COST ANALYSIS OF MERCURY

MONITORING TECHNIQUES 

TASK 1: COST OF MERCURY 

MEASUREMENT TECHNIQUES 

DRAFT REPORT, Revision 1 

3 NOVEMBER 2003 

Infrastructure, buildings, 

environment, communications 

 
Cost Analysis of Mercury 

Monitoring Techniques

Task 1: Cost of Mercury 

Monitoring Techniques 

Draft Report, Revision 1 

Brent Hall 

Project Manager 

Carl Singer 

Project Engineer 

Michiel Doorn 

Project Engineer 

Prepared for: 

U.S. Environmental Protection Agency 

Clean Air Markets Division 

Prepared by: 

ARCADIS G&M, Inc. 

4915 Prospectus Drive 

Suite F 

Durham 

North Carolina 27713 

Tel 919 544 4535 

Fax 919 544 5690 

Our Ref.: 

RN096402.0001 

Date: 

3 November 2003 

This document is intended only for the use 

of the individual or entity for which it was 

prepared and may contain information that 

is privileged, confidential, and exempt from 

disclosure under applicable law. Any 

dissemination, distribution, or copying of 

this document is strictly prohibited. 
i 

Table of Contents 

List of Tables iii

List of Acronyms iv

1. Introduction 1

1.1 Scope 1

1.2 Clear Skies Act 2

1.2.1 Common Provisions 3

1.2.2 Mercury Emissions Reductions 4

1.2.3 Performance Standards for New Sources 4

1.3 General Assumptions 4

2. Ontario Hydro (OH) Analysis 7

2.1 Background 7

2.1.1 Scope and Applicability 7

2.1.2 Technique 7

2.1.3 Accuracy and Precision 8

2.2 Assumptions 8

2.3 Capital Costs 8

2.4 Annual Costs 9

2.4.1 Labor Costs 9

2.4.2 Subcontract and Other Direct Costs (ODC) 9

2.4.3 Annualized Capital Costs 10

2.4.4 Total Annualized Cost 10

2.5 Uncertainties 10

3. Carbon Trap Analysis 12

3.1 Background 12

3.1.1 Preliminary Methods 12

3.1.2 Scope and Applicability 14

3.1.3 Technique 14

3.1.4 Accuracy and Precision 16

3.2 General Assumptions 17

3.3 Capital Costs 18

3.4 Annual Costs 19
ii 

Table of Contents 

3.4.1 Labor Costs 19

3.4.2 Subcontract and ODC 20

3.4.3 Annualized Capital costs 20

3.4.4 Total Annualized Costs 20

3.5 Uncertainties 21

4. CEMS Analysis 23

4.1 Background 23

4.1.1 Scope and Applicability 24

4.1.2 Technique 30

4.1.3 Accuracy and Precision 30

4.2 General Assumptions 32

4.3 Capital Costs 33

4.4 Annual Costs 35

4.4.1 Annual Labor Costs 35

4.4.2 Subcontract and ODC 36

4.4.3 Annualized Capital Costs 36

4.4.4 Total Annualized Costs 36

4.5 Uncertainties 37

5. Fuel Analysis 38

5.1 Background and Methods 38

5.1.1 Scope and Applicability 38

5.1.2 Accuracy and Precision 39

5.2 Assumptions 40

5.3 Annual Costs 41

5.3.1 Labor Costs 41

5.3.2 Subcontract and ODC 42

5.3.3 Total Annualized Costs 42

5.4 Uncertainties 43

6. Discussion and Summary 44

6.1 Comparison Carl: please update this section with revised costs. 44

6.2 Barriers to Cost Analysis 45
iii 

Table of Contents 

6.3 Suggestions for Improvements and Additional Research 46

List of Tables 

Table 1-1. Projected Emissions Reductions under Clear Skies Act (EPA, 2002i.) 3

Table 3-1. Draft MQO for Sorbent Total Mercury by internal Frontier Geosciences Method 13

Table 3.2: Assumed Carbon Trap Analytical Summary 18

Table 4-1. Overview of Mercury CEMs that are (expected to be) Commercially Available 

in the United States 25

Table 4-2. Operation & Maintenance 28

Table 4-3. CEMS Capital Cost (March 2003) 33

Table 5-1. ASTM D-3684-01 Bias 39

Table 6-1. Summary of Mercury Annual Analysis Costs 44
iv 

Table of Contents 

List of Acronyms 

ADAES ADA Environmental Solutions 

ASTM American Society for Testing and Materials 

AWMA Air and Waste Management Association 

BACT Best Available Control Technology 

BART Best Available Retrofit Technology 

CAA Clean Air Act 

CEM Continuous Emission Monitor 

CEMS Continuous Emission Monitoring System 

CRM Certified Reference Material 

CVAAS Cold Vapor Atomic Absorption Spectroscopy 

CVAFS Cold Vapor Atomic Fluorescence Spectroscopy 

DOE Department of Energy 

EPA United States Environmental Protection Agency 

EPRI Electric Power Research Institute 

ETV Environmental Test Verification 

ICR Information Collection Request 

IGCC Integrated Gasification Combined Cycle 

LAER Lowest Achievable Emission Rate 

MESA Mercury Speciation Adsorption 
v 

Table of Contents 

MQO Method Quality Objectives 

NAAQS National Ambient Air Quality Standards 

NIST National Institute of Standards & Technology 

NSPS New Source Performance Standard 

NSR New Source Review 

OAQPS Office of Air Quality Planning and Standards 

ODC Other Direct Costs 

OH Ontario Hydro 

PM Particulate Matter 

QA Quality Assurance 

QSEM Quick Silver Emissions Monitor 

RATA Relative Accuracy Test Audit 

RDF Refuse Derived Fuel 

RSD Relative Standard Deviation 

SIP State Implementation Plan 

SOP Standard Operating Procedures 

TSCA Toxic Substances Control Act 

WRAP Western Regional Air Partnership 
1 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

1. Introduction 

1.1 Scope 

Anthropogenic mercury emissions are considered a potential serious health hazard. As 

a by-product of combustion processes, mercury emitted to the air can be transformed 

into the highly toxic methyl-mercury form by means of a natural process in the 

atmosphere. The Mercury Study and the Utility Hazardous Air Pollutant Reports1

 to 

congress have identified coal-fired power plants as the largest anthropogenic source of 

mercury emissions. In December 2000, the United States Environmental Protection 

Agency (EPA) made the determination to regulate mercury emissions from coal-fired 

power plants under section 112 of the Clean Air Act (CAA) Amendments of 1990. 

EPA is required to promulgate mercury emissions standards to electricity generating 

utility boilers by December 2004, to be implemented by December 2007. According to 

the explicit language of the Clean Air Act, these standards must reflect the utilization 

of “Maximum Achievable Control Technology” (MACT) for mercury. 

As a possible alternative the Bush Administration proposed legislation in 2002 under 

the Clear Skies Initiative to establish a flexible, market-based program to reduce and 

cap emissions of sulfur dioxide, nitrogen oxides, and mercury from coal-fired power 

plants and other electric power generators. Such a program is already in place for sulfur 

dioxide and nitrogen oxides under the Acid Rain Program and the NOX State 

Implementation Plan (SIP) Call. 

As part of a mercury control or cap and trade program, EPA will need to implement 

monitoring requirements that are cost-effective, technically viable, contain sufficient 

quality assurance (QA), and are based on technologies and equipment that are 

compliance-capable. Mercury emission reductions under CAA-MACT or under Clear 

Skies may have different monitoring requirements. 

EPA has conducted several studies to describe and compare various mercury 

monitoring technologies, as well as a cost-effectiveness study based on preliminary 

 

1

 U.S. EPA, 1998. Study of Hazardous Air Pollutant Emissions from Electric Utility Steam 

Generating Units – Final Report to Congress. U.S. EPA, Office of Air Quality Planning and 

Standards Research Triangle Park, NC 27711. February 1998. EPA-453/R-98-004a 
2 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

information.2 This report is a continuation of this previous study and provides a 

detailed cost analysis of four mercury-monitoring technologies applicable at coal-fired 

power plants. The technologies are fuel analysis, the American Society for Testing and 

Materials (ASTM) Ontario Hydro (OH) method, iodated carbon traps, as well as 

continuous emissions monitoring systems (CEMS). 

1.2 Clear Skies Act 

The Clear Skies Act would amend Title IV of the CAA to establish new cap-and-trade 

programs requiring reductions of SO2, NOX, and mercury emissions from electric 

generating facilities and amends Title I of the CAA to provide an alternative regulatory 

classification for units subject to the cap-and-trade programs. The market-based 

approach should allow for the implementation of multi-pollutant control systems. Also, 

the ability to carry over unused allowances is believed to create incentives for early 

reductions, delivering environmental and human health benefits sooner, in exchange 

for a longer compliance window for sources. Ultimately, the cap ensures that the 

emission reduction goals are met and maintained. The EPA projects emission 

reductions for SO2, NOX, and mercury of 73, 67, and 69 percent respectively, 

compared to 2000 emissions. Table 1-1 includes projected emissions reductions. The 

Act does not require reductions in CO2 emissions, although there is a provision to 

maintain CO2 monitoring and reporting requirements that currently exist under the 

CAA. 

As revised by the Clear Skies Act, Title IV of the CAA has five Parts. Part A contains 

provisions common to the control of all three pollutants. Part B contains provisions 

specifically for sulfur dioxide emission reductions. Part C contains provisions 

specifically for nitrogen oxides emission reductions. Part D contains provisions 

specifically for mercury emission reductions. Part E contains performance standards 

for affected units and provisions for research, environmental monitoring, and 

assessment. Part E of the Clear Skies Act includes substantial changes in the New 

 

2

 Cadmus Group, 2003. Mercury Monitoring Cost-Effectiveness Analysis. Draft report prepared 

for Ruben Deza, U.S. EPA. Clean Air Markets Division, Washington DC. Prepared by The 

Cadmus Group, 6330 Quadrangle Drive, Chapel Hill. 
3 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

Source Review (NSR) and New Source Performance Standard (NSPS) sections of the 

existing CAA (EPA, 2002i). Below, summaries are provided for Parts A, D, and E. 

