### Page Intentionally Left Blank

### ENCLOSURE 1
Arizona Revised Statutes § § 49

- 104 , 49

- 106, and 49

- 404

### Page Intentionally Left Blank

### 49

- 104. Powers and duties of the department and director

A. The department shall:

1. Formulate policies, plans and programs to implement this tit le to protect the environment.

2. Stimulate and encourage all local, state, regional and federal governmental agencies and all private persons and enterprises that have similar and related objectives and purposes, cooperate with those agencies, persons and enterprises and correlate depa rtment plans, programs and operations with those of the agencies, persons and enterprises.

3. Conduct research on its own initiative or at the request of the governor, the legislature or state or local agencies pertaining to any department objectives.

4. P rovide information and advice on request of any local, state or federal agencies and private persons and business enterprises on matters within the scope of the department.

5. Consult with and make recommendations to the governor and the legislature on all matters concerning department objectives.

6. Promote and coordinate the management of air resources to assure their protection, enhancement and balanced utilization consistent with the environmental policy of this state.

7. Promote and coordinate the prot ection and enhancement of the quality of water resources consistent with the environmental policy of this state.

8. Encourage industrial, commercial, residential and community development that maximizes

environmental benefits and minimizes the effects of l ess desirable environmental conditions.

9. Assure the preservation and enhancement of natural beauty and man

- made scenic qualities.

10. Provide for the prevention and abatement of all water and air pollution including that related to particulates, gases, d ust, vapors, noise, radiation, odor, nutrients and heated liquids in accordance with article 3 of this chapter and chapters 2 and 3 of this title.

11. Promote and recommend methods for the recovery, recycling and reuse or, if recycling is not possible,

the disposal of solid wastes consistent with sound health, scenic and environmental quality policies. Beginning in 2014, the department shall report annually on its revenues and expenditures relating to the solid and hazardous waste programs overseen or admin istered by the department.

12. Prevent pollution through the regulation of the storage, handling and transportation of solids, liquids and gases that may cause or contribute to pollution.

13. Promote the restoration and reclamation of degraded or despoiled areas and natural resources.

14. Assist the department of health services in recruiting and training state, local and district health department personnel.15. Participate in the state civil defense program and develop the necessary organization and facil ities to

meet wartime or other disasters.

16. Cooperate with the Arizona

- Mexico commission in the governor's office and with researchers at universities in this state to collect data and conduct projects in the United States and Mexico on issues

that are w ithin the scope of the department's duties and that relate to quality of life, trade and economic development in this state in a manner that will help the Arizona

- Mexico commission to assess and enhance the economic competitiveness of this state and of the Arizona

- Mexico region.

17. Unless specifically authorized by the legislature, ensure that state laws, rules, standards, permits, variances and orders are adopted and construed to be consistent with and no more stringent than the corresponding federal law that addresses the same subject matter. This provision shall not be construed to adversely affect standards adopted by an Indian tribe under federal law.

B. The department, through the director, shall:

1. Contract for the services of outside advisers, cons ultants and aides reasonably necessary or desirable to enable the department to adequately perform its duties.

2. Contract and incur obligations reasonably necessary or desirable within the general scope of department activities and operations to enable th e department to adequately perform its duties.

3. Utilize any medium of communication, publication and exhibition when disseminating information, advertising and publicity in any field of its purposes, objectives or duties.

4. Adopt procedural rules that a re necessary to implement the authority granted under this title, but that are not inconsistent with other provisions of this title.

5. Contract with other agencies, including laboratories, in furthering any department program.

6. Use monies, facilities or services to provide matching contributions under federal or other programs that further the objectives and programs of the department.

7. Accept gifts, grants, matching monies or direct payments from public or private agencies or private persons and enter prises for department services and publications and to conduct programs that are consistent with the general purposes and objectives of this chapter. Monies received pursuant to this paragraph shall be deposited in the department fund corresponding to the service, publication or program provided.

8. Provide for the examination of any premises if the director has reasonable cause to believe that a violation of any environmental law or rule exists or is being committed on the premises. The director shall give the owner or operator the opportunity for its representative to accompany the director on an examination of those premises. Within forty

- five days after the date of the examination, the department shall provide to the owner or operator a copy of any repor t produced as a result of any examination of the premises.

9. Supervise sanitary engineering facilities and projects in this state, authority for which is vested in the department, and own or lease land on which sanitary engineering facilities are located, and operate thefacilities, if the director determines that owning, leasing or operating is necessary for the public health,

safety or welfare.

10. Adopt and enforce rules relating to approving design documents for constructing, improving and operating sa nitary engineering and other facilities for disposing of solid, liquid or gaseous deleterious

matter.

11. Define and prescribe reasonably necessary rules regarding the water supply, sewage disposal and garbage collection and disposal for subdivisions. The rules shall:

(a) Provide for minimum sanitary facilities to be installed in the subdivision and may require that water systems plan for future needs and be of adequate size and capacity to deliver specified minimum quantities of drinking water and to treat all sewage.

(b) Provide that the design documents showing or describing the water supply, sewage disposal and garbage collection facilities be submitted with a fee to the department for review and that no lots in any subdivision be offered for sale before compliance w ith the standards and rules has been demonstrated by approval of the design documents by the department.

12. Prescribe reasonably necessary measures to prevent pollution of water used in public or semipublic swimming pools and bathing places and to prevent deleterious conditions at such places. The rules shall prescribe minimum standards for the design of and for sanitary conditions at any public or semipublic swimming pool or bathing place and provide for abatement as public nuisances of premises and facil ities that do not comply with the minimum standards. The rules shall be developed in cooperation with the director of the department of health services and shall be consistent with the rules adopted by the director of the department of health services purs uant to section 36

- 136, subsection H, paragraph 10.

13. Prescribe reasonable rules regarding sewage collection, treatment, disposal and reclamation systems to prevent the transmission of sewage borne or insect borne diseases. The rules shall:

(a) Prescribe minimum standards for the design of sewage collection systems and treatment, disposal and reclamation systems and for operating the systems.

(b) Provide for inspecting the premises, systems and installations and for abating as a public nuisance any

collec tion system, process, treatment plant, disposal system or reclamation system that does not comply

with the minimum standards.

(c) Require that design documents for all sewage collection systems, sewage collection system extensions, treatment plants, proces ses, devices, equipment, disposal systems, on

- site wastewater treatment facilities and reclamation systems be submitted with a fee for review to the department and may require that the design documents anticipate and provide for future sewage treatment nee ds.

(d) Require that construction, reconstruction, installation or initiation of any sewage collection system, sewage collection system extension, treatment plant, process, device, equipment, disposal system, on

- site wastewater treatment facility or reclam ation system conform with applicable requirements.

14. Prescribe reasonably necessary rules regarding excreta storage, handling, treatment, transportation and disposal. The rules shall:(a) Prescribe minimum standards for human excreta storage, handling, t reatment, transportation and

disposal and shall provide for inspection of premises, processes and vehicles and for abating as public nuisances any premises, processes or vehicles that do not comply with the minimum standards.

(b) Provide that vehicles tran sporting human excreta from privies, septic tanks, cesspools and other treatment processes shall be licensed by the department subject to compliance with the rules. The department may require payment of a fee as a condition of licensure. After the effectiv e date of this amendment to this section, the department shall establish by rule a fee as a condition of licensure, including a maximum fee. As part of the rule making process, there must be public notice and comment and a review of the rule by the joint l egislative budget committee. After September 30, 2013, the department shall not increase that fee by rule without specific statutory authority for the increase. The fees shall be deposited, pursuant to sections 35

- 146 and 35

- 147, in the solid waste fee fun d established by

section 49

- 881.

15. Perform the responsibilities of implementing and maintaining a data automation management system to support the reporting requirements of title III of the superfund amendments and reauthorization act of 1986 (P.L. 99

- 49 9) and title 26, chapter 2, article 3.

16. Approve remediation levels pursuant to article 4 of this chapter.

17. Establish or revise fees by rule pursuant to the authority granted under title 44, chapter 9, article 8 and chapters 4 and 5 of this title for the department to adequately perform its duties. All fees shall be fairly assessed and impose the least burden and cost to the parties subject to the fees. In establishing or revising fees, the department shall base the fees on:

(a) The direct and indirect costs of the department's relevant duties, including employees salaries and benefits, professional and outside services, equipment, in

- state travel and other necessary operational expenses directly related to issuing licenses as defined in title 41, chapt er 6 and enforcing the requirements of the applicable regulatory program.

(b) The availability of other funds for the duties performed.

(c) The impact of the fees on the parties subject to the fees.

(d) The fees charged for similar duties performed by the department, other agencies and the private sector.

C. The department may:

1. Charge fees to cover the costs of all permits and inspections it performs to ensure compliance with rules adopted under section 49

- 203, except that state agencies are exempt from paying the fees. Monies collected pursuant to this subsection shall be deposited, pursuant to sections 35

- 146 and 35

- 147, in the water quality fee fund established by section 49

- 210.

2. Contract with private consultants for the purposes of assisting the de partment in reviewing applications for licenses, permits or other authorizations to determine whether an applicant meets the criteria for issuance of the license, permit or other authorization. If the department contracts with a consultant under this parag raph, an applicant may request that the department expedite the application review by requesting that the department use the services of the consultant and by agreeing to pay the department the costs of the consultant's services. Notwithstanding any other law, monies paid by applicants forexpedited reviews pursuant to this paragraph are appropriated to the department for use in paying

consultants for services.

D. The director may:

1. If the director has reasonable cause to believe that a violation of any e nvironmental law or rule exists or is being committed, inspect any person or property in transit through this state and any vehicle in which the person or property is being transported and detain or disinfect the person, property or vehicle as reasonably n ecessary to protect the environment if a violation exists.

2. Authorize in writing any qualified officer or employee in the department to perform any act that the director is authorized or required to do by law.



### 49

- 106

. Statewide application of rules

The rules adopted by the department apply and shall be observed throughout this state, or as provided by their terms, and the appropriate local officer, council or board shall enforce them. This section does not limit the authority of local governing bodie s to adopt ordinances and rules within their respective jurisdictions if those ordinances and rules do not conflict with state law and are equal to or more restrictive than the rules of the department, but this section does not grant local governing bodies any authority not otherwise provided by separate state law.



### 49

- 404

. State implementation plan

A. The director shall maintain a state implementation plan that provides for implementation, maintenance and enforcement of national ambient air quality standards and protection of visibility as required by the

clean air act.

B. The director may adopt rule s that describe procedures for adoption of revisions to the state implementation plan.

C. The state implementation plan and all revisions adopted before September 30, 1992 remain in effect according to their terms, except to the extent otherwise provided b y the clean air act, inconsistent with any provision of the clean air act, or revised by the administrator. No control requirement in effect, or
required to be adopted by an order, settlement agreement or plan in effect, before the enactment of the

clean a ir act in any area which is a nonattainment or maintenance area for any air pollutant may be modified after enactment in any manner unless the modification insures equivalent or greater emission reductions of the air pollutant. The director shall evaluate and adopt revisions to the plan in conformity with federal regulations and guidelines promulgated by the administrator for those purposes until the rules
required by subsection B are effective.

### Page Intentionally Left Blank

### ENCLOSURE 2

State Implementation Plan Completeness Checklist

### Page Intentionally Left Blank

### STATE IMPLEMENTATION PLAN COMPLETENESS CHECKLIST

Submittal of

Arizona State Implementation Plan Revision for the Morenci Sulfur Dioxide Planning Area (1971 NAAQS)

40 CFR Part 51, Appendix V, Criteria for Determining the Completeness of Plan Submissions , contains the “minimum criteria for determining whether a State Implementation Plan submitted for consideration by EPA is an official submission for purposes of review under §51.103,” Submission of plans, preliminary review of plans

. Appendix V requires the following to be included in plan submissions for review by EPA:

1. "A formal letter of submittal from the Governor or his designee, requesting EPA acceptance of the plan or revision thereof (hereafter ‘‘the plan’’)." [Appendix V, 2.1(a)]

See cover letter.

2. "Evidence that the State has adopted the plan in the State code or body of regulations; or issued the permit, order, consent agreement (hereafter ‘‘document’’) in final form. That evidence shall include the date of adoption or final issuance as well as the effective date of the plan, if diffe rent from the adoption/issuance date." [Appendix V, 2.1(b)]

See cover letter

3. "Evidence that the State has the necessary legal authority under State law to adopt and implement the plan." [Appendix V, 2.1(c)]

Refer to Enclosure 1.

4. "A copy of the actual regulation, or document submitted for approval and incorporation by reference into the plan, including indication of the changes made (such as, redline/strikethrough) to the existing approved plan, where applicable ..." [Appendix V, 2.1(d)]

Refer to the Arizona State Implementation Plan Revision Maintenance Plan for the Morenci Sulfur Dioxide Planning Area (1971 NAAQS).

5. "Evidence that the State followed all of the procedural requirements of the State’s laws and constitution in conducting and co mpleting the adoption/issuance of the plan." [ Appendix V, 2.1(e) ] Refer to cover letter, Enclosure 3, and Appendix E.

6. "Evidence that public notice was given of the proposed change consistent with procedures approved by EPA, including the date of pu blication of such notice." [Appendix V, 2.1(f)] Refer to Enclosure 3, Appendix E.

7

. "Certification that public hearing(s) were held in accordance with the information provided in the public notice and the State’s laws and constitution, if applicable an d consistent with the public hearing requirements in 40 CFR 51.102." [ Appendix V, 2.1(g) ] Refer to Enclosure 3, Appendix E.

8

. "Compilation of public comments and the State’s response thereto." [ Appendix V, 2.1(h) ] Refer to Enclosure 3, Appendix E.9

. "Identification of all regulated pollutants affected by the plan." [ Appendix V, 2.2(a) ]

The regulated pollutant is Sulfur Dioxide (SO 2 ).

10

. "Identification of the locations of affected sources including the EPA attainment/nonattainment designation of the locations and the status of the attainment plan for the affected areas(s)." [ Appendix V, 2.2 (b) ] See Enclosure 3, Chapters 1, Chapters 3 and 5

.

11

. "Quantification of the changes in plan allowable emissions from the affected sources; estimates of changes in current actual emissions from affected sources or, where appropriate, quantification of changes in actual emissions from affected sources through calculations of the differences between certain baseline levels and allowable emissions anticipa ted as a result of the
revision." [ Appendix V, 2.2(c) ] See Enclosure 3, Chapters 3, 4

, and 5

.

12

. "The State’s demonstration that the national ambient air quality standards, prevention of significant deterioration increments, reasonable further progress demonstration, and visibility, as applicable, are protected if the plan is approved and implemented. For all requests to redesignate an area to attainment for a national primary ambient air quality standard, under section 107 of the Act, a revision must be submitted to provide for the maintenance of the national primary ambient air quality standards for at least 10 years as required by section 175A
of the Act." [ Appendix V, 2.2(d) ] See Enclosure 3, Chapter s 4, 5 , and 6

.

13

. "Modeling information require d to support the proposed revision, including input data, output data, models used, justification of model selections, ambient monitoring data used, meteorological data used, justification for use of offsite data (where used), modes of models used, assumpt ions, and other information relevant to the determination of adequacy of the modeling analysis." [ Appendix V, 2.2(e) ] See Enclosure 3, Chapter 5

.

14

. "Evidence, where necessary, that emission limitations are based on continuous emission

reduction technology." [ Appendix V, 2.2(f) ] Not applicable.

15

. "Evidence that the plan contains emission limitations, work practice standards and recordkeeping/reporting requirements, where necessary, to ensure emission levels." [ Appendix V, 2.2(g) ] Not appli cable.

16

. "Compliance/enforcement strategies, including how compliance will be determined in practice." [ Appendix V, 2.2(h) ]
See Enclosure 3, Chapter 6

.

17

. "Special economic and technological justifications required by any applicable EPA policies, or an explanation of why such justifications are not necessary." [ Appendix V, 2.2(i) ] No known deviation from EPA policy.

### ENCLOSURE 3

Arizona State Implementation Plan Revision

Maintenance Plan for the Morenci Sulfur Dioxide Planning Area (1971 NAAQS)

December 2014

### Page Intentionally Left Blank

# FINAL

Arizona State Implementation Plan Revision

Maintenance Plan for the
Morenci Sulfur Dioxide Planning Area

(1971 NAAQS)

Air Quality Division

December 18

, 2014

### Page Intentionally Left Blanki



### Table of Contents

Table of Contents ................................................................................................ ............................. i List of Executive Summary Figures ................................................................

.............................. iii List of Figures ................................................................................................

................................ iii

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

................................. iii List of Appendices ................................................................................................

......................... iii

EXECUTIVE SUMMARY ................................

............................................................................. 1

1.0 INTRODUCTION ................................

............................................................................... 3

1.1 Statement of Introduction and Purpose ...................................................................... 3

1.2 National Ambient Air Quality Standards ................................................................... 3

1.3 Sulfur Dioxide Air Quality Standards........................................................................ 3

1.4 Regulatory Background ................................................................ ............................. 4

1.5 Morenci Sulfur Dioxide Planning Area Description ................................................. 7

1.5.1 Morenci Sulfur Dioxide Planning Area Boundary ..................................... 7

1.5.2 Geography and Climate .............................................................................. 9

1.5.3 Population ................................

................................................................... 9

1.5.4 Economy ................................

................................................................... 10

1.6 General SIP Approach

– Regulatory Requirements and Guidance ......................... 10

1.6.1 Clean Air Act Requirements for Maintenance Plans ................................ 11

1.6.2 Clean Air Act Conformity Provisions................................ ....................... 11

1.6.3 EPA Guidance ................................................................ ........................... 12

2.0 AIR QUALITY MONITORING ................................................................ .......................14

2.1 Monitoring Site, Equipment, and Quality Assurance Procedure ............................. 14

2.2 SO 2 

### Data Summary ................................................................ ............................... 15

3.0 EMISSIONS INVENTORIES AND PROJECTIONS TO 2030 ....................................... 17

3 .1 Emissions Inventories (Historical) ........................................................................... 18

3.1.1 Point Sources ................................................................ ............................ 18

3.1.2 Area and Mobile Sources .......................................................................... 18

3.2 2011 Emissions Inventory (Current) ........................................................................ 19

3.2.1 Point Sources ................................................................ ............................ 19

3.2.2 Totals for Mobile, Area and Point Sources ............................................... 22

3.3 Emissions Projections ................................................................ .............................. 22 3.3.1 Point Source Projections .............................................................................. 22 3.3.2 Point Source Projections .............................................................................. 22

4.0 CONTROL MEASURES ................................

.................................................................. 25

4.1 Point Sources ................................

........................................................................... 25

4.2 Area and Mobile Sources ................................................................ ......................... 25

5.0 MODELING DEMONSTRATION ................................................................................... 27

5.1 Historical Modeling Analysis .................................................................................. 27

5.2 Current Modeling Demonstration ............................................................................ 27

6.0 MAINTENANCE PLAN SUMMARY ............................................................................. 30

6.1 Emissions Inventories ................................................................ .............................. 30

6.2 Maintenance Demonstration .................................................................................... 30

6.3 Ambient Monitoring ................................................................ ................................ 31

6.5 Contingency Plan ................................

..................................................................... 32ii



### 6.6 Conclusion ............................................................................................................... 33iii 

### List of Executive Summary Figures

ES

- 1 Total SO 2 Sources within Morenci Maintenance Area

................................ ................................ ....... 1



### List of Figures Figure 1.1: Morenci Sulfur Dioxide Planning Area

................................ ................................ ...................... 8

Figure 3.1: Morenci Sulfur Dioxide Planning Area and 50 km Bu ffer Area Point Sources

....................... 21

Figure 6.1: SO 2 Emissions for Years 1984

- 2030

................................ ................................ ........................ 31



### List of Table s

Table 1.1 1971 Sulfur Dioxide National Ambient Air Quality Standards

................................ .................... 4 Table 1.2 Morenci Sulfur Dioxide Area Description

................................ ................................ .................... 7 Table 1.3 Greenlee County Population Estimates

................................ ................................ ........................ 9
Table 1.4 Labor Force Data for Morenci and Clifton

................................ ................................ ................. 10

Table 2.1: State of Arizona Morenci SO 2 Ambient Air Quality Monitors

................................ ................. 15 Table 2.2: Phelps Dodge Morenci SO2 Ambient Air Quality Stationary and Mobile Monitors

................ 15

Table 3.1: Total Historical Potential to Emit and Actual Emissions in tons for years 1984 and 1999

....... 18

Table 3.2: His torical Greenlee County and Morenci Area and Mobile Source Emissions in tons

............. 18

Table 3.3: SO 2 Point Sources within Morenci Planning Area

................................ ................................ .... 19

Table 3.4: SO 2 Point Sources within 50

- km Buffer

................................ ................................ .................... 20

Table 3.5: Total SO 2 Emissions for the Morenci Planning Area

- 2011

................................ ....................... 22 Table 3.6: Point Source Projections in Planning Area to 2030

................................ ................................ ... 23 Table 3.7: Point Source Projections within the 50km Buffer Area

................................ ............................. 23

Table 3.8: Area and Mobile Sources SO 2 Emissions Projections for the Morenci Planning Area

............. 24

Table 5.1: Emissions of SO 2 for FMMM and FMSM in Renewal Permits

................................ ................ 28 Table 5.2: Cumulative Impacts of FMMM and FMSM on the Morenci Maintenance Area

...................... 29 Table 5.3: Cumulative Impacts of FMMM and FMSM on the Morenci Maintenance Area Boundary

..... 29



### List of Appendices

Ap pendix A Procedures for Processing Requests to Redesignate Areas to Attainment

, Memorandum,

John Calcagni, Director, Air Quality Management Division, U.S. En vironmental Protection

Appen dix B Redesignation of Sulfur Dioxide Nonattainment Areas in the Absence of Monitored

Data

, Memorandum, John Seitz, Director

, Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, October 18, 2000

Appendix C Morenci Maintenance Plan Emissions Inventory

Appendix D Morenci Modeling Analysis

Appendix E State Implementation Plan Revision Public Comment and Hearing Documentationiv

E.1 Notice of Public Hearing E.2 Public Hearing Agenda

E.3 Public Hearing Sign

- In Sheet E.4 Public Hearing Officer Certification and Transcript E.5 Responsiveness Summary1

EXECUTIVE SUMMARY

The Morenci Sulfur Dioxide (SO 2 ) Maintenance Plan demonstrates that the Morenci planning area will conti nue to
meet the 1971 health

- based 24

- hour and annual SO 2 National Ambient Air Quality Standards (NAAQS) for a second maintenance period, through 2030.

An overview of the NAAQS and Clean Air Act (CAA) Requirements are discussed in further detail in Chapte r 1. This chapter also gives a summary of the regulatory background including boundary designations and describes the planning area ’s geography

, climate, population, and economy.

Chapter 2 presents the history of the monitoring network and the monito ring requirements of the planning area

. Due to the closure of facility on December 31, 1984 , which was the primary sour ce of SO2 emissions, no ambient monitors are currently in operation within the area. If a new major source is constructed in the planni ng area, the Arizona Department of Environmental Quality ( ADEQ ) will develop and implement an appropriate monitoring network according to federal and state regulations.

Emissions inventories in Chapter 3 reveal that while in operation, the Phelps Dodge Mi ning Company’s primary copper smelter was the largest point source in the Morenci Nonattainment Area. ES [1] Figure ES

- 1 shows that no other point, area

, or mobile source has generated or currently generates as high a level of SO 2 emissions in the area

as t he smelter did when in operation

. The smelter permanently deactivated in December 1984. D ismantling of the facility began in 1995 and reclamation was completed by December 1996. In 1997, ADEQ verified that the Phelps Dodge Morenci smelter was closed an d dismantled. The closure of this facility resulted in permanent significant

emissions reductions.

Figure ES

- 1 illustrates point source emissions reductions due to the closure of the smelter and shows that future

emissions remain low enough to not caus e a violation of the NAAQS. The 1984 and 2011 levels are based on actual

emission estimates

, while projected emission estimates are based on the potential to emit (PTE) of extant sources

. The 2030 inventory represents emissions projected through the seco nd ten

- year maintenance period.

ES

- 1 Total SO 2 Sources within Morenci Maintenance Area

ES [1 ] Freeport

- McMoRan bought the Phelps Dodge Corporation in
2007; http://seagoedd.org/?s=population+morenci

. 0 10,000 20,000 30,000 40,000 50,000 60,000 70,000 80,000 90,000 100,000

1984 2011 2015 2025 2050

82,432.00

48.54 87.6 87.6 87.6 Tons

Years SO2 Emissions2

Chapter 4 de scribes the implementation of primary control measures used to achieve attainment and maintenance of

the SO 2 NAAQS

. For previ ous SIP revisions, EPA has considered the closure of the smelter as sufficient to meet reasonably available control measure ( RACM ) requirements in the Morenci planning area

. Additional measures to
ensure continued attainment of the SO 2 NAAQS are implement ed through state and county permitting requirements

. There are also s everal national programs that integrate engine and fuel controls for highway vehicles and non

- road equipment to reduce SO 2 emissions for area and mobile sources.

