D. Harris September 22, 2015 Correspondence to R. Kaplan

Exhibit C

USEPA Mercury CEMS Report
Long-Term Field Evaluation of Mercury 

(Hg) Continuous Emission Monitoring 

Systems: Coal-Fired Power Plant 

Burning Eastern Bituminous Coal 

and Equipped With Selective Catalytic 

Reduction (SCR), Electrostatic 

Precipitator (ESP), and 

Wet Scrubber: 

Field Activities From 

November 2004 to September 2005 

Final Report 

Volume 1 (of 3)—Text 

For 

U.S. Environmental Protection Agency 

EPA Contract GS-10F-0127J 

MRI Project No. 110489 

November 29, 2006 
 Long-Term Field Evaluation of Mercury 

(Hg) Continuous Emission Monitoring 

Systems: Coal-Fired Power Plant 

Burning Eastern Bituminous Coal 

and Equipped With Selective Catalytic 

Reduction (SCR), Electrostatic 

Precipitator (ESP), and 

Wet Scrubber: 

Field Activities From 

November 2004 to September 2005 

Final Report 

Volume 1 (of 3)—Text 

For 

U.S. Environmental Protection Agency 

Office of Air Quality Planning and Standards 

Air Quality Assessment Division 

Measurement Technology Group 

Research Triangle Park, North Carolina 27711 

Attn: Mr. Bill Grimley 

EPA Contract GS-10F-0127J 

MRI Project No. 110489 

November 29, 2006 
iii

Preface

This report was prepared by Midwest Research Institute (MRI) for the U.S. 

Environmental Protection Agency (EPA) under Contract No. GS-10F-0127J. Mr. Bill 

Grimley is the EPA Project Manager. Field work activities for the report were performed 

from November 2004 through September 2005. This report was prepared on a follow-up 

contract as the original contract expired in September, 2005. 

The test program was conducted in MRI’s Applied Engineering Division, with 

Mr. John Hosenfeld serving as MRI’s Project Leader. In this report, MRI presents a 

summary of activities surrounding installation of mercury Continuous Emissions 

Monitoring System (Hg CEMS), certification results including the final Relative 

Accuracy Test Audit (RATA), and the long-term monitoring phase. 

 MIDWEST RESEARCH INSTITUTE

John Hosenfeld 

Project Leader 

Approved: 

Roger Starnes 

Director 

September 29, 2006 
iv
v

Contents

Preface................................................................................................................................ iii 

Figures............................................................................................................................... vii 

Tables................................................................................................................................. ix 

Section 1. Introduction................................................................................................... 1-1

1.1 Study Overview......................................................................................... 1-1 

1.2 Performance Testing.................................................................................. 1-2 

1.3 Test Site..................................................................................................... 1-3 

1.4 Summary of Systems Evaluated................................................................ 1-3 

1.5 Test Program Organization........................................................................ 1-5 

Section 2. Durability, Availability, and Maintenance of CEMS ................................... 2-1 

2.1 Durag ......................................................................................................... 2-4 

2.2 Forney/Genesis.......................................................................................... 2-5 

2.3 Horiba........................................................................................................ 2-6 

2.4 Opsis.......................................................................................................... 2-6 

2.5 Tekran........................................................................................................ 2-7 

2.6 Thermo ...................................................................................................... 2-8 

2.7 Summary.................................................................................................... 2-9 

Section 3. Sampling ....................................................................................................... 3-1

3.1 Process Data .............................................................................................. 3-1 

3.2 Flue Gas Sampling Location ..................................................................... 3-1 

3.3 Ontario Hydro Method ..............................Error! Bookmark not defined.1 

3.4 Reference Gases .................................................................................... 3-111 

Section 4. Certification Test Results.............................................................................. 4-1 

4.1 Phase 1 Certification Test Results............................................................. 4-1 

4.2 Phase 2 Certification Test Results........................................................... 4-31 

Section 5. Quality Assurance/Quality Control............................................................... 5-1 

5.1 Phase 1 Certification Testing..................................................................... 5-1 

5.2 Phase 2 Certification Testing................................................................... 5-11 

Section 6. Hg CEMS Conclusions and Recommendations ........................................... 6-1 

6.1 Performance Findings................................................................................ 6-1 

6.2 Conclusions and Recommendations.......................................................... 6-1 
vi

Appendices

Volume 2: Phase 1 Supporting Data 

Appendix A—Plant Process Data 

Appendix B—Sample Traceability 

Appendix C—Ontario Hydro Sampling Data 

Appendix D—Sampling Equipment Calibration Data 

Appendix E—Mercury Analysis Results (Oxford Laboratories) 

Appendix F—Hg CEMS Relative Accuracy Test Data 

Appendix G—Part 75 Appendix K Method Test Data 

Appendix H—Glossary of Acronyms 

Volume 3: Phase 2 Supporting Data 

Appendix A—Plant Process Data 

Appendix B—Sample Traceability 

Appendix C—Ontario Hydro Sampling Data 

Appendix D—Sampling Equipment Calibration Data 

Appendix E—Mercury Analysis Results (Oxford Laboratories) 

Appendix F—Hg CEMS Relative Accuracy Test Data 

Appendix G—Long-Term Monitoring Data: Daily Calibration Error Results 

Appendix H—Long-Term Monitoring Data: Weekly System Integrity Results 

Appendix I —Glossary of Acronyms 
vii

Figures

Figure 1-1. Test Program Organization...................................................................... 1-6 

Figure 2-1. Phase 1 and 2 Long-Term Monitoring Periods...................................... 2-10 

Figure 3-1. Layout of Sampling Ports and Hg CEMS and Other Sampling 

Systems During Phase 1 RATA Test..................................................... 3-33 

Figure 3-2. Layout of Sampling Ports and Hg CEMS and Other Sampling 

Systems During Phase 2 RATA Test....................................................... 3-4 

Figure 3-3. Sampling Location at the Unit #1 Stack North Inlet Duct..................... 3-55 

Figure 3-4. Hg CEMS Sampling Configuration During Phase 1 RATA ................. 3-66 

Figure 3-5. Hg CEMS Sampling Configuration During Phase 2 RATA ................. 3-77 

Figure 3-6. Ontario Hydro Sampling Train .............................................................. 3-99 

Figure 3-7. Ontario Hydro Sample Recovery Scheme ........................................... 3-100 

Figure 4-1. Phase 1 OH Gaseous Phase Mercury Concentrations............................ 4-18 

Figure 4-2. Decision Tree for Blank Corrections ..................................................... 4-20 

Figure 4-3. Summary of RA Phase 1 Tests .............................................................. 4-22 

Figure 4-4. Phase 1 RA—OH Versus Forney/Genesis............................................. 4-23 

Figure 4-5. Phase 1 RA—OH Versus Horiba........................................................... 4-24 

Figure 4-6. Phase 1 RA—OH Versus Tekran .......................................................... 4-24 

Figure 4-7. Phase 1 RA—OH Versus Thermo ......................................................... 4-25 

Figure 4-8. Tekran Hg0

 Spiking................................................................................ 4-31 

Figure 4-9. Phase 2 OH Gaseous Phase Mercury Concentrations............................ 4-67 

Figure 4-10. Decision Tree for Blank Corrections ..................................................... 4-68 

Figure 4-11. Phase 2 Summary of RA Tests .............................................................. 4-70 

Figure 4-12. Phase 2 RA—OH Versus Durag............................................................ 4-71 

Figure 4-13. Phase 2 RA—OH Versus Opsis............................................................. 4-71 

Figure 4-14. Phase 2 RA—OH Versus Tekran .......................................................... 4-72 

Figure 4-15. Phase 2 RA—OH Versus Thermo ......................................................... 4-72 

Figure 6-1. Phase 1 and 2 Long-Term Monitoring Periods........................................ 6-4 
viii
ix

Tables

Table 1-1. Summary of Certification and Relative Accuracy Test 

Performance Criteria................................................................................ 1-2 

Table 1-2. Phase 1 Summary of Hg CEMS Evaluated.............................................. 1-3 

Table 1-3. Phase 2 Summary of Hg CEMS Evaluated.............................................. 1-4 

Table 2-1. Summary of Phase 1 Maintenance Events for Hg CEMS 

(Nov 2004-Feb 2005)............................................................................... 2-2 

Table 2-2. Summary of Phase 2 Maintenance Events for Hg CEMS 

(Mar-Sept 2005)....................................................................................... 2-3 

Table 3-1. Phase 1 Average Plant CEM Data ........................................................... 3-2 

Table 3-2. Phase 2 Average Plant CEM Data ......................................................... 3-22 

Table 3-3. Elemental Mercury Cylinders.............................................................. 3-122 

Table 4-1. Summary of Phase 1 CEMS Certification Criteria and 

Performance (Excluding RATA) ............................................................. 4-1 

Table 4-2. Forney 7-Day Calibration Error Test—Phase 1....................................... 4-2 

Table 4-3. Horiba/Nippon 7-Day Calibration Error Test—Phase 1.......................... 4-3 

Table 4-4. Horiba/Nippon Linearity Test—Phase 1 ................................................. 4-4 

Table 4-5. Horiba/Nippon System Integrity Test—Phase 1...................................... 4-4 

Table 4-6. Horiba/Nippon Measurement Error Test—Phase 1................................. 4-5 

Table 4-7. Horiba/Nippon Zero/Upscale Drift Tests—Phase 1 ................................ 4-5 

Table 4-8. Tekran 7-Day Calibration Error Test—Phase 1....................................... 4-6 

Table 4-9. Tekran Linearity Test—Phase 1 .............................................................. 4-6 

Table 4-10. Tekran System Integrity Test—Phase 1 .................................................. 4-7 

Table 4-11. Tekran Cycle Time—Phase 1 .................................................................. 4-7 

Table 4-12. Tekran Measurement Error Test—Phase 1.............................................. 4-8 

Table 4-13. Tekran Zero/Upscale Drift Tests—Phase 1 ............................................. 4-8 

Table 4-14. Thermo 7-Day Calibration Error Test—Phase 1 ..................................... 4-9 

Table 4-15. Thermo Linearity Test—Phase 1............................................................. 4-9 

Table 4-16. Thermo System Integrity Test—Phase 1 ............................................... 4-10 

Table 4-17. Thermo Cycle Time—Phase 1............................................................... 4-10 

Table 4-18. Thermo Measurement Error Test—Phase 1 .......................................... 4-10 

Table 4-19. Thermo Zero/Upscale Drift Tests—Phase 1.......................................... 4-11 

Table 4-20. Phase 1 RA Test Run Times .................................................................. 4-12 

Table 4-21. Phase 1 RA Test Stack Sampling Data.................................................. 4-13 

Table 4-22. Phase 1 RA Test Ontario Hydro Mercury Analysis Results (μg).......... 4-14 

Table 4-23. Phase 1 RA Total OH Mercury Concentrations .................................... 4-15 

Table 4-24. Phase 1 Gaseous-Phase OH Mercury .................................................... 4-16 

Table 4-25. Phase 1 Duplicate OH Train Relative Deviation ................................... 4-17 

Table 4-26. Phase 1 Summary of All RA Results for All CEMS ............................. 4-21 

Table 4-27. Phase 1 RA Results for Forney/Genesis ................................................ 4-25 

Table 4-28. Phase 1 RA Results for Horiba (All 12 Runs) ....................................... 4-26 

Table 4-29. Phase 1 RA Results for Tekran (All 12 Runs)....................................... 4-27 

Table 4-30. Phase 1 Initial RA Results for Thermo (All 12 Runs)........................... 4-28 

Table 4-31. Phase 1 RA Results for Appendix K Method ........................................ 4-29 

Table 4-32. Comparison of Sorbent Trap and Hg CEMS Data (12/16/04)............... 4-30 
x

Table 4-33. Tekran Elemental Mercury Sample Spikes............................................ 4-30 

Table 4-34. Summary of Phase 2 CEMS Certification Criteria and 

Performance (Excluding RATA) ........................................................... 4-32 

Table 4-35. Durag 7-Day Calibration Error Test—Phase 2...................................... 4-33 

Table 4-36. Durag Linearity Test—Phase 2.............................................................. 4-34 

Table 4-37. Durag System Integrity Test—Phase 2.................................................. 4-35 

Table 4-38. Durag Cycle Time—Phase 2 ................................................................. 4-36 

Table 4-39. Durag Measurement Error Test—Phase 2 ............................................. 4-37 

Table 4-40. Durag Zero/Upscale Drift Tests—Phase 2 ............................................ 4-38 

Table 4-41. Opsis 7-Day Calibration Error Test—Phase 2....................................... 4-40 

Table 4-42. Opsis Linearity Test—Phase 2............................................................... 4-42 

Table 4-43. Opsis System Integrity Test—Phase 2................................................... 4-43 

Table 4-44. Opsis Cycle Time—Phase 2 .................................................................. 4-44 

Table 4-45. Opsis Measurement Error Test—Phase 2.............................................. 4-45 

Table 4-46. Opsis Zero/Upscale Drift Tests—Phase 2 ............................................. 4-46 

Table 4-47. Tekran 7-Day Calibration Error Test—Phase 2..................................... 4-48 

Table 4-48. Tekran Linearity Test—Phase 2 ............................................................ 4-50 

Table 4-49. Tekran System Integrity Test—Phase 2 ................................................ 4-51 

Table 4-50. Tekran Cycle Time Test—Phase 2 ........................................................ 4-52 

Table 4-51. Tekran Measurement Error Test—Phase 2............................................ 4-53 

Table 4-52. Tekran Zero/Upscale Drift Tests—Phase 2 ........................................... 4-54 

Table 4-53. Thermo 7-Day Calibration Error Test—Phase 2 ................................... 4-55 

Table 4-54. Thermo Linearity Test—Phase 2........................................................... 4-56 

Table 4-55. Thermo System Integrity Test—Phase 2 ............................................... 4-57 

Table 4-56. Thermo Cycle Time—Phase 2............................................................... 4-57 

Table 4-57. Thermo Measurement Error Test—Phase 2 .......................................... 4-58 

Table 4-58. Thermo Zero/Upscale Drift Tests—Phase 2.......................................... 4-59 

Table 4-59. Phase 2 RA Test Run Times .................................................................. 4-60 

Table 4-60. Phase 2 RA Test Stack Sampling Data.................................................. 4-61 

Table 4-61. Phase 2 RA Test Ontario Hydro Mercury Analysis Results (μg).......... 4-62 

Table 4-62. RA Total OH Mercury Concentrations.................................................. 4-64 

Table 4-63. Phase 2 RA Gaseous-Phase Mercury From OH Testing ....................... 4-65 

Table 4-64. Phase 2 Duplicate OH Train Relative Deviation (RD).......................... 4-66 

Table 4-65. Phase 2 Summary of All RA Results for All CEMS ............................. 4-69 

Table 4-66. Phase 2 RA Results for Durag ............................................................... 4-73 

Table 4-67. Phase 2 RA Results for Opsis ................................................................ 4-74 

Table 4-68. Phase 2 RA Results for Tekran.............................................................. 4-75 

Table 4-69. Phase 2 RA Results for Thermo............................................................. 4-76 

Table 4-70. IRM Daily Hg Tests During RATA....................................................... 4-77 

Table 5-1. Summary of Phase 1 CEMS Certification Criteria.................................. 5-3 

Table 5-2. Phase 1 Calibration, QC Procedures, and Criteria for 

Ontario Hydro Sampling Equipment ....................................................... 5-4 

Table 5-3. Phase 1 Test Criteria for Emission Measurement and Data 

Quality...................................................................................................... 5-5 

Table 5-4. Phase 1 RA Blank Analysis Results ........................................................ 5-6 

Table 5-5. Percent Difference for Phase 1 Mercury Analysis Results...................... 5-8 
xi

Table 5-6. Phase 1 RA Spike and Audit Sample Results.......................................... 5-9 

Table 5-7. Phase 1 Continuing OH Calibration Check Standards .......................... 5-10 

Table 5-8. Summary of Phase 2 CEMS Certification Criteria................................ 5-13 

Table 5-9. Phase 2 Calibration, QC Procedures, and Criteria for Ontario 

Hydro Sampling Equipment .................................................................. 5-14 

Table 5-10. Phase 2 RA Test Criteria for Emission Measurement and 

Data Quality........................................................................................... 5-16 

Table 5-11. Phase 2 Blank Analysis Results............................................................. 5-17 

Table 5-12. Percent Difference for Phase 2 Mercury Analysis Results.................... 5-18 

Table 5-13. Phase 2 RA Spike and Audit Sample Results........................................ 5-19 

Table 5-14. Phase 2 Continuing OH Calibration Check Standards .......................... 5-21 

Table 6-1. Summary of CEMS Certification Criteria and Performance ................... 6-3 
xii
 1-1

Section 1. 

Introduction 

1.1 Study Overview 

The US Environmental Protection Agency (EPA) has recently promulgated 

regulations for mercury (Hg) emissions from coal-fired electric utilities, which include 

provisions for use of mercury Continuous Emission Monitoring Systems (Hg CEMS) as 

well as other monitoring approaches (FR 5/18/05, 70(95), 28606). The implementation of 

Hg CEMS could be enhanced greatly by the collection of data demonstrating application 

of monitoring technologies to the source category. As a result, EPA conducted the field 

testing described to evaluate Hg CEMS technologies on a long-term continuous basis. 

The purpose of this field test program was to collect data to assess the ability of 

commercially available Hg CEMS to provide reliable and accurate data over an extended 

time period, while meeting certification, durability, data availability, and setup/maintenance requirements. In particular, data were collected to assess the ability of the 

Hg CEMS to satisfy the requirements of Performance Specification 12A (PS-12A) and 

the 40 CFR Part 75 mercury monitoring provisions (FR 5/18/05, 70(95), 28606). 

This report presents a summary of the certification test results and other information 

collected from November 2004, through September 2005. The test facility was a coalfired utility boiler burning eastern bituminous coal and equipped with a selective catalytic 

reduction (SCR) system with ammonia injection that is operated during ozone season 

(May 1 through September 30), an electrostatic precipitator, and a wet limestone 

scrubber. 

The work was separated into two phases, Phase 1 and Phase 2. Phase 1 field work 

was performed from November 2004 through February 2005 and consisted of: 

• Installation and shakedown of four mercury Continuous Emission Monitoring 

Systems (Hg CEMS); 

• Phase 1 certification testing during the first two weeks of continuous Hg CEMS 

operation (with Relative Accuracy Test Audit [RATA], February 22 - 26); 

• Evaluation while the selective catalytic reduction (SCR) system was bypassed; 

and 

• Information gathering on the Hg CEMS operation, durability, and maintenance. 

Phase 2 field work was performed from March through September 2005 and 

consisted of: 

• Installation of two additional Hg CEMS in early May (in addition to the four 

which were previously in operation); 

• Phase 2 certification testing after more than a month of continuous operation by 

the additional two Hg CEMS (with RATA July 7-12); 
 1-2

• Removal of two Hg CEMS when vendors elected to have their systems removed 

from the test program; 

• Evaluation while the SCR was in operation; and 

• Information gathering on the Hg CEMS operation, durability, and maintenance. 

1.2 Performance Testing 

Table 1-1 summarizes the certification test acceptance criteria used during this test 

program. Sorbent trap monitoring was conducted according to 40 CFR Part 75 Appendix 

K (Appendix K) by RMB Associates, and the data are provided in a separate report. 

Dynamic spiking and data collection were also performed using the Tekran Hg CEMS to 

assess potential criteria for a draft instrumental test method for mercury; results of this 

test are provided in Section 4.1.3 of this report. 

Table 1-1. Summary of Certification and Relative Accuracy 

Test Performance Criteria 

Activity Frequency Gas type 

Performance 

criteria Reference 

7-day Calibration 

Error. Check at 2 

pts, zero and 

upscale.a

Once per day for 7-

day consecutive days 

Elemental 

mercury 

≤ 5% of span; or, 

if spanned at 

lowest range of 

10 μg/m3

, then 

≤ 1 μg/m3

Part 75, App A, 

Section 3.1; (FR 

5/18/05, 70(95), 

28691) 

Linearity Check at 

3 pts: low, mid, and 

high.b

 Performed 

in nonrepetitive 

triplicates. 

Once, at beginning of 

certification test 

Elemental 

mercury 

≤ 10% of ref tag 

value; or 

≤ 1 μg/m3

, 

whichever is less 

restrictive 

Part 75, App A, 

Section 3.2; (FR 

5/18/05, 70(95), 

28691) 

System Integrity. 

Check at 3 pts: 

zero, mid, and 

high.b

Once, at beginning of 

certification test 

Oxidized 

mercury 

≤ 5% of span Part 75, App A, 

Section 3.2; (FR 

5/18/05, 70(95), 

28691) and 

PS-12A, 

Sections 8.3 and 

13.1 

Cycle Time Once, at beginning of 

certification test 

Elemental 

mercury 

≤ 15 min Same as existing 

Part 75, App A, 

Section 3.5 

Relative Accuracy 

(RA), performed 

after certification 

checks 

One set of 12 

duplicate test runs, at 

beginning of Phase 1 

evaluation test 

program, and again 

during Phase 2 longterm evaluation 

Stack Gas ≤ 20%; or for low 

emitters with avg. 

conc. < 5 μg/m3

, 

≤ 1 μg/m3

difference 

Part 75, App. A, 

Section 3.3 (FR 

5/18/05, 70(95), 

28691) and 

PS-12A 

Section 13.4 

a

 Conducting the 7-day Cal Error test allows for determination of the Zero and Upscale Drift specification of 

PS-12A, which cannot exceed 5% of span (Sections 13.2 and 13.3). b

 By collecting linearity check data and system integrity check data (per Part 75 requirements), the PS-12A 

Measurement Error and Converter Efficiency tests are also effectively performed, except that the PS-12A 

criterion is ≤5% of span with no alternative criteria when the stack concentration is ≤1 μg/m3

.
 1-3

1.3 Test Site 

The facility at which the evaluation testing was conducted consists of a coal-fired 

generating unit referred to as Unit 1. Unit 1 is 14 years old with a capacity of 550 MW. 

The facility was designed with state-of-the-art pollution controls that include ammonia 

injection and selective catalytic reduction (SCR) for NOx control, an electrostatic 

precipitator for particulate control, and a wet limestone slurry scrubber for SO2 control. 

The facility has been permitted according to EPA criteria for Best Achievable Control 

Technology (BACT). Fuel for the facility is eastern bituminous coal. 

The sampling location was at ~ 350 ft up the stack. Section 3 provides further details 

on the test facility and sampling locations. 

1.4 Summary of Systems Evaluated 

This study was designed to evaluate Hg CEMS that use the latest technology, i.e., 

dry converter or alternative systems rather than the older wet converter systems. A 

summary of the Hg CEMS that were evaluated during Phase 1 using the performance 

certification test criteria is provided in Table 1-2. A summary of the Hg CEMS that were 

evaluated during Phase 2 is provided in Table 1-3. 

Table 1-2. Phase 1 Summary of Hg CEMS Evaluated 

Parameter Forney/Genesis CEM 

Horiba/Nippon 

DM-6D Tekran 3300 Thermo Electron 

Gas Conditioning System Glass fiber particulate 

filter, thermocatalytic 

converter, chilled KOH 

impinger, chilled 

moisture removal 

impinger, acid mist 

filter. 

Glass fiber particulate 

filter, thermocatalytic 

converter, vapor 

separator, chilled 

dehumidifier tube at 

probe. Chilled KOH 

impinger at detector. 

Inertial filter and 

dilution system at 

probe. Thermocatalytic converter, 

water wash system at 

sample conditioner. 

Inertial filter, dilution 

system, 

thermocatalytic 

converter at probe. 

Mercury Detector Cold vapor atomic 

absorption 

Cold vapor atomic 

absorption 

Cold vapor atomic 

fluorescence 

Cold vapor atomic 

fluorescence 

Measurement Range 0-50 μg/m3 0-50 μg/m3 Dilution system allows 

multiple ranges 

0-15 μg/m3

Resolution 0.1 μg/m3 0.1 μg/m3 0.001 μg/m3 0.01 μg/m3

Response Delay Update every 1 

second 

Update every 1 

second 

2.5 minutes per cycle None. Continuous 

reading via 4-20 mA 

output, user configurable time averaging 

on instrument display. 

Sample Flow Rate 3 LPM 0.5 LPM 0.5 LPM 0.75 LPM 

Zero Point Adjustment Automatic, once per 

hour 

Automatic, once per 

hour 

None Automatic, daily 

Daily Calibration 

Requirements 

None. Factory 

calibrated prior to 

installation. 

None. Factory 

calibrated prior to 

installation. 

Daily automatic 

detector calibration via 

internal Hg gas 

generator 

Daily system 

calibration via Hg 

calibration gas 

generator 

Output 4-20 mA 4-20 mA System control 

computer 

4-20 mA 

Reporting Temperature 25°C 0°C 0°C 20°C 

Power Supply 110, 208 VAC 110 VAC 110 VAC 110, 220 VAC 

Other Utilities Required None DI water at probe. Compressed air, 

argon gas, DI water, 

drain. 

Compressed air. 
1-4

Table 1-3. Phase 2 Summary of Hg CEMS Evaluated 

Parameter Durag Forney/Genesis CEM1 Horiba/Nippon DM-6D2 Opsis Tekran 3300 

Gas Conditioning System 

Ceramic filter, heated sample line, thermocatalytic converter 

NA1 NA2 Inertial filter, dilution 

system, and thermocatalytic converter at probe 

Inertial filter and dilution system at probe. Thermocatalconverter, water wasystem at sample conditioner. 

Mercury Detector Cold vapor atomic 

absorption 

NA1 NA2 Cold vapor atomic 

absorption 

Cold vapor atomic fluorescence 

Measurement Range 0-20 μg/dscm multiple 

ranges 

NA1 NA2 0-15 μg/m3 Dilution system allow

multiple ranges 

Resolution 0-1 μg/dscm (0.01 

Bg/dscm if required) 

NA1 NA2 0.05 μg/m3 0.001 μg/m3 

Response Delay None. Continuous 

reading via 4-20 mA output, user configurable time averaging on instrument display. 

NA1 NA2 5 minutes per cycle 2.5 minutes per cyc

Sample Flow Rate 2 LPM NA1 NA2 1.0 LPM 0.5 LPM Zero Point Adjustment Automatic, every 2 h 

up to every 99 h 

NA1 NA2 None None 

Daily Calibration Requirements 

Daily system calibration via Hg calibration with gas cylinder, if required (automatic daily calibration module with ionic mercury will be available in 2006) 

NA1 NA2 Daily: None 

Monthly-Quarterly Calibrations 

Daily automatic detector calibration internal Hg gas generator 

Output 4-20 mA NA1 NA2 4-20 mA/0-10V/RS232 System control 

computer 

Reporting Temperature 0°C NA1 NA2 0°C/20°C 0°C Power Supply 110, 220 VAC NA1 NA2 110 VAC 110 VAC Other Utilities Required None NA1 NA2 Compressed 

instrument air 

Compressed air, arggas, DI water, drain

NOTES: 

1 Forney/Genesis CEM: This instrument was withdrawn from the test program late in Phase 2 testing at the vendor’s reques

2 Horiba/Nippon DM-6D: This instrument was removed at the vendor’s request prior to the second RA test series. 
 1-5

The Durag Inc., Forney Corporation/Genesis Laboratory Systems Inc., Opsis Inc., 

Horiba/Nippon, and ThermoElectron Corporation systems were connected to the MRI 

data logger via their 4 to 20 mA data outputs. The MRI data logger converted each output 

to a 0 to 10 VDC signal which was then used to calculate the instruments’ readings. The 

computer display on the MRI data logger was verified to match the display on each of 

these instruments. 

Rather than a 4 to 20 mA output, the Tekran Inc. system provided instrument 

readings in real-time via its system control computer. The MRI data logger retrieved the 

data over a local area network installed between the trailer and the stack Hg CEM shelter. 

The Horiba International Corporation/Nippon Instruments Corporation CEMS tested 

in the Phase 1 work was inoperative during Phase 2, and the vendor elected to have their 

system removed from further testing. The Forney/Genesis CEMS also elected to have 

their CEMS removed from the test program late in the Phase 2 testing. 

1.5 Test Program Organization 

The following individuals are the key personnel in the management and execution of 

this test project: 

The EPA Work Assignment Manager (WAM) was: 

Mr. Bill Grimley 

U.S. Environmental Protection Agency 

Office of Air Quality Planning and Standards 

Air Quality Assessment Division 

Measurement Technology Group 

Research Triangle Park, NC 27711 

Telephone: (919) 541-1065 

The MRI Work Assignment Leader (WAL) for this test project was: 

Mr. John Hosenfeld 

Midwest Research Institute 

425 Volker Blvd. 

Kansas City, MO 64110-2299 

Telephone: (816) 753-7600, ext. 1336 

Figure 1-1 presents the test program organization, major lines of communication, 

names, and phone numbers of responsible individuals. Midwest Research Institute was 

responsible for the project under contract to EPA’s Office of Air Quality Planning and 

Standards. 

The companies supplying the Hg CEMS for evaluation during the performance 

testing were Durag, Forney/Genesis, Horiba/Nippon Instruments Corporation, Opsis, 

Tekran, and Thermo Electron. The EPA is appreciative of these vendors for their 

participation in this test program. 
1-6

Figure 1-1. Test Program Organization 
 2-1

Section 2. 

Durability, Availability, and Maintenance of CEMS 

The following describes the maintenance related to Hg CEMS operation during the 

commissioning, setup, and ongoing operation of the systems at the test site. Summaries 

of Phase 1 and 2 maintenance events are provided in Tables 2-1 and 2-2, respectively. 

There were two types of maintenance performed on the Hg CEMS: preventative and 

corrective. Preventative maintenance consisted of tasks performed to prevent system 

failure. Corrective maintenance consisted of tasks performed to bring the system back 

into normal operation. Corrective maintenance on the Hg CEMS generally fell onto one 

of six primary categories related to system components/configurations: 

• Calibration 

• Temperature Adjustment 

• Sample Transfer 

• Catalyst/Sample Conditioning 

• Filter Replacement 

• Analyzer Replacement 

Corrective maintenance performed on the systems during the setup phase did not 

attempt to differentiate between required maintenance caused by a natural instrument 

failure and maintenance required by operator intervention to system while performing 

routine checks and measurements. A few examples of maintenance caused by operator 

intervention are: 

• Instrument offset required by unintentional over-pressurization or underpressurization of the system while introducing daily audit gases. 

• Cleaning a blocked orifice caused by introducing contamination to system while 

making connections for system integrity tests. 

• Maintenance caused by accidentally bumping the probe, transfer lines, or 

analyzer and dislodging accumulated scale or sludge into downstream 

components. 

• Maintenance caused by temperature overcompensation when opening probe 

enclosures to make measurement attachments. 
2-2

Table 2-1. Summary of Phase 1 Maintenance Events for Hg CEMS (Nov 2004-Feb 2005

Forney/Genesis Horiba/Nippon Tekran 

System leaks: replaced a damaged union and most Teflon fittings 

Critical orifice in probe became clogged: Added particulates filter. 

A tear was pump was 

The 450-ft heated line between sample conditioner and analyzer cabinet was found to have severe contamination. Repeated attempts at cleaning failed. The heated line was abandoned and the analyzer was moved to the stack platform 

A crack in the probe moisture sensor allowed leakage: replaced the sample line with smaller diameter Teflon tubing 

Stack thermocouple broke loose from probe: remaining parts were removed and the port plugged 

Data outpustart of Run from an unu

Short heated line between sample conditioner and probe was contaminated and was replaced 

Data output showed excessive amounts of electrical noise: installed a filtering circuit to correct 

A hole in the "stinger" portion of the probe allowed leakage of acid gases into the heater causing failure 

Low flow thorifice: chatemporarily 

Several analyzers failed over a period of several months: acid mist filter just prior to the analyzer was installed (also prevents condensation from reaching the analyzer) 

Repeated condensation in sample transfer line: replaced with heated line between probe and analyzer 

About every 2 months material buildup on probe's main sample loop created blockage: periodically cleaned sample loop and replaced motive air heater 

Impingers used for SO2 removal were found to cause significant loss of mercury in sample gas. Impingers were modified. 

Calcium deposits were accumulating at the inlet of the KOH impinger: connected hourly water wash system 

Probe blowback system was disabled and used as the sample line after the original sample line became unusable 

Analyzer exhaust line was blocked: installed heated exhaust assembly to prevent condensation from freezing 

Problems with condensation in the sample line between conditioner and analyzer. Improvements made to chiller efficiency 

Gas/liquid separator and dehumidifier tube had signs of selenium contamination: connected 3X daily 

water wash system 

Ceramic probe filter caused loss of mercury in sample gas. Replacement with glass fiber filter did not help. 

Before and during the RATA, the catalytic converter suffered from buildup of calcium: replacement would remedy for 2 to 5 days 

Data output showed excessive amounts of electrical noise with intermittent output signal. Output module was replaced 
2-3

Table 2-2. Summary of Phase 2 Maintenance Events for Hg CEMS (Mar-Sept 2005)

Durag 

Forney/ 

Genesis 

Horiba/ 

Nippon Opsis Tekran Th

Low airflow; replaced filter to UV detector 

Replaced broken glass tube in analyzer (improper overtightening) to correct leak 

Replaced probe and analyzer components 

Closed pressure btimes. 

