DAQ-2025-003454

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DAQC-CI109200001-25
Site ID 10920 (B1)

MEMORANDUM

TO: FILE – ARDENT MILLS, LLC – Ogden Flour Mill

THROUGH: Chad Gilgen, Minor Source Compliance Section Manager

FROM: Susan Weisenberg, Environmental Scientist

DATE: May 19, 2025

SUBJECT: FULL COMPLIANCE EVALUATION, Minor, Weber County

INSPECTION DATE: April 30, 2025

SOURCE LOCATION: 2780 G Avenue
Ogden, UT
DIRECTIONS: From I-15 north bound, Exit 342 to UT-53 and F Avenue. Turn
on G Avenue. The office is a brown brick building on the west
side of the silos. The office entrance is up the ramped stairs on
the silo side of the building.

SOURCE CONTACTS: Jason Gauderman, Plant Manager
801-395-3153 [e-mail]

OPERATING STATUS: Operating normally

PROCESS DESCRIPTION: Ardent Mills, LLC, operates a wheat storage and flour mill. The
wheat is received by truck and railcar. The product is stored until
the mill is ready for processing. The wheat and grain are
unloaded at the unloading stations. The whet is then transferred,
binned, cleaned, and milled into flour and blended into various
products according to the buyers' specifications. The flour is
bagged and shipped to customers. The mill can operate
continuously 24-hours a day, seven days a week, and is capable
of producing 30 tons of flour per hour.

APPLICABLE REGULATIONS: Approval Order (AO) DAQE-AN109200010-24, dated July 17,
2024
SOURCE EVALUATION:

Name of Permittee: Permitted Location:

Ardent Mills, LLC - Ogden Flour Mill
2780 G Avenue 2780 G Avenue
Ogden, UT 84401 Ogden, UT

SIC Code: 2041: (Flour & Other Grain Mill Products)
0 . ) $ . ) - "
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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 limits were exceeded based on the site observations and a review of the submitted documents. No additional equipment or processes were detected.
Preventative maintenance occurs and is recorded as required. No applicable breakdowns
have occurred. Emission Inventories are submitted as required. A notification of the installation and operation of the new equipment was provided following this inspection and
is included as an attachment. The notification was emailed to the NSR engineer Enqiang
He, and NSR Administrative Tech, Jeree Greenwood to be added to the NSR Laserfiche files.

Section II: SPECIAL PROVISIONS

II.A The approved installations shall consist of the following equipment:

