DAQ-2025-000649

1
DAQC-CI103670001-25
Site ID 10367 (B1)

MEMORANDUM

TO: FILE – ASAHI REFINING USA, INC. – Precious Metals Refinery

THROUGH: Chad Gilgen, Minor Source Compliance Section Manager

FROM: Susan Weisenberg, Environmental Scientist

DATE: January 26, 2025

SUBJECT: FULL COMPLIANCE EVALUATION, Minor, Salt Lake County

INSPECTION DATE: December 10, 2024

SOURCE LOCATION: 4601 West 2100 South
West Valley City, UT 84120

DIRECTIONS: From UT-201, take Exit 11. Be aware that the frontage road
leading to the facility is located on the south side of the highway.

SOURCE CONTACTS: Stewart Hogan, EHS Manager
801-201-6089, [e-mail]

OPERATING STATUS: Operating normally.

PROCESS DESCRIPTION: Asahi Refining USA, Inc. (Asahi) operates a precious metals
refinery in West Valley City, Salt Lake County. Mined doré and
scrap are melted and tested for purity using small electric
induction furnaces and then separated depending on gold and
silver content. Separation is achieved by using various inorganic
chemicals and electrolytic methods. Silver is poured into anode
molds and then placed into the electrolytic cells. The cells
contain silver nitrate solution, and the low voltage current causes
silver crystal to form onto a cathode plate. The silver crystal is
scraped off and collected.

APPLICABLE REGULATIONS: Approval Order (AO) DAQE-AN103670031-24, dated
October 7, 2024

NSPS (Part 60) JJJJ: Standards of Performance for Stationary
Spark Ignition Internal Combustion Engines
NESHAP (Part 63) ZZZZ: National Emissions Standards for
Hazardous Air Pollutants for Stationary Reciprocating Internal
Combustion Engines.

SOURCE EVALUATION:

0 . ) $ . ) - "
2
Name of Permittee: Permitted Location:

Asahi Refining USA, Inc.
Precious Metals Refinery

4601 West 2100 South 4601 West 2100 South
West Valley City, UT 84120 West Valley City, UT 84120

SIC Code: 3339: (Primary Smelting & Refining of Nonferrous Metals, Except Copper &
Aluminum)

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. No equipment or processes not listed on this AO were observed
during this inspection. All maintenance is conducted by site personnel and the records are
kept as required. No R307-107 applicable breakdowns have occurred during the previous
3
12 months. Emissions are not currently required for this facility. The new emergency
natural gas-powered engine, the new electric arc furnace, and the associated scrubber #761,
had not yet been installed at the time of this inspection. The installation is scheduled for
October of 2025. The plant manager, Stewart Hogan, stated that the startup notification
will be sent to the DAQ within the 18-month time period requirement.

Section II: SPECIAL PROVISIONS II.A The approved installations shall consist of the following equipment: II.A.1 Metal Refinery Precious Metals Refinery Plant II.A.2 Wastewater Treatment Wastewater effluent treatment. Process controlled by scrubber #760 II.A.3 Electrolytic Cells Silver electrolytic cell (refining of silver). Process controlled by scrubber #761. II.A.4 Electrolytic Cells Gold electrolytic cell (refining of gold). Process controlled by scrubber #359. II.A.5 Wet Circuit Gold refinery wet circuits (part of the gold refining process). Process controlled by scrubber #359. II.A.6 Chlorination Gold chloride electrolytic production (refining of gold). Process controlled by scrubber #359. II.A.7 Slime Washing Silver anode slime washing process (recovery of gold). Process controlled by scrubber #248. II.A.8 Wet Chlorides Treatment Hydrometallurgical process for silver chlorides sludge processing (recovery of gold). Controlled by scrubber #359. II.A.9 Fabric-Filter Baghouse Four (4) fabric-filter baghouses One baghouse controls emissions from the sweeps preparation process. Two baghouses control emissions from the melt room furnaces, the electric tilt furnaces, and the electric push-out furnaces. One baghouse controls the ashing furnace (Item II.A.25). II.A.10 Boiler One (1) boiler, natural gas-fueled, rated less than 5 MMBtu/hr II.A.11 Dust Collector Dust collector for welding fume and grinding dust control in maintenance shop II.A.12 Electrostatic Precipitator One (1) wet-electrostatic precipitator (ID: WESP II) II.A.13 Chlorination Furnaces Four (4) electric-induction chlorination furnaces. Process controlled by venturi scrubber, WESP II, and scrubber #359.
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II.A.14 Melt Furnaces Two (2) melt-room furnaces, natural gas-fueled, rated less than 5 MMBtu/hr each. Process
controlled by a nanofilter baghouse made by UAS or the combination of the venturi
scrubber, WESP II, and scrubber #359.
II.A.15 Tilt Furnaces (One New)
Nine (9) electric-tilt furnaces. Process controlled by a nanofilter baghouse made by UAS or the combination of the venturi scrubber, WESP II, and scrubber #359.

II.A.16 Push-out Furnaces Four (4) electric push-out furnaces. Process controlled by baghouse or the combination of
the venturi scrubber, WESP II, and scrubber #359.
II.A.17 Combustion Afterburner
One (1) incinerator, natural gas-fueled, rated less than 5 MMBtu/hr

II.A.18 Nitrate Plant
Silver nitrate plant (recovery of silver). Process controlled by scrubber #248.

II.A.19 Slime Plant
Slime plant (recovery of gold). Process controlled by scrubber #248.

II.A.20 Drying Cabinets
Five (5) electric drying cabinets. Process controlled by the combination of the venturi
scrubber, WESP II, and scrubber #359.

