United States Science Advisory EPA-SAB-HEC-96-018 I
Environmental Board (1400) August 1996
oEPA AN SAB REPORT:
VERIFICATION OF CEMS FOR
HAPS
RECOMMENDATIONS FOR
PERFORMANCE VERIFICATION OF
CONTINUOUS EMISSION MONITBRS
FOR HAZARDOUS AIR POLLUTANTS
A REPORT OF THE HAZARDOUS AIR
POLLUTANTS SUBCOMMITTEE OF
THE ENVIRONMENTAL ENGINEERING
COMMITTEE
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August 21, 1995
EPA-SAB-EEC-95-018
Honorable Carol M. Browner
Administrator
U.S. Environmental Protection Agency
401M Street, S.W.
Washington, D.C. 20460
RE: Science Advisory Board Subcommittee Review on Verification of Innovative
Continuous Air Emission Monitors
Dear Administrator Browner:
The Hazardous Air Pollutant Monitoring Subcommittee of the Science Advisory Board's
Environmental Engineering Committee (EEC) has completed its review of the Office of Research
and Development's planned initiative in the Verification of Innovative Continuous Air Emissions
Monitors. The Subcommittee was composed of EEC members, consultants, and invited
participants with expertise in continuous emissions monitors, air emissions from stationary
sources, measurement systems, analytical instrumentation manufacturing and emissions
regulations. The Subcommittee met April 24-25, 1995, to address the following charge:
a) The technical framework of the proposed Continuous Emissions
Monitoring (CEM) verification may require more flexibility than is
currently allowed under existing ambient air reference and equivalent
methods regulations. What would increase general applicability, modify
technical concepts, or otherwise improve the ambient air equivalency
procedures for use in CEM verification?
b) The EPA is considering a CEM verification program that combines the best
features of the ambient air equivalency program (40 CFR 53) and the
German "TUV" field verification program. What variables need to be
considered in developing the optimal CEM verification program?
c) Method 301 of Title 40 CFR, Part 63 is a protocol for the field validation
of measurement methods written specifically for manual test methods
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where a discrete sample is collected, usually for analysis at a later time. What
modifications would be reasonable?"
The Subcommittee also considered barriers to the commercialization of innovative CEMS.
The Verification of Innovative Continuous Air Emissions Monitors initiative is a proposed
pilot project under the Environmental Technology Innovation and Commercialization
Enhancement (EnTICE) program and the initiative has not yet been actively pursued by the
Agency. The Subcommittee, therefore, is providing prospective input regarding this proposed
initiative and is not reviewing a completed project or even a project in progress. The Committee
believes that such an early input on a broad range of related issues is an effective use of SAB
expertise and processes which allows advisory inputs to be given to the Agency before a program
becomes more intractable to change.
Continuous emissions monitors (CEMs) for criteria and acid rain pollutants (e.g., NOx,
SOx, CO) have been routinely utilized in the past due to regulatory requirements and industrial
practices. However, the Clean Air Act Amendments of 1990 addresses a broader range of air
pollutants including particulate matter and hazardous air pollutants (HAPs). There is interest in
continuously monitoring some HAPs. For example, when there is significant process variability or
when more continuous performance assurance of health and environmental protection is needed.
For many of these HAPs, CEMs are currently not available commercially, and hence in those
instances, the development and commercialization of innovative CEMs is encouraged.
The lack of CEMs for HAPs is caused by a number of barriers to commercialization of
innovative CEMs. However, the barriers to the development and commercialization of
innovative CEMs are more complex than currently articulated in the initiative documents and
presentations. These barriers need to be comprehensively reviewed and evaluated early in the
execution of the initiative. The Agency should first determine all of the barriers and then address
them in a systematic manner following an integrated approach. After reviewing the barriers the
Agency should consider where the verification process properly fits into the process of promoting
the development and commercialization of innovative HAP CEMs.
The Subcommittee identified several potential barriers to the availability of commercial,
cost-effective CEMs in the marketplace. These barriers can be categorized as technical
uncertainties related directly to CEM technologies and market uncertainties related to industry's
willingness to invest money and resources in bringing these technologies to market. The
Subcommittee concluded that EPA's regulatory mandates control many of the market drivers and
uncertainties and that these mandates need to be addressed along with the other technical and
market uncertainties that exist. The Subcommittee recommends that both the technical and
market barriers and uncertainties be defined further through broad stakeholder involvement and
Agency evaluation.
After the EPA has defined and prioritized the barriers to CEM commercialization such as
those defined above, the program could be structured to address how EPA can systematically
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reduce the barriers. The Subcommittee suggested several potential actions that EPA could
consider in eliminating perceived and real barriers.
Finally, any CEM system verification procedures to be developed in the United States
need to be consistent with those followed by other countries to provide for international
competitiveness and widespread data acceptance. Performance-based specifications have been
published by the International Organization for Standards (ISO). The adoption of verification
methods that differ too greatly from the international performance-based standards, or that are
perceived as being less rigorous, can result in questions regarding the validity of the data obtained
and may do harm to the international markets for CEMs based on these verification methods.
We appreciate the opportunity to review this planned program. Our most important
recommendation is that the Agency determine all of the barriers and then address them in a
systematic manner following an integrated approach. After reviewing the barriers the Agency
should consider where the verification process properly fits into the process of promoting the
development and commercialization of innovative continuous emissions monitors for hazardous
air pollutants. We look forward to your response to our recommendations.