II.A.1 Ardent Mills, LLC Wheat Storage and Flour Mill
II.A.2 E-01 Baghouse Service Area: Elevator, Garner, Scales & Distribution (Grain Handling EU03, Grain Storage EU04, Grain Loadout Truck EU05, Grain Loadout Rail EU06, Wheat Cleaning 1 EU08) Exhaust Flow Rate: 12,800 ACFM Installed Date: 1968
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II.A.3 E-06 Baghouse Service Area: Elevator Basement & Truck Receiving (Grain Receiving Truck EU01 and Grain Receiving Rail EU02, Wheat Cleaning 1 EU08) Exhaust Flow Rate: 20,750 ACFM Installed Date: 1979
II.A.4 E-08 Baghouse Service Area: Mill Feed Load-out Conveyors (Feed Load-Out Truck EU24) Exhaust Flow Rate: 11,700 ACFM Installed Date: 1971
II.A.5 E-09 Baghouse Service Area: Grain Load-out System (Grain Handling EU03, Grain Storage EU04, Grain Loadout Truck EU05, Grain Loadout Rail EU06, Wheat Cleaning 1 EU08) Exhaust Flow Rate: 2,500 ACFM Installed Date: 1977
II.A.6 E-10 Baghouse Service Area: Wheat Cleaning System (Color Sort Wheat Cleaning System EU07) Exhaust Flow Rate: 13,000 ACFM Installed Date: 1971
II.A.7 E-16 Baghouse Service Area: Whole Wheat Load-out System (Whole Wheat Storage EU17, Whole Wheat Load-Out Truck EU18, Whole Wheat Load-Out Rail EU19) Exhaust Flow Rate: 3,500 ACFM Installed Date: 2014 The baghouse is vented indoors
II.A.8 M-01 Baghouse Service Area: Flour Mill, Roll Suction (Flour Milling A Mill EU10) Exhaust Flow Rate: 11,480 ACFM Installed Date: 1958
II.A.9 M-03 Baghouse Service Area: South Mill Purifiers 1-6 (Flour Milling A Mill EU10) Exhaust Flow Rate: 9,840 ACFM Installed Date: 1958
II.A.10 M-07 Baghouse Service Area: General Suction-All Mill Scales, Conveyors, Pin Mill Equipment & Flour Bins (Flour Milling A Mill EU10, Flour Milling B Mill EU11, Flour Storage EU13, Packaging/Bulk Loading Truck EU15, Packaging/Bulk Loading Rail EU16) Exhaust Flow Rate: 20,000 CFM Installed Date: 1955
II.A.11 M-08 Baghouse Service Area: All Whole Wheat Equipment (Whole Wheat Flour Milling C Mill EU12) Exhaust is vented internally and not discharged to the atmosphere
II.A.12 M-09 Baghouse Service Area: Mill Pneumatics System (Flour Milling A Mill EU10) Exhaust Flow Rate: 17,500 ACFM Installed Date: 1988
II.A.13 M-10 Baghouse Service Area: Aspirators, Brk Rolls and Mill Legs (Flour Milling B Mill EU11) Exhaust Flow Rate: 22,036 ACFM Installed Date: 2009
II.A.14 M-11 Baghouse Service Area: Mill Pneumatics System (Flour Milling B Mill EU11) Exhaust Flow Rate: 22,036 ACFM Installed Date: 2009
II.A.15 CH-01 Baghouse Service Area: Grinding Bin, Combinators, 2nd Temper Entoleters and Leg (Wheat Cleaning 2 EU09) Exhaust Flow Rate: 13,000 CFM Installed Date: 1965
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II.A.16 CH-05 Baghouse Service Area: Wheat Cleaning Equipment (Wheat Cleaning 1 EU08, Screenings Storage EU20, Feed Storage A Mill EU22) Exhaust Flow Rate: 23,400 ACFM Installed Date: 1980
II.A.17 CH-07 Baghouse Service Area: Screenings Grinding (Screening Hammermill EU21) Exhaust Flow Rate: 1,600 ACFM Installed Date: 1999
II.A.18 CH-08 Baghouse Service Area: Wheat Cleaning Equipment (Wheat Cleaning 1 EU08, Feed Storage B Mill EU23, Organic Bran Storage EU28) Exhaust Flow Rate: 22,036 ACFM Installed Date: 2009
II.A.19 P-01 Baghouse Service Area: Bulk-All Truck and Rail Loading Equipment (Packaging/Bulk Loading Truck EU15, Packaging/Bulk Loading Rail EU16) Exhaust Flow Rate: 22,036 ACFM Installed Date: 2009
II.A.20 P-06 Baghouse Service Area: Ingredient Cut-In Equipment (Malt Flour Ingredient Handling EU14A) Exhaust is vented internally and not discharged to the atmosphere
II.A.21 P-06B Baghouse - new equipment Service Area: the malt ingredient storage unit (surge bin) (Malt Ingredient Storage EU14B) Exhaust Flow Rate: 570 SCFM Installed Date: 2023 The baghouse is vented indoors
II.A.22 P-07 Baghouse Service Area: Elevator Load/Unload Bin Vent (Food Grade Bran Feed Storage EU26) Exhaust Flow Rate: 200 ACFM Installed Date: 2002 Exhaust is vented indoors
II.A.23 Mill feed Loadout Equipment (Feed Loadout Truck EU24 and Feed Load Rail EU25) Bran Mill Loadout Equipment includes: 1. A conveyor of the type that is designed to raise and lower to the top of the truck, which will reduce open freefall and choke feed the remainder of the load. 2. A quick opening/closing door system on the entrance to the existing loadout building.
II.A.24 Truck/Rail Grain Receiving Pits (Grain Receiving Truck EU01/FP01 & Grain Receiving Rail EU02/FP02) 1. Baffles below the grating 2. A quick opening/closing door system on the entrance to the existing receiving building 3. Aspiration below the baffles to baghouse E-06
Status: In Compliance. The P-06B Baghouse identified by II.A.21, has been installed and is operating. All other equipment identified within Section II.A has been installed and is operating as noted by the previous inspection DAQC-Cl109200001-23.

