DAQ-2025-002583

1
DAQC-477-25
Site ID 10327 (B5)

MEMORANDUM

TO: FILE – INTERMOUNTAIN POWER SERVICE

THROUGH: Harold Burge, Major Source Compliance Section Manager

FROM: Rob Leishman, Environmental Scientist

DATE: May 16, 2025

SUBJECT: Intermountain Power Service (IPP), Major, NSPS, Title V, Acid Rain, Millard
County, FRS # UT00000049002700010

INSPECTION TYPE: State Electronic Data Report (SEDR) Review

REVIEW DATE: May 16, 2025

SOURCE LOCATION: 850 West Brush Wellman Road/Millard County

SOURCE CONTACT: Mike Ferrell – 435-864-6487

APPLICABLE
REGULATIONS: Title V Operating Permit 2700010006
Date of Permit: November 21, 2023
Date of Last Revision: November 21, 2023

SOURCE INSPECTION
EVALUATION: This review will only address the findings of the quarterly report.
Approval Order and Title V permit conditions addressing continuous
emission monitoring requirements will be addressed in IPP’s relative
accuracy performance specification test review memorandum.

SEDR Review

First Quarter 2025
% Monitor Availability (MA) Performance Test Dates
(N/A to Opacity)
Summary of Excess Emissions During
Point Source Operation
Point
Source
Op.
hrs. Channel MA CGA Lin RATA Point
Source Channel Hrs. Limitation
Unit 1 1923 SO2 100% 01/06/25 01/06/25 07/16/24 Unit 1 Opacity 0.00 20 % - 6 min.
Unit 1 1923 CO2 100% 01/06/25 01/06/25 07/16/24 Unit 1 SO2 0.00
0.138
lb/mmbtu -
30 DRA
Unit 1 1923 Opacity 99% Unit 1 NOx 0.00
0.461
lb/mmbtu -
30 DRA
Unit 1 1923 SO2 100% 01/06/25 01/06/25 07/16/24 Unit 2 Opacity 0.00 20 % - 6 min.

1 8 2

2
First Quarter 2025
% Monitor Availability (MA) Performance Test Dates
(N/A to Opacity)
Summary of Excess Emissions During
Point Source Operation
Point
Source
Op.
hrs. Channel MA CGA Lin RATA Point
Source Channel Hrs. Limitation
Unit 1 1923 NOx 100% 01/06/25 01/06/25 07/13/24 Unit 2 SO2 0.00
0.138
lb/mmbtu -
30 DRA
Unit 1 1923 CO2 100% 01/06/25 01/06/25 07/16/24 Unit 2 NOx 0.00
0.461
lb/mmbtu -
30 DRA
Unit 2 2160 SO2 100% 01/06/25 01/06/25 07/15/24
Unit 2 2160 CO2 100% 01/06/25 01/06/25 07/15/24
Unit 2 2160 Opacity 99%
Unit 2 2160 SO2 100% 01/06/25 01/06/25 07/15/24
Unit 2 2160 NOx 100% 01/06/25 01/06/25 07/12/24
Unit 2 2160 CO2 100% 01/06/25 01/06/25 07/15/24
Summary of SO2 Emission Reduction
Percent Removal Required
% Reduction

Point
Source Channel Min Max Days in violation Status
Unit 1 SO2 94% 95% 90% 0 In compliance
Unit 2 SO2 93% 94% 90% 0 In compliance

Excess Emission Report - Hourly Summary
Point
Source Channel
Startup
&
Shutdown
Control
Equipment
Problems
Process
Problems
Other
Known
Causes
Unknown
Causes
Emission
Limit
Unit 1 Opacity 0 0 0 0 0 20 % - 6 min.
Unit 1 SO2 0 0 0 0 0 0.138 lb/mmbtu - 30 DRA
Unit 1 NOx 0 0 0 0 0 0.461 lb/mmbtu - 30 DRA
Unit 2 Opacity 0 0 0 0 0 20 % - 6 min.
Unit 2 SO2 0 0 0 0 0 0.138 lb/mmbtu - 30 DRA
Unit 2 NOx 0 0 0 0 0 0.461 lb/mmbtu - 30 DRA

CMS Performance Summary - Hourly Summary
Point
Source Channel Monitor
Malfunction
Non-monitor
Malfunction
QA
Calibrations
Other
Known
Causes
Unknown
Causes
Unit 1 SO2 7 0 0 0 0
Unit 1 CO2 7 0 0 0 0
Unit 1 Opacity 0 0 12 0 0
Unit 1 SO2 0 0 0 1 0
Unit 1 NOx 0 0 0 1 0

3
CMS Performance Summary - Hourly Summary
Point
Source Channel Monitor
Malfunction
Non-monitor
Malfunction
QA
Calibrations
Other
Known
Causes
Unknown
Causes
Unit 1 CO2 0 0 0 2 0
Unit 2 SO2 2 0 0 1 0
Unit 2 CO2 0 0 0 1 0
Unit 2 Opacity 0 0 13 0 0
Unit 2 SO2 0 0 0 1 0
Unit 2 NOx 0 0 0 1 0
Unit 2 CO2 0 0 0 1 0

Type Code 280 (COMS Attenuator Filters) Procedure 3
Point Source &
Location
Attenuator
I.D.
Attenuator
Certification
Date
Certified
Attenuator
Opacity
OPLR,
SECR,
or
PLCF,
Corrected
Opacity
Value
Range
Low,
Mid,
&
High
Certification
1-year or 5-
year
Unit 1 - Scrubber Duct S10405 12/18/24 26.72 0.56 15.98 Low 1
Unit 1 - Scrubber Duct S10348 12/18/24 37.29 0.56 23 Mid 1
Unit 1 - Scrubber Duct S10425 12/18/24 58.42 0.56 38.82 High 1
Unit 2 - Scrubber Duct S10412 12/7/23 26.96 0.56 16.13 Low 1
Unit 2 - Scrubber Duct S10349 12/7/23 37.62 0.56 23.22 Mid 1
Unit 2 - Scrubber Duct S10425 12/7/23 59.64 0.56 39.84 High 1

