San Manuel Sulfur Dioxide Maintenance Plan Renewalstatic.azdeq.gov/pn/sip_sanmanuel.pdf · San...

San Manuel Sulfur Dioxide Maintenance Plan Renewal

1971 Sulfur Dioxide National Ambient Air Quality Standards

Air Quality Division March 10, 2017 Proposed

Planning Lead:

Elias Toon – [email protected]

Technical Lead:

Catherine Lucke-McDowell – [email protected]

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Table of Contents Table of Contents ............................................................................................................................ 1

List of Figures .................................................................................................................................. 2

List of Tables ................................................................................................................................... 2

List of Appendices ........................................................................................................................... 3

1 Introduction ........................................................................................................................ 2

1.1 Statement of Purpose ............................................................................................. 2

1.2 SO2 Pollution ........................................................................................................... 2

1.3 National Ambient Air Quality Standards ................................................................. 3

1.3.1 1971 SO2 NAAQS ...................................................................................... 3

1.4 San Manuel Regulatory Background ....................................................................... 5

1.5 San Manuel Maintenance Area Description ........................................................... 8

1.6 Physical, Demographic, and Economic Description of the San Manuel Area ...... 11

1.6.1 Climate and Physiography ..................................................................... 11

1.6.2 Population .............................................................................................. 11

1.6.3 Economy ................................................................................................. 12

1.7 General SIP Approach - Regulatory Requirements and Guidance ........................ 13

1.7.1 Clean Air Act Requirements ................................................................... 13

1.7.2 EPA Guidance ......................................................................................... 18

2 Ambient Monitoring Network .......................................................................................... 19

2.1 SO2 Monitoring Requirements .............................................................................. 19

2.2 Air Quality Data ..................................................................................................... 21

2.3 Continued Attainment of the Standards .............................................................. 24

3 Emissions Inventories ....................................................................................................... 25

3.1 Requirements ........................................................................................................ 25

3.2 Approach ............................................................................................................... 26

3.3 Methodologies ...................................................................................................... 27

3.3.1 Base Year ................................................................................................ 27

3.3.2 Future Years ........................................................................................... 27

3.4 Base Year Emissions – All Sources ........................................................................ 28

3.5 Future Year Emissions – All Sources ..................................................................... 28


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3.6 Summary ............................................................................................................... 29

4 Control Measures .............................................................................................................. 31

4.1 Requirements ........................................................................................................ 31

4.2 Point Sources ........................................................................................................ 31

4.2.1 BHP Copper San Manuel Smelter .......................................................... 31

4.2.2 Other Point Sources ............................................................................... 32

4.3 Area and Mobile Sources ...................................................................................... 33

5 Maintenance Plan ............................................................................................................. 35

5.1 Maintenance Demonstration ................................................................................ 35

5.2 Ambient Monitoring ............................................................................................. 38

5.3 Verification of Attainment .................................................................................... 38

5.4 Contingency Plan .................................................................................................. 39

5.5 Conclusion ............................................................................................................. 40

List of Figures Figure 1.1 San Manuel Sulfur Dioxide Maintenance Area ............................................................ 10 Figure 2.1: San Manuel (LDS Church) Maximum 3-hour SO2 Concentrations ............................. 22 Figure 2.2: San Manuel (LDS Church) Maximum 24-hour SO2 Concentrations ........................... 23 Figure 2.3: San Manuel (LDS Church) Annual Average SO2 Concentrations ................................ 23 Table 3.1: San Manuel SO2 Emission Inventories ......................................................................... 26 Figure 3.2: San Manuel Maintenance Area SO2 Emissions Projections 1998-2028 ...................... 30 Figure 3.3: San Manuel Maintenance Area SO2 Emissions Projections 2005-2028 ...................... 30 Figure 5.1: San Manuel Maintenance Area SO2 Emissions 1998-2028 ........................................ 36 Figure 5.2: San Manuel Maintenance Area SO2 Emissions 2005-2028 ......................................... 37

List of Tables Table 1.1 1971 Sulfur Dioxide Ambient Air Quality Standards ....................................................... 4 Table 1.2 San Manuel Sulfur Dioxide Area Description .................................................................. 8 Table 1.3 Population Distribution, Selected Years, 2010-2028 .................................................... 12 Table 1.4: Applicable Regulatory Requirements .......................................................................... 14 Table 2.1: San Manuel Historic Ambient Monitoring Network ................................................... 20 Table 3.1: SO2 Emissions in the San Manuel MA in 2014 ............................................................. 28 Table 3.2: SO2 Emissions in the MA in Maintenance Years .......................................................... 29 Table 4.1: Point Source Emissions - PTE and actual Emissions ..................................................... 33


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List of Appendices Appendix A – San Manuel SO2 Emission Inventory Technical Support Document

Chapter A1 – Introduction Chapter A2 – Monitoring Network Chapter A3 – Emissions Inventory Exhibit AI – Population Estimation and Projection Exhibit AII – MOVES Planning and Assumptions


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1 Introduction This chapter describes the purpose of this State Implementation Plan (SIP) revision for the San Manuel Sulfur Dioxide (SO2) Maintenance Area (MA), summarizes the regulatory background and requirements, and provides a general overview of the planning area and SO2 National Ambient Air Quality Standards (NAAQS).

1.1 Statement of Purpose Pursuant to Clean Air Act (CAA) Section 107(d)(3)(E), the U.S. Environmental Protection Agency (EPA) redesignated the San Manuel nonattainment area to attainment/maintenance for the 1971 SO2 NAAQS in 2008 after approving Arizona Department of Environmental Quality’s (ADEQ) first maintenance plan submittal.1

ADEQ is responsible for the preparation and submittal of this Maintenance Plan Renewal. This SIP demonstrates that the San Manuel MA will continue to meet the 1971 SO2 primary NAAQS through the second maintenance period of 2018-2028.

1.2 SO2 Pollution SO2 is a highly reactive gas and is part of the sulfur oxides family. Fossil fuels are the largest source of SO2 and other sulfur oxides.2 These emissions are generated by combustion at power plants and other industrial facilities. SO2 is a precursor to PM2.5, or particulate matter that is 2.5 micrometers in diameter or smaller. PM2.5 is a major contributor to smog and can cause premature death and lung disease.

Scientific evidence demonstrates that short-term exposure to SO2 emissions can lead to adverse health effects including bronchoconstriction and increased asthma symptoms. These symptoms can also cause economic consequences such as increased hospital admissions and missed work/school days. SO2, in addition to nitrogen dioxide (NO2), is a primary cause of acid rain3 which can deteriorate infrastructure, toxify water sources, destroy vegetation, and impair visibility.

EPA sets the NAAQS to lessen the impact of SO2 emissions on public health, welfare, and the environment.

1 See 73 FR 3396 (Jan. 18, 2008). 2 Sulfur Dioxide, U.S. Environmental Protection Agency. (2 Jan. 2017) Retrieved: http://www3.epa.gov/airquality/sulfurdioxide/index.html. 3 For more information on acid rain’s impacts, visit EPA’s website at: http://www.epa.gov/airmarkets/acid-rain-program.

http://www3.epa.gov/airquality/sulfurdioxide/index.html

http://www.epa.gov/airmarkets/acid-rain-program

http://www.epa.gov/airmarkets/acid-rain-program


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1.3 National Ambient Air Quality Standards Title I of the CAA requires EPA to set the NAAQS for those pollutants that are considered harmful to both the public health and the environment, otherwise referred to as “criteria pollutants.” There are six criteria pollutants:

1. ground-level ozone 2. particulate matter 3. carbon monoxide 4. nitrogen dioxide 5. sulfur dioxide 6. lead

There are two types of NAAQS: primary and secondary. Primary standards are set to protect human health and secondary standards are established to protect public welfare, such as visibility, animals, crops, vegetation, and buildings.4

The standard for each pollutant is set at a maximum concentration in parts per million (ppm) by volume, parts per billion (ppb) by volume, or micrograms per cubic meter of air (µg/m3). Each standard also has a distinct averaging time in order to provide the necessary level of protection. These standards are reviewed periodically in accordance with CAA section 108 and are retained or revised based on scientific literature and analyses.

1.3.1 1971 SO2 NAAQS

In 1971, EPA established the first SO2 NAAQS to set a 24-hour primary standard at 0.14 ppm and a primary annual average standard at 0.03 ppm to protect human health. EPA also set a three-hour secondary standard at 0.5 ppm and a secondary annual standard at 0.02 ppm to protect public welfare and the environment. In 1973, EPA revoked the secondary annual standard.5

In 1996, EPA reviewed the primary NAAQS, but did not revise them.6 On December 8, 2009, EPA proposed to retain the current SO2 secondary standard to provide requisite protection for the direct effects on vegetation and ecosystems (74 FR 64810).7 At the same time, EPA proposed to add a secondary standard identical to the new primary SO2 1-hour standard set at 75 ppb. In its notice of final rulemaking EPA retained the current secondary standard but did not add a secondary standard at the level of the new primary standard (77 FR 20218; April 3, 2012).

4 National Ambient Air Quality Standards (NAAQS), U.S. Environmental Protection Agency. (2 Jan. 2017) Retrieved: http://www3.epa.gov/ttn/naaqs/criteria.html. 5 38 FR 25678 (Sept. 4, 1973). 6 61 FR 25566 (May 22, 1996). 7 http://www.epa.gov/ttn/naaqs/standards/so2/fr/20091208p64810.pdf

http://www3.epa.gov/ttn/naaqs/criteria.html


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On June 22, 2010, EPA promulgated a new one-hour SO2 standard at a level of 75 ppb, based on the three-year average of the annual 99th percentile of one-hour daily maximum concentrations. At the same time, EPA tightened the existing SO2 standards in order to provide requisite protection of public health with an adequate margin of safety.8 In 2012, EPA reviewed and retained the existing secondary SO2 NAAQS without revision.9 Table 1.1 summarizes the history of the SO2 NAAQS for each of EPA’s review cycles from 1971 through 2012.

Table 1.1 1971 Sulfur Dioxide Ambient Air Quality Standards10

Final Rule/Decision Primary/

Secondary Indicator

Averaging Time

Level Form

1971

36 FR 8186 Apr 30, 1971

Primary SO2 24-Hour 0.14 ppm Not to be exceeded more than once per year

Annual 0.03 ppm Annual arithmetic average Secondary 3-Hour 0.5 ppm Not to be exceeded more

than once per year Annual11 0.02 ppm Annual arithmetic average

1973

38 FR 25678 Sept 14, 1973

Secondary Secondary 3-hour SO2 standard retained, without revision; secondary annual SO2 standard revoked.

1996

61 FR 25566 May 22, 1996

Primary Existing primary SO2 standards retained, without revision.

2010

75 FR 35520 Jun 22, 201012

Primary SO2 1-hour 75 ppb 99th percentile, averaged over 3 years 13

Primary annual and 24-hour SO2 standards revoked.

2012

77 FR 20218 April 3, 2012

Secondary Existing secondary SO2 standard retained, without revision.

8 75 FR 35520 (June 22, 2010). 9 77 FR 20218 (April 3, 2012). 10 Sulfur Dioxide (SO2) Primary Standards – Table of Historical SO2 NAAQS, U.S. EPA. (2 Jan. 2017) Retrieved: http://www3.epa.gov/ttn/naaqs/standards/so2/s_so2_history.html. 11 The 1971 final rule also included a secondary 24-hour SO2 standard of 0.1 ppm, maximum 24-hour concentration not to be exceeded more than once per year, as a guide to be used in assessing implementation plans to achieve the annual standard. 12 The 1-hour SO2 standard added in 2010 is a primary standard.

http://www3.epa.gov/ttn/naaqs/standards/so2/s_so2_history.html


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Planning obligations for the 1971 standards, including this renewal of the San Manuel maintenance plan, continue until such time as they are subsumed by any new planning and control requirements associated with the new NAAQS. This plan does not address the 2010 NAAQS for SO2.

1.4 San Manuel Regulatory Background The relationship between major SO2 point sources and ambient air quality in the San Manuel nonattainment area is relatively well-defined. Emissions inventories demonstrate that, while operating, the San Manuel smelter previously operated by BHP Copper Inc. comprised more than 99.5 percent of total SO2 emissions in the nonattainment area.14 As required by the 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, 1972.15 On the same date, EPA proposed revised regulations for control of sulfur oxides emitted by all existing smelters in Arizona.16 These regulations were never finalized due to issues regarding the adequacy of the ambient air quality data used to develop the limits. EPA subsequently established an SO2 monitoring network around each smelter to gather air quality data from June 1973 through October 1974 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, Arizona smelters could intermittently curtail emissions to prevent a violation of the SO2 NAAQS. EPA disapproved this approach and required installation and continuous operation of SO2 emissions controls adequate to ensure attainment of the NAAQS. Consequently, on January 4, 1978, EPA published final emissions limits for Arizona smelters based on the 1973-1974 air quality data and the use of a proportional rollback model.17 These regulations specified emissions rates 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 SO2 emission limits were developed and also allowed certain smelters additional time for emissions control technology to be installed. In response to this action, Arizona began development of new regulations and on September 20, 1979, submitted Ultimate Sulfur Dioxide Emission Limits for Arizona Copper Smelters as a proposed revision to the Arizona SIP.

14 See Chapter 4 of Final Arizona State Implementation Plan Revision, San Manuel Sulfur Dioxide Nonattainment Area, March 2007. 15 37 FR 15081 (July 27, 1972) 16 37 FR 15096 (July 27, 1972) 17 43 FR 755 (Jan 4, 1978)


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In 1978, EPA designated Pima and Pinal counties as nonattainment for the 1971 SO2 primary NAAQS for lack of a state recommendation. 18, 19 In 1979, at the request of ADEQ, EPA approved the state’s recommendation to reduce the nonattainment area to eleven townships and designated four other surrounding townships as unclassified.20 This designation remained in place after the 1990 Clean Air Act Amendments.