Sincerely,
Dr. Genevieve M. Matanoski, Chair
Executive Committee
Dr. Ishwar P. Murarka, Chair
Environmental Engineering Committee
Dr. Wm. Randall Seeker, Chair
Hazardous Air Pollutant Monitoring Subcommittee
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NOTICE
This report has been written as part of the activities of the Science Advisory Board, a
public advisory group providing extramural scientific information and advice to the Administrator
and other officials of the Environmental Protection Agency. The Board is structured to provide
balanced, expert assessment of scientific matters related to problems facing the Agency. This
report has not been reviewed for approval by the Agency and, hence, the contents of this report
do not necessarily represent the views and policies of the Environmental Protection Agency, nor
of other agencies in the Executive Branch of the Federal government, nor does mention of trade
names or commercial products constitute a recommendation for use.
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ABSTRACT
The Hazardous Air Pollutant Monitoring Subcommittee of the EPA Science Advisory
Board's Environmental Engineering Committee (EEC) reviewed a planned program on the
Verification of Innovative Continuous Air Emissions Monitors (CEMs).
Continuous air emissions monitors for criteria and acid rain pollutants are routine due to
regulations and industrial practices. New requirements dictate the need to control a broader range
of air pollutants including particulate matter and hazardous air pollutants (HAPs). In some
instances there may be a need or desire to continuously monitor these HAPs and for many of
these HAPs, CEMs are currently not available commercially. Hence, in those instances, the
development and commercialization of innovative CEMs is encouraged.
The basic premise of the Verification of Innovative Continuous Air Emissions Monitors
initiative is that the lack of a properly structured verification protocols for innovative CEMs is the
critical barrier to commercialization of new CEMs. This premise may be wrong and needs to be
thoroughly reviewed as part of the program. The Subcommittee concluded that the lack of CEMs
for HAPs is caused by a number of barriers to commercialization of innovative CEMs. The
barriers to the development and commercialization of innovative CEMs are more complex than
articulated in the initiative documents and need to be comprehensively reviewed and evaluated
early in the execution of the initiative. The Agency should first determine all of the barriers and
then address them in a systematic and integrated approach. After reviewing the barriers, the
Agency should consider where the verification process properly fits into the process of promoting
the development and commercialization of innovative continuous emissions monitors.
KEY WORDS: Continuous Emissions Monitors, Hazardous Air Pollutants, Verification,
Commercialization, Environmental Technology
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U.S. ENVIRONMENTAL PROTECTION AGENCY
Science Advisory Board
Environmental Engineering Committee
Hazardous Air Pollutant Monitoring Subcommittee
CHAIRMAN
Dr. Wm. Randall Seeker, Senior Vice President, Energy & Environmental
Research Corp., Irvine, CA
MEMBERS
Dr. Wayne M. Kachel, Technical Director, Lockheed Martin Corporation, Oak Ridge, TN
CONSULTANTS
Dr. Nina Bergan French, Senior Member, Technical Staff, Sandia National Laboratory,
Livermore, CA
Dr. Jim Jahnke, Source Technology Associates, Research Triangle Park, NC
Mr. James W. Peeler, President, Emission Monitoring, Inc., Raleigh, NC
Mr. Daniel E. Podkulski, Staff Analyzer Engineer, Chevron Research and Technology Company,
Richmond, CA
INVITED PARTICIPANTS
Dr. Richard Ediger, Principal Scientist, The Perkin-Elmer Corporation,
Norwalk, CT
SCIENCE ADVISORY BOARD STAFF
Mrs. Kathleen W. Conway, Designated Federal Official, U.S. EPA,
Science Advisory Board, 401 M Street, SW., Washington, DC
Mrs. Dorothy M. Clark, Staff Secretary, U.S. EPA, Science Advisory Board,
401 M Street, SW., Washington, DC
m
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U.S. ENVIRONMENTAL PROTECTION AGENCY
Science Advisory Board
Environmental Engineering Committee
CHAIR
Dr. Ishwar P. Murarka, Target Manager, Environmental and Health Sciences Business Unit,
Electric Power Research Institute, Palo Alto, CA
MEMBERS
Dr. Linda M. Abriola, Associate Professor, Dept. of Civil and Environmental Engineering,
University of Michigan, Ann Arbor, MI
Dr. Calvin C. Chien, Environmental Fellow, Corporate Remediation Group,
E.I. DuPont Company, Wilmington, DE
Dr. Hilary I. Inyang, Associate Professor, Department of Civil Engineering, University of
Massachusetts, Lowell, MA
Dr. James H. Johnson, Jr., Acting Dean, School of Engineering, Howard University, Washington,
DC
Dr. Wayne M. Kachel, Technical Director, Lockheed Martin Corporation,
Oak Ridge, TN
Dr. Jo Ann Lighty, Associate Professor, Department of Chemical and Fuels Engineering,
University of Utah, Salt Lake City, UT
Dr. James W. Mercer, President, GeoTrans, Inc., Sterling, VA
Dr. Frederick G. Pohland, Weidlein Chair of Environmental Engineering, Department of Civil and
Environmental Engineering, University of Pittsburgh, Pittsburgh, PA
Dr. Robert B. Pojasek, Senior Program Director, Cambridge Environmental, Inc., Cambridge,
MA
Dr. Wm. Randall Seeker, Senior Vice President
Energy & Environmental Research Corp., Irvine, CA
IV
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SCIENCE ADVISORY BOARD STAFF
Mrs. Kathleen W. Conway, Designated Federal Official, U.S. EPA,
Science Advisory Board, 401 M Street, SW., Washington, DC
Mrs. Dorothy M. Clark, Staff Secretary, U.S. EPA, Science Advisory Board,
401 M Street, SW., Washington, DC
v
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TABLE OF CONTENTS
1. EXECUTIVE SUMMARY 1
2. INTRODUCTION 5
2.1 Background 5
2.2 Charge to the Committee 5
2.3 Content of Report 7
3. FINDINGS AND CONCLUSIONS 8
3.1 Innovative Continuous Emissions Monitoring Systems 8
3.2 Barriers to the Commercialization of Innovative CEMs 9
3.3 Recommendations for Potential Action to Identify and Reduce Barriers 12
3.4 The Verification Barrier to Innovative CEMs 14
3.5 Recommendations on the Verification Process for HAP CEMs 16
3.6 Pilot Project for Verification of CEMs 18
REFERENCES R-l
GLOSSARY G-l
VI
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1. EXECUTIVE SUMMARY
The Environmental Engineering Committee (EEC) of the EPA Science Advisory Board
was requested to provide input to a project planned by the Source Methods Research Branch of
the Atmospheric Research and Exposure Assessment Laboratory (AREAL) to be carried out
under the Environmental Technology Innovation, Commercialization, and Enhancement
(EnTICE) program. The EEC formed a technical subcommittee which included EEC members,
consultants, and invited participants with expertise in continuous emissions monitors, air
emissions from stationary sources, measurement systems, analytical instrumentation
manufacturing and emissions regulations.
