DAQ-2024-011355

DAQE-AN103460063-24

{{$d1 }}

Matt Tobey
Rio Tinto Kennecott Utah Copper LLC
4700 Daybreak Parkway
South Jordan, UT 84009
[e-mail]

Dear Mr. Tobey:

Re: Approval Order: Administrative Amendment to Approval Order DAQE-AN103460062-23
Project Number: N103460063

The attached Approval Order (AO) is issued pursuant to the Notice of Intent (NOI) received on August
23, 2024. Rio Tinto Kennecott Utah Copper LLC must comply with the requirements of this AO, all
applicable state requirements (R307), and Federal Standards.

The project engineer for this action is Stockton Antczak, who can be contacted at [phone] or
[e-mail]. Future correspondence on this AO should include the engineer's name as well as the
DAQE number shown on the upper right-hand corner of this letter.

Sincerely,

{{$s }}

Bryce C. Bird
Director

BCB:SA:jg

cc: Salt Lake County Health Department
EPA Region 8

195 North 1950 West • Salt Lake City, UT
Mailing Address: P.O. Box 144820 • Salt Lake City, UT 84114-4820
Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.utah.gov
Printed on 100% recycled paper
State of Utah

SPENCER J. COX
Governor
DEIDRE HENDERSON
Lieutenant Governor

Department of
Environmental Quality

Kimberly D. Shelley
Executive Director

DIVISION OF AIR QUALITY
Bryce C. Bird
Director

October 29, 2024

STATE OF UTAH
Department of Environmental Quality
Division of Air Quality

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APPROVAL ORDER
DAQE-AN103460063-24
Administrative Amendment to Approval Order
DAQE-AN103460062-23

Prepared By
Stockton Antczak, Engineer
[phone]
[e-mail]

Issued to
Rio Tinto Kennecott Utah Copper LLC - Smelter & Refinery

Issued On
{{$d2 }}

Issued By

{{$s }}

Bryce C. Bird
Director
Division of Air Quality

October 29, 2024
TABLE OF CONTENTS

TITLE/SIGNATURE PAGE ....................................................................................................... 1
GENERAL INFORMATION ...................................................................................................... 3
CONTACT/LOCATION INFORMATION ............................................................................... 3
SOURCE INFORMATION ........................................................................................................ 3
General Description ................................................................................................................ 3
NSR Classification .................................................................................................................. 4
Source Classification .............................................................................................................. 4
Applicable Federal Standards ................................................................................................. 4
Project Description.................................................................................................................. 4
SUMMARY OF EMISSIONS .................................................................................................... 5
SECTION I: GENERAL PROVISIONS .................................................................................... 5
SECTION II: PERMITTED EQUIPMENT .............................................................................. 6
SECTION II: SPECIAL PROVISIONS ................................................................................... 10
PERMIT HISTORY ................................................................................................................... 25
ACRONYMS ............................................................................................................................... 26

DAQE-AN103460063-24
Page 3

GENERAL INFORMATION

CONTACT/LOCATION INFORMATION

Owner Name Source Name
Rio Tinto Kennecott Utah Copper LLC Rio Tinto Kennecott Utah Copper LLC - Smelter & Refinery

Mailing Address Physical Address
4700 Daybreak Parkway 12000 West 2100 South
South Jordan, UT 84009 Magna, UT 84044

Source Contact UTM Coordinates
Name: Jenny Esker 398,678 m Easting
Phone: [phone],508,860 m Northing
Email: [e-mail] Datum NAD83
UTM Zone 12
SIC code 3331 (Primary Smelting & Refining of Copper)

SOURCE INFORMATION
General Description
Rio Tinto Kennecott Utah Copper LLC (KUC) operates a copper smelter and refinery in Salt Lake
County, Utah. The smelter employs flash smelting technology with flash conversion technology to
produce copper anodes and high-concentration sulfur dioxide gases. The gases are treated by electrostatic
precipitators (ESP), baghouses, scrubbers, and a high-efficiency double-contact acid plant. The refinery
uses an electrolytic refining process to convert the Smelter-produced anode copper to cathode copper and
also recovers precious metals from the electrolytic refining slimes in a precious metals circuit.

The copper ore concentrates received at the smelter are first dewatered and then dried to reduce the
moisture content. The dried concentrate is then blended with fluxes and secondary copper-bearing
materials. This mixture is fed to a flash smelting furnace where the ore is melted and reacts to produce
copper matte, a molten solution of copper sulfide mixed with iron sulfide. The Outokumpu flash smelting
process used at the smelter is a closed process that captures the SO2-rich off-gases from the furnace for
the production of sulfuric acid. The copper matte from the smelting furnace is next converted to blister
copper (approximately 98% pure copper) by oxidization to remove the remaining sulfur as SO2 gas and
the iron as a ferrous oxide slag. The smelter uses a continuous copper conversion process in which solid
matte granules are fed to a flash smelting furnace-like vessel. The molten slag from converting is cooled,
processed in slag concentrators to remove residual copper, and ultimately disposed of in on-site waste
piles. The SO2 gases from smelting and converting are vented to a sulfuric acid plant. Molten blister
copper is transferred from the converting vessel to an anode furnace for fire refining to further remove
residual impurities and oxygen. The blister copper is reduced in the anode furnace to remove oxygen by
injecting natural gas, producing a high-purity copper. The molten copper from the anode furnace is
poured in molds to cast solid copper ingots called anodes.
DAQE-AN103460063-24
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The anode copper produced at the Smelter is moved to the copper Refinery co-located near the Smelter,
where it is further purified using an electrolytic process to obtain the high-purity cathode copper sold.

NSR Classification
Administrative Amendment

Source Classification
Located in Northern Wasatch Front O3 NAA, Salt Lake City UT PM2.5 NAA, Salt Lake County SO2
NAA
Salt Lake County
Airs Source Size: A

Applicable Federal Standards
NSPS (Part 60), A: General Provisions
NSPS (Part 60), Db: Standards of Performance for Industrial-Commercial-Institutional Steam
Generating Units
NSPS (Part 60), Dc: Standards of Performance for Small Industrial-Commercial-Institutional
Steam Generating Units
NSPS (Part 60), P: Standards of Performance for Primary Copper Smelters
NSPS (Part 60), OOO: Standards of Performance for Nonmetallic Mineral Processing Plants
NSPS (Part 60), IIII: Standards of Performance for Stationary Compression Ignition Internal
Combustion Engines
NSPS (Part 60), JJJJ: Standards of Performance for Stationary Spark Ignition Internal
Combustion Engines
NSPS (Part 60), KKKK: Standards of Performance for Stationary Combustion Turbines
MACT (Part 63), A: General Provisions
MACT (Part 63), ZZZZ: National Emissions Standards for Hazardous Air Pollutants for
Stationary Reciprocating Internal Combustion Engines
MACT (Part 63), EEEEEE: National Emission Standards for Hazardous Air Pollutants for
Primary Copper Smelting Area Sources
Title V (Part 70) Major Source

Project Description
KUC operates a copper smelter and refinery in Salt Lake County, Utah. KUC requested a modification to
AO DAQE-AN103460062-23 to include missing condition II.B.7.a, regarding opacity limits. This
condition was included in the engineering review but was somehow removed when the AO was issued.
This administrative amendment adds condition II.B.7.a back into the AO and makes no other changes.

DAQE-AN103460063-24
Page 5

SUMMARY OF EMISSIONS

The emissions listed below are an estimate of the total potential emissions from the source. Some
rounding of emissions is possible.

Criteria Pollutant Change (TPY) Total (TPY)
Ammonia 0 9.11
CO2 Equivalent 0 235522.00
Carbon Monoxide 0 168.97
Lead Compounds 0 6.00
Nitrogen Oxides 0 161.25
Particulate Matter - PM10 0 2016.07
Particulate Matter - PM2.5 0 1946.11
Sulfur Dioxide 0 1081.32
Volatile Organic Compounds 0 14.86

Hazardous Air Pollutant Change (lbs/yr) Total (lbs/yr)
Generic HAPs (CAS #GHAPS) 0 14960
Lead Compounds (CAS #LCT000) 0 12000
Change (TPY) Total (TPY)
Total HAPs 0 13.48

SECTION I: GENERAL PROVISIONS

I.1 All definitions, terms, abbreviations, and references used in this AO conform to those used in the UAC R307 and 40 CFR. Unless noted otherwise, references cited in these AO conditions refer to those rules. [R307-101]
I.2 The limits set forth in this AO shall not be exceeded without prior approval. [R307-401]
I.3 Modifications to the equipment or processes approved by this AO that could affect the emissions covered by this AO must be reviewed and approved. [R307-401-1]
I.4 All records referenced in this AO or in other applicable rules, which are required to be kept by
the owner/operator, shall be made available to the Director or Director's representative upon
request, and the records shall include the five-year period prior to the date of the request. Unless otherwise specified in this AO or in other applicable state and federal rules, records
shall be kept for a minimum of five years. [R307-401-8]
I.5 At all times, including periods of startup, shutdown, and malfunction, owners and operators shall, to the extent practicable, maintain and operate any equipment approved under this AO, including associated air pollution control equipment, in a manner consistent with good air pollution control practice for minimizing emissions. Determination of whether acceptable operating and maintenance procedures are being used will be based on information available to the Director which may include, but is not limited to, monitoring results, opacity observations, review of operating and maintenance procedures, and inspection of the source. All maintenance performed on equipment authorized by this AO shall be recorded. [R307-401-4]
I.6 The owner/operator shall comply with UAC R307-107. General Requirements: Breakdowns. [R307-107]

DAQE-AN103460063-24
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I.7 The owner/operator shall comply with UAC R307-150 Series. Emission Inventories. [R307-150] I.8 The owner/operator shall submit documentation of the status of construction or modification to the Director within 18 months from the date of this AO. This AO may become invalid if
construction is not commenced within 18 months from the date of this AO or if construction is discontinued for 18 months or more. To ensure proper credit when notifying the Director, send the documentation to the Director, attn.: NSR Section. [R307-401-18]

SECTION II: PERMITTED EQUIPMENT
II.A THE APPROVED EQUIPMENT
II.A.1 Rio Tinto Kennecott Utah Copper LLC Copper Smelter II.A.2 Filter Plant 1) Filter Plant Wet Feed Conveyor with baghouse (#SME 001, Stack No. 1) (Relocated and resized). 2) Filter Plant Wet Feed Conveyor Bin Vent (#SME 001-A) (NEW)
II.A.3 Feed and Reagent Storage Feed and reagent storage and transfer consisting of: 1) Wet Feed Storage building with baghouse (#SME 002) 2) Wet Feed Conveyor transfer point with baghouse (#SME 003) 3) Outside Wet Feed Hopper with partial enclosure (#SME 002-A) 4) Wet Feed Bins with baghouse (#SME 004) 5) Flash Smelting Furnace Dry Feed Bin with baghouse (#SME 005) 6) Smelter Limestone Flux Bin with bin vent baghouse (#SME 006) II.A.4 Feed and Reagent Storage (Continued) 7) Matte, dust, flux, feed bins with baghouse (#SME 013) 8) Mold Coating Silo with bin vent baghouse (#SME 015) 9) Hydrometallurgical Plant Limestone Silo with bin vent baghouse (#SME 019) 10) Hydrometallurgical Plant Lime Silo with bin vent baghouse (#SME 020) 11) Anode Area Lime Silo with bin vent baghouse (#SME 028) 12) Secondary Gas System Lime Silo with bin vent baghouse (#SME 029)
DAQE-AN103460063-24
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II.A.5 Feed and Reagent Storage (continued) 13) One Hopper 14) Two Storage Bins Control: Bin Vent (each) (vents inside the building) 15) Conveyers with water sprays
II.A.6 Pyrometallurgical Processes - Flash Smelting 1) Rotary Feed Dryer with baghouse followed by a scrubber (#SME 011e)
2) Flash Smelting Furnace (FSF) with (in series) (#SME 011b1)

a) Waste heat boiler
b) Electrostatic precipitator (ESP)
c) Scrubber served by wet ESP and acid plant

d) Emergency generator with turbocharger and aftercooling Maximum Rating: 998 hp

II.A.7 Pyrometallurgical Processes - FS (Continued) 3) Matte Granulation Process: North and South Matte Granulators (#SME 010a) each have a three-stage impingement scrubber equipped with demister pads that vent to the secondary gas system (vents to the main stack)
II.A.8 Pyrometallurgical Processes - Flash Converting
1) Matte Drying and Grinding Plant with baghouse (#SME 011g)

2) Flash Converting Furnace (FCF) with (in series) (#SME 011b2)
a) Waste heat boiler
b) ESP

c) Scrubber served by wet ESP and acid plant
3) Slag Granulation with three-stage impingement scrubber, emissions are either directed:

a) to the scrubber and then to the atmosphere through the vent stack; or

b) to the scrubber and then to the secondary gas system (#SME 010b)

II.A.9 Pyrometallurgical Processes - FCF/FSF 1) Co-Jet Technology Burner System (#SME 011b3) Quantity: 3 co-jet injectors Rating: 13 MMBtu/hr each Fuel: Natural gas/oxy-fuel
DAQE-AN103460063-24
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II.A.10 Pyrometallurgical Processes - Anodes Area 1) Anode furnace system consisting of: a) Anode Furnaces and optional coherent jet lances* with (in series)(#SME 011h1); (1) Quench tower (2) Lime injection (3) Baghouse (4) Two scrubbers in series *The lances are used for material heating and melting on a non-continuous basis. b) Wenmec twin casting wheel and quench tower (#SME 011h4); c) Shaft furnace (#SME 011h2) and holding furnace (#SME 011h3) with baghouse; d) Mold casting furnace (#SME MOLD) II.A.11 Product Recovery/Gas Cleaning Facilities
Product Recovery/Gas Cleaning Facilities that serve FSF and FCF.
1) Wet ESP

2) Acid Plant (#SME 011b) with:
a) Acid Plant Cooling Tower (#SME CT311);
b) Acid Plant Collection System (#SME GLCS) with adjustable negative
pressure ductwork and collection hoses placed as needed for opacity
control;
c) Acid Plant Preheater (#SME 008)

II.A.12 Product Recovery/Gas Cleaning (Continued) Product Recovery/Gas Cleaning Facilities that serve emission sources in the Hot Metals Building, Matte Granulators, or Slag Granulators as needed. 3) Secondary Gas Cleaning System (#SME 011a) with: a) Lime injection system; b) Baghouse; c) Reverse Jet scrubber A and Reverse Jet scrubber B
II.A.13 Intermediate Product Storage
Intermediate Product Storage, Crushing, and Grinding Operations.

1) Slag Concentrator (#SME SLAG)

2) Recycle Materials Crushing and Storage building with baghouse (#SME 027)

a) Furnace dust crusher system, 12 ton/hour capacity

DAQE-AN103460063-24
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II.A.14 Intermediate Product Storage (continued) 3) Crushing and Screening Operation (#SME SLAG) a) Jaw crusher: Maximum 600 ton/hour capacity b) Cone crusher: Maximum 600 ton/hour capacity c) Fines crusher: Maximum 600 ton/hour capacity d) Conveyors: Partially enclosed transfer points with water sprays e) Triple-deck screen f) High-frequency screens
II.A.15 Miscellaneous Support Equipment
1) Miscellaneous mobile diesel equipment

2) Small natural gas-fired space heaters and water heaters (#SME SH, WH)
3) Outdoor storage piles where concentrate, granulated matte, slag, and other process materials
are stored on pads (#SME STRG)
II.A.16 Smelter Powerhouse 1) Superheater with ultra-low NOx burners (#SME 011f) Rating: 45 MMBtu/hr Fuel: Natural gas Vents to main stack 2) Holman Boiler (#SME 026) Rating: 187 MMBtu/hr Fuel: Natural gas 3) Rentech Boiler (#SME 030) Rating: 183 MMBtu/hr Fuel: Natural gas 4) Powerhouse Cooling Tower (#SME CT316) 5) Two Diesel-Fired Emergency Generators (#SME GEN) Rating: 2,847 hp each
II.A.17 Hydrometallurgical Plant (#SME 011d)
Controls: Two scrubbers

II.A.18 Vacuum Cleaning Systems (#SME 017) 1) Matte handling vacuum cleaning system with baghouse 2) FSF vacuum cleaning system ducted to the secondary gas collection system 3) FCF vacuum cleaning system with baghouse
DAQE-AN103460063-24
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II.A.19 Support Facilities 1) Laboratories, with baghouse (#SME 022) 2) Various degreasing parts washers (#SMEi210) 3) Gasoline fueling station (#SME SA-1)
II.A.20 Support Facilities* (continued) 4) Wash rooms
5) Change house
6) Engineering shops
7) Warehouses
8) Administrative buildings

*These are listed for informational purposes only.
II.A.21 Communication Emergency Generator (#SME COM GEN) Maximum Rating: 75 hp Fuel: Liquid propane

SECTION II: SPECIAL PROVISIONS II.B REQUIREMENTS AND LIMITATIONS
II.B.1 Limitations and Test Procedures

II.B.1.a Emissions to the atmosphere from the indicated emission points* shall not exceed the following rates and concentrations: A. #SME 001 - Wet Feed Conveyor Baghouse (Stack No. 1) PM10 0.7 lbs/hr (filterable) 0.008 grains/dscf (68 degrees F, 29.92" Hg) B. #SME 002 - Wet Feed Storage Building Baghouse (Stack No. 2) PM10 3.91 lbs/hr (filterable) 0.008 grains/dscf (68 degrees F, 29.92" Hg) C. #SME 003 - Wet Feed Conveyor Transfer Point Baghouse (Stack No. 3) PM10 0.4 lbs/hr (filterable) 0.016 grains/dscf (68 degrees F, 29.92" Hg) D. #SME 004 - Wet Feed Bin Baghouse (Stack No. 4) PM10 3.4 lbs/hr (filterable) 0.016 grains/dscf (68 degrees F, 29.92" Hg) E. #SME 005 - Flash Smelting Furnace Dry Feed Bin Baghouse (Stack No. 5) PM10 1.2 lbs/hr (filterable) 0.016 grains/dscf (68 degrees F, 29.92" Hg)
DAQE-AN103460063-24
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F. #SME 006 - Smelter Limestone Flux Bin Baghouse (Stack No. 6) PM10 0.3 lbs/hr (filterable) 0.016 grains/dscf (68 degrees F, 29.92" Hg) G. #SME 010b - Slag Granulation Exhaust Scrubber (Stack No. 10b) PM10 1.9 lbs/hr (24 hr. average - calendar day) (filterable) SO2 2.0 lbs/hr (24 hr. average - calendar day) Operating Hours 3504 hrs per rolling 12-month period H. #SME 011 - Main Stack (Stack No. 11) PM10 89.5 lbs/hr (24 hr. average - calendar day) (filterable) 439 lbs/hr (filterable + condensable) PM2.5 85 lbs/hr (filterable) 434 lbs/hr (filterable + condensable) SO2 552 lbs/hr (three-hr. rolling average) 422 lbs/hr (24 hr. average - calendar day) 211 lbs/hr (annual average) NOx 35.0 lb/hr (annual average) 146.5 lb/hr (daily average) . Lead 1.3 lb/hr (annual average) I. #SME 013 - Dry Matte Bin Baghouse (Stack No. 13) PM10 0.3 lbs/hr (filterable) 0.016 grains/dscf (68degrees F, 29.92" Hg) J. #SME 017 - Vacuum Cleaning Systems (Stacks No. 17a & 17c combined) PM10 0.7 lbs/hr (filterable) 0.016 grains/dscf (68degrees F, 29.92" Hg) K. #SME 026 - Holman Boiler (Stack No. 26) NOx 9.34 lbs/hr, 30-day rolling average 14 lbs/hr, calendar-day average L. #SME 030 - Rentech Boiler (Stack No. 30) NOx 3.29 lbs/hr, 30-day rolling average 4.94 lb/hr, calendar-day average M. #SME 011b - Acid Plant Tail Gas SO2 250 ppmdv (six- hr. block average) 170 ppmdv (24 hr. average - calendar day) 100 ppmdv (annual average)
Sulfuric Acid Mist 0.67 mg/scf (68degrees F, 29.92" Hg)
N. #SME 011e - Dedicated Rotary Dryer Baghouse Particulate Emissions (PM) 0.022 grains/dscf (68 degrees F, 29.92" Hg) (filterable)
* Reference to stack numbers above and in Conditions II.B.1.a.2 and II.B.1.a.3 below do not necessarily refer to an exhaust point to the atmosphere. Many emission sources are commingled with emissions from other sources and exit to the atmosphere from a common emission point. "Stack" in these conditions refer to the point prior to mixing with emissions from other sources. [R307-401-8]
DAQE-AN103460063-24
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II.B.1.a.1 To determine compliance with an annual average emission limitation, the owner/operator shall calculate a new annual average by the 20th day of each month using data from the previous 12 months. All annual average emission limits shall be based on a rolling 12-month average using the daily averages from the previous 12 months. [R307-401-8]
II.B.1.a.2 Stack testing to show compliance with the emissions limitations of Condition II.B.1.a shall be performed as specified below:
A. Emission Point Pollutant Testing Status Test Frequency 1) Stack Nos. 2, 3, 4,
5, 6, 13, 17a & 17c PM10 ** every five years 2) Stack No 1 PM10 * every five years
3) Stack Nos. 10b PM10 ** every three years
SO2 ** every three years