In 1981, Arizona submitted a proposed Multi-Point Rollback (MPR) rulemaking as a revision to the Arizona SIP. The use of MPR to establish emissions limits in rule addressed the problem of inherently variable SO2 emissions from smelting operations by correlating the frequency of short-term emissions at various levels with the probability of violating the ambient air quality standards. This technique “rolled back” a yearly emissions profile to a level protective of the standards. The new regulations, which established stack emission limits for smelters, also set requirements for analyzing the impact of fugitive SO2 emissions on ambient air quality. The rule required all existing primary copper smelters in Arizona to implement control technology sufficient to comply with the new stack limits as well as any fugitive emissions controls necessary to assure attainment and maintenance of the NAAQS.

The MPR rules were approved by EPA on January 14, 1983.21 Following approval, a consent decree (CIV 87-106-TUC-WBD, September 28, 1987) between EPA, ADEQ, and Magma Copper Company (the operators of the San Manuel smelter) was agreed to and required installation and implementation of improved control technology. The facility submitted a proposed compliance schedule in response to the consent decree for achievement of the 1979 MPR stack emission limits as expeditiously as practicable. The facility operators subsequently submitted a permit application in 1987 for installation of $157 million worth of emissions collection and control equipment. All on-site construction and installation of emission control equipment and process modification was completed in 1988, meeting the incremental compliance schedule requirements of the consent decree. New controls in 1988 included: replacement of existing reverberatory furnaces with a flash furnace, installation of ducting and hoods for capture and venting of fugitive gases to the stack, and a retrofit to a double absorption acid plant (replacing an outdated sulfuric acid plant installed in 1974) for treatment of all primary process gas.

For purposes of determining compliance with the emissions limits as codified in 1979, Magma Copper Co. was required to install and operate a measurement system for continuously monitoring SO2 concentrations in each stack that could emit 5 percent or more of the allowable annual average SO2 emissions from the smelter. In addition to primary process gas, captured fugitive emissions were continuously monitored and were included when determining compliance with the stack emissions limits. To quantify converter area uncaptured fugitive emissions, Magma Copper Co. installed and operated a continuous emissions monitoring

18 The San Manuel area was not designated nonattainment for the secondary SO2 NAAQS. See Footnote 2 in 73 FR 3396 (January 18, 2008). 19 43 FR 8968 (March 3, 1978). 20 44 FR 21261 (April 10, 1979). 21 48 FR 1717 (Jan 14, 1983)


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system at the outlets of the converter building ventilators (the primary source of fugitive emissions).

The installed controls significantly reduced emissions and enabled the smelter to come into full compliance with the MPR regulations by 1989. The collection and control technology implemented at the smelter reduced emissions sufficiently to demonstrate attainment of the SO2 NAAQS in the San Manuel area. In 1996 Magma Copper Company was acquired by BHP Copper Inc. (BHP Billiton) who became the operators of the San Manuel Smelter.

BHP Billiton was issued a Significant Permit Revision on March 24, 1998, that allowed the company to perform equipment upgrades for certain smelter equipment. The upgrades were completed during a 45-day shutdown beginning in May 1999. Although the smelter was functionally ready to operate at the end of June 1999, BHP made a decision to temporarily cease operations due to low copper prices. In 2001, BHP anticipated restarting smelting operations. However, since the smelter was shut down for more than two years, BHP was required to perform an air quality impact analysis pursuant to Arizona Administrative Code (AAC) Title 18, Chapter 2, Article 4 (AAC R18-2-411) prior to resumption of operations and demonstrate that the startup would not cause or contribute to a violation of the National Ambient Air Quality Standards for SO2. BHP conducted the analysis at much lower emissions limits than those contained in the MPR rules. The demonstration analyzed the impacts of stack and fugitive emissions on ambient concentrations. Based on the analysis, BHP applied for and received a permit revision in 2001 to incorporate these more stringent emission limits in its permit.

A 2002 rulemaking revised AAC R18-2-715 and R18-2-715.01 to include the new emissions limits. The revisions, approved by EPA on November 1, 2004, further reduced the smelter’s stack emissions limits and added new limits for converter roof fugitive emissions (see Appendix A).22 The limits provided a considerable margin of safety to ensure continued protection of the SO2 NAAQS, thus allowing the state to request that the area be redesignated to attainment for SO2. In June 2002, ADEQ submitted Final San Manuel Sulfur Dioxide Nonattainment Area State Implementation and Maintenance Plan. The June 2002 plan demonstrated maintenance of the NAAQS through the year 2015.

In January 2005, BHP Billiton notified ADEQ of their intent to permanently cease operations and remove all equipment and buildings at their San Manuel area smelting facility. In March 2005, ADEQ terminated the permit for this facility (see Appendix B). BHP does not currently hold an active permit, and no subsequent Title V permit application has been submitted to ADEQ for this closed facility. The smelting facility cannot reopen without submittal of a New Source Review and Title V (Part 70) permit application according to Arizona Revised Statutes (ARS) 49-426 and Arizona Administrative Code, Title 18, Chapter 2, Article 4, Permit Requirements for New Major Sources and Major Modifications to Existing Major Sources.

In June 2007, the ADEQ submitted to EPA Region IX its Final Arizona State Implementation Plan Revision, San Manuel Sulfur Dioxide Nonattainment Area, March 2007. This SIP revision

22 69 FR 63321 (Nov 1, 2004)


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updated the attainment demonstration for the San Manuel SO2 Nonattainment Area to reflect the permanent closure of the primary source of SO2 emissions and demonstrated the maintenance of the NAAQS through 2017. On January 18, 2008 the EPA issued a direct final rule approving the Final State Implementation Plan Revision, San Manuel Sulfur Dioxide Nonattainment Area, March 2007, and redesignating the area to attainment, effective March 18, 2008.23

CAA Section 175(A)(b) requires states to submit a subsequent maintenance plan to EPA no later than eight years after the area has been redesignated. This second maintenance plan must demonstrate that the area will continue to maintain the national primary ambient air quality standard for 10 years after the expiration of the first 10-year maintenance period. This SIP revision demonstrates maintenance of the SO2 NAAQS through 2028.

1.5 San Manuel Maintenance Area Description As discussed above, the San Manuel SO2 Nonattainment Area initially comprised all of Pima and Pinal Counties but at the request of the state of Arizona, the boundaries were subsequently reduced to eleven townships around the primary copper smelter located near San Manuel.24 In addition, four adjacent townships were designated as unclassified.25

All but one of the townships that define the maintenance area are located in southeastern Pinal County, with the remaining southernmost township located in neighboring Pima County. The current boundaries for the San Manuel SO2 Maintenance Area are codified at 40 CFR 81.303 and are defined by the complete townships listed in Table 1.2. The San Manuel Maintenance Area is illustrated in Figure 1.1.

Table 1.2 San Manuel Sulfur Dioxide Area Description

Designated Area Better than national standards

T8S, R16E X T8S, R17E X T8S, R18E X T9S, R15E X T9S, R16E X T9S, R17E X T9S, R18E X

T10S, R15E X T10S, R16E X T10S, R17E X T11S, R16E X

23 73 FR 3396 (Jan 18, 2008) 24 43 FR 8968; March 3, 1978 and 44 FR 21261; April 10, 1979 25 The San Manuel area was subsequently classified by operation of law as nonattainment for the primary SO2 standards, effective on November 15, 1990, following the enactment of the 1990 Clean Air Act Amendments.


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T10S, R18E X T11S, R17E X T12S, R16E X T12S, R17E X


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Figure 1.1 San Manuel Sulfur Dioxide Maintenance Area


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1.6 Physical, Demographic, and Economic Description of the San Manuel Area

Sections 1.6.1 through 1.6.3 describe the climate and physiography, demographics, and economy of the San Manuel area.

1.6.1 Climate and Physiography

The San Manuel area is located in south central Arizona in Pinal County, approximately 140 miles southeast of Phoenix and 45 miles northeast of Tucson.

Both desert terrain and mountain ranges are found within Pinal County’s landscape. The western portion of the County is dominated by low desert areas. The eastern portion, where the San Manuel area is located, contains mountain ranges and broad river valleys. Elevations range from near 2,000 to more than 6,000 feet above sea level in the San Manuel SO2 Maintenance Area with the town of San Manuel situated at an elevation near 3,500 feet. Other towns in the maintenance area are Oracle and Mammoth. The town of Oracle is located at an elevation of 4,514 ft., while Mammoth has an elevation of 2,350 ft. The maintenance area is bordered on the southwest by the Santa Catalina Mountains. This mountain range with elevations over 9,000 feet separates the nonattainment area from the city of Tucson and other areas of Pima County.

The varied environment experiences both warm desert and cool montane climates. In the town of San Manuel, the hottest month of the year is July, when the average daily maximum temperature is 97° Fahrenheit (F). January is the coolest month with an average daily minimum temperature of 35° F.

Precipitation generally occurs in two seasons. The wettest month in San Manuel is July when monsoonal thunderstorms produce an average monthly total of 2.67 inches of rain. Pacific winter storms moving across the area in December bring an average of 1.51 inches monthly precipitation in the form of rain or snow. The driest month is June, with an average of 0.25 inches of rain. Average yearly precipitation totals 14.59 inches.

1.6.2 Population

The San Manuel Census Designated Place (CDP) has a current population of less than 4,000.26 Mammoth, Oracle, and San Manuel have been copper mining and milling, smelting, and refining locations in the past. With the decline in mining activities and the shutdown of the BHP

26 U.S. Census Bureau. (2010). Profile of General Population and Housing Characteristics: San Manuel CDP, Arizona.


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Copper smelting and Refining Co. operations in 1999, these areas have experienced declining populations or very slow growth compared to other cities in the county.27

Table 1.3 portrays population estimates from the Arizona Department of Administration (ADOA) and the U.S. Census Bureau.28, 29 The projected growth of the San Manuel SO2 Maintenance Area and Pinal County from 2019 to 2028 are based on projected growth rates calculated by ADEQ.30

Table 1.3 Population Distribution, Selected Years, 2010-2028 Population Estimates and Projections for San Manuel SO2 Maintenance Area 11

Year 2010 (Census) 2014 2019 2023 2028

Maintenance Area 9,549 10,007 10,835 12,011 13,723

Pinal County (MA) 31 9,523 9,981 10,807 11,982 13,693 Pima County (MA) 32 26 27 28 29 31

1.6.3 Economy

Pinal County was created in 1875 from portions of Maricopa and Pima Counties by the Eighth Territorial Legislature. The county covers 5,374 square miles. The State of Arizona is the county’s largest landholder with 35 percent of the total area. Individual and corporate ownership accounts for 22 percent of the land area. Indian reservations cover 23 percent; the U.S. Forest Service and Bureau of Land Management hold 14 percent; and other public lands comprise the remaining 6 percent. The communities of Mammoth, Oracle, and San Manuel are all located within 10 miles of one another and form what is called the tri-community area. According to the Arizona Commerce Authority, smaller mines and quarries, as well as cattle ranches, have also provided employment opportunities in the San Manuel area.33

27 The San Manuel Smelter was closed in 1999 to install new upgrades. The facility did not reopen and then was permanently closed in 2005. For reference to population and economic impact, the 1999 closure is referenced due to its impact on the local community. 28 As required by Exec. Order No. 2011-04 (June 23, 2011), available at http://seago.org/sites/default/files/documents/Executive%20Order%202011-04.pdf. 29 Census Designated Places (CDPs) are delineated for decennial censuses. CDPs are places that are not legally incorporated and represent the statistical counterparts of incorporated places. 30 Please refer to Appendix A for more information on the calculations used to allocate and project the Maintenance Area population. 31This number represents the portion of the total Pinal County population that was allocated to the San Manuel Maintenance Area. 32 This number represents the portion of the total Pima County population that was allocated to the San Manuel Maintenance Area. 33 County Profile for Pinal County, Arizona Commerce Authority. (14 Sept, 2015) Retrieved: http://www.azcommerce.com/a/profiles/ViewProfile/13/Pinal+County/.

http://seago.org/sites/default/files/documents/Executive%20Order%202011-04.pdf

http://www.azcommerce.com/a/profiles/ViewProfile/13/Pinal+County/


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Pinal County is a great source of mineral wealth. Silver originally attracted settlers to the area, but as the silver resources were depleted, copper was mined. In 1944, Magma Copper Company purchased existing mining claims in the eastern portion of the county and launched a development and exploration program. Smelting operations at San Manuel began in 1956. In 1996, Magma was purchased by BHP Copper, which in 2001 became BHP Billiton (BHP). A major local employer in San Manuel has been Magma/BHP which operated underground and open pit copper mines and associated activities. BHP smelting operations were suspended in June 1999. BHP smelting, mining, and milling activities permanently ended by 2006.34

Based on current U.S. Census data, San Manuel CDP experienced a higher unemployment rate than Pinal County did as a whole in 2014. Based on 2010-2014 estimates, San Manuel CDP has an estimated unemployment rate of 10.5% compared to 7.2% for Pinal County.35

1.7 General SIP Approach - Regulatory Requirements and Guidance

In November 1990, the United States Congress enacted a series of amendments to the Clean Air Act (CAA). One of the primary effects of the revision 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 of the NAAQS, and incorporates more stringent sanctions for failure to attain or to meet interim milestones. Section 1.7.1 outlines the Clean Air Act requirements for SO2 nonattainment areas. Section 1.7.2 lists applicable EPA guidance.

1.7.1 Clean Air Act Requirements Clean Air Act, Title I, Part A, and Title I Part D, Subparts 1 and 5 are applicable to this SIP and maintenance plan. Sections 175(A), 176(c)(1)(A), 191, and 192 set forth the requirements, as described in Table 1.4, for SO2 nonattainment areas.

34 See the Final State Implementation Plan Revision, San Manuel Sulfur Dioxide Nonattainment Area, March 2007 for more history on San Manuel’s economy. Available in docket EPA-R09-OAR-2006-0214 Retrieved from: https://www.regulations.gov/docket?D=EPA-R09-OAR-2006-0214. 35 U.S. Census Bureau, 2010-2014 American Community Survey 5-Year Estimates, San Manuel CDP, AZ.

https://www.regulations.gov/docket?D=EPA-R09-OAR-2006-0214


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Table 1.4: Applicable Regulatory Requirements CAA Title I – Air Pollution Prevention and Control; Part D – Plan Requirements for Nonattainment Areas; Section 175A – Maintenance Plan Requirements Regulation Requirement Action to Meet Requirement Location in SIP § 175A(b) – Second Maintenance Plan

"8 years after redesignation of any area as an attainment area under section 107(d), the State shall submit to the Administrator 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)."

