DAQ-2024-010987

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DAQC-CI160800001-24
Site ID 16080 (B1)
MEMORANDUM

TO: FILE – HYRUM CITY POWER – Hyrum Power Plant

THROUGH: Chad Gilgen, Minor Source Compliance Section Manager

FROM: Connor Kijowski, Environmental Scientist

DATE: September 17, 2024

SUBJECT: PARTIAL COMPLIANCE EVALUATION, Minor, Cache County

INSPECTION DATE: August 28, 2024

SOURCE LOCATION: 1350 West 4600 South
Hyrum, UT 84319

SOURCE CONTACTS: Steve Liechty, Power Department Superintendent
[phone], [e-mail]

OPERATING STATUS: Not Operating.

PROCESS DESCRIPTION: Hyrum City Power is a utility company that operates 5 (five)
2.6-Megawatt (MW) natural gas-fired engines continuously
(8,760 hours per year) to generate electricity for the city of
Hyrum. The facility is rated to produce up to 13 MW of
electricity.

APPLICABLE REGULATIONS: Approval Order (AO) DAQE-AN160800002-23, dated
January 9, 2023

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

SOURCE EVALUATION: Name of Permittee: Permitted Location: Hyrum City Power Hyrum Power Plant
60 West Main Street 1350 West 4600 South Hyrum, UT 84319 Hyrum, UT 84319-1002 SIC Code: 4911: (Electric Services)

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

I.5 The owner/operator shall 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]

I.6 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.7 The owner/operator shall comply with UAC R307-107. General Requirements: Breakdowns.
[R307-107]

I.8 The owner/operator shall comply with UAC R307-150 Series. Emission Inventories. [R307-150]

Status: In Compliance. Each condition from Section I was reviewed with the source and
appeared to be in compliance. A construction notification letter was submitted after the
inspection; refer to this letter in the attachments. The source has not been directed to
submit an Emission Inventory at this time.

Section II: SPECIAL PROVISIONS

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

II.A.1 Hyrum City Power Plant
13 MW Electric Power Plant

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II.A.2 Five (5) G3520 Caterpillar Generators
Fuel: Natural Gas
Max. Capacity: 2.6 MW each
Rating: 3,628 HP each

NSPS/MACT Applicability: 40 CFR 60 Subpart JJJJ, 40 CFR 63 Subpart ZZZZ

II.A.3 One (1) Tier 3 Caterpillar Emergency Generator

Fuel: Diesel
Rating: 280 HP

NSPS/MACT Applicability: 40 CFR 60 Subpart IIII, 40 CFR 63 Subpart ZZZZ

Status: In Compliance. No unapproved equipment has been installed. Three of the
five Caterpillar Generators listed in II.A.2 have been installed with the
potential to expand and include the other two generators in the future.

II.B Requirements and Limitations

II.B.1 Facility-Wide Requirements

II.B.1.a The owner/operator shall not allow visible emissions from any source on site to exceed 10%
opacity. [R307-401-8]

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

Status: Not Observed. The stationary equipment was not operating at the time of
inspection. The equipment was recently installed but has not yet operated.

II.B.2 Natural Gas Generator Engine Requirement

II.B.2.a The owner/operator shall use only natural gas as fuel in all 3,628 HP generator engines.
[R307-401-8]

Status: In Compliance. Only natural gas is used as fuel in the 3,628 HP generator engines.

II.B.3 Physical Stack Requirement

II.B.3.a The owner/operator shall install a stack on each 3,628 HP generator engine such that it has a
stack release height of at least 45 feet as measured from the ground. [R307-401-3]

Status: Not Observed. The stack release height appeared to be at least 45 feet from the
ground. However, some equipment was still in the process of being installed and the stacks
could not be safely measured.

II.B.4 Stack Testing Requirement

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II.B.4.a The owner/operator shall not emit more than the following rates from each 2.6 MW Generator:

Pollutant g/hp-hr
NOx 0.07
CO 0.098
VOCs 0.105
[R307-401-8]

II.B.4.a.1 Compliance Demonstration
To demonstrate compliance with the emission limitations above, the owner/operator shall
perform stack testing on the emissions unit according to the stack testing conditions contained in
this AO. [R307-165-2, R307-401-8]

II.B.4.a.2 Initial Test
The owner/operator shall conduct an initial stack test on each emission unit within 180 days after
startup of the emission unit. [R307-165-2]

II.B.4.a.3 Test Frequency
The owner/operator shall conduct a stack test on each emission unit within three (3) years after
the date of the most recent stack test of the emission unit. The Director may require the
owner/operator to perform a stack test at any time. [R307-401-8]

