter. The 1977 Clean Air Act Amendments, however, modified smelter control requirements to allow the temporary use of SCS while ultimate SO2 emission limits were developed and also allowed certain smelters additional time for continuous emissions control technology to be installed. In response to this action, Arizona began development of new regulations and on September 20, 1979, submitted Multi-point Rollback (MPR) rules as a proposed revision to the Arizona SIP.3 The use of MPR to establish stack emissions limits in the rules addressed the problem of inherently variable SO2 emissions from smelting operations by correlating the frequency of emissions at various levels with the probability of violating the ambient standards. This technique, "rolled back" a yearly emission profile to a level protective of the standards. The new regulations also set requirements for analyzing the impact of smelter SO2 fugitive emissions on ambient air quality and the implementation of any necessary fugitive controls. The Hayden area was subsequently classified by operation of law as nonattainment for the primary SO2 standards by EPA following the enactment of the 1990 Clean Air Act Amendments. The nonattainment designation became effective on November 15, 1990. The MPR rules, which established stack emission limits for the smelters, were approved by EPA on January 14, 1983 (48 FR 1717). Following EPA's approval of the rule (and a prior consent decree between EPA, ADEQ and ASARCO (#CIV 81-110-GLO-ACM, dated June 22, 1981)), ASARCO began implementation of improved control technology. The improvements included replacement of 12 multiple-hearth roasters and 2 reverberatory furnaces with a new INCO flash smelting furnace, installation of a 650 ton per day oxygen plant to enrich process gases, and a new double-contact acid plant for treatment of process gas SO2. These controls significantly reduced

Arizona Code of Rules and Regulations (ACRR): Rule (R)9-3-515 (recodified as Arizona Administrative Code (AAC) R18-2-715, Standards of Performance for Existing Primary Copper Smelters; Site-specific Requirements)

emissions and allowed the smelter to come into compliance with the emissions limits in the MPR rules. The Hayden smelter came into full compliance with the MPR regulations in 1984. On April 11, 1996, ASARCO submitted to the Arizona Department of Environmental Quality the results of an SO2 fugitive emissions study to fulfill outstanding SIP commitments for analysis of fugitive emissions. Subsequently, in 2001/2002 ASARCO conducted a further ambient impact analysis of maximum actual emissions (including both stack and fugitive) in relation to resulting ambient concentrations. Based on this analysis, a 2002 rulemaking is in the final stages. The revisions to AAC R18-2-715 and R18-2-715.01 include stack emissions limits and fugitive emission limits (See Appendix A). The new limits provide a considerable margin of safety to ensure protection of the SO2 NAAQS throughout the maintenance period to 2015, thus allowing the state to request the area be redesignated to attainment for SO2. 1.3 1.3.1 Physical, Demographic, and Economic Description of the Hayden Area Climate and Physiography

Both desert terrain and mountain ranges are found across the southern Gila County and eastern Pinal County landscape. Elevations range from near 1,800 to more than 4,400 feet above sea level in the nonattainment area with the town of Hayden situated at an elevation near 2,050 feet. This unique environment experiences both warm desert and cool alpine climates. In Hayden, the hottest month of the year is July, when the average daily maximum temperature is near 98o Fahrenheit (F). January is the coolest month with an average daily minimum temperature of 38o F. Precipitation generally occurs in two seasons. The wettest month in Hayden is August when monsoonal thunderstorms produce an average monthly total of 2.31" (inches) of rain. Pacific winter storms moving across the area in December produce an average of 1.28" monthly precipitation in the form of rain or snow. The driest month is June, with an average of 0.25" of rain. The average yearly precipitation is 12.50". 1.3.2 Population

Hayden is located in the southern part of Gila County on state highway 177, 35 miles south of Globe, the county seat, and 30 miles southeast of Superior.4 Since most of the nonattainment area is geographically located in Pinal County, population data for Pinal County are included. Decennial census data for Hayden, Winkelman, Kearny, Dudleyville CDP, Gila County, and Pinal County are shown in Table 1.2.5 During the 1970s when rural counties outpaced the growth of urban counties in the U.S., Gila and Pinal Counties grew by 26.7 percent and 32.6 percent, respectively. Although Gila County's population growth slowed during the 1980s, its rate of growth was 27.7 percent during the 1990s. Pinal County's population growth declined only slightly during the 1980s, and during the 1990s, its 54.4 percent growth rate was about double Gila County's growth rate. In contrast to the decennial census population growth of these counties, Hayden, Winkelman, and Kearny lost population between 1970 and 2000. The greatest population declines occurred

4 5

Hayden was founded in 1909 by Hayden, Stove and Company that operated nearby mines. Hayden and Winkelman are located in Gila County. Kearny, and Dudleyville are located in Pinal County.

during the 1980s. It appears that the population losses are associated with declining mining sector employment and associated activities, as well as amenities of other geographical locations pulling residents away from these places.

Table 1.2 - Decennial Census Population of Hayden, Winkelman, Kearny, Dudleyville CDP, Gila County, and Pinal County: 1970-2000 Y e ar Hayden Hayden's decennial change Winkelman Winkelman's decennial change Gila County Gila County's decennial change Dudleyville CDP6 Dudleyville's decennial change K earny Kearny's decennial change Pinal County Pinal's decennial change

Source: U.S. Bureau of the Census, decennial census counts.

April 1, 1970 1,283

April 1, 1980 1,205 -6.1%

April 1, 1990 909 -24.6% 676 -36.2% 41,216 8.5%

April 1, 2000 892 -1.9% 443 -34.5% 51,335 27.7% 1,323

974

1,060 8.8%

29,255

37,080 26.7%

2,829

2,646 -6.5%

2,262 -14.5% 116,397 28.0%

2,249 -0.6% 179,727 54.4%

68,579

90,918 32.6%

The DES population projections are the official statistics for the State and differ slightly from the 2000 Census population counts. Table 1.3 portrays the projected growth of Hayden, Winkelman, Kearny, and Dudleyville, as well as Gila County and Pinal County in five-year increments from 2000 to 2015. The population of Hayden is projected to be flat during this time period, compared to Gila County's projected growth rate of 18.5 percent and Pinal County's projected growth rate of 33.8 percent during this 15-year time period. With the exception of Winkelman, the populations of places shown in Tables 1.2 and 1.3 were over projected by ADES while Gila and Pinal Counties were under projected by ADES from the census counts.

Dudleyville is a Census Designated Place (CDP). CDPs represent the statistical counterpart of incorporated places. However, no population data are available for Dudleyville for 1970, 1980, or 1990.

Table 1.3 - Population Projections for Hayden, Winkelman, Kearny, Dudleyville, Gila County, and Pinal County: 2000-2015 Year Hayden Winkelman Gila County K earny Dudleyville CDP Pinal County July 1, 2000 911 419 48,614 2,610 1,970 161,630 July 1, 2005 911 420 51,644 2,762 2,095 181,487 July 1, 2010 912 422 54,603 2,903 2,210 199,715 July 1, 2015 912 423 57,613 3,030 2,313 216,215

Source: Arizona Department of Economic Security, August 1, 1997.

1.3.3 Economy Pinal County was created in 1875 from portions of Maricopa and Pima Counties by the eighth territorial legislature. The county covers 5,371 square miles. The State of Arizona is the county's largest landholder with 35.3 percent of the land area. Individual and corporate ownership accounts for 25.7 percent. Indian reservations cover 20.3 percent; the U.S. Forest Service and Bureau of Land Management hold 17.5 percent; and other public lands comprise the remaining 1.2 percent. Gila County, covering 4,752 square miles, was created in 1881 from portions of Maricopa and Pinal Counties. The U.S. Forest Service is the largest landholder in Gila County accounting for 56 percent of the land area. Indian reservations cover thirty-seven percent; individual and corporate ownership accounts for three percent; the U.S. Bureau of Land Management holds two percent; and the State of Arizona and other public lands comprise the remaining two percent. Tables 1.4 and 1.5 contain employment, expressed as percentages of total non-farm employees, for Pinal and Gila Counties for 1994, 1997, and 2000. These tables also include labor force data, and are included to demonstrate the decline in mining and quarrying activities and the relatively consistent proportions of the other economic activities in the county. The economy of the Hayden area is based almost exclusively on copper mining and smelting, but does include some ranching, government, and tourism. Due to cyclical copper prices, the area's economy is in transition. The Kennecott operation in Hayden, which reduced ores from the nearby Ray Mine, ceased operating in 1982. The ASARCO smelter and Hayden concentrator remain in operation. Despite this, the major category of employment remains the mining and smelting industry. The community is also diversifying its economic base to facilitate tourism and retirement needs. Table 1.6 shows a selected time series of civilian labor force data for Hayden. As noted in Section 1.3.2, minimal population growth is expected between 2000 and 2015 for the Hayden and Winkelman area. During this same time period, however, Kearny's population is projected to grow by about nine percent and Dudleyville CDP's population by seventeen percent. This indicates that additional housing units potentially would need to be constructed for both of these places. Part of the projected population growth could be absorbed by vacant housing units (9.4 percent vacant in Kearny

Table 1.4 - Economic Activity in Pinal County 1994, 1997, and 2000 Economic activity Civilian labor force Unemployment Unemployment rate Total employment Non-farm employment Mining and quarrying Construction Manufacturing Transportation, Communication, and Public Utilities (TCPU) T r ade Finance, Insurance, and Real Estate (FIRE) Services and misc. Government 1994 48,950 2,800 5.7% 46,150 36,100 10.8% 3.3% 11.9% 1.9% 19.9% 1.7% 16.1% 33.2% 1997 54,450 2,725 5.0% 51,725 39,775 13.1% 4.5% 7.6% 2.0% 19.0% 2.1% 18.1% 33.2% 2000 59,425 2,475 4.2% 56,950 36,525 3.7% 3.8% 8.6% 2.3% 21.0% 2.3% 20.3% 38.0%

Source: Derived from Arizona Department of Economic Security data. Totals may not add to 100 percent.

Table 1.5 - Economic Activity in Gila County 1994, 1997, and 2000 Economic activity Civilian labor force Unemployment Unemployment rate Total employment Non-farm employment Mining and quarrying Construction Manufacturing Trans., Communication and Pub. Utilities T r ade Finance, Insurance and Real Estate Services and misc. Government 1994 17,658 1,575 8.6% 16,575 13,100 6.9% 6.1% 12.2% 3.1 % 23.7 % 2.3 % 20.6 % 22.9 % 1997 18,450 1,450 7.9% 17,000 14,350 2.3 % 6.3 % 11.7 % 3.7 % 24.4 % 1.6 % 19.5 % 30.7 % 2000 17,175 1,000 5.8% 16,175 14,225 4.9 % 7.4 % 7.6 % 3.5 % 23.4 % 1.9 % 18.1 %

33.2 %

Source: Derived from Arizona Department of Economic Security data. Totals may not add to 100 percent.

Table 1.6 - Civilian Labor Force Data for Hayden: Selected Years Year Civilian labor force Number Unemployed Unemployment rate 1990 306 36 11.8% 1998 290 29 10.0% 1999 288 28 9.7%

Source: Arizona Department of Commerce, Community Profiles, February, 2001.

and 20.6 percent vacant in Dudleyville CDP).7 Most growth, if any, in Hayden and Winkelman could be accommodated by future residents occupying vacant housing units.8 If additional growth does occur as projected, and additional housing units must be constructed in these places, this would generate associated jobs and activities in these local economies. 1.4 General SIP Approach In November 1990, the United States Congress enacted a series of amendments to the Clean Air Act (CAA) intended to improve air quality across the nation. One of the primary goals of this comprehensive revision to the CAA was to expand and clarify the planning provisions for those areas not currently meeting the NAAQS. The CAA as amended identifies specific emission reduction goals, requires both a demonstration of reasonable further progress and attainment, and incorporates more stringent sanctions for failure to attain or to meet interim milestones. CAA, Title I, Part A, and Title I Part D, Subparts 1 and 5 are applicable to this SIP and maintenance plan. Sections 172, 175(A), 191, and 192 set forth the following requirements for SO2 nonattainment areas: 1.4.1 CAA Section 172(c), Nonattainment Plan Provisions

172(c)(1) - In General: implementation of all reasonably available control measures (RACM) as expeditiously as practicable (including such reductions in emissions for existing sources in the area as may be obtained through the adoption, at a minimum, of reasonably available control technology (RACT)) and provide for attainment of the national primary ambient air quality standards. The ASARCO smelter, the primary source of SO2 emissions in the Hayden nonattainment area, succeeded in implementing RACM/RACT at the smelter sufficient to attain the NAAQS for SO2 and went beyond the required technology to increase the facility's efficiency in capturing and treating SO2. RACT for SO2 emission controls for a flash smelting furnace include:

The 2000 Census shows Kearny with 873 housing units of which 791 occupied, and Dudleyville CDP with 572 housing units of which 454 are occupied. The number of occupied housing units equals the number of households. Persons per household varies from 2.84 in Kearny to 2.91 in Dudleyville. The 2000 Census shows Hayden with 334 housing units of which 288 are occupied, Winkelman with 194 housing units of which 160 are occupied. The number of occupied housing units equals the number of households. Persons per household varies from 3.1 in Hayden to 2.77 in Winkelman.

8 7

1. Dust Collection Equipment (removes dust for better gas treatment), 2. Wet Gas Handling System, 3. Minimization of Leaks, 4. Hooding and venting of gases to the stack, and 5. Contact Sulfuric Acid Plant. Chapter 6 contains further explanation of applicable RACM/RACT for the ASARCO smelting facility and other SO2 point sources in the nonattainment area. 172(c)(2) - Reasonable Further Progress (RFP): plan provisions shall demonstrate reasonable further progress such that annual incremental reductions in emissions ensure attainment of the national ambient air quality standards by the applicable date. This submittal demonstrates that the Hayden nonattainment area has attained and will maintain the SO2 NAAQS with current control measures (See Chapter 6). 172(c)(3) - Inventory: the plan shall include a comprehensive inventory of actual emissions from all sources of relevant pollutant(s). ADEQ maintains a historical and current database of actual emissions from State-permitted point and area sources. The Pinal County Air Quality Control District maintains a similar database of actual emissions from County-permitted sources. All non-permitted source emissions data (i.e.: mobile sources) come from EPA's national emissions inventory.9 Base-year 2000 emissions and projected 2015 emissions are contained in Chapter 4. 172(c)(5) - Permits for New and Modified Major Stationary Sources: the plan shall require permits for the construction and operation of new and modified major stationary sources throughout the nonattainment area. All new sources and modifications to existing sources in Arizona are subject to state requirements for preconstruction review and permitting pursuant to Arizona Administrative Code (AAC), Title 18, Chapter 2, Articles 1 through 5. All new major sources and modifications to existing major sources in Arizona are subject to the New Source Review (NSR) provisions of these rules or Prevention of Significant Deterioration (PSD) for maintenance areas. The State NSR program was conditionally approved by EPA in 1992, and is pending final approval. It should be noted that ADEQ currently has full approval of its Title V permit program. 172(c)(6) - Other Measures: the Plan shall include enforceable emissions limitations and such other control measures, means or techniques, as well as schedule and timetables for compliance, as may be necessary or appropriate to provide for attainment of such standard in such area by the applicable attainment date. AAC R18-2-715 contains the required annual average emission limitations and number of three-hour average emission limits for the ASARCO smelter. AAC R18-715.01 (Standards of Performance for Existing Primary Copper Smelters; Compliance and Monitoring), set forth the compliance date of January 14, 1986, for monitoring, calibration, measurement system performance requirements, record keeping, bypass operation, and issuance of notices of violation.10 Details

AIRData provides access to air pollution data for the entire United States and can be found at: http://www.epa.gov/air/data/index.html Standards of Performance for Existing Primary Copper Smelters; Site-specific Requirements, AAC R18-2-515, renumbered AAC R18-2-715 (1993).

10 9

regarding emissions limitations and control measures for all SO2 sources in the nonattainment area may be found in Chapter 4. 172(c)(7) - Compliance with Section 110(a)(2): the Plan shall be in compliance with Section 110 (a)(2) (Implementation Plans) of CAA. Section 110(a)(2)(A) of CAA requires that states provide for enforceable emission limitations and other control measures, means, or techniques, as well as schedules for compliance. Chapter 4 includes the list of control measures utilized to bring this area into attainment and future maintenance of the SO2 NAAQS. Section 110(a)(2)(B) of CAA requires that states provide for establishment and operation of appropriate devices, methods, systems, and procedures necessary to monitor, compile, and analyze data on ambient air quality. Under ADEQ's air quality assessment program, ambient monitoring networks for air quality are established to sample pollution in a variety of representative settings, to assess the health and welfare impacts and to assist in determining air pollution sources. The monitoring sites are combined into networks, operated by a number of government agencies and regulated companies. Each network is comprised of one or more monitoring sites, whose data are compared to the NAAQS, as well as statistically analyzed in a variety of ways. The agency or company operating a monitoring network also tracks data recovery, quality control, and quality assurance parameters for the instruments operated at their various sites. The collected data are summarized into the appropriate quarterly or annual averages. The samplers are certified by Federal Reference or Equivalent Methods. Regular checks of the stability, reproducibility, precision, and accuracy of the samplers and laboratory procedures are conducted by either the agency or company network operators. The protocol for SO2 monitoring used by the State, local agencies, and companies was established by EPA in the following sections of the Code of Federal Regulations (CFR): 1. 40 CFR Part 50, Appendix A, Reference Method for the Determination of Sulfur Dioxide in the Atmosphere; 2. 40 CFR Part 53, Subpart B, Procedures for Testing Performance Characteristics of Automated Methods for SO2, CO, O3, and NO2; and 3. 40 CFR Part 58, Subpart A, B, and C, Ambient Air Quality Surveillance. Section 110 (a)(2)(C), Section 110 (a)(2)(E), Section 110 (a)(2)(F), and Section 110 (a)(2)(L) of CAA require states to have permitting, compliance, and source reporting authority. Arizona Revised Statutes (ARS) � 49-402 establishes ADEQ's permitting and enforcement authority. As authorized under ARS 49-402, ADEQ retains adequate funding and employs adequate personnel to administer the air quality program. Appendix A includes organization charts for ADEQ's Air Quality Division. Under ADEQ's air permits program, stationary sources that emit regulated pollutants are required to obtain a permit before constructing, changing, replacing, or operating any equipment or process which may cause air pollution. This includes equipment designed to reduce air pollution. Permits are also required if an existing business that causes air pollution transfers ownership, relocates, or otherwise changes operations. Additionally, ADEQ is responsible for assessing fees based on the actual emissions submitted in the emission inventory for all sources under ADEQ jurisdiction pursuant to AAC R18-2-326. Rule R18-2-327 requires that any source subject to a permit must complete and submit to the Director their responses to an annual emissions inventory questionnaire. A current air pollutant emissions inventory of both permitted and non-permitted sources within the state is necessary to 12

properly evaluate the air quality program effectiveness, as well as determine appropriate emission fees. ADEQ is responsible for the preparation and submittal of an emissions inventory report to EPA for sources and emission points prescribed in 40 CFR 51.322, and for sources that require a permit under ARS �49-426 for criteria pollutants. This inventory encompasses those sources under state jurisdiction emitting 1 ton per year or more of any individual regulated air pollutant, or 2.5 tons per year (tpy) or more of any combination of regulated air pollutants.11 Under ADEQ's air quality compliance program, major sources are inspected annually. ADEQ's Air Compliance Section implements compliance assistance initiatives to address noncompliance issues (i.e., seminars and workshops for the regulated community explaining the general permit requirements, individual inspections of all portable sources within a geographical area, mailings, etc.). In addition, compliance initiatives are developed to address upcoming or future requirements (i.e., new general permits) and include such actions as training for inspectors; development of checklists and other inspection tools for inspectors; public education workshops; targeted inspections; mailings, etc. ADEQ's Air Compliance Section also has an internal performance measure to respond to all complaints as soon as possible, but within a minimum of five working days. Section 110(a)(2)(G) of CAA requires that states provide for authority to establish emergency powers and authority and contingency measures to prevent imminent endangerment. AAC R18-2220 prescribes the procedures the Director of ADEQ shall implement in order to prevent the occurrence of ambient air pollution concentrations which would cause significant harm to the public health. As authorized by ARS �49-426.07, ADEQ may seek injunctive relief upon receipt of evidence that a source or combination of sources is presenting an imminent and substantial endangerment to public health or the environment. 172(c)(8) - Equivalent Techniques: the Plan may use equivalent techniques such as equivalent modeling, emission inventory, and planning procedures allowed by the Administrator, upon application by any state. In 1983, EPA approved Multi-point Rollback modeling to establish emissions limits for the ASARCO Hayden smelter, and the limits were updated in 2002 as part of the current SIP process. Modeling for the fugitive emissions study at this facility was conducted with models from EPA's "Guideline on Air Quality Models." 172(c)(9) - Contingency Measures: the Plan shall provide for the implementation of specific measures to take effect without further action by the state or the Administrator in the event the area fails to make reasonable further progress (RFP) or to attain the primary national ambient air quality standards (NAAQS). As noted in 172(c)(2) above, this submittal includes monitoring data and source permit information that demonstrate that the applicable area has attained, and will maintain, the SO2 NAAQS with control measures currently fully implemented. As such, the RFP requirement is met. 1.4.2 CAA Section 175(A) - Maintenance Plans

"Regulated air pollutant" is defined in AAC R18-2-101 as any of the following: (a) Any conventional air pollutant as defined in ARS �49-401.01; (b) Nitrogen oxides and volatile organic compounds; (c) Any air contaminant that is subject to a standard contained in Article 9 of Chapter 2; (d) Any hazardous air pollutant as defined in ARS �49-401.01; (e) Any Class I or II substance listed in Section 602 of the Act.

175(A)(a) - Plan Revisions: each state which submits a request for redesignation of a nonattainment area shall also submit a revision of the applicable SIP to provide for the maintenance of the NAAQS for at least ten years after the redesignation. As documented in Chapter 7, this submittal shows attainment through 2015. 175(A)(b) - Subsequent Plan Revisions: eight years after redesignation as an attainment area, the State shall submit an additional revision of the applicable SIP for maintaining the NAAQS for 10 years after the expiration of the 10-year period referred to in subsection (a). ADEQ commits to submit an additional SIP revision eight years after redesignation. 175(A)(c) - Nonattainment Requirements Applicable Pending Plan Approval: until such plan revision is approved and an area is redesignated as attainment for any area designated nonattainment, the requirements of this part shall continue in force and effect. ADEQ commits to keeping all applicable measures in place. 175(A)(d) - Contingency Provisions: each plan revision submitted under this section shall contain such contingency provisions to assure that the State will promptly correct any violation of the standard which occurs after the redesignation of the area as an attainment area. Such provisions shall include a requirement that the State will implement all measures with respect to the control of the air pollutant concerned before redesignation. ADEQ commits to implementing all identified measures as necessary (See Chapter 7). 1.4.3 CAA Section 191 and 192 - Plan Submission and Attainment Dates

This document fulfills all outstanding implementation plan requirements for the Hayden SO2 nonattainment area. With the submittal of this SIP and Maintenance Plan, ADEQ requests redesignation of the Hayden nonattainment area to attainment. 1.4.4 Conformity Provisions

Section 176(c)(1)(A) of CAA requires SIPs to contain information regarding the State's compliance with conformity requirements. As stated in 40 CFR 93.153(a), "Conformity determinations for Federal actions related to transportation plans, programs and projects developed, funded, or approved under title 23 U.S.C. or the Federal Transit Act (40 U.S.C. 1601 et seq.) must meet the procedures and criteria of 40 CFR part 51, subpart T, in lieu of the procedures set for in this subpart." 40 CFR 93.103(b) waives transportation conformity for SO2 nonattainment areas, but general conformity for the Hayden, Gila/Pinal County area must still be addressed to assure SO2 emissions from any Federal actions or plans do not exceed the rates outlined in 40 CFR 93.153(b)(1) for nonattainment areas or 40 CFR 93.153(b)(2) for maintenance areas. Criteria for making determinations and provisions for general conformity as outlined in 40 CFR 93.153 can be located in R18-2-1438 of the Arizona Administrative Code. There are no federal plans or actions affecting air quality currently in the Hayden, Gila/Pinal County area, nor are any foreseen through the year 2015.

2.0

COMPLIANCE WITH OTHER FEDERAL REGULATIONS

The provisions of 40 CFR 60 Subpart P (��60.160 - 60.166) Standards of Performance for Primary Copper Smelters 12 are applicable to dryer, roaster, smelting furnace, and copper converter equipment in primary copper smelters. Any facility that commences construction or modification after October 16, 1974, is subject to the requirements of this subpart. The Hayden smelter was modified in 1983 when an Inco Flash Furnace, oxygen plant, and #2 acid plant were installed. ADEQ compliance, permit, monitoring, technical, and correspondence files indicate that the facility has complied with all the requirements of this subpart.

Source: 41 FR 2338, Jan. 15, 1976, unless otherwise noted.

3.0

SO2 MONITORING NETWORK

Monitoring began in the Hayden area in 1970 by the State of Arizona.13 ASARCO began continuous ambient SO2 air quality monitoring in the Hayden area in 1974. Since that time, an extensive monitoring network was established with sufficient spatial and temporal coverage to comprehensively evaluate the ambient impact of smelter emissions. More than twenty stationary and mobile monitoring sites were established throughout the area with as many as twelve monitors operating concurrently (See Table 3.1 and Figure 3.1).14 This ambient SO2 network, comprised of EPA, State, and ASARCO monitors, was developed as the result of extensive efforts to identify maximum ambient impact areas using diffusion modeling, monitored atmospheric dispersion parameters, citizen observations, and ambient SO2 monitoring.

Table 3.1 - Ambient Monitoring Network Monitor Site Town Garfield Avenue Fire Station J a il Jail (state) Hayden Junction Junction North Montgomery Ranch Montgomery Ranch (state) Globe Hwy. Winkleman Period of Operation 1970-1975, 1978-1979 1980-present 1975-1977, 1979-1981 1982-present 1974, 1976-present 1974-present 1976-1977 1974-present 1974-1984 1978-present 1974-1979 Monitor Site Winkleman School Meadows Kearny Crescent Ranch Kearny Hartford Mobile I Mobile II Mobile III Mobile IV EPA 4th Avenue Period of Operation 1980-1988 1974-1979, 1981-1988 1974-1981 1974-1979 1978 1979-1980 1980 1982 1973-1974 1994-1995

Sulfur Dioxide Monitoring Network Study, Arizona State Department of Health, Environmental Health Services, Division of Air Pollution Control, 1974. Protocols for SO2 monitoring established by EPA are found in 40 CFR Part 50, Appendix A, Reference Method for the Determination of Sulfur Dioxide in the Atmosphere, Part 58, Subpart B, �58.14, Special Purpose Monitors, Subpart C, �58.20, State and Local Air Monitoring Stations, Air Quality Surveillance: Plan Content, and Subpart D, �58.30, National Air Monitoring Stations (NAMS).

