NOX, CO, AND NMOC EMISSIONS

TESTING REPORT

North Carolina Air Permit No. 08634T03

UNITS 1 & 2

IREDELL TRANSMISSION, LLC

STATESVILLE, NORTH CAROLINA

December, 2008
ii

CONTENTS

Section Page

EXECUTIVE SUMMARY .............................................................................................. IV

1. 0 INTRODUCTION..................................................................................................1

2.0 SOURCE DESCRIPTION....................................................................................1

3.0 SAMPLING AND ANALYTICAL PROCEDURES .............................................2

3.1 STACK GAS VELOCITY AND FLOWRATES (USEPA METHODS 1-2).......3

3.1.1 Sampling Method......................................................................................................3

3.1.2 Method 2 Sampling Equipment .............................................................................3

3.2 OXYGEN AND CARBON DIOXIDE (USEPA METHODS 3A) .......................3

3.2.1 Sampling Method......................................................................................................3

3.2.2 O2 / CO2 Sampling Train .........................................................................................3

3.2.3 Sampling Train Calibration......................................................................................4

3.3 MOISTURE DETERMINATION (USEPA METHOD 4)...................................4

3.3.1 Sampling Method......................................................................................................4

3.4 OXIDES OF NITROGEN AND CARBON MONOXIDE (USEPA METHODS

7E AND 10) ..................................................................................................................4

3.4.1 Sampling Method......................................................................................................4

3.4.2 NOx, and CO Sampling Train.................................................................................4

3.4.3 Sampling Train Calibration......................................................................................5

3.5 METHANE (USEPA METHOD 18)..................................................................5

3.5.1 Sampling Method......................................................................................................5

3.5.2 CH4 Sampling Train.................................................................................................5

3.5.3 Sampling Duration & Frequency ...........................................................................6

3.6 TOTAL HYDROCARBON COMPOUNDS (USEPA METHOD 25A) .............6

3.6.1 Sampling Method......................................................................................................6

3.6.2 THC Sampling Train.................................................................................................6

3.6.3 Sampling Train Calibration......................................................................................6

3.6.4 Sampling Duration & Frequency ...........................................................................6

3.7 QA/QC AND POST TEST PROCEDURES.....................................................7

3.7.1 Quality Control and Assurance (O2, CO2, NOx, and CO).................................7

3.7.2 Quality Control and Assurance (NMOC) .............................................................7

3.8 DATA REDUCTION ........................................................................................8

4.0 OPERATING PARAMETERS.............................................................................8

5.0 RESULTS.............................................................................................................9
iii

6.0 CERTIFICATION STATEMENT........................................................................10

Result Table

Emissions Testing Results: Unit 1

Emissions Testing Results: Unit 2

Figures

1 Units 1 & 2 Stack Drawing & Exhaust Sampling Point Location

2 USEPA Method 3A/7E/10 Sampling Train

3 USEPA Method 25A Sampling Train

4 USEPA Method 18 Sampling Train

Appendices

A NCDER Test Plan and Approval Letter

B Equipment and Analyzer Calibration Data

C Example Calculations

D Flowrate and Moisture Data

E Raw Analyzer Data

F Operational Data

G Analytical Data
iv

DTE Energy Corporate Services, LLC (DECS), a DTE Energy Company (DTE)

performed emissions testing at Iredell Transmission, LLC, located in Statesville, North 

Carolina. The fieldwork, performed on November 5, 2008 was conducted to satisfy

requirements of the North Carolina Air Permit No. 08634T03 and EPA Subpart JJJJ. 

Emissions tests were performed on Units 1 & 2 for oxides of nitrogen (NOx), carbon 

monoxide (CO), and non-methane organic compounds (NMOC).

