HomeMy WebLinkAboutDAQ-2024-0045531
DAQC-CI105710001-23
Site ID 10571 (B1)
MEMORANDUM
TO: FILE – RIO TINTO KENNECOTT UTAH COPPER LLC – Copperton
Concentrator
THROUGH: Chad Gilgen, Minor Source Compliance Section Manager
FROM: Connor Kijowski, Environmental Scientist
DATE: October 16, 2023
SUBJECT: FULL COMPLIANCE EVALUATION, Minor, Salt Lake County
INSPECTION DATE: August 9, 2023
SOURCE LOCATION: 8362 West 10200 South
Bingham Canyon, UT 84006
SOURCE CONTACTS: Sean Daly, Senior Environmental Advisor
801-204-2563; sean.daly3@riotinto.com
OPERATING STATUS: Operating normally at time of inspection.
PROCESS DESCRIPTION: The Copperton Concentrator receives ore from the Bingham
Canyon Mine by way of a 5-mile conveyor system, which dumps
and stockpiles inside an A-frame partial enclosure. From here,
the ore is conveyed to four SAG mills where it is ground to
liberate the copper, gold, silver, and molybdenite minerals from
the host rock. Ground ore under 5/8-inch passes through a
trammel screen to the ball mills for further grinding. Oversized
material is sent to two pebble crushing units. Pebbles are crushed
to an acceptable size and then routed back to the SAG mill.
After grinding, the desired ore minerals are selectively separated
from waste material by a process known as froth flotation.
Ground ore is transported to the flotation cells from the ball
mills, where it is mixed with air and chemicals that separate the
heavier minerals from the copper. The copper floats to the top of
the cell via air bubbles as a foam (froth). The primary product,
copper concentrate, is pumped to the Smelter through a 17-mile,
6-inch diameter pipeline. Waste materials (tailings slurry) flow
by gravity through a 48-inch concrete pipeline to the North
Impoundment.
The molybdenite recovery plant separates molybdenite from the
bulk copper/molybdenite concentrate. In this process, copper
minerals are depressed with sodium hydrosulfide while burner
oil is used to collect and float the molybdenite. Molybdenite
rougher concentrate is thickened and then reground in a 150 hp
) 1
2
verti-mill. This product is upgraded in the first cleaners and then
a bank of second cleaner column cells. Feed to the heat treatment
circuit is thickened and then further dewatered in a circuit
consisting of two disc vacuum filters and a heated oil pressure
filter. After conditioning, a frother is added just prior to the insol
(insoluble minerals) floatation cells. This froth is then passed
through additional cells for removal of the insol/copper material.
The froth from the cells, containing the molybdenite, is
neutralized and then thickened. The thickener underflow is
processed through a verti-mill and conditioner to improve the
final rejection of copper, iron, lead, and insol. The concentrate is
then transported to a wet high intensity magnetic separator for
copper removal prior to thickening. Although the cyanide leach
circuit is not currently operational, if necessary, the thickened,
final concentrate is processed in four cyanide leach tanks to
complete copper reduction. The cyanide leach process further
aids in the removal of the copper from the molybdenite
concentrate. The cyanide leach acts as a filtering agent that
allows the heavier copper minerals to separate from the
molybdenite. The leached product is then filtered in two plate
pressure filters for further dewatering and discharged into the
final molybdenite heated oil screw dryers. The final molybdenite
concentrate is stored in holding bins prior to packaging in 4200
lb. bags. Any minerals not recovered as molybdenite concentrate
in this circuit are combined with the copper concentrate and
delivered to the smelter. Except for the molybdenite recovery
circuit, which has its own control system including two
scrubbers, plant processes are controlled from the central control
room by a microprocessor-based control system. Several
baghouses control process streams from bag loading, laboratory
functions, and storage bins.
APPLICABLE REGULATIONS: Approval Order (AO) DAQE-ANI05710047-21, dated May 10,
2021
NSPS (Part 60) - LL: Standards of Performance for Metallic
Mineral Processing Plants
MACT (Part 63) - ZZZZ: National Emissions Standards for
Hazardous Air Pollutants for Stationary Reciprocating Internal
Combustion Engines,
SOURCE EVALUATION:
Name of Permittee: Permitted Location:
Rio Tinto Kennecott Utah Copper LLC - Mine &
Copperton Concentrator
4700 Daybreak Parkway 8362 West 10200 South
South Jordan, UT 84095 Bingham Canyon, UT 84006
SIC Code: 1021: (Copper Ores)
3
Section I: GENERAL PROVISIONS
I.1 All definitions, terms, abbreviations, and references used in this AO conform to those used in the
UAC R307 and 40 CFR. Unless noted otherwise, references cited in these AO conditions refer to
those rules. [R307-101]
I.2 The limits set forth in this AO shall not be exceeded without prior approval. [R307-401]
I.3 Modifications to the equipment or processes approved by this AO that could affect the emissions
covered by this AO must be reviewed and approved. [R307-401-1]
I.4 All records referenced in this AO or in other applicable rules, which are required to be kept by
the owner/operator, shall be made available to the Director or Director's representative upon
request, and the records shall include the 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.5 At all times, including periods of startup, shutdown, and malfunction, owners and operators shall,
to the extent practicable, maintain and operate any equipment approved under this AO, including
associated air pollution control equipment, in a manner consistent with good air pollution control
practice for minimizing emissions. Determination of whether acceptable operating and
maintenance procedures are being used will be based on information available to the Director
which may include, but is not limited to, monitoring results, opacity observations, review of
operating and maintenance procedures, and inspection of the source. All maintenance performed
on equipment authorized by this AO shall be recorded. [R307-401-4]
I.6 The owner/operator shall comply with UAC R307-107. General Requirements: Breakdowns.
[R307-107]
I.7 The owner/operator shall comply with UAC R307-150 Series. Emission Inventories. [R307-150]
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]
Status: In Compliance. The source appears to be in compliance with each condition of
Section I. A breakdown was reported March 2023, for the conveyor transfer point between
the mine and concentrator. Rio Tinto submitted a temporary relocation permit (C-300-23)
to install and operate a generator during maintenance. Proper notification was received
according to UAC R307-107. The 2022 Emission Inventory was submitted by the required
date and the values are included below.
Section II: SPECIAL PROVISIONS
II.A The approved installations shall consist of the following equipment:
II.A.1 Plant Wide
Copperton Concentrator
II.A.2 One (1) Feed Dryer Oil Heater
Feed dryer oil heater for product molybdenite dryer
Rated capacity: 5.7 MMBtu/hr
Fuel type: Natural gas
Product molybdenite dryer with venturi scrubber
4
II.A.3 One (1) Product Dryer Oil Heater
Product dryer oil heater* for product molybdenite dryer
Rated capacity: 2.2 MMBtu/hr
Fuel type: Natural gas
Product: molybdenite dryer with venturi scrubber
*This equipment is listed for informational purposes only.
II.A.4 Molybdenite Loading
Six (6) molybdenite storage bins
II.A.5 Molybdenite Storage
Two (2) molybdenite storage bins
II.A.6 Two (2) Cooling Towers
Closed-circuit fluid cooling tower for motors used in the grinding circuit.