Installation of additional meteorological instrumentation at the network sites, measuring wind speed and direction, temperature, and humidity parameters helped to further define airflow and pollutant transport in the region. Utilization of mobile monitors allowed evaluation and verification of ambient SO2 concentrations over a greater area. Numerous sites were monitored and subsequently relocated under the direction of state meteorologists when no significant impacts were observed. All monitoring for SO2 was performed with guidance and dispersion modeling analysis from the Arizona Department of Health Services, Bureau of Air Quality Control. The monitoring network was also developed in accordance with Supplementary Control Systems (SCS). Prior to implementation of continuous control technology, SCS utilized analysis of atmospheric conditions and monitored ambient concentrations to vary the rate of smelter emissions to avoid any exceedance of the NAAQS. In 1977, the state adopted rules that codified requirements for concurrent operation of at least eight ambient monitors, including a mobile monitor placed at points representative of observed maximum concentrations. Relocation of a stationary monitor was allowed only when: 1. There were no ambient SO2 violations recorded; 2. No SCS curtailment actions were implemented due to data recorded at that monitor; 3. The foregoing conditions were due to implementation of improved emissions control techniques or other permanent modifications; and 4. A new site was shown to be more representative of the ambient air quality of the area. Historic ambient SO2 monitoring site locations and periods of operation are provided in Table 3.1, and Figure 3.1 and 3.2. Further refinement of the monitoring network was required by the adoption of the MPR rule that established stack emissions limits for the smelter in 1979 based on permanent controls. Placement of additional monitors were established with EPA to further evaluate ambient impacts. Following ASARCO's compliance with emissions limits as defined in AAC R18-2-715(F), and based on continuous control technology, the number of permanent monitors was gradually reduced to the current network of six. These are all high impact ambient monitoring sites found to be representative of air quality for the area. These monitoring site decisions were made by ADEQ and ASARCO, and are in accordance with EPA guidance (See Table 3.2). Current Sampler Type and Siting The five monitoring units operated by ASARCO are Thermo Environmental Instruments (TEI) pulsed fluorescence Model 43 SO2 analyzers. All of these SO2 analyzers are interfaced to ASARCO's data acquisition system. The TEI analyzers measure in the 0-2 ppm range. Redundant recording systems are operated for all of the ASARCO analyzers. The samplers are connected to strip chart recorders for backup and analyzed by planimeter as necessary for validation of recorded concentrations. The ADEQ SO2 analyzer is a Thermo pulse fluorescence analyzer (model 43 C), measuring in the 0-2 ppm range (Figure 3.2 illustrates the current monitor locations and proximity to the Hayden smelter). The ASARCO and ADEQ monitors are operated and maintained in accordance with federal regulations as described in 40 CFR parts 58.13 and 58.22 as well as Appendices A and E of part 58. 3.1

Table 3.2 - Current Monitoring Network Unit15 Montgomery Ranch16 Jail Jail (State) Hayden Junction Garfield Ave. Globe Hwy. Location 2.50 miles NW from ASARCO 0.57 miles W from ASARCO 0.57 miles W from ASARCO 2.12 miles W from ASARCO 0.56 miles SW from ASARCO 0.61 miles E from ASARCO Elevation (feet above sea level) 2354 2052 2052 1932 2040 1964 Operator ASARCO ASARCO ADEQ ASARCO ASARCO ASARCO

3.2

Ambient Data Analysis A review of the SO2 monitoring data in the Hayden nonattainment area verifies that: 1. There have been no recorded exceedances of the annual NAAQS for SO2 since 1982 and annual averages are generally 53 percent of the NAAQS; 2. There have been no recorded exceedances of the 24-hour NAAQS for SO2 since 1994 and maximum 24-hour average SO2 levels are generally 76 percent of the NAAQS; and, 3. There have been no recorded exceedances of the 3-hour NAAQS for SO2 since 1994 and maximum 3-hour averages are generally below 80 percent of the NAAQS. The nonattainment area has recorded more than eight consecutive quarters of quality assured, violation-free data from July 1999 through June 2001. Data for the current monitoring network is presented in Table 3.3.

The Garfield, Jail, Hayden Junction, and Globe Highway monitors are primarily fugitive emissions impact sites. Montgomery Ranch is a mixed stack and fugitive impact site. Ambient sulfur dioxide monitoring at Montgomery Ranch began in 1974. This monitor was the "limiting site" for the original MPR analysis ("Ultimate Sulfur Dioxide Limits for Arizona Copper Smelters," Moyers and Peterson, September 14, 1979).

Table 3.3 - SO2 Ambient Air Quality Monitoring Data (Fg/m3) Year Annual Ave. 24-Hr Max 3-Hr Max Number of Exceedances of the Standard Annual (80 (Fg/m3) 24-hr. (365 Fg/m3) 3-hr. (1300 Fg/m3) Montgomery Ranch con't 1998 1997 1996 1995 1994 1993 1992 1991 1990 1989 1988 1987 1986 1985 1984 1983 1982 1981 1980 1979 1978 1977 1976 1975 1974 41 40 47 52 36 25 41 44 41 55 42 45 34 25 21 44 84 139 93 158 133 180 183 184 262 186 239 286 256 180 143 193 243 187 413 405 301 242 141 245 191 414 498 742 1383 395 772 1058 1576 1442 768 645 1170 950 1096 792 626 831 692 2125 1187 1297 1183 803 688 928 1123 2283 3781 9287 1785 2384 3275 6491 4848 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 Jail 2001 21 152 877 0 0 0 8759 0 0 0 0 0 0 0 0 0 2 1 0 0 0 0 0 2 7 5 9 2 2 2 2 2 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 7 9 13 2 2 2 2 2 8325 8199 8442 8407 8649 8756 8726 8721 8704 7764 8560 8586 8505 8564 8640 8592 8367 8651 8602 8648 8718 8724 8443 8204 7593 No. of 1-hr. Samples

Table 3.3 - SO2 Ambient Air Quality Monitoring Data (Fg/m3) Year Annual Ave. 24-Hr Max 3-Hr Max Number of Exceedances of the Standard Annual (80 (Fg/m3) 24-hr. (365 Fg/m3) 3-hr. (1300 Fg/m3) Jail con't 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 1989 1988 1987 1986 1985 1984 1983 13 14 13 15 20 21 16 10 15 18 19 21 13 15 15 9 10 31 63 89 110 127 88 96 70 64 71 89 163 223 122 237 117 58 127 270 342 432 647 584 529 393 444 335 402 472 821 979 708 1235 697 346 620 1423 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Jail (State) 2001 2000 1999 1998 1997 1996 1995 1994 24 17 24 29 5 16 18 21 157 72 99 122 152 81 97 453 785 322 475 595 697 527 435 464 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 8407 8106 8015 7457 8456 8618 8531 7444 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 8783 8748 8392 8401 8428 8602 8758 8716 8667 8716 8667 8704 7699 8552 8655 8561 8688 8664 No. of 1-hr. Samples

Table 3.3 - SO2 Ambient Air Quality Monitoring Data (Fg/m3) Year Annual Ave. 24-Hr Max 3-Hr Max Number of Exceedances of the Standard Annual (80 (Fg/m3) 24-hr. (365 Fg/m3) 3-hr. (1300 Fg/m3) Jail (State) con't 1993 1992 1991 1990 1989 1988 1987 1986 1985 1984 1983 1982 1981 1980 1979 1978 1977 1976 1975 1974 10 16 16 16 24 24 29 24 19 22 36 57 75 45 71 60 95 113 105 127 84 238 81 199 183 137 422 139 120 177 269 417 382 418 1143 413 619 940 950 1110 372 815 511 1137 697 800 1498 707 750 693 1942 1724 2334 1410 4606 3286 2525 3350 4483 4887 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 Hayden Junction 2001 2000 1999 1998 1997 1996 14 13 13 9 12 9 59 90 69 65 47 52 215 427 404 368 285 374 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 8759 8778 8739 8372 8389 8429 0 0 0 0 0 0 1 0 0 0 0 2 2 1 3 1 2 2 2 2 0 0 0 0 0 0 2 0 0 0 1 5 5 3 10 2 2 2 2 2 8585 8384 8017 8129 8636 8553 8569 8380 8494 8132 8300 8522 8351 7922 8311 7584 8223 8125 7756 7739 No. of 1-hr. Samples

Table 3.3 - SO2 Ambient Air Quality Monitoring Data (Fg/m3) Year Annual Ave. 24-Hr Max 3-Hr Max Number of Exceedances of the Standard Annual (80 (Fg/m3) 24-hr. (365 Fg/m3) 3-hr. (1300 Fg/m3) Hayden Junction con't 1995 1994 1993 1992 1991 1990 1989 1988 1987 1986 1985 1984 1983 1982 1981 1980 1979 1978 1977 1976 1975 1974 1973 1972 1971 1970 1969 13 14 6 7 10 9 10 8 14 11 10 5 21 36 40 22 43 37 66 57 58 115 191 254 336 481 377 77 72 68 48 75 50 93 159 153 155 97 70 152 290 322 214 244 215 514 344 360 542 1091 9504 2136 1877 3849 416 457 160 343 455 319 585 509 744 507 320 492 780 1291 1491 1132 1751 1118 3262 1754 2146 2466 6225 9504 7413 6970 N/A 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2 36 2 2 2 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 2 2 2 2 61 2 2 2 2 8392 8618 8760 8746 8711 8704 7762 8579 8586 8564 8487 8424 8592 8461 8461 8596 8676 8711 8728 8570 8632 7794 7008 7499 2064 4906 5011 No. of 1-hr. Samples

Table 3.3 - SO2 Ambient Air Quality Monitoring Data (Fg/m3) Year Annual Ave. 24-Hr Max 3-Hr Max Number of Exceedances of the Standard Annual (80 (Fg/m3) 24-hr. (365 Fg/m3) 3-hr. (1300 Fg/m3) Garfield Avenue 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 1981 1980 29 21 25 20 22 22 23 22 12 28 23 23 45 35 285 284 313 237 283 336 195 268 202 344 342 263 225 214 873 860 583 770 521 796 1125 633 432 866 1071 939 1355 975 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Globe Highway 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 43 38 35 32 43 52 39 38 29 28 40 37 311 218 209 178 315 226 233 332 148 205 224 292 838 772 735 1284 836 727 1084 1776 551 672 1199 1153 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 8754 8784 8757 8377 8227 8425 8395 8610 8757 8746 8698 8707 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 8760 8784 8753 8395 8427 8452 8464 8617 8758 8764 8733 8742 8615 8322 No. of 1-hr. Samples

Table 3.3 - SO2 Ambient Air Quality Monitoring Data (Fg/m3) Year Annual Ave. 24-Hr Max 3-Hr Max Number of Exceedances of the Standard Annual (80 (Fg/m3) 24-hr. (365 Fg/m3) 3-hr. (1300 Fg/m3) Globe Highway, con't 1989 1988 1987 1986 1985 1984 1983 1982 1981 1980 1979 1978 72 36 33 40 40 20 46 73 86 55 113 102 382 345 223 325 283 152 328 332 302 314 349 404 1643 1595 1092 1270 1556 537 1674 1290 1269 1254 1647 1482 0 0 0 0 0 0 0 0 1 0 1 1 1 0 0 0 0 0 0 0 0 0 0 0 4 1 0 0 1 0 1 0 0 0 3 2 7861 8674 8593 8553 8594 8730 8640 8350 8350 8651 8667 8713 No. of 1-hr. Samples

4.0

SO2 EMISSIONS INVENTORY FOR POINT, AREA AND MOBILE SOURCES

Emissions inventories from all sources in the Hayden nonattainment area indicate that although there are other sources of SO2 emissions, the ASARCO smelter is the primary source for SO2 emissions and comprises more than 99 percent of total SO2emissions in the area. Data shows that no other point, area or mobile sources have contributed or contribute to the same levels of SO2 in the Hayden nonattainment area. Emissions units and rates, and derivation of mobile and area source emissions for the nonattainment area are described in Section 4.1 through Section 4.3 below. 4.1 SO2 Point Sources within the Hayden Nonattainment Area

One point source is located within the Hayden nonattainment area. Point source locations are illustrated in Figure 4.1, on the following page. Attainment year inventories for the source is presented in Table 4.1.17

Table 4.1 - Actual SO2 Emissions for Hayden Nonattainment Area - Point Sources Source Name: ASARCO Hayden Smelting Operations1 8 24 Hour Total: Annual Total: 24 Hr. Annual 1999 58 tpd 21,081 tpy 58 tpd 21,081 tpy 2000 47 tpd 15,934 tpy 47 tpd 2001 51 tpd 18,362 tpy 51 tpd

15,934 tpy

18,362 tpy

4.1.1

ASARCO Hayden Smelter

Smelting and refining of copper ore at ASARCO's primary copper smelter operations produces anode copper for shipment to facilities in Texas for production of copper cathode as well as the byproduct sulfuric acid for sale to customers. More than 99 percent of all SO2 emissions in the nonattainment area are generated by this facility. Based on 2000 emissions data, the majority of this facility's emissions are from the following stack and fugitive units: main stack core including primary flash furnace and converter process gas; main stack annulus furnace vent gas and converter secondary gases; and fugitive emissions from the flash furnace, converters, anode furnace, and slag dump. The maximum allowable annual average SO2 emission rate for stacks was reduced from 9,521 lbs/hr to 6,882 lbs/hr with recent revisions to AAC R18-2-715(F)(2). The revisions also limited annual average fugitive emissions to 295 lbs/hr. The combined limit for the stack and fugitive emissions units is currently 7,177 lbs/hr (31,435 tpy). Additionally, the permit limits sulfur content and usage rates for fuel used in all fuel burning equipment requiring the use of natural gas and low sulfur fuels. Emissions units and rates for the ASARCO smelter are detailed in Appendix B.

Unless otherwise noted, all 24-hour inventories are ton per day (tpd) averages based on the number of operating hours for each respective year.

24-hour inventories are averages calculated by dividing the annual facility emissions by the number of operating days for each

year.

4.2

Major Point Sources within the 50 km Buffer Area 28

In addition to the sources located within the nonattainment area, there are several SO2 point sources within 50 kilometers of the Hayden nonattainment area. The emissions from these point sources do not significantly contribute to levels of SO2 in the nonattainment area. Attainment year inventories are provided in Table 4.2.19

Table 4.2 - SO2 Emissions within 50km of the Hayden Nonattainment Area - Major Point Sources Source Name: APS (Red Rock) BHP San Manuel Smelting Operations 2 0 , 2 1 Phelps-Dodge Miami Smelting Operations21 24 Hour Total: Annual Total: 24 Hr. Annual 24 Hr. Annual 24 Hr. Annual 1999 < 1 tpd 8 tpy 30 tpd 3,622 tpy 22 tpd 7,819 tpy < 53 tpd 11,449 tpy 2000 < 2 tpd 153 tpy < 1 tpd <1 tpy 21 tpd 6,810 tpy < 24 tpd 6,964 tpy 2001 < 6 tpd 497 tpy < 1 tpd <1 tpy 27 tpd 9,062 tpy < 34 tpd 9560 tpy

4.2.1

Arizona Public Service (APS) - Red Rock

The APS Red Rock electric generating station is located 70 km southwest of the Hayden smelter. The facility operates two steam turbine and two gas turbine units. The source's permit limits SO2 emissions from combustion of fuel in the existing equipment to 15,051 tpy, however, the facility's primary fuel is low sulfur natural gas. This station was formerly a peaking plant providing increased electricity generation during periods of high demand. Commencement of full time operations began in 2000. 4.2.2 BHP Copper San Manuel Smelter

The San Manuel primary copper smelter is located approximately 46 kilometers south of the Hayden smelter and separated from the Hayden area by varied terrain that includes the San Pedro river valley and areas of mountainous ridges. When operational, the San Manuel primary copper smelter operations include a flash furnace, converters, and other auxiliary equipment for smelting and refining of copper sulfide ore. The permit limits smelter process and fugitive SO2 emissions to 10,762 tpy. In addition, the permit limits sulfur content and usage rates for fuel used in all fuel burning equipment. The San Manuel area is also a SO2 nonattainment area, and BHP accounts for

Unless otherwise noted, all 24-hour inventories are ton per day (tpd) averages based on the number of operating hours for each respective year.

20 21 19

BHP smelting operations have been temporarily suspended since May 1999. 24-hour inventories are averages calculated by dividing the annual facility emissions by the number of operating days for each

year.

approximately 99 percent of the emissions for that area. Therefore, this smelter is documented in more detail in the San Manuel SO2 State Implementation and Maintenance Plan. ADEQ anticipates submittal of this Plan to EPA in June 2002. 4.2.3 Phelps-Dodge Miami Smelting Operations The Miami primary copper smelter is located 46 kilometers north of the Hayden smelter and is geographically separated from the Hayden area by the 7,000 foot Pinal Mountains. The Miami facility operates an Isasmelt furnace, electric furnace, converters, and other auxiliary equipment for smelting and refining of copper sulfide ore. AAC R18-2-715 limits smelter process and fugitive SO2 emissions to 10,368 tpy. Actual emissions, however, are less than 8,000 tpy. In addition, the permit limits sulfur content and usage rates for fuel used in all fuel burning equipment. The Miami area is also a SO2 nonattainment area, and this smelter is documented in more detail in the Miami SO2 Maintenance and State Implementation Plan. ADEQ anticipates submittal of this Plan to EPA in June 2002. 4.3 Area and Mobile Sources

Emissions for the nonattainment area were derived from EPA NET area and mobile source inventories for Pinal and Gila Counties based on the assumption that area and mobile source emissions are proportionate to population levels. The Hayden SO2 nonattainment area population is estimated to be three percent of the Pinal County population, and three percent of the Gila County population based on the aggregate population centers of Kearny and Dudleyville (Pinal County); and Hayden and Winkelman (Gila County). The remainder of the nonattainment area has a very low population density with low traffic levels and minimal commercial or industrial development.22 Data shows that there are no urban areas that might be significant area or mobile sources located within the Hayden nonattainment area as illustrated in Table 4.3. Area and mobile sources combined were less than one percent of the total emissions during the attainment demonstration period.

Table 4.3 - SO2 Emissions for the Hayden Nonattainment Area - All Sources Source Type:23 Area and Mobile24 24 Hr. Annual 24 Hr. Annual 1999 < 1 tpd 50 tpy 58 tpd 21,081 tpy < 59 21,131 2000 < 1 tpd 51 tpy 47 tpd 15,934 tpy < 48 15,985 2001 < 1 tpd 51 tpy 51 tpd 18,362 tpy < 52

Point 24 Hour Total: Annual Total:

18,413

4.4

Emissions Projections

22 23

See Section 1.3.2 for a more detailed description of population calculations.

Area and mobile source estimates are based on EPA's AIRData for Pinal and Gila Counties. Point source estimates are based on ADEQ annual emissions inventory data. See Appendix B for a more detailed breakdown of area vs. mobile sources.

24-hour inventories are averages based on a 365 day distribution of emissions from these sources.

Arizona does not anticipate any substantial increase in existing point source emissions between 1999 and 2015 for the nonattainment area. Should any growth occur due to construction of additional SO2 point sources, ADEQ's permit program limits all emissions as part of the construction of new point sources or the upgrading of existing sources. 4.4.1 Point Source Projections Projections for copper smelters are based on growth rates contained in the Western Regional Air Partnership (WRAP), Annex to the Report of the Grand Canyon Visibility Transport Commission, October 16, 2000. This report notes that downward pressure on copper prices resulting from the international competition has resulted in a consolidation of the copper industry in the Southwestern United States. Consequently, no expansion of the industry is expected through 2015. Emissions projection estimates for electric utilities are based on an anticipated industry growth rate of 2.6 percent per year contained in the WRAP report. These estimates are predicated, in part, on existing capacity and future demand for generation.25 Table 4.4 and Table 4.5 present projected emissions for point sources within the nonattainment area and within 50 km of the nonattainment boundary.26

Table 4.4 - SO2 Emissions Projections for the Hayden Nonattainment Area - Point Sources Source Name: ASARCO Hayden Smelting Operations2 7 24 Hour Total: Annual Total: 24 Hr. Annual 1999 58 tpd 2000 47 tpd 2001 51 tpd 2005 65 tpd 2010 65 tpd 2015 65 tpd

21,081 tpy 15,934 tpy 18,362 tpy 23,000 tpy 23,000 tpy 23,000 tpy 58 tpd 47 tpd 51 tpd 65 tpd 65 tpd 65 tpd

21,081 tpy 15,934 tpy 18,362 tpy 23,000 tpy 23,000 tpy 23,000 tpy

The WRAP analysis of industry production and projections was used in the smelter and utility projections for this document. The Annex is expected to be approved by EPA at the end of 2002. Unless otherwise noted, all 24-hour inventory projections are calculated based on the average number of operating hours for the period 1999 through 2001. Projected 24-hour inventories are based on the average number of operating days for the period 1999 through 2001 and are assumed to represent typical operating rates for the facility.

27 26

Table 4.5 - SO2 Projected Emissions within 50km of the Hayden Nonattainment Area Major Point Sources Source Name: Electric Utilities28 24 Hr. Annual 1999 < 1 tpd 8 tpy 30 tpd 3,622 tpy 22 tpd 7,819 tpy < 53 tpd 2000 < 2 tpd 153 tpy < 1 tpd <1 tpy 21 tpd 6,810 tpy < 24 tpd 2001 < 6 tpd 497 tpy <1 tpd <1 tpy 27 tpd 9,062 tpy < 34 tpd 9,560 tpy 2005 < 7 tpd 551 tpy 30 tpd 10,900 tpy 23 tpd 8,000 tpy < 60 tpd 2010 < 8 tpd 626 tpy 30 tpd 10,900 tpy 23 tpd 8,000 tpy < 61 tpd 2015 < 9 tpd 712 tpy 30 tpd 10,900 tpy 23 tpd 8,000 tpy < 62 tpd

BHP San Manuel 24 Hr. Smelting Operations29,30 Annual Phelps-Dodge Miami Smelting Operations 3 0 24 Hour Total: Annual Total: 24 Hr. Annual

11,449 tpy 6,964 tpy

19,451 tpy 19,526 tpy 19,612 tpy

4.4.2

Area, Mobile, and Total Source Projections

ADEQ projects emissions of SO2 from area and mobile sources to grow roughly proportionately with the population of the nonattainment area. Appendix B describes the source category emissions projections in greater detail. Table 4.6 presents projected area and mobile, and total source emissions for the Hayden nonattainment area.31

Table 4.6 - SO2 Emissions Projections for Hayden Nonattainment Area -All Sources Source Type: Area and 24 Hr. Mobile Annual Point 24 Hr. Annual 1999 < 1 tpd 50 tpy 58 tpd 21,081 tpy < 59 tpd 21,131 tpy 2000 < 1 tpd 51 tpy 47 tpd 15,934 tpy < 48 tpd 15,985 tpy 2001 < 1 tpd 51 tpy 51 tpd 18,362 tpy < 52 tpd 18,413 tpy 2005 < 1 tpd 53 tpy 65 tpd 23,000 tpy < 66 tpd 2010 < 1 tpd 55 tpy 65 tpd 23,000 tpy < 66 tpd 2015 < 1 tpd 57 tpy 65 tpd 23,000 tpy < 66 tpd

24 Hour Total: Annual Total:

23,053 tpy 23,055 tpy 23,057 tpy

5.0

MODELING DEMONSTRATION

Projections for electric utilities are based on the assumption of continued full time operation of the APS (Red Rock) generating station and were calculated using emissions from the most recent year of full time operations at this facility (497 tons of SO2 emissions were recorded in 2001, the first year of full time operations).

BHP smelting operations were temporarily suspended beginning May 1999. Projections for this smelter assumes resumption of

operations. Projected 24-hour inventories are based on the average number of operating days for the period 1999 through 2001 and are assumed to represent typical operating rates for the facility.

31 30

See Section 1.3.2 for a more detailed analysis of population data.

Attainment is demonstrated through the clean ambient air quality record of more than seven years and use of Multi-point Rollback (MPR) modeling. The improvement in air quality is due to continuous SO2 emissions control technologies implemented by the ASARCO Hayden smelter to comply with the SO2 emission limits regulations adopted for Arizona smelters in September 1979. Additional air quality benefit can be attributed to the 1982 shutdown of a second Hayden smelter operated by Kennecott Corporation. This facility was purchased by ASARCO in 1986 and is only used for storage. All equipment has been scheduled for removal, and the reverberatory furnace has been demolished. A Title V permit application was not submitted to ADEQ for the Kennecott facility, and no subsequent applications for air quality permits have been received. Additionally, since this facility has been closed longer than two years, the smelter can not reopen without submitting a New Source Review (NSR) and Title V (Subpart 71) permit application.32 MPR, which was approved by EPA in January 1983, as a modeling technique for Arizona smelters, was selected as the most precise and reliable method for then determining contemporary and future stack SO2 emission limits. MPR is a proportional rollback technique founded on the assumption that smelter emissions and ambient concentrations are proportional for a given set of dispersion conditions. Thus, a reduction in emissions results in a comparable reduction in ambient concentrations. Based on this assumption, the appropriate level of emission reductions to protect the NAAQS can be achieved if emissions are reduced by the ratio of the corresponding ambient concentrations to the air quality standard. The use of MPR addresses the high variability of both smelter emissions patterns and meteorological conditions, in part, by rolling back an entire emissions curve rather than a single emissions measurement. A rollback factor is determined by fitting a concentration frequency distribution (from observed data) to an appropriate functional curve and calculating a maximum (limiting) value with an expected once per year frequency of occurrence. The rollback or reduction factor is defined as the ratio of the ambient standard to the limiting value. Rollback factors are calculated for all applicable NAAQS averaging periods. The largest calculated rollback factor is used to reduce each emission which occurred over the period of data accumulation (the emissions profile) to establish an allowable distribution of emissions rates that are protective of the NAAQS. The maximum rollback value is chosen to ensure that all primary and secondary standards are protected. In the case of the Hayden smelters, the 3-hour standard was selected as the most conservative limiting standard which is also protective of the 24-hour and annual standards.33 The original analysis used measured stack and calculated total SO2 emissions over the course of a year, as well as knowledge of smelter operations, emissions variability, and meteorological conditions to construct stack emissions curves for the Hayden smelters. The curve was then "rolledback" and the resultant distributions used directly to construct the original MPR cumulative occurrence and 3-hour average emissions limits tables for stacks. Hourly ambient SO2 concentration data from the Montgomery Ranch monitor for the period June 1974 through December 1976, were used in the analysis.34 At the time of the original MPR analysis, two smelters were in operation in the Hayden area, one operated by Kennecott Corporation and one operated by ASARCO Incorporated. The combined emissions impacts from these smelters were evaluated to determine emissions limits. Among the

32 33

In accordance with AAC R18-2-411.