The results of the emissions testing are highlighted below:

Emissions Testing Summary

Iredell Transmission, LLC

Statesville, NC

Units 1 & 2

November 5, 2008

(1) ppm, corrected to 15% O2

EXECUTIVE SUMMARY

Unit 1 Load

(%)

Oxides of 

Nitrogen(1)

(ppm)

Carbon 

Monoxide(1)

(ppm)

NMOC(1)

(ppm)

Test 1 97.0 56.1 410.6 10.5

Test 2 96.7 55.9 403.6 12.2

Test 3 96.9 56.5 410.3 12.2

Average 56.2 408.1 11.6

Unit 2 Load

(%)

Oxides of 

Nitrogen(1)

(ppm)

Carbon 

Monoxide(1)

(ppm)

NMOC(1)

(ppm)

Test 1 96.9 54.8 426.6 15.4

Test 2 97.1 55.1 429.4 13.9

Test 3 97.5 54.7 427.6 19.6

Average 54.9 427.9 16.3

Permit Limit(1) 160 540 86
1

DTE Energy Corporate Services, LLC (DECS), a DTE Energy Company (DTE) 

performed emissions testing at Iredell Transmission, LLC, located in Statesville, 

North Carolina. The fieldwork, performed on November 5, 2008, was conducted to 

satisfy requirements of the North Carolina Air Permit No. 08634T03 and EPA subpart JJJJ.

Testing was performed pursuant to Title 40, Code of Federal Regulations, Part 60, 

Appendix A (40 CFR §60 App. A), Methods 1-4, 7E, 10, 18, and 25A.

The fieldwork was performed in accordance with EPA Reference Methods and 

DECS Intent to Test1, which was approved by the North Carolina Department of 

Environment and Natural Resources (NCDER) on October 27, 20082. The following 

DECS personnel participated in the testing program: Mr. Mark Grigereit, 

Environmental Specialist, and Mr. Fred Meinecke, Environmental Technician. Mr. 

Grigereit was the project leader. Mr. Grigereit has 20 years of source testing 

experience testing for DTE Energy and private consulting firms and Mr. Meinecke 

has 15 years of source testing experience testing for DTE Energy and private 

consulting firms. 

Mr. Thomes Durham, Environmental Engineer, DTE Energy Services, LLC, provided 

the process coordination for the testing program. Mr. Jeffery Johnson, DTE Biomass 

Energy, provided on-site operation of the units. Mr. Gregg O’Neal with the Technical 

Services Section of the NCDER reviewed the Test Plan. Mr. Jim Westmoreland, 

NCDER-Mooresville Regional Office, observed the testing.

The Iredell Transmission, LLC power generating facility, located at 356 Twin Oaks 

Road, Statesville NC is a power generating facility. The facility consists of two (2) 

landfill gas-fired internal combustion engines with associated electrical generators. 

The systems are Caterpillar G3520C – 1200 RPM 1600 kW Gas Generator Sets. 

The purpose of the source is to utilize land fill gas from the Iredell County Landfill to 

produce energy to be sent to the electrical grid. 

 

1 NCDER, Test Plan, Submitted September 22, 2008. (Attached-Appendix A)

2 NCDER, Approval Letter. (Attached-Appendix A)

1. 0 INTRODUCTION

2.0 SOURCE DESCRIPTION
2

See Figure 1 for diagrams of the units’ sampling locations and stack dimensions.

3.0 SAMPLING AND ANALYTICAL PROCEDURES

DTE Energy obtained emissions measurements in accordance with procedures 

specified in the USEPA Standards of Performance for New Stationary Sources. The 

sampling and analytical methods used in the testing program are indicated in the 

table below

Sampling Method Parameter Analysis

USEPA Methods 1-2 Exhaust Gas Flow rates Field data analysis and 

reduction

USEPA Method 3A Oxygen & CO2 Instrumental Analyzer 

Method

USEPA Method 4 Moisture content Field data analysis and 

reduction

USEPA Method 7E Oxides of Nitrogen

Chemilumenecent

Instrumental Analyzer 

Method

USEPA Method 10 Carbon Monoxide

NDIR

Instrumental Analyzer 

Method

USEPA Method 18 Gaseous Organic 

Compounds (Methane)

GC

Analytical Method

(TedlarTM Bag Sample)

USEPA Method 25A Total Hydrocarbon 

Compounds

FID

Instrumental Analyzer 

Method
3

3.1 STACK GAS VELOCITY AND FLOWRATES (USEPA METHODS 1-2)

3.1.1 Sampling Method

Stack gas velocity traverses were conducted in accordance with the 

procedures outlined in USEPA Method 1, “Sample and Velocity Traverses for 

Stationary Sources,” and Method 2, “Determination of Stack Gas Velocity and 

Volumetric Flowrate.” Two (2) sampling ports were utilized on each Unit’s 

exhaust duct, sampling at six (6) points per port for a total of twelve (12) 

points. Sampling was conducted in conjunction with the gaseous emissions 

testing.