II.B.4.a.4 Notification
At least 30 days prior to conducting a stack test, the owner/operator shall submit a source test
protocol to the Director. The source test protocol shall include the items contained in
R307-165-3. If directed by the Director, the owner/operator shall attend a pretest conference.
[R307-165-3, R307-401-8]

II.B.4.a.5 Testing & Test Conditions
The owner/operator shall conduct testing according to the approved source test protocol and
according to the test conditions contained in R307-165-4. [R307-165-4, R307-401-8]

II.B.4.a.6 Access
The owner/operator shall provide Occupational Safety and Health Administration (OSHA)- or
Mine Safety and Health Administration (MSHA)-approved access to the test location.
[R307-401-8]

II.B.4.a.7 Reporting
No later than 60 days after completing a stack test, the owner/operator shall submit a written
report of the results from the stack testing to the Director. The report shall include validated
results and supporting information. [R307-165-5, R307-401-8]

II.B.4.a.8 Possible Rejection of Test Results
The Director may reject stack testing results if the test did not follow the approved source test
protocol or for a reason specified in R307-165-6. [R307-165-6, R307-401-8]

II.B.4.b Test Methods
When performing stack testing, the owner/operator shall use the appropriate EPA-approved test
methods as acceptable to the Director. Acceptable test methods for pollutants are listed below.
[R307-401-8]

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II.B.4.b.1 Standard Conditions
A. Temperature - 68 degrees Fahrenheit (293 K)
B. Pressure - 29.92 in Hg (101.3 kPa)

C. Averaging Time - As specified in the applicable test method
[40 CFR 60 Subpart A, 40 CFR 63 Subpart A, R307-401-8]

II.B.4.b.2 NOx
40 CFR 60, Appendix A, Method 7; Method 7E; or other EPA-approved testing method as
acceptable to the Director. [R307-401-8]

II.B.4.b.3 VOC
40 CFR 60, Appendix A, Method 18; Method 25; Method 25A; 40 CFR 63, Appendix A,
Method 320; or other EPA-approved testing method as acceptable to the Director.
[R307-401-8]

II.B.4.b.4 CO
40 CFR 60, Appendix A, Method 10 or other EPA-approved testing method as acceptable to the
Director. [R307-401-8]

Status: Not Observed. The source planned to conduct initial stack testing September 4-6,
2024. The results from the stack tests have not yet been submitted for review. Refer to the
stack testing pretest protocol review for more information (DAQC-768-24).

II.B.5 Emergency Engine Requirements

II.B.5.a The owner/operator shall install a 280 HP generator engine that is certified to meet a NOx
emission rate of no greater than 2.9 g/hp-hr. [R307-401-8]

II.B.5.a.1 To demonstrate compliance with the above condition, the owner/operator shall either:

A. Own/operate a stationary internal combustion engine which has obtained Tier 3
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]

II.B.5.a.2 The owner/operator shall maintain records of engine certification, the initial performance test, or
the manufacturer's emissions guarantee. [R307-401-8]

Status: In Compliance. The 280 HP generator engine was verified to be EPA Tier 3
certified. Compliance assistance was provided to ensure this record of certification is kept
with the equipment according to this condition.

II.B.5.b The owner/operator shall not operate the 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 engine during emergencies. [40 CFR 63 Subpart ZZZZ, R307-401-8]
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II.B.5.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 the 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: Not Observed. The emergency generator engine was recently installed but has not
operated since installation. Compliance assistance was provided to ensure records are kept
according to this condition. The source is aware there is no operational time limit during
emergencies.

II.B.5.b.2 To determine the duration of operation, the owner/operator shall install a non-resettable hour
meter for the emergency engine. [40 CFR 63 Subpart ZZZZ, R307-401-8]

Status: In Compliance. A non-resettable hour meter is installed on the emergency engine.

II.B.5.c The owner/operator shall not conduct emergency generator readiness testing before 8:00 am or
after 6:00 pm each day. [R307-401-8]

II.B.5.c.1 The owner/operator shall keep and maintain the following records of operation for all periods of
emergency generator readiness testing:

A. Time operations begin each day

B. Time operations end each day. [R307-401-8]

Status: Not Observed. The emergency generator engine was recently installed but has not
operated since installation. Compliance assistance was provided to ensure the engine does
not operate outside of the listed hours for readiness testing and that records will be kept
according to this condition.

