DAQ-2024-009871

DAQE-AN105710048-24

{{$d1 }}

Brendan Murphy
Rio Tinto Kennecott Utah Copper LLC
4700 Daybreak Parkway
South Jordan, UT 84095
[e-mail]

Dear Mr. Murphy:

Re: Approval Order: Modification to Approval Order to DAQE-AN105710047-21, to Add Paste
Plant and Support Equipment
Project Number: N105710048

The attached Approval Order (AO) is issued pursuant to the Notice of Intent (NOI) received on February
9, 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 Tad Anderson, 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. No public comments were
received on this action.

Sincerely,

{{$s }}

Bryce C. Bird
Director

BCB:TA: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

August 7, 2024

STATE OF UTAH
Department of Environmental Quality
Division of Air Quality

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APPROVAL ORDER
DAQE-AN105710048-24
Modification to Approval Order to DAQE-AN105710047-21
to Add Paste Plant and Support Equipment

Prepared By
Tad Anderson, Engineer
[phone]
[e-mail]

Issued to
Rio Tinto Kennecott Utah Copper LLC - Mine & Copperton Concentrator

Issued On
{{$d2 }}

Issued By

{{$s }}

Bryce C. Bird
Director
Division of Air Quality

August 7, 2024
TABLE OF CONTENTS

TITLE/SIGNATURE PAGE ....................................................................................................... 1
GENERAL INFORMATION ...................................................................................................... 3
CONTACT/LOCATION INFORMATION ............................................................................... 3
SOURCE INFORMATION ........................................................................................................ 3
General Description ................................................................................................................ 3
NSR Classification .................................................................................................................. 3
Source Classification .............................................................................................................. 3
Applicable Federal Standards ................................................................................................. 3
Project Description.................................................................................................................. 4
SUMMARY OF EMISSIONS .................................................................................................... 4
SECTION I: GENERAL PROVISIONS .................................................................................... 5
SECTION II: PERMITTED EQUIPMENT .............................................................................. 5
SECTION II: SPECIAL PROVISIONS ..................................................................................... 8
PERMIT HISTORY ................................................................................................................... 18
ACRONYMS ............................................................................................................................... 19

DAQE-AN105710048-24
Page 3

GENERAL INFORMATION

CONTACT/LOCATION INFORMATION

Owner Name Source Name
Rio Tinto Kennecott Utah Copper LLC Rio Tinto Kennecott Utah Copper LLC - Mine &
Copperton Concentrator

Mailing Address Physical Address
4700 Daybreak Parkway 8362 West 10200 South
South Jordan, UT 84095 Bingham Canyon, UT 84006

Source Contact UTM Coordinates
Name: Jenny Esker 407,000 m Easting
Phone: [phone],493,000 m Northing
Email: [e-mail] Datum NAD27
UTM Zone 12

SIC code 1021 (Copper Ores)

SOURCE INFORMATION
General Description
Rio Tinto Kennecott Utah Copper LLC (RTK) owns and operates the Bingham Canyon Mine (BCM) and
the Copperton Concentrator. The BCM is an open-pit mining operation located in the southwest corner of
Salt Lake County, Utah. Ore from the mine is conveyed to the Copperton Concentrator, located
approximately five (5) miles north of the open pit in Copperton, Utah, where it is ground and treated to
produce copper concentrate.

NSR Classification
Minor Modification to Minor Source

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: B

Applicable Federal Standards
NSPS (Part 60), A: General Provisions
NSPS (Part 60), LL: Standards of Performance for Metallic Mineral Processing Plants
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
DAQE-AN105710048-24
Page 4

Combustion Engines
MACT (Part 63), A: General Provisions
MACT (Part 63), ZZZZ: National Emissions Standards for Hazardous Air Pollutants for
Stationary Reciprocating Internal Combustion Engines
Title V (Part 70) Area Source

Project Description
RTK is requesting a modification of BCM Approval Order (AO) DAQE-AN105710047-21 to install and
operate facilities associated with underground mining operations. The underground mining operations
include the use of a new Paste Plant with two (2) storage silos, a mixer dust collector, and four (4)
emergency standby generators for the employee ventilation systems.

The new storage silos at the bottom of the mine support the Paste Plant operations, where RTK will make
usable concrete from lime and other materials. The mixer dust collector captures emissions from the paste
plant mixer process area, where lime and other materials are blended together to make usable concrete.

Process Description
The ore and waste rock at the BCM are transferred from the mining areas to other areas of the mine
through a series of transfers using haul trucks and conveyor belts. Ore is transferred to the in-pit crusher
with haul trucks from the shovel face, and waste rock is hauled to dumping areas with haul trucks. After
the ore is crushed, it is conveyed to the Copperton Concentrator. Once the ore is processed at the
concentrator, it is transferred to the smelter.

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)
CO2 Equivalent 718.29 9038.47
Carbon Monoxide 4.34 1712.04
Nitrogen Oxides 0.60 5842.71
Particulate Matter - PM10 0.41 1519.62
Particulate Matter - PM10 (Fugitives) 0.00 1509.76
Particulate Matter - PM2.5 0.23 369.44
Particulate Matter - PM2.5 (Fugitives) 0.00 367.76
Sulfur Dioxide 0.01 7.44
Volatile Organic Compounds 0.19 314.32

Hazardous Air Pollutant Change (lbs/yr) Total (lbs/yr)
Total HAPs (CAS #THAPS) 100 3580
Change (TPY) Total (TPY)
Total HAPs 0.05 1.79

DAQE-AN105710048-24
Page 5

SECTION I: GENERAL PROVISIONS

I.1 The limits set forth in this AO shall not be exceeded without prior approval. [R307-401]

I.2 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.3 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 two-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 two (2) years. [R307-401-8]

I.4 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.5 The owner/operator shall comply with R307-150 Series. Inventories, Testing and Monitoring.
[R307-150]

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

I.7 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.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 KUC Bingham Canyon Mine
KUC operates the BCM. KUC removes ore from the BCM by drilling, blasting, crushing, and
hauling.

II.A.2 Main In-pit Crusher
Main in-pit crusher
Main in-pit crusher baghouse

DAQE-AN105710048-24
Page 6

II.A.3 Portable Roadbase Crushers
Two (2) portable crushing and screening plants are used to crush material for road bases.
Maximum crusher unit capacity: 700 tons per hour, each

II.A.4 Conveyors
Conveyors and two (2) transfer points with baghouses (Baghouses C6/C7 and Baghouses C7/C8)

II.A.5 Lime Silos
Lime silos with fabric-type bin vent control units

II.A.6 Sample Preparation Equipment
Sample preparation equipment with baghouse

II.A.7 SX/EW plant
SX/EW plant with electrowinning acid mist eliminator

II.A.8 Degreasers
Various degreasing part washers

II.A.9 Gasoline Fueling Stations

II.A.10 LPG-Fired Emergency Generators
Nine (9) Liquefied Petroleum gas-fired emergency generators

Site Maximum Rating
Lark Gate
#1 107 Brake Horsepower (BHP)
#2 49 BHP
Production Control Building 6690 150 BHP
Communications 6190 75 BHP
Mandy's Landing 75 BHP
East Side Dump 49 BHP
Zelnora 49 BHP
SAM Site 49 BHP
Substation 2 49 BHP

II.A.11 Diesel-Fired Emergency Generators
Nine (9) diesel-fired emergency generators (4 NEW).

1) Support Generators 1-5.
1. Maximum rating 2,250 kW
2. Maximum rating 700 kW
3. Maximum rating 700 kW
4. Maximum rating 500 kW
5. Maximum rating 2,000 kW

2) Ventilation System Generators 6-9 (NEW).
6. Maximum rating 2,000 kW
7. Maximum rating 2,000 kW
8. Maximum rating 2,000 kW
9. Maximum rating 3,250 kW

DAQE-AN105710048-24
Page 7

II.A.12 Concrete Batch Plant

1) One (1) 25-cubic-yard per hour batch plant controlled by a baghouse.

2) One (1) cement storage silo controlled by a baghouse.

3) Conveyors and cement trucks.

4) Storage silos with fabric filters.

II.A.13 Crushers and Screens
Portable crushing and screening plants with associated conveyors used to crush ore and waste
rock.

Conveyors
Partially enclosed transfer points or water sprays

II.A.14 Underground Mining Support Equipment

1) One (1) 150 cubic yard per hour batch plant controlled by baghouse.
a) One (1) cement storage silo with a baghouse.
b) Conveyors and cement trucks.
c) Storage silos with fabric filters.

2) One (1) natural gas-fired boiler - 2.0 MMBTU/hr.

3) One (1) natural gas-fired boiler - 4.0 MMBTU/hr.

4) Three (3) diesel-fired heaters - 4.2 MMBTU/hr (each).

5) One (1) diesel-fired generator - 71 kW.

II.A.15 Paste Plant (NEW)

1. Two (2) Storage silos with baghouse.

2. One (1) Mixer Dust Collector with baghouse.

DAQE-AN105710048-24
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SECTION II: SPECIAL PROVISIONS

II.B REQUIREMENTS AND LIMITATIONS

II.B.1 Limitations and Test Procedures
II.B.1.a Emissions at all times from the indicated emission points after primary control shall not exceed
the following rates and concentrations:

A. Main In-Pit Crusher Baghouse Vent

Pollutant lb/hr grains per dry standard cubic foot (dscf)
(68oF, 29.92 in Hg)

PM10 1.77 0.016
PM2.5 0.78 0.007

B. Controlled Drop Point Baghouse Vent (C6/C7, located outside of the pit)

Pollutant lb/hr grains per dry standard cubic foot (dscf)
(68oF, 29.92 in Hg)

PM10 0.31 0.007

C. Controlled Drop Point Baghouse Vent (C7/C8, located outside of the pit)

Pollutant lb/hr grains per dry standard cubic foot (dscf)
(68oF, 29.92 in Hg)

PM10 0.19 0.007

[R307-401-8]

DAQE-AN105710048-24
Page 9

II.B.1.b Stack testing to show compliance with the emission limitations stated in the above condition
shall be performed as specified below:

A. Testing Test
Emissions Point Pollutant Status Frequency

Main In-Pit Crusher Baghouse
Vent PM10 * #
PM2.5 * #

Controlled Drop-Point Baghouse
Vent (C6/C7, located outside of the pit) PM10 * #

Controlled Drop-Point Baghouse
Vent (C7/C8, located outside of the pit) PM10 * #

B. Testing Status

* The initial testing has already been performed.

# Test every three (3) years. If a unit is not in operation when a test is due, the
owner/operator may request an extension for the test.

C. Notification
The Director shall be notified at least 30 days prior to conducting any required emission
testing. A source test protocol shall be submitted with the testing notification is
submitted to the Director.

The source test protocol shall be approved by the Director prior to performing the test(s).
The source test protocol shall outline the proposed test methodologies and stacks to be
tested. A pretest conference shall be held, if directed by the Director.

D. 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.
An Occupational Safety and Health Administration (OSHA) or Mine Safety and
Health Administration (MSHA)-approved access shall be provided to the test
location.

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

F. 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 of 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-AN105710048-24
Page 10

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.

II.B.1.c G. 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.

H. Source Operation
For a new source/emission point, the production rate during all compliance testing
shall be no less than 90% of the production capacity of the equipment. If the maximum
production capacity has not been achieved at the time of the test, the following procedure
shall be followed:

1) Testing shall be at no less than 90% of the production rate achieved to date.

2) If the test is passed, the new maximum allowable production rate shall
be 110% of the tested achieved rate. This new allowable maximum production
rate shall remain in effect until successfully tested at a higher rate. This process
may be repeated until the maximum AO production rate is achieved.

For an existing source/emission point, the production rate during all compliance
testing shall be no less than 90% of the maximum production achieved in the previous
three (3) years.

[R307-401-8]

DAQE-AN105710048-24
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II.B.1.d Visible emissions from the following emission points shall not exceed the following values:

A. Main In-Pit crusher baghouse vent 7% opacity.

B. Controlled drop-point baghouse vent
(C6/C7, located outside of the pit) 7% opacity.

C. Controlled drop-point baghouse vent
(C7/C8, located outside of the pit) 7% opacity.

D. Concrete batch plant baghouse 10% opacity.

E. All other conveyor transfer points 10% opacity.

F. Lime silos 10% opacity.

G. Sample preparation equipment with
baghouse 10% opacity.

H. Drilling 10% opacity.

I. LP gas-fired emergency generators 10% opacity.

J. Nonmetallic Mineral Processing Screens
and Conveyors 7% opacity.

K. Nonmetallic Mineral Processing Crushers 12% opacity.

L. Metallic Mineral Processing Equipment 10% opacity.

M. Electrowinning Plants with electrowinning
acid mist eliminator 15% opacity.

N. All other points, except as defined in other
conditions of this AO 10% opacity.

O. Diesel-fired Equipment 20% opacity.

Opacity observations of emissions from stationary sources shall be conducted according to 40
CFR 60, Appendix A, Method 9.

[R307-201]

II.B.1.e For sources that are subject to NSPS, opacity shall be determined in accordance with 40 CFR
60.11(b) and 40 CFR 60, Appendix A, Method 9. It is the responsibility of the owner/operator of
the source to supply these observations to the Director.

A current certified observer must be used for these observations. Emission points that are subject
to the initial observations are:

A. All crushers.

B. All screens.

C. All conveyor transfer points.

[40 CFR 60 Subpart A]

DAQE-AN105710048-24
Page 12

II.B.1.f The following limits shall not be exceeded:

A. Total material moved (ore and waste) shall not exceed 260,000,000 tons per rolling
12-month period*.

B. Annual emissions of SO2 shall not exceed 7 tons per rolling 12-month period.

C. Maximum total mileage per calendar day for diesel-powered ore and waste haul trucks
shall not exceed 30,000 miles.

D. Minimum design payload per ore and waste haul truck shall not be less than 240 tons.
Minimum design payload for trucks hauling material to develop new mining
technologies, and material from maintenance activities shall not be less than 40 tons.
Trucks used for underground development and operation may be smaller depending
on application.

E. Maximum number of wheels per ore or waste haul truck shall not exceed six (6) wheels.

F. Height of the mine waste dump lift shall not exceed 1000 feet.

G. The surface area of the Solvent Extraction/Electrowinning Plant mixer/settlers
shall not exceed 1,100 ft2.

*Total ore and waste limitation shall be applied to dry tons of new material mined at the
production shovels face.

The owner/operator shall determine compliance with the 12-month period limits on a rolling
12-month total. The owner/operator shall calculate a new 12-month total by the twentieth day of
each month using data from the previous 12 months.

The owner/operator shall keep records of daily total mileage for all periods when the mine is in
operation. The owner/operator shall track haul truck miles with a Global Positioning System or
equivalent. The system shall use real time tracking to determine daily mileage.

SO2 emissions from fuel burning shall be determined using the following formula:

SO2 tpy = (gal fuel/year)*(7.05 lb/gal)*(%S by wt.)/2000 lb/ton*(2 lb SO2/lb S).

[R307-401-8]

II.B.1.g The following site-wide emission limits at the BCM shall not be exceeded:

A. 7,350 tons of NOx, PM10 and SO2 combined per rolling 12-month period.

B. 6,205 tons of NOx, PM2.5 and SO2 combined per rolling 12-month period.

The owner/operator shall determine compliance with the 12-month period limits on a rolling
12-month total per methodology outlined in Appendix A. The owner/operator shall calculate a
new 12-month total by the twentieth day of each month using data from the previous 12 months.

[R307-401-8]

II.B.2 Equipment Requirements
II.B.2.a The Main In-Pit Crusher Baghouse shall control process streams from the Main In-Pit Crusher.
This baghouse shall be sized to handle at least 12,898 Dry Standard Cubic Feet per Minute
(DSCFM). All exhaust air from the main in-pit crusher shall be routed through the baghouse
before being vented to the atmosphere. [R307-401-8]

DAQE-AN105710048-24
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II.B.2.b The lime silos fabric bin vent control units shall control process streams from the lime silos.
This control unit shall be sized to handle at least 616 DSCFM. All exhaust air from the lime silos
shall be routed through the control unit before being vented to the atmosphere. [R307-401-8]

II.B.2.c The Controlled Transfer Drop Point C6/C7 baghouse shall control process streams from the drop
point. This baghouse shall be sized to handle at least 5,120 DSCFM. All exhaust air from the
C6/C7 transfer drop point shall be routed through the baghouse before being vented to the
atmosphere. [R307-401-8]

II.B.2.d The Controlled Transfer Drop Point C7/C8 baghouse shall control process streams from the drop
point. This baghouse shall be sized to handle at least 3,168 DSCFM. All exhaust air from the
C7/C8 transfer drop point shall be routed through the baghouse before being vented to the
atmosphere. [R307-401-8]

II.B.2.e The Sample Preparation baghouse shall control process streams from the sample preparation
building, crushing and grinding equipment. This baghouse shall be sized to handle at least 4,200
DSCFM. All exhaust air from the sample preparation crusher and grinder shall be routed through
the baghouse before being vented to the atmosphere. [R307-401-8]

II.B.2.f The Electrowinning Acid Mist Eliminator shall control process streams from the electrowinning
cells. This mist eliminator shall be sized to handle at least 8,000 actual CFM. Except during
service, inspection, and cathode harvest, all exhaust air from the electrowinning cells shall be
routed through the mist eliminator before being vented to the atmosphere. [R307-401-8]

II.B.2.g The solvent extraction tanks and the stripping mixer/settlers shall be covered at all times except
during inspection, sampling, and adjustment. [R307-401-8]

II.B.2.h The concrete batch plant baghouse shall control all process streams from the 25 cubic yard
concrete batch plant listed in Condition II.A.12. This baghouse shall be sized to handle at least
3,900 DSCFM. All exhaust air from the concrete batch plant shall be routed through the
baghouse before being vented to the atmosphere. [R307-401-8]

II.B.2.i The owner/operator shall only combust diesel fuel 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.2.i.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.3 Roads and Fugitive Dust
II.B.3.a The owner/operator shall abide by a FDCP acceptable to the Director for control of all dust
sources associated with the BCM. The FDCP shall be updated and submitted on an annual basis
to the Director by February 1st of every year. This plan shall contain sufficient controls to
prevent an increase in PM10 emissions above those modeled for this AO. The haul road length,
speed, or any other parameters used to calculate the emissions cannot be changed without prior
approval from the Director, if the change would result in an increase in emissions above the
limitations set in the FDCP. [R307-309]

II.B.3.b The BCM shall comply with all applicable requirements of UAC R307-205 and R307-309 for
Fugitive Emission and Fugitive Dust sources. The provisions of R307-205 and R307-309 shall
not apply to any sources for which limitations for fugitive dust or fugitive emissions are assigned
pursuant to R307-401 or R307-305, nor shall they apply to agricultural or horticultural activities.
[R307-309]

DAQE-AN105710048-24
Page 14

II.B.3.c Control of disturbed or stripped areas is required at all times (24 hours per day, every day) for the
duration of the project/operation until the area is reclaimed. Records of disturbed areas,
treatment, and/or reclamation shall be kept for all periods when the BCM is in operation.
[R307-309]

II.B.3.d Visible fugitive dust emissions from haul-road traffic and mobile equipment in operational areas
shall not exceed 20% opacity at any point. Visible emission determinations shall use procedures
similar to Method 9. The normal requirement for observations to be made at 15-second intervals
over a six-minute period, however, shall not apply. Visible emissions shall be measured at the
densest point of the plume but at a point not less than 1/2 vehicle length behind the vehicle and
not less than 1/2 the height of the vehicle. [R307-309]

II.B.3.e Water sprays, chemical dust suppression sprays, or enclosures shall be installed at the following
points that are not enclosed or have baghouses to control fugitive emissions:

A. All stationary and portable conveyor transfer points.

B. All portable crusher input and output points, and screening unit points or partial
enclosures.

The sprays shall operate whenever dry conditions warrant or as determined necessary by the
Director.

[R307-309]

II.B.3.f The accessible surfaces of all uncovered storage piles shall be sprayed with water or chemical
dust suppressants to minimize generation of fugitive dust, as dry conditions warrant or as
determined necessary by the Director. Records of water and/or chemical dust control treatment
shall be kept for all periods when the plant is in operation. [R307-309]

II.B.3.g The opacity on active waste slopes shall not exceed 20%. A visual opacity survey of waste dump
activity shall be performed on a monthly basis. If visible emissions are observed, an opacity
observation shall be performed by a certified observer within 24 hours. Opacity observations
shall be conducted in accordance with 40 CFR 60, Appendix A, Method 9, but the requirement
for observations to be made at 15-second intervals over a six-minute period shall not apply. At
any time, the owner/operator may propose a compliance method to UDAQ for approval prior to
implementation. [R307-309]

DAQE-AN105710048-24
Page 15

II.B.3.h The owner/operator shall use frequent watering or chemical dust suppressant to control road dust
from all trafficked roads and areas in the mine. The owner/operator shall submit an annual road
dust control report, in conjunction with the FDCP, by February 1st of each calendar year,
containing as a minimum the following:

A. A description of what dust control measures are planned for the coming year.

B. A report of what dust control measures were actually completed during the past year.

C. Specific elements of the report will include:

1) A map of all trafficked areas and roads associated with the mine, indicating
which areas are planned for water and/or chemical dust suppressant treatment.

2) A description of the chemical dust suppressant and how it will be applied (application
rate, application frequency, dilution rate, special application procedure, scarification,
etc.).

3) A list of equipment dedicated either full or part-time to the work area and for road
dust control (number of water trucks, water capacity, number of graders, etc.).

4) A quantification of how much dust suppressant (gallons, tons) was applied the
previous year and when and where it was applied.

5) A quantification of how much watering was accomplished in the previous year
(gallons, water truck operating hours).

6) A map outlining the pit influence boundary.

[R307-309]

II.B.3.i Wet drilling shall be performed for all blast holes. [R307-309]

DAQE-AN105710048-24
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II.B.3.j To minimize fugitive dust on roads at the BCM, the owner/operator shall perform the following
measures:

A. Apply water to all active haul roads located at the BCM as conditions warrant and in
accordance with the FDCP, and shall

1) ensure the surface of the active haul roads located within the pit influence
boundary consists of road base material, blasted waste rock, crushed rock,
or chemical dust suppressant, and

2) apply a chemical dust suppressant to active haul roads located outside
of the pit influence boundary no less than twice per year.

B. Ore conveyors shall be the primary means for transport of crushed ore from the
BCM to the Copperton Concentrator.

C. Chemical dust suppressant shall be applied on unpaved access roads that receive
haul truck traffic and light vehicle traffic as defined in the FDCP.

D. The owner/operator shall use graders to perform haul road maintenance and clean-up
activities as well as other operational functions.

