DAQ-2025-001862

1

DAQC-341-25
Site ID 10259 (B4)

MEMORANDUM

TO: STACK TEST FILE – NORTHWEST PIPELINE LLC – Cisco CS –
Turbines P001-2

THROUGH: Harold Burge, Major Source Compliance Section Manager

FROM: Robert Sirrine, Environmental Scientist

DATE: April 3, 2025

SUBJECT: Source: Unit P001-2 Solar Centaur Compressor Turbines
Location: Near Cisco, Utah. I-70 exit 204, go 3-miles south on Highway 128
Contact: Derek Forsberg, 801-584-6748
Tester: Emissions Science, Inc. James Olinger 970-749-5474 cell
FRS ID#: UT0000004901900016
Permit #: 1900016006 dated March 18, 2024
Subject: Review of Pretest Protocol Received April 2, 2025

On April 2, 2025, the Utah Division of Air Quality (DAQ) received a stack test protocol for emissions
testing of the Northwest Pipeline LLC – Cisco CS, Solar Centaur Compressor Turbines P001-2. Stack
emissions testing will be performed on May 6-7, 2025, to demonstrate compliance with the NOx and CO
emission limits found in Permit Conditions II.B.2.a, II.B.2.b, and II.B.2.c.

PROTOCOL CONDITIONS:

1. RM 1 used to determine sample velocity traverses: OK
2. RM 2 used to determine stack gas velocity and volumetric flow rate: OK
3. RM 3A used to determine dry molecular weight of the gas stream: OK
4. RM 4 used to determine moisture content: OK
5. RM 7E used to determine NOx emissions: OK
6. RM 10 used to determine CO concentrations of emissions: OK
7. RM 19 used to determine NOX and CO emission exhaust flowrates with fuel meter: OK

DEVIATIONS: None noted.

CONCLUSION: The Northwest Pipeline LLC stack testing protocol for testing the Cisco CS
Turbines P001-2 stack emissions, has been evaluated and appears to be
acceptable. * - / $ - - $ )
2

RECOMMENDATION: Send protocol review and test date confirmation notice.

ATTACHMENT: Northwest Pipeline LLC stack test protocol received April 2, 2025.
E.S.I
Grand Junction, CO
Phone [phone] www.emissions-science.com

Emissions Testing Protocol & Source Test Plan

Northwest Pipeline, LLC
Cisco Compressor Station
Grand County, Utah

Utah Department of Environmental Quality Permit

# 1900016006

Source ID:
Turbine # 1 - P001
Turbine # 2 - P002

Model: Solar Centaur 50/H T-5502

Proposed Test Dates:
May 6th & 7th, 2025

Protocol Prepared by:
James Olinger
Emissions Science, Inc.

2
Table of Contents

Introduction: ……………………………….. Page 1

Purpose of Test …………………………….. Page 1

Source to be Tested ….……………………….. Page 1

Test Methods & Procedures…………………….. Page 1 - 5

Contact Personnel ………………………….. Page 5

Proposed Test Dates ……………………….. Page 6

Detailed Source Test Schedule ……………. Page 6

Delivered Data Package …………………… Page 6

Contractor Supplied Equipment …………… Page 6

Appendices
Appendix 1 …………..Sample Calculations Used for Source Testing
Appendix 2 …………..QA/QC Checks for Source Testing
Appendix 3 …………..EPA Method 1 Expected Stack Configuration
Appendix 4 …………..Sample System Schematics (Methods 1-4, 7E, 10)

1
Source Test Plan

Introduction:

Northwest Pipeline, LLC has contracted Emissions Science, Inc. to perform an
emissions test under the requirements set forth in the State of Utah Department of
Environmental Quality Permit # 1900016006. The sources will be tested in
accordance with 40 CFR Part 60 (Methods 1, 2, 3A, 7E, 10 & 19) on two, mechanical
drive gas turbines (RICE) located at the Cisco Compressor Station in Grand County,
Utah. The Cisco Facility is used to compress natural gas into a pipeline for delivery.

Purpose of Test:

The purpose of the test is to demonstrate compliance with the concentrations and mass
emission rates of Carbon Monoxide and Nitrogen Oxides as required under the permit
# 1900016006.