4) Main Stack PM10 ** every year and
continuous particulate monitor

5) Stack No. 11 PM2.5 ** every year SO2 ** CEM
NOx ** CEM
Lead ** continuous particulate monitor

6) Holman Boiler NOx ** every three years Stack No. 26 calendar-day
average
NOx ** CEM or alternate
method
30-day average determined according to Condition II.B.2.b

7) Rentech Boiler NOx ** every three years Boiler Stack No. 30 calendar-day
average
NOx ** CEM or alternate
method 30-day average
determined according to Condition 11.B.2.c

8) Acid Plant Tail gas SO2 ** CEM (concentration)

Sulfuric Acid Mist ** every three years

9) Dedicated Rotary PM ** every five years
Dryer Baghouse/Scrubber

DAQE-AN103460063-24
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B. Testing Status (To be applied above) *Initial testing shall be performed as soon as possible and in no case later than 180 days after start up. ** The initial test has been performed on these sources. C. The owner/operator may petition the Director to reduce the stack testing frequency of an
emission point in a given year after the following: if, after two stack tests for an emission
point in Condition II.B.1.a.2 conducted in accordance with Condition II.B.1.a.3, the
owner/operator can show, either because of reliability of pollution control equipment,
constant emissions, or other appropriate reasons, the stack testing frequency in Condition
II.B.1.a.2 is more frequent than necessary to determine the quantity of emissions.

[R307-401-8]
II.B.1.a.3 Stack testing to show compliance with the emission limitations of Condition II.B.1.a shall be performed as specified below (continued): A. Notification Notification of the date, time, place of test and a copy of the test protocol shall be provided at least 30 days prior to the test. A pretest conference shall be held if directed by the Director. B. Sample Location The emission point shall be designed to conform to the requirements of 40 CFR 60, Appendix A, Method 1, or other EPA-approved methods acceptable to the Director. Occupational Safety and Health Administration (OSHA)-approved and/or Mine Safety and Health Administration (MSHA)-approved access shall be provided to the test location. C. Volumetric Flow Rate 40 CFR 60, Appendix A, Method 2, Method 19, or other EPA-approved testing methods acceptable to the Director. D. PM 40 CFR 60, Appendix A, Method 5 or other EPA-approved testing methods acceptable to the Director. E. PM10/PM2.5 For stacks in which no liquid drops are present, the following methods shall be used: 40 CFR 51, Appendix M, Methods 201 or 201a or other EPA-approved testing method acceptable to the Director. The back half condensable particulate emissions shall also be tested (where applicable) using 40 CFR 51, Appendix M Method 202, or other EPA-approved testing method acceptable to the Director. All particulate captured using Method 202 shall be considered PM2.5 and/or PM10. For stacks in which liquid drops are present, methods to eliminate the liquid drops shall be explored. If no reasonable method to eliminate the drops exists, then the following methods shall be used: 40 CFR 60, Appendix A, Method 5, 5a, 5d, 5i, or other as appropriate. If using Method 5 or any variation of Method 5, a scanning electron microscopy analysis or other equivalent method shall be used to determine the fraction of PM10 and/or PM2.5, as approved by the Director. The back half condensable particulate emissions shall also be tested using 40 CFR 51, Appendix M Method 202 or other EPA-approved testing method acceptable to the Director. All particulate captured using Method 202, shall be considered PM2.5 and/or PM10.
DAQE-AN103460063-24
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For filterable emission limits, condensable emissions shall not be used for compliance demonstrations. For filterable + condensable emission limits, both filterable and condensable emissions shall be used for compliance demonstrations. [R307-401-8] II.B.1.a.4 Stack testing to show compliance with the emission limitations of Condition II.B.1.a shall be performed as specified below (continued):
F. SO2 40 CFR 60 Appendix A, Method 6, 6A, 6B, 6C, or other EPA-approved testing methods
acceptable to the Director. G. Lead
The test method shall be submitted for approval or may be assigned by the Director. A monitoring plan was submitted to the Director on October 10, 2000, and amended in
2007. The owner/operator shall monitor in accordance with the most recent monitoring
plan approved by the Director.
H. Sulfuric Acid Mist
40 CFR 60, Appendix A, Method 8.
I. NOx
40 CFR 60 Appendix A, Method 7, 7A, 7B, 7C, 7D, 7E, or other EPA-approved testing methods acceptable to the Director.

J. Source Operation For stack testing purposes, stack tests shall be done during representative operations.
The production rate during all compliance tests shall be no less than 90% of the
maximum average hourly production rate achieved in a 24-hour period during the previous three years.

K. Calculations To determine mass emission rates (lb/hr, etc.), the pollutant concentration as determined
by the appropriate methods above shall be multiplied by the volumetric flow rate and any
necessary conversion factors determined by the Director, to give the results in the specified units of the emission limitation.

L. Results The results of stack testing shall be submitted to the Director within 60 days of
completion of the testing. Reports shall clearly identify results as compared to permit
limits and indicate compliance status.
[R307-401-8]

DAQE-AN103460063-24
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II.B.2 Holman Boiler and Rentech Boiler NOx Requirements II.B.2.a The owner/operator shall not exceed 23.3 tons of NOx emissions per rolling 12-month period
from the Holman boiler and Rentech boiler combined. [R307-401-8]
II.B.2.a.1 To determine compliance with a rolling 12-month total, the owner/operator shall calculate a new 12-month total by the 20th day of each month using data from the previous 12 months. Records of emissions shall be kept for all periods when the plant is in operation. Monthly totals of NOx emissions from each boiler shall be based on the following: A. The 30-day average NOx emissions rate (lb/hr) of the Holman boiler for the calendar month, determined according to Condition II.B.2.b. B. The hours of operation of the Holman boiler for the calendar month. C. The 30-day average NOx emissions rate (lb/hr) of the Rentech boiler for the calendar month, determined according to Condition II.B.2.c. D. The hours of operation of the Rentech boiler for the calendar month. [R307-401-8]
II.B.2.b Initial compliance with the Holman boiler 30-day average NOx limit was demonstrated with the CEM in accordance with 40 CFR 60.46b(e)(1). The owner/operator shall continue to use the
CEM or propose to the Director an alternative method for demonstrating compliance with the
limit in accordance with 40 CFR 60.46b(e)(1) and (4), 60.48b(g) (1) and (2), and 60.49b(c). Either a CEM or the most recently approved alternate plan approved by the Director shall be
used. [R307-401-8]

II.B.2.c The owner/operator shall demonstrate compliance with the Rentech boiler 30-day average NOx in accordance with 40 CFR 60.46b(e) and either 40 CFR 60.48b(g)(1) or 40 CFR 60.48b(g)(2). For subsequent compliance, either a CEM or the most recently approved alternate plan to monitor boiler operating conditions and predict NOx emission rates shall be used. *Initial compliance was using a CEM in accordance with 40 CFR 60.46b(e) and (e)(1). [R307-401-8]
II.B.2.c.1 The owner/operator shall maintain and operate the CEM in accordance with UAC R307-170. The records and results of monitoring shall be maintained in accordance with 40 CFR 60.49b and
UAC R307-170. [R307-170, R307-401-8]

II.B.2.c.2 If the owner/operator chooses to comply with the monitoring provisions of 40 CFR 60.48b(g)(2) to demonstrate compliance with the Rentech boiler 30-day average NOx limit, the owner/operator shall submit an alternate plan to the Director in accordance with 40 CFR 60.49b(c) that identifies the operating conditions to be monitored and the records to be maintained. This plan shall be submitted to the Director for approval within 360 days of the initial startup of the Rentech boiler. [40 CFR 60 Subpart Db, R307-401-8]
II.B.2.c.3 The owner/operator shall submit notifications and reports as required in 40 CFR 60.49b and
R307-170. Results of the additional certified NOx CEM 30-day CEM tests as required in 40
CFR 60.46b(e) shall be submitted within 60 days of the completion of the test.
[40 CFR 60 Subpart Db, R307-170]

DAQE-AN103460063-24
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II.B.3 Main Stack Continuous Monitoring Requirements II.B.3.a To demonstrate compliance with the main stack mass emissions limits for SO2 and NOx of
Condition II.B.1.a.H, the owner/operator shall calibrate, maintain, and operate the measurement systems for continuously monitoring SO2 and NOx concentrations and stack gas volumetric flow rates in the main smelter stack. [R307-401-8]

II.B.3.a.1 The owner/operator shall comply with all applicable parts of UAC R307-170 "Continuous Emission Monitoring Systems Program," including the requirements for annual Relative Accuracy Test Audits (RATA) and quarterly Relative Accuracy Audits (RAA) or Cylinder Gas Audits (CGA). A. The required RATA, RAA, and CGA shall be conducted following procedures in 40 CFR 60 Appendix B, Specification 2, and 40 CFR 60 Appendix F. B. Acceptable methods for the annual RATA include 40 CFR 60, Appendix A, Method 6 or 6C for SO2, and Method 7 or 7E for NOx. C. All audit and test results shall be submitted to the Director within 60 days after the audit or test is completed. [R307-401-8] II.B.3.a.2 The owner/operator shall perform 40 CFR 52 Appendix E - Performance Specification
procedures on the stack gas flow rate measurement system, if directed by the Director, in the
event that the results of the quarterly and annual tests required by Condition II.B.3.a.1 demonstrate that the SO2 and NOx monitoring systems are not performing properly.
[R307-401-8]

II.B.3.a.3 Failure to measure SO2 at least ninety-five percent of the hours during which emissions occurred in any quarter in accordance with the requirements of this subsection, or failure to measure, in accordance with the requirements of this subsection, any 18 consecutive hours of emissions data shall constitute a violation of Condition II.B.3.a. A. Any hour for which the measurements comply with UAC R307-170 shall be considered as measured. B. Any hours for which the emissions data are greater than 20% in error will be considered to have not been measured for the purposes of Condition II.B.3.a. C. The Director may grant exemptions to the requirements of Condition II.B.3.an if unusual circumstances, not to include malfunction of any of the monitoring instrumentation, arise which prevent the owner/operator from obtaining hourly measurements of emissions in accordance with Condition II.B.3.a. [40 CFR 60 Subpart P, R307-401-8]
II.B.3.a.4 The owner/operator shall maintain a record of all measurements required by Condition II.B.3.a.
Measurement results shall be expressed as pounds of SO2 and NOx emitted per hour calculated at
the end of each day for the preceding 24 hours for SO2 and NOx and calculated at the end of each
hour for the preceding three-hour period for SO2. Records shall include:

A. The total number of hourly periods during the month in which measurements were not
taken.

B. For any periods where loss of measurement is greater than three continuous hours, the
reason for loss of measurement in each period.

DAQE-AN103460063-24
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C. The date(s) on which three and 24-hour emissions averages for SO2 exceeded the applicable emission level in Condition II.B.1.a.H and the number of exceedances. D. The date(s) on which the annual emissions average based on hourly emissions exceeded the applicable emission level in Condition II.B.1.a.H for NOx for the month being reported and the number of such exceedances, and the daily NOx averages. E. All conversion values used to derive the three and 24-hour average and annual average emissions for SO2, and the 24-hour average and annual average for NOx, including temperature and differential pressure of stack gases. [R307-401-8] II.B.3.a.5 Data, reports, or results required to be submitted pursuant to Condition II.B.3.a shall be deemed
to be verified and accepted as valid and not subject to challenge and shall be used by the Director in determining compliance with Condition II.B.1.a.H, unless, within 30 days of the time such
data, reports, or results are submitted, the owner/operator or the Director provides evidence that
the data, results, or reports, or any part thereof, are greater than 20% in error. [R307-401-8]
II.B.3.a.6 During periods of malfunctioning or maintenance of the stack gas temperature and velocity measurement instrumentation, the owner/operator may estimate stack gas flow rate. Such estimates will be considered as measurements for the purpose of Condition II.B.3.a. Records of calculations used to derive the estimated flow rate and a list of the periods where stack gas flow rate was estimated in each month shall be maintained. No more than 10% of the flow rates in any one month may be estimated. [R307-401-8]
II.B.3.b The owner/operator shall continuously measure emissions of particulate matter from the main
stack. For the purposes of determining compliance with Condition II.B.1.a.H, all particulate matter collected shall be reported as PM10. Compliance with the main stack emission limit for
PM10 of Condition II.B.1.a.H shall be demonstrated using the smelter main stack continuous
particulate sampling system to provide a 24-hour value. Collected data shall be available for inspection, and a summary of 24-hour averages shall be submitted to the Director monthly within
20 days of the end of the month. [R307-401-8]

II.B.3.c The owner/operator shall determine the lead emissions from the main stack using the main stack particulate data and laboratory analysis of the material collected by the continuous stack particulate sampler. The owner/operator shall monitor in accordance with the most recent monitoring plan approved by the Director. If the owner/operator cannot monitor the lead emissions using the continuous particulate sampler, then the owner/operator shall monitor the lead emissions using a monitoring plan approved by the Director. [R307-401-8]

DAQE-AN103460063-24
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II.B.4 Scrubber and Baghouse Monitoring Requirements II.B.4.a The owner/operator shall install, calibrate, maintain, and operate the following monitoring
devices for the measurement of the indicated parameters. Continuous recording instruments are optional but are not required. The gauges/devices shall be located such that an inspector can safely read them at any time. The monitoring devices shall be calibrated in accordance with the
manufacturer's instructions. A. A monitoring device for the continuous measurement of the change in pressure of the gas
stream across the secondary ventilation scrubber, rotary dryer scrubber, anode furnace scrubber, and hydrometallurgical plant scrubber(s). A "U" tube manometer is recommended.
B. A monitoring device for the continuous measurement of the scrubbing liquid flow rate to the secondary ventilation scrubber, rotary dryer scrubber, anode furnace scrubber, and
hydrometallurgical plant scrubber(s).
C. A monitoring device for the continuous measurement of the change in pressure of the gas
stream across each baghouse.
The operating range and accuracy of the monitoring devices shall be submitted to the Director.
[R307-401-8]

II.B.4.b The owner/operator shall maintain a monitoring record or log with monitoring data to demonstrate compliance with the operating ranges listed below. [R307-401-8]
II.B.4.b.1 The operating pressure drop across the following equipment shall be maintained within the
following operating ranges:
A. Secondary Ventilation Scrubbers: 3.5" Water Gauge (W.G.) (minimum, across
both scrubbers combined).
B. Rotary Dryer Scrubber: 5" to 19.25" W.G.
C. Anode Furnace Scrubber: 18" to 50.5" W.G.

D. Hydrometallurgical Plant Scrubber Model #480: 5" to 10" W.G.
E. Hydrometallurgical Plant Scrubber Model #575: 6" to 12" W.G.
[R307-401-8]

II.B.4.b.2 The operating scrubbing liquid flow rate for the following equipment shall be maintained within the following operating ranges: A. Secondary Ventilation Scrubber: greater than 4800 gpm (each). B. Rotary Dryer Scrubber: greater than 7360 gpm. C. Anode Furnace Scrubber: greater than 2000 gpm (each). D. Hydrometallurgical Plant Scrubber Model #480: greater than 50 gpm. E. Hydrometallurgical Plant Scrubber Model #575: greater than 40 gpm. [R307-401-8]

DAQE-AN103460063-24
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II.B.4.b.3 Pressure drops for the following baghouses shall be maintained within the following operating ranges: A. Filter Plant Wet Feed Conveyor Baghouse: 0.5" to 4" W.G. B. Wet Feed Storage Building Baghouse: 1.5" to 5" W.G. C. Wet Feed Conveyor Belt Transfer Point Baghouse: 0.5" to 5.25" W.G. D. Wet Feed Bin(s) Baghouse: 2.75" to 5" W.G. E. Flash Smelting Furnace Dry Feed Bin Baghouse: 0.25" to 11" W.G. F. Limestone Flux Bin Baghouse: 0.5" to 4" W.G. G. Secondary Gas Handling System Baghouse: 6" to 15" W.G. H. Matte Drying and Grinding Plant Baghouse: 5" to 15" W.G. I. Dry Matte Bin Baghouse: 0.5" to 13" W.G. J. Anode Refining Furnace Baghouse: 1" to 9" W.G. K. Anode Shaft Furnace Baghouse: 1" to 10" W.G. L. Mold Coating (Barite) Bin Baghouse: 0.25" to 4" W.G. M. Vacuum Cleaning Systems (2 Baghouses): 0.25" to 6" (each) W.G. N. Hydrometallurgical Plant Limestone Storage Bin Baghouse: 0.5" to 4" W.G. O. Hydrometallurgical Plant Lime Storage Bin Baghouse: 0.25" to 4" W.G. P. Recycle Materials Crushing and Storage Building Baghouse: 1" to 5" W.G. [R307-401-8]

DAQE-AN103460063-24
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II.B.5 Natural Gas Consumption Requirements II.B.5.a The natural gas consumption per rolling 12-month period shall not exceed the following
limitations for the equipment listed: A. Acid Plant Preheater - 74,476 MMBTU.
B. Pyrometallurgical Process Group - 1,947,847 MMBTU The Pyrometallurgical Process Group includes the following units:
a) Anode Area: i. SME 011h1 - Anode Furnaces
ii. SME 011h2 - Shaft Furnace iii. SME 011h3 - Holding Furnaces iv. SME MOLD - Mold Casting Furnace.
b) Launder Heaters:
i. SME 011b1 – FSF
ii. SME 011b2 – FCF iii. SME 011b3 - Co-Jet Burner.