E. If, for a 12-month period, the material movement by haul trucks is below 197,000,000
tpy of ore and waste rock combined, the owner/operator may petition the Director to
revise the fugitive dust control measures above.

[R307-309-10]

II.B.4 Monitoring Requirements
II.B.4.a The owner/operator shall operate two (2) ambient monitoring stations to monitor PM10 in
Copperton and lower Butterfield Canyon areas as approved by the Director. The monitoring plan
will be periodically reviewed and revised as necessary. Any changes must be approved by the
Director.

The air monitoring stations shall remain in operation, at a minimum, until the BCM material
moved has achieved a minimum of 234,000,000 TPY. If after that amount of material moved has
been achieved and monitoring data indicates compliance with the NAAQS, the owner/operator
may petition the Director to remove the air monitoring stations. [R307-410]

II.B.4.b The owner/operator shall utilize federal reference method (FRM) or federal equivalent method
PM10 monitors as specified in 40 CFR 53 and quality assurance procedures which are equal to or
exceed the requirements described in the EPA Quality Assurance Manual, including revisions, 40
CFR Parts 50, 53, and 58. [R307-410]

II.B.4.c If the PM10 concentrations measured are greater than 135 ug/m3 (90% of the 24-hr PM10
NAAQS), and if such concentrations have been measured for more than one day per year on an
average over three (3) consecutive years, the owner/operator shall conduct a review of mine
operations and other potential sources and conditions, such as the Natural Events Exception
Criteria.

If it is determined the BCM impacts the elevated ambient PM10 concentrations, the
owner/operator shall work with DAQ to review control practices and possible changes in
practices to avoid future elevated concentrations.

[R307-410]

DAQE-AN105710048-24
Page 17

II.B.4.d The owner/operator shall submit quarterly data reports within 45 days after the end of the
calendar quarter and an annual data report within 90 days after the end of the calendar year.

The quarterly report shall consist of a narrative data summary and a submittal of all data points in
EPA-AIRS record format. The data shall be submitted on a compact disk (CD). The narrative
data summary shall include:

A. A topographic map of appropriate scale with UTM coordinates and a true north arrow
showing the air monitoring site locations in relation to the mine and the general area;

B. A hard copy of the individual data points;

C. The quarterly and monthly arithmetic means for PM10 at actual temperature and
pressure;

D. The first and second highest 24-hour concentrations for PM10;

E. The quarterly and monthly wind roses;

F. A summary of the data collection completeness;

G. A summary of the reasons for missing data;

H. An audit summary;

I. A summary of any ambient air PM10 exceedances;

J. Calibration information; and

K. Laboratory reports (for exceedance filters).

The annual data report shall consist of a narrative data summary containing:

A. A topographic map of appropriate scale with UTM coordinates and a true north arrow
showing the air monitoring site locations in relation to the mine and the general area;

B. A pollution trend analysis;

C. The annual arithmetic means for PM10;

D. The first and second highest 24-hour concentrations for PM10;

E. The annual wind rose;

F. Annual summaries of data collection frequency and completeness;

G. An annual summary of audit data;

H. An annual summary of any ambient standard exceedance;

I. Annual mine material moved in TPY;

J. Annual summary of analytical speciation results for detectable metals (for exceedance
filters); and

K. Recommendations on future monitoring.

The Director reserves the right to audit the air monitoring network, the laboratory performing
associated analysis, and any data handling procedures at unspecified times. On the basis of the
audits and subsequent reports, DAQ reserves the right to recommend or require changes in the air
monitoring system and associated activities in order to improve data quality and completeness.

[R307-410]

DAQE-AN105710048-24
Page 18

II.B.4.e The owner/operator shall contract with an independent firm to conduct quarterly performance
audits of its PM10 monitors.

Exposed PM10 filters that exceed 150 ug/m3 shall be analyzed for metals and other constituents as
requested by the Director. One (1) filter blank per batch of ten (10) filters or less shall also be
submitted for analysis.

[R307-410]

II.B.4.f PM10 and meteorological data (wind speed, wind direction, and ambient temperature) shall be
collected at each site. The meteorological tower shall be located within one mile of the monitor
station. R307-410]

II.B.5 Emergency Generator Engine
II.B.5.a The owner/operator shall not operate each emergency engine on site for more than 100 hours per
rolling 12-month period during non-emergency situations. There is no time limit on the use of
the engines during emergencies. [R307-401-8]

II.B.5.b 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
documenting the operation of each emergency engine shall be kept in a log and shall include the
following:

a. The date the emergency engine was used.

b. The duration of operation in hours.

c. The reason for the emergency engine usage.

[R307-401-8]

II.B.5.c To determine the duration of operation, the owner/operator shall install a non-resettable hour
meter for each emergency engine. [R307-401-8]

II.B.5.d KUC shall not exceed the following limits on the diesel fired emergency generators for the
Ventilation Systems #6, #7, #8, and #9:

Testing of the diesel fired emergency generators shall be allowed between 8 a.m. and 8 p.m.
Only one (1) diesel fired emergency generator shall be tested at the same time. [R307-410]

PERMIT HISTORY

This Approval Order shall supersede (if a modification) or will be based on the following documents:

Supersedes DAQE-AN105710047-21 dated May 10, 2021
Is Derived From NOI dated February 9, 2024
Incorporates Additional Information dated February 28, 2024
Incorporates Additional Information dated April 18, 2024

DAQE-AN105710048-24
Page 19

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-IN105710048-24

June 20, 2024

Brendan Murphy
Rio Tinto Kennecott Utah Copper LLC
4700 Daybreak Parkway
South Jordan, UT 84095
[e-mail]

Dear Mr. Murphy:

Re: Intent to Approve: Modification to Approval Order to DAQE-AN105710047-21, to Add Paste
Plant and Support Equipment
Project Number: N105710048

The attached document is the Intent to Approve (ITA) for the above-referenced project. The ITA is
subject to public review. Any comments received shall be considered before an Approval Order (AO) is
issued. The Division of Air Quality is authorized to charge a fee for reimbursement of the actual costs
incurred in the issuance of an AO. An invoice will follow upon issuance of the final AO.

Future correspondence on this ITA should include the engineer's name, Tad Anderson, as well as the
DAQE number as shown on the upper right-hand corner of this letter. Tad Anderson, can be reached at
[phone] or [e-mail], if you have any questions.

Sincerely,

{{$s }}

Jon L. Black, Manager
New Source Review Section

JLB:TA: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

* ) ' & — 0 ) @ H v A ? A C A A w A D ˜
STATE OF UTAH
Department of Environmental Quality
Division of Air Quality

INTENT TO APPROVE
DAQE-IN105710048-24
Modification to Approval Order to DAQE -AN105710047-21
to Add Paste Plant and Support Equipment

Prepared By
Tad Anderson, Engineer
[phone]
[e-mail]

Issued to
Rio Tinto Kennecott Utah Copper LLC - Mine & Copperton Concentrator

Issued On
June 20, 2024

{{$s }}

New Source Review Section Manager
Jon L. Black
{{#s=Sig_es_:signer1:signature}}

* ) ' & — 0 ) @ H v A ? A C A A w A D ˜

TABLE OF CONTENTS

TITLE/SIGNATURE PAGE ....................................................................................................... 1
GENERAL INFORMATION ...................................................................................................... 3
CONTACT/LOCATION INFORMATION ............................................................................... 3
SOURCE INFORMATION ........................................................................................................ 3
General Description ................................................................................................................ 3
NSR Classification .................................................................................................................. 3
Source Classification .............................................................................................................. 3
Applicable Federal Standards ................................................................................................. 3
Project Description.................................................................................................................. 4
SUMMARY OF EMISSIONS .................................................................................................... 4
PUBLIC NOTICE STATEMENT............................................................................................... 5
SECTION I: GENERAL PROVISIONS .................................................................................... 5
SECTION II: PERMITTED EQUIPMENT .............................................................................. 6
SECTION II: SPECIAL PROVISIONS ..................................................................................... 8
PERMIT HISTORY ................................................................................................................... 20
ACRONYMS ............................................................................................................................... 21

DAQE-IN105710048-24
Page 3

GENERAL INFORMATION

CONTACT/LOCATION INFORMATION

Owner Name Source Name
Rio Tinto Kennecott Utah Copper LLC Rio Tinto Kennecott Utah Copper LLC- Mine &
Copperton Concentrator

Mailing Address Physical Address
4700 Daybreak Parkway 8362 West 10200 South
South Jordan, UT 84095 Bingham Canyon, UT 84006

Source Contact UTM Coordinates
Name: Jenny Esker 407,000 m Easting
Phone: [phone],493,000 m Northing
Email: [e-mail] Datum NAD27
UTM Zone 12

SIC code 1021 (Copper Ores)

SOURCE INFORMATION
General Description
Rio Tinto Kennecott Utah Copper LLC (RTK) owns and operates the Bingham Canyon Mine (BCM) and
the Copperton Concentrator. The BCM is an open-pit mining operation located in the southwest corner of
Salt Lake County, Utah. Ore from the mine is conveyed to the Copperton Concentrator, located
approximately five (5) miles north of the open pit in Copperton, Utah, where it is ground and treated to
produce copper concentrate.
NSR Classification
New Minor Source

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: B

Applicable Federal Standards
NSPS (Part 60), A: General Provisions
NSPS (Part 60), LL: Standards of Performance for Metallic Mineral Processing Plants
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
DAQE-IN105710048-24
Page 4

MACT (Part 63), A: General Provisions
MACT (Part 63), ZZZZ: National Emissions Standards for Hazardous Air Pollutants for
Stationary Reciprocating Internal Combustion Engines
Title V (Part 70) Area Source

Project Description
RTK is requesting a modification of BCM Approval Order (AO) DAQE-AN105710047-21 to install and
operate facilities associated with underground mining operations. The underground mining operations
include the use of a new Paste Plant with two (2) storage silos, a mixer dust collector, and four (4)
emergency standby generators for the employee ventilation systems.

The new storage silos at the bottom of the mine support the Paste Plant operations, where RTK will make
usable concrete from lime and other materials. The mixer dust collector captures emissions from the paste
plant mixer process area, where lime and other materials are blended together to make usable concrete.

Process Description
The ore and waste rock at the BCM are transferred from the mining areas to other areas of the mine
through a series of transfers using haul trucks and conveyor belts. Ore is transferred to the in-pit crusher
with haul trucks from the shovel face, and waste rock is hauled to dumping areas with haul trucks. After
the ore is crushed, it is conveyed to the Copperton Concentrator. Once the ore is processed at the
concentrator, it is transferred to the smelter.

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)
CO2 Equivalent 718.29 9038.47
Carbon Monoxide 4.34 1712.04
Nitrogen Oxides 0.60 5842.71
Particulate Matter - PM10 0.41 1519.62
Particulate Matter - PM10 (Fugitives) 0.00 1509.76
Particulate Matter - PM2.5 0.23 369.44
Particulate Matter - PM2.5 (Fugitives) 0.00 367.76
Sulfur Dioxide 0.01 7.44
Volatile Organic Compounds 0.19 314.32

Hazardous Air Pollutant Change (lbs/yr) Total (lbs/yr)
Total HAPs (CAS #THAPS) 100 3580
Change (TPY) Total (TPY)
Total HAPs 0.05 1.79

DAQE-IN105710048-24
Page 5

PUBLIC NOTICE STATEMENT

The NOI for the above-referenced project has been evaluated and has been found to be consistent with the
requirements of UAC R307. Air pollution producing sources and/or their air control facilities may not be
constructed, installed, established, or modified prior to the issuance of an AO by the Director.

A 30-day public comment period will be held in accordance with UAC R307-401-7. A notification of the
intent to approve will be published in the Salt Lake Tribune and Deseret News on June 23, 2024. During
the public comment period the proposal and the evaluation of its impact on air quality will be available
for the public to review and provide comment. If anyone so requests a public hearing within 15 days of
publication, it will be held in accordance with UAC R307-401-7. The hearing will be held as close as
practicable to the location of the source. Any comments received during the public comment period and
the hearing will be evaluated. The proposed conditions of the AO may be changed as a result of the
comments received.

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.

I.1 The limits set forth in this AO shall not be exceeded without prior approval. [R307-401]

I.2 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.3 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 two-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 two (2) years. [R307-401-8]

I.4 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.5 The owner/operator shall comply with R307-150 Series. Inventories, Testing and Monitoring.
[R307-150]

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

I.7 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]

DAQE-IN105710048-24
Page 6

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.

II.A THE APPROVED EQUIPMENT

II.A.1 KUC Bingham Mine
KUC operates the BCM. KUC removes ore from the BCM by drilling, blasting, crushing, and
hauling.

II.A.2 Main In-pit Crusher
Main in-pit crusher
Main in-pit crusher baghouse

II.A.3 Portable Road base Crushers
Two (2) portable crushing and screening plants used to crush material for road base
Maximum crusher unit capacity: 700 tons per hour, each

II.A.4 Conveyors
Conveyors and two (2) transfer points with baghouses (Baghouses C6/C7 and Baghouses C7/C8)

II.A.5 Lime Silos
Lime silos with fabric type bin vent control units

II.A.6 Sample Preparation Equipment
Sample preparation equipment with baghouse

II.A.7 SX/EW plant
SX/EW plant with electrowinning acid mist eliminator

II.A.8 Degreasers
Various degreasing part washers

II.A.9 Gasoline Fueling Stations

DAQE-IN105710048-24
Page 7

II.A.10 LPG-Fired Emergency Generators
Nine (9) Liquefied Petroleum gas-fired emergency generators

Site Maximum Rating
Lark Gate
#1 107 Brake Horsepower (BHP)
#2 49 BHP
Production Control Building 6690 150 BHP
Communications 6190 75 BHP
Mandy's Landing 75 BHP
East Side Dump 49 BHP
Zelnora 49 BHP
SAM Site 49 BHP
Substation 2 49 BHP

II.A.11 Diesel-Fired Emergency Generators
Nine (9) diesel-fired emergency generators (four 4 NEW)

1) Support Generators 1-5

1. Maximum rating 2,250 kW
2. Maximum rating 700 kW
3. Maximum rating 700 kW
4. Maximum rating 500 kW
5. Maximum rating 2,000 kW

2) Ventilation System Generators 6-9 (NEW)

6. Maximum rating 2,000 kW
7. Maximum rating 2,000 kW
8. Maximum rating 2,000 kW
9. Maximum rating 3,250 kW

II.A.12 Concrete Batch Plant

1) One (1) 25 cubic yard per hour batch plant controlled by a baghouse.

2) One (1) cement storage silo controlled by a baghouse.

3) Conveyors and cement trucks.

4) Storage silos with fabric filters.

II.A.13 Crushers and Screens
Portable crushing and screening plants with associated conveyors used to crush ore and waste
rock.

Conveyors
Partially enclosed transfer points or water sprays

DAQE-IN105710048-24
Page 8

II.A.14 Underground Mining Support Equipment

1) One (1) 150 cubic yard per hour batch plant controlled by baghouse.
a) One (1) cement storage silo with a baghouse.
b) Conveyors and cement trucks.
c) Storage silos with fabric filters.

2) One (1) natural gas-fired boiler - 2.0 MMBTU/hr.

3) One (1) natural gas-fired boiler - 4.0 MMBTU/hr.

4) Three (3) diesel-fired heaters - 4.2 MMBTU/hr (each).

5) One (1) diesel-fired generator - 71 kW.

II.A.15 Paste Plant (NEW)

1. Two (2) Storage silos with baghouse.

2. One (1) Mixer Dust Collector with baghouse.

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.

II.B REQUIREMENTS AND LIMITATIONS

II.B.1 Limitations and Test Procedures
DAQE-IN105710048-24
Page 9

II.B.1.a Emissions at all times from the indicated emission points after primary control shall not exceed
the following rates and concentrations:

A. Main In-Pit Crusher Baghouse Vent

Pollutant lb/hr grains per dry standard cubic foot (dscf)
(68oF, 29.92 in Hg)

PM10 1.77 0.016
PM2.5 0.78 0.007

B. Controlled Drop Point Baghouse Vent (C6/C7, located outside of the pit)

Pollutant lb/hr grains per dry standard cubic foot (dscf)
(68oF, 29.92 in Hg)

PM10 0.31 0.007

C. Controlled Drop Point Baghouse Vent (C7/C8, located outside of the pit)

Pollutant lb/hr grains per dry standard cubic foot (dscf)
(68oF, 29.92 in Hg)

PM10 0.19 0.007

[R307-401-8]

DAQE-IN105710048-24
Page 10

II.B.1.b Stack testing to show compliance with the emission limitations stated in the above condition
shall be performed as specified below:

A. Testing Test
Emissions Point Pollutant Status Frequency

Main In-Pit Crusher Baghouse
Vent PM10 * #
PM2.5 * #

Controlled Drop Point Baghouse
Vent (C6/C7, located outside of the pit) PM10 * #

Controlled Drop Point Baghouse
Vent (C7/C8, located outside of the pit) PM10 * #

B. Testing Status

* The initial testing has already been performed.

# Test every three (3) years. If a unit is not in operation when a test is due,
the owner/operator may request an extension for the test.

C. Notification
The Director shall be notified at least 30 days prior to conducting any required
emission testing. A source test protocol shall be submitted with the testing
notification submitted to the Director.

The source test protocol shall be approved by the Director prior to performing
the test(s). The source test protocol shall outline the proposed test
methodologies and stacks to be tested. A pretest conference shall be held, if
directed by the Director.

D. 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. An Occupational Safety and Health Administration (OSHA) or Mine
Safety and Health Administration (MSHA)-approved access shall be provided to
the test location.

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

F. 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 methods 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 others 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-IN105710048-24
Page 11

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.c G. 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.

H. Source Operation
For a new source/emission point, the production rate during all compliance
testing shall be no less than 90% of the production capacity of the equipment. If
the maximum production capacity has not been achieved at the time of the test,
the following procedure shall be followed:

1) Testing shall be at no less than 90% of the production rate achieved to
date.

2) If the test is passed, the new maximum allowable production rate
shall be 110% of the tested achieved rate. This new allowable maximum
production rate shall remain in effect until successfully tested at a higher
rate. This process may be repeated until the maximum AO production
rate is achieved.

For an existing source/emission point, the production rate during all compliance
testing shall be no less than 90% of the maximum production achieved in the
previous three (3) years.

[R307-401-8]

DAQE-IN105710048-24
Page 12

II.B.1.d Visible emissions from the following emission points shall not exceed the following values:

A. Main In-Pit crusher baghouse vent - 7% opacity.

B. Controlled drop point baghouse vent - 7% opacity.
(C6/C7, located outside of the pit)

C. Controlled drop point baghouse vent - 7% opacity.
(C7/C8, located outside of the pit)

D. Concrete batch plant baghouse - 10% opacity.

E. All other conveyor transfer points - 10% opacity.

F. Lime silos - 10% opacity.

G. Sample preparation equipment with baghouse - 10% opacity.

H. Drilling - 10% opacity.

I. LP gas-fired emergency generators - 10% opacity.

J. Nonmetallic Mineral Processing Screens and Conveyors - 7% opacity.

K. Nonmetallic Mineral Processing Crushers - 12% opacity.

L. Metallic Mineral Processing Equipment - 10% opacity.

M. Electrowinning Plant with electrowinning acid mist eliminator - 15% opacity.

N. All other points except as defined in other conditions of this AO - 10% opacity.

O. Diesel-fired Equipment - 20% opacity.

Opacity observations of emissions from stationary sources shall be conducted according to 40
CFR 60, Appendix A, Method 9.

[R307-201]

II.B.1.e For sources that are subject to NSPS, opacity shall be determined in accordance with 40 CFR
60.11(b) and 40 CFR 60, Appendix A, Method 9. It is the responsibility of the owner/operator of
the source to supply these observations to the Director.

A current certified observer must be used for these observations. Emission points that are subject
to the initial observations are:

A. All crushers.

B. All screens.

C. All conveyor transfer points.

[40 CFR 60 Subpart A]

DAQE-IN105710048-24
Page 13

II.B.1.f The following limits shall not be exceeded:

A. Total material moved (ore and waste) shall not exceed 260,000,000 tons
per rolling 12-month period*.

B. Annual emissions of SO2 shall not exceed 7 tons per rolling 12-month period.

C. Maximum total mileage per calendar day for diesel-powered ore and waste haul
trucks shall not exceed 30,000 miles.

D. Minimum design payload per ore and waste haul truck shall not be less than 240
tons. Minimum design payload for trucks hauling material to develop new
mining technologies and material from maintenance activities shall not be less
than 40 tons. Trucks used for underground development and operation may be
smaller depending on application.

E. Maximum number of wheels per ore or waste haul truck shall not exceed six (6)
wheels.

F. Height of mine waste dump lift shall not exceed 1000 feet.

G. The surface area of the Solvent Extraction/Electrowinning Plant mixer/settlers
shall not exceed 1,100 ft2.

*Total ore and waste limitation shall be applied to dry tons of new material mined at the
production shovels face.

The owner/operator shall determine compliance with the 12-month period limits on a rolling
12-month total. The owner/operator shall calculate a new 12-month total by the twentieth day of
each month using data from the previous 12 months.

The owner/operator shall keep records of daily total mileage for all periods when the mine is in
operation. The owner/operator shall track haul truck miles with a Global Positioning System or
equivalent. The system shall use real time tracking to determine daily mileage.

SO2 emissions from fuel burning shall be determined using the following formula:

SO2 tpy = (gal fuel/year)*(7.05 lb/gal)*(%S by wt.)/2000 lb/ton*(2 lb SO2/lb S).

