United States       Solid Waste and     EPA530-R-01-001
        Environmental Protection  Emergency Response   July 2001
        Agency	(5305W)         www.epa.gov/osw
EPA    Risk Burn Guidance for
        Hazardous Waste
        Combustion Facilities

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                                  ACKNOWLEDGMENTS

This document was developed by the U.S. Environmental Protection Agency (EPA) Region 4 and the
Office of Solid Waste. Beth Antley (EPA Region 4), the primary author/editor of this document,
coordinated the technical approach. Andrew O'Palko (Office of Solid Waste) provided overall direction.
TetraTech EM Inc. contributed significantly to Chapter 2 and provided other technical support.  Dr. Joan
Bursey and Eastern Research Group, under subcontract to Hazardous and Medical Waste Services, Inc.
(HAZMED), deserve special recognition for the final revision of Appendix B.

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                                     EPA530-R-01-001
                                          July 2001
                                     www.epa.gov/osw
       RISK BURN GUIDANCE
                  FOR
HAZARDOUS WASTE COMBUSTION
              FACILITIES
  OFFICE OF SOLID WASTE AND EMERGENCY RESPONSE
     U.S. ENVIRONMENTAL PROTECTION AGENCY
             WASHINGTON, DC 20460

                 REGION 4
     U.S. ENVIRONMENTAL PROTECTION AGENCY
            ATLANTA, GEORGIA 30303

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                             SCIENTIFIC PEER REVIEWERS
                               Hazardous Waste Combustion

                                    Dr. Larry Waterland
                              ARCADIS Geraghty & Miller, Inc.
                                  Dioxin/Furan Formation

                                      Kevin R. Bruce
                              ARCADIS Geraghty & Miller, Inc.


                            Sampling & Analytical Measurements

                                 Dr. Raymond G. Merrill, Jr.
                                Eastern Research Group, Inc.
Risk Burn Guidance for
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July 2001

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                        WORKGROUP AND U.S. EPA REVIEWERS
 Office of Research and Development,
 National Risk Management Research Laboratory
       Dr. Paul Lemieux
       Dr. Brian Gullett
       Dr. William Linak
       JeffRyan

 Office of Research and Development,
 National Exposure Research Laboratory
       Dr. Larry Johnson

 Office of Air Quality Planning and Standards,
 Emissions Measurement Center
       Gene Riley

 Office of Solid Waste,
 Permits and State Programs Division
       Rosemary Workman
       Val de la Fuente

 Office of Solid Waste,
 Economics, Methods and Risk Analysis Division
       Karen Pollard
       Barry Lesnik
       Larry Rosengrant

 Office of Solid Waste
 Hazardous Waste Minimization and Management Division
       Michael Galbraith

 Office of General Counsel
       Karen Kraus
       Brian Grant
EPA Region 2
       John Brogard

EPA Region 3
       Gary Gross

EPA Region 4
       Rick Gillam
       Elizabeth Bartlett
       Denise Housley
       Hugh Hazen
       David Langston
       Analytical Services Branch

EPA Region 5
       Gary Victorine

EPA Region 6
       JeffYurk
       Cynthia Kaleri
       Stan Burger
       Ruben Casso
       David Weeks

EPA Region 7
       John Smith

EPA Region 8
       Carl Daly

EPA Region 10
       Catherine Massimino
 Office of Enforcement and Compliance Assurance
 RCRA Enforcement Division
       Vishnu Katari

 Georgia Department of Natural Resources
       Dr. Michele Burgess
North Carolina Department of
Environment, Health and Natural
Resources
       Katherine O'Neal
Risk Burn, Guidance for
Hazardous Waste Combustion Facilities
                         July 2001
                                in

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                                    CONTENTS
  ection
     Page
 ACRONYM LIST	 ix
 1  INTRODUCTION		1
     1.1    USE OF THIS DOCUMENT	2
     1.2    OBJECTIVES	5
     1.3    REGULATORY REVIEW	6
           1.3.1  RCRA Performance Standards and Trial Burns	6
           1.3.2  Site-Specific Risk Assessments	10
           1.3.3  Hazardous Waste Combustor MACT Standards			11
     1.4    RISK BURN NOMENCLATURE	 13
 2 RISK ASSESSMENT STACK EMISSION DATA NEEDS	15
     2.1    DIOXINS AND FURANS  	15
     2.2    ORGANICS OTHER THAN DIOXINS AND FURANS	17
     2.3    METALS	17
           2.3.1  Human Health and Ecological Concerns for Specific Metals  	19
           2.3.2  Risk Characterization for Lead	22
     2.4    PARTICLE-SIZE DISTRIBUTION	23
     2.5    HYDROGEN CHLORIDE AND CHLORINE	;	24
 3   RISK BURNS	.25
     3.1    RISK-BASED PERMITTING OVERVIEW	25
     3.2    RISK BURN OBJECTIVES	28
           3.2.1  Collection of Appropriate Emissions and  Feed Characterization Information .... 28
           3.2.2  Demonstration of Operating Modes	.30
     3.3    INTEGRATION OF RISK BURNS AND PERFORMANCE TESTING	31
           3.3.1  Combined Testing	32
                 3.3.1.1 Emissions Evaluation	32
                 3.3.1.2 Waste Selection and Feed Parameters	33
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                                 CONTENTS (Continued)

 Section                                                                             Page
                   3.3.1.3 Operating Parameters	34
            3.3.2   Separate Testing	,	35
                   3.3.2.1 Testing at Normal Conditions	35
                   3.3.2.2 Defining and Verifying Normal Conditions	36
                   3.3.2.3 Separate Testing to Resolve a Conflict	39
     3.4    RISK-BASED DATA COLLECTION, EXAMPLE LOGIC	40
     3.5    TEST PLAN SUMMARY INFORMATION	,	43
 4   DIOXIN AND FURAN EMISSIONS	45
     4.1    DIOXIN AND FURAN FORMATION MECHANISMS	45
     4.2    CONTROL PARAMETERS TO BE CONSIDERED FOR RISK BURNS	50
            4.2.1   Post-Combustion Conditions	,	52
                   4.2.1.1 Rapid Wet Quench Systems	,	52
                   4.2.1.2 Partial Wet Quench Temperatures	54
                   4.2.1.3 Dry Paniculate Hold-Up Temperatures	56
            4.2.2   Combustion Conditions	59
                   4.2.2.1 Target Test Conditions	59
                   4.2.2.2 Combustion Parameters	65
                   4.2.2.3 Challenging Combustion Scenarios	67
                          4.2.2.3.1  Transient Conditions	67
                          4.2.2.3.2 Containerized or Batch Wastes	69
                          4.2.2.3.3  High Carbon Monoxide	74
            4.2.3   Feed Composition	74
                   4.2.3.1  Chlorine	74
                   4.2.3.2 Metal Catalysts  	75
                   4.2.3.3 D/F Precursors	76
                   4.2.3.4 D/F Inhibitors	77
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                             CONTENTS (Continued)
Section
          4.2.4
          4.2.5
          4.2.6
            4.2.3.5 Dioxin-ContainingWastes	78
            4.2.3.6 Other Factors	79
            Hysteresis/Memory Effects	80
            D/F Control Technologies	81
            Control Parameter Summary	:	82
4.3    D/F EMISSIONS FROM INCINERATORS	 . ...		84
4.4    D/F EMISSIONS FROM BOILERS	90
4.5    D/F EMISSIONS FROM CEMENT KILNS	92
4.6    D/F EMISSIONS FROM AGGREGATE KILNS	100
ORGANIC EMISSIONS OTHER THAN DIOXINS AND FURANS	103
5.1    STACK DETERMINATIONS FOR ORGANICS	103
      5.1.1  Target Analyte Lists	105
      5.1.2  Tentatively Identified Compounds	107
      5.1.3  Simple Hydrocarbons	107
      5.1.4  Total Organic Emissions	108
5.2    CONTROL PARAMETERS TO BE CONSIDERED FOR RISK BURNS	109
      5.2.1  Combustion Conditions	 110
      5.2.2  Feed Composition	114
5.3    ORGANIC EMISSIONS FROM INCINERATORS AND BOILERS	117
5.4    ORGANIC EMISSIONS FROM CEMENT KILNS AND AGGREGATE KILNS.... 117
METAL EMISSIONS	120
6.1    METAL VOLATILITY GROUPINGS	120
6.2    MACT CONTROL PARAMETERS FOR METALS	125
      6.2.1  Volatile Metals (Mercury)	126
      6.2.2  Semivolatile Metals	129
      6.2.3  Low-Volatile Metals	131
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                               CONTENTS (Continued)
 Section
     6.3    RISK-BASED LIMITATIONS	138
           6.3.1   Regulated Metals  	138
           6.3.2   Other Toxic Metals	142
           6.3.3   Acute Risks  	4		143
           6.3.4   Extrapolation			144
           6.3.5   Surrogate SREs	 148
     6.4    METAL SPECIATION	150
           6.4.1   Mercury	150
           6.4.2   Chromium	151
           6.4.3   Nickel	152
 7   HYDROGEN CHLORIDE/CHLORINE EMISSIONS AND PARTICLE-SIZE
     DISTRIBUTION	154
     7.1    HYDROGEN CHLORIDE AND CHLORINE	154
     7.2    PARTICLE-SIZE DISTRIBUTION	160
           7.2.1   Model Inputs	161
           7.2.2   Test Conditions for Measuring Particle-Size Distribution	 162
           7.2.3   Alternatives When Site-Specific Measurements Are Not Available	162
                  7.2.3.1 Literature Estimates	163
                  7.2.3.2 APCD Vendor Estimates	 166
                  7.2.3.3 Multiple Modeling Runs to Bound Potential Impacts	166
 8   DATA ANALYSIS	:... 167
     8.1    DATA REDUCTION AND COPC SELECTION	167
           8.1.1   Data Reporting and Treatment of Non-Detects	167
           8.1.2   COPC Selection and Treatment of Non-Detects	169
     8.2    EMISSION SCENARIOS TO BE EVALUATED FOR RISK	171
 9   RISK-BASED PERMIT CONDITIONS	174
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                           CONTENTS (Continued)
 Section
 REFERENCES
     177
 Appendix
 A  RISK BURN CONDITIONS AND PERMIT LIMITS FOR EXAMPLE FACILITIES
 B  SAMPLING AND ANALYSIS

                                 TABLES
 4-1 POTENTIAL CONTROL PARAMETERS ASSOCIATED WITH D/F EMISSIONS FROM
    INCINERATORS AND BOILERS	86
 4-2 POTENTIAL CONTROL PARAMETERS ASSOCIATED WITH D/F EMISSIONS FROM
    CEMENT KILNS AND AGGREGATE KILNS	94
 6-1 MACT CONTROL PARAMETERS ASSOCIATED WITH METAL EMISSIONS	132
 7-1 MACT CONTROL PARAMETERS ASSOCIATED WITH HYDROGEN CHLORIDE AND
    CHLORINE EMISSIONS	158
 7-2 GENERALIZED PARTICLE-SIZE DISTRIBUTION TO BE USED AS A DEFAULT IN
    DEPOSITION MODELING IF SITE-SPECIFIC DATA ARE UNAVAILABLE	164

                                 FIGURES
 3-1 RECOMMENDED SITE-SPECIFIC RISK ASSESSMENT DATA COLLECTION FLOW
    CHART	41
 6-1 METAL VOLATILITY REGIMES	122
 6-2 METAL VOLATILITY GROUPS	124
 6-3 METALS EXTRAPOLATION	 145
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                                       ACRONYM LIST
 Hg/m3
 APCD
 ASME
 ATSDR
 AWFCO
 BIF
 Btu
 CEMS
 CFR
 C12
 COPC
 CSF
 D/F
 DQO
 DRE
 dscm
 EDL
 EER
 EMPC
 EPA
 ESP
 FGC
 GC
 g/cm3
 grains/dscf
 GRAY
 HC1
Micrograms per deciliter
Micrograms per cubic meter
Air pollution control device
American Society of Mechanical Engineers
Agency for Toxic Substances and Disease Registry
Automatic waste feed cutoff
Boiler and industrial furnace
British thermal unit
Continuous emissions monitoring system
Code of Federal Regulations
Molecular chlorine
Compound of potential concern
Carcinogenic slope factor
Dioxin and furan
Data quality objective
Destruction and removal efficiency
Dry standard cubic meter
Estimated detection limit
Energy and Environmental Research Corporation
Estimated maximum possible concentration
U.S. Environmental Protection Agency
Electrostatic precipitator
Field gas chromatography
Gas chromatography
Grams per cubic centimeter
Grains per dry standard cubic foot
Gravimetric
Hydrogen chloride
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                                ACRONYM LIST (Continued)
 HEAST    Health Effects Assessment Summary Tables
 HEPA     High efficiency particulate air
 HRA       Hourly rolling average
 IRIS       Integrated Risk Information System
 IWS       Ionizing wet scrubber
 MACT     Maximum achievable control technology
 MDL       Method detection limit
 mg/dscm    Milligrams per dry standard cubic meter
 mg/kg      Milligrams per kilogram
 MS        Mass spectrometry
 ng         Nanograms
 NAAQS    National Ambient Air Quality Standard
 OS W       Office of Solid Waste
 PAH       Polycyclic aromatic hydrocarbon
 PCS       Polychlorinated biphenyl
 PCC       Primary combustion chamber
 PIC        Product of incomplete combustion
 POHC     Principal organic hazardous constituent
 ppm       Parts per million
 ppmv       Parts per million volume
 QAPP      Quality assurance project plan
 RAC       Reference air concentration
 RCRA     Resource Conservation and Recovery Act
 RDL       Reliable detection limit
 RfC        Reference concentration
 RfD       Reference dose
 RME       Reasonable maximum exposure
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                                 ACRONYM LIST (Continued)
 RTI       Research Triangle Institute
 SCC       Secondary combustion chamber
 SQL       Sample quantitation limit
 SRE       System removal efficiency
 TCO       Total chromatographableorganics
 TEQ       Toxic equivalents
 TIC       Tentatively identified compound
 TOE       Total organic emissions
 U/BK      Uptake/biokinetic
 WESP     Wet electrostatic precipitator
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                                     CHAPTER 1
                                 INTRODUCTION
  This document contains the U.S. Environmental Protection Agency (EPA) Office of Solid Waste's
  (OS W's) recommendations regarding stack emissions tests which may be performed at hazardous waste
  combustion facilities for the purpose of supporting multi-pathway, site-specific risk assessments, where
  such a risk assessment has been determined to be necessary by the permit authority. When a site-specific
  risk assessment will be performed as part of the Resource Conservation and Recovery Act (RCRA) permit
  decision for a hazardous waste combustion facility, the supporting emissions data may be collected in
  conjunction with a RCRA trial burn. The emissions data may also be collected during a test event separate
  from the RCRA trial burn, such as a Maximum Achievable Control Technology (MACT) performance test
  or other test. This guidance identifies the types of emissions data that EPA OS W recommends be Collected
  to support site-specific risk assessments. The guidance recommends combustor operating and feed
  conditions that should generally be demonstrated during the testing, and identifies stack sampling and
  analytical techniques for collection of the emissions data. In addition, the relationship between test
  conditions and potential RCRA permit conditions is discussed.

  Hazardous waste combustors include hazardous waste incinerators, as well as boilers and industrial
  furnaces (BIFs) that bum hazardous waste for energy or material recovery. Portions of this guidance may
  also be useful for emissions test efforts at thermal treatment facilities (other than incinerators and BIFs)
  conducting multi-pathway, site-specific risk assessments, as determined appropriate under 40 Code of
  Federal Regulations (CFR) Sections 264.601 and 264.602.

 Multi-pathway human health and ecological risk assessments may be performed for hazardous waste
 combustion facilities to assess potential risks associated with direct and indirect exposures to:
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     •       Polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans, known collectively as
            dioxins and furans (D/Fs);
     •       Organic emissions (volatile, semivolatile, and nonvolatile) other than D/Fs, often referred to
            as products of incomplete combustion (PICs);
     •       Metals that are potentially toxic to human or ecological receptors;
     •       Hydrogen chloride (HC1) and molecular chlorine (C^);

(EPA 1998a, 1999aand  1999b). Direct exposures include exposures via the inhalation pathway (EPA
1998a). Indirect exposures include exposures from contact of human and ecological receptors with soil,
plants or waterbodies on which an emitted chemical has been deposited, resulting in bioaccumulation and
food chain effects (EPA  1998a).

Performance of a site-specific risk assessment can provide the information necessary to determine what, if
any, additional conditions in the RCRA permit may be necessary for each situation to ensure that operation
of the combustion unit is protective of human health and the environment (EPA 1998a). These additional
conditions may include, for example, emissions limits (such as limits on D/Fs, metals, or other site-specific
compounds), process operating conditions, waste feed limitations, or expanded environmental monitoring
(EPA1998a).
 1.1
USE OF THIS DOCUMENT
This document contains EPA OSW's recommendations regarding stack emissions tests which may be
performed at hazardous waste combustion facilities for the purpose of supporting multi-pathway, site-
specific risk assessments. This document does not provide recommendations regarding whether a site-
specific risk assessment should be performed for a particular hazardous waste combustion facility, nor is it
intended to provide guidance about how to conduct a site-specific risk assessment or make risk
management decisions. It is recommended that users of this document consult other documents regarding
risk assessment and risk management issues. The preamble to the hazardous waste combustion MACT
rule published on September 30, 1999 (64 Federal Register 52828) contains EPA's most recent
recommendations regarding when or if a site-specific risk assessment should be considered.  EPA OS W
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 guidance for how to conduct a multi-pathway human health and ecological risk assessment is available in
 peer review draft form (EPA 1998a, 1999a, 1999b). And, EPA OS W's recommended risk and hazard
 targets that may be used when making risk management decisions are provided in an earlier guidance (EPA
 1994a).  Additional risk target information is also available (EPA 1998b). Many of the recommendations
 included in the MACT rule preamble and the human health/ecological risk assessment documents are also
 identified in this document for the convenience of the reader. However, this document is not intended to
 update, revise or replace the information contained in those documents. Revisions to the human health and
 ecological risk assessment documents are in progress, and more recent versions should be consulted when
 available. Other combustion risk assessment guidance (e.g., Research Triangle Institute [RTI] 1997) may
 also be consulted.

 This document updates and replaces the following guidance documents related to emissions testing which
 may be performed for the purpose of supporting multi-pathway, site-specific risk assessments:

            U.S. EPA. Guidance on Trial Burns. June 2, 1994 Draft.
     •      U.S. EPA. Guidance on Structuring RCRA Trial Burns for Collection of Risk Assessment
            Data. May 2,  1997 and September 1997 Drafts.
     •      U.S. EPA. Guidance on Collection of Emissions Data to Support Site-Specific Risk
            Assessments at Hazardous Waste Combustion Facilities. Peer Review Draft.
            EPA530-D-98-002. August 1998.
 This guidance is not intended to update, revise or replace any RCRA or MACT regulatory requirements
 pertaining to stack emissions testing, or the guidance documents which have been developed to support
 .implementation of those requirements. Examples of guidance documents which are not superseded include:
            U.S. EPA. Handbook: Guidance on Setting Permit Conditions and Reporting Trial Burn
            Results.  Volume II of the Hazardous Waste Incineration Guidance Series. Office of
            Research and Development. EPA/625/6-89/019. January 1989.
            U.S. EPA. Handbook: Hazardous Waste Incineration Measurement Guidance Manual.
            Volume III of the Hazardous Waste Incineration Guidance Series. Office of Solid Waste and
            Emergency Response. EPA/625/6-89/021. June 1989.
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            U.S. EPA. Handbook: Quality Assurance/Quality Control (QA/QC) Procedures for
            Hazardous Waste Incineration.  Office of Research and Development. EPA/625/6-89/023.
            January 1990.
            U.S. EPA.  Technical Implementation Document for EPA's Boiler and Industrial Furnace
            Regulations. Office of Solid Waste and Emergency Response. EPA-530-R-92-011. March
            1992.
            U.S. EPA.  Final Technical Support Document for Hazardous Waste Combustor MACT
            Standards,  Volume IV: Compliance with the MACT Standards. Office of Solid Waste and
            Emergency Response. July 1999.
This document provides guidance to EPA regional and state permitting authorities on how best to
implement statutory and regulatory provisions that concern permitting decisions for hazardous waste
combustion facilities under the RCRA program. In particular, this document provides guidance regarding
activities carried out pursuant to RCRA § 3005(c)(3), the "omnibus" authority, as codified in 40 CFR §
270.32(b)(2) and 40 CFR § 270.10(k). For EPA's explanation of the Agency's authority to carry out, or
require, these activities, please refer to EPA OSW's guidance for how to conduct multi-pathway human
health and ecological risk assessments (EPA 1998a and 1999a) and the preamble to the hazardous waste
combustion MACT rule (EPA 1999c).  This document is not intended to provide any new interpretations
regarding the "omnibus" authority or any other statutory or regulatory authority, nor is it intended to
reopen for consideration any statutory or regulatory interpretation in the risk assessment guidance
documents (EPA 1998a and 1999a), the preamble to the MACT rule (EPA 1999c), or any other document.

This document describes statutory provisions and EPA regulations which are legally binding requirements.
It does not substitute for those provisions or regulations, nor is it a regulation itself. Thus, it does not
impose legally binding requirements on EPA, States, or the regulated community. Any decisions made
regarding a particular facility will be made based on the  statute and the regulations. EPA and State
.regulatory authorities retain the discretion to adopt approaches on a case-by-case basis that differ from this
guidance. Therefore, interested parties are free to raise questions and objections about substance of this
guidance and the appropriateness of any recommendations in the guidance with respect to a particular
situation, and the regulatory authorities will consider whether or not the recommendations in the guidance
are appropriate in that situation. This guidance is a living document, and may be updated without public
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        4

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notice. EPA OSW welcomes public comments on this document at any time and will consider those
comments in any future revision of this document.
1.2
OBJECTIVES
The objectives of this guidance are to:
 1.   Provide recommendations to ensure the collection of adequate data to support completion of
     technically sound human health and ecological risk assessments. Specific risk assessment data
     needs generally include: (1) D/F emission rates, (2) emission rates for organics other than D/Fs, (3)
     metals emission rates, (4) site-specific particle-size distribution data, and (5) emission rates for HC1
     and C12. These data needs are discussed in detail in Chapter 2, and sampling and analytical
     procedures are discussed in Appendix B.  Other risk assessment data needs can be addressed on a
     site-specific basis, and can include compounds such as radionuclides or other criteria pollutants not
     specifically addressed in this guidance. Additional discussion of these other compounds can be found
     in the EPA OSW risk assessment guidance (EPA1998a).

 2.   Identify considerations associated with selection of appropriate test conditions for collection of
     emissions data supporting a site-specific risk assessment The emissions data to support a site-
     specific risk assessment may be collected in conjunction with a RCRA trial burn or a MACT
     performance test, where "worst-case" operating conditions are targeted to maximize emissions. It
     may also be appropriate to collect the emissions data during a separate test conducted exclusively for
     collection of risk assessment data, where the combustor might be operated under conditions
     representing long-term average, or normal, operations. Selection of appropriate test conditions for
     collection of risk assessment data is discussed in detail in Chapter 3.

 3.   Identify key control parameters that may influence emissions of D/Fs, organics other than D/Fs,
     metals and HCl/CIj. Feed and operating control parameters that should generally be demonstrated
     during the emissions testing and which may be limited by the final permit are identified and discussed.
     This guidance also identifies inherent design differences between hazardous waste burning
     incinerators, boilers, cement kilns, and lightweight aggregate kilns, and accounts for these differences
     in recommending control parameters to be limited under RCRA. Key control parameters related to
     emissions of D/Fs, organics other than D/Fs, metals, and HC1 and Cl, emissions are discussed  in
     Chapters 4, 5, 6, and 7, respectively.  Particle-size distribution is discussed in Chapter?.

 4.   Provide recommendations regarding how to report emissions data and how to evaluate various
     emission scenarios in the risk assessment These issues are discussed in Chapter 8, and are
     illustrated by the examples  in Appendix A.

 5.   Identify additional permit terms that may be included in the final RCRA permit based upon
     evaluation of the risk burn results and risk assessment These issues are discussed in Chapters 3
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      through 9, and are illustrated by the examples in Appendix A.
 Although general guidelines are provided, this guidance cannot encompass every potential situation. Permit
 writers are encouraged to consider facility-specific circumstances that may not be fully addressed.
 1.3
REGULATORY REVIEW
 This section provides summary information to explain how emissions tests and risk assessments factor into
 the RCRA regulatory framework for hazardous waste combustion facilities. First, background information
 on RCRA performance standards and trial burns is provided. Potential limitations of the RCRA
 regulations are identified, and the use of site-specific risk assessments to supplement those regulations is
 discussed. Finally, MACT standards for hazardous waste combustion facilities (EPA 1999c) are
 introduced briefly, and the relationship between the MACT standards and site-specific risk assessments is
 explained. This review is minimal and provided only for the convenience of the reader. Cited references
 should be consulted. Terms are defined in Section 1.4.
 1.3.1
       RCRA Performance Standards and Trial Burns
 Performance standards for hazardous waste incinerators are described in Title 40 of the Code of Federal
 Regulations (CFR) Part 264, Subpart O. These standards were promulgated on January 23, 1981, and
 have been subsequently amended. The performance standards consist of the following: (1) a destruction
 and removal efficiency (DRE) of principal organic hazardous constituents (POHCs) of 99.99 percent, or
 99.9999 percent for dioxin-listed wastes; (2) particulate matter emissions not to exceed 180 milligrams per
 dry standard cubic meter (mg/dscm) or 0.08 grains per dry standard cubic foot (grains/dscf), corrected to 7
 percent oxygen; and (3) gaseous HC1 emissions not to exceed 1.8 kilograms per hour or a removal
 efficiency of 99 percent. Compliance with these performance standards is generally established through a
 carefully designed trial burn (see 40 CFR § 270.62). Trial burns are typically conducted at extreme
 "worst-case" operating conditions of the unit in order to define the maximum operating range (or operating
 envelope) that assures compliance. Testing at "worst-case" conditions generally involves at least one
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performance test condition conducted at a minimum combustion temperature to demonstrate DRE.
Additional test conditions may be necessary to resolve potential conflicts between operating parameters.
As long as the incinerator continues to operate within the operating envelope demonstrated during a
successful trial burn, it is presumed to be in compliance with the regulatory performance standards.

Ongoing compliance with the three performance standards is generally assured by developing limits for the
following control parameters, as specified in 40 CFR § 264.345:
            Minimum combustion temperature in the primary combustion chamber (PCC) and secondary
            combustion chamber (SCC), to assure sufficient temperatures for destruction of organics;
            Maximum flue gas flow rate (or velocity) and maximum waste feed rate, to assure sufficient
            residence time for destruction of organics and to prevent incomplete combustion due to waste
            overcharging;
            Carbon monoxide concentration in exhaust gas, as an ongoing indicator of combustion
            efficiency;
            Other operating requirements as necessary to ensure that performance standards are met.
 Control parameters are important because performance measures, such as DRE, cannot be directly and
 continuously monitored after the trial burn. The control parameters provide a means for continuously
 assuring that operations remain within the range demonstrated during the trial burn. Guidance pertaining
 to these parameters has been provided previously (EPA 1983 and 1989) and is not repeated here.  EPA's
 1989 guidance also addresses the importance of establishing operating parameters for air pollution control
 devices (APCDs), including wet and dry scrubbers, fabric filters, and electrostatic precipitators (ESPs).
 APCD parameters include minimum and maximum pressure drops, temperatures, flow rates, pH, and
 power.

 Standards for BIFs, including boilers, cement kilns and lightweight aggregate kilns that use hazardous
 waste as a fuel source, are found in 40 CFR Part 266, Subpart H. These standards were published on
 February 21, 1991. 40 CFR Part 266, Subpart H requires that BIFs comply with a DRE performance
 standard as well as emission standards for metals, HC1, C12, particulate matter, carbon monoxide, and total
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 hydrocarbons.  The February 21, 1991 rule also subjected BIFs to the general permitting provisions
 applicable to incinerators, including the requirement to submit a RCRA Part B permit application.
 The BIF standards for 10 metals (antimony, arsenic, barium, beryllium, cadmium, chromium, lead,
 mercury, silver, and thallium), as well as for HC1 and C12, were developed to limit risks from the inhalation
 exposure pathway.  Standards for the carcinogenic metals arsenic, beryllium, cadmium, and hexavalent
 chromium are based on an aggregate (all carcinogenic metals) maximum potential excess lifetime
 carcinogenic risk for an individual of no greater than 1 in 100,000 (1E-5) from the direct inhalation
 exposure pathway.  BIF standards for metals causing health effects other than cancer are based on oral
 reference doses (RfDs) converted to reference air concentrations (RACs) or published reference
 concentrations (RfCs) in air. Standards for lead are based on 10 percent of the National Ambient Air
 Quality Standard (NAAQS).  HC1 and C^ emission rate limits are based on RfCs and RACs. RACs are
 also available for nickel and selenium, and these metals have sometimes been limited in addition to the BIF
 metals as necessary to protect human health and the environment (EPA 1992a).
 Organic emissions from BIFs are controlled using a DRE standard (the same standard as for incinerators)
 and by limiting carbon monoxide (and in some cases total hydrocarbon) concentrations in stack gas (40
 CFR Part 266 Subpart H; EPA 1 992b). The B IF rule also recognizes that hazardous waste combustors
 equipped with dry APCDs operating between 450 and 750 °F may emit higher concentrations of D/Fs than
 units equipped with other types of APCDs. 40 CFR Part 266 Subpart H requires risk evaluations for BIFs
 equipped with dry APCDs operating at 450 to 750 °F to demonstrate that total cancer risk (including D/Fs)
 is less than 1E-5 for the inhalation exposure pathway.

 The regulation of metals under the BIF rule led to the need for an additional performance test condition at
 some facilities, conducted at a high combustion temperature, in order to maximize metal volatility.  Thus,
 under the BIF rule, the combustor operating envelope may be defined by a low-temperature test to
 demonstrate DRE and a high-temperature test to demonstrate system removal efficiency (SRE) for metals.
 Operating limits to control metals that are generally established based on the SRE test condition include
 maximum combustion temperature, maximum metals feed rates, and appropriate APCD operating
 parameters (e.g., temperature, pressure drop, flow rate, or power). The BIF rule requires that maximum
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metal and chlorine feed rates be established using one of the following approaches:  Tier I (assuming zero
SRE without site-specific air dispersion modeling), Adjusted Tier I (assuming zero SRE with site-specific
air dispersion modeling), Tier II (based on emissions data without site-specific air dispersion modeling), or
Tier III (based on emissions data with site-specific air dispersion modeling).  Owners and operators of
BIFs may choose to spike the wastes used during the SRE test with metals and chlorine to demonstrate
performance at maximum feed rates. Spiking helps to ensure that sufficiently flexible metal and chlorine
feed rate limits are established. Similar provisions have been applied at hazardous waste incinerators as
necessary to protect human health and the environment.

EPA trial burn and technical guidance documents for incinerators and BIFs (EPA 1983, 1989 and 1992b)
describe control parameters typically monitored during trial burn testing.  The 1989 document categorizes
these control parameters (monitored during DRE or SRE conditions) as Group A, B, or C.  Short-term
limits, such as hourly rolling averages (HRAs) and instantaneous limits, are typically established for these
parameters in the facility's RCRA permit. The Group A, B, and C designations are reviewed below.

Group A control parameters are generally continuously monitored while hazardous waste is being fed to the
unit and are generally linked with automatic waste feed cutoff (A WFCO) limits to ensure that waste feed is
automatically cut off when specified limits are exceeded.  Examples of Group A parameters include
maximum and minimum PCC and SCC temperatures, maximum combustion gas velocity, maximum waste
feed rate, maximum carbon monoxide concentration, maximum combustion chamber pressure, minimum
venturi scrubber differential pressure, minimum scrubber liquid-to-gas ratio and pH, minimum fabric filter
differential pressure, minimum wet/dry ESP power input, and minimum wet electrostatic precipitator
(WESP) liquid flow rate.

Group B control parameters generally do not involve continuous monitoring and may not be interlocked
with the AWFCO system.  However, detailed operating records are generally maintained to demonstrate
compliance with permitted operating conditions.  Examples of Group B parameters include maximum batch
size for containerized waste and minimum scrubber blow-down. Some Group B operating parameters,
including metal and chlorine feed rates, may be continuously monitored once the supporting analytical data
have been entered into a data system.
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 Group C control parameters are generally set independently of trial burn conditions, and limits are typically
 based on manufacturers'recommendations and good operating practices. Examples of Group C parameters
 include maximum burner turndown and minimum scrubber nozzle pressure. Most Group C parameters do
 not involve continuous monitoring and interlocks with the AWFCO system; however, some may (for
 example, minimum atomization fluid pressure to a liquid injection burner). Similar to Group B parameters,
 detailed operating records for Group C parameters are generally maintained to demonstrate compliance .
 with permitted operating conditions.
 1.3.2
Site-Specific Risk Assessments
 The RCRA performance standards described in Section 1.3.1 were promulgated in 1981 for incinerators
 and in 1991 for BIFs. Since that time, information has become available to suggest that the RCRA
 performance standards may not fully address potentially significant risks (EPA 1998a).

 As documented in the Mercury Study Report to Congress (EPA 1997a), in technical background
 documents associated with the hazardous waste combustor MACT standards (RTI1999), and in EPA
 OSW human health and ecological risk assessment guidance (EPA 1998a and 1999b), there can be
 potentially significant risks from the indirect exposure pathways (e.g., pathways other than direct
 inhalation), especially for bioaccumulative compounds such as D/Fs and mercury. Notable D/F and
 mercury emissions have been observed from hazardous waste combustion facilities (EPA 1996a and
 1997b). The food chain pathway appears to be particularly important, and potential risks associated with
 indirect exposures often exceed potential risks from the direct inhalation pathway (EPA 1998a). Risks via
 the indirect exposure pathways were not directly taken into account when the RCRA regulations described
 in the previous section were developed (EPA 1998a).

 Because the RCRA performance standards for hazardous waste combustors do not directly address indirect
 exposures, EPA recommended in 1993 and  1994 that site-specific risk assessments, including both direct
 and indirect exposure pathways, be conducted for each hazardous waste combustor seeking a RCRA
 permit (EPA 1993 and 1994b). Permitting authorities could then use the results of the site-specific risk
 assessments to determine, on a case-by-case basis, whether operation of the combustor in accordance with
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the RCRA standards would be protective of human health and the environment (EPA 1998a).  In those
cases where a RCRA permitting authority identified a potentially significant risk, it could invoke Section
3005(c)(3) of RCRA (which is commonly referred to as the "omnibus authority" or "omnibus provision")
to augment the RCRA permit with additional conditions as necessary to protect human health and the
environment (EPA 1998a). As discussed in Section  1.3.3, EPA has recently revised its original
recommendation in light of the new hazardous waste combustor MACT standards (EPA 1999c).