C. SME 011g - Matte Grinding Plant.
D. SME 011e - Rotary Concentrate Dryer.
[R307-401-8]

II.B.5.a.1 To determine compliance with a rolling 12-month total, the owner/operator shall calculate a new 12-month total by the 20th day of each month using data from the previous 12 months. Records of consumption shall be kept for all periods when the plant is in operation. Natural gas consumption shall be determined by individual gas meters readings reconciled against monthly billing statements. [R307-401-8]
II.B.5.a.2 The natural gas allocations in Condition II.B.5.a may be reapportioned upon demonstration to the
Director that no increase in potential NOx emissions would result. [R307-401-8]
II.B.5.a.3 Propane may be used as an alternate fuel supply during natural gas curtailment. [R307-401-8]
II.B.6 Fugitive Emissions and Material Handling Requirements
II.B.6.a The emissions from the transfer point between the outside hopper/feeder and the wet feed conveyor on the wet feed conveyor transfer point with baghouse from the Outside Feed Hopper shall be ducted to the wet feed storage building baghouse. [R307-401-8] II.B.6.b All roads, parking lots, and service yards directly servicing the approved constructed installations
listed above in Section II.A, with the exception of II.A.13, of this AO shall be paved.
[R307-401-8]

II.B.6.c The owner/operator shall carry out the current Fugitive Dust Control Plan approved by the Director. [R307-401-8]
II.B.6.d Any open storage piles shall be watered, covered, or chemically treated to minimize generation
of fugitive dusts as dry conditions warrant or as determined necessary by the Director.
[R307-401-8]

II.B.6.e Emissions from the slag concentrator bin shall be controlled with water sprays. Treatment shall be of sufficient frequency and quantity to maintain the surface material in a damp/moist condition unless it is below freezing. The degree of control is a minimum of that required to meet the opacity limitations of Condition II.B.7.a. [R307-401-8]
DAQE-AN103460063-24
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II.B.6.e.1 A visual inspection of the water spray system on the slag concentrator bin shall be performed on a weekly basis to ensure proper operating condition. Records of each inspection shall be maintained in accordance with Condition I.4. [R307-401-8] II.B.6.f The crushing and screening operation shall not process more than 5,000 tons of material per
calendar day and 750,000 tons of material per rolling 12-month period. [R307-401-8]
II.B.6.f.1 To determine compliance with a rolling 12-month total, the owner/operator shall calculate a new 12-month total by the 20th day of each month using data from the previous 12 months. Records of daily material processing shall be kept for all periods when the smelter is in operation. Daily total material processing shall be determined by daily reports. [R307-401-8]
II.B.6.g Water sprays or chemical dust suppression sprays shall be installed at the following points that are not enclosed or have baghouses to control fugitive emissions:
A. All crushers.
B. All stationary conveyor transfer points.
C. The crusher and screening units shall have water spray at the input to the crusher and at
the discharge points from the crusher.
The sprays shall operate whenever dry conditions warrant or as determined necessary by the
Director.
[R307-309]

II.B.7 Site-Wide Requirements
II.B.7.a Visible emissions from the following emission points shall not exceed the following values:
Emission Point Opacity Limit
A. #SME 001 - Wet Feed Conveyor Baghouse (Stack No. 1) 7%

B. #SME 002 - Wet Feed Storage Building Baghouse (Stack No. 2) 7%

C. #SME 003 - Wet Feed Conveyor Transfer Point Baghouse (Stack No. 3) 7%

D. #SME 004 - Wet Feed Bin Baghouse (Stack No. 4) 7%
E. #SME 005 - Flash Smelting Furnace Dry Feed Bin
Baghouse (Stack No. 5) 7%
F. #SME 006 - Smelter Limestone Flux Bin Baghouse
(Stack No. 6) 10%

G. #SME 008 - Acid Plant Preheater (Stack No. 8) 10%

H. #SME 010b - Slag Granulator Scrubber Stack
(Stack No. 10b) 15%

I. #SME 011 - Smelter Main Stack (Stack No. 11) 20%

J. #SME 013 - Dry Matte Bin Baghouse (Stack No. 13) 10%

DAQE-AN103460063-24
Page 22

K. #SME 015 - Mold Coating Silo Baghouse (Stack No. 15) 10% L. #SME 017 - Vacuum Cleaning System (Stacks No. 17a & 17c combined) 10% M. #SME 019 - Hydrometallurgical Plant Limestone Silo Baghouse (Stack No. 19) 10% N. #SME 020 - Hydrometallurgical Lime Silo Baghouse (Stack No. 20) 10% O. #SME 022 - Laboratory Baghouse (Stack No. 22) 10% P. #SME SLAG - Slag Concentrator Bin 10% Q. #SME SLAG - Slag Crushing and Grinding Transfer Points 10% R. #SME 026 - Holman Boiler (stack 26) 10% S. #SME 027 - Recycle Materials Crushing & Storage Building Baghouse (Stack No. 27) 10% T. #SME 028 - Anode Area Lime Silo Baghouse (Stack No. 28) 10% U. #SME 029 - Secondary Gas System Lime Silo Baghouse (Stack No. 29) 10% V. #SME 030- Rentech Boiler (Stack No. 30) 10% W. #SME SLAG - Crushing and Screening Plant 10% X. #SME 001-A - Filter Plant Wet Feed Bin Vent 10%
Y. #SME 011b - Acid Plant Tail Gas 15%

Z. #SME 011e - Rotary Dryer Baghouse/Scrubber Outlet 15%

AA. Hot Metals Building Roof Vents 20%

BB. Acid Plant Process Gas Leaks 20%

CC. All other points 20%

[R307-305-3]

II.B.7.a.1 Opacity observations of emissions from stationary sources shall be conducted in accordance with 40 CFR 60, Appendix A, Method 9. [R307-401-8]

DAQE-AN103460063-24
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II.B.7.a.2 For sources that are subject to NSPS, opacity shall be determined by conducting observations in accordance with 40 CFR 60.11(b) and 40 CFR 60, Appendix A, Method 9. A. For purposes of determining initial compliance, observations shall be conducted according to 40 CFR 60.11(b) unless otherwise specified under the applicable NSPS subpart. B. It is the responsibility of the owner/operator of the source to supply these observations to the Director. C. A currently certified observer must be used for these observations. [40 CFR 60 Subpart A]
II.B.7.a.3 The owner/operator shall install, calibrate, maintain, and operate continuous opacity monitoring systems on the rotary dryer baghouse/scrubber, the main stack, and the acid plant tail gas.
[R307-401-8]

II.B.7.a.4 The owner/operator shall record the output of the systems for measuring the opacity of emissions on the rotary dryer baghouse/scrubber outlet, main stack, and acid plant tail gas. The monitoring systems shall comply with all applicable sections of UAC R307-170 and 40 CFR 60, Appendix B, Specification 1 - Opacity. [R307-401-8]
II.B.7.a.5 Sources equipped with continuous opacity monitors (rotary dryer baghouse/scrubber, acid plant
tail gas, and main stack) shall use the compliance methods contained in 40 CFR 60.11. [R307-305-3]

II.B.7.a.6 The owner/operator shall perform a visual opacity survey of the acid plant process gas leaks emission unit on a weekly basis to minimize emissions from leaks of sulfur dioxide, sulfur trioxide, and other process emissions. A. Surveys shall be conducted by an individual trained on the observation procedures of 40 CFR 60, Appendix A, Method 9. B. If visible emissions other than steam are observed from the acid plant process gas leaks emission unit, an opacity determination shall be performed by a certified observer within 24 hours of the initial survey. The opacity determination shall be performed in accordance with 40 CFR 60, Appendix A, Method 9. C. If visible emissions greater than 15% opacity are observed, then best operational practices shall be initiated within 24 operating hours of the observation to ensure leakage of gases to the ambient air are being controlled to 20% opacity or less. Best operational practices may include, but are not limited to: 1) Placement or adjustment of negative pressure ductwork and collection hoses; 2) Welding of process gas leaks; or 3) Containment of process gas leaks. D. A log of the visual opacity survey(s) shall be maintained. If an opacity determination is indicated, a notation of the determination will be made in the log. [R307-401-8]

DAQE-AN103460063-24
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II.B.7.b The owner/operator shall install, calibrate, maintain, and operate continuous monitoring systems on the acid plant tail gas. [R307-401-8] II.B.7.b.1 The owner/operator shall record the output of the system for measuring the SO2 concentration of the acid plant tail gas. The monitoring system shall comply with all applicable sections of UAC
R307-170, 40 CFR 60, Appendix B, Specification 2 - SO2. [R307-401-8]
II.B.7.c The owner/operator shall only combust diesel fuel ((e.g., fuel oil #1, #2, or diesel fuel oil additives) that meets the definition of ultra-low sulfur diesel (ULSD), which has a sulfur content of 15 ppm or less. [R307-401-8] II.B.7.c.1 To demonstrate compliance with the ULSD fuel requirement, the owner/operator shall maintain
records of diesel fuel purchase invoices or obtain certification of sulfur content from the diesel fuel supplier. The diesel fuel purchase invoices shall indicate that the diesel fuel meets the ULSD requirements. [R307-401-8]

II.B.7.d All gases produced during smelting and/or converting which enter the primary gas handling system shall pass through an online sulfuric acid plant. During the start-up/shutdown process of any equipment, the gas emissions shall be ducted, as necessary, either to the acid plant or to the secondary scrubber for control. [R307-401-8]
II.B.7.e The owner/operator shall employ the following measures for reducing escape of pollutants to the
atmosphere and to capture emissions and vent them through a stack or stacks:
A. Maintenance of all ducts, flues, and stacks in such a fashion that leakage of gases to
the ambient air will be prevented to the maximum extent practicable.
B. Operation and maintenance of gas collection systems in good working order.
C. Making available the preventive/routine maintenance records for the hooding systems;
dust collection mechanism of waste heat boilers; furnace wet scrubbing systems; and
dry electrostatic precipitators.
D. Weekly observation of process units.
E. Monthly inspection of gas handling systems.

F. Maintenance of gas handling systems, available on call on a 24-hour basis.
G. Operation and maintenance of an upwind/downwind fugitive SO2 monitoring system.
The owner/operator may petition the Director to discontinue the operation of this system.

H. Contained conveyance of acid plant effluent solutions.
[R307-401-8]

DAQE-AN103460063-24
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II.B.7.f Secondary hoods and ventilation systems shall be installed on the following points to capture fugitive emissions into the secondary ventilation system or other approved pollution control devices: A. Concentrate Dryer Feed Chute. B. Slag and Matte Granulators. C. Smelting and Converting Furnaces. D. Slag Pot Filling Stations. [R307-401-8]

PERMIT HISTORY

This Approval Order shall supersede (if a modification) or will be based on the following documents: Supersedes AO DAQE-AN103460062-23 dated December 28, 2023 Is Derived From NOI dated August 23, 2024

DAQE-AN103460063-24
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ACRONYMS

The following lists commonly used acronyms and associated translations as they apply to this document:

40 CFR Title 40 of the Code of Federal Regulations
AO Approval Order
BACT Best Available Control Technology
CAA Clean Air Act
CAAA Clean Air Act Amendments
CDS Classification Data System (used by Environmental Protection Agency to classify
sources by size/type)
CEM Continuous emissions monitor
CEMS Continuous emissions monitoring system
CFR Code of Federal Regulations
CMS Continuous monitoring system
CO Carbon monoxide
CO2 Carbon Dioxide
CO2e Carbon Dioxide Equivalent - Title 40 of the Code of Federal Regulations Part 98,
Subpart A, Table A-1
COM Continuous opacity monitor
DAQ/UDAQ Division of Air Quality
DAQE This is a document tracking code for internal Division of Air Quality use
EPA Environmental Protection Agency
FDCP Fugitive dust control plan
GHG Greenhouse Gas(es) - Title 40 of the Code of Federal Regulations 52.21 (b)(49)(i)
GWP Global Warming Potential - Title 40 of the Code of Federal Regulations Part 86.1818-
12(a)
HAP or HAPs Hazardous air pollutant(s)
ITA Intent to Approve
LB/YR Pounds per year MACT Maximum Achievable Control Technology MMBTU Million British Thermal Units NAA Nonattainment Area NAAQS National Ambient Air Quality Standards NESHAP National Emission Standards for Hazardous Air Pollutants NOI Notice of Intent
NOx Oxides of nitrogen
NSPS New Source Performance Standard
NSR New Source Review
PM10 Particulate matter less than 10 microns in size
PM2.5 Particulate matter less than 2.5 microns in size
PSD Prevention of Significant Deterioration
PTE Potential to Emit
R307 Rules Series 307
R307-401 Rules Series 307 - Section 401
SO2 Sulfur dioxide
Title IV Title IV of the Clean Air Act
Title V Title V of the Clean Air Act
TPY Tons per year
UAC Utah Administrative Code
VOC Volatile organic compounds

DAQE-

RN103460063 September 24, 2024 Matt Tobey
Rio Tinto Kennecott Utah Copper LLC 4700 Daybreak Parkway South Jordan, UT 84009
[e-mail] Dear Matt Tobey,
Re: Engineer Review: Administrative Action to Approval Order DAQE-AN103460062-23 Project Number: N103460063 Please review and sign this letter and attached Engineer Review (ER) within 10 business days. For this document to be considered as the application for a Title V administrative amendment, a Title V Responsible Official must sign the next page. Please contact Stockon Antczak at [phone] if you have any questions or concerns about the ER. If you accept the contents of this ER, please email this signed cover letter to Stockon Antczak at [e-mail]. After receipt of the signed cover letter, the DAQ will prepare an Approval Order (AO) for signature by the DAQ Director. If Rio Tinto Kennecott Utah Copper LLC does not respond to this letter within 10 business days, the project will move forward without your approval. If you have concerns that we cannot resolve, the DAQ Director may issue an Order prohibiting construction.
Approval Signature _____________________________________________________________ (Signature & Date)
195 North 1950 West • Salt Lake City, UT
Mailing Address: P.O. Box 144820 • Salt Lake City, UT 84114-4820
Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.utah.gov
Printed on 100% recycled paper
Department of Environmental Quality
Kimberly D. Shelley Executive Director DIVISION OF AIR QUALITY Bryce C. Bird Director
State of Utah
SPENCER J. COX Governor DEIDRE HENDERSON Lieutenant Governor

Engineer Review N103460063: Rio Tinto Kennecott Utah Copper LLC - Smelter & Refinery September 24, 2024 Page 1
OPTIONAL: In order for this Engineer Review and associated Approval Order conditions to be considered as an application to administratively amend your Title V Permit, the Responsible Official, as
defined in R307-415-3, must sign the statement below. THIS IS STRICTLY OPTIONAL. If you do not want the Engineer Review to be considered as an application to administratively amend your Operating Permit only the approval signature above is required. Failure to have the Responsible Official sign below will not delay the Approval Order, but will require submittal of a separate Operating Permit Application to revise the Title V permit in accordance with R307-415-5a through 5e and R307-415-7a through 7i. A guidance document: Title V Operating Permit Application Due Dates clarifies the required due dates for Title V operating permit applications and can be viewed at:
https://deq.utah.gov/air-quality/permitting-guidance-and-guidelines-air-quality “Based on information and belief formed after reasonable inquiry, I certify that the statements and information provided for this Approval Order are true, accurate and complete and request that this Approval Order be considered as an application to administratively amend the Operating Permit.” Responsible Official _________________________________________________ (Signature & Date) Print Name of Responsible Official _____________________________________

Engineer Review N103460063: Rio Tinto Kennecott Utah Copper LLC - Smelter & Refinery September 24, 2024 Page 2
UTAH DIVISION OF AIR QUALITY
ENGINEER REVIEW

SOURCE INFORMATION
Project Number N103460063 Owner Name Rio Tinto Kennecott Utah Copper LLC
Mailing Address 4700 Daybreak Parkway South Jordan, UT, 84009
Source Name Rio Tinto Kennecott Utah Copper LLC - Smelter & Refinery Source Location: 12000 West 2100 South
Magna, UT 84044 UTM Projection 398,678 m Easting, 4,508,860 m Northing UTM Datum NAD83 UTM Zone UTM Zone 12 SIC Code 3331 (Primary Smelting & Refining of Copper) Source Contact Jenny Esker Phone Number [phone] Email [e-mail]
Billing Contact Matt Tobey Phone Number 801-569-3591 Email [e-mail]
Project Engineer Stockon Antczak, Engineer Phone Number [phone]
Email [e-mail] Notice of Intent (NOI) Submitted August 23, 2024 Date of Accepted Application August 28, 2024

Engineer Review N103460063: Rio Tinto Kennecott Utah Copper LLC - Smelter & Refinery September 24, 2024 Page 3
SOURCE DESCRIPTION General Description
Rio Tinto Kennecott Utah Copper LLC (KUC) operates a copper smelter and refinery in Salt Lake County, Utah. The Smelter employs flash smelting technology with flash converting technology to produce copper anodes and high concentration sulfur dioxide gases. The gases are
treated by electrostatic precipitators (ESP), baghouses, scrubbers, and a high-efficiency double contact acid plant. The Refinery uses an electrolytic refining process to convert the Smelter-produced anode copper to cathode copper and also recovers precious metals from the electrolytic refining slimes in a precious metals circuit. The copper ore concentrates received at the Smelter are first dewatered and then dried to reduce the moisture content. The dried concentrate is then blended with fluxes and secondary copper-bearing materials. This mixture is fed to a flash smelting furnace where the ore is melted and reacts to produce copper matte, a molten solution of copper sulfide mixed with iron sulfide. The Outokumpu flash smelting process used at the Smelter is a closed process that captures the SO2-rich off-gases from the furnace for the production of sulfuric acid. The copper matte from the
smelting furnace is next converted to blister copper (approximately 98% pure copper) by oxidization to remove the remaining sulfur as SO2 gas and the iron as a ferrous oxide slag. The Smelter uses a continuous copper converting process in which solid matte granules are fed to a
flash smelting furnace-like vessel. The molten slag from converting is cooled, processed in slag concentrators to remove residual copper, and ultimately disposed in on-site waste piles. The SO2 gases from smelting and converting are vented to a sulfuric acid plant. Molten blister copper is
transferred from the converting vessel to an anode furnace for fire-refining to further remove residual impurities and oxygen. The blister copper is reduced in the anode furnace to remove oxygen by injecting natural gas, producing a high purity copper. The molten copper from the anode furnace is poured in molds to cast solid copper ingots called anodes. The anode copper produced at the Smelter is moved to the copper Refinery co-located near the
Smelter, where it is further purified using an electrolytic process to obtain the high-purity cathode copper sold. NSR Classification: Administrative Amendment Source Classification Located in , Northern Wasatch Front O3 NAA, Salt Lake City UT PM2.5 NAA, Salt Lake County
SO2 NAA, Salt Lake County Airs Source Size: A
Applicable Federal Standards NSPS (Part 60), A: General Provisions
NSPS (Part 60), Db: Standards of Performance for Industrial-Commercial-Institutional Steam Generating Units NSPS (Part 60), Dc: Standards of Performance for Small Industrial-Commercial-Institutional
Steam Generating Units NSPS (Part 60), P: Standards of Performance for Primary Copper Smelters NSPS (Part 60), OOO: Standards of Performance for Nonmetallic Mineral Processing Plants NSPS (Part 60), IIII: Standards of Performance for Stationary Compression Ignition Internal

Engineer Review N103460063: Rio Tinto Kennecott Utah Copper LLC - Smelter & Refinery September 24, 2024 Page 4
Combustion Engines NSPS (Part 60), JJJJ: Standards of Performance for Stationary Spark Ignition Internal
Combustion Engines NSPS (Part 60), KKKK: Standards of Performance for Stationary Combustion Turbines MACT (Part 63), A: General Provisions MACT (Part 63), ZZZZ: National Emissions Standards for Hazardous Air Pollutants for Stationary Reciprocating Internal Combustion Engines MACT (Part 63), EEEEEE: National Emission Standards for Hazardous Air Pollutants for Primary Copper Smelting Area Sources Title V (Part 70) Major Source Project Proposal Administrative Action to Approval Order DAQE-AN103460062-23
Project Description Rio Tinto Kennecott Utah Copper LLC (KUC) operates a copper smelter and refinery in Salt
Lake County, Utah. KUC requested a modification to AO DAQE-AN103460062-23 to include missing condition II.B.7.a, regarding opacity limits. This condition was included in the engineering review for, but was somehow removed when the AO was issued. This administrative
action adds condition II.B.7.a back into the AO and makes no other changes. EMISSION IMPACT ANALYSIS
This is an administrative action. There is no change in PTE so no modeling is required. [Last updated August 29, 2024]

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SUMMARY OF EMISSIONS
The emissions listed below are an estimate of the total potential emissions from the source. Some rounding of emissions is possible.
Criteria Pollutant Change (TPY) Total (TPY) Ammonia 0 9.11 CO2 Equivalent 0 235522.00
Carbon Monoxide 0 168.97
Lead Compounds 0 6.00
Nitrogen Oxides 0 161.25
Particulate Matter - PM10 0 2016.07
Particulate Matter - PM2.5 0 1946.11 Sulfur Dioxide 0 1081.32 Volatile Organic Compounds 0 14.86

Hazardous Air Pollutant Change (lbs/yr) Total (lbs/yr)
Generic HAPs (CAS #GHAPS) 0 14960
Lead Compounds (CAS #LCT000) 0 12000
Change (TPY) Total (TPY) Total HAPs 0 13.48 Note: Change in emissions indicates the difference between previous AO and proposed modification.