Replaced RTD thermocouple connector on temperature controller to correct overheating 

Replaced eductor module to correct plugged orifice 

Cleaned out stingspan check perfor

Replaced converter after attempting to fix by increasing temperature and recalibration 

Replaced probe filter and acid scrubber to improve response time 

Corrected program controlling test sequence, loop flow, and zero calibration gas delivery 

Installed new inerprobe cabinet dooadded time-controsystem 

Rotated UV light filter by 90° and recalibrated to correct for nonlinearity 

Melted Teflon on converter caused overheating of probe. Temporarily replaced RTD thermocouple with a K-type 

Replaced eductor module, repaired melted Teflon gas connection line to correct measurement of zero stack gas concentration 

Removed thermocouple from temperature controller and serviced Gold trap 

Repaired heat tape and heated eductor module to correct for low measurement readings 

Span adjusted to match audit gas Replaced inertial filter 

Increased converter temperature then replaced catalyst and cleaned probe port to correct for slow response time Changed system span and offset 

Replaced dilution pump due to failed bearing Replaced orifice filter on probe 

Increased probe temperature to remove accumulated Hg System span adjusted 

Removed return loop flow tube and cleaned venturi lines + stack gas return tube to correct for zero measurement readings 

Stack gas values pressure bypass dtimes which did nomade over next twresidual debris frolines from probe to temperature to buInstalled redesignadded tee to probintegrity gas to be inertial filter. Replaanalyzed and clea

Replaced probe filter Replaced filter disk at probe (possible 

caused by plant startup) 

Replaced venturi pressure transducer to correct high loop flow measurements 

System did not mebecause an operazero" mode after p

Maintenance to verify that orifice gasket measurement orientation is correct 

New software installed to allow system to operate at higher probe temperature Replaced probe filter during July RATA 

Cleaned out return probe port to correct improper proportional valve measurement 

Analog output to Mresulting in loss of 

Changed probe filter and blew out orifice ports. Also adjusted system span 

Removed and cleaned plug in the eductor orifice. 

Manually zeroed and increased probe temperature Tightened 3 hinged flange bolts to correct Cleaned out return probe 

low measurement values Changed analyzer pump, probe filter, and increased span adjustment to correct low measurement values 

Replaced: sample extraction assembly (including orifice), PMT & power base, Hg conditioner filter, sample filter on Hg analyzer; installed clean inertial filter, and new lamp on Hg analyzer 

Adjusted analyzer pump voltage, analyzer temperature, and system span to correct low measurement values 

Replaced probe filter to correct for low airflow rates 

Vendor elected to have their system removed from the 

test program 

Replaced voltage power distribution board in analyzer. Adjusted span and offset 

Reset software to correct software lockup. Data logger lost synchronization with output link; lost 6 days of data. 
 2-4 

2.1 Durag 

The Durag system was installed by manufacturer representatives during the week of 

May 9. The system was commissioned to stack measurements on May 11. The system 

was programmed to provide a probe blowback and zero offset check every 2 hours. This 

procedure typically takes less than 5 minutes. The system span and zero adjustments were 

performed manually and verified daily by plant personnel throughout the week, Monday 

through Friday. The system was removed from the site on August 11. The total operation 

period was three months. 

2.1.1 Preventative Maintenance and Checks 

Routine preventative maintenance and checks included recording the system sample 

flow, system pressure, and the zero offset value to verify the parameters were within 

normal operating ranges. A system leak check was performed periodically to verify the 

system was leak-free. Also included in the routine preventative maintenance was 

checking and emptying the fluid level of the condensation collection container. The 

container is sized to allow up to 2 months of collection before necessary emptying. 

The probe filter change was performed June after a plant outage. The excessive 

emissions resulting from fuel oil used during plant start-up had a tendency to plug CEM 

filters and this filter change was a preventative measure. 

2.1.2 Corrective Maintenance 

The system operated throughout a 3-month period at the site with some downtime for 

preventative or corrective maintenance. The corrective maintenance activities to the 

Durag system are described below. 

The span and offset adjustments were performed several times during the initial 

system commissioning to confirm proper system measurements. Thereafter, the span and 

offset were adjusted approximately every month. 

The sample conditioning catalyst was changed twice during the 3 months of 

operation. The catalyst was changed the first time in June due to damage resulting from 

increasing the catalyst temperature beyond the recommended temperature limit. The 

catalyst was changed the second time in July prior to the RATA to improve the degrading 

response time. 

In June the analyzer glass cuvet light filter was suspected to be delaminating after 

1 1⁄2 months of operation. The glass cuvet was rotated 90 degrees to bring the system back 

into normal operation. 
 2-5 

The probe and catalyst temperatures were increased several times during the 3-month 

period. The temperature increases were performed in an effort to overcome the system’s 

delayed response. The delayed response occurred 15 minutes after each 2-hour system 

blowback and zero offset check. The time required for system to measure pre-blowback 

stack concentration values increased from a nominal 5 minutes to more than 1 hour. In 

July, the vendor installed new software to allow the probe temperature to be set above the 

original high temperature limit. When the probe temperature was increased, the system 

stack concentration measurements also increased more than 50% above the original 

measurements. 

The probe filter was changed twice to correct system problems. The first probe filter 

change was performed in July during the middle of a RATA test due to higher than 

normal Hg measurements. The second probe filter change was performed in August to 

increase the system flow rate that was measuring below the low limit threshold. 

2.2 Forney/Genesis 

The Forney/Genesis system was installed in early November 2004 by personnel from 

Forney Corporation and Genesis Laboratory Systems. The system seemed functional, but 

exhibited anomalous responses. Testing throughout the first three months following 

installation yielded anomalous responses to both reference gas and zero gas (e.g., 

reference gases were detected at lower than expected concentrations and zero gas read as 

though it had a high background mercury content). 

The Forney/Genesis system, though not operational, remained in the stack 

throughout the period between the February RATA and the May certification testing. 

During the week before the May certification tests, Forney representatives were on-site to 

perform corrective maintenance. Daily corrective and preventative maintenance was 

required to keep the system operating. Efforts to continue corrective and preventative 

maintenance were then ceased due to lack of replacement parts, and the system was not 

operational. 

A Forney representative was on-site to perform corrective maintenance during the 

last day of the June certification tests and during the July RATA. Eventually efforts to 

continue corrective and preventative maintenance were completely stopped. No further 

maintenance was performed on the system after Forney determined that it was 

discontinuing its efforts at the site. The system was removed during the second week in 

August. 

Because the Forney system was rarely operational between corrective maintenance 

visits during Phase 2 of the demonstration project, maintenance efforts have not been 

included in Table 2-2. 
 2-6 

2.3 Horiba/Nippon 

The Nippon DM-6D system was installed in early November 2004 by technicians 

from Horiba Instruments and Nippon Instruments Corporation. Though the system 

performed well immediately after installation, leaks and other problems caused 

deterioration of the system. Further visits were made by Horiba personnel in midNovember and early December, and a Nippon representative was on-site in early January. 

Maintenance details for this time period are included in Table 2-1. 

No preventative or corrective maintenance was performed on the Horiba system 

between February and July. The system was removed at the vendor’s request prior to the 

second RATA test series. When the system was removed from the port, the stainless steel 

probe was discovered to be completely corroded away, leaving nothing but the Teflon 

sample line. 

2.4 Opsis 

The Opsis system was installed by manufacturer representatives during the week of 

May 2. The system was commissioned to stack measurements on May 6. The system was 

programmed to provide a zero check at the top of every hour. This procedure typically 

takes less than 5 minutes. The system span and zero adjustments are performed manually 

and verified daily by plant personnel throughout the week (Monday through Friday). 

2.4.1 Preventative Maintenance and Checks 

Routine preventative maintenance to the system included recording the probe 

temperature, the regulated compressed air pressure, and the dilution pump vacuum to 

ensure they were within the manufacturer’s setpoint. Periodic preventative maintenance 

included replacing the probe filter. 

2.4.2 Corrective Maintenance 

Maintenance during the first month (May) was mainly performed to address a 

temperature control problem and slow response time. A broken glass tube was also 

replaced to correct a leak caused by improper over tightening of a mounting screw. 

Much of the maintenance during the third month (August) was performed to address 

low measurement values. 

During the period of operation, the system had a slow response to known changes in 

Hg concentrations, i.e., from challenges with the reference gases. Corrective maintenance 

during this period included multiple changes of the probe filters. The probe filters were 
 2-7 

changed six times during the 4-month period. The number of probe filter changes was 

high compared to other instruments. 

The instrument output span was adjusted routinely by the Opsis maintenance 

representatives during the 4-month period. Eight known span adjustments were 

performed to bring the instrument output measurements back into alignment with the 

external reference gas concentrations. 

2.5 Tekran 

Technicians from Tekran Systems, Incorporated arrived in mid-November and 

installed the system. The Tekran system remained operating on stack emissions 

throughout the period between installation and system shutdown for project completion 

in mid-September. Periodic preventative and corrective maintenance was necessary 

during this period to keep the system operating. The Tekran system has a programmable 

automatic blow back incorporated into the normal operation that occurs every 2 to 4 

hours. The instrument zero and span is also checked automatically daily. 

2.5.1 Preventative Maintenance 

Preventative maintenance on the system included recording the air supply pressures 

daily, recording the Argon gas cylinder pressure daily and replacing it as needed, adding 

deionized water to the scrubber reservoir, emptying the wasted water reservoir every 

week or as needed, and cleaning the air filter to the probe electronics cabinet weekly. 

The Tekran system has a built-in Hg calibrator. This feature allows the system to be 

programmed to introduce a single or multiple known Hg concentrations to the probe, the 

orifice, or the analyzer. This feature allowed for either self-calibration or diagnostic 

purposes. However, the stack gas concentration could not be monitored while performing 

the self-calibrations or self-diagnostics. As configured, the system conducted its daily 

checks and calibrations over a 4-hour period during the early morning hours, during 

which the system did not monitor the stack gas Hg concentration. 

2.5.2 Corrective Maintenance 

A Tekran representative visited the site in December to make repairs and probe 

modifications. The primary causes for corrective maintenance during the period between 

February and May was due to the loop flow or the dilution eductor orifice becoming 

plugged. The most notable failure was when the plant had a scheduled shut down to 

switch on the SCR system. The Tekran loop flow became plugged immediately after the 

plant came back online. The Tekran system successfully maintained operation after two 

unscheduled plant outages and restarts during June and July. 
 2-8 

During the months between May and the end of the field evaluation in September the 

following corrective maintenance issues were addressed. The loop flow return port 

became plugged nearly each month and required cleaning to dislodge the obstruction. 

The dilution eductor orifice also became plugged nearly each month and required 

disassembly and cleaning. The inertial filter was typically cleaned or replaced during the 

same time as when the dilution eductor was cleaned. The dilution eductor heat tape also 

required replacing twice during the period between May and September primarily due to 

damage caused by repeated disturbing the heat tape to remove the dilution eductor. 

The analyzer portion of the system required corrective maintenance every three 

months. The corrective maintenance included replacing the UV lamp, replacing the 

sample and conditioning filters, and flushing out the photo cartridges. Also included in 

the analyzer corrective maintenance in May was replacing the valve assembly. 

2.6 Thermo 

The Thermo system has remained in the stack throughout the duration between the 

February RATA and the May certification testing. Periodic preventative and corrective 

maintenance was necessary during this period to keep the system operating. The Thermo, 

as tested, had no automated method for zero and span checks. Blowback was added later 

as discussed in the corrective maintenance section below. 

2.6.1 Preventative Maintenance 

Preventative maintenance included recording the air regulator pressure to the system 

daily. Frequently, the orifice became plugged and required closing the ambient bleed port 

at the probe for thirty seconds to dislodge the orifice obstruction. However, the system 

remained operating after the plant had a scheduled 4-day shutdown in late April to bring 

the SCR system on-line. The Thermo system continued to operate after the plant start-up. 

The system also successfully maintained operation after two unscheduled plant outages 

and restarts during June and July. The Thermo, as tested, had no automated method for 

zero and span checks, but they could be done manually. Blowback was added later as 

discussed in the corrective maintenance section below. 

2.6.2 Corrective Maintenance 

The corrective maintenance during the months between May and September 

included cleaning the probe stinger and return port on a monthly basis. The inertial filter 

required replacing every 2 months. A probe blowback system was added to the system on 

June 8. On occasion the orifice became plugged and required closing the ambient bleed 

port at the probe for thirty seconds to dislodge the orifice obstruction. 
 2-9 

On July 9, the system failed during the seventh RATA run. The output measurements 

remained high after a routine system blowback then slowly leveled off to zero 

concentrations and remained there. Thermo maintenance personnel were on-site during 

the week of July 11 to repair the system. The probe heater was turned off overnight to 

allow the system to cool for maintenance. The next morning condensation was found in 

all of the sample lines up to the analyzer. Several attempts were made to clean and repair 

the system during the following 3 weeks. The repair attempts included cleaning the fast 

loop assembly, replacing the complete probe sample conditioning assembly with a third 

generation design sample conditioning assembly, replacing the inertial filter, cleaning the 

probe stinger and return port, replacing the analyzer UV lenses, and replacing four 

process control solenoid valves in the analyzer. The system was back in operation on 

August 4. 

On August 12, the operator left the system in “probe zero” mode which prevented 

the system from measuring stack gas. The status was corrected during the next week visit 

on August 17. Although the system was not measuring stack gas during this period, the 

system was functioning. 

2.7 Summary 

Figure 2-1 shows a summary of the long-term operations for each of the CEMS. This 

summary is presented to clearly illustrate operational gaps due to mechanical or computer 

failure encountered to date by the various units. Operational periods do not take into 

account passing/failure of daily/weekly QA/QC checks and no data are shown past 

August 20. All of the instruments evaluated during this study required preventative 

maintenance. The systems also required corrective maintenance. The primary 

preventative maintenance requirements were probe-related (including probe blockage), 

loop flow blockage, temperature regulation, sample conditioning-related, and routine 

filter changing. 

The analyzer portions of the systems were reliable but required quarterly corrective 

maintenance to keep them functioning properly. 
2-10 

NOTE: Horiba/Nippon and Forney/Genesis data not shown as they elected to remove their systems from the test program. 

Figure 2-1. Phase 1 and 2 Long-Term Monitoring Periods 

Instrument down 

design upgrade 
 3-1 

Section 3. 

Sampling 

3.1 Process Data 

Phase 1 and Phase 2 plant CEMS data as run averages are provided in Tables 3-1 and 

3-2. 

3.2 Flue Gas Sampling Location 

The Hg CEMS and manual ASTM D6784-02 (Ontario Hydro) mercury sampling 

locations were located on the active stack, approximately 345 ft above ground level, 

180 ft (10 duct diameters) above the nearest flow restriction, and 410 ft (> 22 duct 

diameters) from the outlet. The layout of ports, Hg CEMS, Appendix K sampling, and 

manual sampling during Phase 1 testing are shown in Figure 3-1. The layout during 

Phase 2 testing is shown in Figure 3-2. 

The Ontario Hydro Method samples were collected isokinetically at a single point 

approximately 5 ft within the stack. This effective distance was based on traverse 

information provided by the facility. Note that single point sampling is a deviation from 

the method, but it is appropriate for this test program where the goal was to verify 

Hg CEMS accuracy against the reference method. Assessing Hg CEMS probe placement 

in the stack was not part of this test program. 

All of the sampling ports are on the same level, thereby allowing the Hg CEMS and 

Appendix K probes to sample gases similar to those sampled by the Ontario Hydro 

Method. Figure 3-3 indicates elevations of ports relative to flow restrictions and top of 

stack for both phases of testing. The Horiba/Nippon analyzer was in the trailer with its 

own reference gas delivery system while the Durag, Forney/Genesis, Opsis, Tekran, and 

Thermo/Electron analyzers were on the stack platform with a separate reference gas 

delivery system. The Forney/Genesis system initially was operated from the trailer, but 

the analyzer was moved to the stack platform when problems persisted with the heated 

sample line. Figure 3-4 indicates the sampling configuration during Phase 1 and 

Figure 3-5 indicates the sampling configuration during Phase 2. 

3.3 Ontario Hydro Method 

This section provides information on the reference method for the mercury sampling 

and analysis used for the project. 
 3-2 

Table 3-1. Phase 1 Average Plant CEM Data 

Run 

No. 

SO2 low 

range ppm 

NOX conc. 

raw ppm 

CO2 conc. 

raw % 

Exit 

opacity % 

Stack flow 

106 std. 

ft3

/hr 

Chim gas 

Exit 1 

temp. °F 

1 115 211 12 9 65.29 127 

2 107 206 12 9 64.38 126 

3 70 189 12 11 63.98 127 

4 106 201 12 11 64.71 127 

5 108 201 12 11 65.82 128 

6 103 215 12 10 64.60 126 

7 89 211 12 10 64.93 125 

8 100 211 12 11 64.25 126 

9 81 211 12 11 63.97 125 

10 93 210 12 11 64.07 127 

11 67 226 12 11 63.40 127 

12 142 200 12 10 62.61 128 

 

Table 3-2. Phase 2 Average Plant CEM Data 

Run 

No. 

SO2 low 

range ppm 

NOX conc. 

raw ppm 

CO2 

conc. raw 

% 

Exit 

opacity % 

Stack flow 

106 std. 

ft3/hr 

Chim gas 

Exit 1 

temp. °F 

1 244 10 12 10 71 131 

2 201 20 12 10 71 131 

3 173 15 12 11 70 132 

4 169 13 12 10 69 131 

5 137 16 12 9 70 130 

6 142 17 12 9 70 130 

7 241 11 12 8 69 131 

8 231 10 12 8 69 131 

9 148 16 12 9 69 131 

10 159 16 12 10 68 132 

11 224 14 12 10 71 132 

12 179 15 12 10 71 132 
 3-3 

Figure 3-1. Layout of Sampling Ports and Hg CEMS and Other Sampling Systems 

During Phase 1 RATA Test 

N

INACTIVE

ACTIVE

STACK

18'-0"

ESCAPE LADDER ELEVATOR

HORIBANIPPON

CEM

CONDITIONED

SPACE

8'x12'

8-9.00

ELEVATED PLATFORM

C

TEKRAN

75 APPX. K

9-8.00 3-.00

THERMO

PLANT

CEMS

ONTARIO

HYDRO

FORNEYGENESIS
 3-4 

Figure 3-2. Layout of Sampling Ports and Hg CEMS and Other Sampling Systems 

During Phase 2 RATA Test 

N

INACTIVE

ACTIVE

STACK

18'-0"

ESCAPE LADDER ELEVATOR

CEM

CONDITIONED

SPACE

8'x12'

8-9.00

ELEVATED PLATFORM

75 APPX. K

TEKRAN

OPSIS

9-8.00 3-.00

THERMO

PLANT

CEMS

ONTARIO

HYDRO

FORNEYGENESIS

75 APPX. K

DURAG
 3-5 

Figure 3-3. Sampling Location at the Unit #1 Stack North Inlet Duct 
 3-6 

Figure 3-4. Hg CEMS Sampling Configuration During Phase 1 RATA 
 3-7 

Figure 3-5. Hg CEMS Sampling Configuration During Phase 2 RATA 
 3-8 

3.3.1 Method Summary 

The ASTM D 6784-02 “Standard Test Method for Elemental, Oxidized, ParticleBound, and Total Mercury in Flue Gas Generated from Coal-Fired Stationary Sources 

(Ontario Hydro Method),” was used as the reference method per Part 75, Appendix A, 

Section 6.5.10 (FR 5/18/05, 70(95), 2 8691). A schematic of a sampling train is presented 

in Figure 3-6. Further clarifications on the use of the Ontario Hydro method for this 

project were: 

• Two 2-hr paired-train samples were collected isokinetically from a single point 

within the stack for each test run. 

• Quartz fiber filters were used, and had the same specifications as those 

described in the method. Filter supports used in the filter holders were 100% 

Teflon. 

• The HNO3/H2O2 and KMnO4/H2SO4 samples were stored and shipped at water 

ice temperature; the rest of the samples were stored and shipped at room 

temperature. This was done as directed by EPA representatives in response to 

the paper, “The Ontario Hydro Method for Speciated Mercury Measurements: 

Issues and Considerations,” by Jeffery V. Ryan and Robert M. Keeney. 

• The sample recovery scheme is presented in Figure 3-7. 

3.3.2 Determination of Gas Velocity at Sampling Point 

Method 2 in Appendix A of 40 CFR 60 was used to measure the gas velocity with a 

Type S pitot tube during sampling with the Ontario Hydro Method sampling train. 

Results of the Method 2 testing were used to determine the isokinetic sampling rate for 

the single-point sampling. 

An aneroid barometer calibrated against a calibrated mercury barometer was used to 

measure atmospheric pressure at the sampling location. 

3.3.3 Determination of Dry Gas Molecular Weight 

Method 3B in Appendix A of 40 CFR 60 was used to collect integrated gas bag 

samples simultaneously with the Ontario Hydro method point sampling for determination 

of dry gas molecular weight. The integrated gas sampling apparatus used to collect the 

samples is a component of the sampling train. An integrated gas sample is extracted at a 

constant rate from the exhaust of the sampling train just upstream from the outlet of the 

dry gas meter outlet orifice.
3-9

Figure 3-6. Ontario Hydro Sampling Train 

2001.429-

Modified Greenburg-Smith, 100 mL 1N KCIModified Greenburg-Smith, 100 mL 1N KCIGreenburg-Smith, 100 mL 1N KCIModified Greenburg-Smith, 100 mL 5% HNO3/10% H2O2

Sample B

Ice Bath

Thermocoup

Pyrometer

StackWall

Probe

Heater

Thermocouple

Quartz Liner

Pitot Tube

Glass

Filter

Holder

Heated

Area

Quartz

Nozzle

Inclined

Manometer

Thermocouple

Vacuum

Line Vacuum Gauge Fine Control Valve

Orifice

Main Valve

AirtightPump

Dry Test

Meter

Thermocouples

1 2 3 4

1234

5 6 7 8

Modified Greenburg-Smith, 100 mL 4% KMnO4/10% H2SO4

Modified Greenburg-Smith, 100 mL 4% KMnO4/10% H2SO4Greenburg-Smith, 100 mL 4% KMnO4/10% H2SO4Modified Greenburg-Smith, 200 g Silica Gel

5678

Inclined

Manometer
3-10

Figure 3-7. Ontario Hydro Sample Recovery Scheme 

5th, 6th, & 7th

Impingers

(KMnO4/H2SO4)

U-connectors D-F

8th

Impinge

(Silica ge

Measure impinger

contents - weigh

impingers and

subtract weights

from initial

weights.

Measure imp

contents - w

impingers a

subtract we

from initi

weights

Transfer contents

to a tared bottle

and weigh

the bottle.

Save conte

for regenera

and reus

Rinse impingers

and U-connectors

twice with

0.1 N HNO3. A

third rinse must

be done with

0.1 N HNO3 with

several drops of

10% hydroxylamine.

This rinse must

have enough 10%

hydroxylamine such

that the brown

stains are easily

removed.

Rinse impingers

and U-connectors

a final time with

0.1 N HNO3.

2001.4

Nozzle, Probe

Liner, Sample

Transfer line

(if used), Bypass

Filter Holder

Front

Filter

Remove filter from

filter holder and

transfer to the

petri dish.

Quantitatively

remove all filter

fragments and

particulate matter

remaining in filter

holder and transfer

to the petri dish.

Tape cover to

petri with lab

tape to prevent

any loss of

contents.

Transfer rinses

to tared bottle

and weigh

the bottle.

Filter Support,

Filter Holder

Back, 90o

Connector

1st, 2nd, & 3rd

Impingers (KCI)

U-connectors A-B

 4th Impinger

(HNO3/H2O2)

U-connector C

Add small amounts

of 5% KMnO4 to

each KCI impinger

until purple color

remains for

15 minutes.

Measure impinger

contents - weigh

impingers and

subtract weight

from initial weight.

Measure impinger

contents - weigh

impinger and

subtract weight

from initial weight.

Transfer contents

to a tared bottle

and weigh

the bottle.

Rinse the impinger

twice with

0.1 N HNO3.

Transfer rinses to the bottle. If the sample

becomes clear, add a small amount of the

5% KMnO4 solution until a pink or slightly

purple color remains for 90 minutes.

Reweigh sample bottle.

Transfer rinses

to the bottle

and reweigh

the bottle.

Transfer contents

to a tared bottle

and weigh the

bottle.

Rinse the

impingers and

U-connectors

A-B with 10%

HNO3. If brown

stains remain

rinse again with

10% HNO3 with

several drops

of 10%

hydroxylamine.

Rinse impingers

and U-connectors

a final time with

0.1 N HNO3.

Transfer rinses to

the bottle. If sample

becomes clear, add

small amounts of the

5% KMnO4 solution

until a pink or slightly

purple color is obtained.

Preserve the sample

by adding 1ml of 5%

dichromate solution.

Reweigh sample bottle.

Rinse with

brushing three

times or more

with 0.1 N HNO3.

Rinse components

3 times with

0.1 N HNO3.
 3-11

3.3.4 Determination of Moisture Content 

Method 4 in Appendix A of 40 CFR 60 incorporated as part of the Ontario Hydro 

method was used to determine the moisture (water vapor) content of the gas stream. 

Moisture collected during sampling was determined gravimetrically from the difference 

between the initial and final weights of all of the impingers in a train. 

3.3.5 Mercury Analysis 

The sample analysis was performed by Oxford Laboratories in Wilmington, North 

Carolina. The sample components recovered from the Ontario Hydro trains (i.e., rinses, 

filter, and impinger contents) were digested and analyzed according to the procedures 

specified in the method except as explained below. For analysis of the mercury, the 

Ontario Hydro Method incorporates Method 7470A, which is a procedure for cold vapor 

atomic absorption spectroscopy (CVAAS) for mercury previously published in “Test 

Methods for Evaluating Solid Waste, Physical/Chemical (SW-846).” It was discovered 

near the end of the test program that the laboratory had not been clarifying the KMnO4

impingers prior to extracting an aliquot for analysis as described in Section 13.3.5 of the 

Ontario Hydro method. To recover from this omission, ARCADIS G&M, Inc. in 

Research Triangle Park, North Carolina, performed a reanalysis of the KMnO4 impingers. 

3.4 Reference Gases 

MRI used compressed elemental mercury gas standards throughout the project to 

verify instrument response. The gases were also used extensively for troubleshooting 

problems with individual analyzers and specific components within each analyzer. The 

reference, or span, gas standards were purchased from Spectra Gases (Branchburg, New 

Jersey) with a nominal concentration range of 1 to 10 μg/m3

 of elemental mercury in 

nitrogen. Several gas cylinders were used over the course of the project, and Table 3-3 

summarizes the concentrations of each gas cylinder used. Three linearity standards were 

also used during the precertification tests. All gases were certified by Spectra Gases 

based on a cylinder supplied by NIST (secondary certification). Gases have not been 

characterized to the point that the delivered concentration is accurate to a known 

uncertainty. 
 3-12

Table 3-3. Elemental Mercury Cylinders 

Cylinder 

No. 

Certified conc 

(μg/m3) Approx dates of use 

CC19870 1.9 Dec. 04 - End of test program 

CC133357 2.1 Nov. 04 - End of test program 

CC191724 2.2 July - August 05 

CC84954 2.3 Replacement - not used 

CC134442 5.1 July - August 05 

CC191854 5.8 June - July 05 

CC173117 9.03 Nov. 04 - End of test program 

3.4.1 HovaCal Gas 

The Hovacal is a calibration gas generator used to introduce a known concentration 

of oxidized mercury gas (Hg2+) to the Hg CEMS systems for comparing the Hg CEMS 

output measurement readings against a known concentration. The Hovacal performs this 

function by regulating the flow rate of a known concentration of oxidized mercury in an 

aqueous state and by regulating the mass flow rate of a nitrogen carrier gas to a heated 

evaporator where the gas-vapor mixture is introduced into the Hg CEM system prior to 

the converter. 

The Hovacal instrument control parameters were certified by the factory prior to 

operation on November 02, 2004. The instrument mass flow meter, electronic balance 

mass, and temperature meter were checked on August 15, 2005. The check showed all of 

the control parameters were operating within factory tolerances. 

3.4.2 Cylinder Gases 

The Hg reference gas cylinders were provided by Spectra Gases Incorporated. The 

audit gases were provided with a factory concentration certification of ±10% of the stated 

concentration. The reference gases contain a vaporized elemental mercury concentration 

suspended in a nitrogen carrier gas. 

3.4.3 Tekran 3310 Gas 

The Tekran 3310 generates a range of elemental mercury concentrations by 

regulating the heat of an elemental mercury source to create a known vapor. Mass flow 

controllers are used to regulate the ratio of elemental mercury vapor and supplemental 

clean air to provide a known vapor concentration at a desired flow rate. 

The output of the 3310 Hg calibrator was plumbed to a pressure relief bypass tee to 

prevent over pressurization of the calibrator. The output port of the tee dumped to 

atmosphere while the second output port of the tee was attached to input of the 

calibration gas flow regulator attached to the Hg CEM instrument under investigation. 
 4-1

Section 4. 

Certification Test Results 

The certification test results are presented in two parts—the initial certification test 

results (Phase 1) are presented in Subsection 4.1, and the second certification test results 

(Phase 2) are presented in Subsection 4.2. Within each subsection results are provided as 

certification testing minus the RATA, and then the RATA. 

4.1 Phase 1 Certification Test Results 

The certification testing is presented in two parts. Section 4.1.1 presents results from 

the Phase 1 measurement error test, 7-day calibration error test, the linearity test, system 

integrity test, the upscale/downscale drift test, and cycle time test. Section 4.1.2 presents 

results from the Phase 1 RATA test. Additional test results are presented in Section 4.1.3. 

4.1.1 Phase 1 Certification (excluding RATA) Results 

Phase 1 certification tests were conducted between February 15 and 28, 2005 

according to Part 75 and PS-12A requirements. The results for each Hg CEMS are 

provided below. The initial certification for each CEMS included a 7-day calibration 

error test, a linearity check, a system integrity test (which checks converter efficiency), a 

measurement error test, and zero/upscale drift tests. The reported Hg CEMS values are 

based on the resolution of the analyzer even though the believed resolution is more likely 

0.1 mg/m3

. The Hg CEMS results are reported at 20°C. The span was defined at 

10 μg/m3

, and values used to assess CEMS performance are summarized based on that 

span, as shown in Table 4-1 below. 

Table 4-1. Summary of Phase 1 CEMS Certification Criteria and 

Performance (Excluding RATA) 

Criteria Met? (Y/N) 

Test Criteria Forneya

 Horiba Tekran Thermo

7 Day Calibration 

Error Test 

Error must be ≤ 5% of span; or ≤1 μg/m3

(alternative specification when span is defined at 

10 μg/m3

). 

N Y Y Y 

Linearity Test Error must be ≤ 10% of reference gas tag value 

or ≤ 1 μg/m3

, whichever is least restrictive. N N Y Y 

System Integrity 

Test 

Error must be ≤ 5% of span from certified gas 

value (i.e., within ±0.5 μg/m3

 of certified gas 

value). 

N Y Y Y 

Cycle Time Test Cycle times must be ≤ 15 minutes. N N Y Y 

Measurement 

Error Test 

Error must be ≤ 5% of span from certified gas 

value (i.e., within ±0.5 μg/m3

 of certified gas 

value). 

N N Y Y 

Zero and Upscale 

Drift Test 

Error must be ≤ 5% of span (i.e., within 

±0.5 μg/m3

 of certified gas value). N Y N N 

a

 System was not functioning for most of the certification period. 
 4-2

4.1.1.1 Forney/Genesis 

Results for the last two days of the Forney 7-day calibration error test are presented 

in Table 4-2. The system was not functioning except for the last 2 days of the 

certification period (February 25 and 26, 2005) and no data for the linearity check, 

system integrity test (which checks converter efficiency), measurement error test, and 

zero/upscale drift tests were obtained. The remaining tests were not performed due to a 

pending system upgrade being developed. This system as tested was configured to 

operate at the stack sampling elevation. 

Table 4-2. Forney 7-Day Calibration Error Test—Phase 1 

Reference Gas Concentration (μg/m3): 1.3 

 

CEMS reading 

(μg/m3

) 

Error (difference) 

(μg/m3) Result 

Date Time Zero Reference Zero Reference Zero Reference 

02/25/05 7:55:00 0.3 1.5 0.3 0.2 Pass Pass 

02/26/05 8:40:00 0.2 1.5 0.2 0.2 Pass Pass 

7 Day Cal Error Result: Test not completed (system failure). 

4.1.1.2 Horiba/Nippon 

The Horiba 7-day calibration error, and linearity check, system integrity test (which 

checks converter efficiency), and measurement error test results are presented in 

Tables 4-3 through 4-7. The 7-day calibration test was performed February 22 

through 28, 2005. The linearity test was performed on February 28, 2005. The system 

integrity test was performed on February 15, 2005. The measurement error test was 

performed on February 27, 2005. The zero/upscale test was performed from February 22 

through 28, 2005. The data table for the cycle time test is not provided because it could 

not be completed. The sample conditioning system (converter) was located at the stack 

sampling location and the converted sample was transported through a 450-ft heated line 

(100°F) to the analyzer in the on-site test trailer. All reported concentrations are corrected 

to 20°C. The Horiba met the criteria for the 7-day calibration error, system integrity, and 

zero/upscale drift tests, with the catalyst being replaced twice during this period. The 

Horiba system did not meet the criteria for the measurement error, linearity, and cycle 

time tests. 
 4-3

Table 4-3. Horiba/Nippon 7-Day Calibration Error Test—Phase 1 

Reference Gas Concentration (μg/m3): 1.3 

 

CEMS reading 

(μg/m3) 

Error (difference) 

(μg/m3) Result 

Date Time Zero Reference Zero Reference

Zero 

criteria 

met? 

Span 

criteria 

met? 

02/22/05 9:50:00 0.09 0.9 0.1 0.4 Yes Yes 

02/23/05 10:10:00 –0.09 1.0 0.1 0.3 Yes Yes 

02/23/05 9:35:00 0.0 0.8 0.0 0.5 Yes Yes 

02/24/05 9:50:00 0.0 0.8 0.0 0.5 Yes Yes 

02/24/05 15:12:00 –0.2 0.8 0.2 0.5 Yes Yes 

02/25/05 15:52:00 0.5 1.5 0.5 0.2 Yes Yes 

02/25/05 10:05:00 0.00 1.1 0.0 0.2 Yes Yes 

02/26/05 10:05:00 –0.09 1.2 0.1 0.1 Yes Yes 

02/26/05 10:17:00 –0.2 1.0 0.2 0.3 Yes Yes 

02/27/05 10:27:00 –0.2 0.7 0.2 0.6 Yes Yes 

02/27/05 10:27:00 0.0 1.2 0.0 0.1 Yes Yes 

02/28/05 10:09:00 0.0 1.2 0.0 0.1 Yes Yes 

7 Day Cal Error Result: Met criteria. 

NOTE: 2/24/05 at 18:37, longer response time observed. 

 2/25/05 at 08:00 replaced Horiba catalyst. 