Section 3005(c)(3) of RCRA, codified in 40 CFR Section 270.32(b)(2), provides EPA with both the
authority and responsibility to include additional terms and conditions in each RCRA facility permit as
necessary to protect human health and the environment (EPA 1998a). Under 40 CFR Section 270:10(k),
EPA may require a permit applicant to submit the information necessary to establish protective permit
conditions under the omnibus authority (40 CFR Section 270.10(k); EPA 1998a). For hazardous waste
combustors, the information required to establish permit conditions could include a site-specific risk
assessment or the supporting information to conduct a site-specific risk assessment (EPA 1999c). Any
decision to add permit conditions based on a site-specific risk assessment must be documented in the
administrative record for each facility, and the implementing agency must explain the basis for the
additional conditions (40 CFR Sections 124.7 through 124.9; EPA 1998a).
 1.3.3
Hazardous Waste Combustor MACT Standards
 Final MACT standards for certain hazardous waste combustion facilities were promulgated on
 September 30, 1999, and establish technology-based limits for D/Fs, mercury, semivolatile and low-volatile
 metals, HCI and C12, hydrocarbons or carbon monoxide, particulate matter, and ORE (EPA 1999c). These
 standards were promulgated under joint authority of RCRA and the Clean Air Act. The MACT standards
 apply to several categories of hazardous waste combustion facilities including incinerators, hazardous
 waste burning cement kilns, and hazardous waste burning lightweight aggregate kilns. The MACT rule
 requires that these sources achieve compliance with the standards within three years of the rule effective
 date and begin performance testing for stack emissions within three years and six months of the rule
 effective date in accordance with 40 CFR §§63.1206(a) and 63.7(a)(2). MACT emission standards for
 hazardous waste burning boilers and additional industrial furnaces are anticipated in a future rulemaking.
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  The MACT standards are viewed as more stringent than RCRA Subpart O and Subpart H standards for
  incinerators and BIFs (EPA 1999c). A national risk assessment was performed to determine if the MACT
  standards satisfy the RCRA mandate to protect human health and the environment (RTI1999). The
  national assessment was a multi-media, multi-pathway analysis addressing both human health and
  ecological risk.  The assessment was predicated on the assumption that sources whose emissions were
  above the MACT standards would reduce their emissions to MACT levels, and that sources whose
  emissions were below the standards would maintain emissions at the existing levels. Based on this national
  assessment, EPA determined that sources complying with the MACT standards are generally not
  anticipated to pose an unacceptable risk to human health and the environment. However, a definitive
  finding could not be made (RTI 1999; EPA 1999c). Uncertainties remain, especially related to non-dioxin
  PICs (which were not evaluated in the national risk assessment), mercury (where bioaccumulationis very
  dependent on local conditions), and other site-specific factors that could vary from those evaluated in the
  national assessment. Given these uncertainties, EPA continues to believe that site-specific risk assessments
  may be warranted in some cases (EPA 1999c).

  EPA recommends that permit writers evaluate the need for site-specific risk assessments on a case-by-case
  basis (EPA 1999c).  The recommendation that the need for a site-specific risk assessment be evaluated on a
  case-by-case basis represents a modification to the site-specific risk assessment policy recommendation that
  EPA made prior to the publication of the MACT standards in 1993 and 1994^ when EPA recommended
  that site-specific risk assessments be completed as part of the RCRA permitting process for all hazardous
  waste combustors (EPA 1993 and 1994b). The MACT rule preamble provides a list of qualitative factors
  to assist in the determination regarding the need for a site-specific risk assessment (EPA 1999c). EPA
  recommends that the decision be made prior to approval of the MACT comprehensive performance test
  protocol, to the extent possible (EPA 1999c).  Therefore, if risk emissions data have not already been
  collected during a RCRA trial burn or other test, the necessary data can be collected during MACT
  performance testing (as appropriate).

  In summary, promulgation of the MACT standards does not duplicate, supersede, or otherwise modify the
 omnibus authority or its applicability to hazardous waste combustors (EPA  1999c).  Pursuant to the
 omnibus authority, the RCRA permitting authority has the responsibility to supplement the MACT
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 standards as necessary, on a site-specific basis, to ensure adequate protection under RCRA.  Site-specific
 risk assessments provide a quantitative basis for making omnibus determinations at hazardous waste

 combustors (EPA 1999c). The results of site-specific risk assessments provide numerical information
 which can be compared to the MACT standards to determine whether risk-based limits are appropriate for

 a particular source in addition to the MACT requirements (EPA 1999c).
 1.4
RISK BURN NOMENCLATURE
 Key terms are summarized below. These terms are defined strictly for the purpose of supporting the
 concepts presented in this guidance and do not supersede regulatory definitions.
     Control Parameters
     Emissions Testing
     Normal Test
     Operating Envelope
     Performance Test
               Combustor operations are defined by control parameters such as
               temperature, pressure, flow rates, and feed characteristics. The terms
               "control parameters" and "feed and operating parameters" are used
               interchangeably in this guidance.

               Emissions testing refers to the manual collection of stack gas sample(s),
               followed by chemical analysis to determine pollutant concentrations.

               A normal test can generally be described as a test where each control
               parameter is maintained either near the historical mean, or between the
               historical mean and the minimum or maximum (as appropriate) set point,
               while burning representative, but challenging, feeds. A normal test may be
               conducted for the purpose of generating emissions data for subsequent
               evaluation in a site-specific risk assessment and may be used as the basis for
               establishing permit terms. A normal test includes a minimum of one test
               condition, but may include more.

               The term operating envelope refers to the entire range of operation allowed
               for a combustor, as bounded by either physical or regulatory constraints.

               A performance test is a test performed for the purpose of demonstrating
               compliance with a specific regulatory emission limit or performance
               standard. Allowable operating limits are established based on the operation
               demonstrated during the performance test. Thus, the tests are usually
               conducted under worst-case operating conditions. RCRA trial burns and
               MACT performance tests are both performance tests.  For hazardous waste
               combustors, performance testing may include a low-temperature test
               condition to demonstrate DRE for POHCs and a high-temperature test
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     Risk Burn
     Run
condition to demonstrate SRE for metals. Additional test conditions may be
necessary to resolve potential conflicts between targeted operating
parameters.

A risk burn is any emissions testing performed for the purpose of collecting
emissions data for subsequent evaluation in a site-specific risk assessment.
The testing may occur in conjunction with a RCRA trial burn or MACT
performance test, or the risk burn may consist of a completely separate test
effort. A risk burn includes a minimum of one test condition, but may
include more.

A run is the period of time needed to collect a stack gas sample of sufficient
volume for subsequent analysis.  During a run, control parameters are
typically maintained at the same target set point. A minimum of three runs
constitutes a test condition.
     Test
     Test Condition
     Trial Burn
     Worst-Case
The term test is used generically to refer to any emissions testing, without
distinction as to the type of test or purpose of the testing.

A test condition is comprised of at least three runs where control
parameters are maintained at the  same target set point.

The term trial burn refers specifically to emissions testing required by
RCRA regulations. A trial burn is performed for the purpose of
demonstrating compliance with a RCRA regulatory emission limit or
performance standard and is used as the basis for establishing allowable
operating limits. Trial burns may  include a low-temperature test condition
to demonstrate DRE for POHCs and a high-temperature test condition to
demonstrate SRE for metals. Additional test conditions may be necessary to
resolve potential conflicts between-targeted operating parameters.

The term worst-case is used to characterize emissions testing where a
facility operates near the extreme edges  of the operating envelope, and
where emissions are likely to be maximized. The term "worst-case" is a
general, not absolute, characterization.  RCRA trial burns and MACT
performance tests are generally considered to be worst-case tests.
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                                   CHAPTER 2
     RISK ASSESSMENT STACK EMISSION DATA
                                       NEEDS
 The categories of emissions data that are generally necessary for completing a site-specific risk assessment
 include: (1) D/F emission rates, (2) organic emission rates other than those for D/Fs, (3) metals emission
 rates, (4) particle-size distribution, and (5) emission rates of HC1 and C12. This chapter introduces these
 data needs and briefly summarizes their significance with respect to protection of human health and the
 environment.

 EPA OS W recognizes that, for many compounds, only limited information is available regarding health
 effects (EPA 1998a). However, this does not imply that targeted sampling for a limited number of
 compounds should be conducted for the risk burn (EPA 1998a). Stack emissions should generally be
 characterized as completely as possible during a risk burn, regardless of availability of toxicological data
 Although some compounds may eventually be eliminated from quantitative risk evaluation as suggested by
 the compound-of-potential-concern(GOPC) selection process provided in the EPA OS W risk assessment
 guidance (EPA 1998a), it is important that all compounds initially be identified and quantified. New
 toxicological data may become available after the risk burn, or the risk assessor may consider provisional
 toxicity data or surrogate toxicity data from a similar compound in deciding whether to retain the
 compound as a COPC (EPA 1998a). Alternatively, a qualitative risk evaluation may be performed for any
 detected compound and presented as an uncertainty in the risk assessment (EPA 1998a).
 2.1
DIOXINS AND FURANS
 D/Fs are addressed in Chapter 4 of this guidance. D/Fs can pose significant risks through both direct and
 indirect exposure pathways. Their propensity to partition to adipose (fat) tissue and to bioaccumulate can
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 make potential food chain effects particularly significant.  According to the dioxin reassessment review
 (EPA 1995a), the air-to-plant-to-animalexposure pathway is a primary exposure route for humans. Other
 significant exposure pathways include source-to-surface water-to-fish.  Human exposures result from
 ingestion of contaminated milk, beef, fish, and other foods. D/Fs are believed to promote cancer and other
 harmful health effects in humans and other receptors, and the potential potency of 2,3,7,8-
 tetrachlorodibenzo-/?-dioxin as a carcinogen is currently being re-evaluated by EPA.

 D/Fs are a group of anthropogenic chemical compounds created as unintended by-products during
 combustion and industrial activities (EPA 1995a). As described in Chapter 4, the formation of D/Fs in
 hazardous waste combustion units is highly dependent on  post-combustion temperature, time, and the
 presence of a reaction surface. In general, D/Fs addressed in this document contain at least four chlorine
 atoms and can assume a planar configuration that allows for specific biological effects. D/Fs are generally
 quantified in terms of 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalents (TEQ), as discussed in the
 EPA OS W risk assessment guidance (EPA 1998a).  EPA  OS W recommends that emissions testing for the
 tetra- through octa- D/F congeners be performed to support site-specific risk assessments.

 Even though the primary focus in this document and in the EPA OS W risk assessment guidance is on the
 tetra- through octa- D/F congeners, analytical standards have been developed for certain mono- through tri-
 chloro D/F congeners. EPA encourages stack gas analysis for these mono- through tri-chloro congeners
 whenever possible. The analysis can be performed at very little increased cost, and the results may support
 development of a database to determine which (if any) of the mono- through- tri-chloro congeners can act
 as surrogates for the tetra- through octa congeners (EPA 1999c). Identification of an easily measurable
 surrogate may support future development of a continuous emissions monitoring system (CEMS) to
 indicate D/F emissions (see http://www.epagov/appcdwww/crb/empact/index.htm).
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 2.2
ORGANICS OTHER THAN DIOXINS AND FURANS
 Organic compounds other than D/Fs are addressed in Chapter 5 of this guidance. Organics can result in
 increased risks from both direct and indirect exposures. Hazardous waste combustors can emit a variety of
 trace-level organics. As discussed in Chapter 5 of this document, organic emissions from hazardous waste
 combustion facilities typically include compounds such as volatile and semivolatile organics, aromarics,
 polyaromatics, D/Fs, polycyclic aromatic hydrocarbons (PAHs), polychlorinatedbiphenyls (PCBs),
 phthalates, nitrogenated and sulfonated organics, and short-chain alkanes (such as methane and propane).
 Both PAHs and PCBs are considered to be potential human carcinogens (EPA 2000), and are considered to
 be toxic, persistent, and bioaccumulative.  PAHs are frequently associated with particulate matter emitted
 from combustion facilities.  Combustion units have also been identified as major contributors to overall
 PCB emissions (Alcockand others  1999; EPA 1997b), and an increasing body of information supports the
 likelihood that PCBs may be formed in combustion systems regardless of PCB contamination in the feed
 (Lemieux and others 1999). PCBs may be formed by mechanisms similar to those described in Chapter 4
 for D/Fs.

 Target analyte lists for specific organics recommended for identification during a risk burn are provided in
 Appendix B. However, the total identification and quantification of all organics is frequently not possible,
 which adds to the uncertainty of the risk assessment process. Therefore, Chapter 5 and Appendix B of this
 document describe a method for Total Organic Emissions (TOE) analysis for quantifying the total mass of
 organics based on boiling point ranges. This information is useful in indicating the level of uncertainty
 associated with the risk assessment. To reduce uncertainty, stack gas analyses are also recommended for
 constituents that are not typically included on target analyte lists, such as tentatively identified compounds
 (TICs) and simple hydrocarbons.
 2.3
METALS
 Metals are addressed in Chapter 6 of this guidance. Metal emissions can pose potential human and
 ecological risks. EPA's BIF rule (40 CFR 266, Subpart H) identifies ten metals which may pose human
 health risks via the inhalation exposure pathway.  These metals are antimony, arsenic, barium, beryllium,
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cadmium, chromium, lead, mercury, silver, and thallium. A number of these metals also pose human health
risks via the indirect pathways. Mercury, in particular, has significant potential to biotransfer up the food
chain through water and sediments to fish and human receptors. Table A-1, "Information on Compounds
of Potential Interest," of Appendix A of the EPA OSW human health risk assessment guidance
(EPA1998a) and Table A-l, "Chemicals for Consideration as Compounds of Potential Concern," of
Appendix A of the EPA OSW ecological assessment guidance (EPA1999b) identify eight additional metals
as compounds of potential concern for evaluation of human and ecological risks. These eight additional
metals are aluminum, copper, cobalt, manganese, nickel, selenium, vanadium, and zinc.

EPA OSW recommends that a facility conducting a site-specific risk assessment perform stack testing or
develop emission estimates based on other information for the eighteen metals listed above.  Although some
metals may be subsequently eliminated from the risk assessment during the compound of potential concern
(COPC) selection process, it is recommended that all eighteen metals be quantified during the test to
prevent the need for additional testing later. Potential human cancer risks based on carcinogenic slope
factors (CSFs) are typically evaluated for arsenic, beryllium, cadmium, hexavalent chromium, and certain
species of nickel. Health effects other than cancer are based on RfDs and/or RfCs for antimony, barium,
trivalent chromium, copper, manganese, mercury, certain species of nickel, selenium, silver, thallium,
vanadium, and zinc. As explained in Section 2.3.2 of this document, EPA OSW has recommended that
potential health effects from lead be modeled using an alternative approach (EPA 1998a).

EPA OSW's ecological risk assessment guidance (EPA 1999b) describes ecological toxicity reference
values for a number of ecosystems and receptors including freshwater quality, freshwater sediment, marine
and estuarine water quality, marine and estuarine sediment, and specific receptors including earthworms,
terrestrial plants, mammals, and birds. Ecological toxicity reference values have been developed for
aluminum, antimony, arsenic, barium, beryllium, cadmium, copper, hexavalent chromium, total chromium,
lead, mercury, methyl mercury, nickel, selenium, silver, thallium, and zinc. EPA OSW has recommended
that these metals be considered during the COPC selection process for ecological risk assessments (EPA
 1999b).

EPA OSW's human health and ecological risk assessment guidance (EPA  1998a and 1999b) generally
recommend addressing metals in the elemental form, with the exception of mercury, chromium, and nickel.
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 For mercury, chromium, and nickel, the guidance recommends assumptions regarding valence state or
 chemical form. Based on the conservative nature of the recommended assumptions, a facility may want to
 perform speciation sampling during the risk burn or present other information to replace the default
 assumptions with site-specific data This is discussed further in Section 6.4 and Appendix B.
 2.3.1
Human Health and Ecological Concerns for Specific Metals
 The following paragraphs discuss human health and ecological significance of the metals aluminum, cobalt,
 copper, manganese, nickel, selenium, vanadium, and zinc.  This information is provided in the EPA OSW
 risk assessment guidance, as well as other references, and is summarized here because these metals were
 not addressed in the original BIF rule (40 CFR 266, Subpart H). All of these metals (except aluminum and
 cobalt) have published toxicity values (CSFs, RfDs and/or RfCs) in EPA's Integrated Risk Information
 System (IRIS) (EPA 2000) and/or EPA's Health Effects Assessment Summary Tables (HEAST)(EPA
 1997c).  IRIS and HEAST do not currently identify toxicity values for aluminum and cobalt. However, an
 ecological toxicity reference value is available for aluminum, and provisional human health systemic
 toxicity data are available for cobalt. Since aluminum and cobalt can be readily sampled using the multiple
 metals sampling train, emissions determinations for both metals are recommended.

 Aluminum, zinc, and copper are commonly occurring metals that bioaccumulate through the food chain in
 their ionic form (Paasivirta 1991). These metals can accumulate in soils and/or aquatic ecosystems.
 Selenium has been demonstrated to cause significant ecological impacts to wildlife, primarily because of
 the effects from irrigation return water. Nickel has caused both human health as well as ecological effects,
 and it is commonly associated with industrial operations such as plating.

 Aluminum

 Aluminum bioconcentrates in aquatic species and vegetation and can cause toxic effects (Agency for Toxic
 Substances and Disease Registry [ATSDR] 1999; Paasivirta 1991). In mammals, aluminum is poorly
 absorbed and is not readily metabolized (Ganrot 1986). From a human health perspective, toxicity values
 have not been established. Ecological toxicity reference values have been developed for aluminum.
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 Cobalt
 Cobalt is a relatively rare metal that is produced primarily as a by-product during refining of other metals,
 primarily copper. Industrial exposure to airborne cobalt appears to result in sensitization followed by
 irritation and pronounced pulmonary effects (Doull and others 1991).  Provisional human health systemic
 toxicity data are available for cobalt.  Ecological toxicity reference values have not been developed.
 Copper
 Copper is an essential trace element required by numerous oxidative enzymes and is found in all mammals
 and several other classes of organisms; however, high doses can result in adverse effects to humans and
 ecological receptors (Doull and others 1991). In general, humans are less sensitive to copper toxicity than
 other mammals (such as sheep and cattle), and healthy adults usually are not affected by exposure to low,
 chronic doses of copper. Infants and children are susceptible to chronic copper toxicity. Once absorbed,
 copper is distributed to the liver and can bind to deoxyribonucleic acid or generate free radicals.

 Organisms susceptible to absorption of contaminants are most vulnerable to copper toxicity. Aquatic
 organisms such as algae, fungi, certain invertebrates, and  fish represent examples of these types of
 organisms. Thus, aquatic ecosystems would be the most sensitive to copper loading; however, copper
 released to surface waters generally precipitates out or adsorbs to sediments (ATSDR 1990).  Ecological
 toxicity reference values have been developed for copper.

 Manganese

 Manganese is an essential trace element, is present in all living organisms, and is a cofactor in a number of
 enzymatic reactions. Industrial exposures to large doses of airborne manganese dioxide (or other forms of
 manganese) can result in manganese pneumonitis, which can result in permanent lung damage. Chronic
 exposure to airborne manganese can result in central nervous system effects including psychiatric disorders
 and a Parkinson-like syndrome. Liver cirrhosis has  also been observed. It is significant that these effects
 have only been observed in higher primates such as humans and monkeys and not in experimental animals
 such as rats (Doull and others 1991). IRIS (EPA 2000) bases the chronic reference dose for inhalation on
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data collected during occupational exposures to manganese dioxide; therefore, any potential risks from
manganese will be driven by the direct inhalation exposure route. Ecological toxicity reference values for
manganese have not been developed.
Nickel
Nickel is a commonly used industrial metal, and it is frequently associated with iron and copper ores.
Significant loading of nickel to the atmosphere and surface waters has been observed over the past several
decades (Doull and others 1991). EPA has identified certain forms of nickel, including nickel carbonyl,
nickel subsulfide and nickel refinery dust, as potential human carcinogens (EPA 1998a and 2000). The
BIF rule preamble indicates that nickel carbonyl and nickel subsulfide are not likely to be emitted from
combustion devices, given their highly oxidizing conditions.  Nickel oxide, which may be emitted from
combustion devices, is not identified as a carcinogen by itself. However, the EPA OS W human health risk
assessment guidance (EPA 1998a) points out that nickel oxide is a major component of nickel refinery dust,
and the components responsible for the carcinogenicity of nickel refinery dust have not been conclusively
established. Based on this information, EPA OSW has recommended that inhalation risks from nickel be
evaluated using the CSF for nickel refinery dust, or that a facility present information indicating the
absence of carcinogenic nickel refinery dust components (EPA 1998a).  The approach recommended in the
EPA OSW risk assessment guidance of evaluating inhalation risks using the CSF for nickel refinery dust is
supported by the risk assessment methodology used in support of the MACT rule (RTI 1999; EPA 1999c)
and represents a change in EPA OSW's previous policy (EPA 1992a) where it was recommended that
nickel be  evaluated as a noncarcinogen.  Evaluating inhalation risks using the CSF for nickel refinery dust
may result in lower allowable nickel feed rates. For exposure pathways other than inhalation, EPA OSW
recommends that nickel be evaluated as a noncarcinogen (EPA 1998a).  Additional information on nickel
speciation is found in the EPA OSW risk assessment guidance (EPA 1998a) and in Section 6.4.3 of this
document. Ecological toxicity reference values have been developed for nickel.

Selenium

Selenium occurs naturally in soils, is associated with copper refining and several industrial processes, and
has been used in pesticides. It is an essential element, bioaccumulates in certain species of plants, and has
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 been associated with toxic effects in livestock (blind staggers syndrome).  Soils containing high levels of
 selenium (seleniferous soils) can lead to high concentrations of selenium in certain plants, which then pose
 a hazard to livestock and other species. In humans, selenium partitions to the kidneys and liver and is
 excreted through the urine and feces. Toxic effects in humans include central nervous system and
 gastrointestinal effects (Doull and others 1991). Aquatic birds are extremely sensitive to selenium; toxic
 effects include teratogenesis. Ecological toxicity reference values have been developed for selenium.

 Vanadium

 Vanadium is found in several ores, is associated with petroleum products, and is commonly found in food
 oils. It is unclear whether or not vanadium has any essential role in human metabolism. Toxic effects of
 vanadium are usually associated with the inhalation exposure route.  Effects of chronic exposure to
 airborne vanadium compounds in workers include bronchitis, bronchopneumonia, and kidney damage
 (Doull and others 1991). Animal experiments have confirmed effects on the lungs and kidneys.  Ecological
 toxicity reference values for vanadium have not been developed.
 Zinc
 Zinc is an essential trace element that is involved with many enzymatic reactions in humans and other
 species (Doull and others 1991). It generally occurs in the divalent oxidation state. Zinc does
 bioaccumulate, specifically through the indirect soil-to-vegetable exposure pathway. The most common
 observed human health effect from zinc would be depression of enzyme production, resulting in copper
 deficiency.  Ecological effects include a tendency to bioaccumulate and toxic effects to vegetation and
 aquatic organisms (Paasivirta 1991). Ecological toxicity reference values have been developed for zinc.
 2.3.2
Risk Characterization for Lead
 Information on estimating threshold levels of lead exposure is provided in the EPA OS W human health risk
 assessment guidance (EPA 1998a). Toxicity factors (CSFs and RfDs) are not available for lead.
 Therefore, EPA OS W has recommended that adverse health effects for lead be characterized through a
 direct comparison with media-specific health-based levels, adjusted for background exposure (EPA 1998a).
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Under the BIF regulations, emissions and feed rate limits for lead are based on a RAC equivalent to 10
percent of the NAAQS for lead converted to an annual average, or 0.09 micrograms per cubic meter
(jig/m3).  However, this standard only addresses the direct inhalation exposure pathway.  Lead can also be
deposited to soils, where it can be ingested.  Therefore, EPA OS W has recommended that soil lead levels
also be evaluated as part of a site-specific risk assessment (EPA 1998a). The fate and transport equations
in the EPA OSW risk assessment guidance (EPA 1998a) can be used to estimate soil concentrations from
stack emissions.

The neurobiological effects observed in children are used as the sensitive endpoint for evaluating lead
toxicity from ingestion. EPA has recommended a maximum lead concentration in blood of 10 micrograms
per deciliter (jig/dL), which is at the low end of the range of concern for adverse health effects in children
(EPA 1998a). Potential risks from lead are evaluated based on the application of an uptake/biokihetic
(U/BK) modeling approach that evaluates potential risks by predicting blood lead levels associated with
exposure to lead.  When run with standard recommended default values, the U/BK model can calculate a
soil lead concentration in milligrams per kilogram (mg/kg) which corresponds to a prediction that no more
than five percent of exposed children will have blood lead concentrations exceeding 10 ug/dL. In lieu of
direct comparison to a target soil level, the EPA OSW risk assessment guidance (EPA 1998a) also
describes the approach of running the U/BK model.
 2.4
PARTICLE-SIZE DISTRIBUTION
 Particle-size distribution is addressed in Section 7.2 of this guidance. Information on particle-size
 distribution (presented as particle diameters in micrometers, referred to as microns) is needed for the air
 dispersion and deposition modeling that supports the risk assessments (EPA 1998a).  Because particle
 dispersion and subsequent deposition are directly related to particle size, potential risks are directly
 dependent on particle-size distribution. In general, most metals and a few organic COPCs with very low
 volatility are assumed to occur only in the particle phase.  Mercury and more volatile organics are assumed
 to partition between the particle and vapor phases. Very volatile organics are modeled only in the vapor
 phase.

 The EPA OSW risk assessment guidance (EPA 1998a) recommends that facilities perform site-specific
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  measurements to determine particle-size distribution. Measurements for particle-size distribution will
  reflect site-specific combustion characteristics and the efficiency of the APCD. Site-specific particle-size
  measurements are discussed in more detail in Chapter 7 and in Appendix B of this document.
 2.5
HYDROGEN CHLORIDE AND CHLORINE
 HC1 and C12 are addressed in Section 7.1 of this guidance.  Potential risks from HC1 and C^ are limited to
 the inhalation pathway. 40 CFR Part 266 Subpart H already requires BIF facilities to sample stack
 emissions for HC1 and C12, and to limit emissions as necessary to meet direct inhalation RACs specified in
 the regulations. However, updated toxicological information (instead of the RACs specified in Subpart H)
 may be available and may need to be used for site-specific risk assessments at BIF facilities (EPA 1998a).

 For incinerators, 40 CFR Part 264 Subpart O establishes a technology-based emissions limit and requires
 emissions sampling only for HC1. To support site-specific risk assessments, incinerators may also need to
 test their stack emissions for C12.
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                                    CHAPTER 3
                                   RISK BURNS
 In this guidance, the term "risk burn" refers to any testing performed to collect emissions data for
 subsequent evaluation in a site-specific risk assessment. The testing may occur in conjunction with a
 RCRA trial bum or a MACT performance test, or the risk burn may consist of a completely separate test
 effort.

 The objectives of a risk bum are to (1) collect appropriate emissions and feed characterization information
 for evaluation in a site-specific risk assessment, and (2) demonstrate the feed and operating conditions
 which correspond to measured emission levels. Feed and operating parameters (i.e., control parameters)
 may be limited and monitored after the risk burn to provide assurance on an ongoing basis that emissions
 remain at or below the measured levels.

 Since EPA may consider the results of a risk assessment and use such information to establish risk-based
 permit limits under the omnibus authority of RCRA as described in 40 CFR § 270.32(b)(2), the risk burn
 should generally be integrated with trial burn or performance testing to the extent necessary to produce a
 consistent set of enforceable permit conditions. Planning is critical, and this chapter highlights key
 considerations. Terms are defined in Section 1.4.
 3.1
RISK-BASED PERMITTING OVERVIEW
 When a RCRA permit decision includes a site-specific risk assessment and risk burn, the following
 activities are generally involved.
                                     PHASE 1: PLANNING
 1.   The facility-specific risk burn plan and risk protocol are developed, reviewed, and approved
     EPA OSW recommends that the risk burn plan and site-specific risk protocol be carefully coordinated
     to assure that the information generated during the risk burn will fully support the risk assessment and
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 2.
 3.
 final permit decision.

 Collection of appropriate emissions and feed "characterization information is a fundamental objective
 of the risk burn. EPA's recommended data quality objective (DQO) process (EPA 1998c) promotes
 collection of "the right data the first time." The EPA OS W risk assessment guidance (EPA 1998a)
 and this document support that objective by identifying and discussing data needs and measurement
 options.  However, project-specific measurement goals should generally be established for each data
 collection effort. For example, some facilities may decide to achieve lower detection limits for certain
 constituents to demonstrate that risks are below target levels. Preliminary risk modeling can assist in
 determining the quantitative targets for the measurement design.

 Advance planning is also important in choosing the risk burn operating mode. The risk burn operating
 mode affects the outcome of the risk assessment, and may also affect the final permit terms. Some
 hazardous waste combustors operate over a wide range of conditions and emission levels. However,
 the outcome of the risk assessment is linked to specific emission rates measured while operating under
 specific operating mode(s). To assure that the combustor continues to operate within the range where
 emissions have been found to be protective, the RCRA permit may limit control parameters based on
 the risk bum. Ultimately, the risk burn generally should strike a balance between operating modes
 which achieve desired permit flexibility, while also achieving protective emissions levels.  Early
 communication between the permit writer and facility is important. A clear understanding of how the
 permit terms will be derived can assist in determining the risk bum operating modes.  Preliminary risk
 modeling and preliminary emissions testing may also be helpful in planning the risk burn.

                            PHASE 2: DEMONSTRATION

 A risk burn is performed to gather stack emissions data and define the operating envelope that
 corresponds to the risk assessment. The recommended control parameters for defining the operating
 envelope that corresponds to the risk burn and risk assessment are identified in Chapters 4 through 7
 of this document. In some cases, these parameters may need to be limited in the permit to ensure (on
 an ongoing basis) that emissions remain below the levels that were measured during the risk burn and
 found to  be protective. Many of the control parameters identified in Chapters 4 through 7 are
 identical to control parameters which are limited to ensure compliance with regulatory performance
 standards. Therefore, few (if any) additional permit limitations based on the risk burn may be
 necessary when the risk burn can be performed in conjunction with a RCRA trial burn or MACT
 performance test, and when emissions are already controlled to risk burn levels by regulatory limits on
 key control parameters. A greater number of permit limitations may be necessary when the risk burn
 and performance tests reflect different operating modes.

 A risk assessment is performed to verify that the demonstrated operation does not present
 significant risk to human health or the environment The site-specific risk assessment may either
 be performed using the actual data from the risk bum, or using a combination of risk burn data and
 other information. For example, a regulatory standard of allowable permit  limit for metals might be
 evaluated in combination with actual emissions data for specific organics.

Additional iterations of the risk assessment may be  performed if the initial evaluation indicates
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    potentially unacceptable risks. Subsequent iterations might consider additional site-specific
    information that is more representative of the exposure setting, or reduced emissions (EPA 1998a).
    However, in most cases, the need for emissions reductions should generally be identified as part of the
    risk burn planning process, well in advance of performing the risk assessment.

4.  A permit decision is made, either to issue or deny.

                                   PHASE 3: VERIFICATION

5.  Conditions in addition to those specifically required by regulation may be included in the RCRA
    permit as necessary to protect human health and the environment The final permit represents an
    important and integral conclusion to the risk-based permitting process.  The risk burn and risk
    assessment are merely tools; it is the final permit that defines what operational conditions are
    necessary to protect human health and the environment and how that will be assured on an ongoing
    basis (i.e., risk-based permit limitations).  Depending on site-specific considerations, risk-based permit
    limitations may be necessary to  prevent operation at  conditions which could result in higher emissions
    than those represented by the risk burn and risk assessment.

     Risk-based permit terms must be justified on a site-specific basis as limitations that are necessary to
     protect human health and the environment. EPA OS W recommends that the permitting authority
     consider a number of factors including, but not limited to, the operating mode(s) demonstrated during
    the risk burn, the emission levels evaluated in the risk assessment, the conservatism of the risk
     assessment assumptions, the outcome of the risk assessment, and the extent to which emissions are
     already controlled by regulatory standards or other limitations.  Potential risk-based permit limitations
     include:

     •       Emissions limits and stack testing. Specific emission limitations may be cited in the permit
             for certain pollutants. Since most emissions can only be verified by manual stack
             measurements, the permit may include a schedule for periodic stack testing to confirm that
             emissions remain below levels that may present a significant risk to human health and the
             environment.

     •       Feed restrictions, operating limits and monitoring. Emission levels generally cannot be
             verified continuously. However, feed restrictions and operating limits may be established
             based on the risk burn as surrogate indicators of emissions. The feed and  operating control
             parameters can then be continuously monitored to assure that emissions.remain below the
             measured levels on an ongoing basis.

     •       Other limitations. Other permit limitations may be established to control potential risks as
             necessary to protect human health and the environment. For example, environmental
             sampling may be specified to confirm that ambient concentrations of certain pollutants do not
             reach levels that may present a significant risk to human health and the environment.
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  As evident from this risk-based permitting overview, EPA OS W believes that the risk burn, risk
  assessment, and final permit terms will be closely linked for situations where the RCRA permitting
  authority has determined that a site-specific risk assessment is necessary. The risk burn plays a key role in
  the process. Operation during the risk burn may affect whether the measured emissions are found to
  present potential risk to human health and the environment. In addition, operation during the risk burn can
  define an operating envelope that establishes the working assumptions for the risk assessment and final
  permit terms.  Within the bounds of the operating envelope demonstrated during the risk burn, emissions
  are characterized and evaluated for potential risk by the risk assessment. Outside of those bounds (unless
  additional information is available), emissions and risks may be unknown.
 3.2
RISK BURN OBJECTIVES
 This section discusses risk burn objectives in more detail. The objectives of the risk burn are to (1) collect
 appropriate emissions and feed characterization information for evaluation in a site-specific risk
 assessment, and (2) demonstrate the feed and operating conditions which correspond to emission levels that
 do not present a significant risk to human health or the environment.
 3.2.1
       Collection of Appropriate Emissions and Feed Characterization Information
 As discussed in Chapters 1 and 2, collection of site-specific risk assessment data at hazardous waste
 combustion facilities generally involves stack sampling and analysis for D/Fs, non-D/F organics, metals,
 particle-size distribution, and HC1 and C12. Prior to data collection, EPA OS W recommends that specific
 measurement objectives be developed for the risk burn plan and associated quality assurance project plan
 (QAPP) to assure collection of complete and useable data.