The Verification of Innovative Continuous Air Emissions Monitors initiative is a part of
the proposed EnTICE program and has not yet been actively pursued by the Agency. The SAB's
Hazardous Air Pollutant Monitoring Subcommittee was structured to provide advice and
consultation to the Agency on the program as currently planned and as presented to the
Subcommittee. The Subcommittee is providing prospective input regarding this proposed
program and is not reviewing a completed project or even a project in progress. The
Subcommittee believes that this advisory role is an effective use of SAB expertise and processes
which allows input and advice to be given on a broad range of related issues before a program
becomes more intractable to change.
Continuous air emissions monitors (CEMs) for criteria and acid rain pollutants (e.g., NOx,
SOx, CO) have been implemented routinely in the past due to regulations and industrial practices.
However, new requirements dictate the need to control a broader range of air pollutants including
particulate matter and hazardous air pollutants (HAPs) as specified in the Clean Air Act
Amendments of 1990. In some instances there may be a need or desire to continuously monitor
these HAPs, such as when there is significant process variability or when a more continuous
performance assurance of health and environmental protection is needed. For many of these
HAPs, CEMs currently are not available commercially and hence, in those instances, the
development and commercialization of innovative CEMs is encouraged.
The Subcommittee concluded that the lack of CEMs for HAPs is caused by a number of
barriers to commercialization of innovative CEMs. However, the Subcommittee concluded that
the barriers to the development and commercialization of innovative CEMs are more complex
than currently articulated in the initiative documents and presentations and need to be
comprehensively reviewed and evaluated early in the execution of the initiative. The basic
premise of the Verification of Innovative Continuous Air Emissions Monitors initiative, as
currently proposed, is that the lack of properly structured verification protocols for innovative
CEMs is the critical barrier to commercialization of new CEMs. The Subcommittee concluded
1
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that this premise may be wrong and needs to be thoroughly reviewed as part of the program. The
Agency should first determine all of the barriers and then address them in a systematic and
integrated approach. After reviewing the barriers, the Agency should consider where the
verification process properly fits into the process of promoting the development and
commercialization of innovative CEMs.
The Subcommittee identified several potential barriers to the development of commercial,
cost-effective CEMs and to their introduction to the marketplace. These barriers can be
categorized as technical uncertainties related directly to CEM technologies and market
uncertainties related to industry's willingness to invest money and resources in bringing these
technologies to market. The technical barriers identified included:
a) The technical difficulty of producing a rugged, reliable, accurate and cost-effective
CEM;
b) The need for performance specifications for CEMs that are suitable for assuring
performance with technology based standards such as Maximum Achievable
Control Technologies; and
c) The relatively poor precision achieved when using HAP reference methods for
certain pollutants and applications and the lack of reference methods for others.
The Subcommittee identified several market barriers and uncertainties that can also
represent significant barriers to the development and commercialization of innovative CEMs,
including:
a) Whether the use of CEMs for regulatory compliance is mandated or is optional;
b) The number and extent of verification procedures required for separate source
categories;
c) The consistency of Agency policy. If the policy is not consistent, the
manufacturers will tend to avoid a market that is changing so rapidly that it
impedes business development; and
d) Excessive segmentation of the verification procedures for specific source
subcategories.
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The Subcommittee concluded that often EPA mandates drive the market and that these
mandates and uncertainties in these mandates, need to be recognized along with other technical
and market uncertainties that exist.
The Subcommittee recommends that both the technical and market barriers and
uncertainties be further defined through broad stakeholder involvement and Agency evaluation.
After the EPA has defined and prioritized the barriers to CEM commercialization, the program
could be structured to address how EPA can systematically reduce the barriers. The
Subcommittee suggested several potential actions that EPA could undertake to eliminate
perceived and real barriers.
In the present system, a monitoring system is tested for conformance to the requirements
of the Performance Specification as described in 40 CFR 60 Appendix B. The difficulty in
evaluating whether the proposed program is an improvement or barrier relative to the current
system depends very strongly on the detailed technical requirements and procedures that will
apply. The removal of the relative accuracy test requirement may not be realistic in the majority
of applications, and EPA should consider this issue very carefully. Until a better definition of the
alternative verification protocols and QA requirements is available, it is difficult to see how the
proposed verification process would represent an improvement to the current system.
Any CEM system verification procedures developed in the United States should be
consistent with those followed by other countries to provide for international competitiveness and
data acceptance. Performance-based specifications have been published by the International
Organization for Standards (ISO), other countries and international organizations. The adoption
of verification methods that differ too greatly from the international performance-based standards,
or that are perceived as being less rigorous can result in questions regarding the validity of the
data obtained and may do harm to the international markets for U. S. developed CEMs based on
these verification methods.