II.A.21 Drying Cabinet
One (1) drying cabinet, natural gas-fueled, rated less than 5 MMBtu/hr.

II.A.22 Wet Scrubbers
Four (4) packed bed wet scrubbers (ID: 760, 359, 248, 761)

II.A.23 Venturi Scrubber
One (1) venturi scrubber attached to WESP II as a pre-scrubber.

II.A.24 Tank System
Silver reduction tanks (recovery of silver). Process controlled by scrubber #248.

II.A.25 Ashing Furnace
One (1) dental scrap ashing furnace. Process controlled by baghouse (Item II.A.9) and
activated carbon adsorption system (Item II.A.26).

II.A.26 Activated Carbon Adsorption System
One (1) activated carbon adsorption system controls the ashing furnace (Item II.A.25)

II.A.27 Emergency Generator Engine
Rating: 60 kW
Manufacture Year: Pre-2006
Fuel: Natural Gas

NSPS Subpart Applicability: None
MACT Subpart Applicability: Subpart ZZZZ

II.A.28 Emergency Engine (New)
Rating: 850 hp (550 kW)
Manufacture Year: 2022
Fuel: Natural Gas

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NSPS Subpart Applicability: Subpart JJJJ MACT Subpart Applicability: Subpart ZZZZ

Status: In Compliance. The listed equipment associated with the new silver
electrolytic cells processing system is scheduled to be installed in October of
2025. This not yet installed equipment includes II.A.3, the electrolytic cells,
scrubber #761 of the wet scrubbers referenced by II.A.22, and II.A.28, the 850
hp natural gas emergency engine. Other equipment not currently operating
includes the II.A.11, dust collector which is permanently removed, II.A.25, the
ashing furnace, and II.A.26, the activated carbon adsorption system which are
not currently economically practical to operate. All of the rest of the listed
equipment has been installed and is operating as described.

II.B Requirements and Limitations

II.B.1 Site-Wide Requirements

II.B.1.a The owner/operator shall not allow visible emissions from the following emission points to
exceed the following values:

A. All fabric filter baghouse exhaust stacks - 10%

B. All electrostatic precipitator exhaust stacks - 10%

C. All scrubber exhaust stacks - 10%

D. All incinerator exhaust stacks - 10%

E. All boiler exhaust stacks - 10%

F. All other points - 20%

[R307-401-8]

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

Status: In Compliance. Stacks can be viewed from the parking lot. No visible emissions
could be seen from any point during this inspection. Observations were performed in a
manner consistent with Method 9 requirements.

II.B.1.b The owner/operator shall not produce more than the following:

A. 12,000,000 troy ounces of gold per rolling 12-month period

B. 60,000,000 troy ounces of silver per rolling 12-month period

C. 400 tons of sweeps per rolling 12-month period

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[R307-401-8]

Status: In Compliance. The 12-month rolling totals for the period of December 2023
through November 2024 were reported as follows:

Silver = 33,340.087 troy ounces
Gold = 4,357,591 troy ounces

Sweeps for the same time period were reported as 151 tons. See the attached Monthly
Production spreadsheet.

II.B.1.b.1 The owner/operator shall:

A. Determine gold, silver, and sweeps production by company production records

B. Record gold and silver production on a daily basis and record sweeps production
on a monthly basis

C. Use the gold and silver production data to calculate a new rolling 12-month total by
the 20th day of each month using data from the previous 12 months

D. Use the sweeps production data to calculate a new rolling 12-month total by the
20th day of January, April, July and October of each year using data from the
previous 12 months.

E. Keep the gold, silver, and sweeps production records for all periods the plant is in
operation.

[R307-401-8]

Status: In Compliance. Production totals are created monthly and are made for all periods
for when the processes are in operation. Records are tabulated prior to the 20th day of each
month.

II.B.2 Baghouse Requirements

II.B.2.a The owner/operator shall use baghouses to control particulate emissions from the sweeps
preparation process, melt room furnaces, electric tilt furnaces, electric push-out furnaces, and the
ashing furnace. [R307-401-8]

Status: In Compliance. Baghouses operate to control particulate from the referenced
processes.

II.B.2.b The owner/operator shall install a manometer or magnehelic pressure gauge to measure the static
pressure differential across each baghouse. [R307-401-8]

Status: In Compliance. Live electronic pressure gauges have been installed to measure the
static pressure differential across each baghouse. See the attached snap shots of the
monitoring screens.

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II.B.2.b.1 The pressure gauge shall be located such that an inspector/operator can safely read the indicator
at any time. [R307-401-8]

Status: In Compliance. Pressure gauges have been installed and are monitored by live
electronic screens that show the readings to the operators.

II.B.2.b.2 The pressure gauge shall measure the static pressure differential in 1-inch water column
increments or less. [R307-401-8]

II.B.2.c During operation of each baghouse, the owner/operator shall maintain the static pressure
differential within the range recommended by the manufacturer for normal operations.
[R307-401-8]

Status: In Compliance. All pressure gauges are set with an alarm system that alerts the
operators to measurements that occur outside of the recommended ranges. The melt
baghouse manufacturer recommended ranges are between 0.4 and 7.0-inch WG. The melt
dust collector manufacturer recommendation is between 1.0 to 6.0-inch WG. The sweeps
dust collector manufacturer recommendation is between 1.0 and 6.0-inch WG. See the
attached email correspondence.

II.B.2.c.1 The owner/operator shall record the static pressure differential at least once per operating day
while each baghouse is operating. [R307-401-8]

Status: In Compliance. The static pressure differentials are continuously monitored and
recorded for each operating baghouse.