A Cyclonic flow check was performed prior to performing the flowrate testing. 

Testing in the stacks demonstrated that no cyclonic flow is present. Data has 

been included in Appendix E demonstrating the absence of cyclonic flow.

3.1.2 Method 2 Sampling Equipment

DTE Energy’s EPA Method 2 sampling equipment consisted of a 0-10” 

incline manometer, S-type pitot tube (Cp = 0.84) and a type-K calibrated 

thermocouple. 

3.2 OXYGEN AND CARBON DIOXIDE (USEPA METHODS 3A)

3.2.1 Sampling Method

Oxygen (O2) and Carbon Dioxide (CO2) emissions were evaluated using 

USEPA Method 3A, “Gas Analysis for Carbon Dioxide, Oxygen, Excess Air, 

and Dry Molecular Weight (Instrumental Analyzer Method)”. The analyzers

utilize paramagnetic sensors.

3.2.2 O2 / CO2 Sampling Train

The DECS EPA Method 3A sampling system consisted of (1) a single-point 

sampling probe (placed in the center of the stack), (2) a heated TeflonTM

sampling line, (3) a Universalgas conditioner with particulate filter, (4) a 

flexible unheated TeflonTM sampling line, (5) a Servomax 1400 O2/CO2 gas 

analyzer, (6) appropriate USEPA Protocol 1 calibration gases, and (7) a 

ThermoWestronics Data Acquisition System. 
4

Refer to Figure 2 for a schematic of the O2, CO2, NOx, and CO sampling 

train. 

3.2.3 Sampling Train Calibration

The O2 and CO2 analyzers were calibrated according to procedures outlined 

in USEPA Method 7E. Zero, span, and mid range calibration gases were 

introduced directly into the analyzer to determine the instruments linearity. A

zero and mid range span gas for each pollutant was then introduced through 

the entire sampling system to determine sampling system bias for each 

analyzer at the completion of each test.

3.3 MOISTURE DETERMINATION (USEPA METHOD 4)

3.3.1 Sampling Method 

Determination of the moisture content at the outlet each unit was performed 

using the method described in USEPA Method 4, “Determination of Moisture 

Content in Stack Gases”. The moisture was collected in glass impingers, and 

the percentage of water was then derived from calculations outlined in 

USEPA Method 4. A 30-minute moisture sample was collected during each 

test run.

3.4 OXIDES OF NITROGEN AND CARBON MONOXIDE (USEPA METHODS 7E 

AND 10)

3.4.1 Sampling Method

Oxides of nitrogen (NOx) emissions were evaluated using USEPA Method 7E, 

“Determination of Oxides of Nitrogen Emissions from Stationary Sources”. 

The NOx analyzer utilizes a Chemilumenecent detector. Carbon monoxide 

(CO) emissions were evaluated using USEPA Method 10, “Determination of 

Carbon Monoxide Emissions from Stationary Sources”. The CO analyzer 

utilizes a NDIR detector.

3.4.2 NOx, and CO Sampling Train

The EPA Methods 7E and 10 sampling system consisted of (1) a single-point 

sampling probe (placed in the center of the stack), (2) a heated TeflonTM

sampling line, (3) a Universalgas conditioner with particulate filter, (4) a 

flexible unheated TeflonTM sampling line, (5) a TECO 42i Chemilumenecent

NO/NOx gas analyzer, and TECO 48i NDIR CO gas analyzer, (6) appropriate 
5

USEPA Protocol 1 calibration gases, and (7) a ThermoWestronics Data 

Acquisition System. 

Refer to Figure 2 for a schematic of the O2, CO2, NOx, and CO sampling 

train. 