 EPA guidance on quality assurance project plans (EPA1998cand 1998d) describe recommended
 information to  be included in a QAPP.  The QAPP identifies a project's technical and quality objectives
 and documents how quality assurance and quality control will be applied to assure that the data support
 technically sound decision-making. In addition, the QAPP may identify potential limitations regarding use
 of the data.
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 EPA OS W recommends that, whenever possible, project-specific measurement objectives be defined
 considering information from a preliminary risk assessment.  High detection or quantitation limits,
 presence of common laboratory contaminants, and sampling artifacts can artificially inflate risks.  A
 preliminary risk assessment can provide information regarding the necessary detection or quantitation limits
 and constituent concentrations for demonstrating that risks are below levels of concern.  If a proposed
 measurement option will not attain the quantitative objectives, the measurement design may need to be
 modified. For example, if lower detection or quantitation limits are needed, a longer sampling duration or
 use of a high resolution analytical finish might be considered. Conversely, if a facility can tolerate higher
 detection or quantitation limits, more economical measurement options might be selected. As an example, a
 single semivolatile sampling train might be used to sample for D/Fs, PCBs, PAHs and semivolatile
 organics (when a single train is used for multiple determinations, the train components are split and
 detection limits for the semivolatile organics increase). Detection and quantitation limits are discussed in
 more detail in Appendix B.

 The recommended detection or quantitation limits that should generally be reported when constituents are
 not detected in a stack gas emissions sample are discussed in Section 8.1.1  of this document. It is also
 recommended that a facility inform the laboratory of preferred reporting conventions prior to development
 of the risk burn QAPP and analysis of the risk burn samples.

 EPA OS W recommends that the risk burn plan and QAPP also address complete characterization of the
 feed materials to be burned during the risk burn, including wastes, fuels, raw materials, and spike
 materials. Data equivalent to the following should generally be generated for each feed material:
             Proximate analysis, or a comparable evaluation, to determine physical properties including
             moisture, percent solids, heating value, ash, and viscosity or physical form, as well as to
             determine approximate chemical properties including total organic carbon, total chlorine, total
             organic halogens, and elemental composition;
             Quantification of total metals feed rates for aluminum, antimony, arsenic, barium, beryllium,
             cadmium, chromium, cobalt, copper, lead, manganese, mercury, nickel, selenium, silver,
             thallium, vanadium, and zinc;
             Survey analysis or a comparable evaluation to provide an overall description of the chemistry
             of the sample in terms of the major quantities and types of organic compounds that are
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            present, as well as identificationand quantitation of trace quantities of persistent,
            bioaccumulative, and toxic constituents based on analysis for volatile organics, semivolatile
            organics, PCBs, PAHs, and facility-specific compounds.
These data typically define a facility's baseline with respect to long-term impacts and potential effects on
human health and the environment. When constituents are not detected in a feed matrix, it is recommended
that the Sample Quantitation Limit (SQL) as described in Guidance for Data Useability in Risk
Assessment (EPA 1992c) be reported, with appropriate consideration of the level of dilution necessary to
perform the analysis.

EPA OSW recommends that the implications of different measurement options be fully considered during
the initial planning stages of the risk burn.  Risk burn measurement issues and data analysis are discussed
further in the EPA OSW risk assessment guidance (EPA 1998a), and in Section 8.1 and Appendix B of this
document.
 3.2.2
Demonstration of Operating Modes
 The second objective of a risk bum is to determine the feed and operating conditions which will ensure that
 emission levels do not present a significant risk to human health and the environment.  The operating mode
 during the risk bum may affect the outcome of the risk assessment and, subsequently, the final permit
 decision. For this reason, EPA OSW recommends that preliminary information regarding potential
 emission rates and anticipated permit limitations be obtained early in the risk burn planning process.

 Useful information regarding potential emissions and risks can be obtained by performing mini-burns and
 preliminary risk evaluations.  Mini-bums involve stack sampling to collect limited emissions data prior to
 full scale testing. Emissions can also be estimated based upon data gathered at a similar facility, or by
 performing conservative engineering calculations. A preliminary risk evaluation indicates the degree of
 potential risk associated with the emissions levels that are anticipated for the risk burn. If the preliminary
 risk assessment indicates that anticipated emissions are likely to present a significant risk to human health
 and the environment, a facility may choose to reduce the emissions of certain compounds prior to
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 conducting the risk burn. Emissions reductions might involve simple refinements to the risk bum plan,
 such as lowering a target metals feed rate, or more complex measures, such as physically modifying the
 unit (subject to approval by the regulatory agency).

 The risk burn operating mode may also be influenced by the permit limitations which are anticipated to be
 established based on the risk burn. Chapters 4 through 7 identify key control parameters associated with
 emissions of specific contaminants (D/Fs, non-D/F organics, metals and HCl/Ck) and specific types of
 hazardous waste combustion facilities (incinerators, boilers, cement kilns, and lightweight aggregate kilns).
 Depending on site-specific considerations, limitations for these parameters (or other parameters identified
" by the permit writer) may be established in the permit from the risk burn to provide assurance on an
 ongoing basis that emissions remain at or below levels which may pose a significant risk to human health
 and the environment.  Communication between the permit writer and facility regarding the types of permit
 limitations to be established, as well as the manner in which the limits will be established, assists in
 targeting risk burn operating modes to achieve desired permit flexibility.
 3.3
INTEGRATION OF RISK BURNS AND PERFORMANCE TESTING
 In this guidance, the term "performance testing" refers to testing performed for the purpose of
 demonstrating compliance with a regulatory emission limit or performance standard. RCRA trial burns
 and MACT performance tests are both encompassed by this terminology. For hazardous waste
 combustors, performance testing usually includes low-temperature test conditions) to demonstrate DRE
 for POHCs and may include a high-temperature test condition to demonstrate SRE for metals.

 The risk burn may be associated with (1) low-temperature test conditions conducted to demonstrate DRE of
 POHCs, (2) a high-temperature SRE test condition conducted to establish metal feed rates and to account
 for metals emissions and partitioning, and/or (3) a separate test condition (which may be conducted at
 normal operating conditions) specifically for the collection of risk assessment data. Fewer permit
 limitations based on the risk burn may be necessary when the risk burn can be performed in conjunction
 with a RCRA trial burn or MACT performance test. A greater number of permit limitations may be
 necessary when the risk burn and performance tests reflect different operating modes.
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 Decisions regarding integration of the risk burn and DRE/SRE performance tests are not intuitive. The
 objectives and parameters for each potential test condition should be carefully evaluated, and the
 similarities and conflicts identified. Adjustments may be necessary in order to combine test conditions.
 The remainder of Chapter 3 presents information to guide permit writers and facility personnel through
 considerations which affect test design.  A flow chart (Figure 3-1) provides an overview of the process.
3.3.1
Combined Testing
 In deciding whether to perform the risk burn in conjunction with DRE/SRE performance testing, EPA
 OSW recommends that practical considerations, such as timing, be considered, as well as the following
 factors:

     •       emissions evaluation;
     •       waste selection and feed parameters;
     •       operating parameters.
 3.3.1.1
Emissions Evaluation
 Section 3.2.2 discusses EPA OSW's recommendation that a preliminary emissions and risk evaluation be
 conducted to assess the heed for emissions reductions prior to the risk burn. An emissions evaluation also
 provides information that can be factored into the decision of whether to integrate the risk burn and
 DRE/SRE performance tests. As discussed in Section 1.3.1, DRE and SRE tests are generally conducted
 under "worst-case" conditions which tend to maximize emissions. For example, the SRE test may involve
 spiking to increase metal feed rates above  normal levels, resulting in high metal emission rates. However,
 combustion risk assessments typically assess potential risks associated with operation over 30 or more
 years (EPA 1998a).  Incorporating emissions data from DRE and/or SRE testing into the site-specific risk
 assessment could be overly conservative, given that a facility will not operate at the edges of its operating
 envelope or emit at maximum levels for the entire time. Under certain circumstances, it may be appropriate
 to consider emissions data generated during normal operation of the combustion unit in the risk assessment.
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  Emissions during normal operations (as compared to emissions during DRE or SRE conditions) may better
  represent the average emissions and risks posed by the combustion facility over its operating life.

  When "worst-case" emissions from the DRE/SRE test conditions are not projected to pose a significant
  risk to human health and the environment; then a facility may choose to minimize the number of test
  conditions and resulting permit limitations by combining the risk burn and performance tests. Otherwise,
  the facility and permit authority might explore the possibility of performing the risk burn (or a portion of
  the risk burn) under normal operating conditions as a separate test effort.  The option of collecting data
  under normal conditions is discussed further in Section 3.3.2.1.

  It is important to keep in mind that different approaches may be chosen for different constituents (D/Fs,
  non-D/F organics, metals, etc.). In addition, the risk assessment can be performed using information other
  than actual test data for certain constituents. For example, emission rates for some metals can be
  calculated from metal feed rates and conservative zero SRE assumptions (i.e., no partitioning or removal).
  A facility may also choose to evaluate a regulatory emission limit for a particular constituent in the risk
  assessment instead of actual test data (in this case, testing simply confirms whether and under what
  conditions the regulatory standard can be met). EPA OS W recommends that the risk burn plan and risk
  protocol clearly designate which emissions levels for the risk assessment will be based on actual test data,
  and which emission values will be supplied from another source.  These choices are discussed further in
  Sections 3.5 and 8.2.
 3.3.1.2
Waste Selection and Feed Parameters
 Waste selection and feed parameters may also influence the decision of whether to perform the risk burn in
 conjunction with a DRE or SRE performance test. As discussed later in Chapters 4 and 5, EPA OSW
 recommends that representative wastes generally be burned during collection of risk burn emissions data
 for D/Fs and non-D/F organics, and that actual wastes, and not surrogate wastes synthesized from pure
 compounds, be used to the extent possible.
 In some cases, the preference for use of actual waste during the risk burn may be incompatible with the
 waste selection criteria for the DRE or SRE performance test. For example, synthetic "wastes" (wastes

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mixed from pure compounds) are sometimes utilized during performance tests to achieve the worst-case
conditions targeted for those tests. Synthetic wastes may be chosen for ORE or SRE performance tests
because of analytical interferences between the designated POHCS and constituents present in actual
wastes, because of incompatibilities between actual wastes and spiking materials, or because actual waste
volumes are insufficient for completion of three runs per test condition. If circumstances preclude use of
actual wastes (or actual waste spiked with POHCs or other compounds) during the DRE or SRE test
conditions, then integration of risk-based data collection with performance testing may not be an
appropriate option. Additional information on balancing the use of real wastes versus synthetic wastes is
found in Section 5.2.2.

This document also identifies key feed parameters which may affect emissions of D/Fs (Chapter 4), non-
D/F organics (Chapter 5), metals (Chapter 6), and HCyC^ (Section 7.1), and which EPA OSW
recommends be demonstrated during the risk burn. Feed parameters associated with DRE and SRE testing
are identified by regulations, and additional recommendations are discussed in other guidance (EPA 1983,
1989 and 1992b). If there is close overlap and little conflict between the risk burn and DRE/SRE feed
targets, then a facility may prefer to integrate the risk burn and performance tests. Otherwise, it might be
preferable to perform the risk bum (or a portion of the risk burn) as a separate test effort.
3.3.1.3
Operating Parameters
The operating parameters to be demonstrated during the risk burn may also influence whether the risk bum
is performed in conjunction with a DRE or SRE performance test, or as a completely separate test effort.
This document identifies key operating parameters which may affect emissions of D/Fs (Chapter 4), non-
D/F organics (Chapter 5), metals (Chapter 6), and HCl/C^ (Section 7.1), and which EPA OSW
recommends be demonstrated during the risk burn. Operating parameters associated with DRE and SRE
testing are identified by regulations, and additional recommendations are discussed in other guidance (EPA
 1983,1989 and 1992b). If there is close overlap and little conflict between the risk burn and DRE/SRE
operating targets, then a facility may prefer to integrate the risk burn and performance tests. Otherwise, it
might be preferable to perform the risk burn (or a portion of the risk burn) as a separate test effort.
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3.3.
                    Separate Testing
 Section 3.3.2 identifies circumstances where it may be appropriate to perform the risk burn independently
 from the DRE/SRE performance tests. In some situations, a facility may prefer to perform all or part of
 the risk burn under, normal operating conditions to better represent the average emission levels expected
 over the operating life of the unit. Testing at normal conditions is discussed in Sections 3.3.2.1 and
 3.3.2.2. Alternatively, separate testing may be appropriate because of logistical conflicts, such as timing,
 or to resolve a conflict between the risk burn and DRE/SRE waste feed or operating targets. Separate
 testing to resolve a conflict is discussed in Section 3.3.2.3.
 3.3.2.1
                   Testing at Normal Conditions
 As explained in Section 3.3.1.1, it may be appropriate in certain circumstances to perform the risk
 assessment using emissions data generated during normal operation of the combustion unit.  If a facility
 requests that emissions data collected under normal operating conditions be evaluated in the risk
 assessment, then an additional test condition (separate from the DRE/SRE test conditions) may be
 suggested in the risk bum plan. This additional condition is optional and is performed by the facility on a
 voluntary basis.
 The permitting authority should generally consider proposals for use of emissions data generated under
 normal operating conditions in the risk assessment (in conjunction with or instead of data generated during
 a DRE or SRE test) on a case-by-case basis. Additional permit limitations may be needed to ensure that
 conditions represented as normal during the test are, in fact, normal over the long-term operation of the
 facility.

 Some facilities may view the prospect of extra permit limitations as a disincentive to performing the risk
 burn (or a portion of the risk bum) under normal operating conditions. However, the "verification" phase
 of risk-based permitting has been explained in Section 3.1, and the logic is repeated here for emphasis. The
 permit endeavors to prevent operation at conditions which could result in higher emissions than those
 evaluated in the risk assessment and found to pose an insignificant risk to human health and the
 environment. If emissions data from testing at normal conditions are evaluated in the risk assessment (in

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 lieu of emissions data from "worst-case" DRE/SRE testing) and it is determined that such emissions do not
 present a significant risk to human health and the environment, then the permit should generally ensure that
 those emissions, on average, are not exceeded over the long term. Operating limitations from the
 DRE/SRE test conditions may not offer this assurance, because they represent operating extremes and
 elevated emissions. Thus, additional operating limitations may be needed to assure protection of human
 health and the environment. Although these extra permit limitations may indeed be viewed by some
 facilities as a disincentive to performing a risk bum under normal operating conditions, the decision to
 pursue testing at normal conditions rests completely with the facility.

 It is important to mention that data from testing under normal conditions and data from testing under
 "worst-case" DRE/SRE conditions may sometimes be evaluated in a risk assessment as two completely
 separate risk scenarios (for example, to support a more informative risk communication strategy).
 Provided that "worst-case" emissions from DRE/SRE test conditions are evaluated in the risk assessment
 and it is determined that they do not present a significant risk to human health and the environment, then
 extra permit conditions to assure normal operation should not be necessary. Under these circumstances, the
 regulatory and permit limitations associated with the DRE/SRE testing would ensure that ongoing
 emissions remain below levels that may present a significant risk to human health and the environment.
 3.3.2.2
Defining and Verifying Normal Conditions
 Emissions data collected under normal operating conditions may reflect lower emission rates and lower, but
 more representative, potential risks. However, it may not be appropriate for every facility to use emissions
 data collected under normal conditions in the risk assessment. EPA OS W recommends that the following
 be considered when determining whether to test at normal conditions:

 1.      Can the facility provide sufficient information to define normal feed and operating conditions?
        To use emissions data generated during testing at normal conditions in the risk assessment (in lieu
        of data generated during a DRE or SRE test), a facility should be able to characterize "normal" for
        their operations. This characterization could involve plotting control parameters over time,
        assessing typical variation, determining means and standard deviations, characterizing feed
        variability, or a combination of these and other approaches. For the feed characterization, EPA
        OS W recommends that both the hazardous and non-hazardous inputs (including fossil fuels, raw
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         materials, and non-hazardous wastes) be considered. For example, mercury in coal can contribute
         to potential risks and should be considered in the feed characterization.

         Successful characterization of "normal" may be more probable when a facility burns wastes that
         have little temporal variation in chemical and physical properties, at relatively constant rates, and
         under operating conditions that do not fluctuate widely. Facilities that do not operate within these
         guidelines, including facilities that burn highly variable wastes, could experience more difficulty
         defining "normal." If a facility cannot define "normal" for their operation, collection of data for the
         risk assessment may need to be performed in conjunction with the DRE/SRE conditions.

         Site-specific factors will inform what constitutes a "normal" test condition.  However, a "normal"
         test can generally be characterized as a test where each control parameter is maintained either near
         the historical mean, or between the historical mean and the maximum or minimum set point (as
         appropriate), while burning representative, but challenging, feeds. The goal for burning
         representative, but challenging, feeds simply means that wastes which may cause elevated or more
         highly toxic emissions are preferred for the test. Examples include difficult-to-burn wastes, wastes
         that contain dioxin/furan precursors, or wastes that contain toxic or bioaccumulative constituents.
         For example, a hexachlorobenzene waste stream would be preferred over a methanol stream if both
         are routinely processed.

 2.      Can the facility identify additional permit limitations and record keeping provisions to ensure
         that the facility does not operate in excess of the normal conditions over the long term?

         Facilities choosing to use emissions data collected under normal operating conditions in the risk
         assessment (instead of data collected under "worst-case" DRE/SRE conditions) may be subject to
         additional permit limitations as necessary to protect human health and the environment. Additional
         limitations may be necessary to ensure that, on average and over the long term, emissions remain
         within the boundaries represented by a risk assessment. The permit terms  may include long-term
         (monthly, quarterly, semiannual, and/or annual) average limits for certain control parameters, or
         use of control charts similar to those used for industrial quality control.  For example, the control
         charts could be used to ensure that long-term variation does not exceed one or two standard
         deviations from the mean. Waste tracking and record keeping may also be specified. The permit
         may specify that significant changes be reported to the permitting authority.  These changes  may
         be subject to review and determination of the need for possible retesting.

         Permitting approaches involving long-term averaging should generally be considered very
         carefully. In some cases, long-term averaging may not achieve the intended objective of
         maintaining ongoing emissions at levels that do not present a significant risk to human health and
         the environment.  The main consideration, for a given control parameter, is whether high emissions
         caused by short-term perturbations outside of a certain operating range can be offset by lower
         emission rates during periods of more normal operations.  A long-term averaging period may be
         utilized effectively when a control parameter exhibits a linear relationship with  emissions. For
         example, elevated metals emissions from higher metals feed rates can generally be offset by
         commensurate periods of operation at lower metal feed rates. However, for other parameters,
         perturbations simply increase overall emissions. For example, when an interruption in caustic feed
         to a scrubber causes excess acid gas emissions, a facility cannot compensate by subsequently
         adding more caustic. In this situation, a long-term averaging approach may not be appropriate.
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       The facility should propose a permitting approach for ensuring that, over the long term, the unit
       does not operate in excess of the conditions represented as normal during the test. Most likely, the
       approach will closely mirror the approach used to define "normal" in the first place. It should
       generally not be necessary for the permit approach to be so conservative that operation during the
       "normal" test is driven towards the extreme edges of the operating envelope (thereby negating the
       point of the normal test). On the other hand, if testing near an operating extreme seems necessary
       to reflect variations in everyday operation, then it may be appropriate to reconsider whether
       "normal" can truly be defined for that operation.

3.      Are there additional site-specific considerations?

       It may be appropriate to use emissions data collected under DRE and/or SRE conditions in the risk
       assessment because of other circumstances, such as acute risk concerns. For some constituents,
       direct inhalation may cause short-term or acute effects. In these situations, EPA OS W has
       recommended that a maximum, 1-hour emission rate be evaluated in the risk assessment (EPA
        1998a). Maximum emission rates are generally achieved under DRE and/or SRE conditions.
One example of a situation where it may be appropriate to use emissions data collected under normal
operating conditions in the risk assessment is a BIF facility that wishes to perform testing for metals at

normal conditions. If the facility can provide historical data to characterize normal metal feed rates
(consistent with the recommendations in Section 3.3.2.2) and if monthly-average metal feed rate permit

limits could be established based on the risk bum to assure that ongoing operation remains within the range

represented as normal during the test (consistent with the recommendations in Section 3.3.2.2), then it

might be appropriate to use emissions data collected under normal operating conditions in the risk
assessment. The recommended testing and permitting approach for this situation follows:


     •      SRE Test:  The SRE test is conducted at maximum metals feed rates, and could involve
            metals spiking. Emissions from the SRE test are required to be below allowable BIF emission
             limits (which are based only on inhalation risks) pursuant to 40 CFR § 266.106. Hourly
            rolling average metal feed rate limits are established in the permit based upon this test.

     •      Normal Test: This.test is conducted at normal metals feed rates, without metals spiking.
            Emissions data from the normal test are evaluated in the risk assessment to determine
            potential risks from both direct and indirect exposures. Monthly-average metal feed rate
             limits are established in the permit based upon this test.
 An example of a situation where it may not be appropriate to use emissions data collected under normal
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 operating conditions in the risk assessment is a commercial facility with a diverse customer list that
 randomly burns any hazardous waste available on the test day.  This facility may not be able to identify a
 specific waste that represents normal operations, or may not choose to commit to a waste inventory
 tracking scheme and long-term averaging to assess whether the test waste remains representative. In this
 case, it may be more appropriate to collect emissions data for the risk assessment during "worst-case"
 DRE/SRE performance tests.                                             i

 In summary, emission rates (and related feed and operating conditions) that are evaluated in the risk
 assessment should clearly correspond to potential permit terms and conditions. The permit terms can
 ensure protection of human health and the environment by prohibiting operations outside of the operating
 boundaries represented by a risk burn and risk assessment that demonstrates emissions will not pose a
 significant risk. The permit writer should work closely with the facility to determine the appropriate test
 condition(s) for collection of risk burn data and a corresponding permit approach.
 3.3.2.3
Separate Testing to Resolve a Conflict
 Even if a facility does not choose to perform risk burn testing at normal conditions, it may be appropriate
 to perform the risk burn (or a portion of the risk burn) independently from the DRE/SRE performance tests
 to resolve a conflict. The risk burn may be performed independently because of logistical conflicts (for
 example, the DRE/SRE testing may have already been completed before the need for risk burn data was
 identified).  The risk burn may also be performed independently to resolve a conflict between the risk burn
 and DRE/SRE waste feed or operating targets.

 Conflicting parameters are key control parameters that cannot be demonstrated simultaneously (e.g.,
 maximum combustion gas velocity and minimum fabric filter pressure differential). A facility may
 encounter conflicts when attempting to integrate the key control parameters for risk testing (identified in
 Chapters 4 through 7) with key control parameters associated with DRE/SRE performance testing. To
 overcome a conflict, it may be appropriate for a facility to perform duplicate tests as follows:
             A first set of operating conditions to set limits for all control parameters, excluding the ones
             in conflict;
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             Additional operating conditions) to set limits on the conflicting control parameters. To the
             maximum extent practicable, only the conflicting parameters should be varied from the first
             set of operating conditions. All non-conflicting parameters should be maintained as constant
             as possible during all operating conditions.
 As discussed in Sections 3.3.1.2 and 3.3.1.3, it is recommended that the risk burn (or a portion of the risk
 burn) be performed independently of DRE/SRE testing when actual wastes are not utilized for the
 DRE/SRE test, or when there is a conflict between the risk burn and DRE/SRE feed or operating targets.
 3.4
RISK-BASED DATA COLLECTION, EXAMPLE LOGIC
 Figure 3-1 provides example logic (based on the recommendations discussed throughout this chapter) for
 permit writers and facility personnel to consider in determining appropriate test conditions for the risk burn.
 The first step involves determining whether emissions demonstrated under DRE and SRE conditions are
 anticipated to present a significant risk to human health and the environment, considering target risk levels
 as specified by the regulatory agency.  EPA OS W recommends that this question be answered by
 evaluating existing emissions data, by conducting "mini-burns" (as allowed by existing permit or interim
 status conditions), or by evaluating data from similar facilities in a preliminary risk assessment.

 Based on preliminary data analysis, a facility may anticipate that emissions data collected during
 performance testing (DRE and SRE conditions) will indicate that facility emissions do not pose a
 significant risk to human health and the environment. This situation is represented on the right-hand side of
 the flow chart. The permit writer would then work with the facility to determine whether the control
 parameters identified in Chapters 4 through 7 of this document can be demonstrated concurrently with
 parameters to be demonstrated during the DRE and SRE tests. If so, then it may be appropriate to perform
 the risk burn in conj unction with the DRE and SRE test conditions.
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                                              FIGURE 3-1


                   RECOMMENDED SITE-SPECIFIC RISK ASSESSMENT
                             DATA COLLECTION FLOW CHART
                            Yes
 Are emissions from DRE/SRE
performance tests likely to pose
 significant site-specific risks?
                                                                                   No
     Yes
            Can normal conditions be
            defined and maintained?

                          No
    Implement process
    changes to reduce
        emissions.
                                                                       Yes
              Can adjustments be made to
                define normal operating
                     conditions?
       No

                           Yes
              Adjust operating parameters to
                achieve normal operating
                      conditions.
                         Testing
             Perform additional testing at normal
             operating conditions for collection of
                      risk bum data.
  Will risk burn control
parameters (Chapters 4-7)
 be demonstrated during
   performance tests?
                                                                                           i
                                                                                               No
                                         Adjust or add test
                                      conditions as necessary to
                                        demonstrate risk burn
                                         control parameters.
                                                                                       &£S&k&:*
                                             Testing
                                       Collect risk bum data in
                                          conjunction with
                                         performance tests.
                   Site-Specific Risk Assessment
              Evaluate emissions data from the normal test
                       in the risk assessment.

                        Permit Limitations
                  Establish limits for risk bum control
              parameters as appropriate. Additional permit
              limitations may be necessary to ensure that
                normal operations are maintained on an
                          ongoing basis.
                          Site-Specific Risk Assessment
                          Evaluate emissions data from the
                       performance test in the risk assessment.

                               Permit Limitations
                         Establish limits for risk bum control
                         parameters as appropriate. Permit
                         limitations for assurance of normal
                            operation are not necessary.
                   Normal Test Conditions
                            Performance Test Conditions
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In some cases, the control parameters identified in Chapters 4 through 7 of this document may not be
targeted for demonstration during the DRE or SRE test conditions. In these circumstances, it may be
appropriate to adjust the DRE/SRE test conditions to demonstrate appropriate control parameters from
Chapters 4 through 7, or add extra test conditions as described in Section 3.3.2.3. An example is a
hazardous waste boiler that is equipped with a dry APCD for particulate control, but whose waste feeds
contain no metals. Since the waste feed does not contain metals at detectable levels, the facility is not
required (pursuantto 40 CFR §§ 266.102 and 266.106) to perform a maximum temperature SRE test or to
establish maximum inlet temperature limit for the dry APCD to control metals.  However, Section 4.2.1.3
recommends maximum inlet temperature to a dry APCD as a primary control parameter related to D/F
emissions. If the boiler cannot demonstrate maximum APCD inlet temperature during the DRE test
(because of an inability to control APCD temperature independently of combustion temperature, which
would be at a minimum), then it is recommended that an extra test condition be added to the test plan
specifically to demonstrate maximum APCD temperature while sampling for D/Fs.  [Note: The facility
could also provide information to justify D/F testing while operating at normal APCD temperature.
However, as explained in Section 4.2.1.3, the exponential relationship between D/F emissions and APCD
temperature complicates the ability to assure that D/Fs will be maintained at normal levels on an ongoing
basis.]

In some situations, the preliminary data analysis might suggest that a facility's worst-case emissions (as
measured during performance testing under DRE and SRE conditions) may pose potential risk to human
health and the environment if it is assumed that these emissions levels are present all of the time.  This
situation is represented on the left-hand side of the flow chart. In these circumstances, EPA OSW
recommends two options: (1) demonstrate that normal operating conditions can be defined and maintained
and perform additional testing at normal conditions; (2) implement process changes to reduce emissions and
meet risk-based limits under DRE and SRE conditions. Process changes can include changes to improve
combustion efficiency (including burner design and methods of feeding wastes), reductions in feed rates of
certain toxic constituents (like metals), or the addition/modification of air pollution control systems.
 Facilities that demonstrate the ability to define and maintain normal operating conditions may be subject to
 additional permit terms as necessary to protect human health and the environment to ensure that the
 conditions represented as normal during the test are, in fact, normal over the long-term operation of the
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facility. These terms can include long-term average permit limitations for waste feed rates, temperatures,
and other appropriate control parameters, use of control charts, and/or waste tracking and record keeping.

These facilities may also be asked to submit a compliance monitoring plan to demonstrate how compliance

with the permit terms will be maintained and documented.
 3.5
TEST PLAN SUMMARY INFORMATION
A common understanding regarding how the final permit limits will be developed is integral to the design of

the test protocol, and early communication and coordination between the permit writer and facility is

essential. The permit writer is responsible for identifying control parameters which may be limited in the

permit, and for explaining how specific permit terms may be established based on the test results. The

permit writer should generally rely on the facility owner/operator to ensure that risk burn operating

conditions are targeted in a manner that supports permit terms that are acceptable to the facility. EPA

OSW recommends that the following specific types of information generally be included in the test plan to

facilitate this process:
            For each type of emissions data to be evaluated in the risk assessment (D/Fs, non-D/F
            organics, metals and HCl/Cy, an explanation as to whether the facility expects for the risk
            assessment to be performed using: 1) emissions data from a trial burn or performance test; 2)
            emissions data from a normal test, or 3) other information, such as a regulatory standard or
            zero SRE assumptions for metals.

            For instances where the risk assessment will be performed using emissions data from a
            normal test, supporting narrative and historical information as necessary to characterize
            "normal" for the specific operations, as well as a proposed permit approach for assuring that
            conditions remain within those represented as normal on an ongoing basis.

            For each test condition, a narrative discussion explaining the overall objectives and approach,
            as well as a summary matrix listing:

                    The type of test condition (e.g., DRE, SRE, normal, etc.);

            -      Emissions data to be collected and regulatory performance standards to be
                    demonstrated;

            -      The proposed feed characteristics and operating targets for each relevant control
                    parameter. Control parameters include those listed in Chapters 4 through 7, as well as
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                     the control parameters that will be demonstrated during trial burn or performance
                     testing for ORE, SRE, particulate matter, and HC1 an
             A list of conflicting parameters (key control parameters that cannot be maximized or
             minimized simultaneously), along with a detailed explanation of the reasons for the conflict.
             The two or more test conditions that will be performed to resolve the conflict should be
             described, and changes in other control parameters that may be necessary to resolve the
             conflict should be identified.

             A complete list of control parameters which are expected to be limited in the permit.  This list
             should be consistent with the proposed test conditions and the following information should be
             included for each control parameter:

             -      The anticipated permit limit, assuming that all test conditions are executed as
                     planned;

             -      An indication of whether the permit limit will be based on the trial burn or other
                     information (such as a zero SRE assumption for metals);

             —      Specific information on how each permit limit will be established based on trial bum
                     results. This information includes specifying the test condition that will be used to
                     establish the numerical limit and how the numerical limit will be calculated (such as
                     the average over all test runs).

             -      Specific information on how each control parameter will be monitored and recorded
                     to demonstrate compliance with the permit limit (i.e., whether the control parameter
                     will be continuously monitored, the type of record to be maintained and the recording
                     frequency, and what averaging period will be used for the compliance determination).

             -      Statements as to whether the parameter will be interlocked with the AWFCO system,
                     and the corresponding proposed set point.
 EPA OSW recommends that the risk burn be integrated with DRE/SRE performance testing as necessary

 to produce a consistentset of enforceable permit conditions. When permit terms will be established from

 multiple test conditions, the complete list of anticipated limitations should be reviewed for internal
 consistency and potential conflicts.
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                                   CHAPTER 4
                DIOXIN AND FURAN EMISSIONS
 D/Fs can pose significant risks through both direct and indirect exposure pathways. This chapter reviews
 EPA OS W's recommendations for specific operating and feed parameters to be considered for
 demonstration during collection of D/F emissions data for risk burns. Depending on site-specific
 considerations, it may be necessary to limit certain of these control parameters in the RCRA permit to
 protect human health and the environment by ensuring that D/F emissions remain within the levels
 measured during the risk burn on an ongoing basis.

 D/F formation is an extensive and complex subject.  This chapter starts with general information and
 becomes progressively more specific.  Background information regarding formation mechanisms is
 provided in Section 4.1. Key control parameters are reviewed and summarized in Section 4.2, and the
 relevance of the parameters for each industry category (incinerators, boilers, cement kilns, and lightweight
 aggregate kilns) is discussed in Sections 4.3 through 4.6. Tables 4-1 and 4-2 summarize the
 recommendations by industry category.

 This guidance relies on available research and emissions databases to draw general conclusions and provide
 recommendations. However, it is important to note that this guidance cannot encompass every situation.
 Permit writers should evaluate facility-specific operating trends and information in conjunction with the
 principles summarized in this document in order to make their facility-specific permit decisions.
 4.1
DIOXIN AND FURAN FORMATION MECHANISMS
 D/Fs can result from a combination of formation mechanisms, depending on design, combustion conditions,
 feed characteristics, and type and operation of APCD equipment. D/F formation mechanisms have been
 studied since the late 1970s when D/Fs were found in municipal waste combustor emissions.
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 Lustenhouwer originally advanced three theories to explain the presence of D/Fs (Lustenhouwerand others
 1980). The theories may now be described as:

 1.   Survival of trace D/Fs in the fuel.
 2.   D/F formation from gas-phase precursors which are chemically similar to D/Fs, such as chloro-
      aromatics, via
      a.      homogeneous (gas-gas phase) reactions, or
      b.      heterogeneous (gas-solid phase) condensation reactions between gas-phase precursors and a
             catalytic particle surface.
 3.   De novo synthesis of D/Fs from carbon sources that are chemically quite different from the dioxin and
      furan ring structures. De novo synthesis involves heterogeneous, surface-catalyzed reactions between
      carbonaceous particulate and an organic or inorganic chlorine donor.