 2/27/05 at 08:40, replaced Horiba catalyst. 
 4-4

Table 4-4. Horiba/Nippon Linearity Test—Phase 1 

Low-Level Reference Gas Conc. (μg/m3): 1.3 

Mid-Level Reference Gas Conc. (μg/m3): 5.1 

High-Level Reference Gas Conc. (μg/m3): 10.4 

Test Date: 2/28/05 

Cycle Time 

Gas 

type 

CEMS 

reading 

(μg/m3

) 

1 11:03:00 Low 1.2 

1 11:27:00 Mid 3.4 

1 11:40:00 High 5.9 

 

Gas Low Mid High 

Average 1.2 3.4 5.9 

% Rel. Diff. 3.9% 34% 44% 

Linear Error 

(Diff, μg/m3) 0.0 1.7 4.5 

Criteria met? Yes No No 

Linearity 

Result: 

Criteria not met. Only the first cycle 

was performed. 

Table 4-5. Horiba/Nippon System Integrity Test—Phase 1 

Mid-Level Oxidized Mercury Reference Gas Conc. (μg/m3): 3.5 

High-Level Oxidized Mercury Reference Gas Conc. (μg/m3): 5.7 

Test Date: 02/15/05 

Criteria 

Time 

Gas 

type CEMS reading (μg/m3

) 

Error 

(μg/m3) met? 

12:01:00 Zero 0.0 0.0 Yes 

12:14:00 Mid 3.3 0.2 Yes 

12:34:00 High 5.2 0.5 Yes 

Test Result: Criteria met. 
 4-5

Table 4-6. Horiba/Nippon Measurement Error Test—Phase 1 

Mid-Level Reference Gas, Elemental Mercury Conc. (μg/m3): 5.1 

High-Level Reference Gas, Elemental Mercury Conc. (μg/m3): – 

Mid-Level Reference Gas, Oxidized Mercury Conc. (μg/m3): – 

High-Level Reference Gas, Oxidized Mercury Conc. (μg/m3): – 

Test Date: 2/27/2005 

Gas type Time 

CEMS 

reading 

(μg/m3

) 

Error 

(difference) 

(μg/m3

) 

Criteria 

met? 

Zero 12:52 0.0 0.0 Yes 

Hg Mid 13:27 3.3 1.8 No 

Hg High NC NC NC NC 

Oxidized Mercury Mid NC NC NC NC 

Oxidized Mercury High NC NC NC NC 

Measurement Error Result: Test not completed;NC indicates 

check not completed. 

Table 4-7. Horiba/Nippon Zero/Upscale Drift Tests—Phase 1 

Reference Gas Conc. (μg/m3): 1.3 

 

CEMS Reading 

(μg/m3

) 

Drift 

(μg/m3) Result 

Date Time Zero Reference Zero Reference

Zero 

criteria 

met? 

Span 

criteria 

met? 

02/22/05 17:29:00 0.09 0.9 0.1 0.4 Yes Yes 

02/23/05 7:19:00 –0.09 1.0 0.1 0.3 Yes Yes 

02/24/05 7:29:00 0.0 0.8 0.0 0.5 Yes Yes 

02/25/05 17:35:00 0.0 1.1 0.0 0.2 Yes Yes 

02/26/05 8:19:00 –0.09 1.2 0.1 0.1 Yes Yes 

02/27/05 13:30:00 0.0 1.2 0.0 0.1 Yes Yes 

02/28/05 11:03:00 0.0 1.2 0.0 0.1 Yes Yes 

NOTE: 2/25/05 at 08:00 catalyst replaced. 2/27/05 at 08:40 catalyst replaced 

Zero Drift Result: Criteria met 

Upscale Drift Result: Criteria met 

4.1.1.3 Tekran 

The Tekran 7-day calibration error test, linearity check, system integrity test (which 

checks converter efficiency), cycle time, measurement error test, and zero/upscale drift 

test results are presented in Tables 4-8 through 4-13. The 7-day calibration error test was 

performed between February 15 and 21, 2005. The linearity check and the system 

integrity and measurement error tests were performed on February 15, 2005. The cycle 

time and zero/upscale drift tests were performed on February 21, 2005. The system was 

located at the stack sampling platform and configured with a 50-ft heated line (190°C) to 

the analysis system in the CEM shelter on the platform. All reported concentrations are 

corrected to 20°C. The Tekran met the criteria for the 7-day calibration error, system 

integrity, measurement error, linearity, and cycle time tests. It did not meet the criteria for 
 4-6

the zero/upscale drift tests of PS 12A which does not have the alternative criteria 

allowance when the span is defined at 10 ug/m3. 

Table 4-8. Tekran 7-Day Calibration Error Test—Phase 1 

Reference Gas Concentration (mid, μg/m3): 5.1 

 

CEMS reading 

(μg/m3

) 

Error (difference) 

(μg/m3) Result 

Date Time Zero Reference Zero Reference

Zero 

criteria 

met? 

Span 

criteria 

met? 

02/15/05 9:50:00 0.000 4.703 0.000 0.347 Yes Yes 

02/16/05 10:10:00 0.000 4.675 0.000 0.375 Yes Yes 

02/17/05 9:35:00 0.000 4.409 0.000 0.641 Yes Yes 

02/18/05 15:52:00 0.096 4.640 0.096 0.410 Yes Yes 

02/19/05 10:05:00 0.075 4.602 0.075 0.448 Yes Yes 

02/20/05 10:27:00 0.122 4.756 0.122 0.294 Yes Yes 

02/21/05 10:09:00 0.000 4.613 0.000 0.437 Yes Yes 

7-Day Cal Error Result: Criteria met. 

Table 4-9. Tekran Linearity Test—Phase 1 

Low-Level Reference Gas Conc. (μg/m3): * 2.5 

Mid-Level Reference Gas Conc. (μg/m3): * 6.1 

High-Level Reference Gas Conc. (μg/m3): * 9.8 

Test Date: 2/21/05 

Cycle Time 

Gas 

type 

CEMS 

reading 

(μg/m3

) 

1 2:12:00 Low 2.707 

1 2:22:00 Mid 6.574 

1 2:40:00 High 10.191 

2 2:55:00 Low 3.002 

2 3:02:00 Mid 6.743 

2 3:25:00 High 10.356 

3 3:40:00 Low 3.104 

3 3:55:00 Mid 6.818 

3 4:05:00 High 10.357 

 

Gas Low Mid High 

Average 2.937 6.712 10.302 

% Rel. Diff. 19.65% 9.345% 4.859% 

Linear Error 

(Diff, μg/m3

) 0.302 0.124 0.242 

Criteria met? Yes Yes Yes 

* Reference gas produced by Tekran 3310 generator 

Linearity Result: Criteria met. 
 4-7

Table 4-10. Tekran System Integrity Test—Phase 1 

Mid-Level Oxidized Mercury Reference Gas Conc. (μg/m3): 3.5 

High-Level Oxidized Mercury Reference Gas Conc. (μg/m3): 5.7 

Test Date: 02/15/05 

Time 

Gas 

type 

CEMS reading 

(μg/m3

) 

Error 

(μg/m3) 

Criteria 

met? 

12:01:00 Zero 0.000 0.000 Yes 

12:14:00 Mid 3.299 0.231 Yes 

12:34:00 High 5.185 0.465 Yes 

Test Result: Criteria met. 

Table 4-11. Tekran Cycle Time—Phase 1 

Upscale Cycle Time Test

Date: 2/21/2005

Start Time: 4:15:00

Stable Time: 4:30:00

Step Change (μg/m3): 8.834

95% of Step Change: 8.392

Time of 95% Change: 4:20:00

Upscale Cycle Time: 0:05:00

Downscale Cycle Time Test

Date: 2/21/2005

Start Time: 9:22:30

Stable Time: 9:37:30

Step Change (μg/m3): 2.165

95% of Step Change: 2.057

Time of 95% Change:* 9:22:30

Downscale Cycle Time: 0:00:00

Cycle Time: Criteria met 

* This is a semicontinuous reading instrument, so 

the step change occurred at the time the next 

reading was available, which was 2 min and 

30 sec. 
 4-8

Table 4-12. Tekran Measurement Error Test—Phase 1 

Mid-Level Reference Gas, Elemental Mercury Conc. (μg/m3): 1 6.1 

High-Level Reference Gas, Elemental Mercury Conc. (μg/m3): 1 9.8 

Mid-Level Reference Gas, Oxidized Mercury Conc. (μg/m3):2 3.5 

High-Level Reference Gas, Oxidized Mercury Conc. (μg/m3):2 5.7 

Test Date: 2/15/2005 

Gas Type Time 

CEMS reading 

(μg/m3

) 

Error 

(difference) 

(μg/m3

) Criteria met? 

Zero 1:56 0.176 0.176 Yes 

Elemental Hg Mid 2:26 6.574 0.464 Yes 

Elemental Hg High 2:44 10.191 0.367 Yes 

Oxidized Hg Mid 12:14 3.299 0.010 Yes 

Oxidized Hg High 12:34 5.185 0.079 Yes 

1

 Reference gas produced by Tekran 3310 generator, concentration at 20°C. 

2

 Oxidized mercury gas produced by HovaCal unit. 

Measurement Error Result: Criteria met. 

Table 4-13. Tekran Zero/Upscale Drift Tests—Phase 1 

Mid-Level Reference Gas Conc. (μg/m3): 5.05 

 

CEMS reading 

(μg/m3

) 

Drift 

(μg/m3) Result 

Date Time Zero Reference Zero Reference 

Zero 

criteria 

met? 

Span 

criteria 

met? 

02/15/05 9:50:00 0.000 4.703 0.000 0.347 Yes Yes 

02/16/05 9:42:00 0.000 4.675 0.000 0.375 Yes Yes 

02/17/05 9:35:00 0.000 4.409 0.000 0.641 Yes No 

02/18/05 15:52:00 0.096 4.640 0.096 0.410 Yes Yes 

02/19/05 10:05:00 0.075 4.602 0.075 0.448 Yes Yes 

02/20/05 10:27:00 0.122 4.756 0.122 0.294 Yes Yes 

02/21/05 10:09:00 0.000 4.613 0.000 0.437 Yes Yes 

Zero Drift Result: Criteria met. 

Upscale Drift Result: 

Criteria not met on 

2/17/05. 

4.1.1.4 ThermoElectron 

The ThermoElectron 7-day calibration error test, linearity check, system integrity 

(which checks converter efficiency), cycle time test, measurement error test, and 

zero/upscale drift test results are presented in Tables 4-14 through 4-19. The system was 

located at the stack sampling platform and was configured with a 50-ft heated line 

(165°C) to the analysis system in the CEMS shelter on this platform. The 7-day 

calibration error test was performed February 18 through 24, 2005. The linearity test was 

performed on February 26. The system integrity test was performed February 18, 2005. 

The cycle time test was performed on February 20 (downscale) and February 26 

(upscale). The measurement error test was performed on February 18 and 26 and the 

zero/upscale drift test was performed on February 20. The Thermo met the criteria for 

the 7-day calibration error, system integrity, measurement error, linearity, and cycle time 

tests. It did not meet the criteria for the zero/upscale drift tests of PS 12A which does not 

have the alternative criteria allowance when the span is defined at 10 ug/m3

. 
 4-9

Table 4-14. Thermo 7-Day Calibration Error Test—Phase 1 

Reference Gas Concentration (μg/m3): 1.9 

CEMS reading 

(μg/m3

) 

Error (difference) 

(μg/m3) Result 

Date Time Zero Reference Zero Reference

Zero 

criteria 

met 

Span 

criteria 

met 

02/18/05 9:50:00 –0.07 1.84 0.07 0.06 Yes Yes 

02/19/05 10:10:00 0.04 1.93 0.04 0.03 Yes Yes 

02/20/05 9:35:00 0.09 2.32 0.09 0.42 Yes Yes 

02/21/05 9:50:00 0.00 2.74 0.00 0.84 Yes Yes 

02/22/05 15:12:00 0.00 2.31 0.00 0.41 Yes Yes 

02/23/05 15:52:00 0.00 1.95 0.00 0.05 Yes Yes 

02/24/05 10:09:00 –0.09 1.83 0.09 0.07 Yes Yes 

7 Day Cal Error Result: Criteria met. 

Table 4-15. Thermo Linearity Test—Phase 1 

Low-Level Reference Gas Conc. (μg/m3): 1.9 

Mid-Level Reference Gas Conc. (μg/m3): 5.6 

High-Level Reference Gas Conc. (μg/m3): 10.4 

Test Date: 

2/26/05 and 

2/27/05a

Cycle Time 

Gas 

type 

CEMS reading 

(μg/m3

) 

1 12:28:00 Low 1.68 

1 12:32:00 Mid 5.27 

1 8:58:00 High 10.23 

2 14:24:00 Low 1.77 

2 14:28:00 Mid 5.38 

2 9:14:00 High 10.68 

3 14:42:00 Low 2.20 

3 14:47:00 Mid 5.44 

3 9:27:00 High 10.72 

Gas Low Mid High 

Average 1.88 5.36 10.54 

% Rel. Diff. 0.88% 4.23% 1.38% 

Linear Error 

(Diff, μg/m3

) 0.02 0.24 0.14 

Criteria met? Yes Yes Yes 

Linearity Result: Criteria met. 

a

 High conc. 9.03 μg/m3 cylinder was found to be defective; 

10.4 μg/m3

 was substituted and was run on 2/27/05. 
 4-10

Table 4-16. Thermo System Integrity Test—Phase 1 

 

Mid-Level Oxidized Mercury Reference Gas Conc. (μg/m3): 3.5 

High-Level Oxidized Mercury Reference Gas Conc. (μg/m3): 5.7 

Test Date: 02/18/05 

Time 

Gas 

Type 

CEMS reading 

(μg/m3

) 

Error 

(μg/m3) 

Criteria 

met? 

14:45:00 Zero 0.06 0.06 Yes 

16:41:00 Mid 3.43 0.10 Yes 

17:08:00 High 5.80 0.15 Yes 

Test Result: Criteria met. 

Table 4-17. Thermo Cycle Time—Phase 1 

Upscale Cycle Time Test

Date: 2/26/2005

Start Time: 14:55:04

Stable Time: 15:08:04

Step Change (μg/m3): 4.00

95% of Step Change: 3.80

Time of 95% Change: 15:04:44

Upscale Cycle Time: 0:09:40

Downscale Cycle Time Test

Date: 2/20/2005

Start Time: 9:21:04

Stable Time: 9:29:54

Step Change (μg/m3): 2.74

95% of Step Change: 2.60

Time of 95% Change: 9:23:44

Downscale Cycle Time: 0:02:40

Cycle Time Test: Criteria met. 

Table 4-18. Thermo Measurement Error Test—Phase 1 

Mid-Level Reference Gas, Elemental Hg Conc. (μg/m3): 5.6 

High-Level Reference Gas, Elemental Hg Conc. (μg/m3): 10.4 

Mid-Level Reference Gas, Oxidized Hg Conc. (μg/m3): 1 3.5 

High-Level Reference Gas, Oxidized Hg Conc. (μg/m3): 1 5.7 

Test Dates: 2/18/20052 and 2/26/2005 

Gas type Time 

CEMS reading 

(μg/m3

) 

Error 

(difference) 

(μg/m3

) 

Criteria 

met? 

Zero 8:26 –0.26 0.26 Yes 

Hg Mid 12:32 5.27 0.33 Yes 

Hg High 8:58 10.23 0.17 Yes 

Oxidized Hg Mid 16:41 3.43 0.1 Yes 

Oxidized Hg High 17:08 5.8 0.15 Yes 

1

 Oxidized Hg gas produced by HovaCal unit. 

2 Oxidized Hg tests. 

Measurement Error Result: Criteria met. 
 4-11

Table 4-19. Thermo Zero/Upscale Drift Tests—Phase 1 

Mid-Level Reference Gas Conc. (μg/m3): 1.9 

 

CEMS reading 

(μg/m3

) Drift (μg/m3

) Result 

Date Time Zero Reference Zero Reference

Zero 

criteria 

met? 

Reference

criteria 

met? 

02/18/05 9:50:00 –0.07 1.84 0.07 0.06 Yes Yes 

02/19/05 9:42:00 0.04 1.93 0.04 0.03 Yes Yes 

02/20/05 9:35:00 0.09 2.32 0.09 0.42 Yes Yes 

02/21/05 15:52:00 0.00 2.74 0.00 0.84 Yes No 

02/22/05 10:05:00 0.00 2.31 0.00 0.41 Yes Yes 

02/23/05 10:27:00 0.00 1.95 0.00 0.05 Yes Yes 

02/24/05 10:09:00 –0.09 1.83 0.09 0.07 Yes Yes 

Zero Drift Result: Criteria met. 

Upscale Drift Result: Criteria not met on 2/21/05. 

4.1.2 Phase 1 RATA Test Results 

The data presented in this section are from the Initial RA test conducted during 

February 22-26, 2005. The testing consisted of 12 test runs comparing four mercury 

CEMS to the Ontario Hydro (OH) reference method. Overall, emissions as measured by 

OH appeared to remain fairly constant between 2 and 4 μg/m3

. 

The Horiba/Nippon, Tekran, and Thermo instruments collected data for all 12 of the 

RA test runs and Forney/Genesis collected data for 7 RA tests runs. Duplicate OH 

sampling trains were used during all 12 RA test runs. Further details of the Ontario Hydro 

results and results for each mercury measurement system are presented in the sections 

that follow. 

Mercury analysis results are provided in Appendix E of Volume 2 of this report. 

Mercury CEMS data collected during the RA test are provided in Appendix F of 

Volume 2 of this report. 

4.1.2.1 Ontario Hydro Sample Results 

Sampling times for the Ontario Hydro sampling method are provided in Table 4-20. 

All runs had the minimum sample collection time of 2 hr according to the method. 

Samples were collected over a period of several days in order to observe any variation in 

emission data that would be useful in evaluating CEMS response. 
 4-12

Table 4-20. Phase 1 RA Test Run Times

Run 

number 

 

Date 

Stack sampling intervals 

(in minutes per 24-hour clock) 

Sampling time 

(min) 

1 2/22/2005 10:30 - 12:30 120 

2 2/22/2005 14:40 - 16:40 120 

3 2/23/2005 09:20 - 11:20 120 

4 2/23/2005 12:40 - 14:40 120 

5 2/23/2005 15:50 - 17:50 120 

6 2/24/2005 09:00 - 11:00 120 

7 2/24/2005 12:05 - 14:05 120 

8 2/24/2005 15:15 - 17:15 120 

9 2/25/2005 08:40 - 10:40 120 

10 2/25/2005 11:45 - 13:45 120 

11 2/25/2005 14:50 - 16:50 120 

12 2/26/2005 09:30 - 11:30 120 

Table 4-21 summarizes the sampling conditions of the reference method train. 

Ontario Hydro sampling and recovery data are provided in Appendix C of Volume 2 of 

this report. Method 3B sample collection data and the Orsat analysis results for each 

sample are included in Appendix C of Volume 2. Sample traceability data sheets are 

provided in Appendix B and sampling equipment calibration results are provided in 

Appendix D of Volume 2. 

Mercury analysis results are presented in Table 4-22 and were obtained by partially 

following the Ontario Hydro (OH) method analytical procedures. Because it was 

discovered very late in the test program that the analytical laboratory was not performing 

a critical step in the Ontario Hydro method (they had not been clarifying the 

KMnO4/H2SO4 impinger sample prior to extracting an aliquot for analysis), the elemental 

mercury results for the KMnO4/H2SO4 impingers are suspect. This omission affects both 

accuracy and precision. 

Data are presented separately for each sample train component. Tables 4-23 and 4-24 

combine the mercury analysis results with the stack sampling results and provide the 

mercury emissions on a concentration basis. All test runs used duplicate trains, and 

precision information is summarized in Table 4-25. Figure 4-1 shows concentrations of 

the total gaseous and oxidized fraction of mercury along with scatter points from each 

train. The estimated maximum amount of mercury that could be expected to have been 

introduced from the solution blanks is also shown for comparison purposes. 
 4-13

Table 4-21. Phase 1 RA Test Stack Sampling Data

 Sampling Gas Avg. stack Iso- 

 time volume Water temp. kinetic 

 (min) (dscm) (%) (°F) (%) 

Run 1 120 3.127 13.6 125.3 101.3 

Run 1 dup 120 3.023 13.5 125.0 101.1 

Run 2 120 2.529 13.3 124.4 101.3 

Run 2 dup 120 2.412 13.3 123.7 102.1 

Run 3 120 2.343 13.6 125.5 98.8 

Run 3 dup 120 2.298 13.0 123.8 98.8 

Run 4 120 2.559 13.5 125.2 101.6 

Run 4 dup 120 2.433 12.8 123.4 100.9 

Run 5 120 2.514 14.2 127.0 102.4 

Run 5 dup 120 2.445 13.6 125.2 99.4 

Run 6 120 2.519 13.4 124.7 100.0 

Run 6 dup 120 2.386 13.0 123.6 100.0 

Run 7 120 2.467 13.1 123.7 97.3 

Run 7 dup 120 2.451 12.5 122.1 100.0 

Run 8 120 2.504 13.3 124.2 100.1 

Run 8 dup 120 2.379 12.7 122.8 100.0 

Run 9 120 2.461 12.8 123.0 100.0 

Run 9 dup 120 2.441 12.3 121.8 99.9 

Run 10 120 2.510 13.4 124.9 100.0 

Run 10 dup 120 2.423 12.8 123.3 100.0 

Run 11 120 2.406 13.7 125.5 100.0 

Run 11 dup 120 2.356 13.2 124.1 100.1 

Run 12 120 2.432 14.1 126.7 100.6 

Run 12 dup 120 2.307 13.4 124.9 100.1 
4-14

Table 4-22. Phase 1 RA Test Ontario Hydro Mercury Analysis Results (μg) 

Gaseous Phase 

Particle Bound Phase Ionic a Elemental 

Field ID Filter 

Probe 

rinse 

Part. 

bound 

subtotal 

KCl 

impingers 

KCl blank 

corrected 

amt. b

HNO3/H2O2

Impinger 

HNO3/H2O2 

imp. blank 

corrected amt. b

KMnO4/H2SO4

impingers 

(see Note) 

Elem

subt

Run 1 < 0.005 < 0.012 < 0.017 0.165e 0.148 0.037c,e 0.033 9.32 Run 1 dup < 0.005 < 0.011 < 0.016 0.712 0.641 0.038c 0.034 9.99 1Run 2 < 0.005 < 0.013 < 0.018 0.705 0.635 0.059 0.053 7.04 Run 2 dup < 0.005 0.031 0.031 0.556 0.500 0.028c 0.025 7.62 Run 3 < 0.005 0.029 0.029 0.771 0.693 0.031c 0.027 8.42 Run 3 dup < 0.005 0.019 0.019 0.727 0.654 0.015c 0.014 6.26 Run 4 < 0.005 < 0.011 < 0.016 0.871 0.784 0.036c 0.032 6.71 Run 4 dup < 0.005 < 0.010 < 0.015 1.006 0.905 0.035c 0.032 8.20 Run 5 < 0.005 < 0.012 < 0.017 1.040 0.936 0.026c,e 0.024 8.81 Run 5 dup < 0.005 0.016 0.016 1.075 0.968 0.032c 0.028 7.95 Run 6 < 0.006e < 0.011 < 0.017 0.890 0.801 0.028c,e 0.025 11.75 1Run 6 dup < 0.005 < 0.012e < 0.017 0.938 0.844 0.026c 0.024 8.22 Run 7 < 0.005 0.020 0.020 0.767 0.690 0.031c,e 0.028 7.94 Run 7 dup 0.011a 0.020e 0.030a 0.972 0.874 0.030c 0.027 8.13 Run 8 0.016a < 0.017 0.016a 0.906 0.815 0.033c 0.030 7.09 Run 8 dup 0.006a < 0.010 0.006a 0.992 0.893 0.020c,e 0.018 6.28 Run 9 < 0.005 0.012e 0.012 1.190 1.071 0.028c 0.025 7.78 Run 9 dup < 0.005 0.026 0.026 1.125 1.013 0.029c 0.026 7.31 Run 10 < 0.005 0.025 0.025 0.980 0.882 0.031c 0.027 8.07 Run 10 dup < 0.005 < 0.012e < 0.017 1.020 0.918 0.029c 0.026 8.43 Run 11 0.006a < 0.014 0.006a 0.943 0.848 0.027c 0.024 7.65 Run 11 dup < 0.005 0.033 0.033 0.935 0.842 0.068 0.062 7.58 Run 12 < 0.005 0.016e 0.016 0.949 0.854 0.038c 0.034 6.25 Run 12 dup < 0.005 0.022 0.022 0.944 0.849 0.023c 0.021 8.37 FB 0.016e < 0.006 0.475 0.008c,e 0.014 SB < 0.005 < 0.005 0.002 0.004 < 0.001 Est'd. Max. Contribution from hydroxylamine d: 0.002 0.008 FB = Field Blank Train; SB = Solution Blank plus Filter Blank

a The Field Blank Train result exceeded 30% of the measured value; however, the contribution does not significantly impact total results. b Blank corrections performed per OH method. 

c The Solution Blank exceeded 10% of the measured value; however, the contribution does not significantly impact total results. d A maximum of approximately 0.2 mL (1-2 drops) in KCl impingers and 0.5 mL in KMnO4/H2SO4 impingers was used during recovery; amount in blank wae Reanalysis result; original results did not meet < 10% difference for duplicate analyses. NOTE: KMnO4/H2SO4 impinger results are suspect due to improper sample preparation. See Section 5 for details. 
 4-15

Table 4-23. Phase 1 RA Total OH Mercury Concentrations 

 Particle-bound subtotal Gaseous-phase subtotalb

 Mass Concentration Mass Concentration

 (μg) (μg/dscm) (μg) (μg/dscm) 

 

Run 1 < 0.017 N/D 9.50 3.04 

Run 1 dup < 0.016 N/D 10.66 3.53 

Avg. 3.28 

Run 2 < 0.018 N/D 7.73 3.06 

Run 2 dup 0.031 0.013 8.14 3.38 

Avg. 3.22 

Run 3 0.029 0.012 9.14 3.90 

Run 3 dup 0.019 0.008 6.92 3.01 

Avg. 3.46 

Run 4 < 0.016 N/D 7.53 2.94 

Run 4 dup < 0.015 N/D 9.14 3.76 

Avg. 3.35 

Run 5 < 0.017 N/D 9.77 3.89 

Run 5 dup 0.016 0.006 8.94 3.66 

Avg. 3.77 

Run 6 < 0.017a N/Da 12.58 4.99 

Run 6 dup < 0.017 N/D 9.09 3.81 

Avg. 4.40 

Run 7 0.020 0.008 8.66 3.51 

Run 7 dup 0.030a 0.012a 9.03 3.68 

Avg. 3.60 

Run 8 0.016a 0.006a 7.93 3.17 

Run 8 dup 0.006a 0.003a 7.19 3.02 

Avg. 3.09 

Run 9 0.012 0.005 8.87 3.61 

Run 9 dup 0.026 0.010 8.35 3.42 

Avg. 3.51 

Run 10 0.025 0.010 8.97 3.58 

Run 10 dup < 0.017 N/D 9.37 3.87 

Avg. 3.72 

Run 11 0.006a 0.002a 8.52 3.54 

Run 11 dup 0.033 0.014 8.48 3.60 

Avg. 3.57 

Run 12 0.016 0.007 7.13 2.93 

Run 12 dup 0.022 0.009 9.23 4.00 

Avg. 3.47 a

 The field blank train result exceeded 30% of the measured value; these results are not used in the 

gaseous-phase mercury concentration calculations. b

 Results for the elemental mercury portion (KMnO4/H2SO4 impinger samples) of the gaseous-phase are 

considered suspect due to improper sample preparation. See Section 5 for details.
 4-16

Table 4-24. Phase 1 Gaseous-Phase OH Mercury 

 Elemental portiona

 Oxidized portion 

Total 

gaseous 

 Mass Concentration Massb

 Concentration Concentration 

 (μg) (μg/dscm) (μg) (μg/dscm) (μg/dscm) 

% Oxidizedc

(Ionic) 

 

Run 1 9.35 2.99 0.15 0.05 3.04 1.6 

Run 1 dup 10.02 3.316 0.64 0.21 3.53 6.0 

Avg. 3.15 0.13 3.28 3.9 

Run 2 7.09 2.80 0.63 0.25 3.06 8.2 

Run 2 dup 7.64 3.17 0.50 0.21 3.38 6.1 

Avg. 2.99 0.23 3.22 7.1 

Run 3 8.44 3.60 0.69 0.30 3.90 7.6 

Run 3 dup 6.27 2.73 0.65 0.28 3.01 9.4 

Avg. 3.17 0.29 3.46 8.4 

Run 4 6.74 2.63 0.78 0.31 2.94 10.4 

Run 4 dup 8.23 3.38 0.91 0.37 3.76 9.9 

Avg. 3.01 0.34 3.35 10.1 

Run 5 8.83 3.51 0.94 0.37 3.89 9.6 

Run 5 dup 7.97 3.26 0.97 0.40 3.66 10.8 

Avg. 3.39 0.38 3.77 10.2 

Run 6 11.77 4.675 0.801 0.318 4.99 6.4 

Run 6 dup 8.25 3.46 0.84 0.35 3.81 9.3 

Avg. 4.07 0.34 4.40 7.6 

Run 7 7.97 3.23 0.69 0.28 3.51 8.0 

Run 7 dup 8.15 3.33 0.87 0.36 3.68 9.7 

Avg. 3.28 0.32 3.60 8.9 

Run 8 7.12 2.84 0.81 0.33 3.17 10.3 

Run 8 dup 6.29 2.64 0.89 0.38 3.02 12.4 

Avg. 2.74 0.35 3.09 11.3 

Run 9 7.80 3.17 1.07 0.44 3.61 12.1 

Run 9 dup 7.34 3.01 1.01 0.41 3.42 12.1 

Avg. 3.09 0.43 3.51 12.1 

Run 10 8.09 3.22 0.88 0.35 3.58 9.8 

Run 10 dup 8.45 3.49 0.92 0.38 3.87 9.8 

Avg. 3.36 0.37 3.72 9.8 

Run 11 7.67 3.19 0.85 0.35 3.54 10.0 

Run 11 dup 7.64 3.24 0.84 0.36 3.60 9.9 

Avg. 3.21 0.35 3.57 9.9 

Run 12 6.28 2.58 0.85 0.35 2.93 12.0 

Run 12 dup 8.39 3.64 0.85 0.37 4.00 9.2 

Avg. 3.11 0.36 3.47 10.4 a

 The KMnO4/H2SO4 impinger data are considered suspect due to improper sample preparation. See 

Section 5 for details. 

b

 The field blank train result exceeded 30% of the measured value; however, the contribution does not 

significantly impact total results. c

 % Oxidized = (Oxidized Concentration / Total Concentration) * 100. 
 4-17

Table 4-25. Phase 1 Duplicate OH Train Relative Deviation 

 Concentration RD (%) 

Run avg. Oxidized (KCl) Elementala Gaseous phasea

Run 1 63% 5% 7% 

Run 2 10% 6% 5% 

Run 3 2% 14% 13% 

Run 4 10% 12% 12% 

Run 5 3% 4% 3% 

Run 6 5% 15% 13% 

Run 7 12% 1% 2% 

Run 8 7% 4% 2% 

Run 9 2% 3% 3% 

Run 10 4% 4% 4% 

Run 11 1% 1% 1% 

Run 12 2% 17% 15% 

The PS-12A objective is ≤ 10% RD for gaseous phase mercury, where % RD 

= 100 * (Abs(a-b)) / (a+b). 

Values shown in bold for Gaseous Phase have a RD > 10%. 

a

 Results for the elemental mercury portion (KMnO4/H2SO4 impinger 

samples) are considered suspect due to improper sample preparation. 

See Section 5 for details. 

NOTE: Nondetected results in the Particle Bound fraction prevented % RD 

calculations. 
4-18

Figure 4-1. Phase 1 OH Gaseous Phase Mercury Concentrations 

0.01.02.03.04.05.0

1 2 3 4 5 6 7 8 9 10 11 12

Run No.

Hg Conc. (ug/dsm3) 
 4-19

The OH sampling was performed isokinetically from a single point at a similar 

effective sampling location as the Hg CEMS and sorbent trap. As specified in Part 75 

requirements for mercury monitoring and PS-12A, only the ionic (oxidized) and 

elemental fractions of the OH results are included in the gaseous phase concentration 

values used for the RATA calculations. Therefore, the mercury CEMS and the OH results 

are on a similar basis (i.e., gaseous phase only, concentrations per dry standard volume). 

The particle-bound fraction, which constituted less than 1% of the total mercury, is 

reported only for informational purposes. 

The field blank train KCl impinger results on Table 4-22 are noteworthy due to the 

presence of mercury at levels greater than 30% of sample values. The cause is not known. 

As indicated at the bottom of Table 4-22, the calculated contribution from hydroxylamine 

(used in train recovery for the KCl and KMnO4 impingers) could be as high as 0.002 μg 

and 0.008 μg for the KCl and KMnO4 impingers, respectively. The field blank train used 

glassware from the recovered Run 1 train, which remarkably has a low sample result. An 

initial concern was that the Run 1 train recovery was incomplete. However, that seems 

unlikely because no significant increase was observed from recovery of this glassware 

when used for the next run (the same glassware was re-used for even and odd numbered 

runs). Even though the mercury levels in the field blank train were greater than 30% of 

the ionic fraction, it should be noted that the ionic fraction constitutes only about 10% of 

the total mercury in the train. This can be seen in Table 4-24 and Figure 4-1. 

In order to verify that the field blank KCl impinger sample and the Run 1 KCl 

impinger sample had not been switched, the laboratory was contacted. The two sample 

volumes were rechecked and were verified to be correct for each sample type. These two 

samples were also reanalyzed with similar results. No explanation can be given for the 

unusual results obtained from these two samples. 

Results from the remaining field blank samples revealed the presence of mercury in 

the filter, H2O2 impinger, and KMnO4 impinger at levels near the detection limit. Also, 

two of the six solution blanks indicated the presence of mercury near the detection limit 

(the hydroxylamine solution result was higher). The laboratory method blanks showed no 

levels of mercury above detection limits. 