II.B.2.c.2 The owner/operator shall maintain the following records of the static pressure differential:

A. Unit identification;

B. Manufacturer recommended static pressure differential range for the unit;

C. Daily static pressure differential readings;

D. Date of reading.

[R307-401-8]

Status: In Compliance. An electronic reading monitors the water column for each
baghouse for all periods of operation. The electronic screens indicate the unit identification
and provides a live reading. The manufacturer recommended ranges are set by the
computerized monitor that uses an alarm system to alert the operator for any reading that
is outside of the established ranges.

II.B.2.d At least once every 12 months, the owner/operator shall calibrate each pressure gauge in
accordance with the manufacturer's instructions or replace the pressure gauge. [R307-401-8]

Status: In Compliance. The pressure gauges are calibrated annually. The last calibration
occurred on November 20, 2024. See the attached email correspondence.

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II.B.2.d.1 The owner/operator shall maintain records of each pressure gauge calibrations and replacements.
[R307-401-8]

Status: In Compliance. Records of the calibrations and gauge replacements are maintained
at the site office and are required by the Asahi Corporation.

II.B.3 Wet Scrubber Requirements

II.B.3.a The owner/operator shall use the following scrubbers to control the following process streams.

Scrubber Process Stream
Scrubber #248 silver anode slime washing process, silver nitrate plant, and slime
plant

Scrubber #359 gold electrolytic cells, gold refinery wet circuits, gold chloride
electrolytic production, silver chlorides sludge processing,
chlorination furnaces, melt furnaces, tilt furnaces, push-out
furnaces, and drying cabinets

Scrubber #760 wastewater treatment tanks and laboratory

Scrubber #761 silver electrolytic cells

All exhaust air from the above-mentioned process streams shall be routed through the indicated
scrubber before being vented to the atmosphere.

[R307-401-8]

Status: In Compliance. The referenced scrubbers control the process streams as described
with the exception of scrubber #761. The silver electrolytic cell process has not yet been
installed.

II.B.3.b During operation of each scrubber, the owner/operator shall maintain both the pressure drop and
the liquid flow rate within the respective range recommended by the manufacturer for normal
operations. [R307-401-8]

Status: In Compliance. The manufacturer ranges are programed into the computerized
monitoring system. Any reading outside of the established ranges triggers an alarm to alert
the operators.

II.B.3.b.1 The parameters shall be monitored with instruments located such that an inspector/operator can
safely read the output any time. [R307-401-8]

Status: In Compliance. The scrubber monitoring is electronically recorded as a live stream
that can be viewed on various computer screens.

II.B.3.c The owner/operator shall record both the pressure drop and liquid flow rate at least once per
operating day while each scrubber is operating. [R307-401-8]

Status: In Compliance. The pressure drops and liquid flow rates are continuously
monitored and recorded. See the attached snap shot of the scrubber monitoring screen.
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II.B.3.c.1 The owner/operator shall maintain the following records of the pressure drop and liquid flow
rate:

A. Unit identification;

B. Manufacturer recommended pressure drop and liquid flow rate range;

C. Daily pressure drop and liquid flow rate readings;

D. Date of reading.

[R307-401-8]

Status: In Compliance. This facility has a computerized monitoring system that maintains
the scrubber parameters within the historic efficiency control rates. This condition is new
to this AO and was added to the permit to ensure the maximum control conditions for the
future silver electrolytic cell process associated with Scrubber #761 which is scheduled to
be added in October of 2025. The 2024 NOI details for this process, the planned building
addition, and the manufacturer recommended flow rates for that scrubber, is attached to
this memo for reference. Scrubbers #248, #359, and #760 were installed prior to the
requirement to report on the manufacturer flow rate recommendations. The requirement
at the time consisted of reporting the control efficiency rates. The previous owners of the
facility, Johnson Matthey, reported on a December 29, 2009, Letter to the DAQ regarding a
requested "Reduction in Air Contaminants" that references a 99% control efficiency. See
the January 28, 2009, NOI for DAQE-AN0103670014-09 for more information. This
condition was discussed with the source contact who stated that the scrubber flow rates for
the three older processes are effective at 300 to 450 gpm. The live continuous monitoring
includes the unit identification, and live flow rates. See the attached snap shot of the
scrubber screen recording the operation of the three existing older wet scrubbers.

II.B.3.d At least once every 12 months, the owner/operator shall calibrate each instrument in accordance
with the manufacturer's instructions or replace the instrument. [R307-401-8]

Status: In Compliance. The instruments measuring and controlling the scrubber operation
are calibrated every 12 months.

II.B.3.d.1 The owner/operator shall maintain records of each instrument calibrations and replacements.
[R307-401-8]

Status: In Compliance. The last calibration for the scrubber gauges was on November 20,
2024. The last ph meter calibration occurred on November 28, 2024. See the attached email
correspondence.

II.B.3.e The owner/operator shall install a scrubber (ID# 761) that is certified to meet a NOx emission
reduction of no less than 24%. [R307-401-8]

Status: Not Observed. Scrubber #761 is scheduled to be completed in October of 2025.

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II.B.3.e.1 To demonstrate compliance with the above condition, the owner/operator shall maintain records
of the manufacturer's emissions guarantee for the installed scrubber. [R307-401-8]

Status: Not Observed. The new silver electrolytic cells that will be controlled by Scrubber
#761 will be installed in October of 2025.

II.B.4 Emergency Engine

II.B.4.a The owner/operator shall certify that the 850 hp (550 kW) natural gas-fired, emergency engine
installed on site has a NOx emission rate of 0.40 grams per horsepower hour (g/hp-hr) or less, a
CO emission rate of 0.7 g/hp-hr or less, and a VOC emission rate of 0.7 g/hp-hr or less at the
exhaust point. [R307-401-8]

Status: Not Applicable. The natural gas 850 hp (550 kW) engine has not yet been installed.
This engine will be used for the future silver electrolytic cell system scheduled to be
installed in October of 2025.