 It is now generally accepted that Theory (1) cannot explain the levels of D/F emissions which have been
 measured from combustors. Most combustion units do  not burn D/F contaminated wastes, and Schaub and
 Tsang have noted that the gas-phase thermal destruction efficiency for D/Fs is high at the flame
 temperatures typically achieved in a combustion unit (Schaub and Tsang 1983). D/Fs have been found to
 decompose rapidly at temperatures above 1700 °F (Schaub and Tsang 1983).

 Theory (2a) is also believed to play a relatively minor role in the D/F emissions from combustion facilities.
 An early kinetic model developed by Schaub and Tsang suggested that the homogeneous gas-phase rate of
 formation could not account for observed yields of D/Fs (Schaub and Tsang 1983). At the high
 temperatures in a combustion zone, the multi-step process necessary for D/F formation cannot compete
 with destruction. Although Sidhu and others have subsequently demonstrated pure gas-phase formation of
 D/Fs (Sidhu and others 1994), the minor role of homogeneous gas-phase formation is evidenced by
 numerous field measurements which show higher D/Fs downstream of the combustion chamber than in the
 flue gases immediately exiting the combustion chamber (Gullett and Lemieux 1994).

 D/F emissions from combustion devices are now believed to result primarily from heterogeneous, surface-
 catalyzed reactions in the post-furnace regions of the unit (Theories 2b and 3).  Experimental evidence
 suggests that these reactions occur within a temperature range of approximately 390 to 750 °F (200 to
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400 °C) or wider, with maximum formation occurring near 570 °F (300 °C) (Kilgroe and others 1990).

Theories (2b) and (3) are both characterized by heterogeneous, surface-catalyzed reactions. Dickson
summarizes the distinctions between the two heterogeneous formation pathways (Dickson and others 1992).
Theory (2b) can be distinguished by reactions involving gas-phase chloro-aromatic precursors which might
already be present in the fuel, or which could be formed as products of incomplete combustion (Karasek
and Dickson 1987; Dickson and Karasek 1987).  Theory 3 does not require that chloro-aromatic precursors
be present on fly ash or in the gas stream. Instead, both the chloro-aromatic precursors and D/Fs may be
synthesized de novo from gas-solid and solid-solid reactions between carbon particulates, air, moisture and
inorganic chlorides in the presence of a metal catalyst, primarily divalent copper (Stieglitz and others
 1989a and  1989b). Activated carbon has also been implicated as a catalyst (Dickson and others 1992).

Dickson has performed studies to quantitatively determine the relative predominance of the two
heterogeneous formation pathways (Dickson and others 1992). Yields of polychlorinateddibenzo-/?-dioxin
from the precursor compound pentachlorophenol were 72-99,000 times greater than yields formed from
reactions of activated charcoal, air,  inorganic chloride and divalent copper catalyst under identical reaction
 conditions. Citing the kinetic work of Altwicker (Altwicker and others 1990a), Dickson postulated the
 following:

      •       fast reactions involving chloro-aromatic precursors may be expected to predominate in the
             post-combustion and heat exchanger sections of a combustor, where the temperatures range
             from 600 to 250 °C and the residence time of the gas stream and entrained particulates is on
             the order of 1 second, and
      •       slower processes such as de novo synthesis may influence D/F emissions in dry pollution
             control equipment, where paniculate residence times vary from 1 to about  1000 seconds.

 Although both mechanisms may contribute to observed D/F emissions, Gullett and Lemieux have shown
 that "in flight" formation alone (at residence times less than 5 seconds) is sufficiently rapid to explain the
 D/F  concentrations measured in the field (Gullett and Lemieux 1994).
 Molecular chlorine (C12) appears to play a role in D/F formation by chlorinating aromatic D/F precursors
 through substitution reactions. Chlorination of phenol has been shown to be three orders of magnitude

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  greater with C12 than with HC1 (Gullett and others 1990). Although HC1 does not directly participate in
  precursor chlorination to a significant degree, it can produce molecular chlorine via the Deacon reaction
  (Griffin 1986; Gullett and others!990):
2HC1 + !4   < —
  where:
HC1
O2
C12
H2O
                          > C12 + H2O, with copper or other metals serving as catalysts      (Equation 1)
                     hydrogen chloride
                     oxygen
                     chlorine
                     water
  The Deacon reaction depends on the presence of a metal catalyst to overcome kinetic limitations which
  would otherwise limit the production of C12 from HC1 (Griffin 1986). However, the metal catalyst also
  serves another important function. Once the aromatic rings have been chlorinated, the metal catalyst
  supports condensation reactions to form the D/F dual ring structure (Bruce and others 1991; Gullett and
  others 1992).  Gullett has shown that formation of the dual ring structure (biaryl synthesis) is enhanced up
  to three orders of magnitude in the presence of metal catalysts, such as divalent copper (Gullett and others
  1992). Based upon testing with nine different metals and oxidation states, divalent copper appears to
  demonstrate the strongest catalytic activity (Gullett and others 1992;  Stieglitz and others 1989a).

  Radical Cl also appears to play a role in D/F formation. Recent work by Gullett shows that radical Cl
  persists to temperatures where hydrocarbon chlorination occurs (Gullett and others 2000a). This
  mechanism is a likely chlorination route, and is influenced by combustion conditions and their effect on Cl
  radical persistence.

  Sulfur has been shown to decrease D/F emissions. Substantially lower D/F emissions have been observed
  from coal-fired power plants than from municipal waste combustors, even though coal-fired utilities
  operate under conditions that should generally be conducive to D/F formation. The sulfur/chlorine ratio of
 the fuel may explain the difference. The typical S/C1 ratio in a municipal waste combustor is about 0.2,
 which is approximately an order of magnitude lower than that found in coal combustion (Raghunathan and
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 Gullett  1996). Raghunathanand Gullett have demonstrated significant D/F reduction at S/CI ratios as low
 as 0.64 in a natural-gas-firedfurnace, and as low as 0.8 in a coal-fired furnace (expressed as uncorrected
 furnace concentrations of parts per million SO2 /HC1). Additional work has shown that D/F formation is
 substantially inhibited when the S/CI ratio is greater than about 1:1 (Gullett and Raghunathan 1997).

 Researchers have concluded that sulfur may interfere with D/F formation by (1) SQ, depletion of C12
 (Equation 2), and (2) SO2 poisoning of copper catalysts (Equation 3) to prevent biaryl synthesis (Griffin
 1986; Gullett and others 1992; Bruce 1993; Raghunathanand Gullett 1996):
     C12 + SO2 + H2O <=> 2HC1 + SQ
                                            (Equation 2)
where:
    C12     =
    SO2
    H2O    ==
    HC1    =
    SO3    =
and:
    CuO + SQ,+  y,
where:
    CuO    =
    SO2
    H2O    =
    CuSO4 =
chlorine
sulfur dioxide
water
hydrogen chloride
sulfur trioxide

    <=> CuSO4


cupric oxide
sulfur dioxide
water
cupric sulfate
                                             (Equation 3)
 It is also possible that poisoning of the copper catalyst may interfere with the Deacon reaction.

 From this background, it is clear that D/F formation involves many complex reactions.  A complete
 understanding of the reaction chemistry may never be possible. However, for units achieving good
 combustion, the most important reactions appear to depend on gas/solid chemistry in cooler zones
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 downstream of the combustion chamber. Conditions conducive to downstream formation include (1)
 presence of particulates, which allow for solid-catalyzed reactions, (2) post-furnace particulate residence
 time in the critical temperature window (approximately 400 to 750 °F), (3) presence of Gl and organic
 precursors, including chloro-aromatics,and (4) a shortage of formation inhibitors, such as sulfur. Poor
 combustion can substantially increase D/F formation, possibly through increased soot formation (providing
 more catalytic reaction sites for D/F formation), increased formation of PICs (which can serve as D/F
 precursors), and increased gas-phase formation of D/Fs, although sufficient oxygen also appears to be
 necessary (Gullett and others, in press). Approaches that have been successfully demonstrated in full scale
 systems for controlling D/F emissions include:

     •       Maintenance of good combustion conditions to limit organic precursors and soot;
     •       Rapid flue gas quenching or other measures to minimize post-furnace particulate residence
             time in the critical temperature zone;
     •       Use of formation inhibitors;
     •       End-of-pipe flue gas cleaning techniques for D/F removal or catalytic decomposition.
 4.2
CONTROL PARAMETERS TO BE CONSIDERED FOR RISK BURNS
 As explained in Section 4.1, researchers have concluded that D/F formation mechanisms in combustion
 systems are extremely complex. D/F emissions cannot be predicted accurately with kinetic models or
 surrogate monitoring parameters such as carbon monoxide or total hydrocarbons (Santoleri 1995). Even in
 systems achieving good combustion (with low carbon monoxide concentrations), D/F formation may occur
 in cooler zones downstream of the combustion chamber (Santoleri 1995). Almost any combination of
 carbon, hydrogen, oxygen, and chlorine can yield some D/Fs, given the proper time and temperature
 (Altwicker and others 1990b; Santoleri 1995). Factors such as non-detect levels of chlorine in feed
 streams, lack of dry APCD systems, presence of D/F inhibitors (such as sulfur), lack of D/F catalysts
 (such as copper), and lack of D/F precursors (such as chloro-aromatics) may lead to reduced or low
 emissions of D/Fs. However, because mechanisms of D/F formation are extremely complex and are not
 well understood, it is not possible to predict with certainty whether a given facility will have significant D/F
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emissions.

Since D/F emissions cannot be predicted, it is recommended that D/F emissions testing be performed to
develop the emissions data for site-specific risk assessments. This section recommends key control
parameters to be considered in establishing D/F test conditions. After the risk burn, these parameters may
need to be limited in the permit to protect human health and the environment by ensuring that D/F
emissions remain below measured levels on an ongoing basis.
Several of the control parameters identified in this section may already be limited in association with the
DRE standard, and a number of the control parameters will be limited pursuant to the requirements of the
hazardous waste combustor MACT rule. To the extent that risks from D/Fs are already adequately
controlled by regulatory limits on key control parameters, then fewer risk-based limits may be needed in the
RCRA permit.  However, if regulatory controls are not applicable or sufficiently comprehensive, then
additional risk-based limits may be warranted.  A greater number of risk-based permit limitations may be
necessary when the risk burn and RCRA or MACT performance tests reflect different operating modes.

In formulating the recommendations in Section 4.2, a conservative approach has been taken. It is
important that D/F emissions not be underestimated for risk assessments. However, a facility is not
precluded from showing, on a site-specific basis, why a less conservative approach may be warranted, or
from following the procedures in Section 3.3.2.1 to show that D/F testing should be performed at normal
conditions to better represent the risk over the facility's operating life. Conservative recommendations are
appropriate for this guidance because the option of testing at normal conditions may not be appropriate for
every facility. EPA OS W recommends that conditions conducive to D/F formation first be reviewed to
ensure that high-emitting operating modes at a facility are not under-represented by the risk assessment.  In
addition, the option of testing at normal conditions depends on whether a permit approach can be developed
to ensure that emissions remain at or below measured levels.  It may be difficult to ensure that "normal"
D/F emissions will be maintained on an ongoing basis after the risk burn because of the non-linear
relationship between D/F emissions and certain control parameters, such as particulate hold-up temperature
(i.e., short-term perturbations outside of a certain operating range can cause high emissions which cannot
be offset during periods of more normal operations). Finally, some level of conservatism in the D/F testing
and permitting approach may be warranted to compensate for the continuing uncertainty regarding D/F
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  formation mechanisms in general.

  Although Section 4.2 presents each control parameter individually, the relative importance of the
  parameters with respect to one another should generally also be considered.  When one or two control
  parameters are clearly dominant for a particular system, there may be little benefit to demonstrating and
  limiting additional parameters. The hierarchical ranking at the end of this section (Section 4.2.6) provides
  information to be considered in addressing this issue.

  Control parameters are categorized according to post-combustion conditions (Section 4.2.1), combustion
  conditions (Section 4.2.2), feed composition (Section 4.2.3), hysteresis/memory effects (Section 4.2.4), and
  D/F control technologies (Section 4.2.5). All parameters may not be relevant for all systems, and the
  information in Section 4.2 should be considered in conjunction with the industry-specific information
  provided in Sections 4.3 through 4.6, as appropriate, as well as facility-specific information.
 4.2.1
Post-Combustion Conditions
 The flue gas temperature profile through the D/F formation region (approximately 400 to 750 °F)
 downstream of the combustion chamber is a critical factor influencing D/F emissions. Even for advanced
 combustor systems where CO levels are nearly zero (indicating complete combustion), downstream
 formation of D/Fs may still be significant (Buekens and Huang 1998).  Post-combustion situations that
 should generally be considered during risk bum planning include:

      •       rapid wet quench systems;
      •       partial wet quench temperatures;
      •       dry particulate hold-up temperatures.
 4.2.1.1
Rapid Wet Quench Systems
     Recommendation—EPA OSW recommends that facilities-with rapid wet quench systems and "-wet'
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     APCD systems perform risk burn testing for D/Fs in conjunction with the DRE test conditions,
     whenever possible. IfD/F testing during the DRE test is not feasible (for example, due to timing)
     consideration may be given to testing at normal conditions, where appropriate (see Section 3.3.2.2).

     During the risk burn, demonstration of specific control parameters associated with the rapid
     quench system should generally not be necessary. Consequently, permit limits for the rapid wet
     quench system based on the test are not expected to be needed. However, controls based on design
     specifications may be appropriate in some cases to assure that the quench continues to function
     properly.

 A rapid quench system involves rapid liquid quenching (on the order of milliseconds) from combustion
 temperatures to saturation temperatures. Facilities with "wet" APCD trains, such as venturi and packed
 bed scrubbers, utilize rapid wet quench. Wet scrubbers by design operate at stack gas dew point
 temperatures, which typically range from 170 to 200 °F. Thus, a flue gas exit temperature limit for the
 quench column or wet scrubbing device is not necessary to ensure that particulates are not held up in the
 critical 400 to 750 °F temperature window.  (Note: This discussion applies to facilities with completely
 "wet" APCD trains.  Temperature limits may be needed for facilities with "dry" APCD components that
 only perform a partial wet quench prior to a dry APCD, or that initially perform a full que'nch, but then
 reheat flue gases downstream of the wet scrubbing system and prior to a dry APCD. Sections 4.2.1.2 and
 4.2.1.3 address these situations.)

 In systems that perform rapid flue gas cooling from combustion temperatures to saturation (below 200 °F),
 surface-catalyzed D/F formation reactions are effectively precluded. Hazardous waste combustion
 facilities utilizing wet APCD systems are among the lowest-emitting sources of D/Fs (EPA 1999d;
 Santoleri 1998). A database containing more than 40 test conditions indicates that D/F emissions from
 these facilities are almost always less than 0.4 nanograms (ng) TEQ per dry standard cubic meter (dscm),
 and are often less than 0.1 ng TEQ/dscm (EPA 1999d). Ullrich describes reductions in D/F emissions
 which can be achieved through the use of a rapid liquid quench (Ullrich and others 1996).

 A notable exception to the low D/F emissions trend for rapid wet quench systems is documented for one
 source (Source ID No. 330) where two test conditions showed average D/F emissions of 33 and 39 ng
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 TEQ/dscm, and an individual test run reached a maximum of 76 ng TEQ/dscm (EPA 1999d; Santoleri
 1998). This source was burning waste oils with high levels of PCBs (30%). Although other PCB-burning
 sources have demonstrated low D/F emissions (EPA 1999d), it is possible that the PCBs or PCB
 combustion breakdown products could be responsible for significant gas-phase precursor formation of
 D/Fs at Source ID No.330.

 The anomalous nature of the high D/F emissions at Source ID No. 330 emphasizes the inherent uncertainty
 in attempting to predict D/F emissions trends in lieu of actual emissions testing. Even in rapid wet quench
 systems where post-furnace D/F formation reactions are effectively precluded, the possibility of high D/F
 emissions cannot be ruled out. Incomplete combustion due to mixing inhomogeneities or cold pockets may
 generate D/F precursors, and D/Fs may be formed via gas-phase precursor formation mechanisms in
 regions of the combustion chamber where temperatures are below flame temperatures. These concerns lead
 to the recommendation for performing D/F testing at DRE test conditions (which usually represent
 challenging combustion conditions) for rapid wet quench systems whenever possible. Further information
 regarding the relationship between combustion conditions and D/F emissions is provided in Section 4.2.2.
 4.2.1.2
Partial Wet Quench Temperatures
     Recommendation—EPA OSW recommends that facilities that partially quench flue gases to
     between 570 and 800 °F'prior to a dry air pollution control device perform risk burn testing for
     D/Fs at a maximum post-partial quench flue gas temperature (i.e., at the highest temperature within
     the 570 to 800 "F range that the facility wishes to achieve during post-risk burn operation). For
     some facilities, this condition may occur in conjunction with the high temperature SRE test.  Unless
     historical operating data are provided to indicate little variation in post-partial quench
     temperature, EPA OSW recommends against performing D/F testing at normal or average hold-up
     temperatures.  A permit limit on maximum post-partial quench temperature based on the risk burn
     may be necessary to protect human health and the environment by assuring that the measured D/F
     emissions are maintained on an ongoing basis.
 Facilities with "dry" APCD components, such as fabric filters and ESPs, often utilize a wet quench for flue
 gas cooling prior to the APCD. However, unlike the rapid wet quench situation where flue gases are
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quenched to saturation, the flue gas upstream of a dry APCD is only partially quenched, and APCD inlet
temperatures are maintained well above the dew point.

As explained in Section 4.2.1.1, facilities that rapidly quench flue gases to below saturation temperatures
generally have low D/F emissions. However, this may not necessarily be the case for facilities that perform
only a partial quench.  Waterland and Ghorishi observed significant increases in D/F levels in the flue gas
(more than 2 orders of magnitude) as post-partial-quenchtemperatures increased from 711 to 795 °F
(Waterland and Ghorishi 1997).  The observed residence time was approximately 0.5 seconds. This
phenomenon, termed rapid high-temperature D/F formation, appears to be active in a post-partial-quench
temperature range of 570 to 800 °F (Waterland and Ghorishi 1997).

Based on this information, it appears that post-quench temperatures from partial quench systems can be
important.  Therefore, risk burn testing for D/Fs should generally be performed during a maximum post-
partial quench flue gas temperature condition.  For some facilities, this condition may occur in conjunction
with the maximum temperature SRE test. A permit limit on post-partial quench temperature based on the
risk burn may be necessary to protect human health and the environment by assuring that measured D/F
emissions are maintained on an ongoing basis.

Unless historical operating data are provided to indicate little variation in post-partial quench temperature,
EPA OSW recommends against performing D/F testing at normal or average hold-up temperatures. The
exponential relationship observed between the quench temperature and D/F emissions makes it difficult to
ensure that "normal" D/F emissions will be maintained on a ongoing basis after the risk burn (i.e., the D/F
emissions from one minute of operation at 100 °F above normal cannot be offset by one minute of
operation at 100 °F below normal). It is important that D/F emissions not be underestimated for risk
assessments. However, a facility is not precluded from showing,  on a site-specific basis, why a less
conservative approach may be warranted, or from following the procedures in Section 3.3.2.2 to show .why
D/F testing should be  performed at "normal" quench temperatures.  If testing at normal temperatures is
proposed, the facility should be prepared to explain how a monitoring scheme can be developed to reliably
ensure that D/Fs will be maintained at "normal" levels on an ongoing basis.
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  4.2.1.3
Dry Particulate Hold-Up Temperatures
      Recommendation — EPA OSW recommends that facilities with "dry " particulate hold-up areas
      between 400 and 750 °F downstream of the combustion chamber perform risk burn testing for D/Fs
      at a maximum particulate hold-up temperature (i.e., at the highest temperature within the 400 to
      750 "F range that the facility wishes to achieve during post-risk burn operation). For some
      facilities, this condition may occur in conjunction with the maximum temperature SRE test.  Unless
      historical operating data are provided to indicate little variation in the inlet (or outlet, as
      appropriate) temperature to a particulate hold-up device, EPA OSW recommends against
      performing D/F testing at normal or average hold-up temperatures.

      The locations where temperatures should generally be maximized include: 1) the inlet to dryAPCD
      equipment; 2) the outlet of heat exchangers; and 3) the inlet to extensive runs ofun-insulated
      duct\vork at lightweight aggregate kilns where substantial convective cooling occurs.  Permit limits
      on maximum temperatures at these locations based on the risk burn may be necessary to protect
      human health and the environment by ensuring that D/F emissions are maintained at or below the
      measured levels on an ongoing basis.

 Unless a facility utilizes a completely "wet" APCD system and performs rapid liquid quenching (on the
 order of milliseconds) to saturation, as discussed in Section 4.2.1.1, there may be one or more "dry" system
 components downstream of the combustion chamber which are conducive to surface-catalyzed D/F
 formation via precursor condensation and de novo synthesis mechanisms. Downstream components
 conducive to D/F formation include any devices which preclude rapid quench to below  400 °F, as well as
 devices where particulates are physically held up in the critical temperature window (approximately 400 to
 750 °F).  Specific devices include heat exchangers, extensive runs ofun-insulated ductwork at lightweight
 aggregate kilns where substantial convective cooling occurs, and dry APCDs (such as ESPs, fabric filters,
 and possibly high efficiency particulate air [HEPA] filters).

 Data described in numerous literature sources highlight the importance of inlet temperatures for dry
 APCDs, such as ESPs and fabric filters (Harris and others 1994; Lanier and  others 1996; Kilgroe 1996;
 EPA 1999d and 1999e). In general, these data indicate that, within the D/F formation window of
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approximately 400 to 750 °F, D/F formation can increase exponentially with increases in APCD inlet
temperature.  Thus, dry APCD inlet temperature is a critical control parameter.

Heat exchangers also provide the conditions necessary for surface-catalyzed D/F formation. When flue gas
cooling involves a heat exchanger (a waste heat boiler is a type of heat exchanger), the gas is cooled slowly
through the catalytic D/F formation temperature region. In addition, particulates may be held up on the
heat exchanger tubes.  Outlet temperatures from waste heat boilers typically range from 400 to 600 °F
(EPA 1999d). Santoleri, citing numerous studies in Germany and the United States, notes that facilities
with heat recovery boilers have been found to have higher emissions of D/Fs than facilities without heat
recovery (Santoleri 1995). The D/F emissions trend for waste heat recovery boilers is further supported by
data collected in support of the hazardous waste combustor MACT rule which indicates that incinerators
equipped with recovery boilers have significantly higher D/F emissions than other incinerators (EPA 1997d
and 1999d). Acharya has hypothesized that D/Fs in a boiler may be minimized by only cooling combustion
gases to about 800 °F (Acharya and others 1991).  Although energy recovery might be reduced, the gas
temperatures would be maintained outside of the 400 to 750  °F range. Based on this information, the
outlet temperature of a heat exchanger is a critical control parameter.

Data collected in support of the hazardous waste combustor MACT rule also document elevated D/F
emission rates at some lightweight aggregate kilns, where formation apparently occurred in extensive runs
of un-insulated ductwork connecting the kilns to the fabric filters (EPA 1997d and 1999d). Convective
cooling in un-insulated ductwork can result in slow gas cooling through the catalytic D/F formation
temperature region, and the ductwork provides surface area for particulate hold-up. EPA noted that
reductions of D/F emission rates could likely be achieved simply by rapidly quenching gases at the exit of
the kiln to less than 400 °F and insulating the ductwork to maintain gas temperatures above the dew point
prior to the fabric filter. This information indicates that the temperature at the inlet to extensive runs of un-
insulated ductwork at lightweight aggregate kilns (where flue gas can cool through the 400 to 750 °F
temperature range) is a critical control parameter.
 In summary, the relatively low temperature (approximately 400 to 750 °F) "dry" areas of particulate hold-
 up downstream of the combustion zone should generally be emphasized for D/F testing.  These areas are
 conducive to surface-catalyzed D/F formation via precursor condensation and de novo synthesis
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 mechanisms. Available data indicate that particulate matter provides the substrate to act as a chemical
 reactor, given the appropriate temperature, time, and presence of Cl. Thus, any particulate hold-up area
 (including fabric filters, ESPs, HEPA filters, heat exchangers, and extensive runs of ductwork at aggregate
 kilns) operating in the critical temperature range can promote D/F formation.

 Particulate hold-up temperatures should be considered very carefully in determining the appropriate test
 condition for D/F testing. In most instances, it is recommended that facilities perform risk burn testing for
 D/Fs at a maximum particulate hold-up temperature (i.e., at the highest temperature within the 400 to 750
 °F range that the facility wishes to achieve during post-risk burn operation). For some facilities, this
 condition may occur hi conjunction with the high temperature SRE test.  The locations where temperatures
 should generally be maximized include: 1) the inlet to dry APCD equipment; 2) the outlet of a heat
 exchanger; and 3) the inlet to an extensive run of un-insulated ductwork at lightweight aggregate kilns
 where substantial convective cooling occurs. Permit limits on maximum temperatures at these locations
 based on the risk burn may be necessary to protect human health and the environment by ensuring that D/F
 emissions are maintained at or below the measured levels on an ongoing basis. (Note: If the device is
 maintained above the critical temperature range to prevent D/F formation, for example, above 800 °F, a
 minimum temperature limit may be appropriate instead.)

 Unless historical operating data are provided to indicate little variation in the inlet (or outlet, as
 appropriate) temperature to a particulate hold-up device, EPA OS W recommends against performing D/F
 testing at normal or average hold-up temperatures. D/F formation has been observed to increase
 exponentially with increases in temperature over the range of approximately 400 to 750 °F (Harris and
 others 1994; Lanier and others 1996; Kilgroe 1996; EPA 1999e). This non-linear relationship makes it
 difficult to ensure that "normal" D/F emissions will be maintained on a ongoing basis after the risk burn
 (i.e., the D/F emissions from one minute of operation at 100 °F above normal cannot be offset by one
 minute of operation at 100 °F below normal).  It is important that D/F emissions not be underestimated for
 risk assessments.  However, a facility is not precluded from showing, on a site-specific basis, why a less
 conservative approach may be warranted, or from following the procedures in Section 3.3.2.2 to show why
 D/F testing should be performed at "normal" temperatures. If testing at normal temperatures is proposed,
 the facility should be prepared to explain how a monitoring scheme can be developed to reliably ensure that
 D/Fs will be maintained at "normal" levels on an ongoing basis.

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A final consideration involves the use of a reheater in a flue gas cleaning train. One source utilizing a rapid
wet quench and wet scrubbing system (EPA 1999d, Source ID No. 602) has reported somewhat higher D/F
emissions than those observed from most rapid wet quench systems. This source uses a coil-tube reheater
downstream of the wet scrubbing system to reheat flue gases to above saturation temperatures prior to
HEPA filtration. The gases are reheated to approximately 250 °F. Although this flue gas temperature is
outside of the 400-750 °F range, the reheater tubes provide surface area for particulate hold-up and are
estimated to be about 500 °F (EPA 1999d). These tube surface temperatures may promote surface-
catalyzed D/F formation. During a risk burn, specific temperature targets for a reheater should generally
not be necessary (operation of a reheater is expected to be fairly constant). However, it is recommended
that the permit writer ensure that emissions sampling for D/Fs occurs downstream (rather than upstream)
of the reheater.
4.2.2
Combustion Conditions
 Although D/Fs are primarily formed in the post-combustion zone of combustion systems, the reactants or
 precursors for D/F formation originate in the combustion chamber itself (Buekens and Huang 1998). This
 section provides general information regarding the affect of combustion conditions on D/F emissions.
 Since the general discussion may not be entirely relevant for all systems, the industry-specific discussions
 provided in Sections 4.3 through 4.6 should also be consulted. In addition, some information may not be
 relevant to units that operate in a sub-stoichiometricmode. The discussions and recommendations in this
 section are based on the underlying assumption that all hazardous waste combustbrs are required by
 regulation to operate under combustion conditions that meet or exceed 99.99 percent DRE.
 4.2.2.1
Target Test Conditions
     Recommendation— The complex, multi-variate nature of combustion parameters and their
     influence on D/F emissions makes it difficult to isolate effects, and thus to conclusively ascertain the
     relationship between individual parameters and D/F emissions. The difficulty in isolating effects
     complicates the task of targeting test conditions to ensure that D/F emissions are not under-
     represented in the risk assessment.  To capture the potential range of D/F emissions, it is
     recommended that facilities perform testing for D/Fs during all planned test conditions (including
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      both DRE andSRE conditions) whenever possible.

      EPA OSW recommends that the challenging combustion scenarios discussed later in Section 4.2.2.3
      be represented during D/F testing (if applicable to a particular system). The challenging
      combustion situations described in Section 4.2.2.3 include: 1) transient conditions; 2) operation
      with containerized or batch -waste feeds; and 3) high carbon monoxide situations.
      The combustion parameters identified later in Section 4.2.2.2 should automatically be addressed
      •when D/F testing is performed during all planned test conditions, since these parameters are
      typically demonstrated and limited as part of the DRE determination.  The combustion parameters
      listed in Section 4.2.2.2 include: 1) minimum primary and secondary combustion chamber exit
      temperatures; 2) maximum combustion gas velocity; 3) maximum waste feed rate at each feed
      location; 4) limitations on waste feed composition and batch feeds; and 5) maximum flue gas
      carbon monoxide and/or total hydrocarbon concentrations.

      The general recommendationfor D/F testing during all test conditions may be less appropriate for
      situations where downstream formation is of little or no concern (i.e., the rapid wet quench/wet
      APCD configurations discussed in Section 4.2.1.1).  When there is minimal potential for
      downstream formation, D/F emissions will either be low, or are likely to be driven by poor
      combustion situations (see Section 4.2.1.1).  Under these circumstances, D/F testing during only the
      DRE test conditions may be appropriate instead of testing during every test condition.  Even under
      such circumstances, EPA OSW recommends that the challenging combustion scenarios discussed in
      Section 4.2.2.3 be emphasized, if applicable. The combustion parameters listed in Section 4.2.2.2
      should automatically be addressed, since they are typically demonstrated and limited as part of the
      DRE determination. D/F testing during only the DRE test conditions should be less burdensome
      than testing during all conditions, but still conservative.

      The recommendationfor D/F sampling during all test conditions (or during the DRE conditions for
      rapid wet quench/wet APCD configurations) is a general guideline. However, some facilities and
     permit writers may be faced with situations that are not addressed by this general guideline. For
      example, DRE and SRE testing may already have been conducted in advance of the risk burn, or

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     simultaneous stack determinations for consolidated testing may not be possible.  These and other
     situations call for decisions regarding the specific combustion conditions to be demonstrated (in
     addition to the conditions which are conducive to downstream formation discussed in Section
     4.2.1). Therefore, this guidance recommends that the challenging combustion scenarios described
     in Section 4.2.2.3 (if applicable) be preferentially targeted for D/F testing and that, as appropriate,
     permit limits for the Section 4.2.2.2 combustion parameters be established based on D/F testing
     conducted under these challenging combustion scenarios. In addition, EPA OSW recommends that
     a facility-specific review of trial burn and historical operating data be performed to determine
     whether the challenging combustion scenarios correlate with other operating or feed parameters.  If
     so, it is recommended that the correlating parameters be demonstrated during the testing, and it
     may be appropriate to limit those parameters in the permit in addition to, or possibly in lieu of, the
     combustion parameters listed in Section 4.2.2.2.  Caution should be exercised to ensure that targets
     during the D/F testing for the Section 4.2.2.2 combustion parameters are not substantially different
     from those demonstrated during the DEE test.
     Finally, it is important to recognize that some combustion units operate under extremely steady-
     state conditions, at temperatures and residence times that should routinely ensure good combustion.
     Challenging combustion situations, such as those described in Section 4.2.2.3, do not occur. For
     example, a liquid injection incinerator feeding a single high-British thermal unit (Btu) waste stream
     may sustain very constant, high temperatures.  Combustion conditions may not fluctuate at all, and
     carbon monoxide may be near zero.  Ideally, logistics will favor combining the D/F testing with the
     DRE conditions (in addition to performing D/F testing during the conditions conducive to
     downstream formation per Section 4.2.1, if applicable). If so, then the combustion parameters
     listed in Section 4.2.2.2 should automatically be addressed, since they are typically demonstrated
     and limited as part of the DRE determination.  However, if combined testing is not possible, then
     consideration may be given to limiting the D/F testing to only those test conditions which are
     conducive to downstream formation (ifapplicable), and/or testing under normal combustion
     conditions, where appropriate (see Section 3.3.2.2). EPA OSW also recommends that historical
     operating data for the appropriate combustion parameters be reviewed to verify that the facility
     maintains steady-state operations with very few fluctuations. Demonstration of absolute maximum
     or minimum values for the combustion parameters listed in Section 4.2.2.2 during D/F testing may
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     be less critical'for steady-state operations. In lieu of specific permit limits for the parameters listed
     in Section 4.2.2.2, periodic reporting to confirm continued absence of transients may be
     appropriate. When D/F testing cannot be performed in conjunction with the DRE test, caution
     should be exercised to ensure that targets during the D/F testing for the combustion parameters
     listed in Section 4.2.2.2 are not substantially different from the levels demonstrated during the DRE
     test.

 Combustion conditions can play a key role in minimizing the formation of D/F precursors, and thus, in
 potentially minimizing D/F emissions.  Maintenance of good combustion conditions to limit organic
 precursors and soot is repeatedly cited as a prerequisite necessary for achieving low D/Fs (Hasselriis 1987;
 Kilgroe and others 1990; Kilgroe 1996; Prescott 1996; Berger and others 1996; Gullett and Raghunathan
 1997; EPA 1999e).

 Substantial information exists to indicate that D/F emissions can be quite high when combustion
 parameters are not optimized. A majority of the work documenting the influence of combustion quality has
 been performed on municipal waste combustor systems.  Gullett and Raghunathan observed substantial
 increases in D/F emissions under conditions of poor combustion and carbon monoxide levels greater than
 2,000 parts per million (ppm) (Gullett and Raghunathan 1997). Buekens and Huang cite studies where
 poor combustion situations caused order-of-magnitudeD/F increases over those observed during normal
 combustion (Buekens and  Huang 1998). Berger describes a correlation between high D/F emissions and
 high total hydrocarbon emissions (Berger and others 1996). Prescott documents order-of-magnitude
 reductions in D/Fs through the use of good combustion control (Prescott 1996), and Hasselriis found that
 the optimum combustion conditions for minimizing dioxins and fur ans are closely related to those which
 minimize carbon monoxide emissions (Hasselriis 1987).
 Because order-of-magnitude increases in D/F emissions have been observed under certain combustion
 situations, it is important to ensure that potentially high-emitting operating modes are not overlooked when
 planning the risk bum. Therefore, the recommendations in this section focus on identifying and
 demonstrating challenging combustion situations for D/F testing. However, a facility is not precluded from
 showing, on a site-specific basis, why a less conservative approach may be warranted, or from following
 the procedures in Section 3.3.2.2 to show that D/F testing should be performed at normal conditions to
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 better represent the risk over a facility's operating life.