Sources to be Tested:

Two sources at the Cisco Facility will be tested.
The source are as follows;

Turbine # 1 P001. Solar Centaur – 50/H T-5502 Stationary Combustion Turbine
Site Rated HP 5500. Serial Number: TBD

Turbine # 2 P002. Solar Centaur – 50/H T-5502 Stationary Combustion Turbine
Site Rated HP 5500. Serial Number: TBD

Test Methods:

ESI proposes the following EPA reference methods for this source test plan.
Note* The instrumental methods were updated by the EPA in the final rule which was published on
August 14th, 2006.

EPA Reference Method 1
 Purpose: Establishing stack diameter and velocity traverse points.
 Equipment: Measurement device and calculator.
 Calculations: (See Appendix 1)

2
Test Methods: (continued)

EPA Reference Method 2
 Purpose: Determination of Stack Gas Velocity and Volumetric Flow Rate.
 Equipment: Pitot Tube, Manometer / Draft Gauge, Thermocouple, Barometer.
 Calculations: (See Appendix 1)

EPA Reference Method 3A
 Purpose: Determination of Carbon Dioxide (CO2) & Oxygen (O2)
concentrations in exhaust gas.
 Equipment: Instrumental Method using non-dispersive infra-red (NDIR) for
continuous sampling of CO2 and a Paramagnetic sensor for O2.
 Calculations: n/a

EPA Reference Method 7e
 Purpose: Determination of Nitrogen Oxides (NOx) Emissions from Stationary
Sources.
Equipment: Instrumental Method using Chemiluminescence based technology for
continuous sampling of Nitrogen Oxides (NOx), Heated Sample Line capable of
keeping gas sample above the point of condensation (approximately 250 degrees
F), Gas Conditioning System (to remove moisture prior to gas sample entering the
analyzers). All applicable QA/QC assurances required under EPA Method 7E such
as; calibration error checks, system bias checks, interference checks and NO2
convertor efficiency checks will be performed on the analyzer.
 Calculations: (See Appendix 1)

EPA Reference Method 10
 Purpose: Determination of Carbon Monoxide (CO) Emissions from
Stationary Sources.
 Equipment: Instrumental Method using NDIR for continuous sampling of
Carbon Monoxide, Gas Conditioning System, Sample Probe, System Pump,
Etc.
 Calculations: (See Appendix 1)

EPA Reference Method 19
 Purpose: Determination of Nitrogen Oxide and Carbon Monoxide Emission rates.
 Using industry standard of 8710 SCF/MMBTU and Turbine Fuel Meter / Fuel gas-
BTU value for mass emission rate calculations.

3
Detailed Test Procedure:

Prior to the test procedure the test site will be inspected for potential safety hazards
and a Job Site Analysis (JSA) will be held with all persons who may be affected by
the testing program. All equipment will be assembled, allowed to reach operational
temperature and inspected for damage and correct assembly. The exhaust stack will be
measured for inside diameter and proper sample port locations. Sampling traverse
points will be calculated and marked on the pitot tube according to the criteria found
in EPA Method 1. The entire sampling system (including analyzers, sample lines,
moisture trains, gas meter and gas conditioning manifold) will be tested for potential
leaks prior to sampling.

The analyzers will then be challenged with EPA Protocol Gasses and calibrated to
minimize potential drift during the sampling process.

The calibration error test, system bias check, system response time check, NO2 => NO
conversion efficiency test and stack stratification test will be completed prior to
performing any stack sampling.

Operational turbine load will be determined and if found acceptable, the sampling
program will be initiated. Concurrent with the gas sample being delivered to the
analyzers (for EPA methods 3A, 7E and 10). Stack gas will be diverted into a
moisture removal system before introduction to the emissions analyzers. All measured
gas species will be analyzed as parts per million volume-dry (ppmvd).

EPA methods 3A, 7E, 10 and 19 are instrumental methods and will be completed in
accordance with instrument manufacturer specifications and under the individual
method requirements established by the EPA. A data recorder will be used to log
measured data in one-minute increments for each measured gas species to these
analyzers.