1.2.1 Common Provisions 

The Clear Skies Act establishes a new Part A of Title IV of the CAA, which contains 

the program elements shared by the SO2, NOX, and mercury programs. A cap-and-trade 

program will be implemented for each pollutant. Common definitions, allowance 

system procedures, monitoring, permitting and compliance requirements, penalties for 

non-compliance, opt-ins and auction procedures apply to the new trading programs and 

are modeled largely after the existing Acid Rain Program. 

Table 1-1. Projected Emissions Reductions under Clear Skies Act (EPA, 2002i.) 

Actual emissions 

in 2000 

Clear Skies Act emission caps 

Total reduction at full 

implementation First phase of 

reductions 

Second phase 

of reductions 

SO2 (million tons) 11.2 4.5 

(in 20101

) 

3 

(in 20181) 73% 

NOX

2

 (million tons) 5.1 2.1 

(in 20081) 

1.7 

(in 20181) 67% 

Mercury (tons) 48 26 

(in 2010) 

15 

(in 20181

) 69% 

Because sources can reduce emissions early, earn allowances for those actions, and use these 

allowances later, actual emission levels will be higher that the cap in the first years of these 

phases. 

The NOX cap is divided between two zones with separate trading programs under each zone. 

Zone 1 generally includes Eastern states and Zone 2 includes Western states and territories. 

The Administrator must establish an allowance system for SO2, NOX, and mercury that 

is essentially the same as the current Acid Rain Program but provides for a safety 

valve, i.e., a direct sale of allowances by the Administrator at a fixed price for use in 

meeting the requirement to hold allowances at least equal to annual emissions. Criteria 

and the process will be established by which the Administrator may recommend to 

Congress adjustment of the total amounts of allowances available (whether through 

allocation or auction) starting in 2018 under the new SO2, NOX, and mercury trading 

programs. 
4 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

1.2.2 Mercury Emissions Reductions 

The Clear Skies Act establishes Part D, which contains the new, annual caps on total 

mercury allowances and new, allocation procedures starting January 1, 2010. The new 

mercury trading program is analogous to the new SO2 and NOX trading programs and 

cover the same coal-fired units. Annual mercury emissions are capped at 26 tons 

starting in 2010 and 15 tons starting in 2018. Each year, the percentages of allowances 

allocated and auctioned are the same as under the new sulfur and NOX trading 

programs. 

1.2.3 Performance Standards for New Sources 

To ensure that all new affected units have appropriate controls, Part E establishes 

performance standards for all new boilers, combustion turbines, and IGCC plants 

covered under the Act. “New” units are those that commence construction or 

reconstruction after the date of enactment. 

These statutory performance standards include emission limits for four air pollutants: 

NOX, SO2, mercury, and particulate matter (PM). The mercury emission limit applies 

only to coal. In addition, a PM emission limit is established for existing oil-fired boilers 

to ensure reductions of nickel from such units. 

All units subject to a performance standard must monitor emissions using continuous 

emission monitoring systems (CEMS) and use averaging times similar to current 

NSPS. 

1.3 General Assumptions 

The sampling program is assumed to be based on a single stack or single unit testing. 

No discount has been allowed for multiple site testing at a plant or multiple plant 

testing. Multiple units being served by a common stack would be tested under a single 

sampling program. 

For cost estimation, it is assumed that the plant will contract for OH sampling and 

analysis. Costs for the plant to administer the OH analysis program for Hg are based on 
5 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

the Information Collection Request (ICR) supporting statement,3 which assumes the 

following hours on a yearly basis: 

 For obtaining an OH sampling contract, 40 technical hours. 

 For oversight of OH sampling events, 8 technical hours per test. 

 To compile and review analytical data, 8 technical hours per sampling event. 

 To submit test results, 1 technical hour per event. 

 For all technical work, associated management hours have been assumed to total 5 

percent of technical hours and clerical hours have been assumed to total 10 percent 

of technical hours. 

Cost for plant labor hours have been assumed to be the same as used in the ICR 

Supporting Statement: 

Technical hours $47.50, 

Management hours $57.27, and 

Clerical hours $26.96. 

To estimate the cost associated with OH sampling, ARCADIS obtained three estimates 

for a sampling event of three OH runs at one location at a utility stack within 500 miles 

traveling distance from the sampling firm: $8,500,4

 15,000,5 and between 12,000 and 

 

3

“U.S. EPA, “Standard Form 83-1 Supporting Statement for OMB Review of ICR 

No._____:[sic] Information Collection Request for Electric Utility Steam Generating Unit 

Mercury Emissions Information Collection Effort,” November 16, 1998. available at 

http://www.epa.gov/ttn/atw/combust/utiltox/114_ss19.pdf. 

4

 Personal communication from Brian Jacobs, METCO Environmental, to Carl Singer, 

ARCADIS, on March 26, 2003. 

5

 Personal communication from Gene Stephenson, ARCADIS, to Carl Singer, ARCADIS, on 

March 11, 2003. 
6 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

15,0006. The ICR supporting statement contained an estimated cost of $40,020 for 

concurrent OH tests at two locations7

. Consequently, costs for contracting for OH 

sampling and analysis are estimated at $15,000 per sampling event of three tests. It is 

assumed that this number can be broken out as follows: $4,000 for travel and lodging 

of the OH contractor and $11,000 for the three-test event. This can be used to estimate 

the costs of different sampling events. For example, a nine-test event would cost (3 

$11,000) + $4,000 = $37,000. 

 

6

 Personal communication from Ralph Roberson, RMB Consulting, to Carl Singer, ARCADIS, 

on March 11, 2003. 

7

“U.S. EPA, “Standard Form 83-1 Supporting Statement for OMB Review of ICR 

No._____:[sic] Information Collection Request for Electric Utility Steam Generating Unit 

Mercury Emissions Information Collection Effort,” November 16, 1998. available at 

http://www.epa.gov/ttn/atw/combust/utiltox/114_ss19.pdf 
7 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

2. Ontario Hydro (OH) Analysis 

2.1 Background 

The ASTM recently issued the OH method under designation D6784-02 approved 

April 10, 2002. The OH method is a gas sampling method that differentiates mercury 

into particle-bound, oxidized, and elemental fractions. The OH method was widely 

used as the basis for sampling plans under the recent mercury ICR phase III. 

2.1.1 Scope and Applicability 

The OH method is applicable to the determination of elemental, oxidized, particlebound, and total mercury emissions from coal-fired stationary sources. Resulting 

emissions are expressed in concentration terms, μg/Nm3

. Conversion of OH results into 

an annual mass emission will require application of additional methods. 

Though the method explicitly claims applicability to coal-fired stationary sources, the 

method does not appear to exclude the use of other fuels such as coke, orimulsion, oil, 

tires, refuse derived fuel (RDF), or biomass. Use of alternate fuels may produce ash 

that may further confound speciation bias in the OH method but is not expected to 

effect total mercury. 

2.1.2 Technique 

The OH method involves extracting a flue gas sample through either a modified 

method 5 or method 17 sampling train. Sample location and traverse points are 

determined using Methods 1 or 2. Mercury is absorbed from the sample into various 

solutions in the train. The gas volume sampled is metered as the sample exits the 

sampling train. At the conclusion of an integrated sampling event, the train is recovered 

generating analytical samples specific to particular mercury forms. The analytical 

samples are digested and analyzed in a laboratory. 
8 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

2.1.3 Accuracy and Precision 

There are no known biases to the OH method for total Hg, however several conditions 

can affect the speciation of the sample.8

 The relative standard deviations for gas phase 

elemental and oxidized Hg were less than 11 percent for concentrations greater than 3 

μg/m3

 and less than 34 percent for concentrations less than 3μg/m3.

9

 A number of 

revisions to the OH method have been made since the Method 301 evaluation cited in 

the OH method. The precision of the OH method is likely to have improved since the 

initial Method 301 evaluation. 

2.2 Assumptions 

For the purposes of calculating total mercury emissions, 12 OH sampling events are 

assumed with 3 OH tests required for each sampling event. The resulting 36 tests are 

expected to provide an accuracy of ±8.4%, similar to that expected from a nine-point 

Relative Accuracy Test Audit (RATA) for a CEMS. 

For cost estimation, it is assumed that the plant will contract for OH sampling and 

analysis. Further, the sampling program is assumed to be based on each stack such that 

multiple units being served by a common stack would be tested under a single 

sampling program. 

2.3 Capital Costs 

An OH analysis program is likely to be based on sampling after the particulate control 

device and is not expected to result in any significant capital costs. Current stack 

 

8

 D6784-02 Standard Test Method for Elemental, Oxidized, Particle-Bound, and Total Mercury 

in Flue Gas Generated from Coal-Fired Stationary Sources (Ontario Hydro Method), ASTM 

International, West Conshohoken Pennsylvania, June 1, 2002. 

9

 ibid. 
9 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

sampling locations are expected to be adequate for OH sampling and no system 

modifications will be required. 

For purposes of estimation, it is assumed that plants will contract with sampling firms 

for OH sampling. Sampling firms are expected to supply their own sampling 

equipment as part of their cost of doing business. 

2.4 Annual Costs 

2.4.1 Labor Costs 

Costs for administering the OH analysis program are estimated using values from the 

ICR supporting statement.10 The following technical hours have been assumed per 

year: 

 For obtaining an OH sampling contract, 40 technical hours. 

 For oversight of 12 OH sampling events, 288 technical hours. 

 To compile and review analytical data, 96 technical hours. 

 To submit test results, 12 technical hours have been assumed annually. 