II.A.7 Bag Loading
Molybdenite bag loading operations
II.A.8 Cleaning System
Vacuum cleaning system with baghouse
II.A.9 Ore Sorting Plant
Ore sorting baghouse and sample preparation baghouse
II.A.10 Metallurgical Laboratory
Two (2) baghouses
II.A.11 Three (3) Pebble Crushers
Pebble crushers with associated enclosed conveyors and enclosed drop points.
II.A.12 Degreasing Parts Washers
II.A.13 Four (4) Lime Silos
Controlled: bin vents
II.A.14 Three (3) Storage Tanks
Capacity: 25,000 gallons (each)
Contents: frother, collector, and fuel oil
II.A.15 One (1) Emergency Generator
Fueled: Liquid propane-fired
Maximum rating: 75 brake horsepower
II.A.16 Miscellaneous Combustion Sources
Natural gas-fired equipment including water heaters or comfort heaters that are each individually
rated at less than 5 MMBTU/hr. This equipment is listed for informational purposes only.
II.A.17 MH Pilot Plant
Feed Hopper
Conveyors
Baghouse on HM pilot ore treatment plant building with a control efficiency of 99%
II.A.18 Two (2) Lime Slaker Scrubbers
Type: Single stage
5
II.A.19 Cyanide Circuit
Two (2) sodium cyanide storage tanks
Capacity: 8,500 gallons (each)
Status: In Compliance. No unapproved equipment was observed. Additional information
provided below:
II.A.9: Removed in 2014,
II.A.11: Only two pebble crushers on site
II.A.13: Two lime silos installed
II.A.14: Collector is 11,00 gallons, fuel oil is used as a fluctuate and not as burner oil
II.B Requirements and Limitations
II.B.1 Plant Wide Requirements
II.B.1.a Visible emissions from the following emission points shall not exceed the following values:
A. Pebble crushers (subject to NSPS, Subpart LL) - 7% opacity for building exterior
B. Cone crusher (subject to NSPS, Subpart LL) - 10% opacity
C. Fugitive emission points (subject to NSPS, Subpart LL) - 10% opacity
D. Liquid propane (LP) emergency generator - 10% opacity
E. All other points - 10% opacity
F. Baghouse on molybdenite storage bins (subject to NSPS, Subpart LL) - 7% opacity
Opacity observations of emissions from stationary sources shall be conducted in accordance with
40 CFR 60, Appendix A, Method 9.
For sources that are subject to NSPS, opacity shall be determined by conducting observations in
accordance with 40 CFR 60.11(b) and 40 CFR 60, Appendix A, Method 9. [40 CFR 60 Subpart
LL, R307-305-3]
Status: In Compliance. No visible emissions were observed coming from any point or
fugitive emission source during the inspection. The source is aware of the limits.
II.B.1.b All baghouses shall be operated as follows:
A. Whenever the vacuum cleaning system is in use, all exhaust gases from the vacuum
cleaning system shall pass through the baghouse.
B. All exhaust gases from the metallurgical laboratory sample preparation hoods shall
pass through an operating baghouse. [R307-401-8]
Status: In Compliance. The vacuum cleaning system is permanently hooked up to the
baghouse and the baghouse is on if the system is running. Exhaust gases from the
metallurgical laboratory hoods pass through an operating baghouse.
II.B.1.c The pH of the circuit using cyanide shall be maintained at a value no less than 9. [R307-401-8]
II.B.1.c.1 The pH shall be continuously monitored (+/- 0.5) in the flotation circuit upstream of the cyanide
circuit. Records shall be maintained as per Condition I.4. [R307-401-8]
Status: In Compliance. The pH reading is taken on the up-stream of the cyanide circuit and
is interlocked with the ball mill readings and will shut down the entire circuit if the pH
drops below 9.0. The pH was read at 9.73 at the time of inspection.
6
II.B.1.d All wet scrubbers shall comply with 40 CFR 60.384 and 60.385. [40 CFR 60 Subpart A]
Status: In Compliance. Pressure drop and flow rate are continuously measured on the
molybdenite scrubbers. Pressure drops and liquid flow rate readings are checked and
logged twice daily. The last calibration for the pressure gauge was on July 31, 2022, and the
flow meter on November 9, 2022. However, the source stated in an email after the
inspection that both were calibrated again on September 4, 2023.
II.B.1.e KUC shall use only natural gas as a primary fuel and liquid propane as a backup fuel in the dryer
oil heaters and liquid propane as a fuel for the emergency generator. [R307-401-8]
Status: In Compliance. Only natural gas is used in these units. No other connections were
observed.
II.B.2 Roads and Fugitives
II.B.2.a To control fugitive emissions the following controls shall be applied:
A. A baghouse shall control the PM10 and PM2.5 from the MH Pilot Ore Treatment Plant.
B. All copperton milling conveyors shall be partially enclosed.
C. All copperton milling conveyor transfer points shall be enclosed.
D. The pebble crushers shall be enclosed in a building. [R307-309, R307-401-8]
Status: In Compliance. Milling conveyors are enclosed up to the A-frame where they dump
into the main concentrator feed pile. The pebble crushers are enclosed in a building.
II.B.2.b
Water sprays or chemical dust suppression sprays shall be installed at the following points to
control fugitive emissions:
A. All pebble crusher feed conveyors
The sprays shall operate whenever dry conditions warrant or as determined necessary by the
Director. [R307-309]
Status: In Compliance. The pebble crushers are enclosed in a building and have water
sprays.
UTAH SIP conditions on Concentrator:
A. Control emissions from Molybdenite Dryers with a scrubber during operation of the
dryers.
During operation of the dryers, the static pressure differential between the inlet and outlet
of the scrubber shall be within the manufacturer’s recommended range and shall be
recorded weekly.
The manometer of the differential pressure gauge shall be calibrated according to the
manufacturer’s instructions at least once per year.
Status: In Compliance. The molybdenite scrubbers control emissions as required.
The readings during the review (in AO section above) of past records show the
readings to be in normal operating range when the system is operating. The last
calibration for the pressure gauge was on July 31, 2022, and the flow meter on
November 9, 2022. However, the source stated in an email after the inspection that
both were calibrated again on September 4, 2023.
7
Section III: APPLICABLE FEDERAL REQUIREMENTS
In addition to the requirements of this AO, all applicable provisions of the following federal programs
have been found to apply to this installation. This AO in no way releases the owner or operator from any
liability for compliance with all other applicable federal, state, and local regulations including UAC
R307.
NSPS (Part 60), LL : Standards of Performance for Metallic Mineral Processing Plants
60.382 Standard for particulate matter.
Status: In Compliance. The scrubber unit DC-04 initial performance test occurred in June, 2002. The
scrubber unit DC-190 initial performance test occurred in November, 2002. No opacity was observed
from the scrubbing units. The source submits semi-annual Molybdenum Plant Wet Scrubbers reports
which can be found in the file. The most recent semi-annual report was submitted July 26, 2023.
60.384 Monitoring of operations.
Status: In Compliance. The pressure gauges and flow meters are calibrated yearly. The last calibration
for the pressure gauge was on July 31, 2022, and the flow meter on November 9, 2022. However, the
source stated in an email after the inspection that both were calibrated again on September 4, 2023.