The estimated contribution from solution blanks was between 0.5% and 0.7% of the 

total amount of mercury found in the samples. Thus, even though mercury was found in 

the solution blank samples, it did not appear to have an appreciable effect on the overall 

result. The KCl and HNO3/H2O2 samples were blank corrected using the decision tree 

shown in Figure 4-2. 

The relative deviation (RD) results in Table 4-25 indicate that even though the Run 1 

KCl impinger result was anomalous, it did not have an appreciable impact on the overall 

result (8% RD). Most significantly, the RD for four of the 12 runs ranged between 12% 

to 15% RD which is greater than the 10% RD criteria in PS-12A. A review of other 

sampling parameters (O2, CO2, and H2O) indicates that all parameters for all runs were 

within 10% of each other, with the exception of Run 7 O2 with a difference of 11.5%. 
 4-20

Thus sampling variations do not appear to be contributing to the RD variances for those 

four runs (3, 4, 6, and 12). The RD calculation is Equation 12A-1 from the proposed 

revision to PS-12A, which was previously called RSD. 

Figure 4-2. Decision Tree for Blank Corrections 

4.1.2.2 CEMS and Appendix K RA Results 

Table 4-26 summarizes the relative accuracy calculations for each of the Hg CEMS 

tested. Runs 3, 6, and 12 were not used because the RD values were > 10%. The Run 4 

results were used (RD of 12%) in order to provide a 9th run for the RA calculation. 

Calculations followed the procedures of promulgated Part 75, and are provided in Table 

4-27 through 4-31. Results for each Hg CEMS are briefly discussed below. Emissions 

appeared to remain fairly constant around 3 μg/m3

. Because mercury was observed in the 

solution blanks, blank corrections were used for the OH results in accordance with 

Section 13.4.3.1 of the Ontario Hydro Method. Still, Hg levels measured with the OH 

method were higher than all average Hg CEM values. 

The reported values in the RA tables are based on the resolution of the analyzer; 

however, the believed resolution is more likely 0.1 ug/m3. The Hg CEMS results are 

reported at 20°C. 

Table 4-26 and Figure 4-2 show the OH results are consistently higher than CEMS 

results. Three possible reasons for this difference are (1) OH train contamination, 

(2) CEMS catalyst failure, or (3) other CEMS system component failure. Relative 

accuracy calculations were performed in three ways. First, relative accuracy was 

calculated using the average of Run 4 OH data. A second and third relative accuracy 

calculation was then performed using either the Run 4 train or the Run 4 duplicate train 

results. Comparing OH RD values with RA results sometimes helps to identify outliers or 

common trends. 
 4-21

Table 4-26. Phase 1 Summary of All RA Results for All CEMS 

CEMS (μg/dscm)

Run 

number

Use 

for 

RA? 

OH 

gaseous 

mercury Forney Horiba Tekran Thermo Appx. Ke

1 Yes 3.284 N/A 1.8 2.844 2.82 2.611 

2 Yes 3.216 N/A 1.9 2.805 2.91 2.606 

3 No 3.455 N/A 1.7 2.510 2.38 2.485 

4 Yes a 3.348 N/A 1.7b 2.657 2.42 2.457 

5 Yes 3.771 N/A 2.1 3.106 3.10 2.789 

6 No 4.402 1.9 1.7 3.414 3.11 2.955 

7 Yes 3.597 1.7 1.5b 2.982 2.48 2.743 

8 Yes 3.095 4.0 1.3 2.997 2.47 2.865 

9 Yes 3.513 2.3 2.1 3.099 2.23 2.698 

10 Yes 3.721 1.5 2.3 3.076 2.00 2.633 

11 Yes 3.570 1.6 2.3 3.132 2.22d 2.814 

12 No 3.468 2.0 2.2 3.583 3.18 3.127 

Relative Accuracy (5 Runs) 81.9% – – – – 

Relative Accuracy Using Avg Run 4 OH 51.9% 18.4% 37.5% 27.7% 

Relative Accuracy Using Run 4 OH 51.0% 17.2% 37.2% 27.0% 

Relative Accuracy Using Run 4 OH Dup 52.9% 21.3% 38.7% 29.9% a

 Run 4 OH result was 2.941 μg/dscm, Run 4 Dup OH result was 3.755 (Avg. of 3.348). b

 Data from half of run was lost. 

c

 Data from first 1-1/2 minutes were lost. 

d

 Results provided by Thermo software due to 4-20 mA output failure to data logger. e

 From proposed 40 CFR Part 75, Appendix K method. 

NA indicates instrument not available to collect data. 
4-22

Figure 4-3. Summary of RA Phase 1 Tests 

0.00.51.01.52.02.53.03.54.04.5

1 2 3 4 5 6 7 8 9 10 11 

Run No.

Hg Conc. (ug/dsm3) 
 4-23

Calculations for Forney/Genesis system produced a relative accuracy (RA) of 82% 

for the five available test runs. The Horiba/Nippon system relative accuracy was around 

52%. The Thermo system and Appendix K system RA results were similar at 38% and 

28%, respectively. The Tekran system RA results were around 18%. Note that the RA 

criteria is < 20% RA or, if the average reference method concentration is less than 5 

μg/m3, within 1 μg/m3. The Hg CEMS with a difference within 1 μg/m3 were the Tekran, 

the Thermo, and the Appendix K systems. 

Figure 4-2 shows that with the exception of the Forney/Genesis, the CEMS and 

Appendix K values generally tracked with the OH results even if they were all slightly 

lower than the OH results. Figures 4-3 through 4-6 show plots of the run-by-run data for 

each analyzer, and Tables 4-27 through 4-31 show RA results for each analyzer 

compared with the OH method. The Appendix K RA results were provided by EPA and 

are reported here for comparison purposes only. 

Figure 4-4. Phase 1 RA—OH Versus Forney/Genesis 

0

1

2

3

4

5

1 2 3 4 5 6 7 8 9 10 11 12

Run No.

Hg Conc. (ug/m3)

OH

Genesis
 4-24

Figure 4-5. Phase 1 RA—OH Versus Horiba 

Figure 4-6. Phase 1 RA—OH Versus Tekran 

0

1

2

3

4

5

1 2 3 4 5 6 7 8 9 10 11 12

Run No.

Hg Conc. (ug/m3)

OH

Horiba

0

1

2

3

4

5

1 2 3 4 5 6 7 8 9 10 11 12

Run No.

Hg Conc. (ug/m3)

OH

Tekran
 4-25

Figure 4-7. Phase 1 RA—OH Versus Thermo 

Table 4-27. Phase 1 RA Results for Forney/Genesis 

Run 

number 

Use 

for 

RA? Date Time 

CEMS avg. 

response 

(μg/dscm) 

OH gaseous 

Hg response 

(μg/dscm) 

Difference 

(μg/dscm) 

1 No 2/22/2005 10:30 - 12:30 N/A 3.284 3.284 

2 No 2/22/2005 14:40 - 16:40 N/A 3.216 3.216 

3 No 2/23/2005 09:20 - 11:20 N/A 3.455 3.455 

4 No 2/23/2005 12:40 - 14:40 N/A 3.348 3.348 

5 No 2/23/2005 15:50 - 17:50 N/A 3.771 3.771 

6 No 2/24/2005 09:00 - 11:00 1.9 4.402 2.402 

7 Yes 2/24/2005 12:05 - 14:05 1.7 3.597 1.797 

8 Yes 2/24/2005 15:15 - 17:15 4.0 3.095 –1.005 

9 Yes 2/25/2005 08:40 - 10:40 2.3 3.513 1.213 

10 Yes 2/25/2005 11:45 - 13:45 1.5 3.721 2.121 

11 Yes 2/25/2005 14:50 - 16:50 1.6 3.570 1.970 

12 No 2/26/2005 09:30 - 11:30 2.0 3.468 1.368 

Arithmetic Mean a (μg/dscm) 2.2 3.5 1.3 

Bias Adjustment Factorb 1.6 

Standard Deviation c 1.3 

Confidence Coefficient d 1.6 

Relative Accuracy e using 5 runs (% of RM) 81.9% 

a

 Arithmetic Mean = 1/n Σ di. b BAF = 1+ |1/n Σ di| / Hg CEMS (avg) c

 Standard Deviation = [ (Σ di

2

 – (Σ di)

2

 / n) / (n–1) ]1/2. d

 Confidence Coefficient = t0.975 * Standard Deviation / n1/2, where t0.975 = 2.776. e

 Relative Accuracy = ([Difference Arithmetic Mean] + [Confidence Coefficient]) / RM Arithmetic Mean * 100. 

N/A indicates instrument not available for data collection 

0

1

2

3

4

5

1 2 3 4 5 6 7 8 9 10 11 12

Run No.

Hg Conc. (ug/m3)

OH

Thermo
 4-26

Table 4-28. Phase 1 RA Results for Horiba (All 12 Runs) 

 

Run 

number 

Use 

for 

RA? 

 

Date 

 

Time 

CEMS avg. 

response 

(μg/dscm) 

OH gaseous 

response 

(μg/dscm) 

 

Difference

(μg/dscm)

1 Yes 2/22/2005 10:30 - 12:30 1.8 3.284 1.484 

2 Yes 2/22/2005 14:40 - 16:40 1.9 3.216 1.316 

3 No 2/23/2005 09:20 - 11:20 1.7 3.455 1.755 

4 a, b Yes 2/23/2005 12:40 - 14:40 1.7 3.348 1.648 

5 Yes 2/23/2005 15:50 - 17:50 2.1 3.771 1.671 

6 No 2/24/2005 09:00 - 11:00 1.7 4.402 2.702 

7 b Yes 2/24/2005 12:05 - 14:05 1.5 3.597 2.097 

8 Yes 2/24/2005 15:15 - 17:15 1.3 3.095 1.795 

9 Yes 2/25/2005 08:40 - 10:40 2.1 3.513 1.413 

10 Yes 2/25/2005 11:45 - 13:45 2.3 3.721 1.421 

11 Yes 2/25/2005 14:50 - 16:50 2.3 3.570 1.270 

12 No 2/26/2005 09:30 - 11:30 2.2 3.468 1.268 

Relative Accuracy Using Avg. Run 4 OH 

Arithmetic Mean c (μg/dscm) 1.9 3.5 1.6 

BAF 1.8 

Standard Deviation e 0.3 

Confidence Coefficient f 0.2 

Relative Accuracy g (% of RM) 51.9% 

Relative Accuracy Using Run 4 OH 

Arithmetic Mean (μg/dscm) 1.9 3.4 1.5 

BAF 1.8 

Standard Deviation 0.3 

Confidence Coefficient 0.2 

Relative Accuracy (% of RM) 51.0% 

Relative Accuracy Using Run 4 OH Dup 

Arithmetic Mean (μg/dscm) 1.9 3.5 1.6 

BAF 1.9 

Standard Deviation 0.3 

Confidence Coefficient 0.2 

Relative Accuracy (% of RM) 52.9% 

a

 Run 4 OH result was 2.941 μg/dscm, Run 4 Dup OH result was 3.755 (Avg. of 3.348). b

 Data from half of run was lost. 

c

 Arithmetic Mean = 1/n S di.

d

 BAF = 1+ |1/n Σ di| / Hg CEMS (avg) e

 Standard Deviation = [ (S di

2

 - (S di)

2

 / n) / (n-1) ]1/2

f

Confidence Coefficient = t0.975 * Std Dev / n1/2, where t0.975 = 2.306

g

 Relative Accuracy = 

 ([Difference Arithmetic Mean] + [Confidence Coefficient]) / RM Arithmetic Mean * 100 
 4-27

Table 4-29. Phase 1 RA Results for Tekran (All 12 Runs) 

 

Run 

number 

Use 

for 

RA? 

 

Date 

 

Time 

CEMS avg. 

response 

(μg/dscm) 

OH gaseous 

response 

(μg/dscm) 

 

Difference 

(μg/dscm) 

1 Yes 2/22/2005 10:30 - 12:30 2.844 3.284 0.440 

2 Yes 2/22/2005 14:40 - 16:40 2.805 3.216 0.411 

3 No 2/23/2005 09:20 - 11:20 2.510 3.455 0.945 

4a Yes 2/23/2005 12:40 - 14:40 2.657 3.348 0.691 

5 Yes 2/23/2005 15:50 - 17:50 3.106 3.771 0.665 

6 No 2/24/2005 09:00 - 11:00 3.414 4.402 0.988 

7 Yes 2/24/2005 12:05 - 14:05 2.982 3.597 0.615 

8 Yes 2/24/2005 15:15 - 17:15 2.997 3.095 0.098 

9 Yes 2/25/2005 08:40 - 10:40 3.099 3.513 0.414 

10 Yes 2/25/2005 11:45 - 13:45 3.076 3.721 0.645 

11 Yes 2/25/2005 14:50 - 16:50 3.132 3.570 0.438 

12 No 2/26/2005 09:30 - 11:30 3.583 3.468 –0.115 

Relative Accuracy Using Avg. Run 4 OH 

Arithmetic Mean b (μg/dscm) 2.97 3.5 0.5 

BAFc 1.2 

Standard Deviation d 0.2 

Confidence Coefficient e 0.1 

Relative Accuracy f (% of RM) 18.4% 

Relative Accuracy Using Run 4 OH 

Arithmetic Mean (μg/dscm) 2.97 3.4 0.4 

BAFc 1.2 

Standard Deviation 0.2 

Confidence Coefficient 0.1 

Relative Accuracy (% of RM) 17.2% 

Relative Accuracy Using Run 4 OH Dup 

Arithmetic Mean (μg/dscm) 2.97 3.5 0.6 

BAFc 1.2 

Standard Deviation 0.3 

Confidence Coefficient 0.2 

Relative Accuracy (% of RM) 21.3% 

a

 Run 4 OH result was 2.941 μg/dscm, Run 4 Dup OH result was 3.755 (Avg. of 3.348). b

 Arithmetic Mean = 1/n S di. c BAF = 1+ |1/n Σ di| / Hg CEMS (avg) d

 Standard Deviation = [ (S di

2

 - (S di)

2

 / n) / (n-1) ]1/2

e Confidence Coefficient = t0.975 * Std Dev / n1/2, where t0.975 = 2.306

f

 Relative Accuracy = 

 ([Difference Arithmetic Mean] + [Confidence Coefficient]) / RM Arithmetic Mean * 100. 
 4-28

Table 4-30. Phase 1 Initial RA Results for Thermo (All 12 Runs) 

 

Run 

number 

Use 

for 

RA? 

 

Date 

 

Time 

CEMS avg. 

response 

(μg/dscm) 

OH gaseous 

response 

(μg/dscm) 

Difference

(μg/dscm) 

1 Yes 2/22/2005 10:30 - 12:30 2.82 3.284 0.464 

2 Yes 2/22/2005 14:40 - 16:40 2.91 3.216 0.306 

3 No 2/23/2005 09:20 - 11:20 2.38 3.455 1.075 

4 a Yes 2/23/2005 12:40 - 14:40 2.42 3.348 0.928 

5 Yes 2/23/2005 15:50 - 17:50 3.10 3.771 0.671 

6 No 2/24/2005 09:00 - 11:00 3.11 4.402 1.292 

7 Yes 2/24/2005 12:05 - 14:05 2.48 3.597 1.117 

8 Yes 2/24/2005 15:15 - 17:15 2.47 3.095 0.625 

9 Yes 2/25/2005 08:40 - 10:40 2.23 3.513 1.283 

10b Yes 2/25/2005 11:45 - 13:45 2.00 3.721 1.721 

11c Yes 2/25/2005 14:50 - 16:50 2.22 3.570 1.350 

12 No 2/26/2005 09:30 - 11:30 3.18 3.468 0.288 

Relative Accuracy Using Avg. Run 4 OH 

Arithmetic Mean d (μg/dscm) 2.52 3.5 1.0 

BAFc 1.4 

Standard Deviation e 0.5 

Confidence Coefficient f 0.4 

Relative Accuracy g (% of RM) 37.5% 

Relative Accuracy Using Run 4 OH 

Arithmetic Mean (μg/dscm) 2.52 3.4 0.9 

BAFc 1.4 

Standard Deviation 0.5 

Confidence Coefficient 0.4 

Relative Accuracy (% of RM) 37.2% 

Relative Accuracy Using Run 4 OH Dup 

Arithmetic Mean (μg/dscm) 2.52 3.5 1.0 

BAFc 1.4 

Standard Deviation 0.5 

Confidence Coefficient 0.4 

Relative Accuracy (% of RM) 38.7% 

a

 Run 4 OH result was 2.941 μg/dscm, Run 4 Dup OH result was 3.755 (Avg. of 3.348) b

 Data from first 1-1/2 minutes was lost.*

c

 Results provided by Thermo software due to 4-20 mA output failure.*

d

 Arithmetic Mean = 1/n S di e BAF = 1+ |1/n Σ di| / Hg CEMS (avg) f

 Standard Deviation = [ (S di

2

 - (S di)

2

 / n) / (n-1) ]1/2

g

 Confidence Coefficient = t0.975 * Std Dev / n1/2, where t0.975 = 2.306 h

 Relative Accuracy = 

 ([Difference Arithmetic Mean] + [Confidence Coefficient]) / RM Arithmetic Mean * 100 
 4-29

Table 4-31. Phase 1 RA Results for Appendix K Method 

Run 

number 

Use 

for 

Best 9 Date Time 

Appx. K 

avg. 

result 

(μg/dscm) 

OH 

gaseous 

response 

(μg/dscm) 

Difference

(μg/dscm)

1 Yes 2/22/2005 10:30 - 12:30 2.611 3.284 0.673 

2 Yes 2/22/2005 14:40 - 16:40 2.606 3.216 0.610 

3 No 2/23/2005 09:20 - 11:20 2.485 3.455 0.971 

4a Yes 2/23/2005 12:40 - 14:40 2.457 3.348 0.891 

5 Yes 2/23/2005 15:50 - 17:50 2.789 3.771 0.982 

6 No 2/24/2005 09:00 - 11:00 2.955 4.402 1.447 

7 Yes 2/24/2005 12:05 - 14:05 2.743 3.597 0.854 

8 Yes 2/24/2005 15:15 - 17:15 2.865 3.095 0.230 

9 No 2/25/2005 08:40 - 10:40 2.698 3.513 0.815 

10 Yes 2/25/2005 11:45 - 13:45 2.633 3.721 1.089 

11 Yes 2/25/2005 14:50 - 16:50 2.814 3.570 0.755 

12 No 2/26/2005 09:30 - 11:30 3.127 3.468 0.341 

Relative Accuracy Using Avg. Run 4 OH 

Arithmetic Mean b (μg/dscm) 2.69 3.5 0.8 

BAFc 1.3 

Standard Deviation d 0.3 

Confidence Coefficient e 0.2 

Relative Accuracy f (% of RM) 27.7% 

Relative Accuracy Using Run 4 OH 

Arithmetic Mean (μg/dscm) 2.69 3.4 0.7 

BAFc 1.3 

Standard Deviation 0.3 

Confidence Coefficient 0.2 

Relative Accuracy (% of RM) 27.0% 

Relative Accuracy Using Run 4 OH Dup 

Arithmetic Mean (μg/dscm) 2.69 3.5 0.8 

BAFc 1.3 

Standard Deviation 0.3 

Confidence Coefficient 0.2 

Relative Accuracy (% of RM) 29.9% 

a

 Run 4 OH result was 2.941 μg/dscm, Run 4 Dup OH result was 3.755 (Avg. of 3.348) b

 Arithmetic Mean = 1/n Σ di c BAF = 1+ |1/n Σdi| / Hg CEMS (avg) d

 Standard Deviation = [ (Σ di

2

 - (Σ di)

2

 / n) / (n-1) ]1/2

e

 Confidence Coefficient = t0.975 * Standard Deviation / n1/2, where t0.975 = 2.306 f

 Relative Accuracy = ([Difference Arithmetic Mean] + [Confidence Coefficient]) / RM Arithmetic Mean * 100 
 4-30

4.1.3 Additional Testing 

4.1.3.1 Initial Screening of Sorbent Trap Data With Hg CEMS 

EPA Method 324 sorbent trap data from samples collected per Part 75 Section K on 

12/16/04 are compared with Hg CEMS results in Table 4-32. 

Table 4-32. Comparison of Sorbent Trap and Hg CEMS Data (12/16/04) 

Run 

No. Sample ID 

Start 

time 

End 

time 

Sorbent 

trap 

Hg conc. 

(μg/m3) 

Avg. 

sorbent 

trap 

Hg conc. 

(μg/m3

) 

Horiba 

avg. Hg 

conc. 

(μg/m3

) 

Tekran 

avg. Hg 

conc. 

(μg/m3) 

Trap #1 9:24 11:18 3.0 1 

Trap #2 9:24 11:18 3.1 

3.0 3.0 2.695 

Trap #3 11:38 13:31 3.4 2 

Trap #4 11:38 13:31 3.4 

3.4 3.8 3.325 

4.1.3.2 Dynamic Spiking Data 

Dynamic spiking and data collection were performed on the Tekran Hg CEMS as a 

preliminary evaluation of the instrumental reference method concept. Elemental Hg 

spiking was performed at the probe tip at three levels. These data are presented below in 

Table 4-33 and Figure 4-7. 

Table 4-33. Tekran Elemental Mercury Sample Spikes 

 

 Pre-test 

Pre- and 

post-test 

Posttest 

Average Background Hg: 2.523 2.625 2.659 

1.32 μg/m3 Spike 

Instrument Reading: 3.803 

Recovered Hg: 1.280 1.178 1.144 

Recovery %: 97.0% 89.2% 86.6% 

2.64 μg/m3 Spike 

Instrument Reading: 5.458 

Recovered Hg: 2.935 2.833 2.799 

Recovery %: 111.2% 107.3% 106.0% 

3.95 μg/m3 Spike 

Instrument Reading: 7.644 

Recovered Hg: 5.121 5.019 4.984 

Recovery %: 129.6% 127.1% 126.2% 

% Recovery = (Instrm Rdg – Background/Amount Spiked). 
 4-31

Figure 4-8. Tekran Elemental Mercury Spiking 

4.2 Phase 2 Certification Test Results 

4.2.1 Certification (excluding RATA) 

Certification tests for Phase 2 were conducted on three different occasions through 

the late spring and summer of 2005. The first set of certification tests was performed 

during the period between May 13 through 21, 2005, the second set of certification tests 

was performed between June 22 and July 1, 2005 and the third set of certification tests 

was performed between July 6 and 15, 2005. Certification tests were conducted as 

specified in PS-12A and Part 75. Certification tests were performed on the Durag and 

Opsis in May shortly after their installation, and on the four Durag, Opsis, Tekran, and 

Thermo systems during June and July. 

The results for each Hg CEMS are provided in this section. The certification tests for 

each instrument included a 7-day calibration error test, a linearity check, a system 

integrity test (which checks converter efficiency), a measurement error test, and 

zero/upscale drift tests. The span was defined at 10 μg/m3

 for each CEMS, and values 

used to assess CEMS performance are summarized based on that span, as shown in Table 

4-34 below. 

2

3

4

5

6

7

8

14:35 14:55 15:15 15:35 15:55 16:15 16:35 16:55 17:15 17:35

T im e

u g /m 3
 4-32

Table 4-34. Summary of Phase 2 CEMS Certification Criteria and Performance 

(Excluding RATA) 

 Criteria Met? (Y/N) 

Test Criteria Durag Opsis Tekran Thermo 

7 Day Calibration 

Error Test 

Error must be ≤ 5% of span; or ≤ 1 

μg/m3

 (alternative specification when 

span is defined at 10 μg/m3

). 

Y Y Y N 

Linearity Test Error must be ≤ 10% of reference gas 

tag value or ≤ 1 μg/m3

, whichever is least 

restrictive. 

N N Ya N 

System Integrity 

Test 

Error must be ≤ 5% of span from certified 

gas value (i.e., within ±0.5 μg/m3

 of 

certified gas value). 

Yc Yb Yc N 

Cycle Time Test Cycle times must be ≤ 15 minutes. Y Y Y Y 

Measurement 

Error Test 

Error must be ≤ 5% of span from certified 

gas value (i.e., within ±0.5 μg/m3

 of 

certified gas value). 

Ya

 N Ya N 

Zero and Upscale 

Drift Test 

Error must be ≤ 5% of span (i.e., within 

±0.5 μg/m3

 of certified gas value). Y N Yc

 N 

a

 Passed the first of two tests performed in July. 

b

 Passed the test performed in June. 

c

 Passed the test performed in May. 

4.2.1.1 Durag 

The Durag 7-day calibration error test, linearity check, system integrity test (which 

tests converter efficiency), measurement error test, and zero/upscale drift test results are 

presented in Tables 4-35 through 4-40. Testing and test dates are discussed below. 

4.2.1.1.1 7-Day Calibration Error Test 

The Durag system was challenged with three separate 7-day calibration error tests. 

Results from the three calibration error tests are summarized in Table 4-35. The 

instrument met the performance criteria for all three separate tests. The first test was 

conducted between the dates of May 13 and May 20, 2005. The reference gas used during 

the May 7-day calibration error test was from the Tekran 3310 Hg calibration source. The 

purpose of using the Tekran 3310 was due to a limited supply of available reference 

gases during the test period and an effort to conserve the gases for the remaining duration 

of the study. 

The second 7-day calibration error test was conducted between the dates of June 22 

and June 29, 2005. The reference gas used during the June 7-day calibration error test 

varied between the Tekran 3310 Hg calibration source and the 5.8 μg/m3

 cylinder gas 

source. The difference between sources was due to the availability of the source 

concentration at the available time to perform the test. 

A third 7-day calibration error test was conducted between the dates of July 6 and 

July 15, 2005. The reference gas used during the July test was from the 2.2 μg/m3

cylinder gas source. The 7-day calibration error test during the month of July was 

conducted within the same time frame as the RATA. This test information was collected 

and provided to make the test data complete. The information may also be useful in 

determining the instrument integrity. 
 4-33

Table 4-35. Durag 7-Day Calibration Error Test—Phase 2 

Gas Source: Tekran 3310 

Concentration: 2.5 μg/m3 

 CEMS Reading Error Criteria met? 

Date Time Zero Reference Zero Reference Zero Reference

05/13/05 16:32 0.0 2.2 0.00 0.26 Yes Yes 

05/14/05 16:36 0.0 2.4 0.00 0.06 Yes Yes 

05/15/05 11:09 0.0 2.9 0.00 0.44 Yes Yes 

05/16/05 10:52 0.0 2.1 0.00 0.36 Yes Yes 

05/17/05 10:44 0.0 2.4 0.00 0.06 Yes Yes 

05/18/05 9:36 0.0 2.1 0.00 0.36 Yes Yes 

05/19/05 9:03 0.0 2.7 0.00 0.24 Yes Yes 

05/20/05 8:40 0.0 2.5 0.00 0.04 Yes Yes 

7-Day Cal Error Result (5/13 - 5/20): Met criteria. 

Gas Source: Tekran 3310 and Cylinder 

Concentration: 4.9 and 5.8* μg/m3 

 CEMS Reading Error Criteria met? 

Date Time Zero Reference Zero Reference Zero Reference

* 06/22/05 16:33 0.1 5.6 0.10 0.20 Yes Yes 

* 06/23/05 9:23 0.1 5.7 0.10 0.10 Yes Yes 

06/24/05 15:43 0.0 5.3 0.00 0.39 Yes Yes 

* 06/25/05 10:46 0.1 5.8 0.10 0.00 Yes Yes 

* 06/26/05 10:52 0.1 5.3 0.10 0.50 Yes Yes 

06/27/05 9:07 0.2 4.8 0.20 0.11 Yes Yes 

* 06/28/05 7:17 0.1 5.9 0.10 0.10 Yes Yes 

* 06/29/05 14:17 0.1 5.6 0.10 0.20 Yes Yes 

7-Day Cal Error Result (6/22 - 6/29): Met criteria. 

Gas Source: Cylinder 

Concentration: 2.2 μg/m3 

 CEMS Reading Error Criteria met? 

Date Time Zero Reference Zero Reference Zero Reference

07/06/05 16:59 0.0 2.2 0.00 0.00 Yes Yes 

07/07/05 14:06 0.0 2.2 0.00 0.00 Yes Yes 

07/08/05 13:48 0.0 2.0 0.00 0.20 Yes Yes 

07/09/05 11:54 0.0 2.4 0.00 0.20 Yes Yes 

07/10/05 11:41 0.1 2.5 0.10 0.30 Yes Yes 

07/11/05 12:04 0.1 2.5 0.10 0.30 Yes Yes 

07/12/05 12:10 0.1 2.6 0.10 0.40 Yes Yes 

07/13/05 9:10 0.0 1.7 0.00 0.50 Yes Yes 

07/14/05 12:06 0.0 2.2 0.00 0.00 Yes Yes 

07/15/05 10:43 0.0 2.5 0.00 0.30 Yes Yes 

7 Day Cal Error Result (7/06 - 7/15): Met criteria. 

4.2.1.1.2 Linearity Test 

The Durag system was challenged with two separate linearity tests. Results of the 

linearity tests are summarized in Table 4-36. The instrument did not meet the Part 75 

criteria during either of the two tests. The first test was conducted on May 16, 2005. The 

reference gas used during the May measurement error test was from the Tekran 3310 

mercury calibration source. The Tekran 3310 source was used due to a limited supply of 

available cylinder gases during the test period and an effort to conserve the cylinder gases 

for the remaining duration of the study. During the May linearity test, the average of the 

three high-level gas concentrations measured by the instrument was 0.1 μg/m3 above the 

allowable alternative criteria of ±1.0 μg/m3. 
 4-34

The second linearity test was conducted on July 13, 2005. The reference gas 

concentrations used during the July test were from the gas cylinder sources. The July test 

was performed after the RATA, primarily due to the limited time available to conduct the 

test prior to the RATA. The Durag system did not meet the test criteria during the July 

linearity test since the average of the three high-level gas concentrations measured by the 

instrument was 0.3 μg/m3 above the allowable alternative criteria of ±1.0 μg/m3. 

An observation for both Durag linearity tests was that from cycle to cycle, the 

instrument showed an upward measurement trend. 

Table 4-36. Durag Linearity Test—Phase 2 

 From Tekran 3310 

Low-Level Gas Concentration: 2.5 μg/m3

Mid-Level Gas Concentration: 6.1 

High-Level Gas Concentration: 9.8 

Test Date: 5/16/2005 

Cycle Time Gas type CEMS Reading 

1 15:21 Low 2.0 

1 15:36 Mid 6.2 

1 15:51 High 10.5 

2 16:51 Low 2.8 

2 17:01 Mid 6.7 

2 17:17 High 11.2 

3 17:34 Low 2.8 

3 17:51 Mid 6.7 

3 18:07 High 11.1 

Gas Low Mid High 

Average 2.5 6.5 10.9 

% Error 3.19% 6.44% 11.32% 

Linear Error 0.1 0.4 1.1 

Criteria met? Yes Yes No 

5/16/05 Linearity Result: Criteria not met. 

 From Cylinders 

Low-Level Gas Concentration: 2.2 μg/m3

Mid-Level Gas Concentration: 5.1 

High-Level Gas Concentration: 10.4 

Test Date: 07/13/05 

Cycle Time Gas type CEMS reading 

1 9:18 Low 1.7 

1 9:55 Mid 4.8 

1 10:10 High 10.9 

2 10:26 Low 2.7 

2 10:48 Mid 5.4 

2 11:01 High 11.9 

3 11:27 Low 3.1 

3 11:42 Mid 6.0 

3 11:52 High 12.3 

 9:10 Zero 0 

Gas Low Mid High 

Average 2.5 5.4 11.7 

% Error 13.6% 5.9% 12.5% 

Linear Error 0.3 0.3 1.3 

Criteria met? Yes Yes No 

7/13/05 Linearity Result: Criteria not met. 
 4-35

4.2.1.1.3 System Integrity Test 

During the May and June certification test periods, system integrity tests were 

performed on the Durag system. Results of this system integrity testing are summarized 

in Table 4-37. The Durag system met the performance criteria for the first system 

integrity test performed on May 20, 2005, but failed to meet the criteria for the second 

system integrity test conducted on June 28, 2005. A likely cause of the June system 

integrity test results was the degrading cuvet UV light filter in the analyzer that was 

diagnosed three days earlier. 

Throughout the entire duration that the Durag system was operating on-site, weekly 

system integrity tests were performed. The results of all of the weekly system integrity 

tests are provided in Volume 3, Appendix H. The Durag system met the criteria on two of 

the 16 weekly system integrity tests performed. 

Table 4-37. Durag System Integrity Test—Phase 2 

 From Hovacal 

Mid-Level Oxidized Hg Concentration: 

High-Level Oxidized Hg Concentration: 

4.7 

7.6 

Test Date: 05/20/05 

Time Gas type CEMS reading (wet) Error 

Criteria 

met? 

13:13 Zero 0.5 0.5 Yes 

12:42 Mid 4.6 0.1 Yes 

12:13 High 8.6 1.0 Yes 

5/20/05 Converter Test Result: Criteria not met. 

 From Hovacal 

Mid-Level Oxidized Hg Concentration: 

High-Level Oxidized Hg Concentration: 

Test Date: 

4.7 

7.5 

6/28/2005 

Time Gas type CEMS reading (wet) Error 

Criteria 

met? 

15:14 Zero 0.1 0.1 Yes 

15:40 Mid 3.0 1.7 No 

16:01 High 4.4 3.1 No 

6/28/05 Test Result: Criteria not met. 

4.2.1.1.4 Cycle Time Test 

The Durag system was challenged with two complete cycle time tests which are 

summarized in Table 4-38. The instrument met the performance criteria for both tests. 