Total Technical hours for administration of the program is therefore expected to be 436 

hours per year. Accordingly, labor costs for the Hg analysis program at the stack level 

are estimated at $23,134 annually, including management and clerical costs. 

2.4.2 Subcontract and Other Direct Costs (ODC) 

As indicated in Section 1.1.1 costs for contracting for OH sampling and analysis are 

estimated a $15,000 per sampling event of three tests. Subcontracting and ODC costs 

 

10 U.S. EPA, “Standard Form 83-1 Supporting Statement for OMB Review of ICR 

No._____:[sic] Information Collection Request for Electric Utility Steam Generating Unit 

Mercury Emissions Information Collection Effort,” November 16, 1998. available at 

http://www.epa.gov/ttn/atw/combust/utiltox/114_ss19.pdf. 
10 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

for an OH sampling program incorporating 12 sampling events is, therefore, estimated 

at $180,000 per year for each stack in the program. 

2.4.3 Annualized Capital Costs 

No significant capital costs are expected for an OH based monitoring plan. Annualized 

capital costs are therefore estimated at $0/year. 

2.4.4 Total Annualized Cost 

Total Annualized costs for the OH emissions monitoring plan is estimated at $203,134. 

2.5 Uncertainties 

OH is presumed to be the reference method for potential mercury air emissions 

regulation. The draft performance specification for mercury continuous monitoring 

systems cites 40CFR266, Appendix IX, Section 3.1. Use of different reference 

methods such as Method 29, Method 101A or Method 0060 are not expected to 

drastically affect the cost of each test, however, the monitoring program may require 

adjusting to achieve acceptable accuracy and precision. 

The cost of an OH sampling program for determining emissions is largely driven by 

the frequency of sampling and the number of samples. For this analysis, we have 

assumed triplicate runs of OH on a monthly basis. Sites may require more or fewer 

samples to achieve the same confidence interval depending on the actual variability 

encountered. Variability is expected to arise from unit operation and method chosen for 

analysis. 36 OH runs were selected as a basis assuming a 25% relative standard 

deviation (RSD) and a desired confidence interval of ±8.4%. 

An OH sampling program for determining emissions relies on a representative sample 

being collected. Such a program must be designed to collect a representative sample. 

Confounding factors may include changes in fuel, daily, weekly, and seasonal 

variations in operations, and catastrophic events. If there is significant serial correlation 

in mercury sampling, the number of tests may need to be increased to achieve the same 

confidence interval. 
11 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

While it appears probable that an OH sampling program could be designed to provide 

an accurate estimate of the amount of mercury emitted from a stack, OH sampling may 

be inappropriate for an emission trading program. Specifically, it is doubtful that an 

OH sampling program could provide information with the same timeliness as a Hg 

CEMS. With an OH sampling program, it would be difficult to identify changes in 

emissions resulting from either operational or mechanical changes in the system; 

failure in a control system, such as a carbon injection system, would not likely be 

discernable using OH sampling. The applicability of an OH sample program is 

therefore likely dependent on other records and a workable data substitution 

mechanism. Long intervals between sampling events risk compromising the credibility 

of OH-based emissions estimates. 
12 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

3. Carbon Trap Analysis 

3.1 Background 

The carbon sampling trap method is currently under further development in the U.S. It 

is in the laboratory/pilot phase and is being tested on a limited scale. No references 

were found that support that the method has been applied elsewhere. 

Carbon trap sampling involves drawing a gas sample through traps filled with a 

sorbent, generally activated carbon. Gaseous mercury present in the gas is adsorbed 

onto the carbon. The traps are subsequently removed from the sampling apparatus and 

shipped to a laboratory for analysis. For mercury emissions monitoring, exposure of 

nominally one week is envisioned. 

3.1.1 Preliminary Methods 

Through literature research and industry contacts, two general carbon trap methods 

under development in the U.S. were identified. One method, using intermittent 

integrating technology coupled with Method 101A, is being designed by a team headed 

by Walter S. Smith and Associates, Inc., of Apex, North Carolina. The method is 

described by the developer as a prototype; technical specifics are not available, and no 

tests have been performed.11 The second method is an adaptation by the Electric Power 

Research Institute (EPRI, “the manufacturer”) of a method that was originally 

developed by scientists at Brooks Rand Limited and Frontier Geosciences of Seattle, 

Washington, in 1991.12 The earlier version of the method was identified as Mercury 

Speciation Adsorption (MESA). The most recent adaptation combines a larger version 

of the iodated carbon trap used with the MESA method and a specially designed gas 

meter and probe assembly to provide a cumulative average mercury concentration for 

an extended period (1 week to 1 month). The EPRI method, the Quick Silver 

Emissions Monitor (QSEM), differs significantly from MESA, and no peer-reviewed 

 

11 Personal communication from Walter Smith, Walter Smith Associates, Inc. to Michiel Doorn, 

ARCADIS, by email, June 26 and email June 24, 2003. 

12 Personal communication from Sharon Sjostrom, ADAES, to Michiel Doorn, ARCADIS, by 

email June 24, 2003. 
13 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

publications are yet available. The QSEM is currently undergoing testing in North 

Carolina and Missouri. Several groups are assisting with the development of this 

method under contract to EPRI: ADA Environmental Solutions (ADAES) designed the 

sampling consoles and is currently coordinating the testing efforts and subcontractor 

activities, Frontier Geosciences provides the iodated carbon traps and conducts the trap 

analysis, and Apex Instruments is currently providing the sampling hardware. Results 

from the Missouri/North Carolina field tests are expected in the near future. Additional 

testing is planned for late summer 2003. Draft Method Quality Objectives (MQO) for 

laboratory analysis of the iodated carbon traps for sorbent total mercury are included in 

Table 3-1 below.

Further discussion will only cover the QSEM method. A recent modification (Model 2) 

includes an adapter to allow insertion of a smaller-diameter trap appropriate for a threehour test to allow for better comparison to an OH test. A draft operating manual for 

Model 1 is available from the manufacturer. Also available are two proprietary 

standard operating procedures (SOP). The first SOP addresses total mercury analysis 

by Cold Vapor Atomic Fluorescence Spectroscopy (CVAFS) and is a modified version 

of EPA Method 1631E. The second SOP is entitled “Digestion for Gas/Air Samples 

Collected on Iodated Carbon Traps for Total Mercury Analysis” and is a peerreviewed, published method. A recent change to this SOP consists of shipping the traps 

with gloves to be worn by personnel that work with the traps, to minimize 

contamination.13

Table 3-1. Draft MQO for Sorbent Total Mercury by internal Frontier Geosciences Method 

QA Measurement MQO Value 

Laboratory Replicate ± 25% RPD 

Laboratory SRM Spike Recovery 100 ± 20% 

Lab Analysis Matrix Spike Recovery 100 ± 20% 

Field Sample Spike Recovery 100 ± 30% 

Field Sample Duplicate ± 30% RPD 

Method Detection Limit 0.05 g/m3

 @ 30 liters 0.002 g/m3 @ 1500 liters 

 

13 Personal communication from Sharon Sjostrom, ADAES, to Michiel Doorn, Carl Singer, and 

Brent Hall, ARCADIS, July 7, 2003 
14 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

Advantages of the carbon trap method include ease of operation and a simple 

technology. The method can be cost effective, depending on verification requirements. 

The main disadvantage is that the method provides a delayed, “blanket” cumulative 

average without the possibility to identify peaks or periods with minimal emissions. 

Because continuous information may prove necessary for timely response to control 

device operations, this could be a very important disadvantage. The method is neither 

real-time, nor continuous and, furthermore, is still in the development stages. In 

addition, only one manufacturer in the U.S. can currently offer a pilot-test-ready device 

or the treated traps. 

3.1.2 Scope and Applicability 

Once the carbon trap method has reached commercial status, it should be applicable to 

capturing total mercury with 100 percent efficiency from coal-fired stationary sources. 

The method takes a continuous, cumulative sample over a given time period that can 

range from one hour to one week and possibly up to a month. After this time period the 

trap is exchanged for a fresh one, and the used trap is sent to an off-site laboratory to be 

analyzed according to standard methods.14

For use in wet, saturated environments, the manufacturer has designed a modified tip 

for the trap to minimize wetting by large droplets, as well as a heated carbon trap to 

avoid operational difficulties due to the potential high pressure drop across the trap. 

This modified design has not yet been tested.15

3.1.3 Technique 

The carbon trap technique uses 6 mm or 10 mm diameter cylindrical traps containing 

activated carbon impregnated with potassium iodide to adsorb mercury from flue gas. 

The sampling system consists of a sample probe, Teflon® tubing, a glass wool plug to 

collect PM, a two-part sorbent trap, a sample pump, and a gas meter mounted in a 

 

14 Personal communication from Sharon Sjostrom, ADAES, to Michiel Doorn, ARCADIS, by 

email June 24, 2003. 

15 Personal communication from Sharon Sjostrom, ADAES, to Michiel Doorn, ARCADIS, by 

email June 24, 2003. 
15 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

console. The front section of the sorbent trap is used to chemically adsorb mercury. 

The back section, separated from the front by glass wool, collects any mercury that 

breaks through the front section. The flue gas is extracted through the carbon-packed 

trap where the Hg is adsorbed. The sample pump mounted in the console, along with a 

flow meter and temperature gauges, creates the vacuum on the carbon trap. The flow 

meter can be adjusted to achieve any desired flow rate through the sampling system 

according to the time period of sampling and the flow rate of the stack gas. Typically, 

the carbon trap and the probe that secures it are the only things extending into the flue 

gas path. Once the sample has passed the probe and carbon trap, it travels through a 

heated Teflon line to prevent condensation of any moisture that may build up and cause 

operational difficulties. The sample then travels through a water knockout and drying 

column where the moisture is removed before passing through the sample pump and 

gas meter.