The m odeling analysis c ontained in Chapter 5 demonstrates continued attainment of the NAAQS

. The analysis

includes t wo of the largest sources within the planning area

, Freepo r t McMoRan Mine and Safford Mine

. The

m odel estimate s that the mines , which emit a combined total of ab out 169 tons per year of SO 2

, do not contribute to

violations of the 1971 SO 2 NAAQS.

Chapter 6 summarizes the measures that ensure continued maintenance of the NAAQS through the year 2030

. This

discussion shows the permanence and enforceability of the em ission reductions responsible for the air quality improvement and attainment of the NAAQS

. Maintenance of the SO 2 NAAQS in the Morenci area will be tracked through updates to the emissions inventory and permit applications received for SO 2 emitting source s. The C hapter

a lso includes a commitment to resume ambient monitoring before any new major SO 2 source begins operation in the

area.

The permanent and enforceable control measures and projections of future emissions presented in this document

demonstrate that the Morenci area will continue to maintain the SO 2 air quality standards

. W ith this submittal

, ADEQ requests that EPA approve this maintenance plan for the 1971 SO 2 24

- hour and annual NAAQS through

2030 in accordance with CAA § 175 A

.3



### 1.0 IN TRODUCTION

Chapter 1 describes the purpose of th is S tate I mplementation P lan (SIP) revision for the Morenci Sulfur

D ioxide (SO 2 ) P lanning A rea , summarizes the regulatory background of the area, and provides a general overview of the area and county.

1.1 Sta tement of Introduction and Purpose

This SIP r evision demonstrates that the Morenci Planning Area will continue to meet the 1971 health

based 24

- hour average and annual average SO 2 National Ambient Air Quality Standards (NAAQS) for a second maintenance per iod, through 20 30

.

T he Morenci Sulfur Dioxide Nonattainment Area State Impl ementation and Maintenance Plan and redesignation request was submitted to the U.S. Environmental Protection Agency ( EPA ) in June 2002

. The SIP revision summar ized the progress o f the area towards attaining the SO 2 standards

, demonstrated that all Clean Air Act (CAA) requirements had been satisfied, and included a maintenance plan to assure

the area would continue to attain the standard after redesignation, through 2015

. EPA appr oved the plan and redesignated the area to attainme nt effective June 25, 2004 ( 69 FR 22447; April 26, 2004 ). Section 175A(a) of the CAA requires states to demonstrate maintenance of the NAAQS for at least ten years after redesignation to attainment

. The effective first maintenance period for the Morenci area is 2004 through

2015.

A subsequent SIP revision, under CAA Section 175A(b), is due eight years after an area is redesignat ed to
attainment in order to provide for maintenance of the NAAQS for an addi tional 10 years after the expiration of the first 10

- year maintenance period

. The information contained in this document shows that the air quali ty standards will continue to be maintained from the expiration of the first maintenance period through 20 30

.

1.2 National Ambient Air Quality Standards

Title I of the CAA requires EPA to set NAAQ S for those pollutants considered harmful to both public health and the environment. EPA set standards for six air pollutants: ground

- level ozone, particulate

matter, ca rbon monoxide, nitrogen dioxide, sulfur dioxide and lead. There are two types of NAAQS: primary and secondary. Primary standards are set to protect human health and established secondary standards protect public welfare, such as decreased visibility and damage to animals, crops, vegetation and buildings.

The standard for each pollutant is set at a maximum concentration in either parts per million (ppm) by volume, parts per billion (ppb) by volume, or micrograms per cubic meter of air (μ g /m 3 ). Each st andard also has a distinct averaging time that provide s the necessary level of protection

. These standards are reviewed every five years and are retained or revised based on review of scientific literature and analyses

.

1.3 Sulfu r Dioxide Air Quality Standa rds

The federal air quality standards for SO 2 were established in 1971 and identified ambient concentrations

that affect human health and welfare

. The original primary and secondary NAAQS for SO 2 were codified

in Volume 42 of the Code of Federal Re gulati ons (CFR) , Part 410 ( 42 CFR Part 410 ) on April 30, 19714

( 36 FR 81875 ), and recodified in 40 CFR 50.4 and 50.5 on November 25, 1971 ( 36 FR 22384). On May 22, 1996, EPA promulgated several technical changes; however, no changes were made to the level of the standards at that time ( 61 FR 25566). 1 Table 1.1 shows t he 1971 primary and secondary SO 2 NAAQS, as

modified in 1996

. Arizona adopted these standards at Arizona Administrative Code (AAC) R18

- 2

- 202

, effective May 05, 2011

.

Table 1. 1 1971 Sulfur Dioxide National Ambient Air Quality Standards

Final
Rule/Decision Primary/

Secondary Averaging

Time Level Form

1971 Primary 24

- Hour 0.14 ppm 365

μ g /m 3 Not to be exceeded more

than o nce per year Annual 0.03 ppm 80 μ g/m 3 Annual arith metic average

Secondary 2 3

- Hour 0.5 ppm 1300

μ g/m 3 Not to be exceeded more

than o nce per year Annual 0.02 ppm 52 μg/m 3 Annual arithmetic average

1973 Secondary S econdary 3

- hour SO 2 standard retained, without revision; secondary

annual SO 2 standard re voked

. 1996 Primary Existing primary SO 2 standards retained, without revision.

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

.

On June 22, 2010, EPA replaced the existing annual and 24

- hour primary SO 2 standards with a new 1

- hou r SO 2 standard set a level of 75 ppb to better protect public health by reducing public exposure to

elevated short

- term concentrations of SO 2 (75 FR 35520; effective August 23, 2010 )

. Planning obligations for the 1971 standards, including this renewal of the Morenci maintenance plan, continue un til they are subsumed by planning and control requireme nts associated with new NAAQS.

On December 8

, 2009 , EPA propos ed to retain the current SO 2 secondary standard to provide requisite protection for the direct effects on vegetation and ecosystems (7 4 FR 6 4810 ). 3 At the same time, EPA proposed to add a secondary standard identical to the new primary SO 2 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 )

. Th is plan does not

address the 2010 NAAQS for SO 2

.

1.4 Regulatory Background

The relationship between major SO 2 point sources and ambient air quality is relatively well defined . The Phelps Do dge Morenci, Inc. copper smelting facility (PDMI) was the largest SO 2 point source in the Morenci area during its operation

. Data show that no other point, area or mobile sources contributed in the past or curren tly contribute at the same levels of SO 2 emissions as those attributed to the smelter.

1 Technical changes included stating the standards in parts per million (ppm) to make the SO 2 NAAQS consistent with those for other po llutants. The former standards, stated in micrograms per cubic meter (μg/m 3 ) are included in this document for consistency with historic data collection, reporting, and analyses.

2 The 1971 SO 2 NAAQS originally included a secondary standard at 0.02 ppm in an annual arithmetic mean. In 1973 EPA proposed and finalized revocation of the annual mean secondary standard (38 FR 11355; May 7, 1973 and 38 FR 25678; September 14, 1973).

3 http://www.epa.gov/ttn/naaqs/standards/so2/fr/20091208p64810.pdf5

PDMI was located next to the Morenci copper mine in the Gila River air shed at an elevation of about 4,500 feet above sea level. 4

Areas that do not meet the NAAQS m ay be designated nonattainment for the respective standard. The

Morenci SO 2 Nonattainment Area, designated for the 1971 annual and 24

- hour primary standards, initially encompassed all of Greenlee County (43 FR 8968; March 3, 1978) . At the request of the State of Arizona, the boundaries were reduced to eight whole or partial townships roughly centered on the primary copper smelter in Morenci (44 FR 21261; April 10, 1979 ). In addition, one adjacent township was designated as unclassifiable.

As r equired by the CAA , Arizona submitted a SIP in 1971 for all major sources in the State. The portion

of the plan pertaining to attainment and maintenance of the NAAQS for SO 2 did not sufficiently define emissions limitations or require permanent control of emissi ons for existing copper smelters and was disapproved on July 27, 1972 (37 FR 15081). On the same date, EPA proposed revised regulations for control of sulfur oxides emitted by all existing smelters in Arizona (37 FR 15096). These regulations

were not fi nalized due to issues regarding the adequacy of the ambient air quality data used to develop the limits. EPA subsequently established an SO 2 monitoring network around each smelter in the State to gather air quality data from June 1 973, through October 197 4, and provide a bas is for 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), which would utiliz e

am bient monitoring data and allow Arizona smelters to intermittently curtail opera tions and emissions to prevent violations of the SO 2 NAAQS. EPA disapproved this approach and required installation and continuous operation of permanent SO 2 emissions control s adequate to ensure attainment of the NAAQS. On January 4, 1978, EPA published final emissions limits for Arizona smelters based on air quality data

from 1973 to 1974 and the use of a proportional rollback model (43 FR 755). The regulations specified

ma ximum emissions rates and compliance test methods for seven Arizona smelters.

The 1977 Clean Air Act Amendments (CAAA) modified smelter control requirements and allow ed the temporary use of SCS while final SO 2 emission limits were developed and also all owed more time for

certain smelters to install emissions control technology. 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. 5

The new regulations were developed using a “Multi

- Point Rollback (MPR)” technique. The use of MPR to establish emissions limits addressed the problem of variable SO 2 emissions from smelting operations

and vari able meteorological conditions, which define ambient concentrations

, 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 emission s profile to a level protective of the standards. The new regulations established stack emission limits for smelters and set requirements for analyzing the impact of fugitive SO 2 emissions on ambient air quality. The rule required all existing primary co pper smelters in Arizona to implement control technology sufficient to comply with the new

4 The s melter’s geographic coordinates were latitude of 33 3'49.3" N and a longitude coordinate of 109, 20'30.5W.

5 Site specific emissions limits were promulgated at Arizona Administrative Rules and Regulations (AARR) R9

- 3

- 515, later revised and recodified as Ar izona Administrative Code (AAC) R18

- 2

- 715, Standards of Performance for Existing Primary Copper Smelters; Site

- specific Requirements, R18

- 2

- 715.01, Standards of Performance for Existing Primary Copper Smelters; Compliance and Monitoring, and R18

- 2

- 715.02, Standards of Performance for Existing Primary Copper Smelters; Fugitive Emissions.6

stack limits as well as any fugitive emissions controls necessary to assure attainment and maintenance of the NAAQS.

On November 30, 1981, EPA proposed conditiona l approval of Arizona’s Multipoint Rollback (MPR) SIP revision (46 FR 58098). On June 3, 1982, Arizona submitted revisions to correct the conditional approval. EPA formally approved Arizona’s MPR rules as a component of the SIP on January 14, 1983 (48 FR 1717). The rules included performance standards for each existing primary copper smelter (see Arizona Administrative Code (AAC) R18

- 2

- 715 , R18

- 715.02)

. Rule R18

- 2

- 715.01 (D) identified January 14, 1986, as the general compliance date for the provisions of the Section

. Arizona’s SIP revisions were designed to meet the requirements of CAA §§ 110 (state implementation plans) and 123 (smelter stack heights) as amended in 1977 and replaced EPA’s January 4, 1978, SO 2 control regulations applicable to Arizona copper smelters. To complete the Arizona SO 2 SIP, EPA required that Arizona submit necessary fugitive emissions control strategies and regulations for existing smelters by August 1,

1984.

PDMI was subject to a Delayed Compliance Order from 1981 and an earlier compliance date of January 1, 1985. 6 On March 4, 1982, Phelps Dodge responded to EPA, requesting an 18

- month delay in its Compliance Order dates for its Morenci copper smelter, due to financial difficulties

. EPA denied the
request

. On April 17, 1 982, PDMI temporarily ceased copper smelting activities, recommencing operations October 12, 1982 , initiating use of oxygen

- fuel, oxygen sprinkle smelting systems in its

number 3 furnaces in November 1982, as mandated in the PDMI Delayed Compliance/Innovat ive Technology Orders (DCO/ITOs).

PDMI permanently deactivated December 31, 1984

. Additionally, all ambient air quality monitoring was

discontinued at the time of the shutdown. Dismantlement of the Morenci facility began in 1995 and

reclamation was com

plete by December 19 96

. On October 29, 1997, the Arizona Department of Environmental Q uality (ADEQ) verified that the Phelps Dodge Morenci smelter was closed and

dismantled ( see the 2002 SIP submittal, section 1.2 for details )

.

In June 2002, ADEQ submi tted to EPA the Morenci Sulfur Dioxide Nonattainment Area State Implementation and Maintenance Plan and a request to redesignate the area to attainment. CAA Section 175A(a) requires that maintenance of the NAAQS be demonstrated for at least ten years afte r redesignation to attainment. The SIP conta ined demonstrations that the Morenci area attained and would

continue to maintain the 1971 SO 2 NAAQS through 2015

. The SIP also included a commitment to

submit a subsequent SIP revision to ensure maintenance of the NAAQS in the redesignated area for a second maintenance period as required by CAA Section 175A(b). EPA approved the 2002 plan under CAA Sections 110 and 175A and redesignated the area to attainment for the primary SO 2 NAAQS on April 26, 2004 ( 69 FR 22 447; effective June 25 , 2004 )

. 7

This SIP revision demonstrates continued attainment of the 1971 primary SO 2 NAAQS for a second maintenance period through 2030

.

6 The emission regulations violated were defined in Arizona’s 1979 SIP and in 40 CFR §52.125(d) and Regulation

7

- 1

- 3.6 of the Rules and Regulations for Air Pollution Contr ol of the Arizona State Department of Health (ADHS). After issuance of notices to Phelps Dodge for violations of emission regulations at the Morenci smelter, EPA and PDMI negotiated and agreed to Delayed Compliance/Innovative Technology Orders (DCO/ITOs)un der CAA § 113(d)(4)(46 FR 49604 (1984)). EPA issued the final Orders on January 12, 1982 (47 FR 1293). EPA amended the

DCO/ ITO issued PDMI on July 23, 1984 (49 FR 24090). Although the 1984 amendments to the PDMI consent decree changed some interim complian ce dates, the SO 2 compliance deadline remained January 1, 1985.

7 For additional information on the approval of the Morenci plan see: http://www.epa.gov/region09/air/az/morenci/index.html

.7

1.5 Morenci Sulfur Dioxide Planning Area Description

Sections 1.5.1 through 1.5

. 4 describe the boundary, geo graphy and climate , demographics, and economy

of the Morenci planning area.

1.5.1 Morenci Sulfur Dioxide Planning Area Boundary

The current boundaries of the p lanning a rea are codified at 40 CFR § 81.303 ( 1979) and are defined by the townships l isted in Table 1.2

. Figure 1.1 , portrays the townships and ranges within the planning area.

Table 1. 2 Morenci Sulfur Dioxide Area Description

Designated Area Better Than National
Standards Cannot Be Classified

T3S, R28E* X T3S, R29E X T3S, R30E X T4S, R28E* X T4S, R29E X T4S, R30E X T5S, R28E* X T5S, R29E* X T5S, R30E X

* Only that portion in Greenlee County. 8

8 40 CFR§ 81.303 (1979) Ch. 1 (7

- 1

- 10 Edition); ( http://www.gpo.gov/fdsys/pkg/CFR

- 2010

- title40

- vol17/pdf/CFR

2010

- title40

- vol17

- sec81

- 303.pdf ).8 Figure 1. 1 : Morenci Sulfur Dioxide Planning Area9

1.5.2 Geography and Climate

The Morenci SO 2 Planning Area is located in western Greenlee County approximately nine miles west of

the Arizona/New Mexico border. Greenlee County covers a land ar ea of 1,847 square miles and contains

diverse terrain and climat e, from upland desert at its southern tip to high alpine country rising to more than 9,000 feet above sea level at points along the Mogollon Rim.

The diverse natu re of the topography in the County creates wide temperature variations. In the Morenci

are a, the hottest month of the year is July, when the average daily maximum temperature is 101.4 ° Fahrenheit (F) and the average da ily minimum temperature is 71.3° F. The coolest month of the year is January, when the average da ily maximum temperature is 61. 2° F and the average da ily minimum temperature is 31.1° F. T he heaviest rainfall of the year occurs in July and August; average total precipitation for those months is 2.17 inches and 2.27 inches, respectively

. The driest months of the year are May and J une, when average total precipitation is 0.22 inch es and 0.33 inches

. The average annual precipitation in the Morenci area is 12.06 inches. 9

1.5. 3 Population

Population statistics p rovide information about the number of people affected by changes in ai r quality in the Morenci planning area and can be used as a surrogate for estimating current and future emissions from certain source categories (see Chapter 4).

In the 1970s

, when rural counties outpaced the growth of urban counties in the U.S., rural Greenlee

Count y grew by slightly more than 10%

. However, during the 1980s

, Greenlee County’ s population
declined almost 30% and t he population in the unincorporated Morenci area, defined as a ‘Census Designated Place’ (CDP) by the Census Bureau, decreased by 34%

. 10

According to the Arizona Department of Admini stration ( ADOA), the population of Greenlee County in

2011 was estimated at 8,380 residents , which corresponds to the population provided by the U.S. Census

Bureau

. By 2030, the population in the c ounty is expected to increase by 188 people

. The population in

the Morenci area is projected to increase by 30 residents by 2030

, resulting in a total of 1,512 people

. The population of Clifton and Morenci CDP define s the maintenance area population and is approximately 57% of the Greenlee County population. Table 1 .3 illustrates the population trend between 2011 and 2030, which indicates a slight increase in Greenlee County , Clifton, and the Morenci CDP

.

Table 1. 3 Green lee County Population Estimates

Location 2011 2015 2020 2025 2030

Clifton 3,273 3,299 3,323 3,340 3,350

Morenci CDP 1,482 1,489 1,500 1

, 508 1,512 Greenlee County 8,380 8,437 8,499 8,543 8,568 http://www.workforce.az.gov/population

- projections.aspx

9 Source of data is the Arizona Department of Commerc e Community Pro file for Morenci /Clifton

, February 2001.

10 AZ Dept of Economic Security and U

. S

. Census Bureau. See page 1.5 of 2002 SIP.10

1.5.4 Economy

In 2012, Freeport McMo Ran Incorporated ( FMMM ) generated $365.4 million through the Safford and Morenci mining operations , which had an economic impact on Greenlee, Graham County, and the State. By the end of the year, FMMM employed over 2,6 00 people at the Morenci mine. Compensation from

FMMM in Greenlee and Graham counties is estimated at $ 253.8 million, business taxes at $ 15.1 million

, and vendor purchases at $ 25.5 million , with a direct impact total ing $ 294.4 million

. The indirect impac t
totaled $ 71 million because of spending from employees, new tax revenues, and vendor purchases

. The

total from direc t and indirect impacts from FMMM is $ 365.4 million in Greenlee and Graham counties

. The revenue generated from FMMM is estimated at $ 1.1 billion dollars. 11

Other employment sectors in Greenlee County include tourism, agriculture, government, education, retail trade, health and social assistance

. 12 The top occupations in Morenci are in the areas of natural resources, construction, and maint enance occupations, which accounts for 28.3% of total income for the city

. According to USA City Facts, the unemployment rate is high in Morenci at 16.7%; the national average is

7.9%

. 13 Significant economic development is unlikely because 77.1 % of land i s U.S. Forest Service and U.S. Bureau of Land Management and o nly 8. 1% of land is privately owned. Table 1.4 gives an overview of labor force, unemployment, and unemployment rate for the Morenci and Clifton area.

Table 1. 4 Labo r Force Data for Morenci and Clifton

Employment Statistic (Annual Average) 1990 1995 2000 2005 2010 2011

Morenci Labor Force 792 1,188 996 879 1009 n/a Morenci Unemployed 59 74 22 22 62 n/a

Morenci Unemployment Rate 7.4% 6.2% 2.2% 2.5% 6.1% n/a

Clifton Labor Force n/a n/a 1155 1025 1257 1 549

Clifton Unemployed n/a n/a 72 73 205 1 08

Clifton Unemployment Rate n/a n/a 6.2% 7.1% 16.3% 7.0%

Source: Average annual labor force data, Arizona Department of Administration, Local Area Unemployment Statistics, u pdated December 15, 2011. 14

1.6 Genera l SIP Approach

– Regulatory Requirements and Guidance

In November 1990, the U.S. Congress enacted a series of amendments to the CAA . One of the primary effects of the revision was to expand and clarify the planning provisions for those areas not meeting the NAAQS . The CAA, as amended, authorizes comprehensive federal and state programs to provide for

attainment and maintena nce of the NAAQS. Section s 1.6.1 and 1.6.2 outline CAA requirements for SO 2 maintenance areas

. In addition, EPA has published guidance documents to clarify environmental

11 “Morenci”; (http://www.fcx.com/operations/usa_arizona_morenci.htm). “Economic Benefits of the Morenci and Safford Mines upon Greenl ee/Graham Counties and Arizona

- 2012 ”; (http://www.fcx.com/sd/pdf/fast_facts/2013/MorenciSafford_EI_2013.pdf).

12 “Greenlee County industries and sales”;( http://seagoedd.org/?s=population+morenci).

13 http://www.usacityfacts.com/az/greenlee/morenci/economy/

14 Population Projections ;(http://www.workforce.az.gov/population

- projections.aspx). “Local Area Unemployment Statistics (LAU)”; (http://azstats.gov/local

- area

- unemployment

- statistics.aspx).11

regulations relating to maintenance of the NAAQS and to assist in developing approaches for implementing those regulations. Section 1.6.3 summarizes applicable EPA guidance.

1.6.1 Cle an Air Act Req uirements for Maintenance Plan s

Title I, Part A, and Title I, Part D, Subparts 1 and 5 of the CAA contain the nonattainment and maintenance requirements for SO 2 planning areas. Part D, Subpart 1, Section 175A provides the general

framework for maintenance plans as summarized below.

CAA § 175A(a)

. Plan Revision

Under Section 175A(a) maintenance plans must provide for maintenance of the primary ambient air quality standards for at least 10 years after redesignation, including any

additional control measures as may be necessary to ensure such maintenance.

CAA § 175A(b)

. Subsequent Plan Revision s Eight years after redesignation of any area as an attainment area, CAA Section 175(A)(b) requires the state to submit an additional revision of th e applicable state implementation plan for maintaining the national primary ambient air quality standard for 10 years after the expiration of the first 10

- year maintenance period.

CAA § 175A(c)

. Nonattainment Requirements Applicable Pending plan Approval

Under Section 175A(c), pending EPA approval of a SIP revision and request for redesignation of a nonattainment area to attainment, applicable nonattainment area requirements shall remain in full force and effect concerning that area.

CAA § 175A(d)

. Contingency Provisions

Section 175A(d) requires maintenance plans to contain any necessary contingency provisions to assure prompt correction of a violation of the NAAQS that occurs after redesignation to attainment

. The contingency measures must include a requirement that the state will implement all control measures contained in the SIP for the area prior to redesignation.

1.6.2 Clean Air Act Conformity Provisions

CAA Section 176(c)(1)(A) requires SIPs to contain information regarding the State’s compliance w ith conformity requirements.

Transportation Conformity As stated in 40 CFR § 93.153(b), "Conformity determinations for federal actions related to transportation plans, programs and projects developed, funded, or approved under title 23 U.S.C. or the Fed eral Transit Act (40 U.S.C. § 1601 et seq

. ) must meet the procedures and criteria of 40 CFR Part 51, subpart T, in lieu of the procedures set forth in this subpart. ” Title 40 CFR § 93.102(b) waives transportation conformity

for SO 2 nonattainment and maint enance areas.

General Conformity General conformity for the Morenci, Greenlee County area must still be addressed to assure SO 2 emissions from any federal actions or plans do not exceed the rates outlined in 40 CFR § 93.153(b) (see 58 FR 63253; November 3 0, 1993)

. Criteria for making determinations and provisions for general conformity are located in R18

- 2

- 1438 of the Arizona Administrative Code

. There are no known federal plans or actions currently affecting air quality in the Morenci area nor are any f oreseen through the year12

2025

. ADEQ commits to review and comment, as appropriate, on any federal agency general conformity determination it receives pursuant to 40 CFR § 93.155 for activities planned for this air quality planning

area.