[R307-401-8]

II.B.1.g The following site-wide emission limits at the BCM shall not be exceeded:

A. 7,350 tons of NOx, PM10 and SO2 combined per rolling 12-month period.

B. 6,205 tons of NOx, PM2.5 and SO2 combined per rolling 12-month period.

The owner/operator shall determine compliance with the 12-month period limits on a rolling
12-month total per methodology outlined in Appendix A. The owner/operator shall calculate a
new 12-month total by the twentieth day of each month using data from the previous 12 months.
[R307-401-8]

II.B.2 Equipment Requirements
II.B.2.a The Main In-Pit Crusher Baghouse shall control process streams from the Main In-Pit Crusher.
This baghouse shall be sized to handle at least 12,898 Dry Standard Cubic Feet per Minute
(DSCFM). All exhaust air from the Main In-Pit Crusher shall be routed through the baghouse
before being vented to the atmosphere. [R307-401-8]

DAQE-IN105710048-24
Page 14

II.B.2.b The lime silos fabric bin vent control units shall control process streams from the lime silos.
This control unit shall be sized to handle at least 616 DSCFM. All exhaust air from the lime silos
shall be routed through the control unit before being vented to the atmosphere. [R307-401-8]

II.B.2.c The Controlled Transfer Drop Point C6/C7 baghouse shall control process streams from the drop
point. This baghouse shall be sized to handle at least 5,120 DSCFM. All exhaust air from the
C6/C7 transfer drop point shall be routed through the baghouse before being vented to the
atmosphere. [R307-401-8]

II.B.2.d The Controlled Transfer Drop Point C7/C8 baghouse shall control process streams from the drop
point. This baghouse shall be sized to handle at least 3,168 DSCFM. All exhaust air from the
C7/C8 transfer drop point shall be routed through the baghouse before being vented to the
atmosphere. [R307-401-8]

II.B.2.e The Sample Preparation baghouse shall control process streams from the sample preparation
building crushing and grinding equipment. This baghouse shall be sized to handle at least 4,200
DSCFM. All exhaust air from the sample preparation crusher and grinder shall be routed
through the baghouse before being vented to the atmosphere. [R307-401-8]

II.B.2.f The Electrowinning Acid Mist Eliminator shall control process streams from the electrowinning
cells. This mist eliminator shall be sized to handle at least 8,000 actual CFM. Except during
service, inspection, and cathode harvest, all exhaust air from the electrowinning cells shall be
routed through the mist eliminator before being vented to the atmosphere. [R307-401-8]

II.B.2.g The solvent extraction tanks and the stripping mixer/settlers shall be covered at all times except
during inspection, sampling, and adjustment. [R307-401-8]

II.B.2.h The concrete batch plant baghouse shall control all process streams from the 25 cubic yard
concrete batch plant listed in Condition II.A.12. This baghouse shall be sized to handle at least
3,900 DSCFM. All exhaust air from the concrete batch plant shall be routed through the
baghouse before being vented to the atmosphere. [R307-401-8]

II.B.2.i The owner/operator shall only combust diesel fuel 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.2.i.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.3 Roads and Fugitive Dust
II.B.3.a The owner/operator shall abide by a FDCP acceptable to the Director for control of all dust
sources associated with the BCM. The FDCP shall be updated and submitted on an annual basis
to the Director by February 1st of every year. This plan shall contain sufficient controls to
prevent an increase in PM10 emissions above those modeled for this AO. The haul road length,
speed, or any other parameters used to calculate the emissions cannot be changed without prior
approval from the Director, if the change would result in an increase in emissions above the
limitations set in the FDCP. [R307-309]

II.B.3.b The BCM shall comply with all applicable requirements of UAC R307-205 and R307-309 for
Fugitive Emission and Fugitive Dust sources. The provisions of R307-205 and R307-309 shall
not apply to any sources for which limitations for fugitive dust or fugitive emissions are assigned
pursuant to R307-401 or R307-305 nor shall they apply to agricultural or horticultural activities.
[R307-309]

DAQE-IN105710048-24
Page 15

II.B.3.c Control of disturbed or stripped areas is required at all times (24 hours per day every day) for the
duration of the project/operation until the area is reclaimed. Records of disturbed area, treatment
and/or reclamation shall be kept for all periods when the BCM is in operation. [R307-309]

II.B.3.d Visible fugitive dust emissions from haul-road traffic and mobile equipment in operational areas
shall not exceed 20% opacity at any point. Visible emission determinations shall use procedures
similar to Method 9. The normal requirement for observations to be made at 15-second intervals
over a six-minute period, however, shall not apply. Visible emissions shall be measured at the
densest point of the plume but at a point not less than 1/2 vehicle length behind the vehicle and
not less than 1/2 the height of the vehicle. [R307-309]

II.B.3.e Water sprays, chemical dust suppression sprays or enclosures shall be installed at the following
points that are not enclosed or have baghouses to control fugitive emissions:

A. All stationary and portable conveyor transfer points.

B. All portable crusher input and output points, and screening unit points or partial
enclosures.

The sprays shall operate whenever dry conditions warrant or as determined necessary by the
Director.

[R307-309]

II.B.3.f The accessible surfaces of all uncovered storage piles shall be sprayed with water or chemical
dust suppressants to minimize generation of fugitive dusts, as dry conditions warrant or as
determined necessary by the Director. Records of water and/or chemical dust control treatment
shall be kept for all periods when the plant is in operation. [R307-309]

II.B.3.g The opacity on active waste slopes shall not exceed 20%. A visual opacity survey of waste dump
activity shall be performed on a monthly basis. If visible emissions are observed, an opacity
observation shall be performed by a certified observer within 24 hours. Opacity observations
shall be conducted in accordance with 40 CFR 60, Appendix A, Method 9, but the requirement
for observations to be made at 15-second intervals over a six-minute period shall not apply. At
any time, the owner/operator may propose a compliance method to UDAQ for approval prior to
implementation. [R307-309]

DAQE-IN105710048-24
Page 16

II.B.3.h The owner/operator shall use frequent watering or chemical dust suppressant to control road dust
from all trafficked roads and areas in the mine. The owner/operator shall submit an annual road
dust control report, in conjunction with the FDCP, by February 1st of each calendar year,
containing as a minimum the following:

A. A description of what dust control measures are planned for the coming year.

B. A report of what dust control measures were actually completed during the past.
year

C. Specific elements of the report will include:

1) A map of all trafficked areas and roads associated with the mine,
indicating which areas are planned for water and/or chemical dust
suppressant treatment.

2) A description of the chemical dust suppressant and how it will be
applied (application rate, application frequency, dilution rate, special
application procedure, scarification, etc.).

3) A list of equipment dedicated either full or part-time to the work area
and for road dust control (number of water trucks, water capacity,
number of graders, etc.).

4) A quantification of how much dust suppressant (gallons, tons) was
applied the previous year and when and where it was applied.

5) A quantification of how much watering was accomplished in the
previous year (gallons, water truck operating hours).

6) A map outlining the pit influence boundary.

[R307-309]

II.B.3.i Wet drilling shall be performed for all blast holes. [R307-309]

DAQE-IN105710048-24
Page 17

II.B.3.j To minimize fugitive dust on roads at the BCM, the owner/operator shall perform the following
measures:

A. Apply water to all active haul roads located at the BCM as conditions warrant
and in accordance with the FDCP, and shall

1) ensure the surface of the active haul roads located within the pit
influence boundary consists of road base material, blasted waste rock,
crushed rock, or chemical dust suppressant, and

2) apply a chemical dust suppressant to active haul roads located outside
of the pit influence boundary no less than twice per year.

B. Ore conveyors shall be the primary means for transport of crushed ore from the
BCM to the Copperton Concentrator.

C. Chemical dust suppressant shall be applied on unpaved access roads that receive
haul truck traffic and light vehicle traffic as defined in the FDCP.

D. The owner/operator shall use graders to perform haul road maintenance and
clean-up activities as well as other operational functions. [R307-309-10]

E. If, for a 12-month period, the material movement by haul trucks is below
197,000,000 tpy of ore and waste rock combined, the owner/operator may
petition the Director to revise the fugitive dust control measures above.

[R307-309-10]

II.B.4 Monitoring Requirements
II.B.4.a The owner/operator shall operate two (2) ambient monitoring stations to monitor PM10 in
Copperton and lower Butterfield Canyon areas, as approved by the Director. The monitoring plan
will be periodically reviewed and revised as necessary. Any changes must be approved by the
Director.

The air monitoring stations shall remain in operation, at a minimum, until the BCM material
moved has achieved a minimum of 234,000,000 TPY. If after that amount of material moved has
been achieved and monitoring data indicates compliance with the NAAQS, the owner/operator
may petition the Director to remove the air monitoring stations. [R307-410]

II.B.4.b The owner/operator shall utilize federal reference method (FRM) or federal equivalent method
PM10 monitors as specified in 40 CFR 53 and quality assurance procedures which are equal to or
exceed the requirements described in the EPA Quality Assurance Manual including revisions, 40
CFR Parts 50, 53 and 58. [R307-410]

II.B.4.c If the PM10 concentrations measured are greater than 135 ug/m3 (90% of the 24-hr PM10
NAAQS), and if such concentrations have been measured for more than one (1) day per year on
an average over three (3) consecutive years, the owner/operator shall conduct a review of mine
operations and other potential sources and conditions, such as the Natural Events Exception
Criteria.

If it is determined the BCM impacts the elevated ambient PM10 concentrations, the
owner/operator shall work with DAQ to review control practices and possible changes in
practices to avoid future elevated concentrations. [R307-410]

DAQE-IN105710048-24
Page 18

II.B.4.d The owner/operator shall submit quarterly data reports within 45 days after the end of the
calendar quarter and an annual data report within 90 days after the end of the calendar year.

The quarterly report shall consist of a narrative data summary and a submittal of all data points in
EPA-AIRS record format. The data shall be submitted on a compact disk (CD). The narrative
data summary shall include:

A. A topographic map of appropriate scale with UTM coordinates and a true north
arrow showing the air monitoring site locations in relation to the mine and the
general area;

B. A hard copy of the individual data points;

C. The quarterly and monthly arithmetic means for PM10 at actual temperature and
pressure;

D. The first and second highest 24-hour concentrations for PM10;

E. The quarterly and monthly wind roses;

F. A summary of the data collection completeness;

G. A summary of the reasons for missing data;

H. An audit summary;

I. A summary of any ambient air PM10 exceedances;

J. Calibration information; and

K. Laboratory reports (for exceedance filters).

The annual data report shall consist of a narrative data summary containing:

A. A topographic map of appropriate scale with UTM coordinates and a true north
arrow showing the air monitoring site locations in relation to the mine and the
general area;

B. A pollution trend analysis;

C. The annual arithmetic means for PM10;

D. The first and second highest 24-hour concentrations for PM10;

E. The annual wind rose;

F. Annual summaries of data collection frequency and completeness;

G. An annual summary of audit data;

H. An annual summary of any ambient standard exceedance;

I. Annual mine material moved in TPY;

J. Annual summary of analytical speciation results for detectable metals (for
exceedance filters); and

DAQE-IN105710048-24
Page 19

K. Recommendations on future monitoring.
The Director reserves the right to audit the air monitoring network, the
laboratory performing associated analysis, and any data handling procedures at
unspecified times. On the basis of the audits and subsequent reports, DAQ
reserves the right to recommend or require changes in the air monitoring system
and associated activities in order to improve data quality and completeness.

[R307-410]

II.B.4.e The owner/operator shall contract with an independent firm to conduct quarterly performance
audits of its PM10 monitors.

Exposed PM10 filters that exceed 150 ug/m3 shall be analyzed for metals, and other constituents
as requested by the Director. One (1) filter blank per batch of ten (10) filters or less shall also be
submitted for analysis. [R307-410]

II.B.4.f PM10 and meteorological data (wind speed, wind direction, and ambient temperature) shall be
collected at each site. The meteorological tower shall be located within one (1) mile of the
monitor station. [R307-410]

II.B.5 Emergency Generator Engine
II.B.5.a The owner/operator shall not operate each emergency engine on site for more than 100 hours per
rolling 12-month period during non-emergency situations. There is no time limit on the use of
the engines during emergencies. [R307-401-8]

II.B.5.b 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
documenting the operation of each emergency engine shall be kept in a log and shall include the
following:

a. The date the emergency engine was used.

b. The duration of operation in hours.

c. The reason for the emergency engine usage.

[R307-401-8]

II.B.5.c To determine the duration of operation, the owner/operator shall install a non-resettable hour
meter for each emergency engine. [R307-401-8]

II.B.5.d KUC shall not exceed the following limits on the diesel fired emergency generators for the
Ventilation System #6, #7, #8, and #9:

Testing of the diesel fired emergency generators shall be allowed between 8 a.m. and 8 p.m.
Only one (1) diesel fired emergency generator shall be tested at the same time. [R307-410]

DAQE-IN105710048-24
Page 20

PERMIT HISTORY

This Approval Order shall supersede (if a modification) or will be based on the following documents:

Supersedes AO DAQE-AN105710047-21 dated May 10, 2021
Is Derived From NOI Dated February 9, 2024
Incorporates Additional Information dated February 28, 2024
Incorporates Additional Information dated April 18, 2024

DAQE-IN105710048-24
Page 21

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

NOTICE
A Notice of Intent for the following project submitted in accordance with
R307-401-1, Utah Administrative Code (UAC), has been received for
consideration by the Director:
Company NameCompany Name: Rio Tinto Kennecott Utah Copper LLC
Location Location: Rio Tinto Kennecott Utah Copper LLC - Mine & Copperton
Concentrator – 8362 West 10200 South, Bingham Canyon, UT
Project Description:Project Description: Rio Tinto Kennecott Utah Copper LLC owns and
operates the Bingham Canyon Mine and the Copperton Concentrator.
The Bingham Canyon Mine is an open-pit mining operation located in
the southwest corner of Salt Lake County, Utah. Rio Tinto Kennecott
Utah Copper is proposing to install and operate facilities associated with
underground mining operations, which include a new Paste Plant with two
(2) storage silos, a mixer dust collector, and four (4) emergency standby
generators.
The completed engineering evaluation and air quality impact analysis
showed the proposed project meets the requirements of federal air quality
regulations and the State air quality rules. The Director intends to issue an
Approval Order pending a 30-day public comment period. The project
proposal, estimate of the effect on local air quality and draft Approval Order
are available for public inspection and comment at the Utah Division of Air
Quality, 195 North 1950 West, Salt Lake City, UT 84116. Written comments
received by the Division at this same address on or before July 23, 2024
will be considered in making the final decision on the approval/disapproval
of the proposed project. Email comments will also be accepted at
[e-mail]. If anyone so requests to the Director in writing within
15 days of publication of this notice, a hearing will be held in accordance
with R307-401-7, UAC.
Under Section 19-1-301.5, a person who wishes to challenge a Permit Order
may only raise an issue or argument during an adjudicatory proceeding that
was raised during the public comment period and was supported with suf-
ficient information or documentation to enable the Director to fully consider
the substance and significance of the issue.
Date of Notice: June 23, 2024 Date of Notice: June 23, 2024
SLT0028177
The Salt Lake Tribune
Publication Name:
The Salt Lake Tribune
Publication URL:
Publication City and State:
Salt Lake City, UT
Publication County:
Salt Lake
Notice Popular Keyword Category:
Notice Keywords:
rio
Notice Authentication Number:
202406241044510464293
1761527914
Notice URL:
Back
Notice Publish Date:
Sunday, June 23, 2024
Notice Content
NOTICE A Notice of Intent for the following project submitted in accordance with R307-401-1, Utah Administrative Code (UAC), has been
received for consideration by the Director: Company Name: Rio Tinto Kennecott Utah Copper LLC Location: Rio Tinto Kennecott Utah Copper
LLC - Mine & Copperton Concentrator – 8362 West 10200 South, Bingham Canyon, UT Project Description: Rio Tinto Kennecott Utah Copper
LLC owns and operates the Bingham Canyon Mine and the Copperton Concentrator. The Bingham Canyon Mine is an open-pit mining
operation located in the southwest corner of Salt Lake County, Utah. Rio Tinto Kennecott Utah Copper is proposing to install and operate
facilities associated with underground mining operations, which include a new Paste Plant with two (2) storage silos, a mixer dust collector,
and four (4) emergency standby generators. The completed engineering evaluation and air quality impact analysis showed the proposed
project meets the requirements of federal air quality regulations and the State air quality rules. The Director intends to issue an Approval
Order pending a 30-day public comment period. The project proposal, estimate of the effect on local air quality and draft Approval Order are
available for public inspection and comment at the Utah Division of Air Quality, 195 North 1950 West, Salt Lake City, UT 84116. Written
comments received by the Division at this same address on or before July 23, 2024 will be considered in making the final decision on the
approval/disapproval of the proposed project. Email comments will also be accepted at [e-mail]. If anyone so requests to the
Director in writing within 15 days of publication of this notice, a hearing will be held in accordance with R307-401-7, UAC. Under Section 19-
1-301.5, a person who wishes to challenge a Permit Order may only raise an issue or argument during an adjudicatory proceeding that was
raised during the public comment period and was supported with sufficient information or documentation to enable the Director to fully
consider the substance and significance of the issue. Date of Notice: June 23, 2024 SLT0028177
Back

DAQE-NN105710048-24

June 20, 2024

Salt Lake Tribune and Deseret News
Legal Advertising Dept.
P.O. Box 704055
West Valley City, UT 84170
Acct #9001399880

RE: Legal Notice of Intent to Approve

This letter will confirm the authorization to publish the attached NOTICE in the Salt Lake Tribune and
Deseret News on June 23, 2024.

Please mail the invoice and affidavit of publication to the Utah State Department of Environmental
Quality, Division of Air Quality, P.O. Box 144820, Salt Lake City, Utah 84114-4820. If you have any
questions, contact Jeree Greenwood, who may be reached at [phone].

Sincerely,

{{$s }}

Jeree Greenwood
Office Technician

Enclosure

cc: Salt Lake County
cc: Wasatch Front Regional Council

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

DAQE-NN105710048-24
Page 2
NOTICE

A Notice of Intent for the following project submitted in accordance with R307-401-1, Utah
Administrative Code (UAC), has been received for consideration by the Director:

Company Name: Rio Tinto Kennecott Utah Copper LLC
Location: Rio Tinto Kennecott Utah Copper LLC - Mine & Copperton Concentrator – 8362
West 10200 South, Bingham Canyon, UT
Project Description: Rio Tinto Kennecott Utah Copper LLC owns and operates the Bingham Canyon
Mine and the Copperton Concentrator. The Bingham Canyon Mine is an open-pit
mining operation located in the southwest corner of Salt Lake County, Utah. Rio
Tinto Kennecott Utah Copper is proposing to install and operate facilities
associated with underground mining operations, which include a new Paste Plant
with two (2) storage silos, a mixer dust collector, and four (4) emergency standby
generators.

The completed engineering evaluation and air quality impact analysis showed the proposed project meets
the requirements of federal air quality regulations and the State air quality rules. The Director intends to
issue an Approval Order pending a 30-day public comment period. The project proposal, estimate of the
effect on local air quality and draft Approval Order are available for public inspection and comment at the
Utah Division of Air Quality, 195 North 1950 West, Salt Lake City, UT 84116. Written comments
received by the Division at this same address on or before July 23, 2024 will be considered in making the
final decision on the approval/disapproval of the proposed project. Email comments will also be accepted
at [e-mail]. If anyone so requests to the Director in writing within 15 days of publication of
this notice, a hearing will be held in accordance with
R307-401-7, UAC.

Under Section 19-1-301.5, a person who wishes to challenge a Permit Order may only raise an issue or
argument during an adjudicatory proceeding that was raised during the public comment period and was
supported with sufficient information or documentation to enable the Director to fully consider the
substance and significance of the issue.

Date of Notice: June 23, 2024

{{#s=Sig_es_:signer1:signature}}

DAQE-

RN105710048
June 3, 2024

Brendan Murphy
Rio Tinto Kennecott Utah Copper LLC
4700 Daybreak Parkway
South Jordan, UT 84095

Dear Brendan Murphy,

Re: Engineer Review:
Modification to Approval Order to DAQE-AN105710047-21, to Add Paste Plant and Support
Equipment
Project Number: N105710048

The DAQ requests a company representative review and sign the attached Engineer Review (ER). This
ER identifies all applicable elements of the New Source Review permitting program. Rio Tinto
Kennecott Utah Copper LLC should complete this review within 10 business days of receipt.

Rio Tinto Kennecott Utah Copper LLC should contact Tad Anderson at [phone] if there are
questions or concerns with the review of the draft permit conditions. Upon resolution of your concerns,
please email Tad Anderson at [e-mail] the signed cover letter. Upon receipt of the signed
cover letter, the DAQ will prepare an ITA for a 30-day public comment period. At the completion of the
comment period, the DAQ will address any comments and 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 source concurrence. If Rio Tinto Kennecott Utah Copper LLC has
concerns that cannot be resolved and the project becomes stagnant, 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 N105710048: Rio Tinto Kennecott Utah Copper LLC- Mine & Copperton Concentrator
June 3, 2024
Page 1
UTAH DIVISION OF AIR QUALITY
ENGINEER REVIEW

SOURCE INFORMATION

Project Number N105710048
Owner Name Rio Tinto Kennecott Utah Copper LLC
Mailing Address 4700 Daybreak Parkway
South Jordan, UT, 84095

Source Name Rio Tinto Kennecott Utah Copper LLC- Mine & Copperton
Concentrator
Source Location 8362 W 10200 S
Bingham Canyon, UT 84006

UTM Projection 407,000 m Easting, 4,493,000 m Northing
UTM Datum NAD27
UTM Zone UTM Zone 12
SIC Code 1021 (Copper Ores)

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

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

Project Engineer Tad Anderson, Engineer
Phone Number [phone]
Email [e-mail]

Notice of Intent (NOI) Submitted February 9, 2024
Date of Accepted Application April 5, 2024

Engineer Review N105710048: Rio Tinto Kennecott Utah Copper LLC- Mine & Copperton Concentrator
June 3, 2024
Page 2
SOURCE DESCRIPTION

General Description
Rio Tinto Kennecott Utah Copper LLC (RTK) owns and operates the Bingham Canyon Mine
(BCM) and the Copperton Concentrator. The BCM is an open pit mining operation located in the
southwest corner of Salt Lake County, Utah. Ore from the mine is conveyed to the Copperton
Concentrator located approximately five miles north of the open pit in Copperton, Utah where it
is ground and treated to produce copper concentrate.

NSR Classification:
Minor Modification

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: B

Applicable Federal Standards
NSPS (Part 60), A: General Provisions
NSPS (Part 60), LL: Standards of Performance for Metallic Mineral Processing Plants
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
MACT (Part 63), A: General Provisions
MACT (Part 63), ZZZZ: National Emissions Standards for Hazardous Air Pollutants for
Stationary Reciprocating Internal Combustion Engines
Title V (Part 70) Area Source

Project Proposal
Modification to Approval Order to DAQE-AN105710047-21, to Add Paste Plant and Support
Equipment

Project Description
RTK is requesting a modification of BCM Approval Order (AO) DAQE-AN105710047-21 to
install and operate facilities associated with underground mining operations. The underground
mining operations include the use of a new Paste Plant with two storage silos, a mixer dust
collector and four emergency standby generators for the employee ventilation systems.

The new storage silos, at the bottom of the mine, support the Paste Plant operations where RTK
will make usable concrete from lime and other materials. The mixer dust collector captures
emissions from the paste plant mixer process area, where lime and other materials are blended
together to make useable concrete.