Type Code 281 (Procedure 3 - COMS Filter Audit Calibration Error)
Point
Source Location Audit Date
Opacity Monitor Response
(Average of 5) Mean Difference Calibration
Error (≤ 3%) Low Mid High
Unit 1 Scrubber Duct 1/8/25 16 0.140 0.150
Unit 1 Scrubber Duct 1/8/25 23 0.030 0.033
Unit 1 Scrubber Duct 1/8/25 39 0.310 0.324
Unit 2 Scrubber Duct 1/9/25 16 0.070 0.088
Unit 2 Scrubber Duct 1/9/25 23 0.250 0.273
Unit 2 Scrubber Duct 1/9/25 39 0.610 0.639

4
Type Code 282 (Annual Zero Alignment Audit) Procedure 3
Point
Source Location Audit
Date
Alternative
Zero
Alignment
(Yes or No)
COM Clear
Condition
Zero
Response
(CCZR)
COM
Simulated
Zero
Response
(CSZR)
Zero
Alignment
Error
Difference
(CCZR)-
(CSZR)
Adjustment
to COM
Simulated
Zero
Response
(CSZR)
(Yes or No)
Unit 1 Scrubber Duct 10/11/22 No 0.00 0 0 Yes
Unit 2 Scrubber Duct 7/2/24 No 0.00 0.0025 0 Yes

Summary of SO2 Emission Reduction
Percent Removal Required Percent
Reduction

Point
Source Channel Min Max Days in violation
Unit 1 SO2 94% 95% 90% 0
Unit 2 SO2 93% 94% 90% 0

Pollutant Concentration
Exceeded Span of CEM
Monitor Outage During
Point Source Operation
Alternate
Sampling CEM Modifications
0 Hours 50 Hours 0 Hours 0 Events

SOURCE INSPECTION
SUMMARY EVALUATION: IPP maintains its CEMS as required in R307-170 and 40 CFR 60.13.

CURRENT
RECOMMENDATIONS: All deviations appear to be a result of breakdown or process related
problems that do not warrant issuing a violation. Periods of excess
emissions that were recorded by the CMS in service on each point source
during this reporting period are summarized in the SEDR and described
in Pivot Table 400 “Excess Emissions Review.”

IPP was in compliance during this reporting period. No further
enforcement action is recommended.

IPP’s NSPS monitoring system meets the performance standards of 40
CFR 60, Appendix B Performance Specifications.

IPP’s acid rain monitoring system meets the performance standards of 40
CFR 75 Acid Rain Performance Specifications.

HPV: No

RECOMMENDATION
FOR NEXT INSPECTION: Check DAS for daily zero and span drift.
Check the QC program to ensure that monitor drift is being tracked and
that the source can identify excessive drift.

ATTACHMENTS: Excel spreadsheet review

Intermountain Power Service Corporation
850 West Brush Wellman Road, Delta, Utah, 84624 / Telephone: [phone] / FAX: [phone] / Fed. I.D. #87-0388573

April 29, 2025

Mr. Bryce Bird, Director
Utah Division of Air Quality
195 North 1950 West
P.O. Box 144820
Salt Lake City, Utah 84114-4820

Dear Director Bird:

Units 1 and 2 First Quarter, 2025 Emissions Report
Operating Permit #2700010006

As part of Intermountain Power Service Corporation's reporting requirements for the Intermountain
Generating Station, we are submitting Units 1 and 2 First Quarter 2025 Emissions Report in ASCII
electronic format for your review. The report has been electronically transmitted to Mr. Rob Leishman
of the UDAQ.

If you have any questions or comments, please contact Mr. Michael Ferrell, Lead Technical Analyst of
Technical Services, at [phone] or [e-mail].

Sincerely,

Dahl Dalton
President and Chief Operations Officer and Responsible Official

MAF/HBI

cc: Kevin Peng
Tamer Ellyahky
Trevor Johnson

Intermountain Power Service Corporation
850 West Brush Wellman Road, Delta, Utah, 84624 / Telephone: [phone] / FAX: [phone] / Fed. I.D. #87-0388573

April 29, 2025

Mr. Bryce Bird, Director
Utah Division of Air Quality
195 North 1950 West
P.O. Box 144820
Salt Lake City, Utah 84114-4820
Dear Director Bird:
Signed Statement, Deviation Report
Units 1 and 2 First Quarter 2025 As required by R307-415-5d, this signed statement is being submitted for Units 1 and 2 for the First Quarter 2025, Quarterly Report.

1. For any periods for which opacity, sulfur dioxide, or nitrogen oxide emission data are not available, changes were not made in the operation of the emission control system.
2. The required continuous monitoring system calibration, span and drift checks, and other
periodic audits have been performed as specified. 3. The data used to show compliance was obtained in accordance with approved methods
and procedures of Subpart Da and is representative of plant performance.
4. The minimum data requirements have been met.
5. Compliance with the standards has been achieved during the reporting period.
Under penalty of law, all information contained in the report is truthful, accurate, and is a complete record of all monitoring related events which occurred during the reporting period.

This letter provides notice that this report constitutes a deviation report as required under Section I.S.2.c and Section II.B.2.e.3 of our Title V Operating Permit #2700010006. This report is considered prompt notification as stated in Section II.B.2.e.3.d of our Operating Permit.