Experiments by the manufacturer have shown that the carbon captures both elemental 

and oxidized mercury with 100 percent efficiency over at least one week for flue gas 

concentrations typical of coal-fired power plants.16 The sampling system can be 

modified to sample isokinetically for particulate mercury as well as gas phase mercury. 

In the current application, the sampling system has been designed to exclude 

particulate Hg collection. However, some incidental PM may collect on the glass wool 

plug prior to the carbon bed. A separate analysis has indicated that particulate Hg is 

less than 1 percent of total Hg in gas streams after a particulate control device, which is 

similar to results reported by the OH Method.17 

The system currently operates by drawing gas continuously through the trap at a 

constant rate. The samples are typically collected for a week, at which time the carbon 

trap is removed, sealed, and shipped to an analytical laboratory, where the mercury is 

leached from the carbon using a strong acid and subsequently analyzed with Cold 

Vapor Atomic Absorption Spectroscopy (CVAAS). 

 

16 Personal communication from Eric Prestbo, Frontier Geosciences, Inc. to Michiel Doorn, 

ARCADIS, email June 25, 2003 

17 Ibid. 
16 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

Research is underway to develop a proportional sampling approach. The new consoles 

being used incorporate a barometric pressure sensor, a digital manometer, and a flow 

control valve. The sampling consoles are designed to monitor the duct flow using a 

standard pitot connected to the digital manometer. Upon installation, the operator can 

configure the sampling console to use either the duct flow measured by the pitot, or an 

external 0-5 volt signal (such as stack flow from the CEMS, or boiler load) to control 

the sample rate set point. The micro controller in the sampling console automatically 

adjusts the sample flow rate based upon the set point signal. The association of the 

control signal (i.e. digital manometer, stack flow, load, etc.) to the sample flow set 

point can be defined by the operator.18

3.1.4 Accuracy and Precision 

The carbon trap is analyzed in an off-site laboratory. Currently, the only laboratory that 

analyzes these traps is Frontier Geosciences. The quantity of mercury is measured 

using a method with a detection limit of 0.5 g/L (5 ppt) in the leachate. Frontier 

Geosciences estimates that this detection limit is equivalent to about 1 g/m3

 for a oneweek sampling period.19 In addition, Frontier Geosciences maintains that they can 

easily match the OH Method for total mercury.20 

There is data available from the MESA method indicating very good accuracy and 

precision. This method employed a solid trap upstream of the activated carbon to 

capture oxidized mercury. Frontier Geosciences suggests that the new Iodated Carbon 

Traps should perform similarly to the carbon portion of the MESA traps and that data 

should be comparable. Recent tests with Iodated Carbon Traps suggest very good 

precision in the laboratory analysis. The manufacturer is using components from 

standard sampling equipment (i.e. calibrated dry gas meters) and expects the total flow 

 

18 Personal communication from Sharon Sjostrom, ADAES, to Michiel Doorn, ARCADIS, by 

email June 24, 2003. 

19 Personal communication from Eric Prestbo, Frontier Geosciences, Inc. to Michiel Doorn and 

Carl Singer, ARCADIS, May 30, 2003 

20 Personal communication from Eric Prestbo, Frontier Geosciences, Inc. to Michiel Doorn, 

ARCADIS, email, June 24, 2003 
17 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

recorded during each sampling run to be within acceptable accuracy. In addition, the 

manufacturer is currently conducting tests to assess the precision and accuracy of the 

current equipment and carbon traps by running duplicate simultaneous samples in 

conjunction with OH testing.

3.2 General Assumptions 

For the purposes of cost estimation, it is assumed that the method will be developed in 

adequate detail for EPA to include carbon traps as an acceptable method of 

determining annual total mercury emissions. We further assume carbon traps will 

typically sample for one week consistent with the current design strategies. A range of 

sampling strategies may prove viable; each with QA/QC adequate to demonstrate 

annual emissions accuracy. 

Since the currently proposed carbon trap techniques utilized fixed point sampling, 

similar to other CEMS measurements covered in Part 75, it is assumed that a QA/QC 

program will be required to ensure representativeness and accuracy for carbon trap 

measurements. The reference method for mercury is assumed to be the OH method. 

While a RATA of carbon traps sampling for one week does not appear practical due to 

widely differing sampling times with OH, a RATA of carbon traps sampling for 3 

hours, using an adapter and smaller traps, is assumed to be adequate for determining 

representativeness and accuracy. For costing purposes, an annual 9-sample RATA 

against OH is assumed. 

In addition to a RATA, it is assumed that some QA/QC program will be implemented 

to ensure accurate emission estimates are made throughout the year. For cost 

estimating purposes, the QA/QC program will consist of 4 quarterly checks of each 

sample gas metering system and 3 quarterly matrix spike checks. The fully developed 

carbon trap technique is assumed to provide proportional sampling of the stack gas; 

auditing of proportionality is assumed to be integral to the monitoring system. 

Accuracy of the total sample volume measurements is expected to be confirmed with 

quarterly calibration of the sample gas metering system. It is assumed that Hg 

concentration accuracy will be confirmed with some form of spiked carbon trap 

analysis. For costing purposes, it is assumed that mercury spiked carbon traps will be 

available and will sample flue gas in parallel with an unspiked carbon trap over the 

typical one-week sampling period. It is further assumed that an unexposed carbon trap 

will be analyzed as a blank on a quarterly basis. 
18 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

It is assumed that carbon trap sampling will be performed in duplicate. If the QA/QC 

validating carbon trap based emission measurements is performed on a quarterly basis, 

failure to meet QA/QC objectives could invalidate a large portion of the annual 

emissions measurement. Replication is one method of ensuring against the need to use 

currently undefined data substitution. Duplication is therefore expected to represent the 

minimum application of replication adequate for QA/QC requirements and reasonable 

data invalidation protection. Assumed annual requirements for carbon trap emission 

measurements are summarized in Table 3.2 

Table 3.2: Assumed Carbon Trap Analytical Summary 

 Carbon Trap Requirements Other QA/QC Requirements 

RATA 9 3-h traps + 1 weekly tube 9 OH runs + 2 gas meter cals 

12 weeks 24 weekly traps 

QA/QC check 1 3 weekly traps: matrix, matrix spike, 

blank 

2 gas meter cals 

12 weeks 24 weekly traps 

QA/QC check 2 3 weekly traps: matrix, matrix spike, 

blank 

2 gas meter cals 

12 weeks 24 weekly traps 

QA/QC check 3 3 weekly traps: matrix, matrix spike, 

blank 

2 gas meter cals 

12 weeks 24 weekly traps 

Annual Total 9 3-h traps + 106 weekly traps 9 OH runs + 8 gas meter cals 

Travel expenses associated with installation, training, and maintenance by the 

manufacturer are not included. Travel expenses associated with the RATA are included 

in the cost of subcontracting. 

3.3 Capital Costs 

Capital costs for a carbon trap system (sampling console, probe, water knockout 

assembly) is approximately $8,500.21 Installation costs (for equipment location, setup, 

 

21 Personal communication from Sharon Sjostrom, ADAES, to Michiel Doorn, ARCADIS, by 

email June 24, 2003. 
19 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

electrical hook-up and probe insertion) are estimated to require two hours of technical 

labor for a total labor cost of $106 per carbon trap system. As two carbon trap systems 

are assumed, total capital costs are estimated at $17,212. 

3.4 Annual Costs 

3.4.1 Labor Costs 

This section addresses annual labor costs for the plant. The following technical hours 

are estimated to be associated with this method on an annual basis: 

 For operations, 4 hours per week per carbon trap system, to remove the used trap, 

install a new trap, mail the used trap to the manufacturer (or other future 

laboratories/providers), and complete associated paperwork. 

 For routine checks, 3 hours per week per carbon trap system (8 minutes per 8-hour 

shift). 

 For carbon trap flow calibration, 2 hours per quarter per carbon trap system 

Accordingly, it is estimated there are 744 technical hours associated with operation of 

two carbon trap systems. 

It is assumed that awarding a contract for carbon trap analysis will require eight 

technical hours. It will also require eight hours to compile an emissions report. As this 

will occur four times annually, it will result in an additional 32 technical hours. Finally, 

it will require one technical hour to submit the report, but again, this will occur four 

times annually, resulting in another four hours. This results in 44 technical hours for 

reporting, or $2,334 annually, including management and clerical labor. Routine 

operations are therefore estimated to require 788 technical hours annually for a cost of 

$41,812 including management and clerical costs. 

 
20 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

Plant labor associated with RATA testing is estimated to require 121 technical hours. It 

will require 40 hours to obtain a contract for RATA testing, 72 hours for oversight of 

nine tests, 8 annual hours to compile and review analytical data, and 1 hour annually to 

submit test results. Plant labor costs for verification testing are estimated at $6,420 

Thus, combined labor costs for routine operation and verification are estimated at 

$48,232 

3.4.2 Subcontract and ODC 

Basic analytical costs performed by the manufacturer to analyze and replace one 

carbon trap are $200.22 These costs include packing the traps with gloves for sample 

handling (installation and removal), data collection and chain of custody forms, and 

post-test analysis. These costs do not include any additional analyses, and the special 

tip for wet-stack applications. For cost estimation purposes, all traps; 3-h, weekly, or 

spiked, are assumed to cost the same $200 for complete turnaround. In addition to the 

above, $20 per week is assumed for shipping and handling (two ways). Based on the 

assumed 115 annual trap requirement, analytical costs are estimated at $24,040 

annually. 

A nine-test OH sampling event is estimated to cost $37,000 to subcontract. 

Estimated total subcontracting costs and ODC are $61,040. 

3.4.3 Annualized Capital costs 

Based on a three-year straight-line depreciation, annualized capital costs are estimated 

at $5737. 

3.4.4 Total Annualized Costs 

Total annualized costs for mercury emissions determination with the carbon trap 

method are estimated at $115,009. 