Process Description
The ore and waste rock at the BCM are transferred from the mining areas to other areas of the
mine through a series of transfers using haul trucks and conveyor belts. Ore is transferred to the
in-pit crusher with haul trucks from the shovel face and waste rock is hauled to dumping areas

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with haul trucks. After the ore is crushed, it is conveyed to the Copperton Concentrator. Once
the ore is processed at the concentrator, it is transferred to the smelter.

EMISSION IMPACT ANALYSIS
Modeling was submitted for PM10 and NO2. A modeling memo was generated containing the summary
DAQE-MN105710048-24 with recommended conditions for testing times and testing quantity. [Last updated
April 25, 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)
CO2 Equivalent 718.29 9038.47
Carbon Monoxide 4.34 1712.04
Nitrogen Oxides 0.60 5842.71
Particulate Matter - PM10 0.41 1519.62
Particulate Matter - PM10 (Fugitives) 0.00 1509.76
Particulate Matter - PM2.5 0.23 369.44
Particulate Matter - PM2.5 (Fugitives) 0.00 367.76
Sulfur Dioxide 0.01 7.44
Volatile Organic Compounds 0.19 314.32

Hazardous Air Pollutant Change (lbs/yr) Total (lbs/yr)
Total HAPs (CAS #THAPS) 100 3580
Change (TPY) Total (TPY)
Total HAPs 0.05 1.79

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 Equipment

BACT has been conducted for the two storage silos, a mixer dust collector and four emergency
standby generators. The following is a summary of the results.

Storage Silos
BACT was conducted for the storage silos by reviewing the RBLC. The RBLC and CARB
databases identify vent filters/baghouses and enclosures as possible control technologies for
limiting emissions from storage silos. Baghouses are more effective than enclosures in minimizing
emissions from storage silos. BACT for the storage silos is the use of baghouses and a 10 %
opacity limit.

Mixer Dust Collector/Baghouse
BACT was conducted for the mixer dust collector by reviewing the RBLC. The RBLC and CARB
databases identify vent filters/baghouses and enclosures as possible control technologies for
limiting emissions from mixer dust collectors. Baghouses are more effective than enclosures in
minimizing emissions from mixer dust collectors. BACT for the mixer dust collector is the use of
baghouses and a 10 % opacity limit.

Emergency Generators
BACT was conducted for the emergency generator engine by reviewing the RBLC. The following
technologies were specified in the analysis: good combustion practices, maintenance and operating
practices, use of low-sulfur diesel fuel, compliance with applicable NSPS IIII requirements,
compliance with applicable NESHAP ZZZZ requirements and the use of SCR. All of the listed
control technologies are technically feasible, except for SCR. For SCR systems to function
effectively, exhaust temperatures must be 200 degree C to 500 degree C to enable catalyst
activation. SCR control efficiencies are low during the first 20 to 30 minutes after engines start up
during maintenance and testing. There are also complications controlling the excess ammonia
during the engine startup during maintenance and testing from SCR use. SCR is not considered
technically feasible for emergency units.

BACT for diesel-fired emergency engines, is the following:

Good combustion, maintenance, and operating practices
Use of low-sulfur diesel fuel
Compliance with applicable NSPS IIII requirements
Use of a tier certified engine
Limit on hours of operation for maintenance and testing operations
Compliance with applicable NESHAP ZZZZ requirements is not required
[Last updated May 31, 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):

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I.1 The limits set forth in this AO shall not be exceeded without prior approval. [R307-401]

I.2 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.3 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 two-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 two (2) years. [R307-401-8]

I.4 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.5 The owner/operator shall comply with R307-150 Series. Inventories, Testing and Monitoring.
[R307-150]

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

I.7 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.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 KUC Bingham Mine
KUC operates the BCM. KUC removes ore from the BCM by drilling, blasting, crushing and
hauling.

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II.A.2 Main In-pit Crusher
Main in-pit crusher
Main in-pit crusher baghouse

II.A.3 Portable Roadbase Crushers
Two portable crushing and screening plants used to crush material for road base
Maximum crusher unit capacity 700 tons per hour, each

II.A.4 Conveyors
Conveyors and two transfer points with baghouses (Baghouses C6/C7 and Baghouses C7/C8)

II.A.5 Lime Silos
Lime silos with fabric type bin vent control units

II.A.6 Sample Preparation Equipment
Sample preparation equipment with baghouse

II.A.7 SX/EW plant
SX/EW plant with electrowinning acid mist eliminator

II.A.8 Degreasers
Various degreasing parts washers

II.A.9 Gasoline Fueling Stations

II.A.10 LPG-Fired Emergency Generators
Nine Liquefied Petroleum gas-fired emergency generators

Site Maximum Rating
Lark Gate
#1 107 Brake Horsepower (BHP)
#2 49 BHP
Production Control Building 6690 150 BHP
Communications 6190 75 BHP
Mandy's Landing 75 BHP
East Side Dump 49 BHP
Zelnora 49 BHP
SAM Site 49 BHP
Substation 2 49 BHP

II.A.11 Diesel-Fired Emergency Generators
Nine diesel-fired emergency generators (4 NEW)

1) Support Generators 1-5
1. Maximum rating 2,250 kW
2. Maximum rating 700 kW
3. Maximum rating 700 kW
4. Maximum rating 500 kW
5. Maximum rating 2,000 kW

2) Ventilation System Generators 6-9 (NEW)

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6. Maximum rating 2,000 kW
7. Maximum rating 2,000 kW
8. Maximum rating 2,000 kW
9. Maximum rating 3,250 kW

II.A.12 Concrete Batch Plant

1) One 25 cubic yard per hour batch plant controlled by a baghouse
2) One cement storage silo controlled by a baghouses
3) Conveyors and cement trucks
4) Storage silos with fabric filters

II.A.13 Crushers and Screens
Portable crushing and screening plants with associated conveyors used to crush ore and waste
rock.

Conveyors partially enclosed transfer points or water sprays

II.A.14 Underground Mining Support Equipment
1) One (1) 150 cubic yard per hour batch plant controlled by baghouse
a) One (1) cement storage silo with a baghouse
b) Conveyors and cement trucks
c) Storage silos with fabric filters
2) One (1) natural gas-fired boiler - 2.0 MMBTU/hr
3) One (1) natural gas-fired boiler - 4.0 MMBTU/hr
4) Three (3) diesel-fired heaters - 4.2 MMBTU/hr (each)
5) One (1) diesel-fired generator - 71 kW

II.A.15
NEW
Paste Plant (NEW)
1. Two (2) Storage silos with baghouse
2. One (1) Mixer Dust Collector with baghouse

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 at all times from the indicated emission points after primary control shall not
exceed the following rates and concentrations:

A. Main In-Pit Crusher Baghouse Vent

Pollutant lb/hr grains per dry standard cubic foot (dscf)
(68 F, 29.92 in Hg)

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PM10 1.77 0.016
PM2.5 0.78 0.007

B. Controlled Drop Point Baghouse Vent (C6/C7, located outside of the pit)

Pollutant lb/hr grains per dry standard cubic foot (dscf)
(68 F, 29.92 in Hg)

PM10 0.31 0.007

C. Controlled Drop Point Baghouse Vent (C7/C8, located outside of the pit)

Pollutant lb/hr grains per dry standard cubic foot (dscf)
(68 F, 29.92 in Hg)

PM10 0.19 0.007. [R307-401-8]

II.B.1.b
NEW
Stack testing to show compliance with the emission limitations stated in the above condition
shall be performed as specified below:

A. Testing Test
Emissions Point Pollutant Status Frequency

Main In-Pit Crusher Baghouse
Vent PM10 * #
PM2.5 * #

Controlled Drop Point Baghouse
Vent (C6/C7, located outside of the pit) PM10 * #

Controlled Drop Point Baghouse
Vent (C7/C8, located outside of the pit) PM10 * #

B. Testing Status

* The initial testing has already been performed.

# Test every three years. If a unit is not in operation when a test is due, the
owner/operator may request an extension for the test.

C. Notification

The Director shall be notified at least 30 days prior to conducting any required emission
testing. A source test protocol shall be submitted with the testing notification is submitted to
the Director.

The source test protocol shall be approved by the Director prior to performing the test(s). The
source test protocol shall outline the proposed test methodologies, and stack to be tested. A
pretest conference shall be held, if directed by the Director.

D. Sample Location

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The emission point shall be designed to conform to the requirements of 40 CFR60, Appendix
A, Method 1, or other EPA approved methods acceptable to the Director. An Occupational
Safety and Health Administration (OSHA) or Mine Safety and Health Administration
(MSHA) approved access shall be provided to the test location.

E. Volumetric Flow Rate

40 CFR 60, Appendix A, Method 2 or other EPA approved testing methods acceptable
to the Director.

F. 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.

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.c G. 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.

H. Source Operation

For a new source/emission point, the production rate during all compliance testing shall be no
less than 90% of the production capacity of the equipment. If the maximum production
capacity has not been achieved at the time of the test, the following procedure shall be
followed:

1) Testing shall be at no less than 90% of the production rate achieved to date.

2) If the test is passed, the new maximum allowable production rate shall be
110% of the tested achieved rate. This new allowable maximum production
rate shall remain in effect until successfully tested at a higher rate. This

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process may be repeated until the maximum AO production rate is
achieved.

For an existing source/emission point, the production rate during all compliance
testing shall be no less than 90% of the maximum production achieved in the previous
three years. [R307-401-8]

II.B.1.d
NEW
Visible emissions from the following emission points shall not exceed the following values:

A. Main In-Pit crusher baghouse vent 7% opacity

B. Controlled drop point baghouse vent
(C6/C7, located outside of the pit) 7% opacity

C. Controlled drop point baghouse vent
(C7/C8, located outside of the pit) 7% opacity

D. Concrete batch plant baghouse 10% opacity

E. All other conveyor transfer points 10% opacity

F. Lime silos 10% opacity

G. Sample preparation equipment with
baghouse 10% opacity

H. Drilling 10% opacity

I. LP gas-fired emergency generators 10% opacity

J. Nonmetallic Mineral Processing Screens
and Conveyors 7% opacity

K. Nonmetallic Mineral Processing Crushers 12% opacity

L. Metallic Mineral Processing Equipment 10% opacity

M. Electrowinning Plant with electrowinning
acid mist eliminator 15% opacity

N. All other points except as defined in other
conditions of this AO 10% opacity

O. Diesel-fired Equipment 20% opacity

Opacity observations of emissions from stationary sources shall be conducted according to 40
CFR 60, Appendix A, Method 9. [R307-201]

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II.B.1.e For sources that are subject to NSPS, opacity shall be determined in accordance with 40 CFR
60.11(b) and 40 CFR 60, Appendix A, Method 9. It is the responsibility of the owner/operator
of the source to supply these observations to the Director.

A current certified observer must be used for these observations. Emission points that are
subject to the initial observations are:

A. All crushers

B. All screens

C. All conveyor transfer points. [40 CFR 60 Subpart A]

II.B.1.f The following limits shall not be exceeded:

A. Total material moved (ore and waste) shall not exceed 260,000,000 tons
per rolling 12-month period*.

B. Annual emissions of SO2 shall not exceed 7 tons per rolling 12-month period.

C. Maximum total mileage per calendar day for diesel-powered ore and waste haul
trucks shall not exceed 30,000 miles.

D. Minimum design payload per ore and waste haul truck shall not be less than 240 tons.
Minimum design payload for trucks hauling material to develop new mining
technologies, and material from maintenance activities shall not be less than 40 tons.
Trucks used for underground development and operation may be smaller depending
on application.

E. Maximum number of wheels per ore or waste haul truck shall not exceed six wheels.

F. Height of mine waste dump lift shall not exceed 1000 feet.

G. The surface area of the Solvent Extraction/Electrowinning Plant mixer/settlers
shall not exceed 1,100 ft2.

*Total ore and waste limitation shall be applied to dry tons of new material mined at the
production shovels face.

The owner/operator shall determine compliance with the 12-month period limits on a rolling
12-month total. The owner/operator shall calculate a new 12-month total by the twentieth day
of each month using data from the previous 12 months.

The owner/operator shall keep records of daily total mileage for all periods when the mine is
in operation. The owner/operator shall track haul truck miles with a Global Positioning
System or equivalent. The system shall use real time tracking to determine daily mileage.

SO2 emissions from fuel burning shall be determined using the following formula:

SO2 tpy = (gal fuel/year)*(7.05 lb/gal)*(%S by wt.)/2000 lb/ton*(2 lb SO2/lb S). [R307-401-8]

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II.B.1.g The following site-wide emission limits at the BCM shall not be exceeded:

A. 7,350 tons of NOx, PM10 and SO2 combined per rolling 12-month period.

B. 6,205 tons of NOx, PM2.5 and SO2 combined per rolling 12-month period.

The owner/operator shall determine compliance with the 12-month period limits on a rolling
12-month total per methodology outlined in Appendix A. The owner/operator shall calculate a
new 12-month total by the twentieth day of each month using data from the previous 12
months. [R307-401-8]

II.B.2 Equipment Requirements
II.B.2.a The Main In-Pit Crusher Baghouse shall control process streams from the Main In-Pit
Crusher. This baghouse shall be sized to handle at least 12,898 Dry Standard Cubic Feet per
Minute (DSCFM). All exhaust air from the Main In-Pit Crusher shall be routed through the
baghouse before being vented to the atmosphere. [R307-401-8]

II.B.2.b The lime silos fabric bin vent control units shall control process streams from the lime silos.
This control unit shall be sized to handle at least 616 DSCFM. All exhaust air from the lime
silos shall be routed through the control unit before being vented to the atmosphere. [R307-
401-8]

II.B.2.c The Controlled Transfer Drop Point C6/C7 baghouse shall control process streams from the
drop point. This baghouse shall be sized to handle at least 5,120 DSCFM. All exhaust air
from the C6/C7 transfer drop point shall be routed through the baghouse before being vented
to the atmosphere. [R307-401-8]

II.B.2.d The Controlled Transfer Drop Point C7/C8 baghouse shall control process streams from the
drop point. This baghouse shall be sized to handle at least 3,168 DSCFM. All exhaust air
from the C7/C8 transfer drop point shall be routed through the baghouse before being vented
to the atmosphere. [R307-401-8]

II.B.2.e The Sample Preparation baghouse shall control process streams from the sample preparation
building crushing and grinding equipment. This baghouse shall be sized to handle at least
4,200 DSCFM. All exhaust air from the sample preparation crusher and grinder shall be
routed through the baghouse before being vented to the atmosphere. [R307-401-8]

II.B.2.f The Electrowinning Acid Mist Eliminator shall control process streams from the
electrowinning cells. This mist eliminator shall be sized to handle at least 8,000 actual CFM.
Except during service, inspection, and cathode harvest, all exhaust air from the electrowinning
cells shall be routed through the mist eliminator before being vented to the atmosphere.
[R307-401-8]

II.B.2.g The solvent extraction tanks and the stripping mixer/settlers shall be covered at all times
except during inspection, sampling, and adjustment. [R307-401-8]

II.B.2.h The concrete batch plant baghouse shall control all process streams from the 25 cubic yard
concrete batch plant listed in Condition II.A.12. This baghouse shall be sized to handle at
least 3,900 DSCFM. All exhaust air from the concrete batch plant shall be routed through the
baghouse before being vented to the atmosphere. [R307-401-8]

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II.B.2.i The owner/operator shall only combust diesel fuel 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.2.i.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.3 Roads and Fugitive Dust
II.B.3.a The owner/operator shall abide by a FDCP acceptable to the Director for control of all dust
sources associated with the BCM. The FDCP shall be updated and submitted on an annual
basis to the Director by February 1 of every year. This plan shall contain sufficient controls to
prevent an increase in PM10 emissions above those modeled for this AO. The haul road
length, speed, or any other parameters used to calculate the emissions cannot be changed
without prior approval from the Director, if the change would result in an increase in
emissions above the limitations set in the FDCP. [R307-309]

II.B.3.b The BCM shall comply with all applicable requirements of UAC R307-205 and R307-309 for
Fugitive Emission and Fugitive Dust sources. The provisions of R307-205 and R307-309
shall not apply to any sources for which limitations for fugitive dust or fugitive emissions are
assigned pursuant to R307-401 or R307-305 nor shall they apply to agricultural or
horticultural activities. [R307-309]

II.B.3.c Control of disturbed or stripped areas is required at all times (24 hours per day every day) for
the duration of the project/operation until the area is reclaimed. Records of disturbed area,
treatment and/or reclamation shall be kept for all periods when the BCM is in operation.
[R307-309]

II.B.3.d Visible fugitive dust emissions from haul-road traffic and mobile equipment in operational
areas shall not exceed 20% opacity at any point. Visible emission determinations shall use
procedures similar to Method 9. The normal requirement for observations to be made at 15-
second intervals over a six-minute period, however, shall not apply. Visible emissions shall
be measured at the densest point of the plume but at a point not less than 1/2 vehicle length
behind the vehicle and not less than 1/2 the height of the vehicle. [R307-309]

II.B.3.e Water sprays, chemical dust suppression sprays or enclosures shall be installed at the
following points that are not enclosed or have baghouses to control fugitive emissions:

A. All stationary and portable conveyor transfer points
B. All portable crusher input and output points, and screening unit points or partial
enclosures.

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

II.B.3.f The accessible surfaces of all uncovered storage piles shall be sprayed with water or chemical
dust suppressants to minimize generation of fugitive dusts, as dry conditions warrant or as
determined necessary by the Director. Records of water and/or chemical dust control
treatment shall be kept for all periods when the plant is in operation. [R307-309]

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II.B.3.g
NEW
The opacity on active waste slopes shall not exceed 20%. A visual opacity survey of waste
dump activity shall be performed on a monthly basis. If visible emissions are observed, an
opacity observation shall be performed by a certified observer within 24 hours. Opacity
observations shall be conducted in accordance with 40 CFR 60, Appendix A, Method 9, but
the requirement for observations to be made at 15-second intervals over a six-minute period
shall not apply. At any time, the owner/operator may propose a compliance method to UDAQ
for approval prior to implementation. [R307-309]

II.B.3.h The owner/operator shall use frequent watering or chemical dust suppressant to control road
dust from all trafficked roads and areas in the mine. The owner/operator shall submit an
annual road dust control report, in conjunction with the FDCP, by February 1 of each calendar
year, containing as a minimum the following:

A. A description of what dust control measures are planned for the coming year

B. A report of what dust control measures were actually completed during the past year

C. Specific elements of the report will include:

1) A map of all trafficked areas and roads associated with the mine, indicating
which areas are planned for water and/or chemical dust suppressant treatment.

2) A description of the chemical dust suppressant and how it will be
applied (application rate, application frequency, dilution rate, special
application procedure, scarification, etc.).

3) A list of equipment dedicated either full or part time to the work area and
for road dust control (number of water trucks, water capacity, number
of graders, etc.).

4) A quantification of how much dust suppressant (gallons, tons) was
applied the previous year and when and where it was applied.

5) A quantification of how much watering was accomplished the previous
year (gallons, water truck operating hours).

6) A map outlining the pit influence boundary. [R307-309]

II.B.3.i Wet drilling shall be performed for all blast holes. [R307-309]

II.B.3.j To minimize fugitive dust on roads at the BCM, the owner/operator shall perform the
following measures:

A. Apply water to all active haul roads located at the BCM as conditions warrant and in
accordance with the FDCP, and shall

1) ensure the surface of the active haul roads located within the pit influence
boundary consists of road base material, blasted waste rock, crushed rock,
or chemical dust suppressant, and

2) apply a chemical dust suppressant to active haul roads located outside
of the pit influence boundary no less than twice per year.

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B. Ore conveyors shall be the primary means for transport of crushed ore from the
BCM to the Copperton Concentrator.

C. Chemical dust suppressant shall be applied on unpaved access roads that receive
haul truck traffic and light vehicle traffic as defined in the FDCP.

D. The owner/operator shall use graders to perform haul road maintenance and clean-up
activities as well as other operational functions. [R307-309-10]

E. If, for a 12-month period, the material movement by haul trucks is below 197,000,000
tpy of ore and waste rock combined, the owner/operator may petition the Director to
revise the fugitive dust control measures above. [R307-309-10]

II.B.4 Monitoring Requirements
II.B.4.a The owner/operator shall operate two ambient monitoring stations to monitor PM10 in
Copperton and lower Butterfield Canyon area as approved by the Director. The monitoring
plan will be periodically reviewed and revised as necessary. Any changes must be approved
by the Director.

The air monitoring stations shall remain in operation, at a minimum, until the BCM material
moved has achieved a minimum of 234,000,000 TPY. If after that amount of material moved
has been achieved and monitoring data indicates compliance with the NAAQS, the
owner/operator may petition the Director to remove the air monitoring stations. [R307-410]

II.B.4.b The owner/operator shall utilize federal reference method (FRM) or federal equivalent method
PM10 monitors as specified in 40 CFR 53 and quality assurance procedures which are equal to
or exceed the requirements described in the EPA Quality Assurance Manual including
revisions, 40 CFR Parts 50, 53 and 58. [R307-410]

II.B.4.c
NEW
If the PM10 concentrations measured are greater than 135 ug/m3 (90% of the 24-hr PM10
NAAQS) and if such concentrations have been measured for more than one day per year on an
average over three consecutive years, the owner/operator shall conduct a review of mine
operations and other potential sources and conditions such as the Natural Events Exception
Criteria.

If it is determined the BCM impacts the elevated ambient PM10 concentrations, the
owner/operator shall work with DAQ to review control practices and possible changes in
practices to avoid future elevated concentrations. [R307-410]

II.B.4.d
NEW
The owner/operator shall submit quarterly data reports within 45 days after the end of the
calendar quarter and an annual data report within 90 days after the end of the calendar year.

The quarterly report shall consist of a narrative data summary and a submittal of all data
points in EPA-AIRS record format. The data shall be submitted on a compact disk (CD). The
narrative data summary shall include:

A. A topographic map of appropriate scale with UTM coordinates and a true north arrow
showing the air monitoring site locations in relation to the mine and the general area;

B. A hard copy of the individual data points;

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C. The quarterly and monthly arithmetic means for PM10 at actual temperature and
pressure;

D. The first and second highest 24-hour concentrations for PM10;

E. The quarterly and monthly wind roses;

F. A summary of the data collection completeness;

G. A summary of the reasons for missing data;

H. An audit summary;

I. A summary of any ambient air PM10 exceedances;

J. Calibration information; and

K. Laboratory reports (for exceedance filters).

The annual data report shall consist of a narrative data summary containing:

A. A topographic map of appropriate scale with UTM coordinates and a true north arrow
showing the air monitoring site locations in relation to the mine and the general area;

B. A pollution trend analysis;

C. The annual arithmetic means for PM10;

D. The first and second highest 24-hour concentrations for PM10;

E. The annual wind rose;

F. Annual summaries of data collection frequency and completeness;

G. An annual summary of audit data;

H. An annual summary of any ambient standard exceedance;

I. Annual mine material moved in TPY;

J. Annual summary of analytical speciation results for detectible metals (for exceedance
filters); and

K. Recommendations on future monitoring.

The Director reserves the right to audit the air monitoring network, the laboratory performing
associated analysis, and any data handling procedures at unspecified times. On the basis of
the audits and subsequent reports, DAQ reserves the right to recommend or require changes in
the air monitoring system and associated activities in order to improve data quality and
completeness. [R307-410]

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II.B.4.e The owner/operator shall contract with an independent firm to conduct quarterly performance
audits of its PM10 monitors.