Mr. Bryce Bird
April 29, 2025
Page 2
I certify, based on information and belief formed after reasonable inquiry, the statements and
information in the document is true, accurate, and complete. Sincerely,

Dahl Dalton President and Chief Operations Officer and Responsible Official
MAF/HBI
cc: Kevin Peng
Tamer Ellyahky
Trevor Johnson

Intermountain Power EER 1Q2025
Point Source Information Late Expired Cal. Gas Valid Cal. Gas Days Yes No
1 Type Code 100
(Company Information)Type Code Company Manager Company Name AIRS # Phone Number
Environmental
Contact1 100 Dahl Dalton 02700010 435-864-4414 Michael Ferrell
1 100 0 0 0 0
1 Type Code 110
(Point Source Identification)Type Code Point Source
Quarter
1 - 4 Year Point Source
Operating Hrs. in Quarter
1 110 1 2025 1923
1 110 1 2025 2160
1 110 0 0 0
1 Type Code 200
(Monitor Identification)Type Code Point Source Channel Manufacturer Model No. Monitor SN Low Span High Span Installation Date
Monitor
Location
1 200 CO2 TECO 410i 834333319 20 0 4/15/2009 Stack
1 200 CO2 TECO 410i 834333318 20 0 4/8/2009 Scrubber Inlet
1 200 SO2 TECO 43i 534613720 500 1000 11/27/2005 Scrubber Inlet
1 200 NOx TECO 42i 534613722 500 1000 11/28/2005 Stack
1 200 Opacity Teledyne Monitor Labs Lighthawk 560 5602579 100 0 3/24/2014 Scrubber Inlet
1 200 SO2 TECO 43i 534613714 50 1000 11/28/2005 Stack
1 200 CO2 TECO 410i 834333320 20 0 4/15/2009 Stack
1 200 CO2 TECO 410i 834333317 20 0 4/15/2009 Scrubber Inlet
1 200 SO2 TECO 43i 534613725 500 1000 11/27/2005 Scrubber Inlet
1 200 NOx TECO 42i 534613723 500 1000 11/28/2005 Stack
1 200 Opacity Teledyne Monitor Labs Lighthawk 560 5602580 100 0 4/1/2014 Scrubber Inlet
1 200 SO2 TECO 43i 534613718 50 1000 11/28/2005 Stack
1 200 0 0 0 0 0 0 1/0/1900 0
1 Type Code310
(Excess Emissions)SUMMARY REPORT Type Code Channel
Total Hours of Excess Emissions
Excess Emissions -
% of Total Operating Hours
RC 701 Hours -
start up/Shutdown
RC 702 Hours-
Control Equipment Problems
RC 703 Hours -Process Problems
RC 704, 706, 707
Hours -Other Known Causes
RC 705 Hours -
Unknown Causes
Emission Limitation
Emission
Limitation Units
Emission
Limitation
Averaging
Period1 TRUE 310 Opacity 0 0.00% 0 0 0 0 0 20 % 6 min.
1 TRUE 310 SO2 0 0.00% 0 0 0 0 0 0.138 lb/mmbtu 30 DRA
1 TRUE 310 NOx 0 0.00% 0 0 0 0 0 0.461 lb/mmbtu 30 DRA
1 TRUE 310 Opacity 0 0.00% 0 0 0 0 0 20 % 6 min.
1 TRUE 310 SO2 0 0.00% 0 0 0 0 0 0.138 lb/mmbtu 30 DRA
1 TRUE 310 NOx 0 0.00% 0 0 0 0 0 0.461 lb/mmbtu 30 DRA
1 310 0 0 0 0 0 0 0 0 0
1 Type Code 300 (CMSPerformance Summary) Type Code Channel Point Source Operating Hours
Downtime - % of
Total Operating
Hours
Total CMS Downtime
RC 721 Hours -
Monitor
Malfunction
RC 722 Hours -
Non-monitor
Malfunction
RC 723 Hours - QA Calibrations
RC 724 Hours -
Other Known
Causes
RC 725
Hours -
Unknown
Causes1 TRUE 300 SO2 1923 0.36% 7 7 0 0 0 0
1 TRUE 300 CO2 1923 0.36% 7 7 0 0 0 0
1 TRUE 300 Opacity 1923 0.62% 11.9 0 0 11.9 0 0
1 TRUE 300 SO2 1923 0.05% 1 0 0 0 1 0
1 TRUE 300 NOx 1923 0.05% 1 0 0 0 1 0
1 TRUE 300 CO2 1923 0.10% 2 0 0 0 2 0
1 TRUE 300 SO2 2160 0.14% 3 2 0 0 1 0
1 TRUE 300 CO2 2160 0.05% 1 0 0 0 1 0
1 TRUE 300 Opacity 2160 0.61% 13.1 0 0 12.9 0.2 0
1 TRUE 300 SO2 2160 0.05% 1 0 0 0 1 0
1 TRUE 300 NOx 2160 0.05% 1 0 0 0 1 0
1 TRUE 300 CO2 2160 0.05% 1 0 0 0 1 0
1 300 0 0 0 0 0 0
1 Type Code 250(Performance Specification
RATA Results)
Type Code Channel
Date of Most Current
RATA
Date of Preceding
RATA
Months Between
RATA's
Units of
Measurement CEM Value Reference Method
Value
Relative
accuracy Pass/ Fail
1 370 Days 250 SO2 07/16/24 07/12/23 12 lbs/mmbtu 1.133 1.165 5.63% Pass