A detailed discussion of Multi-point Rollback methodology is contained in Ultimate sulfur Dioxide Emission Limits for Arizona Copper Smelters, September, 1979.

The Montgomery monitor is designated as a stack impact site.

considerations in the original analysis were the segregation of the individual smelter's ambient impacts on the airshed and utilization of diffusion modeling to determine the relative contribution of stack and fugitive emissions on ambient concentrations. 5.1 Derivation of New Emissions Limits

Based on EPA's approval as a model, ADEQ utilized the MPR approach for the current attainment demonstration. The updated MPR study analyzes stack emissions and resultant ambient impacts based on current operating levels. Because the Kennecott/Hayden smelter is no longer in operation, the updated analysis is also based on the specific impact of the ASARCO smelter's emissions on the area. In addition to evaluation of stack impacts, Section 5.1.2 includes analysis of ambient impacts due to fugitive emissions. Data from July 1999, through June 2001, are used in the current demonstration and includes continuous measurement data for stack, calculated fugitive SO2 emissions, and measured ambient concentrations. These data were used to establish new stack and fugitive emission limits in rule that will maintain emissions at a level protective of the ambient air quality standards (See Appendix A). 5.1.1 Stack Emissions Limits

The new SO2 limits for stack emissions at the Hayden smelter maintain the basic MPR principles: 1. Smelter emissions and meteorological conditions are two highly variable and independent processes that together, directly influence the impact of emissions on ambient air quality; 2. Emissions limits can be set that assure a high probability of maintaining the applicable ambient air quality standards. The new limits are in the same format as the original MPR tables. However, the derivation of the new values differs from the original in two important aspects. First, the new limits are based on current SO2 emissions measurements. Second, it was not necessary to reduce actual emissions as the SO2 air quality standards were met by a large margin during the two year period (July 1999 through June 2001) from which the emissions data were obtained (See Section 3.1 and 3.2). The following steps outline the method used in the current analysis for the new Hayden smelter stack limits: 1. Calculate a new stack emissions curve in the form of MPR based on the current 3hour average emissions profile, 2. Calculate an average annual emissions level based on current emissions, and 3. Determine an adjustment factor for the 3-hour average and annual average emissions to establish new limits (based on ambient concentrations) to maintain future emissions at a level protective of the NAAQS. As in the original MPR analysis, Step 3 requires segregation of the ambient effects of stack and fugitive emissions to evaluate ambient stack impacts on the airshed and to calculate an adjustment factor. Two years of data, based on actual emissions measurements from the demonstration period (July 1999 through June 2001), were used to determine an annual average emissions value and to build an MPR 3-hour average emissions curve representative of the attainment period. Three-hour 34

running averages for this period were ranked in descending numerical order of value. Each successive pair of ranked 3-hour values was averaged to obtain a single representative profile consisting of 8,760 hourly values for the attainment period. As with the original MPR, the highest 26 percent, or 2,240 hours, of the resulting averages was then sorted into 24 categories of cumulative frequency of occurrence values identical to the occurrence limits in the original MPR tables (0 to 2,240). The values in each emission category (E) were selected using the same conceptual method used in the original MPR where in each category of allowed emission occurrences (n), the lowest actual emissions value in that range was used to establish the new value. For example, the n cumulative frequency of occurrence where n = 7 in the MPR table based on current stack emissions corresponds to the emissions value E where E = 10,368. The measured emissions values that occur in the frequency, where n = 7, are 10,803, 10,396 and 10,368. The method of selecting the cumulative occurrence and 3-hour average emission limits is outlined in Appendix C. The selection of the lowest measured emissions value E in each frequency of occurrence n mimics the selection of the lowest calculated values of the original MPR analysis, which were all below the emissions profile or curve. The annual average emissions for the attainment period was determined from the calculated numerical average of the combined hourly stack emission values for the attainment period (July 1999 through June 2001). Table 5.1 contains the cumulative occurrence and emissions levels derived from attainment period data.

Table 5.1 - Hayden Smelter 3-hour MPR Stack Emissions Curve Based on Attainment Period Number of Cumulative Occurrences (n) 0 1 2 4 7 12 20 32 48 68 94 130 180 July 1, 1999-June 30, 2001 3-hr avg Emissions lb/hr (E) 13177 12284 11607 10867 10368 10021 9442 9085 8748 8453 8070 7713 7367

Table 5.1 - Hayden Smelter 3-hour MPR Stack Emissions Curve Based on Attainment Period Number of Cumulative Occurrences (n) 245 330 435 560 710 890 1100 1340 1610 1910 2240 Annual Average lb/hr 3680 July 1, 1999-June 30, 2001 3-hr avg Emissions lb/hr (E) 7065 6772 6486 6215 5970 5701 5457 5213 4984 4788 4576

Because the ambient air quality standards have been met in the Hayden area by a substantial margin, the next step in the analysis entailed selection of an adjustment factor to adjust the 2002 emissions curve that was calculated from actual emissions from the attainment period, to a new level that continues to maintain the NAAQS. The evaluation of an appropriate adjustment factor is based on the stack emissions impacts at the Montgomery Ranch ambient monitoring site. The Montgomery Ranch monitor is the limiting monitor for ambient stack impacts in the Hayden area. The other area monitors are considered primarily to be fugitive impact sites. The Montgomery Ranch monitor is located in an area where fugitive or low level emissions can also contribute to measured ambient SO2 concentrations. Stack and fugitive impacts at the Montgomery Ranch ambient SO2 monitor are directly related to diurnal variations in atmospheric stability and dispersion patterns. Under stable atmospheric conditions, which are common during nighttime hours, fugitive emissions can influence the monitor while tall stack emissions are prevented from reaching the ground by the stable layer below.35 Conversely during daytime hours, especially in the morning as commonly seen during inversion breakup, unstable conditions cause low level emissions (fugitives) to mix into a very diluted state, while stack emissions are more likely to affect the monitor because

"Stable," as defined by the National Weather Service (http://www.phx.noaa.gov) is the condition when little or no vertical mixing occurs due to the nature of the temperature change with height. Under stable conditions, convection is inhibited, winds are generally on the light side, and pollution is easily trapped near the ground.

the unstable air brings them to lower levels.36 As such, the 3-hour SO2 ambient monitoring record can be separated into categories representative of the relative stack and fugitive ambient impacts. As in the original MPR analysis, the current demonstration segregates the impacts of stack emissions from fugitive emissions based on atmospheric stability parameters. Smelter emissions data corresponding to the 50 highest 3-hour SO2 concentrations recorded at the Montgomery Ranch ambient monitor during the attainment period were evaluated to determine the relative contribution of stack and fugitive emissions for these events and to eliminate those measurements that were predominantly the result of fugitive emissions.37 Of the 50 highest Montgomery Ranch 3-hour sulfur dioxide concentration events, twenty events were determined primarily due to the ambient impact of stack emissions. Thirteen events were primarily due to fugitive impacts, and sixteen events were due to a combination of fugitive plus stack impacts (two of the top 50 events were overlapping, giving a total of 49 individual events). The twenty events determined to be primarily due to stack emissions were used to further analyze ambient impacts from this source. Details of the stack/fugitive segregation method are contained in Appendix C. Because the ambient air quality standards have been met in the Hayden area, an adjustment factor was used to "roll up" the emissions curve calculated from actual emissions during the attainment period. A design value based on the 3-hour standard was selected for determining an adjustment factor as this averaging period has been demonstrated to also be protective of the 24-hour and annual standard.38 In accordance with EPA guidance, emission limits should be based on concentration estimates for the averaging time that results in the most stringent control requirements. When short term standards are the most restrictive for pollutants such as SO2, the highest, second high concentration should be used as the design value.39 Even for the ambient events determined to be primarily due to stack emissions, a small proportion of each event can be attributable to fugitive emissions. As such, this small percentage is accounted for in the analysis. The ambient concentrations due to fugitive and stack impacts in equation 1 and 2 (FI and SI) are derived from the atmospheric stability analysis in Appendix C that was used to distinguish between emissions source impacts at the Montgomery Ranch monitoring site. Term S in equations 1 and 2 provides a more conservative regulatory concentration goal of 85 percent of the 1300 ug/m3 3-hour standard. Consistent with EPA guidance the adjustment factor was determined from the highest second high ambient concentration attributable to stack impacts. The second highest ambient concentration due to stack emission impacts at the Montgomery Ranch monitor during the two year attainment period occurred on June 11, 2000. Based on this event, an event stack limit was calculated using the following equation: Event Stack Limit = (A) * (S) - (FI) (SI) where:

"Unstable," as defined by the National Weather Service (http://www.phx.noaa.gov) is an atmospheric state where warm air below cold air. Since warm air naturally rises above cold air, vertical movement and mixing of air layers can occur. Twenty five of the 50 highest concentrations were selected from hours during expected stable conditions and 25 during expected unstable conditions because an adequate data set is necessary to explore the variability of meteorological conditions and the stack emissions that impact high ambient concentrations.

38 39 37 36

(1)

A design value is an event that was selected for evaluation.

EPA guidance specifies that a violation of a short term standard occurs at a site when the standard is exceeded a second time. Therefore, it is appropriate to base emission limits to protect the standards on the highest, second-highest estimated concentration plus a background concentration which can reasonably be assumed to occur with the concentration (40 CFR Pt. 51, App W �11.2.3.1(a), (b) and (c)).

A = actual 3-hr stack emissions (lb/hr), S = 85 percent of the 1300 ug/m3 3-hour ambient standard or 1105 ug/m3, FI = ambient concentration due to fugitive impact (ug/m3), and SI = ambient concentration due to stack impact (ug/m3). Or Event Stack Limit = (8627) * (1105) - (399 - 379) = 24695 lb/hr (379) The adjustment or roll up factor is determined by the ratio of the event stack limit to the maximum 3-hour stack emissions recorded during the two year attainment demonstration period from Table 5.1. The adjustment factor is calculated by the following equation: Adjustment Factor = (ESL) (Emax) Where: ESL = Stack limit from equation 3 (lb/hr), and Emax = 3-hr maximum stack emissions during two year demonstration period (lb/hr). OR Adjustment Factor = (24695) = 1.87 (13177) The adjustment factor from equation 4 was used to "roll-up" the 3-hour average emissions and the annual average emissions derived from attainment period data, July1, 1999, through June 30, 2001. These values become the new MPR 3-hour average and annual average limits for stack emissions as illustrated in Table 5.2. These new limits are contained in a 2002 rulemaking and will be incorporated in a future permit revision (See Appendix A). (4) (3) (2)

Table 5.2 - Hayden Smelter MPR Stack Emissions Limits Number of Cumulative Occurrences (n) 0 1 2 3-hr Average Emissions (E) (lb/hr) Based on Continuous Emissions Data From July 1, 1999, through June 30, 2001 13177 12284 11607 3-hr avg Emissions Limits (E) (lb/hr), Including 1.87 Adjustment Factor 24641 22971 21705

Table 5.2 - Hayden Smelter MPR Stack Emissions Limits Number of Cumulative Occurrences (n) 4 7 12 20 32 48 68 94 130 180 245 330 435 560 710 890 1100 1340 1610 1910 2240 3-hr Average Emissions (E) (lb/hr) Based on Continuous Emissions Data From July 1, 1999, through June 30, 2001 10867 10368 10021 9442 9085 8748 8453 8070 7713 7367 7065 6772 6486 6215 5970 5701 5457 5213 4984 4788 4576 Annual Average Emissions (lb/hr) 3680 6882 3-hr avg Emissions Limits (E) (lb/hr), Including 1.87 Adjustment Factor 20322 19387 18739 17656 16988 16358 15808 15090 14423 13777 13212 12664 12129 11621 11165 10660 10205 9748 9319 8953 8556

5.1.2

Fugitive Emissions Limits Consistent with EPA guidance, assessment of fugitive emissions and determination of an adjustment factor and appropriate limits is based on the second highest ambient concentration during the attainment period attributable to fugitive impacts.40 The second highest ambient concentration

40 CFR Part 51, Appendix W.

due to fugitive emission sources during the two year demonstration period occurred at the Globe Highway monitor on April 29, 2000.41 Because of the proximity of this monitor to the Hayden smelter, contributions from stack sources are minimal. Based on this event, fugitive limits are calculated using the following equation: Adjustment Factor = (AC) Where: S = 85 percent of the 1300 ug/m3 3-hour ambient standard or 1105 ug/m3, AC = the ambient concentration due to fugitive impacts Or Adjustment Factor = 677 The adjustment factor from equation 6 was used to adjust the annual average fugitive emissions calculated for the attainment period (Equations 7 and 8). This value becomes the new annual average limit, based on a 12 month rolling average, for fugitive emissions. This new limit is also a part of the 2002 rulemaking and will be incorporated in a future permit revision. Annual Average Fugitive Limits = (Fugitive Emissions) * (Adjustment Factor) Where: Fugitive Emissions = Average annual fugitive emissions during 2-year demonstration period (lb/hr). Or Annual Average Fugitive Limits = (181) * (1.63) = 295 lb/hr 5.1.3 Total Stack and Fugitive Limits (8) (7) 1105 = 1.63 (6) (S) (5)

The current analysis reduced allowable annual average stack emissions from the previous rule limit of 9,521 lb/hr to a lower level of 6,882 lb/hr. The reductions in allowable emissions from stack sources alone provide an annual reduction of 11,559 tons (approximately 28 percent for stack emissions). The corresponding reduction in allowable 3-hour average stack emissions is illustrated in Figure 5.1. In addition to the reduction in allowable stack emissions, the rule establishes a new annual average fugitive SO2 emissions limit at 295 lbs/hr or 1,292 tpy. Annual average emissions for the combined stack and fugitive sources are limited by the rule to 7,177 pounds per hour or 31,435 tons per year.

The Globe Highway monitor is a designated fugitive impact site.

Figure 5.1 - Comparison of 1979 and 2002 MPR 3-hour Average Stack Limits42

Allowable 3-hour Average Emissions

40000

35000

30000

Emissions (lbs/hr)

25000

20000

15000

10000

5000

0 0 1 2 4 7 12 20 32 48 68 94 130 180 245 330 435 560 710 890 1100 1340 1610 1910 2240

Cumulative Occurance 1979 MPR Stack Limit 2002 MPR Stack Limit

5.2

Smelter Configuration

Smelter configuration and in particular the location and height, of SO2 releases was a consideration in finding the Hayden smelter in compliance with the original MPR limits and for the current demonstration of attainment of the SO2 NAAQS. The original MPR limits for the Hayden smelter were based on 1976 records of SO2 emissions and ambient concentrations. The smelter achieved compliance with MPR emission limits in 1987 and remains in compliance to date. Although the smelter underwent major modifications and emission reductions over the years, the location and heights of SO2 releases have changed only slightly. Basically, emissions can be grouped into two categories based on the height of release. Low level emissions at heights generally less than 200 feet include fugitive emissions. High level emissions are predominantly from the 1000 foot main stack. Table 5.1 shows the release heights for 1976 compared to the most recent years of operation 1999 through 2001. In addition, distances of the individual emission points to the facility property boundary have changed little since 1976. Thus the ambient SO2 network established in the 1970's and refined in the 1980's, including extensive sampling and testing for fugitive SO2 impact sites, occurred at a time with quite consistent release heights. This consistency of SO2 release locations continued through the 1990's thereby providing assurance that the ambient SO2 monitoring network continues to represent the maximum impact of SO2 emissions from the Hayden smelter.

Limits contained in AAC R18-2-715(F).

Table 5.3 - Hayden Smelter Configuration 1976 to Present Emissions Source Main Stack (core) Main Stack (annulus) 1976 Height (ft) 1000 991.5 P resent Height (ft) 1000 991.5 1976 Process Emission Source High Level Acid Plant Present Process Emission Source Acid Plant

Fugitives

130

Captured dryer, furnace, and Captured dryer, furnace and converter fugitive emissions converter fugitive emissions Low Level Converter, furnace, and Direct converter, furnace, anode furnace gases not and anode furnace fugitive captured by primary or gases secondary hood system

Good Engineering Practice Stack Height The Good Engineering Practice (GEP) Stack Height Limitation codified at AAC R18-2-332 ensures that emissions from a stack do not result in excessive concentrations of any air pollutant as a result of atmospheric downwash, wakes, or eddy effects created by the source itself, nearby structures, or nearby terrain obstacles. The Hayden smelter's 1000 ft stack for the #2 acid plant and a 991.5 ft annular stack for the furnace and converter fugitive emissions was built in 1974. Assessment of GEP stack height at ASARCO's Hayden smelter was conducted jointly by North American Weather Consultants (NAWC) and Colorado State University (CSU). The modeling and analysis demonstrated that the 305 meter (1000 ft) ASARCO stack meets GEP stack height requirements and concluded that emissions from the stack do not result in excessive concentrations of any air pollutant. EPA approved Arizona's SIP determination of GEP stack height on January 14, 1983 (48 FR 1717).

5.2.1

6.0 CONTROL MEASURES Because the ASARCO smelter is responsible for the majority of SO2 emissions in the Hayden area, the following attainment demonstration control measures relate specifically to ASARCO smelting operations. Applicable controls for other point sources in the Hayden nonattainment area are discussed in Chapter 4.0. 6.1 Background 43

Smelting operations began at Hayden in 1912. The original facility employed twelve multiplehearth roasters and two reverberatory furnaces to process copper sulfide ore. Today the Hayden primary copper smelter utilizes an oxygen flash smelting process as well as converters and anode furnaces to produce anode copper . An oxygen plant produces oxygen for the furnace and a sulfuric acid plant recovers the sulfur dioxide produced during smelting. A water treatment plant recovers process water from both the acid plant and flash furnace gas cleaning systems for reuse. The facility has a processing capacity of more than 720,000 tons of copper concentrate per year and meets all federal and state emissions regulations. Concentrate Receiving and Sampling: The processing of copper sulphide ore begins at the mine sites where, to facilitate transportation to smelters, concentration of the ore is accomplished via crushing, grinding, and a flotation process to separate copper mineral from ore. Concentrates, containing approximately equal parts of copper, iron, and sulfur, are received at the Hayden smelter by truck and rail where they are sampled to determine moisture content and analyzed for determination of metal content. The concentrates are then sent to the Unloading Department for further processing. Concentrate Feed and Preparation: The Hayden smelter Unloading Department prepares feed for the flash furnace. The feed consists of concentrate, flux, and recycled by-products from the smelting process. Flux and byproducts are blended with the concentrate to build a homogenous "mix." A sample of the mix is analyzed for input in a computer simulation to determine smelter performance during smelting of the feed. Corrections to the mix are made as needed to ensure proper metallurgical processing performance of the smelter. Flash Furnace: At the Flash Furnace Department wet feed, consisting of pre-blended concentrates, flux, and byproducts, is screened and sized in preparation for drying. The feed is dried in one of two fluid bed dryer circuits and is reclaimed in one of the two baghouses. Dried feed is introduced into the INCO design flash furnace with 95 percent pure oxygen at one of four burners and are rapidly oxidized in the oxygen rich atmosphere. Dust laden hot gas from the flash furnace, containing approximately 75 percent SO2, is drawn through the furnace uptake into the gas handling system. The off gas is ducted

Calculations used in this section were based on the following: a. US EPA, AP-42, Compilation of Air Pollution Emission Factors, Fifth Edition, August 31, 1998. b. ASARCO Smelter Federal Operating Permit Application, submitted November 1, 1994. c. ASARCO Smelter 1998 Emissions Inventory Survey.

to a saturation tower where large particulates are captured and the gas is cooled. From the saturation tower, the gas is ducted to a Venturi scrubber for further dust removal, through a cooling condenser to remove water vapor, and finally through the furnace fan to the acid plant scrubber for treatment in the acid plant. All dust slurry from the saturation tower runs down one of two 12" launders to a clarifier. The clarifier overflow is re-circulated through the saturation tower while the underflow is stripped of SO2 and sent for processing in the water treatment plant. The remaining products of flash smelting are matte and slag. Molten material produced in the flash process separates into two layers in the furnace, the top layer being iron rich slag and the lower layer being heavier, copper laden matte. Molten copper matte is tapped through covered launders for transfer to the converters. Slag is skimmed off the top of the bath and analyzed for copper content for future recovery. The slag temperature is also taken to assist in optimum furnace operation. Converters: The converter department consists of five Pierce-Smith type converters. Molten matte, containing approximately 58 percent copper, is transferred to the converters from the flash furnace for further oxidation of sulfur and slagging of iron and other metals until the copper reaches a purity of about 99 percent. Blister copper is produced in the converters by injecting air into the liquid matte for further oxidation and removal of sulfur from the copper. Silica is also added in the converting process to separate iron from the copper. The silica combines with iron in the matte to generate slag. The slag is skimmed off leaving nearly pure copper ready for transfer to the anode department. Each converter is equipped with primary and secondary hooding systems. The primary hooding system captures the strong SO2 gas for dust removal prior to treatment at the acid plant. The secondary hooding captures any fugitive gases that escape the primary hood or are emitted when skimming and charging. Gases that are collected by the secondary hooding report to a baghouse for dust removal and exhaust to the atmosphere via the 1000-foot stack. Anodes: The anode department consists of two anode furnaces and a spare furnace used when one of the two is out of service. Each furnace holds about 300 tons of copper from the converters. Once an anode furnace is filled, air is blown through the tuyeres to oxidize the copper. The remaining impurities are trapped in this oxide slag along with copper oxide. The oxide slag is skimmed off and the anode furnace is "poled" by bubbling methane (natural gas) through the copper. The poling stage removes excess oxygen left from the oxidizing stage. It produces anode copper, which is more than 99 percent pure, for casting into anodes. Anode copper is cast on two wheels, each with 16 anode molds. One overhead crane removes the anodes from the anode wheels and places them in banding racks or rack rail cars for transport to an off-site electrolytic refinery. Acid Plant: Exit gas from each converter is ducted to cyclones that remove heavy particulate from the gas streams. There are three cyclones for each converter (total of fifteen). Dust collected in the cyclones is conveyed via screw conveyors to a dust bin for pick-up by front end loader and recycle to the bedding system as smelter feed. Converter gases enter the cyclones at 800 deg F and four percent SO2. The gases then report to the spray chambers for further cooling with water sprays. The flow is split equally between two identical chambers and is at about 400 deg F exiting the spray chambers. All the gas then reports to the Cottrell sections that act as settling chambers. Any dust captured is 44

collected by screw conveyors and sent to the pug mill so airborne particulate is minimized. The next step is the three induced draft (I.D.) fans that pull gases from the converters and send them to the scrubber system. These fans are each powered by a 500 H.P. constant speed electric motor. Outlet dampers provide draft for the converters by matching a set point on the Cottrell inlet header. Converter gas finally enters the scrubbing system where it mixes with furnace gas in the 50 percent scrubber. This is a brick lined vessel with co-current sprays fed from a slurry type pump. The gas stream (converters and furnace) splits when it leaves the unit with half going to two (north and south) secondary scrubbers. These units are similar to the 50 percent scrubber except smaller. The gas stream then enters the gas cooling towers. Gas flows upwards through polypropylene packing against the liquor flow from sprays at the top of the tower. The dew point of the gas stream is lowered which forces water to drop out. This further scrubs the gas and minimizes the water being carried to the contact section of the plant. The liquor is pumped from the bottom of the towers through several plate and frame heat exchangers and back to the top of the towers. The water to cool the liquor is provided by a Marley cooling tower. The gas leaving the gas cooling towers is normally between 85 and 95 deg F. The gas is dust free but totally humidified. Mist precipitators are next which use electrostatic fields to remove contained water droplets. Process gas then reports through a fiberglass duct to the inlet of the drying tower. Treatment of the gas in the contact section consists of several steps listed as follows: a. Drying of the sulfur dioxide (SO2) gas from the gas purification system. b. Conversion of sulfur dioxide gas to sulfur trioxide gas. c. Absorption of the sulfur trioxide (SO3) gas in sulfuric acid. Detailed process flow diagrams are included in this submittal in Appendix C. Prior to 1971, all smelting operations process gasses were emitted into the atmosphere after particulate removal by electrostatic precipitators. The installation of an acid plant in late 1971 added SO2 control for primary converter gas. From sulfur balance data the average emissions were reported to be more than 100,000 tpy. A series of improvements in 1983 included replacement of twelve multiple-hearth roasters and two reverberatory furnaces with an INCO Flash smelting furnace. During the flash furnace conversion, ASARCO also installed a 650 ton per day oxygen plant to enrich the smelting process gases and replaced the existing contact acid plant with a new double-contact acid plant with a production capacity of 2,820 tons of sulfuric acid per day for treatment of all flash furnace and converter primary process gases. Reduction of SO2 emissions for this project was estimated at 63,584 tpy. The double-absorption sulfuric acid plant is the predominant control device for primary process SO2 emissions produced by the flash furnace and converters. The flash furnace provides a steady gas feed to the acid plant, enabling optimal plant performance. The acid plant provides control of process gas SO2 at or below the outlet SO2 concentration limit of 0.065 percent by volume set forth in the federal New Source Performance Standard 40 CFR 60, Part P. The SO2 control performance for the ASARCO acid plant is an outlet emission concentration of 0.015 percent by volume. The acid plant input of SO2 gas is 80,000 ppm with an output of 150 ppm, resulting in a 99.81 percent recovery rate. The annual average process capacity for the acid plant is 666,044 tons of acid per year. The average annual process rate for the smelter is estimated at 88 tons per hour (tph) of new sulfide concentrates. Recent process rates (1999 through 2001) have generally been within 80 percent of capacity. The production throughput of this facility, however, is dependent upon the operational 45

capacity of the sulfuric acid plant to treat SO2 emissions from the flash furnace and the five converters. At the present time, the acid plant has the capacity of processing the emissions from the flash furnace in combination with two out of five converters. An increase in furnace or converter facilities would require a corresponding increase in acid plant capacity. The flash furnace, oxygen plant, acid plant, and other improvements made during the transition from the roasters and reverberatory furnaces to the flash furnace, subsequently reduced the SO2 emissions rate by forty percent. This improvement is demonstrated in Figure 6.1, which illustrates the pre-control and post-control SO2 emission levels. In 1998, ASARCO modified the smelter's existing gas handling system and installed an $18.4 million dollar wet gas handling system. Existing equipment including a settling chamber, quench tower, and electrostatic precipitators were replaced with a saturation tower, Venturi scrubber, cooling condenser and ancillary equipment. This modification allowed flash furnace off gas to be treated at temperatures less than 200E F compared to the previous system's 600E F. As a result, the flash furnace off gas volume was lowered and consequently the grade of SO2. This enabled the acid plant to provide more ventilation to the converters and reduce the SO2 in the secondary hooding gases along with any fugitive emissions escaping the secondary hoods. The average rate of SO2 in the secondary hood gases was approximately 6,000 lb/hr in the period 1994 through 1997. This average has been reduced to approximately 3,000 lbs/hr since implementation of the flash furnace scrubber system, and is the largest component of the reduction in annual SO2 emissions. The improved ventilation to the converters provided by the 1998 scrubber installation has decreased stack emissions and the associated fugitive emissions due to escape from the converter secondary hood system. The secondary hooding system is operated at the same nominal 250,000 scfm flow as prior to the modification, however, the SO2 concentration in the secondary hooding gases has been reduced by half. A computerized process control system sets the system dampers at their maximum effectiveness based on the converter cycle. This system is designed to effectively capture fugitive emissions from the primary ventilation system and vent the gases to the stack. Consequently, emissions that escape the secondary hoods, primarily under roll in and roll out conditions, contain 50 percent less SO2 compared to pre-scrubber operation, resulting in a significant reduction in fugitive SO2 emissions. This improvement is demonstrated in Figure 6.2, which illustrates recent the pre-control and post-control SO2 emission levels. The improvement is also reflected by the reduction in peak 3-hour ambient SO2 concentrations (See Chapter 3). Additional equipment improvements have been made to improve the collection and control of fugitive SO2 emissions. As previously noted, sources of secondary process emissions are hooded to minimize release of fugitive emissions directly to the atmosphere. The captured gases are treated with lime injected into the flue system and then directed to baghouses prior to exhausting to the atmosphere. In 1996 ASARCO installed a $4.2 million dollar secondary hood baghouse. The new equipment improved the control of fugitive emissions and reduced opacity. To further reduce fugitive SO2 emissions, ASARCO repaired converter flues, replaced primary converter hoods and jackets, rebuilt all units in the Cottrell electrostatic precipitator, installed concrete sumps and improved sprays in the gas spray chamber of the acid plant in 1991 at a cost of $915,000.00. In 1999, newly designed primary hood doors were installed on two converters. The new design, incorporating a flexible seal, improved the seal between the door and the primary hood and increased the capture efficiency of the primary hood to minimize escape of emissions to the secondary hood system. Additional doors were installed on the remaining three converters in 2000. After the change, a decrease in future sulfur oxides emissions is estimated at 827.6 tpy, which is approximately a five percent reduction in the total 46

smelter emissions. These changes meet or exceed RACT requirements. The emissions control improvements implemented at the ASARCO smelter are summarized in Table 6.1 below.