60.385 Recordkeeping and reporting requirements.
Status: In compliance. The source submits semi-annual Molybdenum Plant Wet Scrubbers reports
which can be found in the source file. The most recent semi-annual report was submitted July 26, 2023.
MACT (Part 63) -ZZZZ: National Emissions Standards for Hazardous Air Pollutants for Stationary
Reciprocating Internal Combustion Engines
Status: In Compliance. The concentrator has one engine (75 bhp, installed July, 2005) which is subject
to this subpart. The engine is operated in accordance with all maintenance plans and maintenance is
tracked and records are available for review. A non-resettable hour meter is installed, and hours are
tracked. The generator operated 11.4 hours for non-emergency usage as of August 7, 2023. Engine
maintenance is performed annually.
Title V (Part 70) Area Source
Status: In Compliance. The source is in compliance with the Title V Area Source requirements by being
in compliance with the conditions of this AO.
8
AREA SOURCE RULES EVALUATION:
The following Area Source Rules were evaluated during this inspection:
Nonattainment and Maintenance Areas for PM10:Emissions and Fugitive Emissions and Fugitive Dust
[R307-309]
Status: In Compliance. The source operates with a FDCP that is updated yearly. The most recent
FDCP was submitted January 16, 2023. Water trucks operate as needed to control dust, and chemical
suppressants are applied throughout the year as needed. See applicable Fugitive Dust Emissions
conditions in the AO for more detail. No fugitive dust or emissions were observed during the
inspection.
Aggregate Processing Operations for PM2.5 Nonattainment Areas [R307-312]
Status: In Compliance. The source is required to maintain the opacity limits listed in R307-312,
however the limits in NSPS subpart LL are lower than the limits in R307-312. No fugitive emissions
or fugitive dust were observed coming from any point during the inspection. See condition II.B.1.a of
this AO for more detail.
National Emission Standards for Hazardous Air Pollutants [R307-214]
Status: In Compliance. This rule is satisfied through compliance with MACT Subpart ZZZZ.
EMISSION INVENTORY:
Listed before are the 2022 Actual Emissions Inventory provided from Rio Tinto Kennecott Utah Copper
LLC - Mine & Copperton Concentrator. A comparison of the estimated total potential emissions (PTE) on
Approval Order (AO) DAQE-ANI05710047-21, dated May 10, 2021, is provided. ** The Emission
Inventory submitted contains the totals for both the Bingham Canyon Mine and the Copperton
Concentrator and is well below the combined calculated total potential to emit for both processes.
(PTE) are supplied for supplemental purposes only.
Criteria Pollutant PTE tons/yr Actuals tons/yr
Ammonia 0.27 1.79 9
CO2 Equivalent 10185.00 N/A
Carbon Monoxide 9.87 6.75
Particulate Matter - PM10 25.30 679.4
Particulate Matter - PM2.5 13.86 82.84
Sulfur Dioxide 0.10 0.023
Volatile Organic Compounds 4.04 4.397
Hazardous Air Pollutant PTE lbs/yr Actuals lbs/yr
Cyanide Compounds (CAS #143339) 100 N/A
Generic HAPs (CAS #GHAPS) 18 N/A
9
PREVIOUS ENFORCEMENT
ACTIONS: Compliance Advisory (DAQC-015-22) and Early Settlement
Agreement (DAQC-134-22) for stack testing exceedances on the
C6/C8 Transfer Point Baghouse.
COMPLIANCE STATUS &
RECOMMENDATIONS: In regards to Approval Order (AO) DAQE-ANI05710047-21,
dated May 10, 2021: In Compliance. The source appears to be
well maintained and operated. Required records were current and
made available during the inspection and after the inspection via
email.
HPV STATUS: Not Applicable.
RECOMMENDATION FOR
NEXT INSPECTION: Inspect at the regular inspection frequency for this type of
source. Long-sleeved shirt, hard hat, steel-toed boots, and
hearing protection are required to tour the source. Gloves are
helpful when touring the molybdenum processing areas. A short
(20 minute) safety video is required to view to access the site.
Contact the environmental contact prior to the inspection as
additional staff at the source will be required to tour the
facilities.
NSR RECOMMENDATIONS:
ATTACHMENTS: Evaluation of AO DAQE-AN105710047-21, dated May 10,
2021 (Bingham Canyon Mine), VEO Form, 2023 Mine FDCP
1
DAQC-105710001-23a
Site ID 10571 (B1)
MEMORANDUM
TO: FILE – RIO TINTO KENNECOTT UTAH COPPER LLC – Bingham Canyon
Mine
THROUGH: Chad Gilgen, Minor Source Compliance Section Manager
FROM: Connor Kijowski, Environmental Scientist
DATE: October 16, 2023
SUBJECT: FULL COMPLIANCE EVALUATION, Minor, Salt Lake County
INSPECTION DATE: August 9, 2023
SOURCE LOCATION: 8362 West 10200 South
Bingham Canyon, 84006
SOURCE CONTACTS: Sean Daly, Senior Environmental Advisor
801-204-2563, Sean.daly3@riotinto.com
OPERATING STATUS: Operating normally at the time of inspection.
PROCESS DESCRIPTION: The open pit mine produces ore to be crushed, concentrated, and
refined into several metals including copper, gold, silver,
molybdenum, and others. The mining location within the pit is
decided by the use of a computer system that engineers use to
determine ore quality. Drill holes are plotted on a pit map and
surveyed at the designated area to be mined. A drill truck is then
dispatched to the blast area and drills holes by wet drilling.
These holes are filled with blasting agent and blasted or
imploded when ready.
Blasted areas are excavated by loading ore into haul trucks with
electric shovels and hauling it to the Main In-Pit Crusher. This
ore is ground into finer sized material and conveyed to
Kennecott's concentrator area. Emissions from conveyors are
controlled by baghouses located at enclosed transfer points.
Overburden and waste is hauled to the dumping slopes at the
edge of the pit. Low-grade ore is hauled to storage areas and may
be used as backup in the event of mining disruptions or other
bottlenecking issues which may limit activity at other areas of
Kennecott's operations.