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Review of BACT for New/Modified Emission Units 1. BACT review regarding New Equipment This is an administrative action. No BACT review required. [Last updated August 29, 2024]
SECTION I: GENERAL PROVISIONS

The intent is to issue an air quality AO authorizing the project with the following recommended conditions and that failure to comply with any of the conditions may constitute a violation of the AO. (New or Modified conditions are indicated as “New” in the Outline Label):
I.1 All definitions, terms, abbreviations, and references used in this AO conform to those used in the UAC R307 and 40 CFR. Unless noted otherwise, references cited in these AO conditions refer to those rules. [R307-101]

I.2 The limits set forth in this AO shall not be exceeded without prior approval. [R307-401] I.3 Modifications to the equipment or processes approved by this AO that could affect the emissions covered by this AO must be reviewed and approved. [R307-401-1]
I.4 All records referenced in this AO or in other applicable rules, which are required to be kept by
the owner/operator, shall be made available to the Director or Director's representative upon request, and the records shall include the five-year period prior to the date of the request. Unless otherwise specified in this AO or in other applicable state and federal rules, records shall be kept for a minimum of five (5) years. [R307-401-8] I.5 At all times, including periods of startup, shutdown, and malfunction, owners and operators shall, to the extent practicable, maintain and operate any equipment approved under this AO,
including associated air pollution control equipment, in a manner consistent with good air pollution control practice for minimizing emissions. Determination of whether acceptable operating and maintenance procedures are being used will be based on information available
to the Director which may include, but is not limited to, monitoring results, opacity observations, review of operating and maintenance procedures, and inspection of the source. All maintenance performed on equipment authorized by this AO shall be recorded. [R307-
401-4] I.6 The owner/operator shall comply with UAC R307-107. General Requirements: Breakdowns. [R307-107]

I.7 The owner/operator shall comply with UAC R307-150 Series. Emission Inventories. [R307-150]

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I.8 The owner/operator shall submit documentation of the status of construction or modification to the Director within 18 months from the date of this AO. This AO may become invalid if construction is not commenced within 18 months from the date of this AO or if construction is
discontinued for 18 months or more. To ensure proper credit when notifying the Director, send the documentation to the Director, attn.: NSR Section. [R307-401-18]

SECTION II: PERMITTED EQUIPMENT
The intent is to issue an air quality AO authorizing the project with the following recommended conditions and that failure to comply with any of the conditions may constitute a violation of the AO. (New or Modified conditions are indicated as “New” in the Outline Label): II.A THE APPROVED EQUIPMENT
II.A.1 Rio Tinto Kennecott Utah Copper LLC
Copper Smelter II.A.2 Filter Plant
Filter Plant Wet Feed Conveyor with baghouse (#SME 001, Stack No. 1) (Relocated and resized) Filter Plant Wet Feed Conveyor Bin Vent (#SME 001-A) (NEW) II.A.3 Feed and Reagent Storage
Feed and reagent storage and transfer consisting of: 1) Wet Feed Storage building with baghouse (#SME 002)
2) Wet Feed Conveyor transfer point with baghouse (#SME 003)
3) Outside Wet Feed Hopper with partial enclosure (#SME 002-A)
4) Wet Feed Bins with baghouse (#SME 004) 5) Flash Smelting Furnace Dry Feed Bin with baghouse (#SME 005) 6) Smelter Limestone Flux Bin with bin vent baghouse (#SME 006)

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II.A.4 Feed and Reagent Storage (Continued) 7) Matte, dust, flux, feed bins with baghouse (#SME 013) 8) Mold Coating Silo with bin vent baghouse (#SME 015) 9) Hydrometallurgical Plant Limestone Silo with bin vent baghouse (#SME 019)
10) Hydrometallurgical Plant Lime Silo with bin vent baghouse (#SME 020)
11) Anode Area Lime Silo with bin vent baghouse (#SME 028)
12) Secondary Gas System Lime Silo with bin vent baghouse (#SME 029)
II.A.5 Feed and Reagent Storage (continued)
13) One Hopper 14) Two Storage Bins
Control: Bin Vent (each)
(vents inside the building)
15) Conveyers with water sprays II.A.6 Pyrometallurgical Processes - Flash Smelting
1) Rotary Feed Dryer with baghouse followed by a scrubber (#SME 011e)
2) Flash Smelting Furnace (FSF) with (in series) (#SME 011b1)
a) Waste heat boiler
b) Electrostatic precipitator (ESP)
c) Scrubber served by wet ESP and acid plant d) Emergency generator with turbocharger and aftercooling
Maximum Rating: 998 hp

II.A.7 Pyrometallurgical Processes - FS (Continued) 3) Matte Granulation process, North and South Matte Granulators (#SME 010a) each have a three stage impingement scrubber equipped with demister pads that vent to the secondary gas system (vents to the main stack)

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II.A.8 Pyrometallurgical Processes - Flash Converting 1) Matte Drying and Grinding Plant with baghouse (#SME 011g)
2) Flash Converting Furnace (FCF) with (in series) (#SME 011b2)
a) Waste heat boiler
b) ESP
c) Scrubber served by wet ESP and acid plant
3) Slag Granulation with three stage impingement scrubber, emissions are either
directed
a) to the scrubber and then to the atmosphere through the vent stack; or
b) to the scrubber and then to the secondary gas system (#SME 010b)
II.A.9 Pyrometallurgical Processes - FCF/FSF 1) Co-Jet Technology Burner System (#SME 011b3)
Quantity: 3 co-jet injectors
Rating: 13 MMBtu/hr each
Fuel: Natural gas/oxy-fuel II.A.10 Pyrometallurgical Processes - Anodes Area
1) Anode furnace system consisting of:
a) Anode Furnaces and optional coherent jet lances* with (in series)
(#SME 011h1)
(1) Quench tower
(2) Lime injection
(3) Baghouse
(4) Two scrubbers in series
*The lances are used for material heating and melting on a
non-continuous basis
b) Wenmec twin casting wheel and quench tower (#SME 011h4)
c) Shaft furnace (#SME 011h2) and holding furnace (#SME 011h3) with
baghouse
d) Mold casting furnace (#SME MOLD

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II.A.11 Product Recovery/Gas Cleaning Facilities Product Recovery/Gas Cleaning Facilities that serve FSF and FCF
1) Wet ESP 2) Acid Plant (#SME 011b) with
a) Acid Plant Cooling Tower (#SME CT311)
b) Acid Plant Collection System (#SME GLCS) with adjustable negative
pressure ductwork and collection hoses placed as needed for opacity
control

c) Acid Plant Preheater (#SME 008)
II.A.12 Product Recovery/Gas Cleaning (Continued) Product Recovery/Gas Cleaning Facilities that serve emission sources in the Hot Metals Building, Matte Granulators, or Slag Granulators as needed
3) Secondary Gas Cleaning System (#SME 011a) with

a) Lime injection system
b) Baghouse
c) Reverse Jet scrubber A and Reverse Jet scrubber B II.A.13 Intermediate Product Storage Intermediate Product Storage, Crushing, and Grinding Operations
1) Slag Concentrator (#SME SLAG)
2) Recycle Materials Crushing and Storage building with baghouse (#SME 027)
a) Furnace dust crusher system 12 ton/hour capacity
II.A.14 Intermediate Product Storage (cont'd) 3) Crushing and Screening Operation (#SME SLAG)
a) Jaw crusher Maximum 600 ton/hour capacity
b) Cone crusher Maximum 600 ton/hour capacity
c) Fines crusher Maximum 600 ton/hour capacity
d) Conveyors Partially enclosed transfer points with water sprays
e) Triple deck screen
f) High frequency screens

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II.A.15 Miscellaneous Support Equipment 1) Miscellaneous mobile diesel equipment
2) Small natural gas-fired space heaters and water heaters (#SME SH, WH) 3) Outdoor storage piles where concentrate, granulated matte, slag, and other process
materials are stored on pads (#SME STRG)

II.A.16 Smelter Powerhouse 1) Superheater with ultra-low NOx burners (#SME 011f)
Rating: 45 MMBtu/hr
Fuel: Natural gas
Vents to main stack 2) Holman Boiler (#SME 026)
Rating: 187 MMBtu/hr
Fuel: Natural gas 3) Rentech Boiler (#SME 030)
Rating: 183 MMBtu/hr
Fuel: Natural gas
4) Powerhouse Cooling Tower (#SME CT316) 5) Two (2) Diesel-Fired Emergency Generators (#SME GEN)
Rating: 2,847 hp each
II.A.17 Hydrometallurgical Plant (#SME 011d) Controls: Two scrubbers
II.A.18 Vacuum Cleaning Systems (#SME 017) 1) Matte handling vacuum cleaning system with baghouse 2) FSF vacuum cleaning system ducted to the secondary gas collection system 3) FCF vacuum cleaning system with baghouse II.A.19 Support Facilities 1) Laboratories, with baghouse (#SME 022)
2) Various degreasing parts washers (#SMEi210)
3) Gasoline fueling station (#SME SA-1)

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II.A.20 Support Facilities* (Continued) 4) Wash rooms
5) Change house 6) Engineering shops 7) Warehouses 8) Administrative buildings
*These are listed for informational purposes only
II.A.21 Communication Emergency Generator (#SME COM GEN) Maximum Rating: 75 hp Fuel: Liquid propane

SECTION II: SPECIAL PROVISIONS
The intent is to issue an air quality AO authorizing the project with the following recommended conditions and that failure to comply with any of the conditions may constitute a violation of the AO. (New or Modified conditions are indicated as “New” in the Outline Label): II.B REQUIREMENTS AND LIMITATIONS
II.B.1 Limitations and Test Procedures II.B.1.a NEW Emissions to the atmosphere from the indicated emission points* shall not exceed the following rates and concentrations:
A. #SME 001 - Wet Feed Conveyor Baghouse (Stack No. 1) PM10 0.7 lbs/hr (filterable)
0.008 grains/dscf (68 degrees F, 29.92" Hg) B. #SME 002 - Wet Feed Storage Building Baghouse (Stack No. 2) PM10 3.91 lbs/hr (filterable)
0.008 grains/dscf (68 degrees F, 29.92" Hg)
C. #SME 003 - Wet Feed Conveyor Transfer Point Baghouse (Stack No. 3)
PM10 0.4 lbs/hr (filterable)
0.016 grains/dscf (68 degrees F, 29.92" Hg) D. #SME 004 - Wet Feed Bin Baghouse (Stack No. 4) PM10 3.4 lbs/hr (filterable)
0.016 grains/dscf (68 degrees F, 29.92" Hg)
E. #SME 005 - Flash Smelting Furnace Dry Feed Bin Baghouse (Stack No. 5)

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PM10 1.2 lbs/hr (filterable)
0.016 grains/dscf (68 degrees F, 29.92" Hg) F. #SME 006 - Smelter Limestone Flux Bin Baghouse (Stack No. 6) PM10 0.3 lbs/hr (filterable)
0.016 grains/dscf (68 degrees F, 29.92" Hg)
G. #SME 010b - Slag Granulation Exhaust Scrubber (Stack No. 10b)
PM10 1.9 lbs/hr (24 hr. average - calendar day) (filterable) SO2 2.0 lbs/hr (24 hr. average - calendar day) Operating Hours 3504 hrs per rolling 12-month period
H. #SME 011 - Main Stack (Stack No. 11)
PM10 89.5 lbs/hr (24 hr. average - calendar day) (filterable)
439 lbs/hr (filterable + condensable) PM2.5 85 lbs/hr (filterable)
434 lbs/hr (filterable + condensable) SO2 552 lbs/hr (three-hr. rolling average)
422 lbs/hr (24 hr. average - calendar day)
211 lbs/hr (annual average)
NOx 35.0 lb/hr (annual average)
146.5 lb/hr (daily average) Lead 1.3 lb/hr (annual average) I. #SME 013 - Dry Matte Bin Baghouse (Stack No. 13) PM10 0.3 lbs/hr (filterable)
0.016 grains/dscf (68degrees F, 29.92" Hg)
J. #SME 017 - Vacuum Cleaning Systems (Stacks No. 17a & 17c combined) PM10 0.7 lbs/hr (filterable)
0.016 grains/dscf (68degrees F, 29.92" Hg) K. #SME 026 - Holman Boiler (Stack No. 26) NOx 9.34 lbs/hr, 30-day rolling average
14 lbs/hr, calendar-day average
L. #SME 030 - Rentech Boiler (Stack No. 30)
NOx 3.29 lbs/hr, 30-day rolling average
4.94 lb/hr, calendar-day average M. #SME 011b - Acid Plant Tail Gas SO2 250 ppmdv (six- hr. block average)
170 ppmdv (24 hr. average - calendar day)
100 ppmdv (annual average) Sulfuric Acid Mist 0.67 mg/scf (68degrees F, 29.92" Hg)
N. #SME 011e - Dedicated Rotary Dryer Baghouse

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Particulate Emissions (PM) 0.022 grains/dscf (68 degrees F, 29.92" Hg) (filterable) * Reference to stack numbers above and in Conditions II.B.1.a.2 and II.B.1.a.3 below do not necessarily refer to an exhaust point to the atmosphere. Many emission sources are commingled with emissions from other sources and exit to the atmosphere from a common emission point. "Stack" in these conditions refer to the point prior to mixing with emissions from other sources. [R307-401-8]
II.B.1.a.1 To determine compliance with an annual average emission limitation, the owner/operator shall
calculate a new annual average by the 20th day of each month using data from the previous 12 months. All annual average emission limits shall be based on a rolling 12-month average using the daily averages from the previous 12 months. [R307-401-8]
II.B.1.a.2 NEW Stack testing to show compliance with the emissions limitations of Condition II.B.1.a shall be performed as specified below: A. Emission Point Pollutant Testing Status Test Frequency 1) Stack Nos. 2, 3, 4, 5,6, 13,17a & 17 c PM10 ** every five (5) years 1a.) Stack No 1 PM10 * every five (5) years 2) Stack Nos. 10b PM10 ** every three (3) years
SO2 ** every three (3) years
3) Main Stack PM10 ** every year and continuous
particulate monitor Stack No. 11 PM2.5 ** every year
SO2 ** CEM
NOx ** CEM
Lead ** continuous particulate monitor
4) Holman Boiler NOx ** every three (3) years
Stack No. 26 calendar-day
average
NOx ** CEM or alternate method
30-day average determined according to
Condition II.B.2.b
5) Rentech Boiler NOx ** every three (3) years Boiler Stack No. 30 calendar-day
average

NOx ** CEM or alternate method
30-day average determined according to
Condition 11.B.2.c

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6) Acid Plant Tail gas SO2 ** CEM (concentration) Sulfuric Acid Mist ** every three (3) years
7) Dedicated Rotary PM ** every five (5) years Dryer Baghouse/Scrubber
B. Testing Status (To be applied above) *Initial testing shall be performed as soon as possible and in no case later than 180 days after start up.
** The initial test has been performed on these sources.

C. The owner/operator may petition the Director to reduce the stack testing
frequency of an emission point in a given year after the following: if, after
two (2) stack tests for an emission point in Condition II.B.1.a.2
conducted in accordance with Condition II.B.1.a.3, the owner/operator
can show, either because of reliability of pollution control equipment,
constant emissions, or other appropriate reasons, the stack testing
frequency in Condition II.B.1.a.2 is more frequent than necessary to
determine the quantity of emissions. [R307-401-8] II.B.1.a.3 NEW Stack testing to show compliance with the emission limitations of Condition II.B.1.a shall be performed as specified below (continued):
A. Notification
Notification of the date, time, place of test and a copy of the test protocol
shall be provided at least 30 days prior to the test. A pretest conference
shall be held if directed by the Director.
B. Sample Location
The emission point shall be designed to conform to the requirements of 40
CFR 60, Appendix A, Method 1 or other EPA-approved methods acceptable
to the Director. Occupational Safety and Health Administration
(OSHA)-approved and/or Mine Safety and Health Administration
(MSHA)-approved access shall be provided to the test location.
C. Volumetric Flow Rate
40 CFR 60, Appendix A, Method 2, Method 19 or other EPA-approved
testing methods acceptable to the Director

D. PM
40 CFR 60, Appendix A, Method 5 or other EPA-approved testing methods
acceptable to the Director
E. PM10/PM2.5
For stacks in which no liquid drops are present, the following methods shall

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be used: 40 CFR 51, Appendix M, Methods 201 or 201a or other
EPA-approved testing method acceptable to the Director. The back half
condensable particulate emissions shall also be tested (where applicable)
using 40 CFR 51, Appendix M Method 202, or other EPA- approved testing
method acceptable to the Director. All particulate captured using Method
202 shall be considered PM2.5 and/or PM10.
For stacks in which liquid drops are present, methods to eliminate the liquid drops shall be explored. If no reasonable method to eliminate the drops exists, then the following methods shall be used: 40 CFR 60, Appendix A, Method 5, 5a, 5d, 5i or other as appropriate. If using Method 5 or any variation of Method 5, a scanning electron microscopy analysis or other equivalent method shall be used to determine the fraction of PM10 and/or PM2.5, as approved by the Director. The back half condensable particulate emissions shall also be tested using 40 CFR 51, Appendix M Method 202 or other EPA- approved testing method acceptable to the
Director. All particulate captured using Method 202 shall be considered PM2.5 and/or PM10.
For filterable emission limits, condensable emissions shall not be used for compliance demonstrations. For filterable + condensable emission limits, both filterable and condensable emissions shall be used for compliance demonstrations. [R307-401-8]
II.B.1.a.4 NEW Stack testing to show compliance with the emission limitations of Condition II.B.1.a shall be performed as specified below (continued):

F. SO2
40 CFR 60 Appendix A, Method 6, 6A, 6B, 6C or other EPA-approved
testing methods acceptable to the Director

G. Lead
The test method shall be submitted for approval or may be assigned by the
Director. A monitoring plan was submitted to the Director on October 10,
2000 and amended in 2007. The owner/operator shall monitor in
accordance with the most recent monitoring plan approved by the Director.
H. Sulfuric Acid Mist
40 CFR 60, Appendix A, Method 8
I. NOx
40 CFR 60 Appendix A, Method 7, 7A, 7B, 7C, 7D, 7E or other EPA-
approved testing methods acceptable to the Director

J. Source Operation
For stack testing purposes, stack tests shall be done during representative
operations. The production rate during all compliance tests shall be no less
than 90% of the maximum average hourly production rate achieved in a
24-hour period during the previous three (3) years.
K. Calculations
To determine mass emission rates (lb/hr, etc.) the pollutant concentration as
determined by the appropriate methods above shall be multiplied by the