 Targeting specific combustion conditions for D/F testing can be extremely challenging, because the
 relationship between individual combustion parameters and D/F emissions is not necessarily intuitive or
 readily demonstrated. Buekens and Huang explain that D/F formation in combustion processes is
 influenced by a number of combustion parameters simultaneously, and is therefore regarded as a multi-
 variate process (Buekens and Huang 1998). Key parameters are likely to vary by facility, and the key
 parameters may or may not be those identified in this guidance. For example, oxygen concentration is not
 specifically addressed during many trial burns, and often varies considerably between test conditions if
 excess air is used to simultaneously achieve minimum combustion temperature and maximum combustion
 gas velocity. Although studies show that D/F emissions may be affected by oxygen levels, contradictory
 conclusions have been reached regarding the specific relationship (Buekens and Huang 1998). Buekens
 and Huang postulate that different combustors may exhibit different behaviors with varying oxygen, and
 that there may not be a universally applicable correlation. The uncertain relationship between oxygen and
 D/Fs is just one example of the difficulty in predicting how different operating scenarios may affect D/F
 emissions.
 Because of the inherent uncertainties involved in correlating D/F emissions and individual combustion
 parameters, it is recommended that D/F emissions be determined during all planned test conditions (e.g.,
 DRE and SRE conditions) whenever possible. By characterizing D/Fs over the entire range of combustion
 conditions, a facility can minimize the possibility of inadvertently omitting combustion situations that may
 play a key role in D/F formation.  In addition, the data collected during multiple conditions can be analyzed
 for trends to determine which combustion parameters may need to be limited in the RCRA permit to control
 D/F emissions. EPA OS W recommends that the challenging combustion scenarios discussed later in
 Section 4.2.2.3 be represented during the testing (if applicable). The challenging combustion situations
 described in Section 4.2.2.3 include: 1) transient conditions; 2) operation with containerized or batch feeds;
 and 3) high carbon monoxide situations.  The combustion parameters identified in Section 4.2.2.2 should
 automatically be addressed when D/F testing is performed during all planned test conditions, since these
 parameters are typically demonstrated and limited as part of the DRE determination. The combustion
 parameters listed in Section 4.2.2.2 include: 1) minimum primary and secondary combustion chamber exit
 temperatures; 2) maximum combustion gas velocity; 3) maximum waste feed rate at each feed location; 4)
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 limitations on waste feed composition and batch feeds; and 5) maximum flue gas carbon monoxide and/or
 total hydrocarbon concentrations.

 At the beginning of Section 4.2.2.1, several situations were identified where it may not be possible (or even
 necessary) to perform D/F sampling during every test condition. For example, DRE and SRE testing may
 have already been conducted in advance of the risk burn. In these situations, EPA OSW recommends that
 the challenging combustion scenarios described in Section 4.2.2.3 be preferentially targeted for D/F testing
 (if applicable). Again, these scenarios include: 1) transient conditions; 2) operation with containerized or
 batch waste feeds; and 3) high carbon monoxide (greater than 100 ppm) situations. These scenarios are
 appropriate to target because of the increased potential for localized oxygen deficiencies and carbon
 monoxide/total hydrocarbon spikes. Numerous test programs have established that D/Fs can be high when
 oxygen is insufficient or when carbon monoxide/total hydrocarbon concentrations are high (Hasselriis
 1987; Kilgroeand others 1990; Harris and others 1994; Kilgroe 1996; Berger and others  1996; Gullett and
 Raghunathan 1997; Buekens and Huang 1998). As appropriate, EPA OSW recommends that permit limits
 for the Section 4.2.2.2 combustion parameters be established based on D/F testing conducted under these
 challenging combustion scenarios. In addition, it is recommended that a facility-specific review of trial
 burn and historical operating data be performed to determine whether the challenging combustion scenarios
 correlate with other operating or feed parameters. If so, then EPA OSW recommends that the correlating
 parameters be demonstrated during the testing, and it may be appropriate to limit them in the permit in
 addition to, or possibly in lieu of, the combustion parameters listed in Section 4.2.2.2.
 At some facilities, the challenging combustion scenarios identified in Section 4.2.2.3 may not occur.
 Although challenging combustion situations can clearly increase D/Fs, there is little information regarding
 the difference between "better" and "best" combustion. One study shows that stack concentrations of D/Fs
 may be somewhat independent of combustion conditions (except in instances of very poor combustion )
 provided that downstream formation of D/Fs is limited or controlled (Kilgroe 1996).  This study would
 seem to indicate that, for steady-state systems, demonstration of absolute minimum or maximum values for
 the Section 4.2.2.2 combustion parameters during the D/F testing  may be less critical. Although
 demonstration of these control parameters can ideally be accomplished by combining the D/F testing with
 the DRE demonstration (which is preferred whenever possible), consideration may be given for some
 steady-state systems to limiting the D/F testing to only those test conditions which are conducive to
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 downstream formation per Section 4.2.1 (if applicable), and/or testing under normal conditions provided
 the facility meets the criteria in Section 3.3.2.2. Periodic reporting to confirm the continued absence of
 transients may be appropriate in lieu of establishing specific permit limits for the Section 4.2.2.2
 combustion parameters.
 4.2.2.2
Combustion Parameters
     Recommendation — To assure combustion quality and minimize D/Fprecursors, EPA OSW
     recommends that the following combustion parameters be demonstrated during D/F testing and
     controlled during subsequent facility operation, consistent with the recommendations in Section
     4.2.2.1:

     •      Minimum PCC andSCC combustion temperatures;
     •      Maximum combustion gas velocity as an indicator of residence time;
     •      Maximum waste feed rate for each feed location;
     •      Limitations on waste feed composition and batch /containerizedfeeds;
     •      Maximum flue gas carbon monoxide and/or total hydrocarbon concentrations.


     If other potentially significant parameters are identified based on a facility-specific review, then it is
     recommended that those parameters be demonstrated during D/F testing and possibly limited in the
     permit in addition to, or possibly in lieu of, the parameters listed above.

 The relationship between these parameters and combustion quality has been discussed at length in other
 EPA documents (EPA 1989 and 1999e), and is not repeated here.  Further discussion on waste feed
 composition, as well as on limitations for batch or containerized feeds, can be found in Section 4.2.2.3.1,
 Section 4.2.2.3.2, and Section 4.2.3 of this document. Controls may also be established on the waste firing
 system to ensure that burners are operated efficiently and in a manner  consistent with manufacturer
 specifications (EPA 1989 and 1999e).
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 It is important to keep in mind that the most influential combustion parameters may not always be the ones
 listed above. EPA OSW recommends that a facility-specific review of test burn and historical operating
 data be performed to determine the potential significance of other operating or feed parameters, especially
 for the challenging combustion scenarios described in Section 4.2.2.3. If other potentially significant
 parameters are identified, then it is recommended that they be demonstrated during D/F testing and possibly
 limited in the permit in addition to, or possibly in lieu of, the parameters listed in this section as necessary
 to protect human health and the environment.

 The importance of a facility-specific review to determine the significant parameters affecting combustion
 quality is illustrated by a situation documented by Branter (Branter and others 1999).  In an initial test
 effort involving containerized waste feeds, the facility did not adequately control downstream D/F
 formation (i.e., the heat exchanger outlet temperature was not maintained as low as possible). For the two
 test conditions conducted at a high heat exchanger outlet temperature, the D/F yields were substantially
 greater at maximum PCC combustion temperatures than at minimum PCC combustion temperatures. This
 result seems counter-intuitive at first, and illustrates the importance of analyzing trial burn or historical
 operating data on a case-by-case basis.

 Although the phenomenon described by Branter initially seems counter-intuitive, it may be explained by the
 work of Lemieux (Lemieuxand others 1990). Lemieux showed that containers may be more rapidly heated
 and ruptured at higher PCC temperatures and higher kiln rotation speeds. Evolution of waste gases from
 the containers can exceed the rate  at which stoichiometric oxygen can be supplied, resulting in increased
 organic emissions, or "puffs." Lower temperatures may lead to more gradual rupture of waste containers,
 and less disruptive organic puffs.  This situation is discussed further in Section 4.2.2.3.2. In the situation
 documented by Branter (Branter and others 1999), the higher PCC temperature test may have been
 associated with more rapid container heating and larger organic puffs, providing more organic precursors
 for downstream D/F formation at the high quench outlet temperature. Despite the higher PCC temperature
 and CO below 100 ppm (hourly rolling average corrected to 7% oxygen), this unit operating at a high PCC
 temperature also failed DRE. The unit passed DRE and experienced reduced D/F emissions during the
 lower PCC temperature run. It is  interesting to note that, once downstream quench temperatures were
 lowered, D/F emissions were reduced and appeared to be independent of PCC temperature.
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 Section 4.2.2.3
        Challenging Combustion Scenarios
 Section 4.2.2.1 recommends D/F sampling during all test conditions whenever possible (or during the DRE
 conditions for rapid wet quench/wet APCD configurations). However, some facilities and permit writers
 may be faced with situations that are not addressed by these general guidelines. DRE and SRE testing may
 have already been conducted in advance of the risk burn, or simultaneous stack determinations for
 consolidated testing may not be possible. These and other situations call for decisions regarding the
 specific combustion conditions to be demonstrated. Therefore, this guidance recommends that the
 following combustion situations (if applicable) be preferentially targeted for D/F testing:

      •       Transient conditions;
      •       Combustion of containerized or batch wastes;
      •       Operation at high carbon monoxide levels, for units with carbon monoxide limits greater than
             100 ppm.
 In all of these situations, there may be an increased potential for incomplete combustion products to act as
 D/F precursors and increase D/F emissions. The remainder of this section provides additional information
 on these scenarios.
 4.2.2.3.1
Transient Conditions
     Recommendation — If a combustion unit normally operates under transient conditions, then EPA
     OSW recommends that this form of operation be represented during D/F testing. It is recommended
     that the facility-specific feed or operating conditions causing the transients be identified and
     targeted for the risk burn. The need for permit conditions to limit transients after the risk burn may
     be necessary to protect human health and the environment and should generally be considered
     taking into account the risk burn emissions data and the facility's operating history.
 Transient combustion conditions are usually indicated by recurring spikes in combustion parameters,
 especially combustion temperatures, combustion chamber pressure, carbon monoxide, or total
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hydrocarbons. Routine spikes should generally be emphasized for the risk burn (i.e., spikes which may
occur as often as several times per hour on an ongoing basis). Upsets are not encompassed by the term
"transient," and are generally not represented during the risk burn unless there is a specific agreement
reached between the facility and permit writer.

Transient spikes indicate potential changes in combustion quality that may increase D/F emissions.
Raghunathan documented an order-of-magnitudeD/F increase during a test run where a few significant CO
spikes occurred, even though the average CO concentration for the 3-hour test run was maintained well
below 100 ppm (Raghunathan and others 1997a). Berger describes a correlation between high D/F
emissions and total hydrocarbon spikes (Berger and others 1996).

If a combustion unit normally operates under transient conditions, then it is recommended that this form of
operation be represented during D/F testing. The permit writer should review historical operating data to
determine whether a facility experiences routine transients.  If so, EPA OS W recommends that the waste
feed or operating conditions that cause the transients be determined.  The feeds or operating conditions
causing transients represent candidate conditions for D/F testing. Particular attention should generally be
given to data indicating transients for combustion temperatures, combustion chamber pressure, carbon
monoxide, and total hydrocarbons. Instantaneous data will be more useful in identify ing transients than
rolling average data, which inherently dampens spikes.

Batch feeds can cause transients, and are discussed separately in Section 4.2.2.3.2. However, other wastes
can cause transients if they are not blended properly, or if they are treated in a unit that is not designed to
accommodate particular waste types. Adequate blending or mixing of waste to minimize variations in
heating value, volatility and moisture content can reduce combustion transients associated with improper
feed conditions (Kilgroe 1996). Examples of wastes that can cause transients if handled improperly
include:

      •       Stratified or highly viscous liquids and sludges;
      •       Aqueous or low heating value liquids;
      •       Liquids with a high percentage of solids;
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      •       Highly chlorinated wastes;
      •       Low heating value solids and sludges;
      «       Wastes with a high moisture content; and
      •       Batch feeds with high moisture, volatility, or instantaneous oxygen demand.

 During D/F testing, EPA OS W recommends that the facility treat actual wastes (and not surrogate wastes
 synthesized from pure compounds) whenever possible. Candidate wastes should generally be selected
 based upon a review of the wastes handled at a particular facility, with special consideration given to those
 wastes burned at commercial facilities due to their variation and complexity.
 4.2.2.3.2
Containerized or Batch Wastes
     Recommendation— When a facility feeds containerized or batch wastes, EPA OSW recommends
     that D/F testing be performed while operating under simulated "worst-case " containerized or batch
     feeding conditions.  It may be appropriate to spike actual wastes to maximize the volatility and
     oxygen demand of each batch charge.

     EPA OSW recommends that maximum total waste feed rate to the batch feed system (e.g., Ib/hr) be
     maintained as part of the "worst-case " test demonstration.  The individual batch size and feeding
     frequency will depend on the feeding practices at a particular facility.

     During the risk burn, EPA OSW recommends that the airflow to the combustion unit generally be
     adjusted to minimize excess oxygen at the location in the combustion chamber where the batch is
     fed. In addition, the testing should generally be performed at higher kiln temperatures and higher
     •kiln rotation speeds.
     In most cases, permit limits for maximum total waste feed rate to the batch feed system (e.g., Ib/hr)
     and maximum flue gas carbon monoxide/total hydrocarbon concentrations will be established to
     meet regulatory requirements (see Section 1.3). Additional permit limits may be necessary to
     protect human health and the environment, taking into account whether preventive controls are
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    necessary to assure that good combustion practice is maintained. Preventive controls may be
    needed if operating extremes for the batch feed system cannot be adequately represented during the
    risk burn, or if the facility has historically experienced frequent operational upsets or waste cutoffs
    due to batch feeds.

    If preventive controls are needed, other permit limitations -which might be considered include: 1)
    maximum batch size; 2) maximum batch charge heat content; 3) maximum batch feeding frequency;
    4) minimum oxygen concentration at the location where the batch is fed; 5) maximum kiln
    temperature; 6) maximum kiln rotational speed; and 7) limitations on -waste volatility, composition,
    or heat content.
Overcharging conditions can occur when containerized or batch wastes are fed to a combustion unit,
especially if waste parameters and feeding practices are not closely matched to the unit design. When
highly combustible or volatile wastes are exposed to the high temperatures in a combustion chamber, a
surge of waste vapors rapidly evolves from the batch.  This surge can deplete local oxygen, causing
formation of fuel rich gas pockets that may escape the combustor without being adequately oxidized. This
situation is often described as "puffing." Stack emissions may be affected, depending on whether the
organics are destroyed elsewhere (such as in an afterburner).

Transient puffs arising from batch feed  operations are well documented based on measurements conducted
at the PCC exit of both pilot scale and full scale incinerators (Linak and others 1987; Cundy and others
1-991; Lemieux and others 1990). At a pilot-scale facility, Linak documented PCC exit total hydrocarbon
levels in excess of 10,000 ppm during very intense puffs, and performed chemical analysis to show that the
puffs can contain numerous hazardous compounds, even though adequate DREs (>99.99%) may be
achieved (Linak and others  1987). In several of the measurements, D/Fs were also formed at part-per-
trillion levels. Both D/Fs and other chlorinated hazardous organics were formed most readily when
chlorinated compounds were fed together with high heating value materials, such as toluene, which caused
high magnitude, high intensity puffs. Linak observed that higher kiln temperatures and rotation speeds
adversely affect puff intensity, because de-volatilization rates are enhanced by the increased temperatures
and bed mixing. This observation has been confirmed by Lemieux (Lemieux and others 1990), and Branter
(Branter and others 1999) has documented higher D/F emissions at higher PCC temperatures for a full-

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 scale facility (see the discussion in Section 4.2.2.2).

 Because the soot and chlorinated organic precursors from transient puffs can affect D/F emissions, this
 guidance recommends that the risk burn be performed while operating under simulated "worst-case" batch
 feeding conditions (i.e., conditions that maximize precursor generation) to ensure that D/F emissions are
 not under-estimated for the risk assessment. Historical information on operating trends and AWFCO
 events should generally be reviewed in an effort to determine which batch characteristics are most likely to
 cause transients for a particular facility. Some batch-charged and containerized wastes can volatilize
 rapidly, causing an instantaneous release of heat and gases that completely consume the available oxygen.
 This rapid volatilization results in a momentary oxygen-deficient condition that can result in poor
 combustion. Conversely, if too large a batch of aqueous waste or  wet soil is fed, there  is danger that the
 batch can instantaneously quench temperature.

 During the risk burn, EPA OSW recommends that actual wastes be spiked as necessary to maximize the
 volatility and oxygen demand of each batch charge. This maximization can  be achieved-by spiking with
 low boiling point/low latent heat of vaporization organics (preferably chlorinated), together with high
 heating value organics that have a high stoichiometric oxygen demand (Linak and others 1987; Wendt and
 others 1990; Cundy and others 1991). In rotary kilns, spiking compounds may be fed in bottles placed
 within the batch (instead of sorbed onto a solid matrix) to maximize the rate of volatilization.

 The individual batch size and feeding frequency to be targeted for  the risk burn should generally be based
 on the feeding practices at a particular facility. The "total waste feed rate" for the batch feed system (e.g.,
 Ib/hr) is a target combustion parameter (see Section 4.2.2.2) and should generally be maximized anyway.
 However, risk burn goals for individual batch size and feeding frequency may conflict (i.e., a facility may
 not be able to simultaneously feed their largest batch at their highest frequency). For the most part, the
 work of Lemieux suggests that larger batches  fed less frequently will be worse than smaller batches fed
 more frequently at a given total feed rate (Lemieux and others 1991). In defining maximum batch size, the
 "maximum batch charge heat content" (maximum Btu/charge) is just as important as (and perhaps more
 important than) total mass.
 The test plan for a batch-fed facility should generally include a description of the procedures used to
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 maintain adequate oxygen while feeding batch or containerized wastes. During the risk burn, the air flow
 to the combustion unit should generally be adjusted to minimize excess oxygen at the location in the
 combustion chamber where the batch is fed.  In addition, the testing should generally be performed at
 higher kiln temperatures and rotation speeds, since these parameters have been shown to exhibit a strong
 correlation with puff intensity. Demonstration of high kiln rotation speed may be less imperative if spiking
 compounds are added in bottles to the batch instead of sorbed to a solid matrix, since this spiking method
 should generally assure a high volatilization rate. Multiple test conditions may be necessary to demonstrate
 high kiln temperatures, as well as the minimum temperatures recommended in Section 4.2.2.2. For some
 incinerators, a worst-case test may involve maximum PCC temperatures demonstrated in conjunction with
 minimum SCC temperatures.

 The effect of transient puffs on stack emissions may vary substantially from facility to facility. Variations
 may depend on: 1) unit design and operation (including size, presence of an afterburner or SCC, and fuel-
 to-air controls); 2) waste characteristics (including volatility, instantaneous oxygen demand, heating value,
 and moisture content); and 3) feeding practices (including batch size, feeding frequency, feed location,
 excess oxygen, and the oxygen demand of batch feeds versus the oxygen demand of other fuels).
 Historically, batch feed practices at some facilities have caused DRE failures, upset conditions, carbon
 monoxide spikes, and excessive waste feed cutoffs. At other facilities, batch feeds do not appear to
 significantly affect either emissions or day-to-day operations.

 The variable effect of batch feeds on emissions and day-to-day operations suggests that a facility-specific
 evaluation may be necessary to determine appropriate permit restrictions after the risk burn. In most cases,
 permit limits for maximum total waste feed rate to the batch feed system (e.g., Ib/hr) and maximum flue
 gas carbon monoxide/total hydrocarbon concentrations will be established anyway to ensure compliance
 with RCRA and MACT regulatory performance standards (see Section 1.3). These parameters also assure
 combustion quality and minimization of D/F precursors, as discussed in Section 4.2.2.2.
 Although total waste feed rate to the batch feed system (e.g., Ib/hr) will be limited to meet specific RCRA
 or MACT regulatory requirements, this limitation may not be adequate for all situations because a facility
 can theoretically feed a very large batch on a very infrequent basis. A batch feed rate limit may be
 sufficient when it is based on a worst-case test, and when other system constraints are present (for example,
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 maximum batch size may be limited by the physical constraints of the batch feed system). However, in
 some cases, it may be preferable to augment a pound-per-hour feed rate limit with additional restrictions on
 maximum batch size or maximum batch charge heat content.

 Carbon monoxide/total hydrocarbon levels have routinely been used to characterize combustion
 perturbations associated with batch feeds (Linak and others 1987; Cundy and others 1991; Lemieuxand
 others 1991). Establishing limits for these parameters in conjunction with a "worst-case" batch feed test
 may be sufficient for assuring that ongoing operations are protective at some facilities.  However, carbon
 monoxide or total hydrocarbon monitoring alone may not be adequate for all batch feed operations.
 Because oxygen depletion can occur very rapidly due to batch overcharging, carbon monoxide/total
 hydrocarbon levels may exceed the permit limit before corrective action can be initiated. For some
 operations, additional preventive measures may be necessary to protect human health and the environment
 by assuring that good combustion practice is maintained.

 Other permit limitations which might be considered if preventive measures are needed include: 1) maximum
 batch size; 2) maximum batch charge heat content; 3) maximum batch feeding frequency; 4) minimum
 oxygen concentration at the location where the batch is fed; 5) maximum kiln temperature; 6) maximum
 kiln rotation speed; and 7) limitations on waste volatility, composition or heat content.  Implementation of
 minimum oxygen limits for rotary kilns can sometimes be difficult, due to potentially significant gas-phase
 stratification (Cundy and others 1991). If gas-phase stratification is a problem, alternative monitoring
 locations may need to be considered.

 The need for preventive controls should generally be determined based on a review of test conditions,
 emissions data, and the facility's operating history.  There may be less need for preventive controls if
 operating extremes for the batch feed system can be adequately represented during the risk burn (or if
 emissions appear to be unrelated to batch feed operations), and if the facility routinely operates with few
 operational  upsets or waste cutoffs related to batch feeds. Conversely, there may be more justification for
 establishing preventive controls on the batch feed system if operating extremes for the batch feed system
 cannot be adequately represented during the risk burn, or if the facility experiences frequent operational
 upsets or waste cutoffs due to batch feeds.
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 4.2.2.3.3    High Carbon Monoxide

     Recommendation — EPA OSW recommends that units -with carbon monoxide limits greater than
     100ppm perform D/F emissions testing while carbon monoxide levels are maximized.

 When D/F emissions data are evaluated by normalizing the data based on APCD inlet temperature and
 carbon monoxide, low carbon monoxide levels (less than 100 ppm) are found to be associated with very
 low D/F emissions (less than 1 ng/dscm on a total basis) (EPA 1994c; Harris and others 1994). For
 carbon monoxide levels greater than 100 ppm, temperature-normalizeddioxin emissions are found to be
 significantly higher (in the range of 10 to 100 ng/dscm on a total basis).  This observation suggests that
 units with carbon monoxide limits greater than 100 ppm should generally perform D/F testing under
 conditions that maximize carbon monoxide levels.
 4.2.3
Feed Composition
 In addition to the physical waste characteristics described in Sections 4.2.2.3.1 and 4.2.2.3.2 that may
 contribute to poor combustion, there are several chemical feed characteristics that have been evaluated with
 respect to their potential influence on D/F emissions.  These characteristics include chlorine concentration,
 the presence of metals (such as copper, iron, and nickel) that can act as catalysts for D/F formation, the
 presence of D/F precursors (such as chlorobenzenes and chlorophenols), and the presence of D/F inhibitors
 (such as sulfur, calcium hydroxide, and ammonia). Each of these is discussed below.
 4.2.3.1
Chlorine
     Recommendation — For D/F testing, EPA OSW recommends that chlorine feed rates be maintained
     at normal levels (i. e., chlorine should not be biased low). Permit limits on total chlorine feed rate
     generally should not need to be established based on the risk burn.
 While the presence of chlorine is a necessary prerequisite for D/F formation, there does not appear to be a
 direct correlation between the level of chlorine in the feed and the level of D/Fs in the flue gas at full-scale
 combustion facilities. The American Society of Mechanical Engineers (ASME) (Rigo and others 1995)
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analyzed over 1,700 test results with chlorine feed concentrations ranging from less than 0.1 percent up to
80 percent, and found no statistically significant relationship between D/F emission rates and chlorine
concentration. Gullett provides a possible explanation for the poor correlation (Gullett and others 2000a).
Obviously, no D/Fs can be formed in the complete absence of chlorine. However, extremely low
concentrations of chlorine may be sufficient to form D/Fs at the trace levels of concern.  An excess of
chlorine does not necessarily yield greater quantities of D/Fs, and other parameters, such as APCD inlet
temperature, appear to have a more significant influence on D/F yields.                 f

Based on this information, there does not appear to be a need to demonstrate maximum chlorine feed rates
during the risk burn, or to establish specific feed rate limits on total chlorine in the permit based upon the
D/F testing. However, it is reasonable to expect that facilities will  maintain normal levels of chlorine for
the D/F testing (i.e., chlorine should generally not be biased low).  Chlorinated wastes are preferred over
non-chlorinated wastes for the risk burn, where the choice exists. In this guidance, the term "chlorine"
refers to total chlorine from all sources, including both organic and inorganic forms.
 4.2.3.2
Metal Catalysts
     Recommendation —EPA OSWrecommends the use of wastes or other feed materials containing
     copper overfeeds without copper during the D/F testing, where the choice exists. However, specific
     permit limits on copper (or other catalytic metal) feed rates based upon the D/F testing are
     generally not anticipated to be necessary to protect human health and the environment.

 Abundant pilot-scale and fundamental research has shown that certain metals, such as copper, may
 catalyze the formation of D/Fs (see Section 4.1).  However, there does not appear to be a direct correlation
 between the level of copper in the feed and the level of D/Fs in the flue gas at full-scale combustion
 facilities. Copper spiking during full-scale testing of a cement kiln showed little or no influence on D/F
 emissions (Lanier and others 1996), although the testing may have been conducted in a system that was
 influenced by other, more dominant factors.

 Luijk has shown that copper plays a competing role in both the formation and destruction of D/Fs (Luijk
 and others 1994). Copper contributes to de novo synthesis of D/Fs, but it also catalyzes their oxidative

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  destruction. Luijk and others hypothesize that CuCl2 levels in the ppm range (no greater than the levels
  normally observed in municipal waste combustion fly ash) may offer optimum conditions for the formation
  ofD/Fs.

  Based on this information, there does not appear to be a need to spike copper during the D/F testing, or to
  establish specific permit limits on copper (or other catalytic metals). However, EPA OS W recommends the
  use of wastes or other feed materials containing copper over feeds without copper, where the choice exists.
 4.2.3.3
D/F Precursors
      Recommendation —If a facility burns wastes containing significant quantities of D/F precursors,
      EPA OSW recommends that these wastes be used for D/F testing, rather than wastes without
      precursors. Although specific D/F precursor feed rate limits in the permit are not anticipated to be
      necessary to protect human health and the environment, it may be appropriate to consider a permit
      condition requiring waste profile tracking to determine whether increased quantities of precursor
      wastes warrant retesting.

 The role of organic precursors with respect to D/F formation is discussed in Section 4.1. Some waste
 combustors that burn wastes containing D/F precursors, including chlorobenzenes, chlorophenols, and
 PCBs, have been shown to have high D/F emissions (for example, see the discussion regarding Source ID
 No. 330 in Section 4.2.1.1). EPA has compared a limited number of facilities that feed known D/F
 precursors to those that do not feed D/F precursors (EPA 1996a). This limited comparison suggested no
 strong correlation between the level of precursors and D/F formation; however, the issue has not been
 examined in detail.
 Since higher D/F emissions have been observed at some facilities burning D/F precursors, wastes
 containing significant quantities of D/F precursors are generally preferred over wastes without precursors
 for D/F testing. Specific feed rate limits on D/F precursors in the permit generally should not be necessary.
 However, it may be necessary for protection of human health and the environment to include a permit
 condition requiring waste profile tracking to determine whether increased quantities of precursor wastes
 warrant retesting.
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4.2.3.4
D/F Inhibitors
     Recommendation — In reviewing the D/F test protocol, EPA OSW recommends that the permit
     •writer verify that the facility will not burn a high sulfur waste or fuel in quantities that bias the S/Cl
     feed ratio above normal.  At S/Cl molar feed ratios approaching 0.3 or greater, it may be
     appropriate for protection of human health and the environment after the risk burn to require waste
     and fossil fuel tracking to ensure that a minimum S/Cl ratio is maintained on an ongoing basis. If
     sulfur or other D/F inhibitors are intentionally added to the system to achieve D/F control, then
     EPA OSW suggests that the recommendations in Section 4.2.5 be followed.

The role of SO2 in suppressing D/F formation is discussed in Section 4.1.  D/F inhibitors, such as sulfur,
have been commercially marketed as feed stream additives to control D/F emissions.  These same
compounds may naturally be present in fossil fuels (such as coal) or hazardous waste fuels.

Numerous pilot-scale and full-scale tests on municipal solid waste combustors have proven that D/F
emissions reductions can be achieved via coal co-firing to increase SO2 or SO2 injection (Raghunathan and
Gullett 1996; Gullett and Raghunathan 1997; Raghunathan and others 1997a; Buekens and Huang 1998;
Gullett and others 2000b). The suppression effect is well documented when sulfur is present at levels
nearly stoichiometric to the chlorine in the feed (i.e., S/Cl molar feed ratio of approximately 1:1). Ullrich
has also shown that sulfur levels well below stoichiometric ratios with chlorine can reduce dioxin formation
measurably in a full-scale hazardous waste incinerator (Ullrich and others 1996). Significant decreases in
D/F emission rates were observed at sulfur-to-chlorinemolar ratios as low as 0.3 in the feed (Ullrich and
others 1996).
 In reviewing the D/F test protocol, EPA OSW recommends that the permit writer verify that the facility
 will not burn a high sulfur waste or fuel in quantities that bias the S/Cl feed ratio above normal. The
 particular S/Cl ratio that begins to cause a D/F suppression effect is likely to be system specific, and D/F
 suppression may be influenced by other, more significant facility-specific variables (Gullett and others,
 2000b). However, the results from Ullrich suggest that S/Cl molar feed ratios above approximately 0.3,
 considering both waste and fossil fuel inputs, should generally be viewed with caution (Ullrich and others
 1996).  If S/Cl molar ratios approach 0.3 or greater during the risk burn, then waste and fossil fuel tracking
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 conditions in the permit may be necessary to protect human health and the environment by ensuring that a
 minimum S/C1 ratio is maintained on an ongoing basis.

 This discussion primarily applies to situations where naturally-occurring sulfur may be introduced to the
 combustor with fossil fuels, or when sulfur is normally present in the waste fuel.  In some cases, sulfur or
 other D/F inhibitors are intentionally added to the combustion system to achieve D/F control.  For these
 situations, EPA OS W suggests that the recommendations in Section 4.2.5 be followed.

 4.2.3.5      Dioxin-Containing Wastes

     Recommendation—If a facility burns dioxin-containing wastes (such as F020, F021, F022, F023,
     F026, F027, F032, F039 or K099), EPA OSW recommends that those wastes be represented during
     D/F testing. Specific permit limits on D/F contributions from these wastes may be necessary to
     protect human health and the environment by ensuring that dioxin/furans are not being burned in
     higher amounts than those represented during the risk burn and found to be protective.

 For many combustion units, D/F emissions are primarily influenced by formation within the combustion
 system. However, a few hazardous waste combustors burn dioxin-containing wastes (such as F020, F021,
 F022, F023, F026, F027, F032, F039 or K099), and D/F emissions from those units may be significantly
 affected by survival of trace D/Fs introduced with the waste feed (even at an adequate level of DRE).
 When a facility burns these dioxin-containing wastes, the potential waste feed D/F contribution to total D/F
 emissions should generally be accounted for in the risk burn and risk assessment.

 Ideally, the waste feed D/F contribution to total D/F emissions can be accounted for by feeding dioxin-
 containing wastes during the risk burn to achieve a maximum D/F input. After the risk burn, specific
 permit limits on waste feed D/F contributions from F020, F021, F022, F023, F026, F027, F032, F039 or
 K099 wastes may be necessary to protect human health and the environment by ensuring that D/Fs are not
 subsequently burned in higher amounts than those represented during the risk burn and found to be
 protective.
 If dioxin-containing wastes are not available for the risk burn, then the D/F emissions measured during the

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risk burn will only represent the D/Fs formed within the combustion system.  In this case, it may be
necessary to approximate a potential waste feed D/F contribution based on the maximum anticipated D/F
feed input and the applicable DRE. Dioxin-listed wastes, including F020, F021, ¥022, F023, F026, and
F027, are required by the RCRA and MACT regulations to be burned in a 99.9999% DRE combustion
unit. Other dioxin-containing wastes, such as F032, may be burned in a 99.99% DRE combustion unit. A
total D/F emissions estimate may be developed for the risk assessment by calculating the residual D/F
remaining after 99.99% or 99.9999% DRE, and then adding that value to the D/F emissions measured
during the risk burn (i.e., the D/Fs formed within the combustion system).

When waste feed D/F contributions are approximated, it is recommended that follow-up testing to confirm
D/F emission levels be planned to coincide with receipt of an appropriate dioxin-containing waste shipment.
A D/F emissions approximation is uncertain in that it cannot reflect potential differences between the
congener profile (the TEQ) of the waste and resulting emissions, or the potential for waste D/F
contributions to overload D/F control systems, or the potential for partial combustion products from
dioxin-containing wastes to exacerbate downstream D/F formation.
4.2.3.6
Other Factors
 Other waste feed components may potentially affect D/F emissions. The presence of bromine, in
 particular, has been found to affect emissions of chlorinated organic PICs and D/Fs in pilot-scale
 experiments (Lemieux and Ryan 1998a and 1998b).  Lemieux and Ryan have observed that D/F emissions
 can be enhanced by the addition of bromine, although there appears to be a threshold below which minimal
 enhancement occurs and above which significant enhancement occurs (Lemieux and Ryan 1998a). For the
 particular study showing these effects, this threshold appeared to lie in a range of Br/Cl molar feed ratios
 between 0.1 and 0.5.