This maintenance plan renewal satisfies this requirement.

See this submittal.

§ 175A(c) - NAA Requirements

"Until such plan revision is approved and an area is redesignated as attainment for any area designated as a nonattainment area, the requirements of this part shall continue in force and effect with respect to such area."

This provision is not applicable for this maintenance plan renewal because the San Manuel SO2 planning area is no longer designated nonattainment.

No additional location.

§ 175A(d) -Contingency Provisions

"Each plan revision submitted under this section shall contain such contingency provisions as the Administrator deems necessary 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 which were contained in the State implementation plan for the area before redesignation..."

Because the primary source of SO2 emissions in the San Manuel MA (BHP Copper Inc. smelter) no longer exists, the area is not subject to such stringent contingency measure requirements. In general, the maintenance area would be subject to new source permitting requirements under ADEQ's Prevention of Significant Deterioration (PSD) program as a contingency measure.

See chapter 5.


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CAA Title I – Air Pollution Prevention and Control; Part D – Plan Requirements for Nonattainment Areas; Section 176 – General and Transportation Conformity Requirements Regulation Requirement Action to Meet Requirement Location in SIP

§ 176(c) - General Conformity Regulations

Section 176(c) of the Clean Air Act prohibits Federal entities from taking actions in nonattainment or maintenance areas which do not conform to the State implementation plan (SIP) for the attainment and maintenance of the NAAQS. Therefore, the purpose of conformity is to (1) ensure Federal activities do not interfere with the budgets in the SIPs; (2) ensure actions do not cause or contribute to new violations, and (3) ensure attainment and maintenance of the NAAQS.

General conformity needs to be addressed to assure SO2 emissions from any federal actions or plans do not exceed the rates outlined in 40 CFR § 93.153(b).36 Criteria for general conformity are located in R18-2-1438 of the Arizona Administrative Code. There are no known federal plans or actions affecting air quality currently in the San Manuel area. ADEQ commits to review and comment, as appropriate, on federal agency draft general conformity determinations it receives pursuant to 40 CFR § 93.155 for activities planned for this air quality planning area.


§ 176(c) -Transportation Conformity

Transportation conformity is required by the CAA section 176 (42 U.S.C. 7506(c)) to ensure that federal funding and approval are given to highway and transit projects that are consistent with the air quality goals established by a state’s SIP. Conformity, to the purpose of the SIP, means that transportation activities will not cause new air quality violations, worsen existing violations, or delay timely attainment of the NAAQS.

Title 40 CFR § 93.102(b) waives transportation conformity for SO2 nonattainment and maintenance areas.


36 58 FR 63253; November 30, 1993


16

EPA Guidance: Procedures for Processing Requests to Redesignate Areas to Attainment, Memorandum issued by John Calcagni in 1992 Regulation Requirement Action to Meet Requirement Location in SIP Calcagni Memo (5) - Maintenance Projection Duration

"The maintenance demonstration should project maintenance for 10 years, beginning from a date which factors in the time necessary for EPA review and approval action on the redesignation request [at least 18 months]."

This maintenance plan renewal projects maintenance through 2028, which is 10 years after the first maintenance period.

See chapters 3 and 5.

Calcagni Memo (5)(a)-Attainment Emissions Inventory

"The State should develop an attainment emissions inventory to identify the level of emissions in the area which is sufficient to attain the NAAQS."

This submittal includes an emissions inventory for the base year of 2014 using the most recently available National Emissions Inventory (NEI) data.


Calcagni Memo (5)(b)-Maintenance Demonstration

"A State may generally demonstrate maintenance of the NAAQS by either showing that future emissions of a pollutant or its precursors will not exceed the level of the attainment inventory, or by modeling to show that the future mix of sources and emission rates will not cause a violation of the NAAQS."

This submittal includes emissions inventories for the maintenance period between 2018 and 2028.


Calcagni Memo (5)(c)-Verification of Attainment Through Monitoring Network

"The maintenance plan should contain provisions for continued operation of air quality monitors that will provide such verification [of attainment status of the area]."

While ambient air quality monitoring has ceased in the San Manuel SO2 maintenance area due to the permanent closure of the primary source and in accordance with 40 CFR 58.14(c)(3), ADEQ commits to resume monitoring should any new sources apply through the permitting process.37


37 As initially discussed in the ADEQ Ambient Air Monitoring Network Annual Plan for 2007, Federal regulations at 40 CFR 58.14 allows sites to be closed under specific circumstances. Specifically, the option under 40 CFR 58.14(c)(3) allows for discontinuation of a monitor within an attainment, nonattainment, or maintenance area, “…provided the monitor has not measured violations of the applicable NAAQS in the previous five years, and the approved SIP provides for


17

Calcagni Memo (5)(d)-Progress Tracking

"Each State should ensure that it has the legal authority to implement and enforce all measures necessary to attain and to maintain the NAAQS.....the State submittal should indicate how the State will track the progress of the maintenance plan."

ADEQ has general authority to implement and enforce all measures to maintain the 1971 SO2 primary NAAQS per A.R.S. §§ 49-104, 49-404, 49-422, and 49-424. ADEQ will track the progress of this maintenance plan renewal by updating emission inventories and through permitting requirements.

See chapter 5.

Calcagni Memo 5(e) - Maintenance Contingency Plan

"...The contingency plan is considered to be an enforceable part of the SIP and should ensure that the contingency measures are adopted expediently once they are triggered. The plan should clearly identify the measures to be adopted, a schedule and procedure for adoption and implementation, and a specific time limit for action by the State...the State should also identify specific indicators, or triggers, which will be used to determine when the contingency measures need to be implemented."

The contingency provisions for the San Manuel SO2 maintenance area are implemented through the state’s PSD program.

See chapter 5.

a specific, reproducible approach to representing the air quality of the affected county in the absence of actual monitoring data.” ADEQ closed the monitor at this site in accordance with these regulations.

San Manuel SO2 Maintenance Plan Renewal

18

1.7.2 EPA Guidance

The following EPA guidance was referenced in the development and submission of this SIP:

• Procedures for Processing Requests to Redesignate Areas to Attainment, Memorandum from John Calcagni. U.S. Environmental Protection Agency. September 4, 1992.

• Second 10-Year Maintenance Plans for the National Ambient Air Quality Standards, Frequently Asked Questions. U.S. Environmental Protection Agency. December 2014.


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2 Ambient Monitoring Network Section 2.1 presents an overview of monitoring requirements for SO2 planning areas that no longer have monitoring networks in place and Section 2.2 presents a history of the San Manuel maintenance area’s air quality. Section 2.3 describes ADEQ’s commitment to resume monitoring should a new source enter the area. Finally, section 2.4 summarizes the area’s continued attainment of the 1971 SO2 primary standard.

2.1 SO2 Monitoring Requirements EPA’s protocols for SO2 air monitoring and designations are located in the following sections of the CFR:

• 40 CFR Part 50, Appendix A, Reference Method for the Determination of Sulfur Dioxide in the Atmosphere

• 40 CFR Part 53, Subpart B, Procedures for Testing Performance Characteristics of Automated Methods for SO2, CO, O3, and NO2

• 40 CFR Part 58, Subparts A, B, and C, Ambient Air Quality Surveillance

Ambient SO2 monitoring began in the San Manuel area as early as 1969 by the State of Arizona.38 Smelting facility operators began continuous ambient SO2 air quality monitoring in 1973. Over a period of years, an extensive monitoring network was developed with sufficient spatial and temporal coverage to comprehensively evaluate the ambient impact of smelter emissions. More than eighteen stationary and mobile monitoring sites were established throughout the area with as many as ten monitors operating concurrently. A table of historic monitoring sites from the 2007 San Manuel SIP is included below in Table 2.1 for context of the extensive monitoring network that previously existed in the Maintenance Area.39

38 Sulfur Dioxide Monitoring Network Study, Arizona State Department of Health, Environmental Health Services, Division of Air Pollution Control, 1969. 39 Please refer to the first San Manuel maintenance plan submission for a full description of the historic monitoring network. Final State Implementation Plan Revision, San Manuel Sulfur Dioxide Nonattainment Area, March 2007.


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Table 2.1: San Manuel Historic Ambient Monitoring Network 40

San Manuel Historic Ambient Monitoring

Monitor Site Period of Operation

LDS Church41 1975-1999 and 2002-2007

Townsite42 1969-1974 and 1979-2002 Hospital43 1987-2002 Dorm Site44 1978-2002 Golf Course 1974-1997 3-C Ranch 1981-1982 and 1987-1994 Elks 1987-1994 Oracle Courthouse 1975-1994 Minesite 1974-1994 Mammoth Courthouse 1974-1987 Redington 1976-1985 Mammoth Aravaipa Canyon 1980-1981 Industrial Hygiene 1981 Mercer Ranch 1979-1980 Oracle Holy Cross Canyon 1978-1979 Mobile45 1977-1978 Upper Shopping Center 1975-1978 East Peppersauce Wash 1974-1978 Trailer Park 1974-1975 EPA46 1973-1974

40 See EPA approved 2007 San Manuel Maintenance Plan SIP. 73 FR 3396 (Jan 18, 2008), and ADEQ Annual Air Monitoring Network Plans. 41 The LDS Church monitor was removed in October 1999 due to the closure of the BHP smelter. This monitoring site was reestablished in March 2002. 42 Monitoring site closed at the end of 2002. 43 See footnote 36. 44 See footnote 36. 45 The 1977/1978 San Manuel Smelter Operations and Maintenance Manual notes eleven experimental mobile monitoring locations to date. 46 Monitors at three EPA established sites were operated during this period.


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The San Manuel smelter was by far the largest source of SO2 in the San Manuel area and was shut down in 1999. Following the shutdown of the smelter, SO2 concentrations in the area decreased and the facility-operated Townsite, Dorm Site, and Hospital monitors were closed. In addition, the fourth monitor located at the LDS Church site was also initially closed in 1999. However, after internal review of the necessary monitoring regulations and requirements for modification of the monitoring network for ambient air quality surveillance, ADEQ reopened the monitor in 2002 and continued to operate the LDS Church site monitor until 2007 when it was closed in accordance with 40 CFR 58.14(c)(3) after 5 years.47

2.2 Air Quality Data A review of historic ambient SO2 monitoring data in the San Manuel Nonattainment Area verifies that no violations of the primary SO2 NAAQS have been recorded since 1979 and no violations of the secondary SO2 NAAQS have been recorded since 1985.48

Implementation of control measures and subsequent emissions reductions at the San Manuel copper smelter enabled the area to attain the SO2 NAAQS.49 Measured maximum concentrations from the LDS Church monitoring site, as presented in Figure 2.1, Figure 2.2, Figure 2.3, illustrate the improvement in air quality from 1975 through 2007.

47 40 CFR 58.14(c)(3) 48 See Arizona Department of Health Services, Bureau of Air Quality Control and Arizona Department of Environmental Quality annual reports 1970 through 2007 and EPA Air Quality System annual summary reports. 49 See Chapter 1 and the EPA approved 2007 San Manuel Maintenance Plan SIP. 73 FR 3396 (Jan 18, 2008).


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Figure 2.1: San Manuel (LDS Church) Maximum 3-hour SO2 Concentrations 50

50 See citation 41

0

500

1000

1500

2000

2500

3000

3500

4000ug

/m3

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monitored maximum concentration 3 hour standard

* The 1996 exceedance was determined due to a process/equipment malfunction at the San Manuel smelting facility. The LDS Church monitor was removed in October 1999 due to the closure of the BHP smelter. This monitoring site was reestablished and operated from March 2002 until permanently closed in 2007.


23

Figure 2.2: San Manuel (LDS Church) Maximum 24-hour SO2 Concentrations 51

Figure 2.3: San Manuel (LDS Church) Annual Average SO2 Concentrations 52

Monitoring data for 1997 through 1999, while the San Manuel smelter was still operating, indicate that maximum ambient concentrations were less than 55 percent of the NAAQS for the

51 See citation 41 52 See citation 41

0

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0

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* The 1994 exceedance was determined due to a process/equipment malfunction at the San Manuel smelting facility.


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3-hour standard; less than 59 percent of the NAAQS for the 24-hour standard; and less than 33 percent of the NAAQS for the annual standard.

Closure of the smelter in 1999 further reduced emissions and resultant ambient SO2 concentrations. Monitoring data for 2002 through 2007 indicate that maximum ambient concentrations were two percent of the NAAQS for the 3-hour standard; less than three percent of the NAAQS for the 24-hour standard; and less than seven percent of the NAAQS for the annual standard.

ADEQ does not currently operate any ambient air monitors in the San Manuel area after the permanent closure of the LDS Church monitor in accordance with 40 CFR 58.14(c)(3) after recording 5 years of clean data. 53

2.3 Continued Attainment of the Standards Under CAA Section 107(d)(3)(E), states must show that a maintenance area continues to attain the NAAQS. Usually this requirement is met through ambient air quality data and modeling. But for areas like San Manuel, where large sources of SO2 shut down and air monitoring is no longer conducted, current air quality data is not available.

For this reason, EPA’s Calcagni Memo provides directions on how states may demonstrate maintenance. In section 5(b) of the Calcagni Memo, it states that “a state may generally demonstrate maintenance of the NAAQS by either showing that future emissions of a pollutant or its precursors will not exceed the level of the attainment inventory…”.54 Further section 5(b) states that “the state should project emissions for the 10 year period following redesignation, either for the purpose of showing that emissions will not increase over the attainment inventory or for conducting modeling.”

In line with this guidance, for the first 10-year SO2 maintenance plan for San Manuel, ADEQ demonstrated that the nonattainment area had recorded more than eight current, consecutive quarters of quality assured, violation-free data. The SIP also included emissions inventories that demonstrated attainment and maintenance of the 1971 SO2 primary standards.