Table 6.1 - Implementation of SO2 Process and Control Technology at the Hayden Smelter Year 1971 1972 1973 1974 1975 1976 1978 1980 1983 Installation of N0. 1 Acid Plant. Acid Plant Mist Precipitator Modification. Installation of Reverberatory Vent Fans to improve ventilation. Installation of Acid Coolers (Crane) for improved acid plant performance and Matte Fume Vent to improve the capture of fugitive emissions. Installation of Converter Spray Chamber for particulate removal and Plate Heat Exchanger. Matte Fume Enclosing to improve the capture of fugitive emissions. Installation of Separator - Demister to improve acid plant performance. Installation of Flue Gas Sampling Station. Installation of secondary hooding on the converters to minimize release of fugitive emissions directly to atmosphere. Replacement of multiple-hearth roasters and reverberatory furnaces with an Inco flash smelting furnace and gas handling equipment including slag skimming hoods, matte tapping hoods, and slag return hoods at the flash furnace for improved sulfur recovery. Installation of gas cleaning mist precipitators. 1983/ 1984 1988 1989 1991 Installation of Monsanto acid plant No. 2 for treatment of all primary process gases. Installation of acid plant APV Heat Exchanger to improve gas cleaning performance. Electric slag cleaning vessel with an SO2 control device; a caustic scrubber that controls a portion of the overall SO2. Shutdown of acid plant No.1. Repair of a gas-to-gas heat exchanger leak at the acid plant. Repaired converter flues; replaced primary converter hoods and jackets; rebuilt all units in the Cottrell electrostatic precipitator; installed concrete sumps and improved sprays in the gas spray chamber of the acid plant to reduce fugitive SO2 emissions. 1993 1993 1995 Upgrade of acid plant mist precipitator and acid plant intermediate fan. Modification of flash furnace uptake and replacement of cooling fins on the settling chamber to prevent the generation of fugitive emissions caused by inadequate cooling. Replacement of acid plant heat exchanger and retube of cold heat exchanger. Equipment

Table 6.1 - Implementation of SO2 Process and Control Technology at the Hayden Smelter 1997 1998 Retube of Tail Gas Reheater Heat Exchanger. Installation of wet gas handling system for improved treatment of furnace emissions. Installation of new Hot IP Heat Exchanger; Cold IP Heat Exchanger; SX Distribution in IP Absorbing Tower; Foxboro IA distributive process control system. 1999/ 2000 2000 Redesign of converter primary hood doors. The gaps in the primary hoods at the converter mouths were redesigned and a flexible seal installed to minimize the escape of fugitive emissions to the secondary hooding system. CEM Upgrade (Stack Monitors)

Figure 6.1 - Asarco Smelter SO2 Emissions and Percent Control

250000

100

200000 80

Emissions (tpy)

60 100000

40 50000

0 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000

Year emissions percent control

Figure 6.2 - Asarco Smelter SO2 Emissions

Control (%)

150000

35000

30000

Emissions (Tons/Year)

25000

20000

15000

10000

5000

0 1996 1997 1998 1999 2000 2001

Year Stack Emissions Fugitive Emissions Total Emissions

6.2

Emissions Limitations for ASARCO Hayden Smelter

6.2.1 AAC Rule R18-2-715(F), R18-2-715(G) and R18-2-715.01 - Standards of Performance for Existing Primary Copper Smelters: Site specific requirements; Compliance and Monitoring Measure Description: In 1979, ADEQ promulgated site specific emissions limits at Arizona Code of Rules and Regulations R9-3-515, currently codified at AAC R18-2-715 (See Appendix A). The rule required all existing primary copper smelters to implement control technology sufficient to comply with the 1979 MPR stack limits as well as any fugitive emissions control technology necessary to assure attainment and maintenance of the NAAQS. The following emissions limits were specified for the ASARCO copper smelter at Hayden: 1. Annual average stack emissions, as calculated pursuant to AAC R18-2-715.01(C) through (J) shall not exceed 9,521 lbs/hr. The number of three-hour emissions, as calculated pursuant to AAC R18-2-715.01(C) through (J) shall not exceed the limits as listed in AAC R18-2-715(F). ADEQ's 2002 rule revision incorporated the following voluntary stack limits and added fugitive limits for the ASARCO smelter (See Appendix A for rule revision): 1. Annual average stack emissions, as calculated pursuant to AAC R18-2-715.01(C), shall not exceed 6,882 lbs/hr. The number of three-hour emissions, as calculated pursuant to AAC R18-2-715.01(C), shall not exceed the revised limits listed in AAC R18-2-715(F). 2. Annual average fugitive emissions, as calculated under AAC R18-2-715.01(T), shall not exceed 295 lbs/hr. Estimated SO2 Emission Reduction: 49

Emissions were reduced 63,584 tpy following compliance with the 1979 rule (due to installation of flash furnace). Subsequent implementation of additional emissions collection and control measures enabled the 2002 revision that provides a further reduction in allowable emissions of 11,559 tpy for stack sources. Responsible Agency and Authority for Implementation: ADEQ is the responsible agency with authority designated by ARS �49-104(A)(11) and ARS �49-422. Implementation Schedule: The 1979 rule provided a compliance date of January 14, 1986, unless otherwise provided in a consent decree or a delayed compliance order. The compliance date for the 2002 rule revision is the effective date of the rule. Level of Personnel and Funding Allocated for Implementation: No additional personnel are required; implementation funding for ADEQ personnel is underwritten through emission and inspection fees. The approximate cost to the smelter is $123,000 per annum for operation and maintenance of the ambient air analyzers. Expenditures for emissions collection and control improvements at the smelter are noted below. Enforcement Program: ADEQ is responsible for tracking the progress made through the implementation of this measure and for enforcing all applicable regulations through the schedule of inspections and the development of compliance and enforcement actions. (See Section 7.3 for a description of inspection and compliance and enforcement procedures.) Measure Monitoring Program: ASARCO submitted a proposed compliance schedule in 1982, for achievement of the 1979 MPR stack emission limits as expeditiously as practicable. The smelter subsequently submitted a permit application in 1983 (permit #0308-85) for installation of $123 million worth of emissions collection and control improvements. All on-site construction and installation of emission control equipment and process modification was completed by 1984, meeting the compliance date of January 14, 1986. The collection and control technology implemented by ASARCO including installation of the wet gas handling system in 1998 has allowed the facility to reduce emissions sufficient to demonstrate attainment and to accept additional emissions reductions in 2002 (See Section 6.2 for a description of the implemented equipment). For purposes of determining compliance with the emissions limits as codified in 1979, ASARCO was required to install, calibrate, maintain, and operate a measurement system for continuously monitoring SO2 concentrations and stack gas volumetric flow rates in each stack that could emit five percent or more of the allowable annual average SO2 emissions from the smelter. Demonstrations of stack gas volumetric flow rate and SO2 concentration measurement systems required by subsections AAC R18-2-715.01 (K)(5)(a) and (b) were initiated in 1983. The location of all stack sampling points were approved by ADEQ prior to installation and operation of the continuous emission monitoring systems (CEMS). In response to a Consent Decree (CIV 81-110 GLO ACM, dated June 22, 1981), ASARCO installed and operated a continuous emissions monitoring system. ASARCO operates CEMS at the outlets of number 2 acid plant, the furnace vent gas flue, and the converter secondary hood flue. In addition to primary process gas, captured fugitive emissions including those captured by the secondary hooding system are continuously monitored for SO2 concentrations and stack gas volumetric flow rates, and are included when determining compliance with the cumulative occurrence and emissions limits contained in R18-2-715(F)(1). Monitoring and emissions data submitted by ASARCO indicated that the smelter was in compliance 50

with the 1979 emission limits by 1984. Provisions for minimum performance and operating specifications for CEMS at this facility are contained in AAC R18-2-715.01(K)(5). Additional requirements for emission monitoring of the sulfuric acid plant are contained in AAC R18-2-313, Existing Source Emissions Monitoring. The ASARCO smelter stack and fugitive continuous emissions monitoring system is subject to the manufacturer's recommended zero adjustment and calibration procedures at least once per 24-hour operating period and meets all applicable performance specification and quality assurance procedures contained in 40 CFR 60, Appendix B and F. Daily calibration and quarterly audits conducted by ASARCO are reported to ADEQ. To ensure continued compliance, ASARCO maintains on hand and has ready for immediate installation sufficient spare parts or duplicate systems for the continuous monitoring equipment to allow for the replacement within six hours of any monitoring equipment part which fails or malfunctions during operation. As required by AAC R18-2-715.01 (L), ASARCO measures at least 95 percent of the hours during which emissions occurred in any month and has not failed to measure any twelve consecutive hours of emissions. ASARCO maintains records of all average hourly emissions measurements for at least five years following the date of measurement as required by 40 CFR 60 Subpart P - Standards of Performance for Primary Copper Smelters. All of the following measurement results are expressed as pounds per hour of SO2, summarized monthly, and submitted to ADEQ within 20 days after the end of each month: 1. The annual average of the month; 2. The total number of hourly periods during the month in which measurements are not taken and the reason for loss of measurement for each period; 3. The number of three-hour emissions averages which exceeded each of the applicable emissions levels listed in AAC R18-2-715(F) (and AAC R18-2-715(G)) subsequent to the 2002 revision) for the compliance periods ending on each day of the month being reported; 4. The date on which a cumulative occurrence limit listed in R18-715(F) (and R18-2715(G) subsequent to the 2002 revision) was exceeded if such exceedance occurred during the month being reported. These submitted reports have shown continued compliance with all applicable regulations and averaging standards. ADEQ has not issued any notices of compliance actions for a monitoring violation to this facility. As a means of determining total overall emissions, ASARCO performs a monthly material balance for sulfur and includes the results in the monthly compliance reports to ADEQ. Based on these reports, the smelter documents a sulfur recovery rate over 95 percent. In addition to monthly compliance reports, ADEQ also receives from ASARCO quarterly audit, upset, and excess emissions reports, as well as annual emissions inventory reports based in part on the SO2 CEMS data. The rule also specifies requirements regarding bypass operations. At each point in the smelter facility where a means exists to bypass the sulfur removal equipment, the bypass is instrumented to detect and record all periods that the bypass is in operation. The facility's emergency ventilation damper has been used during periods when the plant is shut down for repairs or in emergencies. All production activities at the smelter cease during use of the emergency ventilation damper. ASARCO reports the required information to ADEQ, not later than the 15th day of each month, and includes an explanation for the necessity of the use of the emergency damper.

6.2.2 AAC Rule R18-2-715.02 Standards of Performance for Existing Primary Copper Smelters; Fugitive Emissions Measure Description: This measure provides for an evaluation of the ambient impact of fugitive emissions from the Hayden smelter. The regulation requires a measurement or accurate estimate of fugitive SO2 emissions to determine whether these emissions have the potential to contribute to violations of the ambient SO2 standards in the vicinity of the smelter. The rule also requires the adoption of rules specifying emission limits or other appropriate measures necessary to maintain the standards. Estimated SO2 Emission Reduction: A reduction of 828 tpy is estimated due to implementation of fugitive emissions collection and control measures. Responsible Agency and Authority for Implementation: ADEQ is the responsible agency with authority designated by ARS �49-104(A)(11) and ARS �49422. Implementation Schedule: The rule provides a compliance date of January 14, 1986. Level of Personnel and Funding Allocated for Implementation: No additional personnel is required; implementation funding for the fugitive emission evaluation study was provided by ASARCO. The approximate cost of the SO2 fugitive emission evaluation study was one million dollars. Enforcement Program: ADEQ is responsible for tracking the progress made through the implementation of this measure and for enforcing this measure through the schedule of inspections and the development of compliance and enforcement actions (See Section 7.3 for a description of inspection and compliance enforcement procedures). Measure Monitoring Program: Fugitive SO2 emissions at the ASARCO smelter are primarily generated from the flash furnace, converter, and anode process areas. Emissions escape the ventilation systems and exit the buildings through roof vents. These structures mounted on the roofs of the building provide an escape route for uncaptured emissions. A portion of the SO2 emissions may escape through other exit points, such as open walls and doors in the building. These alternate exit points were identified by ASARCO through flow visualization tests and survey sampling. The following study and other data gathered demonstrated that the majority of the SO2 fugitive emissions escape from the furnace and the converter processes and identify the converter area as the primary source of uncaptured emissions at the smelter. On April 11, 1996, ASARCO submitted to the Arizona Department of Environmental Quality a fugitive SO2 emissions description, evaluation, and ambient impact study, to fulfill the outstanding SIP commitments for analysis of fugitive emissions. The study was conducted from September 6, 1994, through March 22, 1995, and utilized meteorological data collected to characterize fugitive SO2 emission dispersion conditions and measured emissions to evaluate the impact of fugitive emissions in the Hayden area. The study concluded that fugitive SO2 emissions from the converter and furnace buildings represent nearly 99 percent of the fugitive SO2 emissions from the smelter and identified converter operations as the major source of fugitive emissions. The furnace building emitted 288 lbs/hr or thirty-five percent and the converter building emitted 525 lbs/hr or 64 percent. The studies concluded that fugitive emissions will neither cause nor significantly contribute to a violation of the NAAQS. Summaries of the fugitive emissions studies are contained in Appendix C. 52

Measures to improve collection and control of fugitive emissions together with control of primary process gasses have reduced total emissions to a level protective of the NAAQS in the Hayden area (See Section 6.2 for a description of implemented equipment). Captured fugitive emissions currently comprise more than 85 percent of total facility emissions and are included when determining compliance with the stack limits described in Section 6.3.1. 6.2.3 ASARCO Permit Conditions Reasonably Available Control Technology (RACT) for sources located in SO2 nonattainment areas is defined as "that control technology necessary to achieve the NAAQS and is determined by the technological and economic feasibility of the control."44 Submittal of biennial compliance certifications under AAC R18-2-309(2)(a) are required to demonstrate the compliance status of the source with all applicable permit conditions. Controls implemented by ASARCO to reduce smelter emissions and comply with emissions limit regulations are included in the following permits outlined in Table 6.2, found on the following page. All listed controls have been captured in the facility's Title V permit. Additionally, ASARCO submitted a standard Title V permit application form to ADEQ on November 2, 1994. The application for the ASARCO smelter including the Inco oxygen flash furnace, Pierce-Smith converters, anode furnaces, concentrate dryers, double absorption acid plants, oxygen plant, gas cleaning plant including electrostatic precipitators, filter plant, revert crushing plant and associated equipment has been processed and the final permit was issued on October 9, 2001. Table 6.2 - Permit Conditions Date

September 10, 1984 April 4, 1989 October 9, 2001

Permit #

0308-85 1215 1000042

Controls

Retrofit to install Inco Flash Furnace, oxygen plant, and double contact acid plant to treat process gases. Installation of electric slag cleaning vessel. Requires maintenance and operation of all collection, process, and control equipment in a manner consistent with good air pollution control practice. Continued operation of CEMS is required to monitor and record SO2 discharge emissions rates from the smelting facility. Continued operation, maintenance, and calibration of all current ASARCO ambient SO2 monitors are also required.

7.0

MAINTENANCE PLAN

Section 107 (d) (3) of the amended CAA requires that nonattainment areas must have a fullyapproved maintenance plan meeting the requirements of Section 175 (A) before they can be

US EPA Office of Air and Radiation, Office of Air Quality Planning and Standards, "SO2 Guideline Document," February 1994.

redesignated to attainment. Section 175 (A) requires submittal of a SIP revision that provides for the maintenance of the NAAQS for at least 10 years after the redesignation to attainment. The required components of the maintenance plan include: 1. A demonstration that future emissions of SO2 will not cause a violation of the SO2 NAAQS, 2. A commitment to continue to operate an appropriate air quality monitoring network to verify the attainment status of the area, 3. Assurance that the state has the legal authority necessary to implement and enforce all necessary measures used to attain and maintain the NAAQS, 4. An indication of how the state will track the progress of the maintenance plan, and 5. A contingency plan that contains measures to promptly correct any violation of the NAAQS that occurs after redesignation. This submittal demonstrates that all of the above required elements have been met. ADEQ also commits to a SIP revision subsequent to this submittal providing for maintenance of the NAAQS for an additional ten years. This subsequent revision is due eight years into the first ten year maintenance period. 7.1 Maintenance Demonstration

Copper smelting operations at the ASARCO facility are the single greatest source of SO2 emissions in the Hayden nonattainment area comprising more than 99 percent of total emissions in the area. The conservative emissions limits that have been established for the smelter are based on actual emissions for July 1999 through June 2001 of smelter operations showing attainment of the SO2 NAAQS (See Chapter 4). Once the area is redesignated,