Exposed PM10 filters that exceed 150 ug/m3 shall be analyzed for metals, and other
constituents as requested by the Director. One filter blank per batch of ten filters or less shall
also be submitted for analysis. [R307-410]

II.B.4.f PM10 and meteorological data (wind speed, wind direction, and ambient temperature) shall be
collected at each site. The meteorological tower shall be located within one mile of the
monitor station. [R307-410]

II.B.5
NEW
Emergency Generator Engine
II.B.5.a
NEW
The owner/operator shall not operate each emergency engine on site for more than 100 hours
per rolling 12-month period during non-emergency situations. There is no time limit on the
use of the engines during emergencies. [R307-401-8]

II.B.5.b
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 documenting the operation of each emergency engine shall be kept in a log and shall
include the following:

a. The date the emergency engine was used

b. The duration of operation in hours

c. The reason for the emergency engine usage. [R307-401-8]

II.B.5.c
NEW
To determine the duration of operation, the owner/operator shall install a non-resettable hour
meter for each emergency engine. [R307-401-8]

II.B.5.d
NEW
KUC shall not exceed the following limits on the diesel fired emergency generators for the
Ventilation System #6, # 7, 8, and #9:

Testing of the diesel fired emergency generators shall be allowed between 8 am and 8 pm.
Only one (1) diesel fired emergency generator shall be tested at the same time. [R307-410]

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PERMIT HISTORY

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

Incorporates Additional Information dated February 28, 2024
Is Derived From NOI Dated dated February 9, 2024
Supersedes DAQE-AN105710047-21 dated May 10, 2021
Incorporates Additional Information dated April 18, 2024

REVIEWER COMMENTS

1. Comment regarding Emission Estimates:
The emergency generators PTE emissions estimates for PM10, PM2.5 NOx, VOC, and CO were
generated using Tier 4 specs for PM10 and PM 2.5, NOx, CO and VOC emissions. The SOx
emissions were generated using AP-42 Chapter 3. The CO2e calculated used table A-1 "Global
Warming Potentials" from 40 Code of Federal Regulations (CFR) Part 98. The engines are all
limited by 100 hours of operation per year (each). [Last updated May 1, 2024]

2. Comment regarding Site Information:
The Site Indicator (SI) number has two facilities associated with it. The Copperton Concentrator has
the permit number DAQE-AN105710035-13 with the 10571 SI number. The Bingham Canyon
Mine is regulated under permit number DAQE-AN105710037-15 with the 10571 SI number. These
two permits have separate equipment lists and separate requirements. If the two facilities were to be
combined, the source would still be considered a minor area source. The permits are held separate
for historical purposes. [Last updated April 18, 2024]

3. Comment regarding SIP Listed Source:
Kennecott is a listed major source with conditions in Part H.12.g.i of the PM2.5 Serious
Nonattainment SIP. The PM2.5 Serious Nonattainment SIP has been approved by the Air Quality
Board but has not been approved by Region 8 EPA. The PM2.5 Serious Nonattainment SIP
conditions have been incorporated into the current appropriate AO. No additional SIP /permitting
action is required for the addition of the new equipment. [Last updated May 22, 2024]

4. Comment regarding SIP Source Requirements:
Kennecott is a listed source with conditions in Part H.12.g.i of the PM2.5 Serious Nonattainment SIP.
The SIP requirement pertaining to the BCM are included in this permit already. [Last updated April
18, 2024]

5. Comment regarding Permit Modification, Site Analysis:
This permit modification is being conducted in conjunction with a permit modification for the
concentrator to add equipment for underground mining operations. Both modifications were
reviewed to determine if combined increase for both modifications triggered significant emissions
increase per UAC R307-101-2. Both modifications combined emissions increase are as follows
(tons per year): 0.44 of point source PM10, 0.26 of PM2.5, 1.28 of NOx, 7.93 of CO, 1.12 of SOx and
0.43 of VOC. The total combined emissions increase from both modifications does not trigger
significant. [Last updated April 18, 2024]

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6. Comment regarding Offset Requirements:
The Kennecott, Copperton BCM is located in a Nonattainment area for PM10, PM2.5 and Ozone. An
analysis of the emissions increases for both modifications was conducted to determine if the
emissions triggered significant which would require offsetting. The analysis determined that
significant was not triggered which makes this a minor modification (not a major modification) so
offsets are not required per UAC R307-403, UAC R307-420 and UAC-R307-421. [Last updated
April 18, 2024]

7. Comment regarding Kennecott Aggregation:
UDAQ has previously divided Kennecott's operations into the following separate stationary sources;

Smelter and Refinery,
Central Laboratory, Tailings Impoundment, and Utah Power Plant
Bingham Canyon Mine and Copperton Concentrator, and
Bonneville Borrow Area Plant

These site aggregation determinations were addressed during implementation of the Title V and
were separated by pollutant-emitting activities which belong to the same industrial grouping.
Pollutant-emitting activities shall be considered as part of the same industrial grouping if they have
the same two-digit code of the Standard Industrial Classification.

The Smelter and Refinery each have a separate AO but are combined into the same site ID 10346
and classified as a major source. The Central Laboratory, Tailings Impoundment and Utah Power
Plant all have separate AOs and were historically combined into the same site ID 10572 when they
were classified as a major source. When the Utah Power Plant AO was issued in 2020, site ID 10572
was no longer major source and the Title V permit was rescinded. All sites are currently minor
sources. The Bingham Canyon Mine and Copperton Concentrator each have separate AOs and are
combined into the same site ID 10571 and classified as a minor source (majority of PTE emissions
are fugitives/tailpipe). The Bonneville Borrow Area Plant has a site ID 16035 and is classified as a
minor source.

To determine major source classification, fugitive emissions are counted only if the source category
is a listed source category. Mining activities are not a listed source category and the fugitive
emissions are not counted towards source classification.
[Last updated May 22, 2024]

8. Comment regarding New Equipment Conditions:
The new equipment being added for this modification consists of two storage silos, a mixer dust
collector and four emergency standby generators.

The storage silos and the mixer dust collector have a BACT limit of 10% opacity limit. The 10%
BACT opacity limit is exist in the sitewide visible emissions limit, labeled "All other points except
as defined in other conditions of this AO".

The emergency standby generators will have additional conditions added to the updated AO for
tracking the non-emergency hours of operation and limits on when the engines can be tested. The
sulfur content limit exist in the site wide condition and the limit is not just limited to emergency
generators. [Last updated April 25, 2024]

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9. Comment regarding Point Source:
The KUC BCM is classified as a minor source due to the amount of point sources emissions. The
point source emissions are as follows; 9.86 TPY of PM10, 1.68 TPY of PM2.5, 0.003 TPY of SOx,
2.01 TPY of NOx, 3.97 TPY of CO and 1.81 TPY of VOCs. To determine major source
classification, fugitive emissions are counted only if the source category is a listed source category.
Mining activities are not a listed source category and the fugitive emissions are not counted towards
source classification. [Last updated May 22, 2024]

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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 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-

RN105710048
June 3, 2024

Brendan Murphy
Rio Tinto Kennecott Utah Copper LLC
4700 Daybreak Parkway
South Jordan, UT 84095

Dear Brendan Murphy,

Re: Engineer Review:
Modification to Approval Order to DAQE-AN105710047-21, to Add Paste Plant and Support
Equipment
Project Number: N105710048

The DAQ requests a company representative review and sign the attached Engineer Review (ER). This
ER identifies all applicable elements of the New Source Review permitting program. Rio Tinto
Kennecott Utah Copper LLC should complete this review within 10 business days of receipt.

Rio Tinto Kennecott Utah Copper LLC should contact Tad Anderson at [phone] if there are
questions or concerns with the review of the draft permit conditions. Upon resolution of your concerns,
please email Tad Anderson at [e-mail] the signed cover letter. Upon receipt of the signed
cover letter, the DAQ will prepare an ITA for a 30-day public comment period. At the completion of the
comment period, the DAQ will address any comments and 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 source concurrence. If Rio Tinto Kennecott Utah Copper LLC has
concerns that cannot be resolved and the project becomes stagnant, 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
Lieutenant Governor

6/12/2024

Engineer Review N105710048: Rio Tinto Kennecott Utah Copper LLC- Mine & Copperton Concentrator
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Page 1
UTAH DIVISION OF AIR QUALITY
ENGINEER REVIEW

SOURCE INFORMATION

Project Number N105710048
Owner Name Rio Tinto Kennecott Utah Copper LLC
Mailing Address 4700 Daybreak Parkway
South Jordan, UT, 84095

Source Name Rio Tinto Kennecott Utah Copper LLC- Mine & Copperton
Concentrator
Source Location 8362 W 10200 S
Bingham Canyon, UT 84006

UTM Projection 407,000 m Easting, 4,493,000 m Northing
UTM Datum NAD27
UTM Zone UTM Zone 12
SIC Code 1021 (Copper Ores)

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

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

Project Engineer Tad Anderson, Engineer
Phone Number [phone]
Email [e-mail]

Notice of Intent (NOI) Submitted February 9, 2024
Date of Accepted Application April 5, 2024

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SOURCE DESCRIPTION

General Description
Rio Tinto Kennecott Utah Copper LLC (RTK) owns and operates the Bingham Canyon Mine
(BCM) and the Copperton Concentrator. The BCM is an open pit mining operation located in the
southwest corner of Salt Lake County, Utah. Ore from the mine is conveyed to the Copperton
Concentrator located approximately five miles north of the open pit in Copperton, Utah where it
is ground and treated to produce copper concentrate.

NSR Classification:
Minor Modification

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: B

Applicable Federal Standards
NSPS (Part 60), A: General Provisions
NSPS (Part 60), LL: Standards of Performance for Metallic Mineral Processing Plants
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
MACT (Part 63), A: General Provisions
MACT (Part 63), ZZZZ: National Emissions Standards for Hazardous Air Pollutants for
Stationary Reciprocating Internal Combustion Engines
Title V (Part 70) Area Source

Project Proposal
Modification to Approval Order to DAQE-AN105710047-21, to Add Paste Plant and Support
Equipment

Project Description
RTK is requesting a modification of BCM Approval Order (AO) DAQE-AN105710047-21 to
install and operate facilities associated with underground mining operations. The underground
mining operations include the use of a new Paste Plant with two storage silos, a mixer dust
collector and four emergency standby generators for the employee ventilation systems.

The new storage silos, at the bottom of the mine, support the Paste Plant operations where RTK
will make usable concrete from lime and other materials. The mixer dust collector captures
emissions from the paste plant mixer process area, where lime and other materials are blended
together to make useable concrete.

Process Description
The ore and waste rock at the BCM are transferred from the mining areas to other areas of the
mine through a series of transfers using haul trucks and conveyor belts. Ore is transferred to the
in-pit crusher with haul trucks from the shovel face and waste rock is hauled to dumping areas

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with haul trucks. After the ore is crushed, it is conveyed to the Copperton Concentrator. Once
the ore is processed at the concentrator, it is transferred to the smelter.

EMISSION IMPACT ANALYSIS
Modeling was submitted for PM10 and NO2. A modeling memo was generated containing the summary
DAQE-MN105710048-24 with recommended conditions for testing times and testing quantity. [Last updated
April 25, 2024]

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Page 4
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)
CO2 Equivalent 718.29 9038.47
Carbon Monoxide 4.34 1712.04
Nitrogen Oxides 0.60 5842.71
Particulate Matter - PM10 0.41 1519.62
Particulate Matter - PM10 (Fugitives) 0.00 1509.76
Particulate Matter - PM2.5 0.23 369.44
Particulate Matter - PM2.5 (Fugitives) 0.00 367.76
Sulfur Dioxide 0.01 7.44
Volatile Organic Compounds 0.19 314.32

Hazardous Air Pollutant Change (lbs/yr) Total (lbs/yr)
Total HAPs (CAS #THAPS) 100 3580
Change (TPY) Total (TPY)
Total HAPs 0.05 1.79

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 Equipment

BACT has been conducted for the two storage silos, a mixer dust collector and four emergency
standby generators. The following is a summary of the results.

Storage Silos
BACT was conducted for the storage silos by reviewing the RBLC. The RBLC and CARB
databases identify vent filters/baghouses and enclosures as possible control technologies for
limiting emissions from storage silos. Baghouses are more effective than enclosures in minimizing
emissions from storage silos. BACT for the storage silos is the use of baghouses and a 10 %
opacity limit.

Mixer Dust Collector/Baghouse
BACT was conducted for the mixer dust collector by reviewing the RBLC. The RBLC and CARB
databases identify vent filters/baghouses and enclosures as possible control technologies for
limiting emissions from mixer dust collectors. Baghouses are more effective than enclosures in
minimizing emissions from mixer dust collectors. BACT for the mixer dust collector is the use of
baghouses and a 10 % opacity limit.

Emergency Generators
BACT was conducted for the emergency generator engine by reviewing the RBLC. The following
technologies were specified in the analysis: good combustion practices, maintenance and operating
practices, use of low-sulfur diesel fuel, compliance with applicable NSPS IIII requirements,
compliance with applicable NESHAP ZZZZ requirements and the use of SCR. All of the listed
control technologies are technically feasible, except for SCR. For SCR systems to function
effectively, exhaust temperatures must be 200 degree C to 500 degree C to enable catalyst
activation. SCR control efficiencies are low during the first 20 to 30 minutes after engines start up
during maintenance and testing. There are also complications controlling the excess ammonia
during the engine startup during maintenance and testing from SCR use. SCR is not considered
technically feasible for emergency units.

BACT for diesel-fired emergency engines, is the following:

Good combustion, maintenance, and operating practices
Use of low-sulfur diesel fuel
Compliance with applicable NSPS IIII requirements
Use of a tier certified engine
Limit on hours of operation for maintenance and testing operations
Compliance with applicable NESHAP ZZZZ requirements is not required
[Last updated May 31, 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):

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I.1 The limits set forth in this AO shall not be exceeded without prior approval. [R307-401]

I.2 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.3 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 two-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 two (2) years. [R307-401-8]

I.4 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.5 The owner/operator shall comply with R307-150 Series. Inventories, Testing and Monitoring.
[R307-150]

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

I.7 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.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 KUC Bingham Mine
KUC operates the BCM. KUC removes ore from the BCM by drilling, blasting, crushing and
hauling.

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II.A.2 Main In-pit Crusher
Main in-pit crusher
Main in-pit crusher baghouse

II.A.3 Portable Roadbase Crushers
Two portable crushing and screening plants used to crush material for road base
Maximum crusher unit capacity 700 tons per hour, each

II.A.4 Conveyors
Conveyors and two transfer points with baghouses (Baghouses C6/C7 and Baghouses C7/C8)

II.A.5 Lime Silos
Lime silos with fabric type bin vent control units

II.A.6 Sample Preparation Equipment
Sample preparation equipment with baghouse

II.A.7 SX/EW plant
SX/EW plant with electrowinning acid mist eliminator

II.A.8 Degreasers
Various degreasing parts washers

II.A.9 Gasoline Fueling Stations

II.A.10 LPG-Fired Emergency Generators
Nine Liquefied Petroleum gas-fired emergency generators

Site Maximum Rating
Lark Gate
#1 107 Brake Horsepower (BHP)
#2 49 BHP
Production Control Building 6690 150 BHP
Communications 6190 75 BHP
Mandy's Landing 75 BHP
East Side Dump 49 BHP
Zelnora 49 BHP
SAM Site 49 BHP
Substation 2 49 BHP

II.A.11 Diesel-Fired Emergency Generators
Nine diesel-fired emergency generators (4 NEW)

1) Support Generators 1-5
1. Maximum rating 2,250 kW
2. Maximum rating 700 kW
3. Maximum rating 700 kW
4. Maximum rating 500 kW
5. Maximum rating 2,000 kW

2) Ventilation System Generators 6-9 (NEW)

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6. Maximum rating 2,000 kW
7. Maximum rating 2,000 kW
8. Maximum rating 2,000 kW
9. Maximum rating 3,250 kW

II.A.12 Concrete Batch Plant

1) One 25 cubic yard per hour batch plant controlled by a baghouse
2) One cement storage silo controlled by a baghouses
3) Conveyors and cement trucks
4) Storage silos with fabric filters

II.A.13 Crushers and Screens
Portable crushing and screening plants with associated conveyors used to crush ore and waste
rock.

Conveyors partially enclosed transfer points or water sprays

II.A.14 Underground Mining Support Equipment
1) One (1) 150 cubic yard per hour batch plant controlled by baghouse
a) One (1) cement storage silo with a baghouse
b) Conveyors and cement trucks
c) Storage silos with fabric filters
2) One (1) natural gas-fired boiler - 2.0 MMBTU/hr
3) One (1) natural gas-fired boiler - 4.0 MMBTU/hr
4) Three (3) diesel-fired heaters - 4.2 MMBTU/hr (each)
5) One (1) diesel-fired generator - 71 kW

II.A.15
NEW
Paste Plant (NEW)
1. Two (2) Storage silos with baghouse
2. One (1) Mixer Dust Collector with baghouse

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 at all times from the indicated emission points after primary control shall not
exceed the following rates and concentrations:

A. Main In-Pit Crusher Baghouse Vent

Pollutant lb/hr grains per dry standard cubic foot (dscf)
(68 F, 29.92 in Hg)

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PM10 1.77 0.016
PM2.5 0.78 0.007

B. Controlled Drop Point Baghouse Vent (C6/C7, located outside of the pit)

Pollutant lb/hr grains per dry standard cubic foot (dscf)
(68 F, 29.92 in Hg)

PM10 0.31 0.007

C. Controlled Drop Point Baghouse Vent (C7/C8, located outside of the pit)

Pollutant lb/hr grains per dry standard cubic foot (dscf)
(68 F, 29.92 in Hg)

PM10 0.19 0.007. [R307-401-8]

II.B.1.b
NEW
Stack testing to show compliance with the emission limitations stated in the above condition
shall be performed as specified below:

A. Testing Test
Emissions Point Pollutant Status Frequency

Main In-Pit Crusher Baghouse
Vent PM10 * #
PM2.5 * #

Controlled Drop Point Baghouse
Vent (C6/C7, located outside of the pit) PM10 * #

Controlled Drop Point Baghouse
Vent (C7/C8, located outside of the pit) PM10 * #

B. Testing Status

* The initial testing has already been performed.

# Test every three years. If a unit is not in operation when a test is due, the
owner/operator may request an extension for the test.

C. Notification

The Director shall be notified at least 30 days prior to conducting any required emission
testing. A source test protocol shall be submitted with the testing notification is submitted to
the Director.

The source test protocol shall be approved by the Director prior to performing the test(s). The
source test protocol shall outline the proposed test methodologies, and stack to be tested. A
pretest conference shall be held, if directed by the Director.

D. Sample Location

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The emission point shall be designed to conform to the requirements of 40 CFR60, Appendix
A, Method 1, or other EPA approved methods acceptable to the Director. An Occupational
Safety and Health Administration (OSHA) or Mine Safety and Health Administration
(MSHA) approved access shall be provided to the test location.

E. Volumetric Flow Rate

40 CFR 60, Appendix A, Method 2 or other EPA approved testing methods acceptable
to the Director.

F. 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.

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.c G. 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.

H. Source Operation

For a new source/emission point, the production rate during all compliance testing shall be no
less than 90% of the production capacity of the equipment. If the maximum production
capacity has not been achieved at the time of the test, the following procedure shall be
followed:

1) Testing shall be at no less than 90% of the production rate achieved to date.

2) If the test is passed, the new maximum allowable production rate shall be
110% of the tested achieved rate. This new allowable maximum production
rate shall remain in effect until successfully tested at a higher rate. This

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process may be repeated until the maximum AO production rate is
achieved.

For an existing source/emission point, the production rate during all compliance
testing shall be no less than 90% of the maximum production achieved in the previous
three years. [R307-401-8]

II.B.1.d
NEW
Visible emissions from the following emission points shall not exceed the following values:

A. Main In-Pit crusher baghouse vent 7% opacity

B. Controlled drop point baghouse vent
(C6/C7, located outside of the pit) 7% opacity

C. Controlled drop point baghouse vent
(C7/C8, located outside of the pit) 7% opacity

D. Concrete batch plant baghouse 10% opacity

E. All other conveyor transfer points 10% opacity

F. Lime silos 10% opacity

G. Sample preparation equipment with
baghouse 10% opacity

H. Drilling 10% opacity

I. LP gas-fired emergency generators 10% opacity

J. Nonmetallic Mineral Processing Screens
and Conveyors 7% opacity

K. Nonmetallic Mineral Processing Crushers 12% opacity

L. Metallic Mineral Processing Equipment 10% opacity

M. Electrowinning Plant with electrowinning
acid mist eliminator 15% opacity

N. All other points except as defined in other
conditions of this AO 10% opacity

O. Diesel-fired Equipment 20% opacity

Opacity observations of emissions from stationary sources shall be conducted according to 40
CFR 60, Appendix A, Method 9. [R307-201]

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II.B.1.e For sources that are subject to NSPS, opacity shall be determined in accordance with 40 CFR
60.11(b) and 40 CFR 60, Appendix A, Method 9. It is the responsibility of the owner/operator
of the source to supply these observations to the Director.

A current certified observer must be used for these observations. Emission points that are
subject to the initial observations are:

A. All crushers

B. All screens

C. All conveyor transfer points. [40 CFR 60 Subpart A]

II.B.1.f The following limits shall not be exceeded:

A. Total material moved (ore and waste) shall not exceed 260,000,000 tons
per rolling 12-month period*.

B. Annual emissions of SO2 shall not exceed 7 tons per rolling 12-month period.

C. Maximum total mileage per calendar day for diesel-powered ore and waste haul
trucks shall not exceed 30,000 miles.

D. Minimum design payload per ore and waste haul truck shall not be less than 240 tons.
Minimum design payload for trucks hauling material to develop new mining
technologies, and material from maintenance activities shall not be less than 40 tons.
Trucks used for underground development and operation may be smaller depending
on application.