 

22 Personal communication from Sharon Sjostrom, ADAES, to Michiel Doorn, ARCADIS, by 

email, June 24, 2003. 
21 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

This may be compared to the preliminary cost estimate submitted for the prototype by 

Walter S. Smith and Associates. No tests have been performed, but total annual costs, 

including a lease, are estimated to be less than $50,000. Technical specifics are 

confidential at this point.23 Assuming this technique would be performed in duplicate 

and would require a RATA as well, total annual costs for the Walter S. Smith and 

Associates monitoring technique would be less than $137,000. 

3.5 Uncertainties 

Application of carbon traps for mercury emissions measurements will be dependent on 

continued development and acceptance of the technique as a method. Methods are 

often validated against various spiking techniques or against a standard method. EPA 

acceptance may require such validation on multiple sources, depending on how EPA 

views source categories. 

Implementation of carbon traps for mercury emissions will likely require the 

development of QA/QC procedures and limits as part of published procedures. The 

procedures to be defined include: 

 Leak-check documentation and limits 

 Sample metering calibration 

 Proportional sampling validation 

 Chain of Custody 

 Back-half capture limits 

 Laboratory calibration, continuing calibration verification, independent calibration 

verification 

 Laboratory duplicates 

 

23 Personal communication from Walter Smith, Walter Smith Associates, Inc. to Michiel Doorn, 

ARCADIS, by email, June 26 and email June 24, 2003. 
22 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

 Blanks 

 Carbon tube analytical hold times. 

In addition, methods to audit both sample collection and analysis are likely to be 

crucial to acceptance of the technique. One route to auditing both collection and 

analysis is the development of a standard technique to spike mercury onto a carbon 

trap. Techniques for spiking the carbon traps, either in the field or in the laboratory, 

have been implemented by method developers. 

The effectiveness of the carbon traps depends on various parameters, such as sorbent 

properties, coal type, flue gas conditions and composition, and reaction kinetics. These 

conditions will vary with site configuration and coal composition. Although the 

method does not distinguish between the elemental and oxidized forms of mercury, the 

efficiency of adsorption for both oxidized and elemental mercury must be validated 

over a variety of stack conditions, as well as fly ashes. One method of validation would 

be analysis of duplicates samples, one collected on a clean carbon trap and one 

collected on a mercury spiked carbon trap. 
23 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

4. CEMS Analysis 

4.1 Background 

Hg CEMS are undergoing continuing development, with current technology being 

tested under various programs. Few, if any, applications at coal-fired power plants 

currently exist in the United States, but the technology is developing rapidly. Many 

CEMS have been undergoing field tests, and some have participated in several. Most 

manufacturers are in the process of making significant improvements or refinements to 

their monitors as time proceeds. Consequently, the CEMS information in this report, 

and similar reports, may need to be updated in the relatively short term. 

In Germany, automatic mercury sampling devices have been applied since the early 

1990s. The Federal Republic of Germany issued regulations for both emission limits 

and continuous monitoring of total mercury in incinerator flue gases. Under the 

regulation, CEMS need certification for approval. The German emission limit of 

0.05 μg/m3

 was adopted for the European Union in 1994.24 

CEMS can be classified according to their method of converting oxidized Hg to 

elemental Hg as dry or wet. Wet systems convert Hg in impinger solutions, while dry 

systems thermally or catalytically convert the Hg species. Most CEMS can provide 

speciated Hg emissions values, but the development trend in industry is toward total 

Hg measurement. 

Based on operational experience and industry knowledge, the dry systems appear to 

offer more operational availability and require less maintenance compared to wet 

systems. They provide quick real-time Hg concentrations and many have inherent auto 

zeroing and system checks built into them. The dry systems are easier to operate 

overall and offer a more reliable Hg number because of not having any chemical 

interactions. The disadvantages of wet systems include increased maintenance and 

potential problems with the gas conditioning systems malfunctioning. Also, the 

 

24 Sigl, W., 2000. Continuous monitoring of mercury emissions in combustion flue gases with 

the Hg-CEMS 'MERCEM'. In “Recent advances in the science and management of air toxics”, 

Proceedings of the joint international specialty conference, exhibition and workshop of the Air 

and Waste Management Association, 9 - 12 April 2000, Banff, Canada. 
24 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

solutions used in wet systems may react with flue gas components in unexpected ways. 

Another disadvantage of current wet systems is that they only yield a mercury 

concentration every 4-6 minutes, depending on the cycle set up; they are not truly 

“continuous” Hg monitors. For the purpose of further discussion, only the dry systems 

are addressed. 

It is apparent through the results from each subsequent field evaluation that the 

reliability and accuracy of Hg CEMS has greatly improved. Hg CEMS are viewed as a 

viable choice for Hg monitoring because of the continuous data delivery, as well as 

their improving accuracy. It is anticipated that Hg CEMS would be a preferred method 

of Hg monitoring, provided the costs are comparable to other viable methods. 

For this report and other recent associated draft reports, technical, performance, and 

cost information was requested from 12 vendors. Eleven vendors provided technical 

and performance information, while seven manufacturers responded with cost 

information. Table 4-1 summarizes technical information of 12 different Hg CEMS. 

Table 4-2 includes performance information related to operation and maintenance. All 

data in Tables 4-1 and 4-2 are from manufacturer responses. 

4.1.1 Scope and Applicability 

There is currently no regulatory driver or performance standard for CEMS; although a 

draft performance standard has been developed25 against which Hg CEMS can be 

evaluated. However, quality requirements can not be fully defined at this point. A 

regulation for Hg could, conceivably, require monitoring of elemental, oxidized, or 

total Hg, resulting in different potential equipment needs. 

Hg CEMS could find wide use for monitoring flue gas emissions at coal-fired power 

plants. As indicated earlier, there is widespread use of Hg CEMS in Europe, but mostly 

at municipal, or medical waste incinerators.

 

25 Draft Performance Specification 12 – Specifications and test procedures for total mercury 

continuous monitoring systems in stationary sources. http://www.epa.gov/ttnemc01/propperf/ps12.pdf 
Table 4-1. Overview of Mercury CEMs that are (expected to be) Commercially Available in the United States 

Model Principles of operation Speciation Interferences Zero Drift Calibration Drift Relative Accuracy Field Application US 

Cooper 

X-CMM X-ray fluorescence Total none 

No zero 

adjustment is 

necessary 

Calibration 

every few 

months 

na na 

Durag 

HM-1400 TR 

Dual-Beam CVAAS Total and Elemental None below 1500 ppm SO2 < ±1.5% F.S. per week < ±2 % F.S. per week ± 5% F.S. (total accuracy) none 

Ecochem 

HG - MKII 

CVAAS with gold 

trap 

Total and 

Elemental none 

Uses preset 

intervals with 

alert system 

No information na none 

Envimetrics 

Argus-Hg 

Plasma source 

spectrometer 

Elemental, 

Oxidized na 

No zero 

adjustment is 

necessary 

Automatic 

calibration with 

built-in Hg 

standard 

na na 

Genesis 

Quicksilver 

Sky Monitor 

Dry method 

Particulate, 

Oxidized, 

Elemental 

na na 

No errors, 

proprietary 

technology 

na na 

Nippon26

AM-2/ AM-3 

CVAAS with gold 

trap Elemental 

Cl2 and to a 

lesser extent 

HCl 

Hg0 0.96 g/m3

Hg0 2.93 g /m3

Hg0 18% 

Hg0 16% 

Hg0 14% 

Hg0 23% none 

26 Nippon Instruments Corporation Model AM-2 Elemental Mercury Continuous Emission Monitor; Environmental Technology Verific

Report. U.S. Environmental Protection Agency in cooperation with Battelle, Inc. August 2001. 
Model Principles of operation Speciation Interferences Zero Drift Calibration Drift Relative Accuracy Field Application US 

Nippon27

MS1/DM5 

CVAAS and wet 

scrubbing plus 

chemical for total Hg 

Elemental 

and Oxidized HCl 

‘0.1 g/m3 

‘0.1 ug/m3 

‘0.1 g/m3 ‘0.1 g/m3 

Hg0 14% 

Hg+2 13% 

Hg0 12% 

Hg+2 11% 

HgT 13% 

Hg0 11% 

Hg+2 55% 

HgT 39% 

Hg0 49% 

Hg+2 50% 

none 

Ohio Lumex28

CVAAS, with 

Zeeman highfrequency 

polarization 

background 

correction 

Total and 

Elemental HCl and Cl2

0.20 HgT

0.37 Hg0

2.45 HgT

0.17 Hg0

62% HgT

92% Hg0

24% HgT

18% Hg0

HgT 58% 

Hg0 50% 

Hg+2 99% 

HgT 71% 

Hg0 107% 

Hg+2 69% 

none 

27 Nippon Instruments Corporation Model MS-1/DM-5 Elemental Mercury Continuous Emission Monitor; Environmental Technology 

Verification Report. U.S. Environmental Protection Agency in cooperation with Battelle, Inc. August 2001. 

28 Lumex Ltd. Mercury Continuous Emission Monitor; Environmental Technology Verification Report. U.S. Environmental Protection 

Agency in cooperation with Battelle, Inc. August 2001. 

Table 4-1 continued. 
Model Principles of operation Speciation Interferences Zero Drift Calibration Drift Relative Accuracy Field Application US 

Opsis 

HG200 

Dual beam 

absorption 

photometer 

Total and 

Elemental 

SO2 may be 

issue na na na 

Two test 

sites 

PS 

Analytical29

Sir Galahad II 

Atomic fluorescence 

with gold trap 

Total, 

Oxidized, and 

Elemental 

Elemental: Cl2 0.003 g/m3 0.013 g/m3 12% 11% 

HgT 21% 

Hg0 23% 

Hg+2 27% 

HgT 33% 

Hg0 30% 

Hg+2 33% 

18 units, 

mainly for 

research 

ST2 

SM-3 CVAAS Total SO2 < 1 g/m3 after 1 week of testing See TüV report See page 38 of TüV report none 

Tekran Atomic fluorescence with gold trap Total and Elemental None 

On-line 

automated zero 

and multi-level 

span checks 

Automatic 

recalibration 

using internal 

permeation 

source 

na none 

na = not applicable 

29 PS Analytical Ltd. Sir Galahad II Mercury Continuous Emission Monitor; Environmental Technology Verification Report. U.S. 