Description

Rating
TITLE	Hayden sulfur dioxide nonattainment area state implementation and maintenance plan: final
CREATOR	Arizona. Dept. of Environmental Quality. Air Quality Division.
SUBJECT	Pollutants--Arizona--Hayden; Air pollution--Arizona--Hayden;
Browse Topic	Land and resources
DESCRIPTION	65 pages (PDF version). File size: 775.296 KB.
Language	English
Publisher	Arizona. Dept. of Environmental Quality. Air Quality Division.
TYPE	Text
Material Collection	State Documents
Acquisition Note	Publication or link to publication sent to reports@lib.az.us
RIGHTS MANAGEMENT	Copyright to this resource is held by the creating agency and is provided here for educational purposes only. It may not be downloaded, reproduced or distributed in any format without written permission of the creating agency. Any attempt to circumvent the access controls placed on this file is a violation of United States and international copyright laws, and is subject to criminal prosecution.
Time Period	2000s (2000-2009)
ORIGINAL FORMAT	Born Digital
Source Identifier	ENQ 4.2:H 19
Location	155196248
DIGITAL IDENTIFIER	haydensip.pdf
DIGITAL FORMAT	PDF (Portable Document Format)
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Full Text	FINAL HAYDEN SULFUR DIOXIDE NONATTAINMENT AREA STATE IMPLEMENTATION AND MAINTENANCE PLAN AIR QUALITY DIVISION ARIZONA DEPARTMENT OF ENVIRONMENTAL QUALITY June 2002 TABLE OF CONTENTS 1.0 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Executive Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Regulatory Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.3 Physical, Demographic, and Economic Description of the Hayden Area . . . . . . . 6 1.3.1 Climate and Physiography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.3.2 Population . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.3.3 Economy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 1.4 General SIP Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 1.4.1 CAA Section 172(c), Nonattainment Plan Provisions . . . . . . . . . . . . . . 10 1.4.2 CAA Section 175(A) - Maintenance Plans . . . . . . . . . . . . . . . . . . . . . . . 14 1.4.3 CAA Section 191 and 192 - Plan Submission and Attainment Dates . . 14 1.4.4 Conformity Provisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 COMPLIANCE WITH OTHER FEDERAL REGULATIONS . . . . . . . . . . . . . . . . . . . 16 SO2 MONITORING NETWORK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.1 Current Sampler Type and Siting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.2 Ambient Data Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 SO2 EMISSIONS INVENTORY FOR POINT, AREA AND MOBILE SOURCES . . . 28 4.1 SO2 Point Sources within the Hayden Nonattainment Area . . . . . . . . . . . . . . . . 28 4.1.1 ASARCO Hayden Smelter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 4.2 Major Point Sources within the 50 km Buffer Area . . . . . . . . . . . . . . . . . . . . . . 30 4.2.1 Arizona Public Service (APS) - Red Rock . . . . . . . . . . . . . . . . . . . . . . . 30 4.2.2 BHP Copper San Manuel Smelter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 4.2.3 Phelps-Dodge Miami Smelting Operations . . . . . . . . . . . . . . . . . . . . . . 31 4.3 Area and Mobile Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 4.4 Emissions Projections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 4.4.1 Point Source Projections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 4.4.2 Area, Mobile, and Total Source Projections . . . . . . . . . . . . . . . . . . . . . . 33 MODELING DEMONSTRATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 5.1 Derivation of New Emissions Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 5.1.1 Stack Emissions Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 5.1.2 Fugitive Emissions Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 5.1.3 Total Stack and Fugitive Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 5.2 Smelter Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 5.2.1 Good Engineering Practice Stack Height . . . . . . . . . . . . . . . . . . . . . . . . 43 2.0 3.0 4.0 5.0 6.0 CONTROL MEASURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 6.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 ii 6.2 Emissions Limitations for ASARCO Hayden Smelter . . . . . . . . . . . . . . . . . . . . 50 6.2.1 AAC Rule R18-2-715(F), R18-2-715(G) and R18-2-715.01 - Standards of Performance for Existing Primary Copper Smelters: Site specific requirements; Compliance and Monitoring . . . . . . . . . . . . . . . . . . . . . . . 50 6.2.2 AAC Rule R18-2-715.02 Standards of Performance for Existing Primary Copper Smelters; Fugitive Emissions . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 6.2.3 ASARCO Permit Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 7.0 MAINTENANCE PLAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 7.1 Maintenance Demonstration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 7.2 Ambient Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 7.3 Verification of Continued Attainment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 7.4 Contingency Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 7.4.1 Notification Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 7.4.2 First Action Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 7.4.2(a) Analysis of Gas Handling Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . 59 7.4.3 Second Action Level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 7.4.4 Special Measure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 8.0 iii LIST OF FIGURES Figure 1.1 Figure 3.1 Figure 3.2 Figure 4.1 Figure 5.1 Figure 6.1 Figure 6.2 Figure 7.1 Hayden SO2 Nonattainment Area Hayden SO2 Nonattainment Area Monitor Locations Hayden SO2 Nonattainment Area Magnification of Monitor Locations Hayden SO2 Nonattainment Area 50 Kilometer Buffer Comparison of 1979 and 2002 MPR Limits Hayden Smelter SO2 Emissions and Percent Control 1972-2001 Hayden Smelter SO2 Emissions 1996-2001 Hayden Nonattainment Area SO2 Emissions Projections LIST OF TABLES Table 1.1 Table 1.2 Table 1.3 Table 1.4 Table 1.5 Table 1.6 Table 3.1 Table 3.2 Table 3.3 Table 4.1 Table 4.2 Table 4.3 Table 4.4 Table 4.5 Table 4.6 Table 5.1 Table 5.2 Table 5.3 Table 6.1 Table 6.2 Current Study Area Definition Decennial Census Population of Hayden area and Gila and Pinal County: 1970-2000 Population Projections for Hayden area and Gila and Pinal County: 2000-2015 Economic Activity in Pinal County by Number of Employees: 1994, 1997, 2000 Economic Activity in Gila County by Number of Employees: 1994, 1997, 2000 Civilian Labor Force Data for Hayden Nonattainment Area Ambient Monitoring Network Current Monitoring Network SO2 Ambient Air Quality Monitoring Data SO2 Emissions for Hayden Nonattainment Area - Point Sources SO2 Emissions within 50km of the Hayden Nonattainment Area - Point Sources SO2 Emissions for Hayden Nonattainment Area - All Sources SO2 Emissions Projections for Hayden Nonattainment Area - Point Sources SO2 Projected Emissions within 50km of the Hayden Nonattainment Area - Point Sources SO2 Emissions Projections for Hayden Nonattainment Area - All Sources Hayden Smelter 3-hour MPR Stack Emissions Curve Based on Attainment Period Hayden Smelter MPR Stack Emissions Limits Hayden Smelter Configuration 1976 to Present Implementation of SO2 Process and Control Technology Permit Conditions iv 1.0 1.1 INTRODUCTION Executive Summary This document includes an attainment demonstration and formal request to the United States Environmental Protection Agency (EPA) to redesignate the Hayden, Arizona Sulfur Dioxide (SO2) Nonattainment Area to attainment for the health-based 24-hour average and annual average SO2 National Ambient Air Quality Standards (NAAQS). It summarizes the progress of the area in attaining the SO2 standards, demonstrates that all Clean Air Act (CAA) requirements for attainment have been adopted, and includes a maintenance plan to assure continued attainment after redesignation. The air quality record included in Chapter 2 of this document shows that ambient air quality monitors located in the Hayden nonattainment area have recorded no violations of the primary or secondary SO2 NAAQS since 1989. This meets the EPA requirement to demonstrate eight consecutive quarters of ambient air quality measurements below the SO2 NAAQS. This document also demonstrates that the emission reduction control measures responsible for the air quality improvement are both permanent and enforceable. Based on state point source and EPA National Emissions Trends (NET) mobile and area source emissions inventories, the primary source of SO2 in the nonattainment area is the copper smelter located near Hayden, Arizona. The 2000 base-year Hayden nonattainment area emissions inventory, presented in Chapter 4, lists the sources in the nonattainment area and their SO2 emissions. Chapter 5 contains a modeling demonstration, and Chapter 6 describes the primary control measures implemented to achieve attainment. These measures include implementation of reasonably available control measures (RACM) to reduce emissions from the smelter near Hayden. Chapter 7 describes in detail measures designed to ensure continued maintenance of the SO2 NAAQS for at least 10 years after redesignation of the area to attainment. The clean air quality record, enforceable control measures, and projections of future emissions presented in this document, all demonstrate that the area has attained and will continue to maintain the SO2 air quality standards. With this submittal, ADEQ requests that EPA approve this attainment demonstration and maintenance plan for the Hayden SO2 nonattainment area and redesignate the area to attainment for the 24-hour and annual NAAQS. 1.2 Regulatory Background The federal air quality standards for SO2 were established to identify maximum ambient concentrations above which adverse effects on human health and welfare may occur. Accordingly, the SO2 standards are divided into two types: primary and secondary. The primary standards are based on the protection of public health and the secondary standard is based on protection of the environment, including protection against damage to animals, vegetation, buildings, and decreased visibility. The original national primary and secondary NAAQS for SO2 were codified in Volume 42 of the Code of Federal Regulations, Part 410 (42 CFR 410) on April 30, 1971, (36 FR 81875) and recodified to 40 CFR 50.4 and 50.5 on November 25, 1971 (36 FR 22384). On May 22, 1996, the 1 EPA promulgated the current primary and secondary NAAQS for SO2 (61 FR 25566) as follows:1 Standard 2 Primary Secondary Annual 0.030 ppm (80 Fg/m3) 24-hour 0.14 ppm (365 Fg/m3) 0.5 ppm (1300 Fg/m3) 3-hour Areas that do not meet the NAAQS may be designated nonattainment for the respective standard. The Hayden SO2 nonattainment area comprises nine townships in southern Gila County and northeastern Pinal County. In addition, six adjacent townships are designated as unclassified (See Figure 1.1 for location map). The current boundaries of the nonattainment and unclassified areas are codified at 40 CFR 81.303 and are defined by the complete townships on the following pages. Table 1.1 - Study Area Definition Hayden Area Description T4S, R14E T4S, R15E T4S, R16E T5S, R14E T5S, R15E T5S, R16E T6S, R14E T6S, R15E T6S, R16E T4S, R13E T4S, R17E T5S, R13E T5S, R17E Does Not Meet Primary Standards X X X X X X X X X X X X X Cannot Be Classified Several technical changes were made at this time including stating the standards in parts per million (ppm) to make the SO2 NAAQS consistent with those for other pollutants. The former standards, stated in micrograms per cubic meter (ug/m3), are in parentheses. Violations of the primary and secondary standards are determined as follows. The annual arithmetic mean of measured hourly ambient SO2 concentrations must not exceed the level of the annual standard in a calendar year. The 24-hour and 3-hour averages of measured concentrations must not exceed the level of the respective standard more than once per calendar year. 2 1 2 Table 1.1 - Study Area Definition Hayden Area Description T6S, R13E T6S, R17E Does Not Meet Primary Standards Cannot Be Classified X X 3 4 The relationship of major SO2 point sources and ambient air quality is relatively well-defined. Emissions inventories demonstrate that the smelter, owned and operated by ASARCO, comprises 99 percent of total SO2 emissions in the nonattainment area (See Chapter 4). The primary copper smelter is located near the town of Hayden, Gila County, Arizona; at latitude 33E 00' 29" N and longitude 110E 47' 17" W, at an elevation of 2,050 feet above mean sea level (See Figure 1.1). As required by the Clean Air Act (CAA), Arizona submitted a State Implementation Plan (SIP) for all major sources in the state in 1972. The portion of the SIP pertaining to attainment and maintenance of the NAAQS for SO2 did not sufficiently define emissions limitations or require permanent control of emissions for existing copper smelters and was, therefore, disapproved on July 27, 1972 (37 FR 15081). On the same date, EPA proposed revised regulations for control of sulfur oxides emitted by all existing smelters in Arizona (37 FR 15096). These regulations were never finalized due to issues regarding the adequacy of the air quality data used to develop the limits. EPA subsequently established an SO2 monitoring network around each smelter (June 1973 - October 1974) to gather air quality data upon which to base emissions limitations. EPA and State efforts to develop comprehensive emissions limits continued through the 1970s. In 1977, the State developed rules for the use of Supplementary Control Systems (SCS), whereby, based on ambient monitoring data, the smelters could intermittently curtail emissions to meet the SO2 NAAQS. EPA disapproved this approach and required installation of continuous SO2 emissions controls adequate to meet the NAAQS. Consequently, on January 4, 1978, EPA published final emissions limits for the Arizona smelters based on the 1973-1974 air quality data and the use of a proportional rollback model (43 FR 755). These regulations specified an emission rate and compliance test methods for each smelter. The 1977 Clean Air Act Amendments, however, modified smelter control requirements to allow the temporary use of SCS while ultimate SO2 emission limits were developed and also allowed certain smelters additional time for continuous emissions control technology to be installed. In response to this action, Arizona began development of new regulations and on September 20, 1979, submitted Multi-point Rollback (MPR) rules as a proposed revision to the Arizona SIP.3 The use of MPR to establish stack emissions limits in the rules addressed the problem of inherently variable SO2 emissions from smelting operations by correlating the frequency of emissions at various levels with the probability of violating the ambient standards. This technique, "rolled back" a yearly emission profile to a level protective of the standards. The new regulations also set requirements for analyzing the impact of smelter SO2 fugitive emissions on ambient air quality and the implementation of any necessary fugitive controls. The Hayden area was subsequently classified by operation of law as nonattainment for the primary SO2 standards by EPA following the enactment of the 1990 Clean Air Act Amendments. The nonattainment designation became effective on November 15, 1990. The MPR rules, which established stack emission limits for the smelters, were approved by EPA on January 14, 1983 (48 FR 1717). Following EPA's approval of the rule (and a prior consent decree between EPA, ADEQ and ASARCO (#CIV 81-110-GLO-ACM, dated June 22, 1981)), ASARCO began implementation of improved control technology. The improvements included replacement of 12 multiple-hearth roasters and 2 reverberatory furnaces with a new INCO flash smelting furnace, installation of a 650 ton per day oxygen plant to enrich process gases, and a new double-contact acid plant for treatment of process gas SO2. These controls significantly reduced Arizona Code of Rules and Regulations (ACRR): Rule (R)9-3-515 (recodified as Arizona Administrative Code (AAC) R18-2-715, Standards of Performance for Existing Primary Copper Smelters; Site-specific Requirements) 3 5 emissions and allowed the smelter to come into compliance with the emissions limits in the MPR rules. The Hayden smelter came into full compliance with the MPR regulations in 1984. On April 11, 1996, ASARCO submitted to the Arizona Department of Environmental Quality the results of an SO2 fugitive emissions study to fulfill outstanding SIP commitments for analysis of fugitive emissions. Subsequently, in 2001/2002 ASARCO conducted a further ambient impact analysis of maximum actual emissions (including both stack and fugitive) in relation to resulting ambient concentrations. Based on this analysis, a 2002 rulemaking is in the final stages. The revisions to AAC R18-2-715 and R18-2-715.01 include stack emissions limits and fugitive emission limits (See Appendix A). The new limits provide a considerable margin of safety to ensure protection of the SO2 NAAQS throughout the maintenance period to 2015, thus allowing the state to request the area be redesignated to attainment for SO2. 1.3 1.3.1 Physical, Demographic, and Economic Description of the Hayden Area Climate and Physiography Both desert terrain and mountain ranges are found across the southern Gila County and eastern Pinal County landscape. Elevations range from near 1,800 to more than 4,400 feet above sea level in the nonattainment area with the town of Hayden situated at an elevation near 2,050 feet. This unique environment experiences both warm desert and cool alpine climates. In Hayden, the hottest month of the year is July, when the average daily maximum temperature is near 98o Fahrenheit (F). January is the coolest month with an average daily minimum temperature of 38o F. Precipitation generally occurs in two seasons. The wettest month in Hayden is August when monsoonal thunderstorms produce an average monthly total of 2.31" (inches) of rain. Pacific winter storms moving across the area in December produce an average of 1.28" monthly precipitation in the form of rain or snow. The driest month is June, with an average of 0.25" of rain. The average yearly precipitation is 12.50". 1.3.2 Population Hayden is located in the southern part of Gila County on state highway 177, 35 miles south of Globe, the county seat, and 30 miles southeast of Superior.4 Since most of the nonattainment area is geographically located in Pinal County, population data for Pinal County are included. Decennial census data for Hayden, Winkelman, Kearny, Dudleyville CDP, Gila County, and Pinal County are shown in Table 1.2.5 During the 1970s when rural counties outpaced the growth of urban counties in the U.S., Gila and Pinal Counties grew by 26.7 percent and 32.6 percent, respectively. Although Gila County's population growth slowed during the 1980s, its rate of growth was 27.7 percent during the 1990s. Pinal County's population growth declined only slightly during the 1980s, and during the 1990s, its 54.4 percent growth rate was about double Gila County's growth rate. In contrast to the decennial census population growth of these counties, Hayden, Winkelman, and Kearny lost population between 1970 and 2000. The greatest population declines occurred 4 5 Hayden was founded in 1909 by Hayden, Stove and Company that operated nearby mines. Hayden and Winkelman are located in Gila County. Kearny, and Dudleyville are located in Pinal County. 6 during the 1980s. It appears that the population losses are associated with declining mining sector employment and associated activities, as well as amenities of other geographical locations pulling residents away from these places. Table 1.2 - Decennial Census Population of Hayden, Winkelman, Kearny, Dudleyville CDP, Gila County, and Pinal County: 1970-2000 Y e ar Hayden Hayden's decennial change Winkelman Winkelman's decennial change Gila County Gila County's decennial change Dudleyville CDP6 Dudleyville's decennial change K earny Kearny's decennial change Pinal County Pinal's decennial change Source: U.S. Bureau of the Census, decennial census counts. April 1, 1970 1,283 April 1, 1980 1,205 -6.1% April 1, 1990 909 -24.6% 676 -36.2% 41,216 8.5% April 1, 2000 892 -1.9% 443 -34.5% 51,335 27.7% 1,323 974 1,060 8.8% 29,255 37,080 26.7% 2,829 2,646 -6.5% 2,262 -14.5% 116,397 28.0% 2,249 -0.6% 179,727 54.4% 68,579 90,918 32.6% The DES population projections are the official statistics for the State and differ slightly from the 2000 Census population counts. Table 1.3 portrays the projected growth of Hayden, Winkelman, Kearny, and Dudleyville, as well as Gila County and Pinal County in five-year increments from 2000 to 2015. The population of Hayden is projected to be flat during this time period, compared to Gila County's projected growth rate of 18.5 percent and Pinal County's projected growth rate of 33.8 percent during this 15-year time period. With the exception of Winkelman, the populations of places shown in Tables 1.2 and 1.3 were over projected by ADES while Gila and Pinal Counties were under projected by ADES from the census counts. Dudleyville is a Census Designated Place (CDP). CDPs represent the statistical counterpart of incorporated places. However, no population data are available for Dudleyville for 1970, 1980, or 1990. 6 7 Table 1.3 - Population Projections for Hayden, Winkelman, Kearny, Dudleyville, Gila County, and Pinal County: 2000-2015 Year Hayden Winkelman Gila County K earny Dudleyville CDP Pinal County July 1, 2000 911 419 48,614 2,610 1,970 161,630 July 1, 2005 911 420 51,644 2,762 2,095 181,487 July 1, 2010 912 422 54,603 2,903 2,210 199,715 July 1, 2015 912 423 57,613 3,030 2,313 216,215 Source: Arizona Department of Economic Security, August 1, 1997. 1.3.3 Economy Pinal County was created in 1875 from portions of Maricopa and Pima Counties by the eighth territorial legislature. The county covers 5,371 square miles. The State of Arizona is the county's largest landholder with 35.3 percent of the land area. Individual and corporate ownership accounts for 25.7 percent. Indian reservations cover 20.3 percent; the U.S. Forest Service and Bureau of Land Management hold 17.5 percent; and other public lands comprise the remaining 1.2 percent. Gila County, covering 4,752 square miles, was created in 1881 from portions of Maricopa and Pinal Counties. The U.S. Forest Service is the largest landholder in Gila County accounting for 56 percent of the land area. Indian reservations cover thirty-seven percent; individual and corporate ownership accounts for three percent; the U.S. Bureau of Land Management holds two percent; and the State of Arizona and other public lands comprise the remaining two percent. Tables 1.4 and 1.5 contain employment, expressed as percentages of total non-farm employees, for Pinal and Gila Counties for 1994, 1997, and 2000. These tables also include labor force data, and are included to demonstrate the decline in mining and quarrying activities and the relatively consistent proportions of the other economic activities in the county. The economy of the Hayden area is based almost exclusively on copper mining and smelting, but does include some ranching, government, and tourism. Due to cyclical copper prices, the area's economy is in transition. The Kennecott operation in Hayden, which reduced ores from the nearby Ray Mine, ceased operating in 1982. The ASARCO smelter and Hayden concentrator remain in operation. Despite this, the major category of employment remains the mining and smelting industry. The community is also diversifying its economic base to facilitate tourism and retirement needs. Table 1.6 shows a selected time series of civilian labor force data for Hayden. As noted in Section 1.3.2, minimal population growth is expected between 2000 and 2015 for the Hayden and Winkelman area. During this same time period, however, Kearny's population is projected to grow by about nine percent and Dudleyville CDP's population by seventeen percent. This indicates that additional housing units potentially would need to be constructed for both of these places. Part of the projected population growth could be absorbed by vacant housing units (9.4 percent vacant in Kearny 8 Table 1.4 - Economic Activity in Pinal County 1994, 1997, and 2000 Economic activity Civilian labor force Unemployment Unemployment rate Total employment Non-farm employment Mining and quarrying Construction Manufacturing Transportation, Communication, and Public Utilities (TCPU) T r ade Finance, Insurance, and Real Estate (FIRE) Services and misc. Government 1994 48,950 2,800 5.7% 46,150 36,100 10.8% 3.3% 11.9% 1.9% 19.9% 1.7% 16.1% 33.2% 1997 54,450 2,725 5.0% 51,725 39,775 13.1% 4.5% 7.6% 2.0% 19.0% 2.1% 18.1% 33.2% 2000 59,425 2,475 4.2% 56,950 36,525 3.7% 3.8% 8.6% 2.3% 21.0% 2.3% 20.3% 38.0% Source: Derived from Arizona Department of Economic Security data. Totals may not add to 100 percent. Table 1.5 - Economic Activity in Gila County 1994, 1997, and 2000 Economic activity Civilian labor force Unemployment Unemployment rate Total employment Non-farm employment Mining and quarrying Construction Manufacturing Trans., Communication and Pub. Utilities T r ade Finance, Insurance and Real Estate Services and misc. Government 1994 17,658 1,575 8.6% 16,575 13,100 6.9% 6.1% 12.2% 3.1 % 23.7 % 2.3 % 20.6 % 22.9 % 1997 18,450 1,450 7.9% 17,000 14,350 2.3 % 6.3 % 11.7 % 3.7 % 24.4 % 1.6 % 19.5 % 30.7 % 2000 17,175 1,000 5.8% 16,175 14,225 4.9 % 7.4 % 7.6 % 3.5 % 23.4 % 1.9 % 18.1 % 33.2 % Source: Derived from Arizona Department of Economic Security data. Totals may not add to 100 percent. 9 Table 1.6 - Civilian Labor Force Data for Hayden: Selected Years Year Civilian labor force Number Unemployed Unemployment rate 1990 306 36 11.8% 1998 290 29 10.0% 1999 288 28 9.7% Source: Arizona Department of Commerce, Community Profiles, February, 2001. and 20.6 percent vacant in Dudleyville CDP).7 Most growth, if any, in Hayden and Winkelman could be accommodated by future residents occupying vacant housing units.8 If additional growth does occur as projected, and additional housing units must be constructed in these places, this would generate associated jobs and activities in these local economies. 1.4 General SIP Approach In November 1990, the United States Congress enacted a series of amendments to the Clean Air Act (CAA) intended to improve air quality across the nation. One of the primary goals of this comprehensive revision to the CAA was to expand and clarify the planning provisions for those areas not currently meeting the NAAQS. The CAA as amended identifies specific emission reduction goals, requires both a demonstration of reasonable further progress and attainment, and incorporates more stringent sanctions for failure to attain or to meet interim milestones. CAA, Title I, Part A, and Title I Part D, Subparts 1 and 5 are applicable to this SIP and maintenance plan. Sections 172, 175(A), 191, and 192 set forth the following requirements for SO2 nonattainment areas: 1.4.1 CAA Section 172(c), Nonattainment Plan Provisions 172(c)(1) - In General: implementation of all reasonably available control measures (RACM) as expeditiously as practicable (including such reductions in emissions for existing sources in the area as may be obtained through the adoption, at a minimum, of reasonably available control technology (RACT)) and provide for attainment of the national primary ambient air quality standards. The ASARCO smelter, the primary source of SO2 emissions in the Hayden nonattainment area, succeeded in implementing RACM/RACT at the smelter sufficient to attain the NAAQS for SO2 and went beyond the required technology to increase the facility's efficiency in capturing and treating SO2. RACT for SO2 emission controls for a flash smelting furnace include: The 2000 Census shows Kearny with 873 housing units of which 791 occupied, and Dudleyville CDP with 572 housing units of which 454 are occupied. The number of occupied housing units equals the number of households. Persons per household varies from 2.84 in Kearny to 2.91 in Dudleyville. The 2000 Census shows Hayden with 334 housing units of which 288 are occupied, Winkelman with 194 housing units of which 160 are occupied. The number of occupied housing units equals the number of households. Persons per household varies from 3.1 in Hayden to 2.77 in Winkelman. 8 7 10 1. Dust Collection Equipment (removes dust for better gas treatment), 2. Wet Gas Handling System, 3. Minimization of Leaks, 4. Hooding and venting of gases to the stack, and 5. Contact Sulfuric Acid Plant. Chapter 6 contains further explanation of applicable RACM/RACT for the ASARCO smelting facility and other SO2 point sources in the nonattainment area. 172(c)(2) - Reasonable Further Progress (RFP): plan provisions shall demonstrate reasonable further progress such that annual incremental reductions in emissions ensure attainment of the national ambient air quality standards by the applicable date. This submittal demonstrates that the Hayden nonattainment area has attained and will maintain the SO2 NAAQS with current control measures (See Chapter 6). 172(c)(3) - Inventory: the plan shall include a comprehensive inventory of actual emissions from all sources of relevant pollutant(s). ADEQ maintains a historical and current database of actual emissions from State-permitted point and area sources. The Pinal County Air Quality Control District maintains a similar database of actual emissions from County-permitted sources. All non-permitted source emissions data (i.e.: mobile sources) come from EPA's national emissions inventory.9 Base-year 2000 emissions and projected 2015 emissions are contained in Chapter 4. 172(c)(5) - Permits for New and Modified Major Stationary Sources: the plan shall require permits for the construction and operation of new and modified major stationary sources throughout the nonattainment area. All new sources and modifications to existing sources in Arizona are subject to state requirements for preconstruction review and permitting pursuant to Arizona Administrative Code (AAC), Title 18, Chapter 2, Articles 1 through 5. All new major sources and modifications to existing major sources in Arizona are subject to the New Source Review (NSR) provisions of these rules or Prevention of Significant Deterioration (PSD) for maintenance areas. The State NSR program was conditionally approved by EPA in 1992, and is pending final approval. It should be noted that ADEQ currently has full approval of its Title V permit program. 172(c)(6) - Other Measures: the Plan shall include enforceable emissions limitations and such other control measures, means or techniques, as well as schedule and timetables for compliance, as may be necessary or appropriate to provide for attainment of such standard in such area by the applicable attainment date. AAC R18-2-715 contains the required annual average emission limitations and number of three-hour average emission limits for the ASARCO smelter. AAC R18-715.01 (Standards of Performance for Existing Primary Copper Smelters; Compliance and Monitoring), set forth the compliance date of January 14, 1986, for monitoring, calibration, measurement system performance requirements, record keeping, bypass operation, and issuance of notices of violation.10 Details AIRData provides access to air pollution data for the entire United States and can be found at: http://www.epa.gov/air/data/index.html Standards of Performance for Existing Primary Copper Smelters; Site-specific Requirements, AAC R18-2-515, renumbered AAC R18-2-715 (1993). 