1.6.3 EPA Guidance

App licable guidance for demonstrating maintenance of the NAAQS includes the following EPA

memoranda:

The September 4, 1992, Memorandum, Procedures for Processing Requests to Redesignate Areas to

Attainment , John Calcagni, Director, Air Quality Management Div ision, U.S. Environmental Protection Agency (see Appendix A), recommends several core provisions for states to consider when developing maintenance plans

. These provisions include:

1) An attainment emissions inventory to identify the level of emissions

suff icient to attain the NAAQS,

2) A maintenance demonstration that either shows that future emissions will not exceed the level of the attainment inventory or includes a modeling analysis to show that the future mix of sources will not cause a

violation of t he NAAQS,

3) Continued operation of an appropriate air quality

- monitoring network to verify the attainment status of an area,

4) Verification of continued attainment through tracking changes in the emissions inventory, or other methods, as well as assura nce that the state has the legal authority necessary to implement and enforce all measures used to attain and maintain the NAAQS, and

5) A Contingency Plan designed to correct any violation of the NAAQS after redesignation of the area to attainment.

EPA' s historic redesignation policy has called for eight quarters of clean ambient air quality data as a prerequisite for redesignation of an area to attainment. The October 18, 2000, Memorandum, Redesignation of Sulfur Dioxide Nonattainment Areas in the Abse nce of Monitored Data

, from John Seitz, Director of the Office of Air Quality Planning and Standards (see Appendix B) , was developed to provide guidance on redesignating SO 2 areas to attainment where an area's historic violations were caused by major point sources of SO 2 emissions that are no longer in operation and where SO 2 monitors were removed immediately following the shutdown of the emissions sources, and therefore lack sufficient air quality data demonstrating attainment of the standard.

The guida nce provides an approach for demonstrating attainment and maintenance of the air quality standards and exempts these areas from requirements for continued ambient monitoring

. Four separate elements for demonstrating maintenance of the SO 2 NAAQS are outlin ed below :

1) Emissions inventories representing actual emissions when violations occurred, current emissions, and emissions projected to the 10th year after redesignation;13 2) Dispersion modeling analysis of all point sources in, and within 50 kilometers (km) o f, the nonattainment area boundary showing that no NAAQS violations occur or can be projected for the next 10 years anywhere within the nonattainment area, and that the shutdown source or sources were the dominant cause of the high concentrations in the pa st;

3) Evidence that if the shutdown source or sources resume operation they will be considered new sources and be required to obtain a permit under

the Prevention of Significant Deterioration program, and

4) A commitment to resume monitoring before any major SOx source commences operation.14



### 2.0 AIR QUALITY MONITORING

No ambient monitors are currently in operat ion within the Morenci SO 2 planning a rea . The information

in this section provides historical background to compare the status of air quality to a t ime when exceedances of the NAAQS occurr ed

.

Ambient monitori ng networks for air quality are established to sample pollution in a variety of representative settings, to assess health and welfare impacts and to assist in determining air pollution

sources. These networks contain individual m onitoring sites that are operated by a number of government agencies and regulated companies

. The data gathered by the monitors within the are statistic ally analyzed

and compared to the NAAQS.

EPA’s p rotocols for SO 2 monitoring are located in the following sections of the C ode of Federal Regulations (CFR) :

1. 40 CFR Part 50, Appendix A, Reference Method for the Determination of Sulfur Dioxide in the Atmosphere;

2. 40 CFR Part 53, Subpart B, Procedures for Testing Performa nce Characteristics of

Automated Methods for SO 2 , CO, O 3 , and NO 2 ; and

3. 40 CFR Part 58, Subpart A, B, and C, Ambient Air Qu ality Surveillance.

2 .1 Monitoring Site, Equipment, and Quality Assurance Procedure

A n e xtensive monitoring network was established in the Morenci area with sufficient spatial and temporal coverage to comprehensively evaluate the ambient impact of smelter emission s. In 1969 , the Arizona Department of Health, Division of Air Pollution Control (ADH), began monitoring ambient SO 2 air

qua lity in Arizona. ADH established eight coulometric SO 2 monitors around the seven

- smelter towns in Arizona, including one in Clifton between October 1 , 1969 and December 31, 1969

. 15

Phelps Dodge began ambient SO 2 monitoring at its Morenci smelter facility i n 1974

. The facility operated coulometric monitors at both stationary and mobile sites

. During that same year, t he State established two monitoring sites in the same area. The sites were coulometric monitors

, but by 1984,

both had been replaced with a p ulsed fluorescent type

.

All monitors o wned and operated by PDMI in the area of the Morenci sme lter were deactivated when they ceased operations in December 31, 1984

. Both State sites were deactivated after the smelter close d

in 1985

. From 1986 to the p resent, no ambient SO 2 monitors are operating in the Morenci area.

Historic ambient SO 2 monitoring sites and periods of operation are provided in Table 2.1 and 2.2

. For a map of m onitor locations and their proximity to the Morenci smelter , see Appendix A, Section A.2 of the

2002 Maintenance Plan

.

15 Arizona State Department of Health, Environmental Health Serv ices, Division of Air Pollution Control , Sulfur Dioxide Monitoring Network Study , 1969.15 Table 2. 1 : State of Arizona Morenci SO 2 Ambient Air Quality Monitors

Monitor Site Site Location Activation

Deactivation

Cadillac Point Latitude 33 ○ 05’20.1” N, Longitude 109 ○ 22’4 8.8”W 1974

- 1985 Stargo Latitude 33 o 04’17.6”N,Longitude 109 ○ 21’46.3”W 1974

- 1985

Table 2. 2 : Phelps Dodge Morenci SO2 Ambient Air Quality Stationary and Mobile Monitors

Monitor Site Site Location Activation

- Deactivation

Cadill ac Point Latitude 33 ○ 05'22.9"N, Longitude

109 ○ 22'43.7"W 1976

- 1984

Fina Station Latitude 33 ○ 03'14.3"N, Longitude

109 ○ 18'59"W 1974

- 1984

Fairbanks Latitude 33 ○ 02'10.19"N, Longitude 109 ○ 19'37.2"W 1976

- 1984

Metcalf Latitude 33 ○ 06'47.1"N, Longitude

109 ○ 22'25. 2"W 1974

- 1984

Oroville Latitude 33 ○ 05'28.6"N, Longitude

109 ○ 18'25.2"W 1974

- 1981

Stargo Latitude 33 ○ 04'14"N, Longitude

10921'44"W 1974

- 1984

Eagle Creek Latitude33 ○ 03'20.1"N, Longitude

109 ○ 25'33.7"W 1974

- 1979

Mobile Monitors

Mobile

- Standpipe Latitu de 33 ○ 02'58.8"N, Longitude

109 ○ 23'9.9"W 1979

- 1984

Mobile

- Center Market Latitude 33 ○ 03'24.7"N, Longitude

109 ○ 19'50.4"W 1979

- 1980

Mobile

- Buena Vista Latitude33 ○ 03'25.8"N, Longitude

109 ○ 19'59.3"W 1982

- 1984

Mobile

- Lower Stargo Latitude 33 ○ 03'55.5"N, Longitude

109 ○ 21'20.5"W 1981

- 1984

Mobile

- Newton Latitude3 3 ○ 04'33.1"N, Longitude

109 ○ 21'19.8"W 1980

- 1982

Source: Air Quality Control for Arizona, Annual Report, Arizona Department of Health Services, 1974

– 1985

.

2.2 SO 2 Data Summary

N oted in previous section , a mbient m onitoring of the Phelps Dodge facility began in 1969

. T he highest

number of recorded exceedances occurred in 197 5 , with concentrations between 219 to 237 micrograms per cubic meter ( μg/m 3) in the Clifton, Morenci area

. Forty

- nine exceedances o f the SO 2 24

- hour average

standard at PDMI were recorded in 1976 and the next highes t number , 42 exceedances, occurred in 1982

. In 1981

, only five exceedances of the SO 2 annual average standard were recorded

. Monitoring data provided in Appendix D of the 2002 SIP indicates that the last recorded violation of either the 24

- hour or

annual SO 2 NAAQS occurred in 1984. Throughout the history of the network, annual average SO 2 levels16

were generally one

- half of the 1971 NAAQS, which is about 0.030 ppm or 80 μg/ m 3

. 16

Implementation of control measures and subsequent emissions reductions at the Morenci copper smelter

are a were reflected in reduce d ambient SO 2 concentrations beginning in the mid

- 1970s

. 17 Measured maximum concentrations at selected monitoring sites are presented in Appendix D, in the 2002 Morenci Sulfur Dioxide Nonattainment Area Plan, for the period 1979 through 1985

.

Due to the shutdown of the primary SO 2 point source and termination of the monitoring network, redesignation of this area was comp leted according to Director John Seitz's October 18, 2000, Memorandum, Redesignation of Sulfur Dioxide Nonattainment Areas in the Absence of Monitored Data (see Appendix B)

. As outlined in the guidance, redesignation did not require eight current consecut ive quarters (two years) of quality

- assured, violation

- free data. The policy also exempts the Morenci area from maintenance plan requirements for continued monitoring within the area . The maintenance plan

should include commitments to resume ambient moni toring before any major source of SOx emissions commences operation. In the event any new major point source begins operations in the area, new

monitors will be installed to ensure continued attainment. For more information on historical monitoring

infor mation, see the 2002 Morenci Sulfur Dioxide Nonattainment Area State Implementation and

Maintenance Plan.

16 See Arizona Department of Health Services, Bureau of Air Quality Control annual reports 1970 through 1985, EPA Air Quality System annual summary reports, and Appe ndix D of the 2002 SIP.

17 S ee Chapter 2 of the 2002 SIP

.17



### 3 .0 EMISSIONS INVENTORIES AND PROJECTIONS TO 2030

T he current boundaries of the Morenci SO 2 planning area lie solely wi thin Greenlee County

. However,
the maintenance demonstration takes into consideration emissions sources within a 50 km buffer around

the boundaries of the maintenance area. The 50 km buffer include s southern portions of Apache County, eastern portions of Graham County and the western parts of three New Mexico counties: Hidalgo, Grant

and Catron

. The nonatt ainment area and 50km buffer are illustrated in F igure 3.1

.

The Seitz Memo, Redesignation of Sulfur Dioxide Nonattainment Areas in the Absence of Moni tored

Data on October 18, 2002

, lists three required inventories in the maintenance plan: an emissions inventory representing actual emissions when violat ions occurred; an inventory representing current

actual and allowable (or potential) emissions; and an inventory that projects allowable (or potential) emissions to the tenth year after redesignation. The guidance further advises, "the inventories should display emissions from each point source of SO 2 , with explanations of significant emissions changes,

i ncluding source shutdowns." In addition to the inclusive (point, area, and mobile) Morenci Planning

A rea inventories, the inventory should include emissions from all SO 2 point sources within a 50 km range of the planning area . The following inventories w ere included in the 2002 maintenance plan.

 Year 1980

- 198 4 Inventory

. This inventory characterizes emissions at the time the Morenci smelter was still operating and monitored violations

of the NAAQS were occurring.

 Year 1990

- 1999 Inventory

. The 199 9 inve ntory represents the

“current” or “ attainment inventory” following the closure of the Morenci

smelter.

 Projected Year 2015 Inventory

. The 2002 plan included a future 2015 inventory to demonstrate , through dispersion modeling, emissions would

remain at a level sufficient to maintain the NAAQS

.

T his SIP revision demonstrates continued attainment of the NAAQS for a second maintenance period through 2030

. I n addition to the historical inventories listed above, which are included in Section 3 .1 for

contex t, updates to current and projected emis sions are provided in Sections 3 .2 and 3 .3 as follows.

 Year 2011 Inventory

. The 2011 inventory is the updated “current” inventory.

 Year 2015

- 20 30 (Projected Inventory)

. The 2002 plan projected

emissions for the first maintenance period, through 2015. This document includes inventory projections of total emissions for the Planning Area and 50 km point source emissions through the second maintenan ce period or 2030. Continued maintenance of the NAAQS through the second maintenance period is demonstrated, in part, by showing that

future emissions of SO 2 are expected to remain well below levels during the time when violations of the NAAQS were occurring

.18

3 .1 Emissions I nventories (Historical)

Sections 3.1 through 3 .2 describe historical emissions sources and rates for the Morenci Planning Area. The 1984 inventory reflect s emissions during the last year of smelter operations. The 1999 inventory was the baseline year for the 2002 maintenance plan submittal, which shows emissions after the closer of the

smelter.

3 .1.1 Point Sources

During its operation and until its closure on December 31, 1984 , the Morenci primary copper smelter was the only major SO 2 point source in the area

. Smelting and refining of cop per ore at Morenci ’s primary copper smelter operations produced copper anode for further refining and sale to customers. The Morenci

smelter ’s last full years of operation were 1983 and 1984

.

Table 3. 1 : Total Historical Poten tial to Emit and Actual Emissions in to ns for years 1984 and 1999

In Nonattainment area 1984 1999

Potential to Emit (tpy) 297,110 .00 (Allowable) 123.533

Actual Emissions (tpy) 82,432 .00 0.390

Within 50km Buffer 1984 1999

Potential to Emit (tpy) Unav ailable 186.533

Actual Emissions (tpy) Unavailable 1.218

3 .1.2 Area and Mobile Sources

Area and mobile source e missions estimates for the Morenci P lanning A rea were derived from EPA’s

AIR Data for 1999 for Greenlee County and 1984 emissions were der ived from the prior 2002 SIP

submittal

. In t he Morenci Planning area

, SO 2 emissions from mobile and area source s were approximately 31 tons in 1999

. Area source emissions estimates did not include wildfire emissions

. Detailed i nformation on population l evels and the methodology used to calculate are a and mobile source

emissions are contained in the 2002 SIP, Appendix C

. 4.

Table 3. 2 : Historical Greenlee County and Morenci Area and Mobile Source Emissions in tons

18 There was no data available for 1984, therefore, 1980 data is used to estimate 19 84 emissions.

Area 1 984 1999 Greenlee County Unavailable 56 Morenci Planning Area 59 18 3119

3

. 2 2011 Emissions Inventory (Current )

Year 2011 was selected as the base year for this maintenance plan for consistency with the most recently

available National Emissions Invento ry data as well as data from the Arizona Department of Environmental Quality (ADEQ) updated Industrial point source inventory

. The source categories covered

in the emissions inventory include :

 Non

- road Mobile (exhaust) sources

 On

- roads Mobile (exhaust) s ources

 Industrial (point) sources

 Area (non

- point) sources

3

. 2.1 Point Sources

Since 2011 , t wo permi tted point sources were located within the Morenci Planning Area and 7 sources of

SO 2 emissions were located within the 50 km buffer.

The Phelps Dodge copper smelte r was permanently closed in 1984 ; however, mining operations continue under Freeport McMoRan

. M ining operations account ed for the highest emission rates in 2011 from point sources, at 48.5 tons per year (tpy)

, with a potential to emit of appr oximately 87.6 tpy

. The Morenci Townsite emergency generators accounted for 0.003 tpy of emissions with a potential to emit of 4.9 0 tpy

.

Table 3.3 illustrates the two major point sources in the planning area for 2011

. T otal emissions generated

for 201 1 is 48.532 tpy with a combined potential to emit of 92.50 tpy

.

Table 3. 3 : SO 2 Point Sources within Morenci Planning Area

Source 2011 (tons/yr) PTE

(tons/yr)

Freeport

- McMoran Morenci, Inc. 48.529 87.60

Morenci Townsite WWTP E mergency Generators 0.003 4.90

Total Emissions 48.532 92.50
Data Source: Arizona Department of Environmental Quality ( ADEQ) and 2011

NEI

In 2011, there were thirteen point sources located within 50 km , outside of the boundaries for the Morenci planning area. Table 3.4 illustrates the actual and potential to emit from the se facilities in 2011

, 38.03 tpy
and 167.38 tpy, respectively

.20 Table 3. 4 : SO 2 Point Sources within 50

- km Buffer

Source Latitude Longitude 2011 Actu al

Emissions (tons/yr.) PTE

(tons/yr) Permit

Status as of

2014

Arizona State

Prisons

- Safford Complex 32.8289

- 109.565 0.193 4.96 Terminated

City of Safford

– Water Reclamation

Plant 32.8424

- 109.7241 0.214 24.26 Terminated

CKC Construction Company 32.8563

- 109.6878 0.126 33.78 Active

Freeport McMoran Analytical Service

Center 32.8165

- 109.6482 0.002 0.39 Active

Freeport McMoran Corporation

- Bee Canyon Well Field 33.3167

- 109.4667 1.044 41.4 Active

Freeport McMoran Corporation

- Mud Springs We ll Field 33.3833

- 109.4833 1.087 36.48 Active

Freeport

- McMoran

Safford Inc. 32.9473

- 109.6509 35 81.2 Active

Glenbar Gin, Inc. 32.9839

- 109.8567 0.0012 0.02 Active

Level 3

Communications 32.8351

- 109.7081

- 0.21 Terminated

Mt. Graham Regional Medi cal Center, Inc. 32.8228

- 109.7352 0.09 2.804 Terminated

Select Cleaners 32.8327

- 109.7161 0.001 0.163 Terminated

Tri County

Materials

- Hot Mix Asphalt Plant 32.8021

- 109.7077 0.155 22.22 Active

USDOJFCI

- Safford 32.7667

- 109.7167 0.122 24.27 Terminated

Total Emissions 38.05 167.38

Data Source: Arizona Department of Environmental Quality (ADEQ) and the 2011 NEI21

Figure 3. 1 : Morenci Sulfur Dioxide Planning Area and 50 km Buffer Area Point Sources22

3

. 2.2 Totals f

or Mobile , Area and Point S ources

Curr ent emissions estimates for area and mobile sources are derived from EPA’s 20 11 Na tional Emissions Inventory data

. 19 Certified emissions data were scaled to the Morenci area using a population

ratio or an area adjustm ent ratio to that of Greenlee County

. Please note that 2011 area emissions

estimates include wildfire emissions, which accounts for the large difference between the 1999 an d 2011

area source inventories. Wildfire emissions account for 91.43% of t otal cum ulative emissions

.

For more information on the calculation s , see the emissions inventory data in A ppendix C

Table 3. 5 i llustrates a

rea and mobile source emissio ns for the Morenci planning area

. The source categories include on

- road mobile, non

- road mobil e, and area (non

- point) sources

. The largest source of

emissions comes from area sou rces at 525.67 tpy

, which includes wildfire emissions

. Point area sources

account for 48.532 tpy

. The total SO 2 emissions from all the se categories are 574.882 tpy

. The largest

source of emissions is area (Non

- point) sources contributing most of the emissions at 525.94 tpy

.

Table 3. 5 : Total SO 2 Emissions for the Morenci Planning Area

- 2011

Source Type (tons per year)

On

- Road Mobile 0.33

N on

- Road Vehicle 0.08 Point (Industrial) 48.5 4 Area (Non

- point) Sources 525.94

Total 574.8 9

3

. 3 E missions Projections

S ections 3.3.1 and 3. 3.2 contain point

, area, and mobile source emission s projected through the year 2030. Emissions are projected to ensure compliance with the NAAQS. Difficulties surrounding changes in economic growth, emissions control measures, capital turnover, fuel switching, and technological change make projections hard to estimate, therefore, a conservative forecasting appr oach was applied to the projections

. Conservative foreca sting included years 2010 to 203 5 and is based on potential to emit

.

3.3.1 Point Source Projections

Projecting future SO 2 emissions is problematic due to many factors and uncertainties. Arizona does not anticipate any substantial increase in existing point source emissions between 2011 and 2030, for the planning area. New point sources or upgrades to existing sources of SO 2 will be subject to review through ADEQ’s Permitting Program.

3. 3.2 Po int Source Projections

Emissions projections are conservatively based on potential to emit (PTE) and point source emissions are assumed to remain constant at maximum permitted levels. With the permanent closure of the Morenci smelter, no major point sour ces exist in the Planning Area or within 50 km of its boundary. Total

emissions as illustrated in Table 3.6 shows point source emissions within the planning area totaling 87.60

19 EPA’s 2008 National Emission Inventory, Version 1.5 (released May 16, 2011) was the most recent ava ilable data at the time of drafting.23

tons of emissions to 2030

. Total emissions as illustrated in Table 3.7 shows projected emissions

estimates are 201.88 tons to 2030

. Combined total emissions for planning and 50km buffer area total

289.48 tons of emissions to 2030.

Table 3. 6 : Point Source Projections in Planning Area to 2030

Source Categ ory 2011

( a ctual s ) 2011

( pte ) 2015

( pte ) 2020

( pte ) 2025

( pte ) 2030

( pte ) Freeport

McMoran 48.529 87.60 87.60 87.60 87.60 87.60

Morenci

Townsite

WWTP Emergency

Generators 0.003 4.90

- - - -

Total
Emissions 48.532 92.50 87.60 87.60 87.60 87.60

Note; S y mbol (

- ) indicates that permit has been terminated

.

Table 3. 7 : Point Source Projections within the 50km Buffer Area

Source Category 2011

( a ctuals) 2011

( pte) 2015

( pte ) 2020

( pte ) 2025

( pte ) 2030

( pte )

CKC

Construction Company 0.126 33.78 33.78 33.78 33.78 33.78

Freeport

McMoran Analytical

Service Center 0.002 0.39 0.39 0.39 0.39 0.39

Freeport

McMoran Corporation

- Bee Canyon

Well Field 1.044 41.4 41.4 41.4 41.4 41.4

Freeport

McMoran Corporation

- Mud Springs

Well Field 1.08 7 36.48 36.48 36.48 36.48 36.48

Freeport

McMoran
Safford Inc. 35 81.2 81.2 81.2 81.2 81.2

Glenbar Gin,

Inc. 0.0012 0.02 0.02 0.02 0.02 0.02

Tri Country

Materials

- Hot Mix Asphalt

Plant 0.155 22.22 8.61 8.61 8.61 8.61

Total Emissions 37.4152 215.49 201. 88 201.88 201.88 201.8824

3

. 3.2 Area, Mobile , Point Source Projections

ADEQ projects that SO 2 emissions from area and m obile sources will grow proportionately with the population of the P lanning A rea. Appendix D describes the source category emissions an d derivation of

mobile and area source emissions estimates for the Morenci area in detail.

Table 3. 8 contains area and mobile source emissions projections for the Morenci Planning Area through 2030. Actual emissions for 2011 total 574.89 tpy and projec tions total 613.96 tpy based on PTE.

Table 3. 8 : Area and Mobile Sources SO 2 Emissions Projections for the Morenci Planning Area

Source Type 2011 (tpy) 2015 (tpy) 2020 (tpy) 2025

(tpy) 2030

(tpy )

On

- Road Vehicle Sources 0.33 0.3 0 0.30 0.31 0.33

Non

- Road Vehicle Sources(Locomotives and Aircraft) 0.05 0.05 0.05 0.05 0.05

Non

- Road Vehicle Sources (Other) 0.03 0.03 0.03 0.03 0.03 Industrial (point) Sources 48.54 87.60 87.60 87.60 87.60 Area(Non

- point) Sources (Fires) 525.67 525.6 7 525.67 525.67 525.67 Area (Non

- point) Sources (Other) 0.27 0.27 0.27 0.28 0.28

Total Emissions 574.89 613. 92 613.92 613.94 613.9625



### 4 .0 CONTROL MEASURES

Sections 4

. 1 and 4 .2 describe SO 2 emission control measures for sources wit hin the Morenci Planning

Area and point sources located within the 50 km buffer zone of the Planning Area

.

4 .1 Point Sources

Nonattainment area plans are required to provide for the implementation of all reasonably a vailable

control measures (RACMs) 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 SO 2 nonattainment areas. RACT is determined, in pa rt, by the technological and economic feasibility of the control for the specific source and is generally defined for SO 2 as control technology which will achieve the NAAQS within statutory timeframes. 20 Maintenance plans should

ensure that the level of co ntrol that allowed t he area to reach attainment continue s in the future.

Morenci Copper Smelter

The PDMI smelter was subject to all requirements in R18

- 2

- 715.01 (A)

- (T), which define, “Standards of Performance for Existing Primary Copper Smelters; Comp liance and Monitoring” and the January 14, 1986, compliance date for the provisions of this rule, in accordance with R18

- 2

- 715.01. Compliance was achieved when Phelps Dodge permanently closed the copper smelter on December 31, 1984.

Closure of the coppe r smelter in 1984 resulted in SO 2 emission reductions in 1985 of at least 46,012 tpy, based on permitted SO 2 stack emission limits effective for PDMI, January 1, 1985. The permanent shutdown of the smelter reduced total emissions in the Planning Area to less than 0.1% of pre

- closure levels, which meets RACT requirements.