For this maintenance plan renewal, continued attainment is illustrated using emissions inventories to show that projected future emissions do not exceed the level of the attainment inventory for the second 10-year maintenance period between 2018 and 2028 (see sections 3 and 5).

53 For more information on historic monitoring requirements, data, and deployment, please refer to the 2007 San Manuel Maintenance Plan SIP 73 FR 3396 (Jan 18, 2008) 54 See Procedures for Processing Requests to Redesignate Areas to Attainment, memorandum issued by John Calcagni, Environmental Protection Agency, issued September 4, 1992, page 9.


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3 Emissions Inventories Section 3.1 presents the regulatory requirements for the emission inventories for a SO2 maintenance area. ADEQ then presents its technical approach for developing emission inventories for the base year (2014), and all future maintenance years (2019, 2023, and 2028) in Section 3.2. The results of such inventories are in Sections 3.4 and 3.5. Lastly, a summary of ADEQ’s analysis is provided in Section 3.6.

3.1 Requirements ADEQ is required to submit to EPA a maintenance plan renewal to demonstrate that the San Manuel SO2 MA will continue to attain the 1971 SO2 NAAQS ten years after the first maintenance plan duration.55 The 1992 Calcagni Memo suggests that states develop two types of inventories for the maintenance plan:

1. an attainment emissions inventory to identify the level of emissions in the area which is sufficient to attain the NAAQS.

2. a series of projected emission inventories: “the State should project emissions for the 10 year period following redesignation for the purposes of showing that that future emissions will not exceed the level of the attainment inventory”. 56

For this second maintenance plan, ADEQ has chosen to achieve these requirements by relying on emission inventories for San Manuel for five distinct time periods.57

1. a year in which the smelter was operating and the monitor was in attainment (1998);

2. a year in which the smelter was closed and the monitor was in attainment (2005);

3. the current actual and allowable emissions (2014 NEI);

4. two interim years between the current actual emissions and the final year of the maintenance period (2019 &2023); and

5. a projected inventory to the tenth year of the first San Manuel SO2 maintenance plan (2028).

55 See CAA § 175A 56 See Procedures for Processing Requests to Redesignate Areas to Attainment, memorandum issued by John Calcagni, Environmental Protection Agency, issued September 4, 1992 57 See Figure 3.1 below


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Table 3.1: San Manuel SO2 Emission Inventories Inventory Year Inventory Purpose Data Source 1998 Support 58 San Manuel Maintenance SIP 2007 2005 Attainment Year 59 San Manuel Maintenance SIP 2007

2014 Base Year 2014 NEIv1, MOVES2014a modeling & Pinal Point Source Database

2019 Maintenance Demonstration Projected from base year 2023 Maintenance Demonstration Projected from base year 2028 Maintenance Demonstration Projected from base year

3.2 Approach In order to meet the inventory requirements outlined above, ADEQ developed inventories for a support year, an attainment year, a base year, and three projected years. By using these six emission inventories, ADEQ demonstrates the dramatic reduction in emissions that has occurred since the closure of the primary emissions source in the San Manuel maintenance area, and that these reductions will be maintained into the future.

In order to satisfy the first inventory requirement outlined above to create an attainment inventory, ADEQ relied on the 2005 emissions inventory that was originally developed for the EPA-approved Final State Implementation Plan Revision, San Manuel Sulfur Dioxide Nonattainment Area, March 2007. 60 This inventory fulfils the requirement by demonstrating NAAQS attainment while the monitor was operating and after the closure of the primary source. To help complement this maintenance demonstration, point source inventory data for the year 1998 was also included in some graphs and tables to help demonstrate the dramatic difference in area emission between when the smelter was operating (1998) and a year when the smelter was closed (2005).

For the remaining inventories, ADEQ used two different sources to collect its data. The first was point source emissions gathered from Pinal County’s internal point source database. The second source for other categories (nonpoint & nonroad) were based primarily on EPA’s 2014 National Emissions Inventory (NEI) Version 1. Because the 2014 NEI and Pinal County point source database provided the most recent comprehensive inventory of SO2 emissions in Pinal and Pima Counties, ADEQ selected 2014 as the base inventory and built additional inventories through the end of the second maintenance period for 2019, 2023, and 2028.

58 Support year in which the smelter was open and meeting the NAAQS. 59 Attainment year in which the smelter was closed 60 See 73 FR 3396 (Jan 18, 2008)


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This chapter provides a summary of methodologies used to calculate emissions. The following subsections summarize total SO2 emissions inventoried from point, mobile (nonroad and onroad), and area (nonpoint) source categories. A detailed description of the development of these inventories is in the Emission Inventory Technical Support Document found in Appendix A.

3.3 Methodologies

3.3.1 Base Year

The base year for the San Manuel SO2 SIP revision will be 2014. The 2014 NEIv1 was chosen because it represents the most current, accurate, and comprehensive inventory available for area sources.

ADEQ, Pinal County Air Quality Department (PCAQD), and Pima County Department of Environmental Quality (PDEQ) share jurisdiction over air quality matters in the San Manuel SO2 Maintenance Area. PCAQD has jurisdiction over the Pinal County portions of the San Manuel SO2 Maintenance Area. PDEQ has jurisdiction over the Pima County portion. Currently only PCAQD has active permits in the San Manuel SO2 Maintenance Area. PCAQD collects annual emissions data from all permitted air facilities under their jurisdiction. These annual emission inventory reports were the basis for the point source inventory.

For most area and mobile source sectors, ADEQ utilized a top down approach scaling the 2014 National Emissions Inventory version one (2014 NEIv.1) to the planning area. The scaling factors which allocate emissions from Pima and Pinal County at large down to the MA vary depending on the source(s) in question. ADEQ examined each area (nonpoint) and mobile source of SO2 from the 2014 NEI and determined the most appropriate surrogate for allocation, for example, population or railway length. ADEQ then estimated emissions for the MA using top-down allocation factors.

3.3.2 Future Years

In order to demonstrate attainment throughout the second maintenance period, ADEQ projected emissions in the MA and for ten years after 2018 using the maximum potential to emit value of SO2 emissions for each facility. ADEQ projected inventories starting with 2014 (the last inventory year included in the 2005 maintenance plan supplement) and continued increments through the end of the second maintenance period; the inventory years are 2014, 2019, 2023, and 2028.

For most emissions sources in the MA, ADEQ developed growth factors, which are presented in the EI TSD. ADEQ applied these factors to develop Pima and Pinal County emissions estimates for each future year. These county-level projections map down to the MA using the same allocation methods as in the base year inventory.


28

ADEQ estimated growth factors for mobile source emissions by using EPA’s Motor Vehicle Emissions Simulator (MOVES) to model SO2 emissions totals for the MA.

Methodologies are further detailed in the EI TSD in Appendix A.

3.4 Base Year Emissions – All Sources In the 2014 base year, mobile sources and permitted point sources contributed most of the SO2

emissions in the MA. Table 3.1 summarizes SO2 emissions estimates for the MA in 2014.

Table 3.1: SO2 Emissions in the San Manuel MA in 2014

Source Category Maintenance Area Emissions TPY

On-road Mobile 1.41

Non-road Mobile 1.14

Area

Fires 0.52 Fuel Combustion 0.64 Industrial Processes 0.60 Waste Disposal 0.82 Solvent 0.00

Point Permitted 3.80

Total 8.92

3.5 Future Year Emissions – All Sources Table 3.2 below summarizes SO2 emissions projections for the San Manuel MA through the second maintenance period. The decrease in contribution from area/mobile sources can be attributed to changes in the diesel fuel standard.61 The increased emissions are due to the ADOA population growth projected for the San Manuel MA.

61 66 FR 5002, January 18, 2001; 77 FR 75868, December 26, 2012; 69 CFR 38958, June 29, 2004;80 FR 9078, February 19, 2015


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Table 3.2: SO2 Emissions in the MA in Maintenance Years

Source Category Maintenance Area Emissions (tons)

2019 2023 2028

On-road Mobile 0.72 0.75 0.80

Non-road Mobile 1.30 1.45 1.65

Area

Fires 0.52 0.52 0.52

Fuel Combustion 0.72 0.80 0.91

Industrial Processes 0.68 0.76 0.87

Waste Disposal 0.94 1.04 1.19

Solvent 0.00 0.00 0.00

Point Permitted 4.54 4.54 4.54 Total 9.43 9.86 10.48

3.6 Summary ADEQ estimated that nearly 8.92 tons of SO2 were emitted in the MA in 2014.

Figure 3.2 below shows that in future years, actual SO2 emissions are projected to remain below the 2005 attainment inventory. The 2005 SO2 emissions are 27.6 tons and the 2028 emissions are projected to be 10.48 tons. This means that SO2 emissions for the duration of the maintenance period will remain at levels below the levels where the area was in attainment.

For additional context the year 1998 was included to demonstrate the dramatic difference in area emission between when the smelter was operating (1998) and a year when the smelter was closed (2005). It should also be noted that in 1998 the San Manuel Maintenance area was still in attainment despite the 10,440 tons emitted in the area. The total SO2 emissions for the year are detailed in the graph callouts.


30

Figure 3.2: San Manuel Maintenance Area SO2 Emissions Projections 1998-2028

Figure 3.3 below shows emissions at greater resolution. It shows that area and mobile sources account for over half of the total emissions in the area. The total SO2 emissions for the year is detailed in the callout. Since, the total emissions projected for 2028 are 38 percent of 2005 total emission the MA still meets the Ambient Air standards for the SO2 NAAQS.

Figure 3.3: San Manuel Maintenance Area SO2 Emissions Projections 2005-2028

10440

27.6 8.9 9.43 9.86 10.480

2000

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6000

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1998 2005 2014 2019* 2023* 2028*

Emis

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area/mobile point total

27.6

8.9 9.43 9.86 10.48

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Emis

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*Projected


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4 Control Measures This chapter discusses the necessary control-related provisions for the San Manuel MA. Section 4.1 outlines the regulatory requirements. Sections 4.2 and 4.3 present the applicable SO2 emission control measures for sources within the San Manuel SO2 maintenance area.

4.1 Requirements Nonattainment area plans are required to provide for the implementation of all reasonably available control measures (RACM) including reductions in emissions from existing sources in the area that may be obtained through reasonably available control technology (RACT). RACT is the emissions control level for sources located in SO2 nonattainment areas. RACT is determined, in part, by the technological and economic feasibility of the control for the specific source and is generally defined for SO2 as control technology which will achieve the NAAQS within statutory timeframes.62

The BHP copper smelter was the primary source of SO2 emissions in the San Manuel MA. Emissions inventories demonstrate that, while it was operating, the San Manuel smelter comprised more than 99.5 percent of total SO2 emission in the nonattainment area (see Chapter 3). No other SO2 emitting sources of this magnitude have historically operated or currently operate in the San Manuel area. Implementation of new emissions control technologies at the smelter in 1988 reduced emissions by more than 150,000 tons per year. These emissions reductions enabled the area to attain the NAAQS. The permanent closure of this facility in March 2005 provided additional emissions reductions of more than 10,000 tons per year (see Chapter 1 for a regulatory history of the San Manuel area). Closure of the smelter is considered to meet RACM requirements.

Maintenance plans, per CAA Section 175A, should ensure that the level of control that allowed the area to reach attainment will continue to do so in the future.

4.2 Point Sources

4.2.1 BHP Copper San Manuel Smelter

As previously noted, the BHP smelter was the major source of emissions in the San Manuel SO2

MA. When this facility was in operation in 1973, the source emitted an annual total of roughly 451,000 tons of SO2. The source was subject to R18-2-715(A)-(E), Standards of Performance for Existing Primary Copper Smelters; Site-Specific Requirements; R18-2-715.01, Compliance and

62 U.S. EPA, Office of Air and Radiation, Office of Air Quality Planning and Standards, SO2 Guideline Document, February 1994.


32

Monitoring; and R18-2-715.02, Fugitive Emissions.63 R18-2-715, known as a Multi-Point Rollback Rule (MPR rule), contained site-specific requirements for all existing primary copper smelters. The MPR rule included a compliance date of January 14, 1986.

The permanent closure of the BHP Copper smelting operations greatly reduced SO2 emissions in the maintenance area, thus meeting RACM requirements. Since the BHP Copper San Manuel Smelter was the only major source of emissions, adoption of additional control measures is not necessary to maintain the NAAQS. Furthermore, since the closure of smelter, there have been no new sources of SO2 the magnitude of BHP San Manuel Smelter. Should new major sources enter, or major modifications to existing sources arise in the San Manuel SO2 maintenance area, they would be subject to Arizona’s PSD permitting program in order to protect air quality.

4.2.2 Other Point Sources

Point Sources in the San Manuel SO2 Maintenance Area

ADEQ identified six other point sources within the San Manuel SO2 MA, aside from the now closed BHP Copper San Manuel Smelter. These are:

1. Bonito Quarry - Rock Quarry

2. San Manuel School - School

3. Decorative Rock Sales – Sand and Gravel Operation

4. Biosphere 2 – Tourism

5. Saddlebrooke Ranch Water Reclamation Plant – Water Reclamation

6. Oracle Compressor Station – Natural Gas Transport

As previously mentioned in this document, ADEQ, Pinal County Air Quality Department (PCAQD), and Pima County Environmental Quality (PDEQ) share air quality jurisdiction in the San Manuel MA. Currently of these 3, PCAQD is the only department that holds active permits in the area. PCAQD collects annual emissions data from all permitted air facilities, and that data was used to create the point source inventory for this maintenance plan renewal.

The permits for these sources limit emissions to less than 4 tons per year combined. Looking at actual reported emissions from 2015, the point sources identified above emitted less than 3 tons per year (TPY) combined for 2015 (see Table 4.1 below). These current emissions represent less than one half of a percent of the 1998 example year inventory emissions and demonstrate that the remaining sources are all minor in comparison with the original source that caused the NAAQS violations.

63 Please note that at the time of this SIP’s development, R18-2-715 and R18-2-715.01 were in the process of being amended as part of the 2010 SO2 NAAQS SIPs for the Hayden and Miami nonattainment areas. These amendments, however, do not directly affect the San Manuel MA.