Environmental Protection Agency in cooperation with Battelle, Inc. August 2001. 

Table 4-1 concluded. 
Table 4-2. Operation & Maintenance 

Model Principles of operation Operation continued Conditioning System Filter Trap 

Cooper 

X-CMM X-ray fluorescence Works with filter tape No pre-treatment necessary Automatic No 

Durag 

HM-1400 TR 

Dual-Beam CVAAS nav 

Heated lines; 

Thermo-catalytic 

converter 

Particle filter 

Gold trap; C

1x/day by 

Aromatics, S

are interfer

Ecochem 

HG - MKII CVAAS with gold trap nav 

Teflon or heated 

parts; Dry catalytic 

device 

nav Gold trap; De

into pure 

Envimetrics 

Argus-Hg Plasma source spectrometer No chemical reagents 

Solid catalytic 

converter; Peltier 

cooling 

nav -- 

Genesis 

Quicksilver Sky 

Monitor 

Dry method SOX removal by scrubbing -- nav -- 

Nippon 

MS1/DM5 

CVAAS and wet scrubbing 

plus chemical for total Hg nav 

Distilled water 

scrubber; 

Dehumidifier; Two 

coolers 

Dust filter, 

membrane 

filter 

Gold tra

Heater; N

purified 

OhioLumex 

CVAAS, with Zeeman highfrequency polarization 

background correction 

Two-channel instrument “Pyrolyzer” converter 

Particle filter 

and zero Hg 

absorption 

filter 

No gold 
Model Principles of operation Operation continued Conditioning System Filter Trap 

Opsis 

HG200 

Dual beam absorption 

photometer nav 

Dilution system; 

Dry thermocatalytic converter; 

Cooler 

nav Gold tr

PS Analytical 

Sir Galahad II 

Atomic fluorescence with gold 

trap 

Converts Hg into Hg0 with 

aqueous reagent 

Scrubber; Tubing 

and agents 

replaced every 2 

weeks 

Filter 

Gold trap

concentratio

Needs arg

ST2 

SM-3 CVAAS nav nav nav No carrie

Tekran Atomic fluorescence with gold trap Inert probe, dry converter nav nav Gold tr

nav = not available or not provided by the vendor 

Table 4-2 concluded. 
30 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

4.1.2 Technique 

EPA defines the CEMS as “The total equipment required for the determination of a 

pollutant concentration.30” Total equipment includes the major sub-systems such as the 

sampling interface, pollutant analyzer, diluent analyzer, and data recorder. 

Mercury CEMS typically measure only Hg0

 using some variation of CVAAS or 

CVAFS. Many incorporate a process that converts gaseous ionic Hg to gaseous Hg0

, 

resulting in measurements of total gaseous Hg. PM is typically filtered from the sample 

before analysis, which removes particle-bound Hg. This process therefore results in 

underestimates of total Hg; it also may cause bias in speciation and bias in total 

gaseous Hg. Some fly ashes react with Hg, resulting in the oxidation of Hg0

 in the 

probe and on filters, which in turn overestimates ionic Hg. Fly ash may also adsorb or 

desorb Hg, which biases estimates of total gaseous Hg because the ash is not 

subsequently analyzed for Hg. 

The measurement techniques used by CEMS are often affected by common coal 

combustion contaminants. The draft performance specification lists eight potentially 

interfering components: carbon monoxide, carbon dioxide, oxygen, sulfur dioxide, 

nitrogen dioxide, water vapor, hydrogen chloride, and chlorine. Such interferences are 

often dealt with in a manner specific to each CEMS. One common mechanism is to 

amalgamate the Hg on a gold trap and regenerate the mercury captured on the gold trap 

into a carrier gas that is then analyzed. 

4.1.3 Accuracy and Precision 

Evaluation of Accuracy and Precision of Hg CEMS is confounded by the rapid and 

continuing development of Hg CEMs by vendors and the lack of published information 

on CEM performance. Evaluation of the performance of CEMs will improve when 

suitable reference materials or procedures become available. A National Institute of 

 

30 Draft Performance Specification 12 – Specifications and test procedures for total mercury 

continuous monitoring systems in stationary sources. Website: 

http://www.epa.gov/ttnemc01/propperf/ps-12.pdf. 
31 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

Standards & Technology (NIST) approved elemental mercury gas standard is still 

under development. EPA has developed a draft performance specification, PS-12, 

which defines relative accuracy requirements for Hg CEMS measurement along with 

certain other QA requirements; a relative accuracy of 20% is currently specified in 

PS-12. 

EPA’s Office of Research and Development conducted Relative Accuracy tests on four 

Hg CEMs under the Environmental Test Verification (ETV) program in January 2001. 

The ETV program was created to facilitate the use of innovative environmental 

technologies [including continuous emission monitors (CEM)] by testing their 

performance and making the results available to those involved in their design, 

distribution, permitting, purchase, and use. These ETV tests were performed on a pilotscale natural gas-fired combustor.31 As shown in Table 4-1, a vintage 2001 Nippon 

CEMs was able to achieve 13% relative accuracy during the ETV tests. 

Six Hg CEMs were also recently evaluated under the ETV program at a Department of 

Energy (DOE) Toxic Substances Control Act (TSCA) incinerator in Oak Ridge, 

Tennessee; this source category was not pursued as a source of CEM data due to 

expected differences in the flue gas composition. Results from the TSCA incinerator 

were presented at the Air and Waste Management Association (AWMA) conference in 

San Diego.32

EPA’s Office of Air Quality Planning and Standards (OAQPS) is undertaking a series 

of field tests of several mercury CEMs at coal-fired power plants. The first series of 

Relative Accuracy tests at a full-scale coal-fired power plant were conducted in 

October 2002 but are not yet published. OAQPS is currently conducting two Hg CEM 

demonstrations/evaluations at full-scale coal-fired power plants. The results of these 

tests are expected to be available in October 2003. EPRI recently published CEMs 

 

31 Environmental Technology Verification Program. Website: 

http://www.epa.gov/etv/verifications/vcenter1-11.html 

32 Dunn, J.E., et al. 2003. Evaluation of Mercury Continuous Emission Monitors at the U.S. 

DOE TSCA Incinerator. AWMA, 96th Annual Conference, June 22-26, 2003, San Diego, CA. 
32 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

measurements of Hg emissions at several coal-fired power plants; QA information 

regarding the performance of the CEMs was not found in the paper.33

4.2 General Assumptions 

 A three year, straight-line write-off for capital costs is assumed. 

 Capital costs do not include installation costs. 

 Technician training is assumed to be included in capital costs. 

 Costs for utilities (water, electricity, heat, cooling) are not included. 

 Calibration costs have not been included, pending guidance from EPA. None of 

the manufacturers submitted calibration cost information. 

 Because of the trend in the industry, only systems that can measure total Hg are 

considered. This includes systems that can do both total and elemental Hg. 

 The trend in the industry seems to be toward dry systems. The labor, sampling and 

analysis costs reflect estimates for dry systems only, while the capital cost analysis 

includes all systems. 

Similar to the performance verification of SO2 monitors, it is assumed that the plant 

would perform one RATA annually using the OH method, consisting of nine (9) tests, 

as well as perform three (3) cylinder audits on the Hg CEMS. The cylinder audits are 

assumed to be performed by the plant. A cylinder audit would typically require using a 

certified gaseous elemental Hg standard and introducing this gas through the probe or 

directly to the detector and the entire sampling system. This would facilitate 

determining if there were any bias being imparted by the sampling systems as opposed 

to the detector. It is assumed that the cylinder audits could be performed by the plant 

personnel with the procurement of a gas standard. 

 

33 Chu, Paul, et al., Characterization of “Longer Term” Mercury Emissions from Coal-Fired 

Power Plants, 2003 MEGA Symposium, Washington, DC. 
33 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

4.3 Capital Costs 

Capital costs for CEMS that are available on the U.S. market, or that are expected to be 

available soon, are listed in Table 4-3. This information was collected through an email 

request and ensuing telephone conversations with individual vendors. Costs have been 

standardized to the extent possible to reflect a complete CEMS and to exclude 

installation. Capital costs are especially dependent on the configuration of the system. 

Also, the systems differ in both basic and ancillary supporting technology. For several 

vendors, these costs are preliminary. 

Table 4-3 includes 15 entries representing CEMS from 11 manufacturers. When a 

manufacturer provided a large range for capital cost, as was the case with Genesis and 

OhioLumex, both the low-end and the high-end estimate were included in the table and 

in the summary calculations. In other words, the submittals were regarded as separate 

instruments. The Nippon MS-1A instrument was excluded because it can not measure 

total mercury. 

Table 4-3. CEMS Capital Cost (March 2003) 

Vendor Name Model Capital Cost Notes Mercury System Type 

Dry Systems:

Cooper 

Environmental 

Services 

X-CMM $100,000 

Estimate for complete 

system. Filters would cost 

around $5,000 per year. 

Total 

Dry, 

uses filter 

tape 

Durag HG-1400 TR $45,000 

Does not include heated 

sample line. Heated probe 

of $3,000 is optional. 

Speciating Dry 

Ecochem HG-MKII $59,400 -- Speciating Dry 

Envimetrics Argus-Hg 

1000 $54,200 

Estimate. Includes sample 

probe, heated sample line 

and controller. 

Speciating Dry 

Genesis 

Laboratory 

Systems 

Quicksilver 

Sky Monitor $35,000 

Estimate for CEM ($20,000) 

plus low-end gas 

conditioning system. 