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II.B Requirements and Limitations

II.B.1 The Ogden Flour Mill shall be subject to the following:

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

A. Truck/Railcar unloading station - 5% opacity

B. Railcar loading station - 5% opacity

C. Truck loading station - 10% opacity

D. All baghouse exhaust stacks - 10% opacity

E. All other points - 20% opacity
[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. [R307-201-3]

Status: In Compliance. No visible emissions could be seen from any stack or vent. Most stacks are visible from the ground. See the attached VEO.

II.B.2 Baghouse Requirements
II.B.2.a The owner/operator shall install a manometer or magnehelic pressure gauge to measure the
differential pressure across the fabric filters in each of the following baghouses: E-01, E-06, E-08, E-09, E-10, M-01, M-03, M-07, M-09, M-10, M-11, CH-01, CH-05, CH-07, CH-08, and P-
01. All exhaust air from the processes shall be routed through their designated baghouses before
being vented to the atmosphere. [R307-401-8]
Status: In Compliance. The referenced baghouse gauges have been installed and are
operational. The gauge differential pressure measurements are monitored with a live continuous electronic screen and a daily reading which is printed and logged. The three
recently added baghouse gauges for E-08, M-07, and CH-01 were not yet integrated into
the daily printed log but were being monitored by the continuous electronic system. See the attached May 12, 2025, email correspondence and the submitted Pressure Drop Reading
electronic screen shot.
II.B.2.a.1 The pressure gauges shall be located such that an inspector/operator can safely read the
indicators at any time. [R307-401-8]
Status: In Compliance. All gauges are continuously electronically monitored. An electronic
screen is set up to observe the live measurements. The physical gauges are located where an
inspector or a staff member can easily read the indicators.
II.B.2.a.2 The pressure gauges shall measure the pressure drop in 0.5-inch water column increments or less. [R307-401-8]
Status: In Compliance. Both the physical and the electronic continuous gauges measure the pressure drops in .25 increments.

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II.B.2.b During operation of the baghouses, the owner/operator shall maintain the static pressure drop across the baghouses between 0.5 and 8.0 inches of water column. [R307-401-8] Status: In Compliance. The baghouse gauges measure the pressure drops that normally range between 0.5 and 8.0 inches of water column. Any reading outside of the ranges require an employee to check the airflow and the corresponding physical gauge for discrepancies. See the April 28, 2025, Daily Differential Report. The gauges for E-08, M-07, and CH-01 are not included on this printout, but a screen shot of the live electronic monitoring was submitted to document the differential pressure drop operating within the recommended range. II.B.2.b.1 The owner/operator shall record the pressure drop through each baghouse for each day the controlled processes are in operation. [R307-401-8] Status: In Compliance. The pressure drop readings are electronically monitored continuously for all periods for when the processes are in operation. II.B.2.b.2 The owner/operator shall maintain the following records of the pressure drop readings: A. Unit identification; B. Date of reading; C. Daily static pressure drop readings. [R307-401-8] Status: In Compliance. The unit identification, date, and recorded pressure drop are included in the continuous and daily printed log readings. II.B.2.c The owner/operator shall operate, maintain, and calibrate the pressure gauges in accordance with the manufacturer's instructions/recommendations or replace the gauges. [R307-401-8] Status: In Compliance. Gauges are maintained and are calibrated as per the manufacturer's recommendations. Any discrepancies between the physical and the electronic gauge measurements will result in a work order for maintenance and calibration of the gauge. II.B.2.c.1 The Owner/operator shall keep the following records: A. Unit identification B. Dates of pressure gauge calibration or replacement. [R307-401-8] Status: In Compliance. The plant manager stated that the gauges are re-calibrated by Ardent staff whenever there is a discrepancy between the physical gauge reading and the electronic monitoring reading. Any maintenance of calibration that cannot be corrected by the in-house staff results in a work order created to schedule the mechanical repair. Work orders for gauge repair include the unit identification, work required, and the date of the maintenance. See the attached E-10-gauge calibration example.