3.4.3 Sampling Train Calibration

The Sampling train was calibrated according to procedures outlined in 

USEPA Method 7E. Zero, span, and mid range calibration gases were 

introduced directly into the analyzer to determine the instruments linearity. A 

zero and mid range span gas for each pollutant was then introduced through 

the entire sampling system to determine sampling system bias for each 

analyzer at the completion of each test.

3.5 METHANE (USEPA METHOD 18)

3.5.1 Sampling Method

Methane (CH4) emissions were evaluated using USEPA Method 18, 

“Measurement of Gaseous Organic Compound Emissions by Gas 

Chromatography (TedlarTM Bag Sampling)”. This method involves the 

collection of exhaust gas in a TedlarTM bag, which is then analyzed at an offsite laboratory by gas chromatography (GC). According to the test plan 

submitted to the NCDER, DTE was originally going to test for non-methane 

organic compounds (NMOC), utilizing a methane/non-methane FID. 

Following discussions with the Agency, Method 18 was substituted as the 

method performed to collect the CH4. This modification to the test plan was 

agreed upon with the NCDER prior to the initiation of field activities.

3.5.2 CH4 Sampling Train

The Method 18 sampling system consisted of (1) a single-point sampling 

probe (placed in the center of the stack), (2) an un- heated TeflonTM sampling 

line (kept to the minimum length required), (3) a sampling lung with 15-liter

TedlarTM bag, and (4) a vacuum pump with regulator.

Refer to Figure 4 for a schematic of the Method 18 sampling train. 
6

3.5.3 Sampling Duration & Frequency

Methane samples were collected simultaneously with the other gaseous 

pollutants measured. The vacuum pump flowrate was set to allow for a 

constant rate sample, collected for the duration of each test run. Analytical 

results for M18 are located in Appendix G. 

3.6 TOTAL HYDROCARBON COMPOUNDS (USEPA METHOD 25A)

3.6.1 Sampling Method

Total hydrocarbon compound (THC) emissions were evaluated using USEPA 

Method 25A, “Determination of Total Hydrocarbon Emissions from Stationary 

Sources (Instrumental Analyzer Method)”. The THC analyzer utilizes a flame 

ionization detector (FID). The FID measures total hydrocarbon compounds. 

3.6.2 THC Sampling Train

DECS’ EPA Method 25A sampling system consisted of (1) a single-point 

sampling probe (placed in the center of the stack), (2) a heated TeflonTM

sampling line, (3) a JUM 109ATHC gas analyzer, (4) appropriate certified 

calibration gases, and (5) a ThermoWestronics Data Acquisition System. 

Refer to Figure 3 for a schematic of the THC sampling train. 

3.6.3 Sampling Train Calibration

In accordance with USEPA Method 25A, a 4-point (zero, low, mid, and high) 

calibration check was performed on the THC analyzer. The analyzer was 

calibrated in the 0-1,600 ppm range. Calibration drift checks were performed 

at the completion of each run. 

3.6.4 Sampling Duration & Frequency

The THC gaseous emission testing was performed simultaneously with the 

O2, CO2, NOx, and CO sampling. Data was recorded at 4-second intervals

and average over 1-minute periods. 
7

3.7 QA/QC AND POST TEST PROCEDURES

3.7.1 Quality Control and Assurance (O2, CO2, NOx, and CO)

All sampling and analytical equipment was calibrated according to the 

guidelines referenced in Methods 3A, 7E, and 10. Calibration gases were 

EPA Protocol 1 gases and the concentrations were within the acceptable 

ranges (40-60% mid range and span) specified in Methods 3A and 7E. 

Calibration gas certification sheets are located in Appendix B. 

DTE performed converter efficiency testing by directly challenging the NOx

analyzer with a nitrogen dioxide (NO2) calibration gas of 51.5 ppm. Results 

from the converter efficiency test demonstrated that the analyzer met the 

requirements of Method 7E(Eq. 1).

Eq. 1

 91.5%

51.5

47.1

2   

v

Dir

NO C

C

Eff

3.7.2 Quality Control and Assurance (NMOC)

The THC sampling equipment was calibrated with propane (C3H8) according 

to the guidelines referenced in Methods 25A. Calibration gases were EPA 

Protocol 1 gases and the concentrations were within the acceptable ranges 

(25-35% low range, 45-55% mid range and 80-100 span). 