E. Maximum number of wheels per ore or waste haul truck shall not exceed six wheels.

F. Height of mine waste dump lift shall not exceed 1000 feet.

G. The surface area of the Solvent Extraction/Electrowinning Plant mixer/settlers
shall not exceed 1,100 ft2.

*Total ore and waste limitation shall be applied to dry tons of new material mined at the
production shovels face.

The owner/operator shall determine compliance with the 12-month period limits on a rolling
12-month total. The owner/operator shall calculate a new 12-month total by the twentieth day
of each month using data from the previous 12 months.

The owner/operator shall keep records of daily total mileage for all periods when the mine is
in operation. The owner/operator shall track haul truck miles with a Global Positioning
System or equivalent. The system shall use real time tracking to determine daily mileage.

SO2 emissions from fuel burning shall be determined using the following formula:

SO2 tpy = (gal fuel/year)*(7.05 lb/gal)*(%S by wt.)/2000 lb/ton*(2 lb SO2/lb S). [R307-401-8]

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II.B.1.g The following site-wide emission limits at the BCM shall not be exceeded:

A. 7,350 tons of NOx, PM10 and SO2 combined per rolling 12-month period.

B. 6,205 tons of NOx, PM2.5 and SO2 combined per rolling 12-month period.

The owner/operator shall determine compliance with the 12-month period limits on a rolling
12-month total per methodology outlined in Appendix A. The owner/operator shall calculate a
new 12-month total by the twentieth day of each month using data from the previous 12
months. [R307-401-8]

II.B.2 Equipment Requirements
II.B.2.a The Main In-Pit Crusher Baghouse shall control process streams from the Main In-Pit
Crusher. This baghouse shall be sized to handle at least 12,898 Dry Standard Cubic Feet per
Minute (DSCFM). All exhaust air from the Main In-Pit Crusher shall be routed through the
baghouse before being vented to the atmosphere. [R307-401-8]

II.B.2.b The lime silos fabric bin vent control units shall control process streams from the lime silos.
This control unit shall be sized to handle at least 616 DSCFM. All exhaust air from the lime
silos shall be routed through the control unit before being vented to the atmosphere. [R307-
401-8]

II.B.2.c The Controlled Transfer Drop Point C6/C7 baghouse shall control process streams from the
drop point. This baghouse shall be sized to handle at least 5,120 DSCFM. All exhaust air
from the C6/C7 transfer drop point shall be routed through the baghouse before being vented
to the atmosphere. [R307-401-8]

II.B.2.d The Controlled Transfer Drop Point C7/C8 baghouse shall control process streams from the
drop point. This baghouse shall be sized to handle at least 3,168 DSCFM. All exhaust air
from the C7/C8 transfer drop point shall be routed through the baghouse before being vented
to the atmosphere. [R307-401-8]

II.B.2.e The Sample Preparation baghouse shall control process streams from the sample preparation
building crushing and grinding equipment. This baghouse shall be sized to handle at least
4,200 DSCFM. All exhaust air from the sample preparation crusher and grinder shall be
routed through the baghouse before being vented to the atmosphere. [R307-401-8]

II.B.2.f The Electrowinning Acid Mist Eliminator shall control process streams from the
electrowinning cells. This mist eliminator shall be sized to handle at least 8,000 actual CFM.
Except during service, inspection, and cathode harvest, all exhaust air from the electrowinning
cells shall be routed through the mist eliminator before being vented to the atmosphere.
[R307-401-8]

II.B.2.g The solvent extraction tanks and the stripping mixer/settlers shall be covered at all times
except during inspection, sampling, and adjustment. [R307-401-8]

II.B.2.h The concrete batch plant baghouse shall control all process streams from the 25 cubic yard
concrete batch plant listed in Condition II.A.12. This baghouse shall be sized to handle at
least 3,900 DSCFM. All exhaust air from the concrete batch plant shall be routed through the
baghouse before being vented to the atmosphere. [R307-401-8]

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II.B.2.i The owner/operator shall only combust diesel fuel 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.2.i.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.3 Roads and Fugitive Dust
II.B.3.a The owner/operator shall abide by a FDCP acceptable to the Director for control of all dust
sources associated with the BCM. The FDCP shall be updated and submitted on an annual
basis to the Director by February 1 of every year. This plan shall contain sufficient controls to
prevent an increase in PM10 emissions above those modeled for this AO. The haul road
length, speed, or any other parameters used to calculate the emissions cannot be changed
without prior approval from the Director, if the change would result in an increase in
emissions above the limitations set in the FDCP. [R307-309]

II.B.3.b The BCM shall comply with all applicable requirements of UAC R307-205 and R307-309 for
Fugitive Emission and Fugitive Dust sources. The provisions of R307-205 and R307-309
shall not apply to any sources for which limitations for fugitive dust or fugitive emissions are
assigned pursuant to R307-401 or R307-305 nor shall they apply to agricultural or
horticultural activities. [R307-309]

II.B.3.c Control of disturbed or stripped areas is required at all times (24 hours per day every day) for
the duration of the project/operation until the area is reclaimed. Records of disturbed area,
treatment and/or reclamation shall be kept for all periods when the BCM is in operation.
[R307-309]

II.B.3.d Visible fugitive dust emissions from haul-road traffic and mobile equipment in operational
areas shall not exceed 20% opacity at any point. Visible emission determinations shall use
procedures similar to Method 9. The normal requirement for observations to be made at 15-
second intervals over a six-minute period, however, shall not apply. Visible emissions shall
be measured at the densest point of the plume but at a point not less than 1/2 vehicle length
behind the vehicle and not less than 1/2 the height of the vehicle. [R307-309]

II.B.3.e Water sprays, chemical dust suppression sprays or enclosures shall be installed at the
following points that are not enclosed or have baghouses to control fugitive emissions:

A. All stationary and portable conveyor transfer points
B. All portable crusher input and output points, and screening unit points or partial
enclosures.

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

II.B.3.f The accessible surfaces of all uncovered storage piles shall be sprayed with water or chemical
dust suppressants to minimize generation of fugitive dusts, as dry conditions warrant or as
determined necessary by the Director. Records of water and/or chemical dust control
treatment shall be kept for all periods when the plant is in operation. [R307-309]

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II.B.3.g
NEW
The opacity on active waste slopes shall not exceed 20%. A visual opacity survey of waste
dump activity shall be performed on a monthly basis. If visible emissions are observed, an
opacity observation shall be performed by a certified observer within 24 hours. Opacity
observations shall be conducted in accordance with 40 CFR 60, Appendix A, Method 9, but
the requirement for observations to be made at 15-second intervals over a six-minute period
shall not apply. At any time, the owner/operator may propose a compliance method to UDAQ
for approval prior to implementation. [R307-309]

II.B.3.h The owner/operator shall use frequent watering or chemical dust suppressant to control road
dust from all trafficked roads and areas in the mine. The owner/operator shall submit an
annual road dust control report, in conjunction with the FDCP, by February 1 of each calendar
year, containing as a minimum the following:

A. A description of what dust control measures are planned for the coming year

B. A report of what dust control measures were actually completed during the past year

C. Specific elements of the report will include:

1) A map of all trafficked areas and roads associated with the mine, indicating
which areas are planned for water and/or chemical dust suppressant treatment.

2) A description of the chemical dust suppressant and how it will be
applied (application rate, application frequency, dilution rate, special
application procedure, scarification, etc.).

3) A list of equipment dedicated either full or part time to the work area and
for road dust control (number of water trucks, water capacity, number
of graders, etc.).

4) A quantification of how much dust suppressant (gallons, tons) was
applied the previous year and when and where it was applied.

5) A quantification of how much watering was accomplished the previous
year (gallons, water truck operating hours).

6) A map outlining the pit influence boundary. [R307-309]

II.B.3.i Wet drilling shall be performed for all blast holes. [R307-309]

II.B.3.j To minimize fugitive dust on roads at the BCM, the owner/operator shall perform the
following measures:

A. Apply water to all active haul roads located at the BCM as conditions warrant and in
accordance with the FDCP, and shall

1) ensure the surface of the active haul roads located within the pit influence
boundary consists of road base material, blasted waste rock, crushed rock,
or chemical dust suppressant, and

2) apply a chemical dust suppressant to active haul roads located outside
of the pit influence boundary no less than twice per year.

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B. Ore conveyors shall be the primary means for transport of crushed ore from the
BCM to the Copperton Concentrator.

C. Chemical dust suppressant shall be applied on unpaved access roads that receive
haul truck traffic and light vehicle traffic as defined in the FDCP.

D. The owner/operator shall use graders to perform haul road maintenance and clean-up
activities as well as other operational functions. [R307-309-10]

E. If, for a 12-month period, the material movement by haul trucks is below 197,000,000
tpy of ore and waste rock combined, the owner/operator may petition the Director to
revise the fugitive dust control measures above. [R307-309-10]

II.B.4 Monitoring Requirements
II.B.4.a The owner/operator shall operate two ambient monitoring stations to monitor PM10 in
Copperton and lower Butterfield Canyon area as approved by the Director. The monitoring
plan will be periodically reviewed and revised as necessary. Any changes must be approved
by the Director.

The air monitoring stations shall remain in operation, at a minimum, until the BCM material
moved has achieved a minimum of 234,000,000 TPY. If after that amount of material moved
has been achieved and monitoring data indicates compliance with the NAAQS, the
owner/operator may petition the Director to remove the air monitoring stations. [R307-410]

II.B.4.b The owner/operator shall utilize federal reference method (FRM) or federal equivalent method
PM10 monitors as specified in 40 CFR 53 and quality assurance procedures which are equal to
or exceed the requirements described in the EPA Quality Assurance Manual including
revisions, 40 CFR Parts 50, 53 and 58. [R307-410]

II.B.4.c
NEW
If the PM10 concentrations measured are greater than 135 ug/m3 (90% of the 24-hr PM10
NAAQS) and if such concentrations have been measured for more than one day per year on an
average over three consecutive years, the owner/operator shall conduct a review of mine
operations and other potential sources and conditions such as the Natural Events Exception
Criteria.

If it is determined the BCM impacts the elevated ambient PM10 concentrations, the
owner/operator shall work with DAQ to review control practices and possible changes in
practices to avoid future elevated concentrations. [R307-410]

II.B.4.d
NEW
The owner/operator shall submit quarterly data reports within 45 days after the end of the
calendar quarter and an annual data report within 90 days after the end of the calendar year.

The quarterly report shall consist of a narrative data summary and a submittal of all data
points in EPA-AIRS record format. The data shall be submitted on a compact disk (CD). The
narrative data summary shall include:

A. A topographic map of appropriate scale with UTM coordinates and a true north arrow
showing the air monitoring site locations in relation to the mine and the general area;

B. A hard copy of the individual data points;

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C. The quarterly and monthly arithmetic means for PM10 at actual temperature and
pressure;

D. The first and second highest 24-hour concentrations for PM10;

E. The quarterly and monthly wind roses;

F. A summary of the data collection completeness;

G. A summary of the reasons for missing data;

H. An audit summary;

I. A summary of any ambient air PM10 exceedances;

J. Calibration information; and

K. Laboratory reports (for exceedance filters).

The annual data report shall consist of a narrative data summary containing:

A. A topographic map of appropriate scale with UTM coordinates and a true north arrow
showing the air monitoring site locations in relation to the mine and the general area;

B. A pollution trend analysis;

C. The annual arithmetic means for PM10;

D. The first and second highest 24-hour concentrations for PM10;

E. The annual wind rose;

F. Annual summaries of data collection frequency and completeness;

G. An annual summary of audit data;

H. An annual summary of any ambient standard exceedance;

I. Annual mine material moved in TPY;

J. Annual summary of analytical speciation results for detectible metals (for exceedance
filters); and

K. Recommendations on future monitoring.

The Director reserves the right to audit the air monitoring network, the laboratory performing
associated analysis, and any data handling procedures at unspecified times. On the basis of
the audits and subsequent reports, DAQ reserves the right to recommend or require changes in
the air monitoring system and associated activities in order to improve data quality and
completeness. [R307-410]

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II.B.4.e The owner/operator shall contract with an independent firm to conduct quarterly performance
audits of its PM10 monitors.

Exposed PM10 filters that exceed 150 ug/m3 shall be analyzed for metals, and other
constituents as requested by the Director. One filter blank per batch of ten filters or less shall
also be submitted for analysis. [R307-410]

II.B.4.f PM10 and meteorological data (wind speed, wind direction, and ambient temperature) shall be
collected at each site. The meteorological tower shall be located within one mile of the
monitor station. [R307-410]

II.B.5
NEW
Emergency Generator Engine
II.B.5.a
NEW
The owner/operator shall not operate each emergency engine on site for more than 100 hours
per rolling 12-month period during non-emergency situations. There is no time limit on the
use of the engines during emergencies. [R307-401-8]

II.B.5.b
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 documenting the operation of each emergency engine shall be kept in a log and shall
include the following:

a. The date the emergency engine was used

b. The duration of operation in hours

c. The reason for the emergency engine usage. [R307-401-8]

II.B.5.c
NEW
To determine the duration of operation, the owner/operator shall install a non-resettable hour
meter for each emergency engine. [R307-401-8]

II.B.5.d
NEW
KUC shall not exceed the following limits on the diesel fired emergency generators for the
Ventilation System #6, # 7, 8, and #9:

Testing of the diesel fired emergency generators shall be allowed between 8 am and 8 pm.
Only one (1) diesel fired emergency generator shall be tested at the same time. [R307-410]

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PERMIT HISTORY

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

Incorporates Additional Information dated February 28, 2024
Is Derived From NOI Dated dated February 9, 2024
Supersedes DAQE-AN105710047-21 dated May 10, 2021
Incorporates Additional Information dated April 18, 2024

REVIEWER COMMENTS

1. Comment regarding Emission Estimates:
The emergency generators PTE emissions estimates for PM10, PM2.5 NOx, VOC, and CO were
generated using Tier 4 specs for PM10 and PM 2.5, NOx, CO and VOC emissions. The SOx
emissions were generated using AP-42 Chapter 3. The CO2e calculated used table A-1 "Global
Warming Potentials" from 40 Code of Federal Regulations (CFR) Part 98. The engines are all
limited by 100 hours of operation per year (each). [Last updated May 1, 2024]

2. Comment regarding Site Information:
The Site Indicator (SI) number has two facilities associated with it. The Copperton Concentrator has
the permit number DAQE-AN105710035-13 with the 10571 SI number. The Bingham Canyon
Mine is regulated under permit number DAQE-AN105710037-15 with the 10571 SI number. These
two permits have separate equipment lists and separate requirements. If the two facilities were to be
combined, the source would still be considered a minor area source. The permits are held separate
for historical purposes. [Last updated April 18, 2024]

3. Comment regarding SIP Listed Source:
Kennecott is a listed major source with conditions in Part H.12.g.i of the PM2.5 Serious
Nonattainment SIP. The PM2.5 Serious Nonattainment SIP has been approved by the Air Quality
Board but has not been approved by Region 8 EPA. The PM2.5 Serious Nonattainment SIP
conditions have been incorporated into the current appropriate AO. No additional SIP /permitting
action is required for the addition of the new equipment. [Last updated May 22, 2024]

4. Comment regarding SIP Source Requirements:
Kennecott is a listed source with conditions in Part H.12.g.i of the PM2.5 Serious Nonattainment SIP.
The SIP requirement pertaining to the BCM are included in this permit already. [Last updated April
18, 2024]

5. Comment regarding Permit Modification, Site Analysis:
This permit modification is being conducted in conjunction with a permit modification for the
concentrator to add equipment for underground mining operations. Both modifications were
reviewed to determine if combined increase for both modifications triggered significant emissions
increase per UAC R307-101-2. Both modifications combined emissions increase are as follows
(tons per year): 0.44 of point source PM10, 0.26 of PM2.5, 1.28 of NOx, 7.93 of CO, 1.12 of SOx and
0.43 of VOC. The total combined emissions increase from both modifications does not trigger
significant. [Last updated April 18, 2024]

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6. Comment regarding Offset Requirements:
The Kennecott, Copperton BCM is located in a Nonattainment area for PM10, PM2.5 and Ozone. An
analysis of the emissions increases for both modifications was conducted to determine if the
emissions triggered significant which would require offsetting. The analysis determined that
significant was not triggered which makes this a minor modification (not a major modification) so
offsets are not required per UAC R307-403, UAC R307-420 and UAC-R307-421. [Last updated
April 18, 2024]

7. Comment regarding Kennecott Aggregation:
UDAQ has previously divided Kennecott's operations into the following separate stationary sources;

Smelter and Refinery,
Central Laboratory, Tailings Impoundment, and Utah Power Plant
Bingham Canyon Mine and Copperton Concentrator, and
Bonneville Borrow Area Plant

These site aggregation determinations were addressed during implementation of the Title V and
were separated by pollutant-emitting activities which belong to the same industrial grouping.
Pollutant-emitting activities shall be considered as part of the same industrial grouping if they have
the same two-digit code of the Standard Industrial Classification.

The Smelter and Refinery each have a separate AO but are combined into the same site ID 10346
and classified as a major source. The Central Laboratory, Tailings Impoundment and Utah Power
Plant all have separate AOs and were historically combined into the same site ID 10572 when they
were classified as a major source. When the Utah Power Plant AO was issued in 2020, site ID 10572
was no longer major source and the Title V permit was rescinded. All sites are currently minor
sources. The Bingham Canyon Mine and Copperton Concentrator each have separate AOs and are
combined into the same site ID 10571 and classified as a minor source (majority of PTE emissions
are fugitives/tailpipe). The Bonneville Borrow Area Plant has a site ID 16035 and is classified as a
minor source.

To determine major source classification, fugitive emissions are counted only if the source category
is a listed source category. Mining activities are not a listed source category and the fugitive
emissions are not counted towards source classification.
[Last updated May 22, 2024]

8. Comment regarding New Equipment Conditions:
The new equipment being added for this modification consists of two storage silos, a mixer dust
collector and four emergency standby generators.

The storage silos and the mixer dust collector have a BACT limit of 10% opacity limit. The 10%
BACT opacity limit is exist in the sitewide visible emissions limit, labeled "All other points except
as defined in other conditions of this AO".

The emergency standby generators will have additional conditions added to the updated AO for
tracking the non-emergency hours of operation and limits on when the engines can be tested. The
sulfur content limit exist in the site wide condition and the limit is not just limited to emergency
generators. [Last updated April 25, 2024]

Engineer Review N105710048: Rio Tinto Kennecott Utah Copper LLC- Mine & Copperton Concentrator
June 3, 2024
Page 21
9. Comment regarding Point Source:
The KUC BCM is classified as a minor source due to the amount of point sources emissions. The
point source emissions are as follows; 9.86 TPY of PM10, 1.68 TPY of PM2.5, 0.003 TPY of SOx,
2.01 TPY of NOx, 3.97 TPY of CO and 1.81 TPY of VOCs. To determine major source
classification, fugitive emissions are counted only if the source category is a listed source category.
Mining activities are not a listed source category and the fugitive emissions are not counted towards
source classification. [Last updated May 22, 2024]

Engineer Review N105710048: Rio Tinto Kennecott Utah Copper LLC- Mine & Copperton Concentrator
June 3, 2024
Page 22
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-MN105710048-24

M E M O R A N D U M

TO: Tad Anderson, NSR Engineer

FROM: Dave Prey, Air Quality Modeler

DATE: April 24, 2024
SUBJECT: Modeling Analysis Review for the Notice of Intent for Rio Tinto Kennecott Utah
Copper LLC- Bingham Canyon Mine, Salt Lake County, Utah
_____________________________________________________________________________________
This is not a Major Prevention of Significant Deterioration (PSD) Source.

I. OBJECTIVE
Rio Tinto Kennecott Utah Copper LLC (RTK) is seeking an approval order for their Bingham
Canyon Mine (BKM) located in Salt Lake County, Utah. The BCM is an open pit mining operation
located in the southwest corner of Salt Lake County, Utah. Ore from the mine is conveyed to the
Copperton Concentrator located approximately five miles north of the open pit in Copperton, Utah
where it is ground and treated to produce copper concentrate. RTK is requesting a modification of
BCM Approval Order (AO) DAQE-AN105710047-21 to install and operate facilities associated
with underground mining operations. The underground mining operations include the use of a new
Paste Plant with two storage silos, a mixer dust collector and four emergency standby generators for
the employee ventilation systems.

This report, prepared by the Staff of the New Source Review Section (NSR), contains a review of
the air quality impact analysis (AQIA) including the information, data, assumptions and modeling
results used to determine if the facility would be in compliance with State and Federal
concentration standards.

II. APPLICABLE RULE(S)

Utah Air Quality Rules:

R307-401-6 Condition for Issuing an Approval Order
R307-410-3 Use of Dispersion Models
R307-410-4 Modeling of Criteria Pollutants in Attainment Areas
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

DP
DP
DAQE-MN105710048-24
Page 2

III. MODELING METHODOLOGY

A. Applicability

Emissions from the facility include PM10, NOx, CO, SO2, and HAPs. Modeling for NO2 and PM10
was performed by RTK.

B. Assumptions

1. Topography/Terrain

The Plant is at an elevation 7383 feet with terrain features that have no affect on
concentration predictions.

a. Zone: 12

b. Approximate Location:

UTM (NAD83): 403633 meters East
4484086 meters North

2. Urban or Rural Area Designation

After a review of the appropriate 7.5 minute quadrangles, it was concluded the area is
“rural” for air modeling purposes.

3. Ambient Air

It was determined the Plant boundary used in the AQIA meets the State’s definition of
ambient air.

4. Building Downwash

The source was modeled with the AERMOD model. All structures at the plant were used in
the model to account for their influence on downwash.

5. Meteorology

Five (5) years of off-site surface and upper air data were used in the analysis consisting of
the following:

Surface – Herriman, UT UDAQ: 2016-2020
Upper Air – Salt Lake Airport, UT NWS: 2016-2020

DAQE-MN105710048-24
Page 3
6. Background

No background concentrations were needed for the Significant Impact Analysis (SIA).

7. Receptor and Terrain Elevations

The modeling domain used consisted of receptors including property boundary receptors.
This area of the state contains mountainous terrain and the modeling domain has simple and
complex terrain features in the near and far fields. Therefore, receptor points representing
actual terrain elevations from the area were used in the analysis.

8. Model and Options

The State-accepted AERMOD model was used to predict air pollutant concentrations under
a simple/complex terrain/wake effect situation. In quantifying concentrations, the
regulatory default option was selected.