10 9 11 regarding emissions limitations and control measures for all SO2 sources in the nonattainment area may be found in Chapter 4. 172(c)(7) - Compliance with Section 110(a)(2): the Plan shall be in compliance with Section 110 (a)(2) (Implementation Plans) of CAA. Section 110(a)(2)(A) of CAA requires that states provide for enforceable emission limitations and other control measures, means, or techniques, as well as schedules for compliance. Chapter 4 includes the list of control measures utilized to bring this area into attainment and future maintenance of the SO2 NAAQS. Section 110(a)(2)(B) of CAA requires that states provide for establishment and operation of appropriate devices, methods, systems, and procedures necessary to monitor, compile, and analyze data on ambient air quality. Under ADEQ's air quality assessment program, ambient monitoring networks for air quality are established to sample pollution in a variety of representative settings, to assess the health and welfare impacts and to assist in determining air pollution sources. The monitoring sites are combined into networks, operated by a number of government agencies and regulated companies. Each network is comprised of one or more monitoring sites, whose data are compared to the NAAQS, as well as statistically analyzed in a variety of ways. The agency or company operating a monitoring network also tracks data recovery, quality control, and quality assurance parameters for the instruments operated at their various sites. The collected data are summarized into the appropriate quarterly or annual averages. The samplers are certified by Federal Reference or Equivalent Methods. Regular checks of the stability, reproducibility, precision, and accuracy of the samplers and laboratory procedures are conducted by either the agency or company network operators. The protocol for SO2 monitoring used by the State, local agencies, and companies was established by EPA in the following sections of the Code of Federal Regulations (CFR): 1. 40 CFR Part 50, Appendix A, Reference Method for the Determination of Sulfur Dioxide in the Atmosphere; 2. 40 CFR Part 53, Subpart B, Procedures for Testing Performance Characteristics of Automated Methods for SO2, CO, O3, and NO2; and 3. 40 CFR Part 58, Subpart A, B, and C, Ambient Air Quality Surveillance. Section 110 (a)(2)(C), Section 110 (a)(2)(E), Section 110 (a)(2)(F), and Section 110 (a)(2)(L) of CAA require states to have permitting, compliance, and source reporting authority. Arizona Revised Statutes (ARS) � 49-402 establishes ADEQ's permitting and enforcement authority. As authorized under ARS 49-402, ADEQ retains adequate funding and employs adequate personnel to administer the air quality program. Appendix A includes organization charts for ADEQ's Air Quality Division. Under ADEQ's air permits program, stationary sources that emit regulated pollutants are required to obtain a permit before constructing, changing, replacing, or operating any equipment or process which may cause air pollution. This includes equipment designed to reduce air pollution. Permits are also required if an existing business that causes air pollution transfers ownership, relocates, or otherwise changes operations. Additionally, ADEQ is responsible for assessing fees based on the actual emissions submitted in the emission inventory for all sources under ADEQ jurisdiction pursuant to AAC R18-2-326. Rule R18-2-327 requires that any source subject to a permit must complete and submit to the Director their responses to an annual emissions inventory questionnaire. A current air pollutant emissions inventory of both permitted and non-permitted sources within the state is necessary to 12 properly evaluate the air quality program effectiveness, as well as determine appropriate emission fees. ADEQ is responsible for the preparation and submittal of an emissions inventory report to EPA for sources and emission points prescribed in 40 CFR 51.322, and for sources that require a permit under ARS �49-426 for criteria pollutants. This inventory encompasses those sources under state jurisdiction emitting 1 ton per year or more of any individual regulated air pollutant, or 2.5 tons per year (tpy) or more of any combination of regulated air pollutants.11 Under ADEQ's air quality compliance program, major sources are inspected annually. ADEQ's Air Compliance Section implements compliance assistance initiatives to address noncompliance issues (i.e., seminars and workshops for the regulated community explaining the general permit requirements, individual inspections of all portable sources within a geographical area, mailings, etc.). In addition, compliance initiatives are developed to address upcoming or future requirements (i.e., new general permits) and include such actions as training for inspectors; development of checklists and other inspection tools for inspectors; public education workshops; targeted inspections; mailings, etc. ADEQ's Air Compliance Section also has an internal performance measure to respond to all complaints as soon as possible, but within a minimum of five working days. Section 110(a)(2)(G) of CAA requires that states provide for authority to establish emergency powers and authority and contingency measures to prevent imminent endangerment. AAC R18-2220 prescribes the procedures the Director of ADEQ shall implement in order to prevent the occurrence of ambient air pollution concentrations which would cause significant harm to the public health. As authorized by ARS �49-426.07, ADEQ may seek injunctive relief upon receipt of evidence that a source or combination of sources is presenting an imminent and substantial endangerment to public health or the environment. 172(c)(8) - Equivalent Techniques: the Plan may use equivalent techniques such as equivalent modeling, emission inventory, and planning procedures allowed by the Administrator, upon application by any state. In 1983, EPA approved Multi-point Rollback modeling to establish emissions limits for the ASARCO Hayden smelter, and the limits were updated in 2002 as part of the current SIP process. Modeling for the fugitive emissions study at this facility was conducted with models from EPA's "Guideline on Air Quality Models." 172(c)(9) - Contingency Measures: the Plan shall provide for the implementation of specific measures to take effect without further action by the state or the Administrator in the event the area fails to make reasonable further progress (RFP) or to attain the primary national ambient air quality standards (NAAQS). As noted in 172(c)(2) above, this submittal includes monitoring data and source permit information that demonstrate that the applicable area has attained, and will maintain, the SO2 NAAQS with control measures currently fully implemented. As such, the RFP requirement is met. 1.4.2 CAA Section 175(A) - Maintenance Plans "Regulated air pollutant" is defined in AAC R18-2-101 as any of the following: (a) Any conventional air pollutant as defined in ARS �49-401.01; (b) Nitrogen oxides and volatile organic compounds; (c) Any air contaminant that is subject to a standard contained in Article 9 of Chapter 2; (d) Any hazardous air pollutant as defined in ARS �49-401.01; (e) Any Class I or II substance listed in Section 602 of the Act. 11 13 175(A)(a) - Plan Revisions: each state which submits a request for redesignation of a nonattainment area shall also submit a revision of the applicable SIP to provide for the maintenance of the NAAQS for at least ten years after the redesignation. As documented in Chapter 7, this submittal shows attainment through 2015. 175(A)(b) - Subsequent Plan Revisions: eight years after redesignation as an attainment area, the State shall submit an additional revision of the applicable SIP for maintaining the NAAQS for 10 years after the expiration of the 10-year period referred to in subsection (a). ADEQ commits to submit an additional SIP revision eight years after redesignation. 175(A)(c) - Nonattainment Requirements Applicable Pending Plan Approval: until such plan revision is approved and an area is redesignated as attainment for any area designated nonattainment, the requirements of this part shall continue in force and effect. ADEQ commits to keeping all applicable measures in place. 175(A)(d) - Contingency Provisions: each plan revision submitted under this section shall contain such contingency provisions to assure that the State will promptly correct any violation of the standard which occurs after the redesignation of the area as an attainment area. Such provisions shall include a requirement that the State will implement all measures with respect to the control of the air pollutant concerned before redesignation. ADEQ commits to implementing all identified measures as necessary (See Chapter 7). 1.4.3 CAA Section 191 and 192 - Plan Submission and Attainment Dates This document fulfills all outstanding implementation plan requirements for the Hayden SO2 nonattainment area. With the submittal of this SIP and Maintenance Plan, ADEQ requests redesignation of the Hayden nonattainment area to attainment. 1.4.4 Conformity Provisions Section 176(c)(1)(A) of CAA requires SIPs to contain information regarding the State's compliance with conformity requirements. As stated in 40 CFR 93.153(a), "Conformity determinations for Federal actions related to transportation plans, programs and projects developed, funded, or approved under title 23 U.S.C. or the Federal Transit Act (40 U.S.C. 1601 et seq.) must meet the procedures and criteria of 40 CFR part 51, subpart T, in lieu of the procedures set for in this subpart." 40 CFR 93.103(b) waives transportation conformity for SO2 nonattainment areas, but general conformity for the Hayden, Gila/Pinal County area must still be addressed to assure SO2 emissions from any Federal actions or plans do not exceed the rates outlined in 40 CFR 93.153(b)(1) for nonattainment areas or 40 CFR 93.153(b)(2) for maintenance areas. Criteria for making determinations and provisions for general conformity as outlined in 40 CFR 93.153 can be located in R18-2-1438 of the Arizona Administrative Code. There are no federal plans or actions affecting air quality currently in the Hayden, Gila/Pinal County area, nor are any foreseen through the year 2015. 14 2.0 COMPLIANCE WITH OTHER FEDERAL REGULATIONS The provisions of 40 CFR 60 Subpart P (��60.160 - 60.166) Standards of Performance for Primary Copper Smelters 12 are applicable to dryer, roaster, smelting furnace, and copper converter equipment in primary copper smelters. Any facility that commences construction or modification after October 16, 1974, is subject to the requirements of this subpart. The Hayden smelter was modified in 1983 when an Inco Flash Furnace, oxygen plant, and #2 acid plant were installed. ADEQ compliance, permit, monitoring, technical, and correspondence files indicate that the facility has complied with all the requirements of this subpart. 12 Source: 41 FR 2338, Jan. 15, 1976, unless otherwise noted. 15 3.0 SO2 MONITORING NETWORK Monitoring began in the Hayden area in 1970 by the State of Arizona.13 ASARCO began continuous ambient SO2 air quality monitoring in the Hayden area in 1974. Since that time, an extensive monitoring network was established with sufficient spatial and temporal coverage to comprehensively evaluate the ambient impact of smelter emissions. More than twenty stationary and mobile monitoring sites were established throughout the area with as many as twelve monitors operating concurrently (See Table 3.1 and Figure 3.1).14 This ambient SO2 network, comprised of EPA, State, and ASARCO monitors, was developed as the result of extensive efforts to identify maximum ambient impact areas using diffusion modeling, monitored atmospheric dispersion parameters, citizen observations, and ambient SO2 monitoring. Table 3.1 - Ambient Monitoring Network Monitor Site Town Garfield Avenue Fire Station J a il Jail (state) Hayden Junction Junction North Montgomery Ranch Montgomery Ranch (state) Globe Hwy. Winkleman Period of Operation 1970-1975, 1978-1979 1980-present 1975-1977, 1979-1981 1982-present 1974, 1976-present 1974-present 1976-1977 1974-present 1974-1984 1978-present 1974-1979 Monitor Site Winkleman School Meadows Kearny Crescent Ranch Kearny Hartford Mobile I Mobile II Mobile III Mobile IV EPA 4th Avenue Period of Operation 1980-1988 1974-1979, 1981-1988 1974-1981 1974-1979 1978 1979-1980 1980 1982 1973-1974 1994-1995 Sulfur Dioxide Monitoring Network Study, Arizona State Department of Health, Environmental Health Services, Division of Air Pollution Control, 1974. Protocols for SO2 monitoring established by EPA are found in 40 CFR Part 50, Appendix A, Reference Method for the Determination of Sulfur Dioxide in the Atmosphere, Part 58, Subpart B, �58.14, Special Purpose Monitors, Subpart C, �58.20, State and Local Air Monitoring Stations, Air Quality Surveillance: Plan Content, and Subpart D, �58.30, National Air Monitoring Stations (NAMS). 14 13 16 17 Installation of additional meteorological instrumentation at the network sites, measuring wind speed and direction, temperature, and humidity parameters helped to further define airflow and pollutant transport in the region. Utilization of mobile monitors allowed evaluation and verification of ambient SO2 concentrations over a greater area. Numerous sites were monitored and subsequently relocated under the direction of state meteorologists when no significant impacts were observed. All monitoring for SO2 was performed with guidance and dispersion modeling analysis from the Arizona Department of Health Services, Bureau of Air Quality Control. The monitoring network was also developed in accordance with Supplementary Control Systems (SCS). Prior to implementation of continuous control technology, SCS utilized analysis of atmospheric conditions and monitored ambient concentrations to vary the rate of smelter emissions to avoid any exceedance of the NAAQS. In 1977, the state adopted rules that codified requirements for concurrent operation of at least eight ambient monitors, including a mobile monitor placed at points representative of observed maximum concentrations. Relocation of a stationary monitor was allowed only when: 1. There were no ambient SO2 violations recorded; 2. No SCS curtailment actions were implemented due to data recorded at that monitor; 3. The foregoing conditions were due to implementation of improved emissions control techniques or other permanent modifications; and 4. A new site was shown to be more representative of the ambient air quality of the area. Historic ambient SO2 monitoring site locations and periods of operation are provided in Table 3.1, and Figure 3.1 and 3.2. Further refinement of the monitoring network was required by the adoption of the MPR rule that established stack emissions limits for the smelter in 1979 based on permanent controls. Placement of additional monitors were established with EPA to further evaluate ambient impacts. Following ASARCO's compliance with emissions limits as defined in AAC R18-2-715(F), and based on continuous control technology, the number of permanent monitors was gradually reduced to the current network of six. These are all high impact ambient monitoring sites found to be representative of air quality for the area. These monitoring site decisions were made by ADEQ and ASARCO, and are in accordance with EPA guidance (See Table 3.2). Current Sampler Type and Siting The five monitoring units operated by ASARCO are Thermo Environmental Instruments (TEI) pulsed fluorescence Model 43 SO2 analyzers. All of these SO2 analyzers are interfaced to ASARCO's data acquisition system. The TEI analyzers measure in the 0-2 ppm range. Redundant recording systems are operated for all of the ASARCO analyzers. The samplers are connected to strip chart recorders for backup and analyzed by planimeter as necessary for validation of recorded concentrations. The ADEQ SO2 analyzer is a Thermo pulse fluorescence analyzer (model 43 C), measuring in the 0-2 ppm range (Figure 3.2 illustrates the current monitor locations and proximity to the Hayden smelter). The ASARCO and ADEQ monitors are operated and maintained in accordance with federal regulations as described in 40 CFR parts 58.13 and 58.22 as well as Appendices A and E of part 58. 3.1 18 19 Table 3.2 - Current Monitoring Network Unit15 Montgomery Ranch16 Jail Jail (State) Hayden Junction Garfield Ave. Globe Hwy. Location 2.50 miles NW from ASARCO 0.57 miles W from ASARCO 0.57 miles W from ASARCO 2.12 miles W from ASARCO 0.56 miles SW from ASARCO 0.61 miles E from ASARCO Elevation (feet above sea level) 2354 2052 2052 1932 2040 1964 Operator ASARCO ASARCO ADEQ ASARCO ASARCO ASARCO 3.2 Ambient Data Analysis A review of the SO2 monitoring data in the Hayden nonattainment area verifies that: 1. There have been no recorded exceedances of the annual NAAQS for SO2 since 1982 and annual averages are generally 53 percent of the NAAQS; 2. There have been no recorded exceedances of the 24-hour NAAQS for SO2 since 1994 and maximum 24-hour average SO2 levels are generally 76 percent of the NAAQS; and, 3. There have been no recorded exceedances of the 3-hour NAAQS for SO2 since 1994 and maximum 3-hour averages are generally below 80 percent of the NAAQS. The nonattainment area has recorded more than eight consecutive quarters of quality assured, violation-free data from July 1999 through June 2001. Data for the current monitoring network is presented in Table 3.3. Table 3.3 - SO2 Ambient Air Quality Monitoring Data (Fg/m3) Year Annual Ave. 24-Hr Max 3-Hr Max Number of Exceedances of the Standard Annual (80 (Fg/m3) 24-hr. (365 Fg/m3) 3-hr. (1300 Fg/m3) Montgomery Ranch 2001 2000 1999 45 41 45 184 210 231 685 799 1013 0 0 0 0 0 0 0 0 0 8710 8767 8761 No. of 1-hr. Samples The Garfield, Jail, Hayden Junction, and Globe Highway monitors are primarily fugitive emissions impact sites. Montgomery Ranch is a mixed stack and fugitive impact site. Ambient sulfur dioxide monitoring at Montgomery Ranch began in 1974. This monitor was the "limiting site" for the original MPR analysis ("Ultimate Sulfur Dioxide Limits for Arizona Copper Smelters" Moyers and Peterson, September 14, 1979). 16 15 20 Table 3.3 - SO2 Ambient Air Quality Monitoring Data (Fg/m3) Year Annual Ave. 24-Hr Max 3-Hr Max Number of Exceedances of the Standard Annual (80 (Fg/m3) 24-hr. (365 Fg/m3) 3-hr. (1300 Fg/m3) Montgomery Ranch con't 1998 1997 1996 1995 1994 1993 1992 1991 1990 1989 1988 1987 1986 1985 1984 1983 1982 1981 1980 1979 1978 1977 1976 1975 1974 41 40 47 52 36 25 41 44 41 55 42 45 34 25 21 44 84 139 93 158 133 180 183 184 262 186 239 286 256 180 143 193 243 187 413 405 301 242 141 245 191 414 498 742 1383 395 772 1058 1576 1442 768 645 1170 950 1096 792 626 831 692 2125 1187 1297 1183 803 688 928 1123 2283 3781 9287 1785 2384 3275 6491 4848 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 Jail 2001 21 152 877 0 0 0 8759 0 0 0 0 0 0 0 0 0 2 1 0 0 0 0 0 2 7 5 9 2 2 2 2 2 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 0 7 9 13 2 2 2 2 2 8325 8199 8442 8407 8649 8756 8726 8721 8704 7764 8560 8586 8505 8564 8640 8592 8367 8651 8602 8648 8718 8724 8443 8204 7593 No. of 1-hr. Samples 21 Table 3.3 - SO2 Ambient Air Quality Monitoring Data (Fg/m3) Year Annual Ave. 24-Hr Max 3-Hr Max Number of Exceedances of the Standard Annual (80 (Fg/m3) 24-hr. (365 Fg/m3) 3-hr. (1300 Fg/m3) Jail con't 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 1989 1988 1987 1986 1985 1984 1983 13 14 13 15 20 21 16 10 15 18 19 21 13 15 15 9 10 31 63 89 110 127 88 96 70 64 71 89 163 223 122 237 117 58 127 270 342 432 647 584 529 393 444 335 402 472 821 979 708 1235 697 346 620 1423 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Jail (State) 2001 2000 1999 1998 1997 1996 1995 1994 24 17 24 29 5 16 18 21 157 72 99 122 152 81 97 453 785 322 475 595 697 527 435 464 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 8407 8106 8015 7457 8456 8618 8531 7444 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 8783 8748 8392 8401 8428 8602 8758 8716 8667 8716 8667 8704 7699 8552 8655 8561 8688 8664 No. of 1-hr. Samples 22 Table 3.3 - SO2 Ambient Air Quality Monitoring Data (Fg/m3) Year Annual Ave. 24-Hr Max 3-Hr Max Number of Exceedances of the Standard Annual (80 (Fg/m3) 24-hr. (365 Fg/m3) 3-hr. (1300 Fg/m3) Jail (State) con't 1993 1992 1991 1990 1989 1988 1987 1986 1985 1984 1983 1982 1981 1980 1979 1978 1977 1976 1975 1974 10 16 16 16 24 24 29 24 19 22 36 57 75 45 71 60 95 113 105 127 84 238 81 199 183 137 422 139 120 177 269 417 382 418 1143 413 619 940 950 1110 372 815 511 1137 697 800 1498 707 750 693 1942 1724 2334 1410 4606 3286 2525 3350 4483 4887 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 Hayden Junction 2001 2000 1999 1998 1997 1996 14 13 13 9 12 9 59 90 69 65 47 52 215 427 404 368 285 374 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 8759 8778 8739 8372 8389 8429 0 0 0 0 0 0 1 0 0 0 0 2 2 1 3 1 2 2 2 2 0 0 0 0 0 0 2 0 0 0 1 5 5 3 10 2 2 2 2 2 8585 8384 8017 8129 8636 8553 8569 8380 8494 8132 8300 8522 8351 7922 8311 7584 8223 8125 7756 7739 No. of 1-hr. Samples 23 Table 3.3 - SO2 Ambient Air Quality Monitoring Data (Fg/m3) Year Annual Ave. 24-Hr Max 3-Hr Max Number of Exceedances of the Standard Annual (80 (Fg/m3) 24-hr. (365 Fg/m3) 3-hr. (1300 Fg/m3) Hayden Junction con't 1995 1994 1993 1992 1991 1990 1989 1988 1987 1986 1985 1984 1983 1982 1981 1980 1979 1978 1977 1976 1975 1974 1973 1972 1971 1970 1969 13 14 6 7 10 9 10 8 14 11 10 5 21 36 40 22 43 37 66 57 58 115 191 254 336 481 377 77 72 68 48 75 50 93 159 153 155 97 70 152 290 322 214 244 215 514 344 360 542 1091 9504 2136 1877 3849 416 457 160 343 455 319 585 509 744 507 320 492 780 1291 1491 1132 1751 1118 3262 1754 2146 2466 6225 9504 7413 6970 N/A 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 2 36 2 2 2 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 2 2 2 2 61 2 2 2 2 8392 8618 8760 8746 8711 8704 7762 8579 8586 8564 8487 8424 8592 8461 8461 8596 8676 8711 8728 8570 8632 7794 7008 7499 2064 4906 5011 No. of 1-hr. Samples 24 Table 3.3 - SO2 Ambient Air Quality Monitoring Data (Fg/m3) Year Annual Ave. 24-Hr Max 3-Hr Max Number of Exceedances of the Standard Annual (80 (Fg/m3) 24-hr. (365 Fg/m3) 3-hr. (1300 Fg/m3) Garfield Avenue 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 1981 1980 29 21 25 20 22 22 23 22 12 28 23 23 45 35 285 284 313 237 283 336 195 268 202 344 342 263 225 214 873 860 583 770 521 796 1125 633 432 866 1071 939 1355 975 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Globe Highway 2001 2000 1999 1998 1997 1996 1995 1994 1993 1992 1991 1990 43 38 35 32 43 52 39 38 29 28 40 37 311 218 209 178 315 226 233 332 148 205 224 292 838 772 735 1284 836 727 1084 1776 551 672 1199 1153 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 8754 8784 8757 8377 8227 8425 8395 8610 8757 8746 8698 8707 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 8760 8784 8753 8395 8427 8452 8464 8617 8758 8764 8733 8742 8615 8322 No. of 1-hr. Samples 25 Table 3.3 - SO2 Ambient Air Quality Monitoring Data (Fg/m3) Year Annual Ave. 24-Hr Max 3-Hr Max Number of Exceedances of the Standard Annual (80 (Fg/m3) 24-hr. (365 Fg/m3) 3-hr. (1300 Fg/m3) Globe Highway, con't 1989 1988 1987 1986 1985 1984 1983 1982 1981 1980 1979 1978 72 36 33 40 40 20 46 73 86 55 113 102 382 345 223 325 283 152 328 332 302 314 349 404 1643 1595 1092 1270 1556 537 1674 1290 1269 1254 1647 1482 0 0 0 0 0 0 0 0 1 0 1 1 1 0 0 0 0 0 0 0 0 0 0 0 4 1 0 0 1 0 1 0 0 0 3 2 7861 8674 8593 8553 8594 8730 8640 8350 8350 8651 8667 8713 No. of 1-hr. Samples 26 4.0 SO2 EMISSIONS INVENTORY FOR POINT, AREA AND MOBILE SOURCES Emissions inventories from all sources in the Hayden nonattainment area indicate that although there are other sources of SO2 emissions, the ASARCO smelter is the primary source for SO2 emissions and comprises more than 99 percent of total SO2emissions in the area. Data shows that no other point, area or mobile sources have contributed or contribute to the same levels of SO2 in the Hayden nonattainment area. Emissions units and rates, and derivation of mobile and area source emissions for the nonattainment area are described in Section 4.1 through Section 4.3 below. 4.1 SO2 Point Sources within the Hayden Nonattainment Area One point source is located within the Hayden nonattainment area. Point source locations are illustrated in Figure 4.1, on the following page. Attainment year inventories for the source is presented in Table 4.1.17 Table 4.1 - Actual SO2 Emissions for Hayden Nonattainment Area - Point Sources Source Name: ASARCO Hayden Smelting Operations1 8 24 Hour Total: Annual Total: 24 Hr. Annual 1999 58 tpd 21,081 tpy 58 tpd 21,081 tpy 2000 47 tpd 15,934 tpy 47 tpd 2001 51 tpd 18,362 tpy 51 tpd 15,934 tpy 18,362 tpy 4.1.1 ASARCO Hayden Smelter Smelting and refining of copper ore at ASARCO's primary copper smelter operations produces anode copper for shipment to facilities in Texas for production of copper cathode as well as the byproduct sulfuric acid for sale to customers. More than 99 percent of all SO2 emissions in the nonattainment area are generated by this facility. Based on 2000 emissions data, the majority of this facility's emissions are from the following stack and fugitive units: main stack core including primary flash furnace and converter process gas; main stack annulus furnace vent gas and converter secondary gases; and fugitive emissions from the flash furnace, converters, anode furnace, and slag dump. The maximum allowable annual average SO2 emission rate for stacks was reduced from 9,521 lbs/hr to 6,882 lbs/hr with recent revisions to AAC R18-2-715(F)(2). The revisions also limited annual average fugitive emissions to 295 lbs/hr. The combined limit for the stack and fugitive emissions units is currently 7,177 lbs/hr (31,435 tpy). Additionally, the permit limits sulfur content and usage rates for fuel used in all fuel burning equipment requiring the use of natural gas and low sulfur fuels. Emissions units and rates for the ASARCO smelter are detailed in Appendix B. Unless otherwise noted, all 24-hour inventories are ton per day (tpd) averages based on the number of operating hours for each respective year. 18 17 24-hour inventories are averages calculated by dividing the annual facility emissions by the number of operating days for each year. 27 4.2 Major Point Sources within the 50 km Buffer Area 28 In addition to the sources located within the nonattainment area, there are several SO2 point sources within 50 kilometers of the Hayden nonattainment area. The emissions from these point sources do not significantly contribute to levels of SO2 in the nonattainment area. Attainment year inventories are provided in Table 4.2.19 Table 4.2 - SO2 Emissions within 50km of the Hayden Nonattainment Area - Major Point Sources Source Name: APS (Red Rock) BHP San Manuel Smelting Operations 2 0 , 2 1 Phelps-Dodge Miami Smelting Operations21 24 Hour Total: Annual Total: 24 Hr. Annual 24 Hr. Annual 24 Hr. Annual 1999 < 1 tpd 8 tpy 30 tpd 3,622 tpy 22 tpd 7,819 tpy < 53 tpd 11,449 tpy 2000 < 2 tpd 153 tpy < 1 tpd <1 tpy 21 tpd 6,810 tpy < 24 tpd 6,964 tpy 2001 < 6 tpd 497 tpy < 1 tpd <1 tpy 27 tpd 9,062 tpy < 34 tpd 9560 tpy 4.2.1 Arizona Public Service (APS) - Red Rock The APS Red Rock electric generating station is located 70 km southwest of the Hayden smelter. The facility operates two steam turbine and two gas turbine units. The source's permit limits SO2 emissions from combustion of fuel in the existing equipment to 15,051 tpy, however, the facility's primary fuel is low sulfur natural gas. This station was formerly a peaking plant providing increased electricity generation during periods of high demand. Commencement of full time operations began in 2000. 4.2.2 BHP Copper San Manuel Smelter The San Manuel primary copper smelter is located approximately 46 kilometers south of the Hayden smelter and separated from the Hayden area by varied terrain that includes the San Pedro river valley and areas of mountainous ridges. When operational, the San Manuel primary copper smelter operations include a flash furnace, converters, and other auxiliary equipment for smelting and refining of copper sulfide ore. The permit limits smelter process and fugitive SO2 emissions to 10,762 tpy. In addition, the permit limits sulfur content and usage rates for fuel used in all fuel burning equipment. The San Manuel area is also a SO2 nonattainment area, and BHP accounts for Unless otherwise noted, all 24-hour inventories are ton per day (tpd) averages based on the number of operating hours for each respective year. 20 21 19 BHP smelting operations have been temporarily suspended since May 1999. 24-hour inventories are averages calculated by dividing the annual facility emissions by the number of operating days for each year. 29 approximately 99 percent of the emissions for that area. Therefore, this smelter is documented in more detail in the San Manuel SO2 State Implementation and Maintenance Plan. ADEQ anticipates submittal of this Plan to EPA in June 2002. 4.2.3 Phelps-Dodge Miami Smelting Operations The Miami primary copper smelter is located 46 kilometers north of the Hayden smelter and is geographically separated from the Hayden area by the 7,000 foot Pinal Mountains. The Miami facility operates an Isasmelt furnace, electric furnace, converters, and other auxiliary equipment for smelting and refining of copper sulfide ore. AAC R18-2-715 limits smelter process and fugitive SO2 emissions to 10,368 tpy. Actual emissions, however, are less than 8,000 tpy. In addition, the permit limits sulfur content and usage rates for fuel used in all fuel burning equipment. The Miami area is also a SO2 nonattainment area, and this smelter is documented in more detail in the Miami SO2 Maintenance and State Implementation Plan. ADEQ anticipates submittal of this Plan to EPA in June 2002. 4.3 Area and Mobile Sources Emissions for the nonattainment area were derived from EPA NET area and mobile source inventories for Pinal and Gila Counties based on the assumption that area and mobile source emissions are proportionate to population levels. The Hayden SO2 nonattainment area population is estimated to be three percent of the Pinal County population, and three percent of the Gila County population based on the aggregate population centers of Kearny and Dudleyville (Pinal County); and Hayden and Winkelman (Gila County). The remainder of the nonattainment area has a very low population density with low traffic levels and minimal commercial or industrial development.22 Data shows that there are no urban areas that might be significant area or mobile sources located within the Hayden nonattainment area as illustrated in Table 4.3. Area and mobile sources combined were less than one percent of the total emissions during the attainment demonstration period. Table 4.3 - SO2 Emissions for the Hayden Nonattainment Area - All Sources Source Type:23 Area and Mobile24 24 Hr. Annual 24 Hr. Annual 1999 < 1 tpd 50 tpy 58 tpd 21,081 tpy < 59 21,131 2000 < 1 tpd 51 tpy 47 tpd 15,934 tpy < 48 15,985 2001 < 1 tpd 51 tpy 51 tpd 18,362 tpy < 52 Point 24 Hour Total: Annual Total: 18,413 4.4 Emissions Projections 22 23 See Section 1.3.2 for a more detailed description of population calculations. Area and mobile source estimates are based on EPA's AIRData for Pinal and Gila Counties. Point source estimates are based on ADEQ annual emissions inventory data. See Appendix B for a more detailed breakdown of area vs. mobile sources. 