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II.B.3 All Haul Roads and Fugitive Dust Sources shall be subject to the following: II.B.3.a The owner/operator shall periodically sweep or water spray the in-plant paved haul road to meet the following visible emission limits: A. 20% opacity on site, and B. 10% opacity at the property boundary. [R307-309-5, R307-401] Status: In Compliance. Ardent Mills submitted their FDCP as a recommended commitment to dust control measures in an April 12, 2024, amendment to their NOI for this AO. The requested dust control measures were incorporated into Condition II.B.3.a.1. No visible dust or flour track out was observed during the site inspection. II.B.3.a.1 The owner/operator shall keep records of sweeps and water sprays to include the following: A. Date of sweeps or water sprays B. Time of day sweeps or water sprays conducted The owner/operator may stop sweeps when the paved haul roads are covered with snow, and may stop water spray when the temperature is below freezing. [R307-401-8] Status: In Compliance. The grounds and all potential spill points are reportedly checked weekly as part of the facility's Master Sanitation Schedule. All clean up measures are reported on work orders. See the attached order dated April 30, 2025. II.B.3.a.2 The records shall be kept for all periods when the plant is in operation. [R307-401-8] Status: In Compliance. Road sanitation work orders are kept for all periods when the plant is in operation. II.B.3.a.3 Visible emission determinations for fugitive dust emissions from haul-road traffic and mobile equipment in operational areas 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, R307-401-8] Status: In Compliance. No visible emissions were observed from any vehicle or truck during the site observations. II.B.3.b The owner/operator shall conduct its operations in such a way to minimize fugitive dust and fugitive emissions and shall comply with all applicable requirements of R307-309. [R307-309] Status: In Compliance. This facility minimizes flour spills as they occur. The operation areas are paved. Road and operation areas are swept or sprayed when necessary in accordance with the April 12, 2024, letter incorporated into Condition II.B.3.a.1.

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.

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AREA SOURCE RULES EVALUATION:

The following Area Source Rules were evaluated during this inspection:

Nonattainment and Maintenance Areas for PM10: Emission Standards [R307-305]

Status: In Compliance. No visible emissions were observed at the time of this inspection. Fugitive
dust and fugitive emissions are actively mitigated.

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

Status: In Compliance. Refer to Conditions II.B.3.a and II.B.3.a.1 for more information.

EMISSION INVENTORY:
Listed below are the Actual Emissions Inventory provided from Ardent Mills, LLC - Ogden Flour Mill. A
comparison of the estimated total potential emissions (PTE) on AO: DAQE-AN109200010-24, dated July
17, 2024, is provided. PTE are supplied for supplemental purposes only.

Criteria Pollutant PTE tons/yr Actuals tons/yr
Particulate Matter - PM10 43.80 41.666
Particulate Matter - PM2.5 23.73 14.022

Hazardous Air Pollutant PTE lbs/yr Actuals lbs/yr

PREVIOUS ENFORCEMENT
ACTIONS: No enforcement actions on record for the last five years.

COMPLIANCE STATUS &
RECOMMENDATIONS: In Compliance with the conditions of the AO
DAQE-AN109200010-24 dated July 17, 2024.

HPV STATUS: Not Applicable.
RECOMMENDATION FOR
NEXT INSPECTION: Inspect as usual maintaining the same targeting frequency.
Check for the inclusion of pressure drop readings for baghouse
gauges E-08, M-07, and CH-01 in the daily printed log. Steel
toed boots, hard hat, safety glasses, and hearing protection are
required to tour the facility. Most of the silo stacks and vents are
visible from the ground.

NSR RECOMMENDATIONS: None at this time.

ATTACHMENTS: VEO, P-06 Baghouse Installation Notification, Filter Daily
Differential Pressure Report, Baghouse Gauge monitoring
correspondence, Baghouse Pressure Gauge live screen shot,
example magnehelic calibration Work Order, example Work
Order for dust control for operation areas, and 2023 activity year
Emissions Inventory Report.
Susan Weisenberg <[e-mail]>
Completion of Installation - P-06B Baghouse
1 message
Ian Fraser <[e-mail]>Wed, Apr 30, 2025 at 10:56 AM
To: "[e-mail]" <[e-mail]>
Cc: Jason Gauderman <[e-mail]>, Adam Varo <[e-mail]>
Susan,
As per I.8 of the AO, installaon is complete for P-06B Baghouse and is operaonal.
Thank you.
5/19/25, 6:33 PM State of Utah Mail - Completion of Installation - P-06B Baghouse
https://mail.google.com/mail/u/0/?ik=bffac613d3&view=pt&search=all&permthid=thread-f:1830847453449509176%7Cmsg-f:1830847453449509176&s…1/1
P0
1
E1
0
Mi
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l
Susan Weisenberg <[e-mail]>
Re: Requested Documentation - Ardent Mills
1 message
Ian Fraser <[e-mail]>Mon, May 12, 2025 at 7:17 AM
To: Susan Weisenberg <[e-mail]>
Susan,
I apologize for the delay as I was in all day trainings this past week. Aached is a screen shot with E-08, M-
07, and CH-01 and their readings (they are marked in the black box in the screenshot). Please note that
some filters are currently being turned off for cleaning.
Hope you have a great day.
Thank you.
From: Susan Weisenberg <[e-mail]>
Sent: Wednesday, May 7, 2025 8:40 AM
To: Ian Fraser <[e-mail]>
Subject: Re: Requested Documentaon - Ardent Mills