The first test was conducted on May 19, 2005, and the second test was conducted on July 

14, 2005, after the RATA. Another cycle time test was attempted on the Durag system on 

June 26, 2005, but the system-automated 2-hour back-flush event interrupted the test 

results. Limited time availability prevented the test being repeated in June prior to the 

RATA that followed the next week. 
 4-36

Table 4-38. Durag Cycle Time—Phase 2 

Date: 05/19/05 

Time 

CEM 

reading Comments 

16:44 7.7 Pretest stable stack measurement 

17:06 0 Zero and stable 

17:06:30 Release CEM back to stack gas 

17:13:00 5.9 Reach 95% of stable range 

17:21:30 6.2 Stack gas measurement stable 

6:30 min Tolerance< 00:15:00 

17:28 6.1 Pretest stable stack measurement 

17:35 9.9 High level (10.4) reference Gas and stable 

17:37:00 Release CEM back to stack gas 

17:45:02 6.8 Reach 95% of stable range 

17:52:00 6.6 Stack gas measurement stable 

8:02 min Tolerance< 00:15:00 

Cycle time Test Results: Criteria met. 

Date: 07/14/05 

Time 

CEM 

reading Comments 

12:19 3.2 Pretest stable stack measurement 

12:28 11.0 Zero and stable 

12:29:00 Release CEM back to stack gas 

12:39:00 3.1 Reach 95% of stable range 

12:44:00 3.1 Stack gas measurement stable 

10:00 min Tolerance< 00:15:00 

12:53 3.0 Pretest stable stack measurement 

13:02 0 High level (9.85) reference Gas and stable 

13:04:00 Release CEM back to stack gas 

13:13:00 2.8 Reach 95% of stable range 

13:19:00 2.8 Stack gas measurement stable 

9:00 min Tolerance< 00:15:00 

Cycle time Test Results: Criteria met.

4.2.1.1.5 Measurement Error Test 

The Durag system was challenged with two separate measurement error tests. 

Results of measurement error testing are summarized in Table 4-39. The first test was 

conducted on May 16, 2005. The reference gas used during the May measurement error 

test was from the Tekran 3310 Hg calibration source. The Tekran 3310 source was used 

due to a limited supply of available cylinder gases during the test period and an effort to 

conserve the gases for the remaining duration of the study. 

The second measurement test was conducted on July 13, 2005. The reference gas 

concentrations used during the July measurement error test were from the reference gas 

cylinder. The July test was performed after the RATA primarily due limited time 

available to conduct the test prior to the RATA. 
 4-37

The Durag system did not meet the performance criteria for the high level gas for the 

first test (off by 0.2 μg/m3), but did meet them for the second test. 

Table 4-39. Durag Measurement Error Test—Phase 2 

 From Tekran 3310 

Low-Level Gas Concentration: 2.5 

Mid-Level Gas Concentration: 6.1 

High-Level Gas Concentration: 9.8 

Test Date: 05/16/05 

Gas Type Time CEMS Reading Error 

Criteria 

met? 

Zero 15:06 0.0 0 Yes 

Low 15:21 2.0 0.5 Yes 

Mid 15:36 6.2 0.1 Yes 

High 15:51 10.5 0.7 No 

5/17/05 Measurement Error Result: Criteria not met. 

 From Cylinders 

Low-Level Gas Concentration: 

Mid-Level Gas Concentration: 

High-Level Gas Concentration: 

2.2 

5.1 

10.4 

Test Date: 7/13/2005 

Gas Type Time CEMS Reading Error 

Criteria 

met? 

Zero 9:10 0.0 0 Yes 

Low 9:18 1.7 0.5 Yes 

Mid 9:55 4.8 0.3 Yes 

High 10:10 10.9 0.5 Yes 

7/13/05 Measurement Error Result: Met criteria. 

4.2.1.1.6 Zero/Upscale Drift Test 

The Durag system was challenged with three separate zero/upscale drift tests results 

of which are summarized in Table 4-40. The instrument met the performance criteria for 

all three separate tests. The first zero/upscale drift test was conducted between the dates 

of May 13 and May 20, 2005. The reference gas used during the test period was from the 

Tekran 3310 Hg calibration source. The purpose of using the Tekran 3310 was due to a 

limited supply of available reference cylinder gases during the test period and an effort to 

conserve the gases for the remaining duration of the study. 

The second zero/upscale drift test was conducted between the dates of June 22 and 

June 29, 2005. The reference gas used during the June zero/upscale drift test varied 

between the Tekran 3310 Hg calibration source and the 5.8 μg/m3

 concentration gas 

cylinder. The difference between gas sources was due to the availability of the gas 

cylinder at the available time to perform the test. 
 4-38

Table 4-40. Durag Zero/Upscale Drift Tests—Phase 2 

Gas Source: Tekran 3310 

Reference Gas Concentration: 2.5 

 CEMS Reading Drift Result 

Date Time Zero Reference Zero Reference 

Zero 

criteria 

met? 

Span 

criteria

met? 

05/13/05 16:32 0.0 2.2 0.00 0.26 Yes Yes 

05/14/05 16:36 0.0 2.4 0.00 0.06 Yes Yes 

05/15/05 11:09 0.0 2.9 0.00 0.44 Yes Yes 

05/16/05 10:52 0.0 2.1 0.00 0.36 Yes Yes 

05/17/05 10:44 0.0 2.4 0.00 0.06 Yes Yes 

05/18/05 9:36 0.0 2.1 0.00 0.36 Yes Yes 

05/19/05 9:03 0.0 2.7 0.00 0.24 Yes Yes 

05/20/05 8:40 0.0 2.5 0.00 0.04 Yes Yes 

5/13 - 5/20 Zero Drift Result: Criteria met. 

5/13 - 5/20 Upscale Drift Result: Criteria met. 

Gas Source: Tekran 3310 and Cylinder* 

Reference Gas: 4.9 and 5.8* 

 CEMS Reading Drift Result 

Date Time Zero Reference Zero Reference 

Zero 

criteria 

met? 

Span 

criteria

met? 

* 06/22/05 16:33 0.1 5.6 0.10 0.20 Yes Yes

* 06/23/05 9:23 0.1 5.7 0.10 0.10 Yes Yes

06/24/05 15:43 0.0 5.3 0.00 0.39 Yes Yes

* 06/25/05 10:46 0.1 5.8 0.10 0.00 Yes Yes

* 06/26/05 10:52 0.1 5.3 0.10 0.50 Yes Yes

06/27/05 9:07 0.2 4.8 0.20 0.11 Yes Yes

* 06/28/05 7:17 0.1 5.9 0.10 0.10 Yes Yes

* 06/29/05 14:17 0.1 5.6 0.10 0.20 Yes Yes 

6/22 - 6/29 Zero Drift Result: Criteria met. 

6/22 – 6/29 Upscale Drift Result: Criteria met. 

Gas Source: Cylinder 

Reference Gas Concentration: 2.2 

 CEMS Reading Drift Result 

Date Time Zero Reference Zero Reference 

Zero 

criteria 

met? 

Span 

criteria

met? 

07/06/05 16:59 0.0 2.2 0.00 0.00 Yes Yes 

07/07/05 14:06 0.0 2.2 0.00 0.00 Yes Yes 

07/08/05 13:48 0.0 2.0 0.00 0.20 Yes Yes 

07/09/05 11:54 0.0 2.4 0.00 0.20 Yes Yes 

07/10/05 11:41 0.1 2.5 0.10 0.30 Yes Yes 

07/11/05 12:04 0.1 2.5 0.10 0.30 Yes Yes 

07/12/05 12:10 0.1 2.6 0.10 0.40 Yes Yes 

07/13/05 9:10 0.0 1.7 0.00 0.50 Yes Yes 

7/6 - 7/13 Zero Drift Result: Criteria met. 

7/6 - 7/13 Upscale Drift Result: Criteria met. 
 4-39

A third zero/upscale drift test was conducted between the dates of July 6 and July 13, 

2005. The reference gas used during the July zero/upscale drift test was from the 

2.2 ug/m3 concentration reference gas cylinder. The July zero/upscale drift test was 

conducted within the same time frame as the RATA. This test information was collected 

and provided to make the test data complete. The information may also be useful in 

determining the instrument integrity. 

4.2.1.2 Opsis 

The Opsis 7-day calibration error test, linearity check, system integrity test (which 

checks converter efficiency), measurement error test, and zero/upscale drift test results 

are presented in Tables 4-41 through 4-46. Testing and test dates are discussed below. 

4.2.1.2.1 7-Day Calibration Error Test 

The Opsis system was challenged with three separate 7-day calibration error tests. 

Results of the calibration error testing are summarized in Table 4-41. The instrument met 

the performance criteria for three 7-day test periods. 

The first test was performed between the dates of May 14 and May 21, 2005. The 

reference gas used during the May 7-day calibration error test was a 2.46 μg/m3 

concentration from the Tekran 3310 Hg calibration source. The Tekran 3310 was used 

due to the limited supply of available cylinder gases during the test period. On the eighth 

day of the testing, the Opsis system measured 0.8 μg/m3 lower than the 1.0 μg/m3 

tolerance limit specified by Part 75. This eighth day measurement was conducted after 

the gold trap was damaged by the trace nitric acid used in the oxidized mercury solution 

for the system integrity test. 

The second 7-day calibration error test was conducted between June 23 and July 1, 

2005. The reference gas used during this 7-day calibration error test varied between the 

Tekran 3310 Hg calibration source and the 5.8 μg/m3

 concentration reference cylinder 

gas source. The difference between sources was due to the availability of the source 

concentration at the available time to perform the test. 
 4-40

Table 4-41. Opsis 7-Day Calibration Error Test—Phase 2 

Gas Source: Tekran 3310 

Reference Gas Concentration: 2.5 

 CEMS Reading Error Result 

Date Time Zero Reference Zero Reference 

Zero 

criteria 

met? 

Span 

criteria 

met? 

05/14/05 14:23 0.4 2.3 0.4 0.2 Yes Yes 

05/15/05 10:37 0.0 2.3 0.0 0.2 Yes Yes 

05/16/05 10:25 0.1 2.0 0.1 0.6 Yes Yes 

05/17/05 9:40 0.2 1.9 0.2 0.7 Yes Yes 

05/18/05 8:58 0.0 2.0 0.0 0.5 Yes Yes 

05/19/05 15:38 0.7 2.2 0.7 0.3 Yes Yes 

05/20/05 9:58 0.0 2.7 0.0 0.5 Yes Yes 

05/21/05 5:09 0.3 0.7 0.3 1.8 Yes No 

7-Day Cal Error Result (5/14 - 5/20): Criteria met. 

Gas Source: Tekran 3310 and Cylinder* 

Reference Gas Concentration: 4.9 and 5.8* 

 CEMS Reading Error Result 

Date Time Zero Reference Zero Reference 

Zero 

criteria 

met? 

Span 

criteria 

met? 

* 06/22/05 13:32 0.2 7.5 0.2 1.7 Yes No 

* 06/23/05 9:59 0.2 5.2 0.2 0.6 Yes Yes 

* 06/24/05 16:19 0.3 6.4 0.3 0.6 Yes Yes 

* 06/25/05 10:58 0.0 6.5 0.0 0.7 Yes Yes 

* 06/26/05 10:52 0.1 6.0 0.1 0.2 Yes Yes 

06/27/05 8:58 0.1 4.6 0.1 0.3 Yes Yes 

* 06/28/05 7:19 0.3 4.9 0.3 0.9 Yes Yes 

* 06/29/05 14:19 0.1 5.4 0.1 0.4 Yes Yes 

06/30/05 9:26 0.4 5.5 0.4 0.6 Yes Yes 

07/01/05 8:10 0.2 4.5 0.2 0.4 Yes Yes 

7-Day Cal Error Result (6/23 - 7/01): Criteria met. 

Gas Source: Cylinder 

Reference Gas Concentration: 2.2 

 CEMS Reading Error Result 

Date Time Zero Reference Zero Reference 

Zero 

criteria 

met? 

Span 

criteria 

met? 

07/06/05 14:26 0.0 1.9 0.0 0.3 Yes Yes 

07/07/05 10:00 0.1 2.1 0.1 0.1 Yes Yes 

07/08/05 10:24 0.0 1.8 0.0 0.4 Yes Yes 

07/09/05 11:38 0.1 2.3 0.1 0.1 Yes Yes 

07/10/05 11:30 0.0 2.1 0.0 0.1 Yes Yes 

07/11/05 11:44 0.0 2.0 0.0 0.2 Yes Yes 

07/12/05 12:28 0.3 1.5 0.3 0.7 Yes Yes 

07/13/05 12:47 0.2 1.6 0.2 0.6 Yes Yes 

07/14/05 9:01 0.1 1.8 0.1 0.4 Yes Yes 

7 Day Cal Error Result (7/06 - 7/14): Criteria met. 

A third 7-day calibration error test was conducted between the dates of July 6 and 

July 14, 2005. The reference gas used during the July 7-day calibration error test was 

from the 2.2 μg/m3

 concentration cylinder gas source. The 7-day calibration error test 

during the month of July was conducted within the same time frame as the RATA. 
 4-41

4.2.1.2.2 Linearity Test 

The Opsis system was challenged with three separate linearity tests. Linearity test 

results are summarized in Table 4-42. The Opsis instrument did not meet the Part 75 

performance criteria during any of the three linearity tests conducted. The first test was 

conducted on May 20, 2005. The reference gas used during the May linearity test was 

from the Tekran 3310 Hg calibration source. The purpose of using the Tekran 3310 was 

due to a limited supply of available cylinder gases during the test period and an effort to 

conserve the gases for the remaining duration of the study. The Opsis system did not 

meet the criteria for the zero concentration or the low-, mid-, or high-level Hg 

concentrations during the May test. The May linearity test was discontinued after the 

linear error of mid-level concentration measured 2.8 μg/m3 below the +1.0 μg/m3 test 

criteria. 

An investigation by Opsis representatives in June concluded that the analyzer gold 

trap was damaged, perhaps by the nitric acid in the oxidized mercury solution used 

during the system integrity test conducted immediately prior to the measurement error 

test. 

A second linearity test was conducted on the Opsis system on June 29, 2005. The 

reference gas used during the June linearity test was from the Tekran 3310 Hg calibration 

source. The linear error measured for the high-level Hg concentration was 0.4 μg/m3 

beyond the ±1.0 μg/m3 test criteria. 

A third linearity test was conducted on the Opsis system on July 14, 2005. The 

reference gas concentrations used during the July linearity error test were from the gas 

cylinder sources. The July test was performed after the RATA to confirm the results of 

the linearity test performed prior to the RATA. The linear error from the mid-level and 

high-level Hg concentration were 0.7 μg/m3 and 2.4 μg/m3, respectively, beyond the test 

criteria. 
 4-42

Table 4-42. Opsis Linearity Test—Phase 2 

Low-Level Gas Concentration: 2.5 

Mid-Level Gas Concentration: 6.1 

High-Level Gas Concentration: 9.8 

Test Date: 05/20/05 

Cycle Time Gas type CEMS reading 

1 21:51 Low 1.7 

1 22:16 Mid * 2.3 

Level Average % Error Linear error Criteria met? 

Low 1.7 0.32 0.78 Yes 

Mid 2.3 0.62 3.81 No 

5/20/05 Linearity Result: Incomplete. 

* Test aborted; inadequate mid level performance. 

Low-Level Gas Concentration: 2.455 

Mid-Level Gas Concentration: 6.138 

High-Level Gas Concentration: 9.821 

Test Date: 6/29/2005 

Cycle Time Gas type CEMS reading 

1 18:31 Low 2.0 

1 18:48 Mid 5.0 

1 19:03 High 7.9 

2 19:18 Low 2.4 

2 19:33 Mid 5.4 

2 19:48 High 8.7 

3 20:00 Low 2.2 

3 20:11 Mid 5.2 

3 20:23 High 8.8 

Level Average % Error Linear error Criteria met? 

Low 2.21 10.18% 0.250 Yes 

Mid 5.22 15.00% 0.921 Yes 

High 8.45 13.99% 1.374 No 

6/29/05 Linearity Result: Criteria not met. 

Reference Gas Sources From Cylinders 

Low-Level Gas Concentration: 2.2 

Mid-Level Gas Concentration: 5.1 

High-Level Gas Concentration: 10.4 

Test Date: 7/14/2005 

Cycle Time Gas type CEMS reading 

1 9:01 Low 1.8 

1 9:18 Mid 3.2 

1 9:33 High 6.5 

2 9:48 Low 2.0 

2 10:08 Mid 3.4 

2 10:26 High 7.2 

3 10:47 Low 2.0 

3 11:03 Mid 3.6 

3 11:23 High 7.3 

Level Average % Error Linear error Criteria met? 

Low 1.89 13.9% 0.305 Yes 

Mid 3.39 33.6% 1.715 No 

High 6.99 32.8% 3.412 No 

7/14/05 Linearity Result: Criteria not met. 
 4-43

4.2.1.2.3 System Integrity Test 

System integrity tests were performed on the Opsis system on two separate 

occasions. Results of those tests are summarized in Table 4-43. The first system integrity 

test was performed on the Opsis system on May 20, 2005. The Opsis system did not meet 

the test criteria during this test, and the test was discontinued after the mid-level 

concentration measurements were recorded. The system consistently measured 

abnormally low stack gas values after conducting the system integrity test. All 

certification tests performed after the system integrity test did not meet the test criteria. 

MRI was requested by the on-site Opsis representative to refrain from conducting 

further system integrity tests on the Opsis system until an investigation could be 

performed to determine the cause of the low measurements obtained. An investigation by 

Opsis representatives in June concluded that the analyzer gold trap was damaged and the 

cause was suspected to be the nitric acid in the oxidized mercury solution used in the 

system integrity test. 

A second system integrity test was performed on June 28, 2005. New zero and 

oxidized mercury solutions were prepared for the HovaCal that did not include nitric 

acid. The solutions were prepared with 0.001N HCl. The Opsis system met the system 

integrity test criteria using the modified solutions. These modified solutions were made 

up weekly for the Opsis system integrity tests during the remainder of the test program. 

The results of weekly system integrity tests are provided in Volume 3, Appendix H. The 

Opsis met the criteria on two of the 11 weekly system integrity tests performed. 

Table 4-43. Opsis System Integrity Test—Phase 2 

Mid-Level Oxidized Mercury Concentration: 

High-Level Oxidized Mercury Concentration:

From Hovacal 

2.9 

* 

Test Date: 05/20/05 

Time Gas type CEMS reading Error Criteria met? 

4:50 Zero 0.47 0.46 Yes 

19:19 Mid 1.40 1.70 No 

 High * 

5/20/05 Conv. Test Result: Criteria not met. 

*Test discontinued. 

 From Hovacal 

Mid-Level Oxidized Mercury Concentration: 

High-Level Oxidized Mercury Concentration:

3.3 

5.3 

Test Date: 6/28/2005 

Time Gas type CEMS reading Error Criteria met? 

17:58 Zero 0 0.0 Yes 

18:19 Mid 3.7 0.4 Yes 

18:41 High 5.8 0.5 Yes 

6/28/05 Test Result: Criteria met. 
 4-44

4.2.1.2.4 Cycle Time Test 

The Opsis system was challenged with one complete cycle time test. An effort was 

made to perform a cycle time test during the month of May, but the Opsis system was not 

operating properly resulting in cycle times up to 1 hour. The first complete cycle test was 

conducted on June 27, 2005. The Opsis instrument met the performance criteria during 

the June cycle time test and the results are shown in Table 4-44. 

Table 4-44. Opsis Cycle Time—Phase 2 

Note: No test in May due to slow response time. 

Date: 06/27/05 

Time 

CEM 

reading Comments 

14:20 1.2 Pretest stable stack measurement 

14:28 0 Zero and stable 

14:45:08 Release CEM back to stack gas 

14:53:08 1.1 Reach 95% of stable range 

15:00:00 2.55 Stack gas measurement stable 

0:08:00 Tolerance< 00:15:00 

 2.7 Pretest stable stack measurement 

17:23 9.6 High level (9.85) reference Gas and stable 

17:25:38 Release CEM back to stack gas 

17:38:08 2.7 Reach 95% of stable range 

17:40:38 2.6 Stack gas measurement stable 

0:12:30 Tolerance< 00:15:00 

6/27/05 Cycle time Test Results: Criteria met. 

4.2.1.2.5 Measurement Error Test 

The Opsis system was challenged with three separate measurement error tests. 

Results of measurement error testing are summarized in Table 4-45. The Opsis 

instrument did not meet the performance criteria during any of the three tests conducted. 

The first test was conducted on May 20, 2005. The reference gas used during the May 

measurement error test was from the Tekran 3310 Hg calibration source. The purpose of 

using the Tekran 3310 was due to a limited supply of available cylinder gases during the 

test period and an effort to conserve the cylinder gases for the remaining duration of the 

study. The Opsis system did not meet the criteria for the zero concentration point nor any 

of the mercury concentrations attempted during the May test. The test was aborted after 

the mid-level mercury concentration was 4.3 μg/m3 below the 0.5 μg/m3 tolerance limit. 

An investigation by Opsis representatives in June concluded that the analyzer gold 

trap may have been damaged by the nitric acid in the oxidized mercury solution used 

during the system integrity test conducted prior to the measurement error test. 

The second Opsis measurement error test was conducted on June 29, 2005. The 

reference gas used during the June measurement error test was from the Tekran 3310 Hg 

calibration source. The mid-level Hg result was 0.4 μg/m3 beyond and high-level Hg result 

was 0.6 μg/m3 beyond the 0.5 μg/m3 tolerance limit. No explanation is available as to why 

the instrument did not meet the test criteria. 
 4-45

Table 4-45. Opsis Measurement Error Test—Phase 2 

 From Tekran 3310 

Low-Level Gas Concentration: 2.5 

Mid-Level Gas Concentration: 6.1 

High-Level Gas Concentration: 9.8 

Test Date: 05/20/05 

Test aborted; system unable to measure adequate mid-levels 

Gas type Time CEMS reading Error 

Criteria

met? 

Zero 20:58 0.6 0.6 No 

Low 21:51 1.7 1.0 No 

Mid 22:15 2.3 4.3 No 

High 10.5 No 

5/20/05 Measurement Error Result: Criteria not met. 

 From Tekran 3310 

Low-Level Gas Concentration: 

Mid-Level Gas Concentration: 

High-Level Gas Concentration: 

2.455 

6.138 

9.821 

Test Date: 6/29/2005 

Gas type Time CEMS reading Error 

Criteria 

met? 

Zero 20:43 0.2 0.2 Yes 

Low 20:00 2.2 0.2 Yes 

Mid 20:11 5.2 0.9 No 

High 20:23 8.8 1.1 No 

6/29/05 Measurement Error Result: Criteria not met. 

 From Cylinders 

Low-Level Gas Concentration: 2.2 

Mid-Level Gas Concentration: 5.1 

High-Level Gas Concentration: 10.4 

Test Date: 7/14/2005 

Gas type Time CEMS reading Error 

Criteria

met? 

Zero 8:43 0.1 0.1 Yes 

Low 9:01 1.8 0.4 Yes 

Mid 9:18 3.2 1.9 No 

High 9:33 6.5 3.9 No 

7/14/05 Measurement Error Result: Criteria not met. 

A third measurement error test was conducted on July 14, 2005. The reference gas 

concentrations used during the July measurement error test were from the gas cylinder 

sources. The July test was performed after the RATA primarily due limited time available 

to conduct the test prior to the RATA. The Opsis system did not meet the performance 

criteria since the mid-level Hg result was 1.4 μg/m3 beyond and high-level Hg result was 

3.4 μg/m3 beyond the 0.5 μg/m3 test criterion. 

4.2.1.2.6 Zero/Upscale Drift Test 

The Opsis system was challenged with three separate zero/upscale drift tests. Results 

of those tests are summarized in Table 4-46. The instrument did not meet the 

performance criteria for all three test periods. This test does not have the alternate 

≤ 1 μg/m3

 criteria for a 10 μg/m3 like the 7-day calibration error test. The first 
 4-46

zero/upscale drift test was performed between May 14 and May 21, 2005. The reference 

gas used during the May zero/upscale drift test was a 2.46 μg/m3 concentration from the 

Tekran 3310 Hg calibration source. The purpose of using the Tekran 3310 was due to the 

limited supply of available cylinder gases during the test period. On the sixth day, the 

Opsis system measured 0.2 μg/m3 beyond the 0.5 μg/m3 test tolerance for the zero gas 

and on the fourth day, the system did not meet the upscale gas test criteria both because 

PS 12A does not have the alternative criteria allowance when the span is defined at 10 

ug/m3

. The eighth day measurement which was made after the gold trap was damaged 

also did not meet the criteria. 

Table 4-46. Opsis Zero/Upscale Drift Tests—Phase 2 

Gas Source: Tekran 3310 

Reference Gas Concentration: 2.5 

CEMS reading Drift Result 

 

Date 

 

Time Zero Reference Zero Reference 

Zero criteria 

met? 

Span criteria 

met? 

05/14/05 14:23 0.4 2.3 0.4 0.2 Yes Yes 

05/15/05 10:37 0.0 2.3 0.0 0.2 Yes Yes 

05/16/05 10:25 0.1 2.0 0.1 0.5 Yes Yes 

05/17/05 9:40 0.2 1.9 0.2 0.6 Yes No 

05/18/05 8:58 0.0 2.0 0.0 0.5 Yes Yes 

05/19/05 15:38 0.7 2.2 0.7 0.3 No Yes 

05/20/05 9:58 0.0 2.7 0.0 0.2 Yes Yes 

05/21/05 5:09 0.3 0.7 0.3 1.8 Yes No 

5/14 - 5/21 Zero Drift Result: Criteria not met. 

5/14 - 5/21 Upscale Drift Result: Criteria not met.

Gas Source: Tekran 3100 and Cylinder* 

Reference Gas Concentration: 4.9 (Tekran) and 5.8* 

CEMS reading Drift Result 

Date Time Zero Audit Zero Audit 

Zero 

criteria 

met 

Span 

criteria 

 met? 

* 06/23/05 9:59 0.2 5.2 0.2 0.6 Yes No 

* 06/24/05 16:19 0.3 6.4 0.3 0.6 Yes No 

* 06/25/05 10:58 0.0 6.5 0.0 0.7 Yes No 

* 06/26/05 10:52 0.1 6.0 0.1 0.2 Yes Yes 

06/27/05 8:58 0.1 4.6 0.1 0.3 Yes Yes 

* 06/28/05 7:19 0.3 4.9 0.3 0.9 Yes No 

* 06/29/05 14:19 0.1 5.4 0.1 0.4 Yes Yes 

06/30/05 9:26 0.4 5.5 0.4 0.6 Yes No 

6/23 - 6/30 Zero Drift Result: Criteria met. 

6/23 - 6/30 Upscale Drift Result: Criteria not met. 

Gas Source: Cylinder 

Reference Gas Concentration: 2.2 

CEMS reading Drift Result 

Date Time Zero Audit Zero Audit Zero criteria met? Span criteria met?

07/06/05 14:26 0.0 1.9 0.0 0.3 Yes Yes 

07/07/05 10:00 0.1 2.1 0.1 0.1 Yes Yes 

07/08/05 10:24 0.0 1.8 0.0 0.4 Yes Yes 

07/09/05 11:38 0.1 2.3 0.1 0.1 Yes Yes

07/10/05 11:30 0.0 2.1 0.0 0.1 Yes Yes 

07/11/05 11:44 0.0 2.0 0.0 0.2 Yes Yes 

07/12/05 12:28 0.3 1.5 0.3 0.7 Yes No 

07/13/05 12:47 0.2 1.6 0.2 0.6 Yes No 

7/06 - 7/13 Zero Drift Result: Criteria met. 

7/06 - 7/13 Upscale Drift Result: Criteria not met. 
 4-47

The second 7-day calibration error test was conducted between the dates of June 23 

and June 30, 2005. The reference gas used during the June 7-day calibration error test 

varied between the Tekran 3310 Hg gas source and the 5.8 μg/m3

 concentration gas 

cylinder. Two sources were used due to the availability of the source concentration at the 

time available to perform the test. The system did not meet the upscale drift criteria 

because PS 12A does not have the alternative criteria allowance when the span is defined 

at 10 ug/m3

. 

A third 7-day calibration error test was conducted between July 6 and July 13, 2005. 

The reference gas used during the July 7-day calibration error test was from the 2.2 μg/m3

gas cylinder. The 7-day calibration error test during the month of July was conducted 

within the same time frame as the RATA. On the fourth day of the test, the system 

measured 0.1 μg/m3 beyond the 0.5 μg/m3 tolerance limit (5% of span) specified by 

PS 12A. 

4.2.1.3 Tekran 

The Tekran 7-day calibration error test, linearity check, system integrity test (which 

checks converter efficiency), measurement error test, and zero/upscale drift test results 

are presented in Tables 4-47 through 4-52. The Tekran system was located at the stack 

sampling platform and was configured with a 50-ft heated line (190°C) to the analysis 

system in the CEMS shelter on this platform. All reported concentrations are corrected to 

20°C. Testing and test dates are discussed below. 

4.2.1.3.1 7-Day Calibration Error Test 

The Tekran system was challenged with two complete 7-day calibration error tests. 

Those test results are summarized in Table 4-47. The instrument met the performance 

criteria for both tests. The first test was performed between May 13 and May 20, 2005. 

The reference gas used during the May 7-day calibration error test varied between the 

Tekran 3310 Hg calibration source, and two gas cylinders with concentrations of 

1.9 μg/m3

 and 2.2 μg/m3. The purpose of using the Tekran 3310 was due to the limited 

supply of available cylinder gases during the test period; the purpose of using gas 

cylinder sources was to provide an external reference gas source. 
 4-48

Table 4-47. Tekran 7-Day Calibration Error Test—Phase 2 

Gas Source: Tekran 3310 and Cylinders 

Reference Gas Concentration: 2.5, 1.9* and 2.1** μg/m3 

CEMS reading Error Result 

Date Time Zero Reference Zero Reference 

Zero 

criteria 

met 

Span 

criteria 

met? 

05/13/05 13:28 0.0 2.2 0.00 0.28 Yes Yes 

05/14/05 8:42 0.0 2.3 0.00 0.19 Yes Yes 

* 05/15/05 9:49 0.0 1.9 0.00 0.01 Yes Yes 

05/15/05 12:11 0.0 2.1 0.00 0.31 Yes Yes 

* 05/16/05 11:59 0.0 2.0 0.00 0.11 Yes Yes 

05/16/05 13:54 0.0 2.0 0.00 0.44 Yes Yes 

05/17/05 11:28 0.0 2.0 0.00 0.44 Yes Yes 

* 05/17/05 13:55 0.0 1.9 0.00 0.01 Yes Yes 

* 05/18/05 12:15 0.0 2.0 0.00 0.13 Yes Yes 

05/18/05 15:42 0.0 1.9 0.00 0.52 Yes Yes 

** 05/19/05 10:09 0.0 2.1 0.00 0.01 Yes Yes 

** 05/20/05 15:57 0.0 2.1 0.00 0.03 Yes Yes 

7-Day Cal Error Result (5/13 - 5/20): Met criteria. 

Gas Source: Tekran 3310 and Cylinder 

Reference Gas Concentration: 2.5 and 2.2* μg/m3 

CEMS Reading Error Result 

Date Time Zero Reference Zero Reference 

Zero 

criteria 

met? 

Span 

criteria 

met? 

* 07/06/05 17:34 0.0 1.957 0.00 0.40 Yes Yes 

* 07/07/05 9:03 0.0 2.014 0.00 0.35 Yes Yes 

07/08/05 9:34 0.0 2.071 0.00 0.56 Yes Yes 

07/09/05 8:58 0.0 1.957 0.00 0.68 Yes Yes 

07/10/05 8:54 0.0 1.923 0.00 0.71 Yes Yes 

07/11/05 8:54 0.0 1.923 0.00 0.71 Yes Yes 

07/12/05 8:49 0.0 2.008 0.00 0.63 Yes Yes 

* 07/13/05 9:15 0.1 2.423 0.09 0.06 Yes Yes 

* 07/14/05 9:32 0.0 2.389 0.00 0.03 Yes Yes 

* 07/15/05 10:19 0.0 2.454 0.00 0.09 Yes Yes 

7-Day Cal Error Result (7/6 - 7/15): Criteria met. 

An effort made to conduct a 7-day calibration error test during the month of June 

was interrupted by a system dilution orifice blockage on June 24. The June 25 daily 

measurement was not made since the system was not back in operation until June 26. The 

primary purpose of the July 7-day calibration error test was to repeat the interrupted June 

test. 
 4-49

The second Tekran 7-day calibration error test was conducted between July 6 and 

July 15, 2005 which also overlapped with the RATA. The reference gas used during the 

July test varied between the Tekran 3310 Hg calibration source and the 2.2 μg/m3

cylinder gas source. Two different reference gases were used in an effort to conserve the 

cylinder gases thereby ensuring that there would be enough gases to complete the 

certification tests on all of the Hg CEMS. 

4.2.1.3.2 Linearity Test 

The results of the two linearity tests completed on the Tekran system are shown in 

Table 4-48. No effort was made to conduct a linearity test on the Tekran system during 

the month of May. An automated linearity test using reference gases generated by the 

Tekran 3310 Hg calibration source was attempted on July 1, 2005 but was interrupted 

when on-site operators unintentionally terminated the test to conduct a daily calibration 

error test. Another automated linearity test was completed on July 8, 2005 using the 

Tekran 3310 Hg calibration source and the test criteria were met. 

A second linearity test was completed on July 13, 2005. The reference gas 

concentrations used during the July 13 test were from the gas cylinder sources. The July 

test was performed after the RATA primarily due to the fact that no low concentration 

cylinder gas was available in June to conduct a test independent of the Tekran 3310 Hg 

calibration source. The Tekran system did not meet the test criteria during the July 13 

linearity test since the average of the three high-level gas concentrations measured by the 

instrument was 0.2 μg/m3 beyond the allowable test criteria of ±1.0 μg/m3. 
 4-50

Table 4-48. Tekran Linearity Test—Phase 2 

 From Tekran 3310 

Low-Level Gas Concentration: 2.5 

Mid-Level Gas Concentration: 6.1 

High-Level Gas Concentration: 9.8 

Test Date: 07/08/05 

Cycle Time Gas type CEMS reading 

1 1:43 Low 2.613 

1 4:53 Mid 6.655 

1 2:10 High 10.507 

2 2:25 Low 2.692 

2 2:43 Mid 6.63 

2 2:57 High 10.147 

3 3:12 Low 2.729 

3 3:25 Mid 6.636 

3 3:42 High 10.531 

 1:30:00 Zero 0 

Gas Low Mid High 

Average 2.678 6.640 10.395 

% Error 1.63% 0.79% 1.39% 

Linear Error 0.043 0.052 0.146 

Criteria met? Yes Yes Yes 

7/8/05 Linearity Result: Met criteria. 