II.B.4.a.1 To demonstrate compliance with the above condition, the owner/operator shall either:

A. Purchase a stationary internal combustion engine which has obtained certification
as defined in 40 CFR 1039.801; or

B. Conduct an initial performance test according to 40 CFR part 1039.

C. Maintain the manufacturer's emissions guarantee for the installed engine model.

[R307-401-8]

Status: Not Applicable. The natural gas engine will be installed in October of 2025.

II.B.4.b 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 63 Subpart ZZZZ, R307-401-8]

Status: In Compliance. The 60-kW generator was used for the 13-month period of
December 1, 2023, through December 11, 2024, for 51.1 hours. See the attached emergency
generator hourly use report.

II.B.4.b.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: 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. The use log for the 60-kW generator includes the date, duration, and reason for use and is recorded at the time of each use. See the attached submitted emergency generator log.
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II.B.4.c The owner/operator shall only use natural gas as fuel in each emergency engine. [R307-401-8]

Status: In Compliance. Only natural gas is used in the currently used emergency engine.

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) JJJJ: Standards of Performance for Stationary Spark Ignition Internal Combustion Engines

Status: Not Applicable. Not applicable at this time, but this subpart will be enforced when the 2022
manufacture year 850 hp natural gas engine has been installed and is operational.

NESHAP (Part 63) ZZZZ: National Emissions Standards for Hazardous Air Pollutants for Stationary
Reciprocating Internal Combustion Engines.

Status: In Compliance. A 60-kW natural gas-powered emergency generator manufactured in 2000 is
located on site. The generator is equipped with a non-resettable hour meter and is typically tested on
Wednesdays. Cummins is the contractor that provides routine required maintenance. The total
maintenance hours for the 13-month period of December 2023 through December 2024 was reported as
under the 100-hour federal limit.

AREA SOURCE RULES EVALUATION:

The following Area Source Rules were evaluated during this inspection:

Stationary Sources [R307-210]

Status: Not Applicable. R307-210 Stationary Sources incorporates NSPS Subpart JJJJ for natural
gas engines that were manufactured after July 1, 2008. This Subpart will apply to this facility after
II.A.28, the 2022 850 hp natural gas fired emergency engine has been installed and is operational
following October of 2025.

National Emission Standards for Hazardous Air Pollutants [R307-214]

Status: In Compliance. R307-214 incorporates MACT Subpart ZZZZ for the pre-2006
manufactured natural gas 60 kW emergency engine. See the Federal Requirements Section for
Subpart ZZZZ for more information.

Nonattainment and Maintenance Areas for PM10: Emissions and Fugitive Emissions and Fugitive Dust
[R307-309]

Status: In Compliance. The entrance, the surrounding parking, and truck load out areas to this
facility are paved. The source contact is trained to observe visible emissions and regularly monitors
the site. No visible dust or visible emissions were observed during this inspection.

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EMISSION INVENTORY:
Emissions Inventories are currently not required for this facility. The emissions listed below are an
estimate of the total potential emissions (PTE) from Asahi Refining USA, Inc. – Precious Metals Refinery
on the Approval Order (AO) DAQE-AN103670031-24, dated October 7, 2024. PTE are supplied for
supplemental purposes only.

Criteria Pollutant PTE tons/yr
Ammonia 0.06
CO2 Equivalent 994.70
Carbon Monoxide 0.80
Lead 0.01
Nitrogen Oxides 4.35
Particulate Matter - PM10 2.01
Particulate Matter - PM2.5 2.01
Sulfur Dioxide 6.11
Volatile Organic Compounds 0.16

Hazardous Air Pollutant PTE lbs/yr
Chlorine (CAS #7782505) 800
Formaldehyde (CAS #50000) 31
Generic HAPs (CAS #GHAPS) 10
Hexane (CAS #110543) 20
Hydrochloric Acid (Hydrogen Chloride) (CAS #7647010) 1600
Lead (CAS #7439921) 20
Selenium & Compounds (CAS #253) 60

PREVIOUS ENFORCEMENT
ACTIONS: No compliance actions are on record for the previous five years.

COMPLIANCE STATUS &
RECOMMENDATIONS: Asahi Refining should be considered to be in compliance with
the AO DAQE-AN103670031-24, dated October 7, 2024, and
NSPS Subpart ZZZZ. The new equipment associated with this
AO had not yet been installed at the time of this inspection. This
facility is well maintained and routinely keeps the required
records.

HPV STATUS: Not Applicable.

RECOMMENDATION FOR
NEXT INSPECTION: Check on the installation of the new equipment and associated
processes during the next inspection. This facility is a secured
operation and will require scheduling the inspection in advance.
A metal detection scan is required prior to entrance. No jewelry
or other metals are allowed on site. Use standard PPE.

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NSR RECOMMENDATIONS: No recommendation for NSR at this time. A full review of the
AO DAQE-AN103670031-24, dated October 7, 2024, new
equipment will occur after the installation is completed.