An analyzer response factor (RF) for CH4 of 3 was applied to the CH4 

concentration in the exhaust gas, as determined by Method 18. The CH4 (as

methane) is converted to CH4 (as propane)

in order to subtract the CH4 from the THC 

measured in the field(Eq. 2).

Eq. 2

 27.5

3

1,326 469.5

4 ( 4)

( 3 8)  











  















 

RF

CH

NMOC THC ppm asCH

PPM asC H
8

Calibration gas certification sheets are located in Appendix E. 

3.8 DATA REDUCTION

Data collected during the emissions testing was reported according to 

emissions limits specified in the facility’s Air Permit. NOx, CO, and NMOC

emissions are reported as parts per million, corrected to 15% O2. 

Emissions calculations are based on calculations located in USEPA Method 

1-4, 7E, 10, 18, and 25A. The results are located in the Results Tables. 

The test program included the collection of generator load (kW), engine speed 

(RPM), inlet manifold air pressure (psi), fuel upper heating value (BTU), fuel 

flow (scfm) and generator operating hours (kW-hour). 

Operational data are located in Appendix F. 

4.0 OPERATING PARAMETERS
9

5.0 RESULTS

The Results of the testing indicate that Units 1 & 2 are in compliance with North 

Carolina Air Permit No. 08634T03 and EPA sub-part JJJJ. 

. 

Emissions Testing Summary

Iredell Transmission, LLC

Statesville, NC

Units 1 & 2

November 5, 2008

(1) ppm, corrected to 15% O2

Unit 1 Load

(%)

Oxides of 

Nitrogen(1)

(ppm)

Carbon 

Monoxide(1)

(ppm)

NMOC(1)

(ppm)

Test 1 97.0 56.1 410.6 10.5

Test 2 96.7 55.9 403.6 12.2

Test 3 96.9 56.5 410.3 12.2

Average 56.2 408.1 11.6

Unit 2 Load

(%)

Oxides of 

Nitrogen(1)

(ppm)

Carbon 

Monoxide(1)

(ppm)

NMOC(1)

(ppm)

Test 1 96.9 54.8 426.6 15.4

Test 2 97.1 55.1 429.4 13.9

Test 3 97.5 54.7 427.6 19.6

Average 54.9 427.9 16.3

Permit Limit(1) 160 540 86
10

6.0 CERTIFICATION STATEMENT

“I certify that I believe the information provided in this document is true, accurate, and 

complete. Results of testing are based on the good faith application of sound 

professional judgment, using techniques, factors, or standards approved by the 

Local, State, or Federal Governing body, or generally accepted in the trade.”

_________________________________

Mark R. Grigereit, QSTI

This report prepared by: 

 Mr. Mark R. Grigereit, QSTI

 Specialist, Stationary Source & Ambient Monitoring

 Environmental Management and Resources

 DTE Energy Corporate Services, LLC

This report reviewed by: 

 Mr. Mark Mullen

 Supervisor, Stationary Source & Ambient Monitoring

 Environmental Management and Resources

 DTE Energy Corporate Services, LLC
RESULTS TABLES
FIGURES
APPENDIX A

NCDER TEST PLAN AND 

APPROVAL LETTER
APPENDIX B

EQUIPMENT AND ANALYZER CALIBRATION DATA
APPENDIX C

EXAMPLE CALCULATIONS
EXAMPLE CALCULATIONS

Note: answers obtained by sample calculations may deviate from that presented 

within the report because of rounding differences. 

UNIT 1 – RUN 2

USEPA METHOD 4 

Moisture Content

Where: Vwc = volume of water vapor condensed in impingers at standard 

conditions (ft3)

K1 = 0.04707 ft3/mL water

V1 = volume of water collected in impingers (mL)

Vwsg = volume of water vapor collected in silica gel at standard 

conditions (ft3)

K2 = 0.04715 ft3/g water

V2 = mass of water collected by silica gel (g)

For example, 72 g of water were condensed in the impingers and the silica gel. The 

volume of water collected in each section of the sampling train, in ft3, was calculated 

as follows: (Note: Impingers and silica gel were weighed)

The total volume of water collected was 3.3948 ft3.