 From Cylinders 

Low-Level Gas Concentration: 2.2 

Mid-Level Gas Concentration: 5.1 

High-Level Gas Concentration: 10.4 

Test Date: 07/13/05 

Cycle Time Gas type CEMS reading 

1 9:30 Low 2.423 

1 9:55 Mid 4.42 

1 10:19 High 9.198 

2 10:31 Low 2.503 

2 10:43 Mid 4.539 

2 11:01 High 9.152 

3 11:20 Low 2.509 

3 11:42 Mid 4.585 

3 11:57 High 9.17 

 9:15:00 Zero 0.085 

Gas Low Mid High 

Average 2.478 4.515 9.173 

% Error 12.65% 11.48% 11.79% 

Linear Error 0.278 0.585 1.227 

Criteria met? Yes Yes No 

7/13/05 Linearity Result: Criteria not met. 
 4-51

4.2.1.3.3 System Integrity Test 

During the May and June certification test periods, two system integrity tests were 

performed on the Tekran system as shown in Table 4-49. The Tekran system met the test 

criteria during first system integrity test performed on May 19, 2005 but did not meet the 

test criteria during the second system integrity test conducted on June 28, 2002. On June 

28, the result for the mid-level gas was 0.2 μg/m3 beyond the 0.5 μg/m3 test criteria and 

the result for the high-level gas was 0.7 μg/m3 beyond the 0.5 μg/m3 test criteria. 

The Tekran system not meeting the test criteria during the June 28 test could have 

been due to a failure of the dilution eductor heater that occurred on the same day. The 

heater failure likely occurred due to an operator maintenance error installing the heater on 

June 26. 

Results of the weekly system integrity tests are provided in Volume 3, Appendix H. 

The Tekran met the criteria for 11 of the 22 tests performed. 

Table 4-49. Tekran System Integrity Test—Phase 2 

 From Hovacal 

Mid-Level Oxidized Mercury Concentration: 3.5 

High-Level Oxidized Mercury Concentration: 5.6 

Test Date: 05/19/05 

Time Gas type CEMS reading Error 

Criteria 

met? 

15:09 Zero 0.125 0.13 Yes 

16:05 Mid 3.510 0.03 Yes 

16:33 High 5.785 0.22 Yes 

 5/19/05 Test Result: Met criteria. 

 From Hovacal 

Mid-Level Oxidized Mercury Concentration: 3.3 

High-Level Oxidized Mercury Concentration: 5.3 

Test Date: 6/28/2005 

Time Gas type CEMS reading Error 

Criteria 

met? 

11:28 Zero 0.205 0.19 Yes 

11:52 Mid 2.821 0.70 No 

12:14 High 4.454 1.19 No 

6/28/05 Test Result: Criteria not met. 

4.2.1.3.4 Cycle Time Test 

The Tekran system was challenged with one complete cycle time test on July 14, 

2005 and met the test criteria during the test as shown in Table 4-50. Two other cycle 

time tests were attempted on June 30, 2005 but were aborted. The first attempt was 

aborted due to an operator error while the second was aborted due to unstable stack 

concentrations during the test period. Limited time availability prevented another attempt 

of the cycle time test in June prior to the RATA that followed the next week. 
 4-52

Table 4-50. Tekran Cycle Time Test—Phase 2 

Date: 07/14/05 

Time 

CEM 

reading Comments 

12:10 1.97 Pretest stable stack measurement 

13:02 0 Zero and stable 

13:04:10 Release CEM back to stack gas 

13:09:00 2.036 Reach 95% of stable range 

13:19:00 2.059 Stack gas measurement stable 

0:04:50 Tolerance< 00:15:00 

12:10 2.02 Pretest stable stack measurement 

12:28 9.073 High level (9.85) cylinder Gas and stable 

12:29:10 Release CEM back to stack gas 

12:37:00 1.951 Reach 95% of stable range 

12:44:00 1.928 Stack gas measurement stable 

0:07:50 Tolerance< 00:15:00 

7/14/05 Cycle time Test Results: Met criteria.

4.2.1.3.5 Measurement Error Test 

No effort was made to conduct a measurement error test on the Tekran system during 

the month of May. An automated measurement error test using the Tekran 3310 Hg 

calibration source was attempted on July 1, 2005, but was interrupted by on-site operators 

unintentionally terminating the test to conduct a daily calibration error test. Another 

automated measurement error test was completed on July 8, 2005 using the Tekran 3310 

Hg calibration source and the instrument met the test criteria. 

The second measurement error test was conducted on July 13, 2005. The reference 

gas concentrations used during the July measurement error test were from the reference 

gas cylinder sources. The July test was performed after the RATA primarily due to the 

lack of available low concentration reference gas in June to conduct a test independent of 

the Tekran 3310 Hg calibration source. The Tekran system did not meet the test criteria 

during the July 13 test. The result for the high-level gas was 0.7 μg/m3 beyond the 

0.5 μg/m3 test criteria limit. The results of all of the completed measurement error tests 

are shown in Table 4-51. 
 4-53

Table 4-51. Tekran Measurement Error Test—Phase 2 

From Tekran 3310 From Tekran 3310 

Low-Level Gas Concentration: 2.5 

Mid-Level Gas Concentration: 6.1 

High-Level Gas Concentration: 9.8 

Test Date: 7/8/2005 

Gas type Time CEMS reading Error Criteria met? 

Zero 1:30 0.0 0.0 Yes 

Low 1:43 2.613 0.0 Yes 

Mid 4:53 6.655 0.1 Yes 

High 2:10 10.507 0.0 Yes 

 7/08/05 Measurement Error Result: Met criteria. 

 From Cylinders 

Low-Level Gas Concentration: 2.2 

Mid-Level Gas Concentration: 5.1 

High-Level Gas Concentration: 10.4 

Test Date: 7/13/2005 

Gas type Time CEMS reading Error Criteria met? 

Zero 9:15 0.1 0.1 Yes 

Low 9:30 2.423 0.2 Yes 

Mid 9:55 4.420 0.7 No 

High 10:19 9.198 1.2 No 

 7/13/05 Measurement Error Result: Criteria not met. 

4.2.1.3.6 Zero/Upscale Drift Test 

Results of the Tekran zero/upscale drift testing are shown in Table 4-52. The Tekran 

system was challenged with two separate drift tests. The instrument met the test method 

criteria for the first test. The first zero/upscale drift test was conducted between May 13 

and May 17, 2005. The reference gas used during the May zero/upscale drift test varied 

between the Tekran 3310 Hg calibration source, and the 1.9 μg/m3 and the 2.1 μg/m3 Hg 

concentration gas cylinder sources. The difference between Hg sources was due to the 

availability of the source concentration at the available time to perform the test. 

A second zero/upscale drift test was conducted between July 8 and July 15, 2005. 

The reference gas used during the July zero/upscale drift test also varied between the 

Tekran 3310 Hg calibration source and the 2.2 μg/m3 Hg concentration gas cylinder. The 

difference between sources was due to the availability of the source concentration at the 

available time to perform the test. On the first four days of the test, the system measured 

less than 0.5 μg/m3 tolerance limit (5% of span) specified by PS 12A which does not have 

an alternative criteria for spans at 10 μg/m3. 
 4-54

Table 4-52. Tekran Zero/Upscale Drift Tests—Phase 2 

Reference Gas Source: Tekran 3310 and Cylinder 

Reference Gas Concentration: 2.5, 1.9*, 2.1** 

 CEMS Reading Drift Result 

Date Time Zero Reference Zero Reference

Zero 

criteria 

met? 

Span 

criteria 

met? 

05/13/05 13:28 0.0 2.2 0.00 0.28 Yes Yes 

05/14/05 8:42 0.0 2.3 0.00 0.19 Yes Yes 

* 05/15/05 9:49 0.0 1.9 0.00 0.01 Yes Yes 

05/15/05 12:11 0.0 2.1 0.00 0.31 Yes Yes 

* 05/16/05 11:59 0.0 2.0 0.00 0.11 Yes Yes 

05/16/05 13:54 0.0 2.0 0.00 0.44 Yes Yes 

05/17/05 11:28 0.0 2.0 0.00 0.44 Yes Yes 

* 05/17/05 13:55 0.0 1.9 0.00 0.01 Yes Yes 

5/13 - 5/17 Zero Drift Result: Met criteria. 

5/13 - 5/17 Upscale Drift Result: Met criteria. 

Reference Gas Source: Tekran 3310 and Cylinder 

Low-Level Gas Concentration: 2.5, 2.2* 

 CEMS Reading Drift Result 

Date Time Zero Reference Zero Reference

Zero 

criteria 

met? 

Span 

criteria 

met? 

07/08/05 9:34 0.0 2.071 0.00 0.56 Yes No 

07/09/05 8:58 0.0 1.957 0.00 0.68 Yes No

07/10/05 8:54 0.0 1.923 0.00 0.71 Yes No

07/11/05 8:54 0.0 1.923 0.00 0.71 Yes No

07/12/05 8:49 0.0 2.008 0.00 0.63 Yes No

* 07/13/05 9:15 0.1 2.171 0.09 0.06 Yes Yes 

* 07/14/05 9:32 0.0 2.389 0.00 0.03 Yes Yes 

* 07/15/05 10:19 0.0 2.454 0.00 0.09 Yes Yes 

7/8 - 7/15 Zero Drift Result: Met criteria. 

7/8 - 7/15 Upscale Drift Result: Criteria not met. 

4.2.1.4 ThermoElectron 

The ThermoElectron 7-day calibration error test, linearity check, system integrity 

test (which checks converter efficiency), measurement error test, and zero/upscale drift 

test results are presented in Tables 4-53 through 4-58. The Thermo CEMS system was 

located at the stack sampling platform and configured with a 50-ft heated line (165°C) to 

the analysis system in the CEMS shelter on this platform. 

4.2.1.4.1 7-Day Calibration Error Test 

The Thermo system was challenged with one partial and one complete 7-day 

calibration error test. The partial test was performed between May 13 and May 20, 2005. 

The reference gas used during the May 7-day calibration error test was from the 

Tekran 3310 Hg calibration source. Maintenance to the system by Thermo 

representatives on the sixth day prevented an opportunity to obtain the sixth of seven 
 4-55

consecutive days of measurements. Although all of the recorded measurements leading to 

the sixth day as well as the seventh day were within the 1.0 μg/m3 test, the test did not 

meet the test criteria since 7 consecutive days were not completed. 

A complete 7-day calibration error test was conducted on the Thermo system 

between June 23 and June 30, 2005. The reference gas used during this 7-day calibration 

error test varied between the Tekran 3310 Hg calibration source and the 5.8 μg/m3

reference gas cylinder. The Thermo system did not meet the test criteria during the test 

performed in June. During the first five days and last day of testing, the Thermo system 

measured from 0.2 μg/m3 to 1.7 μg/m3 beyond the 1.0 μg/m3 test criteria limit. The results 

for both 7-day calibration error tests are shown in Table 4-53. 

Plans to repeat the 7-day calibration error test during the period of the RATA were 

unsuccessful after the Thermo system failed to operate properly and required corrective 

maintenance in the middle of the fifth RATA test run. 

Table 4-53. Thermo 7-Day Calibration Error Test—Phase 2 

Gas Source: Tekran 3310 

Reference Gas Concentration: 2.5 

 CEMS reading Error Result 

Date Time Zero Reference Zero Reference 

Zero 

criteria 

met? 

Span

criteria

met? 

5/14/05 0.70 –0.12 2.81 0.12 0.35 Yes Yes 

5/15/05 0.48 –0.04 2.60 0.04 0.14 Yes Yes 

5/16/05 0.48 –0.38 2.63 0.38 0.17 Yes Yes 

5/17/05 0.44 –0.34 2.40 0.34 0.06 Yes Yes 

5/18/05 0.40 –0.34 2.29 0.34 0.17 Yes Yes 

5/19/05 Maintenance to system prevented daily measurement 

5/20/05 0.65 0.03 2.70 0.03 0.24 Yes Yes 

7 Day Cal Error Result: Incomplete 

Gas Source: Tekran 3310 and Cylinder* 

Reference Gas Concentration: 4.9 and 5.8* 

 CEMS reading Error Result 

Date Time Zero Reference Zero Reference 

Zero 

criteria 

met? 

Span

criteria

met? 

* 06/22/05 17:02 0.25 7.76 0.25 1.96 Yes No 

* 06/23/05 11:29 0.28 6.99 0.28 1.19 Yes No 

* 06/24/05 11:33 0.18 7.44 0.18 1.64 Yes No 

* 06/25/05 11:50 0.37 8.32 0.37 2.52 Yes No 

* 06/26/05 11:20 0.22 7.63 0.22 1.83 Yes No 

06/27/05 9:22 0.26 4.52 0.26 0.39 Yes Yes 

* 06/28/05 12:11 0.43 6.59 0.43 0.79 Yes Yes 

* 06/29/05 11:51 0.05 5.89 0.05 0.09 Yes Yes 

* 06/30/05 11:12 0.46 6.11 0.46 0.31 Yes Yes 

* 07/01/05 8:22 0.03 8.48 0.03 2.68 Yes No 

7-Day Cal Error Result (6/22 - 7/01): Criteria not met. 
 4-56

4.2.1.4.2 Linearity Test 

Results of linearity testing of the Thermo system are summarized in Table 4-54. One 

linearity test was conducted on the Thermo system on June 29, 2005. The reference gas 

concentrations used were from the Tekran 3310 Hg calibration source. The Thermo 

system did not meet the test criteria during this linearity test since the average of the three 

high-level gas concentrations measured by the instrument was 0.1 μg/m3 beyond the 

allowable tolerance of ±1.0 μg/m3. 

Table 4-54. Thermo Linearity Test—Phase 2 

 From Tekran 3310 

Low-Level Gas Concentration: 2.5 

Mid-Level Gas Concentration: 6.1 

High-Level Gas Concentration: 9.8 

Test date: 6/29/2005 

Cycle Time Gas type CEMS reading 

1 18:33 Low 2.19 

1 18:47 Mid 5.26 

1 18:58 High 8.81 

2 19:18 Low 2.53 

2 19:24 Mid 5.38 

2 19:44 High 8.75 

3 19:49 Low 2.47 

3 20:09 Mid 5.29 

3 20:19 High 8.53 

 20:34 Zero 0.27 

Gas Low Mid High 

Average 2.40 5.31 8.70 

% Error 2.6% 13.5% 11.4% 

Linear Error 0.063 0.830 1.12 

Criteria met? Yes Yes No 

6/29/05 Linearity Result: Criteria not met.

4.2.1.4.3 System Integrity Test 

The results of the weekly system integrity tests on the Thermo system are provided 

in Table 4-55. System integrity tests were performed on the Thermo during both the May 

and June, 2005 certification test periods. The Thermo system did not meet the test criteria 

during either of the two system integrity tests performed. The results for the high-level 

gas were 0.4 μg/m3 beyond the allowable test tolerance of + 0.5 μg/m3 for both the May 

and June tests. Results of the weekly system integrity tests are provided in Volume 3, 

Appendix H. The Thermo met the criteria for three of the 22 tests performed. 
 4-57

Table 4-55. Thermo System Integrity Test—Phase 2 

 From Hovacal 

Mid-Level Oxidized Mercury Concentration: 3.3 

High-Level Oxidized Mercury Concentration: 5.3 

Test Date: 05/19/05 

Time Gas type CEMS reading Error Criteria met? 

12:45 Zero –0.13 0.13 Yes 

12:23 Mid 3.64 0.33 Yes 

11:59 High 6.21 0.88 No 

5/19/05 Converter Test Result: Criteria not met. 

 From Hovacal 

Mid-Level Oxidized Mercury Concentration: 3.3 

High-Level Oxidized Mercury Concentration: 5.3 

Test Date: 6/29/2005 

Time Gas Type CEMS Reading Error Criteria met? 

14:34 Zero 0.17 0.17 Yes 

14:54 Mid 3.72 0.43 Yes 

15:09 High 6.18 0.85 No 

6/29/05 Test Result: Criteria not met. 

4.2.1.4.4 Cycle Time Test 

The Thermo system was challenged with one cycle time test on June 26, 2005. The 

instrument met the test method criteria during the test. The results of the June 26 cycle 

time test are shown in Table 4-56. 

Table 4-56. Thermo Cycle Time—Phase 2 

Date: 06/26/05 

Time CEM reading Comments 

15:57 2.6 Pretest stable stack measurement 

16:12 0.7 Zero and stable 

16:14:00 Release CEM back to stack gas 

16:19:48 2.45 Reach 95% of stable range 

16:24:08 2.55 Stack gas measurement stable 

0:05:48 Tolerance< 00:15:00 

Pretest stable stack measurement 

16:39 11.39 High level (9.85) reference Gas and stable 

16:38:00 Release CEM back to stack gas 

16:49:08 2.82 Reach 95% of stable range 

16:58:58 2.64 Stack gas measurement stable 

0:11:08 Tolerance< 00:15:00 

6/26/05 Cycle time Test Results: Met criteria.

4.2.1.4.5 Measurement Error Test 

A measurement error test was conducted on the Thermo system using the Tekran 

3310 Hg calibration source on June 29, 2005. The Thermo system did not meet the test 

criteria. The results for both the mid- and high-level Hg gases were beyond the 0.5 μg/m3 

test tolerance limit. Results of the measurement error test are shown in Table 4-57. 
 4-58

Table 4-57. Thermo Measurement Error Test—Phase 2 

 From Tekran 3310 

Low-Level Gas Concentration: 2.5 

Mid-Level Gas Concentration: 6.1 

High-Level Gas Concentration: 9.8 

Test Date: 6/29/2005 

Gas type Time CEMS reading Error 

Criteria 

met? 

Zero 20:34 0.27 0.27 Yes 

Low 19:49 2.47 0.01 Yes 

Mid 20:09 5.29 0.85 No 

High 20:19 8.53 1.29 No 

6/29/05 Measurement Error Result: Criteria not met. 

4.2.1.4.6 Zero/Upscale Drift Test 

Zero/upscale drift test results for the Thermo system are shown in Table 4-58. The 

Thermo system underwent one partial and one complete zero/upscale drift test. The 

Thermo did not meet the test criteria on either of the two tests conducted. The partial test 

was performed between May 13 and May 20, 2005. The reference gas used during the 

May zero/upscale drift test was from the Tekran 3310 Hg calibration source. 

Maintenance to the system by Thermo representatives on the sixth day prevented an 

opportunity to obtain the sixth of seven consecutive days of measurements. All the 

recorded measurements leading to the sixth day as well as the seventh day were within 

the 0.5 μg/m3 test limitation, due to the missed sixth day of comparative test data, the 

Thermo system did not meet the test method criteria for the May zero/upscale drift test. 

A second zero/upscale drift test was conducted between June 23 and June 30, 2005. 

The reference gas used during the June zero/upscale drift test varied between the Tekran 

3310 Hg calibration source and the 5.8 μg/m3 Hg concentration reference gas cylinder 

source. The difference between sources was due to the availability of the source 

concentration at the available time to perform the test. The Thermo instrument measured 

from 0.3 μg/m3 to 2.0 μg/m3 beyond the allowable 0.5 μg/m3 test tolerance on five of 

eight test dates. 

 
 4-59

Table 4-58. Thermo Zero/Upscale Drift Tests—Phase 2 

 Gas Source: Tekran 3310 

Reference Gas Concentration: 2.5 

 CEMS reading Drift Result 

Date Time Zero Reference Zero Reference 

Zero 

criteria 

met? 

Span 

criteria

met? 

05/14/05 16:41 –0.1 2.8 0.12 0.35 Yes Yes 

05/15/05 11:34 0.0 2.6 0.04 0.14 Yes Yes 

05/16/05 11:28 –0.4 2.6 0.38 0.17 Yes Yes 

05/17/05 10:35 –0.3 2.4 0.34 0.06 Yes Yes 

05/18/05 9:36 –0.3 2.3 0.34 0.17 Yes Yes 

05/19/05 Maintenance to system prevented daily measurement 

05/20/05 15:38 0.0 2.7 0.03 0.24 Yes Yes 

Zero Drift Result: Incomplete 

Upscale Drift Result: Incomplete 

 Gas Source: Tekran 3310 and Cylinder 

Reference Gas Concentration: 4.9 and 5.8* 

 CEMS reading Drift Result 

Date Time Zero Reference Zero Reference 

Zero 

criteria 

met? 

Span 

criteria

met? 

* 06/23/05 11:29 0.28 6.99 0.28 1.19 Yes No 

* 06/24/05 11:33 0.18 7.44 0.18 1.64 Yes No 

* 06/25/05 11:50 0.37 8.32 0.37 2.52 Yes No 

* 06/26/05 11:20 0.22 7.63 0.22 1.83 Yes No 

06/27/05 9:22 0.26 4.52 0.26 0.39 Yes Yes 

* 06/28/05 12:11 0.43 6.59 0.43 0.79 Yes No 

* 06/29/05 11:51 0.05 5.89 0.05 0.09 Yes Yes 

* 06/30/05 11:12 0.46 6.11 0.46 0.31 Yes Yes 

6/23 - 6/30 Zero Drift Result: Met criteria. 

6/23 - 6/30 Upscale Drift Result: Criteria not met. 

4.2.2 Phase 2 RATA Test Results 

The data presented in this section are from the RA test conducted during July 7-12, 

2005. The testing consisted of 12 test runs comparing four mercury Hg CEMS to the 

Ontario Hydro (OH) reference method. Overall, emissions as measured by OH displayed 

a general downward trend from 3 to 1.4 μg/m3

 over the course of 12 runs. 

The Durag, Opsis, and Tekran instruments collected data for all 12 of the RA tests 

and the Thermo instrument collected usable data for most of the first 5 RA test runs. 

Duplicate OH sampling trains were used during all 12 RA test runs. Further details of the 

Ontario Hydro results and results for each mercury CEMS are presented in the sections 

that follow. 

Mercury analysis results are provided in Appendix E of Volume 3. Mercury CEMS 

data collected during the RA test are provided in Appendix F of Volume 3. 
 4-60

4.2.2.1 Ontario Hydro Sample Results 

Sampling times for the Ontario Hydro sampling method are provided in Table 4-59. 

All runs had sample collection times of 2 hr according to the method. Samples were 

collected over a period of several days in order to observe any variation in emission data 

that would be useful in evaluating CEMS response. 

Table 4-59. Phase 2 RA Test Run Times

Run 

number 

 

Date 

Stack sampling intervals 

(in minutes per 24-hour clock) 

Sampling time 

(min) 

1 7/7/2005 10:45 - 12:45 120 

2 7/7/2005 14:35 - 16:35 120 

3 7/8/2005 10:00 - 12:00 120 

4 7/8/2005 13:55 - 15:55 120 

5 7/9/2005 9:25 - 11:25 120 

6 7/9/2005 13:10 - 15:10 120 

7 7/10/2005 9:25 - 11:25 120 

8 7/10/2005 12:40 - 14:40 120 

9 7/11/2005 09:15 - 11:15 120 

10 7/11/2005 14:00 - 16:00 120 

11 7/12/2005 9:45 - 11:45 120 

12 7/12/2005 13:00 - 15:00 120 

Table 4-60 summarizes the sampling conditions of the reference method trains. 

Ontario Hydro sampling and recovery data are provided in Appendix C of Volume 3 of 

this report. Method 3B sample collection data and the Orsat analysis results for each 

sample are also included with Appendix C. Sample traceability data sheets are presented 

in Appendix B, and sampling equipment calibration results are in Appendix D of Volume 

3. 

Mercury analysis results are presented in Table 4-61 and were obtained using the 

Ontario Hydro (OH) method analytical procedures. Data are presented separately for each 

sample train component. 

The reproducibility between run duplicates for the KMnO4/H2SO4 fraction of the OH 

sampling trains was large (> 10% RD) for 8 of the 12 runs. The analytical laboratory was 

asked to reanalyze this fraction from each of the trains. This time a different set of 8 runs 

had large RD (> 10%) values, so the laboratory was contacted. During a conversation 

with the laboratory, it was discovered that they had did not clear the KMnO4 samples 

prior to extracting an aliquot for analysis. Reanalysis results are included in Appendix E 

of Volume 3 of this report. 

Because the highest amount of mercury is found in the KMnO4/H2SO4 impingers, 

with much of it located in the brown residue inside the sample bottle, both the first and 

second KMnO4/H2SO4 sample results were considered nonrepresentative of the sample. 
 4-61

Table 4-60. Phase 2 RA Test Stack Sampling Data

 Sampling Gas Orsat Analysis Avg. stack Iso- 

 time volume Oxygen CO2 Water temp. kinetic 

 (min) (dscm) (%) (%) (%) (°F) (%) 

Run 1 120 2.615 5.6 12.4 16.0 131.1 102.7 

Run 1 dup 120 2.589 5.0 13.4 15.2 129.3 103.6 

Run 2 120 2.084 5.6 12.4 15.9 130.7 102.6 

Run 2 dup 120 2.107 5.2 13.4 15.1 128.9 104.2 

Run 3 120 2.027 5.6 12.6 16.3 131.8 101.2 

Run 3 dup 120 2.042 4.8 13.4 15.6 130.2 102.7 

Run 4 120 2.026 5.4 12.8 15.7 130.7 102.5 

Run 4 dup 120 2.059 4.8 13.4 14.9 128.6 103.8 

Run 5 120 2.015 5.6 12.6 15.6 130.3 99.7 

Run 5 dup 120 2.060 6.4 12.2 15.0 128.9 102.4 

Run 6 120 2.031 5.8 12.6 15.2 129.5 97.6 

Run 6 dup 120 2.090 6.0 12.6 14.5 127.7 102.3 

Run 7 120 2.035 5.6 12.8 15.5 130.1 100.6 

Run 7 dup 120 2.042 5.6 12.8 14.9 128.7 102.5 

Run 8 120 2.068 5.6 12.6 15.8 130.8 102.5 

Run 8 dup 120 2.060 5.6 13.0 15.0 129.0 102.3 

Run 9 120 2.011 5.4 12.8 16.0 131.1 100.9 

Run 9 dup 120 2.031 5.4 12.8 15.3 129.3 102.5 

Run 10 120 2.018 5.4 12.8 15.9 131.0 102.7 

Run 10 dup 120 2.001 5.0 13.2 15.4 129.6 102.3 

Run 11 120 2.070 5.2 13.2 16.0 130.9 102.4 

Run 11 dup 120 2.060 5.2 13.2 15.6 130.0 102.6 

Run 12 120 2.147 5.6 12.8 15.8 130.5 103.5 

Run 12 dup 120 2.082 5.6 12.8 15.4 129.7 102.4 
4-62

Table 4-61. Phase 2 RA Test Ontario Hydro Mercury Analysis Results (μg) 

Gaseous phase 

Ionic Elemental 

Particle bound phase 

Field ID Filter 

Probe 

rinse 

Part. bound 

subtotal 

KCl

impingers

HNO3/H2O2

impinger

HNO3/H2O2

imp. blank 

corrected 

amt. b

KMnO4/H2SO4

impingersc

Element

subtota

Run 1 0.011 a 0.020 0.031 0.980 0.170 0.160 5.76 5.93 Run 1 dup 0.021 a 0.030 0.052 1.013 0.164 0.154 6.30 6.46 Run 2 < 0.005 < 0.015 < 0.020 0.486 0.072 a 0.062 3.91 3.98 Run 2 dup < 0.005 < 0.011 < 0.016 0.636 0.082 a 0.072 2.43 2.51 Run 3 < 0.005 < 0.018 < 0.023 0.509 0.087 a 0.077 3.99 4.08 Run 3 dup < 0.005 < 0.016 < 0.021 0.579 0.106 a 0.096 4.05 4.16 Run 4 0.013 a 0.064 0.077 0.487 0.095 a 0.085 3.21 3.31 Run 4 dup < 0.005 0.061 0.061 0.531 0.078 a 0.068 3.19 3.27 Run 5 < 0.005 0.029 0.029 0.455 0.076 a 0.066 3.14 3.22 Run 5 dup < 0.005 0.029 0.029 0.456 0.100 a 0.090 3.01 3.11 Run 6 < 0.005 0.024 0.024 0.306 0.101 a 0.091 3.08 3.18 Run 6 dup < 0.005 0.036 0.036 0.385 0.060 a 0.050 2.96 3.02 Run 7 < 0.005 0.046 0.046 0.441 0.133 a 0.123 3.09 3.22 Run 7 dup < 0.005 < 0.019 < 0.024 0.499 0.120 a 0.110 2.23 2.35 Run 8 < 0.005 0.023 0.023 0.458 0.123 a 0.113 3.12 3.25 Run 8 dup < 0.005 < 0.022 < 0.027 0.637 0.099 a 0.089 3.30 3.39 Run 9 < 0.005 < 0.021 < 0.026 0.550 0.096 a 0.086 4.27 4.37 Run 9 dup < 0.005 < 0.019 < 0.024 0.771 0.071 a 0.061 4.15 4.22 Run 10 0.006 a 0.055 0.061 0.897 0.058 a 0.048 4.42 4.48 Run 10 dup < 0.005 0.033 0.033 0.769 0.052 a d 0.042 3.18 3.23 Run 11 0.007 a < 0.016 0.007 0.370 0.113 a 0.103 3.40 3.52 Run 11 dup < 0.005 0.019 0.019 0.357 0.081 a 0.071 3.69 3.77 Run 12 < 0.005 < 0.020 < 0.025 0.337 0.096 a 0.086 2.84 2.94 Run 12 dup < 0.005 < 0.020 < 0.025 0.341 0.080 a 0.070 2.05 2.13 FB-2 0.006 < 0.007 < 0.012 0.032 < 0.016 FB-4 0.010 < 0.008 < 0.014 0.057 0.019 SB < 0.005 < 0.006 < 0.001 0.006 0.003 Hydroxylaminee 0.00004 0.00004 FB = Field Blank Train; SB = Solution Blank plus Filter Blank. 

a The Field Blank Train result exceeded 30% of the measured value, however the contribution does not significantly impact total results. b Blank corrections performed per OH method. c Results were reanalyzed with no way to correct for solution blank; however, the estimated blank contribution is less than 1% of the mercury total. d The Solution Blank exceeded 10% of the measured value; however the contribution does not significantly impact total results. e A maximum of approximately 0.2 mL (1-2 drops) in KCl impingers and 0.2 mL in KMnO4/H2SO4 impingers was used during recovery; amount in blank wa

NOTE: Bolded sample results are biased low. 
 4-63

A second laboratory (ARCADIS G&M, Inc. in Research Triangle Park, NC) was 

asked to reanalyze the remaining portion of the original KMnO4/H2SO4 samples. Upon 

receipt at ARCADIS, the remaining sample volume in the bottles did not add up correctly. 

Subsequent conversations with Oxford Laboratory revealed that one 50-mL aliquot was 

extracted from each sample for preparation and duplicate analysis (i.e., one sample aliquot 

processed, then analyzed twice). Also, the four KMnO4/H2SO4 samples which had been 

spiked were missing an additional 100-mL to 200-mL volume with no corresponding 

analytical data. 

In order to determine the fraction of mercury contained in the KMnO4 fraction of each 

train, analytical results from each Oxford aliquot times the aliquot volume was added to 

the ARACADIS analytical result times the remaining sample volume to obtain a sum total 

mass. Because the four spiked samples from Oxford were missing an additional 100-mL to 

200-mL of sample, the results on those samples are biased low since those missing 

amounts cannot be added into the total. 

Tables 4-62 and 4-63 combine the mercury analysis results with the stack sampling 

results and provide the mercury emissions on a concentration basis. All test runs used 

duplicate trains, and precision information is summarized in Table 4-64. The relatively 

large RD for the elemental fraction on Runs 2, 7, 10, and 12 is most likely the result of not 

having the complete samples for analysis for those runs. Figure 4-9 shows concentrations 

of the total gaseous and oxidized fraction of mercury along with scatter points from each 

train. 

The OH sampling was performed isokinetically from a single point at a similar 

effective sampling location as the Hg CEMS and sorbent trap monitoring system. As 

specified in Part 75 requirements for mercury monitoring and PS-12A, only the ionic 

(oxidized) and elemental fractions of the OH results are included in the gaseous phase 

concentration values used for the RATA calculations. Therefore, the mercury CEMS and 

the OH results are on a similar basis (i.e., gaseous phase only, concentrations per dry 

standard volume). The particle-bound fraction, which constituted 1% (or less) of the total 

mercury, is reported only for informational purposes. 

The field blank train HNO3/H2O2 impinger results previously shown on Table 4-61 are 

noteworthy due to the presence of mercury at levels greater than 30% of the field sample 

values. The cause is not known. Even though the mercury levels in the field blank trains 

were greater than 30% of the stack samples, it should be noted that this fraction constitutes 

only about 5% of the total mercury in the train. 
 4-64

Table 4-62. RA Total OH Mercury Concentrations 

Particle-bound subtotal Gaseous-phase subtotal 

Mass 

(μg) 

Concentration 

(μg/dscm) 

Mass 

(μg) 

Concentration 

(μg/dscm) 

Run 1 0.031 a 0.012 6.90 2.64 

Run 1 rep 0.052 a 0.020 7.47 2.89 

Avg. 2.77 

Run 2 <0.020 N/D 4.46 b 2.14 

Run 2 rep <0.016 N/D 3.13 b 1.49 

Avg. 1.82 

Run 3 <0.023 N/D 4.58 b 2.26 

Run 3 rep <0.021 N/D 4.73 b 2.32 

Avg. 2.29 

Run 4 0.077 a 0.038 3.78 b 1.87 

Run 4 rep 0.061 0.030 3.79 b 1.84 

Avg. 1.86 

Run 5 0.029 0.014 3.66 b 1.82 

Run 5 rep 0.029 0.014 3.56 b 1.73 

Avg. 1.78 

Run 6 0.024 0.012 3.47 b 1.71 

Run 6 rep 0.036 0.017 3.39 b 1.62 

Avg. 1.67 

Run 7 0.046 0.023 3.65 b 1.79 

Run 7 rep <0.024 N/D 2.83 b 1.39 

Avg. 1.60 

Run 8 0.023 0.011 3.69 b 1.79 

Run 8 rep <0.027 N/D 4.02 b 1.95 

Avg. 1.87 

Run 9 <0.026 N/D 4.91 b 2.44 

Run 9 rep <0.024 N/D 4.98 b 2.45 

Avg. 2.45 

Run 10 0.061 a 0.030 5.37 b 2.66 

Run 10 rep 0.033 0.016 3.99 b d 1.99 

Avg. 2.33 

Run 11 0.007 a 0.003 3.88 b 1.87 

Run 11 rep 0.019 0.009 4.12 b 2.00 

Avg. 1.94 

Run 12 <0.025 N/D 3.27 b 1.52 

Run 12 rep <0.025 N/D 2.46 b 1.18 

Avg. 1.36 a

 The field blank train result exceeded 30% of the measured value; these results are not used in the 

gaseous-phase mercury concentration calculations. b

 The Field Blank Train result exceeded 30% of the measured value, however the contribution does 

not significantly impact total results. c

 The Solution Blank exceeded 10% of the measured value; however, the contribution does not 

significantly impact total results.