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volumetric flow rate and any necessary conversion factors determined by the
Director, to give the results in the specified units of the emission limitation.
L. Results
The results of stack testing shall be submitted to the Director within 60 days
of completion of the testing. Reports shall clearly identify results as
compared to permit limits and indicate compliance status. [R307-401-8] II.B.2 Holman Boiler and Rentech Boiler NOx Requirements
II.B.2.a The owner/operator shall not exceed 23.3 tons of NOx emissions per rolling 12-month period from the Holman boiler and Rentech boiler combined. [R307-401-8]
II.B.2.a.1
NEW
To determine compliance with a rolling 12-month total, the owner/operator shall calculate a
new 12-month total by the 20th day of each month using data from the previous 12 months. Records of emissions shall be kept for all periods when the plant is in operation. Monthly totals of NOx emissions from each boiler shall be based on the following:
A. The 30-day average NOx emissions rate (lb/hr) of the Holman boiler for the calendar
month, determined according to Condition II.B.2.b
B. The hours of operation of the Holman boiler for the calendar month
C. The 30-day average NOx emissions rate (lb/hr) of the Rentech boiler for the calendar
month, determined according to Condition II.B.2.c
D. The hours of operation of the Rentech boiler for the calendar month
[R307-401-8]

II.B.2.b Initial compliance with the Holman boiler 30-day average NOx limit was demonstrated with the CEM in accordance with 40 CFR 60.46b(e)(1). The owner/operator shall continue to use the CEM, or propose to the Director an alternative method for demonstrating compliance with the limit in accordance with 40 CFR 60.46b(e)(1) and (4), 60.48b(g) (1) and (2), and 60.49b(c). Either a CEM or the most recently approved alternate plan approved by the Director shall be used. [R307-401-8]

II.B.2.c The owner/operator shall demonstrate compliance with the Rentech boiler 30-day average NOx in accordance with 40 CFR 60.46b(e) and either 40 CFR 60.48b(g)(1) or 40 CFR 60.48b(g)(2). For subsequent compliance, either a CEM or the most recently approved alternate plan to monitor boiler operating conditions and predict NOx emission rates shall be used. *Initial compliance was using a CEM in accordance with 40 CFR 60.46b(e) and (e)(1). [R307-401-8]

II.B.2.c.1 The owner/operator shall maintain and operate the CEM in accordance with UAC R307-170.
The records and results of monitoring shall be maintained in accordance with 40 CFR 60.49b and UAC R307-170. [R307-170, R307-401-8]
II.B.2.c.2 If the owner/operator chooses to comply with the monitoring provisions of 40 CFR
60.48b(g)(2) to demonstrate compliance with the Rentech boiler 30-day average NOx limit,

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the owner/operator shall submit an alternate plan to the Director in accordance with 40 CFR 60.49b(c) that identifies the operating conditions to be monitored and the records to be maintained. This plan shall be submitted to the Director for approval within 360 days of the
initial startup of the Rentech boiler. [40 CFR 60 Subpart Db, R307-401-8] II.B.2.c.3 The owner/operator shall submit notifications and reports as required in 40 CFR 60.49b and R307-170. Results of the additional certified NOx CEM 30-day CEM tests as required in 40 CFR 60.46b(e) shall be submitted within 60 days of the completion of the test. [40 CFR 60 Subpart Db, R307-170] II.B.3 Main Stack Continuous Monitoring Requirements II.B.3.a To demonstrate compliance with the main stack mass emissions limits for SO2 and NOx of Condition II.B.1.a.H, the owner/operator shall calibrate, maintain and operate the measurement systems for continuously monitoring SO2 and NOx concentrations and stack gas volumetric flow rates in the main smelter stack. [R307-401-8]
II.B.3.a.1 The owner/operator shall comply with all applicable parts of UAC R307-170 "Continuous Emission Monitoring Systems Program", including the requirements for annual Relative Accuracy Test Audits (RATA) and quarterly Relative Accuracy Audits (RAA) or Cylinder Gas Audits (CGA). A. The required RATA, RAA, and CGA shall be conducted following procedures in 40 CFR 60 Appendix B, Specification 2 and 40 CFR 60 Appendix F.
B. Acceptable methods for the annual RATA include 40 CFR 60, Appendix A, Method 6 or
6C for SO2 and Method 7 or 7E for NOx.
C. All audit and test results shall be submitted to the Director within 60 days after the audit or test is completed. [R307-401-8] II.B.3.a.2 The owner/operator shall perform 40 CFR 52 Appendix E - Performance Specification procedures on the stack gas flow rate measurement system, if directed by the Director, in the event that the results of the quarterly and annual tests required by Condition II.B.3.a.1 demonstrate that the SO2 and NOx monitoring systems are not performing properly. [R307-401-8]

II.B.3.a.3 Failure to measure SO2 at least ninety-five percent (95%) of the hours during which emissions occurred in any quarter in accordance with the requirements of this subsection, or failure to measure, in accordance with the requirements of this subsection, any 18 consecutive hours of
emissions data shall constitute a violation of Condition II.B.3.a.
A. Any hour for which the measurements comply with UAC R307-170 shall be considered as measured. B. Any hours for which the emissions data are greater than 20% in error will be considered to have not been measured for the purposes of Condition II.B.3.a. C. The Director may grant exemptions to the requirements of Condition II.B.3.a if unusual circumstances, not to include malfunction of any of the monitoring instrumentation, arise
which prevent the owner/operator from obtaining hourly measurements of emissions in accordance with Condition II.B.3.a. [40 CFR 60 Subpart P, R307-401-8]

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II.B.3.a.4 NEW The owner/operator shall maintain a record of all measurements required by Condition II.B.3.a. Measurement results shall be expressed as pounds of SO2 and NOx emitted per hour calculated at the end of each day for the preceding 24 hours for SO2 and NOx and calculated at the end of each hour for the preceding three-hour period for SO2. Records shall include:
A. The total number of hourly periods during the month in which measurements were not
taken.
B. For any periods where loss of measurement is greater than three continuous hours, the
reason for loss of measurement in each period. C. The date(s) on which three and 24-hour emissions averages for SO2 exceeded the
applicable emission level in Condition II.B.1.a.H and the number of exceedances. D. The date(s) on which the annual emissions average based on hourly emissions exceeded
the applicable emission level in Condition II.B.1.a.H for NOx for the month
being reported and the number of such exceedances, and the daily NOx averages.
E. All conversion values used to derive the three and 24-hour average and annual average
emissions for SO2, and the 24-hour average and annual average for NOx, including
temperature and differential pressure of stack gases. [R307-401-8]
II.B.3.a.5 Data, reports, or results required to be submitted pursuant to Condition II.B.3.a, shall be
deemed to be verified and accepted as valid and not subject to challenge and shall be used by the Director in determining compliance with Condition II.B.1.a.H, unless, within 30 days of the time such data, reports, or results are submitted, the owner/operator or the Director
provides evidence that the data, results, or reports or any part thereof, are greater than 20% in error. [R307-401-8]
II.B.3.a.6 During periods of malfunctioning or maintenance of the stack gas temperature and velocity measurement instrumentation, the owner/operator may estimate stack gas flow rate. Such estimates will be considered as measurements for the purpose of Condition II.B.3.a. Records of calculations used to derive the estimated flow rate and a list of the periods where stack gas
flow rate was estimated in each month shall be maintained. No more than 10% of the flow rates in any one month may be estimated. [R307-401-8]
II.B.3.b The owner/operator shall continuously measure emissions of particulate matter from the main stack. For the purposes of determining compliance with Condition II.B.1.a.H, all particulate matter collected shall be reported as PM10. Compliance with the main stack emission limit for PM10 of Condition II.B.1.a.H shall be demonstrated using the smelter main stack continuous
particulate sampling system to provide a 24-hour value. Collected data shall be available for inspection, and a summary of 24-hour averages shall be submitted to the Director monthly within 20 days of the end of the month. [R307-401-8]
II.B.3.c The owner/operator shall determine the lead emissions from the main stack using the main stack particulate data and laboratory analysis of the material collected by the continuous stack particulate sampler. The owner/operator shall monitor in accordance with the most recent monitoring plan approved by the Director. If the owner/operator cannot monitor the lead

Engineer Review N103460063: Rio Tinto Kennecott Utah Copper LLC - Smelter & Refinery September 24, 2024 Page 20
emissions using the continuous particulate sampler, then the owner/operator shall monitor the lead emissions using a monitoring plan approved by the Director. [R307-401-8]
II.B.4 Scrubber and Baghouse Monitoring Requirements II.B.4.a NEW The owner/operator shall install, calibrate, maintain, and operate the following monitoring devices for the measurement of the indicated parameters. Continuous recording instruments
are optional but are not required. The gauges/devices shall be located such that an inspector can safely read them at any time. The monitoring devices shall be calibrated in accordance with the manufacturer's instructions.
A. A monitoring device for the continuous measurement of the change in pressure of the gas stream across the secondary ventilation scrubber, rotary dryer scrubber, anode furnace scrubber, and hydrometallurgical plant scrubber(s). A "U" tube manometer is recommended. B. A monitoring device for the continuous measurement of the scrubbing liquid flow rate to the secondary ventilation scrubber, rotary dryer scrubber, anode furnace scrubber, and hydrometallurgical plant scrubber(s).
C. A monitoring device for the continuous measurement of the change in pressure of the
gas stream across each baghouse.
The operating range and accuracy of the monitoring devices shall be submitted to the Director.
[R307-401-8]
II.B.4.b The owner/operator shall maintain a monitoring record or log with monitoring data to demonstrate compliance with the operating ranges listed below. [R307-401-8]
II.B.4.b.1 NEW The operating pressure drop across the following equipment shall be maintained within the following operating ranges:
A. Secondary Ventilation Scrubbers: 3.5" Water Gauge (W.G.) (minimum, across
both scrubbers combined) B. Rotary Dryer Scrubber: 5" to 19.25" W.G. C. Anode Furnace Scrubber: 18" to 50.5" W.G.
D. Hydrometallurgical Plant Scrubber Model #480: 5" to 10" W.G. E. Hydrometallurgical Plant Scrubber Model #575: 6" to 12" W.G. [R307-401-8]
II.B.4.b.2 The operating scrubbing liquid flow rate for the following equipment shall be maintained within the following operating ranges: A. Secondary Ventilation Scrubber: greater than 4800 gpm (each) B. Rotary Dryer Scrubber: greater than 7360 gpm
C. Anode Furnace Scrubber: greater than 2000 gpm (each) D. Hydrometallurgical Plant Scrubber Model #480: greater than 50 gpm E. Hydrometallurgical Plant Scrubber Model #575: greater than 40 gpm [R307-401-8]
II.B.4.b.3 Pressure drops for the following baghouses shall be maintained within the following operating

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NEW ranges: A. Filter Plant Wet Feed Conveyor Baghouse: 0.5" to 4" W.G. B. Wet Feed Storage Building Baghouse: 1.5" to 5" W.G.
C. Wet Feed Conveyor Belt Transfer Point Baghouse: 0.5" to 5.25" W.G. D. Wet Feed Bin(s) Baghouse: 2.75" to 5" W.G. E. Flash Smelting Furnace Dry Feed Bin Baghouse: 0.25" to 11" W.G.
F. Limestone Flux Bin Baghouse: 0.5" to 4" W.G. G. Secondary Gas Handling System Baghouse: 6" to 15" W.G. H. Matte Drying and Grinding Plant Baghouse: 5" to 15" W.G.
I. Dry Matte Bin Baghouse: 0.5" to 13" W.G. J. Anode Refining Furnace Baghouse: 1" to 9" W.G. K. Anode Shaft Furnace Baghouse: 1" to 10" W.G. L. Mold Coating (Barite) Bin Baghouse: 0.25" to 4" W.G. M. Vacuum Cleaning Systems (2 Baghouses): 0.25" to 6" (each) W.G. N. Hydrometallurgical Plant Limestone Storage Bin Baghouse: 0.5" to 4" W.G. O. Hydrometallurgical Plant Lime Storage Bin Baghouse: 0.25" to 4" W.G. P. Recycle Materials Crushing and Storage Building Baghouse: 1" to 5" W.G. [R307-401-8]
II.B.5 Natural Gas Consumption Requirements II.B.5.a The natural gas consumption per rolling 12-month period shall not exceed the following limitations for the equipment listed: A. Acid Plant Preheater - 74,476 MMBTU B. Pyrometallurgical Process Group - 1,947,847 MMBTU The Pyrometallurgical Process Group includes the following units: A) Anode Area: i. SME 011h1 - Anode Furnaces ii. SME 011h2 - Shaft Furnace iii. SME 011h3 - Holding Furnaces iv. SME MOLD - Mold Casting Furnace
B) Launder Heaters i. SME 011b1 - FSF ii. SME 011b2 - FCF
iii. SME 011b3 - Co-Jet Burner C. SME 011g - Matte Grinding Plant D. SME 011e - Rotary Concentrate Dryer
[R307-401-8]
II.B.5.a.1 To determine compliance with a rolling 12-month total, the owner/operator shall calculate a new 12-month total by the 20th day of each month using data from the previous 12 months. Records of consumption shall be kept for all periods when the plant is in operation. Natural gas consumption shall be determined by individual gas meters readings reconciled against monthly billing statements. [R307-401-8] II.B.5.a.2 The natural gas allocations in Condition II.B.5.a may be reapportioned upon demonstration to the Director that no increase in potential NOx emissions would result. [R307-401-8]

II.B.5.a.3 Propane may be used as an alternate fuel supply during natural gas curtailment. [R307-401-8]

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II.B.6 Fugitive Emissions and Material Handling Requirements
II.B.6.a The emissions from the transfer point between the outside hopper/feeder and the wet feed conveyor on the wet feed conveyor transfer point with baghouse from the Outside Feed Hopper shall be ducted to the wet feed storage building baghouse. [R307-401-8]
II.B.6.b All roads, parking lots, and service yards directly servicing the approved constructed
installations listed above in Section II.A, with the exception of II.A.13, of this AO shall be paved. [R307-401-8]
II.B.6.c The owner/operator shall carry out the current Fugitive Dust Control Plan approved by the
Director. [R307-401-8]
II.B.6.d Any open storage piles shall be watered, covered, or chemically treated to minimize generation of fugitive dusts as dry conditions warrant or as determined necessary by the Director. [R307-401-8]
II.B.6.e Emissions from the slag concentrator bin shall be controlled with water sprays. Treatment shall be of sufficient frequency and quantity to maintain the surface material in a damp/moist condition unless it is below freezing. The degree of control is a minimum of that required to
meet the opacity limitations of Condition II.B.7.a. [R307-401-8] II.B.6.e.1 A visual inspection of the water spray system on the slag concentrator bin shall be performed on a weekly basis to ensure proper operating condition. Records of each inspection shall be
maintained in accordance with Condition I.4. [R307-401-8] II.B.6.f The crushing and screening operation shall not process more than 5,000 tons of material per calendar day and 750,000 tons of material per rolling 12-month period. [R307-401-8]
II.B.6.f.1 To determine compliance with a rolling 12-month total, the owner/operator shall calculate a new 12-month total by the 20th day of each month using data from the previous 12 months. Records of daily material processing shall be kept for all periods when the smelter is in operation. Daily total material processing shall be determined by daily reports. [R307-401-8]

II.B.6.g Water sprays or chemical dust suppression sprays shall be installed at the following points that are not enclosed or have baghouses to control fugitive emissions: A. All crushers B. All stationary conveyor transfer points C. The crusher and screening units shall have water spray at the
input to the crusher and at the discharge points from the crusher. The sprays shall operate whenever dry conditions warrant or as determined necessary by the Director. [R307-309]
II.B.7 Site-Wide Requirements
II.B.7.a NEW Visible emissions from the following emission points shall not exceed the following values: Emission Point Opacity Limit A. #SME 001 - Wet Feed Conveyor Baghouse (Stack No. 1) 7%

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B. #SME 002 - Wet Feed Storage Building Baghouse (Stack No. 2) 7% C. #SME 003 - Wet Feed Conveyor Transfer Point Baghouse (Stack No. 3) 7% D. #SME 004 - Wet Feed Bin Baghouse (Stack No. 4) 7% E. #SME 005 - Flash Smelting Furnace Dry Feed Bin Baghouse (Stack No. 5) 7% F. #SME 006 - Smelter Limestone Flux Bin Baghouse (Stack No. 6) 10%
G. #SME 008 - Acid Plant Preheater (Stack No. 8) 10% H. #SME 010b - Slag Granulator Scrubber Stack (Stack No. 10b) 15%
I. #SME 011 - Smelter Main Stack (Stack No. 11) 20%
J. #SME 013 - Dry Matte Bin Baghouse (Stack No. 13) 10% K. #SME 015 - Mold Coating Silo Baghouse (Stack No. 15) 10% L. #SME 017 - Vacuum Cleaning System (Stacks No. 17a & 17c combined) 10% M. #SME 019 - Hydrometallurgical Plant Limestone Silo Baghouse (Stack No. 19) 10%
N. #SME 020 - Hydrometallurgical Lime Silo Baghouse (Stack No. 20) 10%
O. #SME 022 - Laboratory Baghouse (Stack No. 22) 10%
P. #SME SLAG - Slag Concentrator Bin 10%
Q. #SME SLAG - Slag Crushing and Grinding Transfer Points 10%
R. #SME 026 - Holman Boiler (stack 26) 10%
S. #SME 027 - Recycle Materials Crushing & Storage Building Baghouse (Stack No. 27) 10%
T. #SME 028 - Anode Area Lime Silo Baghouse
(Stack No. 28) 10% U. #SME 029 - Secondary Gas System Lime Silo Baghouse (Stack No. 29) 10%

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V. #SME 030- Rentech Boiler (Stack No. 30) 10%
W. #SME SLAG - Crushing and Screening Plant 10%
X. SME 001a - Filter Plant Wet Feed Bin Vent 10% Y. #SME 011b - Acid Plant Tail Gas 15% Z. #SME 011e - Rotary Dryer Baghouse/Scrubber Outlet 15% AA. Hot Metals Building Roof Vents 20% BB. Acid Plant Process Gas Leaks 20%
CC. All other points 20% [R307-305-3]
II.B.7.a.1 Opacity observations of emissions from stationary sources shall be conducted in accordance with 40 CFR 60, Appendix A, Method 9. [R307-401-8]

II.B.7.a.2 For sources that are subject to NSPS, opacity shall be determined by conducting observations in accordance with 40 CFR 60.11(b) and 40 CFR 60, Appendix A, Method 9. A. For purposes of determining initial compliance, observations shall be conducted according to 40 CFR 60.11(b) unless otherwise specified under the applicable NSPS subpart. B. It is the responsibility of the owner/operator of the source to supply these observations to the Director.
C. A currently certified observer must be used for these observations. [40 CFR 60 Subpart A]

II.B.7.a.3 The owner/operator shall install, calibrate, maintain, and operate continuous opacity
monitoring systems on the rotary dryer baghouse/scrubber, the main stack, and the acid plant tail gas. [R307-401-8]
II.B.7.a.4 The owner/operator shall record the output of the systems for measuring the opacity of
emissions on the rotary dryer baghouse/scrubber outlet, main stack, and acid plant tail gas. The monitoring systems shall comply with all applicable sections of UAC R307-170 and 40 CFR 60, Appendix B, Specification 1 - Opacity. [R307-401-8]

II.B.7.a.5 Sources equipped with continuous opacity monitors (rotary dryer baghouse/scrubber, acid plant tail gas and main stack) shall use the compliance methods contained in 40 CFR 60.11. [R307-305-3]

II.B.7.a.6 The owner/operator shall perform a visual opacity survey of the acid plant process gas leaks emission unit on a weekly basis to minimize emissions from leaks of sulfur dioxide, sulfur trioxide, and other process emissions. A. Surveys shall be conducted by an individual trained on the observation procedures of 40 CFR 60, Appendix A, Method 9.