2
APPLICABLE REGULATIONS: Approval Order (AO) DAQE-AN105710047-21, dated May 10,
2021
NSPS (Part 60) - LL : Standards of performance for Metallic
Mineral Processing Plants,
NSPS (Part 60) - IIII : Standards of Performance for Stationary
Compression Ignition Internal Combustion Engines,
NSPS (Part 60) - JJJJ : Standards of Performance for Stationary
Spark Ignition Internal Combustion Engines,
NSPS (Part 60) - OOO : Standards of Performance for
Nonmetallic Mineral Processing Plants,
MACT (Part 63) - ZZZZ : National Emissions Standards for
Hazardous Air Pollutants for Stationary Reciprocating Internal
Combustion Engines
UTAH STATE IMPLEMENTATION PLAN (SIP)
SOURCE EVALUATION:
Name of Permittee: Permitted Location:
Rio Tinto Kennecott Utah Copper LLC -
Mine & Copperton Concentrator
4700 Daybreak Parkway 8362 West 10200 South
South Jordan, UT 84095 Bingham Canyon, 84006
SIC Code: 1021: (Copper Ores)
Section I: GENERAL PROVISIONS
I.1 All definitions, terms, abbreviations, and references used in this AO conform to those used in the
UAC R307 and 40 CFR. Unless noted otherwise, references cited in these AO conditions refer to
those rules. [R307-101]
I.2 The limits set forth in this AO shall not be exceeded without prior approval. [R307-401]
I.3 Modifications to the equipment or processes approved by this AO that could affect the emissions
covered by this AO must be reviewed and approved. [R307-401-1]
I.4 All records referenced in this AO or in other applicable rules, which are required to be kept by
the owner/operator, shall be made available to the Director or Director's representative upon
request, and the records shall include the 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.5 At all times, including periods of startup, shutdown, and malfunction, owners and operators shall,
to the extent practicable, maintain and operate any equipment approved under this AO, including
associated air pollution control equipment, in a manner consistent with good air pollution control
practice for minimizing emissions. Determination of whether acceptable operating and
maintenance procedures are being used will be based on information available to the Director
which may include, but is not limited to, monitoring results, opacity observations, review of
operating and maintenance procedures, and inspection of the source. All maintenance performed
on equipment authorized by this AO shall be recorded. [R307-401-4]
I.6 The owner/operator shall comply with R307-150 Series. Inventories, Testing and Monitoring.
[R307-150]
3
I.7 The owner/operator shall comply with UAC R307-107. General Requirements: Breakdowns.
[R307-107]
Status: In Compliance. The source appears to be in compliance with each condition of
Section I. A breakdown was reported March 2023, for the conveyor transfer point between
the mine and concentrator. Rio Tinto submitted a temporary relocation permit (C-300-23)
to install and operate a generator during maintenance. Proper notification was received
according to UAC R307-107. The 2022 Emission Inventory was submitted by the required
date and the values are included below.
Section II: SPECIAL PROVISIONS
II.A The approved installations shall consist of the following 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 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
4
II.A.11 Diesel-Fired Emergency Generators
Five diesel-fired emergency generators
1) Support Generator 1
Maximum rating 2,250 kW
2) Support Generator 2
Maximum rating 700 kW
3) Support Generator 3
Maximum rating 700 kW
4) Support Generator 4
Maximum rating 500 kW
5) Support Generator 5
Maximum rating 2,000 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 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 Under Ground Mining Support Equipment
1) One (1) 150 cubic yard per hour batch plant controlled by baghouse
a) One (1) cement storage silo controlled by baghouse
b) Conveyors and cement trucks
c) Storage silos with fabric filters
2) One (1) natural gas-fired boiler rated at maximum of 2.0 MMBTU/hr
3) One (1) natural gas-fired boiler rated at maximum of 4.0 MMBTU/hr
4) Three (3) diesel-fired heaters, each rated maximum of 4.2 MMBTU/hr
5) One (1) diesel-fired generator, rated maximum of 71 kW
Status: In Compliance. No unapproved equipment was observed during the inspection.
Additional equipment information is listed below:
II.A.6: The lime silos are installed at the concentrator but are listed on both mine and
concentrator AOs
II.A.7: SX/EW plant was shut down in 2015
II.A.10: Zelnora generator was removed from the site,
Building 6690 listed generator is at building 6190
II.A.11: Generators 3, 4, and 5 have been not installed and generator 2 has been
installed but is not operating,
II.A.12: 25 cubic yard batch plant has not yet been installed
II.A.14: The concrete batch plant has not been installed yet, the source sent a
notification on September 3, 2022, stating that they are starting construction. The
source has not finished construction as of this inspection. Additionally, the diesel-
fired generator is currently not installed for underground mining.
5
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 @ Tunnel Exit Near Copperton (C6/C7)
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 @ Copperton (C7/C8)
Pollutant lb/hr grains per dry standard cubic foot (dscf)
(68oF, 29.92 in Hg)
PM10 0.19 0.007. [R307-401-8]
Status: In Compliance. Stack testing has been performed and results have been submitted
to DAQ for review. DAQ-calculated test results are as follows:
Unit Test Date Results lb/hr Results gr/dscf
In-pit Crusher PM2.5 10/29/2021 0.156 0.0011
In-pit Crusher PM10 10/29/2021 0.563 0.0038
C6/C7 (Removed 2020) 11/14/2019 0.028 0.0007
C7/C8 (renamed C6/C8) 3/25/2022 0156 0.00397
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 @ Tunnel Exit Near
Copperton (C6/C7) PM10 * #
Controlled Drop Point Baghouse
Vent @ Copperton (C7/C8) PM10 * #
B. Testing Status
* The initial testing has already been performed.
6
# 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
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 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]
Status: In Compliance. Stack testing for C6/C7 was done in November, 2019; but the
transfer point has since been removed. Main pit crusher was tested October 29, 2021; due
again in 2024. Transfer point C7/C8 has been renamed C6/C8 at the source. The C6/C8
transfer point baghouse was tested on October 29, 2022, but failed and a compliance
advisory and early settlement agreement was sent to the source (see DAQC-015-22 and
DAQC-134-22). It was retested on March 25, 2022, and was determined to be in compliance
(DAQC-882-22), and will be due again in 2025.
7
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 years. [R307-401-8]
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
@ tunnel exit near Copperton (C6/C7) 7% opacity
C. Controlled drop point baghouse vent
@ Copperton (C7/C8) 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
8
N. All other points except as defined in other
conditions of this AO 10% opacity
Opacity observations of emissions from stationary sources shall be conducted according to 40
CFR 60, Appendix A, Method 9. [R307-201]
Status: In Compliance. The C6/C7 controlled drop point has been removed, and the C7/C8
controlled drop point was renamed to C6/C8 at the source. A VEO was performed on the
C6/C8 controlled drop point baghouse; no opacity was observed. No excess emissions were
noted from any other emission point during the inspection. Refer to the VEO Form for
more details.
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]
Status: In Compliance. Previous inspections indicate initial observations on the equipment
occurred on July 1, 1993. The road base crushing plant was modified in 2018, and initial
opacity observations for it occurred on July 16, 2018 (DAQC-2018-013021).
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.
9
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]
Status: In Compliance.
A: This information is tracked on the Mine Management system and showed 11,829,450
tons for the 12-month period ending in June 2023.
B: This is tracked through fuel use as card and showed 2.16 tons for the 12-month period
ending in June 2023.
C: Daily mileage is tracked on each truck through GPS and is recorded automatically.
Tracker shows total mileage as well as highest day mileage. Highest day mileage showed no
day over the allowed limit. Highest June 2023, daily number was 14,019, May daily number
was 13,470, and April daily number was 12,819 miles based on spread sheet formula for
highest input.
D: All mine trucks are above 240 ton (320 tons) with some exceptions for the road base
trucks which are maintenance vehicles and over 40 tons.
E: All observed trucks had 6 wheels (two front and four back wheels).
F: The waste dump lift is designed to not exceed 1000 feet, with most design heights not
exceeding 200 feet, which is audited by MSHA.
G: The surface area of the Solvent Extraction/Electrowinning Plant mixer/settlers is
calculated as 252 ft2; this unit has been shut down since 2015.
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]
Status: In Compliance. These units are tracked through the Mine Management system.