NOTE: Shaded sample results are biased low.
 4-65

Table 4-63. Phase 2 RA Gaseous-Phase Mercury From OH Testing 

Elemental portion Oxidized portion 

Total 

gaseous 

Mass 

(μg) 

Concentration 

(μg/dscm) 

Mass

(μg)

Concentration 

(μg/dscm) 

Concentration 

(μg/dscm) 

% Oxidized a

(Ionic)

 

Run 1 5.93 2.27 0.980 0.375 2.64 14.2 

Run 1 rep 6.46 2.50 1.013 0.391 2.89 13.6 

Avg. 2.38 0.383 2.77 13.9 

Run 2 3.98 1.91 0.486 0.233 2.14 10.88 

Run 2 rep 2.51 1.19 0.636 0.302 1.49 20.2 

Avg. 1.55 0.268 1.82 14.72 

Run 3 4.08 2.01 0.509 0.251 2.26 11.1 

Run 3 rep 4.16 2.04 0.579 0.284 2.32 12.2 

Avg. 2.03 0.267 2.29 11.7 

Run 4 3.31 1.63 0.487 0.240 1.87 12.8 

Run 4 rep 3.27 1.59 0.531 0.258 1.84 14.0 

Avg. 1.61 0.249 1.86 13.4 

Run 5 3.22 1.60 0.455 0.226 1.82 12.4 

Run 5 rep 3.11 1.51 0.456 0.221 1.73 12.8 

Avg. 1.55 0.223 1.78 12.6 

Run 6 3.18 1.56 0.306 0.150 1.72 8.77 

Run 6 rep 3.02 1.443 0.385 0.184 1.62 11.3 

Avg. 1.50 0.167 1.67 10.0 

Run 7 3.22 1.58 0.441 0.216 1.79 12.04 

Run 7 rep 2.35 1.15 0.499 0.244 1.39 17.5 

Avg. 1.37 0.230 1.60 14.4 

Run 8 3.25 1.57 0.458 0.221 1.79 12.4 

Run 8 rep 3.39 1.65 0.637 0.309 1.96 15.8 

Avg. 1.61 0.265 1.87 14.2 

Run 9 4.37 2.17 0.550 0.274 2.44 11.2 

Run 9 rep 4.22 2.08 0.771 0.380 2.45 15.5 

Avg. 2.12 0.327 2.45 13.3 

Run 10 4.48 2.22 0.897 0.445 2.66 16.7 

Run 10 rep 3.23 1.614 0.769 0.38 2.00 19.2 

Avg. 1.92 0.414 2.33 17.8 

Run 11 3.52 1.70 0.370 0.179 1.87 9.5 

Run 11 rep 3.77 1.83 0.357 0.173 2.00 8.6 

Avg. 1.77 0.176 1.94 9.1 

Run 12 2.94 1.37 0.337 0.157 1.52 10.3 

Run 12 rep 2.130 1.02 0.341 0.164 1.18 13.8 

Avg. 1.20 0.160 1.36 11.8 a

 % Oxidized = (Oxidized Concentration / Total Concentration) * 100.

NOTE: Runs 2Rep, 7Rep, 10Rep, and 12Rep (shaded) are biased low.
 4-66

Table 4-64. Phase 2 Paired OH Train Relative Deviation (RD) 

Concentration %RD 

Run Avg Oxidized (KCl) Elemental Gaseous subtotal 

Run 1 2% 5% 5% 

Run 2 13% 23% 18% 

Run 3 6% 1% 1% 

Run 4 4% 1% 1% 

Run 5 1% 3% 3% 

Run 6 10% 4% 3% 

Run 7 6% 16% 13% 

Run 8 17% 2% 4% 

Run 9 16% 2% 0.2% 

Run 10 7% 16% 14% 

Run 11 2% 4% 3% 

Run 12 2% 14% 13% 

 

The PS-12A objective is <10% RD, where %RD = 100 * (Abs(a-b)) / (a+b). 

Values shown in bold for Gaseous Subtotal have a RD >10%. 

Shaded values have RD calculated from samples with low biased results. 
4-67

Figure 4-9. Phase 2 OH Gaseous Phase Mercury Concentrations 

012345

1 2 3 4 5 6 7 8 9 10 11 12

Run No.

Hg Conc. (ug/dsm3) 
 4-68

Results from the remaining field blank samples revealed the presence of mercury in 

the filter and KMnO4 impingers at levels near the detection limit. Also, two of the six 

solution blanks indicated the presence of mercury near the detection limit. As previously 

indicated at the bottom of Table 4-67, the calculated contribution from hydroxylamine 

(used in train recovery for the KCl and KMnO4 impingers) is not expected to have 

contributed significantly to the remaining impingers. The laboratory method blanks 

showed no levels of mercury above detection limits. 

The estimated contribution from solution blanks was less than 1% of the total 

amount of mercury found in the samples. Thus, even though mercury was found in the 

HNO3/H2O2 and KMnO4/H2SO4 solution blank samples, it did not appear to have an 

appreciable effect on the overall result. The HNO3/H2O2 samples were blank-corrected 

using the decision tree shown below in Figure 4-10, as described in Section 13.4.3.1 of 

the Ontario Hydro Method. The KMnO4/H2SO4 samples could not be blank corrected 

since the results are a combination of more than one analysis. 

Figure 4-10. Decision Tree for Blank Corrections 

Most significantly, the Relative Deviation (RD) for seven of the 12 runs exceeded 

the 10% RD criteria in PS-12A. The greatest deviation is attributed to the KMnO4/H2SO4

impingers. These impingers were reanalyzed, but since the H2O2 impinger results 

contributed < 5% of the total and were consistent over a narrow concentration range, 

those impingers were not reanalyzed. A review of other sampling parameters (O2, CO2, 

and H2O) indicates that all parameters for all runs were within 8% of each other. Thus 

sampling variations do not appear to be contributing to the RD variances for those four 

runs (3, 4, 6, and 12). The RD calculation (previously called RSD) is Equation K-7 from 

Part 75 Appendix K (per 75.22) and Equation 12A-1 from PS-12A. 

4.2.2.2 CEMS RA Results 

Table 4-65 summarizes the relative accuracy calculations for each of the CEMS 

evaluated. Because four of the runs had a RD > 10%, and only three could be eliminated 
 4-69

the two runs with the largest RD (Runs 2 and 10) were eliminated first. The remaining 

two runs had a RD of 13% (Runs 7 and 12). The RA was calculated using first one then 

the other of these remaining two runs. The run which produced the lowest RA value was 

included for reporting. Calculations followed the procedures of Part 75, and are provided 

in Table 4-66 through 4-69. Hg CEMS data are included in Appendix F, and results for 

each analyzer are briefly discussed below. Emissions appeared to follow a generally 

decreasing trend from around 3 μg/m3

 to 1.4 μg/m3 throughout the course of the test. 

Because mercury was observed in the solution blanks, blank corrections were applied to 

the OH results. Hg levels measured with the OH method were fairly consistent with all 

average Hg CEM values. 

The reported values in the RA tables are based on the resolution of the analyzer; 

however the believed resolution is more likely 0.1 ug/m3

. 

Table 4-65 and Figure 4-11 show that despite the large RD numbers seen in Runs 2, 

7, 10, and 12, the average OH results are consistent with much of the CEMS results. 

Table 4-65. Phase 2 Summary of All RA Results for All CEMS 

Run CEMS (μg/dscm)

number

OH gaseous

mercury Durag Opsis Tekran Thermo 

1 2.77 6.07 2.19 2.41 2.19 

2 1.82 3.88 2.01 1.93 1.79 

3 2.29 3.67 1.77 2.08 1.94 

4 1.86 2.59 1.69 1.40 1.47 

5 1.78 2.51 1.34 1.37 2.19 

6 1.67 1.53 1.50 1.44 –0.32 

7 1.60 2.15 1.24 1.55 –0.26 

8 1.87 1.79 1.70 1.57 –0.21 

9 2.45 2.69 1.28 2.16 –0.20 

10 2.33 2.65 1.45 1.92 –0.11 

11 1.94 1.56 1.19 1.65 0.38 

12 1.36 1.29 1.05 1.31 3.03 

Relative Accuracy using 

best 9 runs 75.7% 36.2% 18.8% 94.5% 

NOTE: Data in bold indicates that run was not used to calculate Relative Accuracy. 

Note that the RA criteria can be either < 20% RA or + 1 μg/m3. All four CEMS met 

the mean difference criteria of < 1 μg/m3

 (though the Thermo system quit operating 

accurately during Run 5.) Calculations for Durag produced a relative accuracy of 76% for 

the best 9 test runs. Opsis relative accuracy was around 36%. Tekran RA results were 

around 19%. The Thermo RA results were about 95% . 

Figures 4-12 through 4-15 show plots of the run-by-run data for each analyzer, and 

Tables 4-66 through 4-69 show RA results for each analyzer compared with the OH 

method. 
4-70

Figure 4-11. Phase 2 Summary of RA Tests 

-0.5

0.00.51.01.52.02.53.03.54.04.5

1 2 3 4 5 6 7 8 9 10 11 12

Run No.

Hg Conc. (ug/dsm3) 
 4-71

Figure 4-12. Phase 2 RA—OH Versus Durag 

Figure 4-13. Phase 2 RA—OH Versus Opsis 

0

1

2

3

4

5

6

7

1 2 3 4 5 6 7 8 9 10 11 12

Run No.

H g C o n c . ( u g /m 3 )

O H M e th o d

Durag

0

1

2

3

1 2 3 4 5 6 7 8 9 10 11 12

Run No.

H g C o n c . ( u g /m 3 )

O H M e th o d

O p s is
 4-72

Figure 4-14. Phase 2 RA—OH Versus Tekran 

Figure 4-15. Phase 2 RA—OH Versus Thermo 

-0 .5

0 .0

0 .5

1 .0

1 .5

2 .0

2 .5

3 .0

3 .5

1 2 3 4 5 6 7 8 9 10 11 12

Run No.

H g C o n c . ( u g /m 3 )

O H M e th o d

Thermo

0

1

2

3

1 2 3 4 5 6 7 8 9 10 11 12

Run No.

H g C o n c . ( u g /m 3 )

O H M e th o d

Tekran
 4-73

Table 4-66. Phase 2 RA Results for Durag 

 CEMS Avg. OH Total Hg Difference 

Run Response Response (d) 

Number Use Date Time (ug/dscm) (ug/dscm) (ug/dscm) 

1 Yes 7/7/2005 10:45 - 12:45 6.07 2.77 -3.30 

2 No 7/7/2005 14:35 - 16:35 3.881 1.82 -2.061 

3 Yes 7/8/2005 10:00 - 12:00 3.67 2.29 -1.38 

4 Yes 7/8/2005 13:55 - 15:55 2.59 1.86 -0.73 

5 Yes 7/9/2005 9:25 - 11:25 2.51 1.78 -0.73 

6 Yes 7/9/2005 13:10 - 15:10 1.53 1.67 0.14 

7 No 7/10/2005 9:25 - 11:25 2.15 1.6 -0.55 

8 Yes 7/10/2005 12:40 - 14:40 1.79 1.87 0.08 

9 Yes 7/11/2005 09:15 - 11:15 2.69 2.45 -0.24 

10 No 7/11/2005 14:00 - 16:00 2.654 2.33 -0.324 

11 Yes 7/12/2005 9:45 - 111:45 1.56 1.94 0.38 

12 Yes 7/12/2005 13:00 - 15:00 1.29 1.36 0.07 

 

Arithmetic Mean a

(ug/dscm): 2.63 2.00 -0.63 

BAF b 1.24 

Standard Deviation 1.14 

Confidence Coefficient d 0.88 

Relative Accuracy e (% of RM) 75.7% 

a

 Arithmetic Mean = 1/n S di 

b

 BAF = 1 + I 1/n S di I / HgCEMS(avg) 

c

 Standard Deviation = [ (S di

2

 - (S di)

2

 / n) / (n-1) ]1/2 

d

 Confidence Corfficient = t0.975 * Standard Deviation / n1/2, where t0.975 = 2.306 e

 Relative Accuracy = ([Difference Arithmetic Mean] + [Confidence Coefficient]) / RM Arithmetic Mean * 

100 
 4-74

Table 4-67. Phase 2 RA Results for Opsis 

 CEMS Avg. OH Total Hg Difference 

Run Response Response (d) 

Number Use Date Time (ug/dscm) (ug/dscm) (ug/dscm) 

1 Yes 7/7/2005 10:45 - 12:45 2.19 2.77 0.58 

2 No 7/7/2005 14:35 - 16:35 2.007 1.82 -0.187 

3 Yes 7/8/2005 10:00 - 12:00 1.77 2.29 0.52 

4 Yes 7/8/2005 13:55 - 15:55 1.69 1.86 0.17 

5 Yes 7/9/2005 9:25 - 11:25 1.34 1.78 0.44 

6 Yes 7/9/2005 13:10 - 15:10 1.50 1.67 0.17 

7 Yes 7/10/2005 9:25 - 11:25 1.24 1.60 0.36 

8 Yes 7/10/2005 12:40 - 14:40 1.70 1.87 0.17 

9 Yes 7/11/2005 09:15 - 11:15 1.28 2.45 1.17 

10 No 7/11/2005 14:00 - 16:00 1.449 2.33 0.881 

11 Yes 7/12/2005 9:45 - 111:45 1.19 1.94 0.75 

12 No 7/12/2005 13:00 - 15:00 1.053 1.36 0.307 

 

Arithmetic Mean a

(ug/dscm): 1.55 2.03 0.48 

BAF b 1.31 

Standard Deviation b 0.33 

Confidence Coefficient d 0.25 

Relative Accuracy e (% of RM) 36.2% 

a

 Arithmetic Mean = 1/n S di 

b

 BAF = 1 + I 1/n S di I / HgCEMS(avg) 

c

 Standard Deviation = [ (S di

2

 - (S di)

2

 / n) / (n-1) ]1/2 

d

 Confidence Corfficient = t0.975 * Standard Deviation / n1/2, where t0.975 = 2.306 e

 Relative Accuracy = ([Difference Arithmetic Mean] + [Confidence Coefficient]) / RM Arithmetic Mean * 

100 
 4-75

Table 4-68. Phase 2 RA Results for Tekran 

 

CEMS 

Avg. 

OH Total 

Hg Difference 

Run Response Response (d) 

Number Use Date Time (ug/dscm) (ug/dscm) (ug/dscm) 

1 Yes 7/7/2005 10:45 - 12:45 2.41 2.77 0.36 

2 No 7/7/2005 14:35 - 16:35 1.931 1.82 -0.111 

3 Yes 7/8/2005 10:00 - 12:00 2.08 2.29 0.21 

4 Yes 7/8/2005 13:55 - 15:55 1.40 1.86 0.46 

5 Yes 7/9/2005 9:25 - 11:25 1.37 1.78 0.41 

6 Yes 7/9/2005 13:10 - 15:10 1.44 1.67 0.23 

7 Yes 7/10/2005 9:25 - 11:25 1.55 1.60 0.05 

8 Yes 7/10/2005 12:40 - 14:40 1.57 1.87 0.30 

9 Yes 7/11/2005 09:15 - 11:15 2.16 2.45 0.29 

10 No 7/11/2005 14:00 - 16:00 1.915 2.33 0.415 

11 Yes 7/12/2005 9:45 - 111:45 1.65 1.94 0.29 

12 No 7/12/2005 13:00 - 15:00 1.307 1.36 0.05 

 

Arithmetic Mean a

(ug/dscm): 1.7 2.0 0.3 

BAF b 1.17 

Standard Deviation c 0.1 

Confidence Coefficient d 0.1 

Relative Accuracy e (% of RM) 18.8% 

a

 Arithmetic Mean = 1/n S di 

b

 BAF = 1 + I 1/n S di I / HgCEMS(avg) 

c

 Standard Deviation = [ (S di

2

 - (S di)

2

 / n) / (n-1) ]1/2 

d

 Confidence Corfficient = t0.975 * Standard Deviation / n1/2, where t0.975 = 2.306 e

 Relative Accuracy = ([Difference Arithmetic Mean] + [Confidence Coefficient]) / RM Arithmetic Mean * 

100 
 4-76

Table 4-69. Phase 2 RA Results for Thermo 

 CEMS Avg. 

OH Total 

Hg Difference 

Run Response Response (d) 

Number Use Date Time (ug/dscm) (ug/dscm) (ug/dscm) 

1 Yes 7/7/2005 10:45 - 12:45 2.19 2.77 0.58 

2 Yes 7/7/2005 14:35 - 16:35 1.789 1.82 0.03 

3 Yes 7/8/2005 10:00 - 12:00 1.94 2.29 0.35 

4 Yes 7/8/2005 13:55 - 15:55 1.46 1.86 0.40 

5 Yes 7/9/2005 9:25 - 11:25 2.19 1.78 -0.41 

6 Yes 7/9/2005 13:10 - 15:10 -0.32 1.67 1.99 

7 Yes 7/10/2005 9:25 - 11:25 -0.261 1.6 1.86 

8 No 7/10/2005 12:40 - 14:40 -0.21 1.87 2.08 

9 No 7/11/2005 09:15 - 11:15 -0.20 2.45 2.65 

10 No 7/11/2005 14:00 - 16:00 -0.109 2.33 2.44 

11 Yes 7/12/2005 9:45 - 111:45 0.38 1.94 1.57 

12 Yes 7/12/2005 13:00 - 15:00 3.03 1.36 -1.67 

 

Arithmetic Mean a

(ug/dscm): 1.16 2.00 0.84 

BAF b 1.72 

Standard Deviation c 1.37 

Confidence Coefficient d 1.05 

Relative Accuracy e (% of RM) 94.5% a

 Arithmetic Mean = 1/n S di b

 BAF = 1 + I 1/n S di I / HgCEMS(avg) c

 Standard Deviation = [ (S di

2

 - (S di)

2

 / n) / (n-1) ]1/2 d

 Confidence Corfficient = t0.975 * Standard Deviation / n1/2, where t0.975 = 2.306 e

 Relative Accuracy = ([Difference Arithmetic Mean] + [Confidence Coefficient]) / RM Arithmetic Mean * 

100 

4.2.3 Additional Testing 

4.2.3.1 Instrumental Reference Method Testing 

The instrumental reference method (IRM) evaluations were performed towards 

development of an instrumental alternative to the Ontario Hydro reference method as 

used to perform Hg CEMS Relative Accuracy Test Audits (RATA). Results of the IRM 

testing are shown in Table 4-70. The technique of dynamic spiking was employed as an 

approach to assess matrix interferences and begin determination of appropriate method 

performance criteria. 

Known mass and volumetric feed rates of elemental and oxidized Hg were 

dynamically introduced at the probe of an Hg CEMS and the resulting recoveries 

calculated. By holding the sampling rate at a known constant, the resulting diluted 

concentration was determined. The elemental and oxidized Hg dynamic spikes were 
 4-77

introduced at a volumetric flow that did not dilute the total stack sample flow rate by 

more than 10%. 

The Tekran Hg CEMS was used to perform the IRM test procedures because it is 

capable of extracting a high volume of stack gas through the probe at a controlled and 

measured flowrate and it was already appropriately configured for dynamic spiking. The 

probe allows for introduction of gas at the entrance of the dilution orifice which is 

downstream of the inertial separator/filter, and the probe tip upstream of the inertial 

separator/filter. Both of these injection locations were used to perform the IRM test. 

Table 4-70. IRM Daily Hg Tests During RATA 

 Hg Source Tekran 

Test date μg/m3 Pre-Run Post-Run 

zero (N2) elemental 0.000 * n/a 

2.2 elemental (cylinder gas) 1.957 * n/a 

zero (N2) Ionic 0.444 n/a 7/6/2005 

2.6 Ionic 1.974 n/a 

zero (N2) elemental 0.000 0.000 

2.2 elemental (cylinder gas)** 2.014 2.019 

zero (N2) elemental 0.000 0.000 

2.455 elemental (3310 gas)** 2.313 2.230 

zero (N2) Ionic 0.097 0.142 

7/7/2005 

2.6 Ionic 1.456 1.451 

zero (N2) elemental 0.000 0.000 

2.455 elemental (3310 gas) 2.071 2.008 

zero (N2) Ionic 0.114 0.131 7/8/2005 

2.6 Ionic 1.797 1.776 

zero (N2) elemental 0.000 0.000 

2.455 elemental (3310 gas) 1.957 1.985 

zero (N2) Ionic 0.108 0.131 7/9/200 

2.6 Ionic 1.752 1.712 

zero (N2) elemental 0.000 0.000 

2.455 elemental (3310 gas) 1.923 2.014 

zero (N2) Ionic 0.142 0.097 7/10/2005 

2.6 Ionic 1.741 1.680 

zero (N2) elemental 0.000 0.000 

2.455 elemental (3310 gas) 1.923 1.991 

zero (N2) Ionic 0.108 0.085 7/11/2005 

2.6 Ionic 1.763 1.712 

zero (N2) elemental 0.000 0.000 

2.455 elemental (3310 gas) 2.008 2.143 

zero (N2) Ionic 0.114 0.097 7/12/2005 

2.6 Ionic 1.786 1.900 

* Measured at orifice; all measurements after 7/6/05 were made at the probe. 

** Supply of 2.2 μg/m3 cylinder gas was insufficient to complete test series. 

4.2.3.2 Screening of Sorbent Trap Data with Hg CEMS 

RMB Associates collected sorbent trap samples per Part 75 Section K during the 

6 days of RATA testing. Those data were not available for inclusion in this report. 
 5-1

Section 5. 

Quality Assurance/Quality Control 

The Quality Assurance/Quality Control (QA/QC) requirements, emission 

measurement, and data quality objectives for this test project are summarized in this 

section. The QC procedures and acceptance criteria specified in the EPA methods and the 

QAPP were used. The procedures included, but were not limited to, (1) sampling 

equipment calibrations, (2) procedural elements of the methods, such as leak checks, 

placement of the sampling probe, verification of the integrity of metering systems prior to 

the start and at the completion of each sampling run, etc., and (3) the use of QC samples 

and analytical approaches such as reagent blank samples, method blanks, matrix spike 

samples, duplicate analysis, and surrogate spiking for both manual methods and CEMS. 

The performance and results of all QC procedures were recorded on appropriate forms, 

data sheets, field logs, and laboratory notebooks, as appropriate. 

This QA/QC section is divided into two parts. The first part, 5.1, provides a 

summary of the Phase 1 November 2004 through February 2005, and the second part, 

5.2, provides a summary of the Phase 2 testing performed March through 

September 2005. 

5.1 Phase 1 Certification Testing 

5.1.1 QA/QC Issues 

It was discovered very late in the test program that a deviation from the OntarioHydro method had occurred during the laboratory analysis. The brown residue found in 

KMnO4/H2SO4 impinger samples was not cleared (see Section 13.3.5 of Ontario Hydro 

method) prior to extracting an aliquot for analysis. This is a critical step which greatly 

affects the analytical result. By the time MRI was made aware of this method deviation 

the samples had already been discarded and it was too late to perform any reanalysis. 

Omission of this step adversely affects both precision and accuracy. For that reason the 

elemental mercury from the KMnO4/H2SO4 impinger samples are considered suspect. 

More information on this method deviation is provided in Section 5.2.1. 

The field blank KCl impinger result was > 30% of the results for the field samples. 

This, coupled with extremely low Run 1 KCl impinger results, casts doubt on those 

sample results. However, since the oxidized mercury captured in the KCl impinger 

comprises on average < 10% of the total captured mercury, the impact is minimal. The 

paired train relative deviation (RD) criterion of ≤ 10% RD was met for 8 of the 12 runs. 

The RA results for three of the four CEMS evaluated were greater than the 20% criteria 

and had differences greater than 1 μg/m3

 for 9 runs. Two of the four CEMS met the 

remaining initial certification criteria listed in Table 5-1. Minor variances from the data 

quality criteria are noted in the remainder of this section. 
 5-2

5.1.2 Ontario Hydro Sampling Equipment Calibration 

QC procedures, acceptability limits for sampling equipment calibrations, and 

calibration results are presented in Table 5-2. Calibration data sheets and equipment 

condition checklists used during calibration are provided in Appendix C of Volume 2 of 

this report. Equipment used for sample analysis was calibrated according to the 

procedures in the approved methods and manufacturers’ manuals. 

5.1.3 Hg CEMS Emission Measurement and Data Quality Objectives 

The QC procedures, acceptability limits, and calibration results are presented in 

Table 5-2. Detailed information for these results was presented in Section 4 of this report. 

5.1.4 Ontario Hydro Emission Measurement and Data Quality Objectives 

Specific QC procedures were followed to ensure the continuous generation of useful 

and valid data. Table 5-3 presents a summary of criteria for assessing overall emission 

measurement and data quality for the initial RATA test. Section 5.4.1 presents a brief 

summary of the QA sample results for the RATA. All samples were analyzed within the 

28-day holding time; however, shipping and storage temperatures for HNO3/H2O2 and 

KMnO4/H2SO4 samples could not be verified. 

5.1.4.1 QA Sample Results 

It was discovered very late in the test program that the laboratory did not perform the 

Ontario-Hydro method closely. They had not cleared the brown residue found in 

KMnO4/H2SO4 impinger samples prior to extracting an aliquot for analysis. This is a 

critical step which greatly affects the analytical result. By the time MRI was made aware 

of this method deviation, the samples had already been discarded and it was too late to 

perform any reanalysis. Omission of this step adversely affects both precision and 

accuracy. For that reason the elemental mercury from the KMnO4/H2SO4 sample 

fractions are considered suspect. More information on this method deviation is provided 

in Section 5.2.1. 

Blanks

Results of blank analysis are shown in Table 5-4. Results for 4 of the 5 field blank 

train components indicated detectable levels of mercury, with the KCl impinger result at 

greater than 10 times the detection limit. Results from the field blank train analysis 

showed that mercury levels were > 30% of the field sample results for the KCl impingers 

and 5 of the 24 filters. These sample results have been flagged. 
5-3

Table 5-1. Summary of Phase 1 CEMS Certification Criteria 

 Crite

Test Method of determination Frequency Criteria Forney Hor

7-Day Calibration Error Test 

Once per day for 7-day consecutive days 

At 24-hr intervals for 7 consecutive days 

Error must be ≤1 μg/m3 (alternative 

when span is defined at 10 μg/m3). N Y 

Linearity Test At beginning of test 

program, then quarterly 

Once, at beginning of test program 

Error must be ≤ 10% or ≤ 1 μg/m3, whichever is least restrictive. N N 

Cycle Time Test 

Once, at beginning of test program 

Once, at beginning of test program 

Cycle times must be ≤ 15 minutes. 

N N 

System Integrity Test 

At beginning of test program, then weekly 

Once, at beginning of test program 

Error must be ≤ 5% of span from 

certified gas value (i.e., within ±0.5 μg/m3 of certified gas value). 

N Y 

Measurement Error Test 

Performance of Linearity and Converter Efficiency tests 

Once, at beginning of test program 

Error must be ≤ 5% of span from 

certified gas value (i.e., within ±0.5 μg/m3 of certified gas value). 

N N 

Zero and Upscale Drift Test 

Determines magnitude of drift at 24-hr intervals 

7 consecutive days 

Error must be ≤ 5% of span (i.e., 

within ±0.5 μg/m3 of certified gas 

value). 

N Y 

Relative Accuracyb

(RATA) 

One set of 12 test runs, at beginning of test program, and again after 6 months 

After initial certification checks 

≤ 1 μg/m3 difference (alternative 

when average RM indicates Hg concentration is < 5.0 ug/m3). N N 

a Using Run 4 Avg. result. b A method deviation from the OH reference method makes all RATA results suspect. 
5-4

Table 5-2. Phase 1 Calibration, QC Procedures, and Criteria for Ontario Hydro Sampling Eq

Parameter Calibration technique Reference standard Acceptance limit Frequ

Sampling nozzle Measure 3 diameters to nearest 

0.001 in and average measurements

Micrometer Difference between high and low 

measurements, # 0.004 in

Prior to sam

Dry gas metering system— volume

Compare with calibrated critical orifices, 40 CFR 60, Appendix A, 

Method 5, Section 5.3

Calibrated critical orifice

Difference between individual calibration factor values and average value, # ±0.02

After test se

Use field test data to compute a calibration check value, EPA Method 5, ALT-007

NA Difference between calibration check value 

must be # ±5% of initial calibration factor

After test se

Dry gas meter temperature sensors (thermocouples)

Compare to mercury-in-glass thermometer

ASTM thermometer # ±5.4EF difference from reference Before and a

series

Gas stream (stack) temperature sensor (thermocouple)

Compare to value generated by dry well monitored with potentiometer thermocouple system

Hart Model 9100A dry well calibration system

Difference of # ±1.5% of minimum 

absolute stack temperature from absolute reference temperature (unsaturated gas streams); # ±1EF difference from reference 

(saturated gas streams)

Before and aseries

Final impinger outlet temperature sensor (thermocouple)

Compare to mercury-to-glass thermometer

ASTM thermometer # ±2EF difference from reference Before and a

series

Filter temperature sensor (thermocouple)

Compare to mercury-to-glass thermometer

ASTM thermometer # ±5.4°F difference from reference Before and a

series

Aneroid barometer Compare to calibrated mercury 

barometer

Mercury column barometer

# ±0.1 in Hg difference from reference Before and a

series

Type S pitot tube Measure dimensions according to 

40 CFR 60, Appendix A, Method 2 for baseline coefficient of 0.84

Micrometer and angle finder

Meets dimensional criteria specified in Method 2, Section 6.1 and Figures 2-2 and 2-3

Before and aseries
5-5

Table 5-3. Phase 1 Test Criteria for Emission Measurement and Data Quality 

Test 

parameters Matrix Method of determination Frequency Accuracy objective Precision objectiv

Hg Ontario Hydro train 

samples

Analysis of blank train sample components (field blank)

Once to demonstrate system control (no gross contamination)

Hg levels >30% of measured results must be flagged

Analysis of field reagent solutions (solution blank)

Each time new reagents are prepared

Hg levels >10% of measured results must be flagged

Duplicate train analyses Each run RD must be within 10% of eDuplicate analysis Every sample analyzed Results must be within 10% 

other

Triplicate analysis Every 10th sample 

analyzed

Results must be within 10% other

Matrix spikes Every 10th sample 

analyzed

65%-135% recovery < 40% RPD 

Spiked lab reagent blanks simulating front-half and back-half train components

Two lab control spikes for each component (or combined components) at 10X the estimated detection limit

65%-135% recovery < 40% RPD 

Continuing calibration check Check standard every 

10 samples 

90% to 110% recovery NA 

QC check standard (certified standard, independent of working calibration standards)

After each initial calibration

85% to 115% recovery NA 

Moisture pressure temperature velocity

Gas stream being measured

Secondary technical review of field test data and equipment calibration records relative to EPA Methods 1-5

Ongoing during testing Validated by meeting posttest 

equipment calibration tolerances

NA, but multiple test runs mas indication of overall operavariability

Analysis of ambient air Once prior to bag 

sample analysis

±0.2 percent by volume for ambient air oxygen

O2 and CO2 by Method 3B criteria 

Orsat

Gas bag samples

Triplicate analysis of bag samples Each bag sample NA Method 3B criteria 

Note 1 Mercury was reported in filter blank results at 0.017 μg. This level was > 30% of sample results for 5 of 24 filter samples. Mercury was also reported in the KCl im

sample values. The reported results have been flagged.

Note 2 Mercury was reported in the HNO3/H2O2 impinger blank result at 0.004 μg. This level was > 10% of sample results for 21 of 24 impinger samples. The reported r

Note 3 Replicate results on approximately 10% of samples submitted were above the ±10% difference criteria. Analytical values for particle-bound samples were near t

significantly impact data quality. The KCl and HNO3/H2O2 impinger samples have been reanalyzed and met the acceptance criteria. The reanalyzed results have 

report.

Note 4 Only a single spiked lab reagent blank was performed and showed 98% recovery.

Note 5 A filter sample and a H2O2 impinger sample were slightly outside of the acceptance criteria at 86% and 112%, respectively. 

Note 6 The RD was not met for 4 of the 12 runs. Runs 3, 6, and 12 had RDs of 13%, 13%, and 15%, respectively. Run 4 had an RD of 12% and variations of the train a

the Relative Accuracy calculations. 