The pilot project has proposed the use of one CEM technology, called Laser Imaging
Direction and Ranging (LIDAR), as a case study for CEM verification. This case study, as
currently envisioned was selected primarily as a target of opportunity and may not be a good
candidate for an innovative CEM verification. Specifically, LIDAR as proposed, is designed to
monitor NOx in ambient environments. However, NOx instruments for stacks and ambient
monitors are already in wide commercial use. In addition, this technology is still highly
developmental and there remains significant technical issues associated with its calibration due to
the line-of-site nature of the technology; thus it is not a suitable test for verification since it is
innovative, does not measure HAPs, and is not well suited to stack measurements.
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2. INTRODUCTION
2.1 Background
The Environmental Engineering Committee (EEC) of the EPA Science Advisory Board
(SAB) was requested to provide input to a project planned by the Source Methods Research
Branch of the Atmospheric Research and Exposure Assessment Laboratory (AREAL) to be
carried out under the Environmental Technology Innovation, Commercialization, and
Enhancement (EnTICE) program. The AREAL initiative is entitled: "Verification of Innovative
Continuous Air Emissions Monitors". The EEC formed a technical subcommittee which included
both EEC members, consultants, and invited participants with expertise in continuous emissions
monitors, air emissions from stationary sources, measurement systems, analytical instrumentation
manufacturing and emissions regulations. A list of panelists is provided in the roster.
2.2 Charge to the Committee
The Agency and the EEC agreed upon the following charge to guide the review:
a) The "Ambient Air Monitoring Reference and Equivalent Methods"
requirements are contained in 40 CFR, Part 53. The technical framework
of the proposed Continuous Emissions Monitoring (CEM) verification may
require more flexibility than is currently allowed under 40 CFR 53. In
reviewing the proposed program on enhanced monitoring in light of 40
CFR 53, what would increase general applicability, modify technical
concepts, or otherwise improve the documents?
b) The field component of the CEM verification program should be conducted
at a site which is representative of the industry conditions and over a period
of time which adequately tests for process changes and instrument
performance. The German TUV field verification program appears to
accomplish this. EPA might arrive at a Continuous Emissions Monitor
(CEM) verification program that combines the best features of the 40 CFR
53 equivalency program and the TUV field verification program. What
variables need to be considered in developing the optimal CEM verification
program?
c) Method 301 of Title 40 CFR, Part 63 is a protocol for the "Field Validation
of Pollutant Measurement Methods from Various Waste Media." Method
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301 was written specifically for manual test methods where a discrete
sample is collected, usually for analysis at a later time. Therefore, as
currently written, the Method 301 Procedures are not applicable for use
with CEM data. Thus, many of the concepts of Method 301 need to be
modified so that a relationship can be established between the reference test
method and the CEM results. The SAB is asked to comment on the nature
of modifications that would be reasonable to use.
A full text of the project description and the charge is provided in Appendix A. The
Agency provided a series of documents to the Subcommittee which address the Verification of
Innovative Continuous Air Emissions Monitors initiative. This information also included aspects
of potentially affected rules along with material on several prospective model protocols for the
verification program. A list of this reference material is provided in Section 4. The
Subcommittee held a review meeting on April 24 and 25th in Research Triangle Park, NC wherein
representatives of AREAL presented background material and a discussion of the verification
proposal along with concepts for integration of the proposal concepts into new Clean Air Act
Rules.
The program, which is the subject of this review, was conceived and proposed as part of
the EnTICE program. The goal of the EnTICE program is to substantially accelerate the entrance
of new environmental technology into the domestic and international marketplaces. The function
of the EnTICE program is to provide purchasers and permitters with credible performance/cost
data which are generated by unbiased third parties under EPA auspices. A separate review of the
overall EnTICE program by the SAB EEC took place after this review was undertaken and is the
subject of a separate report currently under preparation by the Environmental Engineering
Committee. No effort was made to integrate the findings of the Innovative Technology
Subcommittee's EnTICE review into this report. However, it is worth noting that the general
findings of the two subcommittees are similar.
The Verification of Innovative Continuous Air Emissions Monitors initiative is a proposed
EnTICE pilot project and has not yet been actively pursued by the Agency. The SAB's
Hazardous Air Pollutant Monitoring Subcommittee is structured to provide advice and
consultation to the Agency on the program as currently planned and as presented to the
Subcommittee. The Subcommittee is providing prospective input regarding this proposed
program and is not reviewing a completed project or even a project in progress. The
Subcommittee feels that this prospective advisory role is an effective use of SAB expertise and
processes which allows input and advice to be given on a broad range of related issues before a
program becomes more intractable to change.
2.3 Content of Report
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The Subcommittee addressed the charge, as well as a number of broader issues associated
with the proper role of verification in the promotion of innovative CEM commercialization. This
SAB report first addresses the panelists' perspective on innovative CEMs for Hazardous Air
Pollutants (HAPs), then addresses the various technical and market barriers to commercialization
of new CEMs. Recommendations are made on how EPA can identify and reduce these barriers.
The charge to the SAB provided three models that may potentially be used in the new verification
process. These various models were discussed along with other models identified by the panelists.
These models are discussed in the section entitled "The Verification Barrier to Innovative CEMs."
The report includes a specific recommendation on a verification model that can also be
considered. Finally the report addresses the pilot project currently envisioned involving the use of
the Laser Imaging Direction and Ranging (LIDAR) technology.