Records for the 12-month period July 2022, to June 2023, are as follows:
A. NOx/SO2/PM10 emissions of 345 tons
B. NOx/SO2/PM2.5 emissions of 303 tons
II.B.1.h 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. [40 CFR 60 Subpart IIII, 40 CFR 63 Subpart ZZZZ,
R307-401-8]
II.B.1.h.1 To determine compliance with a rolling 12-month total, the owner/operator shall calculate a new
12-month total by the 20th day of each month using data from the previous 12 months. Records
documenting the operation of each emergency engine shall be kept in a log and shall include the
following:
10
A. The date the emergency engine was used
B. The duration of operation in hours
C. The reason for the emergency engine usage. [40 CFR 63 Subpart ZZZZ, R307-401-8]
Status: In Compliance. Emergency generators are used only during power supply
interruptions and for maintenance purposes. Use logs have been kept and indicated that no
generators operated for more than 100 hours for maintenance during the previous 12-
month period. These units are contracted to a third party.
Generator Hours
Lark Gate 0.4
#1 6.1
#2 0.9
Production Control Building 6690/ 93.8
Communications 6190
Mandy's Landing 20.4
East Side Dump 10.3
Zelnora removed
SAM Site 20.3
Substation 2 33.7
Support Generator 1 0
II.B.1.h.2 To determine the duration of operation, the owner/operator shall install a non-resettable hour
meter for each emergency engine. [40 CFR 63 Subpart ZZZZ, R307-401-8]
Status: In Compliance. All units have non-resettable hour meters installed.
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]
Status: In Compliance. The Main In-Pit Crusher baghouse controls process streams from
the Main In-Pit Crusher. According to the source, the baghouse is rated for 16,800 DSCFM
from the manufacturer. All exhaust from the crusher is routed through the baghouse.
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]
Status: Not Applicable. The lime silos are at the concentrator, are also listed on the
concentrator AO and are addressed in that report. However, the source stated that the lime
silo baghouses are rated to handle at least 616 DSCFM.
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]
Status: Not Applicable. The C6/C7 Controlled Transfer Drop Point has been removed, and
is no longer in service.
11
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]
Status: In Compliance. The C7/C8 Controlled Transfer Drop Point has been renamed the
C6/C8 Controlled Transfer Drop Point. The source stated that the baghouse is rated for
7,000 ACFM from the manufacturer. All exhaust air from the C6/C8 transfer drop point is
routed through the baghouse before being vented to the atmosphere.
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]
Status: In Compliance. The Sample Preparation baghouse controls process streams from
the sample preparation building crushing and grinding equipment. All exhaust air from the
sample preparation crusher and grinder is routed through the baghouse before being
vented to the atmosphere.
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]
Status: Not Applicable. This unit has been shut down since 2015.
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]
Status: Not Applicable. These tanks are part of the Electrowinning Acid Mist Eliminator.
This unit has been shut down since 2015.
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]
Status: Not Applicable. The 25 cubic yard concrete batch plant listed in Condition II.A.12
is not installed or operational.
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]
Status: In Compliance. A certificate of analysis provided by Sinclair indicates the fuel
meets the ULSD requirement and was reviewed during the inspection.
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]
Status: In Compliance. A certificate of analysis provided by Sinclair indicates the fuel
meets the ULSD requirement and was reviewed during the inspection.
12
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]
Status: In Compliance. Rio Tinto submitted an annual road dust control report in
conjunction with the FDCP on January 16, 2023. This plan was reviewed and found to
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 have not changed. Refer to this document in the attachments.
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]
Status: In Compliance. The FDCP incorporates the applicable requirements of R307-205
and R307-309 for Fugitive Emission and Fugitive Dust sources.
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]
Status: In Compliance. Disturbed or stripped areas are controlled at all times until the area
is reclaimed. The source currently operates eight dedicated water trucks. Magnesium
chloride is applied once a month using a hydro seeder truck for light vehicle roadways.
Surfactant is mixed into each large water truck load and applied on the haul roads.
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]
Status: In Compliance. No visible dust emissions were observed from haul-road traffic or
mobile equipment. The haul roads were visibly wet during the inspection and water trucks
were in operation throughout the mine.
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]
Status: In Compliance. All stationary and portable conveyor transfer points are enclosed or
controlled by baghouses. All portable crushing equipment has water sprays that are
included in Rio Tinto's preventative maintenance schedule. Additionally, the source has
water sprays installed and operating at various points along the length of the conveyor
system.
13
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]
Status: In Compliance. The source sprays uncovered storage piles as necessary to control
fugitive dust. Records of watering have been kept. No emissions of fugitive dust were
observed from any storage pile during this inspection.
II.B.3.g The opacity on active waste slopes shall not exceed 20%. 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]
Status: In Compliance. The source has performed and recorded monthly opacity
observations at the active dump faces. No emissions were observed during the inspection
from any waste slopes.
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]
Status: In Compliance. Rio Tinto uses MgCl2 and has seven dedicated water trucks which
operate daily in order to control dust. Rio Tinto submitted an annual road dust control
report in conjunction with the FDCP on January 16, 2023. This report has been reviewed
for accuracy and is included in the attachments. No excess emissions were noted during this
inspection. All roads appeared to be moist and dust was controlled.
II.B.3.i Wet drilling shall be performed for all blast holes. [R307-309]
Status: In Compliance. All drills are equipped with water to control fugitive dust emissions
during operation. No drilling was observed during this inspection.
14
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]
Status: In Compliance. Ore conveyors are the primary means of transporting crushed ore
from the BCM to the Copperton Concentrator. Grader hours of operation and road base
crusher throughput are recorded to demonstrate that applicable haul roads are being
covered with road base and crushed rock. MgCl2 and surfactant are added into water
loads. Dedicated haul trucks apply water to all active haul roads as conditions warrant and
in accordance with the FDCP. All road surfaces appeared to be wet and no excess dust was
noted due to traffic. Water trucks were in use during this inspection.
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]
Status: In Compliance. Both monitoring stations were in existence pre-dating this AO. See
Conditions below for compliance requirement details. The two stations are listed on the
ambient monitoring report as Copperton C3 and High-Country sites.
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]
Status: In Compliance. Rio Tinto utilizes 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. A contractor (Trinity
Consultants) performs independent audits quarterly, and results of these audits have been
submitted to DAQ for review. Reports are in the main source files.
15
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 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 may be the source of 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]
Status: In Compliance. Measured PM10 concentrations have not been greater than
135µg/m3 for more than one day per year on an average over three consecutive years. Data
summaries are reported to DAQ in quarterly and annual independent auditor reports. All
reports are reviewed by DAQ staff and are in the main source files.
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;
16
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 may 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 may recommend or require changes in the air monitoring system and
associated activities in order to improve data quality and completeness. [R307-410]
Status: In Compliance. Rio Tinto has submitted quarterly and annual data reports
containing the information required by this condition. These reports have been reviewed
for accuracy and are contained in DAQ's source files.
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]
Status: In Compliance. Rio Tinto has contracted with an independent firm (Trinity
Consultants) to conduct quarterly performance audits of its PM10 monitors. Audit results
have been submitted to the DAQ in quarterly data reports. Additional analysis for metals
and other constituents has not been necessary.