24 24-hour inventories are averages based on a 365 day distribution of emissions from these sources. 30 Arizona does not anticipate any substantial increase in existing point source emissions between 1999 and 2015 for the nonattainment area. Should any growth occur due to construction of additional SO2 point sources, ADEQ's permit program limits all emissions as part of the construction of new point sources or the upgrading of existing sources. 4.4.1 Point Source Projections Projections for copper smelters are based on growth rates contained in the Western Regional Air Partnership (WRAP), Annex to the Report of the Grand Canyon Visibility Transport Commission, October 16, 2000. This report notes that downward pressure on copper prices resulting from the international competition has resulted in a consolidation of the copper industry in the Southwestern United States. Consequently, no expansion of the industry is expected through 2015. Emissions projection estimates for electric utilities are based on an anticipated industry growth rate of 2.6 percent per year contained in the WRAP report. These estimates are predicated, in part, on existing capacity and future demand for generation.25 Table 4.4 and Table 4.5 present projected emissions for point sources within the nonattainment area and within 50 km of the nonattainment boundary.26 Table 4.4 - SO2 Emissions Projections for the Hayden Nonattainment Area - Point Sources Source Name: ASARCO Hayden Smelting Operations2 7 24 Hour Total: Annual Total: 24 Hr. Annual 1999 58 tpd 2000 47 tpd 2001 51 tpd 2005 65 tpd 2010 65 tpd 2015 65 tpd 21,081 tpy 15,934 tpy 18,362 tpy 23,000 tpy 23,000 tpy 23,000 tpy 58 tpd 47 tpd 51 tpd 65 tpd 65 tpd 65 tpd 21,081 tpy 15,934 tpy 18,362 tpy 23,000 tpy 23,000 tpy 23,000 tpy The WRAP analysis of industry production and projections was used in the smelter and utility projections for this document. The Annex is expected to be approved by EPA at the end of 2002. Unless otherwise noted, all 24-hour inventory projections are calculated based on the average number of operating hours for the period 1999 through 2001. Projected 24-hour inventories are based on the average number of operating days for the period 1999 through 2001 and are assumed to represent typical operating rates for the facility. 27 26 25 31 Table 4.5 - SO2 Projected Emissions within 50km of the Hayden Nonattainment Area Major Point Sources Source Name: Electric Utilities28 24 Hr. Annual 1999 < 1 tpd 8 tpy 30 tpd 3,622 tpy 22 tpd 7,819 tpy < 53 tpd 2000 < 2 tpd 153 tpy < 1 tpd <1 tpy 21 tpd 6,810 tpy < 24 tpd 2001 < 6 tpd 497 tpy <1 tpd <1 tpy 27 tpd 9,062 tpy < 34 tpd 9,560 tpy 2005 < 7 tpd 551 tpy 30 tpd 10,900 tpy 23 tpd 8,000 tpy < 60 tpd 2010 < 8 tpd 626 tpy 30 tpd 10,900 tpy 23 tpd 8,000 tpy < 61 tpd 2015 < 9 tpd 712 tpy 30 tpd 10,900 tpy 23 tpd 8,000 tpy < 62 tpd BHP San Manuel 24 Hr. Smelting Operations29,30 Annual Phelps-Dodge Miami Smelting Operations 3 0 24 Hour Total: Annual Total: 24 Hr. Annual 11,449 tpy 6,964 tpy 19,451 tpy 19,526 tpy 19,612 tpy 4.4.2 Area, Mobile, and Total Source Projections ADEQ projects emissions of SO2 from area and mobile sources to grow roughly proportionately with the population of the nonattainment area. Appendix B describes the source category emissions projections in greater detail. Table 4.6 presents projected area and mobile, and total source emissions for the Hayden nonattainment area.31 Table 4.6 - SO2 Emissions Projections for Hayden Nonattainment Area -All Sources Source Type: Area and 24 Hr. Mobile Annual Point 24 Hr. Annual 1999 < 1 tpd 50 tpy 58 tpd 21,081 tpy < 59 tpd 21,131 tpy 2000 < 1 tpd 51 tpy 47 tpd 15,934 tpy < 48 tpd 15,985 tpy 2001 < 1 tpd 51 tpy 51 tpd 18,362 tpy < 52 tpd 18,413 tpy 2005 < 1 tpd 53 tpy 65 tpd 23,000 tpy < 66 tpd 2010 < 1 tpd 55 tpy 65 tpd 23,000 tpy < 66 tpd 2015 < 1 tpd 57 tpy 65 tpd 23,000 tpy < 66 tpd 24 Hour Total: Annual Total: 23,053 tpy 23,055 tpy 23,057 tpy 5.0 MODELING DEMONSTRATION 28 Projections for electric utilities are based on the assumption of continued full time operation of the APS (Red Rock) generating station and were calculated using emissions from the most recent year of full time operations at this facility (497 tons of SO2 emissions were recorded in 2001, the first year of full time operations). 29 BHP smelting operations were temporarily suspended beginning May 1999. Projections for this smelter assumes resumption of operations. Projected 24-hour inventories are based on the average number of operating days for the period 1999 through 2001 and are assumed to represent typical operating rates for the facility. 31 30 See Section 1.3.2 for a more detailed analysis of population data. 32 Attainment is demonstrated through the clean ambient air quality record of more than seven years and use of Multi-point Rollback (MPR) modeling. The improvement in air quality is due to continuous SO2 emissions control technologies implemented by the ASARCO Hayden smelter to comply with the SO2 emission limits regulations adopted for Arizona smelters in September 1979. Additional air quality benefit can be attributed to the 1982 shutdown of a second Hayden smelter operated by Kennecott Corporation. This facility was purchased by ASARCO in 1986 and is only used for storage. All equipment has been scheduled for removal, and the reverberatory furnace has been demolished. A Title V permit application was not submitted to ADEQ for the Kennecott facility, and no subsequent applications for air quality permits have been received. Additionally, since this facility has been closed longer than two years, the smelter can not reopen without submitting a New Source Review (NSR) and Title V (Subpart 71) permit application.32 MPR, which was approved by EPA in January 1983, as a modeling technique for Arizona smelters, was selected as the most precise and reliable method for then determining contemporary and future stack SO2 emission limits. MPR is a proportional rollback technique founded on the assumption that smelter emissions and ambient concentrations are proportional for a given set of dispersion conditions. Thus, a reduction in emissions results in a comparable reduction in ambient concentrations. Based on this assumption, the appropriate level of emission reductions to protect the NAAQS can be achieved if emissions are reduced by the ratio of the corresponding ambient concentrations to the air quality standard. The use of MPR addresses the high variability of both smelter emissions patterns and meteorological conditions, in part, by rolling back an entire emissions curve rather than a single emissions measurement. A rollback factor is determined by fitting a concentration frequency distribution (from observed data) to an appropriate functional curve and calculating a maximum (limiting) value with an expected once per year frequency of occurrence. The rollback or reduction factor is defined as the ratio of the ambient standard to the limiting value. Rollback factors are calculated for all applicable NAAQS averaging periods. The largest calculated rollback factor is used to reduce each emission which occurred over the period of data accumulation (the emissions profile) to establish an allowable distribution of emissions rates that are protective of the NAAQS. The maximum rollback value is chosen to ensure that all primary and secondary standards are protected. In the case of the Hayden smelters, the 3-hour standard was selected as the most conservative limiting standard which is also protective of the 24-hour and annual standards.33 The original analysis used measured stack and calculated total SO2 emissions over the course of a year, as well as knowledge of smelter operations, emissions variability, and meteorological conditions to construct stack emissions curves for the Hayden smelters. The curve was then "rolledback" and the resultant distributions used directly to construct the original MPR cumulative occurrence and 3-hour average emissions limits tables for stacks. Hourly ambient SO2 concentration data from the Montgomery Ranch monitor for the period June 1974 through December 1976, were used in the analysis.34 At the time of the original MPR analysis, two smelters were in operation in the Hayden area, one operated by Kennecott Corporation and one operated by ASARCO Incorporated. The combined emissions impacts from these smelters were evaluated to determine emissions limits. Among the 32 33 In accordance with AAC R18-2-411. A detailed discussion of Multi-point Rollback methodology is contained in Ultimate sulfur Dioxide Emission Limits for Arizona Copper Smelters, September, 1979. 34 The Montgomery monitor is designated as a stack impact site. 33 considerations in the original analysis were the segregation of the individual smelter's ambient impacts on the airshed and utilization of diffusion modeling to determine the relative contribution of stack and fugitive emissions on ambient concentrations. 5.1 Derivation of New Emissions Limits Based on EPA's approval as a model, ADEQ utilized the MPR approach for the current attainment demonstration. The updated MPR study analyzes stack emissions and resultant ambient impacts based on current operating levels. Because the Kennecott/Hayden smelter is no longer in operation, the updated analysis is also based on the specific impact of the ASARCO smelter's emissions on the area. In addition to evaluation of stack impacts, Section 5.1.2 includes analysis of ambient impacts due to fugitive emissions. Data from July 1999, through June 2001, are used in the current demonstration and includes continuous measurement data for stack, calculated fugitive SO2 emissions, and measured ambient concentrations. These data were used to establish new stack and fugitive emission limits in rule that will maintain emissions at a level protective of the ambient air quality standards (See Appendix A). 5.1.1 Stack Emissions Limits The new SO2 limits for stack emissions at the Hayden smelter maintain the basic MPR principles: 1. Smelter emissions and meteorological conditions are two highly variable and independent processes that together, directly influence the impact of emissions on ambient air quality; 2. Emissions limits can be set that assure a high probability of maintaining the applicable ambient air quality standards. The new limits are in the same format as the original MPR tables. However, the derivation of the new values differs from the original in two important aspects. First, the new limits are based on current SO2 emissions measurements. Second, it was not necessary to reduce actual emissions as the SO2 air quality standards were met by a large margin during the two year period (July 1999 through June 2001) from which the emissions data were obtained (See Section 3.1 and 3.2). The following steps outline the method used in the current analysis for the new Hayden smelter stack limits: 1. Calculate a new stack emissions curve in the form of MPR based on the current 3hour average emissions profile, 2. Calculate an average annual emissions level based on current emissions, and 3. Determine an adjustment factor for the 3-hour average and annual average emissions to establish new limits (based on ambient concentrations) to maintain future emissions at a level protective of the NAAQS. As in the original MPR analysis, Step 3 requires segregation of the ambient effects of stack and fugitive emissions to evaluate ambient stack impacts on the airshed and to calculate an adjustment factor. Two years of data, based on actual emissions measurements from the demonstration period (July 1999 through June 2001), were used to determine an annual average emissions value and to build an MPR 3-hour average emissions curve representative of the attainment period. Three-hour 34 running averages for this period were ranked in descending numerical order of value. Each successive pair of ranked 3-hour values was averaged to obtain a single representative profile consisting of 8,760 hourly values for the attainment period. As with the original MPR, the highest 26 percent, or 2,240 hours, of the resulting averages was then sorted into 24 categories of cumulative frequency of occurrence values identical to the occurrence limits in the original MPR tables (0 to 2,240). The values in each emission category (E) were selected using the same conceptual method used in the original MPR where in each category of allowed emission occurrences (n), the lowest actual emissions value in that range was used to establish the new value. For example, the n cumulative frequency of occurrence where n = 7 in the MPR table based on current stack emissions corresponds to the emissions value E where E = 10,368. The measured emissions values that occur in the frequency, where n = 7, are 10,803, 10,396 and 10,368. The method of selecting the cumulative occurrence and 3-hour average emission limits is outlined in Appendix C. The selection of the lowest measured emissions value E in each frequency of occurrence n mimics the selection of the lowest calculated values of the original MPR analysis, which were all below the emissions profile or curve. The annual average emissions for the attainment period was determined from the calculated numerical average of the combined hourly stack emission values for the attainment period (July 1999 through June 2001). Table 5.1 contains the cumulative occurrence and emissions levels derived from attainment period data. Table 5.1 - Hayden Smelter 3-hour MPR Stack Emissions Curve Based on Attainment Period Number of Cumulative Occurrences (n) 0 1 2 4 7 12 20 32 48 68 94 130 180 July 1, 1999-June 30, 2001 3-hr avg Emissions lb/hr (E) 13177 12284 11607 10867 10368 10021 9442 9085 8748 8453 8070 7713 7367 35 Table 5.1 - Hayden Smelter 3-hour MPR Stack Emissions Curve Based on Attainment Period Number of Cumulative Occurrences (n) 245 330 435 560 710 890 1100 1340 1610 1910 2240 Annual Average lb/hr 3680 July 1, 1999-June 30, 2001 3-hr avg Emissions lb/hr (E) 7065 6772 6486 6215 5970 5701 5457 5213 4984 4788 4576 Because the ambient air quality standards have been met in the Hayden area by a substantial margin, the next step in the analysis entailed selection of an adjustment factor to adjust the 2002 emissions curve that was calculated from actual emissions from the attainment period, to a new level that continues to maintain the NAAQS. The evaluation of an appropriate adjustment factor is based on the stack emissions impacts at the Montgomery Ranch ambient monitoring site. The Montgomery Ranch monitor is the limiting monitor for ambient stack impacts in the Hayden area. The other area monitors are considered primarily to be fugitive impact sites. The Montgomery Ranch monitor is located in an area where fugitive or low level emissions can also contribute to measured ambient SO2 concentrations. Stack and fugitive impacts at the Montgomery Ranch ambient SO2 monitor are directly related to diurnal variations in atmospheric stability and dispersion patterns. Under stable atmospheric conditions, which are common during nighttime hours, fugitive emissions can influence the monitor while tall stack emissions are prevented from reaching the ground by the stable layer below.35 Conversely during daytime hours, especially in the morning as commonly seen during inversion breakup, unstable conditions cause low level emissions (fugitives) to mix into a very diluted state, while stack emissions are more likely to affect the monitor because "Stable" as defined by the National Weather Service (http://www.phx.noaa.gov) is the condition when little or no vertical mixing occurs due to the nature of the temperature change with height. Under stable conditions, convection is inhibited, winds are generally on the light side, and pollution is easily trapped near the ground. 35 36 the unstable air brings them to lower levels.36 As such, the 3-hour SO2 ambient monitoring record can be separated into categories representative of the relative stack and fugitive ambient impacts. As in the original MPR analysis, the current demonstration segregates the impacts of stack emissions from fugitive emissions based on atmospheric stability parameters. Smelter emissions data corresponding to the 50 highest 3-hour SO2 concentrations recorded at the Montgomery Ranch ambient monitor during the attainment period were evaluated to determine the relative contribution of stack and fugitive emissions for these events and to eliminate those measurements that were predominantly the result of fugitive emissions.37 Of the 50 highest Montgomery Ranch 3-hour sulfur dioxide concentration events, twenty events were determined primarily due to the ambient impact of stack emissions. Thirteen events were primarily due to fugitive impacts, and sixteen events were due to a combination of fugitive plus stack impacts (two of the top 50 events were overlapping, giving a total of 49 individual events). The twenty events determined to be primarily due to stack emissions were used to further analyze ambient impacts from this source. Details of the stack/fugitive segregation method are contained in Appendix C. Because the ambient air quality standards have been met in the Hayden area, an adjustment factor was used to "roll up" the emissions curve calculated from actual emissions during the attainment period. A design value based on the 3-hour standard was selected for determining an adjustment factor as this averaging period has been demonstrated to also be protective of the 24-hour and annual standard.38 In accordance with EPA guidance, emission limits should be based on concentration estimates for the averaging time that results in the most stringent control requirements. When short term standards are the most restrictive for pollutants such as SO2, the highest, second high concentration should be used as the design value.39 Even for the ambient events determined to be primarily due to stack emissions, a small proportion of each event can be attributable to fugitive emissions. As such, this small percentage is accounted for in the analysis. The ambient concentrations due to fugitive and stack impacts in equation 1 and 2 (FI and SI) are derived from the atmospheric stability analysis in Appendix C that was used to distinguish between emissions source impacts at the Montgomery Ranch monitoring site. Term S in equations 1 and 2 provides a more conservative regulatory concentration goal of 85 percent of the 1300 ug/m3 3-hour standard. Consistent with EPA guidance the adjustment factor was determined from the highest second high ambient concentration attributable to stack impacts. The second highest ambient concentration due to stack emission impacts at the Montgomery Ranch monitor during the two year attainment period occurred on June 11, 2000. Based on this event, an event stack limit was calculated using the following equation: Event Stack Limit = (A) * (S) - (FI) (SI) where: "Unstable" as defined by the National Weather Service (http://www.phx.noaa.gov) is an atmospheric state where warm air below cold air. Since warm air naturally rises above cold air, vertical movement and mixing of air layers can occur. Twenty five of the 50 highest concentrations were selected from hours during expected stable conditions and 25 during expected unstable conditions because an adequate data set is necessary to explore the variability of meteorological conditions and the stack emissions that impact high ambient concentrations. 38 39 37 36 (1) A design value is an event that was selected for evaluation. EPA guidance specifies that a violation of a short term standard occurs at a site when the standard is exceeded a second time. Therefore, it is appropriate to base emission limits to protect the standards on the highest, second-highest estimated concentration plus a background concentration which can reasonably be assumed to occur with the concentration (40 CFR Pt. 51, App W �11.2.3.1(a), (b) and (c)). 37 A = actual 3-hr stack emissions (lb/hr), S = 85 percent of the 1300 ug/m3 3-hour ambient standard or 1105 ug/m3, FI = ambient concentration due to fugitive impact (ug/m3), and SI = ambient concentration due to stack impact (ug/m3). Or Event Stack Limit = (8627) * (1105) - (399 - 379) = 24695 lb/hr (379) The adjustment or roll up factor is determined by the ratio of the event stack limit to the maximum 3-hour stack emissions recorded during the two year attainment demonstration period from Table 5.1. The adjustment factor is calculated by the following equation: Adjustment Factor = (ESL) (Emax) Where: ESL = Stack limit from equation 3 (lb/hr), and Emax = 3-hr maximum stack emissions during two year demonstration period (lb/hr). OR Adjustment Factor = (24695) = 1.87 (13177) The adjustment factor from equation 4 was used to "roll-up" the 3-hour average emissions and the annual average emissions derived from attainment period data, July1, 1999, through June 30, 2001. These values become the new MPR 3-hour average and annual average limits for stack emissions as illustrated in Table 5.2. These new limits are contained in a 2002 rulemaking and will be incorporated in a future permit revision (See Appendix A). (4) (3) (2) Table 5.2 - Hayden Smelter MPR Stack Emissions Limits Number of Cumulative Occurrences (n) 0 1 2 3-hr Average Emissions (E) (lb/hr) Based on Continuous Emissions Data From July 1, 1999, through June 30, 2001 13177 12284 11607 3-hr avg Emissions Limits (E) (lb/hr), Including 1.87 Adjustment Factor 24641 22971 21705 38 Table 5.2 - Hayden Smelter MPR Stack Emissions Limits Number of Cumulative Occurrences (n) 4 7 12 20 32 48 68 94 130 180 245 330 435 560 710 890 1100 1340 1610 1910 2240 3-hr Average Emissions (E) (lb/hr) Based on Continuous Emissions Data From July 1, 1999, through June 30, 2001 10867 10368 10021 9442 9085 8748 8453 8070 7713 7367 7065 6772 6486 6215 5970 5701 5457 5213 4984 4788 4576 Annual Average Emissions (lb/hr) 3680 6882 3-hr avg Emissions Limits (E) (lb/hr), Including 1.87 Adjustment Factor 20322 19387 18739 17656 16988 16358 15808 15090 14423 13777 13212 12664 12129 11621 11165 10660 10205 9748 9319 8953 8556 5.1.2 Fugitive Emissions Limits Consistent with EPA guidance, assessment of fugitive emissions and determination of an adjustment factor and appropriate limits is based on the second highest ambient concentration during the attainment period attributable to fugitive impacts.40 The second highest ambient concentration 40 40 CFR Part 51, Appendix W. 39 due to fugitive emission sources during the two year demonstration period occurred at the Globe Highway monitor on April 29, 2000.41 Because of the proximity of this monitor to the Hayden smelter, contributions from stack sources are minimal. Based on this event, fugitive limits are calculated using the following equation: Adjustment Factor = (AC) Where: S = 85 percent of the 1300 ug/m3 3-hour ambient standard or 1105 ug/m3, AC = the ambient concentration due to fugitive impacts Or Adjustment Factor = 677 The adjustment factor from equation 6 was used to adjust the annual average fugitive emissions calculated for the attainment period (Equations 7 and 8). This value becomes the new annual average limit, based on a 12 month rolling average, for fugitive emissions. This new limit is also a part of the 2002 rulemaking and will be incorporated in a future permit revision. Annual Average Fugitive Limits = (Fugitive Emissions) * (Adjustment Factor) Where: Fugitive Emissions = Average annual fugitive emissions during 2-year demonstration period (lb/hr). Or Annual Average Fugitive Limits = (181) * (1.63) = 295 lb/hr 5.1.3 Total Stack and Fugitive Limits (8) (7) 1105 = 1.63 (6) (S) (5) The current analysis reduced allowable annual average stack emissions from the previous rule limit of 9,521 lb/hr to a lower level of 6,882 lb/hr. The reductions in allowable emissions from stack sources alone provide an annual reduction of 11,559 tons (approximately 28 percent for stack emissions). The corresponding reduction in allowable 3-hour average stack emissions is illustrated in Figure 5.1. In addition to the reduction in allowable stack emissions, the rule establishes a new annual average fugitive SO2 emissions limit at 295 lbs/hr or 1,292 tpy. Annual average emissions for the combined stack and fugitive sources are limited by the rule to 7,177 pounds per hour or 31,435 tons per year. 41 The Globe Highway monitor is a designated fugitive impact site. 40 Figure 5.1 - Comparison of 1979 and 2002 MPR 3-hour Average Stack Limits42 Allowable 3-hour Average Emissions 40000 35000 30000 Emissions (lbs/hr) 25000 20000 15000 10000 5000 0 0 1 2 4 7 12 20 32 48 68 94 130 180 245 330 435 560 710 890 1100 1340 1610 1910 2240 Cumulative Occurance 1979 MPR Stack Limit 2002 MPR Stack Limit 5.2 Smelter Configuration Smelter configuration and in particular the location and height, of SO2 releases was a consideration in finding the Hayden smelter in compliance with the original MPR limits and for the current demonstration of attainment of the SO2 NAAQS. The original MPR limits for the Hayden smelter were based on 1976 records of SO2 emissions and ambient concentrations. The smelter achieved compliance with MPR emission limits in 1987 and remains in compliance to date. Although the smelter underwent major modifications and emission reductions over the years, the location and heights of SO2 releases have changed only slightly. Basically, emissions can be grouped into two categories based on the height of release. Low level emissions at heights generally less than 200 feet include fugitive emissions. High level emissions are predominantly from the 1000 foot main stack. Table 5.1 shows the release heights for 1976 compared to the most recent years of operation 1999 through 2001. In addition, distances of the individual emission points to the facility property boundary have changed little since 1976. Thus the ambient SO2 network established in the 1970's and refined in the 1980's, including extensive sampling and testing for fugitive SO2 impact sites, occurred at a time with quite consistent release heights. This consistency of SO2 release locations continued through the 1990's thereby providing assurance that the ambient SO2 monitoring network continues to represent the maximum impact of SO2 emissions from the Hayden smelter. 42 Limits contained in AAC R18-2-715(F). 41 Table 5.3 - Hayden Smelter Configuration 1976 to Present Emissions Source Main Stack (core) Main Stack (annulus) 1976 Height (ft) 1000 991.5 P resent Height (ft) 1000 991.5 1976 Process Emission Source High Level Acid Plant Present Process Emission Source Acid Plant Fugitives 130 130 Captured dryer, furnace, and Captured dryer, furnace and converter fugitive emissions converter fugitive emissions Low Level Converter, furnace, and Direct converter, furnace, anode furnace gases not and anode furnace fugitive captured by primary or gases secondary hood system Good Engineering Practice Stack Height The Good Engineering Practice (GEP) Stack Height Limitation codified at AAC R18-2-332 ensures that emissions from a stack do not result in excessive concentrations of any air pollutant as a result of atmospheric downwash, wakes, or eddy effects created by the source itself, nearby structures, or nearby terrain obstacles. The Hayden smelter's 1000 ft stack for the #2 acid plant and a 991.5 ft annular stack for the furnace and converter fugitive emissions was built in 1974. Assessment of GEP stack height at ASARCO's Hayden smelter was conducted jointly by North American Weather Consultants (NAWC) and Colorado State University (CSU). The modeling and analysis demonstrated that the 305 meter (1000 ft) ASARCO stack meets GEP stack height requirements and concluded that emissions from the stack do not result in excessive concentrations of any air pollutant. EPA approved Arizona's SIP determination of GEP stack height on January 14, 1983 (48 FR 1717). 5.2.1 42 6.0 CONTROL MEASURES Because the ASARCO smelter is responsible for the majority of SO2 emissions in the Hayden area, the following attainment demonstration control measures relate specifically to ASARCO smelting operations. Applicable controls for other point sources in the Hayden nonattainment area are discussed in Chapter 4.0. 6.1 Background 43 Smelting operations began at Hayden in 1912. The original facility employed twelve multiplehearth roasters and two reverberatory furnaces to process copper sulfide ore. Today the Hayden primary copper smelter utilizes an oxygen flash smelting process as well as converters and anode furnaces to produce anode copper . An oxygen plant produces oxygen for the furnace and a sulfuric acid plant recovers the sulfur dioxide produced during smelting. A water treatment plant recovers process water from both the acid plant and flash furnace gas cleaning systems for reuse. The facility has a processing capacity of more than 720,000 tons of copper concentrate per year and meets all federal and state emissions regulations. Concentrate Receiving and Sampling: The processing of copper sulphide ore begins at the mine sites where, to facilitate transportation to smelters, concentration of the ore is accomplished via crushing, grinding, and a flotation process to separate copper mineral from ore. Concentrates, containing approximately equal parts of copper, iron, and sulfur, are received at the Hayden smelter by truck and rail where they are sampled to determine moisture content and analyzed for determination of metal content. The concentrates are then sent to the Unloading Department for further processing. Concentrate Feed and Preparation: The Hayden smelter Unloading Department prepares feed for the flash furnace. The feed consists of concentrate, flux, and recycled by-products from the smelting process. Flux and byproducts are blended with the concentrate to build a homogenous "mix." A sample of the mix is analyzed for input in a computer simulation to determine smelter performance during smelting of the feed. Corrections to the mix are made as needed to ensure proper metallurgical processing performance of the smelter. Flash Furnace: At the Flash Furnace Department wet feed, consisting of pre-blended concentrates, flux, and byproducts, is screened and sized in preparation for drying. The feed is dried in one of two fluid bed dryer circuits and is reclaimed in one of the two baghouses. Dried feed is introduced into the INCO design flash furnace with 95 percent pure oxygen at one of four burners and are rapidly oxidized in the oxygen rich atmosphere. Dust laden hot gas from the flash furnace, containing approximately 75 percent SO2, is drawn through the furnace uptake into the gas handling system. The off gas is ducted 43 Calculations used in this section were based on the following: a. US EPA, AP-42, Compilation of Air Pollution Emission Factors, Fifth Edition, August 31, 1998. b. ASARCO Smelter Federal Operating Permit Application, submitted November 1, 1994. c. ASARCO Smelter 1998 Emissions Inventory Survey. 