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Table 4.1: Point Source Emissions - PTE and actual Emissions

4.3 Area and Mobile Sources For the 2014 base year, ADEQ estimated area and mobile source emissions at about 5.1 tons per year (tpy) within the MA. In 2028, area and mobile emissions are projected to total 5.9 tpy. The emissions from area and mobile sources are too minimal to require control measures.

Additionally, there are several EPA programs in place related to the sulfur content of fuels. Due to these national programs, future SO2 emissions are low, as projected in Chapter 3 of this SIP and in the Emissions Inventory TSD in Appendix A. Federal programs include:

1. Tier 2 Vehicle and Gasoline Sulfur Program for passenger vehicles 2. Tier 3 Vehicle Emission and Fuel Standards Program 3. Heavy-Duty Engine and Vehicle Standards and Highway Diesel Fuel Sulfur Control

Requirements for highway trucks and buses 4. Clean Air Nonroad Diesel Rule for nonroad diesel equipment

EPA’s Tier 2 program implements stringent emissions standards for nitrogen oxides from all passenger cars and light trucks. To meet the emission standards, the program incorporates requirements that substantially reduce sulfur levels in gasoline. Sulfur in fuel impairs the effectiveness of vehicle emission control systems and by removing most of the sulfur from gasoline, emission controls work longer and more efficiently. As a result, the standards reduce the average national sulfur content in gasoline by up to 90 percent.67

64 TPY stands for tons per year. 65 PTE as of 2016, PTE stands for “Potential to Emit” 66 The PTE for Bonito Quarry is shown as lower than the actual emissions due to the permit being revised in 2016 and the point source database from PCAQD being updated to reflect their new PTE for 2016. No permit violations occurred for this facility. 67 To learn more about the Tier 2 vehicle program, visit http://www3.epa.gov/tier2/.

Facility Facility SO2 TPY 64

PTE 65 2013 2014 2015 BONITO QUARRY 0.80 66 2.91 1.85 1.87 SAN MANUEL SCHOOLS 0.03 0.00 0.00 0.00 DECORATIVE ROCK SALES 0.70 0.51 0.67 0.02 BIOSPHERE 2 0.71 0.04 .03 0.03 SADDLEBROOKE RANCH WATER RECLM PLANT 0.40 0.00 0.00 0.00

ORACLE COMPRESSOR STATION 1.90 1.46 1.28 1.07

http://www3.epa.gov/tier2/


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The Tier 3 program, published in 2014, will set more stringent vehicle emissions standards and will lower sulfur content in gasoline beginning in 2017. The vehicle standards will reduce both tailpipe and evaporative emissions from passenger cars, light-duty trucks, medium-duty passenger vehicles, and some heavy-duty vehicles. The gasoline sulfur standard will enable more stringent vehicle emissions standards and will make emissions control systems more effective.68

The 2007 Heavy-Duty Engine and Vehicle standards and Highway Diesel Fuel Sulfur Control program established new nitrogen oxides and particulate matter emissions standards for heavy-duty highway engines and vehicles. The standards are based on high-efficiency catalytic exhaust emission control technologies. Because emissions control devices are damaged by sulfur, associated regulations reduce the sulfur in highway diesel fuel by 97 percent.69

The Clean Air Nonroad Diesel Rule established new oxides of nitrogen and particulate matter emission standards that are applicable to diesel engines used in construction, agricultural, industrial, and other equipment. To prevent damage to emissions control systems, the regulations also require a reduction in sulfur levels in nonroad diesel fuel from the current approximately 3,000 parts per million to 15 parts per million when fully implemented. Fuel sulfur reductions are being phased in over a number of years that began in 2007.70

68 To learn more about the Tier 3 vehicle program, visit http://www3.epa.gov/otaq/tier3.htm. http://www.epa.gov/otaq/tier3.htm 69 To learn more about the Heavy-Duty Highway Diesel program, visit http://www3.epa.gov/otaq/highway-diesel/index.htm. 70 To learn more about the Nonroad Diesel rule and requirements, visit http://www3.epa.gov/otaq/nonroad-diesel.htm.

http://www3.epa.gov/otaq/tier3.htm

http://www.epa.gov/otaq/tier3.htm

http://www3.epa.gov/otaq/highway-diesel/index.htm

http://www3.epa.gov/otaq/highway-diesel/index.htm

http://www3.epa.gov/otaq/nonroad-diesel.htm

http://www3.epa.gov/otaq/nonroad-diesel.htm


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5 Maintenance Plan Section §175A of the Clean Air Act requires submittal of a SIP revision that provides for 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 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.

Subsection (b) of §175A of the Clean Air Act requires states to demonstrate continued attainment of the NAAQS for 10 years beyond the initial maintenance period for a MA (throughout a second maintenance period). This Chapter addresses the core provisions for maintenances plans outlined above and as recommended in the September 4, 1992, Memorandum, Procedures for Processing Requests to Redesignate Areas to Attainment.

5.1 Maintenance Demonstration Maintenance plans should provide a demonstration that future emissions of SO2 will not cause a violation of the NAAQS. This SIP revision demonstrates the San Manuel area will continue to maintain the 1971 primary SO2 NAAQS, in part, by showing that future emissions of SO2 will not exceed the level of the attainment inventory. Figure 5.1 compares the level of the attainment inventory (2005) to the maximum expected level of point, area, and mobile source emissions in the San Manuel SO2 MA for a second maintenance period, through 2028. Current (2014 NEI) and future (2028) emissions from all sources do not exceed the level of the attainment inventory, and in fact, are estimated to be less than half the attainment period levels (2005). In addition, to help support the maintenance demonstration, data for 1998 was included to represent a year in which the smelter was operating and still attaining the NAAQS, despite the 10,440 tons emitted. The total SO2 emissions for the year are detailed in the graph callouts.


36

Figure 5.1: San Manuel Maintenance Area SO2 Emissions 1998-2028 71

For a closer look at the attainment year and the projected future years, Figure 5.2 clearly demonstrates that the projected future inventory years of 2019, 2023, and 2028 will all be well under the level of the attainment inventory by more than half.

71 This graph details emission totals combining totals of point and area/mobile sources for the years 1998-2028. For years 2019-2028 the emissions are projected from the 2014 NEI utilizing the methods detailed in Chapter 3 and Appendix A. The emission inventories for 1998 and 2005 were taken from the SIP approved 2007 San Manuel Maintenance Plan SIP. See Chapter 3 and 73 FR 3396 (Jan 18, 2008) for more information on those inventories.

10440

27.6 8.9 9.43 9.86 10.480

2000

4000

6000

8000

10000

12000

1998 2005 2014 2019* 2023* 2028*

Emis

sion

s (to

ns/y

ear)

Year




37

Figure 5.2: San Manuel Maintenance Area SO2 Emissions 2005-2028

To further complement this demonstration, below is a graph that shows a comparison between the ambient monitoring data from 1998 and 2005 compared to the 1971 NAAQS 24-hour limit. It can be clearly seen that even when the smelter was operating (represented by 1998) that the San Manuel MA was attaining the 1971 24-hour standard.

The emissions inventories for the Maintenance Area demonstrate a stringent level of protection of ambient air quality, the permanent and enforceable emissions reductions due to the closure

27.6

8.9 9.43 9.86 10.48

0

10

20

30

40

50

2005 2014 2019* 2023* 2028*

Emis

sion

s (to

ns/y

ear)

Year



102.4 µg/m3

8.1 µg/m3

365 µg/m3

0

50

100

150

200

250

300

350

400

1998 2005

Ambi

ent M

onito

r Dat

a (µ

g/m

3 )

Year

Comparison of LDS Church Site Ambient Monitoring Data for 1998 and 2005 vs. 1971 24 hour Sulfur Dioxide NAAQS

LDS Church Monitor (24 hour average) 1971 24 hour Sulfur Dioxide NAAQS


38

of the San Manuel smelter are greater than needed to attain and maintain the NAAQS. Therefore, the area is expected to continue to exhibit a substantial margin of safety that is protective of the 1971 SO2 NAAQS.

5.2 Ambient Monitoring Once an area is redesignated to attainment, continued operation of an appropriate air quality monitoring network is generally required to verify the attainment status of the area. In the San Manuel area, historic violations were caused by a major point source of SO2 emissions that is no longer in operation and ambient SO2 monitors were removed immediately following the shutdown of the emissions source. However after internal review of future data needs, the LDS Church monitor that had been closed in 1999 was reopened in 2002 and continued to operate until 2007 when it was closed in accordance with 40 CFR 58.14(c)(3) after 5 years of clean data. The ADEQ does not currently operate any air monitors for the San Manuel MA.

ADEQ will continue to demonstrate maintenance of the SO2 NAAQS through verification of the emissions inventory. In addition, ADEQ commits to reestablish an appropriate ambient monitoring network before any major source of SO2 begins operations in the San Manuel MA.

5.3 Verification of Attainment The state is required to provide assurance that it has the legal authority necessary to implement and enforce all necessary measures used to attain and maintain the NAAQS and include an indication of how it will track the progress of the maintenance plan.72

ADEQ anticipates no relaxation of any implemented control measures used to attain and maintain the ambient air quality standards. ADEQ commits to submit to EPA Region 9 any changes to rules or emission limits applicable to SO2 sources as a SIP revision. ADEQ also commits to maintain the necessary resources to actively enforce any violations of the provisions contained in this submittal.

Emissions reductions sufficient to meet the NAAQS were accomplished due to the permanent closure of the primary source of SO2 emissions in the area. BHP Copper Inc. does not currently hold an active permit, and no subsequent Title V permit application has been submitted to ADEQ for the closed San Manuel smelter. The smelting facility cannot rebuild and reopen without submittal of a Prevention of Significant Deterioration (PSD) and Title V (Part 70) permit application according to A.R.S. § 49-426 and A.A.C. R18-2-406, Permit Requirements for Sources Located in Attainment and Unclassifiable Areas. The emission reductions achieved following the closure of this facility are both permanent and enforceable.

72 ADEQ, PDEQ, and PCAQD have permitting and planning jurisdiction for the San Manuel SO2 MA within Pinal and Pima County. See A.R.S. § 49-402. ADEQ, PDEQ, and PCAQD have general authority to implement and enforce all measures to maintain the 1971 SO2 NAAQS per A.R.S §§ 49-104, 49-404, 49-422, and 49-424.


39

Any new major sources or major modifications to existing point sources of SO2 in the San Manuel MA are subject to the new source permitting procedures contained the SIP-approved rule, R18-2-406.73 These regulations were established to preserve the air quality in areas where ambient concentrations are below the NAAQS and require stationary sources to undergo preconstruction review, install Best Available Control Technology (BACT), and conduct modeling demonstrating protection of the SO2 NAAQS and increments before the facility is constructed, modified, or reconstructed.

ADEQ also does not anticipate any unexpected growth in area and mobile sources. The San Manuel MA does not have any major cities or point sources within its boundaries and is not along any significant traffic corridors. The area is expected to experience lower growth than the rest of Pinal County as a whole and further growth in area and mobile sources will be verified when looking at the emissions inventories.

Maintenance of the SO2 NAAQS in the San Manuel area will be tracked through verification of maintenance through the annual statewide EI update, and through permit applications received for SO2 emitting sources. Any permitted sources are subject to the monitoring, reporting, and certification procedures contained in AAC R 18-2-306 and AAC R 18-2- 309 respectively (or similar County rules). ADEQ has authority pursuant to ARS § 49-101 et seq. to monitor and ensure source compliance with all applicable rules and permit conditions for sources in its jurisdiction. Pinal County Air Quality Department (PCAQD), and Pima County Department of Environmental Quality (PDEQ) have authority for sources under their jurisdiction under ARS § 49-402.

5.4 Contingency Plan Contingency plans should contain measures to promptly correct any violation of the NAAQS that occurs after redesignation. According to the 1992 guidance Procedures for Processing Requests to Redesignate Areas to Attainment, the contingency plan must require, at a minimum, implementation of all measures contained in the Part D nonattainment plan for the area prior to redesignation.

The only threat to the 1971 SO2 NAAQS in the San Manuel MA would be from new sources. Because the primary source of SO2 emissions in the San Manuel area permanently closed, measures to ensure continued attainment of the SO2 NAAQS are PSD and permitting requirements.

As mentioned earlier in Section 5.3, new major sources of SO2 would be subject to PSD requirements in A.A.C. R18-2-406. Under the PSD program, new major sources are required to undergo preconstruction review, install BACT, and conduct modeling demonstrating protection of the SO2 NAAQS and increments before the facility is constructed, modified, or reconstructed. These requirements also apply to existing sources making major modifications that would

73 See 80 FR 67319, November 2, 2015.


40

increase SO2 emissions. If a new SO2 source is deemed minor instead of major, it would also be required to obtain a permit under A.A.C. R18-2-334, Minor New Source Review.74

Through the permitting process, ADEQ is able to identify the potential for SO2 violations before they occur and is therefore able to ascertain what measures would be needed to avoid such violations. The Pinal County Air Quality Control District and Pima County Department of Environmental Quality have authority for sources under their jurisdiction.

5.5 Conclusion The San Manuel SO2 MA continues to meet the 1971 24-hour SO2 NAAQS. This submittal demonstrates that all the essential regulatory elements have been met and the San Manuel maintenance area will continue to attain the 1971 primary SO2 NAAQS SO2 NAAQS for an additional ten years, through year 2028. This is due to the permanent closure of the San Manuel Copper Smelter, the primary copper smelter that was operated by BHP Billiton.

Maintenance of the NAAQS in the San Manuel area has been demonstrated by the emissions inventories in chapter 3 and Appendix A, and the control measures discussed in chapter 4. In sum, these analyses show that:

1. No SO2 NAAQS violations are expected to occur during the next 10 years anywhere within the maintenance area; and,

2. The major point source, which has since shutdown, was the dominant source contributing to high SO2 concentrations.

As a contingency measure to protect the NAAQS, ADEQ’s new source permitting programs will require pre-permitting modeling and adequate controls for any future sources that may operate nearby.