Existing Point Sources

There are currently eight active sources located within the planning area and the 50 km buffer zone. There

is two point sources located in the Morenci planning area. There are thirteen point

- sources that exist in the 50km buffer zone, details of these facilities are discussed below.

ADEQ issues permits point sources within the planning area

. The seven other point sources within the 50km buffer are also permit ted by ADEQ

. Permit limits combined emissions to 87.60 tons per year for the planning area point sources and less than 201.88 tons per year for the buffer area point sources. In the event a new source moves into the area, or any modifications are made to an existing source, they will be subject to ADEQ’s permitting and monitoring requirements.

4 .2 Area and Mobile Sources

Emissions data reflect that SO 2 from area and mobile sources in the Morenci planning area account for approximately 13 % of the total area and mobile source emissions in Greenlee County. In 2011 on

- road

and non

- road mobile emissions total ed 0.41 tons. Area sources total 525.94 tons. Of the area source total

522.95 tons were due to wildfires

, more than 99% of area source emissions. ADE Q predicts nominal growth in SO 2 emissions for the area through 2030

.

20 U.S. EPA, Office of Air and Radiation, Office of Air Quality Planning and Standards, SO 2 Guideline Document

, February 1994.26

Several EPA programs are related to the sulfur content of fuels. These programs integrate engine and fuel controls for emissions reductions in highway vehicles and non

- road equipment . Due to these national programs, future sulfur emissions are likely to be lower than those projected i n Chapter 4 of this

document

. The programs are as follows:

1) Tier 2 Vehicle and Gasoline Sulfur Program for passenger vehicles, 2) Tier 3 Vehicle and Gas oline Sulfur Program for passenger vehicles, 3) Heavy

- Duty Engine and Vehicle Standards and Highway Diesel Fuel Sulfur Control Requirements for highway trucks and buses, and 4) Clean Air Non

- road Diesel Rule for non

- road diesel equipment.

EPA’s Tier 2 program

, begun in 2004, implements more stringent emissions standards for the reduction of oxides of nitrogen emissions from all passenger cars and light trucks. To meet the new emission standards the program incorporates gasoline 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, new emission controls work longer and more efficiently. As a result, the

standards reduce the average national sulfur content of gasoline by up to 90%

.

EPA’s Tier 3 program per FR Vol 79 No 81 published on April 28, 2014

, establishes more string ent
vehicle emissions standards and wi ll reduce the sulfur content of gasoline beginning in 2017, as part of a systems approach to ad dressing the impacts of motor vehicles and fuels on air quality and public health

. The gas oline sulfur standard will make emission control systems more effective for both existing and new vehicles, and wil l enable more stri ngent vehicle e missions standards

. The vehicle standards will reduce both tailpipe an d evapo rative emissions from passenger cars, light

- duty trucks, medium

- duty passenger vehicles, and some heavy

- duty vehicles

. This will result in significan t reductions in pollutants such as ozone, particu late matter, and air toxics across the country and h elp state and loc al agencies in their

efforts to a ttain and maintain health

- based National Ambient Air Quality Standards. 21

The 2007 Heavy

- Duty Engine and Vehicle stan dards and Highway Diesel Fuel Sulfur Control program established new oxides of nitrogen and particulate matter emissions standards for heavy

- duty highway engines and vehicles. The standards are based on high

- efficiency catalytic exhaust emission control

t echnologies. Because emissions control devices are damaged by sulfur, associated regulations reduce the sulfur in highway di esel fuel by 97%

.

The Clean Air Non

- road 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 non

- road diesel fuel from the current a pproximately 3,000 parts per million to 15 parts per million when fully implemented. Fu el sulfur reductions are being phased in over a number of years beginning in 2007.

21 To see more information regarding EPA’s tier program see: http://www.epa.gov/otaq/tier3.htm l.27



### 5.0 MODELING DEMONSTRATION

Chapter 5.0 provides an overview of EPA’s and A DEQ’s modeling demonstration that was conducted for the Morenci Planning Area.

5.1 Historical Modeling Analysis

On June 21, 2002, ADEQ submitted to EPA the “Morenci Sulfur Dioxide Nonattainment Area State Implementation and Maintenance Plan” with a reque st to approve the plan and redesignate the area to attainment for the 1971 primary SO 2 NAAQS. As part of its final rulemaking for the plan, EPA conducted an analysis on the plan based on the October 18, 2000, Memorandum from Director John Seitz to the Reg ional Office Air Division Directors, “Redesignation of Sulfur Dioxide Nonattainment Areas in the Absence of Monitored Data.” The Seitz memo provides guidance for redesignation to attainment in those situations where major point sources are no longer in op eration and in the absence of monitoring

data. Results of EPA’s analysis are contained in the “Technical Support Document for Notice of Direct Final Rulemaking on Sulfur Dioxide (SO 2 ) Redesignation Request and Maintenance Plan for Morenci, Arizona, March 2004

. ” An overview of the historical dispersion modeling analysis is provided below

. 22

P helps D odge M orenci, Inc permanently closed the smelter on D ecember 3 1 , 1984, and dismantled the facility by December 1996. The area remains sparsel y settled and ther e has been no significant population growth

. T here are some industrial and commercial activities, estimated emissions are located

in C hapter 3.0. There are no significant sources and past violations were attributed to emissions from the smelter, which is no longer in existence. Emissions of SO 2 from other sources have not significantly changed since the closure of the smelter.

Using the criteria established in the Seitz memo, EPA conducted screen modeling to show that the non

smelter sources were insign ificant and the smelter was the domina n t source , which contributed to high

SO 2 concentrations

During the last maintenance plan submission the two largest sources in t he 50

- kilometer buffer area were, Other sources including several cotton gins and a pris on had projected PTE ranging from .01 to .47 tons per year for 2015. No other sources were modeled due to their low output of emissions and because they were outside of the planning area. EPA determined that the ambient SO 2 projection requirement for

red esignations and mainte nance requirements were satisfied

. 23

5.2 Current Modeling Demonstration

For this second maintenance plan, ADEQ conducted a modeling analysis similar to EPA’s where the two largest sources in the Maintenance Area or within the 50km b uffer were modeled. The Fre eport

McMoRan Morenci Mine ( FMMM ) is located within the Maintenance Area and has a potential to emit ( PTE ) of 88 t ons/year (tpy ) . T he Freeport

- McMoRan Safford Mine (FMSM) is located within the 50 km

buffer and has a PTE of 81 t py

. No other point sources were modeled because of their low or negligible

emissions. I nspection of the individual point sources indicates many are emergency generators with

actual emissions less than one tpy and therefore considered negligible.

22 For more information, see “Technical Support Document for Notice of Direct Final Rulemaking on Sulfur Dioxide (SO2) Redesignation Request and Maintenance Plan for Morenci, Arizona” Air Division U.S. Environmental Protection Agency, Region at: http://w ww.epa.gov/region9/air/az/morenci/tsd0415.pdf

. 23 IBID28

Using t he data from the two facilities

, ADEQ projected emissions to 2030 (based on PTE/maximum allowable emissions). The results show that low levels of point source emissions are expected to persist through the second maintenance period. State and local permit ting programs will protect the attainment status of the area for any future sources that may operate nearby

. D etails of the NSR/PSD prog ram are discussed in chapter 6.

ADEQ issued renewal permits to FMSM and FMMM in February 2 012 and October 2013

. Tabl e 5.1

summarizes the PTE of SO 2 emissions for FMSM and FMMM based on the two renewal permits and shows that there is no change in total SO 2 emission limits for both facilities.

Table 5. 1 : Emissions of SO 2 for FMMM and FMSM in Renewal Permits

Facility PTE in renewal permits (tpy) Modeled Emission (tpy)

Point Fugitive Total Point Fugitive Total

FMMM 0.8 86.8 87.6 0.78 86.75 87.5

FMSM 50 31 81 50.02 31.03 81.05

The standard EPA screening dispersion model, AERSCREEN ( version 11126) was used to estimate the impact of SO 2 sources in or near the Morenci nonattainment area. AERSCREEN is the s creening version of AERMOD, EPA’s preferred model for near

- field dispersion. AERSCREEN generates estimates of

“worst

- case” 1

- hour c oncentrations for a single source, without the need for hourly meteorological data,
and also includes conversion factors to estimate “worst

- case” 3

- hour, 8

- hour, 24

- hour, and annual concentrations. AERSCREEN is intended to produce concentration estimates that are equal to or greater than the estimates produced by AERMOD with a fully developed set of meteorological and terrain data. According to an EPA memorandum dated April 11, 2011, AERSCREEN has replaced SCREEN3 as the recommended screening model. 24

Th e AERSCREEN model consists of two main components: 1) the MAKEMET program; and 2) the

AERSCREEN command

- prompt interface program. The MAKEMET program generates application

specific worst

- case meteorology using representative ambient air temperatures, minim um wind speed, and

site

- specific surface characteristics (albedo, Bowen ratio, and surface roughness obtained with the

AERSURFACE tool ). The AERSCREEN program interfaces with AERMAP (terrain processor in AERMOD) and BPIPPRM (building downwash tool in AERM OD) to process terrain and building information respectively, and interfaces with the AERMOD model utilizing the SCREEN option to perform the modeling runs.

An initial modeling analysis was performed in 2012 using AERSCREEN version 11126, which is still the most recent version of AERSCREEN. However, the AERSURFACE version (version 08009) used in the 2012 analysis has been updated to the new version 13016. A test run

, performed in 2014, indicates that the two versions generated identical surface charact eristic parameters.

Another issue, is related to the terrain da ta. The 2012 analysis used Digital Elevation Model (DEM) data, which are no longer updated by the USGS. Instead, National Elevation Dataset (NED) data are being actively supported and chec ked for quality. Therefore, NED represents a more up

- to

- date and improved

24 According to the EPA’s memorandum dated April 11, 2011, titled “AERSCREEN Released as the EPA Recommended Screening Model”; AERSCREEN has replaced SCREEN3 as the recommended preferred model.29

resource for terrain elevations for regulatory modeling purposes. In order to address this issue, a test run was performed to compare modeled concentrations from the FMMM’s blasting emissions by using the

DEM data vs. the NED data. The results show that the modeled concentrations based on the DEM data and the NED data are nearly identical (150.6 μg/m3 vs. 150.2 μg/m3 for 24

- hour SO2).

Based on the discussions above, it is conclu ded that the 2012 modeling analysis is still valid and no updates are needed. Further details of the modeling analysis are included in Appendix D.

Table 5.2 and 5.3 present the cumulative impact of the FMMM and FMSM facilit ies on the Morenci

Maintenance A rea and at the boundary of the Maintenance Area. The modeling results are shown in micrograms per cubic meter ( μ g/m 3 ) for comparison to the 1971 primary 24

- hour and annual SO 2 NAAQS

. The modeling demonstrates that these sources will not cause a violatio n of the 1971 primary

SO 2 NAAQS

Table 5. 2 : Cumulative Impacts of FMMM and FMSM on the Morenci Maintenance Area

Facility Average Max. impact

on Morenci

maintenance area (μg/m 3 ) Total

modeled

conc. Backgroun

d conc. (μg/m 3 ) Total

conc. (μg/m 3 ) NAAQS

(μg/m 3 ) %

Standard

FMMM 24

- hour 151.5 171.5 20 191.5 365 53% FMSM 20

FMMM Annual 25.3 28.6 5 33.6 80 42 % FMSM 3.3

Table 5. 3 : Cumulative Impacts of FMMM and FMSM on the Morenci Maintenance Area Boundary

Facility Average Max. impact

on Morenci

maintenance

area boundary (μg/m 3 ) Total

modeled

conc. Background

conc. (μg/m 3 ) Total

conc. (μg/m 3 ) NAAQS

(μg/m 3 ) %

Standard

FMMM 24

- hour 20 40 20 60 365 16% FMSM 20

FMMM Annual 3.3 6.6 5 1 1.6 80 15 % FMSM 3.330



### 6 .0 MAINTENANCE PLAN SUMMARY

Section 107 (d)(3) of the C AA requires that nonattainment areas have a fully approved maintenance plan meeting the requirements of Section 175A before they can be redesignated to attainme nt. Section 175A

also requires submittal of a SIP revision that provides for maintenance of the NAAQS for at least 10 years after the redesignation to attainment. A subsequent SIP revision providing for maintenance of the NAAQS for an additional 10 years is due eight years into the first ten

- year maintenance period.

Thi s section addresses the core provisions for maintenances plans as recommended in the September 4, 1992, Memorandum, “ Procedures for Processing Requests to Redesignate Areas to Attainment ”

. Additional guidance applicable to the Morenci P lanni ng A rea is contained in the October 18, 2000, Memorandum, “ Redesignation of Sulfur Dioxide Nonattainment Areas in the Absence of Monitored

Data ” , regarding individual components of maintenance demonst rations for areas where historic violations of the NAAQS were caused by sources that are no longer operating.

6 .1 Emissions Inventories

According to the 1992 guidance, states should develop an attainment emissions inventory to identify the

level of emis sions in an area sufficient to attain a given NAAQS. The October 18, 2000, "S eitz guidance " outlines three inventories that should be included in the maintenance plan: an inventory representing actual emissions during the period when violations of the NAA QS were occurring; an inventory representing current and allowable (or potential) emissions; and an inventory that projects allowable (or potential) emissions to the tenth year after redesignation.

The 2002 SIP contained the recommended historical inven tories ; a 198 4 inventory for the last full year of smelter operations and a 1999 post

- smelter inventory; as well as projected point, area, and mobile source emissions for the Morenci Planning A rea and point source emissions within 50 km of the Planning A re a through the first 10

- year maintenance period (2015). Chapter 3 of this document includes a summary of

t hese previously submitted inventories , an updated 2011 "current" inventory, and projected emissions through 2030

.

6 .2 Main tenance Demonstration

Mai ntenance plans should provide a demonstration that future emissions of SO 2 will not cause a violation of the NAAQS. Figure 6.1 shows historical emissions based on point sources, current and projected emissions are totals from all sectors, which illustrat es continued attainment. This SIP revision

demonstrates the level of emissions in the Morenci area will remain well below those that occurred during the period of recorded ambient SO 2 NAAQS violations. Projected emissions and the results of the dispersion modeling analysis contained in Chapter 5 both demonstrate that the Morenci area will continue to maintain the 1971 primary SO 2 NAAQS

.31 Figure 6. 1 : SO 2 Emissions for Years 1984

- 2030

T he emissions inventories for the Planning A rea and 50 km buffer demonstrate a stringent level of protection of ambient a ir quality (see Chapter 5 ), the permanent and enforceable emissions reductions due

to the closure of the Morenci 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 SO 2 NAAQS.

6.3 Ambient Monitoring

Once an area is redesignated to attainment, continued operation of an appropriate air quali ty monitoring network is generally required to verify the attainment status of the area. In the Morenci area historic violations were caused by a major point source of SO 2 emissions that is no longer in operation and

ambient SO 2 monitors were removed imme diately following the shutdown of the emissions source. In such cases, the October 18, 2000, Seitz Memorandum, “ Redesignation of Sulfur Dioxide Nonattainment

Areas in the Absence of Monitored Data

, ” exempts these areas from requirements for continued ambi ent monitoring. The maintenance plan, however, should include commitments to resume ambient monitoring before any major source of SO 2 emissions commences operations.

ADEQ will continue to demonstrate maintenance of the SO 2 NAAQS through updates to the em issions inventory. In addition, ADEQ commits to reestablish an appropriate ambient monitoring network before any major source of SO 2 begins operations in the Morenci Planning Area.

6

. 4 Verification of Continued Attainment

The state is required to prov ide assurance that it has the legal authority necessary to implement and enforce all necessary measures used to attain and maintain the NAAQS and include a n indication of how

it will track the progress of the maintenance plan

.

ADEQ anticipates no relaxati on of any implemented control measures used to attain and maintain the

0.00 10,000.00 20,000.00 30,000.00 40,000.00 50,000.00 60,000.00 70,000.00 80,000.00 90,000.00

1984 2011 2015 2020 2025 2030 Tons of SO 2

Years SO2 Emissions32

ambient air quality standards. ADEQ co mmits to submit to EPA Region 9 any changes to rules or emission limits applicable to SO 2 sources as a SIP revision. ADEQ also commits to maintai n 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 SO 2 emissio ns in the ar ea, the Morenci copper smelter. Freeport

- McMoRan Copper & Gold Inc. ( successor to Phelps Dodge

, owner and operator of the defunct Morenci copper smelter) does not currently hold an active permit, and no subsequent Title V permit application has been

submi tted to ADEQ for this closed facility. The smelting facility cannot rebuild and reopen without

submittal of a New Source Review (NSR) and Title V (Part 70) permit application according to Arizona Revised Statutes (ARS) 49

- 426 and Arizona Administrative Co de, Title 18, Chapter 2, Article 4, Permit Requirements for New Major Sources and Major Modifications to Existing Major Sources. The emission reductions achieved following the closure of this facility are both permanent and enforceable.

Further, any ne w major sources or major modifications to existing point sources of SO 2 are subject to the new source permitting procedures contained in AAC Title 18, Chapter 2, Article 4, specifically, ADEQ’s Prevention of Significant Deterioration (PSD) Permitting Pro gr am contained in AAC R18

- 2

- 406 . 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, utilizing Best Available

Control Tech nology ( BACT ) , before the facility is constructed, modified, or reconstructed.

In general

, S tate permitting program s for major and minor sources are conta ined in Arizona

Administrative C ode Title 18, Chapter 2, Articles 3 and 4

. 25 Although the Morenci Ma inteinance Area is located entirely within the Arizona state boundary, a portion of the 50 km buffer area extends into New

Mexico. The New Mexico Environment Depart ment , Air Quality Bureau has a permitting program for sources constructing within their jur isdiction; not including Bernalillo County and tribal lands.

Maintenance of the SO 2 NAAQS in the Morenci area will be tracked through updates to the emissions inventory and permit applications received for SO 2 emitting sources. Any permitted sources are subject to the monitoring, reporting, and certification procedures contained in AAC R18

- 2

- 306 and AAC R18

- 2

- 309 respectively. 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.

6 .5 Contingency Plan

Contingency plans should contain measures to correct any violation of the NAAQS that occurs after redesignation. According to the 1992 guidance Procedures for Processing Requests to Red esignate 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 SO 2 NAAQS in this Planning A rea wou ld be from new sources. Because the primary source of SO 2 emissions in the Morenci area permanently closed, measures to ensure continued

attainment of the SO 2 NAAQS are PSD and permitting requirements. As noted in Section 6 .4, a ny new

25 ADEQ implements a SIP approved PSD program for all regulated NSR pollutants except for PM 10 and greenhouse gases (GHGs). For PM 10 and GHGs, ADEQ implements the Federal PSD program in 40 CFR § 52.21 pursuant to delegation agreements with EPA

. A proposed S tate Implementation Plan revisio n was submitted to EPA on April 10, 2012

, to bring the Arizona SIP for area s under the jurisdiction of ADEQ into compliance with the NSR and PSD requirements of CAA Section 110(a)(2)(C) and 40 C.F.R. Part 51, Subpart I, with the exception of the requirements perta ining to GHGs

.33

major source propos ing to operate in the Morenci area is subject to the provisions of AAC R18

- 2

- 406, “Permit Requirements for Sources Located in Attainment and Unclassified Areas.” These programs

address New Source Review and PSD requirements applicable to SO 2 sources. 26 Un der the PSD program stationary sources are required to undergo preconstruction review before the facility is constructed, modified, or rec onstructed and to apply BACT . If a new source is not a major source it is required to obtain a permit under minor sou rce permitting rules at AAC R18

- 2

- Article 3.

6

. 6 Conclusion

The Morenci Planning Area continues to meet the 1971

, 24

- hour and annual primary SO 2 NAAQS. This

submittal demonstrates th at all of the essential regulatory elements have been met and the More nci area

will maintain the 1971 primary SO 2 NAAQS for an additional ten years, through year 2030

. M aintenance of the NAAQS is demonstrated by the closure of the only significant source of SO 2 emissions in the area, existing limits and controls on the rema ining sources, and the requirement to impose PSD requirements

on any new stationary sources. ADEQ requests that EPA appro ve this demonstration of maintenance through year 2030

.

26 AAC R

- 18

- 2

- 403 “Permits for Sources Located in Nonattainment Areas” and R18

- 2

- 406 “Permit requirements for Sources Located in Attainment and Unclassifiable Areas” were adopted effective November 15 , 1993, and most recently amended by final rulemaking at 18 A.A.R 1542, effective August 7, 2012. New Source Review standards are defined in 40 CFR § 51.307, Prevention of Significant Deterioration standards, in 40 CFR § 51.166.

### Page Intentionally Left Blank

### Appendix A

Procedures for Processing Requests to Redesignate Areas to Attainment

, Memorandum, John Calcagni, Director, Air Quality Management Division, U.S.

Environmental Protection Agency

### Page Intentionally Left BlankAIR PKOOnAl.!s BR.ANCi 

### (@I UNITED STATES ENVIRONMENTAL PROTECTION AGE

Office of Air·Quality Planning andSta'ldards
Research Triangle Park. North Carolina 27711 

# 4 SEP 

# 1992 

# U

. .J?nn f1

# ~ SEP 8 1992**.L!:b~**

I I!IPM\BOIOlf 

### IV ATLANTA. GA.



### MEMORANDUM

SUBJECT: Procedures for processing

to Attainment

FROM:

TO:

Purpose John Calcagni,**Directo~~~~** 

### Air Quality Management

Director, Air, Pestic' es and Toxics nt Division, Regions I 

### and IV 

### Director, Air and Waste Management Division, Region II 

### Director, Air, Radiation and Toxics Division, Region III Director, Air and Radiation Division, Region V Director, Air, Pesticides and Toxics Division, Region VI 

### Director, Air and Toxics Division, Regions VII, VIII,. IX, 

### and X 

### Areas

The Office of Air Quality Planning and Standards (OAQPS) expects that a number of redesignation requests will be submitted in the near future. Thus, Regions will need to have guidance bn the applicable procedures for handling these requests, including maintenance plan provisions. This memorandum, therefore, 

# I.

consolidates the Environmental Protection Agency's (EPA!s) guidance regarding the processing of requests for redesignation of nonattainmentareas to attainment for ozone (03)' carbon 

## I m(:moxide (<;:0)( 

### particulate matter (PM-IO)

..**~ulfur dioxid~** **(S02~' n~trogen** **d~ox~de** 

### (NO ), and lead (Pb).**Reg~ons** 

### should**useth~s** 

### guidance as a

### genera~ framework for drafting Federal Register 

## I
notices pertaining to redesignation requests. Special concerns for areas seeking redesignation from unclassifiable to attainment will be addressed on a case-by-case basis.

Background

Section l07(d) (3) (E) of the Clean Air Act·, as amended,

states that an area can be redesignated to attainment if the following conditions are met:2



### 1. The EPA has determined that the national ambient air quaE ty standards '( NMQS) have been attained.

2.' 

### The applicable implementation plan has been fully approved by EPA under section 110(k).

3. The EPA has determined that the improvement in air quality is due::to permanent and enforceable reductions in

. emissions.

4. The state has met all applicable requirements for the

area under section 110 and Part D.

5. The EPA has fully approved a maintenance

.. plan, including

a contingency plan, for the area under section 175A.

Each of these criteria is**di~cussed** 

### in more detail in the following paragraphs. Particular attention is given to maintenance plan provisions at the end of this document since maintenance plans constitute a new requirement under the amended Clean Air Act. Exceptions to the guidance will' be considered on

a case-by-case basis.

.

1. Attainment of the Standard

The State must show that the area is attaining the applicable NAAQS. There are two components involved in making this demonstration which should be considered interdependently. The first component relies upon ambient air quality data. The data that are used to demonstrate attainment should be the product of ambient monitoring that is representative of the area of highest concentration. These monitors should remain at the

same location for the duration of. the monitoring"period required for demonstrating attainment. The data should be collected and quality-assured in accordance with 40 CFR 58 and recorded in the Aerometric Information Retrieval System (AIRS) in order for it to be available to the public for review. For purposes of redesignation, the Regional Office. should verify that the integrity of the air quality monitoring network has been

. preserved

..
ForPM-lO, an area may be considered attaining the NAAQS if 1:he.numberof expected exceedances per year, according to 40 CFR 50.6, is less than or equal to 1. 