1 370 Days 250 CO2 07/16/24 07/12/23 12 CO2 11.608 11.1 5.88% Pass
1 369 Days 250 SO2 07/13/24 07/10/23 12 lbs/mmbtu 0.048 0.043 13.04% Pass
1 369 Days 250 NOx 07/13/24 07/10/23 12 lbs/mmbtu 0.207 0.197 6.62% Pass
1 369 Days 250 CO2 07/13/24 07/10/23 12 CO2 11.233 11.311 1.43% Pass
1 368 Days 250 SO2 07/15/24 07/13/23 12 lbs/mmbtu 1.193 1.126 10.40% Pass
1 368 Days 250 CO2 07/15/24 07/13/23 12 CO2 12.402 12.489 2.12% Pass
1 367 Days 250 SO2 07/12/24 07/11/23 12 lbs/mmbtu 0.043 0.041 14.71% Pass
1 367 Days 250 NOx 07/12/24 07/11/23 12 lbs/mmbtu 0.207 0.196 6.40% Pass
1 367 Days 250 CO2 07/12/24 07/11/23 12 CO2 11.333 11.233 2.67% Pass
1 0 Days 250 0 01/00/00 01/00/00 0 0 0 0 0.00% 0
0
Unit 2
Unit 2
Unit 2
Unit 2
Unit 1
Unit 1
Unit 1
Unit 1
Unit 2
Unit 1
IPP
0
Unit 1
Unit 1
Unit 1
Unit 1
Unit 1
Unit 1
Unit 2
Unit 2
Unit 2
Unit 2
Unit 2
Unit 2
0
Unit 1
Unit 1
Unit 1
Unit 2
0
Unit 2
Unit 2
Unit 2
Unit 2
0
Unit 1
Unit 2
Unit 2
Unit 1
Unit 1
Unit 1
Unit 2
Unit 2
Unit 1
Unit 1
Unit 1
Unit 2
0
Point Source
Point Source
Point Source
Intermountain Power EER 1Q2025
1 Type Code 260(CGA Results)Type Code Channel Date Audit Point No. Cylinder ID
Cylinder Expiration
Date
Type of
Certification
Units of
Measurement CEM Value Cylinder
Value
Precision
%Pass/ Fail Range - High or
Low1 Valid Cal. Gas 260 CO2 01/06/25 1 CC309064 02/19/28 P1 PERCENT 5.16 5.1 1.09% P LOW
1 Valid Cal. Gas 260 CO2 01/06/25 2 DT0013672 10/04/28 P1 PERCENT 11.34 10.96 1.94% P LOW
1 Valid Cal. Gas 260 CO2 01/06/25 1 SA14046 03/26/29 P1 PERCENT 5.05 5.09 -0.76% P LOW
1 Valid Cal. Gas 260 CO2 01/06/25 2 DT0013672 10/04/28 P1 PERCENT 11.02 10.96 -0.40% P LOW
1 Valid Cal. Gas 260 SO2 01/06/25 1 SA14046 03/26/29 P1 PPM 121.77 121.3 0.39% P LOW
1 Valid Cal. Gas 260 SO2 01/06/25 1 CC506716 01/31/26 P1 PPM 276.73 278 -0.46% P HIGH
1 Valid Cal. Gas 260 SO2 01/06/25 2 CC506716 01/31/26 P1 PPM 271.87 278 -2.20% P LOW
1 Valid Cal. Gas 260 SO2 01/06/25 2 EB0058219 07/17/27 P1 PPM 547.36 551 -0.66% P HIGH
1 Valid Cal. Gas 260 NOx 01/06/25 1 CC309064 02/19/28 P1 PPM 130.22 128.6 1.26% P LOW
1 Valid Cal. Gas 260 NOx 01/06/25 1 CC317320 03/03/28 P1 PPM 275.23 273 0.82% P HIGH
1 Valid Cal. Gas 260 NOx 01/06/25 2 DT0013672 10/04/28 P1 PPM 282.71 275 0.61% P LOW
1 Valid Cal. Gas 260 NOx 01/06/25 2 CC244820 12/06/30 P1 PPM 530.83 531 -0.03% P HIGH
1 Valid Cal. Gas 260 SO2 01/06/25 1 CC309064 02/19/28 P1 PPM 12.36 12.3 0.47% P LOW
1 Valid Cal. Gas 260 SO2 01/06/25 2 DT0013672 10/04/28 P1 PPM 26.97 27.1 -0.47% P LOW
1 Valid Cal. Gas 260 SO2 01/06/25 1 CC317320 03/03/28 P1 PPM 275.62 274 0.59% P HIGH
1 Valid Cal. Gas 260 SO2 1/6/25 2 CC244820 12/6/30 P1 PPM 556 554 0 P HIGH
1 Valid Cal. Gas 260 CO2 1/6/25 1 CC309064 2/19/28 P1 PERCENT 5 5 0 P LOW
1 Valid Cal. Gas 260 CO2 1/6/25 2 DT0013672 10/4/28 P1 PERCENT 11 11 0 P LOW
1 Valid Cal. Gas 260 CO2 1/6/25 1 SA14046 3/26/29 P1 PERCENT 5 5 0 P LOW
1 Valid Cal. Gas 260 CO2 1/6/25 2 DT0013672 10/4/28 P1 PERCENT 11 11 0 P LOW
1 Valid Cal. Gas 260 SO2 1/6/25 1 SA14046 3/26/29 P1 PPM 124 121 0 P LOW
1 Valid Cal. Gas 260 SO2 1/6/25 1 CC506716 1/31/26 P1 PPM 275 278 0 P HIGH
1 Valid Cal. Gas 260 SO2 1/6/25 2 CC506716 1/31/26 P1 PPM 274 278 0 P LOW
1 Valid Cal. Gas 260 SO2 1/6/25 2 EB0058219 7/17/27 P1 PPM 548 551 0 P HIGH
1 Valid Cal. Gas 260 NOx 1/6/25 1 CC309064 2/19/28 P1 PPM 129 129 0 P LOW
1 Valid Cal. Gas 260 NOx 1/6/25 1 CC317320 3/3/28 P1 PPM 275 273 0 P HIGH
1 Valid Cal. Gas 260 NOx 1/6/25 2 DT0013672 10/4/28 P1 PPM 284 275 0 P LOW
1 Valid Cal. Gas 260 NOx 1/6/25 2 CC244820 12/6/30 P1 PPM 531 531 0 P HIGH
1 Valid Cal. Gas 260 SO2 1/6/25 1 CC309064 2/19/28 P1 PPM 12 12 0 P LOW