ADEQ requests that EPA approve this demonstration of maintenance through the second maintenance period.

74 R18-2-334 and R18-2-406 were approved into Arizona’s SIP on November 2, 2015 (see 80 FR 67319).

Appendix A San Manuel SO2 Emission Inventory Technical Support Document

Air Quality Division March 10, 2017 Proposed

Appendix A - San Manuel SO2 Emission Inventory Technical Support Document

March 10, 2017 Proposed Page A-iii

Table of Contents Table of Contents ........................................................................................................................ A-iii

Index of Figures ........................................................................................................................... A-iii

Index of Tables ............................................................................................................................ A-iv

A1 Introduction ..................................................................................................................... A-1

A1.1 Background and Purpose ..................................................................................... A-1

A1.2 Sources of SO2 Emissions ..................................................................................... A-2

A1.3 Base Year Determination ..................................................................................... A-2

A1.4 Population ............................................................................................................ A-2

A2 Monitoring Network ........................................................................................................ A-6

A3 Emission Inventory ........................................................................................................... A-7

A3.1 Point Source Inventory ........................................................................................ A-7

A3.2 Nonpoint Source Inventory .................................................................................. A-8

A3.2.1 Emission Calculation Methodology ...................................................... A-9

A3.2.2 Emission Allocation Methodology ...................................................... A-10

A3.2.3 Emission Projection Methodology ...................................................... A-12

A3.3 Mobile Source Inventory ................................................................................... A-14

A3.3.1 Emission Calculation Methodology .................................................... A-14

A3.3.2 Emission Allocation Methodology ...................................................... A-15

A3.3.3 Emission Projection Methodology ...................................................... A-16

A3.3.4 Transportation Conformity ................................................................. A-17

Exhibit AI – Population Estimation and Projection ................................................................... AI-1

AI1 Population Estimation and Projection Methodology ......................................... AI-2

Exhibit AII - MOVES Planning and Assumptions ........................................................................ AII-1

AII1 Planning Assumptions ........................................................................................ AII-2

Index of Figures Figure A-1: San Manuel SO2 Maintenance Area .......................................................................... A-5 Figure A-2: Monitoring Actions in San Manuel SO2 Maintenance Area ...................................... A-6

Appendix A - San Manuel SO2 Emission Inventory Technical Support Document

March 10, 2017 Proposed Page A-iv

Index of Tables Table A-1: Emission Inventory Outline ........................................................................................ A-1 Table A-2: Geographic Location and Population ......................................................................... A-4 Table A-3: Emission Summary TPY ............................................................................................... A-7 Table A-4: Point Sources .............................................................................................................. A-7 Table A-5: Point Source SO2 Emissions – PTE and actual Emissions ............................................ A-8 Table A-6: Emission Totals - Nonpoint ......................................................................................... A-8 Table A-7: Calculation Methods ................................................................................................... A-9 Table A-8: Nonpoint Sector Allocation Methods ....................................................................... A-10 Table A-9: Population................................................................................................................. A-11 Table A-10: Population Allocation Factors ................................................................................ A-11 Table A-11: Land Area ................................................................................................................ A-11 Table A-12: Land Area Allocation Factors .................................................................................. A-12 Table A-13: Nonpoint Sector Projection Methods .................................................................... A-12 Table A-14: Emission Totals - Mobile ......................................................................................... A-14 Table A-15: Mobile Calculation Methods .................................................................................. A-14 Table A-16: Emission Totals - On-road Motor Vehicles ............................................................. A-14 Table A-17: Mobile Allocation Methods .................................................................................... A-15 Table A-18: Airport Activity ........................................................................................................ A-15 Table A-19: Airport Activity Allocation Factors .......................................................................... A-16 Table A-20: Rail Length .............................................................................................................. A-16 Table A-21: Rail Length Allocation Factors ................................................................................ A-16 Table A-22: Mobile Sector Projection Methods ........................................................................ A-16 Table A-23 .................................................................................................................................. AII-2 Table A-24 .................................................................................................................................. AII-3 Table A-25 .................................................................................................................................. AII-3 Table A-26 .................................................................................................................................. AII-4 Table A-27 .................................................................................................................................. AII-5 Table A-28 .................................................................................................................................. AII-6 Table A-29 .................................................................................................................................. AII-7

Appendix A

March 10, 2017 Proposed Page A-1

A1 Introduction

A1.1 Background and Purpose The Arizona Department of Environmental Quality (ADEQ) is preparing this technical support document (TSD) to support a State Implementation Plan revision for the San Manuel Maintenance Area. This SIP revision seeks to:

1. Show that the San Manuel area is currently in attainment with the SO2 NAAQS 2. Provide justification that the San Manuel area will maintain compliance with the NAAQS

through the end of the second maintenance period.

To achieve these goals, the SIP revision relies on emission inventories of San Manuel for five distinct time periods:

1) a year in which the smelter was open and the monitor was in attainment;

2) a year in which the smelter was closed and the monitor was in attainment;

3) the current actual and allowable emissions;

4) two interim years between the current actual emissions and the final year of the maintenance period; and

5) a projected inventory to the tenth year of the second San Manuel SO2 maintenance period.

ADEQ is planning to use 2014 as the base year, the periodic inventory years of 2019 and 2024 and the final maintenance year of 2028. These years are presented in Table A-1. ADEQ intends to develop emission inventories as outlined in the San Manuel SO2 Maintenance Area Inventory Preparation Plan, all of which will rely primarily on two data sources: EPA’s 2014 National Emission Inventory version 1 (NEIv1) and Pinal County Air Quality’s point source database. This TSD is based off of the San Manuel Inventory Preparation Plan developed in September 2016.

Table A-1: Emission Inventory Outline Inventory Year Inventory Purpose Data Source 1998 Support Year1 San Manuel Maintenance SIP 2007 2005 Attainment Year2 San Manuel Maintenance SIP 2007

2014 Base Year 2014 NEIv1, MOVES2014a modeling & Pinal Point Source Database

2019 Maintenance Demonstration Projected from base year 2023 Maintenance Demonstration Projected from base year 2028 Maintenance Demonstration Projected from base year

1 Attaining year in which the smelter was open 2 Attaining year in which the smelter was closed

Appendix A


ADEQ operated the monitor in San Manuel past the shutdown of the smelter to fulfill the option under 40 CFR 58.14(c)(3) allowing for discontinuation of a monitor within an attainment, nonattainment, or maintenance area, “…provided the monitor has not measured violations of the applicable NAAQS in the previous five years, and the approved SIP provides for a specific, reproducible approach to representing the air quality of the affected county in the absence of actual monitoring data.” This allows for a direct comparison with the 1998 inventory while the smelter was operating and the 2005 inventory when the smelter was not operating. ADEQ will demonstrate through these emissions inventories that projected future emissions do not exceed the level of emissions while the area was in attainment (with the major source operating and shut down) for a 10-year period of 2019 through 2028.

A1.2 Sources of SO2 Emissions Source categories to be included in the inventory are: Point Source Emissions Nonpoint Source Emissions Nonroad Mobile Emissions Onroad Mobile Emissions

ADEQ has compiled inventories containing actual SO2 emissions from the source categories listed above. A more detailed description of these sectors is provided in Section A3. Point source emissions will be gathered from Pinal County’s point source database while other categories (nonpoint & nonroad) will be based primarily on 2014 NEIv1 data.

A1.3 Base Year Determination The base year for the San Manuel SO2 SIP revision will be 2014. The 2014 NEIv1 was chosen because it represents the most current, accurate, and comprehensive inventory available.

A1.4 Population The San Manuel SO2 maintenance area has been codified in 40 CFR 81.303 and is comprised of the portions of Pima County and Pinal County bound by the townships and ranges listed in Table A-2. Population estimates for the entire San Manuel SO2 maintenance area as well as the respective proportions of Pima and Pinal Counties are also presented in Table A-2. The San Manuel SO2 maintenance area encompasses the town of Mammoth and the census designated places of Oracle, San Manuel, and Saddlebrooke, which is represented in Figure A-1.

Pima County is located in the central part of Arizona; surrounded by Yuma County to the west, Maricopa and Pinal Counties to the north, Graham County to the northeast, Cochise County to the east, Santa Cruz County and Sonora, Mexico to the south. The county seat of Pima County is Tucson. The incorporated communities of Marana, Oro Valley, and Sahuarita also reside within Pima County as well as the Pascua Yaqui, San Xavier, and Tohono O’odham Reservations. ADOA estimated the 2014 population of Pima County at 980,263 persons. Pima County had a

Appendix A


2010 population density of only 106.7 persons per square mile, compared to 414.9 and 56.3 persons per square mile for Maricopa County and the state respectively3.

Pinal County is one of five interior counties in the central part of Arizona; surrounded by Maricopa and Gila Counties to the north, Graham County to the east, Pinal County to the south, and Maricopa County to the west. The county seat of Pinal County is Florence, which lies approximately 61 linear miles southeast from Phoenix. The incorporated communities of Apache Junction, Casa Grande, Coolidge, Eloy, Kearny, Mammoth, and Superior also reside within Pinal County. ADOA estimated the 2014 population of Pinal County at 375,770 persons. Pinal County had a 2010 population density of 70.0 persons per square mile, compared to 414.9 and 56.3 persons per square mile for Maricopa County and the state respectively4.

3 Note: from US Census Bureau. (November 2, 2016), State and County QuickFacts. U.S. Department of Commerce. Retrieved from: http://quickfacts.census.gov/qfd/states/04/04007.html on November 2, 2016. 4 Note: from US Census Bureau. (April 1, 2010), State and County QuickFacts. U.S. Department of Commerce. Retrieved from: http://quickfacts.census.gov/qfd/states/04/04007.html on November 2, 2016.

http://quickfacts.census.gov/qfd/states/04/04007.html%20on%20November%202

http://quickfacts.census.gov/qfd/states/04/04007.html%20on

Appendix A


Table A-2: Geographic Location and Population

San Manuel SO2 Maintenance Area5 Land Area 382 mi2

2014 Population 10,007 2019 Projected Population 11,475 2023 Projected Population 12,011 2028 Projected Population 14,535

Pima County Portion Pinal County Portion Land Area 102.0 mi2 Land Area 494.5 mi2

2014 Population 27 2014 Population 9,981 2019 Projected Population 28 2019 Projected Population 11,448 2023 Projected Population 29 2023 Projected Population 11,982 2028 Projected Population 31 2028 Projected Population 14,504

MA Townships (40 CFR 81.303) T8S, R16E, T8S, R17E, T8S, R18E, T9S, R15E, T9S, R16E, T9S, R17E, T9S, R18E, T10S, R15E, T10S, R16E, T10S, R17E, T11S, R16E

5 ADEQ’s projection methodologies are presented in Exhibit AI1 of this TSD.

Appendix A


Figure A-1: San Manuel SO2 Maintenance Area

Appendix A


A2 Monitoring Network No major point sources have existed in the maintenance area since the permanent closure of the San Manuel smelter. The base year and projected maintenance year emissions inventories do not show substantial increases in existing point source emissions between 2014 and 2028 for the maintenance area. Any additional SO2 point sources will require permitting by ADEQ, Pinal County Air Quality Control District, or Pima County Department of Environmental Quality permitting programs. These permitting programs are required to ensure that construction of new point sources or upgrading of existing sources do not cause or contribute to a violation of the NAAQS.

Figure A-2: Monitoring Actions in San Manuel SO2 Maintenance Area

Monitoring Action Year

Ambient SO2 monitoring for San Manuel area began by the State of Arizona6 1969

Smelter facility operators began continuous ambient SO2 monitoring7 1973

Monitoring network of 18 stationary and mobile sites established by facility 1973-1979

Monitoring network of permanent monitors reduced to 4 sites 1979

After shutdown of the smelter remaining 4 monitors were closed 1999

After review ADEQ reopened and continued to operate the LDS Church monitor 2002

LDS Church monitor closed in accordance with 40 CFR 58.14(c)(3) after 5 years 2007

6 Sulfur Dioxide Monitoring Network Study, Arizona State Department of Health, Environmental Health Services, Division of Air Pollution Control, 1969. 7 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).

Appendix A


A3 Emission Inventory A summary of the San Manuel SO2 emission inventory is provided below in Table A-3. This summary details the annual SO2 totals (in tons) for 1998 when the smelter was operating and 2005 (after the smelter had been shut down and the permit closed), actual emissions from 2014, and provides projected future emissions for years 2019, 2023, and 2028. For ease of review this summary provides emissions for only two, high-level categories: point and area/mobile. Further sections of this TSD provide greater levels of detail for each of these categories.

Table A-3: Emission Summary TPY Source 1998 2005 2014 2019 2024 2028 Point 10,410 0.6 3.8 4.5 4.5 4.5 Area/Mobile 30 27 5.1 4.9 5.3 5.9 Total 10,440 28 8.9 9.4 9.9 10.5

A3.1 Point Source Inventory ADEQ, Pinal County Air Quality Department (PCAQD), and Pima County Department of Environmental Quality (PDEQ) share jurisdiction over air quality matters in the San Manuel SO2 Maintenance Area. PCAQD has jurisdiction over the Pinal County portions of the San Manuel SO2 Maintenance Area. PDEQ has jurisdiction over the Pima County portion. Currently only PCAQD has active permits in the San Manuel SO2 Maintenance Area as noted in Table A-4. PCAQD collects annual emissions data from all permitted air facilities under their jurisdiction. These annual emission inventory reports were the basis for the point source inventory presented in this section. The PTE and actual emissions are detailed in Table A-5.