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3. FINDINGS AND CONCLUSIONS
3.1 Innovative Continuous Emissions Monitoring Systems
Continuous air emissions monitoring can provide several potential benefits over periodic
sampling and analysis of flue gas, including: a) an increased level of compliance assurance, b) an
increased level of performance assurance to the public, c) new insight into the temporal
characteristics of emissions that are important to the establishment of protective emissions
standards and operating parameters which control emissions, and d) in some cases, more real-
time, direct control schemes. The Subcommittee decided to remain neutral relative to advocating
the increased use of HAP CEMs. However, when situations indicate that continuous monitoring
is necessary to better indicate the variations in emissions, then a CEM may be preferred.
Development of CEMs will need to progress as these situations are identified.
CEMs must be properly designed, operated, and maintained to function in a regulatory
and/or process control mode. They often are designed to function in very specific environments,
which can limit their flexibility. Hence they are not always readily interchangeable. For example,
a monitor designed to measure a parameter in a dry gas stream sometimes will not necessarily
function in a stream with a high moisture content.
After reviewing the various documents provided by the Agency and discussing the merits
and potential directions of the Verification of Innovative Continuous Air Emissions Monitors
initiative, it is clear that the verification of HAP CEMS is important. Continuous air emissions
monitors CEMs for criteria and acid rain pollutants (e.g., NOx, SOx, CO) have been routinely
implemented in the past due to regulations and industrial practices. However, new requirements
dictate the need to control a broader range of air pollutants including particulate matter and
hazardous air pollutants (HAPs) as specified in the Clean Air Act Amendments of 1990. In some
instances there may be a need or desire to continuously monitor these HAPs such as when there is
significant process variability or when more continuous performance assurance of health and
environmental protection is needed. For many of these HAPs, CEMs currently are not
commercially available, and hence in those instances, the development and commercialization of
innovative CEMs should be encouraged.
While a number of commercially available CEM instruments are available for criteria and
acid rain pollutants, developing and implementing CEMs for hazardous air pollutants (HAPs)
represent a significant additional technical challenge largely due to the significant number of
species and the much lower concentration levels of interest. There are substantial problems and
limitations with both reference method procedures and monitoring performance specifications for
many of these applications. Furthermore, EPA must consider the number of different industrial
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processes, the range of effluent conditions, difficult sample matrix problems, the need to
simultaneously monitor multiple pollutant concentrations, as well as the relatively primitive
understanding about HAP emissions that exists today. New approaches are needed and the
approval of new technologies will certainly present problems which are unforeseen at this time.
In the past, the EPA regulatory offices have not specified the use of continuous emission
monitors for HAPs in regulations sometimes due to the lack of available CEMs for the pollutants
of interest. The Subcommittee noted that this is a quandary related to what must come first;
namely, the regulatory mandate for CEMs that drives the market, or commercially available
CEMs that allow the regulators to mandate the use of CEMs. Some regulation writers working
on MACT standards have indicated that there are benefits associated with the specification of new
continuous monitoring requirements in standards development, but they cannot mandate CEM use
until they are assured that there are cost-effective, commercially available instruments. When the
Agency, in the rule-making process, has determined that the HAP CEMs are necessary, then cost-
effective HAP CEMs need to be available.
The above factors result in a fundamental conflict in priorities. On one hand, the Agency
must have the confidence that a CEM is capable of fulfilling its performance needs before the rule
is written incorporating that monitoring technology. On the other hand, instrument developers
and manufacturers are not likely to conduct the expensive R&D required to make CEMs available
unless the Agency mandates their use. Some means of breaking this deadlock is necessary before
the Agency can move ahead with the appropriate implementation of CEMs.
3.2 Barriers to the Commercialization of Innovative CEMs
The lack of CEMs for HAPs is caused by a number of barriers to commercialization of
innovative CEMs. However, the barriers to the development and commercialization of
innovative CEMs are more complex than currently articulated in the initiative documents and
presentations. The basic premise of the Verification of Innovative Continuous Air Emissions
Monitors initiative, as currently proposed, is that the lack of a properly structured verification
protocol for innovative CEMs is the critical barrier to commercialization of new CEMs. This
premise may be wrong and needs to be thoroughly reviewed as part of the program.
The Agency should first determine all of the barriers and then address them in a systematic
manner following an integrated approach. After reviewing the barriers, the Agency should
consider where the verification process properly fits into the process of promoting the
development and commercialization of innovative continuous emissions monitors. An
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understanding of the drivers for new technology development is key to this review. Even the
most effective verification process will be unsuccessful if there are not adequate markets to
warrant the efforts of analyzer suppliers. After reviewing the entire process, the Agency should
then consider where and how a verification process could be supportive of the innovative CEM
development and commercialization in a manner consistent with regulatory policy and technology
development needs.
Any inadequacies in the current CEM verification process that is to be addressed in this
Verification of Innovative Continuous Air Emissions Monitors initiative are equaled or even
overshadowed by a more fundamental problem: the general lack of commercialized CEMs for the
majority of HAPs. As indicated, there appear to be several causes for this lack of CEMs:
a) The technical difficulty of producing a rugged, reliable, accurate and cost-effective
CEM;
b) The absence of economic incentive for instrument manufacturers to invest in the
development of CEMs for the regulatory market. The necessary R&D for their
availability is not likely to occur unless instrumentation developers have sufficient
market incentive to fund internal CEM development projects; and
c) The relatively poor precision achieved when using HAP reference methods for
certain pollutants and applications and the lack of reference methods for others.
The technical uncertainties identified by the Subcommittee can be put in the form of the
following questions:
a) What are appropriate performance specifications for CEMs?
b) How should Maximum Achievable Control Technology (MACT)-based emission
limits be coupled with CEM data e.g., for Office of Solid Waste (OSW) hazardous
waste combustion rule-making currently underway?
c) What are the performance specification verification procedures (i.e., Verification
of Innovative Continuous Air Emissions Monitors initiative)?