1 Valid Cal. Gas 260 SO2 1/6/25 2 DT0013672 10/4/28 P1 PPM 27 27 0 P LOW
1 Valid Cal. Gas 260 SO2 1/6/25 1 CC317320 3/3/28 P1 PPM 277 274 0 P HIGH
1 Valid Cal. Gas 260 SO2 1/6/25 2 CC244820 12/6/30 P1 PPM 554 554 0 P HIGH
1 260 0 1/0/00 0 0 1/0/00 0 0 0 0 0 0 0
1 Type Code 270
(Linearity Test Results)Type Code Channel Date Audit Point No. Cylinder ID
Cylinder Expiration
Date
Type of
Certification
Units of
Measurement CEM Value Cylinder
Value
Precision
%Pass/ Fail Range - High or
Low
1 Valid Cal. Gas 270 CO2 01/06/25 Low CC309064 02/19/28 P1 PERCENT 5.16 5.1 109.00% P LOW
1 Valid Cal. Gas 270 CO2 01/06/25 Mid DT0013672 10/04/28 P1 PERCENT 11.34 10.96 194.00% P LOW
1 Valid Cal. Gas 270 CO2 01/06/25 High CC272099 06/12/28 P1 PERCENT 18.71 18.84 70.00% P LOW
1 Valid Cal. Gas 270 NOx 01/06/25 Low CC309064 02/19/28 P1 PPM 130.22 128.6 126% P LOW
1 Valid Cal. Gas 270 NOx 01/06/25 Low CC317320 03/03/28 P1 PPM 275.23 273 82% P HIGH
1 Valid Cal. Gas 270 NOx 01/06/25 Mid DT0013672 10/04/28 P1 PPM 282.71 275 61% P LOW
1 Valid Cal. Gas 270 NOx 01/06/25 High CC272099 06/12/28 P1 PPM 445.32 443 52.00% P LOW
1 Valid Cal. Gas 270 NOx 01/06/25 Mid CC244820 12/06/30 P1 PPM 530.83 531 3.00% P HIGH
1 Valid Cal. Gas 270 NOx 01/06/25 High DT0008522 04/22/29 P1 PPM 885.26 892 76.00% P HIGH
1 Valid Cal. Gas 270 SO2 01/06/25 Low CC309064 02/19/28 P1 PPM 12.36 12.3 47.00% P LOW
1 Valid Cal. Gas 270 SO2 01/06/25 Mid DT0013672 10/04/28 P1 PPM 26.97 27.1 47.00% P LOW
1 Valid Cal. Gas 270 SO2 01/06/25 High CC272099 06/12/28 P1 PPM 39.34 40 164.00% P LOW
1 Valid Cal. Gas 270 SO2 01/06/25 Low CC317320 03/03/28 P1 PPM 275.62 274 59.00% P HIGH
1 Valid Cal. Gas 270 SO2 01/06/25 Mid CC244820 12/06/30 P1 PPM 556.18 554 39.00% P HIGH
1 Valid Cal. Gas 270 SO2 01/06/25 High DT0008522 04/22/29 P1 PPM 881.15 883 21.00% P HIGH
1 Valid Cal. Gas 270 CO2 01/06/25 Low CC309064 02/19/28 P1 PERCENT 5.07 5.1 50% P LOW
1 Valid Cal. Gas 270 CO2 01/06/25 Mid DT0013672 10/04/28 P1 PERCENT 11.15 10.96 25% P LOW
1 Valid Cal. Gas 270 CO2 01/06/25 High CC272099 06/12/28 P1 PERCENT 18.86 18.84 12% P LOW
1 Valid Cal. Gas 270 NOx 01/06/25 Low CC309064 02/19/28 P1 PPM 129.26 128.6 52.00% P LOW
1 Valid Cal. Gas 270 NOx 01/06/25 Low CC317320 03/03/28 P1 PPM 275.14 273 78.00% P HIGH
1 Valid Cal. Gas 270 NOx 01/06/25 Mid DT0013672 10/04/28 P1 PPM 283.85 275 101.00% P LOW
1 Valid Cal. Gas 270 NOx 01/06/25 High CC272099 06/12/28 P1 PPM 444.02 443 23.00% P LOW
1 Valid Cal. Gas 270 NOx 01/06/25 Mid CC244820 12/06/30 P1 PPM 531.4 531 7.00% P HIGH
1 Valid Cal. Gas 270 NOx 01/06/25 High DT0008522 04/22/29 P1 PPM 889.77 892 25.00% P HIGH
1 Valid Cal. Gas 270 SO2 01/06/25 Low CC309064 02/19/28 P1 PPM 12.27 12.3 22.00% P LOW
1 Valid Cal. Gas 270 SO2 01/06/25 Mid DT0013672 10/04/28 P1 PPM 27.2 27.1 35.00% P LOW
1 Valid Cal. Gas 270 SO2 01/06/25 High CC272099 06/12/28 P1 PPM 39.88 40 30.00% P LOW
1 Valid Cal. Gas 270 SO2 01/06/25 Low CC317320 03/03/28 P1 PPM 276.6 274 95.00% P HIGH
1 Valid Cal. Gas 270 SO2 01/06/25 Mid CC244820 12/06/30 P1 PPM 554.35 554 6.00% P HIGH
1 Valid Cal. Gas 270 SO2 01/06/25 High DT0008522 04/22/29 P1 PPM 878.64 883 49.00% P HIGH
1 270 0 01/00/00 0 0 01/00/00 0 0 0 0 0.00% 0 0
1 Type Code 210
(Pollutant ConcentrationExceeded Span of CEM)
Type Code Channel Start Date Start Time End Date End Time Hours
1 0 0 0 1/0/00 0:00 1/0/00 0:00
1
1 None Reported
1 0 TC 220 Hours 50.00 TC 220 Hours 0.00 TC 230 Hours 0.00 Events 0.00 Hours 0.00 Events 0.00 0.00
1 50.00 TC 300 Hours 0.00 TRUE
Unit 2
Unit 2
Unit 1
Unit 2
Unit 2
Unit 2
Unit 1
Unit 1
Unit 1
Unit 1
Unit 1
Unit 1
Unit 1
Unit 1
Unit 1
Unit 1
Unit 2
Unit 2
Unit 1
Unit 1