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B. If visible emissions other than steam are observed from the acid plant process gas leaks emission unit, an opacity determination shall be performed by a certified observer within 24
hours of the initial survey. The opacity determination shall be performed in accordance with 40 CFR 60, Appendix A, Method 9. C. If visible emissions greater than 15% opacity are observed, then best operational practices shall be initiated within 24 operating hours of the observation to ensure leakage of gases to the
ambient air are being controlled to 20% opacity or less. Best operational practices may include, but are not limited to: 1) Placement or adjustment of negative pressure ductwork and collection hoses; 2) Welding of process gas leaks; or 3) Containment of process gas leaks.
D. A log of the visual opacity survey(s) shall be maintained. If an opacity determination is indicated, a notation of the determination will be made in the log. [R307-401-8] II.B.7.b The owner/operator shall install, calibrate, maintain, and operate continuous monitoring systems on the acid plant tail gas. [R307-401-8]

II.B.7.b.1 The owner/operator shall record the output of the system for measuring the SO2 concentration of the acid plant tail gas. The monitoring system shall comply with all applicable sections of UAC R307-170, 40 CFR 60, Appendix B, Specification 2 - SO2. [R307-401-8]

II.B.7.c The owner/operator shall only combust diesel fuel ((e.g. fuel oil #1, #2, or diesel fuel oil
additives) that meets the definition of ultra-low sulfur diesel (ULSD), which has a sulfur content of 15 ppm or less. [R307-401-8]
II.B.7.c.1 To demonstrate compliance with the ULSD fuel requirement, the owner/operator shall
maintain records of diesel fuel purchase invoices or obtain certification of sulfur content from the diesel fuel supplier. The diesel fuel purchase invoices shall indicate that the diesel fuel meets the ULSD requirements. [R307-401-8]

II.B.7.d All gases produced during smelting and/or converting which enter the primary gas handling system shall pass through an online sulfuric acid plant. During the start-up/shutdown process of any equipment, the gas emissions shall be ducted, as necessary, either to the acid plant or to
the secondary scrubber for control. [R307-401-8] II.B.7.e NEW The owner/operator shall employ the following measures for reducing escape of pollutants to the atmosphere and to capture emissions and vent them through a stack or stacks: A. Maintenance of all ducts, flues, and stacks in such a fashion that leakage of gases to
the ambient air will be prevented to the maximum extent practicable
B. Operation and maintenance of gas collection systems in good working order C. Making available the preventive/routine maintenance records for the hooding systems;
dust collection mechanism of waste heat boilers; furnace wet scrubbing systems; and

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dry electrostatic precipitators
D. Weekly observation of process units
E. Monthly inspection of gas handling systems F. Maintenance of gas handling systems, available on call on a 24-hour basis G. Operation and maintenance of an upwind/downwind fugitive SO2 monitoring system.
The owner/operator may petition the Director to discontinue the operation of this
system.
H. Contained conveyance of acid plant effluent solutions. [R307-401-8] II.B.7.f Secondary hoods and ventilation systems shall be installed on the following points to capture fugitive emissions into the secondary ventilation system or other approved pollution control devices: A. Concentrate Dryer Feed Chute
B. Slag and Matte Granulators
C. Smelting and Converting Furnaces
D. Slag Pot Filling Stations. [R307-401-8]

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PERMIT HISTORY When issued, the approval order shall supersede (if a modification) or will be based on the
following documents: Supersedes DAQE-AN103460062-23 dated December 28, 2023
Is Derived From NOI dated August 23, 2024
REVIEWER COMMENTS

1. Comment regarding Summary of Changes: This administrative action was requested to add a condition which had been missing from the previous AO. When the engineering review for the previous AO was conducted, condition II.B.7.a regarding opacity limits was included. When the AO was issued, this condition was missing. This administrative action adds that condition back into the AO and makes no other changes. [Last updated August 29, 2024]

Engineer Review N103460063: Rio Tinto Kennecott Utah Copper LLC - Smelter & Refinery September 24, 2024 Page 28
ACRONYMS The following lists commonly used acronyms and associated translations as they apply to this document:
40 CFR Title 40 of the Code of Federal Regulations AO Approval Order BACT Best Available Control Technology
CAA Clean Air Act CAAA Clean Air Act Amendments CDS Classification Data System (used by EPA to classify sources by size/type) CEM Continuous emissions monitor CEMS Continuous emissions monitoring system CFR Code of Federal Regulations CMS Continuous monitoring system CO Carbon monoxide CO2 Carbon Dioxide CO2e Carbon Dioxide Equivalent - 40 CFR Part 98, Subpart A, Table A-1 COM Continuous opacity monitor
DAQ/UDAQ Division of Air Quality DAQE This is a document tracking code for internal UDAQ use EPA Environmental Protection Agency
FDCP Fugitive dust control plan GHG Greenhouse Gas(es) - 40 CFR 52.21 (b)(49)(i) GWP Global Warming Potential - 40 CFR Part 86.1818-12(a)
HAP or HAPs Hazardous air pollutant(s) ITA Intent to Approve LB/HR Pounds per hour
LB/YR Pounds per year MACT Maximum Achievable Control Technology MMBTU Million British Thermal Units
NAA Nonattainment Area NAAQS National Ambient Air Quality Standards NESHAP National Emission Standards for Hazardous Air Pollutants NOI Notice of Intent NOx Oxides of nitrogen NSPS New Source Performance Standard NSR New Source Review PM10 Particulate matter less than 10 microns in size
PM2.5 Particulate matter less than 2.5 microns in size PSD Prevention of Significant Deterioration PTE Potential to Emit
R307 Rules Series 307 R307-401 Rules Series 307 - Section 401 SO2 Sulfur dioxide
Title IV Title IV of the Clean Air Act Title V Title V of the Clean Air Act TPY Tons per year
UAC Utah Administrative Code VOC Volatile organic compounds
DAQE-

RN103460063
September 24, 2024

Matt Tobey
Rio Tinto Kennecott Utah Copper LLC
4700 Daybreak Parkway
South Jordan, UT 84009
[e-mail]

Dear Matt Tobey,

Re: Engineer Review:
Administrative Action to Approval Order DAQE-AN103460062-23
Project Number: N103460063

Please review and sign this letter and attached Engineer Review (ER) within 10 business days. For this
document to be considered as the application for a Title V administrative amendment, a Title V
Responsible Official must sign the next page.

Please contact Stockon Antczak at [phone] if you have any questions or concerns about the ER.
If you accept the contents of this ER, please email this signed cover letter to Stockon Antczak at
[e-mail]. After receipt of the signed cover letter, the DAQ will prepare an Approval Order
(AO) for signature by the DAQ Director.

If Rio Tinto Kennecott Utah Copper LLC does not respond to this letter within 10 business days, the
project will move forward without your approval. If you have concerns that we cannot resolve, the DAQ
Director may issue an Order prohibiting construction.

Approval Signature _____________________________________________________________
(Signature & Date)

195 North 1950 West • Salt Lake City, UT
Mailing Address: P.O. Box 144820 • Salt Lake City, UT 84114-4820
Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.utah.gov
Printed on 100% recycled paper
Department of
Environmental Quality

Kimberly D. Shelley Executive Director

DIVISION OF AIR QUALITY
Bryce C. Bird
Director

State of Utah

SPENCER J. COX
Governor
DEIDRE HENDERSON
Lieutenant Governor

Engineer Review N103460063: Rio Tinto Kennecott Utah Copper LLC - Smelter & Refinery
September 24, 2024
Page 1
OPTIONAL: In order for this Engineer Review and associated Approval Order conditions to be
considered as an application to administratively amend your Title V Permit, the Responsible Official, as
defined in R307-415-3, must sign the statement below. THIS IS STRICTLY OPTIONAL.

If you do not want the Engineer Review to be considered as an application to administratively amend
your Operating Permit only the approval signature above is required.

Failure to have the Responsible Official sign below will not delay the Approval Order, but will require
submittal of a separate Operating Permit Application to revise the Title V permit in accordance with
R307-415-5a through 5e and R307-415-7a through 7i. A guidance document: Title V Operating Permit
Application Due Dates clarifies the required due dates for Title V operating permit applications and can
be viewed at:

https://deq.utah.gov/air-quality/permitting-guidance-and-guidelines-air-quality

“Based on information and belief formed after reasonable inquiry, I certify that the
statements and information provided for this Approval Order are true, accurate and
complete and request that this Approval Order be considered as an application to
administratively amend the Operating Permit.”

Responsible Official _________________________________________________
(Signature & Date)

Print Name of Responsible Official _____________________________________

Engineer Review N103460063: Rio Tinto Kennecott Utah Copper LLC - Smelter & Refinery
September 24, 2024
Page 2

UTAH DIVISION OF AIR QUALITY
ENGINEER REVIEW

SOURCE INFORMATION

Project Number N103460063
Owner Name Rio Tinto Kennecott Utah Copper LLC
Mailing Address 4700 Daybreak Parkway
South Jordan, UT, 84009

Source Name Rio Tinto Kennecott Utah Copper LLC - Smelter & Refinery
Source Location:
12000 West 2100 South
Magna, UT 84044

UTM Projection 398,678 m Easting, 4,508,860 m Northing
UTM Datum NAD83
UTM Zone UTM Zone 12
SIC Code 3331 (Primary Smelting & Refining of Copper)

Source Contact Jenny Esker
Phone Number [phone]
Email [e-mail]

Billing Contact Matt Tobey
Phone Number 801-569-3591
Email [e-mail]

Project Engineer Stockon Antczak, Engineer
Phone Number [phone]
Email [e-mail]

Notice of Intent (NOI) Submitted August 23, 2024
Date of Accepted Application August 28, 2024

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September 24, 2024
Page 3
SOURCE DESCRIPTION

General Description
Rio Tinto Kennecott Utah Copper LLC (KUC) operates a copper smelter and refinery in Salt
Lake County, Utah. The Smelter employs flash smelting technology with flash converting
technology to produce copper anodes and high concentration sulfur dioxide gases. The gases are
treated by electrostatic precipitators (ESP), baghouses, scrubbers, and a high-efficiency double
contact acid plant. The Refinery uses an electrolytic refining process to convert the Smelter-
produced anode copper to cathode copper and also recovers precious metals from the electrolytic
refining slimes in a precious metals circuit.

The copper ore concentrates received at the Smelter are first dewatered and then dried to reduce
the moisture content. The dried concentrate is then blended with fluxes and secondary copper-
bearing materials. This mixture is fed to a flash smelting furnace where the ore is melted and
reacts to produce copper matte, a molten solution of copper sulfide mixed with iron sulfide. The
Outokumpu flash smelting process used at the Smelter is a closed process that captures the SO2-
rich off-gases from the furnace for the production of sulfuric acid. The copper matte from the
smelting furnace is next converted to blister copper (approximately 98% pure copper) by
oxidization to remove the remaining sulfur as SO2 gas and the iron as a ferrous oxide slag. The
Smelter uses a continuous copper converting process in which solid matte granules are fed to a
flash smelting furnace-like vessel. The molten slag from converting is cooled, processed in slag
concentrators to remove residual copper, and ultimately disposed in on-site waste piles. The SO2
gases from smelting and converting are vented to a sulfuric acid plant. Molten blister copper is
transferred from the converting vessel to an anode furnace for fire-refining to further remove
residual impurities and oxygen. The blister copper is reduced in the anode furnace to remove
oxygen by injecting natural gas, producing a high purity copper. The molten copper from the
anode furnace is poured in molds to cast solid copper ingots called anodes.

The anode copper produced at the Smelter is moved to the copper Refinery co-located near the
Smelter, where it is further purified using an electrolytic process to obtain the high-purity cathode
copper sold.

NSR Classification:
Administrative Amendment

Source Classification
Located in , Northern Wasatch Front O3 NAA, Salt Lake City UT PM2.5 NAA, Salt Lake County
SO2 NAA,
Salt Lake County
Airs Source Size: A

Applicable Federal Standards
NSPS (Part 60), A: General Provisions
NSPS (Part 60), Db: Standards of Performance for Industrial-Commercial-Institutional Steam
Generating Units
NSPS (Part 60), Dc: Standards of Performance for Small Industrial-Commercial-Institutional
Steam Generating Units
NSPS (Part 60), P: Standards of Performance for Primary Copper Smelters
NSPS (Part 60), OOO: Standards of Performance for Nonmetallic Mineral Processing Plants
NSPS (Part 60), IIII: Standards of Performance for Stationary Compression Ignition Internal

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September 24, 2024
Page 4
Combustion Engines
NSPS (Part 60), JJJJ: Standards of Performance for Stationary Spark Ignition Internal
Combustion Engines
NSPS (Part 60), KKKK: Standards of Performance for Stationary Combustion Turbines
MACT (Part 63), A: General Provisions
MACT (Part 63), ZZZZ: National Emissions Standards for Hazardous Air Pollutants for
Stationary Reciprocating Internal Combustion Engines
MACT (Part 63), EEEEEE: National Emission Standards for Hazardous Air Pollutants for
Primary Copper Smelting Area Sources
Title V (Part 70) Major Source

Project Proposal
Administrative Action to Approval Order DAQE-AN103460062-23

Project Description
Rio Tinto Kennecott Utah Copper LLC (KUC) operates a copper smelter and refinery in Salt
Lake County, Utah. KUC requested a modification to AO DAQE-AN103460062-23 to include
missing condition II.B.7.a, regarding opacity limits. This condition was included in the
engineering review for, but was somehow removed when the AO was issued. This administrative
action adds condition II.B.7.a back into the AO and makes no other changes.

EMISSION IMPACT ANALYSIS
This is an administrative action. There is no change in PTE so no modeling is required. [Last updated August
29, 2024]

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September 24, 2024
Page 5
SUMMARY OF EMISSIONS

The emissions listed below are an estimate of the total potential emissions from the source. Some
rounding of emissions is possible.

Criteria Pollutant Change (TPY) Total (TPY)
Ammonia 0 9.11
CO2 Equivalent 0 235522.00
Carbon Monoxide 0 168.97
Lead Compounds 0 6.00
Nitrogen Oxides 0 161.25
Particulate Matter - PM10 0 2016.07
Particulate Matter - PM2.5 0 1946.11
Sulfur Dioxide 0 1081.32
Volatile Organic Compounds 0 14.86

Hazardous Air Pollutant Change (lbs/yr) Total (lbs/yr)
Generic HAPs (CAS #GHAPS) 0 14960
Lead Compounds (CAS #LCT000) 0 12000
Change (TPY) Total (TPY)
Total HAPs 0 13.48

Note: Change in emissions indicates the difference between previous AO and proposed modification.

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September 24, 2024
Page 6
Review of BACT for New/Modified Emission Units

1. BACT review regarding New Equipment

This is an administrative action. No BACT review required. [Last updated August 29, 2024]

SECTION I: GENERAL PROVISIONS

The intent is to issue an air quality AO authorizing the project with the following recommended
conditions and that failure to comply with any of the conditions may constitute a violation of the
AO. (New or Modified conditions are indicated as “New” in the Outline Label):

I.1 All definitions, terms, abbreviations, and references used in this AO conform to those used in
the UAC R307 and 40 CFR. Unless noted otherwise, references cited in these AO conditions
refer to those rules. [R307-101]

I.2 The limits set forth in this AO shall not be exceeded without prior approval. [R307-401]

I.3 Modifications to the equipment or processes approved by this AO that could affect the
emissions covered by this AO must be reviewed and approved. [R307-401-1]

I.4 All records referenced in this AO or in other applicable rules, which are required to be kept by
the owner/operator, shall be made available to the Director or Director's representative upon
request, and the records shall include the five-year period prior to the date of the request.
Unless otherwise specified in this AO or in other applicable state and federal rules, records
shall be kept for a minimum of five (5) years. [R307-401-8]

I.5 At all times, including periods of startup, shutdown, and malfunction, owners and operators
shall, to the extent practicable, maintain and operate any equipment approved under this AO,
including associated air pollution control equipment, in a manner consistent with good air
pollution control practice for minimizing emissions. Determination of whether acceptable
operating and maintenance procedures are being used will be based on information available
to the Director which may include, but is not limited to, monitoring results, opacity
observations, review of operating and maintenance procedures, and inspection of the source.
All maintenance performed on equipment authorized by this AO shall be recorded. [R307-
401-4]

I.6 The owner/operator shall comply with UAC R307-107. General Requirements: Breakdowns.
[R307-107]

I.7 The owner/operator shall comply with UAC R307-150 Series. Emission Inventories. [R307-
150]

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I.8 The owner/operator shall submit documentation of the status of construction or modification
to the Director within 18 months from the date of this AO. This AO may become invalid if
construction is not commenced within 18 months from the date of this AO or if construction is
discontinued for 18 months or more. To ensure proper credit when notifying the Director,
send the documentation to the Director, attn.: NSR Section. [R307-401-18]

SECTION II: PERMITTED EQUIPMENT
The intent is to issue an air quality AO authorizing the project with the following recommended
conditions and that failure to comply with any of the conditions may constitute a violation of the
AO. (New or Modified conditions are indicated as “New” in the Outline Label):

II.A THE APPROVED EQUIPMENT

II.A.1 Rio Tinto Kennecott Utah Copper LLC
Copper Smelter

II.A.2 Filter Plant

Filter Plant Wet Feed Conveyor with baghouse (#SME 001, Stack No. 1) (Relocated and
resized)

Filter Plant Wet Feed Conveyor Bin Vent (#SME 001-A) (NEW)

II.A.3 Feed and Reagent Storage

Feed and reagent storage and transfer consisting of:

1) Wet Feed Storage building with baghouse (#SME 002)

2) Wet Feed Conveyor transfer point with baghouse (#SME 003)

3) Outside Wet Feed Hopper with partial enclosure (#SME 002-A)

4) Wet Feed Bins with baghouse (#SME 004)

5) Flash Smelting Furnace Dry Feed Bin with baghouse (#SME 005)

6) Smelter Limestone Flux Bin with bin vent baghouse (#SME 006)

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II.A.4 Feed and Reagent Storage (Continued)
7) Matte, dust, flux, feed bins with baghouse (#SME 013)

8) Mold Coating Silo with bin vent baghouse (#SME 015)

9) Hydrometallurgical Plant Limestone Silo with bin vent baghouse (#SME 019)

10) Hydrometallurgical Plant Lime Silo with bin vent baghouse (#SME 020)

11) Anode Area Lime Silo with bin vent baghouse (#SME 028)

12) Secondary Gas System Lime Silo with bin vent baghouse (#SME 029)

II.A.5 Feed and Reagent Storage (continued)
13) One Hopper

14) Two Storage Bins
Control: Bin Vent (each)
(vents inside the building)

15) Conveyers with water sprays
II.A.6 Pyrometallurgical Processes - Flash Smelting

1) Rotary Feed Dryer with baghouse followed by a scrubber (#SME 011e)

2) Flash Smelting Furnace (FSF) with (in series) (#SME 011b1)

a) Waste heat boiler

b) Electrostatic precipitator (ESP)

c) Scrubber served by wet ESP and acid plant

d) Emergency generator with turbocharger and aftercooling
Maximum Rating: 998 hp

II.A.7 Pyrometallurgical Processes - FS (Continued)

3) Matte Granulation process, North and South Matte Granulators (#SME 010a) each
have a three stage impingement scrubber equipped with demister pads that vent to the
secondary gas system (vents to the main stack)

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II.A.8 Pyrometallurgical Processes - Flash Converting

1) Matte Drying and Grinding Plant with baghouse (#SME 011g)

2) Flash Converting Furnace (FCF) with (in series) (#SME 011b2)

a) Waste heat boiler

b) ESP

c) Scrubber served by wet ESP and acid plant

3) Slag Granulation with three stage impingement scrubber, emissions are either
directed

a) to the scrubber and then to the atmosphere through the vent stack; or

b) to the scrubber and then to the secondary gas system (#SME 010b)
II.A.9 Pyrometallurgical Processes - FCF/FSF
1) Co-Jet Technology Burner System (#SME 011b3)
Quantity: 3 co-jet injectors
Rating: 13 MMBtu/hr each
Fuel: Natural gas/oxy-fuel