 Although the effects of bromine have not been clearly established during full-scale testing, permit writers
 should be aware of this issue when selecting waste feeds for trial burns, particularly if the facility burns
 brominated waste during normal operations.  Very little brominated waste is generated and few facilities
 burn it, but some do.
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 4.2.4
Hysteresis/Memory Effects
      Recommendation—EPA OSW recommends that the recent operating history at a facility be
      considered in planning the risk burn.  The risk burn generally should not be performed immediately
      after refractory replacement or other maintenance activity involving soot removal from boiler tubes,
      ductwork, or other locations -where soot and catalytic metals may have deposited. In addition, the
      risk burn generally should not be performed.immediately after a period of firing high sulfur fuel or
      injecting sulfur additives.

 D/F emissions in full-scale combustion units can be influenced by hysteresis, or "memory effects"
 (Buekens and Huang 1998). Hysteresis means that deposits or residual contaminants remaining within the
 unit from previous operations can have an ongoing effect on emissions, even after operating or feed
 conditions have changed.  Raghunathan has shown that soot deposits from periods of inefficient
 combustion can enhance subsequent D/F yields, with the yields decaying over time (Raghunathan and
 others 1996). Combined soot-copper deposits cause more D/F formation than a deposit of soot or copper
 alone, and D/F formation from soot deposits is inhibited in the presence of sulfur dioxide (Raghunathan and
 others 1996 and 1997b).

 Recent work by Gullett provides further insight regarding the influence of past operating conditions on D/F
 emissions (Gullett and others 2000b; in press). Gullett examined the effect of co-firing coal with municipal
 waste in a field-scale unit to determine whether sulfur in the coal would inhibit D/F formation (Gullett and
 others 2000b). D/F concentrations were in fact reduced up to 80 percent from co-firing coal, and past
 operating conditions were found to have a lingering and significant effect on D/F concentrations.  Gullett
 concluded that the influence of past conditions on D/F levels was consistent with a D/F formation
 mechanism involving combustor wall deposits as sites for formation, and proposed that the effect of higher
 sulfur dioxide concentration from co-firing coal was to  alter the deposits in a way that either reduced
 chlorine contact with active sites or reduced the catalytic activity of the deposits (thereby reducing ongoing
 D/F formation). In research involving a hazardous waste fired boiler, Gullett and others (in press) found
 that boiler tube deposits became a sink and source for D/F reactants (copper and chlorine), resulting in
 continued D/F formation and emissions long after waste co-firing ceased. From these two studies, it
 appears that deposits can have both a negative and positive effect on ongoing D/F emissions. Deposits

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 affected by sulfur dioxide can act to suppress ongoing D/F emissions, whereas deposits that serve as a sink
 for D/F reactants may enhance ongoing emissions.

 These data suggest that the recent operating history at a facility should be considered in planning the risk
 burn.  The risk burn should generally not be performed immediately after refractory replacement or other
 maintenance activity involving soot removal from boiler tubes, ductwork, or other locations where soot and
 catalytic metals may have deposited. In addition, memory effects can persist for at least a day, and a given
 test condition may continue to reflect, in part, what happened during the previous operation (Gullett 1999).
 Therefore, for example, EPA OS W does not recommend performing the risk burn immediately after a
 period of firing high sulfur fiiel or injecting sulfur additives.
 4.2.5
D/F Control Technologies
 Some facilities may install specific D/F control technologies such as carbon injection, carbon beds,
 catalytic oxidizers, and D/F inhibitor technologies. If a facility uses one of these technologies, then EPA
 OSW recommends that key control parameters related to performance of these technologies be
 demonstrated during the D/F test conditions of the risk burn and limited in the permit as necessary for
 protection of human health and the environment.  Relevant control parameters are identified in a technical
 support document for the hazardous waste combustor MACT standards (EPA 1999e), and are not
 addressed further here.
 Although control technologies involving carbon can achieve reductions in stack emissions of D/Fs, permit
 writers should be aware that the use of carbon may sometimes increase total D/F synthesis when D/Fs in
 the solid residues are considered. Carbon has been used successfully in a variety of applications.
 However, carbon injection at higher temperature locations downstream of the combustor can be
 problematic. Schreiber reported that dioxin concentrations in cement kiln dust increased by approximately
 2 orders of magnitude when carbon was injected between the kiln and ESP at operating temperatures in
 excess of 500 °F (Schreiber and others 1995). A similar result is documented by Ullrich, where D/F levels
 in the fabric filter dust increased by a factor of 100 over levels without carbon injection when carbon was
 injected directly to the fabric filter (instead of at a lower temperature location downstream of the fabric
 filter) (Ullrich and others 1996). The quantities of D/Fs in the fabric filter dust exceeded the quantities
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 removed in the stack gas by a factor of 50.
 4.2.6
Control Parameter Summary
 Although Section 4.2 presents each control parameter individually, EPA OS W recommends that the

 relative importance of the parameters with respect to one another also be considered. When one or two

 control parameters are clearly dominant for a particular system, there may be little benefit to limiting

 additional parameters in the permit.


 Based on a review of existing information, this guidance prioritizes control parameters and conditions

 associated with D/F formation as primary, secondary, or tertiary. These hierarchical designations should

 not be considered absolute, but are intended to emphasize the relative importance of demonstrating various

 control parameters during D/F testing and limiting those parameters in the final RCRA permit. A summary

 of primary, secondary, and tertiary control parameters follows.
 1.   Primary control parameters are those which have shown the highest correlation with D/F emissions in
      full-scale tests, and which are therefore expected to dominate D/F formation and removal. EPA OSW
      recommends that these parameters be demonstrated during the D/F testing, and that permit writers
      consider whether specific quantitative limits on these parameters are necessary to protect human
      health and the environment.  The primary control parameters are focused on surface-catalyzedD/F
      formation downstream of the combustion chamber, survival of trace D/Fs from waste feeds, and the
      use of specific D/F control technologies.  Primary control parameters include:

                    Partial wet quench temperatures;
                    Dry particulate hold-up temperatures;
                    Combustion parameters listed in Section 4.2.2.2, for systems that operate under the
                    challenging combustion scenarios discussed in Section 4.2.2.3;
                    Sulfur-to-chlorinemolar feed ratio, unless the S/C1 ratio is well below 0.3;
                    D/F contributions from dioxin-containingwastes;
                    Key control parameters for specific D/F control technologies, including the
                    intentional addition of sulfur as a D/F inhibitor.
 2.   Secondary control parameters are those that may influence D/F emissions under certain
     circumstances. However, there is less information indicating a direct correlation between these
     parameters and D/F emission rates. These parameters may or may not be appropriate to demonstrate
     during the D/F test, and corresponding permit terms may or may not be necessary to protect human
     health and the environment, depending on the significance of these parameters for a given system
     configuration and the presence or absence of dominant primary parameters. Secondary control  .
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     parameters include:
                    Combustion parameters listed in Section 4.2.2.2, for steady-state systems that
                    routinely maintain good combustion and are equipped with rapid wet quench/wet
                    APCDs;
                    Conditions other than combustion quality that may produce organic precursors (such
                    as organics from raw materials in cement kilns and lightweight aggregate kilns, as
                    discussed later in Section 4.5).
3.   Tertiary control parameters pertain to feed composition.' These control parameters have been the
     subject of fundamental and pilot-scale research on D/F formation, but have not routinely been
     correlated with D/F emissions during full-scale testing. These parameters may influence the selection
     of feeds for D/F testing and subsequent waste profile tracking, but it is generally not expected that
     specific feed rate limits in the permit will be necessary to protect human health and the environment.
     Tertiary control parameters include:

                    Chlorine feed rates;
                    Presence of D/F catalysts (such as copper);
                    Presence of D/F precursors (such as chlorinated aromatics);
                    Presence of naturally-occurring D/F inhibitors (such as sulfur), provided that the S/C1
                    molar feed ratio is well below 0.3.
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 4.3
D/F EMISSIONS FROM INCINERATORS
 Hazardous waste incinerator designs include rotary kiln, liquid injection, fluidized bed, and fixed hearth.
 Incinerator designs are described in detail in a technical support document to the hazardous waste
 combustorMACT rule (EPA 1999f). Commercial incineration facilities typically accept hazardous wastes
 from a variety of generators, and the wastes fed to commercial units can be highly variable.  Wastes may
 range from low- and high-Btu liquids, to laboratory packs, to soils contaminated with low levels of RCRA
 hazardous wastes.  Large chemical facilities sometimes operate "captive" incinerators that treat on-site
 wastes, as well as wastes generated off-site by corporate affiliates. Wastes fed to a captive unit may also
 be highly variable, especially if the facility burns a number of wastes from different production operations
 without the capability to blend the wastes to a consistent specification. Some facilities operate small on-
 site incinerators that treat only one or two waste streams. The wastes fed to small on-site incinerators can
 sometimes be more predictable and/or homogeneous than those fed to commercial or captive units.

 Air pollution control for hazardous waste incinerators typically involves an exhaust gas cooling step,
 followed by particulate matter and acid gas control. A few incinerators treat low-ash, low-halogen wastes
 and do not utilize any air pollution control. Exhaust gas cooling can be performed using a waste heat
 boiler or heat exchanger, mixing with ambient air, or injection of water into the exhaust gas.  As discussed
 in Section 4.2.1 of this document, the procedures used for exhaust gas cooling can have a significant affect
 on D/F emissions.
 Particulate matter and acid gas control systems for hazardous waste incinerators can generally be grouped
 into three categories: I) "wet" systems; 2) "dry" systems; and 3) "hybrid wet/dry" systems (EPA 1999f).
 In wet systems, wet scrubbers are used for both particulate and acid gas control. These scrubbers may
 include venturi scrubbers, packed bed scrubbers, ionizing wet scrubbers, wet ESPs, innovative high
 efficiency scrubbers, or some combination of these.  In dry systems, a fabric filter or ESP is used for
 particulate matter control. Dry scrubbing may also be utilized upstream of the dry APCD to achieve acid
 gas control.  In hybrid systems, a dry technique (i.e., ESP or fabric filter) is  used to control particulate
 matter (possibly in combination with dry scrubbing for acid gas control), followed by wet scrubbing for
 acid gas control. Some new technologies are being developed, and several facilities are injecting activated
 carbon for control of D/Fs, non-D/F organics, and mercury.
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 D/F emissions data are available from a variety of hazardous waste incinerators. Units equipped with
 rapid wet quench and wet APCD systems are among the lowest-emitting sources and generally have D/F
 emissions below 0.4 ng TEQ/dscm.  D/F emissions from units equipped with dry air pollution control
 components range from 0.15 to 20 ng TEQ/dscm. Systems equipped with waste heat boilers or other types
 of heat exchangers have D/F emissions ranging from about 1 to 40 ng TEQ/dscm (EPA 1999d).

 The level of D/F emissions from incinerators may be dependent on incinerator design, APCD type,
 paniculate hold-up temperatures, type of quench or presence of a heat recovery unit, combustion
 conditions, and feed composition.  In summary, all of the considerations discussed previously in Section 4.2
 apply to hazardous waste incinerators. The most predominant factors influencing D/F emissions from
 incinerators seem to be the presence of a heat recovery unit and the temperature profile of dry APCD
 systems.

 Table 4-1 summarizes potential control parameters associated with D/F emissions from incinerators. If
 dry APCD equipment or heat recovery devices are present in the downstream control system, the
 temperature profile across these devices is recognized as a primary control parameter directly related to
 D/F formation (see Section 4.2.1). Demonstration of maximum post-combustion temperature is likely to
 coincide with SRE testing (unless the facility can adjust inlet temperature to obtain the requisite
 temperature profiles during DRE testing). Combustion efficiency is also a primary control parameter for
 D/F formation, especially for transient operations, units burning containerized wastes, or high carbon
 monoxide situations as discussed in Section 4.2.2. Demonstration of control parameters affecting
 combustion efficiency will most likely coincide with the DRE test conditions.

 Facilities with more predictable, homogeneous waste feeds, few operating fluctuations, and no particulate
 hold-up devices may prefer to collect D/F emissions data during a risk burn conducted under normal
 operating conditions, as appropriate (see Section 3.3.2.2). Waste feed selection should generally be based
 on representative waste streams, with a preference for D/F precursors such as chlorophenols and minimal
 amounts of D/F inhibitors (such as sulfur).
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r
                                                             TABLE 4-1

                   POTENTIAL CONTROL PARAMETERS ASSOCIATED WITH D/F EMISSIONS FROM INCINERATORS AND BOILERS
1 t
h , "
' Control
Parameter
., * ' fj
p * i ->
Most Likely
A<;hieved
During
, Parameter
Type/Example *
AveragingPeriod*
"How Limit May Be
; Established*
> «•
Other Considerations
•?•
t T
PRIMARY CONTROL PARAMETERS
Post-Combustion Conditions:
See'Section 4.2,1
Maximum post-partial
wet quench temperature
(within the range of 570-
800 °F)
Maximum dry ESP inlet
temperature (within the
range of 400-750 °F)
Maximum fabric filter
inlet temperature (within
the range of 400-750 °F)
Maximum HEPA filter
inlet temperature (within
the range of 400-750 °F)
Maximum heat exchanger
exit temperature (within
the range of 400-750 °F)
SRE test,
unless a
variable
quench is used
SRE test,
unless a
variable
quench is used
Any test that
achieves the
critical
temperature
window
Group A;
1 hour rolling average
Group A
1 hour rolling average
j
Group A
1 hour rolling average
Average of the test run
averages
Average of the test run
averages
Average of the test ran
averages
See Section 4.2. 1.2
See Section 4.2. 1.3
See Section 4.2. 1.3.
Establish & minimum limit
if the device is operated
above the critical
temperature range to
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                                       TABLE 4-1 (continued)

POTENTIAL CONTROL PARAMETERS ASSOCIATED WITH D/F EMISSIONS FROM INCINERATORS AND BOILERS
!?\ *
k ' j
*'x *
' "'*"- ?£•>"•"' •> ' i
" fCtatox)!1
«';, ^Parameter
Most Likely
Achieved
"*' During
Mrahfefer ''
Type/Exapple
Averaging Period*
I AowfciinftMay.Be
•' 'Established1* t
* >t r^ ^ *~*
j > „
Other Considerations
r " if „
PRIMARY CONTROL PARAMETERS (Continued)
Combustion Conditions:

(// is recommended that these
parameters also be limited to control
non-D/F organics, see Section 5.3)
See Sections 4.2.2 and 4.2.6

Combustion parameters are most
critical for challenging combustion
scenarios including:

• transient operations
- batch operations
- high carbon monoxide operations
Combustion parameters may be less
critical for steady-state systems.
Although demonstration of these
control parameters during DRE
conditions is preferred whenever
possible, D/F testing at normal
combustion conditions may be
considered for some steady-state units.







Minimum combustion
temperature, each
chamber




Maximum combustion gas
velocity





Maximum waste feed
rate, each location












DRE






DRE/SRE






DRE













Group A:

1 hour rolling average


Record keeping and
periodic reporting to
confirm continued
absence of transients
may be appropriate in
lieu of hourly average
limits for some steady-
state systems.















Average of the test run
averages

























See Section 4.2.2.2













Consider limits for:
- maximum organic
liquids to PCC
- maximum aqueous
liquids to PCC
- maximum sludges to
PCC
• maximum solids to PCC
• maximunvbatch feeds to
PCC
- maximum organic
liquids to SCC
- maximum aqueous
liquids to SCC
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                                       TABLE 4-1 (continued)

POTENTIAL CONTROL PARAMETERS ASSOCIATED WITH D/F EMISSIONS FROM INCINERATORS AND BOILERS
•
Control
Parameter
Most Likely
• Achieved
During
Parameter
Type/Example
, Averaging Period*
How Limit May Be
Established111
• I
Other Considerations
PRIMARY CONTROL PARAMETERS (Continued)
Combustion Conditions:
(Continued):
Feed Composition:
See Section 4.2.3
Waste variability that
could cause transients
Batch feed conditions:
- see "Maximum waste
feed rate, each location"
- see "Maximum carbon
monoxide and/or total
hydrocarbons"
Maximum carbon
monoxide and/or total
hydrocarbons
Minimum sulfur-to-
chlorine feed ratio
(unless the S/C1 molar
feed ratio during the test
is well below 0.3)
D/F contributions from
dioxin-containing wastes
DRE
ORE
DRE
Any test
condition
where a S/C1
feed ratio >
0.3 is used
Any test with
dioxin-
containing
wastes
This is not a continuously monitored parameter, but
pertains to selection of wastes for testing. Conditions .
for waste profile tracking may be specified by the
permit writer.

Group A
1 hour rolling average
Group B:
Feed stream analyses
may be specified to
monitor sulfiir-to-
chlorine feed ratios
Group B: Feed stream
analyses may be
specified to monitor
dioxin input

Establish per applicable
regulations
Average of the test run
averages
Average of the test run
averages
See Section 4.2.2.3.1
Wastes with physical
properties that can cause
combustion transients
should be selected.
See Section 4.2.2.3.2
Test wastes with high
volatility and oxygen
demand.
Other parameters that may
be necessary to limit are
listed in Section 4.2.2.3.2
See Section 4.2.2.3.3
See Section 4.2.3.4
See Section 4.2.3.5
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July 2001
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                                                        TABLE 4-1 (continued)

POTENTIAL CONTROL PARAMETERS ASSOCIATED WITH D/F EMISSIONS FROM INCINERATORS AND BOILERS
i * * "S-\
r !-J-
i "^
\
vt' * ^^^ -
' Control •
' , ^Parameter
* i ^ * *
Most Lfkelyl
Achieved
Daring -
PRIMARY CONTROL PARAMETERS (Continued)
D/F Control Technologies:
See Section 4.2.5
> Parameter • „*
Type/Bsfample-"
: Averaging Pcriotf*

Howtjmit'May'Be'v
Esla6lisTied* ' "j,
*• *
• i "• j
Other Considerations
v f
?
«. f *

D/F-specific control technologies include carbon injection, carbon bed, catalytic oxidizers and D/F inhibitor technologies. If one of
these control technologies is used to limit D/F emissions, permit limits on key control parameters as described in a technical support
document to the hazardous waste combustor MACT rule (EPA 1999e) may be appropriate.
TERTIARY CONTROL PARAMETERS
Feed Composition:
See Section 4.2.3
Total Chlorine
D/F Catalysts
D/F Precursors
D/F Inhibitors
These are not continuously monitored parameters, but pertain to selection
of wastes and fuels for testing. Conditions for waste profile tracking may
be specified by the permit writer.
Considerations are
discussed in Section 4.2.3
Notes:  D/F   - =  dioxins and furans

       DRE   =  destruction and removal efficiency
       EPA   =  U.S. Environmental Protection Agency
ESP   = electrostatic precipitator

HEPA = high efficiency paniculate air
PCC   .= primary combustion chamber
SCC  = secondary combustion chamber
SRE  = system removal efficiency
                 See Section 1.3.1 for a description of the Group A, B and C designations. Hourly rolling averaging periods are specified as examples, but other averaging
                 periods and techniques may be considered. By establishing operating limits from the test as "the average of the test run averages," the permit writer can
                 better ensure consistency between the manual emissions measurements and the permit. It is less desirable to establish an operating limit as "the average of
                 the minimum (or maximum) hourly rolling averages from the three test runs," because the minimum or maximum operating extremes may only be   '
                 demonstrated during a minor portion of the total stack sampling period.
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4.4
D/F EMISSIONS FROM BOILERS
Boilers recover thermal energy from combustion of hazardous waste and export the energy in the form of
steam, heated fluids, or heated gases. General boiler designs are discussed in Combustion Emissions
Technical Resource Document (EPA 1994c), and requirements for boilers burning hazardous waste are
defined in 40 CFR Part 266.100 et seq. The following characteristics of a boiler are prescribed by 40 CFR
Part 260 for RCRA regulatory purposes: 1) the combustion chamber and primary energy recovery section
must be of integral design; 2) thermal recovery efficiency must be at least 60%; and. 3) at least 75% of the
recovered energy must be exported (i.e., not for internal boiler use).  Hazardous waste is most commonly
burned in firetube boilers, although watertube boilers are used in some cases. Most boilers treating
hazardous waste are on-site units at chemical production facilities.  Many oil- and gas-fired boilers burn
low-ash, low-halogen wastes and are not equipped with any air pollution control.  Some boilers utilize Wet
scrubbing or fabric filtration, and a few units (primarily coal-fired devices) are equipped with ESPs.

The database of D/F emissions from hazardous waste burning boilers is not as extensive as for incinerators
and cement kilns (EPA 1994c). EPA provides data on two boilers equipped with ESPs indicating average
D/F emissions less than 0.03 ng TEQ/dscm (EPA1994c). Handrich summarizes data from testing at 21
boilers in Louisiana (Handrich 1999).  D/F emissions range from less than 0.008 ng TEQ/dscm to as high
as 0.88 ng TEQ/dscm for a unit equipped with a fabric filter. Finally, Gullett and others (in press) provide
data from a firetube boiler where the boiler was intentionally operated under poor combustion conditions to
assess the maximum potential for D/F formation. After a period of flame wall impingement and soot
formation on the boiler tubes, combustion conditions were improved and D/F emissions increased to as high
as 49 ng TEQ/dscm.

D/F emissions from boilers are expected to be dependent on boiler design, APCD type, particulate hold-up
temperatures, combustion conditions, and feed composition. Table 4-1 summarizes control parameters
associated with D/F and other organic emissions from boilers. Depending on the system configuration,
demonstration of control parameters associated with D/F formation in boilers, may coincide with both the
DRE and SRE test conditions.

As explained in Section 4.2.1.3, boiler tubes may serve as particulate hold-up areas and lead to D/F
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 emissions. Because boilers typically have no rapid quench, the flue gas time and temperature window may
 be suitable for D/F formation.  This premise is supported by data for incineration systems equipped with
 waste heat boilers or other types of heat exchangers, where D/F emissions ranging from about 1 to 40 ng
 TEQ/dscm have been measured (EPA 1999d). Heat exchanger exit temperature (measured at the exit of
 the last heat exchanger section) is considered a primary control parameter for D/F formation and control.
 Collection of D/F emissions data for boilers is recommended during conditions that achieve heat exchanger
 exit temperatures in the upper end of (but well within) the 400 to 750 °F range. For example, for a facility
 with heat exchanger exit temperatures ranging from 350 to 550 °F, D/F testing at the exit temperature of
 550 °F would be preferred over testing at the exit temperature of 350 °F. Heat exchanger exit
 temperatures may fall in the upper end of the D/F formation window during either DRE or SRE conditions,
 depending on the facility-specific operating envelope. (Note: If the heat exchanger outlet temperature is
 maintained above the critical temperature range to prevent D/F formation, for example, above 800 °F, a
 minimum temperature limit may be appropriate instead. However, this situation is not expected to be
 likely, since the thermal recovery efficiency for the  boiler would be compromised.) For boilers equipped
 with a dry APCD, the inlet temperature to the dry APCD is also considered a primary control parameter.

 Demonstration of parameters related to combustion quality (see Section 4.2.2) can also be a consideration,
 especially for boilers that burn wastes resulting in combustion transients. Some boilers at chemical
 facilities burn different production run wastes in campaigns. These conditions should generally be
 evaluated by the permit writer prior to trial burn to  determine the potential for transients. Demonstration of
 control parameters affecting combustion efficiency will most likely coincide with the DRE test condition.

 Demonstrating key control parameters related to combustion quality may be problematic for some boilers
 based on potential test condition conflicts (Schofield and others 1997). For example, depending on the
 capacity of the forced draft fan, a facility burning a single high-Btu waste stream may be unable to add
 enough excess combustion air to demonstrate minimum combustion temperature and maximum feed rate
 simultaneously. Thus, two test conditions may be appropriate in some cases to demonstrate all of the key
 control parameters related to combustion.

 Conducting D/F emissions testing during the DRE condition may not always be possible for reasons
 discussed in Section 4.2.2 (e.g., because simultaneous stack determinations for consolidated testing may
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 not be possible, or because the risk testing is being performed separately from performance testing).  In
 these situations, it may be appropriate for a facility with predictable, homogeneous waste feeds and few
 combustion transients to conduct testing under normal combustion conditions (see Section 3.3.2.2). It is
 recommended that the facility still demonstrate heat exchanger exit temperatures (as well as inlet
 temperatures to a dry APCD device) in the upper end of the 400 to 750 °F range.

 In summary, boilers with highly variable operations should generally collect D/F emission samples during
 DRE-like test conditions, as well as any other condition necessary to achieve heat exchanger exit
 temperatures (and inlet temperatures to a dry APCD device) in the upper end of the 400 to 750 °F window.
 This objective could result in multiple test conditions. Facilities with more predictable, homogeneous waste
 feeds and few combustion transients may opt to test only during the test condition achieving the requisite
 heat exchanger exit temperatures and APCD inlet temperatures, as appropriate (see Section 3.3.2.2).

 Finally, EPA OSW recommends that normal soot blowing practices at a boiler generally be reflected during
 the D/F testing. Buekens and Huang summarize measurements showing that D/F emissions during soot-
 blowing can increase as much as 30-fold over normal operations (Buekens and Huang 1998). However,
 data for long operating periods are not available, and it is possible that more frequent cleaning of heat
 surfaces could lead to lower D/F formation overall on a long term basis (Buekens and Huang 1998).  This
 guidance recommends that normal soot blowing procedures be determined from the facility's operating
 record and reflected during the D/F testing according to the methodology specified in Technical
 Implementation Document for EPA's Boiler and Industrial Furnace Regulations (EPA 1992b).  Prior to.
 the test, soot blowing should generally not be performed on a more rapid cycle than normal.
 4.5
D/F EMISSIONS FROM CEMENT KILNS
 Cement kiln designs are described in detail in a report sponsored by the Portland cement kiln industry
 (Dellinger and others 1993). The majority of hazardous waste burning cement kilns utilize a long wet kiln
 design. A few hazardous waste burning kilns are long dry or preheater/precalcinerdry units, and several
 facilities are beginning to replace long wet units with dry preheater/precalcineror semi-dry
 preheater/precalcinerdesigns (Yonley 2000).

 Cement kilns burn hazardous waste commercially (i.e., they accept waste from off-site generators) for use
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as a fuel supplement in the production of Portland cement. Liquid wastes are typically injected into the hot
end of the kiln. Solid wastes may be introduced into the calcining zone at some facilities. For long kilns,
this means that the solid waste is introduced mid-kiln, and for preheater/precalciner kilns it is introduced
onto the feed shelf.  Containerized solid wastes may also be projected into the calcining zone by an air
cannon mounted to the kiln hood. According to a technical support document to the hazardous waste
combustor MACT rule (EPA 1999f), all cement kilns are equipped with either ESPs or fabric filters for
particulate matter control.  In some cases, the flue gases are cooled prior to the dry APCD. Add-on acid
gas pollution control devices are not used at cement kilns, since the raw materials are highly alkaline and
provide some degree of acid gas control.

D/F emissions data are available for most hazardous waste burning cement kilns.  Test condition averages
are highly variable, ranging from 0.004 to nearly 50 ng TEQ/dscm (EPA 1999d). The level of D/F
emissions from a cement kiln may potentially be affected by a number of factors. However, the inlet
temperature to the particulate matter control device is one factor that has been shown to consistently affect
D/F formation (EPA 1999d).

Table 4-2 summarizes potential control parameters associated with D/F and other organic emissions from
cement kilns. Data presented in numerous documents (Harris and others 1994; Lanier and others 1996;
EPA 1999d and  1999e) demonstrate that D/F emissions from cement kilns increase exponentially with
increases in inlet temperatures to the dry APCD within the D/F formation window (400 to 750 °F). A
number of kilns have recently added flue gas quenching units upstream of the APCD to reduce inlet APCD
temperature, and these additions have significantly reduced D/F emissions (EPA 1999d).  This information
suggests that maximum inlet temperature to the dry APCD system, as discussed previously in Section
4.2.1.3, is the primary control parameter related to D/F emissions for cement kilns. Collection of D/F
emissions data should generally occur during a test condition that achieves maximum APCD inlet
temperatures (for example, the SRE test condition, which is performed at a maximum APCD inlet
temperature).

Parameters related to combustion quality (as described in Section 4.2.2) are generally less relevant for
cement kilns than for incinerators and boilers. The operating envelope of cement kilns is dictated largely by
the American Society for Testing and Materials specifications for their final product. Cement kilns operate
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                                             TABLE 4-2
   POTENTIAL CONTROL PARAMETERS ASSOCIATED WITH D/F EMISSIONS FROM CEMENT KILNS AND AGGREGATE
                                              KILNS

Control Parameter
1 , it *i
1 * * i -
Most Likely
Achieved
During
Parameter
Type/Example
Averaging Period*
How Limit May Be
Established*
i
Other Considerations
PRIMARY CONTROL PARAMETERS
Post-Combustion Conditions:
See Sections 4.2.1, 4.5 and 4.6
Combustion Conditions:
(It is also recommended that these
parameters be limited to control non-
D/Forganics, see Section 5.4)
See Sections 4.2.2, 4.2.6, 4.5 and 4.6
Maximum dry ESP inlet
temperature (within the
range of 400-750 °F)
Maximum fabric filter
inlet temperature (within
the range of 400-750 °F)
Aggregate Kilns
Maximum inlet
temperature to extensive
runs of ductwork (where
cooling through the 400-
750 °F temperature
range occurs)
Batch feed conditions:
- maximum batch waste
feed rate at the location
where the batch is fed
- maximum carbon
monoxide and/or total
hydrocarbons
Aggregate Kilns:
Consider Section 4.2.2.2
parameters on a case-by- .
case basis
SRE
Any test where
the post-
combustion
parameters
identified in
Section 4.2.1
are also
demonstrated

Group A:
1 hour rolling average
Group A:
1 hour rolling average

Average of the test run
averages
Average of test run averages
For carbon monoxide and/or
total hydrocarbons, establish
per applicable regulations

See Section 4.2. 1.3
See Section 4.2.2.3.2
Test wastes with high
volatility and oxygen
demand.
Other batch feed parameters
that may be necessary to
limit are listed in Section
4.2.2.3.2

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                                             TABLE 4-2
  POTENTIAL CONTROL PARAMETERS ASSOCIATED WITH D/F EMISSIONS FROM CEMENT KILNS AND AGGREGATE
                                          KILNS (Continued)
*>-
* Cent? oll^rattifftr
Slosf 'Likely
Achieved '
", feu^rig
Parameter
Type/Example
Awa$n| Period*
ffiw Limit iflayBe- -
1 EstaMsBed,*
J ^*
Other Considerations
PRIMARY CONTROL PARAMETERS (Continued)
Feed Composition:
See Sections 4.2.3, 4.5 and 4.6
D/F Control Technologies:
See Section 4.2.5
Minimum sulfur-to-
chlorine ratio at the stack
(unless the S/C1 molar
ratio during the test is
well below 0.3)
D/F contributions from
dioxin-containing wastes
Any test
condition
where a S/C1
ratio > 0.3 is
used
Any test with
dioxin-
containing
wastes
Group B:
Feed stream analyses
may be specified to
monitor sulfur input
Group B: Feed stream
analyses may be
specified to monitor
dioxin input
Average of the test run
averages
Average of the test run
averages
See Sections 4.2.3.4, 4.5 and
4.6
See Section 4.2.3.5
D/F-specific control technologies include carbon injection, carbon bed, catalytic oxidizers and D/F inhibitor technologies. If one of
these control technologies is used to limit D/F emissions, permit limits on key control parameters as described in a technical suppor
document to the hazardous waste combustor MACT rule (EPA 1999e) may be appropriate .
SECONDARY CONTROL PARAMETERS
Control of Precursors from Raw
Material Organics:
(It is recommended that these
parameters also be limited to control
non-D/F organics, see Section 5,4)
See Sections 4.5 and 4.6
Maximum total
hydrocarbons, as
measured at both the
main and bypass stacks,
not to exceed regulatory
limits
SRE
Group A:
1 hour rolling average
Establish per applicable
regulations.
LimitS-in addition to those
specifically prescribed by
regulation may be considered
based on the results of the
risk assessment.
Temporary total hydrocarbon
monitors may be needed if
the facility does not normally
measure total hydrocarbons
in both .stacks.
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                                                              TABLE 4-2
   POTENTIAL CONTROL PARAMETERS ASSOCIATED WITH D/F EMISSIONS FROM CEMENT KILNS AND AGGREGATE
                                                          KILNS (Continued)
-
Control Parameter
Most Likely
Achieved
During
TERTIARY CONTROL PARAMETERS
Feed Composition:
See Sections 4.2.3, 4.5 and 4.6
Total Chlorine
D/F Inhibitors
Parameter
Type/Example
Averaging Period*

How Limit May Be
Established"1
Other Considerations

These are not continuously monitored parameters, but pertain to
selection of wastes and fuels for testing. Conditions for waste profile
tracking may be specified by the permit writer.
Considerations are discussed
in Sections 4.2.3, 4.5 and 4.6
 Notes:  D/F     =  dioxins and furans                        ESP
        EPA    =  U.S. Environmental Protection Agency         SRE
electrostatic precipitator
system removal efficiency
                   •See Section 1.3.1 for a description of the Group A, B and C designations. Hourly rolling averaging periods are specified as examples, but other
                   averaging periods and techniques may be considered. By establishing operating limits from the test as "the average of the test run averages," the permit
                   writer can better ensure consistency between the manual emissions measurements and the permit. It is less desirable to establish an operating limit as
                   "the average of the minimum (or maximum) hourly rolling averages from the three test runs," because the minimum or maximum operating extremes
                   may only be demonstrated during a minor portion of the total stack sampling period.
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 at high temperatures (approaching 3,500 °F) to achieve material temperatures of at least 2,700 °F, with
 typical gas residence times from 4 seconds to as high as 16 seconds.  These conditions are conducive to
 highly efficient organic destruction. Although some cement kilns operate at elevated carbon monoxide
 levels, these levels are not necessarily indicative of poor combustion. A portion of the carbon monoxide in
 cement kilns is due to the calcination process. The calcination process releases large quantities of carbon
 dioxide, which can subsequently decompose into carbon monoxide at the extremely high temperatures in the
 kiln.  In addition, carbon monoxide may be formed at the kiln exit where total hydrocarbons are volatilized
 from the raw materials and are partially oxidized.