Type Code 210
(Pollutant ConcentrationExceeded Span of CEM)
Type Code 220
(Monitor OutageDuring Point Source Operation)
Type Code 230(Manual Sample - AlternateSampling During Monitor
Outage)
Type Code 240(CEM Modifications)
Type Code 530
(Excess Emissions During Emergency Conditions)
Unit 2
0
Unit 2
Unit 2
Unit 2
Unit 2
Unit 2
Unit 2
Type Code 550(Changes in Operation in Control Equipment When
CEM Data Not Available)
Type Code 500
(Boiler Operating Daysw/o 18 Hours of Data)
Type Code 450(Data Excluded)
Unit 2
Unit 1
Unit 1
Unit 2
Unit 1
Point Source
Point Source
Point Source
Yes
Unit 1
Unit 1
Unit 1
Unit 1
Unit 1
Unit 2
Unit 2
Unit 2
Unit 1
Unit 2
Unit 1
Unit 1
Unit 1
Unit 1
Unit 1
Unit 1
Unit 2
Unit 1
Unit 1
Unit 1
Unit 2
Unit 2
Unit 2
Unit 2
Unit 2
Unit 2
Unit 2
Unit 2
Unit 2
Unit 2
0
0
None Reported None Reported Yes None Reported None Reported None Reported
Intermountain Power EER 1Q2025
Relative Accuracy Overview
Point Source Channel
Date of Most
Current
RATA
Date of
Preceding
RATA
Months Between
RATA's
Units
Measured CEM Value Reference Method
Value
Relative
Accuracy Pass/ Fail 2025
Unit 1 SO2 07/16/24 07/12/23 12 lbs/mmbtu 1.133 1.17 5.63% Pass
Unit 1 CO2 07/16/24 07/12/23 12 CO2 11.608 11.10 5.88% Pass
Unit 1 SO2 07/13/24 07/10/23 12 lbs/mmbtu 0.048 0.04 13.04% Pass
Unit 1 NOx 07/13/24 07/10/23 12 lbs/mmbtu 0.207 0.20 6.62% Pass
Unit 1 CO2 07/13/24 07/10/23 12 CO2 11.233 11.31 1.43% Pass
Unit 2 SO2 07/15/24 07/13/23 12 lbs/mmbtu 1.193 1.13 10.40% Pass
Unit 2 CO2 07/15/24 07/13/23 12 CO2 12.402 12.49 2.12% Pass
Unit 2 SO2 07/12/24 07/11/23 12 lbs/mmbtu 0.043 0.04 14.71% Pass
Unit 2 NOx 07/12/24 07/11/23 12 lbs/mmbtu 0.207 0.20 6.40% Pass
Unit 2 CO2 07/12/24 07/11/23 12 CO2 11.333 11.23 2.67% Pass
*
NSPS CGA First 2025
Audit Gas Ranges Audit Gas Ranges
AP1 Low AP2 Low AP1 High AP2 High
Unit 1 CO2 1/6/25 20 5.1 5 to 8
Unit 1 CO2 1/6/25 20 10.96 10 to 14
Unit 1 CO2 1/6/25 20 5.09 5 to 8
Unit 1 CO2 1/6/25 20 10.96 10 to 14
Unit 1 SO2 1/6/25 500 121.3 100 to 150
Unit 1 SO2 1/6/25 1000 278 200 to 300
Unit 1 SO2 1/6/25 1000 278 200 to 300
Unit 1 SO2 1/6/25 1000 551 500 to 600
Unit 1 NOx 1/6/25 500 128.6 100 to 150
Unit 1 NOx 1/6/25 1000 273 200 to 300
Unit 1 NOx 1/6/25 500 275 250 to 300
Unit 1 NOx 1/6/25 1000 531 500 to 600
Unit 1 SO2 1/6/25 50 12.3 10 to 15
Unit 1 SO2 1/6/25 50 27.1 25 to 30
Unit 1 SO2 1/6/25 1000 274 200 to 300
Unit 1 SO2 1/6/25 1000 554 500 to 600
Unit 2 CO2 1/6/25 20 5.1 5 to 8
Unit 2 CO2 1/6/25 20 10.96 10 to 14
Unit 2 CO2 1/6/25 20 5.09 5 to 8
Unit 2 CO2 1/6/25 20 10.96 10 to 14
Unit 2 SO2 1/6/25 500 121.3 100 to 150
Unit 2 SO2 1/6/25 1000 278 200 to 300
Unit 2 SO2 1/6/25 1000 278 200 to 300
Unit 2 SO2 1/6/25 1000 551 500 to 600
Unit 2 NOx 1/6/25 500 128.6 100 to 150
Unit 2 NOx 1/6/25 1000 273 200 to 300
Unit 2 NOx 1/6/25 500 275 250 to 300
Unit 2 NOx 1/6/25 1000 531 500 to 600
Unit 2 SO2 1/6/25 50 12.3 10 to 15
Unit 2 SO2 1/6/25 50 27.1 25 to 30
Unit 2 SO2 1/6/25 1000 274 200 to 300
Unit 2 SO2 1/6/25 1000 554 500 to 600
*
Acid Rain Audit Linearity First 2025
Low Span Gas Ranges High Span Gas Ranges
Low Mid High Low Mid High
Unit 1 CO2 1/6/25 20 5.1 4 to 6
Unit 1 CO2 1/6/25 20 10.96 10 to 12
Unit 1 CO2 1/6/25 20 18.84 16 to 20
Unit 1 NOx 1/6/25 500 128.6 100 to 150
Unit 1 NOx 1/6/25 1000 273 200 to 300
Unit 1 NOx 1/6/25 500 275 250 to 300
Unit 1 NOx 1/6/25 500 443 400 to 500
Unit 1 NOx 1/6/25 1000 531 500 to 600
Unit 1 NOx 1/6/25 1000 892 800 to 1000
Unit 1 SO2 1/6/25 50 12.3 10 to 15
Unit 1 SO2 1/6/25 50 27.1 25 to 30
Unit 1 SO2 1/6/25 50 40 40 to 50
Unit 1 SO2 1/6/25 1000 274 200 to 300
Unit 1 SO2 1/6/25 1000 554 500 to 600