9. Air Pollutant Emission Rates

Source
UTM Coordinates Modeled Emission Rates
Easting Northing Nox
(m) (m) (lb/hr) (tons/yr) hrs/year
PIT 403633 4484086 4.80 10.52 4380

Total 4.80 10.52

Source
UTM Coordinates Modeled Emission Rates
Easting Northing PM10
(m) (m) (lb/hr) (tons/yr) hrs/year
PIT 403633 4484086 0.2974 1.303 8760

Total 0.30 1.30

10. Source Location and Parameters

Source Type
Source Parameters
Elev, Ht Sigma-Y Area
(ft) (m) (ft) (m) (m^2)
PIT AREA_POLY 7383.0 0.0 0.0 0.00 17516473.3
DAQE-MN105710048-24
Page 4

IV. RESULTS AND CONCLUSIONS

A. National Ambient Air Quality Standards

The below tables provide a comparison of the predicted total air quality concentrations with the
Significant Impact Levels (SIL). The predicted concentrations are less than their respective
SILs.

Air
Pollutant
Period Prediction Class II
Significant
Impact Level
Background Nearby
Sources*
Total NAAQS Percent
(μg/m3) (μg/m3) (μg/m3) (μg/m3) (μg/m3) (μg/m3) SIL
NO2
1-
Hour 5.8 7.5 188 77.6%

Air
Pollutant
Period Prediction Class II
Significant
Impact Level
Background Nearby
Sources*
Total NAAQS Percent
(μg/m3) (μg/m3) (μg/m3) (μg/m3) (μg/m3) (μg/m3) SIL
PM10 24-
Hour 0.09 5.0 150 1.9%

V. PERMIT CONDITIONS

The following suggested permit language should be included under the Terms and Conditions in the
AO:

• Testing of the emergency generators shall be allowed between 8 am and 8 pm.
• Only one (1) emergency generator shall be tested at the same time.

DP:jg

Rio Tinto Kennecott, 4700 Daybreak Parkway, South Jordan, Utah, 84009
December 27, 2023
Mr. Bryce Bird – Director
Utah Division of Air Quality
195 N 1950 W
Salt Lake City, UT 84116

Subject: Rio Tinto Kennecott Utah Copper LLC
Bingham Canyon Mine and Copperton Concentrator

Dear Director Bird,

On May 31, 2023, the Utah Division of Air Quality (UDAQ) sent a letter to Rio
Tinto Kennecott Utah Copper LLC (Kennecott) outlining potential impacts to the
Bingham Canyon Mine and Copperton Concentrator resulting from designation of
the Northern Wasatch Front to serious nonattainment classification in February
2025. The letter identified Kennecott’s Bingham Canyon Mine and Copperton
Concentrator as a potential major source for ozone (VOCs and NOx as
precursors). This letter outlines that the Bingham Canyon Mine and Copperton
Concentrator are not major sources under the serious nonattainament
classification.

The Bingham Canyon Mine and Copperton Concentrator are a single source for
Title V applicability, but the Copperton Concentrator operates under a separate
Approval Order from the Bingham Canyon Mine. Under R307 -101, a Major
Source is defined as
“Major Source” means, to the extent provided by the federal
Clean Air Act as applicable to Title R307:
(1) any stationary source of air pollutants which emits, or has the
potential to emit, one hundred tons per year or more of any
pollutant subject to regulation under the Clean Air Act; or
. . .
(b) any source located in Salt Lake or Davis Counties or in a
nonattainment area for ozone which emits, or has the potential to
emit, VOC or nitrogen oxides in the amounts outlined in Section
182 of the federal Clean Air Act with respect to the severity of the
nonattainment area as outlined in Section 182 of the federal
Clean Air Act . . . .
Utah Admin. Code 307-101-2
Emissions of stationary sources (point sources) at the Bingham Canyon Mine and
the Copperton Concentrator are shown in Table 1. Table 1 shows that
aggregated emissions from stationary sources at the Bi ngham Canyon Mine and
Copperton Concentrator are below all major source thresholds and neither the
Rio Tinto Kennecott
4700 Daybreak Parkway
South Jordan, Utah
84009
Tel: [phone]

2 / 2
Bingham Canyon Mine nor Copperton Concentrator, individually or collectively,
approach any major source threshold. The Bingham Canyon Mine and Copperton
Concentrator are separate operating facilities and are therefore under separate
Approval Orders.
Table 1
Combined Emissions, Mine and Concentrator

Point Sources
at Bingham
Canyon Mine
Point Sources
at Copperton
Concentrator
Total Point
Source
Emissions
Major
Source
Thresholds
PM10 Emissions (tpy) 9.86 1.75 11.62 100
PM2.5 Emissions (tpy) 1.68 1.09 2.77 70
SO2 Emissions (tpy) 0.003 0.02 0.02 100
NOX Emissions (tpy) 2.01 6.83 8.84 50
CO Emissions (tpy) 3.97 3.36 7.33 100
VOC Emissions (tpy) 1.81 1.89 3.70 50

Based on emissions information listed in Table 1, the Bingham Canyon Mine and
Copperton Concentrator are a minor source. As it has done as part of previous
SIP planning, Kennecott will however participate in the ozone SIP process and
submit a RACT analysis for these facilities. Despite Kennecott’s participation in
the ozone SIP process, Kennecott requests that the record clearly state that the
Bingham Canyon Mine and Copperton Concentrator are minor sources.
If you have questions, please contact me at [e-mail] .

Yours sincerely,

Jenny Esker Evans
Principal Advisor, Air Quality

Rio Tinto Kennecott, 4700 Daybreak Parkway, South Jordan, Utah, 84009
February 9, 2024
Mr. Bryce Bird – Director
Environmental Engineer, Air Quality Policy Section
Utah Division of Air Quality
195 N 1950 W
Salt Lake City, UT 84116

Subject: Rio Tinto Kennecott Utah Copper
Notice of Intent Application for Bingham Canyon Mine

Dear Mr. Bird,

Rio Tinto Kennecott Utah Copper LLC (RTK) is submitting this Notice of Intent (NOI) application to modify
Bingham Canyon Mine Approval Order (AO) DAQE-AN105710047-21. RTK is proposing to install and
operate facilities associated with underground mining operations. The Proposed Project includes a new
Paste Plant with two storage silos and a mixer dust collector and four emergency standby generators to
support employee ventilation systems (Proposed Project).
Process Description
At the Bingham Canyon Mine, as the underground mining operations develop, RTK proposes to add
additional, auxiliary equipment to keep working conditions safe for employees. To ensure safety, RTK has
improved infrastructure in the area; however, to ensure backup for the life safety systems, RTK proposes
to add a total of four emergency standby generators. RTK plans to operate the proposed generators
during emergency periods only, as necessary.
The proposed storage silos, which are to be located at the bottom of the mine, will support Paste Plant
operations where RTK will make usable concrete from lime and other materials. The proposed silos will
store lime and will be equipped with bin vents to capture dust emissions. The mixer dust collector will
capture emissions from the paste plant mixer process area, where lime and other materials are blended
together to make useable concrete.
Emissions Information

Emergency Standby Generators
Emissions will be generated during testing and maintenance of standby emergency generators. Three of
the generators will be 2,000-kilowatt (kW) engines and the fourth will be a 3,250-kW engine. The
generators will be equipped with U.S. Environmental Protection Agency (EPA) Tier 4 certified engines.
The hours of operation for the generators will be limited to 100 hours per year for routine testing and
maintenance purposes. Emissions are estimated using DieselNet Tier 4 emissions standards. Emissions
of sulfur oxide (SOX) are estimated using a mass balance from AP-42 Fifth Edition, Section 3.4, Table
3.4-1 (EPA 1996) and assuming the use of ultra-low sulfur diesel with a maximum sulfur content of
0.0015 percent by weight. Emissions of hazardous air pollutants (HAPs) are estimated using a
combination of emission factors from AP-42 Fifth Edition, Section 3.4, Tables 3.4-3 and 3.4-4 (EPA 1996)
and Supplemental Instructions for Reporting Procedures for AB2588 Facilities for Reporting their
Rio Tinto Kennecott
4700 Daybreak Parkway
South Jordan, Utah 84009
Tel: [phone]

2 / 6
Quadrennial Air Toxics Emission Inventory, Table B-2 for Stationary and Portable Internal Combustion
Engines (South Coast Air Quality Management District 2016). Greenhouse gas emissions are estimated
using the methodology outlined in 40 Code of Federal Regulations (CFR) 98.33, Equations C-2a and C-
9a.
Proposed Project emissions are summarized in Table 1. The emissions calculations are included in
Attachment A.
Storage Silos
The two proposed lime storage silos are to be equipped with bin vents to capture particulate emissions
from the transfer of material. PM10 and PM2.5 emissions are estimated using values provided in similar
filter engineering documentation specifications and good engineering judgement. The silos will also be
located within the pit influence boundary, and therefore the pit escape factor is used in emission
calculations. Proposed Project emissions are summarized in Table 1. The emissions calculations are
included in Attachment A.
Mixer Dust Collector
The paste plant mixer is to be equipped with a baghouse to capture particulate emissions from the mixing
process. PM10 and PM2.5 emissions are estimated using values provided in similar filter engineering
documentation specifications and good engineering judgement. The dust collector will also be located
within the pit influence boundary, and therefore the pit escape factor is used in emission calculations.
Proposed Project emissions are summarized in Table 1. The emissions calculations are included in
Attachment A.
Table 1. Summary of Proposed Project Emissions
Potential Emissions in Tons Per Year
Source PM10 PM2.5 SOX NOX VOC CO HAP CO2e
2,000-kW Standby
Generators
1.98E-02 1.98E-02 4.95E-03 4.50E-01 1.26E-01 2.34E+00 3.16E-02 4.70E+02
3,250-kW Standby
Generator
1.06E-02 1.06E-02 2.64E-03 2.40E-01 6.72E-02 1.25E+00 1.66E-02 2.48E+02
Storage Silos 3.18E-01 1.67E-01 - - - - - -
Mixer Dust
Collector
5.92E-02 3.11E-02 - - - - - -
Total Emissions 4.07E-01 2.28E-01 7.60E-03 6.90E-01 1.93E-01 3.59E+00 4.82E-02 7.19E+02
Notes:
- = not applicable
CO = carbon monoxide
CO2e = carbon dioxide equivalent
HAP = hazardous air pollutant
NOx = nitrogen oxide
PM2.5 = particulate matter less than 2.5 micrometers in diameter
PM10 = particulate matter less than 10 micrometers in diameter
SOx = sulfur oxide
VOC = volatile organic compound
Best Available Control Technology Analyses
As required by Utah Administrative Code (UAC) R307-401-8(1)(a), the Director will issue an AO if it is
determined through plan review that the following condition has been met: the degree of pollution control

3 / 6
for emissions, to include fugitive emissions and fugitive dust, is at least best available control technology
(BACT) except as otherwise provided in UAC R307. Utah has adopted the emissions control BACT
process described in 40 Code of Federal Regulations 52.21(j) and incorporated by reference into
UAC R307-405-11.
BACT Analysis for Emergency Standby Generators
Combustion of diesel fuel from the use of the emergency standby generators will generate emissions.
The following presents a BACT analysis for the proposed standby generators:
 Step 1—Identify All Control Technologies. Potential emission control technologies identified in the
RACT/BACT/LAER Clearinghouse (RBLC) and California Air Resources Board (CARB) for similar-
sized diesel standby generators include implementing good combustion practices, limiting hours of
operation, and limiting the sulfur content of diesel fuel to 0.0015 percent. Certification and compliance
with applicable New Source Performance Standards (NSPS) are acceptable means of demonstrating
BACT for emergency fire pumps.
 Step 2—Eliminate Technically Infeasible Options. Not applicable as all identified control
technologies are technically feasible.
 Step 3 and Step 4—Rank Remaining Control Technologies by Control Effectiveness and
Evaluate Most Effective Controls and Document Results. Complying with 40 CFR Subpart IIII
requirements, implementing good combustion practices, limiting hours of operation, and using ultra-
low sulfur diesel are effective BACT in minimizing emissions from these sources.
 Step 5—Select BACT. Complying with 40 CFR Subpart IIII requirements and NSPS, implementing
good combustion practices, limiting hours of operation to no more than 100 hours, and limiting the
sulfur content of fuel to 0.0015 percent, are identified as BACT for the emergency standby diesel
generators.
BACT Analysis for Storage Silos
Particulate emissions will be emitted from the lime storage silos. The following presents a BACT analysis
for the proposed storage silos:
 Step 1—Identify All Control Technologies. The RBLC and CARB databases identify vent
filters/baghouses and enclosures as possible control technologies for limiting emissions from storage
silos.
 Step 2—Eliminate Technically Infeasible Options. Not applicable as all identified control
technologies are technically feasible.
 Step 3 and Step 4—Rank Remaining Control Technologies by Control Effectiveness and
Evaluate Most Effective Controls and Document Results. Baghouses are more effective than
enclosures in minimizing emissions from storage silos.
 Step 5—Select BACT. Based on this analysis and review of EPA’s RBLC database, the use of
baghouses is selected as BACT for the storage silos.
BACT Analysis for Mixer Dust Collector
Particulate emissions will be emitted from the mixer dust collector. The following presents a BACT
analysis for the proposed process:
 Step 1—Identify All Control Technologies. The RBLC and CARB databases identify vent
filters/baghouses and enclosures as possible control technologies for limiting emissions from the lime
mixing process.
 Step 2—Eliminate Technically Infeasible Options. Not applicable as all identified control
technologies are technically feasible.

4 / 6
 Step 3 and Step 4—Rank Remaining Control Technologies by Control Effectiveness and
Evaluate Most Effective Controls and Document Results. Baghouses are more effective than
enclosures in minimizing emissions from the mixing process.
 Step 5—Select BACT. Based on this analysis and review of EPA’s RBLC database, the use of
baghouses is selected as BACT for the mixer process.
Modeling Analysis
RTK has performed an air dispersion modeling analysis using AERMOD for PM10 and nitrogen dioxide
(NO2), as discussed in conversations with the Utah Division of Air Quality. The modeled results from this
analysis were compared to the applicable significant impact levels (SILs). The predicted impacts for the
Proposed Project are less than the respective SILs. Therefore, the NO2 and PM10 impacts from the
Project are not significant and would not cause or contribute to a violation of the National Ambient Air
Quality Standards. The results from this analysis are included in Attachment B.
RTK looks forward to working with the Utah Division of Air Quality on this NOI application. Should you
have any questions, please feel free to contact me at [phone].
Yours sincerely,