ATTACHMENTS: VEO, email correspondence, production totals, live screen
baghouse, sweeps, and scrubber snapshots, and reported
emergency generator hours.
Susan Weisenberg <[e-mail]>
RE: scheduling a routine air quality inspection for new Approval Order
1 message
Stewart Hogan <[e-mail]>Wed, Dec 11, 2024 at 5:14 PM
To: Susan Weisenberg <[e-mail]>
Hi Susan,

Please find the information as requested attached and below.
1. Production totals spreadsheet attached.
2. Baghouse snapshots
a. Snapshot melt attached, Melt baghouse manufacture recommendation is between 0.4 in and
7.0 in WG.
b. Melt dust collector snapshot, manufacture recommendation is between 1.0 in and 6.0 in WG
c. Sweeps dust collector snapshot, manufacture recommendation is between 1.0 in and 6.0 in WG
3. All three were last calibrated on November 20, 2024
4. Scrubber snapshot attached.
5. All Scrubber pressure drop gages were last calibrated November 20, 2024. All pH meters last
calibrated November 28, 2024.

Let me know if you have any questions.

Thanks,
Stewart

Stewart Hogan CIH | Environmental Health & Safety Manager, NA
A: Asahi Refining USA, Inc. | 4601 W 2100 S | Salt Lake City, UT 84120
E: [e-mail] | W: https://www.asahirefining.com
O: [phone] | D: [phone] | M: [phone]

From: Susan Weisenberg <[e-mail]>
Sent: Tuesday, December 10, 2024 5:46 PM
1/26/25, 8:28 PM State of Utah Mail - RE: scheduling a routine air quality inspection for new Approval Order
https://mail.google.com/mail/u/0/?ik=bffac613d3&view=pt&search=all&permthid=thread-a:r1230571497031491651%7Cmsg-f:1818191446918943423…1/4
To: Stewart Hogan <[e-mail]>
Subject: Re: scheduling a roune air quality inspecon for new Approval Order

Thank you for the site visit today. Just as a recap, please submit 1. the 12-month production totals as per II.B.1.b.A - II.B.1.C. 2. a snapshot showing the baghouse pressure differential water column
sophospsmartbannerend
Thank you for the site visit today. Just as a recap, please submit
1. the 12-month production totals as per II.B.1.b.A - II.B.1.C.
2. a snapshot showing the baghouse pressure differential water column for the four baghouses with a statement of each
baghouse's manufacturer's recommendation ranges.
3. the date of the most recent calibration for each baghouse.
4. a snapshot showing the scrubber pressure drops and liquid flow rates for each operating scrubber.
5. The date of the most recent calibration for each scrubber.

Let me know if you have any questions or comments.

Susan Weisenberg,
Environmental Scientist
Office: 385-306-6512

On Thu, Dec 5, 2024 at 6:00 PM Stewart Hogan <[e-mail]> wrote:
Hi Susan,

It is a busy time of year for everyone I think but we would be glad to have you either Tuesday 12/10 after
9:30AM or Monday 12/16 any time.

For your information none of the new equipment on the AO has arrived on site yet.