Unit 1 SO2 1/6/25 1000 883 800 to 1000
Unit 2 CO2 1/6/25 20 5.1 4 to 6
Unit 2 CO2 1/6/25 20 10.96 10 to 12
Unit 2 CO2 1/6/25 20 18.84 16 to 20
Unit 2 NOx 1/6/25 500 128.6 100 to 150
Unit 2 NOx 1/6/25 1000 273 200 to 300
Unit 2 NOx 1/6/25 500 275 250 to 300
Unit 2 NOx 1/6/25 500 443 400 to 500
Unit 2 NOx 1/6/25 1000 531 500 to 600
Unit 2 NOx 1/6/25 1000 892 800 to 1000
Unit 2 SO2 1/6/25 50 12.3 10 to 15
Unit 2 SO2 1/6/25 50 27.1 25 to 30
Unit 2 SO2 1/6/25 50 40 40 to 50
Unit 2 SO2 1/6/25 1000 274 200 to 300
Unit 2 SO2 1/6/25 1000 554 500 to 600
Unit 2 SO2 1/6/25 1000 883 800 to 1000
*
Audit Gas Used High Span Audit Gas Used
High SpanAudit Gas Used
Point Source Channel Audit Date Low Span
Point Source Channel Audit Date Low Span Audit Gas Used
Intermountain Power EER 1Q2025
Type Code 280 (COMS Attenuator Filters) Procedure 3
Point Source Location
Attenuator
I.D.
Attenuator
Certification Date
Certified Attenuator
Opacity
OPLR,
SECR, or
PLCF,
Corrected Opacity
Value
Range
Low, Mid, & High
Certification
1-year or 5-year
Unit 1 Scrubber
Duct S10405 12/18/24 27 0.56 15.98
Low 1
Unit 1 Scrubber
Duct S10348 12/18/24 37 0.56 23
Mid 1
Unit 1 Scrubber
Duct S10425 12/18/24 58 0.56 38.82 High 1
Unit 2 Scrubber
Duct S10412 12/7/23 26.96 0.56 16.13
Low 1
Unit 2 Scrubber
Duct S10349 12/7/23 37.62 0.56 23.22
Mid 1
Unit 2 Scrubber
Duct S10425 12/7/23 59.64 0.56 39.84
High 1
*
Opacity Monitor Response (Average of 5)
Low Range Mid Range High Range
Unit 1 Scrubber
Duct 1/8/25 16 0.140 0.013 0.006 0.150
Unit 1 Scrubber
Duct 1/8/25 23 0.030 0.014 0.006 0.033
Unit 1 Scrubber
Duct 1/8/25 39 0.310 0.020 0.009 0.324
Unit 2 Scrubber
Duct 1/9/25 16 0.070 0.046 0.020 0.088
Unit 2 Scrubber
Duct 1/9/25 23 0.250 0.044 0.019 0.273
Unit 2 Scrubber
Duct 1/9/25 39 0.610 0.057 0.025 0.639
*
Point Source Location Audit Date
Alternitive Zero
Alignment
(Yes or No)
COM Clear
Condition Zero
Response
(CCZR)
COM Simulated
Zero Response
(CSZR)
Zero Alignment
Error Difference
(CCZR)-(CSZR)
Adjustment to COM
Simulated Zero
Response
(CSZR)
(Yes or No)
Unit 1 Scrubber
Duct 10/11/22 No 0.000 0.000 0.000 Yes
Unit 2 Scrubber
Duct 7/2/24 No 0.003 0.003 0.001 Yes
Type Code 282 (Procedure 3 - Annual Zero Alignment Audit)
Point
Source Location Audit Date Mean Difference Standard Deviation
Confidence
Coefficient
Calibration
Error (≤ 3%)
Type Code 281 (Procedure 3 - COMS Filter Audit Calibration Error)
Intermountain Power EER 1Q2025
Monitoring Information TC 210, 230, & 240
Type Code 210
(Pollutant Concentration Exceeded Span of CEM) - 500 (All)
*
Sum of Hours Column Labels
Row Labels (blank) Grand Total
(blank)0 0
Grand Total 0 0
*
Type Code 230
(Manual Sample - Alternate Sampling During Monitor Outage) - 500 (All)
*
Sum of Hours Column Labels
Row Labels (blank) Grand Total
(blank)0 0
Grand Total 0 0
*
Type Code 240
(CEM Modifications) - 100 (All)
*
Count of Channel Column Labels
Row Labels (blank) Grand Total
(blank)
(blank)
Grand Total
Intermountain Power EER 1Q2025
Type Code 220
(Monitor Outage During Point Source Operation) - 600 (All)
*
Sum of Hours Column Labels
Row Labels 721 724 723 Grand Total
Unit 1
SO2
S1 Inlet CEM analyzers calibrations out of control. Dilution eductor
blockage. Purged with reverse pressure. 2/1/2025 removed and cleaned
eductor system. System calibrated and return to service.
14.0 14.0
Routine Maintenance. 1.0 1.0
NOx
Routine Maintenance. 1.0 1.0
CO2
Routine Maintenance. 2.0 2.0
Opacity
Daily Opacity Calibration Check.8.1 8.1
Opacity Monitor Quarterly Procedure 3 Audit.3.7 3.7
System calibration.0.1 0.1
Unit 2
SO2
Routine Maintenance. 2.0 2.0