### 0., For 0 3 , the area must show that the average

.. annual number of expected exceedances, according

to 40 CFR 50.9, is less than or equal to 1.0 based on data from all monitoring sites in the area or its affected downwind' environs. In making this showing, both PM-10 and 0 3 must rely on 3 complete,.,.consecutive. ·,calendar, .years. fof,

.. quality.-assured".al·r"

.. ,,, .. '"., quality monitoring data, collected' in accordance with 40 CFR 50, Appendices Hand K. For CO, an area may be considered attaining the NAAQS if there are no violations, as determined in accordance3



### with 40 CFR 50.8, based on 2 complete, consecutive calendar**ye~rs** 

### of quality-assured monitoring data. For 5° 2 , according to 40 CFR 50.4; an area must show no more than· one exceedance annually and for Pb,**~ccording** 

### to section 50.12, an area may show no exceedances on a quarterly basis.

The second component relies upon supplemental EPA-approved air quality modeling. No such supplemental modeling is required for 03 nonattainment areas seeking redesignation. Modeling may be necessary to determine the representativeness of'. the .moni tored data. For pollutants such as 502 and CO; a small number of 

## I monitors typically is not representative of areawide air quality

or areas ,of highest concentration. When dealing with S02' Pb'l PM-10 (except for a limited number of initial moderate

, nonattainment areas), and CO (except moderate areas with design values of 12.7 parts per million or lower at the time of passage of the Clean Air Act Amendments of 1990), dispersion modeling 

# I

will generally be necessary to evaluate comprehensively sources' impacts and to' determine the areas of expected high ' '. 

## I concentrations based upon current conditions. Areas which were designated nonattainment based on modeling will generally not be redesignated to attainment unless an acceptable modeling analysis indicates attainment. Regions should consult with OAQPS for· further guidance addressing the need for modeling in specific circumstances.

.

2. 

### state Implementation Plan (SIP) Approval

Thr SIP for the area must be fully approved under section l10(k), and must satisfy all requirements that apply to the

area. It should be noted that approval action on SIP elements and the redesignation request may occur simultaneously., An area cannot be redesignated if a required element of its plan is the subject of a disapproval; a finding of failure to submit or tol implement the SIP; or ·partial, conditional, or limited approval. However, this does not mean that earlier issues with regard to the SIP will be reopened. Regions should not reconsider those things that have already been approved and for which the Clean Air Act Amendments did not alter what is required. In contrast,
to the extent the Amendments add a requirement or alter an 

### I existing. requirement so that it adds something more, Regions should consider those issues. In addition, requests from areas known to be affected by dispersion techniques which are inconsistent with EPA guidance will continue to be considered unapprovable under section 110 and will not qualify for redesignation.

1section 110(k) contains the requirements for EPA ac'tion on plan submissions; It addresses completeness, deadlines, full and partial approval, conditional approval,'and disapproval.4



### 3., Permanent and' Enforceable Improvement in Air Quality

The State must be able to reasonably attribute the ' improvement in air quality to emission reductions which are permanent and enforceable. 2 Attainment resulting from temporary reductions iri emission rates (e.g., reduced production or shutdown due to temporary adverse economic,conditions) or
, unusually favorable meteorology would not qualify as an air quality improvement due to permanent and enforceable emission r,eductions. "

.

In making this showing, the'State should'estimate the percent .reduction (from the year that was used to determine the design value for designation and classification) achieved,from Federal ,measures such as the Federal Motor Vehicle Control Program and fuel volatility rules as well as control measures that have been adopted and implemented by the' state. This

, estimate should consider emission rates, production capacities, and other related information to clearly show that'the air, quality improvements are the result of implemented controls. The analysis should assume that sources are operating at permitted levels (or historic peak,levels),unless evidence is presented that such an assumption is unrealistic.

4. Section,110 and Part P Requirements

For the purposesof'redesignation, a'State must meet all requirements of section 110 and Part 0 that were applicable prior

to submittal of the complete redesignation**reque~t.** 

### When evaluating a redesignation request, Regions should not consider

, whether the state has met requirements that come due**und~r** 

### the

Act after submittal of a complete redesignation request.

,

2 Th is is consistent'with EPA's existing policy on redesignations as ,stated iri an April 21, 1983 memorandum titled "Section 107 Designation Policy Summary." This memorandum states that in order for an area to be redesignated to attainment, the

state must show that "actual enforceable emission reductions are responsible for the recent air quality improvement." This element of the policy retains its validity under the. amended Act pursuant to section 193. [Note: other aspects of the April 21; 1983 memorandum have since been superseded by subsequent**memorandums~.interested** 

### parties should consult with OAQPS before relying on these aspects, e.g. those relating to required years of air quality data.]

3under section 175A(C), however, the requirements of Part D**remain·~in** 

### ' force

.. and ,·eff ect

. for·' the areaunt·i 1 'such "time" as it 'is' redesignated. Upon redesignation to attainment, the requirements that became due under section 175A(C) after submittal of the

. complete redesignation request would no longer be applicable.

## ;-i~:1~;~-~

..**:~"** 5



### However, any requirements that came due prior to sUbmittal of the redesignation request must be fully approved into the plan at**o~** 

### before the time EPA redesignates the area.

To avoid confusion concerning what requirements will be applicable for purposes of redesignation, Regions should

encourage states to work closely with the appropriate RegiQnal Office early in the process. This will help to ensure that a redesignation request submitted by the state has a high

, likelihood of being approved by EPA. Regions**'sho~ld** 

### advise

states of the practical planning consequences if EPA disapproves the redesignation request or if the request is invalidated, 

### I because of violations recorded during EPA's review. ' Under such circumstances, EPA does not have the discretion to adjust" schedules for implementing SIP requirements. As a result, an

area may risk sanct,ions and/or Federal implementation plan implementation that could result from failure to meet SIP submittal or implementation requirements.

a. Section 110 Reguirements

section 110(a)(2) contains general requirements nonattainment plans. Most of the provisions of this the same as those contained in the pre-amended Act. provide guidance on these requirements'as needed. 4

b. Part P Reguirements for section We will are

Part D consists of general requirements applicable to all

areas which are designated nonattainment based on a violation of the NAAQS. The general requirements are followed by a series of subparts specific to each pollutant. The general requirem.ents 

# I

appear in subpart 1. The requirements relating to 0 3 , CO, PM-10, S02' N02' and Pb appear in subparts 2 through 5. In those instances where an area is subject to both the general nonattainment provisions in subpart 1 as well as one of the pollutant-specific subparts, the general provisions may'be subsumed within, or superseded by, the more specific requirements of subparts 2 through 5. '

If an area was not'classified under 'section 181 for '0 3 , or section 186 for CO, then that area is only subject to the provisions of subpart 1, "Nonattainment Areas in General." In addition to relevant provisions in subpart**1~** 

### an 0 3 and CO area, which is classified, must meet all applicable requ1rements in 

## r subpart 2, "Additional Provisions for Ozone Nonattainment Areas," and subpart 3, "Additional Provisions for Carbon Monoxide

4General guidance regarding the requirements for SIP'S may be found in the "General Preamble to Title I of the 1990 Clean Air Act Amendments,"57 FR 13498 (April 16, 1992).6



### Nonattainment"Areas," respectively, before the area may be**rede~ignated** 

### to,attainment. All PM-lO nonattainment areas (whether classified**a~** 

### moderate or serious) must similarly meet the applicable general provisions of subpart 1 and the specific PM-10 provisions in subpart 4, '"'Additional Provisions for Particulate Matter Nonattainment Areas." Likewise, s02' N0 2 , and Pb nonattainment areas are subject to the applicable**gener~1** 

### nonattainment "provisions in subpart 1 as well as the more specific requirements in subpart 5, "Additional Provisions for Areas Designated Nonattainme,Ht for Sulfur Oxides, "Nitrogen Dioxide, and Lead."

. "

i. Section 172 (c) Requirements·

This section contains general requirements. for nonat:tainment plans. A thorough discussion of.these requirements may be found in the General Preamble to Title I [57 FR 13498 (April 16, 1992)]. The EPA anticipates that areas will already have met
most or all of these requirements to the extent that they are not superseded by more specific Part D requirements. The requirements for reasonable further progress, identification of certain emissions increases, and other measures needed for. attainment will not apply for redesignations because they only have meaning for areas not attaining the standard. The requirements for.an emission inventory will be" satisfied by the inventory requirements of the maintenance plan. The requirements of the Part D new source review program will be replaced by the prevention of significant deterioration (PSD) program once the

area has been redesignated. However, in order to ensure that the PSD program will become fully.effective immediately upon redesignation, either the state must be delegated the Federal PSD

program or the State must make any needed modifications ·to its rules to have the approved PSD program apply to the ·affected area upon r:edesignation.

"d·



### ii. ". Conformity

The state must work with EPA to show that· its SIP provisions are consistent with section 176(c)(4) conformity" requirements. The redesignation request should include conformity procedures, if the state already has these procedures in place: Additionally, we currently interpret the conformity" requirement to apply to attainment areas. However, EPA has not yet issued its conformity regulations specifying what areas are subject" to the conformity requirement. Therefore, if a state does not have conformity**proc~dures** 

### in place at the time that it" submits a**redesig~ation** 

### request, the state" must commit to follow EPA'!; conformity regulation upon issuance, as applicable. If the

state sUbmits the "redesignationrequest" subsequent" to EP1\'s' " issuance of the conformity regulations, and the conformity requirement became applicable to the area prior to submis!;ion,

.

,**~** .7



### the state must adopt the applicable conformity requirements before EPA can redesignate the area.

5. Maintenance Plans

section 107(d)(3)(E) of 'the amended Act stipulates that for

an area to be redesignated, EPA must fully approve a maintenance plan which meets the requirements of section 1'75A. A state**ma~** 

### submit both the redesignation request and the maintenance plan at the same time and rulemaking on both may proceed on a parallel, track. Maintenance plans may, of course, be 

### submitted and approved by EPA before a redesignation is requested. However, according to section 175A(c), pending approval of the maintenance ,plan and redesignation request, all ,applicable' nonattainment ar'ea requirements shall remain in place. ,I

section 175A defines the general framework of a ,maintenance plan. The maintenance plan Wil,l constitute a SIP revisi,on arid I
must provide for maintenance of the relevant NAAQS in the area ' for at least 10 years after redesignation. Section 175A further

states that the plan shall contain such additional measures, 

## ii

any, as may be necessary to ensure such maintenance. Because the Act requires a demonstration of maintenance for 10 years after Ian

area is redesignated (not 10 years after submittal of a redesignation request), the State should plan for some lead time for EPA action on the request. In other words, 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. In determining the amount of lead time to allow, States should consider that I section 107(d)(3)(D) grants the Administrator up to 18 months from receipt of a complete ,submittal to process a redesignation request. The statute also requires the State to submit a I revision of the SIP 8 years after the original redesignation request is approved to provide for maintenance ,of the NAAQS**fo~** 

### an additional 10 years following the first 10-year period [see section 175A(b)].

In addition, the maintenance plan shall contain such contingency measures as the'Administrator deems necessary to

ensure prompt correctiori of any violation of the NAAQS [see section 175A(d)]. The Act provides that, at a minimum, the contingency measures must include a requirement that the State will implement all measures contained in the nonattainment SIP prior to redesignation. Failure to maintain the NAAQS and triggering of the contingency plan will not necessitate a revision' of the SIP unless required by the Administrator, as stated in section 175A(d).

The following is a list of core provisions that we anticipate will be necessary to ensure maintenance of the relevant NAAQS in an 'area seeking redesignation from8



### nonattainment to attainment.. We**th~refore** 

### recommend that States seeking redesignation of a' nonattainment area consider these provisions. However. any final 'EPA determination regarding the adequacy of a maintenance plan will be made following review of the plan submittal in light of the particular 'circumstances facing the area proposed for redesignation and based on all relevant information available at the time.

I

.



### a

.. , Attainment Inventory

The State should develop an attainment emissions inventory

to identify .the level of emissigns in the area which is

, sufficient to attain the NMQS.

. This inventory, 'should be '. 'consisterit 'with EPA's most recent guidance on emission

inventories for nonattainment areas available at the time and should include the emissions during the time period associated with the monitoring data showing attainment. 6

.

, , 

### Source size thresholds are 100 tons/year for SO

, N0 2 • and PM-10 areas, and 5 tons/year for Pb based upon

## 40,CF~ 51.100(k) and 51.322, as well as established practice for AIRS data. The

source size threshold for serious PM-IO areas is 70 ,tons/year

5Where the State has made an adequate demonstration that air quality has improved as a result of the SIP (as discussed previously). the attainment inventory will generally be**th~** 

### actual inventory at the time the area attained the standard.

6 The EPA's current guidance on the

### prepar~tion of emission inventories for 0 3 and CO nonattainment.areas is contained in the following documents:. "Procedures for the Preparation of Emission Inventories for Carbon Monoxide and Precursors of Ozone: Volume I" (EPA-450/4-91':'016). "Procedures for the Prepara'tion of

. Emission Inventories for Carbon Monoxide and Precursors of Ozone: Volume II" (EPA-450/4-91-014). "Emission Inventory Requirements for Ozone state Implementation Plans" (EPA-450/4-91-010), "Emission Inventory Requirements for Carbon Monoxide Implementation Plans" (EPA-450/4-91-011), "Guideline for Regulatory Application of the Urban Airshed Model" (EPA-450/4-91- 013). "Procedures for Emission Inventory Preparation: Volume IV, Mobile Sources" (EPA-450/4-81-026d). and "Procedures for Preparing 'Emission. Inventory Projections" (EPA-450/4-91-019). The EPA does not currently have specific guidance on attainment emissions inventories'for S02" In lieu thereof. States are referred to the guidance on emissions data to be used as input to modeling demonstrations. contained in Table 9.1 of EPA's "Guideline on Air Quality Models (Revised)" (EPA-450/2-78-027R). July 1987 .,J.,hJc;:h is.**q~nerally** 

### applicable to, all, criteria

.. ,', pollutants.Emission inventory procedures and requirements documents are currently being prepared by' OAQPS 'for PM-,10 and Pb; these documents are due for release by summer 19.92.

### ·

....**,#,~s** 9



### according to Clean Air' Act section l89(b)(3). HoweVer, the inventory should include sources below these size thresholds i these smaller sources were included in the SIP attainment demonstration. Where sources below the 100; 70, 

### and 5 tons/ye rsize thresholds (e.g., areas with smaller source size definitions) are subject to a state's minor source permit

program, these sources need only be addressed in the aggregate to the extent tha.t: they result in areawide growth.**~.** 

### For 03 nonattainment areas, the invento)."y should be based on actual "typical summer day" emissions of'O J 

### precursors (volatile organic compounds and,nitrogen oxides) dur).ng the attainment·

year. This will generally correspond to one of the periodic inventories required for nonattainment areas to reconcile milestones. FOr CO nonattainment areas, the inventory should be based on actual "typical Co season day" emissions for the attainment year. This will generally correspond to one of the periodic inventories required for nonattainment areas.

b. Maintenance Demonstration

A State may generally demonstrate maintenance of the NAAQS by either showing that future emissions of a pollutant or its

I 

### 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. Under the Clean Air Act, many areas are required to submit nodeled attainment demonstrations to show that proposed'reductions in emissions will be sufficient to attain the applicable NAAQS.**~or** 

### these areas, the maintenance demonstration should be based upon the same level of modeling. In areas where no such modeling wa!s' required, the State should be able to rely on the attainment 

### I inventory approach. In both instances, the demonstration shouldbe for'a period of 10 

### years following the redesignation.

. c:::


### Where modeling is relied upon to demonstrate maintenance, each plan should contain a summary of the air quality concentrations expected to result from application of the control strategy. In the process, the plan should identify and descrii:Je the dispersion model or other air quality model used to**projec~** 

### ambient concentrations (see 40 

### CFR 51. 46) •

. .0 

# I'

In either case, to satisfy the demonstration requirement

## t~e state should project emissio. nsfor the lO-year period fOllowin g

l 

### redesignation, either for the purpose of showing that emissions will not**~ncrease** 

### over the attainment inventory or for conducting modeling. The projected inventory should consider future growth, including 'population and industry, should be consistent

7 Gu idance for projecting emissions may be found in the emissions inventory guidance cited in footnote 6. 

# .. )"**~,**

### 10

with the attainment inventory, and 'should doCument data inputs and assumptions. All elements of the demonstration (e. g.', emission projections, new source growth, and**m~deling)** 

### should be consistent with current EPA modeling guidance. For 0 3 and CO, the projected emissions should reflect the expected actual emissions based on**enforce~ble** 

### emission rates and typical' production**rat~s.**



### For CO, a state should address the areawide component of the' maintenance demonstration either by showing that future CO' emissions will not increase or by conducting areawide modeling. Preferably, the State should carry out hot-spot ,modeling that is consistent with the Guideline on AirOuality Models (Revised), in order to demonstrate maintenance of the NAAQS. In particular, if the.nonattainment problem is related to a pattern of hot-spots then hot-spot modeling should generally be ,conducted. However, hot-spot modeling is not automatically required

.. For example, if the nonattainment problem was related solely to stationary point

sources, or if highway improvements have been implemented and the associated emission reductions ,and travel characteristics can be qualitatively documented, then hot-spot modeling is not required. In such cases, adequate documentation as well as the concurrence of Headquarters is needed. "'.,

Any assumptions concerning emission rates must reflect permanent, enforceable measures. In other words, a State generally cannot'take credit in the maintenance demonstration for reductions unless there are'regulations in place requiring those 'reductions or the reductions are-otherwise.shown to be permanent. Therefore, the State will be expected to maintain its implemented control strategy despite redesignation to attainment, unless such

measures are shown to be unnecessary for maintenance or**a~e** 

### . replaced with measures that achieve equivalent reductions (see additional discussion under "contingency Plan"). Emission reductions from source shutdowns can be considered permanent and enforceable to the extent. that those shutdowns have been reflected in**t~e** 

### SIP and all applicable permits have been modified accordingly.

Modeling used to demonstrate attainm!!nt may be, relied upon in the maintenance demonstration where the modeling conforms to
current EPA guidance and where the State has projected no significant changes in the.modeling inputs during the intervening time. Where the original attainment demonstration may no longer be relied upon, States will be expected to remodel using current

8 The EPA-approved modeling guidance may be found in the

. fOllowing documents: "Guideline on Air Quality Models (Revised) ," OAQPS, RTP, NC (EPA-450/2-78-027R); July 1986; 'and "PM-I0 SIP Development Guideline," OAQPS, RTP, NC(EPA-450/2-86- 001), June 1987.

### 11

EPA referenced techniques. 9 This may be necessary where, for example, there has been a change in emissions or a change in t e siting of new sources or modifications' such that air quality m y

no longer be accurately represented by the existing modeling.

c. Monitoring Network

Once an area has been redesignated, the State should continue to operate an appropriate air quality monitoring network., ln accordance with 40 CFR'Part 58, to verify the attainment status'of the area. The maintenance plan should contain provisions for continued operation of air quality monitors that will provide such verification. In cases where measured 'mobile source parameters (e.g., vehicle miles traveled congestion) have changed over time, the state may also need tol perform a saturation monitoring study to determine the need for, and location of, additional permanent monitors.

d. Verification of Continued Attainment

Each State should ensure that it has the legal authority to implement and enforce all measures necessary to attain and to I 

### maintain the NAAQS •. Sections 110(a)(2)(B) and (F) of the Clean Air Act, as amended, and regulations promulgated at 40 CFR 51.110(k), suggest that one such measure is the acquisition of ambient and source emission data to demonstrate attainment and maintenance.

Regardless of whether the maintenance demonstration is based

on a showing that future emission inventories will not exceed the attainment inventory or on modeling, the state submittal should indicate how the state will track the progress of the maintenance plan.- This is necessary due to the fact that the emission projections made for the maintenance demonstration depend on assumptions of point and area source growth.

,- One option for tracking the progress of the maintenance demonstration, provided here as an example, would be for the State to periodically update the emissions inventory. In this

case, the maintenance plan should specify the frequency of any planned inventory updates. such an update could be based, in part, 'on the annual AIRS update and could indicate new source growth and other changes from the attainment inventory (e.g., changes in vehicle miles travelled or in traffic patterns). As

an alternative to a complete update of the inventory, the State!

may choose to dO. a comprehensiv. e review of the factors that wez'le used in developing the attainment inventory to show no significant change. If this review does show a significant change, the State should then perform an update of the inventory.

9 see references for modeling guidance cited in footnote 8.

### 12

Where the demonstration is based on modeling, an option for tracking. 'progress would be for the State to periodically

. (typically every 3 years) reevaluate the modeling assumptions and

, input data. In any event, the state should monitor the

indicators for triggering contingency measures (as discussed below)

.

e. contingency Plan

section 175A of the,Act als6 requires that**amaintenanc~** 

### plan include contingency provisions, as necessary, to promptly

correct any violation of the NAAQS**~hat** 

### occurs after redesignation of the area. These contingency measures are distinguished from those generally required for nonattainment

areas under section 172(c)(9) and those specifically' required for

o 'and CO nonattainment areas under sections 182(c)(9) and

## 1~7(a)(3), respectively. For the purposes of section 175A, a state is not required to have fully 'adopted contingency measures tha,t will take effect ,without further action by the state in order for the maintenance plan to be approved. However, 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. As a necessary part of the plan, the state should also identify specific indicators, or triggers, which will be used to determine when the contingency measures need to be implemented.

Where the maintenance demonstration is based 6n the inventory, ,the State may, for example, identify an "action level" of emissions as the indicator. If later inventory updates show that the inventory has exceeded the action level, the State would take the necessary steps to implement the contingency measures., The indicators would allow a State to take early action to address potential violations of the NAAQS before they occur. By taking early action, States may be 

### able to prevent any actual violations of the NAAQS and, therefore, eliminate the need on the part of EPA to redesignate an area to nonattainment •

. Other indicators to consider include monitored or modeled' violations of the NAAQS (due to the inadequacy of monitoring data in some situations). It is important to note that air quality data in excess of the NAAQS will not automatically necessitate a revision of the SIP ,where implementation of contingency measures is adequate to address the cause of the violation. The need for

a SIP revision is subject to the Administrator's discretion.

, , 

### The EPA will review what constitutes a contingency plan on a case-by-case basis. At a minimum, it must require that the State will implement all measures contained in the Part D nonattainment13



### plan for the area prior to redesignation [see section l75A(d)]. This language suggests that a State may submit a SIP revision kt the time of its redesignation request to remove or reduce the
I 

### stringency of control measures. Such a revision can be approved by EPA if it provides for .compensating equivalent reductions. 

## I A demonstration that measurEls are equivalent would have. to include appropriate modeling or an adequate justification.**Altern~­** 

### tively, a state might be able to demonstrate (through EPA-approved modeling) that the measures are not necessary for maintenance of the standard. In either case, the contingency plan would have to provide for implementation of any measures that were reduced or removed after redesignation of the area.

Summary

As stated previously, this memorandum consolidates EPA's redesignation and maintenance plan guidance and Regions should rely upon it as a general framework in drafting Federal Regist'er notices. It is strongly suggested that the Regional Offices 

### I share this document with the appropriate States. This should give the States a better understanding of .what is expected from a redesignation request and maintenance plan under existing poli'cy. Any necessary changes to existing Agency policy will be made through our action on specific redesignation requests and the review of section 175A maintenance plans for these particular

areas, both of which are subject to notice and comment rulemaking

. procedures. Thus, in applying this memorandum to specific 

### I circumstances in a rulemaking, Regions should consider the applicability of the underlying policies to the particular 'facts

, . 

### , and to comments**subm~tted** 

### by any person. If your staff**membe~ls** 

### have questions which require clarification, they may contact Sharon Reinders at (919) 541-5284 for 0 3 - and**CO~related** 

### issues, and Eric Ginsburg at (919) 541-0877 for S02-' PM-10-, and Pb-related issues.

cc: Chief, Air Branch, Regions I-X John Cabaniss, OMS Denise Devoe, OAQPS Bill Laxton, TSD Rich Ossias, OGC John Rasnic, SSCD John Seitz, OAQPS Mike Shapiro, OAR Lydia Wegman, OAQPS

### Page Intentionally Left Blank

### Appendix B

Redesignation of Sulfur Dioxide Nonattainment Areas in the Absence of

Monitored Data

, Memorandum, John Seitz, Director, Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, October 18, 2000

### Page Intentionally Left Blank

# -.**~ -~~-~** 

. ,"Il,

. '. "



## . / 

### '

,

J' /. 1 I . ' . 

# RECE1'VEO'

.'. OCT 26 2Doo

. . . . uNITED STATES· ENVIRONMENTAL PROnCTION AGENCY

RESEARCH TRIANGLE PARK. NC 2771 1 AIR DIVISION '. U.S; EPA, REGION'9



### OCT, 1 8 ,- "':-

I\tIEMORANDUM ' . OFFICE Of
AIR. QUAUTY PlANNING
AND STANDARCS

.