The market uncertainties represent barriers at least as important as the technical
uncertainties. The Subcommittee identified several market barriers and uncertainties that also can
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represent significant barriers to the development and commercialization of innovative CEMs,
including the following:
a) Will manufacturers invest in commercialization of CEMs if CEMs' are not
mandated for regulatory compliance? Will both large and small manufacturers
invest?
b) Will users buy CEMs or use CEM data if not mandated by EPA for regulatory
compliance?
c) Will the proposed verification program over-burden CEM development and
commercialization by adding excessive costs and procedures?
d) Will the proposed verification program lead to market segmentation in sizes too
small to entice industry to invest in CEM technology?
e) How does inconsistent EPA policy (e.g. the elimination of CEMS from the
proposed enhanced monitoring rule) affect industry's willingness to invest money
in the technology?
f) How can EPA assist industry?
The primary incentive for the instrument manufacturer to develop new CEMs is the
existence of sufficient market size to provide a return on investment for development costs. In a
very real way, the Agency drives the CEM market and is ultimately responsible for the overall
availability of innovative CEMs. The factors - all under Agency control - that define the market
are: a) whether the use of CEMs for regulatory compliance is mandated or optional, b) the
number and extent of verification procedures required for separate source categories, and c) the
consistency of Agency policy. Each of the above issues drive the market and therefore affect
CEM availability.
The most significant market driver is the mandated use of CEMs. Unless their
implementation is required, the number of potential installed units is
insufficient to justify development costs. This opinion is borne out by statements of both end
users and the instrument manufacturers.
Another potential impediment to general CEM availability is excessive segmentation of the
verification procedures for specific source subcategories. Verification procedures can be
expensive for both the manufacturers and the end user. Although it is certainly recognized that
CEM performance must be verified for major differences in source characteristics, decreasing the
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number of source sub-categories requiring individual verification procedures will increase the
attractiveness of the CEM market to instrument manufacturers.
The recent EPA re-evaluation of the Enhanced Monitoring program and the withdrawal of
CEM mandates has resulted in severe reservations on the part of instrument developers about
being able to build long-term development plans around Agency policy. If the policy is not
consistent, the manufacturers will tend to avoid a market that is changing so rapidly that it
impedes business development.
3.3 Recommendations for Potential Action to Identify and Reduce Barriers
CEM verification must be put in context with other barriers that affect innovation and
availability of CEMs. The development and manufacturing of CEMs need to be encouraged so
that when EPA decides that CEMs are necessary, they will be available at appropriate costs.
Technology innovation and commercialization of CEMs are taking place in both larger and
smaller companies and hence enticements for both types of companies need to be evaluated and
fostered.
The Subcommittee identified several potential barriers to availability of commercial cost-
effective CEM's in the market place. These barriers can be categorized as technical uncertainties
related directly to CEM technologies and market uncertainties related to industry's willingness to
invest money and resources in bringing these technologies to market. The Subcommittee
concluded that often EPA regulatory mandates determines the markets and their uncertainties and
that these mandates need to be addressed along with the other technical and market uncertainties
that exist. The Subcommittee recommends that both the technical and market barriers and
uncertainties be further defined through broad stakeholder involvement and Agency evaluation.
The potential stakeholders that could be engaged in these discussions include: a) CEM
Developers; b) Federal Regulation Writers (e.g., OSW, OAQPS); c) State and Federal Permitting
Authorities; d) User Industry (affected sources and their consultants); e) Enforcement and
Compliance Staff; f) Academia; g) Office of General Council.
As part of this process, the EPA needs to evaluate the relative importance of the
uncertainties identified and to develop a priority for the effort so as to address the most important
barriers first.
After the EPA has defined, evaluated, and prioritized the barriers, such as those defined
above, to innovative CEM commercialization, the EPA could address the barriers in a systematic
and integrated fashion. Several potential actions that EPA could consider in eliminating real and
perceived barriers are:
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a) Work with rule writers to define appropriate performance requirements. Acquire
CEM data from several sources to examine performance and determine how
reduced risk through the use of CEMs should be considered in MACT-based
emissions limits.
b) Establish an instrument verification program such that rule writers accept (i.e. not
oppose during rule-making) and use CEMs for regulatory compliance.
c) EPA mandates control the market. Where possible, establish policy that "promises"
to mandate CEMs if they meet pre-defined criteria, thereby encouraging
manufacturers to invest in technology by creating a market.
d) Structure a verification program to insure that it does not add another layer of
bureaucracy and expense (see discussion in next section), e.g. these verification
tests can be simplified for generic applications to avoid segmenting market into too
small of pieces.
e) Be aware of effects of changing policy on manufacturers certainty of market
potential and communicate directly with developers and manufacturers on EPA
intentions.
f) Ensure that establishing of emission limits and CEM performance capabilities are
consistent and compatible, (e.g., MACT-based emission limits can be very low
with respect to risk-based limits and are generally based upon emissions data
generated by manual methods with long sampling times. Therefore, specifications
of continuous emission monitors for assurance with compliance to MACT-based
rules will need to be compatible with these differences in sampling duration and
frequency with the recognition of the enhanced monitoring capabilities of CEMS.)
g) Develop reference methods and calibration techniques for HAP CEMs.
3.4 The Verification Barrier to Innovative CEMs
The Verification of Innovative Continuous Air Emissions Monitors initiative would
attempt to address the lack of HAP CEMs by developing new or alternative procedures for
verifying innovative CEMs. Three models for such verification were proposed and discussed.
The model procedures proposed by AREAL (as presented in the charge to the SAB) were the
German TUV Field Verification Program, Method 301 for Field Validation of Pollutant
Measurement Methods from Various Waste Media (40 CFR, Part 63), and the Ambient Air
Monitoring Reference and Equivalent Methods.