Thanks,
Stewart

From: Susan Weisenberg <[e-mail]>
Sent: Thursday, December 5, 2024 9:53 AM
1/26/25, 8:28 PM State of Utah Mail - RE: scheduling a routine air quality inspection for new Approval Order
https://mail.google.com/mail/u/0/?ik=bffac613d3&view=pt&search=all&permthid=thread-a:r1230571497031491651%7Cmsg-f:1818191446918943423…2/4
Baghouse snapshot melt.jpg
84K
Melt dust collector snapshot.jpg
93K
Sweeps dust collector snapshot.jpg
85K
Scrubber screen snapshot.jpg
108K
Prod Summary_Air Permit_24.xls
33K
1/26/25, 8:28 PM State of Utah Mail - RE: scheduling a routine air quality inspection for new Approval Order
https://mail.google.com/mail/u/0/?ik=bffac613d3&view=pt&search=all&permthid=thread-a:r1230571497031491651%7Cmsg-f:1818191446918943423…4/4
Asahi Refining Monthly ProductionAir Permit Averages
Production Limits
Au 12 x 106 ozt per rolling 12-month period
Ag 60 x 106 ozt per rolling 12-month periodSweeps400tons per 12-month period
As per Section II.B.1.c of Approval Order due no later than 20 days after the end of each month
Ag Au (ozt)(tons)
Dec-23 2,395,099 459,222 489,102 16.8
Jan-24 3,185,686 475,428 205,953 7.1
Feb-24 4,347,126 435,150 224,732 7.7
Mar-24 2,688,396 326,174 511,516 17.5
Apr-24 2,520,959 322,536 863,491 29.6
May-24 2,376,135 363,390 291,103 10.0
Jun-24 2,691,371 288,319 655,647 22.5
Jul-24 2,336,812 338,577 50,045 1.7
Aug-24 3,723,327 318,599 367,564 12.6
Sep-24 2,498,474 381,012 303,908 10.4
Oct-24 2,336,812 338,577 100,090 3.4
Nov-24 2,239,890 310,607 343,759 11.812 Mo. Total 33,340,087 4,357,591 151
(ozt)
Sweeps
Weight
Gold & Silver
Emergency Generator Use Log
Date Start (Hours) End (Hours) Duration (Hours)
Reason (PM, Test, UP&L
Outage,etc)
fri 12/1/2023 796.3 796.3 0 Not used
mon 12/4/2023 796.3 796.3 0 Not used
tue 12/5/2023 796.3 796.3 0 Not used
wed 12/6/2023 796.3 796.8 0.5 Regular Maintenance
thu 12/7/2023 796.8 796.8 0 Not used
fri 12/8/2023 796.8 796.8 0 Not used
mon 12/11/2023 796.8 796.8 0 Not used
tue 12/12/2023 796.8 796.8 0 Not used
wed 12/13/2023 796.8 797.3 0.5 Regular Maintenance
thu 12/14/2023 797.3 797.3 0 Not used
fri 12/15/2023 797.3 797.3 0 Not used
mon 12/18/2023 797.3 797.3 0 Not used
tue 12/19/2023 797.3 797.3 0 Not used
wed 12/20/2023 797.3 797.4 0.1 Maintenance?
thu 12/21/2023 797.4 797.4 0 Not used
fri 12/22/2023 797.4 797.4 0 Not used
mon 12/25/2023 797.4 797.4 0 Not used
tue 12/26/2023 797.4 797.4 0 Not used
wed 12/27/2023 797.4 797.4 0 No apparent maintenance
thu 12/28/2023 797.4 797.4 0 Not used
fri 12/29/2023 797.4 797.4 0 Not used
mon 1/1/2024 797.4 797.4 0 Not used
tue 1/2/2024 797.4 797.4 0 Not used
wed 1/3/2024 797.4 797.9 0.5 Regular Maintenance
thu 1/4/2024 797.9 797.9 0 Not used
fri 1/5/2024 797.9 797.9 0 Not used
mon 1/8/2024 797.9 797.9 0 Not used
tue 1/9/2024 797.9 797.9 0 Not used
wed 1/10/2024 797.9 798.4 0.5 Regular Maintenance
thu 1/11/2024 798.4 798.4 0 Not used
fri 1/12/2024 798.4 798.4 0 Not used
mon 1/15/2024 798.4 798.4 0 Not used
tue 1/16/2024 798.4 798.4 0 Not used
wed 1/17/2024 798.4 798.9 0.5 Regular Maintenance
thu 1/18/2024 798.9 798.9 0 Not used
fri 1/19/2024 798.9 798.9 0 Not used
mon 1/22/2024 798.9 798.9 0 Not used
tue 1/23/2024 798.9 798.9 0 Not used
wed 1/24/2024 798.9 799.4 0.5 Regular Maintenance
thu 1/25/2024 799.4 799.4 0 Not used
fri 1/26/2024 799.4 799.4 0 Not used
mon 1/29/2024 799.4 799.4 0 Not used
tue 1/30/2024 799.4 799.4 0 Not used
wed 1/31/2024 799.4 799.4 0 Maintenance did not run
thu 2/1/2024 799.4 799.4 0 Not used
fri 2/2/2024 799.4 799.4 0 Not used
mon 2/5/2024 799.4 799.4 0 Not used
tue 2/6/2024 799.4 799.4 0 Not used
wed 2/7/2024 799.4 799.5 0.1
Abnormal regular maintenance.
Contacted Craig about this.
thu 2/8/2024 799.5 799.5 0 Not used
fri 2/9/2024 799.5 799.6 0.1
Abnormal regular maintenance.
Contacted Craig about this.
mon 2/12/2024 799.6 799.6 0 Not used
tue 2/13/2024 799.6 799.6 0 Not used
wed 2/14/2024 799.6 800.1 0.5
Cummins came in for
maintenance. Battery was
nearly dead so he replaced this.
Recommend replace every 3
years or sooner.
thu 2/15/2024 800.1 800.1 0 Not used
fri 2/16/2024 800.1 800.1 0 Not used
mon 2/19/2024 800.1 800.1 0 Not used
tue 2/20/2024 800.1 800.1 0 Not used
wed 2/21/2024 800.1 800.6 0.5 Regular Maintenance
thu 2/22/2024 800.6 800.6 0 Not used
fri 2/23/2024 800.6 800.6 0 Not used