### SUBJECT: Redesigna#on 

### of

### S~ Dioxide

### Nonatt:ljnm~' 

# Areas in

### th~ Absence 

### of

Monitored, Data



### John S. 

### Seltz, Directo

Office.of 

### Air Quality 

### PI

TO: Regional Office 

### Air Division Directors 

### -1"0)

. . 

### The purpose of 

### this memorandmn is to proVide 

### guidance 

## .on redesignating·.sulfW dioxide 

### (S02)**nona~ent** 

### areas to**a~ent,** 

### in cases where**th~** 

### areas' historic violations were 

### caused by inajor 

### point-sources .of 

### sulfur oxide 

### (SOx)**~ssio;ns** that 

### are no lopger in operation.



### States in some cases**have~** 

### with 

### out approval, removed 

### S02 momtQrs from these areaS 

### immediately following the shutdown of 

### the SOx 

### emissl<;>Os 

## sources

.. In 

### these 

# tases,states face the'prospect of continued nonattirinment designations' for areas where there 

### is no 

### reas«::>nable basis

for**as~g** that 

### S02 

### violations persist.

. I..



### . . This,guidance provides 

### an approach 

### for redesigruiting these**m:~as** to attaiDment 

### in the



### . absence of monitoring data and 

## for exempting 

### 1'h:ese are.3$ 

## froin 'the**mainten~ce** plan

. .



### . requirements for 

### coDrlnued monitoring 

### within the areas. 

### In addition, this policy deScnces' 

### how**a~ent** and continued 

### mruntenance should be demonstrated 

### and how SOUl'ces currently 

### shirt

. " doWn shouJd be treated 

### if they

### resume·operation~. TJl,erefore, this policy amends:portions of

.

previous redesignation policies, including 

### '"Procec.:lures for**~ce~sing Requ~ts**  to Redesignate

.

. .

.Areas 

### to 

### Attamment, " memo 

### from John Calcagni, AQMD 

### Director,. dated' 

### 9/4/92;' 

### "Section "1'07

.

. .Desigpation 

### Policy SUmmary,"

### m~o from Sheldon 

### Meyers,

### dAQPSDirectO~, dated 4121183,

pe$ining to 

### ambient air qualitY 

### data 

## shOwlDg aitai.nri:Ient aDd 

### maintenance of the 

### S02 National



### . Ambient 

### Air Quality

### Standar~s 

### (NMQS); and·**~** Attainment

### Deiermin~tk)li Pelley 

### for**S~.** Dioxide NonattainInent**Areas;'~** memo ·ftpm 

### Sally 1. Shaver, AQSSD 

### Director, dated 

### 1/26/95.,



### All'other pro:visions of the 

### previous redesignation policies 

## still apply,**inc1ti~g** 

### provisrons relating to contingency**me~s.·** 

### " .'. ,..' .:.

" "**~.,**

-"

.. '

# • II·

. II



# II 

# .'

1 (\,',

'J 

# II

II

I



# I
I

I 

# It.

I


# I



# - 1\ I,

W· . 2

. The Environmental Protection Agency's (EPA) 'historic redisigIfation policy for S02 has

called-for 8 quarters ofclean ambient 

### air· quality data for**rede.signatio~** to attainment. Although

. EPA has allowed as few as 4 quarters of ambient data if 

# an acceptable modeling analysis haS

been perfonned. I Areas that lack S02 monitors cannot meet. even the requirement for 4' quarters

. of clean' data' However, EPA believes that 

### it is not a reasonable use ofliIDited monitoring

resources to reesmblishmonitors in ord.er to collect at 

### least.4 quarters of data.in areas where

violations of the S02 

### NAAQS were caused by sources that no**10n~er** operate.

pespite the absence of clean 

### air quality data, EPA believes ·that it may approve a State's

request to redesignate such 802 nonattainment areas to att8.inment providect that**th~** State

submits a maintenance plan that addresses 

# certain criteria.

.

First, the plan should include 3 emissions inventories:

(a) An inventory representing actual emissions during the period 'when there were

. violations of the S02 

### NAAQ8;

. . 

### . (b) An inventory representing current actual and allowable emissions (or potential
emissions, 

### if there is no allowable emissions level); and

(c) 

### An inventory projecting allowable emissions (or potential emissions, 

### if there is no allowable emissions leyel) to the 10th year after redesignation.

The inventories should display emisslons from each poult source of SOx, with explanations of significant emissions changes, includmg source shutdoWns. 2 The inventories should include SOx

emissions from all SOx point sources 

### in; and 

### within a 50 kilbmeter range of, the nonattainmeilt

area boundary

.. Again, 

### if there is no allowable emissions level, potential emissions should be**~~.** . . .

Second, the maintenance plan should

### fuclud~**~** dispersion'modelinganaIysis: 

## of**all-S0~'** . point sources in,**~d** 

### within 

## 50 kilometers of, the**nona~ent** area**bound,an~s** USing the

emissions inventories described above and the techi;riques and data prescribed in 

### 40,CI:R 51 Appendix W. The modeling .analysis· Should show that:

.

ISee the Meyers memQ referenced above. -Both the Meyers and Calcagni memos recognize that for S02 nonattamment areas monitoring data alone may not be sufficient for redesignating areas to attainment; dispersion modeling may be needed.

2The inventories should include other sources 

## if they were included 

### in the attainment
demonstration.'

..., ............... 

### -

....... -.-

..... 

### -

..........**-~** ..... ':



### 3

. (a) No S02 NAAQS violations**pres~nt1y** 

### occur cir**c~:.·be** 

### projected·to occur chir:ing

the next 10 years**anywb~e** 

## Within the nonattaimnent area;; 

### and,
- .

. ! •.•• •

....

(b) 

### Point sources, which have since shut**do~** 

### were the dominant sources contributing 

### tc? high S02 concentrations in the airshed.

Third, the mamteoance 

### .plan should include**evid~ce** 

### that if the**SO~** 

### point source 

### that

caused the S02 NAAQS 

### Violations in 

### the past resumes operation1 itwould be 

### 'considered a
,**"new'~** 

### source.' Thus the maintenance plan should show that iftbis ''D.ew'· $Ox source woqld be a major**source~** 

### it should obtain 

# a**pe~t** 

### conforining to applicable:requjrements. 6fthe Prevention

of 

### Significant Deterioration 

### program**b~fore** 

### resuming operations; 

### or if it would not 

### be a major '

source, it should 

### obtain 

# a Imnor source permit under 

### .the ,State' 

### s**8IP-approv~d** 

### minor source**p~rmitting** 

### rules in 

### effect at the time it"obtains a. permi4: before it may reSUI:Jle operation. The

·maintenance plan should'provide 

### that before such 

### a permit is 

### issued, the dispersion model 

### should
be re-run., using the 

### same meteorological 

### data 

### base, to determine 

### whetherre-Starting' the source would'interfere 

### withmaintemince, and 

### should provide 

### that the 

### permit will not 

### be issued 

### if the
model indicates that 

### re-starting the 

### source would interfere 

### with. maintenance.,

.

A' 

### Fourth, the maintenance 

### plan should include commitments 

### to.reSU!¥e ambient monitoring



### before 

### any major source .of SOx: emissions 

### commences operation.**·'~1**

.**~.... .~~**  ...

. ...ft

. . ••**~** •• ;.

d'· .:' •**~** ••**:~** ,.

, . , . , ,'Tiris 

### policy applies. 

### only,to S02 

### nona-rtahnnent areas because violations in such 

## areas are

### ~erally dominated 

### by**rel~tive1y** few point 

### sources (such as cOpper

### smelt~rs or power plants) 

### arid have insi gnificant. area 

### and mobile source emission contributions. 

### As: 

## h result, there is 

### a direct 

### association between the point sources' emissions' and ambient 802 c-{)ncentIations. 

### DisperSion modeling 

### will assure that 802 

### NAAQS violations are no longer occurring and 

### wolild

not 

### be expected to recur 

### in 

### the 

## future.

. .........**~** .. 

### :;

," This gUidance

## memo~dum does not hnpose

## binding~ enforceable

## :,~quirements on any 

### party, arid may not apply,to a particular situation 

### based upon: the circumstances. The EPA 

### r¢tains

. ·1'**.,:th,~.** qiscretion 

### to adopt'approaches to addressing 

### maintenance plan provisionS that 

### differ from this
,.'- guidance 

### where appropriate., Any 

### final decisions 

### by 

### EPA regarding:a'pamcular S02 '

r 

### maintenance plan will 

### only, 

## be made, 

### in 

### the context of a rulemalcing, action 

## regarcting that**~ainten3nce** 

### plan based upon the applicable statUtory and 

### regulatory provisions, which do**c~n~** 

### legally·binding requirements. Therefore, interested 

### parties, including States, are free to



## .' 'nuse questions and objections' about 

### the appropriateness 

# of this guidance 

### or the 

### application of



## tl:i:is guid3nce 

### to a particular situation; 

### EP A will 

### consider. whether or not the recommendations in

the 

### guidance 

# are appropnate in that 

### situation. The 

### EPA welcomes public ·comments on $is

. document at 

### any time and will consi4er 

### those comments in 

### any future revisiQD 

### of this guidance 

### do.cUment, which may occur withoUt public 

### notice. .,
'o'

### 4



### I urge Regions to coordinatec1os¢ly with 

### OAQPS' Air 

### Quality Standards and Strategies

. Division in deterniining.whether S02 redesignation requests may be subject to this policy and to
ensure.that States' submissIons adequately-address this and the·preVious**polici~s'** 

### criteria for redesignating 802 nomittaimnent**are~** 

### to attainment

- .

cc: Lydia Wegman, AQSSD
David Mobley, 

### EMAD

, Joe**Paisie~** 

### IPSG

Rich Ossias, OGe. ....... : •... ;.;,:.: •.•.••.••.• I**',~~.:. ::~~.i{~·:~** **\~~~~~\\**

### ·"{~i~:t

'\:

# 502 Redesignation**Poli~y** 

# M·emo

Policy Purpose: To amend existing. requirements for redesignating**80~** 

### NAAs to attainm(3nt, in

order to allow for redesignations· .where:

(1) past violations were due to emissions
from a single source;

. (2) the single sour.ce has shut down; 

### (3) all monitors have been removed.



### Policy Approach:

. Maintenance 

## plan must i[lclude:



## Policy Application:

.. . Policy Benefits: (1)

. 

### emissions inventories representing (a) actual emissions when violations occurred; (b) current emissions; and (c)

emissions projected to the· 1 Oth year after .redesignation). (2)

### dispersio~~ modeling showing (a) no NAAQ8 violations occur or can be projected for ·the next.. 

### 10 years; and (b)

the shutdown sources were the 90rninant

cause of high**conc~ntratjons** 

### in 

### the past. (3) evidence that 

## if the shutdown sources

resume· operation ·they will be considered

new sources and required to obtain a
PSD 

### permit 

### (4)**commjtment~** 

### to resume 

### mbnitorin·g
before any major 

### SOx source

.
commences operation.

Restr.icted to 

## .$02 NAAs· because 

## 802

violations are frequently caused 

### by a .few point sources

Allows redesignationof $everal 

## 802

. NAAs t6 attainment, without requiring

collection of ambient data

### Page Intentionally Left Blank

### Appendix C

SO 2 

### Emissions Inventories for 2011 and Subsequent Years through 2030, Arizona Department of Environmental Quality, June 20, 2014

### Page Intentionally Left Blank

# SO2 Emissions

Inventories for 2011 and Subsequent Years through 2030

Technical Support Document
for the Morenci SO2

Maintenance Plan

Arizona Department of Environmental Quality

June 20 , 2014

### Table of Contents

1. EMISSIONS INVENTORY & METHODOLOGY

................................ ................................ .... 1
1.1 Emission Inventory for the SO 2 24

- hour and Annual Standard

................................ ................................ ............... 1 1.2 2011 Baseline Emissions Inventory

– Methodology

................................ ................................ ............................... 1 1.2.1 Population and Area Based Emission Allocation Methodology

................................ ................................ ........... 1

1.2.2 Non

- Road Mobile Activities

................................ ................................ ................................ ................................ .. 3

1.2.3 On

- Road Mobile Activities

................................ ................................ ................................ ................................ .... 4 1.2.4 Area (non

-

point ) Activities

................................ ................................ ................................ ................................ .... 4 1.2.5 Industrial (point) Sources

................................ ................................ ................................ ................................ ..... 6 Figure 1: Morenci SO 2 Maintenance Area with 50 Kilometer Buffer

................................ ................................ ........ 10 

### 2. MORENCI SO 2 

### MAINTENANCE AREA EMISSIONS INVENTORY FOR POINT, AREA

AND MOBILE SOURCES FOR THE BASE YEAR 2011

................................ .......................... 11

3. PROJECTED SO 2 

### EMISSIONS INVENTORY FOR POINT, AREA AND MOBILE

SOURCES THROUGH 2030

................................ ................................ ................................ ........ 11
3.1 Summary of Emissions Projections for 2011

– 2030

................................ ................................ ............................. 13 

### 4. REFERENCES

................................ ................................ ................................ .......................... 15

LIST OF TABLES

TABLE 1: ADOA 2011 POPULATION OF MORENC I CDP, CLIFTON, AND GREENLEE CO.

......................... 2

TABLE 2: NON

- ROAD MOBILE SO 2 EMISSIONS FOR GREENL EE COUNTY AND THE MO RENCI SO 2 MAINTENANCE AREA

................................ ................................ ................................ ................................ ..... 3

TABLE 3: ON

- ROAD MOBILE SO 2 EMISSIONS FOR GREENL EE COUNTY AND THE MO RENCI

MAINTENANCE AREA

................................ ................................ ................................ ................................ ..... 4

TABLE 4 : AREA (NON

- POINT) SO 2 EMISSIONS FOR GREENL EE COUNTY AND THE MO RENCI AREA

.. 6

TABLE 5: SO 2 POINT SOURCES WITHIN MORENCI SO 2 MAIN TENANCE AREA

................................ .......... 8

TABLE 6: SO 2 POINT SOURCES WITHIN 50

- KM BUFFER, OUTSIDE M ORENCI SO 2 MAINTENANCE

AREA

................................ ................................ ................................ ................................ ................................ ... 9

TABLE 7: MORENCI SO 2 MAINTENANCE AREA

– 2011 BASELINE EMISSI ON ESTIMATES

.................... 11

TABLE 8: MORENCI SO 2 MAINTENANCE AREA 201 1

– 2030 POPULATION PROJ ECTION

........................ 12

TABLE 9: MORENCI SO2 MAINTENANCE AREA 201 1

– 2030 PROJECTED EMISS ION ESTIMATES

........ 14



### LIST OF FIGURES

FIGURE 1: MORENCI S O 2 MAINTENANCE AREA WIT H 50 KILOMETER BUFFE R

................................ ..... 10

### 1



## 1

. EMISSIONS INVENTORY & METHODOLOGY

1.1 Emission Inventory for the SO 2 

### 24

- hour and Annual Standard

The followin g sections in this Technical Support Document (TSD) provide a discussion of the methodolog ies used to develop the 2011 baseline emissions inventory and future year inventories

for the Morenci maintenance area from identified contributing source categories and a presentation of the derived inventor ies

. This TSD was developed to help demonstrate continued

maintenance of the 1971 24

- hour and annual SO 2 

### NAAQS for the Morenci SO 2 

### planning area.



### 1.2 2011 Baseline Emissions Inventory

– Methodology

The source ca tegories used in the emissions inventory are a standardized list of sources which has been followed in previous State Implementation Plan s ( SIP s )

. These categories include:

 Non

- road Mobile (exhaust) sources

 On

- road Mobile (exhaust) sources

 Industrial ( point) sources

 Area ( non

- point ) sources

Area and Mobile emission data were updated using 20 11 National Emission Inventory (NEI)

Version 1 data. Since ADEQ permits industrial point source s, ADEQs datasets were used because they were the most accurate and r ecent SO 2 

### emissions data for facilities located within

the maintenance area and the surrounding 50 km buffer area.



### 1.2.1 Population and Area Based Emission Allocation Methodology

ADEQ implemented a top down methodology by u tilizing the 20 11 NEI Version 1 inventory for

Greenlee County. For source categories whose emissions may be significantly associated with the general population, t he county

- wide emissions reported in the 20 11 NEI Version 1 , the most recent EPA certified emissions data available, were ad justed to the Morenci Maintenance A rea using the population ratio of the Town of Clifton and the Morenci CDP to that of Greenlee County as a metric for scaling county level emissions to the Morenci Maintenance A rea 1



### .

Population adjustments :

2011 Morenc i Maintenance Area Pop

. = 2011 Clifton Pop

. + 2011 Morenci CDP Pop

. = 4, 75 5

1 The designation “ Morenci Maintenance Area” refers to the combined population of the Towns of Morenci and

Clifton and the designation “Morenci CDP” refers to the population of the Town of Morenci, AZ.

### 2

2011 Greenlee County Pop

. = 8, 3 80

Therefore

, the Population Adjustment Ratio = 2011 Morenci Maintenance Area Population /

2011 Greenlee County Population , or:

4, 75 5 / 8, 3 80 = 0

. 5 674 ( 5 6

. 74 %)

Population Adjustment Ratio = 56.74 %

Table 1 : ADOA 2011 Population of Morenci CDP, Clifton, and Greenlee Co.

Location 2011

Morenci CDP 1,482

Clifton 3,273

Morenci Maintenance Area 4,755

Greenlee County 8,380

Source: Arizona Department of Administration (ADOA) http://www.workforce.az.gov/population

- projections.aspx



### Area adjustments:

Source emission s not adjusted from the County level to the Morenci SO 2 

### Maintenance Area based on the population adjustment ratio calculated above were adjusted based on the Area Adjustment Ratio of 13.31 % calculated below:

Greenlee County Area = 4787.4 km 2



### Morenci Maintenance Area = 637.3 km 2



### Area Adjustm ent Ratio = Morenci SO 2 

### Maintenance Area / Greenlee Co Area

Area Adjustment Ratio = 637.3 km 2 

### / 4787.4 km 2 

### = 13.31%

Railway adjustment

Since some of the r ail way s in Greenlee County w ere outside the maintenance plan boundaries

and the remainder railways were inside the SO 2 

### maintenance area

, it was important to appropriately adjust the Greenlee County n on

- road

, locomotive mobile source emissions to the

Morenci SO 2 

### Maintenance Area. Google Earth was used to measure the length of railway both

outside and in side the maintenance area. The railway length ratio was found to be approximately
20 % and the calculations are shown below.

Greenlee County railway length = 40 miles

Morenci Maintenance area railway length = 8 miles

### 3

Railway length Adjustment Ratio = Mor enci SO 2 

### Maintenance Area / Greenlee Co Area

Railway length Adjustment Ratio 8 miles / 40 miles = 20%



### 1.2. 2 Non

- Road Mobile Activities

For the Non

- Road Mobile Activities category, ADEQ employed a top down methodology using

the 20 11 NEI Version 1 inven tory for Greenlee County. The county

- wide emissions reported in

the 20 11 NEI Version 1 were adjusted to the Morenci Maintenance A rea using either the population adjustment ratio

, the area adjustment ratio

, or the railway length adjustment ratio of

the More nci Maintenance Area to that of Greenlee County.

Non

- Road Mobile Emissions Calculations

The NEI reported a total of 0. 33 tons of SO 2 

### emissions from non

- road mobile source activities in

Greenlee County (see Table 2 ) for the year of 20 11 . Based on the popu lation adjustment ratio of

56.74 % and the railway track ratio of about 20 %

, SO 2 

### e missions from n on

- road mobile sources

in the Morenci SO 2 

### Maintenance Area were estimated to be 0. 08 tons for 20 11

.

Table 2 : Non

- Road Mobile SO 2 

### Em issions for Greenlee County and the Morenci SO 2 

### Maintenance Area

Source Description Tons/yr (Greenlee Co.) Adjustment

Ratio *Tons/yr

(Morenci

Maintenance

A rea)

Mobile Locomotives 0.26 20.00 % 0.0 5

Mobile Non

- Road Equipment

- Diesel 0.03 56.74 % 0.02

Mob ile Non

- Road Equipment

- Gasoline 0.02 56.74 % 0.01

Mobile Non

- Road Equipment

- Other 0.00 56.74 % 0.00

Total 0.3 1 0. 0 8

Data downloaded on 2

- 2 4

- 201 4 from EPA 2011 National Emission Inventory Version 1 (NEI, 20 11 )

* Tons per Year (TPY) for the Morenci M aintenance Area were cal culated by multiplying TPY (Greenlee Co

. ) by the Population Adjustment Ratio of 56.74 % or the Area Adjustment Ratio of 13.31%.

### 4



### 1.2. 3 On

- Road Mobile Activities

On

- road m obile source a ctivities were calculated by ADEQ by again u sing a top

- down methodology, implementing the 20 11 NEI Version 1 inventory for Greenlee County. The
county

- wide emi ssions reported in the 20 11 NEI Version 1 represent the most recent EPA

certified emissions data available

. These values were estimated for the Morenci Maintenance Area using the population adjustment ratio of the Morenci CDP and Clifton to that of Greenlee County ( 56.74 %) as a scaling metric for estimating Morenci Maintenance Area SO 2 

### emissions from county level values

.

On

- Road Mobile Emissi ons Calculations

The 20 11 NEI Version 1 reported a total of 0. 5 8 tons of SO 2 

### emissions from on

- road mobile

vehicle activities in Greenlee County during 2011 (Table 3) . Based on the population adjustment ratio, SO 2 

### emissions from on

- road mobile sources in the Morenci SO 2 

### Maintenance Area were

estimated to be 0.3 3 tons for the year of 2011 ( 56.74 % of 0. 5 8 ton s).

Table 3 : On

- Road Mobile SO 2 

### Emissions for Greenlee County and the Morenci

Maintenance Area

Source Description Tons/yr

. ( Greenlee County) Adjustment

Ratio *Tons/yr

(Morenci

Maintenance

A rea)

Mobile On

- Road Diesel Heavy Duty Vehicles 0.07 56.74 % 0.04

Mobile On

- Road Diesel Light Duty Vehicles 0.00 56.74 % 0.00

Mobile On

- Road Gasoline Heavy Duty Vehicles 0.03 56.74 % 0.02

Mobile On

- Road Gasoline Light Duty Vehicles 0.48 56.74 % 0.27

Total 0.58 0.33

Data downloaded on 2

- 2 4

- 201 4 from EPA 2011 National Emission Inventory Version 1 (NEI, 20 11 )

* Tons per Year (TPY) for the Morenci Maintenance Area were calculated by multiplying TPY (Greenlee Co. ) by the Population Adjustment Ratio of 5 6.74 %.



### 1.2

. 4 Area (

n on
- point ) Activities

For Area ( n on

- point ) Activities sources, ADEQ again used the top

- down methodology for

calculation of Morenci Maintenance Area SO 2 

### emission s based on the 20 11 NEI Version 1 for

Greenlee County. The county

- wide emissions reported in the 20 11 NEI Version 1 represent the

most recent EPA certified emissions data available for fuel combustion source types . These

values were estimated for the More nci Maintenance Area using the population adjustment ratio

### 5

of the Morenci Maintenance Area to that of Greenlee County ( 56.74 %) as a scaling metric for estimating Morenci Maintenance Area SO 2 

### emissions from county level values, as shown in

section 1.2.1. 2 011 Greenlee County SO 2 

### emissions for agricultural field b urning

, wildfires and prescribed fires are also listed below. These values were estimated for the Morenci Maintenance Area by use of the area adjustment ratio of 13.31%

.

Area ( n on

-

point ) Emissions Calculations

NEI and ADEQ reported a total of 3

, 949.93 tons of SO 2 

### emitted from Area ( non

- point ) source activities in Greenlee County during the year of 2011 (Table 4). While mining activities are included as Area ( non

- point ) SO 2 

### sources in the 2011 NEI Version 1 , ADEQ excluded the Freeport

- McMoran Morenci, Inc. mining source activities from Area ( non

- point ) source

activities as to eliminate redundancy in this emission report since these emissions are included in Industrial ( p oint) source activities (Sect ion 1.2.5.). Based on the population adjustment ratio of

56.74 % and the area adjustment ratio of 13.31%, SO 2 

### emissions from Area ( non

- point ) sources

in the Morenci SO 2 

### Maintenance Area were estimated to be 525.94 tons for the year of 20 11

.