EXTERNAL EMAIL: This email originated from outside of Ardent Mills. Do not click links or open attachments unless you
recognize the sender and know the content is safe.
Thanks - can you provide me with a screenshot that includes E-08, M-07, and CH-01 showing the pressure drop readings
for these filters? That will provide documentation of full compliance with Condition II.B.2.a.
Susan Weisenberg,
Environmental Scientist
Office: 385-306-6512
On Wed, May 7, 2025 at 7:16 AM Ian Fraser <[e-mail]> wrote:
Hello Susan,
Thank you for the follow up regarding gauges on the Daily Differential Pressure Reports.
As for filters: E-08, M-07, and CH-01; they are installed and are not yet being recorded on the daily print
out report, as mentioned above.
However, the filters are monitored in real time via our digital monitoring system, which you saw on the
computer. We are working to have those filters added into the Daily Differential Pressure Reports.
Thank you.
From: Susan Weisenberg <[e-mail]>
Sent: Tuesday, May 6, 2025 8:00 AM
5/19/25, 11:46 AM State of Utah Mail - Re: Requested Documentation - Ardent Mills
https://mail.google.com/mail/u/0/?ik=bffac613d3&view=pt&search=all&permthid=thread-f:1830849158531107229%7Cmsg-f:1831920845132841148&s…1/2
To: Ian Fraser <[e-mail]>
Subject: Re: Requested Documentaon - Ardent Mills

EXTERNAL EMAIL: This email originated from outside of Ardent Mills. Do not click links or open attachments unless you
recognize the sender and know the content is safe.
Hello Ian,
Please accept my apologies for the delayed response. I recently noted a discrepancy regarding Condition II.B.2.a in
your current Air Operating Permit (AO). It appears that pressure gauges E-08, M-07, and CH-01, which are referenced
in the AO, are not currently included in the Daily Differential Pressure Reports.
Could you please clarify whether these gauges were ever installed? Alternatively, if they are installed, could you let me
know if the differential pressure readings for these gauges are just not yet being recorded in the reports?
Thank you for your time and assistance with this.
Sincerely,
Susan
Susan Weisenberg,
Environmental Scientist
Office: 385-306-6512
Pressure Drop Readings.pptx
254K
5/19/25, 11:46 AM State of Utah Mail - Re: Requested Documentation - Ardent Mills
https://mail.google.com/mail/u/0/?ik=bffac613d3&view=pt&search=all&permthid=thread-f:1830849158531107229%7Cmsg-f:1831920845132841148&s…2/2
2023 Emissions Inventory Report
Ardent Mills, LLC - Ogden Flour Mill (10920)
Emissions Summary
CRITERIA AIR POLLUTANT (CAP) EMISSIONS TOTALS
Pollutant Code/CAS #Pollutant Name Emissions
(tons,
excluding
tailpipe)
Tailpipe
Emissions
(tons)
Total Emissions
(tons)*
PM10-PRI PM10 Primary (Filt + Cond)41.66669 <.00001 41.66669
PM25-PRI PM2.5 Primary (Filt + Cond)14.02196 <.00001 14.02196

HAZARDOUS AIR POLLUTANT (HAP) and/or OTHER POLLUTANT EMISSIONS TOTALS
Pollutant Code/CAS #Pollutant Name Is VOC/PM? Total Emissions
(tons)*

*Rounded to 5 digits past the decimal point. Note that where rounding results in 0, <.00001 is indicated.
1/2