43 to a saturation tower where large particulates are captured and the gas is cooled. From the saturation tower, the gas is ducted to a Venturi scrubber for further dust removal, through a cooling condenser to remove water vapor, and finally through the furnace fan to the acid plant scrubber for treatment in the acid plant. All dust slurry from the saturation tower runs down one of two 12" launders to a clarifier. The clarifier overflow is re-circulated through the saturation tower while the underflow is stripped of SO2 and sent for processing in the water treatment plant. The remaining products of flash smelting are matte and slag. Molten material produced in the flash process separates into two layers in the furnace, the top layer being iron rich slag and the lower layer being heavier, copper laden matte. Molten copper matte is tapped through covered launders for transfer to the converters. Slag is skimmed off the top of the bath and analyzed for copper content for future recovery. The slag temperature is also taken to assist in optimum furnace operation. Converters: The converter department consists of five Pierce-Smith type converters. Molten matte, containing approximately 58 percent copper, is transferred to the converters from the flash furnace for further oxidation of sulfur and slagging of iron and other metals until the copper reaches a purity of about 99 percent. Blister copper is produced in the converters by injecting air into the liquid matte for further oxidation and removal of sulfur from the copper. Silica is also added in the converting process to separate iron from the copper. The silica combines with iron in the matte to generate slag. The slag is skimmed off leaving nearly pure copper ready for transfer to the anode department. Each converter is equipped with primary and secondary hooding systems. The primary hooding system captures the strong SO2 gas for dust removal prior to treatment at the acid plant. The secondary hooding captures any fugitive gases that escape the primary hood or are emitted when skimming and charging. Gases that are collected by the secondary hooding report to a baghouse for dust removal and exhaust to the atmosphere via the 1000-foot stack. Anodes: The anode department consists of two anode furnaces and a spare furnace used when one of the two is out of service. Each furnace holds about 300 tons of copper from the converters. Once an anode furnace is filled, air is blown through the tuyeres to oxidize the copper. The remaining impurities are trapped in this oxide slag along with copper oxide. The oxide slag is skimmed off and the anode furnace is "poled" by bubbling methane (natural gas) through the copper. The poling stage removes excess oxygen left from the oxidizing stage. It produces anode copper, which is more than 99 percent pure, for casting into anodes. Anode copper is cast on two wheels, each with 16 anode molds. One overhead crane removes the anodes from the anode wheels and places them in banding racks or rack rail cars for transport to an off-site electrolytic refinery. Acid Plant: Exit gas from each converter is ducted to cyclones that remove heavy particulate from the gas streams. There are three cyclones for each converter (total of fifteen). Dust collected in the cyclones is conveyed via screw conveyors to a dust bin for pick-up by front end loader and recycle to the bedding system as smelter feed. Converter gases enter the cyclones at 800 deg F and four percent SO2. The gases then report to the spray chambers for further cooling with water sprays. The flow is split equally between two identical chambers and is at about 400 deg F exiting the spray chambers. All the gas then reports to the Cottrell sections that act as settling chambers. Any dust captured is 44 collected by screw conveyors and sent to the pug mill so airborne particulate is minimized. The next step is the three induced draft (I.D.) fans that pull gases from the converters and send them to the scrubber system. These fans are each powered by a 500 H.P. constant speed electric motor. Outlet dampers provide draft for the converters by matching a set point on the Cottrell inlet header. Converter gas finally enters the scrubbing system where it mixes with furnace gas in the 50 percent scrubber. This is a brick lined vessel with co-current sprays fed from a slurry type pump. The gas stream (converters and furnace) splits when it leaves the unit with half going to two (north and south) secondary scrubbers. These units are similar to the 50 percent scrubber except smaller. The gas stream then enters the gas cooling towers. Gas flows upwards through polypropylene packing against the liquor flow from sprays at the top of the tower. The dew point of the gas stream is lowered which forces water to drop out. This further scrubs the gas and minimizes the water being carried to the contact section of the plant. The liquor is pumped from the bottom of the towers through several plate and frame heat exchangers and back to the top of the towers. The water to cool the liquor is provided by a Marley cooling tower. The gas leaving the gas cooling towers is normally between 85 and 95 deg F. The gas is dust free but totally humidified. Mist precipitators are next which use electrostatic fields to remove contained water droplets. Process gas then reports through a fiberglass duct to the inlet of the drying tower. Treatment of the gas in the contact section consists of several steps listed as follows: a. Drying of the sulfur dioxide (SO2) gas from the gas purification system. b. Conversion of sulfur dioxide gas to sulfur trioxide gas. c. Absorption of the sulfur trioxide (SO3) gas in sulfuric acid. Detailed process flow diagrams are included in this submittal in Appendix C. Prior to 1971, all smelting operations process gasses were emitted into the atmosphere after particulate removal by electrostatic precipitators. The installation of an acid plant in late 1971 added SO2 control for primary converter gas. From sulfur balance data the average emissions were reported to be more than 100,000 tpy. A series of improvements in 1983 included replacement of twelve multiple-hearth roasters and two reverberatory furnaces with an INCO Flash smelting furnace. During the flash furnace conversion, ASARCO also installed a 650 ton per day oxygen plant to enrich the smelting process gases and replaced the existing contact acid plant with a new double-contact acid plant with a production capacity of 2,820 tons of sulfuric acid per day for treatment of all flash furnace and converter primary process gases. Reduction of SO2 emissions for this project was estimated at 63,584 tpy. The double-absorption sulfuric acid plant is the predominant control device for primary process SO2 emissions produced by the flash furnace and converters. The flash furnace provides a steady gas feed to the acid plant, enabling optimal plant performance. The acid plant provides control of process gas SO2 at or below the outlet SO2 concentration limit of 0.065 percent by volume set forth in the federal New Source Performance Standard 40 CFR 60, Part P. The SO2 control performance for the ASARCO acid plant is an outlet emission concentration of 0.015 percent by volume. The acid plant input of SO2 gas is 80,000 ppm with an output of 150 ppm, resulting in a 99.81 percent recovery rate. The annual average process capacity for the acid plant is 666,044 tons of acid per year. The average annual process rate for the smelter is estimated at 88 tons per hour (tph) of new sulfide concentrates. Recent process rates (1999 through 2001) have generally been within 80 percent of capacity. The production throughput of this facility, however, is dependent upon the operational 45 capacity of the sulfuric acid plant to treat SO2 emissions from the flash furnace and the five converters. At the present time, the acid plant has the capacity of processing the emissions from the flash furnace in combination with two out of five converters. An increase in furnace or converter facilities would require a corresponding increase in acid plant capacity. The flash furnace, oxygen plant, acid plant, and other improvements made during the transition from the roasters and reverberatory furnaces to the flash furnace, subsequently reduced the SO2 emissions rate by forty percent. This improvement is demonstrated in Figure 6.1, which illustrates the pre-control and post-control SO2 emission levels. In 1998, ASARCO modified the smelter's existing gas handling system and installed an $18.4 million dollar wet gas handling system. Existing equipment including a settling chamber, quench tower, and electrostatic precipitators were replaced with a saturation tower, Venturi scrubber, cooling condenser and ancillary equipment. This modification allowed flash furnace off gas to be treated at temperatures less than 200E F compared to the previous system's 600E F. As a result, the flash furnace off gas volume was lowered and consequently the grade of SO2. This enabled the acid plant to provide more ventilation to the converters and reduce the SO2 in the secondary hooding gases along with any fugitive emissions escaping the secondary hoods. The average rate of SO2 in the secondary hood gases was approximately 6,000 lb/hr in the period 1994 through 1997. This average has been reduced to approximately 3,000 lbs/hr since implementation of the flash furnace scrubber system, and is the largest component of the reduction in annual SO2 emissions. The improved ventilation to the converters provided by the 1998 scrubber installation has decreased stack emissions and the associated fugitive emissions due to escape from the converter secondary hood system. The secondary hooding system is operated at the same nominal 250,000 scfm flow as prior to the modification, however, the SO2 concentration in the secondary hooding gases has been reduced by half. A computerized process control system sets the system dampers at their maximum effectiveness based on the converter cycle. This system is designed to effectively capture fugitive emissions from the primary ventilation system and vent the gases to the stack. Consequently, emissions that escape the secondary hoods, primarily under roll in and roll out conditions, contain 50 percent less SO2 compared to pre-scrubber operation, resulting in a significant reduction in fugitive SO2 emissions. This improvement is demonstrated in Figure 6.2, which illustrates recent the pre-control and post-control SO2 emission levels. The improvement is also reflected by the reduction in peak 3-hour ambient SO2 concentrations (See Chapter 3). Additional equipment improvements have been made to improve the collection and control of fugitive SO2 emissions. As previously noted, sources of secondary process emissions are hooded to minimize release of fugitive emissions directly to the atmosphere. The captured gases are treated with lime injected into the flue system and then directed to baghouses prior to exhausting to the atmosphere. In 1996 ASARCO installed a $4.2 million dollar secondary hood baghouse. The new equipment improved the control of fugitive emissions and reduced opacity. To further reduce fugitive SO2 emissions, ASARCO repaired converter flues, replaced primary converter hoods and jackets, rebuilt all units in the Cottrell electrostatic precipitator, installed concrete sumps and improved sprays in the gas spray chamber of the acid plant in 1991 at a cost of $915,000.00. In 1999, newly designed primary hood doors were installed on two converters. The new design, incorporating a flexible seal, improved the seal between the door and the primary hood and increased the capture efficiency of the primary hood to minimize escape of emissions to the secondary hood system. Additional doors were installed on the remaining three converters in 2000. After the change, a decrease in future sulfur oxides emissions is estimated at 827.6 tpy, which is approximately a five percent reduction in the total 46 smelter emissions. These changes meet or exceed RACT requirements. The emissions control improvements implemented at the ASARCO smelter are summarized in Table 6.1 below. Table 6.1 - Implementation of SO2 Process and Control Technology at the Hayden Smelter Year 1971 1972 1973 1974 1975 1976 1978 1980 1983 Installation of N0. 1 Acid Plant. Acid Plant Mist Precipitator Modification. Installation of Reverberatory Vent Fans to improve ventilation. Installation of Acid Coolers (Crane) for improved acid plant performance and Matte Fume Vent to improve the capture of fugitive emissions. Installation of Converter Spray Chamber for particulate removal and Plate Heat Exchanger. Matte Fume Enclosing to improve the capture of fugitive emissions. Installation of Separator - Demister to improve acid plant performance. Installation of Flue Gas Sampling Station. Installation of secondary hooding on the converters to minimize release of fugitive emissions directly to atmosphere. Replacement of multiple-hearth roasters and reverberatory furnaces with an Inco flash smelting furnace and gas handling equipment including slag skimming hoods, matte tapping hoods, and slag return hoods at the flash furnace for improved sulfur recovery. Installation of gas cleaning mist precipitators. 1983/ 1984 1988 1989 1991 Installation of Monsanto acid plant No. 2 for treatment of all primary process gases. Installation of acid plant APV Heat Exchanger to improve gas cleaning performance. Electric slag cleaning vessel with an SO2 control device; a caustic scrubber that controls a portion of the overall SO2. Shutdown of acid plant No.1. Repair of a gas-to-gas heat exchanger leak at the acid plant. Repaired converter flues; replaced primary converter hoods and jackets; rebuilt all units in the Cottrell electrostatic precipitator; installed concrete sumps and improved sprays in the gas spray chamber of the acid plant to reduce fugitive SO2 emissions. 1993 1993 1995 Upgrade of acid plant mist precipitator and acid plant intermediate fan. Modification of flash furnace uptake and replacement of cooling fins on the settling chamber to prevent the generation of fugitive emissions caused by inadequate cooling. Replacement of acid plant heat exchanger and retube of cold heat exchanger. Equipment 47 Table 6.1 - Implementation of SO2 Process and Control Technology at the Hayden Smelter 1997 1998 Retube of Tail Gas Reheater Heat Exchanger. Installation of wet gas handling system for improved treatment of furnace emissions. Installation of new Hot IP Heat Exchanger; Cold IP Heat Exchanger; SX Distribution in IP Absorbing Tower; Foxboro IA distributive process control system. 1999/ 2000 2000 Redesign of converter primary hood doors. The gaps in the primary hoods at the converter mouths were redesigned and a flexible seal installed to minimize the escape of fugitive emissions to the secondary hooding system. CEM Upgrade (Stack Monitors) Figure 6.1 - Asarco Smelter SO2 Emissions and Percent Control 250000 100 200000 80 Emissions (tpy) 60 100000 40 50000 0 1972 1974 1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996 1998 2000 20 Year emissions percent control Figure 6.2 - Asarco Smelter SO2 Emissions 48 Control (%) 150000 35000 30000 Emissions (Tons/Year) 25000 20000 15000 10000 5000 0 1996 1997 1998 1999 2000 2001 Year Stack Emissions Fugitive Emissions Total Emissions 6.2 Emissions Limitations for ASARCO Hayden Smelter 6.2.1 AAC Rule R18-2-715(F), R18-2-715(G) and R18-2-715.01 - Standards of Performance for Existing Primary Copper Smelters: Site specific requirements; Compliance and Monitoring Measure Description: In 1979, ADEQ promulgated site specific emissions limits at Arizona Code of Rules and Regulations R9-3-515, currently codified at AAC R18-2-715 (See Appendix A). The rule required all existing primary copper smelters to implement control technology sufficient to comply with the 1979 MPR stack limits as well as any fugitive emissions control technology necessary to assure attainment and maintenance of the NAAQS. The following emissions limits were specified for the ASARCO copper smelter at Hayden: 1. Annual average stack emissions, as calculated pursuant to AAC R18-2-715.01(C) through (J) shall not exceed 9,521 lbs/hr. The number of three-hour emissions, as calculated pursuant to AAC R18-2-715.01(C) through (J) shall not exceed the limits as listed in AAC R18-2-715(F). ADEQ's 2002 rule revision incorporated the following voluntary stack limits and added fugitive limits for the ASARCO smelter (See Appendix A for rule revision): 1. Annual average stack emissions, as calculated pursuant to AAC R18-2-715.01(C), shall not exceed 6,882 lbs/hr. The number of three-hour emissions, as calculated pursuant to AAC R18-2-715.01(C), shall not exceed the revised limits listed in AAC R18-2-715(F). 2. Annual average fugitive emissions, as calculated under AAC R18-2-715.01(T), shall not exceed 295 lbs/hr. Estimated SO2 Emission Reduction: 49 Emissions were reduced 63,584 tpy following compliance with the 1979 rule (due to installation of flash furnace). Subsequent implementation of additional emissions collection and control measures enabled the 2002 revision that provides a further reduction in allowable emissions of 11,559 tpy for stack sources. Responsible Agency and Authority for Implementation: ADEQ is the responsible agency with authority designated by ARS �49-104(A)(11) and ARS �49-422. Implementation Schedule: The 1979 rule provided a compliance date of January 14, 1986, unless otherwise provided in a consent decree or a delayed compliance order. The compliance date for the 2002 rule revision is the effective date of the rule. Level of Personnel and Funding Allocated for Implementation: No additional personnel are required; implementation funding for ADEQ personnel is underwritten through emission and inspection fees. The approximate cost to the smelter is $123,000 per annum for operation and maintenance of the ambient air analyzers. Expenditures for emissions collection and control improvements at the smelter are noted below. Enforcement Program: ADEQ is responsible for tracking the progress made through the implementation of this measure and for enforcing all applicable regulations through the schedule of inspections and the development of compliance and enforcement actions. (See Section 7.3 for a description of inspection and compliance and enforcement procedures.) Measure Monitoring Program: ASARCO submitted a proposed compliance schedule in 1982, for achievement of the 1979 MPR stack emission limits as expeditiously as practicable. The smelter subsequently submitted a permit application in 1983 (permit #0308-85) for installation of $123 million worth of emissions collection and control improvements. All on-site construction and installation of emission control equipment and process modification was completed by 1984, meeting the compliance date of January 14, 1986. The collection and control technology implemented by ASARCO including installation of the wet gas handling system in 1998 has allowed the facility to reduce emissions sufficient to demonstrate attainment and to accept additional emissions reductions in 2002 (See Section 6.2 for a description of the implemented equipment). For purposes of determining compliance with the emissions limits as codified in 1979, ASARCO was required to install, calibrate, maintain, and operate a measurement system for continuously monitoring SO2 concentrations and stack gas volumetric flow rates in each stack that could emit five percent or more of the allowable annual average SO2 emissions from the smelter. Demonstrations of stack gas volumetric flow rate and SO2 concentration measurement systems required by subsections AAC R18-2-715.01 (K)(5)(a) and (b) were initiated in 1983. The location of all stack sampling points were approved by ADEQ prior to installation and operation of the continuous emission monitoring systems (CEMS). In response to a Consent Decree (CIV 81-110 GLO ACM, dated June 22, 1981), ASARCO installed and operated a continuous emissions monitoring system. ASARCO operates CEMS at the outlets of number 2 acid plant, the furnace vent gas flue, and the converter secondary hood flue. In addition to primary process gas, captured fugitive emissions including those captured by the secondary hooding system are continuously monitored for SO2 concentrations and stack gas volumetric flow rates, and are included when determining compliance with the cumulative occurrence and emissions limits contained in R18-2-715(F)(1). Monitoring and emissions data submitted by ASARCO indicated that the smelter was in compliance 50 with the 1979 emission limits by 1984. Provisions for minimum performance and operating specifications for CEMS at this facility are contained in AAC R18-2-715.01(K)(5). Additional requirements for emission monitoring of the sulfuric acid plant are contained in AAC R18-2-313, Existing Source Emissions Monitoring. The ASARCO smelter stack and fugitive continuous emissions monitoring system is subject to the manufacturer's recommended zero adjustment and calibration procedures at least once per 24-hour operating period and meets all applicable performance specification and quality assurance procedures contained in 40 CFR 60, Appendix B and F. Daily calibration and quarterly audits conducted by ASARCO are reported to ADEQ. To ensure continued compliance, ASARCO maintains on hand and has ready for immediate installation sufficient spare parts or duplicate systems for the continuous monitoring equipment to allow for the replacement within six hours of any monitoring equipment part which fails or malfunctions during operation. As required by AAC R18-2-715.01 (L), ASARCO measures at least 95 percent of the hours during which emissions occurred in any month and has not failed to measure any twelve consecutive hours of emissions. ASARCO maintains records of all average hourly emissions measurements for at least five years following the date of measurement as required by 40 CFR 60 Subpart P - Standards of Performance for Primary Copper Smelters. All of the following measurement results are expressed as pounds per hour of SO2, summarized monthly, and submitted to ADEQ within 20 days after the end of each month: 1. The annual average of the month; 2. The total number of hourly periods during the month in which measurements are not taken and the reason for loss of measurement for each period; 3. The number of three-hour emissions averages which exceeded each of the applicable emissions levels listed in AAC R18-2-715(F) (and AAC R18-2-715(G)) subsequent to the 2002 revision) for the compliance periods ending on each day of the month being reported; 4. The date on which a cumulative occurrence limit listed in R18-715(F) (and R18-2715(G) subsequent to the 2002 revision) was exceeded if such exceedance occurred during the month being reported. These submitted reports have shown continued compliance with all applicable regulations and averaging standards. ADEQ has not issued any notices of compliance actions for a monitoring violation to this facility. As a means of determining total overall emissions, ASARCO performs a monthly material balance for sulfur and includes the results in the monthly compliance reports to ADEQ. Based on these reports, the smelter documents a sulfur recovery rate over 95 percent. In addition to monthly compliance reports, ADEQ also receives from ASARCO quarterly audit, upset, and excess emissions reports, as well as annual emissions inventory reports based in part on the SO2 CEMS data. The rule also specifies requirements regarding bypass operations. At each point in the smelter facility where a means exists to bypass the sulfur removal equipment, the bypass is instrumented to detect and record all periods that the bypass is in operation. The facility's emergency ventilation damper has been used during periods when the plant is shut down for repairs or in emergencies. All production activities at the smelter cease during use of the emergency ventilation damper. ASARCO reports the required information to ADEQ, not later than the 15th day of each month, and includes an explanation for the necessity of the use of the emergency damper. 51 6.2.2 AAC Rule R18-2-715.02 Standards of Performance for Existing Primary Copper Smelters; Fugitive Emissions Measure Description: This measure provides for an evaluation of the ambient impact of fugitive emissions from the Hayden smelter. The regulation requires a measurement or accurate estimate of fugitive SO2 emissions to determine whether these emissions have the potential to contribute to violations of the ambient SO2 standards in the vicinity of the smelter. The rule also requires the adoption of rules specifying emission limits or other appropriate measures necessary to maintain the standards. Estimated SO2 Emission Reduction: A reduction of 828 tpy is estimated due to implementation of fugitive emissions collection and control measures. Responsible Agency and Authority for Implementation: ADEQ is the responsible agency with authority designated by ARS �49-104(A)(11) and ARS �49422. Implementation Schedule: The rule provides a compliance date of January 14, 1986. Level of Personnel and Funding Allocated for Implementation: No additional personnel is required; implementation funding for the fugitive emission evaluation study was provided by ASARCO. The approximate cost of the SO2 fugitive emission evaluation study was one million dollars. Enforcement Program: ADEQ is responsible for tracking the progress made through the implementation of this measure and for enforcing this measure through the schedule of inspections and the development of compliance and enforcement actions (See Section 7.3 for a description of inspection and compliance enforcement procedures). Measure Monitoring Program: Fugitive SO2 emissions at the ASARCO smelter are primarily generated from the flash furnace, converter, and anode process areas. Emissions escape the ventilation systems and exit the buildings through roof vents. These structures mounted on the roofs of the building provide an escape route for uncaptured emissions. A portion of the SO2 emissions may escape through other exit points, such as open walls and doors in the building. These alternate exit points were identified by ASARCO through flow visualization tests and survey sampling. The following study and other data gathered demonstrated that the majority of the SO2 fugitive emissions escape from the furnace and the converter processes and identify the converter area as the primary source of uncaptured emissions at the smelter. On April 11, 1996, ASARCO submitted to the Arizona Department of Environmental Quality a fugitive SO2 emissions description, evaluation, and ambient impact study, to fulfill the outstanding SIP commitments for analysis of fugitive emissions. The study was conducted from September 6, 1994, through March 22, 1995, and utilized meteorological data collected to characterize fugitive SO2 emission dispersion conditions and measured emissions to evaluate the impact of fugitive emissions in the Hayden area. The study concluded that fugitive SO2 emissions from the converter and furnace buildings represent nearly 99 percent of the fugitive SO2 emissions from the smelter and identified converter operations as the major source of fugitive emissions. The furnace building emitted 288 lbs/hr or thirty-five percent and the converter building emitted 525 lbs/hr or 64 percent. The studies concluded that fugitive emissions will neither cause nor significantly contribute to a violation of the NAAQS. Summaries of the fugitive emissions studies are contained in Appendix C. 52 Measures to improve collection and control of fugitive emissions together with control of primary process gasses have reduced total emissions to a level protective of the NAAQS in the Hayden area (See Section 6.2 for a description of implemented equipment). Captured fugitive emissions currently comprise more than 85 percent of total facility emissions and are included when determining compliance with the stack limits described in Section 6.3.1. 6.2.3 ASARCO Permit Conditions Reasonably Available Control Technology (RACT) for sources located in SO2 nonattainment areas is defined as "that control technology necessary to achieve the NAAQS and is determined by the technological and economic feasibility of the control."44 Submittal of biennial compliance certifications under AAC R18-2-309(2)(a) are required to demonstrate the compliance status of the source with all applicable permit conditions. Controls implemented by ASARCO to reduce smelter emissions and comply with emissions limit regulations are included in the following permits outlined in Table 6.2, found on the following page. All listed controls have been captured in the facility's Title V permit. Additionally, ASARCO submitted a standard Title V permit application form to ADEQ on November 2, 1994. The application for the ASARCO smelter including the Inco oxygen flash furnace, Pierce-Smith converters, anode furnaces, concentrate dryers, double absorption acid plants, oxygen plant, gas cleaning plant including electrostatic precipitators, filter plant, revert crushing plant and associated equipment has been processed and the final permit was issued on October 9, 2001. Table 6.2 - Permit Conditions Date September 10, 1984 April 4, 1989 October 9, 2001 Permit # 0308-85 1215 1000042 Controls Retrofit to install Inco Flash Furnace, oxygen plant, and double contact acid plant to treat process gases. Installation of electric slag cleaning vessel. Requires maintenance and operation of all collection, process, and control equipment in a manner consistent with good air pollution control practice. Continued operation of CEMS is required to monitor and record SO2 discharge emissions rates from the smelting facility. Continued operation, maintenance, and calibration of all current ASARCO ambient SO2 monitors are also required. 7.0 MAINTENANCE PLAN Section 107 (d) (3) of the amended CAA requires that nonattainment areas must have a fullyapproved maintenance plan meeting the requirements of Section 175 (A) before they can be 44 US EPA Office of Air and Radiation, Office of Air Quality Planning and Standards, "SO2 Guideline Document" February 1994. 53 redesignated to attainment. Section 175 (A) requires submittal of a SIP revision that provides for the maintenance of the NAAQS for at least 10 years after the redesignation to attainment. The required components of the maintenance plan include: 1. A demonstration that future emissions of SO2 will not cause a violation of the SO2 NAAQS, 2. A commitment to continue to operate an appropriate air quality monitoring network to verify the attainment status of the area, 3. Assurance that the state has the legal authority necessary to implement and enforce all necessary measures used to attain and maintain the NAAQS, 4. An indication of how the state will track the progress of the maintenance plan, and 5. A contingency plan that contains measures to promptly correct any violation of the NAAQS that occurs after redesignation. This submittal demonstrates that all of the above required elements have been met. ADEQ also commits to a SIP revision subsequent to this submittal providing for maintenance of the NAAQS for an additional ten years. This subsequent revision is due eight years into the first ten year maintenance period. 7.1 Maintenance Demonstration Copper smelting operations at the ASARCO facility are the single greatest source of SO2 emissions in the Hayden nonattainment area comprising more than 99 percent of total emissions in the area. The conservative emissions limits that have been established for the smelter are based on actual emissions for July 1999 through June 2001 of smelter operations showing attainment of the SO2 NAAQS (See Chapter 4). Once the area is redesignated,

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Hayden sulfur dioxide nonattainment area state implementation and maintenance plan: final

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