Table A-4: Point Sources

Facility Permitting Agency Agency ID BONITO QUARRY PCAQD 10661 SAN MANUEL SCHOOLS PCAQD 10240 DECORATIVE ROCK SALES PCAQD 10324 BIOSPHERE 2 PCAQD 10072 SADDLEBROOKE RANCH WATER RECLM PLANT

PCAQD 10571

ORACLE COMPRESSOR STATION PCAQD 10180

Appendix A


Table A-5: Point Source SO2 Emissions – PTE and actual Emissions

Facility Facility SO2 TPY

PTE8 2013 2014 2015 BONITO QUARRY 0.80 2.91 1.85 1.87 SAN MANUEL SCHOOLS 0.03 0.00 0.00 0.00 DECORATIVE ROCK SALES 0.70 0.51 0.67 0.02 BIOSPHERE 2 0.71 0.04 .03 0.03 SADDLEBROOKE RANCH WATER RECLM PLANT 0.40 0.00 0.00 0.00

ORACLE COMPRESSOR STATION 1.90 1.46 1.28 1.07

Total 4.54 4.92 3.83 2.99

A3.2 Nonpoint Source Inventory The nonpoint SO2 emission inventory for the San Manuel maintenance area is presented in Table A-6.

Table A-6: Emission Totals - Nonpoint

Emission Sector SO2 TPY 2014 2019 2023 2028

Fires - Agricultural Field Burning 0.036 0.036 0.036 0.036 Fires - Prescribed Fires 0.172 0.172 0.172 0.172 Fires - Wildfires 0.315 0.315 0.315 0.315 Fuel Comb - Comm/Institutional - Biomass 0.110 0.126 0.140 0.160 Fuel Comb - Comm/Institutional - Coal 0.000 0.000 0.000 0.000 Fuel Comb - Comm/Institutional - Natural Gas 0.038 0.043 0.048 0.055 Fuel Comb - Comm/Institutional - Oil 0.003 0.004 0.004 0.005 Fuel Comb - Comm/Institutional - Other 0.000 0.000 0.000 0.000 Fuel Comb - Electric Generation - Coal 0.033 0.034 0.036 0.037 Fuel Comb - Electric Generation - Natural Gas 0.108 0.123 0.137 0.156 Fuel Comb - Electric Generation - Oil 0.000 0.000 0.000 0.000 Fuel Comb - Industrial Boilers, ICEs - Biomass 0.001 0.001 0.001 0.001 Fuel Comb - Industrial Boilers, ICEs - Coal 0.013 0.015 0.017 0.019 Fuel Comb - Industrial Boilers, ICEs - Natural Gas 0.046 0.053 0.058 0.067 Fuel Comb - Industrial Boilers, ICEs - Oil 0.245 0.281 0.311 0.356 Fuel Comb - Industrial Boilers, ICEs - Other 0.000 0.000 0.000 0.000 Fuel Comb - Residential - Natural Gas 0.016 0.019 0.021 0.024 Fuel Comb - Residential - Oil 0.000 0.000 0.000 0.000

8 PTE is lower than actual emissions in 2013-2015 due to the new permit issued in 2016, the previous permit had a higher PTE which is not reflected in the updated value.

Appendix A



Fuel Comb - Residential - Other 0.002 0.002 0.002 0.002 Fuel Comb - Residential - Wood 0.021 0.023 0.026 0.030 Industrial Processes - Cement Manuf 0.000 0.000 0.000 0.000 Industrial Processes - Mining 0.596 0.683 0.757 0.866 Industrial Processes - NEC 0.001 0.001 0.001 0.001 Industrial Processes - Pulp & Paper 0.000 0.000 0.000 0.000 Solvent - Industrial Surface Coating & Solvent Use 0.818 0.938 1.040 1.188 Waste Disposal 0.001 0.001 0.001 0.001 Total 5.12 4.89 5.32 5.94

A3.2.1 Emission Calculation Methodology The calculation methodologies ADEQ used to develop the nonpoint emission inventory are summarized in Table A-7 below. All of the emission sectors rely on 2014 NEIv1 data as the basis for the emission totals. County level data from the NEI are allocated and projected for the San Manuel SO2 Maintenance Areausing the methodology presented in A3.2.2

Table A-7: Calculation Methods Emission Sector Calculation Method Fires - Agricultural Field Burning 2014 NEIv1 Fires - Prescribed Fires 2014 NEIv1 Fires - Wildfires 2014 NEIv1 Fuel Comb - Comm/Institutional - Biomass 2014 NEIv1 Fuel Comb - Comm/Institutional - Coal 2014 NEIv1 Fuel Comb - Comm/Institutional - Natural Gas 2014 NEIv1 Fuel Comb - Comm/Institutional - Oil 2014 NEIv1 Fuel Comb - Comm/Institutional - Other 2014 NEIv1 Fuel Comb - Electric Generation - Coal 2014 NEIv1 Fuel Comb - Electric Generation - Natural Gas 2014 NEIv1 Fuel Comb - Electric Generation - Oil 2014 NEIv1 Fuel Comb - Industrial Boilers, ICEs - Biomass 2014 NEIv1 Fuel Comb - Industrial Boilers, ICEs - Coal 2014 NEIv1 Fuel Comb - Industrial Boilers, ICEs - Natural Gas 2014 NEIv1 Fuel Comb - Industrial Boilers, ICEs - Oil 2014 NEIv1 Fuel Comb - Industrial Boilers, ICEs - Other 2014 NEIv1 Fuel Comb - Residential - Natural Gas 2014 NEIv1 Fuel Comb - Residential - Oil 2014 NEIv1 Fuel Comb - Residential - Other 2014 NEIv1 Fuel Comb - Residential - Wood 2014 NEIv1 Industrial Processes - Cement Manuf 2014 NEIv1 Industrial Processes - Mining 2014 NEIv1 Industrial Processes - NEC 2014 NEIv1 Industrial Processes - Pulp & Paper 2014 NEIv1 Waste Disposal 2014 NEIv1

Appendix A


Emission Sector Calculation Method Solvent - Industrial Surface Coating & Solvent Use 2014 NEIv1

A3.2.2 Emission Allocation Methodology This TSD relies on the 2014 NEIv1 for nonpoint source emission estimates. County-level emissions were obtained from the 2014 NEIv1 and allocated down to the San Manuel SO2 Maintenance Area based on an allocation method that was most appropriate. These allocation methods include population, land area, rail length, LTO, and MOVES. The methodologies associated with these allocation methods are described in the following sub-sections.

Table A-8 summarizes the allocation methods used for each of the nonpoint emission sectors. No changes in allocation methodology have been made since the initial Inventory Preparation Plan.

Table A-8: Nonpoint Sector Allocation Methods Emission Sector Allocation Method Fires - Agricultural Field Burning Land Area Fires - Prescribed Fires Land Area Fires - Wildfires Land Area Fuel Comb - Comm/Institutional - Biomass Population Fuel Comb - Comm/Institutional - Coal Population Fuel Comb - Comm/Institutional - Natural Gas Population Fuel Comb - Comm/Institutional - Oil Population Fuel Comb - Comm/Institutional - Other Population Fuel Comb - Electric Generation - Coal Population Fuel Comb - Electric Generation - Natural Gas Population Fuel Comb - Electric Generation - Oil Population Fuel Comb - Industrial Boilers, ICEs - Biomass Population Fuel Comb - Industrial Boilers, ICEs - Coal Population Fuel Comb - Industrial Boilers, ICEs - Natural Gas Population Fuel Comb - Industrial Boilers, ICEs - Oil Population Fuel Comb - Industrial Boilers, ICEs - Other Population Fuel Comb - Residential - Natural Gas Population Fuel Comb - Residential - Oil Population Fuel Comb - Residential - Other Population Fuel Comb - Residential - Wood Population Industrial Processes - Cement Manuf Population Industrial Processes - Mining Population Industrial Processes - NEC Population Industrial Processes - Pulp & Paper Population Waste Disposal Population Solvent - Industrial Surface Coating & Solvent Use Population

Appendix A


A3.2.2.1 Population The population allocation methodology is a ratio of population in a given county to the population in that county’s portion of the maintenance area, as shown in the equation below. 2014 population totals were used to derive the allocation factor.

𝑃𝑃𝑎𝑎𝑃𝑃𝑐𝑐

= 𝐴𝐴𝐴𝐴𝑝𝑝

Where: Pa= Population estimate for county portion of maintenance area Pc= Population estimate of entire county AFp= Population allocation factor

Table A-9: Population

Area 2014 Population Pima County 1,007,162

Pima portion of MA 27 Pinal County 396,237

Pinal portion of MA 9,480

Table A-10: Population Allocation Factors

Area Allocation Factor Pima County 0.00003 Pinal County 0.02393

A3.2.2.2 Land Area The land area allocation methodology is a ratio of land area in a given county to the land area of that county’s portion of the maintenance area, as shown in the following equation:

𝐿𝐿𝐴𝐴𝑎𝑎𝐿𝐿𝐴𝐴𝑐𝑐

= 𝐴𝐴𝐴𝐴𝑙𝑙

Where: LAa= Land area estimate for county portion of maintenance area LAc= Land area estimate of entire county AFl= Land area allocation factor

Table A-11 lists the land area totals for the maintenance area, Pima and Pinal County, and the Pima and Pinal County portions of the maintenance area. These totals served as inputs to the land area allocation equation and resulted in the allocation factors presented in Table A-12.

Table A-11: Land Area

Area Land Area (mi2) Pima County 9,165

Appendix A


Area Land Area (mi2) Pima portion of NAA 102

Pinal County 5,360 Pinal portion of NAA 347

Table A-12: Land Area Allocation Factors

Area Allocation Factor Pima County 0.01113 Pinal County 0.06468

A3.2.3 Emission Projection Methodology In general, this TSD relied on the county-level 2014 NEI for emission estimates. These county-level emissions were allocated to the maintenance area as explained in Section A3.2.2. Once appropriately allocated to the maintenance area, the emissions were then projected to establish emission estimates for future years. Since 2014 served as the baseline emission inventory, all other inventory years were projected forward from this 2014 dataset. As with the allocation methodologies, the most appropriate projection methodologies were used for the individual emission sectors.

Table A-13 summarizes the projection methods used for each of the nonpoint emission sectors.

Table A-13: Nonpoint Sector Projection Methods Emission Sector Projection Method Fires - Agricultural Field Burning Constant Fires - Prescribed Fires Constant Fires - Wildfires Constant Fuel Comb - Comm/Institutional - Biomass Population Fuel Comb - Comm/Institutional - Coal Population Fuel Comb - Comm/Institutional - Natural Gas Population Fuel Comb - Comm/Institutional - Oil Population Fuel Comb - Comm/Institutional - Other Population Fuel Comb - Electric Generation - Coal Population Fuel Comb - Electric Generation - Natural Gas Population Fuel Comb - Electric Generation - Oil Population Fuel Comb - Industrial Boilers, ICEs - Biomass Population Fuel Comb - Industrial Boilers, ICEs - Coal Population Fuel Comb - Industrial Boilers, ICEs - Natural Gas Population Fuel Comb - Industrial Boilers, ICEs - Oil Population Fuel Comb - Industrial Boilers, ICEs - Other Population Fuel Comb - Residential - Natural Gas Population Fuel Comb - Residential - Oil Population Fuel Comb - Residential - Other Population Fuel Comb - Residential - Wood Population

Appendix A


Emission Sector Projection Method Industrial Processes - Cement Manuf Population Industrial Processes - Mining Population Industrial Processes - NEC Population Industrial Processes - Pulp & Paper Population Waste Disposal Population Solvent - Industrial Surface Coating & Solvent Use Population

Appendix A


A3.3 Mobile Source Inventory Table A-14: Emission Totals - Mobile

A3.3.1 Emission Calculation Methodology

ADEQ calculated the Mobile source inventory from the 2014 NEI and the EPA approved Motor Vehicle Emission Simulator (MOVES). County level data from the NEI are allocated and projected for the San Manuel SO2 Maintenance Area. The methods used are detailed in Table A-15

Table A-15: Mobile Calculation Methods Emission Sector Calculation Method Mobile - Aircraft 2014 NEIv1 Mobile - Locomotives 2014 NEIv1 Mobile - Non-Road Equipment - Diesel 2014 NEIv1 Mobile - Non-Road Equipment - Gasoline 2014 NEIv1 Mobile - Non-Road Equipment - Other 2014 NEIv1 Mobile - On-Road Heavy & Light Duty Vehicles All Fuel Types MOVES2014a

MOVES is an emission modeling system that estimates emissions for mobile sources. ADEQ used MOVES2014a the most recent model version at the time of the inventory’s development. Details about the MOVES inputs are detailed in the MOVES Modeling TSD for San Manuel 2016 (Exhibit AII). The results are presented in Table A-16 for the base year and projected years.

Table A-16: Emission Totals - On-road Motor Vehicles


Running Exhaust 1.38 0.68 0.71 0.75 Start Exhaust 0.02 0.01 0.01 0.01 Extended Idle Exhaust 0.01 0.03 0.03 0.04 Total 1.41 0.72 0.76 0.79


Mobile - Aircraft 0.697 0.800 0.887 1.014 Mobile - Locomotives 0.367 0.420 0.466 0.533 Mobile - Non-Road Equipment - Diesel 0.057 0.065 0.072 0.082 Mobile - Non-Road Equipment - Gasoline 0.016 0.018 0.020 0.023 Mobile - Non-Road Equipment - Other 0.001 0.001 0.001 0.001 Mobile - On-Road non-Diesel Light Duty Vehicles 1.409 0.718 0.753 0.797 Total 2.55 2.02 2.20 2.45

Appendix A


A3.3.2 Emission Allocation Methodology ADEQ utilized several different methods in allocating emissions to the San Manuel area, which are summarized below in Table A-17. The mobile on-road sectors were not explicitly allocated to the San Manuel area, instead parameters were input into the MOVES2014a model for the San Manuel area. Therefore, the resulting emission totals pertained to only the San Manuel area.