 Results from both kinetic modeling and field studies suggest that organics are efficiently destroyed when
 fed at the hot end of cement kilns (Dellinger and others 1993). DRE results seem to confirm this. DRE
 failures at cement kilns are extremely limited, and can generally be explained by high blank or baseline
 (non-hazardous waste) levels of POHCs. In one instance, DRE failure has been attributed to poor atomizer
 design (Dellinger and others 1993). However, facility-specific DRE testing should generally be sufficient
 to reveal design problems. For these reasons, Table 4-2 does not recommend control parameters related to
 combustion of liquid hazardous wastes introduced to the hot end of cement kilns.

 Table 4-2 does recommend limiting combustion control parameters when kilns feed batch waste at mid- or
 feed-end locations. Batch wastes injected at mid- or feed-end locations may not experience the same
 elevated temperatures and long residence times as liquid wastes introduced at the hot end. In a worst-case
 scenario, volatile compounds may be released from the charge so rapidly that they are not able to mix with
 oxygen and ignite before they cool below a critical temperature, forming PICs (Dellinger and others 1993).
 Increased PICs, or precursor organics, may enhance formation of D/Fs. To ensure that D/F emissions are
 not under-estimated for the risk assessment, EPA OS W recommends that batch wastes be fed under
 simulated "worst-case" feeding conditions during the risk burn as discussed in Section 4.2.2.3.2.  The
 recommended permit limits in Table 4-2 are also discussed in Section 4.2.2.3.2, together with a listing of
 other batch feed parameters that may be limited on a case-by-case basis, as necessary to protect human
 health and the environment. Some cement kilns self-restrict individual batch size to less than 1% of the
 total hourly fuel feed, and this practice may be considered in determining appropriate permit limitations.
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In cement kilns, main stack emissions of total hydrocarbons are dominated by organics that are volatilized
from the raw materials prior to entering the high temperature regions of the kiln (Schreiber and Strubberg
1994). The chlorination of these hydrocarbons is a potential source of D/F precursors, such as
monochlorobenzene (Dellinger and others 1993). Bench-scale, as well as full-scale, tests by the industry
have confirmed that hydrocarbons from raw materials play a significant role in governing the production of
D/Fs (Sidhu and Dellinger 1997; Schreiber undated). In addition, D/Fs may actually be present in the raw
materials and may volatilize once the raw materials reach sufficient temperatures, although the significance
of these contributions to total D/F stack emissions is still under debate (EPA 1999d). Considering this
information, EPA OSW recommends that D/F testing be performed at the upper end of the operating range
for total hydrocarbons, as measured in both the main and bypass stacks, not to exceed applicable
regulatory limits.

Although the operating conditions necessary for achieving high total hydrocarbon emissions may vary by
facility, maximum total hydrocarbon levels are likely to be achieved by some combination of high
production rate, high gas temperatures at the raw material feed end of the kiln, and low oxygen at the raw
material feed end of the kiln. Dellinger observed an inverse relationship between total hydrocarbons and
stack oxygen concentrations (Dellinger and others 1993), and Schreiber and Strubberg observed that raw-
material-generated hydrocarbons decrease as kiln oxygen increases (Schreiber and Strubberg 1994). The
organic content of the raw material can also significantly influence hydrocarbon levels. However, raw
material characteristics are largely dictated by quarry location, and are not easily controlled for the purpose
of testing.  If total hydrocarbon levels increase substantially after the risk burn because of changes in raw
materials, then re-testing may be necessary.

In the context of D/F and other organic testing, total hydrocarbon levels are recommended for use as a
control parameter indicating levels of organics within raw materials that may be chlorinated from the
hazardous waste fuel. In this case, total hydrocarbons are not being used strictly as an indicator of waste
fuel combustion efficiency. EPA OSW recommends that site-specific risk assessments quantify risks from
hazardous waste combustor emissions, regardless of source.  Therefore, it may be appropriate for cement
 kilns that only monitor carbon monoxide, or that only monitor carbon monoxide or total hydrocarbons in a
 bypass stack, to install temporary total hydrocarbon monitors in the main and bypass stacks prior to and
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  during the D/F tests to ensure that total hydrocarbon emissions are being maximized. The need for
  permanent total hydrocarbon monitoring can be assessed by the permit writer after the risk assessment is
  completed and potential risks are evaluated.

  Feed characteristics that can potentially influence D/F emissions are discussed in Section 4.2.3. The
  relevance to cement kilns is discussed here. Contradictory information exists regarding the significance of
  waste fuel chlorine. It has been proposed that the highly alkaline environment in a cement kiln scavenges
  available chlorine, making it unavailable for chlorination of organics.  Data presented by Lanier from
  testing conducted at a full-scale facility showed 97% acid gas capture by the alkali material, and no effect
  on D/F emissions due to variations in chlorine feed rate (Lanier and others 1996).  However, equilibrium
  calculations show lower chlorine capture at high temperatures and conversion of HC1 to C^, suggesting
  that even a highly basic chemical species such as calcium hydroxide would not always be expected to
  effectively control chlorinated hydrocarbon formation (including D/Fs) at temperatures above 400 °F
  (Dellinger and others 1993).  In addition, D/F emissions were reduced during full-scale testing at another
  facility where NajCO, was injected at the fuel end to react with chlorine, suggesting that fuel-based
  chlorine can affect D/F emissions in cement kilns (Schreiberand others 1995).  Considering the uncertainty
  on this issue, a recommendation to maintain normal levels of chlorine during the risk burn is reasonable.

  Metal catalysts in the waste, as discussed in Section 4.2.3.2, are not expected to be relevant to D/F testing
  at cement kilns. Spiking wastes with copper was not observed to affect D/F emission rates during full-
  scale testing of a cement kiln (Lanier and others 1996). Also, other metals that have been identified as D/F
  catalysts (iron and aluminum) are major ingredients in cement kiln raw materials.

  D/F precursors, as discussed in Section 4.2.3.3, are expected to be dominated by precursors in the cement
  kiln raw materials, rather than precursors in the waste. However, if a facility burns wastes with significant
 quantities of D/F precursors, these wastes are recommended for use during D/F testing, rather than wastes
 without the precursors.

 Naturally occurring D/F inhibitors, such as sulfur, are discussed in Section 4.2.3.4. Sulfur is expected to
 be present in the coal used for co-firing a cement kiln. During the D/F  testing, EPA OS W recommends that
 coal not be fed at higher-than-normal rates, and low sulfur coal is preferred if a facility uses several coal
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suppliers. Section 4.2.3.4 suggests that, if S/C1 molar feed ratios approach 0.3 or greater, waste and fossil
fuel tracking conditions in the permit may be necessary after the risk burn to protect human health and the
environment by ensuring that a minimum S/C1 ratio is maintained on an ongoing basis.  In cement kilns,
where the alkali raw materials provide some control of acid gases, the S/CI molar ratio in the stack may be
more relevant than the ratio in the feed. Other potential D/F inhibitors, such as calcium, may already be
present in the raw materials.

In some cases, sulfur or other D/F inhibitors are intentionally added to a cement kiln to achieve D/F
control. Schreiber has documented D/F emissions reductions after sulfur was added to the raw materials to
increase the stack concentrations of SOX from less than 20 ppm to above 300 ppm (Schreiber and others
 1995).  Schreiber also documented D/F emissions reductions when Na^C^ was injected at the fuel feed
end to react with chlorine in the system (Schreiber 1995). If sulfur or other D/F inhibitors are intentionally
added to the system to achieve D/F control, then EPA OS W suggests that the recommendations in Section
4.2.5 for specific D/F control technologies should be followed.

There are currently no hazardous waste burning cement kilns utilizing carbon injection for D/F control. A
special consideration for cement kilns is that injected carbon may interfere with the common practice of
recycling cement kiln  dust back into the production process. For a cement kiln to effectively utilize carbon
injection, the carbon injection system may have to be installed after the APCD, along with a second APCD
to collect the carbon.  In addition, the use  of carbon may increase total D/F synthesis when D/Fs in the
cement kiln dust are accounted for, as explained in Section 4.2.5.
 4.6
D/F EMISSIONS FROM AGGREGATE KILNS
 Lightweight aggregate kiln design and operating practices are described in detail in a technical support
 document to the hazardous waste combustor MACT rule (EPA 1999f). Lightweight aggregate kilns
 typically burn only high-Btu, liquid fuel, and do not burn wastes at locations other than the hot end.
 Depending on the feed and system design, the temperature at the hot end of the kiln varies from 2,050 to
 2,300 °F, and combustion gas exit temperatures vary from 300 to 1,200 °F (EPA 1999f). All hazardous
 waste burning lightweight aggregate kilns utilize fabric filters for particulate matter control (EPA 1999f).
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D/F emissions data are available for only a few hazardous waste burning lightweight aggregate kilns. Test
condition averages range from 0.04 to 2.9 ng TEQ/dscm (EPA 1999d). The data suggest that D/F
emissions from lightweight aggregate kilns are influenced by more than APCD operating temperature, since
all available D/F emissions data were generated at similar fabric filter inlet temperatures of around 400 °F.
As explained in Section 4.2.1.3, D/F emissions from lightweight aggregate kilns appear to be primarily
affected by the  inlet temperature to extensive runs of un-insulated ductwork downstream of the kiln, where
flue gas cools slowly through the 400 to 750 °F temperature range.

Table 4-2 summarizes potential control parameters associated with D/F and other organic emissions from
lightweight aggregate kilns.  Dry particulate hold-up temperatures to extensive runs of ductwork and
fabric filters are the primary control parameters related to D/F formation (see Section 4.2.1.3). Collection
of D/F emissions data should generally occur during a test condition that achieves maximum ductwork inlet
temperatures and APCD inlet temperatures (for example, the SRE test condition, which is performed at a
maximum APCD inlet temperature).

Parameters related to combustion quality are discussed in Section 4.2.2. Demonstration of combustion
parameters at lightweight aggregate kilns should generally be considered on a case-by-case basis.
Lightweight aggregate kilns do not operate at combustion temperatures as high as those in cement kilns (see
Section 4.5). However, the potential for poor combustion situations may be minimized, because aggregate
kilns typically only burn high-Btu,  liquid wastes in the flame zone.  Historical operating data should
generally be reviewed to determine whether a facility frequently experiences operating transients, as
discussed in Section 4.2.2.3.1. If so, then the transient operations should generally be represented during
the D/F testing. Permit limitations on the combustion parameters listed in Section 4.2.2.2 (or other
parameters as appropriate) may be  necessary to protect human health and the environment. However, if a
facility maintains steady-state, operations with very few fluctuations, demonstration of absolute minimum
or maximum values for the Section 4.2.2.2 combustion parameters may be less critical.

As discussed in Section 4.5 for cement kilns, the raw materials which are fed to the cold end of aggregate
kilns may contribute to elevated organic precursor concentrations which can affect D/F emissions.
Therefore, D/F testing should generally be performed at the upper end of the operating range for total
hydrocarbons.  Since most aggregate kilns only monitor carbon monoxide, it may be appropriate to install
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 temporary total hydrocarbon monitors for the testing.


 Feed composition is discussed in Section 4.2.3.  Recommendations regarding feed characteristics that can
 potentially influence D/F emissions are similar to those discussed in Section 4.5 for cement kilns.
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                                   CHAPTER 5
   ORGANIC EMISSIONS OTHER THAN DIOXINS
                                 AND  FURANS
 EPA OS W has recommended that human health and ecological risk assessments evaluate potential risks
 associated with organic emissions other than D/Fs, in addition to the risks from D/Fs (EPA 1998a and
 1999b). The EPA OS W risk assessment guidance (EPA 1998aand 1999b) recommends that the final risk
 assessment clearly distinguish between the portion of stack emissions evaluated for risk, the portion
 considered to be non-toxic, and the portion that remains unknown. Therefore, the objective for the risk
 burn should be to characterize organic stack emissions as completely as possible. As stated in Chapter 2, it
 is recommended that the largest possible percentage of organic emissions be identified and quantified
 initially to minimize the need for re-testing, even though some compounds may eventually be eliminated
 from quantitative risk evaluation as part of the COPC selection process recommended in the EPA OS W
 risk assessment guidance (EPA 1998a).  .

 This chapter addresses identification and quantification of organic emissions other than dioxins and furans.
 Stack determinations are discussed in Section 5.1. Key control parameters that EPA OSW recommends be
 demonstrated during the testing are identified in Section 5.2. All parameters may not be relevant for all
 systems, and the information in Section 5.2 should be considered in conjunction with the industry-specific
 information provided for incinerators and boilers in Section 5.3, and for cement kilns and lightweight
 aggregate kilns in Section 5.4, as well as  facility-specific information.
 5.1
STACK DETERMINATIONS FOR ORGANICS
 EPA has conducted research to identify the types and quantities of organics emitted from hazardous waste
 combustion facilities (EPA 1998e; Ryan and others, 1996 and 1997; Midwest Research Institute and A.T.
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 Kearney 1997; Lemieux and others 1999). These research efforts indicate frequent detection of volatile
 and semivolatile organics including chloro-, bromo-, and mixed bromochloro-alkanes, alkenes, alkynes,
 aromatics, and polyaromatics, D/Fs, PAHs, PCBs, phthalates, nitrogenated and sulfonated organics, and
 short-chain alkanes (such as methane and propane). EPA reports frequent detection of chlorinated and
 brominated alkanes and alkenes (such as chlorinated ethenes), and suggests that chlorinated ethenes can
 serve as potential indicators of D/F formation (EPA 1998e). EPA supports ongoing research to improve
 the identification and quantification of organic emissions.  However, uncertainty remains regarding the full
 suite of organic emissions from hazardous waste combustion facilities and the potential risks associated
 with those emissions.

 Because organic emissions cannot be reliably predicted based on the feed, design, or operating practices at
 a particular facility, this guidance recommends that comprehensive organic emissions testing be performed
 to develop emissions data for site-specific risk assessments to accomplish the following three objectives:
                Identification and quantification of specific toxic organic compounds (such as PAHs and
                PCBs) to assess their contribution to the total potential risk posed by the facility;
                Identification and quantification of as many other constituents as possible, regardless of
                toxicity, to reduce uncertainty for the risk assessment;
                Construction of an organics mass balance which estimates the completeness of the organic
                emissions characterization, to evaluate remaining uncertainty associated with the risk
                assessment.
 The first objective can typically be achieved by sampling and analysis for specific compounds listed on
 volatile, semivolatile, and other target analyte lists. The second objective involves determinations for
 constituents that are not typically included on target analyte lists. Examples include tentatively identified
 compounds, as well as simple hydrocarbons. The third objective involves a measurement of Total Organic
 Emissions. Each of these objectives is discussed in more detail.
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 5.1.1
Target Analyte Lists
 The first recommended objective of organics testing is to identify and quantify specific toxic organic
 compounds to assess their contribution to the total potential risk posed by the facility. Recommended
 target analyte lists for organics are provided in Appendix B of this document.  Standard EPA methods
 (EPA 1996b) can be used to identify and quantify many organics that are potentially toxic, persistent, and
 bioaccumulative. For volatile and semivolatile organic compounds, S W-846 Methods 8260 and 8270 gas
 chromatography/massspectrometry (GC/MS) procedures are preferred (EPA 1996b). The EPA methods,
 as written, are intended as guidance and are recommended as starting points for the development of
 standard operating procedures that will actually be used. Guidance on appropriate method modifications is
 provided in S W-846 (refer to Chapter 2 of S W-846 [EPA 1996b] and the applicable methods.) However,
 the facility should be able to demonstrate and document that the modified methods meet the DQOs for the
 particular application.  Other methods not found in S W-846 may also be used if the  user can demonstrate
 and document that the methods will generate data that meet the appropriate DQOs.

 Stack determinations for PCBs are also recommended, based  on evidence that PCBs can be emitted from
 combustion sources regardless of PCB contamination in the feed. An increasing body of information
 supports the likelihood that PCBs may be emitted as by-products of the combustion process. It is possible
 that PCBs are formed by the same reactions that produce D/Fs, discussed previously in Section 4.1.
 Lemieux hypothesized that, if PCBs and D/Fs are formed by similar mechanisms, then emissions of PCBs
 should correlate with emissions of D/Fs (Lemieux and others 1999). This hypothesis was tested by
 reviewing data where both PCBs and D/Fs were measured. An apparent trend was indeed found showing
 increased PCB emissions with increased D/F emissions.  In most cases, PCBs were found in the stack even
 when there were no PCBs in the feed.  Overall, PCB emissions exceeded D/F emissions by approximately a
 factor of 20, and this trend appeared to hold over five orders of magnitude in D/F emissions.

 Alcock (Alcock and others 1999) and EPA (EPA 1997b) have established that waste combustion units
 contribute significantly to total emission inventories of PCBs. In addition, PCBs can be important from a
 risk standpoint. In the United Kingdom, where a TEQ is used to assess the potential  toxicity of complex
 mixtures of D/Fs and PCBs, the PCBs contributed up to 60% of the TEQ for a cement kiln facility. For
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other sources, the PCB contribution was more minimal.
The current toxicity approach for PCBs (EPA 1996c; Van den Berg and others 1998) calls for data on:
               Total PCB concentration; and
               Congener-specific analysis for the 12 toxic dioxin-like coplanar and mono-ortho-
               substitutedPCBs listed in Table B.5-1.
The 12 dioxin-like PCBs are important because the rings can rotate into the same plane, similar to that of a
D/F molecule. Studies have shown that these dioxin-like congeners can react with the aryl hydrocarbon
receptor. This is the same reaction that is believed to initiate the adverse effects of D/Fs.  The World
Health Organization has derived interim toxicity equivalency factors (TEFs) for these coplanar PCBs (Van
den Berg and others 1998).  The TEFs are applied to congener-specific concentrations to evaluate dioxin-
like toxicity. Risks  from the dioxin-like congeners (evaluated using the slope factor for dioxins) are then
added to risks from the rest of the mixture (evaluated using the slope factor for PCBs applied to total PCBs
reduced by the amount of dioxin-like congeners). With proper planning, the PCB determination can be
made using portions of the D/F sampling train extracts. More detail regarding sampling and analysis for
PCBs is provided in Appendix B.

Finally, it may be appropriate for a facility to sample and analyze for additional constituents based on the
types of wastes burned.  For example, in addition to constituents on the volatile, semivolatile, and other
target analyte lists, it may be appropriate for a facility to sample and analyze for compounds such as
pesticides, nitroaromatics, and cyanides.  It is recommended that stack determinations be considered for any
highly toxic, persistent, or bioaccumulative constituent burned in significant quantities. Section 5.2.2 lists
examples of historical waste feed information that can be reviewed to determine the significance of a
particular constituent. Although the determination is somewhat subjective, a constituent may be
appropriate to address as part of the stack sampling and analysis if it is prominent on several of the
suggested rankings. Additional information on testing for facility-specific compounds is provided in
Appendix B.
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  5.1.2
Tentatively Identified Compounds
 The second recommended objective of organics testing is to identify and quantify as many non-target
 constituents as possible, regardless of toxicity. By identifying a larger portion of the unknown peaks in a
 chromatogram, a more complete organics mass balance can be achieved; and uncertainty in the risk
 assessment can be reduced.

 In support of this second objective, a MS library search to identify non-target compounds is recommended,
 followed by review of the results by an experienced mass spectroscopist. Constituents identified based on
 the library search are referred to as tentatively identified compounds (TICs), since there is no reference
 standard analyzed at the same time as the unknown.  The nearest internal standard is used for quantisation,
 and a relative response factor of one (1) is assumed.  The resulting concentration is considered to be a
 semi-quantitative estimate, due to lack of a compound-specific response factor. Determinations for
 tentatively identified compounds are discussed further in Appendix B.

 The EPA OSW risk assessment guidance (EPA 1998a) recommends that the semi-quantitative results for
 tentatively identified compounds be added into the "identified" portion of the stack emissions to ensure that
 appropriate credit is given to defensible efforts at identifying the maximum number of organic compounds.
 EPA OSW recommends that tentatively identified compounds that could significantly contribute to risk be
 considered for confirmation and quantification through the use of known standards.
 5.1.3
Simple Hydrocarbons
 Many organics lack EPA toxicity values, or they may not be toxic at all. These compounds are not
 typically included on standard target analyte lists. However, an important advantage of identifying, and
 quantifying as many organics as possible is the reduction of uncertainty for the risk assessment. Methane
 and other aliphatics can comprise a significant percentage of total stack organics, and specific
 determinations for methane, propane, and other short-chain aliphatics can potentially alleviate concerns
 about the percentage of the total organic mass that might be toxic.
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One simple way to quantify non-toxic volatile hydrocarbons without expanding the sampling effort is to
utilize information already available as part of the Total Organic Emissions determination (discussed in
Section 5.1.4). The Total Organic Emissions determination involves measurement of volatiles by field gas
chromatography, and an initial calibration is performed using methane, ethane, propane, butane, pentane,
hexane and heptane.  If sample analysis shows that a stack gas constituent has the same retention time as
one or more of the calibration standards, then that constituent can be quantified and included in the
"identified" portion of the stack emissions. A facility may also prefer to calibrate the field gas
chromatograph with additional compounds to identify more volatile hydrocarbons, thereby moving those
compounds from the "unknown" to the "identified" portion of the organic stack emissions. Analysis for
simple hydrocarbons is discussed further in Appendix B.
5.1.4
Total Organic Emissions
Unfortunately, only a limited number of organic compounds can be accurately identified and quantified
using standard stack gas sampling and analysis methods. A portion of the emissions profile remains
unaccounted for.  The third recommended objective of organics testing is construction of an organics mass
balance to qualify the completeness of the organic emissions characterization. This information is used to
evaluate remaining uncertainty associated with the risk assessment. This third objective involves a
measurement of Total Organic Emissions.

The Total Organic Emissions determination (EPA 1996d) measures organic fractions for three boiling
point ranges: 1) a volatile field gas chromatography (FGC) fraction (boiling points less than 100 °C); 2)
the semivolatile, total chromatographable organics (TCO) fraction (boiling points between 100 and 300
 °C); and 3) the non-volatile, gravimetric (GRAY) fraction (boiling points greater than 300 °C). The sum
of the concentrations for the three fractions represents total organic mass. The procedure is discussed
further in Appendix B.

EPA OS W recommends the procedure described in Appendix B as the best currently available way to cost
effectively determine total recoverable organic mass and characterize uncertainty in the risk assessment.
Permit writers should generally consider updated or expanded techniques if and when they become
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available.

EPA OS W has recommended that the final result from the Total Organic Emissions determination be used
to compute a total organic emissions (TOE) factor, defined as total organic emissions divided by the sum of
the identified organics (EPA 1998a). The TOE factor is typically presented in the uncertainly section of
the risk assessment report to clearly qualify how much of the stack emissions have been evaluated for risk.
Permitting authorities can evaluate the TOE factor and assess to what extent actual risks may be greater
than estimated risks (EPA 1998a). TOE factors ranging from 2 to 40 have been computed (EPA 1998a).
Lower TOE factors can be achieved by more complete characterization of stack emissions (i.e., more
"identified" compounds in the denominator), and facilities should consider this in determining appropriate
stack measurements for the risk burn (Sections 5.1.1 through 5.1.3).

The importance of the Total Organic Emissions determination for site-specific risk assessments cannot be
over-emphasized. Studies (EPA 1976; Pellizzari and others 1980) have shown that analyses based strictly
on target analyte lists may account for less than 20% of the total organic material in an emission sample.
Without a Total Organic Emissions determination, a final risk assessment report cannot explain how much
of the total stack emissions have been evaluated for risk, significantly complicating the risk management
decision.
 5.2
CONTROL PARAMETERS TO BE CONSIDERED FOR RISK BURNS
 This section identifies key control parameters that are expected to affect organic emissions, and that EPA
 OSW recommends be considered in establishing the risk burn test conditions. Depending on site-specific-
 considerations, these control parameters may need to be limited in the RCRA permit after the risk burn to
 protect human health and the environment by ensuring that organic emissions remain within the measured
 levels on an ongoing basis.

 Most of the control parameters listed in this section pertain to combustion conditions that have already been
 discussed in Section 4.2.2.  Information from Section 4.2.2 is referenced, as appropriate, instead of
 repeating the information here.
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  Several of the control parameters identified in this section may currently be limited in association with the
  ORE standard, or will soon be limited pursuant to the requirements of the hazardous waste combustor
  MACT rule. To the extent that risks from non-D/F organics are already adequately controlled by
  regulatory limits on key control parameters, then fewer risk-based limits may be needed in the RCRA
  permit. However, if regulatory controls are not applicable or sufficiently comprehensive, then additional
  risk-based limits may be necessary to protect human health and the environment. A greater number of risk-
  based permit limitations may be necessary when the risk burn and RCRA or MACT performance tests
  reflect different operating modes.

  Recommended control parameters that are expected to affect organic emissions are categorized according
  to combustion conditions (Section 5.2.1) and feed composition (Section 5.2.2). All parameters may not be
  relevant for all systems, and the information in Section 5.2 should be considered in conjunction with the
  industry-specific information provided for incinerators and boilers in Section 5.3, and for cement kilns and
  lightweight aggregate kilns in Section 5.4, as well as facility-specific information. The discussions and
  recommendations in this section are based on the underlying assumption that all hazardous waste
  combustors are required by RCRA or MACT regulation to operate under combustion conditions that meet
  or exceed 99.99 percent DRE.
 5.2.1
Combustion Conditions
        Recommendation—EPA OSW recommends that, whenever possible, facilities perform testing
        for non-D/F organics during the DRE test conditions and that the challenging combustion  •
        scenarios discussedin Section 4.2.2.3 be represented during the testing (if applicable too
        particular system).  The challenging combustion situations described in Section 4.2.2.3 include:
        1) transient conditions; 2) operation with containerized or batch waste feeds; and 3) high carbon
        monoxide situations.

        Combustion parameters identified in Section 4.2.2.2 should automatically be addressed when
        organics testing is performed during the DRE test conditions, since these parameters are
        typically demonstrated and limited as part of the DRE determination.  The combustion
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       parameters listed in Section 4.2.2.2 include: 1) minimum primary and secondary combustion
       chamber exit temperatures; 2) maximum combustion gas velocity; 3) maximum -waste feed rate at
       each feed location; 4) limitations on waste feed composition and batch feeds; and 5) maximum
       flue gas carbon monoxide and/or total hydrocarbon concentrations.

       The recommendationfor organics sampling during the DRE test is a general guideline. Some
       facilities and permit writers may be faced with situations where this general guideline is not
       appropriate. For example, DRE testing may already have been conducted in advance of the risk
       burn, or the use of surrogate waste for the DRE test might conflict with the objective to use
       actual wastes during the non-D/F organic testing. These and other situations call for decisions
       regarding the specific combustion conditions to be demonstrated. Therefore, this guidance
       recommends that the challenging combustion scenarios described in Section 4.2.2.3 (if
       applicable)  be preferentially targeted for organics testing. As appropriate, it is recommended
       that permit limits for the Section 4.2.2.2 combustion parameters be established based on
       organics testing conducted under these challenging combustion scenarios. In addition, a
       facility-specific review of trial burn and historical operating data should generally be performed
       to determine whether the challenging combustion scenarios correlate with other operating or
       feed parameters. If so, it is recommended that the correlating parameters be demonstrated
       during the testing and limited in the permit as necessary to protect human health and the
       environment in addition to, or possibly in lieu of, the combustion parameters listed in Section
       4.2.2.2. Caution should be exercised to ensure that targets during the organics testing for the
       Section 4.2.2.2 combustion parameters are not substantially different from those demonstrated
       during the DRE test.

       Finally, it is important to recognize that some combustion units operate under extremely steady-
       state conditions, at temperatures and residence times that should routinely ensure good
       combustion. Challenging combustion situations, such as those described in Section 4.2.2.3, do
       not occur. Combustion conditions may not fluctuate at all, and carbon monoxide may be near
       zero.  Ideally, logistics will favor combining the organics testing with the DRE test. If so, then
        the combustion parameters listed in Section 4.2.2.2 should automatically be addressed, since
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         they are typically demonstrated and limited as part of the DRE determination.  However, if
         combined testing is not possible, then consideration may be given to testing under normal
         combustion conditions, as appropriate (see Section 3.3.2.2). Historical operating data for the
         appropriate combustion parameters should generally be reviewed to verify that the facility
         maintains steady-state operations with very few fluctuations.  Demonstration of absolute
         maximum or minimum values for the combustion parameters listed in Section 4.2.2.2 during
         organics testing may be less critical for steady-state operations.  In lieu of specific permit limits
        for the parameters listed in Section 4.2.2.2, periodic reporting to confirm continued absence of
         transients may be appropriate. When organics testing cannot be performed in conjunction with
         the DRE test, caution should be exercised to ensure that targets during the organics testing for
         the combustion parameters listed in Section 4.2.2.2 are not substantially different from the levels
         demonstrated during the DRE test.

 For most incineration and boiler systems, the generation of organic products of incomplete combustion is
 typically associated with poor combustion situations (organic emissions from cement kilns and lightweight
 aggregate kilns are typically dominated by organics that are volatilized from the raw materials, but this is
 discussed later in Section 5.4).  Berger has documented the effects of inefficient burner operation and
 oxygen control (Berger and others 1996).  These conditions led to incomplete combustion and  subsequent
 increases in fly ash and carbon monoxide and total hydrocarbon concentrations. Linak has documented
 PCC exit total hydrocarbon levels in excess of10,000 ppm during very intense transient puffs arising from
 batch feed operations at a pilot-scale unit, and has performed chemical analysis to show that the puffs can
 contain numerous hazardous compounds, even though adequate DREs (>99.99%) may be achieved (Linak
 and others 1987).  Historically, levels of oxygen, carbon monoxide, and total hydrocarbons have been used
 as surrogate indicators of good combustion to minimize PIC emissions.

 Examples of operating conditions that may lead to increased PIC formation include:
        •      Insufficient temperatures in either the PCC or SCC, leading to incomplete combustion.
        •      Excess flue gas velocity or flow leading to shorter residence times in the combustion unit
               and incomplete combustion;
        •      Batch-fed containers with high oxygen demand that can lead to transient, low oxygen

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                conditions and incomplete combustion;
         •       Feeding of low-Btu solids or aqueous liquids that can reduce combustion temperatures.


 These situations are typically addressed during performance testing under DRE conditions. To the extent
 possible, DRE tests are conducted at minimum combustion temperatures in the PCC and SCC, maximum
 flue gas velocity or flow, and maximum feed rate of each waste type (EPA 1989 and 1992b). Therefore, a
 successful DRE test should generally result in the maximum organic PIC emissions for incinerators and
 boilers. In addition, the challenging combustion scenarios discussed in Section 4.2.2.3 should generally be
 represented during the testing if they are applicable to a particular system. The challenging combustion
 situations described in Section 4.2.2.3 include: 1) transient conditions; 2) operation with containerized or
 batch feeds; and 3) high carbon monoxide situations.

 The combustion parameters which should generally be emphasized for organic emission testing are the
 same as those identified in Section 4.2.2.2. These parameters include:
         *       Minimum PCC and SCC combustion temperatures;
         •       Maximum combustion gas velocity as an indicator of residence time;
         •       Maximum waste feed rate for each feed location;
         •       Limitations on waste feed composition and batch/containerized feeds;
         •       Maximum flue gas carbon monoxide and/or total hydrocarbon concentrations.
 These parameters are usually demonstrated in conjunction with the DRE test condition. However, there
 may be situations where it may not be possible to perform non-D/F organic emissions testing during the
 DRE test.  For example, the use of surrogate waste for the DRE test might conflict with the objective to use
 actual wastes during the non-D/F organic testing. In these situations, EPA OS W recommends that the
 challenging combustion scenarios described in Section 4.2.2.3 be preferentially targeted for organics testing
 (if applicable) because of increased potential for localized oxygen deficiencies and carbon monoxide/total
 hydrocarbon spikes. As necessary to protect human health and the environment, permit limits for the
 Section 4.2.2.2 combustion parameters should be established based on organics testing conducted under
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these challenging combustion scenarios. In addition, a facility-specific review of trial burn and historical
operating data should generally be performed to determine whether the challenging combustion scenarios
correlate with other operating or feed parameters. If so, it is recommended that the correlating parameters
be demonstrated during the testing and limited in the permit as necessary to protect human health and the
environment in addition to, or possibly in lieu of, the combustion parameters listed in Section 4.2.2.2.

At some facilities, the challenging combustion scenarios identified in Section 4.2.2.3 may not occur. For
steady-state systems, demonstration of absolute minimum or maximum values for the Section 4.2.2.2
combustion parameters during organics testing may be less critical. Although demonstration of these
control parameters can ideally be accomplished by combining the organics testing with the DRE
demonstration (which is preferred whenever possible), consideration may be given for  some steady-state
systems to performing the organics testing under normal conditions. As discussed in Section 3.3.2.2,
testing at normal conditions may be appropriate where the facility can establish a monitoring plan and
permit conditions can be developed as necessary to protect human health and the environment to ensure that
the test conditions are representative of long-term operations.  A permit writer generally should consider the
extent to which normal conditions represent potential emissions and risks over the permitted operating
range in determining whether testing at normal conditions is appropriate.  If organic emissions data are
collected under normal conditions, caution should be exercised with respect to operating parameters where
the average value is significantly different than operating extremes.

5.2.2          Feed Composition

        Recommendation—EPA OSWrecommends that, whenever possible, actual wastes (rather than
        surrogate wastes synthesizedfrom pure compounds) be burned during the non-D/F organics
        testing, and that representative, but challenging, feeds be selected for the test.  High quantity,
        routine and recurring waste streams are generally preferred, with special emphasis on wastes
        that may cause combustion transients (Section 4.2.2.3.1) and wastes containing highly toxic,
        persistent and bioaccumulative constituents.

 Waste selection for non-D/F organic testing can be very important, because the types of organic PICs may
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  relate directly to the chemical composition of the waste.  EPA OSW recommends that actual wastes, and

  not surrogate wastes synthesized from pure compounds, be used whenever possible. The goal for the risk

  burn is to choose representative, but challenging, feeds: actual wastes which may cause elevated or more
  highly toxic emissions are preferred for the test.


  When choosing actual wastes, EPA OSW recommends that the focus be on high quantity, routine, and

  recurring waste streams, with special emphasis on wastes that may cause combustion transients (Section

  4.2.2.3.1) and wastes containing highly toxic, persistent, or bioaccumulative constituents.  Examples of
  historical information that can assist in a review of actual wastes include the following:


         •       A listing of the top percentage (e.g., top 75 percent) waste receipts by quantity for a given
                period with descriptions of:

                               source or process generating the waste;
                               annual weight treated;
                               hazardous waste code(s);
                               physical description;
                               chemical description;
                               feed mechanism and feed location to the combustion unit

         •       A ranking by weight of the top percentage of chemical constituents treated over a given
                period.