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In reviewing the Agency proposal for the development of a verification process for
continuous emissions monitors there seems to be an unstated assumption that the present system
does not work. In the present system, a monitoring system is developed and tested for
conformance to the requirements in the Performance Specifications. The present system (40 CFR
60 Appendix B) has been around for twenty years and it is not clear that it has failed in this
instance. There are limitations relative to monitoring HAPs due to lack of reference methods for
all HAPs and often a lack of techniques to calibrate CEMs for trace levels of HAPs. Replacing
the old program in and of itself, would not necessarily promote the development and
commercialization of innovative CEMs.
The proposed verification system is intended as an improvement. However, if not
properly established, it may actually become an additional barrier to the introduction of new
monitoring technologies. The critical issue is likely to be the specific technical requirements or
QA procedures which would be required at the time a particular monitoring system is installed.
EPA should evaluate this issue very carefully at the outset of the proposed program.
The purpose of the project is to develop an improved system for verifying the performance
of air emission monitoring systems. Based on the proposal and other information presented by
the EPA, and pending the successful completion of a three-year pilot program and other
development efforts, third-party independent verification entities would be in place, capable, and
authorized to implement evaluation protocols for new monitoring technologies. An important
aspect of the proposed program is that the verification entities would eventually operate on a self-
sufficient basis, obtaining funds for conducting the evaluations through fees charged to the
sponsors or developers of the new technology to be evaluated.
It is expected that the protocols for conducting these performance verifications would
include appropriate laboratory and field evaluations to verify monitor performance for specific
industry applications, although the technical requirements are not known at this time. It has been
suggested in charge question (b) that these tests might be similar to the German TUV suitability
tests for particular monitor types or models. Additional performance tests or quality assurance
activities might also be required to be performed for each monitoring system at the time that it is
installed, but again these requirements are not known at this time. Such tests are required as part
of the German program for certain types of monitors and similar requirements are adopted by
other countries and the International Organization for Standards (ISO).
Based on the Subcommittee's discussions and review of the charge, it would seem that
one of the major cost savings anticipated from the suggested approach derives from elimination of
the current relative accuracy test requirement for CEMs. (This requirement is by far the most
expensive component of performance test approach, because it involves side-by-side comparisons
with manual reference methods.) However, if it is subsequently decided that the relative accuracy
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test requirement must be retained, then the cost of conducting a monitor performance test at the
time of monitor installation remains largely unchanged. In this event, the fees paid by technology
developers to the verification entities would represent additional costs relative to the current
performance testing approach for CEMs. Hence, rather than creating a cost savings, the
proposed program could in fact increase the cost of verifying the performance of a new
monitoring technique. The additional step required in this scenario could actually delay the
acceptance of the new monitoring technology, thus further increasing the cost and risk to the
instrument developer.
The difficulty in evaluating whether the proposed program is an improvement or barrier
relative to the current system depends very strongly on the detailed technical requirements and
procedures that will apply. The Subcommittee questions whether the removal of the relative
accuracy test requirement is realistic in the majority of applications and encourages EPA to
consider this issue very carefully. Until a better understanding of the verification protocols and
QA requirements is available, it is difficult to see how the proposed verification process would
represent an improvement to the current system.
EPA should consider whether the proposed verification program should supplement the
current performance specification testing approach or serve as a new approval process for
innovative technologies and alternative monitoring techniques or procedures. The proposal seems
to suggest that the verification system to be developed will replace the existing performance
specification test approach. It may be appropriate to evaluate this for existing criteria pollutant
CEMs and hazardous air pollutant monitors as separate cases. For criteria pollutants, there may
be good cause to reduce the currently required QA activities or modify calibration requirements
based on accumulated information, but there is not a great need to modify initial performance
verification procedures. Some simplification of procedures for the replacement of CEMs or major
components could be developed quite simply and quickly. The EPA should evaluate carefully
whether the development of an entirely new approval program is justified for these applications.
Finally, any CEM system verification procedures to be developed in the United States
need to be consistent with those followed by other countries to provide for international
competitiveness and data comparability. Performance-based specifications have been published
by the International Organization for Standards (ISO), other countries and international
organizations. The adoption of verification methods that differ too greatly from the
performance-based standards, or that are perceived as being less rigorous can result in questions
regarding the validity of the data obtained. With respect to the U.S.-Canadian Clean Air Accords,
dissimilar methods of system approvals could lead to problems in achieving program goals if data
were not accepted as being comparable.
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3.5 Recommendations on the Verification Process for HAP CEMs
EPA should consider the option of developing an alternate, parallel approval path for new
monitoring technology and/or new procedures while retaining the existing approach. Perhaps the
affected industrial facility would be able to choose to use a CEM demonstrated to perform
according to traditional performance specifications or verified by a new procedure. Perhaps, this
choice would only be available on a source category basis in some cases. Nevertheless, the
parallel verification approach avoids upsetting the apple cart or creating long delays for new
programs. It also does not try to fix what is not broken. A parallel approach offering two
approval paths will probably be ineffective unless both paths are widely considered as equivalent
by federal, state, and local control agencies.
An alternative approval path for innovative monitoring approaches may be particularly
appropriate in a number of applications, including:
a) Situations where reference test methods have not been developed or where the
application of existing methods is problematic such as when results have poor
repeatability and thus relative accuracy testing is infeasible.
b) Facilities where measurement of multiple pollutants is required (e.g., numerous
volatile organic hazardous air pollutants) and where alternate calibration
procedures are appropriate to accommodate new technology.
c) Cases where alternative calibration procedures or QA activities can be
demonstrated to provide adequate data quality at reduced costs for either new or
existing monitoring applications.