II.A.10 Pyrometallurgical Processes - Anodes Area

1) Anode furnace system consisting of:

a) Anode Furnaces and optional coherent jet lances* with (in series)
(#SME 011h1)

(1) Quench tower
(2) Lime injection
(3) Baghouse
(4) Two scrubbers in series

*The lances are used for material heating and melting on a
non-continuous basis

b) Wenmec twin casting wheel and quench tower (#SME 011h4)

c) Shaft furnace (#SME 011h2) and holding furnace (#SME 011h3) with
baghouse

d) Mold casting furnace (#SME MOLD

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II.A.11 Product Recovery/Gas Cleaning Facilities

Product Recovery/Gas Cleaning Facilities that serve FSF and FCF

1) Wet ESP

2) Acid Plant (#SME 011b) with

a) Acid Plant Cooling Tower (#SME CT311)

b) Acid Plant Collection System (#SME GLCS) with adjustable negative
pressure ductwork and collection hoses placed as needed for opacity
control

c) Acid Plant Preheater (#SME 008)

II.A.12 Product Recovery/Gas Cleaning (Continued)

Product Recovery/Gas Cleaning Facilities that serve emission sources in the Hot Metals
Building, Matte Granulators, or Slag Granulators as needed

3) Secondary Gas Cleaning System (#SME 011a) with

a) Lime injection system

b) Baghouse

c) Reverse Jet scrubber A and Reverse Jet scrubber B

II.A.13 Intermediate Product Storage
Intermediate Product Storage, Crushing, and Grinding Operations

1) Slag Concentrator (#SME SLAG)

2) Recycle Materials Crushing and Storage building with baghouse (#SME 027)

a) Furnace dust crusher system 12 ton/hour capacity

II.A.14 Intermediate Product Storage (cont'd)
3) Crushing and Screening Operation (#SME SLAG)
a) Jaw crusher Maximum 600 ton/hour capacity
b) Cone crusher Maximum 600 ton/hour capacity
c) Fines crusher Maximum 600 ton/hour capacity
d) Conveyors Partially enclosed transfer points with water sprays
e) Triple deck screen
f) High frequency screens

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II.A.15 Miscellaneous Support Equipment

1) Miscellaneous mobile diesel equipment

2) Small natural gas-fired space heaters and water heaters (#SME SH, WH)

3) Outdoor storage piles where concentrate, granulated matte, slag, and other process
materials are stored on pads (#SME STRG)

II.A.16 Smelter Powerhouse

1) Superheater with ultra-low NOx burners (#SME 011f)
Rating: 45 MMBtu/hr
Fuel: Natural gas
Vents to main stack

2) Holman Boiler (#SME 026)
Rating: 187 MMBtu/hr
Fuel: Natural gas

3) Rentech Boiler (#SME 030)
Rating: 183 MMBtu/hr
Fuel: Natural gas

4) Powerhouse Cooling Tower (#SME CT316)

5) Two (2) Diesel-Fired Emergency Generators (#SME GEN)
Rating: 2,847 hp each

II.A.17 Hydrometallurgical Plant (#SME 011d)

Controls: Two scrubbers
II.A.18 Vacuum Cleaning Systems (#SME 017)

1) Matte handling vacuum cleaning system with baghouse

2) FSF vacuum cleaning system ducted to the secondary gas collection system

3) FCF vacuum cleaning system with baghouse

II.A.19 Support Facilities

1) Laboratories, with baghouse (#SME 022)

2) Various degreasing parts washers (#SMEi210)

3) Gasoline fueling station (#SME SA-1)

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II.A.20 Support Facilities* (Continued)

4) Wash rooms

5) Change house

6) Engineering shops

7) Warehouses

8) Administrative buildings

*These are listed for informational purposes only

II.A.21 Communication Emergency Generator (#SME COM GEN)

Maximum Rating: 75 hp
Fuel: Liquid propane

SECTION II: SPECIAL PROVISIONS
The intent is to issue an air quality AO authorizing the project with the following recommended
conditions and that failure to comply with any of the conditions may constitute a violation of the
AO. (New or Modified conditions are indicated as “New” in the Outline Label):

II.B REQUIREMENTS AND LIMITATIONS

II.B.1 Limitations and Test Procedures

II.B.1.a
NEW
Emissions to the atmosphere from the indicated emission points* shall not exceed the
following rates and concentrations:

A. #SME 001 - Wet Feed Conveyor Baghouse (Stack No. 1)
PM10 0.7 lbs/hr (filterable)
0.008 grains/dscf (68 degrees F, 29.92" Hg)

B. #SME 002 - Wet Feed Storage Building Baghouse (Stack No. 2)
PM10 3.91 lbs/hr (filterable)
0.008 grains/dscf (68 degrees F, 29.92" Hg)

C. #SME 003 - Wet Feed Conveyor Transfer Point Baghouse (Stack No. 3)
PM10 0.4 lbs/hr (filterable)
0.016 grains/dscf (68 degrees F, 29.92" Hg)

D. #SME 004 - Wet Feed Bin Baghouse (Stack No. 4)
PM10 3.4 lbs/hr (filterable)
0.016 grains/dscf (68 degrees F, 29.92" Hg)

E. #SME 005 - Flash Smelting Furnace Dry Feed Bin Baghouse (Stack No. 5)

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PM10 1.2 lbs/hr (filterable)
0.016 grains/dscf (68 degrees F, 29.92" Hg)

F. #SME 006 - Smelter Limestone Flux Bin Baghouse (Stack No. 6)
PM10 0.3 lbs/hr (filterable)
0.016 grains/dscf (68 degrees F, 29.92" Hg)

G. #SME 010b - Slag Granulation Exhaust Scrubber (Stack No. 10b)
PM10 1.9 lbs/hr (24 hr. average - calendar day) (filterable)
SO2 2.0 lbs/hr (24 hr. average - calendar day)
Operating Hours 3504 hrs per rolling 12-month period

H. #SME 011 - Main Stack (Stack No. 11)
PM10 89.5 lbs/hr (24 hr. average - calendar day) (filterable)
439 lbs/hr (filterable + condensable)

PM2.5 85 lbs/hr (filterable)
434 lbs/hr (filterable + condensable)

SO2 552 lbs/hr (three-hr. rolling average)
422 lbs/hr (24 hr. average - calendar day)
211 lbs/hr (annual average)

NOx 35.0 lb/hr (annual average)
146.5 lb/hr (daily average)

Lead 1.3 lb/hr (annual average)

I. #SME 013 - Dry Matte Bin Baghouse (Stack No. 13)
PM10 0.3 lbs/hr (filterable)
0.016 grains/dscf (68degrees F, 29.92" Hg)

J. #SME 017 - Vacuum Cleaning Systems (Stacks No. 17a & 17c combined)
PM10 0.7 lbs/hr (filterable)
0.016 grains/dscf (68degrees F, 29.92" Hg)

K. #SME 026 - Holman Boiler (Stack No. 26)
NOx 9.34 lbs/hr, 30-day rolling average
14 lbs/hr, calendar-day average

L. #SME 030 - Rentech Boiler (Stack No. 30)
NOx 3.29 lbs/hr, 30-day rolling average
4.94 lb/hr, calendar-day average

M. #SME 011b - Acid Plant Tail Gas
SO2 250 ppmdv (six- hr. block average)
170 ppmdv (24 hr. average - calendar day)
100 ppmdv (annual average)

Sulfuric Acid Mist 0.67 mg/scf (68degrees F, 29.92" Hg)

N. #SME 011e - Dedicated Rotary Dryer Baghouse

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Particulate Emissions (PM) 0.022 grains/dscf (68 degrees F, 29.92" Hg)
(filterable)

* Reference to stack numbers above and in Conditions II.B.1.a.2 and II.B.1.a.3 below do not
necessarily refer to an exhaust point to the atmosphere. Many emission sources are
commingled with emissions from other sources and exit to the atmosphere from a common
emission point. "Stack" in these conditions refer to the point prior to mixing with emissions
from other sources. [R307-401-8]

II.B.1.a.1 To determine compliance with an annual average emission limitation, the owner/operator shall
calculate a new annual average by the 20th day of each month using data from the previous 12
months. All annual average emission limits shall be based on a rolling 12-month average
using the daily averages from the previous 12 months. [R307-401-8]

II.B.1.a.2
NEW
Stack testing to show compliance with the emissions limitations of Condition II.B.1.a shall be
performed as specified below:

A. Emission Point Pollutant Testing Status Test Frequency

1) Stack Nos. 2, 3, 4,
5,6, 13,17a & 17 c PM10 ** every five (5) years

1a.) Stack No 1 PM10 * every five (5) years

2) Stack Nos. 10b PM10 ** every three (3) years
SO2 ** every three (3) years

3) Main Stack PM10 ** every year and continuous
particulate monitor
Stack No. 11 PM2.5 ** every year
SO2 ** CEM
NOx ** CEM
Lead ** continuous particulate
monitor

4) Holman Boiler NOx ** every three (3) years
Stack No. 26 calendar-day
average

NOx ** CEM or alternate method
30-day average determined according to
Condition II.B.2.b

5) Rentech Boiler NOx ** every three (3) years
Boiler Stack No. 30 calendar-day
average

NOx ** CEM or alternate method
30-day average determined according to
Condition 11.B.2.c

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6) Acid Plant Tail gas SO2 ** CEM (concentration)
Sulfuric Acid Mist ** every three (3) years

7) Dedicated Rotary PM ** every five (5) years
Dryer Baghouse/Scrubber

B. Testing Status (To be applied above)

*Initial testing shall be performed as soon as possible and in no case later than 180 days after
start up.

** The initial test has been performed on these sources.

C. The owner/operator may petition the Director to reduce the stack testing
frequency of an emission point in a given year after the following: if, after
two (2) stack tests for an emission point in Condition II.B.1.a.2
conducted in accordance with Condition II.B.1.a.3, the owner/operator
can show, either because of reliability of pollution control equipment,
constant emissions, or other appropriate reasons, the stack testing
frequency in Condition II.B.1.a.2 is more frequent than necessary to
determine the quantity of emissions.

[R307-401-8]

II.B.1.a.3
NEW
Stack testing to show compliance with the emission limitations of Condition II.B.1.a shall be
performed as specified below (continued):

A. Notification
Notification of the date, time, place of test and a copy of the test protocol
shall be provided at least 30 days prior to the test. A pretest conference
shall be held if directed by the Director.

B. Sample Location
The emission point shall be designed to conform to the requirements of 40
CFR 60, Appendix A, Method 1 or other EPA-approved methods acceptable
to the Director. Occupational Safety and Health Administration
(OSHA)-approved and/or Mine Safety and Health Administration
(MSHA)-approved access shall be provided to the test location.

C. Volumetric Flow Rate
40 CFR 60, Appendix A, Method 2, Method 19 or other EPA-approved
testing methods acceptable to the Director

D. PM
40 CFR 60, Appendix A, Method 5 or other EPA-approved testing methods
acceptable to the Director

E. PM10/PM2.5
For stacks in which no liquid drops are present, the following methods shall

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be used: 40 CFR 51, Appendix M, Methods 201 or 201a or other
EPA-approved testing method acceptable to the Director. The back half
condensable particulate emissions shall also be tested (where applicable)
using 40 CFR 51, Appendix M Method 202, or other EPA- approved testing
method acceptable to the Director. All particulate captured using Method
202 shall be considered PM2.5 and/or PM10.

For stacks in which liquid drops are present, methods to eliminate the liquid drops shall be
explored. If no reasonable method to eliminate the drops exists, then the following methods
shall be used: 40 CFR 60, Appendix A, Method 5, 5a, 5d, 5i or other as appropriate. If using
Method 5 or any variation of Method 5, a scanning electron microscopy analysis or other
equivalent method shall be used to determine the fraction of PM10 and/or PM2.5, as approved
by the Director. The back half condensable particulate emissions shall also be tested using 40
CFR 51, Appendix M Method 202 or other EPA- approved testing method acceptable to the
Director. All particulate captured using Method 202 shall be considered PM2.5 and/or PM10.

For filterable emission limits, condensable emissions shall not be used for compliance
demonstrations. For filterable + condensable emission limits, both filterable and condensable
emissions shall be used for compliance demonstrations.

[R307-401-8]

II.B.1.a.4
NEW
Stack testing to show compliance with the emission limitations of Condition II.B.1.a shall be
performed as specified below (continued):

F. SO2
40 CFR 60 Appendix A, Method 6, 6A, 6B, 6C or other EPA-approved
testing methods acceptable to the Director

G. Lead
The test method shall be submitted for approval or may be assigned by the
Director. A monitoring plan was submitted to the Director on October 10,
2000 and amended in 2007. The owner/operator shall monitor in
accordance with the most recent monitoring plan approved by the Director.

H. Sulfuric Acid Mist
40 CFR 60, Appendix A, Method 8

I. NOx
40 CFR 60 Appendix A, Method 7, 7A, 7B, 7C, 7D, 7E or other EPA-
approved testing methods acceptable to the Director

J. Source Operation
For stack testing purposes, stack tests shall be done during representative
operations. The production rate during all compliance tests shall be no less
than 90% of the maximum average hourly production rate achieved in a
24-hour period during the previous three (3) years.

K. Calculations
To determine mass emission rates (lb/hr, etc.) the pollutant concentration as
determined by the appropriate methods above shall be multiplied by the

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volumetric flow rate and any necessary conversion factors determined by the
Director, to give the results in the specified units of the emission limitation.

L. Results
The results of stack testing shall be submitted to the Director within 60 days
of completion of the testing. Reports shall clearly identify results as
compared to permit limits and indicate compliance status.

[R307-401-8]

II.B.2 Holman Boiler and Rentech Boiler NOx Requirements
II.B.2.a The owner/operator shall not exceed 23.3 tons of NOx emissions per rolling 12-month period
from the Holman boiler and Rentech boiler combined. [R307-401-8]

II.B.2.a.1
NEW
To determine compliance with a rolling 12-month total, the owner/operator shall calculate a
new 12-month total by the 20th day of each month using data from the previous 12 months.
Records of emissions shall be kept for all periods when the plant is in operation. Monthly
totals of NOx emissions from each boiler shall be based on the following:

A. The 30-day average NOx emissions rate (lb/hr) of the Holman boiler for the calendar
month, determined according to Condition II.B.2.b

B. The hours of operation of the Holman boiler for the calendar month

C. The 30-day average NOx emissions rate (lb/hr) of the Rentech boiler for the calendar
month, determined according to Condition II.B.2.c

D. The hours of operation of the Rentech boiler for the calendar month

[R307-401-8]

II.B.2.b Initial compliance with the Holman boiler 30-day average NOx limit was demonstrated with
the CEM in accordance with 40 CFR 60.46b(e)(1). The owner/operator shall continue to use
the CEM, or propose to the Director an alternative method for demonstrating compliance with
the limit in accordance with 40 CFR 60.46b(e)(1) and (4), 60.48b(g) (1) and (2), and
60.49b(c). Either a CEM or the most recently approved alternate plan approved by the
Director shall be used. [R307-401-8]

II.B.2.c The owner/operator shall demonstrate compliance with the Rentech boiler 30-day average
NOx in accordance with 40 CFR 60.46b(e) and either 40 CFR 60.48b(g)(1) or 40 CFR
60.48b(g)(2). For subsequent compliance, either a CEM or the most recently approved
alternate plan to monitor boiler operating conditions and predict NOx emission rates shall be
used. *Initial compliance was using a CEM in accordance with 40 CFR 60.46b(e) and (e)(1).
[R307-401-8]

II.B.2.c.1 The owner/operator shall maintain and operate the CEM in accordance with UAC R307-170.
The records and results of monitoring shall be maintained in accordance with 40 CFR 60.49b
and UAC R307-170. [R307-170, R307-401-8]

II.B.2.c.2 If the owner/operator chooses to comply with the monitoring provisions of 40 CFR
60.48b(g)(2) to demonstrate compliance with the Rentech boiler 30-day average NOx limit,

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the owner/operator shall submit an alternate plan to the Director in accordance with 40 CFR
60.49b(c) that identifies the operating conditions to be monitored and the records to be
maintained. This plan shall be submitted to the Director for approval within 360 days of the
initial startup of the Rentech boiler. [40 CFR 60 Subpart Db, R307-401-8]

II.B.2.c.3 The owner/operator shall submit notifications and reports as required in 40 CFR 60.49b and
R307-170. Results of the additional certified NOx CEM 30-day CEM tests as required in 40
CFR 60.46b(e) shall be submitted within 60 days of the completion of the test. [40 CFR 60
Subpart Db, R307-170]

II.B.3 Main Stack Continuous Monitoring Requirements
II.B.3.a To demonstrate compliance with the main stack mass emissions limits for SO2 and NOx of
Condition II.B.1.a.H, the owner/operator shall calibrate, maintain and operate the
measurement systems for continuously monitoring SO2 and NOx concentrations and stack gas
volumetric flow rates in the main smelter stack. [R307-401-8]

II.B.3.a.1 The owner/operator shall comply with all applicable parts of UAC R307-170 "Continuous
Emission Monitoring Systems Program", including the requirements for annual Relative
Accuracy Test Audits (RATA) and quarterly Relative Accuracy Audits (RAA) or Cylinder
Gas Audits (CGA).

A. The required RATA, RAA, and CGA shall be conducted following procedures in 40 CFR
60 Appendix B, Specification 2 and 40 CFR 60 Appendix F.

B. Acceptable methods for the annual RATA include 40 CFR 60, Appendix A, Method 6 or
6C for SO2 and Method 7 or 7E for NOx.

C. All audit and test results shall be submitted to the Director within 60 days after the audit or
test is completed. [R307-401-8]

II.B.3.a.2 The owner/operator shall perform 40 CFR 52 Appendix E - Performance Specification
procedures on the stack gas flow rate measurement system, if directed by the Director, in the
event that the results of the quarterly and annual tests required by Condition II.B.3.a.1
demonstrate that the SO2 and NOx monitoring systems are not performing properly. [R307-
401-8]

II.B.3.a.3 Failure to measure SO2 at least ninety-five percent (95%) of the hours during which emissions
occurred in any quarter in accordance with the requirements of this subsection, or failure to
measure, in accordance with the requirements of this subsection, any 18 consecutive hours of
emissions data shall constitute a violation of Condition II.B.3.a.

A. Any hour for which the measurements comply with UAC R307-170 shall be considered as
measured.

B. Any hours for which the emissions data are greater than 20% in error will be considered to
have not been measured for the purposes of Condition II.B.3.a.

C. The Director may grant exemptions to the requirements of Condition II.B.3.a if unusual
circumstances, not to include malfunction of any of the monitoring instrumentation, arise
which prevent the owner/operator from obtaining hourly measurements of emissions in
accordance with Condition II.B.3.a. [40 CFR 60 Subpart P, R307-401-8]

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II.B.3.a.4
NEW
The owner/operator shall maintain a record of all measurements required by Condition
II.B.3.a. Measurement results shall be expressed as pounds of SO2 and NOx emitted per hour
calculated at the end of each day for the preceding 24 hours for SO2 and NOx and calculated at
the end of each hour for the preceding three-hour period for SO2. Records shall include:

A. The total number of hourly periods during the month in which measurements were not
taken.

B. For any periods where loss of measurement is greater than three continuous hours, the
reason for loss of measurement in each period.

C. The date(s) on which three and 24-hour emissions averages for SO2 exceeded the
applicable emission level in Condition II.B.1.a.H and the number of exceedances.