Table A-17: Mobile Allocation Methods Emission Sector Allocation Method Mobile – Aircraft Airport Activity – See A3.3.2.1 Mobile - Locomotives Rail Line Length – See A3.3.2.2 Mobile - Non-Road Equipment - Diesel Population Mobile - Non-Road Equipment - Gasoline Population Mobile - Non-Road Equipment - Other Population Mobile - On-Road Heavy & Light Duty Vehicles All Fuel Types MOVES2014a – See A3.2.1

A3.3.2.1 Airport Activity The airport activity allocation factor is only used to allocate emissions in the Mobile – Aircraft emission sector. ADEQ based this allocation methodology on a ratio of the LTO values given in the Point – LTO estimates used in 2014NEIv1 Aircraft Emission estimates as a surrogate for Airport activity in the maintenance area, as shown in the following equation:

𝐴𝐴𝐴𝐴𝑎𝑎𝐴𝐴𝐴𝐴𝑐𝑐

= 𝐴𝐴𝐴𝐴𝑎𝑎

Where: AAa= Airport activity estimate for county portion of maintenance area AAc= Airport activity estimate of entire county AFa= Airport activity allocation factor

ADEQ obtained the list of airports and their associated activity levels from the 2014 National Emissions Inventory (NEI) Documentation page in the point source documents.9

Table A-18: Airport Activity

Area Airport Activity (LTO) Pinal County 129786

Pinal portion of MA 7005 Pima County 208635

Pima portion of MA 0

9 https://www.epa.gov/air-emissions-inventories/2014-national-emissions-inventory-nei-documentation

Appendix A


Table A-19: Airport Activity Allocation Factors

Area Allocation Factor Pima County 0 Pinal County 0.05397

A3.3.2.2 Rail Line Length The rail length allocation methodology is a ratio of rail length in a given county to the rail length of that county’s portion of the maintenance area, as shown in the following equation:

𝑅𝑅𝐿𝐿𝑎𝑎𝑅𝑅𝐿𝐿𝑐𝑐

= 𝐴𝐴𝐴𝐴𝑟𝑟𝑙𝑙

Where: RLa= Rail length estimate for county portion of maintenance area RLc= Rail length estimate of entire county AFrl= Rail length allocation factor

Table A-20: Rail Length

Area Rail Length (miles) Pima County 184

Pima portion of MA 0

Pinal County 276 Pinal portion of MA 6

Table A-21: Rail Length Allocation Factors

Area Allocation Factor Pima County 0 Pinal County 0.021157

A3.3.3 Emission Projection Methodology ADEQ used two methods to project future-year emissions: population growth and MOVES. For the aircraft, locomotive, and non-road sectors ADEQ used population growth as an indicator of future emissions growth. For the on-road sectors, ADEQ did not specifically project the emission totals, rather future-year parameter values were input into MOVES2014a. Examples of this are projected Vehicle Miles Traveled (VMT) totals obtained from the Arizona Department of Transportation (ADOT).

Table A-22: Mobile Sector Projection Methods Emission Sector Projection Method Mobile – Aircraft Population Growth Mobile - Locomotives Population Growth

Appendix A


Emission Sector Projection Method Mobile - Non-Road Equipment - Diesel Population Growth Mobile - Non-Road Equipment - Gasoline Population Growth Mobile - Non-Road Equipment - Other Population Growth Mobile - On-Road Heavy & Light Duty Vehicles All Fuel Types

MOVES2014a

A3.3.4 Transportation Conformity Transportation conformity is used to ensure that any federally funded transportation plans, programs, and projects do not interfere with an area’s ability to attain the NAAQS. SO2 does not require conformity with transportation planning.10

10 40 CFR §93.102(b)(1)

Appendix A

March 10, 2017 Proposed Page AI-1

Exhibit AI – Population Estimation and Projection

Appendix A


AI1 Population Estimation and Projection Methodology

Methodology for Population Estimates of San Manuel SO2 maintenance area

1. ArcMap 10.3.1 was used to overlay the San Manuel SO2 Maintenance Area boundary shapefiles onto the 2010 Census TIGER shapefiles for census blocks in Pima and Pinal Counties.

2. ArcMap calculated the acreage within each census block. (Areacensus)

3. The blocks were then clipped to within the San Manuel SO2 maintenance area boundary.

4. The acreage was calculated for the new clipped blocks. (Areaclipped)

5. Total population for the Maintenance area was calculated using the following equation:

𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑀𝑀𝑀𝑀 = 𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶 ∗𝐴𝐴𝐴𝐴𝐴𝐴𝑃𝑃𝑐𝑐𝑙𝑙𝑐𝑐𝑝𝑝𝑝𝑝𝐶𝐶𝑐𝑐𝐴𝐴𝐴𝐴𝐴𝐴𝑃𝑃𝑐𝑐𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶𝐶

Methodology for Population Projections of San Manuel SO2 maintenance area

1. ADEQ used ADOA population projections for Pima and Pinal counties and calculated the percent growth using the following equation:

𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃 𝐺𝐺𝐴𝐴𝑃𝑃𝐺𝐺𝑃𝑃ℎ𝑐𝑐𝑖𝑖 =𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑖𝑖 − 𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑐𝑐

𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑐𝑐× 100%

Where;

Population Growthij = Growth from year i to year j

Populationi = Population from year j

Populationi = Population from year i

2. ADEQ applied these the population growth rate to the base year to project population in the maintenance area.

Appendix A


County Descriptor ACRES SQ_MILES Census Population

Pima County Total 5,865,373.3 9,164.6 1,007,162 Pinal County Total 3,430,367.3 5,359.9 396,237 San Manuel SO2 Maintenance Area

Total 244,622.5 382.2 9,507

Pima County Area in MA 65,262.7 102.0 27 Pinal County Area in MA 221,892.3 346.7 9,480

County Descriptor Pima County % Area in MA = 1.11% Pinal County % Area in MA= 6.47% Pima County % Population in MA= 0.00% Pinal County % Population in MA= 2.39%

Appendix A


County Descriptor ACRES SQ_MILES Census Population

Pima County Total 5,865,373.3 9,164.6 1,007,162 Pinal County Total 3,430,367.3 5,359.9 396,237

San Manuel SO2 Maintenance Area (total) 244,622.5 382.2 9,507

Pima County Area in SO2 Area 65,262.7 102.0 27

Pinal County Area in SO2 Area 221,892.3 346.7 9,480

County Descriptor

Pima County %Area in SO2 Area = 1.11% Pinal County %Area in SO2 Area = 6.47% Pima County %Population in SO2 Area = 0.00%

Pinal County %Population in SO2 Area = 2.39%

Appendix A

March 10, 2017 Proposed Page AII-1

Exhibit AII - MOVES Planning and Assumptions

Appendix A


AII1 Planning Assumptions

AII1.1 Summary To calculate and project mobile road emissions for the San Manuel SO2 Maintenance area ADEQ used EPA’s Motor Vehicle Emission Simulator (MOVES). MOVES is an emission modeling system that estimates emissions for mobile sources. ADEQ used MOVES2014a the most recent model version at the time of the plan’s development.

Detailed below in Table A-23 are the planning assumptions used in the base year and the projection years.

Table A-23

AII1.2 Population and Employment

Planning Assumptions Assumption Source

Population and Employment

Under the Governor’s Executive Order No. 2011-04 all State agencies are required to use population estimates and population projections produced by ADOA.

Age Distribution July 2014 vehicle registration data was provided by ADOT Source Type Population July 2014 vehicle registration data was adjusted by maintenance

area ADOA population factor. Meteorology Data Default Values were applied. I/M Programs No I/M program information applied, there are no programs

implemented in the San Manuel maintenance area. Vehicle Miles of Travel VMT calculated from traffic counts from CY 2014 provided from

ADOT. ADEQ used the EPA conversion tool to calculate monthly and daily VMT fractions.

Fuels Default Values were applied. Average Speed Distribution

Default Values were applied.

Road Type Distribution GIS data from Arizona Transportation Information System (ATIS) was used to calculate distribution in San Manuel Maintenance Area.

Fuels Default Values were applied. Ramp Fraction No values were applied.

Appendix A


Under the Governor’s Executive Order No. 2011-04 the Arizona Department of Administration was designated the State agency responsible for preparing official population estimates and projections for the state of Arizona. All State agencies are required to use population estimates and population projections produced by ADOA.

ADEQ prepared official Arizona population projections for Pinal and Pima counties using the 2010 U.S. census data as the base and ADOA population projects for future years. The official methodology used by ADEQ, which is consistent with ADOA’s methodology, can be found in Exhibit AI to the San Manuel SO2 TSD. Values used are provided in Table A-24. Values calculated are provided in Table A-25.

Table A-24 Percentage of County Population in San Manuel SO2 Maintenance Area County Percentage Pima 0.0026% Pinal 2.53%

Table A-25 San Manuel SO2 Maintenance MA Population Estimates and Projection Growth

Factors

Year

Pima County Maintenance

Area Population

Pinal County Maintenance

Area Population

Nonattainment Area Total Population

Pima Growth

from 2010

Pinal Growth

from 2010

2010 26 9,523 9,549 0.00% 0.00% 2014 27 9,981 10,007 2.65% 4.80% 2019 28 11,448 11,475 4.51% 14.70% 2024 29 13,029 13,058 10.27% 30.54% 2028 31 14,504 14,535 14.67% 45.32%

AII1.3 Source Type Population ADOT provided the vehicle registration data for July 2014. Since the data provided by Arizona vehicle registration only contained the HPMS vehicle type ADOT also provided a conversion process spreadsheet to convert HPMS vehicle type IDs to MOVES Source Type IDs.

Appendix A


Table A-26 2014 Source Type Population Values for Pinal and Pima Counties

Source Types Source Type ID Population Population

Allocation sourceTypePopulation

Pinal County Pinal Maintenance Area Motorcycles 11 11,712 2.53% 297 Passenger Car 21 103,707 2.53% 2,628 Passenger Truck 31 70,184 2.53% 1,779 Light Commercial Truck 32 17,511 2.53% 444

Intercity Bus 41 26 2.53% 1 Transit Bus 42 98 2.53% 2 School Bus 43 880 2.53% 22 Refuse Truck 51 1,434 2.53% 36 Single Unit Short-haul Truck 52 47,892 2.53% 1,214

Single Unit Long-haul Truck 53 2,014 2.53% 51

Motor Home 54 12,073 2.53% 306 Combination Short-haul Truck 61 1,798 2.53% 46

Combination Long-haul Truck 62 1,967 2.53% 50

Pima County Pima Maintenance Area Motorcycles 11 27,313 0.0026% 1 Passenger Car 21 28,9572 0.0026% 8 Passenger Truck 31 195,967 0.0026% 5 Light Commercial Truck 32 48,895 0.0026% 1

Intercity Bus 41 77 0.0026% 0.0 Transit Bus 42 288 0.0026% 0.0 School Bus 43 2,585 0.0026% 0.1 Refuse Truck 51 3,340 0.0026% 0.1 Single Unit Short-haul Truck 52 111,578 0.0026% 3

Single Unit Long-haul Truck 53 4,693 0.0026% 0.1

Motor Home 54 28,127 0.0026% 1 Combination Short-haul Truck 61 5,923 0.0026% 0.2

Combination Long-haul Truck 62 6,483 0.0026% 0.2

Appendix A


Future source vehicle populations are projected using population growth factors found in Table A-24. These values are detailed in Table A-27.

Table A-27 San Manuel SO2 Maintenance Area Source

Type Population

Type ID sourceTypePopulation

2014 2019 2023 2028 11 298 341 388 432 21 2636 3023 3441 3831 31 1784 2046 2329 2592 32 445 511 581 647 41 1 1 1 1 42 2 3 3 4 43 22 26 29 32 51 36 42 48 53 52 1217 1396 1588 1768 53 51 59 67 74 54 307 352 400 446 61 46 52 60 66 62 50 57 65 73

AII1.4 Age Distribution To determine vehicle age distribution ADEQ used ADOT registration data from 2014. ADOT’s MOVES converter was then used to convert said data from the MVD values to a MOVES compatible format.

Projected values for age distribution were calculated using EPA’s age distribution projection tool Version 11/21/2014 using the 2014 values as the base value for each projected year.

AII1.5 Meteorology Data Since Pinal County accounts for 78 percent of the maintenance area and the Santa Catalina mountain range separates the San Manuel maintenance area from the rest of Pima County ADEQ used the default input for Pinal County.

Appendix A


AII1.6 I/M Programs There are no I/M programs currently implemented or planning for the San Manuel Maintenance Area.

AII1.6.1 Vehicle Miles of Travel ADEQ used traffic counts obtained from ADOT’s Automatic Traffic Recorders (ATRs). ATRs collect data 24 hours a day, 365 days a year for each lane including traffic volumes, speed and classification of vehicles. ADEQ used ATRs GIS data to pull the roads tracked by ATRs within the San Manuel SO2 Maintenance Area. ADEQ multiplied the segment mileage by the average annual daily traffic (AADT) to calculate the average annual daily vehicle miles traveled (AADVMT) for each HPMS vehicle type for the Maintenance Area.

ADOT projected AADT to 2030, and ADEQ interpolated the projection year (AADVMT) from these values. These values for AADVMT as are detailed in Table A-28.

Table A-28 DVMT for San Manuel SO2 Maintenance Area for years 2014, 2019, 2023, 2028 HPMS Vehicle Type 2014 2019 2023 2028 10 2443 3003 3452 4012 25 373055 458192 526301 611437 40 2427 2983 3428 3984 50 22998 28244 32441 37686 60 27280 33391 38281 44393

ADEQ calculated monthly, daily, and hourly VMT fractions using an EPA supplied AADVMT calculator for MOVES2014. Adjustments and assumptions made in the calculator included: selecting average weekday values for the AADVMT values, no monthly adjustment factor, using MOVES defaults for a rural county, and using MOVES defaults for hourVMTFractions.

AII1.7 Fuels ADEQ used the default input for Pinal County.

AII1.8 Road Type Distribution ADEQ calculated road type distribution from GIS files from ADOT’s ATIS. ADEQ calculated the mileage for all roads in the San Manuel Maintenance Area and all restricted rural roads (highways) in the maintenance area. ADEQ obtained the totals for unrestricted rural roads (local roads) by subtracting the mileage for restricted rural roads from the mileage for all roads. There are no restricted or unrestricted urban roads in the maintenance area. The values obtained from this methodology are displayed in Table A-29.

Appendix A


Table A-29 Road Type Distribution in San Manuel Maintenance

Area Road Miles Distribution

Total 353.50 1.00 Rural Restricted 85.93 0.24 Rural Unrestricted 267.57 0.76

AII1.8.1 Ramp Fraction No ramp fraction was applied.

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