A stack stratification test will be performed on each turbine prior to the
commencement of sampling. The stainless-steel probe will be marked at 3 points
(16.7, 50 & 83.3% of inside stack diameter) for the stratification test. If the source is <
5% stratified as allowed under Method 7E, the sampling will occur from a point near
the center area of the duct while the source maintains the desired load conditions. If
the stack is found to be stratified, multiple point sampling will be used as directed by
the test method.

4
Detailed Test Procedure (continued):

Testing will be performed over 4 load ranges selected by Williams NW Pipeline to
best represent normal operating scenarios from the combustion turbine.

Each of the four load ranges will be sampled for 1, 60-minute sample period and will
measure concentrations of CO & NOx (ppmvd) and the diluent of O2% from the
source at each load range.

The test program will correct NOx & CO concentration to ppmvd @ 15% O2 for
comparison against any NOx permit limits normalized to the diluent concentration at
15% O2. Oxides of Nitrogen will also be corrected to ISO ambient standard
conditions.

Operational turbine load will be determined and if found acceptable, the sampling
program will be initiated. Concurrent with the gas sample being delivered to the
analyzers (for EPA methods 3A, 7E and 10. The pitot traverse procedure will be
performed with a dual-inclined manometer to collect the data used to calculate stack
velocity and volumetric flow from EPA method 2.
If the volumetric flow (Method 2) and fuel usage results from the compressor station
Coriolis fuel meter agree, within 10% of the turbine fuel usage on sample run # 1
(converted to MMBtu/Hr and with an exception for a scenario where the difference
could cause a failing source to pass) then the turbine fuel meter results will be used for
the determination of mass emission rates for sample runs 2-4 at the selected load
ranges for each source. If the fuel meter achieves the required accuracy, the turbine
fuel meter values from each sample run and the BTU value of the fuel gas will be used
with EPA Method 19 to determine mass emission rates of NOx & CO for remaining
sample runs. The accepted industry standard of 8710 SCF/MMBTU for the F-factor
will be used in the calculation for mass rates. The testing at various load conditions
should ensure the turbine is meeting the permitted limits across a wide range of
operating conditions. At least one load condition will be at 90-110% of turbine
maximum capacity.

Turbine operating parameters such as RPM’s, Suction Pressure, Discharge Pressure,
Operation Hours, Ambient Temperature and Humidity, Etc. will be collected during
each test-run. The running horsepower or turbine heat output will be provided to ESI
technicians by NW Pipeline personnel.

5
Detailed Test Procedure (continued):

It is the responsibility of, NW Pipeline, LLC personnel to provide safe access to hand-
tight, EPA compliant sample ports. It is also the responsibility of NW Pipeline, LLC
to select the load ranges for the testing based on allowances under Subpart GG. The
high test load should be performed first.

The sources tests will be used to determine compliance with the following mass
emission rate limitations.

Carbon Monoxide (CO) - 5.8 lb/hr
Nitrogen Oxides (NOx) - 17.9 lb/hr & STD @ 15% O2 (ISO)

Sulfur compounds such as SO2 will not be measured during this testing event as
Northwest Pipeline has determined that the sulfur concentrations in the fuel gas are
below the threshold that would trigger testing for SO2.

Contact Personnel:

Northwest Pipeline, LLC Northwest Pipeline, LLC
295 Chipeta Way 295 Chipeta Way
Salt Lake City, UT 84108 Salt Lake City, UT 84108
Mr. Derek Forsberg Ms. Cecilia Diaz
Environmental Specialist Engineer Sr.
[phone] [phone]

Emissions Science, Inc.
635 19 ½ Road
Grand Junction, CO 81507
Mr. James Olinger
970.628.4849 Office or 970.749.5474 Cell

State of Utah,
Department of Environmental Quality -DAQ
1950 West North Temple
Salt Lake City, UT 84114
Compliance Division
801.536.4129

6
Proposed Test Dates:

Cisco Compressor Station. Source ID’s # P001 & P002.
Testing for NOx & CO Concentrations and mass emissions rates.
May 6th – 7th, 2025.