mon 2/26/2024 800.6 800.6 0 Not used
tue 2/27/2024 800.6 800.6 0 Not used
wed 2/28/2024 800.6 801.1 0.5 Regular Maintenance
thu 2/29/2024 801.1 801.1 0 Not used
fri 3/1/2024 801.1 801.1 0 Not used
mon 3/4/2024 801.1 801.1 0 Not used
tue 3/5/2024 801.1 801.1 0 Not used
wed 3/6/2024 801.1 801.6 0.5 Regular Maintenance
thu 3/7/2024 801.6 801.6 0 Not used
fri 3/8/2024 801.6 801.6 0 Not used
mon 3/11/2024 801.6 801.6 0 Not used
tue 3/12/2024 801.6 801.6 0 Not used
wed 3/13/2024 801.6 802.1 0.5 Regular Maintenance
thu 3/14/2024 802.1 802.1 0 Not used
fri 3/15/2024 802.1 802.1 0 Not used
mon 3/18/2024 802.1 802.1 0 Not used
tue 3/19/2024 802.1 802.1 0 Not used
wed 3/20/2024 802.1 802.6 0.5 Regular Maintenance
thu 3/21/2024 802.6 802.6 0 Not used
fri 3/22/2024 802.6 802.6 0 Not used
mon 3/25/2024 802.6 802.6 0 Not used
tue 3/26/2024 802.6 802.6 0 Not used
wed 3/27/2024 802.6 803.1 0.5 Regular Maintenance
thu 3/28/2024 803.1 803.1 0 Not used
fri 3/29/2024 803.1 803.1 0 Not used
mon 4/1/2024 803.1 803.1 0 Not used
tue 4/2/2024 803.1 803.1 0 Not used
wed 4/3/2024 803.1 803.6 0.5 Regular Maintenance
thu 4/4/2024 803.6 803.6 0 Not used
fri 4/5/2024 803.6 803.6 0 Not used
sat 4/6/2024 803.6 806.7 3.1
Weekend shutdown.
Maintenance work to fix
electrical hot spots.
mon 4/8/2024 806.7 806.7 0 Not used
tue 4/9/2024 806.7 806.7 0 Not used
wed 4/10/2024 806.7 807.2 0.5 Regular Maintenance
thu 4/11/2024 807.2 807.2 0 Not used
fri 4/12/2024 807.2 807.2 0 Not used
mon 4/15/2024 807.2 807.2 0 Not used
tue 4/16/2024 807.2 807.2 0 Not used
wed 4/17/2024 807.2 807.7 0.5 Regular Maintenance
thu 4/18/2024 807.7 807.7 0 Not used
fri 4/19/2024 807.7 807.7 0 Not used
mon 4/22/2024 807.7 807.7 0 Not used
tue 4/23/2024 807.7 807.7 0 Not used
wed 4/24/2024 807.7 808.2 0.5 Regular Maintenance
thu 4/25/2024 808.2 808.2 0 Not used
fri 4/26/2024 808.2 808.2 0 Not used
mon 4/29/2024 808.2 808.2 0 Not used
tue 4/30/2024 808.2 808.2 0 Not used
wed 5/1/2024 808.2 808.7 0.5 Regular Maintenance
thu 5/2/2024 808.7 808.7 0 Not used
fri 5/3/2024 808.7 808.7 0 Not used
mon 5/6/2024 808.7 808.7 0 Not used
tue 5/7/2024 808.7 808.7 0 Not used
wed 5/8/2024 808.7 809.2 0.5 Regular Maintenance
thu 5/9/2024 809.2 809.2 0 Not used
fri 5/10/2024 809.2 809.2 0 Not used
mon 5/13/2024 809.2 809.2 0 Not used
tue 5/14/2024 809.2 809.2 0 Not used
wed 5/15/2024 809.2 809.7 0.5 Regular Maintenance
thu 5/16/2024 809.7 809.7 0 Not used
fri 5/17/2024 809.7 809.7 0 Not used
mon 5/20/2024 809.7 809.7 0 Not used
tue 5/21/2024 809.7 809.7 0 Not used
wed 5/22/2024 809.7 810.2 0.5 Regular Maintenance
thu 5/23/2024 810.2 810.2 0 Not used
fri 5/24/2024 810.2 810.2 0 Not used
mon 5/27/2024 810.2 810.2 0 Not used
tue 5/28/2024 810.2 810.2 0 Not used
wed 5/29/2024 810.2 810.7 0.5 Regular Maintenance
thu 5/30/2024 810.7 810.7 0 Not used
fri 5/31/2024 810.7 810.7 0 Not used
mon 6/3/2024 810.7 810.7 0 Not used
tue 6/4/2024 810.7 810.7 0 Not used
wed 6/5/2024 810.7 811.2 0.5 Regular Maintenance
thu 6/6/2024 811.2 811.2 0 Not used
fri 6/7/2024 811.2 811.2 0 Not used
mon 6/10/2024 811.2 811.2 0 Not used
tue 6/11/2024 811.2 811.2 0 Not used
wed 6/12/2024 811.2 811.7 0.5 Regular Maintenance
thu 6/13/2024 811.7 811.7 0 Not used
fri 6/14/2024 811.7 811.7 0 Not used
mon 6/17/2024 811.7 811.7 0 Not used
tue 6/18/2024 811.7 811.7 0 Not used
wed 6/19/2024 811.7 812.2 0.5 Regular Maintenance
thu 6/20/2024 812.2 812.2 0 Not used
fri 6/21/2024 812.2 812.2 0 Not used
mon 6/24/2024 812.2 812.2 0 Not used
tue 6/25/2024 812.2 812.2 0 Not used
wed 6/26/2024 812.2 812.7 0.5 Regular Maintenance
thu 6/27/2024 812.7 812.7 0 Not used
fri 6/28/2024 812.7 812.7 0 Not used
mon 7/1/2024 812.7 812.7 0 Not used
tue 7/2/2024 812.7 812.7 0 Not used
wed 7/3/2024 812.7 813.2 0.5 Regular Maintenance
thu 7/4/2024 813.2 813.2 0 Not used
fri 7/5/2024 813.2 813.2 0 Not used
mon 7/8/2024 813.2 813.2 0 Not used
tue 7/9/2024 813.2 813.2 0 Not used
wed 7/10/2024 813.2 813.7 0.5 Regular Maintenance
thu 7/11/2024 813.7 813.7 0 Not used
fri 7/12/2024 813.7 813.7 0 Not used
mon 7/15/2024 813.7 813.7 0 Not used
tue 7/16/2024 813.7 817.8 0.1 Power bump
wed 7/17/2024 817.8 832.5 19.7
Power outage, transfer switch
open, ran past power coming
back on. Power went out
roughly 8:30 PM Tuesday,
returned 8:15 AM Wednesday
thu 7/18/2024 832.5 832.5 0 Not used