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]
Status: In Compliance. PM10 and meteorological data (wind speed, wind direction, and
ambient temperature) is collected at the sites. Rio Tinto reports summary data in quarterly
data reports. These reports are submitted to and reviewed by DAQ. Reports are in the
main source files.
UTAH STATE IMPLEMENTATION PLAN (SIP)
g. Kennecott Utah Copper (KUC): Mine
i. Bingham Canyon Mine (BCM)
A. Maximum total mileage per calendar day for diesel-powered ore and waste haul trucks
shall not exceed 30,000 miles.
KUC shall keep records of daily total mileage for all periods when the mine is in
operation. KUC shall track haul truck miles with a Global Positioning System or
equivalent. The system shall use real time tracking to determine daily mileage.
B. To minimize fugitive dust on roads at the mine, the owner/operator shall perform the
following measures:
I. Apply water to all active haul roads as weather and operational conditions warrant
except during precipitation or freezing weather conditions, and shall apply a
17
chemical dust suppressant to active haul roads located outside of the pit influence
boundary no less than twice per year.
II. Chemical dust suppressant shall be applied as weather and operational conditions
warrant except during precipitation or freezing weather conditions on unpaved
access roads that receive haul truck traffic and light vehicle traffic.
III. Records of water and/or chemical dust control treatment shall be kept for all
periods when the BCM is in operation.
IV. KUC is subject to the requirements in the most recent federally approved Fugitive
Emissions and Fugitive Dust rules.
C. To minimize emissions at the mine, the owner/operator shall:
I. Control emissions from the in-pit crusher with a baghouse.
Status: In Compliance. All requirements of this SIP have been incorporated into the
AO conditions above and are reported under those conditions.
Section III: APPLICABLE FEDERAL REQUIREMENTS
In addition to the requirements of this AO, all applicable provisions of the following federal programs
have been found to apply to this installation. This AO in no way releases the owner or operator from any
liability for compliance with all other applicable federal, state, and local regulations including UAC
R307.
NSPS (Part 60) -LL : Standards of performance for Metallic Mineral Processing Plants
Status: In Compliance. According to previous inspection memos initial observations of the main pit
crusher baghouse and other metallic mineral processing equipment occurred on July 1, 1993. No
fugitive emissions greater than 10 percent opacity were observed during the inspection. The main in-pit
crusher is required to be stack tested and is limited to 0.016 gr/dscf PM which is less than the 0.0218
gr/dscf (0.05 g/dscm) limit in subpart LL. The main in-pit crusher was last stack tested on October 29,
2021, and the result was 0.0038 gr/dscf (DAQC-005-22).
According to previous inspection memos initial observations of the main pit crusher baghouse and other
metallic mineral processing equipment occurred on July 1, 1993.
NSPS (Part 60) -IIII : Standards of Performance for Stationary Compression Ignition Internal Combustion
Engines
Status: In Compliance. The 2,250 kW Diesel generator is applicable this subpart. The generator has the
required certificate and is operated in accordance with manufacturer maintenance requirements. The
engine has a non-resettable hour meter and all hours, reason for firing, and maintenance activities are
logged. This engine did not operate in excess of 100 non-emergency hours during the previous 12 month
period. Yearly maintenance is done and includes all the required items. Only ultra-low sulfur fuel is
ordered for this unit.
18
NSPS (Part 60) -JJJJ : Standards of Performance for Stationary Spark Ignition Internal Combustion Engines
Status: In Compliance. The units applicable to this subpart are the LPG engines newer than 2009 as
listed above. All units have the required certifications. All engines follow the manufacturer maintenance
requirements. All units have non-resettable hour meters and none have exceeded 100 hours of non-
emergency operations in the past 12-month period. Records are kept of hours, reasons for use, and any
maintenance activities. No exceedance of hours or other compliance issues have occurred.
NSPS (Part 60) -OOO : Standards of Performance for Nonmetallic Mineral Processing Plants
Status: In Compliance. An initial performance test was conducted on the road-base crushing operation
on July 16, 2018 (DAQC-2018-013021). Only minimal opacity was observed during the inspection.
MACT (Part 63) -ZZZZ : National Emissions Standards for Hazardous Air Pollutants for Stationary
Reciprocating Internal Combustion Engines
Status: In Compliance. This federal requirement is satisfied through compliance with NSPS Subpart
IIII and NSPS Subpart JJJJ.
AREA SOURCE RULES EVALUATION:
The following Area Source Rules were evaluated during this inspection:
Nonattainment and Maintenance Areas for PM10:Emissions and Fugitive Emissions and Fugitive Dust
[R307-309]
Status: In Compliance. The source operates with a FDCP that is updated yearly. Water trucks
operate as needed to control dust, and chemical suppressants are applied throughout the year as
needed. See applicable fugitive dust emissions conditions in the AO for more detail. No fugitive dust
was observed during the inspection.
Aggregate Processing Operations for PM2.5 Nonattainment Areas [R307-312]
Status: In Compliance. The source is required to maintain the opacity limits listed in R307-312,
however the limits in NSPS subpart LL are lower than the limits in R307-312. Only minimal fugitive
emissions were observed from the aggregate processing equipment. See the applicable opacity
conditions in the AO for more detail.
National Emission Standards for Hazardous Air Pollutants [R307-214]
Status: In Compliance. This rule is satisfied through compliance with MACT Subpart ZZZZ. Refer
to the Federal Requirements section for more details.
Davis and Salt Lake Counties and Ozone Nonattainment Areas: Ozone Provisions [R307-325]
Status: In Compliance. No VOC's were observed to be spilled, stored in open contains, or handled in
any other manner that would result in greater evaporation of VOCs than would have if reasonably
available control technology had been applied.
19
Degreasing and Solvent Cleaning Operations [R307-335]
Status: In Compliance. The source has several degreasers for cleaning hand tools within the truck
shop. The degreasers are kept closed, written procedures are posted on the degreasers, no uncovered
waste containers were observed, the equipment appeared to be maintained in good operating
condition, and no leaks or spills were observed at any of the degreasers.
EMISSION INVENTORY:
Listed before are the 2022 Actual Emissions Inventory provided from Rio Tinto Kennecott Utah Copper
LLC - Mine & Copperton Concentrator. A comparison of the estimated total potential emissions (PTE) on
AO: DAQE-AN105710047-21, dated May 10, 2021, is provided.
(PTE) are supplied for supplemental purposes only.
Criteria Pollutant PTE tons/yr Actuals tons/yr
CO2 Equivalent 8320.18 N/A
Carbon Monoxide 1707.70 6.751
Nitrogen Oxides 5842.11 4.757
Particulate Matter - PM10 1519.21 679.4
Particulate Matter - PM2.5 369.21 82.84
Sulfur Dioxide 7.43 0.023
Volatile Organic Compounds 314.13 4.397
Hazardous Air Pollutant PTE lbs/yr Actuals lbs/yr
Total HAPs (CAS #THAPS) 3480 N/A
PREVIOUS ENFORCEMENT
ACTIONS: Compliance Advisory (DAQC-015-22) and Early Settlement
Agreement (DAQC-134-22) for stack testing exceedances on the
C6/C8 Transfer Point Baghouse.