### 6

Table 4 : Area (non

- point) SO 2 

### Emissions for Greenlee County and the Morenci Area

Source Description Tons/yr

. (Greenlee Co.) Adjustment Ratio *Tons/ yr. (Morenci

Maintenance

Area )

Fires Agricultural Field Burning 0.11 13.31% 0.015

Fires Pres cribed Fires 20.38 13.31% 2.71

Fires Wildfires 3,928.97 13.31% 522.95

Fuel

Combustion Comm/Institutional

–

Biomass 0.01 56.74 % 0.00

Fuel

Combustion Comm/Institutional

- Oil 0.01 56.74 % 0.01

Fuel

Combustion Electric Generation

- Natural

Gas 0.00 56 .74 % 0.00

Fuel

Combustion Electric Generation

- Other 0.00 56.74 % 0.00

Fuel

Combustion Industrial Boilers, ICEs

-

Natural Gas 0.00 56.74 % 0.00

Fuel

Combustion Residential

- Natural Gas 0.03 56.74 % 0.02

Fuel

Combustion Residential

- Oil 0.01 56. 74 % 0.00

Fuel

Combustion Residential

- Other 0.00 56.74 % 0.00

Fuel

Combustion Residential

- Wood 0.20 56.74 % 0.11

Industrial

Processes Industrial Processes

- Oil &

Gas Production 0.00 56.74 % 0.00

Miscellaneous Non

- Industrial NEC 0.00 56.74 % 0.00

Waste Disposal 0.21 56.74 % 0.12

Total 39 4 9. 93 5 2 5. 9 4

Source: 20 11 National Emission Inventory Version 1 (NEI) ( Data was downloaded on 2

- 2 4

- 201 4 ).



### 1.2. 5 Industrial (

p oint ) Sources

When building an Emission I nventory (EI) of point sources within the Morenci Maintenance Area, a large discrepancy was found to have occu rr ed in emissions from the Freeport

- McMoran

Mo r enci, Inc. Copper Mine (previously permitted as the ‘Phelps Dodge Morenci Mine’ (PDMM) ) between the years of 1990

- 1999 and 2000

- 2010. P rior to the year 2000, emissions from the facility rarely exceeded 1 ton/yr. From 2000

- 2010 the facility never emitted less than 25 tons/yr. Review of historical ADEQ EI’s for the facility revealed fugitive emissions from blasting were not reported until the year of 2000 and thus were not included in the 2002

‘ MORENCI SULFUR DIOXIDE NONATTAINMENT AREA STATE IMPLEMENTATION

AND MAINTENANCE PLAN ’ EI or modeling efforts. Due to this discrepancy, the Morenci

Maintenance Area EI and modeling efforts w ere updat ed to include these emissions in the currently submitted EI and modeling summary report.

### 7

Within the Morenci Maintenance Area, two SO 2 

### emission facilities were identified: 1) Freeport

McMoran Morenci (FMMM) , Inc. and 2) Morenci Townsite Wastewater Treatme nt P lant ( WWTP ) Emergency Generators (Table 5).

Freeport

- McMoran Morenci, Inc.

The FMMM open

- pit copper mine, ore processing and copper extraction facilities, located at

33.0700 latitude and

- 109.3433 longitude, ha s been in existence since the early 1970s. It was originally permitted by the Arizona Department of Health Services ( ADHS ) and later by ADEQ. FMMM produces copper through conventional milling and froth flotation. ADEQ considers FMMM a major source for NO x and particulates. Due to the closin g of the Copper smelter in 1985, ADEQ no longer considers FMMM a major source for SO 2 

### with the facility having a current potential to emit (PTE) of 87.6 tons/yr. Recent FMMM emissions inventory data for SO 2 

### indicate emission levels ranging from 25.0 tons/yr

. to 56.0 tons/yr

.

Current operating equipment with potential SO 2 

### emissions at the source includes: 2 SO 2 

### tanks, 2

industrial boilers working in parallel with 2 gas turbines, 5 small industrial boil ers, and one natural gas boiler. The total permitted all owable annual SO 2 

### emissions from this process equipment is 1.61 tons. In contrast, the facility blasts rock during its regular mining efforts. This blasting has a PTE of 86.75 tons/ yr. accounting for a potential of upwards of 98% of the

annual FMMM SO 2 

### e missions originating from this process.

Morenci Townsite WWTP Emergency Generators

The Morenci Townsite WWTP Emergency Generators permit allows for the emergency generation of power to the Morenci copper mine waste water treatment plant through the

opera tion of four diesel generators. These generators range in size between 72.4 and 181 hp. As these generators are only permitted for use during emergency, maintenance, and testing periods, emissions are minimal (Table 5). This facility accounted for less than 0.01% of total SO 2 

### emissions from all industrial (point) sources within the Morenci SO 2 

### Maintenance Area.

50 Kilometer buffer surrounding the Morenci SO2 Maintenance Area

SO 2 

### point source data were assembled for a 50

- km buffer area around the Morenc i SO 2 

### Maintenance Area. Thi s area includes portions of Greenlee and Graham c ounties in Arizona and Catron, Grant, and Hidalgo counties in New Mexico . Sources in the two Arizona counties were

determined by the ADEQ permitted facility list. It was confirmed, by the New Mexico Environment Department (NMED) , that there were no New Mexico point sources within the 50

km buffer

.

There were 15 identified point sources in 2011 in the 50

- km buffer region ( Figure 1). Two of the point sources are within the Morenci SO 2 

### Maintenance Area and the remaining 13 are within the

50

- km Buffer, but outside the Morenci SO 2 

### Maintenance Area. Actual emissions and potential to

emit (PTE) total s are shown in Tables 5 and 6 in t ons per year (tpy)

.

### 8

Table 5 shows that the actual e mis sions for point sources within the Morenci SO 2 

### Maintenance

Area (i.e. Freepor t

- McMor an Morenci’s Copper Mine and the Morenci Townsite WWTP Emergency Generators) emit well below the PTE limits listed for these sources. Those facilities

located within the 50 km buffer show similar emission pat terns where actual emissions only total

38.05 tons for the year of 20 11 , while the PTE for this year was 167.38 tons. In order to be

conservative

, the PTE was used in the emission estimation s for future years

. Table 5 presents

emission sources found within the Morenci SO 2 

### M aintenance A rea, while Table 6 presents those

sources located within the SO 2 

### 50 km buffer region but not within the Morenci SO 2 

### M aintenance

A rea.

Table 5 : SO 2 

### Point Source s within Morenci SO 2 

### Maintenance Area

ID Source Latitude Longitude 201 1 (tons/ da y) 201 1

(tons/yr

. ) PTE

(tons/yr

. ) Permit

Status as

of 2014

1 Freeport

McMoran Morenci, Inc. 33.0700

- 109.3433 0.133 48.529 87.60 Active

2 Morenci

Townsite

WWTP Emergency

Gen erators 33.0650

- 109.3422 0.000 0.003 4.90 Terminated

Total
Emissions 0.133 48.532 92.50

Data Source: Arizona Depart ment of Environmental Quality (A DEQ) and the 20 11 NEI Version 1 . Data verified by ADEQ Permits Section.

### 9

Table 6 : SO 2 

### Point Sources within 50

- km Buffer, outside Morenci SO 2 

### Maintenance Area

ID Source Latitude Longitude 2011

Actual

Emissions (tons/day) 2011

Actual

Emissions (tons/yr.) PTE

(tons/yr.) Permit

Status as

of 2014

3 Arizona State Prisons

- Saffor d Complex (2010) 32.8289

- 109.565 0.001 0.193 4.96 Terminated



### 4 City of Safford

– Water Reclamation

Plant 32.8424

- 109.7241 0.001 0. 214 24.26 Terminated



### 5 CKC Construction Company (2012) 32.8563

- 109.6878 0.000 0.126 11.60 Active

6 Freeport McMoran

- Ce ntral Analytical

Service Center 32.8165

- 109.6482 0.000 0.002 0.39 Active

7 Freeport McMoran Corporation

- Bee Canyon Well Field 33.3167

- 109.4667 0.003 1.044 8.24 Active

8 Freeport McMoran Corporation

- Mud Springs Well Field 33.3833

- 109.4833 0.003 1.0 87 5.62 Active

9 Freeport

- McMoran

Safford Inc. 32.9473

- 109.6509 0.096 35 81.20 Active

10 Glenbar Gin, Inc. 32.9839

- 109.8567 0.000 0.012 0.02 Active

11 Level 3

Communications 32.8351

- 109.7081 N/A N/A 0.21 Terminated



### 12 Mt. Graham Regional

Medical Ce nter, Inc. 32.8228

- 109.7352 0.000 0.09 2.80 Terminated



### 13 Select Cleaners (2010) 32.8327

- 109.7161 0.000 0.001 0.16 Terminated



### 14 Tri County Materials

- Hot Mix Asphalt Plant 32.8021

- 109.7077 0.000 0.155 8.61 Active

15 USDOJ FCI

- Safford 32.7667

- 109 .7167 0.000 0.122 24.27 Terminated



### Total Emissions 0.104 38.05 167.38
Data Source: Arizona Department of Environmental Quality (ADEQ) and the 20 11 NEI Version 1 . Data verified by ADEQ Permits Section.

### 10

Figure 1 : Morenci S O 2 

### Maintenance Area with 50 Kilometer Buffer

### 11 

## 2

. MORENCI SO 2 

## MAINTENANCE AREA EMISSIONS INVENTORY FOR POINT, AREA AND MOBILE SOURCES FOR
THE BASE YEAR 20 11

Summary of Estimated Emissions

Table 7 provides a summary of both annual and daily emissions estim ates for the Morenci SO 2 

### Maintenance Area calculated from the previously identified source categories and each source categories’ relative contribution to total SO 2 

### emissions

.

Table 7 : Morenci SO 2 

### Maintenance Area

– 2011 Baselin e Emission Estimates

Source Category SO 2 

### Emissions (tons per year) Morenci

Maintenance
Area SO 2 

### Emissions * (tons per day) Percent of

total SO 2 

### Emissions in

Morenci

Maintenance

Area Greenlee County Morenci

Maintenance

Area

On

- Road Vehicle

Sources 0.58 0.33 0.00090 0. 06 %

Non

- Road Vehicle

Sources 0. 3 1 0. 0 8 0. 000 22 0.01%

Industrial ( p oint)

Sources ** N/A 48. 5 4 0. 1329 6 8. 44 %

Area ( non

- point )

Sources 3,949.93 525.94 1. 44094 91. 49 %

Total N/A 574. 8 9 1. 57502 100 .00 %

* Tons per Year/365

** The point sources were located within the Morenci SO 2 Maintenance Area.



## 3

. PROJECTED SO 2 

## EMISSIONS INVENTORY FOR POINT,
AREA AND MOBILE SOURCES THROUGH 20 30

Projecting future SO 2 

### emissions requires taking into account economic growth, emissions control

measures, capital turnover, fuel switching, technological change, and other activities of impact

mak i ng a ccurate projections of SO 2 

### emissions difficult to forecast. Therefore, conservative forecasting of SO 2 

### emissions is necessary to e nsure future compliance with N ational Ambient Air Quality Standards (NAAQS ).

ADEQ performed conservative forecasts of SO 2 

### emissions from 2011 to 2030 through the utilization of point source facility PTE values (held constant), in place of actual emissions. The areas of the inventory w hich could be reasonably associated with population growth are Area ( non

point ) Sources excluding fires, On

- Road Mobile Vehicle Sources (through the use of MOVES),

### 12 and Non

- Road Mobile Vehicle Sources. The emissions from these source categories were grown

f or future years based on the population projected growth factor shown in Table 8. Point source emissions (PTE), wildfire and prescribed fire emissions within the Morenci SO 2 

### Maintenance Area and the 50 km buffer (Table 5 and 6) are assumed to remain const ant through 2030. From Table 9 it can be seen that from 2015 to 2030, the tons per year of SO 2 

### increased by only 0.04 tons. This small change is due mainly to the small increase in population (2.2%) over the same period and the assumption that emissions fr om fires and the two industrial point sources did not change.

Table 8 : Morenci SO 2 

### Maintenance Area 2011

– 2030 Population Projection

Morenci SO 2 Maintenance Area Population Projection
Source Category 2011 2015 2020 2025 2030

Period 2011

- 2015 2016

- 2020 2021

- 2025 2026

- 2030



### Morenci CDP 1,482 1,489 1,500 1,508 1,512

Clifton 3,273 3,299 3,323 3,340 3,350

Morenci Maintenance

Area 4,755 4,788 4,823 4,848 4,862

Greenlee County 8,380 8,437 8,499 8,543 8,568 Population projected growth factor 0.68% 0.73% 0.53% 0.29%

Source: Arizona Department of Administration (ADOA) http://www.workforce.az.gov/population

- projections.aspx



### Onroad Emissions Projections

E PA considers on

- road emissions from the NEI as a more accurate emissions estimate than on

road emissions calculated using MOVES with the default database. Therefore , it was decided to run MOVES for 2011, 2015, 2020, 2025, and 2030 using the national defau lt database and ratio

the 2011 MOVES results to 2011 NEI Version 1

. The MOVES ratio (MR) is then applied to the 2015, 2020, 2025 and 2030 (default database) MOVES runs. See the following equations for

mathematical details.

MR 2011 

### = MOVES ratio = 2011 NEI Version 1 to 2011 MOVES SO 2 

### Ratio

= M 2011NEI 

### / M 2011RUN



### W here :

M 2011NEI 

### = Greenlee County Onroad Mobile emissions as determined from the

2011 NEI Version 1 = 0.58 tons/yr

.

M 2011RUN 

### = Greenlee County Onroad Mobile emissions as determined by running MO VES using

the 2011 national default database = 0.88 tons/yr

.

MR 2011 

### = MOVES ratio = 0.58 tons/yr. / 0.88 tons/yr. = 0.657

### 13

Once the NEI to MOVES national default ratio is determined, that ratio can then be applied to subsequent year MOVES national defau lt runs to estimate emissions for Greenlee County. An example calculation is provided below.

OR GC 2015 

### = On

- road emissions (Greenlee County) 2015 = M 2015 RUN 

### x M R 2011 

### ratio = 0.81 tons/yr. x 0.657 = 0.53 tons/yr.

Once the Greenlee County emissions are c alculated, those emissions can then be allocated to the Morenci Maintenance Area by using the same population adjustment ratio (0.5674) that was calculated as shown in Section 1.2.1. An example calculation for determining onroad emissions

for the Morenci Maintenance Area for 2015 is provided below.

OR MMA2015 

### = On

- road emissions (Morenci Maintenance Area) 2015 =

OR GC 2015 

### x Population ratio Morenci Maintenance Ar ea to Greenlee County = 0.53 x 0.567 4 = 0.30 tons/yr.



### 3. 1 Summary of Emissions Projections for 2011

– 2030

This TSD describes the methodologies utilized in developing updated emission inventories for the Morenci SO2 Maintenance area. A baseline emission inventory was developed for the year 2011 and serves as a base for projecting emissions th rough 2030. The p rojection of the Emission

Inve ntory from 2011 to 20 30 was performed by increasing portions or the entirety of each category: On

- road Vehicle Emissions, Non

- road Vehicle Emissions, and Area ( non

- point )

emissions . Both non

- road and area sou rce emissions were grown using the p opulation projected growth factor s shown in Table 8. The resultant emissions are shown in Table 9

. Between 2011 and 2030, emissions are shown to have potentially increased by 6.8% compared to 2011 emissions. The majorit y of this increase is attributed to growth in emissions from permitted point sources due to the use of PTE for future years compared to actual emissions from the baseline year.

### 14

Table 9 : Morenci SO2 Maintenance Area 2011

– 2030 Projected Emission Estimates

Morenci Maintenance Area SO 2 Emissions (tons per year)

Source Category 2011 2015 2020 2025 2030 Projection

Method

On

- Road Vehicle Sources 0.33 0.30 0.30 0.31 0.33 MOVES

Non

- Road Vehicle Sources (Locomotives) 0.0 5 0.05 0.05 0 .05 0.05 Population

Non

- Road Vehicle Sources (Other) 0.03 0.03 0.03 0.03 0.03 Population

Industrial (point) Sources 48.54 87.60 87.60 87.60 87.60 No change Area (non

- point) Sources (Fires) 525.67 525.67 525.67 525.67 525.67 No change

Area (non

- point) S ources (Other) 0. 27 0. 27 0.27 0. 28 0. 28 Population

Total 574.89 613.92 613.92 613.94 613.96

### 15 

## 4

. R EFERENCES

2011NEI: National Emission Inventory (NEI)

, 20 11 Arizona and New Mexico Emission Report http://www.epa.gov/ttnchie1/net/2011inventory.html

Air Quality Division, Arizona Department of Environmental Quality : “ MORENCI SULFUR

DIOXIDE NONATTAINMENT AREA STATE IMPLEMENTATION AND MAINTENANCE

PLAN ”, June 2002

2011 A DOA: http://www.azstats.gov/population

- estimates.aspx

, 2013

- 2050 SUB

- COUNTY

POPULATION PROJECTIONS

, “Greenlee .xls x”

2002Morenci: “ MORENCI SULFUR DIOXIDE NONATTAINMENT AREA STATE

IMPLEMENTA TION AND MAINTENANCE PLAN ”, June 2002

### Page Intentionally Left Blank

### Appendix D

Morenci Modeling Analysis

### Page Intentionally Left Blank

# Modeling

Analysis

Maintenance Plan

for the Morenci

Sulfur Dioxide Planning Area (1971 NAAQS)

Arizona Department of Environmental Quality

### Modeling Analysis

1.0 Overview of Modeling Approach

The standard EPA screening dispersion model, AERSCREEN (ve rsion 11126) was used to estimate the impact of SO 2 

### sources in or near the Morenci nonattainment area. AERSCREEN is the screening version of AERMOD, the EPA’s preferred model for

near

- field dispersion. AERSCREEN generates estimates of “worst

- case” 1

- hour concentrations for a single source, without the need for hourly meteorological data, and
also includes conversion factors to estimate “worst

- case” 3

- hour, 8

- hour, 24

- h o ur, and

annual concentrations. AERSCREEN is intended to produce concentration estimate s that are equal to or greater than the estimates produced by AERMOD with a fully developed set of meteorological and terrain data. According to the EPA’s memorandum dated April 11, 2011, AERSCREEN has replaced SCREEN3 as the recommended screening model.

The AERSCREEN model consists of two main components: 1) the MAKEMET program; and 2) the AERSCREEN command

- prompt interface program

. The MAKEMET program generates application

- specific worst

- case meteorology using representative ambient air temperatures, m inimum wind speed, and site

- specific surface characteristics (albedo, Bowen ratio, and surface roughness). The AERSCREEN

program interfaces with AERMAP (terrain processor in AERMOD) and BPIPPRM (building downwash tool in AERMOD) to process terrain and bui lding information respectively, and interfaces with the AERMOD model utilizing the SCREEN option to perform the modeling runs.

Based on the emission inventories as shown in 3.0

, the two largest sources in and within

50 kilometers of the Morenci nonattai nment area were modeled. The sources modeled

were the Freeport

- McMoRan Morenci Mine (FMMM) with a PTE of 88 tons/year and the Freeport

- McMoR an Safford Mine (FMSM) with a PTE of 81 tons/year. No other point sources were modeled because of their low or neg ligible emissions

. The emission

in ventory represented in 3.2 lists several S02 sources within the 50K buffer with PTE

above 5 TPY

. Closer inspection of the individual point sources indicates many are emergency generators with actual emission less that 1 TY P and therefore considered negligible to this exercise

. The modeling analysis included the following major steps:

 Collected SO 2 

### sour ce information including emission rates , locations, and release parameters by reviewing the FMMM’s Title V permit and the FMSM’s Class II permit.

 Determined representa tive minimum ambient temperature, maximum ambient
temperatures, and minimum wind speed by reviewing the meteorological data

collected from the Morenci/Safford area

. Ran AERSURFACE to generate site

specific sur face characteristics (albedo, Bowen ratio, and surf ace roughness). Ran

MAKEMET to generate site

- specific worst

- case meteorology.

 Downloaded the USGS Digital Elevation Model (DEM) data

. R an the AERMAP terrain processor to take the terrain features into account.

###  Modeled FMMM and FMSM separately

. Representative background concentrations were added to modeled impacts and the total concentrations w ere then compared to the NAAQS.

 Estimated the cumulative impacts of the tw o facilities on the Morenci

nonatta inment area.

2 .0 Modeling for Freeport

- McMoRan Morenci Mine (FMMM)

2.1 Source Inputs

All SO 2 

### sources along with their maximum allowable emissions are listed in Table 1. Blasting is the dominant source in FMMM, as the emission from blasting activiti es account for 99 percent of the total facility emission

. Other emission sources include SO 2 

### tanks, small industrial boilers, and steam boiler and turbine units. The total maximum

allowable emission for these small source s is less than 1 ton/year

. Tabl e 2 summarizes stack release parameters for SO 2 

### sources

. Since Units 1

- 2 gas turbines and boilers have comparable release parameters, these four sources were combined together and modeled

as a single point source. Similarly, SO 2 

### tanks and small industri al boilers were combined together and modeled as another single point source.

Table 2. 1 SO 2 

### S ources in the FMMM facility

Operations Emission rate (tons/y ear) Note Blasting 86.75

SO2 Tank #1 0.01

SO2 Tank #2 0.01 Unit 1 gas turbine 0.33

Unit 1+Unit 2 gas turbine <=0.33
Unit 1+Unit 2 boiler <=0.13 Unit 1 boiler 0.13 Unit 2 gas turbine 0.33

Unit 2 boiler 0.13

Small Industrial Boiler #1 0.13

Boiler#1+#2+#3+#4+#5 <=0.33 Small Industrial Boiler #2 0.13

Small Industrial Boiler #3 0.13

Small Industrial Boiler #4 0.13

Small Industrial Boiler #5 0.13 Natural gas start up boiler 0.02



### Table 2. 2 Stack Release Parameters for SO 2 

### Sources

Operations Stack height (m) Stack diameter

(m) Exit velocity

(m/s) Exit gas

temper a ture (K)

Blas ting N/A N/A N/A N/A Unit 1 gas turbine 24.4 2.1 19.8 310.9

Unit 1 boiler 21.3 2.4 19.8 310.9 Unit 2 gas turbine 24.4 2.1 19.8 310.9

Unit 2 boiler 21.3 2.4 19.8 310.9

Small Industrial Boiler #1 10.1 7.3 11.6 419.3

Small Industrial Boiler #2 10.1 7 .3 11.6 419.3Small Industrial Boiler #3 10.1 7.3 11.6 419.3

Small Industrial Boiler #4 10.1 7.3 11.6 419.3

Small Industrial Boiler #5 10.1 7.3 11.6 419.3 Natural gas start up boiler N/A N/A N/A N/A

SO2 Tank #1 N/A N/A N/A N/A

SO2 Tank #2 N/A N/A N/ A N/A



### 2.2 Modeling Blasting O perations

Blasting operations generate instantaneous emissions of gaseous pollutants including

SO 2



### . Historically, ADEQ has used the Open burn/Open Detonation Model (OBODM), developed by Strategic Environmental Research and Development Program (SERDP), to assess impacts from blasting sources. H owever, upon the review of the OBODM technical documents, it was found that that the OBODM model may not be appropriate for the screening modeling purposes. As the buoyant rise of a plume from a detonation in

OBODM strongly depends on the quantity of material detonated, modeling the blasting operations as a single volume source may result in an extremely high plume rise and thus significantly underestimate the ground level impact. An extreme case occurs when the calculated plume height for the imaginary source is far above the top of the surface mixing layer, leading to a zero ground level concentration. This is because OBODM assumes the concentration contribution from the plume mate rial that resides above the top of the surface layer can be neglected

. Based on the discussions above, the OBODM

model was not used in this modeling analysis. Instead, AERSCREEN was used to conservatively estimate the impacts from the blasting operation s.

Blasting operations vary spatially over the mining area. For screening modeling purposes, the blasting activities were assumed to be limited to a 200 by 200

- meter area
and were modeled a single volume source. Furthermore, a vertical dimension of 30

- meter was assum ed to represent a conservative estimate of the averaging vertical

dimension of a typi cal blast release

. To model a volume source, three parameters including the release height, the initial lateral dimension ( σ yo 

### ), and the initial vertical dimension ( σ z o 

### ) of initial plume must be defined. According to USER’S GUIDE FOR

THE AMS/EPA REGULATORY MODEL

– AERMOD, EPA 2004a , the initial lateral dimension ( σ yo 

### ) and the initial vertical dimension ( σ z o 

### ) were estimated by the following equations:

σ yo 

### = horizontal dimension of source divided by 4.3 = 200/4.3 = 46.51 meters (Eq. 1)

σ zo 

### = vertical dimension of source divided by 2.15 = 30/2.15 = 13.95 meters (Eq.2)

The rele ase height was determined as 15 meter s
, the height of the center of the volume

source

.