fri 7/19/2024 832.5 832.5 0 Not used
mon 7/22/2024 832.5 832.5 0 Not used
tue 7/23/2024 832.5 832.5 0 Not used
wed 7/24/2024 832.5 832.5 0 No maintenance run
thu 7/25/2024 832.5 832.6 0.1 Transfer switch replacement
fri 7/26/2024 832.6 832.6 0 Not used
mon 7/29/2024 832.6 832.6 0 Not used
tue 7/30/2024 832.6 832.6 0 Not used
wed 7/31/2024 832.6 833.2 0.6 Regular Maintenance
thu 8/1/2024 833.2 833.2 0 Not used
fri 8/2/2024 833.2 833.2 0 Not used
mon 8/5/2024 833.2 833.2 0 Not used
tue 8/6/2024 833.2 833.2 0 Not used
wed 8/7/2024 833.2 833.7 0.5 Regular Maintenance
thu 8/8/2024 833.7 833.7 0 Not used
fri 8/9/2024 833.7 833.7 0 Not used
mon 8/12/2024 833.7 833.7 0 Not used
tue 8/13/2024 833.7 833.7 0 Not used
wed 8/14/2024 833.7 834.3 0.6 Regular Maintenance
thu 8/15/2024 834.3 834.3 0 Not used
fri 8/16/2024 834.3 834.3 0 Not used
mon 8/19/2024 834.3 834.3 0 Not used
tue 8/20/2024 834.3 834.3 0 Not used
wed 8/21/2024 834.3 834.9 0.6 Regular Maintenance
thu 8/22/2024 834.9 834.9 0 Not used
fri 8/23/2024 834.9 834.9 0 Not used
mon 8/26/2024 834.9 834.9 0 Not used
tue 8/27/2024 834.9 834.9 0 Not used
wed 8/28/2024 834.9 835.5 0.6 Regular Maintenance
thu 8/29/2024 835.5 835.5 0 Not used
fri 8/30/2024 835.5 835.5 0 Not used
mon 9/2/2024 835.5 835.5 0 Not used
tue 9/3/2024 835.5 835.5 0 Not used
wed 9/4/2024 835.5 839.3 3.8
3 hour power outage in the
middle of the night + regular
maintenance in the afternoon.
thu 9/5/2024 839.3 839.3 0 Not used
fri 9/6/2024 839.3 839.3 0 Not used
mon 9/9/2024 839.3 839.3 0 Not used
tue 9/10/2024 839.3 839.3 0 Not used
wed 9/11/2024 839.3 839.8 0.5 Regular Maintenance
thu 9/12/2024 839.8 839.8 0 Not used
fri 9/13/2024 839.8 839.8 0 Not used
mon 9/16/2024 839.8 839.8 0 Not used
tue 9/17/2024 839.8 839.8 0 Not used
wed 9/18/2024 839.8 840.4 0.6 Regular Maintenance
thu 9/19/2024 840.4 840.4 0 Not used
fri 9/20/2024 840.4 840.4 0 Not used
mon 9/23/2024 840.4 840.4 0 Not used
tue 9/24/2024 840.4 840.4 0 Not used
wed 9/25/2024 840.4 841 0.6 Regular Maintenance
thu 9/26/2024 841 841 0 Not used
fri 9/27/2024 841 841 0 Not used
mon 9/30/2024 841 841 0 Not used
tue 10/1/2024 841 841 0 Not used
wed 10/2/2024 841 841.6 0.6 Regular Maintenance
thu 10/3/2024 841.6 841.6 0 Not used
fri 10/4/2024 841.6 841.6 0 Not used
mon 10/7/2024 841.6 841.6 0 Not used
tue 10/8/2024 841.6 841.6 0 Not used
wed 10/9/2024 841.6 842.2 0.6 Regular Maintenance
thu 10/10/2024 842.2 842.2 0 Not used
fri 10/11/2024 842.2 842.2 0 Not used
mon 10/14/2024 842.2 842.2 0 Not used
tue 10/15/2024 842.2 842.2 0 Not used
wed 10/16/2024 842.2 842.8 0.6 Regular Maintenance
thu 10/17/2024 842.8 842.8 0 Not used
fri 10/18/2024 842.8 842.8 0 Not used
mon 10/21/2024 842.8 842.8 0 Not used
tue 10/22/2024 842.8 842.8 0 Not used
wed 10/23/2024 842.8 843.3 0.5 Regular Maintenance
thu 10/24/2024 843.3 843.3 0 Not used
fri 10/25/2024 843.3 843.3 0 Not used
mon 10/28/2024 843.3 843.3 0 Not used
tue 10/29/2024 843.3 843.3 0 Not used
wed 10/30/2024 843.3 843.9 0.6 Regular Maintenance
thu 10/31/2024 843.9 843.9 0 Not used
fri 11/1/2024 843.9 843.9 0 Not used
mon 11/4/2024 843.9 843.9 0 Not used
tue 11/5/2024 843.9 843.9 0 Not used
wed 11/6/2024 843.9 844.5 0.6 Regular Maintenance
thu 11/7/2024 844.5 844.5 0 Not used
fri 11/8/2024 844.5 844.5 0 Not used
mon 11/11/2024 844.5 844.5 0 Not used
tue 11/12/2024 844.5 844.5 0 Not used
wed 11/13/2024 844.5 845.1 0.6 Regular Maintenance
thu 11/14/2024 845.1 845.1 0 Not used
fri 11/15/2024 845.1 845.1 0 Not used
mon 11/18/2024 845.1 845.1 0 Not used
tue 11/19/2024 845.1 845.1 0 Not used
wed 11/20/2024 845.1 845.7 0.6 Regular Maintenance
thu 11/21/2024 845.7 845.7 0 Not used
fri 11/22/2024 845.7 845.7 0 Not used
mon 11/25/2024 845.7 845.7 0 Not used
tue 11/26/2024 845.7 845.7 0 Not used
wed 11/27/2024 845.7 846.3 0.6 Regular Maintenance
thu 11/28/2024 846.3 846.3 0 Not used
fri 11/29/2024 846.3 846.3 0 Not used
mon 12/2/2024 846.3 846.3 0 Not used
tue 12/3/2024 846.3 846.3 0 Not used
wed 12/4/2024 846.3 846.8 0.5 Regular Maintenance
thu 12/5/2024 846.8 846.8 0 Not used
fri 12/6/2024 846.8 846.8 0 Not used
mon 12/9/2024 846.8 846.8 0 Not used
tue 12/10/2024 846.8 846.8 0 Not used
wed 12/11/2024 846.8 847.4 0.6 Regular Maintenance
thu 12/12/2024 847.4
Total Time Run 12/1/2023-12/12/2024: 51.1 Hours