COMPLIANCE STATUS &
RECOMMENDATIONS: In regards to Approval Order (AO) DAQE-AN105710047-21,
dated May 10, 2021: In Compliance. The source appears to be
well maintained and operated. Required records were current and
made available during the inspection.
HPV STATUS: Not Applicable.
RECOMMENDATION FOR
NEXT INSPECTION: Inspect at the regular inspection frequency for this type of
source. Long-sleeved shirt, hard hat, steel-toed boots, and
hearing protection are required for the inspection. Gloves will be
helpful if you will be inspecting the Concentrator when touring
the molybdenum processing areas. A short safety video is
required to access the site. Contact the environmental contact
prior to the inspection as additional staff at the source will be
required to tour the facilities.
ATTACHMENTS: None.
Rio Tinto Kennecott
4700 Daybreak Parkway
South Jordan, Utah 84009
January 16, 2023
Mr. Bryce Bird, Director
Utah Department of Environmental Quality
Division of Air Quality
P.O. Box 44820
Salt Lake City, UT 84114-4820
Attention: Mr. Conner Kijowski
Subject: Kennecott Utah Copper Bingham Canyon Mine
Approval Order DAQE-AN105710047-21
2022 Annual Road Dust Control Report
2023 Fugitive Dust Control Plan
Dear Mr. Bird:
As required by Condition II.B.3.a of the Bingham Canyon Mine Approval Order DAQE-
AN105710042-18, Kennecott Utah Copper LLC (KUC) submits the Bingham Canyon Mine
Annual Fugitive Dust Control Report for 2022 and the Fugitive Dust Control Plan for
2023.
If you have any questions or concerns please contact me or Sean Daly at 801-204-2563.
Sincerely,
Brendan Murphy
General Manager, Minerals
801-569-6200
Attachment (1)
Rio Tinto Kennecott Utah Copper, LLC. 4700 Daybreak Parkway, South Jordan, Utah 84009.
.
DocuSign Envelope ID: A8059C4D-4A87-4A28-810F-0101C13CEE8C
Page 2 of 7
KENNECOTT UTAH COPPER BINGHAM CANYON MINE 2020
ANNUAL ROAD DUST CONTROL REPORT
2021 FUGITIVE DUST CONTROL PLAN
1.0 Introduction
In compliance with Condition II.B.3.a of the Bingham Canyon Mine Approval Order DAQE-
AN105710047-21, the following report describes dust control measures completed in 2022 and those
planned for 2023.
2.0 Overview - 2022 Dust Control Measures and Permit Conditions
Routine water spraying and/or chemical dust suppressant application on haulage roads (governed
by weather, roadway moisture, and operating conditions) as required by Condition II.B.3.j.
Wet drilling was performed for all blast holes , as required by Condition II.B.3.i.
Chemical treatment of ancillary roads with a magnesium chloride dust suppressant.
Per Condition II.B.3.j.A.1, KUC continued application of road base material on active mine haul roads
within the pit influence boundary .
Routine water spraying and vacuuming of roads around the C6/C 8 conveyor as well as the conveyor
road (governed by weather, roadway moisture , and operating conditions).
Total material moved did not exceed 260,000,000 tons of ore and waste as required by Condition
II.B.1.e.A.
Maximum daily total mileage for ore and waste haul trucks did not exceed 30,000 miles as required
by Condition II.B.1.e.C.
Ore and waste haul truck fleet had a minimum design payload of 240 tons and a maximum of 6 wheels
each, as required by Co ndition II.B.1.e.D & E.
Per Condition II.B.1.e.F, active mine waste dumps did not exceed a height of 1,000 feet.
Per Condition II.B.3.j.B, KUC continued its use of the 5 mile-ore conveyor as its primary means of
transporting ore from the Mine to the Concentrator, thereby reducing fugitive emissions by displacing
transport by truck.
KUC has integrated haul trucks of a higher capacity into the fleet, reducing vehicle miles travelled.
All active haul roads at the Bingham Canyon Mine received at least two app lications of dust
suppressant.
2.1 Water Applied to Roads in 2022
A fleet of ten (10) pieces of equipment performed road watering activities including:
DocuSign Envelope ID: A8059C4D-4A87-4A28-810F-0101C13CEE8C
Page 3 of 7
Eight (8) CAT 793 with specifically engineered road watering capabilities (52,000-58,500 gallons/load)
Two (2) Drill & Blast (D&B) water trucks
o One (1) 4,000 gallon capacity
o One (1) 3,600 gallon capacity
The large capacity water trucks provided dust suppression on the primary haul/access roads and the
smaller trucks spot-watered the narrow access roads and around shops, support facilities and blasting
activities. A fleet of smaller, rented water trucks were used throughout the year as needed.
The primary water filling stations for dust control are located at 6190, near underground operations
offices (5690), 6880 and SEW haul road. The total water volume applied, mainly by the large water
trucks on haul roads, in 2019 was estimated to be approximately 500,000,000 gallons.
The smaller water trucks are used around administrative and maintenance buildings, light vehicle access
roads as well as to supplement the large volume water trucks in the event they are temporarily out of
service. Smaller trucks also supply water to drills during the blasting process. Based upon previous annual
accounting estimates, it is assumed that thes e trucks have applied greater than 1,000,000 gallons per
year.
Road maintenance was accomplished with twelve (12) graders.
2.2 Conveyor Transfer Points
In 2020, a 4,000 gallon capacity water truck was used to perform watering of roads and wash down
around the conveyor transfer points outside the pit (C6/C8 transfer point). Depending upon seasonal
weather conditions, the truck is run to wet down areas along the belt line that are not paved. In addition,
the truck is used to wash down accumulated dust and sediment from underneath the C7 belt and
corresponding transfer points.
A vacuum truck was utilized to assist along the conveyor system and at the transfer points to minimize
accumulation of materials underneath and along the conveyor system.
2.3 Chemical Dust Suppressant Applied in 2020
Approximately 1,445,586 pounds of magnesium chloride and 255,858 pounds of Nalco Haulage DC
Surfactant were applied to the areas identified in the 2022 Fugitive Dust Control Plan. Active haul roads
outside of the Pit Influence Boundary (PIB) received at least two applications of chemical dust
DocuSign Envelope ID: A8059C4D-4A87-4A28-810F-0101C13CEE8C
Page 4 of 7
suppressant in 2020, which is detailed in the attached map titled “Fugitive Dust Suppression Activities,
2021 Bingham Canyon Mine”
The applications were made with KUC equipment. The magnesium chloride solution was applied at an
average concentration of 30% magnesium chloride to roads that were prepared by grading and watering.
Surfactant was applied at 330 parts per million.
2.4 Asphalt Applied in 2022
During 2022 repairs were made to access roads but no new areas were paved with asphalt.
2.5 Paved Access Roads and Parking Areas
A sweeper truck was hired to remove excess sediment from paved and/or concrete areas in proximity to
administrative and maintenance facilities as well as the paved access road beginning at Lark Gate and
leading to the Mine facilities. The service was performed frequently during the drier spring, summer and
fall months. In the winter months, the service was performed as conditions permitted.
A new parking lot was constructed near the mine entrance in 2012. Mine employees park their personal
vehicles and utilize buses for transport to the mine. This significantly decreases the amount of vehicles
travelling on the mine access road, which decreases the potential for fugitive dust generation.