3 .0 Meteorological Data

Minimum Wind S peed

### One of the key meteorological parameters for the AERSCREEN inputs is the minimum

wind speed

. The default minimum wind speed in AERSCREEN is 0.5 m/s. However,

th is number may be over conservative for modeling 24

- hour average SO 2 

### impacts because a wind speed of 0.5 m/s for continuous 24

- hours will represent unrealistic wind

conditions in the area of concern

. Therefore, the available meteorological data in the

Saff ord/Morenci area were reviewed and the site

- specific minimum wind speed was

determined.

Three meteorological data sets are available in the Safford/Morenci area :

 ASOS at the Safford Regional Airport (SAD) station : The SAD station was

installed in 1997 and the first available meteorological data set was available in

1998. Currently ADEQ has four

- year AERMET pre

- processed meteorological

data sets for SAD (2001

- 2004). As shown in Figure 1, 8. 2 percent of the hourly wind speeds fell below 1.5 m/s and 5. 7 percent of the data was missing

. For wind speed observations less than 1.5 m/s, th e SAD data sets report them as zero ( hourly “calm” observations)

. Dispersion under calm or missing wind conditions

is not modeled in AERMOD.

 Safford AZMET station: The Arizona Meteorological Network (AZMET) began full operation in January of 1986 with the mission to provide meteorological data

and weather

- based information for agricultural and horticultural interests operating in southern and central Arizona

. The Saffo rd AZMET data are the most complete data sets available in the Safford area

. However, the issue with the AZMET data is that the anemometer height is 10 feet, not 10 meters. Moreover,

since this station is located in a flat lower agricultural area , the S aff ord AZME T wind data may not represent the wind speeds in a mountainous area where

FMMM and FMSM are located.

 Freeport

- McMoRan Safford Mine (FMSM ) station: As part of the permitting effort, FMSM began collecting meteorological data at the project sit e in Octo ber

1993

. The most complete one

- year period of on

- site data is from November 8, 1995 to November 7, 1996. These data have been reviewed and approved by ADEQ for the NAA QS modeling demonstration

. As shown in Figure 1, 4.7
percent of the observat ions are calm (0 m/s) and 6.8 percent of the observations

lie in the range from 0 m/s to 1.5 m/s.

As presented above, a small percentage of hourly wind speeds in the Safford/Morenci

area are below 1.5 m/s

. Moreover, in the Morenci maintenance plan renew al, the averaging time being assessed is 24

- hours and annual rather than 1

- hour

. Therefore, a wind speed of 1.5 m/s was used for the AERSCREEN modeling

. It is believed that this wind speed should provide a reasonable but still conservative estimation fo r modeling 24

- hour average and annual impacts.

### Figure 3.1 Hourly Wind Speed from Safford Regional Airport and FMSM Station s

### Land Use Analysis

When applying the MAKEMET program to prepare the meteorologic al data for AERSCREEN, the values for three surface characteristics including surface roughness, albedo, and Bowen ratio must be determi ned. The surface roughness relates the height of obstacles to the wind flow and is, in principle, the height at which t he mean horizontal wind speed is zero. The surface roughness length influences the surface shear stress and is an important factor in determining the magnitude of mechanical turbulence and the stability of the boundary layer. The albedo is the fraction o f total incident solar radiation reflected by the surface ba ck to space without absorption. The daytime Bowen ratio, an indicator of surface moisture, is the ratio of sensible heat flux to latent heat flux and is used for determining planetary boundary la yer parameters for convective conditions driven by the surface sensible heat flux.

Estimates of the surface characteristics were made wit h 1 km of an imaginary FMMM blasting site using EPA’s AERSURFACE program. Surface characteristics were developed bas ed upon twelve sectors by season

. The detailed setup is shown below.

Land Cover input file opened: arizona_NLCD_090600_erd.tif

AERMET

- formatted output file opened: morenci_surface Type of Coordinates Entered: LATLON Latitude (decimal degrees): 33.110000 Longitude (decimal degrees):

- 109.390000
Datum: NAD83 Study Radius for surface roughness (km): 1.0 Is surface roughness varied by sector? Y
# Sectors = 12 Sector beginning directions: 0 30 60 90 120 150 180 210 240 270 300 330 Temporal resolution (ANNUAL, MONTHLY, SEASONAL): SEASONAL
Continuous snow cover for most of the winter? N Is site located at an airport? N Is site considered an arid region? Y Characterization of surface moisture at site: Average Log file opened: morenci_surface.log



### 4 .0 Receptors

Based on the scaled FMMM facility map, the minimum distance to ambient air was

determined as 1 km. This is the shortest distance from the potential blasting areas to the FMMM property boundary. The probe dista nce was set to 10 km. Two receptor spacing

values were used: 25

- m from 1 km to 5 km; and 50

- m from 5 km to 10 km.

4 .1 Terrain Data

Given the complex topography of the Morenci nearby area, the terrain features were

taken into consideration in the mode ling analysis. USGS 1/3 arc

- second (

~ 10m

resolution ) DEM data were used to extract the elevations of receptors and sources.

All AERSCREEN model inputs are summarized in Table 3

.

### Table 4.1 Inputs for Modeling FMMM Blasting Operations

Parameters In puts Input values
Source Source type Volume

Source emission rate 2.5 g/s

Initial lateral dimension 46.50 m

Initial vertical dimension 13.95 m Volume height 15 m Building Include building downwash No Meteorology Minimum temperature 272 k

Maximum temperature 311 k Minimum wind speed 1.5 m/s Anemometer height 10 m
Source of surface characteristics AERSURFACE

Terrain Include terrain Yes

Coordinate type Latitude and longitude
Source latitude 33.11 ̊ Source longitude

- 109.39 ̊

NAD 83

Initial Probe distance 10000 m
Source elevation 1700 m Override input elevation with AERMAP derived value No Other Inputs Rural/Urban Rural

Minimum ambient distance 1000 m Use flagpole receptors N o Use discrete receptors No



### 4 .2 Background Concentration

Other than the FMMM facility itself, there are no other major sour ces of gaseous pollutants in this area. Consequently, background concentrations for the NAAQS modeling analysis should repr esent “natural” background concentrations

. The historical

SO 2 

### monitoring data from San Manuel, Pinal County and Page, Coconino County were

taken to determine the “natural” background concentrations (Table 4). The San Manuel

data for Years 2005

- 2007 were collected after the closure of the San Manuel copper

smelter and thus may represent the “natural” background concentrations for rural areas

. The Page data also have been used by ADEQ as the recommended SO 2 

### background

concentrations for rural areas if th e actual measurements are not available

. The background concentrations for 24

- hour and annual SO 2 

### were calculated by averaging the

maximum measurements over the 3

- years of available data from the two monitors. T his

results in a 24

- hour background concen tration of 20 μg/m 3 

### and an annual background

concentration of 5 μg/m 3 

### , respectively

.

Table 4 .3 Background Concentrations for 24

- hour and Annual SO 2Monitor ing Station Year Maximum 24

- hour

a verage conc. (μg/m 3 ) Annual conc. (μg/m 3 )

San Manuel, Pin al County 2007 10 6

2006 17 5

2005 8 5

Page, Coconino County 1998 24 4

1999 17 2

2000 7 1 Background 20 5



### 5.0 Results

The modeling r esults for FMMM are summarized in Table 5

. As shown in Table 5 , these

sources will not cause SO 2 

### NAAQS ex ceedances in the Morenci nonattainment area

. Blasting is the dominant contributor to the modeled SO 2 

### impacts while the impacts from

other sources are nearly negligible . Since blasting was modeled as a surface

- based volume source, t he modeled maximum conc entrations occurred in or near the property boundary of FMMM.

Table 5 .1 Modeling Results for FMMM

Source Average Modeled

conc. (μg/m 3 ) Facility

wide

modeled

conc. (μg/m 3 ) Background

conc. (μg/m 3 ) Total

conc. (μg/m 3 ) NAAQS

(μg/m 3 ) %

Standard

Blasting

24

- hour 150.6

151.5 20 171.5 365 47% Units 1

- 2

turbine/boiler 0.74

Other sources 0.17 Blasting

Annual 25.1

25.3 5 30.3 80 38% Units 1

- 2

turbine/boiler 0.12

Other sources 0.03

### 5.1 Model ing for Freeport

- McMoRan Saf ford Mine (FMS M)

Freeport

- McMoRan Safford Mine (FMSM) is located approximately 13 km north

northeast of Safford, Graham County. Construction of the facility began in 2006 and the operations consist of open

- pit mining, metallic minerals crushing, heap lea ch, solution extraction/electrowining (SE/EW) , and sulfur burning & acid production.

Table 6 lists all FMSM SO 2 

### sources along with their maximum allowable emissions and related release parameters. There are two major sources within the FMSM facility, o ne is blasting and the other is sulfur burning & acid production. The combined emissions from the two sources account for approximately 97 percent of the total facility emission. Other

emission sources include small industrial generat ors, heaters, boiler s , and firewater pump.

T he total maxi mum allowable emission for these minor sources is only 1.6 ton s /year,

Table 5.2 SO 2 

### Sources in the FMS M facility

The modeling methodology for the blasting source in FMSM was identical to th at of FMMM with one exception, different size of the blasting area. As FMSM is much smaller than FMMM, the blasting area in FMSM was assumed to be 100 by 100 meter s. The sulfur burning & acid production plant was modeled as a point source. Other mino r sources were combined together and modeled as a single point sou rce. Based on the scaled facility map of FMSM

, the minimum distance to ambient air for blasting, sulfur burning& acid production , and other minor sources was determined as 1 km, 2.4 km, and 2.4 km, respectively.

The m inimum temperature, the maximum ambient temperature

, and the minimum wind speed used were identical to those previously presented in the FMMM modeling

. A
separate AERSURFACE run was conducted to calculate site

- specific surfac e characteristics when modeling blasting and the sulfur burning& acid production individually.

All model inputs for blasting and sulfur burning & acid production are summarized in

Table 7 and Table 8 , respectively.

Operations Emission rate (tons/year) Stack

height (m) Stack
diameter (m) Exit

velocity (m/s) Exit gas

temp. (k) Blasting 31.03 N/A N/A N/A N/A Sulfur Burning & Acid Production 48.4 38.1 1.07 29.25 302.6

Generators #1 0.05 6.1 0.30 103.75 645.4

Generator #2 0.0117 6.1 0.30 103.75 645.4 Firewater Pump #1 0.0099 6.1 0.15 24.63 804.3 Firewater Pump #2 0 .019 6.1 0.15 24.63 804.3 Sulphur pre

- heater 1.13 12.2 0.91 13.65 783.2 Sulphur Furnace Startup Boiler 0.38 7.0 0.30 10.88 505.0

Hot Water Heater 0.015 6.1 0.30 13.78 455.4

### Table 5.3 Inputs for Modeling FMSM B lasting Operations

Parameters Inputs Input values
Source Source type Volume

Source emission rate 0.892 g/s

Initial lateral dimension 23.26 m

Initial vertical dimension 13.95 m Volume height 15 m Building Include building downwash No

Meteoro logy Minimum temperature 272 k

Maximum temperature 311 k Minimum wind speed 1.5 m/s Anemometer height 10 m
Source of surface characteristics AERSURFACE

Terrain Include terrain Yes

Coordinate type Latitude and longitude
Source latitude 32 .96 ̊ Source longitude

- 109.67 ̊

NAD 83

Initial Probe distance 10000 m
Source elevation 1230 m Override input elevation with AERMAP derived value No Other Inputs Rural/Urban Rural

Minimum ambient distance 1000 m Use flagpole receptors No Use discrete receptors No



### Table 5.4 Inputs for Modeling FMSM Sulfur Burning & Acid Production

Parameters Inputs Input values
Source Source type Point

Source emission rate 1.3923 g/s Stack height 38.10 m
Stack inner diameter 1.07 m

Exit gas velocity 29.25 m/s Exit gas temperature 302.6 k Building Include building downwash No Meteorology Minimum temperature 272 k

Maximum temperature 311 k Minimum wind speed 1.5 m/s Anemometer height 10 m
Source of surface characteristics A ERSURFACE

Terrain Include terrain Yes

Coordinate type Latitude and longitude
Source latitude 32.93  ̊ Source longitude

- 109.705  ̊

NAD 83

Initial Probe distance 10000 m
Source elevation 1230 m Override input elevation with AERMAP derived va lue No Other Inputs Rural/Urban Rural

Minimum ambient distance 2400 m Use flagpole receptors No Use discrete receptors No

### AERSCREEN was ru n to model each source (blasting, sulfur burning & acid production,

and other sources) separately and th en the maximum impacts from eac h model run were summed up to determine an overall impact from FMSM (regardless of different impact locations at different times)

. The modeling results for FMSM are summarized in Table 9

. As shown in Table 9, the sources i n FMSM will not cause SO 2 

### NAAQS exceedances

. The modeled impact from the blasting source was higher than that from the su lfur burning & acid production, mainly due to a relative lower release height.

Table 5.5 Modeling Results for FMSM

Source Avera ge Modeled

conc. (μg/m 3 ) Facility

wide

modeled

conc. (μg/m 3 ) Background

conc. (μg/m 3 ) Total

conc. (μg/m 3 ) NAAQS

(μg/m 3 ) %

Standard

Blasting

24

- hour 66.9

112.5 20 132.5 365 36% Sulfur burning & acid production 44.6

Other sources 0.97

Bla sting

Annual 11.2

18.8 5 23.8 80 30% Sulfur burning & acid production 7.4

Other sources 0.16



### 6.0 Cumulative Impact Discussion

6. 1 Cumulative Impacts of FMMM and FMSM on the Morenci Nonattainment Area

Figure 2 shows the locations of the F reeport

- McMoRan Morenci Mine (FMMM) and Freeport

- McMoRan Safford Mine (FMSM) relative to the Morenci Nonattainment area

. FMMM is located within the nonattainment area while FMSM is about 20 km outside of the nonattainment area. As presented in Section 4.2 , the maximum 24

- hour average and annual average impacts of FMMM on the Morenci Nonattainment area were 151.5 μg/m 3


### and 25.3 μg/m 3 

### respectively, which occurred in or near the property boundary of FMMM

. To estimate the cumulative impacts, the impacts of FMSM on the nonattainm ent area
must be determined

.

In the AERSCREEN model run, a probe distance (10 km) was used, thus allowing the

calculation of t he maximum concentration for a given distance less than or equal to 10

km. The results are shown in Fi gure 3

. As indicated in Figure 3 , the modeled concentration dropped rapidly with the increasing of the distance

. For the receptors that

were located at 10 km away from either facility, the maximum modeled 24

- hour

concentration was less than 20 μg/m 3



### . Since the shortest distance from FMSM to the nonattainment area is around 20 km, the impacts of FMSM to the nonattainment area

should be far below 20 μg/m 3 

### . As the ratio of the 24

- hour average concentration to the annual average concentration in AERSCREEN is fixed at 6.0, the annual impact of

FMSM on the nonattainment area should be much lower than 3.3 μg/m 3



### . Furthermore, as

the distance between FMSM and FMMM is around 30 km, the impact s of FMSM on the

### FMMM surrounding area are expected to be insignifican t

. In other words, the impacts

from FMMM itself dominate the cumulative impacts on the Morenci non

- attainment area.

Figure 6.1 Locations of FMSM and FMMM relative to the Morenci Nonattainment

Area

To be conservative, it was assumed that the maximum 24

- hour average and annual average impacts of FMSM on the Morenci Nonattainment area were 20 μg/m 3 

### and 3.3 μg/ m 3



### , respectively. Based on this conservative assumption, the cumulative impacts of

FMMM and FMSM on the Morenci nona ttainment area were estimated and the results

are summarized in Table 10 . The cumulative impacts were 53 percent and 42 percent of

the 24

- hour and annual NAAQS, respectively.

FMSM FMM M

### Figure 6.2 Modeled Maximum 24

- hour Concentration vs. D istance from Facilities to

Receptors

Table 6.1 Cumulative Impacts of FMMM and FMSM on the Morenci

Nonattainment Area

Facility Average Max. impact on

Morenci non

attainment area (μg/m 3 ) Total

modeled

conc. Background

conc. (μg /m 3 ) Total

conc. (μg/m 3 ) NAAQS

(μg/m 3 ) %

Standard

FMMM 24

- hour 151.5 171.5 20 191.5 365 53 % FMSM 20

FMMM Annual 25.3 28.6 5 33.6 80 42 % FMSM 3.3



### 6.2 Cumulative Impacts on the Morenci Nonattainment Area Boundary

As shown in Figure 2, the shortest distance from the FMMM modeled source (blasting) to the Morenci nonattainment area boundary is around 10 km. Therefore, the maximum

modeled 24

- hour impact of FMMM on the boundary was 20 μg/m 3 

### (see Figure 3). By using the fixed conversion rat io of 6.0 in AERSCREEN, the annual impact of FMMM on the boundary was estimated as 3.3 μg/m 3 

### . In combination with the impacts from FMSM as discussed in Section 4.4.1, the overall impacts for 24

- hour average and annual average were 16 percent and 15 percen t of the NAAQS, respectively (Table 11).

Table 6.2 Cumulative Impacts of FMMM and FMSM on the Morenci

Nonattainment Area Boundary

Facility Average Max. impact on

Morenci non

attainment area boundary (μg/m 3 ) Total

modeled

conc. Background

conc. (μg /m 3 ) Total

conc. (μg/m 3 ) NAAQS

(μg/m 3 ) %

Standard

FMMM 24

- hour 20 40 20 60 365 16 % FMSM 20

FMMM Annual 3.3 6.6 5 11.6 80 15 % FMSM 3.3

### 7.0 Update of Modeling Analysis

The modeling analysis as presented in Sections 4.1

- 4.4 was conducted in Year 2012. It is necessary to verify if the previous modeling analysis is still valid because any significant changes in source inputs or modeling methodologies since Year 2012 may lead to significant changes in

the model results.

ADE Q issued a renewal permit to FMSM and FMMM in February 2012 and October 2013, respectively

. Table 12 summarizes the potential to emit (PTE) of SO 2 for FMSM and FMMM based on the two renewal permits. As shown in Table 12, there is no any change in SO 2 emission

limits for the two facilities.

Table 7.1 Emissions of SO 2 for FMMM and FMSM in Renewal Permits

Facility PTE in renewal permits (tpy) Modeled Emission (tpy)

Point Fugitive Total Point Fugitive Total

FMMM 0.8 86.8 87.6 0.78 86 .75 87.5

FMSM 50 31 81 50.02 31.03 81.05

The 2012 modeling analysis used AERSCREEN version 11126, which is still the most recent version of AERSCREEN (no updates). However, the AERSURFACE version (version 08009) used in the 2012 analysis has been upda ted to the new version 13016

. A test run indicates that the two versions generated identical surface characteristic parameters.

Another issue is related to the terrain data. The 2012 analysis used the Digital Elevation Model (DEM) data, which are n o longer updated by the USGS. Instead, National Elevation Dataset (NED) data are being actively supported and checked for quality. Therefore, NED represents a

more up

- to

- date and improved resource for terrain elevations for regulatory modeling purposes

. In order to address this issue, a test run was performed to compare modeled concentrations from the FMMM’s blasting emissions by using the DEM data vs. the NED data

. The results show that

the modeled concentrations based on the DEM data and the NED data are nearly identical (150.6 μg/m 3 vs. 150.2 μg/m 3 for 24

- hour SO 2 ).

Based on the discussions above, it is concluded that the 2012 modeling analysis is still valid and no updates are needed.

### Appendix E.1

Notice of Public Hearing

### Page Intentionally Left Blank

### Page Intentionally Left Blank

### Appendix E.2

Public Hearing Agenda

### Page Intentionally Left BlankAIR QUALITY DIVISION

HEARING ON PROPOSED Arizona State Implementation Plan Revision Maintenance Plan for the Morenci Dioxide Planning Area (1971 NAAQS) Morenci Community Center 438 Plaza Drive Morenci, AZ 85540

15, December and 15, 2014, at 1:00 p.m.

Pursuant to 40 CFR § 51.102 notice is hereby given that the above referenced meeting is open to the public.

1. Welcome and Introductions

2. Purposes of the Oral Proceeding

3. Procedure for Making Public Comment

4. Brief Overview of the proposed SIP revision

5. Question and Answer Period

6. Oral Comment Period

7. Adjournment of Oral Proceeding

Copies of the proposal are available for review at the Arizona Department of Environmental Quality (ADEQ) Records Center, First Floor, 1110 W. Washington St., Phoenix, Arizona 85007, 1110 W. Washington St., Phoenix, Arizona, and 

### http://www.azdeq.gov/environ/air/plan/index.html and at Clifton Public Library located at 102 School St., Clifton AZ 85533

. For additional information regarding the hearing please call Adrian Peshlakai, ADEQ Air Quali ty Division, at (602) 771

- 6428 or 1

- 800

- 234

- 5677, Ext. 771

- 6428.

Upon request, the Department will provide appropriate auxiliary aids and services to persons with disabilities, at no charge, to assist in accessible communication to enable people who ha ve speech, hearing, vision, learning, or other impairments to participate equally, including qualified sign language interpreters. To request an auxiliary aid or service, to obtain this document in alternative format, or for further information, please con tact Alicia Pollard at (602) 771

- 4791 or via email at aap@azdeq.gov as early as possible to allow time to arrange the accommodation . TTY/TTD Services: 7

- 1

- 1. The ADA does not require the Department to take any action th at would fundamentally alter the nature of it programs, services or activities, or impose an undue financial or administration burden on the Department.

### Page Intentionally Left Blank

### Appendix E.3

Public Hearing Sign

- In Sheet

### Page Intentionally Left Blank

### Page Intentionally Left Blank

### Appendix E.4

Public Hearing Officer Certification and Transcript

### Page Intentionally Left Blank1



### PUBLIC HEARING ON THE PROPOSED ARIZONA STATE 1



### IMPLEMENTATION PLAN REVISION MAINTENANCE PLAN for the 2



### MORENCI SULFUR DIOXIDE PLANNING AREA (1971 NAAQS) 3

4



### Oral Proceeding 5



### December 1 5 , 2014 6

7



### Good afternoon , thank you for coming. I now open this hearing on the proposed A rizona State 8



### Implementation Pla n Revision Maintenance Plan for the Morenci Sulfur Dioxide Planning Area 9



### (1971 NAAQS)

. 10

11



### It is Monday

, December 1 5 , 2014; the time is 12:07. T he location is the Morenci Community 12



### Center at 438 Plaza Drive Morenci Arizona 85540. 13

14



### My name is Michael Orman

, and I have been appointed by the Director of the Arizona 15



### Department of Environmental Quality (ADEQ) to preside at this proceeding. 16

17



### The purposes of this proceedi ng are to provide the public an opportunity to: 18

19



### 1) h ear about the substance of the proposed SIP ; 20



### 2) a sk q uestions regarding the SIP ; and

, 21



### 3) p resent oral argument s , data

, and views regarding the SIP in the form of comments on the 22



### record. 232

24



### Adrian Peshlakai is here representing ADEQ from the Air Quality Division, State 25



### Implementation Plan Section

. 26

27



### Public notice appeared in the Copper Era and ADEQ’s website beginning November 1 2 , 2014

. 28



### Copies of the proposed SIP revision were mad e available at the ADEQ Records Center and 29



### ADEQ’s website and the Clifton, Arizona library beginning December 15 , 2014

. 30

31



### As the purpose of the public hearing is to receive public from the public and there are no 32



### members of the public present this hearing is adjourned the time is 12:08. 33

### Page Intentionally Left Blank

### Appendix E.5

Responsiveness Summary

### Page Intentionally Left Blank

### RESPONSIVENESS SUMMARY

to Testimony Taken at Oral Proceeding on the December, 2014 Proposed Arizona State Implementation Plan Revision

The oral proceeding on the December 2014, Proposed Arizona State Implementation Plan Revision, Maintenance Plan for the Morenci Sulfur Dioxide Planning Area (1971 NAAQS), was held on Monday December 15, 2014 at 1:00 p.m., at the Morenci Community Center lo cated at 438 Plaza Drive Morenci, AZ 85540. The Arizona Department of Environmental Quality (ADEQ) received no verbal or written comments on the proposed State Implementation Plan

Revision.

No changes were made in response to the public comments, however, during its final review of the proposed State Implementatio n Plan Revision, ADEQ made typographical corrections to
Table 1.4 and added insets in Figure 3.1 to clearly identify sources within the planning area

. Other minor revisions were ma de for clarit y, grammar and formatting.