S2 SO2 analyzer High Range calibration failure due to calibration gas
bottle regulator pressure loss. Reset pressure and system calibrated.
Replaced reulator 1/22/2025 system calibrated.
2.0 2.0
NOx
Routine Maintenance. 1.0 1.0
CO2
Routine Maintenance. 2.0 2.0
Opacity
Daily Opacity Calibration Check.9.0 9.0
Opacity Monitor Quarterly Procedure 3 Audit.3.8 3.8
System calibration.0.1 0.1
CEM computer off-line for maintenance.0.2 0.2
Grand Total 16.0 9.2 24.8 50.0
Intermountain Power EER 1Q2025
Opy *
Opy Count of Magnitude of Emissions Column Labels
Opy Row Labels 701 Grand Total
Opy Unit 1 1 1
Opy
Unit 1, Shutdown activities. Unit Shutdown from March 22 to end
of first Quarter 2025 for coal supply reserves.The baghouse was in
service during the burning of coal and or the Generator
synchronization to the Electrical Grid. Six minute period of opacity
occurred after cessation of fuel in boiler during shutdown.
1 1
Opy Grand Total 1 1
SO2 *
SO2 Type Code 410 (SO2) - 6000 (All)
SO2 *
SO2 Count of Magnitude of Emissions Column Labels
SO2 Row Labels Grand Total
SO2 Grand Total
NOx *
NOx Type Code 420 (NOx) - 6000 (All)
NOx *
NOx Count of Magnitude of Emissions Column Labels
NOx Row Labels Grand Total
NOx Grand Total
NOx d *
NOx d Type Code 421 (Daily NOx Emissions) - 500 (All)
NOx d *
NOx d Count of Reason Code Column Labels
NOx d Row Labels (blank)Grand Total
NOx d Unit 1
NOx d 0
NOx d Unit 2
NOx d 0
NOx d Grand Total
Dat Ex *
Dat Ex Type Code 450
(Data Excluded) - 6000 (All)
Dat Ex *
Dat Ex Count of Channel Column Labels
Dat Ex Row Labels (blank)724 Grand Total
Dat Ex Unit 1
Dat Ex InletSO2 1 1
Dat Ex Emissions data excluded from the calculation of averaged
emissions due to a NBOD. Unit 1 in shutdown TC701A from March
22 2025 to end of First Quarter due to coal supply reserves
1 1
Dat Ex InletCO2 1 1
Dat Ex Emissions data excluded from the calculation of averaged
emissions due to a NBOD. Unit 1 in shutdown TC701A from March
22 2025 to end of First Quarter due to coal supply reserves
1 1
Dat Ex SO2 1 1
Dat Ex Emissions data excluded from the calculation of averaged
emissions due to a NBOD. Unit 1 in shutdown TC701A from March
22 2025 to end of First Quarter due to coal supply reserves
1 1
Dat Ex NOx 1 1
Dat Ex Emissions data excluded from the calculation of averaged
emissions due to a NBOD. Unit 1 in shutdown TC701A from March
22 2025 to end of First Quarter due to coal supply reserves
1 1
Dat Ex CO2 1 1
Dat Ex Emissions data excluded from the calculation of averaged
emissions due to a NBOD. Unit 1 in shutdown TC701A from March
22 2025 to end of First Quarter due to coal supply reserves
1 1
Dat Ex Grand Total 5 5
Intermountain Power EER 1Q2025
Type Code 500
Before February 28, 2005 (Boiler Operating Days w/o 18 Hours of
Data) After February 28, 2005 (90% Operating Hours For each 30 BOD)
- 500
(All)
*
Count of Channel Column Labels
Row Labels Grand Total
Grand Total
*
Type Code 510
(F-factor, Equations & Conversion Factors) - 500 (All)
Count of F-factor Column Labels
Row Labels SO2 NOx Grand Total
Unit 1
1800 3 1 4
Unit 2
1800 3 1 4
Grand Total 6 2 8
*
Type Code 520
(Minimum Data Not
Obtained <22/30 BODs) - 500
(All)
Count of Channel Column Labels
Row Labels Grand Total
Grand Total
*
Type Code 530
(Excess Emissions During Emergency Conditions) - 500 (All)
Count of Date Column Labels
Row Labels Grand Total
Grand Total
*
Type Code 540
(Fuel Pre-treatment Credit SO2) - 500 (All)
Count of Date Column Labels
Row Labels Grand Total
Grand Total
*
TypeCode 550
(Changes in Operation in Control Equipment When CEM Data Not
Available) - 500
(All)
Column Labels
Row Labels Grand Total
Grand Total