2.6 Road Base Crusher
A portable road base crushing and screening unit has been permitted, tested and operating since October
2006 to crush road base material. Based on testing and application of the road bas e material, general road
quality and surfaces improved while reducing fine particulate matter. In 2022, 1,755,894 tons of material
were crushed for use on unpaved haul roads.
2.7 Haul Trucks/Conveyor/A-Frame
KUC continues to integrate haul trucks with a payload capacity of 320 tons. The integration of these
higher capacity trucks into the haulage fleet reduced fugitive emissions by requiring less vehicle miles
travelled.
DocuSign Envelope ID: A8059C4D-4A87-4A28-810F-0101C13CEE8C
Page 5 of 7
KUC continued use of its five mile conveyor system as its primary means of transporting crushed ore from
the mine to the concentrator. Ore material in the A-Frame was kept in accordance with the BCM AO.
3.0 Planned Dust Control Measures for 2023
Total material moved at the mine shall not exceed 260 ,000,000 tons of ore and waste under the
current AO.
Active ore and waste haulage roads within the pit influence boundary shall be water sprayed
and/or treated with commercial dust suppressant as conditions warrant.
Maximum daily total mileage for ore and waste haul trucks shall not exceed 30,000 miles.
Ore and waste haul truck fleet shall have a minimum design payload of 240 tons and a maximum
of 6 wheels each.
Mine waste dumps to not exceed a height of 1,000 feet.
Accessible areas of uncovered storage piles shall be sprayed wit h water or dust suppressants as
dry conditions warrant and accessibility permits.
Apply commercial dust suppressant as road conditions warrant to light du ty and service vehicle
access roads.
Apply commercial dust suppressant on active haul roads outside o f the pit influence boundary
twice per year.
KUC will continue its use of the 5 mile -ore conveyor as its primary means of transporting crushed
ore from the mine to the concentrator, thereby reducing fugitive emissions by displacing transport
by truck.
KUC will continue integrating haul trucks of a higher capacity, reducing vehicle miles travelled.
KUC will continue its use of a road base crusher to provide material for application on active ore
and waste haulage roads.
3.1 Unpaved Roads – Primary Ore and Waste Haulage
Dust control measures planned for 2023 include continued water application on haul roads as governed
by continual monitoring of road and meteorological (dry) conditions. The attached dust control plan map
titled “Fugitive Dust Suppression Activities, 2023 Bingham Canyon Mine” details these areas. Active haul
roads outside of the pit influence boundary (PIB) will all receive at a minimum two applications of
chemical dust suppressant in 2023. Watering will be concentrated on highly trafficked ore and waste haul
haulage roads between shovels and the in-pit crusher and the active waste rock dumps. The primary ore
and waste haulage roads depicted in attached drawing are based upon an aerial survey and are
approximate to the 2022 haul truck traffic patterns. All haul truck traffic patterns are subject to change as
ore faces and waste rock dumps progress throughout the year.
The planned road watering fleet consist s of:
Eight (8) CAT 793 with specifically engineered road watering capabilities (52,000-58,500 gallons/load)
DocuSign Envelope ID: A8059C4D-4A87-4A28-810F-0101C13CEE8C
Page 6 of 7
Two (2) Drill & Blast (D&B) water trucks
o One (1) 4,000 gallon capacity
o One (1) 3,600 gallon capacity
KUC has twelve (12) graders to perform road maintenance as well as other operational functions. The
number of graders used for road maintenance at any given time varies as road conditions warrant.
Experience has determined that rapid removal of mud slurry after a storm event eliminates a saturation
source for the road base and also helps to ultimately reduce fugitive emissions caused when the slurry
dries.
A portable road base crushing and screening unit has been permitted, tested and operating since October
2006 to crush road base material. Based on testing and application of the road base material, results
found general road quality and surfaces improved while reducing fine particulate matter. KUC will
continue to operate the road base crushers in 2021.
3.2 Unpaved Roads –Light Duty and Service Vehicles
Continued use of commercial dust suppression is planned in 2021 for unpaved roads that receive minimal
haul truck traffic and elevated light vehicle and service truck traffic. Application areas will be similar to
those areas that received magnesium chloride in 2020. Historically a 30% magnesium chloride and water
mixture has been used. The dust suppressant may be reapplied as needed to select areas throughout the
summer and fall. The light duty and service vehicle access roads will also utilize the same fleet of water
trucks described in section 3.1 as conditions warrant and access allows.
The crushing and conveying department will continue to water roads along the conveyor as condit ions
warrant. The crushing and conveying department at the Copperton Concentrator purchased a 4,000
gallon capacity water truck in 2010 which is primarily dedicated to dust control measures associated with
the conveyor belt between the mine and the coarse ore stockpile.
3.3 Paved Roads and Areas
Haul trucks and most support vehicles are restricted to haul roads in the pit and on the waste rock dumps.
Haul trucks in particular do not travel on paved roads unless to access the upper pushback of the east cut
in which case the trucks briefly cross the Mine access road. Only support vehicles such as service vehicles
and light duty trucks regularly travel between paved and unpaved surfaces. In order to minimize dust
tracked onto internal paved roads, a parking lot was constructed near the mine entrance. Mine employees
park their personal vehicles and utilize buses for transport to the mine. This significantly d ecreases the
amount of vehicles travelling on the mine access road. Very few Kennecott company vehicles leave the
property and they must generally drive on four miles of paved road before reaching the front gate. There
is minimal opportunity for mud or dust to be tracked off property onto public roads. Paved roads on the
property will be swept and vacuumed, bladed or washed on a routine basis similar to 2020 to minimize
fugitive dust.
DocuSign Envelope ID: A8059C4D-4A87-4A28-810F-0101C13CEE8C
Page 7 of 7
Paved areas along the C8 conveyor and around the A-frame stockpile will continue to be watered in 2023,
as conditions warrant. A vacuum truck will also be utilized in 2023 to assist along the conveyor system
and at the transfer points to minimize accumulation of materials underneath and along the conveyor
system.
3.4 Waste Rock Disposal Areas
Opacity surveys will be conducted monthly in an area where waste rock is being placed. The observation
shall be conducted in accordance with Condition II.B.3.g of the Bingham Canyon Mine Approval Order
(DAQE- AN105710047-21. Control measures such as dumping and pushing with dozers, or wetting with
water may be implemented in order to achieve compliance with Condition II.B.3.g.
3.5 Water Trucks
The Mine plans to operate a fleet of eight large capacity and two smaller capacity water trucks throughout
2023 and apply water as conditions warrant. The fleet will consist of eight 55,000-58,500 gallon capacity
water trucks. The two Drill and Blast water trucks will be used to provide water to the drills, wetting of
drill patterns and waterin g of light vehicle access areas that are too narrow for the large capacity water
trucks.
3.6 Supporting Activities
Water will be utilized to minimize fugitive dust , as conditions warrant, from various supporting activities
that may occur at the Bingha m Canyon Mine; including but not limited to, facility construction and
maintenance, yard area maintenance, equipment erection and water system work .
DocuSign Envelope ID: A8059C4D-4A87-4A28-810F-0101C13CEE8C