Note 7 A method deviation (omission of clarification step of KMnO4/H2SO4 sample prep) makes all results for this sample fraction suspect. 
 5-6

Table 5-4. Phase 1 RA Blank Analysis Results 

Description 

Hg 

result 

Detection 

limit 

(μg) 

Field Blank Train (μg) 

 Filter 0.017 0.005 

 Probe Rinse < 0.006 0.006 

 0.1 N KCl (Impingers 1-3) 0.475 0.010 

 5% HNO3/10% H2O2 (Impinger 4) 0.014 0.007 

 4% KMnO4/10% H2SO4 (Impingers 5-7) 0.014 0.020 

 

Field Solution Blanks 

 Filter (μg) < 0.005 0.005 

 0.1 N HNO3 (μg) < 0.005 0.005 

 0.1 N KCl (μg) 0.002 0.001 

 5% HNO3/10% H2O2 (μg) 0.004 0.002 

 4% KMnO4/10% H2SO4 (μg) < 0.001 0.001 

 10% Hydroxylamine (μg/mL) * 0.0157 0.020 

 

Laboratory Method Blanks (μg) 

 Filter < 0.0010 0.001 

 0.1 N HNO3 < 0.0010 0.001 

 0.1 N KCl < 0.0200 0.001 

 5% HNO3/10% H2O2 < 0.0010 0.001 

 4% KMnO4/10% H2SO4 < 0.0200 0.0011 

* At 0.0157 μg/mL, estimated maximum amounts in the KCl and KMnO4 impingers 

are 0.002 μg and 0.008 μg, respectively. 

Results shown in bold have values > 10 times the detection limit. 
 5-7

Results for three of the six solution blanks indicated detectable levels of mercury, 

with hydroxylamine result at greater than 10 times the detection limit. The blank results 

for hydroxylamine are shown in units of μg/mL because the amount used per train 

component varied. The maximum amounts estimated to have been used in the KCl and 

KMnO4 impingers were around 0.2 mL and 0.5 mL, respectively. Therefore, the 

estimated maximum amounts of mercury contributed to those train components was 

0.002 μg and 0.008 μg, respectively. 

Replicate Sample Analyses

Percent differences for duplicate and triplicate analysis are shown in Table 5-5. 

Approximately 10% of the sample replicates had > 10% difference. These samples were 

reanalyzed and the revised results were within the acceptance criteria. 

Spikes and Audit Sample

Matrix spike results are found in Table 5-6. All of the matrix spikes met the QA 

criteria of ±10%. Also, the audit sample result was within the QC criteria. The blank 

spike was only performed on the filter portion of the train and analyzed once. However, 

the percent recovery was within the accuracy objective. 

Continuing Calibration Checks 

Results of continuing calibration checks are provided in Table 5-7. All of the 

calibration checks met the ±10% criteria with the exception of two (a filter and a H2O2

impinger sample) which were slightly outside those criteria at 86% and 112%, 

respectively. 
 5-8

Table 5-5. Percent Difference for Phase 1 Mercury Analysis Results 

Percent Difference (%) 

Particle bound Oxidized Elemental 

 Field ID Lab ID Filtera Probe 

rinse 

KCl 

Iipingers 

HNO3/H2O2

Impinger 

KMnO4/H2SO4

Impingers 

Run 1 Lab 1 N/A a N/A 8% 0% 1% 

Run 1 dup train Lab 2/3 N/A N/A 3% 8% 1% 

 

Run 2 Lab 4 N/A N/A 1% 2% 1% 

Run 2 dup train Lab 5 N/A 9% 5% 10% 7% 

Run 3 Lab 7 N/A 0% 2% 3% 1% 

Run 3 dup train Lab 8 N/A 0% 3% 0% 1% 

Run 4 Lab 9 N/A N/A 1% 8% 1% 

Run 4 dup train Lab 10 N/A N/A 3% 0% 3% 

Run 5 Lab 11 N/A N/A 4% 10% 9% 

Run 5 dup train Lab 12 N/A 7% 3% 10% 6% 

Run 6 Lab 13 N/A N/A 0% 4% 1% 

Run 6 dup train Lab 14/15 N/A N/A 3% 7% 1% 

 

Run 7 Lab 16 N/A 5% 1% 0% 2% 

Run 7 dup train Lab 17 10% 5% 3% 7% 6% 

 

Run 8 Lab 19 7% N/A 0% 0% 1% 

Run 8 dup train Lab 20 0% N/A 1% 0% 2% 

 

Run 9 Lab 21 N/A 8% 3% 0% 2% 

Run 9 dup train Lab 22 N/A 4% 1% 0% 3% 

 

Run 10 Lab 23 N/A 8% 2% 3% 0% 

Run 10 dup train Lab 24 N/A N/A 2% 0% 0% 

 

Run 11 Lab 25 0% N/A 3% 0% 2% 

Run 11 dup train Lab 26/27 N/A 6% 1% 7% 2% 

 

Run 12 Lab 28 N/A 0% 2% 8% 1% 

Run 12 dup train Lab 29 N/A 5% 1% 8% 0% 

Field Blank Lab 31 N/A N/A 0% 0% N/A 

Blank Train Lab 32 6% N/A 0% 0% 0% 

The QA objective is < 10% Difference [%Diff = (1 – (Analysis 1 / Analysis 2) ) * 100; for triplicate analysis, the 

values with greatest difference are used]. 

a

 An "N/A" indicates that Percent Difference calculation is not applicable due to one or more value below 

being the detection limit. 

Values shown in bold did not initially meet the ≤ 10% Diff. objectives and were reanalyzed; reanalysis results are 

reported. 
 5-9

Table 5-6. Phase 1 RA Spike and Audit Sample Results 

Spike recoveries (as % of spiked) 

Particle bound Oxidized 

Field ID Lab ID Filter Probe rinse KCl imp. HNO3/H2O2 im

Spiked 

(μg) 

Found 

(μg) % Rec.

Spiked 

(μg) 

Found 

(μg) % Rec.

Spiked 

(μg) 

Found 

(μg) % Rec.

Spiked 

(μg) 

Found 

(μg) % 

Matrix SpikeRun 2 Lab 6 0.0250 0.0262 105% 0.025 0.025 99.2% 0.250 0.268 107% 0.025 0.024 Run 7 Lab 18 0.0250 0.0253 101% 0.025 0.025 100% 0.250 0.241 96.4% 0.025 0.023 Run 12 Lab 30 0.0250 0.0243 97.2% 0.025 0.025 100% 0.250 0.267 107% 0.025 0.023 

RPD: 8% RPD: 1% RPD: 10% RPD: 7% 

Blank Spike

0.0200 0.0196 98.0% Not performed Not performed Not performed 

Audit (QC Check) Sample Audit Amount (μg) Amount Found (μg) % Rec. 1020 Lab 34 2.8 2.65% 94.6% % Recovery = (Amount Found in Spiked Sample – Average Amount Found in Unspiked Sample) / Amount Spiked x 100. 

Values shown in bold do not meet the QA objectives. 
 5-10

Table 5-7. Phase 1 Continuing OH Calibration Check Standards 

Spike recoveries (as % of spiked) 

Particle bound Oxidized Elemental 

Filter Probe rinse KCl imp. HNO3/H2O2 imp. 

Spiked 

(μg) 

Found 

(μg) % Rec. 

Spiked 

(μg) 

Found 

(μg) % Rec.

Spiked 

(μg) 

Found 

(μg) % Rec.

Spiked 

(μg) 

Found 

(μg) % Rec.

Spik

(μg

0.005 0.0051 102% 0.005 0.0048 96% 0.250 0.246 98% 0.005 0.005 102% 0.250.005 0.0046 92% 0.005 0.0052 104% 0.250 0.240 96% 0.005 0.005 104% 0.250.005 0.0045 90% 0.005 0.0050 100% 0.250 0.234 94% 0.005 0.005 108% 0.250.005 0.0048 96% 0.005 0.0053 106% 0.250 0.248 99% 0.005 0.005 98.0% 0.250.005 0.0046 92% 0.005 0.0054 108% 0.250 0.228 91% 0.005 0.005 92.0% 0.250.005 0.0046 92% 0.005 0.0053 106% 0.250 0.249 99% 0.005 0.005 94.0% 0.250.005 0.0046 92% 0.005 0.0051 102% 0.250 0.242 97% 0.005 0.005 96.0% 0.250.005 0.0053 106% 0.005 0.0054 108% 0.250 0.248 99% 0.005 0.006 112% 0.250.005 0.0043 86% 0.005 0.0051 102% 0.250 0.243 97% – – – 0.250.005 0.0046 92% 0.005 0.0051 102% – – – – – – – 0.005 0.0045 90% 0.005 0.0052 104% – – – – – – – 

Note: Accuracy objective is 90% to 110% recovery. Values in bold are outside the objective. 
 5-11

5.1.5 Phase 1 Summary 

QA audits were carried out for the manual Ontario Hydro Method and the CEMS. 

Sampling procedures and analytical data were evaluated against the quality objectives 

presented in the QAPP and the Site Specific Test Plan. 

The Ontario Hydro data did not meet the data quality and measurement criteria for 

this work assignment as described earlier in Section 5.1.1 and 5.1.4.1. The omission of a 

critical sample preparation step in the laboratory causes concerns regarding the OH data 

quality. 

Two CEMS met the Part 75 data quality and measurement criteria. The remaining 

two CEMS did not meet all the criteria. 

An assessment of the overall quality of the data generated for Phase 1 was conducted 

and the OH data were found to be suspect. The data assessment included a review of the 

sample collection preparation and analysis data. 

5.2 Phase 2 Certification Testing 

5.2.1 QA/QC Issues 

Because the Phase 2 Relative Deviation (RD) for KMnO4/H2SO4 replicate impinger 

samples was unexplainably large (seven out of 12 replicate results had an RD larger than 

16%, with the highest at 47% RD), these samples were reanalyzed. When the reanalyzed 

results were also unexplainably large with no reproducibility between the first and second 

analyses, the contract laboratory was questioned and it was discovered that the brown 

residue found in the KMnO4/H2SO4 impinger samples had not been clarified prior to 

extracting an aliquot for analysis. This is a critical step which affects the analytical 

accuracy and precision. 

Because the highest amount of mercury is found in the KMnO4/H2SO4 impingers, 

with much of it located in the brown residue on the side of the sample bottle, all 

KMnO4/H2SO4 impinger results had to be considered nonrepresentative of the samples. A 

second laboratory (ARCADIS G&M, Inc.) was contracted to reanalyze the remaining 

KMnO4/H2SO4 samples from Phase 2 sampling (Phase 1 samples had long since been 

discarded). The four KMnO4/H2SO4 samples which had been spiked were missing a 100-

mL to 200-mL volume with no corresponding analytical data. This is likely because the 

original laboratory often prepares extra aliquots in case there is some problem with 

preparation. The laboratory did provide some additional analytical spike data, but it was 

not sufficient to account for the missing 100-mL to 200-mL volume. 

In order to determine the mercury values for the KMnO4/H2SO4 samples, the 

analytical results for each aliquot (as reported by the original laboratory) was multiplied 

by the aliquot volume, then summed and added to the ARCADIS labs’ analytical result 
 5-12

times the remaining sample volume to obtain a total mass. Because the four spiked 

samples from the original laboratory were missing an additional 100-mL to 200-mL of 

sample, those results are biased low since the unknown amount of mercury in those 

missing volumes cannot be added to the total. 

The analytical results from the Phase 1 KMnO4/H2SO4 samples must be considered 

suspect and the difficulties discussed above would account for the difficulty in meeting 

the RD criteria of < 10% RD. Because the Phase 2 KMnO4/H2SO4 samples were 

reanalyzed, these results were mostly salvageable, with the exception of the spiked 

samples (Runs 2, 7, 10, and 12) which are biased low because a significant volume of the 

sample was missing prior to reanalysis. 

The field blank HNO3/H2O2 impinger results for mercury were > 30% of field 

sample results. However, since the elemental mercury captured in the HNO3/H2O2

impinger comprises on average < 3% of the total captured mercury, the impact was 

minimal. 

The RD criterion of ≤ 10% RD was met for 8 of the 12 runs. A review of other 

sampling parameters (O2, CO2, and H2O) were within 8% of each other for all runs and 

do not appear to have contributed to the RD values. Despite the large RD observed for 

the OH method results, three CEMS had differences less than 1 μg/m3 as compared to 

the OH results for all 12 runs. 

5.2.2 Hg CEMS Emission Measurement and Data Quality Objectives 

The QC procedures, acceptability limits, and calibration results are presented in 

Table 5-8. Detailed results were presented in Section 4 of this report. 

5.2.3 Ontario Hydro Sampling Equipment Calibration 

QC procedures, acceptability limits for sampling equipment calibrations, and 

calibration results are presented in Table 5-9. Calibration data sheets and equipment 

condition checklists used during calibration are provided in Appendix C of Volume 3 of 

this report. Equipment used for sample analysis was calibrated according to the 

procedures in the approved methods and manufacturers’ manuals. 
5-13

Table 5-8. Summary of Phase 2 CEMS Certification Criteria 

Criteria 

Test Method of determination Frequency Criteria Durag Opsis 

7 Day Calibration Error Test 

Once per day for 7 consecutive days 

At 24-hr intervals for 7 consecutive days 

Error must be ≤ 1 μg/m3

(alternative when span is defined at 10 μg/m3). Y Y 

Linearity Test At beginning of test 

program, then quarterly 

Once, at beginning of test program 

Error must be ≤ 10% or ≤ 1 μg/m3, 

whichever is least restrictive. 

N N 

Cycle Time Test 

Once, at beginning of test program 

Once, at beginning of test program 

Cycle times must be ≤ 15 minutes. 

Y Y 

System Integrity Test 

At beginning of test program, then weekly 

Once, at beginning of test program 

Error must be ≤ 5% of span from 

certified gas value (i.e., within ± .5 μg/m3 of certified gas value). Yc Yb 

Measurement Error Test 

Performance of Linearity and Converter Efficiency tests 

Once, at beginning of test program 

Error must be ≤ 5% of span from certified gas value (i.e., within ± .5 μg/m3 of certified gas value). Ya N 

Zero and Upscale Drift Test 

Determine magnitude of drift at 24hr intervals 

7 consecutive days 

Error must be ≤ 5% of span (i.e., 

within ± 0.5 μg/m3 of certified gas 

value). Y N 

Relative Accuracy (RATA)d

One set of 12 test runs, at beginning of test program, and again after 6 months 

After certification checks ≤ 20%; or, for low emitters with 

avg conc < 5 μg/m3, ≤ 1 μg/m3

difference. Y Y 

a Passed first of two tests in July. b Passed the test performed in June. c Passed the test performed in May. d A method deviation with missing sample volume caused Runs 2, 7, 10, and 12 to be biased low which resulted in la

acceptable RD values and suspect data for these Reference Method results. 
5-14

Table 5-9. Phase 2 Calibration, QC Procedures, and Criteria for Ontario Hydro Sampling Eq

Parameter Calibration technique Reference standard Acceptance limit Frequ

Sampling nozzle Measure 3 diameters to nearest 

0.001 in and average measurements

Micrometer Difference between high and low 

measurements, # 0.004 in

Prior to sam

Dry gas metering system— volume

Compare with calibrated critical orifices, 40 CFR 60, Appendix A, 

Method 5, Section 5.3

Calibrated critical orifice

Difference between individual calibration factor values and average value, # ±0.02

After test se

Use field test data to compute a calibration check value, EPA Method 5, ALT-007

NA Difference between calibration check value 

must be # ±5% of calibration factor

After test se

Dry gas meter temperature sensors (thermocouples)

Compare to mercury-in-glass thermometer

ASTM thermometer # ±5.4EF difference from reference Before and a

series

Gas stream (stack) temperature sensor (thermocouple)

Compare to value generated by dry well monitored with potentiometer thermocouple system

Hart Model 9100A dry well calibration system

Difference of # ±1.5% of minimum 

absolute stack temperature from absolute reference temperature (unsaturated gas streams); # ±1EF difference from reference 

(saturated gas streams)

Before and aseries

Final impinger outlet temperature sensor (thermocouple)

Compare to mercury-to-glass thermometer

ASTM thermometer # ±2EF difference from reference Before and a

series

Filter temperature sensor (thermocouple)

Compare to mercury-to-glass thermometer

ASTM thermometer # ±5.4°F difference from reference Before and a

series

Aneroid barometer Compare to calibrated mercury 

barometer

Mercury column barometer

# ±0.1 in Hg difference from reference Before and a

series

Type S pitot tube Measure dimensions according 

to 40 CFR 60, Appendix A, Method 2 for baseline coefficient of 0.84

Micrometer and angle finder

Meets dimensional criteria specified in Method 2, Section 6.1 and Figures 2-2 and 2-3

Before and aseries
 5-15

5.2.4 Ontario Hydro Emission Measurement and Data Quality Objectives 

Specific QC procedures were followed to ensure the continuous generation of useful 

and valid data. Table 5-10 presents a summary of criteria for assessing overall emission 

measurement and data quality for the RATA test. Section 6.4.1 presents a brief summary 

of the QA sample results for the RATA. All samples were analyzed within the 28-day 

holding time; however, shipping and storage temperatures for HNO3/H2O2 and 

KMnO4/H2SO4 samples could not be verified. 

5.2.5 QA Sample Results 

It was discovered very late in the test program that the laboratory did not perform the 

Ontario Hydro method closely. They had not cleared the brown residue found in 

KMnO4/H2SO4 impinger samples prior to extracting an aliquot for analysis. This is a 

critical step which greatly affects the analytical result. As soon as MRI was made aware of 

this method deviation, a second laboratory was contacted to reanalyze the KMnO4/H2SO4

samples. Four of the 12 runs were not completely reanalyzed (see discussion in 5.2.1). 

Omission of this step adversely affects both precision and accuracy. For that reason, the 

elemental mercury from the Run 2, 7, 10, and 12 KMnO4/H2SO4 samples are considered 

biased low and are suspect. More information on this method deviation was provided in 

Section 5.2.1. 

Blanks 

Results of blank analysis are shown in Table 5-11. Results for the filter, HNO3/H2O2, 

and KMnO4 field blank train components indicated detectable levels of mercury, with the 

HNO3/H2O2 impinger result at greater than 10 times the detection limit. Results from 

blank train analysis showed that mercury levels were > 30% of sample results for 

HNO3/H2O2 impingers for all runs except Run 1. Mercury levels were also > 30% of 

sample results for 5 of the 24 filters. These sample results have been flagged. 

Results for three of the six solution blanks indicated detectable levels of mercury. 

The blank results for hydroxylamine are shown in units of μg/mL because the amount 

used per train component varied. The maximum amount estimated to have been used in 

the KCl and KMnO4 impingers were around 0.2 mL. Therefore, the estimated maximum 

amount of mercury contributed to the train components was 0.00004 μg. 

Replicate Sample Analyses

Percent differences for duplicate and triplicate analysis are shown in Table 5-12. The 

Run 11 filter and the Solution Blank HNO3/H2O2 impinger sample replicates had > 10% 

difference. These samples were not reanalyzed. 
5-16

Table 5-10. Phase 2 RA Test Criteria for Emission Measurement and Data Quality 

Test 

parameters Matrix Method of determination Frequency Accuracy objective Precision objectiv

Hg Ontario Hydro train 

samples

Analysis of blank train sample components (field blank)

Once to demonstrate system control (no gross contamination)

Hg levels >30% of measured results must be flagged

Analysis of field reagent solutions (solution blank)

Each time new reagents are prepared

Hg levels >10% of measured results must be flagged

Duplicate train analyses Each run RD must be within 10% of e

9 or 12 runs 

Duplicate analysis Every sample analyzed Results must be within 10% 

other

Triplicate analysis Every 10th sample 

analyzed

Results must be within 10% other

Matrix spikes Every 10th sample 

analyzed

65%-135% recovery < 40% RPD 

Spiked lab reagent blanks simulating front-half and back-half train components

Two lab control spikes for each component (or combined components) at 10X the estimated detection limit

65%-135% recovery < 40% RPD 

Continuing calibration check Check standard every 

10 samples 

90% to 110% recovery NA 

QC check standard (certified standard, independent of working calibration standards)

After each calibration 85% to 115% recovery NA 

Moisture pressure temperature velocity

Gas stream being measured

Secondary technical review of field test data and equipment calibration records relative to EPA Methods 1-5

Ongoing during testing Validated by meeting posttest 

equipment calibration tolerances

NA, but multiple test runs mas indication of overall operavariability

Analysis of ambient air Once prior to bag 

sample analysis

±0.2 percent by volume for ambient air oxygen

O2 and CO2 by Method 3B criteria 

Orsat

Gas bag samples

Triplicate analysis of bag samples Each bag sample NA Method 3B criteria 

Note 1 Mercury was reported in the HNO3/H2O2 impinger results at > 30% of Runs 2-12 sample values. The reported results have been flagged. Note 2 Mercury was reported in the HNO3/H2O2 impinger blank result at 0.006 μg. This level was > 10% of sample result for one impinger sample from Run 6. The repo

Note 3 The RD was met for only 4 of the 12 runs. Note 4 Replicate results for Run 11 filter and field blank train HNO3/H2O2 impinger were > 10% of each other. These samples were not reanalyzed. 

Note 5 Recoveries were outside criteria for one HNO3/H2O2 impinger and for two KMnO4/H2SO4 impingers. The RPD was outside criteria for the HNO3/H2O2 and KMnO

Note 6 A method deviation with resultant missing sample volume caused Runs 2, 7, 10, and 12 to be biased low, which resulted in suspect data for these Reference Me
 5-17

Table 5-11. Phase 2 Blank Analysis Results 

Description 

Hg 

result 

Detection 

limit 

(μg) 

Field Blank Train-2 (μg) 

 Filter 0.006 0.001 

 Probe Rinse < .007 0.001 

 0.1 N KCl (Impingers 1-3) < .012 0.001 

 5% HNO3/10% H2O2 (Impinger 4) 0.032 0.001 

 4% KMnO4/10% H2SO4 (Impingers 5-7) < .016 0.0011 

 

Field Blank Train-4 (μg) 

 Filter 0.010 0.001 

 Probe Rinse < .008 0.001 

 0.1 N KCl (Impingers 1-3) < .014 0.001 

 5% HNO3/10% H2O2 (Impinger 4) 0.057 0.001 

 4% KMnO4/10% H2SO4 (Impingers 5-7) 0.019 0.0011 

 

Field Solution Blanks 

 Filter (μg) < .005 0.001 

 0.1 N HNO3 (μg) < .006 0.001 

 0.1 N KCl (μg) < .001 0.001 

 5% HNO3/10% H2O2 (μg) 0.006 0.001 

 4% KMnO4/10% H2SO4 (μg) 0.003 0.0011 

 10% Hydroxylamine (μg/mL) * 0.0002 0.0008 

 

Laboratory Method Blanks (μg) 

 Filter < .005 0.001 

 0.1 N HNO3 < .001 0.001 

 0.1 N KCl (low calibration curve) < .001 0.001 

 0.1 N KCl (high calibration curve) < .02 0.019 

 5% HNO3/10% H2O2 < .001 0.001 

 4% KMnO4/10% H2SO4 (low calibration curve) < .001 0.0011 

 4% KMnO4/10% H2SO4 (high calibration curve) < .02 0.022 
 5-18

Table 5-12. Percent Difference for Phase 2 Mercury Analysis Results 

 Percent Difference (%) 

 Particle Bound Oxidized Elemental

 Probe KCl HNO3/H2O2 KMnO4/H2SO4

Field ID Filter a rinse impingers impinger impingers 

Run 1 0% 0% 1% 1% 2% 

Run 1 dup train 5% 9% 2% 1% 2% 

Run 2 N/A N/A 3% 9% 1% 

Run 2 dup train N/A N/A 3% 2% 0% 

Run 3 N/A N/A 3% 3% 1% 

Run 3 dup train N/A N/A 7% 2% 1% 

Run 4 0% 0% 4% 3% 2% 

Run 4 dup train N/A 0% 4% 3% 5% 

Run 5 N/A 0% 8% 1% 1% 

Run 5 dup train N/A 4% 1% 2% 7% 

Run 6 N/A 4% 2% 2% 3% 

Run 6 dup train N/A 5% 5% 0% 4% 

Run 7 N/A 4% 1% 0% 2% 

Run 7 dup train N/A N/A 6% 1% 3% 

Run 8 N/A 8% 2% 3% 3% 

Run 8 dup train N/A N/A 0% 4% 2% 

Run 9 N/A N/A 0% 4% 0% 

Run 9 dup train N/A N/A 6% 0% 3% 

Run 10 0% 0% 0% 2% 0% 

Run 10 dup train N/A 6% 1% 2% 1% 

Run 11 14% N/A 3% 1% 7% 

Run 11 dup train N/A 5% 8% 2% 3% 

Run 12 N/A N/A 7% 2% 5% 

Run 12 dup train N/A N/A 8% 1% 3% 

Field Solution Blank N/A N/A N/A 20% 0% 

Blank Train-1 N/A N/A 1% 0% 1% 

Blank Train-2 0% N/A N/A 6% N/A 

Blank Train-3 N/A N/A 0% 2% 0% 

Blank Train-4 0% N/A N/A 2% 6% 

Blank Train-5 N/A N/A 1% 2% 1% a

 The Method Blank exceeded 10% of the measured value for all filter results; therefore, 

results should be considered suspect. 

The QA objectives are < 10% Difference [%Diff = (1 - (Analysis 1 / Analysis 2) ) * 100; for 

triplicate analysis, the values with greatest difference are used]. 

Values shown in bold do not meet the QA objectives. 
5-19

Table 5-13. Phase 2 RA Spike and Audit Sample Results 

Spike recoveries (as % of spiked) 

Particle bound Oxidized Ele

Field ID Lab ID Filter Probe rinse KCl imp. HNO3/H2O2 imp. 

Spiked 

(μg) 

Found 

(μg) % Rec. 

Spiked 

(μg) 

Found 

(μg) % Rec. 

Spiked 

(μg) 

Found 

(μg) % Rec. 

Spiked 

(μg) 

Found 

(μg) % Rec. 

Matrix Spike

Run 2 Rep Lab 6 0.0250 0.0245 98.0% 0.025 0.0270 108% 0.250 0.229 91.8% 0.025 0.0236 94.4% Run 7 Rep Lab 18 0.0250 0.0254 102% 0.025 0.0232 92.8% 0.025 0.024 95.2% 0.025 0.0256 102% 

Run 10 Rep Lab 26 0.0250 0.0280 112% 0.025 0.0270 108% 0.025 0.027 107% 0.025 0.0249 100% Run 12 Rep Lab 32 0.0250 0.0273 109% 0.025 0.0243 97.2% 0.025 0.023 91.6% 0.025 0.0247 98.8% 

 RPD: 13% RPD: 16% RPD: 16% RPD: 8% 

Blank SpikeFilter Spike 0.0200 0.0201 100.5% Blank Train-1 Spike < 0.005 none < 0.007 none 0.996 0.860 86.3% 0.050 0.019 38% Blank Train-2 Spike < 0.005 none < 0.007 none 0.996 0.897 90.1% 0.050 0.058 115% Blank Train-3 Spike < 0.005 none < 0.007 none 0.996 0.941 94.4% 0.050 0.113 227%  RPD: 9% RPD: 149% Audit (QC Check) Sample Audit Amount (ng/mL) Amount Found (ng/mL) % Rec. 1017 Lab 40 2.8 2.82 100.7% % Recovery = (Amount Found in Spiked Sample – Average Amount Found in Unspiked Sample) / Amount Spiked x 100. Note: Results outside of QC criteria are shown in bold. 
 5-20

Spikes and Audit Sample 

Matrix spike results are found in Table 5-13. All of the matrix spikes met the QA criteria of 

±10%. Also, the audit sample result was within the QC criteria. Blank spikes for the HNO3/H2O2 

and KMnO4/H2SO4 impingers are noteworthy due to the erratic recoveries and poor precision 

(large RPDs). These samples were reanalyzed along with all of the sample KMnO4/H2SO4

impingers. 

Continuing Calibration Checks 

Results of continuing calibration checks are provided in Table 5-14. All of the calibration 

checks met the ±10% criteria. 

5.2.6 Phase 2 Summary 

QA audits were carried out for the manual Ontario Hydro Method and the CEMS. Sampling 

procedures and analytical data were evaluated against the quality objectives presented in the 

QAPP and the Site Specific Test Plan. 

The Ontario Hydro data met the data quality and measurement criteria for this work 

assignment as described earlier in Section 5.2.1 and 5.2.4.1. None of the CEMS met all of the 

draft PS-12A and Part 75 data quality and measurement criteria. The RD criteria of ≤ 10% for 

four of the 12 OH test runs were not met because of a method deviation by the contract 

laboratory which resulted in data from Runs 2, 7, 10, and 12 being suspect. 

An assessment of the overall quality of the data generated for this work assignment was 

conducted and the data were found to be acceptable for 8 of the 12 Phase 2 RATA runs. Because 

of a method deviation, the data from Runs 2, 7, 10, and 12 are biased low and should be 

considered suspect. 
5-21

Table 5-14. Phase 2 Continuing OH Calibration Check Standards 

Spike recoveries (as % of spiked) 

Particle bound Oxidized Elemental 

Filter Probe rinse KCl imp. HNO3/H2O2 imp. 

Spiked 

(μg) 

Found 

(μg) % Rec. 

Spiked 

(μg) 

Found 

(μg) % Rec.

Spiked 

(μg) 

Found 

(μg) % Rec.

Spiked 

(μg) 

Found 

(μg) % Rec.

Spik

(μg

0.005 0.0048 96.0% 0.005 0.0050 100% 0.005 0.0052 104% 0.005 0.0046 92.0% 0.250.005 0.0049 98.0% 0.005 0.0052 104% 0.005 0.0047 94.0% 0.005 0.0046 92.0% 0.250.005 0.0049 98.0% 0.005 0.0046 92.0% 0.005 0.0051 102% 0.005 0.0049 98.0% 0.250.005 0.0050 100% 0.005 0.0046 92.0% 0.005 0.0048 96.0% 0.005 0.0047 94.0% 0.250.005 0.0054 108% 0.005 0.0052 104% 0.250 0.2592 104% 0.005 0.0047 94.0% 0.250.005 0.0047 94.0% 0.005 0.0048 96% 0.250 0.2595 104% 0.005 0.0055 110% 0.000.005 0.0048 96.0% 0.005 0.0054 108% 0.005 0.0049 98.0% 0.000.005 0.0051 102% 0.005 0.0050 100% 0.005 0.0045 90.0% 0.000.005 0.0050 100% 0.005 0.0055 110% 0.005 0.005 106% 0.00

 0.005 0.0054 108% 0.005 0.004 86.0% 0.25 0.005 0.0054 108% 0.005 0.005 92.0% 0.25

 0.005 0.0050 100% 0.005 0.0054 86.0% 0.25 0.005 0.0052 104%  0.005 0.0049 98.0%  0.005 0.0048 96.0%  0.005 0.0048 96.0%  0.005 0.0051 102% 
 6-1

Section 6. 

Hg CEMS Conclusions and Recommendations 

6.1 Performance Findings 

While all of the Hg CEMS participating in this test program had some difficulty at 

times meeting the certification criteria and providing continuous data, much was learned 

as a result of field evaluation which was evidenced by improvements made to the Hg 

CEMS over the course of this program. Table 6-1 provides an overall summary of the 

Phase 1 and 2 performance results. The ability of each Hg CEMS to provide continuous 

data is summarized in the long-term monitoring summary, Figure 6-1. 

In general, the Hg CEMS consisted of a sample extraction component (probe), a 

sample conditioning component (dilution probe—converter—SO2 neutralizer), and an 

analytical component (CVAA, CVAF, or UV detection). The analytical component of the 

systems is well established and did not generally contribute to measurement problems. 

However, multiple problems were observed with the sample transfer and conditioning of 

the stack gas. The most commonly observed problems related to either physical plugging 

of the probe during sample transfer or fouling of the converter. Often it would take some 

time for this type of problem to be evident. In some cases, more than one attempt was 

necessary to meet performance criteria and system maintenance was required. 

The challenges to the Hg CEMS were more mechanical or physical than chemical. 

These challenges have provided a test bed for Hg CEMS improvement. Also, many of the 

challenges to the Hg CEMS are also applicable to non-mercury continuous emissions 

monitoring systems. 

6.2 Conclusions and Recommendations 

This test program demonstrated that the source characteristics can have a significant 

effect on Hg CEMS performance. Regardless of the vendor supplying the Hg CEMS, the 

CEMS should be appropriately modified for the source. For instance, the source sampled 

for this demonstration project has a wet emission matrix and thus requires an Hg CEMS 

with efficient sample transfer and conditioning capabilities in order to function properly. 

Because of the extent to which source characteristics influence Hg CEMS 

performance, it is suggested that: 

• Potential purchasers review available Hg CEMS performance testing data 

obtained from sources similar to their own. 

• Potential purchasers ask vendors to provide specific experience, including 

ongoing improvements that the vendor has made as a result of their experience 

at similar sources. 
 6-2

Because the source characteristics can greatly affect the performance of the 

Hg CEMS and because it may take some time for problems to manifest, it is also 

suggested that: 

• An Hg CEMS considered for purchase be operated on-site for six months to 

demonstrate its capability to perform (reliability and accuracy) under the 

site-specific conditions before acceptance. 

• The above should be part of a performance warranty agreement. 
6-3

Table 6-1. Summary of CEMS Certification Criteria and Performance 

 Phase 1 Criteria Met? (Y/N) Phase 

Test Criteria Forney Horiba Tekran Thermo Durag O

7 Day Calibration Error Test 

Error must be ≤ 1 μg/m3 (span is defined 

at 10 μg/m3). 

N Y Y Y Y 

Linearity Test Error must be ≤ 10% or ≤ 1 μg/m3, 

whichever is least restrictive. 

N N Y Y N 

Cycle Time Test Cycle times must be ≤ 15 minutes. N N Y Y Y System Integrity Test (includes Converter Efficiency) 

Error must be ≤ 5% of span from certified gas value (i.e., within ±.5 μg/m3 of 

certified gas value). 

N Y Y Y Yd 

Measurement Error Test Error must be ≤ 5% of span from certified 

gas value (i.e., within ±.5 μg/m3 of 

certified gas value). 

N N Y Y Yb 

Zero and Upscale Drift Test Error must be ≤ 5% of span (i.e., within 

±0.5 μg/m3 of certified gas value). 

N Y N N Y 

Relative Accuracy (RATA) ≤20%; or, for low emitters with avg conc 

<5 μg/m3, difference within ±1.0 μg/m3. 

N N Ya Ya Y 

a Using Run 4 Avg. result b Passed the first of two tests performed in July. C Passed the test performed in June. d Passed the test performed in May. 
6-4

Figure 6-1. Phase 1 and 2 Long-Term Monitoring Periods 

Instrument down 

for design upgrade