II.B.5.d The owner/operator shall only use diesel fuel (e.g. fuel oil #1, #2, or diesel fuel oil additives) as
fuel in the emergency engine. [R307-401-8]

II.B.5.d.1 The owner/operator shall only combust diesel fuel that meets the definition of ultra-low sulfur
diesel (ULSD), which has a sulfur content of 15 ppm or less. [R307-401-8]

II.B.5.d.2 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: Not Observed. The source indicated that only ultra-low sulfur diesel will be used as
fuel for the emergency engine. The engine was recently installed and has not operated yet,
so this requirement could not be verified at the time of the inspection.
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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) IIII: Standards of Performance for Stationary Compression Ignition Internal Combustion Engines Status: In Compliance. A non-resettable hour meter is installed. The engine was recently installed but has not yet operated. Compliance assistance was provided to track maintenance and operational hours.
NSPS (Part 60) JJJJ: Standards of Performance for Stationary Spark Ignition Internal Combustion Engines

Status: Not Observed. The applicable generator engines listed in II.A.2 were scheduled for initial stack
tests on September 4-6, 2024, according to this subpart. The results of the tests have not yet been
submitted for review. Refer to the stack testing pretest protocol review for more information
(DAQC-768-24).

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

Status: In Compliance. A non-resettable hour meter is installed. The source plans to utilize ultra-low
sulfur fuel for the emergency engine. However, the engine was recently installed and has not yet
operated. Compliance assistance was provided to track maintenance and operational hours.

AREA SOURCE RULES EVALUATION:
The following Area Source Rules were evaluated during this inspection: Stationary Sources [R307-210] Status: In Compliance. This rule is satisfied by NSPS Subpart IIII and JJJJ. Refer to these subparts in the Federal Requirements section.
National Emission Standards for Hazardous Air Pollutants [R307-214]

Status: In Compliance. This rule is satisfied by MACT Subpart ZZZZ. Refer to this subpart in the
Federal Requirements section.

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

Status: In Compliance. No fugitive emissions or dust were observed during the inspection. The site is
still partially under construction but is mostly paved or enclosed. The potential for fugitive dust is
low.

EMISSION INVENTORY:
The emissions listed below are an estimate of the total potential emissions (PTE) from Hyrum City
Power – Hyrum Power Plant on the Approval Order (AO) DAQE-AN160800002-23, dated January 9,
2023. PTE are supplied for supplemental purposes only.
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Criteria Pollutant PTE tons/yr
CO2 Equivalent 3686.65
Carbon Monoxide 17.19
Nitrogen Oxides 12.35
Particulate Matter - PM10 5.55
Particulate Matter - PM2.5 5.55
Sulfur Dioxide 0.33
Volatile Organic Compounds 18.39

Hazardous Air Pollutant PTE lbs/yr
1,3-Butadiene (CAS #106990) 148
2,2,4-Trimethylpentane (CAS #540841) 139
Acetaldehyde (CAS #75070) 4650
Acrolein (CAS #107028) 2859
Benzene (Including Benzene From Gasoline) (CAS #71432) 245
Biphenyl (CAS #92524) 118
Formaldehyde (CAS #50000) 12612
Generic HAPs (CAS #GHAPS) 317
Hexane (CAS #110543) 194
Methanol (CAS #67561) 438

PREVIOUS ENFORCEMENT
ACTIONS: No enforcement actions in the past five years.

COMPLIANCE STATUS &
RECOMMENDATIONS: In regards to Approval Order (AO) DAQE-AN160800002-23,
dated January 9, 2023, the overall status is: In Compliance. The
equipment was recently installed but is not yet operating.
Compliance assistance was provided to ensure records are
tracked and maintained according to the conditions listed in the
AO.

HPV STATUS: Not Applicable.

RECOMMENDATION FOR
NEXT INSPECTION: Look for emergency engine operating hour records, diesel fuel
certification, maintenance records, stack test results, and stack
heights.

NSR RECOMMENDATIONS: None at this time.

ATTACHMENTS: Construction Status Letter

August 29, 2024
Submitted electronically to [e-mail]
Utah Department of Environmental Quality
Division of Air Quality
P.O. Box 144820
Salt Lake City, UT 84114-4820

City of Hyrum, Utah, Approval Order DAQE-AN160800001-22, Section 1.5 Status of Construction or
Modification.

City of Hyrum hereby submits this notification as required by Section 1.5 of DAQE-AN160800001-22, that
the equipment listed in Section II.A.2 (3) G3520 Caterpillar Generators and Section II.A.3 (1) Caterpillar
Emergency Generator of the Approval Order have been installed and is now operational.

Please reach out to me with any further questions or comments regarding this notification.
Phone [phone] or by email at [e-mail].

Best regards,

Steve Liechty
City of Hyrum
Power Department Superintendent