Vwc K1 V1  

Vwsg K2 V2  

 

3

3

0 mL 0.0000 ft

mL

ft 0.04707  















Vwc 

 

3

3

72g 3.3948 ft

g

ft 0.04715  















Vwsg 
Gas Volume Standardization

Where: Vstd = volume of gas sampled at standard conditions

Vm = volume of gas measured by dry gas meter (ft3)

Ym = dry gas meter correction factor (dimensionless)

Tstd = standard temperature (oR = 460 + oF)

Pstd = standard pressure (“Hg)

Pb = barometric pressure (“Hg)

H = average orifice differential pressure (“H2O)

Tm = average meter temperature (oR)

For example, the volume of gas measured at the dry gas meter for of the moisture 

sampling was 22.990 ft3. The dry gas meter correction factor was 0.972. Standard 

temperature and pressure are 530oR and 29.92”Hg, respectively. The barometric 

pressure at the time of testing was 29.29”Hg. The average orifice differential, and 

meter temperature were 1.70 and 532.72oR, respectively. The volume of gas 

sampled was corrected to standard conditions as follows:























 





















m

b

std

std

std m m

T

H

P

P

T

V V Y

13.6

   21.66 ft ,standard

532.72

"Hg

"H O

13.6

1.70"H O

29.29"Hg

29.92"Hg

530 22.990 ft 0.972 3

o

2

2

3



























































R

R

V

o

std
Moisture Fraction

Where: Bws = exhaust gas moisture content

For example, from previously calculated values, the exhaust gas moisture fraction 

was calculated as follows:

Absolute Stack Gas Temperature, Ts (

oR)

s s T  460  t

Where: ts = Measured stack gas temperature (oF)

For example, the average stack temperature was 944.8oF. The average temperature 

in degrees Rankine is therefore 944.8+ 460 = 1,404.8oR.

Absolute Stack Gas Pressure, Ps (in. Hg)













 

13.6

stat

s bar

P

P P

Where: Pbar = Barometric pressure at test site (in. Hg)

Pstat = Stack static pressure (in. Hg)

For example, the barometric and stack static pressures were 29.29”Hg, and –0.76” 

H2O, respectively. The absolute stack pressure is then:

Ps 29.23"Hg

13.6

0.76 29.29  









 

 

wc wsg std

wc wsg

ws V V V

V V

B

 





0.1355

3.3948 ft 21.66 ft

3.3948 ft

3 3

3





Bws 
Stack Gas Molecular Weight, Dry Basis (lb/lb mole)

0.44(% ) 0.32(% ) 0.28(% % ) M d  CO2  O2  N2  CO

For example, the average O2 content of the exhaust gas stream was 7.6%. The CO2

content of the gas stream was 11.9%. The CO content was assumed to be 

negligible, and the N2 content is assumed to make up the balance of the gas content 

(i.e. 100-7.6-11.9-0.0-0.0 = 80.5%). The dry stack gas molecular weight is therefore:

lb mol

lb Md  0.44(11.9%)  0.32(7.6%)  0.28(80.5%)  30.21

Stack Gas Molecular Weight, Wet Basis (lb/lb mole)













 











 

100

18

100

1

ws ws

s d

B B

M M

The stack gas moisture content for at the stack exhaust was 13.55%. The wet stack 

gas molecular weight is then:

lb mol

lb 28.68

100

13.55 18

100

13.55 1

lb mol

lb 30.21  











 









 M s  

Stack Gas Velocity, Vs (fpm)

s s

s

s p p

PM

T

V K C P













min

sec 60

Where: Kp = Pitot tube constant equal to 85.49 

( )( . )

( / )( . )

sec R in H2O

ft lb lb mole in Hg

o



Cp = Pitot tube coefficient, dimensionless

P = The average square root of the velocity head of stack gas (in. 