Detailed Source Test Schedule:

The test trailer will be set up on site on May 5th, 2025 and the NDIR analyzer will be
energized overnight to ensure it is up to operating temperature.
Arrival time at the Cisco Facility on May 6th is expected to be 7:30 AM. The
calibration procedure and job preparation tasks are expected to take approximately 2.5
hours. Testing of the source is expected to occur as follows.
Approximate start time 10:00-10:30 AM

Delivered Data Package:

Emissions Science, Inc. will deliver the draft data package within 3 weeks of the
source test(s). One additional week will be allowed to deliver the final data package if
any corrections or revisions are needed.

Contractor Supplied Equipment:

Emissions Science, Inc. will supply all analysis equipment, tools and personnel
necessary for the scope of this project as is required under the test methods section
found in this document. (Pages 2-6).

Appendix 1
Sample Calculations used for Source Testing

2
Sample Calculations for EPA Reference Method Tests

Note: As the calculations, formulae and unit conversions used for these test procedures are too
numerous to list, the following is a selection of the primary calculations used in the various
methods.

EPA Reference Method 1
 Stack Diameter * Distance Percentage from Stack Wall
(Based on # of Traverse Points from Table F1-2)

EPA Reference Method 2
 Section 12.5: Molecular Weight of Stack Gas
Ms = Md (1 – Bws) + 18.0*Bws …Eq. 2-6
Where:
Ms = Molecular weight of stack gas, wet basis… (lb/lbmole)
Md = Molecular weight of stack gas, dry basis
Bws = Water vapor in the gas stream proportion by volume

Section 12.6: Average Stack Gas Velocity
o KPCP√∙Pavg√(Ts(abs) / PsMs) …Eq. 2-7

 85.49 m/sec [(1b/1b-mole) (in. Hg) / (oR) (in. H20)]1/2
Where:
Kp = Velocity equation constant.
Cp = Pitot tube coefficient, dimensionless
∙Pavg = Average velocity head of stack gas… (in. H2O)
Ts(abs) = Absolute stack temperature… (oR)
Ps = Absolute stack pressure (Pbar + Pg)… (in. Hg)
Ms = Molecular weight of stack gas, wet basis… (lb/lbmole

 Section 12.7: Average Stack Gas Dry Volumetric Flow Rate
o Q = 3600 (1-Bws) Vs A[ Tstd Ps / Ts(abs) Pstd] …Eq. 2-8
Where:
3600 = Conversion Factor… (Sec/hr)
Bws = Water vapor in the gas stream proportion by volume
Vs = Average stack gas velocity… (ft/sec)
A = Cross-sectional area of stack… (ft2)
Tstd = Standard absolute temperature… (528 oR)

3
Ts(abs) = Absolute stack temperature… (oR)
Pstd = Standard absolute pressure… (29.92 in. Hg)
Sample Calculations for EPA Reference Method Tests

EPA Reference Method 4

Dry Gas Volume:

Vm Y Pm Tstd Vm Pm
Vm(std) = __________ = K4 Y ______ Eq 4-3

Pstd Tm Tm

Where:
Vm(std) = Dry gas volume measured by the dry gas meter, corrected to standard conditions, dscm
(dscf).
Vm = Dry gas volume measured by dry gas meter, (dcf)
Y = Dry gas meter calibration factor.
Pm = Absolute pressure (for this method, same as barometric pressure) at the dry gas meter, (in.
Hg).
Tstd = Standard absolute temperature, 528 degrees R
Pstd = Standard absolute pressure, 760 mm Hg
Tm = Absolute temperature at meter, (R)

Moisture Content:

Vwstd
Bwo = ______

Vmstd + Vwstd

Where:
Bwo = Proportion by volume of water in the gas stream (dimensionless)
Vwstd =Volume of water in the gas sample (standard conditions) cu. Ft.
Vmstd = Volume of gas sample through the dry gas meter (standard conditions)

4
Sample Calculations for EPA Reference Method Tests

EPA Method 7E

ER = Cd * 1.912 * 10-3 * Q * T
__________________

Hp-hr
Where:
ER =Emission Rate of NOx in g/hp-hr
Cd = Measured NOx concentration in parts per million by volume (ppmv).
1.912 x 10-3 = Conversion constant for ppm NOx to grams per standard cubic meter at 20
degrees Celsius.
Q = Stack gas volumetric flow rate, in standard cubic meter per hour, dry basis.
T = Time of test run, in hours.
HP-hr = Brake work of the engine, horsepower-hour (HP-hr).