Speciating Dry 

Genesis 

Laboratory 

Systems 

Quicksilver 

Sky Monitor $85,000 

Estimate for CEM ($20,000) 

plus high-end, specialized 

gas conditioning system. 

Speciating Dry 
34 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

Vendor Name Model Capital Cost Notes Mercury System Type 

OhioLumex CEM $40,000 

Low-end estimate. “CEM, 

based on AA with Zeeman 

correction for interferences, 

dry converter system, total 

Hg, detection limit- 0.1 

μg/dscm. Installation is not 

included.” 

Speciating Dry 

OhioLumex CEM $60,000 High-end estimate. Speciating Dry 

Opsis HG200 $80,000 

Basic instrument: $30k, 

Basic instrument (30k) with 

converter ($50k) and 

conditioning system. 

Speciating Dry 

ST2 Service 

Technologies SM-3 $47,666 Complete system, simple probe. Total Dry 

Tekran $85,000 Preliminary estimate Speciating Dry 

(Semi-)wet systems

Nippon 

Instruments DM-6 $38,000 Standard gas generator and 

KOH scrubber an optional Speciating Semi-dry 

Nippon 

Instruments DM-6A $34,000 -- Speciating Semi-dry 

PS Analytical Mercury CEM $80,000 

Low-end estimate. “The PS 

Analytical Mercury CEM 

can be configured in a 

number of ways using its 

stream selection capability. 

Systems include the unique 

calibration device.” 

Speciating Wet 

Not considered:

Nippon 

Instruments MS-1A $13,000 Not including probe unit Elemental Semi-dry 

The average capital cost of the speciating and total Hg CEMS is $60,233, while the 

median value is $56,800. The lowest value is $35,000 and the highest value is 
35 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

$100,000. Additional information, such as copies of correspondence with 

manufacturers and copies of quotations may be found in a draft EPA report.34 In the 

ensuing cost calculations, the average capital cost of $60,233 is used. 

4.4 Annual Costs 

4.4.1 Annual Labor Costs 

Based on the ARCADIS expert review and review of the data submitted by the 

vendors, a yearly technical labor allocation for dry systems of 219 hours is estimated. 

This number is built up of one 10-minute inspection per shift, three shifts per day, and 

365 days per year, as well as three hours of maintenance per month. Thirty-two 

technical hours are assumed for compiling and validating four quarterly emissions 

reports. Four additional hours are estimated for submission of these four reports. 

Routine operations of Hg CEMs are therefore estimated to require 255 technical hours. 

As mentioned, three cylinder audits per year are assumed. Four technical hours are 

estimated for the performance of a single cylinder audit and to prepare a report, a total 

of 12 hours per year. Additional labor costs associated with the performance of three 

cylinder audits is therefore estimated at $637. 

Plant labor costs associated with relative accuracy verification testing (one events with 

nine tests) are estimated to be 121 technical hours including: 

 40 hours for OH contacting 

 72 hours for OH oversight 

 8 hours for report review 

 1 hour for report submission 

 

34 EPA, 2003. Cost of Mercury Measurement Techniques. Draft Report submitted on March 28, 

2003, by Perrin Quarles Associates, Inc. 
36 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

Including managerial and clerical support. the labor costs for the verification 

component for this program are estimated to be $6,420. 

4.4.2 Subcontract and ODC 

Based on the expert review and review of the data submitted by the vendors, 

ARCADIS estimates an annual materials operations and maintenance budget 

associated with sampling and analysis for a generic dry CEMS of $2,500. This budget 

includes the cost for replacement parts, including the catalyst, tubing, pumps, and 

fittings. Because many CEMS are still in the pilot stage and the technologies are often 

proprietary, this estimate is preliminary. 

It is assumed that the procurement of the gas standard associated with the three 

cylinder gas audits the standard would cost $5,000 annually.35 

One nine-test OH RATA is estimated to cost $37,000 to subcontract. This number 

consists of $4,000 in travel and $33,000 in testing costs. 

Accordingly, subcontracting and ODC for generic a dry CEMS are estimated to be 

$44,500. 

4.4.3 Annualized Capital Costs 

Based on a three-year straight-line depreciation, annualized capital costs are estimated 

to be $20,077 based on the capital cost average for both wet and dry systems, as 

submitted by the vendors. 

4.4.4 Total Annualized Costs 

Total annualized costs for mercury monitoring with a CEMS are estimated at $84,142. 

Note that this estimate may be low, in regard to administrative, sampling and analysis 

cost, for the first year, because the CEM is likely to undergo extra scrutiny from 

 

35 Current rate quoted by Spectrum Gases. 
37 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

management. Also, additional vendor maintenance calls may take place which will 

increase the vendor’s budget as well as require time from plant personnel. 

4.5 Uncertainties 

 The technology is still under development.

 Limited field experience has been collected.

 No performance standard has been defined for CEMS.

 No calibration method has been defined. 

 Demonstration of oxidized Hg conversion efficiency is difficult without OH 

testing. Currently envisioned cylinder audit would not demonstrate conversion. 
38 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

5. Fuel Analysis 

5.1 Background and Methods 

Fuel analysis as an emissions measurement technique implicitly utilizes an emission 

factor approach; mercury emissions are some fraction of all the mercury inputs. 

Mercury in the fuel is generally considered the sole source of mercury emissions 

though other mercury inputs could easily be incorporated into this approach if deemed 

necessary. Mercury content in the fuel and the amount of fuel burned are used to 

determine the mercury inputs to a unit. In the extreme or maximum emissions case, 

mercury emissions from a unit could be estimated as the total measured mercury 

inputs, discounting mercury retained in residuals such as fly ash or gypsum. An 

alternate approach is to apply an emission factor, either based on unit specific emission 

measurements or some classification average emission measurements, to the measured 

mercury inputs. 

Measuring mercury content in the fuel and fuel inputs to units appears to be an integral 

part of proposed mercury control legislation. Mercury inputs provide the baseline 

which emissions are compared to in control-based legislation. Similarly, the proposed 

Clear Skies Act of 2003 reverts, should the administrator not establish the emissions 

trading system, to a control-based mercury emissions requirement based on fuel 

mercury content36. 

5.1.1 Scope and Applicability 

Fuel analysis will determine the total amount of mercury in the fuel. Mercury in the 

fuel can be expressed on either a mass basis, either wet or dry, or can be normalized to 

the heating value of the fuel and be expressed on an energy basis. When the fuel is 

burned, the mercury in the fuel will be converted to elemental, oxidized, and particlebound mercury. Though the fuel analysis is most directly related to total mercury 

emissions, it may be possible to estimate the partitioning of the mercury based on other 

fuel components and fuel firing conditions. 

 

36 “Clear Skies Act of 2003” accessed at http://www.epa.gov/air/clearskies/Air_005.pdf 
39 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

5.1.2 Accuracy and Precision 

Accuracy and Precision for mercury fuel analysis appear to be dependent upon both the 

analytical method and the specific matrix being analyzed. ASTM D-3684-01 is 

reported to have a bias with respect to three reference materials analyzed, as 

summarized in Table 5-1. Bias was significant at a 95 percent confidence level for all 

three reference materials but appears to be dependent on the specific matrix. The mean 

Hg content from ICR phase II for bituminous coals at electric utilities was 0.11 ppm37. 

This was quite comparable to the Certified Reference Material (CRM) used to evaluate 

bias in the ASTM method. Repeatability of the method is reported as 0.036 ppm, while 

reproducibility of the method is reported as 0.054 ppm.38

Table 5-1. ASTM D-3684-01 Bias39

CRM Description CRM value, ppm Bias, ppm 

SRM 1630a Bituminous Coal, PA40 0.0938 0.0081 

SRM 2692b Bituminous Coal, WV41 0.1333 -0.0087 

SARM 20 Subbituminous to Bituminous Coal, 

South Africa42

0.25 -0.06 

 

37 National Risk Management Research Laboratory, “CONTROL OF MERCURY EMISSIONS 

FROM COAL-FIRED ELECTRIC UTILITY BOILERS: INTERIM REPORT INCLUDING 

ERRATA DATED 3-21-02,” EPA-600/R-01-109, April 2002. 

38 D3684-01 Standard Test Method for Total Mercury in coal by the Oxygen Bomb 

Combustion/Atomic Absorption Method, ASTM International, West Conshohoken 

Pennsylvania 

39 D3684-01 Standard Test Method for Total Mercury in coal by the Oxygen Bomb 

Combustion/Atomic Absorption Method, ASTM International, West Conshohoken 

Pennsylvania 

40 http://patapsco.nist.gov/srmcatalog/certificates/view_cert2gif.cfm?certificate=1630a 

41 http://patapsco.nist.gov/srmtcatalog/certificates/2692b.pdf 
40 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

5.2 Assumptions 

For this cost estimate, the fuel Hg sample is assumed to be derived from fuel samples 

already being collected and shipped for analysis. The equipment and techniques 

required to take the sample are therefore assumed to be established for each unit. It is 

assumed that fuel analysis will be contracted. 

The form of any regulation is expected to specify the sampling and analysis frequency. 

Under ICR phase II, over 152,400 shipments were recorded and over 39,500 analyses 

performed43. One thousand one hundred and forty (1,140) coal-fired units were 

identified at approximately 450 facilities44. Assuming a similar frequency for potential 

regulation will result in approximately 35 analyses per unit per year. Assuming an 

unbiased measurement technique and 15% RSD with respect to mercury inputs, 35 

analyses should provide an annual estimate within 5.2% of actual mercury inputs with 

95% confidence. 

There are several ASTM methods available for measuring mercury including D3684-

01, D6414-01, and D6722-01. Without further regulatory guidance, ASTM D-3684 is 

assumed to be the utilities method of choice and will be used in this cost estimate. 

ASTM D-3684 appears to have been widely, though not uniformly, chosen for fuel 

analysis in the ICR. 