A monitor certification program similar to the existing 40 CFR 60, Appendix B,
Performance Specification 1 provides an example of a self-certification program carried out by
monitor manufacturers. This procedure may be less costly and more expedient to implement and
could provide many of the advantages sought by the proposed initiative. The EPA should
consider adopting appropriate elements of this approach in a revised monitor verification
procedure. Performance Specification 1 for opacity CEMs provides an important example for
cases where an appropriate method does not exist for performing relative accuracy tests. In
developing and implementing this specification for many years, EPA has correctly realized that the
comparison of in-stack opacity as measured by a transmissometer and visible emission observation
measurements of a human observer are not necessarily directly comparable. Thus, the EPA has
employed a different approach for opacity monitors than for gas monitors throughout its source
monitoring regulations.
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The Performance Specification 1 approach includes a number of important design
specifications in addition to performance specifications. Opacity monitor manufacturers are
required to conduct specific tests to determine conformance with the design specifications for
each group of instruments produced. The manufacturer then provides a certificate of
conformance which, together with a simplified set of field performance tests, constitute the
verification procedure. Provisions for conducting audits of installed monitors are also required as
a design specification to facilitate subsequent performance evaluations.
Elements of the self-certification approach should be considered in developing the
applicable evaluation protocols. Such procedures may incorporate many benefits of an expanded
monitor verification procedure. For example, poorly designed monitors may not be able to
operate properly over the full range of expected ambient temperatures. This is most easily
determined through tests which should be performed by the manufacturer and at the
manufacturer's facility rather than through empirical operating experience in the field. A set of
requirements that cause manufacturers to fully evaluate instrument performance prior to sale
would eliminate many problems which are difficult to avoid with the existing procedures. The
implementation of such requirements might be best accomplished through a self-certification
process.
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3.6 Pilot Project for Verification of CEMs
The Subcommittee had specific concerns about the pilot project as proposed. The pilot
project proposed the use of one CEM technology, called LIDAR, as a case study for CEM
verification. This case study as currently envisioned was selected as a target of opportunity and
may not be a good candidate for an innovative CEM verification. Specifically, LIDAR is designed
to monitor NOx in ambient environments. However, NOx instruments for stacks and ambient
monitors are already in wide spread commercial use. In addition, this technology is still highly
developmental, and there remains significant technical issues associated with calibration (e.g.,
among other reasons, due to the line-of-site nature of the measurement). Thus it is not a suitable
test of the verification protocols since it is too innovative and not commercially ready, does not
measure HAPS, but rather is for a criteria pollutant and is not well suited to stack measurements.
Case studies should be carefully selected to fully investigate the verification issues
associated with innovative CEM issues. Some possible selection criteria include the following:
a) high EPA monitoring priority,
b) good chance of success relative to laboratory and field verification,
c) techniques already verified by German TUV process in order to compare
procedures, and
d) targets of opportunity (cost sharing by industry).
The selection criteria should first be established and then a competitive cooperative
agreement should be developed based upon the responses.
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REFERENCES
EPA, 1995. Verification of Innovative Continuous Air Emission Monitoring Systems. AREAL
EnTICE Proposal (undated, probably 1995)
EPA, 1994.40 CFR Part 63 - National Emission Standards for Hazardous Air Pollutants for
Certain Source Categories; Final Rule (Fed. Register Vol 59 No. 78/April 22, 1994)
EPA, 1994. 40 CFR Part 64 (Preamble/Rule) - September 12, 1994 Draft Predecisional
Material-Enhanced Monitoring Program
EPA, 1988. Air Pollution Control Manual of Continuous Emission Monitoring. Regulations and
Procedures for Emission Measurements. The (German) Federal Ministry for Environment,
Nature Conservation, and Nuclear Safety, 1988
EPA, 1995. Revised Charge for SAB Review of Proposed Program on Enhanced Monitoring,
March 2, 1995
EPA, 40 CFR (Part 63 Appendix A) Test Methods Method 301 - Field Validation of Pollutant
Measurement Methods from Various Waste Media
EPA, 1990. Implementation Strategy for the Clean Air Act Amendments of 1990, Jan 15, 1991
U.S. EPA (Office of Air and Radiation)
EPA, 1994. Ambient Air Monitoring Reference and Equivalent Methods, 40 CFR subchapter C—
Air Program -Part 53, 1994.
TUV, 1994. Institute for Environmental Protection and Power Engineering (German Suitability
Tests) Report on the exemplary performance test of the multi-component emission measuring
system OPSIS AR 602 Z of OPSIS AB, Furhlund/Sweden, for metallic mercury Report No.
936/804002/Hg. 1994 Nonofficial English translation provided by OPSIS AB, Furhlund, Sweden
SAB, 1995. An SAB Report: Verification Strategies for EnTICE, (EPA-SAB-EEC-95-016).
U.S. EPA, Science Advisory Board, Washington, DC, August 1995.
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GLOSSARY
AREAL
CEM
CFR
EEC
EnTICE
HAP
ISO
LIDAR
MACT
ORD
SAB
TUV
Atmospheric Research and Exposure Assessment Laboratory
Continuous Emission Monitor
Code of Federal Regulations
Environmental Engineering Committee of the Science Advisory Board,
U.S. EPA
Environmental Technology Innovation and Commercialization
Enhancement
Hazardous Air Pollutant
International Organization for Standards
Laser Imaging Direction and Ranging
Maximum Achievable Control Technology
Office of Research and Development
Science Advisory Board, U.S. EPA
Technisher Ueberwachungs-Verein, a German Technical Institute
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Director, Office of Policy Analysis
Director, Climate Change Division
EPA Headquarters Library
EPA Regional Libraries
EPA Research Laboratory Directors
National Technical Information Service
Congressional Research Service
Library of Congress
Office of Technology Assessment
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