Jenny Esker
Principal Advisor, Air Quality Permitting and Compliance

Attachment A
Emissions Calculations

Emission Sources PM10 PM2.5 SOX NOX VOC CO HAP CO2e
2,000-kW Standby Generators 1.98E-02 1.98E-02 4.95E-03 0.450 1.26E-01 2.34E+00 3.16E-02 4.70E+02
3,250-kW Standby Generators 1.06E-02 1.06E-02 2.64E-03 0.240 6.72E-02 1.25E+00 1.66E-02 2.48E+02
Storage Silos 3.18E-01 1.67E-01 - - - - - -
Mixer Dust Collector 5.92E-02 3.11E-02 - - - - - -
Total Project Emissions 4.07E-01 2.28E-01 7.60E-03 6.90E-01 1.93E-01 3.59E+00 4.82E-02 7.19E+02
Current BCM PTEs 1,519.21 369.21 7.43 5,842.11 314.13 1,707.70 1.74 8,320.18
Post Project BCM PTEs 1,519.62 369.44 7.44 5,842.80 314.32 1,711.29 1.79 9,038.74
PTEs taken from AO DAQE-AN105710047-21.
Notes:
- = not applicable
AO = Approval Order
BCM = Bingham Canyon Mine
CO = carbon monoxide
CO2e = carbon dioxide equivalent
HAP = hazardous air pollutant
kW = kilowatt
NOx = nitrogen oxide
PM2.5 = particulate matter less than 2.5 micrometers in diameter
PM10 = particulate matter less than 10 micrometers in diameter
PTE = potential to emit
SOx = sulfur oxide
VOC = volatile organic compound
TABLE A-1
Potential to Emit Summary
Paste Plant Notice of Intent Application
Potential Emissions in Tons Per Year
230510090319_f0a713eb 1 of 1
Source Type Annual Hours of
Operation Quanitity Rating (hp) Rating (kW) Fuel Use (gal/hr)
PM10
Emissions
(tpy)
PM2.5
Emissions
(tpy)
SOX
Emissions
(tpy)
NOX
Emissions
(tpy)
VOC
Emissions
(tpy)
CO
Emissions
(tpy)
Total HAP
Emissions
(tpy)
Paste Plant Standby
Generators 100 3 2721 2000 138.9 0.02 0.02 4.95E-03 0.45 0.13 2.34 3.16E-02
Note:
Engines are EPA Tier 4
GHG Emissions Calculations
Source Annual Hours of
Operation
Fuel Use
(gal/hr)
CO2 Emissions
(tpy)
CH4 Emissions
(tpy)
N2O Emissions
(tpy)
CO2e
Emissions
(tpy)
Paste Plant Standby
Generators 100 138.9 468.81 1.90E-02 3.80E-03 470.42
Notes:
Conversion 0.746 kw/hp
Power conversion 3.412 Btu/hr per Watt
Grams to lb conversion 0.002204624 lb/gram 453.592
Fuel consumption taken from manufacturer's specifications, assuming standby at 60 Hz, 100% load (pg 3, spec); Bhp rating taken from performance data at 100% load (pg 5, emiss spec).
Emissions taken from rated speed nominal data versus site variation data.
Assume PM10=PM2.5
Pollutant Emission Factor Units Source
PM10 0.022 g/bhp-hr DieselNet Tier 4 specs for gensets >2015, >560kW
PM2.5 0.022 g/bhp-hr DieselNet Tier 4 specs for gensets >2015, >560kW
SOx 0.000012135 lb/hp-hr AP-42 Chapter 3 Table 3.4-1
NOx 0.5 g/bhp-hr DieselNet Tier 4 specs for gensets >2015, >560kW
VOC 0.14 g/bhp-hr DieselNet Tier 4 specs for gensets >2015, >560kW
CO 2.6 g/bhp-hr DieselNet Tier 4 specs for gensets >2015, >560kW
CO2 73.96 kg/MMBtu 40 CFR 98.33 Table C-1
CH4 0.003 kg/MMBtu 40 CFR 98.33 Table C-2
N2O 0.0006 kg/MMBtu 40 CFR 98.33 Table C-2
Diesel heat rating 0.138 MMBtu/gal 40 CFR 98.33 Table C-1
Conversion 1.1023 ton/tonne
Sulfur content of diesel 0.0015 percent
GHG emissions are calculated using 40 CFR 98.33 Equation C-2a and C-9a.
DieselNet standards can be found at: https://dieselnet.com/standards/us/nonroad.php#tier4.
TABLE A-2
2,000-kW Standby Generators
Paste Plant Notice of Intent Application
230510090319_f0a713eb 1 of 2
TABLE A-2
2,000-kW Standby Generators
Paste Plant Notice of Intent Application
HAP Emissions
Pollutant
AP-42 Emission
Factor
(lb/MMBtu)a
SCAQMD
Emission
Factor
(lb/MMBtu)b
SCAQMD
Emission Factor
(lb/1000 gal)c
Proposed
Emission Factor
(lb/MMBtu)d
Emissions
(lbs/yr)
Emissions
(tons/yr)
Benzene 7.76E-04 1.35E-03 1.86E-01 7.76E-04 4.46E+00 2.23E-03
Toluene 2.81E-04 7.64E-04 1.05E-01 2.81E-04 1.62E+00 8.08E-04
Xylenes 1.93E-04 3.07E-04 4.24E-02 1.93E-04 1.11E+00 5.55E-04
1,3-Butadiene --1.58E-03 2.17E-01 1.58E-03 9.06E+00 4.53E-03
Formaldehyde 7.89E-05 1.25E-02 1.73E+00 7.89E-05 4.54E-01 2.27E-04
Acetaldehyde 2.52E-05 5.68E-03 7.83E-01 2.52E-05 1.45E-01 7.25E-05
Acrolein 7.88E-06 2.46E-04 3.39E-02 7.88E-06 4.53E-02 2.27E-05
Naphthalene 1.30E-04 1.43E-04 1.97E-02 1.30E-04 7.48E-01 3.74E-04
Acenaphthylene 9.23E-06 ----9.23E-06 5.31E-02 2.65E-05
Acenaphthene 4.68E-06 ----4.68E-06 2.69E-02 1.35E-05
Fluorene 1.28E-05 ----1.28E-05 7.36E-02 3.68E-05
Phenanthrene 4.08E-05 ----4.08E-05 2.35E-01 1.17E-04
Anthracene 1.23E-06 ----1.23E-06 7.07E-03 3.54E-06
Fluoranthene 4.03E-06 ----4.03E-06 2.32E-02 1.16E-05
Pyrene 3.71E-06 ----3.71E-06 2.13E-02 1.07E-05
Benzo(a)anthracene 6.22E-07 ----6.22E-07 3.58E-03 1.79E-06
Chrysene 1.53E-06 ----1.53E-06 8.80E-03 4.40E-06
Benzo(b)fluoranthene 1.11E-06 ----1.11E-06 6.38E-03 3.19E-06
Benzo(k)fluoranthene 2.18E-07 ----2.18E-07 1.25E-03 6.27E-07
Benzo(a)pyrene 2.57E-07 ----2.57E-07 1.48E-03 7.39E-07
Indeno(1,2,3-cd)pyrene 4.14E-07 ----4.14E-07 2.38E-03 1.19E-06
Dibenz(a,h)anthracene 3.46E-07 ----3.46E-07 1.99E-03 9.95E-07
Benzo(g,h,i)perylene 5.56E-07 ----5.56E-07 3.20E-03 1.60E-06
TOTAL PAH 2.12E-04 4.05E-04 5.59E-02 2.12E-04 1.22E+00 6.10E-04
Cadmium --1.09E-05 1.50E-03 1.09E-05 6.25E-02 3.13E-05
Hexavalent Chromium --7.25E-07 1.00E-04 7.25E-07 4.17E-03 2.08E-06
Arsenic --1.16E-05 1.60E-03 1.16E-05 6.67E-02 3.33E-05
Lead --6.01E-05 8.30E-03 6.01E-05 3.46E-01 1.73E-04
Nickel --2.83E-05 3.90E-03 2.83E-05 1.63E-01 8.13E-05
Ammonia f --5.80E-03 8.00E-01 5.80E-03 3.33E+01 1.67E-02
Copper --2.97E-05 4.10E-03 2.97E-05 1.71E-01 8.54E-05
Ethylbenzene --7.90E-05 1.09E-02 7.90E-05 4.54E-01 2.27E-04
Hexane --1.95E-04 2.69E-02 1.95E-04 1.12E+00 5.60E-04
Hydrogen Chloride --1.35E-03 1.86E-01 1.35E-03 7.76E+00 3.88E-03
Manganese --2.25E-05 3.10E-03 2.25E-05 1.29E-01 6.46E-05
Mercury --1.45E-05 2.00E-03 1.45E-05 8.33E-02 4.17E-05
Selenium --1.59E-05 2.20E-03 1.59E-05 9.17E-02 4.58E-05
a Emission factors from AP-42 Chapter 3, Table 3.4-3 and 3.4-4.Total 63.12 3.16E-02
b Emission factors converted from lb/1000 gallons to lb/MMBtu using the 40 CFR 98.33 default HHV of 0.138 MMBtu/Gal.
d Proposed emission factors reflect the minimum emission factor between AP-42 and SCAQMD.
c Emission factors from South Coast Air Quality Management District Supplemental Instructions for Reporting Procedures for AB2588 Facilities
for Reporting their Quadrennial Air Toxics Emissions Inventory, Table B-2 for Stationary and Portable Internal Combustion Engines
(http://www.aqmd.gov/docs/default-source/planning/annual-emission-reporting/supplemental-instructions-for-ab2588-facilities.pdf?sfvrsn=12).
230510090319_f0a713eb 2 of 2
Source Type Annual Hours of
Operation Quanitity Rating (hp) Rating (kW) Fuel Use (gal/hr)
PM10
Emissions
(tpy)
PM2.5
Emissions
(tpy)
SOX
Emissions
(tpy)
NOX
Emissions
(tpy)
VOC
Emissions
(tpy)
CO
Emissions
(tpy)
Total HAP
Emissions
(tpy)
Paste Plant Standby
Generators 100 1 4357 3250 219.8 0.01 0.01 2.64E-03 0.24 0.07 1.25 1.66E-02
Note:
Engines are EPA Tier 4.
GHG Emissions Calculations
Source Annual Hours of
Operation
Fuel Use
(gal/hr)
CO2 Emissions
(tpy)
CH4 Emissions
(tpy)
N2O Emissions
(tpy)
CO2e
Emissions
(tpy)
Paste Plant Standby
Generators 100 219.8 247.29 1.00E-02 2.01E-03 248.14
Notes:
Conversion 0.746 kw/hp
Grams to lb conversion 0.002204624 lb/gram
Fuel consumption taken from manufacturer's specifications, assuming standby at 60 Hz, 100% load (pg 2, spec).
Emissions taken from rated speed nominal data versus site variation data.
Assume PM10=PM2.5
Pollutant Emission Factor Units Source
PM10 0.022 g/bhp-hr DieselNet Tier 4 specs for gensets >2015, >560kW
PM2.5 0.022 g/bhp-hr DieselNet Tier 4 specs for gensets >2015, >560kW
SOx 0.000012135 lb/hp-hr AP-42 Chapter 3 Table 3.4-1
NOx 0.5 g/bhp-hr DieselNet Tier 4 specs for gensets >2015, >560kW
VOC 0.14 g/bhp-hr DieselNet Tier 4 specs for gensets >2015, >560kW
CO 2.6 g/bhp-hr DieselNet Tier 4 specs for gensets >2015, >560kW
CO2 73.96 kg/MMBtu 40 CFR 98.33 Table C-1
CH4 0.003 kg/MMBtu 40 CFR 98.33 Table C-2
N2O 0.0006 kg/MMBtu 40 CFR 98.33 Table C-2
Diesel heat rating 0.138 MMBtu/gal 40 CFR 98.33 Table C-1
Conversion 1.1023 ton/tonne
Sulfur content of diesel 0.0015 percent
GHG emissions are calculated using 40 CFR 98.33 Equation C-2a and C-9a.
DieselNet standards can be found at: https://dieselnet.com/standards/us/nonroad.php#tier4.
TABLE A-3
3,250-kW Standby Generator
Paste Plant Notice of Intent Application
230510090319_f0a713eb 1 of 2
TABLE A-3
3,250-kW Standby Generator
Paste Plant Notice of Intent Application
HAP Emissions
Pollutant
AP-42 Emission
Factor
(lb/MMBtu)a
SCAQMD
Emission
Factor
(lb/MMBtu)b
SCAQMD
Emission Factor
(lb/1000 gal)c
Proposed
Emission Factor
(lb/MMBtu)d
Emissions
(lbs/yr)
Emissions
(tons/yr)
Benzene 7.76E-04 1.35E-03 1.86E-01 7.76E-04 2.35E+00 1.18E-03
Toluene 2.81E-04 7.64E-04 1.05E-01 2.81E-04 8.52E-01 4.26E-04
Xylenes 1.93E-04 3.07E-04 4.24E-02 1.93E-04 5.85E-01 2.93E-04
1,3-Butadiene --1.58E-03 2.17E-01 1.58E-03 4.78E+00 2.39E-03
Formaldehyde 7.89E-05 1.25E-02 1.73E+00 7.89E-05 2.39E-01 1.20E-04
Acetaldehyde 2.52E-05 5.68E-03 7.83E-01 2.52E-05 7.64E-02 3.82E-05
Acrolein 7.88E-06 2.46E-04 3.39E-02 7.88E-06 2.39E-02 1.20E-05
Naphthalene 1.30E-04 1.43E-04 1.97E-02 1.30E-04 3.94E-01 1.97E-04
Acenaphthylene 9.23E-06 ----9.23E-06 2.80E-02 1.40E-05
Acenaphthene 4.68E-06 ----4.68E-06 1.42E-02 7.10E-06
Fluorene 1.28E-05 ----1.28E-05 3.88E-02 1.94E-05
Phenanthrene 4.08E-05 ----4.08E-05 1.24E-01 6.19E-05
Anthracene 1.23E-06 ----1.23E-06 3.73E-03 1.87E-06
Fluoranthene 4.03E-06 ----4.03E-06 1.22E-02 6.11E-06
Pyrene 3.71E-06 ----3.71E-06 1.13E-02 5.63E-06
Benzo(a)anthracene 6.22E-07 ----6.22E-07 1.89E-03 9.43E-07
Chrysene 1.53E-06 ----1.53E-06 4.64E-03 2.32E-06
Benzo(b)fluoranthene 1.11E-06 ----1.11E-06 3.37E-03 1.68E-06
Benzo(k)fluoranthene 2.18E-07 ----2.18E-07 6.61E-04 3.31E-07
Benzo(a)pyrene 2.57E-07 ----2.57E-07 7.80E-04 3.90E-07
Indeno(1,2,3-cd)pyrene 4.14E-07 ----4.14E-07 1.26E-03 6.28E-07
Dibenz(a,h)anthracene 3.46E-07 ----3.46E-07 1.05E-03 5.25E-07
Benzo(g,h,i)perylene 5.56E-07 ----5.56E-07 1.69E-03 8.43E-07
TOTAL PAH 2.12E-04 4.05E-04 5.59E-02 2.12E-04 6.43E-01 3.22E-04
Cadmium --1.09E-05 1.50E-03 1.09E-05 3.30E-02 1.65E-05
Hexavalent Chromium --7.25E-07 1.00E-04 7.25E-07 2.20E-03 1.10E-06
Arsenic --1.16E-05 1.60E-03 1.16E-05 3.52E-02 1.76E-05
Lead --6.01E-05 8.30E-03 6.01E-05 1.82E-01 9.12E-05
Nickel --2.83E-05 3.90E-03 2.83E-05 8.57E-02 4.29E-05
Ammonia f --5.80E-03 8.00E-01 5.80E-03 1.76E+01 8.79E-03
Copper --2.97E-05 4.10E-03 2.97E-05 9.01E-02 4.51E-05
Ethylbenzene --7.90E-05 1.09E-02 7.90E-05 2.40E-01 1.20E-04
Hexane --1.95E-04 2.69E-02 1.95E-04 5.91E-01 2.96E-04
Hydrogen Chloride --1.35E-03 1.86E-01 1.35E-03 4.09E+00 2.05E-03
Manganese --2.25E-05 3.10E-03 2.25E-05 6.81E-02 3.41E-05
Mercury --1.45E-05 2.00E-03 1.45E-05 4.40E-02 2.20E-05
Selenium --1.59E-05 2.20E-03 1.59E-05 4.84E-02 2.42E-05
a Emission factors from AP-42 Chapter 3, Table 3.4-3 and 3.4-4.Total 33.29 1.66E-02
b Emission factors converted from lb/1000 gallons to lb/MMBtu using the 40 CFR 98.33 default HHV of 0.138 MMBtu/Gal.
d Proposed emission factors reflect the minimum emission factor between AP-42 and SCAQMD.
c Emission factors from South Coast Air Quality Management District Supplemental Instructions for Reporting Procedures for AB2588
Facilities for Reporting their Quadrennial Air Toxics Emissions Inventory, Table B-2 for Stationary and Portable Internal Combustion Engines
(http://www.aqmd.gov/docs/default-source/planning/annual-emission-reporting/supplemental-instructions-for-ab2588-facilities.pdf?sfvrsn=12).
230510090319_f0a713eb 2 of 2
Source Name Quantity
PM10 Emission
Factor (gr/scf)
Design Flow
Rate (acfm)
Design Flow
Rate (scfm)
PM10 Emissions
(lb/hr)
PM2.5 Emissions
(lb/hr)
PM10 Pit
Escape Factor
(%)
PM2.5 Pit
Escape Factor
(%)
Controlled
PM10 Emissions
(lb/hr)
Controlled
PM2.5
Emissions
(lb/hr)
Controlled
PM10
Emissions
(tpy)
Controlled
PM2.5
Emissions
(tpy)
Control
System and
Comments
Storage Silos 2 0.02 1,075 1,059 3.63E-01 1.81E-01 20 21 7.26E-02 3.81E-02 3.18E-01 1.67E-01 Bin vents
Notes:
- Emissions from baghouse dust collector based on information provided by RTK in email correspondence.
- PM2.5 emissions are estimated to be 50% of PM10 emissions.
- SCFM was converted from ACFM using the below equation and the following assumptions:
SCFM = ACFM * (14.7+PSIG/14.7) * (520/ 460+T)
P = PSIG of process, assume to be 0
T = Actual air temperature in F, assume to be 68F
Assumes STP, 60F and 14.7 psia
- Annual Hours of Operation 8760
TABLE A-4
Storage Silos
Paste Plant Notice of Intent Application
230510090319_f0a713eb 1 of 1
Source Name Quantity
PM10 Emission
Factor (gr/scf)
Design Flow
Rate (acfm)
Design Flow
Rate (scfm)
PM10 Emissions
(lb/hr)
PM2.5 Emissions
(lb/hr)
PM10 Pit
Escape Factor
(%)
PM2.5 Pit
Escape Factor
(%)
Controlled
PM10 Emissions
(lb/hr)
Controlled
PM2.5
Emissions
(lb/hr)
Controlled
PM10
Emissions
(tpy)
Controlled
PM2.5
Emissions
(tpy)
Control
System and
Comments
Mixer Dust Collector 1 0.02 400 394 6.75E-02 3.38E-02 20 21 1.35E-02 7.09E-03 0.00E+00 0.00E+00 Baghouse
Notes:
- Emissions from paste mixer dust collector based on information provided by RTK in email correspondence.
- PM2.5 emissions are estimated to be 50% of PM10 emissions.
- SCFM was converted from ACFM using the below equation and the following assumptions:
SCFM = ACFM * (14.7+PSIG/14.7) * (520/ 460+T)
P = PSIG of process, assume to be 0
T = Actual air temperature in F, assume to be 68F
Assumes STP, 60F and 14.7 psia
- Annual Hours of Operation: 8760 .
TABLE A-5
Mixer Duster Collector
Paste Plant Notice of Intent Application
230510090319_f0a713eb 1 of 1

Attachment B
Modeling Analysis Results

Memorandum

Jacobs
230510090319_f0a713eb
1

Bingham Canyon Mine Paste Plant Notice of Intent: Air Dispersion Modeling Report
Date: January 4, 2024 Jacobs
6440 S. Millrock Drive
Suite 300
Holladay, UT 84121
United States
United States
T +1385.474.8500
www.jacobs.com
Project name: Notice of Intent for Bingham Canyon Mine
Attention: Jenny Esker/RTK
Company: Rio Tinto Kennecott Utah Copper LLC
Prepared by: Jacobs

1. Introduction
Rio Tinto Kennecott Utah Copper LLC (RTK) is submitting a Notice of Intent (NOI) application to modify
Bingham Canyon Mine Approval Order (AO) DAQE-AN105710047-21. RTK proposes to add auxiliary
equipment to the Paste Plant, specifically four emergency standby generators, two storage silos, and one
mixer dust collector to support the underground mining operations (Proposed Project). The storage silos
will be equipped with baghouses. Details regarding the process, associated emissions, and best available
control technology (BACT) analysis can be found in the NOI application.
Discussions with the Utah Department of Air Quality (UDAQ) on April 11, 2023, indicated an air dispersion
modeling analysis is required for particulate matter less than 10 micrometers in diameter (PM10) and
nitrogen dioxide (NO2). This modeling report was prepared in support of the NOI and outlines the
methodology and results of the modeling analysis for PM10 and NO2.
2. Project Emissions
The Proposed Project includes emissions from four (4) emergency generators, three (3) with a rated
capacity of two (2) megawatts (MW) and one (1) with a rated capacity of 3.25 MW. Each of these
generators will be powered by a U.S. Environmental Protection Agency (EPA) Tier 4 certified engine with a
rated capacity of approximately 2,721 horsepower (hp) for the 2 MW units and 4,357 hp for the 3.25 MW
unit. Each generator has an assumed operation of no more than 100 hours per year for maintenance and
testing. Maintenance and testing activities would occur for one unit at any given time. Additionally, the
Proposed Project will include mixer dust collector and two new lime storage silos equipped with
baghouses to capture and control particulate emissions from the transfer of material. Each silo and the
mixer dust collector is assumed to operate 8,760 hours per year.
All proposed sources in the NOI will be located within the Bingham Canyon Mine (BCM) pit and utilize the
pit escape fraction for non-combustion-related particulate emissions; this includes emissions from the
lime storage silos as outlined in the approval order.
A summary of the controlled emissions associated with the Proposed Project, as presented in the NOI
application, is provided in Table 2-1. Additional details regarding the emission estimates can be found in
the NOI application.

Memorandum

Jacobs
230510090319_f0a713eb
2

Table 2-1. Summary of Proposed Project Emissions
Source
Potential Emissions in Tons per Year
PM10 PM2.5 SOX NOX VOC CO HAP
Standby
Generators 3.04E-02 3.04E-02 7.60E-03 6.90E-01 1.93E-01 3.59E+00 4.82E-02
Storage
Silos 3.18E-01 1.67E-01 — — — — —
Mixer Dust
Collector
5.92E-02 3.11E-02 — — — — —
Total
Emissions 4.07E-01 2.28E-01 7.60E-03 6.90E-01 1.93E-01 3.59E+00 4.82E-02
Notes:
- = not applicable
CO = carbon monoxide
HAP = hazardous air pollutant
NOx = nitrogen oxide
PM2.5 = particulate matter less than 2.5 micrometers in diameter
SOx = sulfur oxide
VOC = volatile organic compound
3. Air Quality Dispersion Modeling Analysis
Section 3.1 describes the air dispersion modeling methodology. Section 3.2 describes the source
characterization.
3.1 Air Dispersion Modeling Methodology
This section presents the methodology employed by Jacobs to conduct the air dispersion modeling.
3.1.1 Meteorological Data
Five years of processed meteorological data were provided by UDAQ for the Herriman Meteorological
Station, which is owned and operated by UDAQ and located at 14058 Mirabella Drive in Herriman.
The dataset represents the five-year meteorological period from 2016 to 2020. UDAQ indicated this
meteorological dataset is most representative for the BCM based on proximity and surrounding geography.
The predominate wind directions for this meteorological dataset are winds blowing from the
west--southwest and south. The average wind speed for the 5-year meteorological period (2016-2020) is
3.05 meters per second. A wind rose for this meteorological dataset is depicted in Figure 3-1.

Memorandum

Jacobs
230510090319_f0a713eb
3

Figure 3-1. UDAQ Herriman Station Meteorological Data Wind Rose, 2016 through 2020
3.1.2 Receptors
The ambient air boundary was defined based on parcel data provided to Jacobs; these data delineate what
areas are under RTK ownership or within RTK controlled access areas. Parcels owned by RTK are not
considered ambient air and therefore had no receptors placed within them. Other features such as publicly
accessible roads and highways that run through RTK-owned parcels were considered ambient air and
therefore receptors were placed within the parcels. The selection of receptors in AERMOD for this analysis
consisted of nested cartesian grids with the following spacing from the main RTK parcel:
 Discrete receptors every 25 meters around the ambient air boundary
 25-meter spacing from the ambient air boundary to 100 meters from the grid origin
 50-meter spacing from beyond 100 meters to 500 meters from the grid origin
 100-meter spacing from beyond 500 meters to 1,000 meters from the grid origin
 500-meter spacing from beyond 1,000 meters to 5,000 meters from the grid origin
 1,000-meter spacing from beyond 5,000 meters to 15,000 meters from the grid origin

Memorandum

Jacobs
230510090319_f0a713eb
4

The ambient air boundary and receptor grid used in this modeling analysis are shown in Figure 3-2.
All receptors are expressed in the Universal Transverse Mercator North American Datum 1983, Zone 12
coordinate system. U.S. Geological Survey National Elevation Dataset terrain data were used in conjunction
with the AERMAP preprocessor (Version 18081) to determine receptor elevations and terrain maxima.

Figure 3-2. Air Dispersion Modeling Analysis Reduced Receptor Grid

Memorandum

Jacobs
230510090319_f0a713eb
5

3.1.3 Building Downwash
Building downwash effects in AERMOD are applicable to the point source type and take into account stack
dimensions, building dimensions, and building elevations. This modeling analysis does not include any
point sources; therefore, building downwash effects were not considered.
3.1.4 Nitrogen Dioxide Modeling Procedures
The Guideline on Air Quality Models, Appendix W to 40 CFR Part 51 (EPA 2017), recommends a tiered
screening approach to characterize the conversion of total NOX from the proposed source to NO2. A Tier 1
approach assumes a 100 percent conversion of total NOx to NO2. The Tier 2 approach allows for the use of
the Ambient Ratio Method- 2 (ARM2). The Tier 1 and Tier 2 options do not require EPA approval.
A Tier 2 approach was applied using ARM2 options in AERMOD to calculate ambient NO2 concentrations
surrounding the site by applying a default NO2/NOx equilibrium ratio of 0.90 and an NO2/NOx ISR of 0.1 as
indicated in discussions with UDAQ.
3.2 Source Characterization
The model layout and source characterization in this modeling analysis were developed based on the data
provided for the Proposed Project and the BCM. The model source layout for each of the scenarios is
shown on Figure 3-2. The specific source parameters and characterization for each source type are
outlined in the following section.
Generator maintenance and testing operations would occur during the hours of 8 AM and 8 PM. As a
result, the 1-hour and annual NO2 modeling utilized the hour of day emission factor within AERMOD to
account for these operating hours. Specifically, the 1-hour analysis assumed a single-highest emitting
generator, and the annual analysis assumes all generators. The 24-hour PM10 analysis conservatively
assumes 24 hours of generator operation of the single-highest emitting generator and the storage silos
and mixer dust collector.
3.2.1 BCM Pit
The BCM pit is represented as a single AREAPOLY source in the model based on the BCM pit influence
boundary (PIB). All emissions from sources within the PIB are modeled through this AREAPOLY source,
which represents the top of the BCM pit. The approach of modeling the BCM pit as an AREAPOLY source
has been validated using computational fluid dynamics and through historical use in modeling analyses
for UDAQ, including State Implementation Plan analyses. The source parameters modeled for this source
are shown in Table 3-1.
Table 3-1. BCM Pit Source Parameters
Source
ID
Base Elevation
(m)a
Release Height
(m)
Number of
Vertices
Initial Vertical Dimension
(m)
PIT 2,329 0 89 0
a Base elevation was obtained from mine topographical data provided by RTK and processed with AERMAP Version 18081.
Note: m = meter(s)
The BCM pit emissions include all sources specified in the NOI as they are located within the BCM pit.
Details of the modeled emission rates are shown in Table 3-2.

Memorandum

Jacobs
230510090319_f0a713eb
6

Table 3-2. BCM Pit Source Emission Rates

Max Hourly PM10 Emissions
(lbs/hr)a
Max Hourly NO2 Emissions
(lbs/hr)b
Annual NO2 Emissions
(tpy)c
0.297 4.80 0.69
a Emission rate represents the maximum hourly emission rate, which includes the 3,250-kW generator as well as both lime storage silos and the mixer dust
collector for the PM10 analyses.
b Emission rate represents the maximum hourly emission rate, which includes one single 3,250-kW standby generator operating at a time for the 1-hour NO2
analyses.
c Emission rate represents the maximum annual emissions, which includes 100 hours per year for one single 3,250-kW standby generator operating at a time.
Notes:
lbs/hr = pound(s) per hour
tpy = ton(s) per year
4. Results
The modeled results from this analysis were compared to the applicable significant impact levels (SILs)
shown in Table 4-1. The predicted impacts for the Proposed Project are less than the respective SILs.
Therefore, the NO2 and PM10 from the Proposed Project are not significant (that is, less than the SIL) and
would not cause or contribute to a violation of the National Ambient Air Quality Standards. Figure 4-1
illustrates the point of maximum impact for each modeled pollutant and averaging period.
Table 4-1. Air Dispersion Modeling Analysis Results
Pollutant
Averaging
Period
Modeled Concentration
(µg/m3)
Significant Impact Level
(µg/m3)
Exceeds
SIL?
NO2 1-Houra 5.90 7.55 No
Annualb 0.00319 1 No
PM10 24-Hourc 0.09313 5 No
a Modeled concentration represents the maximum daily 1-hour average concentration averaged over the five modeled years (2016-2020).
b Modeled concentration represents the maximum annual average concentration during the five modeled years (2016-2020).
c Modeled concentration represents the maximum 24-hour average concentration during the five modeled years (2016-2020).
Note: µg/m3 = microgram(s) per cubic meter

Memorandum

Jacobs
230510090319_f0a713eb
7

Figure 4-1. Air Dispersion Modeling Analysis Points of Maximum Impact
5. Reference
U.S. Environmental Protection Agency (EPA). 2017. Appendix W of 40 CFR Part 51—Guideline On Air
Quality Models (Revised), Office of Air Quality Planning and Standards, Research Triangle Park, North
Carolina. January.