Costs for emission factor development, if implemented, are assumed to be on a unit 

basis. The emission factor is assumed to validate the percentage of mercury inputs 

emitted from the stack. The emission factor could similarly be required to demonstrate 

no significant bias in the mercury analysis technique. While procedures for 

implementing such a validation have yet to be developed, this cost estimate will 

include quarterly (4) OH sampling events with three tests per sampling event. No 

 42 http://energy.er.usgs.gov/products/papers/B1823/append.htm 

43 U.S. EPA, “ICR Data Analysis Presentation for NWF; September 8, 2000,” 

http://www.epa.gov/ttn/atw/combust/utiltox/nwf_9_8.pdf 

44 ibid. 
41 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

additional coal samples and analysis are assumed to be associated with the emission 

factor validation. 

5.3 Annual Costs 

5.3.1 Labor Costs 

Costs for administering the fuel analysis program for Hg are derived using estimates 

from the ICR supporting statement.45 Though not specified in the ICR Supporting 

Statement, two technical hours per year have been included to support contracting for 

additional analysis. Thirty-two technical hours, 8 hours per quarter, are assumed for 

compiling and reviewing analytical data. Four technical hours are estimated for 

quarterly submission of analytical results. Routine operations are therefore expected to 

require 38 technical hours per year. Labor costs for routine operation of a mercury 

sampling program are estimated at $2,016, including management and clerical costs. 

If an emission factor verification were included, additional costs would be associated 

with administering this program. The program is assumed to consist of four (4) OH 

sampling events with three (3) tests per sampling event. The following technical hours 

have been assumed on an annual basis for verification testing: 

 For obtaining an OH sampling contract, 40 technical hours. 

 For oversight of 12 tests, 96 technical hours. 

 

45 U.S. EPA, “Standard Form 83-1 Supporting Statement for OMB Review of ICR 

No._____:[sic] Information Collection Request for Electric Utility Steam Generating Unit 

Mercury Emissions Information Collection Effort,” November 16, 1998. available at 

http://www.epa.gov/ttn/atw/combust/utiltox/114_ss19.pdf 
42 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

 To compile and review analytical data, 32 technical hours. 

 To submit test results, 4 technical hours. 

Total technical hours for administration of the emission factor verification program are 

therefore expected to be 172 per year. Including management and clerical hours labor 

costs for the emission factor verification program at the stack level are estimated at 

$9,126 annually. 

5.3.2 Subcontract and ODC 

Cost of mercury analysis is estimated at $54 per occurrence, which is the average of 

vendor indicated analysis costs of $5046 and $5847. Shipping to the contract laboratory 

is expected to be covered by current analytical requirements. A total of 35 mercury 

analysis per year results in a mercury analysis cost of $1,890 per year per unit. 

As mentioned in section 1.1.1, costs for contracting for OH sampling and analysis are 

estimated a $15,000 per sampling event with three tests each. An emission factor 

verification program consisting of four (4) sampling events is, thus, estimated to cost 

$60,000 per year for each unit. 

5.3.3 Total Annualized Costs 

Annual costs for the mercury analysis program are estimated to be $3,906 with no 

emission factor verification program. Cost of an emission factor verification program is 

estimated to be $69,126. Whether an emission factor verification program would be 

required for all units or just for those wishing to demonstrate a level of mercury control 

would have to be defined by regulation. Annual cost for the mercury analysis program 

with an emission factor verification program is estimated at $72,926 per unit. 

 

46 Personal communication from Kim Risi, PSC Analytical Services to Carl Singer, ARCADIS 

on March 24, 2003. 

47 Personal communication from Ken Munger, SGS Commercial Testing and Engineering, to 

Carl Singer, ARCADIS, on March 12, 2003. 
43 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

5.4 Uncertainties 

Use of Hg fuel analysis for quantifying mercury emissions is confounded by the matrix 

specific bias associated with the analytical technique. Reducing this bias or quantifying 

the matrix effects may greatly influence the need to perform emission factor 

verification testing. It may also be necessary to estimate bias associated with non-coal 

fuels such as pet-coke, RDF or biomass with respect to the chosen analytical technique. 

Additionally, QA necessary for defensible analysis at the desired detection levels must 

be established. 

The cost of Hg fuel analysis for quantifying Hg emissions could be significantly 

reduced if a reliable emission factor were developed for important equipment and fuel 

classes. This approach may be particularly applicable to units expecting little or no Hg 

control. Units burning sub-bituminous or lignite coals controlled only by ESPs appear 

to exhibit limited control.48 On the other hand, use of a single emission factor for a unit 

may not be appropriate in all cases, especially for units which change fuel or fuel 

blends, because the emission factor may change significantly dependent on the fuel due 

to changes in Hg partitioning between elemental, oxidized, and particle-bound forms. 

The use of fuel analysis for quantifying Hg emissions may not be appropriate for all 

units or within and market based trading scenario. The Hg emissions can be influenced 

by a number of factors, which may vary due to plant operating conditions and may not 

be representatively captured during verification tests. These parameters may include 

fuel sources, combustion conditions, and control device operations. 

 

48 EPA-600/R-01-109 
44 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

6. Discussion and Summary 

6.1 Comparison Carl: please update this section with revised costs. 

Table 6-1 includes an overview of the estimated annual costs associated with the four 

methods that have been reviewed. The costs for OH analysis for annual emissions 

estimation is $203,134. The cost for carbon trap analysis for annual Hg emissions 

estimation is$115,009 .The cost for CEMS and fuel analysis for annual Hg emissions 

estimation are $85,164 and $73,032, respectively. A large portion of the monitoring 

costs are associated with validating the proposed measurement against a reference 

method. In this case, the reference method, OH, samples representatively across the 

stack as opposed to point sampling used for Carbon Traps and CEMS or inlet Hg based 

fuel analysis.. 

Table 6-1. Summary of Mercury Annual Analysis Costs 

OH Method Carbon Trap CEMS Fuel Analysis 

Labor 

 Routine Operations, Technical 

Hours 436 772 255 38 

 Verification Testing, Technical 

Hours n/a 137 133 172 

Total Technical Hours 436 909 388 210 

 Technical Labor, $ 20,710 43,178 18,430 9,975 

 Management Labor, $ 1,248 2,603 1,111 601 

 Clerical Labor, $ 1,175 2,451 1,046 566 

Total Labor, $ 23,134 48,232 20,587 11,142 

Subcontract & ODC

 Verification Testing 180,000 39,400 37,000 60,000 

 Other Analysis n/a 21,640 n/a 1,890 

 Audit Cylinder n/a n/a 5,000 n/a 

 Parts & Consumables n/a n/a 2,500 n/a 

Total Subcontract & ODC, $ 180,000 61,040 44,500 61,890 

Annualized Capital Cost 
45 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

Annualized Capital Cost, $ 0 5737 20,077 n/a 

Total Annual Costs, $ 203,134 115,009 85,164 73,032 

6.2 Barriers to Cost Analysis 

The accuracy of cost estimates is limited by the developing nature of the mercury 

emission monitoring industry. The accuracy and precision of the measurement methods 

are improving but are largely unquantified. The requirements of mercury monitoring 

are similarly undefined by regulation. The validation requirements must also be 

developed to satisfy the accuracy and precision requirements defined by regulation. 

Finally, the market for these validations will mature dependent on the requirements of 

the mercury emission monitoring industry. 

The accuracy and precision of OH testing, carbon trap testing, and CEMS are currently 

undergoing evaluation under several coal-fired plant configurations. While OH testing 

is widely used as the reference method, the precision of the method is poorly 

established confounding comparisons to alternative methods. Alternatively, generally 

accepted independent standards by which to judge accuracy and precision are not 

available; an elemental mercury gas standard is under development but an oxidized or 

total mercury gas standard is unavailable. 

Mercury emissions from coal-fired boilers are not currently regulated under federal 

authority. The measurement and reporting requirements of any proposed regulation, 

including incentives and penalties, will shape the type and frequency of mercury 

measurements. The marketplace will either develop based on industry perception of 

risk and reward or based on regulatory command and control requirements. 

Information on the reliability, O&M costs, and other metrics of various monitoring 

techniques are largely unavailable, though they are being evaluated by EPA during 

short-term testing at coal-fired power plants. 

Validation of the mercury monitoring can have a large impact on the total costs of a 

mercury monitoring approach. Validation will depend on the regulatory framework 

required for mercury monitoring. Our estimates assumed validation techniques to 

provide results nominally equivalent to a RATA. 
46 

Task 1: Cost of Mercury 

Measurement Techniques 

Draft Report, Revision 1 

Finally, the cost of validation of mercury monitoring will likely change as the market 

for these services develop. These costs are currently based on OH testing at an 

individual stack in the current market. The volume of contracting required may 

significantly affect costs as the amount of travel and number of deployments are 

reduced. The number and location of sampling firms providing this service will be 

affected by the amount of contracting that develops. Competitive pressures are also 

likely to drive down costs. 

6.3 Suggestions for Improvements and Additional Research 

The accuracy and precision of the OH tests need to be quantified in order to establish 

appropriate validation procedures with this method. This precision may define the 

number of tests required to achieve desired accuracy. It is particularly important to 

understand the precision at low levels of mercury where analytical variability may 

become a large fraction of the total variability. Improvements to the accuracy and 

precision, especially at low mercury levels, should be incorporated into the method 

prior to the evaluation of precision. A sampling program to evaluate the precision and 

accuracy of the OH method is therefore recommended to evaluate low, medium, and 

high concentration sources. 

A more accurate estimate of annual monitoring costs will require additional 

information regarding continuous application of each method. While short-term 

evaluations of CEMS and a version of carbon traps are ongoing or planned, these 

evaluations are not likely to extend for a year, the benchmark typically encountered in 

Part 75. Quantitative information regarding operation and maintenance and reliability 

will be necessary for method comparison. Preferably, these evaluations should 

encompass a wide range of coals and plant configurations. 
End of Document