H2O)

Ms = Molecular weight of the stack gas, wet basis (lb/lb mole)
For example, flowrate testing at the boiler stack exhaust, the average square root of 

the velocity head of the stack gas was 1.7148”H2O. Using values already calculated, 

the average stack gas velocity was calculated as follows:

  

  

 

 

 

min

9,564

lb mol

lb 29.23 . 28.68

1404.8

1.7148

0.84

.

lb/lb mol .

sec

85.49

min

sec 60

2

ft

in Hg

R

R in H O

ft in Hg V

o

s o















































Average Stack Gas Volumetric Flowrate, Qs (cfm)

Qs  Vs A

Where: Vs = Stack gas velocity (fpm)

A = Cross-sectional area of stack (ft2)

For example, the exhaust stack has a 16” diameter. The cross-sectional area of the 

stack is calculated as follows:

2 2

R 1.396 ft

The stack gas volumetric flowrate was then calculated as follows:

 

min

1.396 13,354

min

9,564

3

2

ft ft ft Qs  













Standard Stack Gas Volumetric Flowrate, Qstd (scfm)



































in Hg

P

T

R

Q Q

s

s

o

std s

29.92 .

530

Where: Ts = Absolute stack gas temperature (oR)

Ps = Absolute stack gas pressure (in. Hg)
For example, the standard stack gas volumetric flowrate was calculated as follows:

,standard

min

4,922

29.92 .

29.23. .

1404.8

530

min

13,354

3 3

ft

in Hg

in Hg

R

ft R

Q o

o

std 

































Dry Standard Stack Gas Volumetric Flowrate, Qstd,dry (dscfm)

  Qstd dry  Qstd  Bws 1 ,

For example, the dry standard stack gas volumetric flowrate was calculated as 

follows:

  ,standard dry

min

,standard* 1 0.1355 4,256

min

4,922

3 3

,

ft ft Qstd dry   

USEPA METHODS 3A, 7E, AND 10

Analyzer Drift Correction

 



















 

m o

ma

o

C C

C

C C C

Where: C = Effluent gas concentration, dry basis (ppm).

C = Average gas concentration indicated by gas analyzer, dry basis 

(ppm).

Co = Average of initial and final system calibration bias check 

responses for the zero gas (ppm).

Cma = Actual concentration of the upscale calibration gas (ppm).

Cm = Average of initial and final system calibration bias check 

responses for the upscale calibration gas (ppm).

For example, the average of the initial and final NOx outlet zero gas calibration 

checks was 2.1ppmv. The average of the initial and final NOx midscale gas 

calibration checks was 190.85 ppmv. The actual concentration was 191.8 ppmv. 

The average outlet NOx concentration indicated by the gas analyzer was 126.2

ppmv. The actual stack gas NOx concentration, corrected for analyzer drift, is then:
C   126.1 ppm

190.85 2.1

191.8

126.2 2.1  













 

Concentration Standardization to 15% Oxygen

Where: %O2 = measured exhaust gas oxygen content (%)

C'NOx = NOx concentration (ppmv) 

For example, the measured exhaust gas oxygen content for Run 2 was 7.6%. The 

NOx concentration (C’NOx) was standardized to 15% oxygen as follows:

USEPA METHOD 18 & 25A

For example, the measured concentration of methane (per Method 18) was 1,326 

ppm (as CH4). The results must be converted to parts per million (as C3H8).

Therefore, the non-methane organic compounds (NMOC) are determined as follows:

The NMOC concentration is then corrected for 15% O2 following the same procedure 

used for Methods 7E and 10.





















9 % 2 20.

5.9

'

O

C NO x CNOx

55.9 ppmv NO @15% oxygen

20.9 7.6

5.9

' 126.1ppmv   x













C NOx 

3

'

4( )

4( )

CH asmethane

CH aspropane

C

C 

442.0

3

1,326 '

4( )

  C CH aspropane

NMOC  469.5ppm  442.0 ppm  27.5ppm
APPENDIX D

FLOWRATE AND MOISTURE DATA
APPENDIX E

RAW ANALYZER DATA
APPENDIX F

OPERATIONAL DATA
APPENDIX G

ANALYTICAL DATA