D. The date(s) on which the annual emissions average based on hourly emissions exceeded
the applicable emission level in Condition II.B.1.a.H for NOx for the month
being reported and the number of such exceedances, and the daily NOx averages.

E. All conversion values used to derive the three and 24-hour average and annual average
emissions for SO2, and the 24-hour average and annual average for NOx, including
temperature and differential pressure of stack gases.

[R307-401-8]

II.B.3.a.5 Data, reports, or results required to be submitted pursuant to Condition II.B.3.a, shall be
deemed to be verified and accepted as valid and not subject to challenge and shall be used by
the Director in determining compliance with Condition II.B.1.a.H, unless, within 30 days of
the time such data, reports, or results are submitted, the owner/operator or the Director
provides evidence that the data, results, or reports or any part thereof, are greater than 20% in
error. [R307-401-8]

II.B.3.a.6 During periods of malfunctioning or maintenance of the stack gas temperature and velocity
measurement instrumentation, the owner/operator may estimate stack gas flow rate. Such
estimates will be considered as measurements for the purpose of Condition II.B.3.a. Records
of calculations used to derive the estimated flow rate and a list of the periods where stack gas
flow rate was estimated in each month shall be maintained. No more than 10% of the flow
rates in any one month may be estimated. [R307-401-8]

II.B.3.b The owner/operator shall continuously measure emissions of particulate matter from the main
stack. For the purposes of determining compliance with Condition II.B.1.a.H, all particulate
matter collected shall be reported as PM10. Compliance with the main stack emission limit for
PM10 of Condition II.B.1.a.H shall be demonstrated using the smelter main stack continuous
particulate sampling system to provide a 24-hour value. Collected data shall be available for
inspection, and a summary of 24-hour averages shall be submitted to the Director monthly
within 20 days of the end of the month. [R307-401-8]

II.B.3.c The owner/operator shall determine the lead emissions from the main stack using the main
stack particulate data and laboratory analysis of the material collected by the continuous stack
particulate sampler. The owner/operator shall monitor in accordance with the most recent
monitoring plan approved by the Director. If the owner/operator cannot monitor the lead

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emissions using the continuous particulate sampler, then the owner/operator shall monitor the
lead emissions using a monitoring plan approved by the Director. [R307-401-8]

II.B.4 Scrubber and Baghouse Monitoring Requirements
II.B.4.a
NEW
The owner/operator shall install, calibrate, maintain, and operate the following monitoring
devices for the measurement of the indicated parameters. Continuous recording instruments
are optional but are not required. The gauges/devices shall be located such that an inspector
can safely read them at any time. The monitoring devices shall be calibrated in accordance
with the manufacturer's instructions.

A. A monitoring device for the continuous measurement of the change in pressure of the
gas stream across the secondary ventilation scrubber, rotary dryer scrubber, anode furnace
scrubber, and hydrometallurgical plant scrubber(s). A "U" tube manometer is recommended.

B. A monitoring device for the continuous measurement of the scrubbing liquid flow rate
to the secondary ventilation scrubber, rotary dryer scrubber, anode furnace scrubber, and
hydrometallurgical plant scrubber(s).

C. A monitoring device for the continuous measurement of the change in pressure of the
gas stream across each baghouse.

The operating range and accuracy of the monitoring devices shall be submitted to the Director.

[R307-401-8]

II.B.4.b The owner/operator shall maintain a monitoring record or log with monitoring data to
demonstrate compliance with the operating ranges listed below. [R307-401-8]

II.B.4.b.1
NEW
The operating pressure drop across the following equipment shall be maintained within the
following operating ranges:

A. Secondary Ventilation Scrubbers: 3.5" Water Gauge (W.G.) (minimum, across
both scrubbers combined)
B. Rotary Dryer Scrubber: 5" to 19.25" W.G.
C. Anode Furnace Scrubber: 18" to 50.5" W.G.
D. Hydrometallurgical Plant Scrubber Model #480: 5" to 10" W.G.
E. Hydrometallurgical Plant Scrubber Model #575: 6" to 12" W.G.

[R307-401-8]

II.B.4.b.2 The operating scrubbing liquid flow rate for the following equipment shall be maintained
within the following operating ranges:
A. Secondary Ventilation Scrubber: greater than 4800 gpm (each)
B. Rotary Dryer Scrubber: greater than 7360 gpm
C. Anode Furnace Scrubber: greater than 2000 gpm (each)
D. Hydrometallurgical Plant Scrubber Model #480: greater than 50 gpm
E. Hydrometallurgical Plant Scrubber Model #575: greater than 40 gpm

[R307-401-8]

II.B.4.b.3 Pressure drops for the following baghouses shall be maintained within the following operating

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NEW ranges:
A. Filter Plant Wet Feed Conveyor Baghouse: 0.5" to 4" W.G.
B. Wet Feed Storage Building Baghouse: 1.5" to 5" W.G.
C. Wet Feed Conveyor Belt Transfer Point Baghouse: 0.5" to 5.25" W.G.
D. Wet Feed Bin(s) Baghouse: 2.75" to 5" W.G.
E. Flash Smelting Furnace Dry Feed Bin Baghouse: 0.25" to 11" W.G.
F. Limestone Flux Bin Baghouse: 0.5" to 4" W.G.
G. Secondary Gas Handling System Baghouse: 6" to 15" W.G.
H. Matte Drying and Grinding Plant Baghouse: 5" to 15" W.G.
I. Dry Matte Bin Baghouse: 0.5" to 13" W.G.
J. Anode Refining Furnace Baghouse: 1" to 9" W.G.
K. Anode Shaft Furnace Baghouse: 1" to 10" W.G.
L. Mold Coating (Barite) Bin Baghouse: 0.25" to 4" W.G.
M. Vacuum Cleaning Systems (2 Baghouses): 0.25" to 6" (each) W.G.
N. Hydrometallurgical Plant Limestone Storage Bin Baghouse: 0.5" to 4" W.G.
O. Hydrometallurgical Plant Lime Storage Bin Baghouse: 0.25" to 4" W.G.
P. Recycle Materials Crushing and Storage Building Baghouse: 1" to 5" W.G.

[R307-401-8]

II.B.5 Natural Gas Consumption Requirements
II.B.5.a The natural gas consumption per rolling 12-month period shall not exceed the following
limitations for the equipment listed:
A. Acid Plant Preheater - 74,476 MMBTU
B. Pyrometallurgical Process Group - 1,947,847 MMBTU The Pyrometallurgical Process
Group includes the following units:
A) Anode Area:
i. SME 011h1 - Anode Furnaces
ii. SME 011h2 - Shaft Furnace
iii. SME 011h3 - Holding Furnaces
iv. SME MOLD - Mold Casting Furnace
B) Launder Heaters
i. SME 011b1 - FSF
ii. SME 011b2 - FCF
iii. SME 011b3 - Co-Jet Burner
C. SME 011g - Matte Grinding Plant
D. SME 011e - Rotary Concentrate Dryer

[R307-401-8]

II.B.5.a.1 To determine compliance with a rolling 12-month total, the owner/operator shall calculate a
new 12-month total by the 20th day of each month using data from the previous 12 months.
Records of consumption shall be kept for all periods when the plant is in operation. Natural
gas consumption shall be determined by individual gas meters readings reconciled against
monthly billing statements. [R307-401-8]

II.B.5.a.2 The natural gas allocations in Condition II.B.5.a may be reapportioned upon demonstration to
the Director that no increase in potential NOx emissions would result. [R307-401-8]

II.B.5.a.3 Propane may be used as an alternate fuel supply during natural gas curtailment. [R307-401-8]

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II.B.6 Fugitive Emissions and Material Handling Requirements
II.B.6.a The emissions from the transfer point between the outside hopper/feeder and the wet feed
conveyor on the wet feed conveyor transfer point with baghouse from the Outside Feed
Hopper shall be ducted to the wet feed storage building baghouse. [R307-401-8]

II.B.6.b All roads, parking lots, and service yards directly servicing the approved constructed
installations listed above in Section II.A, with the exception of II.A.13, of this AO shall be
paved. [R307-401-8]

II.B.6.c The owner/operator shall carry out the current Fugitive Dust Control Plan approved by the
Director. [R307-401-8]

II.B.6.d Any open storage piles shall be watered, covered, or chemically treated to minimize
generation of fugitive dusts as dry conditions warrant or as determined necessary by the
Director. [R307-401-8]

II.B.6.e Emissions from the slag concentrator bin shall be controlled with water sprays. Treatment
shall be of sufficient frequency and quantity to maintain the surface material in a damp/moist
condition unless it is below freezing. The degree of control is a minimum of that required to
meet the opacity limitations of Condition II.B.7.a. [R307-401-8]

II.B.6.e.1 A visual inspection of the water spray system on the slag concentrator bin shall be performed
on a weekly basis to ensure proper operating condition. Records of each inspection shall be
maintained in accordance with Condition I.4. [R307-401-8]

II.B.6.f The crushing and screening operation shall not process more than 5,000 tons of material per
calendar day and 750,000 tons of material per rolling 12-month period. [R307-401-8]

II.B.6.f.1 To determine compliance with a rolling 12-month total, the owner/operator shall calculate a
new 12-month total by the 20th day of each month using data from the previous 12 months.
Records of daily material processing shall be kept for all periods when the smelter is in
operation. Daily total material processing shall be determined by daily reports. [R307-401-8]

II.B.6.g Water sprays or chemical dust suppression sprays shall be installed at the following points that
are not enclosed or have baghouses to control fugitive emissions:

A. All crushers
B. All stationary conveyor transfer points
C. The crusher and screening units shall have water spray at the
input to the crusher and at the discharge points from the crusher.

The sprays shall operate whenever dry conditions warrant or as determined necessary by the
Director. [R307-309]

II.B.7 Site-Wide Requirements
II.B.7.a
NEW
Visible emissions from the following emission points shall not exceed the following values:

Emission Point Opacity Limit

A. #SME 001 - Wet Feed Conveyor Baghouse (Stack No. 1) 7%

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B. #SME 002 - Wet Feed Storage Building Baghouse
(Stack No. 2) 7%

C. #SME 003 - Wet Feed Conveyor Transfer Point
Baghouse (Stack No. 3) 7%

D. #SME 004 - Wet Feed Bin Baghouse (Stack No. 4) 7%

E. #SME 005 - Flash Smelting Furnace Dry Feed Bin
Baghouse (Stack No. 5) 7%

F. #SME 006 - Smelter Limestone Flux Bin Baghouse
(Stack No. 6) 10%

G. #SME 008 - Acid Plant Preheater (Stack No. 8) 10%

H. #SME 010b - Slag Granulator Scrubber Stack
(Stack No. 10b) 15%

I. #SME 011 - Smelter Main Stack (Stack No. 11) 20%

J. #SME 013 - Dry Matte Bin Baghouse (Stack No. 13) 10%

K. #SME 015 - Mold Coating Silo Baghouse (Stack No. 15) 10%

L. #SME 017 - Vacuum Cleaning System
(Stacks No. 17a & 17c combined) 10%

M. #SME 019 - Hydrometallurgical Plant Limestone
Silo Baghouse (Stack No. 19) 10%

N. #SME 020 - Hydrometallurgical Lime Silo Baghouse
(Stack No. 20) 10%

O. #SME 022 - Laboratory Baghouse (Stack No. 22) 10%

P. #SME SLAG - Slag Concentrator Bin 10%

Q. #SME SLAG - Slag Crushing and Grinding Transfer
Points 10%

R. #SME 026 - Holman Boiler (stack 26) 10%

S. #SME 027 - Recycle Materials Crushing & Storage
Building Baghouse (Stack No. 27) 10%

T. #SME 028 - Anode Area Lime Silo Baghouse
(Stack No. 28) 10%

U. #SME 029 - Secondary Gas System Lime Silo
Baghouse (Stack No. 29) 10%

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V. #SME 030- Rentech Boiler (Stack No. 30) 10%

W. #SME SLAG - Crushing and Screening Plant 10%

X. SME 001a - Filter Plant Wet Feed Bin Vent 10%

Y. #SME 011b - Acid Plant Tail Gas 15%

Z. #SME 011e - Rotary Dryer Baghouse/Scrubber Outlet 15%

AA. Hot Metals Building Roof Vents 20%

BB. Acid Plant Process Gas Leaks 20%

CC. All other points 20%

[R307-305-3]

II.B.7.a.1 Opacity observations of emissions from stationary sources shall be conducted in accordance
with 40 CFR 60, Appendix A, Method 9. [R307-401-8]

II.B.7.a.2 For sources that are subject to NSPS, opacity shall be determined by conducting observations
in accordance with 40 CFR 60.11(b) and 40 CFR 60, Appendix A, Method 9.

A. For purposes of determining initial compliance, observations shall be conducted according
to 40 CFR 60.11(b) unless otherwise specified under the applicable NSPS subpart.

B. It is the responsibility of the owner/operator of the source to supply these observations to
the Director.

C. A currently certified observer must be used for these observations. [40 CFR 60 Subpart A]

II.B.7.a.3 The owner/operator shall install, calibrate, maintain, and operate continuous opacity
monitoring systems on the rotary dryer baghouse/scrubber, the main stack, and the acid plant
tail gas. [R307-401-8]

II.B.7.a.4 The owner/operator shall record the output of the systems for measuring the opacity of
emissions on the rotary dryer baghouse/scrubber outlet, main stack, and acid plant tail gas.
The monitoring systems shall comply with all applicable sections of UAC R307-170 and 40
CFR 60, Appendix B, Specification 1 - Opacity. [R307-401-8]

II.B.7.a.5 Sources equipped with continuous opacity monitors (rotary dryer baghouse/scrubber, acid
plant tail gas and main stack) shall use the compliance methods contained in 40 CFR 60.11.
[R307-305-3]

II.B.7.a.6 The owner/operator shall perform a visual opacity survey of the acid plant process gas leaks
emission unit on a weekly basis to minimize emissions from leaks of sulfur dioxide, sulfur
trioxide, and other process emissions.

A. Surveys shall be conducted by an individual trained on the observation procedures of 40
CFR 60, Appendix A, Method 9.

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B. If visible emissions other than steam are observed from the acid plant process gas leaks
emission unit, an opacity determination shall be performed by a certified observer within 24
hours of the initial survey. The opacity determination shall be performed in accordance with
40 CFR 60, Appendix A, Method 9.

C. If visible emissions greater than 15% opacity are observed, then best operational practices
shall be initiated within 24 operating hours of the observation to ensure leakage of gases to the
ambient air are being controlled to 20% opacity or less. Best operational practices may
include, but are not limited to:

1) Placement or adjustment of negative pressure ductwork and collection hoses;

2) Welding of process gas leaks; or

3) Containment of process gas leaks.

D. A log of the visual opacity survey(s) shall be maintained. If an opacity determination is
indicated, a notation of the determination will be made in the log. [R307-401-8]

II.B.7.b The owner/operator shall install, calibrate, maintain, and operate continuous monitoring
systems on the acid plant tail gas. [R307-401-8]

II.B.7.b.1 The owner/operator shall record the output of the system for measuring the SO2 concentration
of the acid plant tail gas. The monitoring system shall comply with all applicable sections of
UAC R307-170, 40 CFR 60, Appendix B, Specification 2 - SO2. [R307-401-8]

II.B.7.c The owner/operator shall only combust diesel fuel ((e.g. fuel oil #1, #2, or diesel fuel oil
additives) that meets the definition of ultra-low sulfur diesel (ULSD), which has a sulfur
content of 15 ppm or less. [R307-401-8]

II.B.7.c.1 To demonstrate compliance with the ULSD fuel requirement, the owner/operator shall
maintain records of diesel fuel purchase invoices or obtain certification of sulfur content from
the diesel fuel supplier. The diesel fuel purchase invoices shall indicate that the diesel fuel
meets the ULSD requirements. [R307-401-8]

II.B.7.d All gases produced during smelting and/or converting which enter the primary gas handling
system shall pass through an online sulfuric acid plant. During the start-up/shutdown process
of any equipment, the gas emissions shall be ducted, as necessary, either to the acid plant or to
the secondary scrubber for control. [R307-401-8]

II.B.7.e
NEW
The owner/operator shall employ the following measures for reducing escape of pollutants to
the atmosphere and to capture emissions and vent them through a stack or stacks:

A. Maintenance of all ducts, flues, and stacks in such a fashion that leakage of gases to
the ambient air will be prevented to the maximum extent practicable

B. Operation and maintenance of gas collection systems in good working order

C. Making available the preventive/routine maintenance records for the hooding systems;
dust collection mechanism of waste heat boilers; furnace wet scrubbing systems; and

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dry electrostatic precipitators

D. Weekly observation of process units

E. Monthly inspection of gas handling systems

F. Maintenance of gas handling systems, available on call on a 24-hour basis

G. Operation and maintenance of an upwind/downwind fugitive SO2 monitoring system.
The owner/operator may petition the Director to discontinue the operation of this
system.

H. Contained conveyance of acid plant effluent solutions.
[R307-401-8]

II.B.7.f Secondary hoods and ventilation systems shall be installed on the following points to capture
fugitive emissions into the secondary ventilation system or other approved pollution control
devices:

A. Concentrate Dryer Feed Chute

B. Slag and Matte Granulators

C. Smelting and Converting Furnaces

D. Slag Pot Filling Stations. [R307-401-8]

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PERMIT HISTORY

When issued, the approval order shall supersede (if a modification) or will be based on the
following documents:

Supersedes DAQE-AN103460062-23 dated December 28, 2023
Is Derived From NOI dated August 23, 2024

REVIEWER COMMENTS

1. Comment regarding Summary of Changes:
This administrative action was requested to add a condition which had been missing from the
previous AO. When the engineering review for the previous AO was conducted, condition II.B.7.a
regarding opacity limits was included. When the AO was issued, this condition was missing. This
administrative action adds that condition back into the AO and makes no other changes. [Last
updated August 29, 2024]

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Page 28
ACRONYMS
The following lists commonly used acronyms and associated translations as they apply to this
document:
40 CFR Title 40 of the Code of Federal Regulations
AO Approval Order
BACT Best Available Control Technology
CAA Clean Air Act
CAAA Clean Air Act Amendments
CDS Classification Data System (used by EPA to classify sources by size/type)
CEM Continuous emissions monitor
CEMS Continuous emissions monitoring system
CFR Code of Federal Regulations
CMS Continuous monitoring system
CO Carbon monoxide
CO2 Carbon Dioxide
CO2e Carbon Dioxide Equivalent - 40 CFR Part 98, Subpart A, Table A-1
COM Continuous opacity monitor
DAQ/UDAQ Division of Air Quality
DAQE This is a document tracking code for internal UDAQ use
EPA Environmental Protection Agency
FDCP Fugitive dust control plan
GHG Greenhouse Gas(es) - 40 CFR 52.21 (b)(49)(i)
GWP Global Warming Potential - 40 CFR Part 86.1818-12(a)
HAP or HAPs Hazardous air pollutant(s)
ITA Intent to Approve
LB/HR Pounds per hour
LB/YR Pounds per year
MACT Maximum Achievable Control Technology
MMBTU Million British Thermal Units
NAA Nonattainment Area
NAAQS National Ambient Air Quality Standards
NESHAP National Emission Standards for Hazardous Air Pollutants
NOI Notice of Intent
NOx Oxides of nitrogen
NSPS New Source Performance Standard
NSR New Source Review
PM10 Particulate matter less than 10 microns in size
PM2.5 Particulate matter less than 2.5 microns in size
PSD Prevention of Significant Deterioration
PTE Potential to Emit
R307 Rules Series 307
R307-401 Rules Series 307 - Section 401
SO2 Sulfur dioxide
Title IV Title IV of the Clean Air Act
Title V Title V of the Clean Air Act
TPY Tons per year
UAC Utah Administrative Code
VOC Volatile organic compounds