EPA Method 19

NOx Lb/Hr =
(ppm NOx) (1.19 x 10-7) ( F-Factor) ( 20.9 / 20.9-O2%) (Heat Input MMBTU/Hr)

EPA Method 7E (Section 12.9) NO2 convertor oven efficiency

(NOx final – NOfinal)
EFFNO2 = ________________ X 100

(NOx peak – NOx final)

Where:
EffNO2 = NO2 to NO converter efficiency, percent.
NOX Final = The final NOX concentration observed during the converter efficiency test ppmv.
NO Final = The average NO concentration observed with the analyzer in the NO mode during the
converter efficiency test ppmv.
NOX Peak = The highest NOX concentration observed during the converter efficiency test, ppmv.

5
Sample Calculations for EPA Reference Method Tests

EPA Method 10

ER = Cd * 1.164 * 10-3 * Q * T
__________________

Hp-hr
Where:
ER =Emission Rate of CO in g/hp-hr
Cd = Measured CO concentration in parts per million by volume (ppmv).
1.164 x 10-3 = Conversion constant for ppm CO to grams per standard cubic meter at 20
degrees Celsius.
Q = Stack gas volumetric flow rate, in standard cubic meter per hour, dry basis.
T = Time of test run, in hours.
HP-hr = Brake work of the engine, horsepower-hour (HP-hr).

EPA Method 19

CO Lb/Hr =
(ppm NOx) (7.27 x 10-8) ( F-Factor) ( 20.9 / 20.9-O2%) (Heat Input MMBTU/Hr)

NOx ppm @ 15% O2 = (NOx ppm) (5.9 / 20.9-O2%)

Note: The proceeding test calculations are examples of the equations used in the testing
procedures. Additional or alternate EPA approved equations may also be used during the testing
program. Some equations may not be used for this specific job.

Appendix 2

Sample QA/QC Checks for Source Testing

Emissions Science, Inc
Quality Assurance / Quality Control Plan
(As noted and under the allowable tolerances in EPA method 7E)

¾ Verification of correct Calibration Gas Selection and check on expiration dates.

¾ Verification of heated sample line (above dew point of H2O) and thermocouple integrity.

¾ Use of non-reactive sample transport and probe material (stainless-steel, glass, PTFE).

¾ Complete system leak check.

¾ Analyzer Calibration Error Check (3-point linearity check).

¾ Sample system bias check.

¾ System Response Time.

¾ Analyzer Drift Assessment.

¾ NO2 => NO conversion test.

¾ System Purge Time.

¾ Stack stratification test or minimum sample time at each point.

¾ One-minute intervals for data recorder on sample run data (averaged at end of run).

¾ Post-test bias check.

¾ Calibration and run ‘raw’ data preserved as indelible record.

Appendix 3
Expected Stack Configuration

Emissions Science, Inc.
EPA Method 1
Field Data Sheet
Client:Site:Unit ID:
Date:Time:
Stack Diameter (I.D.) =
Port Depth =
Upstream Disturbance =
Upstream Disturbance =
Downstream Disturbance =
Downstream Disturbance =
Notes:
Exhaust Stack with sample ports @ 90 º angles
Emissions Science, Inc
Appendix 4

Sample System Schematics

Emissions Science, Inc
Emissions Science, Inc.
EPA Method 7E
Exhaust Stack with sample ports
Calibration
Gas Line
3/8" Heated
System manifold with
pump, flow control
valves, overflow
valve, Etc.
System Moisture
Removal Manifold
& Particualte Filter
C.A.I.
Chemiluminescence Analyzer
C.A.I. ZRE NDIR
& Paramagetic
O2 Analyzer
System Data
Recorder
Data Collection and
calculation system
Certified
Calibration gas
Probe with
particulate filter