         •       A ranking which identifies wastes containing constituents with the highest toxicity,
                persistence, and bioaccumulation potential.

         •       A summary of minimum, maximum, and average values for the wastes fed via each feed
                mechanism into the combustion unit over a given period for:

                               heating value;
                               percentage total chlorine;
                               percent ash;
                               percent water;
                               percent solids;
                               viscosity (as appropriate).

         •       If historical operating data indicates that the facility experiences routine transients, a
                summary of the waste streams or waste characteristics which appear to correspond to the
                transient operations.
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 EPA OSW recommends that candidate wastes for organic emissions testing be identified considering the
 ability of the waste to achieve the desired combustion conditions (i.e., tax the combustion unit), the ability
 of the waste to represent toxic, persistent, and bioaccumulative compounds, and predicted availability of
 sufficient quantities of the waste streams to complete the relevant portions of the risk bum. Efforts
 generally should be made to schedule the testing for a time period when the target wastes will be available.
 However, it may be appropriate to review and evaluate waste selection a few weeks prior to the test based
 on actual waste stockpiles or scheduled waste receipts.

 If a facility burns a large number of small waste streams, or if large quantities of uniform wastes are not
 available, then the inventory of actual wastes might be insufficient for completing the non-D/F organics
 emissions testing. A combination of real waste and synthetic waste (or spiked actual wastes) should
 generally be used in this situation. To the extent possible, simulated wastes should represent the high
 quantity, routine actual waste streams at a facility, while also achieving the goals outlined in this section.
 For example, simulated wastes should generally be physically and chemically configured to challenge the
 combustion unit. Key characteristics from Section 4.2.2.3.1 include physical form, viscosity, moisture,
 heating value, chlorine, volatility and oxygen demand. It may also be appropriate to spike the simulated
 wastes to be chemically similar to actual wastes in terms of highly toxic, persistent, or bioaccumulative
 constituents. In certain circumstances (e.g., to represent a significant waste stream that is not yet being
 generated, or to represent mixed hazardous/radioactive wastes which present special sampling and
 analytical challenges), it may be appropriate to use 100 percent surrogate wastes.  In the case of batch or
 containerized wastes, it will generally be more important to focus on maximizing the amount of volatile
 material within each container, as discussed in Section 4.2.2.3.2, than to use a real waste with less oxygen
 demand.

 Finally, the facility should generally provide protocols for monitoring and tracking waste stream
 information on an ongoing basis.  The protocols should generally identify methods and procedures for
 comparing future waste characteristics to the wastes burned during the organic emissions testing. This
 information may be used to  define the permitted variation in waste stream composition after the test, or to
 determine the need for retesting. Parameters of interest are generally expected to closely mirror those
 reviewed to plan the test in the first place.
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5.3
ORGANIC EMISSIONS FROM INCINERATORS AND BOILERS
Hazardous waste incineration and boiler systems are described briefly in Sections 4.3 and 4.4. Non-D/F
organic emissions from incinerators and boilers are likely to be dependent on both combustion conditions
and feed composition: In summary, all of the considerations discussed in Section 5.2 are also appropriate
to consider with respect to incinerators and boilers. Key control parameters are summarized in Table 4-1.

As discussed in Section 4.4, demonstrating key control parameters related to combustion quality may be
problematic for some boilers. For boilers, conflicting parameters of maximum waste feed rate and
minimum combustion temperature are very prevalent, especially for those boilers with varying production
loads for steam generation. Minimum combustion temperature will occur at minimum loads (and therefore
at lower fuel  feed rates). Maximum waste feed rate will normally occur at maximum production load
(maximum steam generation) at a temperature higher than the minimum. Thus, two test conditions may be
appropriate in some cases to demonstrate all of the key control parameters related to combustion.
 5.4
ORGANIC EMISSIONS FROM CEMENT KILNS AND LIGHTWEIGHT
AGGREGATE KILNS
 Cement kiln and lightweight aggregate kiln systems are described briefly in Sections 4.5 and 4.6. As
 discussed in Section 4.5, parameters related to combustion quality are generally less relevant for cement
 kilns and lightweight aggregate kilns than for incinerators and boilers. However, naturally occurring
 organics are driven out of the raw materials at the cold end of the kiln.

 Control parameters associated with organic emissions from cement kilns are identified in Table 4-2.
 Conditions relative to combustion quality are generally limited to situations where batch or containerized
 wastes are fed. Batch wastes injected at mid- or feed-end locations may not experience the same elevated
 temperatures and long residence times as liquid wastes introduced at the hot end. The remaining
 recommendations in Section 5.2.1 regarding combustion conditions are not typically relevant to cement
 kilns.

 Since organic emissions from cement kilns are likely to be dominated by organics volatilized from the raw
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 materials, the recommended focus during the risk burn is to maximize total hydrocarbon emissions in the
 main and bypass stacks, not to exceed applicable regulatory limits. Although the operating conditions
 necessary for achieving high total hydrocarbon emissions may vary by facility, maximum total hydrocarbon
 levels are likely to be achieved by some combination of high production rate, high gas temperatures at the
 raw material feed end of the kiln, and low oxygen at the raw material feed end of the kiln. These conditions
 are most likely to be achieved during a high temperature or SRE test. The recommendation to maximize
 total hydrocarbon emissions is discussed further in Section 4.5.

 Control parameters associated with organic emissions from lightweight aggregate kilns are identified in
 Table 4-2. For lightweight aggregate kilns, EPA OSW recommends that demonstration of combustion
 parameters be considered on a case-by-case basis.  Lightweight aggregate kilns do not operate at
 combustion temperatures as high as those in cement kilns. However, the potential for poor combustion
 situations may be minimized, because aggregate kilns typically only burn high-Btu, liquid wastes in the
 flame zone.  Historical operating data should generally be reviewed to determine whether a facility
 frequently experiences operating transients, as discussed in Section 4.2.2.3.1. If so, it is recommended that
 the transient operations be represented during the organic emissions testing and permit limitations on the
 combustion parameters listed in Section 4.2.2.2 (or other parameters as appropriate) may be necessary to
 protect human health and the environment. However, if a facility maintains steady-state operations with
 very few fluctuations, demonstration of absolute minimum or maximum values for the Section 4.2.2.2
 combustion parameters may be less critical. As discussed for cement kilns, raw materials may contribute
 to elevated organic emissions at lightweight aggregate kilns, and it is recommended that organics testing be
 performed at the upper end of the operating range for total hydrocarbons.

 The recommendations in Section 5.2.2 regarding feed composition are generally appropriate for cement
 kilns and lightweight aggregate kilns. Although organic emissions may be influenced more by the raw
 materials than the waste feeds, it is reasonable to expect that representative, actual wastes should be burned
 for the risk burn. Selection of liquid wastes burned at the hot end of a cement kiln or aggregate kiln is
 expected to be less complex than for incinerators and boilers, because wastes are blended to meet fuel
 specifications. However, the waste characterization information discussed in Section 5.2.2 generally
 should be provided for the as-blended fuel to the extent possible, as well as for wastes fed at locations other
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than the hot end of the kiln. For blended fuel, it may not be possible to perform a characterization by top
percentage of waste receipts. In this case, EPA OSW recommends that an alternate ranking scheme be
developed to reflect the chemical and physical characteristics of the blended fuel.
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                                     CHAPTER 6
                             METAL EMISSIONS
 EPA OS W has recommended that metal emissions be evaluated in site-specific risk assessments because
 they can pose potential human and ecological risks (EPA 1998a and 1999b). Since most facilities are
 either controlling metals emissions or will soon control metals emissions pursuant to the requirements of the
 hazardous waste combustor MACT rule, the primary consideration for the risk burn is whether additional
 control beyond applicable regulatory standards may be warranted at a particular site (see also Sections
 1.3.2 and 1.3.3). This chapter reviews emissions and operating data that may need to be gathered during
 the risk burn to assist in this determination.

 Metal emissions from hazardous waste combustors are highly dependent on metal volatility, metal feed
 rates, and air pollution control efficiency. Section 6.1 provides information on metals volatility. Section
 6.2 reviews specific feed and APCD control parameters that can influence metal emissions, with emphasis
 on the control parameters identified in the hazardous waste combustor MACT rule. Section 6.3 discusses
 additional risk-based emissions and feed rate limitations which may need to be considered on a site-specific
 basis. Finally, Section 6.4 discusses metals speciation. Although recommended speciation assumptions for
 combustion risk assessments are provided in the EPA OS W risk assessment guidance (EPA 1998a),
 additional emissions data may need to be collected during the risk burn if a facility wishes to utilize site-
 specific information.
 6.1
METAL VOLATILITY GROUPINGS
 Metals can be grouped as volatile, semivolatile, or low-volatile. The distinctions between the three
 volatility groupings are not absolute, since metals behavior can vary for different combustion systems.
 However, volatility is a fundamental indicator of metals behavior and control in hazardous waste
 combustion systems, and the volatility groupings establish a general framework regarding metals behavior.
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 This section reviews the general characteristics of each volatility group and graphically depicts the relative
 volatility of the eighteen potentially toxic metals identified in Section 2.3. The discussion in this section is
 intended to be a general discussion encompassing all of the metals that may be addressed in a risk
 assessment. For six metals specifically regulated under the MACT rule, volatility groupings are defined by
 regulation, and the MACT rule volatility designations are reviewed later in Section 6.2.

 Volatile metals are defined by EPA as metals that have high vapor pressures (and are typically in vapor
 form) in the combustion chamber as well as in the cooler downstream APCD components of the
 combustion system (EPA 1997e). Emissions of volatile metals are highly dependent on feed rate and the
 use of air pollution control techniques involving adsorption or absorption (e.g., carbon technologies and wet
 scrubbers). Volatile metals are not controlled by air pollution control technologies designed for removal of
 paniculate matter, such as fabric filters or electrostatic precipitators. (EPA 1996a,  1997e, 1999d,and
 1999e).

 The theoretical relationship between metal feed rate and emissions for volatile metals, assuming that all
 other variables are held constant, is depicted in Figure 6-1 (EPA 1997e). Volatile metals are dominated by
 the regime designated as "Region A"  on Figure 6-1, where the metal  completely vaporizes in the
 combustion chamber and remains in a vapor form throughout the entire system, including the cooler APCD
 components. Conversely, Region A is relatively small or non-existent for semivolatile and low-volatile
 metals, due to their very low vapor pressures at APCD temperatures.

 Semivolatile metals typically have higher vapor pressures at combustion temperatures and lower vapor
 pressures at APCD temperatures (EPA 1997e), leading to vaporization in the combustion chamber,
 followed by condensation onto particulates (often of less than a 1-micron diameter) before entering the
 APCD (EPA  1996a, I997e and 1999d).  Emissions of semivolatile metals are a function of both feed rate
 and APCD removal efficiency for fine, submicron paniculate matter (EPA 1996a, 1997eand  1999d).

 Figure 6-1 depicts the theoretical relationship between metal feed rate and emissions for semivolatile
 metals, assuming that all other variables are held constant (EPA 1997e). Semivolatile metals  are
 dominated by the regime designated as "Region B" on Figure 6-1. As the feed rate of a metal  increases, the
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                                         FIGURE 6-1
                              METAL VOLATILITY REGIMES
                   tO
                   o:
                   £
                  UJ
High Volatile
Metals
                                                         Low-Volatile
                                                         Metals
                                    Metal Feed Rate

                A - Metal in vapor phase                1 - Saturated vapor at
                B - Metal condensed on fine particulate        APCD temperature
                C - Metal entrained as larger particulate  2 - Saturated vapor at
                                                           combustion temperature
                                  Reproduced from EPA (1997e)
 metal vapor at the APCD temperature becomes saturated (Point 1). In Region B, the metal begins to

 condense at the APCD temperatures, primarily onto fine particulate matter. The slope of the line in Region

 B is determined by the APCD removal efficiency for fine particulate matter.


 Low-volatile metals vaporize to a lesser extent at combustion temperatures and partition to a greater extent

 to bottom ash, other residue, cement kiln clinker, or entrained particulate matter in the flue gas (EPA

 1996a, 1997e and 1999d). Low-volatile metal emissions are more strongly related to the operation of the

 APCD than to feed rate. Evaluations conducted by Springsteen (Springsteen and others 1997) and EPA
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 (EPA 1997e) indicate that there is a stronger relationship between emissions and feed rate for volatile and
 semivolatile metals than for low-volatile metals. For low-volatile metals, SREs tend to increase strongly
 with increasing feed rate (i.e., emissions increases are not generally proportional to feed rate increases).

 The theoretical relationship between metal feed rate and emissions for low-volatile metals, assuming that all
 other variables are held constant, is depicted in Figure 6-1 (EPA 1997e). Low-volatile metals are
 dominated by the regime designated as "Region C" on Figure 6-1 because of their low vapor pressures,
 even at high combustion temperatures. As the feed rate of a metal increases, the metal vapor at the
 combustion temperature becomes saturated (Point 2). Additional metals fed beyond this rate remain as
 solids in the combustion chamber. Metal emissions continue to increase somewhat with increased feed rate
 in Region C, due to increased concentrations of metals in the  entrained fly ash. However, emissions do not
 increase as rapidly as in Region B because no more metals vaporize, and metals entrained as larger
 particulate are captured in the APCD more efficiently than metals condensed onto submicron particulate
 matter.

 Figure 6-2, reproduced from Trace Elements - Emissions from Coal Combustion and Gasification (Clark
 and Sloss 1992), graphically depicts the relative volatility for sixteen of the potentially toxic metals
 discussed in Section 2.3. Group 1 represents the low-volatile metals, Group 2 represents the semivolatile
 metals, and Group 3 represents the volatile metals. The overlapping circles indicate .that partitioning
 behavior can vary for different combustion systems with different operating conditions.

 Aluminum and silver were not categorized by Clark and Sloss.  However, based on vapor pressure data for
 aluminum and on information found in a report sponsored by the Portland cement kiln industry (Dellinger
 and others  1993), aluminum would be expected to exhibit low-volatile behavior as an oxide.  As a chloride,
 aluminum could be semivolatile to volatile. Silver would likely be classified as a low-volatile metal, based
 on the species expected to be formed within combustion environments.

 It is important to note that distinctions between volatile, semivolatile, and low-volatile metals can vary
 among studies, test conditions, and type of facility (Springsteen and others 1997; Clark and Sloss 1992).
 Moreover, metal emissions are affected by design differences  in combustion units (such as differences
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                                  FIGURE 6-2
                          METAL VOLATILITY GROUPS
                 Group 3
                 Group 2
                 Group 1
                                             Hg
                                             Se
As Cd  Pb
Sb Tl Zn
                                       Ba Be  Co  Cr
                                          Cu Ni V
                                            Mn
                        Reproduced from Clark and Sloss (1992)
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among kilns, liquid injection, and controlled air designs), combustion stoichiometry and flue gas flow rates
(higher gas velocities can lead to higher particle/metal entrainment), operating temperatures (metal
volatility typically increases with increasing temperature), the physical form and species of the metal, the
presence of mineral species which may preferentially bind with metals (these may be contained in the raw
materials in cement kilns and lightweight aggregate kilns), the presence of chlorine (which generally
increases metal volatility), and APCD removal efficiency (Energy and Environmental Research
Corporation [EER] 1991; Cesmebasi and others 1991; Springsteen and others 1997; Linak and Wendt
1998). The figure reproduced from Clark and Sloss may not fully represent the behavior of certain metals
in certain systems.  For example, Springsteen found that the metals antimony and arsenic exhibit low-
volatile behavior in cement kilns (probably due to their affinity for the cement matrix) (Springsteen and
others 1997).

Control parameters for volatile, semivolatile, and low-volatile metals and their expected behavior in
incinerators, boilers, cement kilns, and lightweight aggregate kilns are discussed further in the following
section.
6.2
MACT CONTROL PARAMETERS FOR METALS
The metals emission standards which apply to hazardous waste combustors vary considerably, depending
on the type of combustion device and the time frame being considered. For hazardous waste burning
boilers and industrial furnaces, metals emissions have been regulated since 1991 under the BIF rule (40
CFR Part 266 Subpart H). The BIF standards are risk-based standards, but only consider exposures via
the inhalation exposure pathway, as explained previously in Section 1.3.1. BIF control parameters are
discussed in Technical Implementation Document for EPA's Boiler and Industrial Furnace Regulations
(EPA 1992b). Similar provisions have been applied at some hazardous waste incineration facilities
through individual permit decisions, pursuant to the omnibus authority of Section 3005(c)(3) of RCRA, as
codified at 40 CFR 270.32(b)(2). More recently, technology-based MACT metals emission limits have
been promulgated for hazardous waste burning incinerators, cement kilns, and lightweight aggregate kilns
(EPA 1999c). Facilities have three years from the MACT rule promulgation date (September 30, 1999) to
comply with the revised standards.  Upon documentation of compliance with MACT, the BIF metal
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  emissions standards are superseded (however, any RCRA permit requirements or conditions related to the
  combustor remain in effect until that permit is either modified to remove the conditions or the permit is
  terminated or expires). Technology-based standards for hazardous waste burning boilers are anticipated in
  a future MACT rulemaking.                                    .

  This section reviews the key control parameters influencing metal emissions, with emphasis on the control
  parameters identified in the hazardous waste combustor MACT rule. The MACT control parameters for
  metals are similar to BIF control parameters. However, the MACT parameters have been reviewed more
  recently against an extensive metals emissions database.

  The purpose of reviewing MACT control parameters is not to suggest that MACT emissions standards
  should necessarily be imposed within the context of risk-based permitting, or to imply that any facility will
  be required to achieve early compliance with MACT emissions standards. Rather, the purpose of
  reviewing the MACT control parameters in this guidance is to identify the feed and operating conditions
  that influence metals emissions, as well as to highlight the controls which will be implemented at most
  hazardous waste combustors in accordance with the requirements of the MACT rule. To the extent that
  risks from metals are already adequately controlled by regulatory limits on key control parameters, then
  fewer site-specific risk-based limits may be needed in the RCRA permit. However, if regulatory controls
  are not applicable or sufficiently comprehensive, then additional site-specific risk-based limits may be
  necessary to ensure protection of human health and the environment. A greater number of risk-based
  permit limitations may be necessary when the risk burn and RCRA or MACT performance tests reflect
  different operating modes.
  6.2.1
Volatile Metals (Mercury)
 The MACT rule regulates mercury as a volatile metal. EPA considers mercury to be a high priority
 hazardous air pollutant with the potential to cause significant human health and environmental effects (EPA
 1996a, 1997a and 1999c). Mercury is the most volatile regulated metal, is the most difficult metal to
 control, and has been the subject of many detailed studies, including the Mercury Study Report to Congress
 (EPA 1997a).
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At temperatures found in hazardous waste combustion devices, nearly all mercury volatilizes to form
gaseous mercury that includes both elemental (reduced) and divalent (oxidized) forms (EPA 1999d).
Partitioning between elemental and divalent mercury is critical, because it directly affects the ability to
control mercury in the APCD system (EPA 1999d). In general, the divalent form of mercury is more likely
to be removed in the APCD.

Mercury speciation is dependent on both the fuel and physical characteristics of the combustor, and may
vary for an individual unit as feed and operating conditions change.  Mercury speciation in the flue gas
depends on factors such as waste composition (in particular, chlorine and sulfur levels), the flue gas
temperature profile, and the type of air pollution control (EPA 1999d). If chlorine is not present or if
sulfur levels are high, elemental mercury can comprise a significant fraction of the total mercury.
Elemental mercury is not soluble in water, and is usually not well controlled by wet scrubbers.  Control of
elemental mercury may involve the use of an adsorption technology, such as carbon injection.

In the presence of chlorine, formation of divalent mercuric chloride is thermodynamically favored in
combustion systems. Mercuric chloride is soluble in water and is readily captured by wet scrubbers.  Slow
gas cooling (instead of rapid quenching) has been shown to maximize the levels of soluble mercuric
chloride and increase wet scrubber performance.

Mercury emissions are primarily controlled by limiting feed rate and through the use of air pollution control
techniques involving adsorption or absorption (e.g., carbon technologies and wet scrubbers). MACT
control parameters related to mercury emissions from hazardous waste combustion facilities include the
following (EPA 1999e):
                Mercury emissions increase with increasing mercury feed rate.  The MACT rule (EPA
                1999c) requires that limits be established for total maximum mercury feed rate to the unit
                (including hazardous waste, raw materials, and fossil fuels). A separate limit for
                pumpable feed streams is not necessary, since mercury is highly volatile in any form.
                Chlorine feed rate may affect mercury emissions when wet scrubbers are used as APCDs.
                In the case of mercury, the presence of chlorine is expected to decrease emissions through
                conversion to the soluble divalent species.  However, because only de minimis levels of
                chlorine are necessary for mercury conversion to the soluble salt, minimum chlorine limits
                are not recommended.  A maximum chlorine limit is typically established for most metals
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                (because increased levels of chlorine can increase metal volatility). However, a maximum
                chlorine limit is not necessary for mercury, since mercury is already volatile.

                Combustion chamber temperature is not believed to be a critical operating parameter. At
                typical mercury feed rates and combustion temperatures, all mercury vaporizes in the
                combustion chamber.

                Wet scrubbers have been demonstrated to be effective at controlling water soluble forms of
                mercury. The MACT rule (EPA 1999c) requires that limits be established for operating
                parameters associated with wet scrubbers (such as minimum pressure drop across the
                scrubber, minimum liquid feed pressure, and minimum liquid-to-flue-gas ratio).  Caspar
                and others have observed that rapid quenching of hot flue gases from municipal waste
                incinerators reduces mercury removal in wet scrubbers (Caspar and others 1997). They
                believe that rapid quenching does not allow sufficient residence time for elemental mercury
                (which is favored at typical incineration temperatures) to shift to soluble mercuric chloride
                (which is favored at temperatures below approximately 600 °C in the presence of
                chlorine).  This concern is reiterated in a technical support document to the MACT rule
                (EPA 1999d).

                Carbon injection and carbon bed technologies may also be used for mercury control.
                When carbon technologies are used, the MACT rule (EPA 1999c) requires that limits be
                established for operating parameters associated with those technologies as described in a
                technical support document to the MACT rule (EPA 1999e).
 MACT control parameters for mercury are summarized in Table 6-1. If a facility bases compliance on an
 assumption of zero SRE, then only mercury feed rate is limited.


 In hazardous waste incinerators and boilers, mercury emissions are currently controlled by limiting waste

 feed rates and, in some cases, by using wet scrubbers designed for acid gas removal. EPA has estimated

 that the addition of carbon injection or carbon bed technologies could increase mercury removal in
 incineration systems up to 90 to 99 percent (EPA 1996a).


 Cement kilns and lightweight aggregate kilns currently control mercury emissions by limiting mercury feed

 rate. Raw materials and coal (as an auxiliary fuel) can add to the mercury emissions. Once mercury is in a

 cement kiln or lightweight aggregate kiln system, it is generally regarded as "uncontrolled," even though

 mercury SREs have been documented in some cases (EPA 1999d). Currently, cement kilns and lightweight

 aggregate kilns do not employ adsorptive or absorptive control technologies (e.g., carbon technologies or

 wet scrubbers), and mercury is typically not contained in clinker or cement kiln dust unless the cement kiln
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  dust has an elevated carbon content, which is unlikely (EPA 1999d). The mercury SREs which have been

  reported for cement kilns and lightweight aggregate kilns may be due to measurement uncertainties

  associated with the very low levels of mercury in the stack gas or feed streams (EPA 1999d).
 6.2.2
Semivolatile Metals
 MACT regulates lead and cadmium as semivolatile metals. Emissions of semivolatile metals are a function

 of both feed rate and APCD removal efficiency for fine, submicron participate matter (Springsteen and

 others 1997; EPA 1996a, 1997e and 1999d). Wet scrubbers are generally considered more effective at

 controlling larger particulates, whereas fabric filters, ESPs and ionizing wet scrubber (I WS) devices are

 considered most effective in removing smaller particulates (Clarke and Sloss 1992; EER 1991; EPA

 1999d). MACT control parameters for semivolatile metal emissions from hazardous waste combustion
 facilities include the following (EPA 1999e):


        •       Semivolatile metal emission rates increase as the metal feed rates increase. The MACT
                rule (EPA  1999c) requires that limits be established for total maximum semivolatile feed
                rate to the unit (including hazardous waste, raw materials, and fossil fuels). A separate
                limit for pumpable feed streams is not necessary, because partitioning between the
                combustion flue gas and bottom ash or product does not appear to be affected by physical
                state.

                Chlorine increases metal volatility. The MACT rule (EPA 1999c) requires that a limit be
                established for maximum chlorine feed rate to the unit. The limit is based on total chlorine
                from all sources, including organic and inorganic chlorine sources.

        •       Higher combustor gas flow rates can increase particulate and metals entrainment. The
                MACT rule (EPA 1999c) requires that a limit be established on maximum gas flow rate or
                kiln production rate.

        •       Maximum combustion chamber temperature has traditionally been established under the
                BIF rule to control metal volatility. However, maximum combustion chamber temperature
                is less important than other operating parameters when considering metal emissions from
                most hazardous waste combustion facilities. For semivolatile metals, typical combustion
                temperatures are generally high enough to volatilize most of the metals in the combustion
                chamber, and evaluation of emissions data does not provide any support for a relationship
                between combustion chamber temperature and semivolatile metals emissions levels (EPA
                1999e).

        •       APCD type and operating parameters are recognized as critical to the control of
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               semivolatile metals, and the MACT rule (EPA 1999c) requires that limits be established
               on APCD parameters. In addition, the operating temperature of the APCD inay also be
               important. For metals which volatilize in the combustion chamber and are carried out with
               the flue gas, the APCD temperature affects the degree of condensation and control (lower
               temperatures result in a higher degree of condensation and control). The MACT rule
               (EPA 1999c) requires that a limit be established on maximum inlet temperature to the dry
               APCD to control semivolatile metals emissions.
               Cement kilns and lightweight aggregate kilns that recycle collected particulate matter
               should receive special consideration to ensure that emissions reach steady-state prior to
               testing, as described in two earlier EPA documents (EPA 1992b and 1999c).
MACT control parameters for semivolatile metals are summarized in Table 6-1. If a facility bases
compliance on an assumption of zero SRE, then only total semivolatile feed rate is limited.

In hazardous waste incinerators and boilers, semivolatile metals emissions are most effectively controlled
by limiting waste feed rates and utilizing APCD systems that control fine particulate matter (i.e., fabric
filters, ESPs, and IWS devices). Units equipped with wet scrubbers are typically less efficient at
controlling semivolatile metals. A few incinerators and boilers are not equipped with any air pollution
control systems, and therefore rely strictly on feed rate control.

Hazardous waste burning cement kilns and lightweight aggregate kilns currently control semivolatile metal
emissions by limiting waste feed rates and utilizing fabric filters or ESPs. It is also speculated that certain
raw material constituents preferentially bind with semivolatile metals, providing additional control.
Semivolatile metals behavior varies to some extent in cement kilns, depending on the particular system
configuration. For kilns with in-line raw mills, semivolatile metals emissions are generally lower when the
in-line raw mill is operating, due to additional scavenging of vapors in the low temperature raw mill. For
short, dry cement kilns equipped with alkali bypass stacks, the majority of semivolatile metals concentrate
in the bypass APCD.  Semivolatile metals concentrate preferentially in the bypass due to an internal recycle
where metals vaporize at kiln temperatures and condense in the preheater towers (EPA 1999d).
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  6.2.3
Low-Volatile Metals
  MACT regulates arsenic, beryllium and total chromium as low-volatile metals.  Emissions of low-volatile

  metals are a function of both feed rate and APCD efficiency for paniculate matter (EPA 1997e and

  1999d). MACT control parameters associated with the low-volatile metals are consistent with those for the
  semivolatile metals described in Section 6.2.2, with the following exceptions (EPA 1999e):
                The MACT rule (EPA 1999c) requires that a separate limit be established for low-volatile
                metals in pumpable feed streams, since these may partition at a higher rate to the
                combustion flue gas.  However, if a facility wants to base their total feed rate limit only on
                the feed rate of the pumpable waste feed streams during the test, then separate feed rate
                limits for total and pumpable feed streams are not needed.

                Low-volatile metals are less apt to vaporize completely at typical combustion
                temperatures. Thus, a limit on maximum combustion temperature could theoretically be
                more important for low-volatile metals than for semivolatile metals. However, the amount
                of additional vaporization at slightly higher temperatures could be negligible compared to
                the amount of metals contained in entrained flue gas paniculate matter, especially for kilns
                and pulverized coal boilers.  Thus, maximum combustion chamber temperature is most
                likely less important than APCD operating parameters. In addition, analysis of emissions
                data does not indicate a strong relationship between combustion chamber temperature and
                low-volatile metal emissions levels (EPA 1999e).
 MACT control parameters for low-volatile metals are summarized in Table 6-1. If a facility bases

 compliance on an assumption of zero SRE, then only total low-volatile metal feed rate is limited.


 Similar to the semivolatile metals, operation of the APCD is critical to removal of low-volatile metals. In

 cement kilns, a significant fraction of the low-volatile metals partitions to the clinker product.  Low-volatile

 metals do not tend to become concentrated in cement kiln bypass gases or build up an internal recycle to the

 same extent as semivolatile metals. There is also no strongly expected influence of in-line raw mill

 operational status on low-volatile metal emissions from cement kilns (EPA 1999d).
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                                              TABLE 6-1

                    MACT CONTROL PARAMETERS ASSOCIATED WITH METALS EMISSIONS

Control
, „, Parameter
Limits From
? r
Averaging
• Period
How Limit Is
Established
Other Considerations
VOLATILE METAL CONTROL PARAMETERS (MERCURY)
Feed Rate
Wet Scrubbers
High Energy:
- venturi
- hydrosonic
- collision
-free jet
Low Energy:
- spray tower
- packed bed
- tray tower
Maximum total mercury
feed rate in all feed
streams '
Maximum flue gas flow
rate or kiln production
rate
High energy scrubbers:
minimum pressure drop
across scrubber
Low energy scrubbers:
minimum pressure drop
&cross scrubber
. Low energy scrubbers:
minimum liquid feed
oressure
Minimum liquid pH
Minimum liquid scrubber
flow rate and maximum
flue gas flow rate or
minimum liquid/gas ratio
Ionizing wet scrubbers:
minimum power input
Comprehensive
performance test
Comprehensive
performance test
Comprehensive
performance test
Manufacturer
specifications
Manufacturer
specifications
Comprehensive
performance test
Comprehensive
performance test
Comprehensive
performance test
12 hour
1 hour
1 hour
1 hour
1 hour
1 hour
1 hour
1 hour
Average of the test run averages
Average of the maximum hourly
rolling averages for each run
Average of the test run averages
N/A
N/A
Average of the test run averages
Average of the test run averages
Average of the test run averages








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July 2001
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                                               TABLE 6-1

                MACT CONTROL PARAMETERS ASSOCIATED WITH METALS EMISSIONS (Continued)

^ • Control
Parameter
Limit's From
Averaging
Period
, HptyLimitJSs' \
'*' Established -
- r * x .'-•it.
~ Other Considerations
VOLATILE METAL CONTROL PARAMETERS (MERCURY)
Activated Carbon Injection
Activated Carbon Bed
Maximum flue gas flow
rate or kiln production
rate
Minimum carbon feed
rate
Minimum carrier fluid
flow rate or nozzle
pressure drop
Identification of carbon
brand and type or
adsorption properties
Good paniculate matter
control
Maximum flue gas flow
rate or kiln production
rate
Determination of
maximum age of each
carbon segment
Comprehensive
performance test
Comprehensive
performance test
Manufacturer
specifications
Comprehensive
performance test
See control
parameters listed for
wet scrubbers, fabric
filters, ESPs, and
IWS devices under
semivolatile metals
Comprehensive
performance test
Comprehensive
performance test
1 hour
1 hour
1 hour
N/A

1 hour
N/A
Average of the maximum hourly
rolling averages for each run
Average of the test run averages
N/A
Same properties based on
manufacturer specifications

Average of the maximum hourly
rolling averages for each run
Maximum age of each segment
during testing






Age limits may be based
on manufacturer
specifications for the
initial performance test
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July 2001
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r
                                                               TABLE 6-1

                                MACT CONTROL PARAMETERS ASSOCIATED WITH METALS EMISSIONS (Continued)
»
Control^
Parameter
Limits From
Averaging
Period ,
How Limit Is
Established
Other Considerations
VOLATILE METAL CONTROL PARAMETERS (MERCURY)
Activated Carbon Bed
(continued)
Identification of carbon
brand and type or
adsorption properties
Maximum gas
temperature at the inlet or
exit of the bed
Good particulate matter
control
Comprehensive
performance test
Comprehensive
performance test
Same as. for
activated carbon
injection
N/A
1 hour

Same properties based on
manufacturer specifications
Average of the test run averages




SEMIVOLATILE METAL CONTROL PARAMETERS (Pb, Cd)
Feed Rate
Chlorine
Gas Flow Rate
Inlet Temperature to Dry
Paniculate Matter Control Device
Maximum total
semivolatile metal feed
rates from all feed
streams '
Maximum total chlorine
feed rate from all feed
streams '
Maximum, flue gas flow
rate or kiln production
rate
Maximum temperature
Comprehensive
performance test
Comprehensive
performance test
Comprehensive
performance test
Comprehensive
performance test
12 hour
12 hour
1 hour
1 hour
Average of the test run averages
Average of the test run averages
Average of the maximum hourly
rolling averages for each run
Average of the test run averages




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July 2001
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                                               TABLE 6-1

                MACT CONTROL PARAMETERS ASSOCIATED WITH METALS EMISSIONS (Continued)
<" - " • VVS, "/:
'^^'Coiiiroif '; *
', ^ * Parameter ,^ t
' vLimits Fronr - -
Averaging
Period
'Howiimitls'; '
1 Established
Dther Considerations
SEMIVOLATILE METAL CONTROL PARAMETERS (Pb, Cd)
Wet Scrubber: High Energy and
Ionizing Scrubbers
All Wet Scrubbers
Maximum flue gas flow
rate or kiln production
rate
For high energy wet
scrubbers only, minimum
pressure drop across
scrubber
For high energy wet
scrubbers only, minimum
scrubber liquid flow rate
and maximum flue gas
flow rate, or minimum
liquid/gas ratio
Minimum blowdown rate
and minimum scrubber
tank volume or level, or
Maximum solids content
of water
Comprehensive
performance test
Comprehensive
performance test
Comprehensive
performance test
Comprehensive
performance test
Comprehensive
performance test
1 hour
1 hour
1 hour
1 hour
12 hour for
continuous
monitor
1 hour for
manual
sampling
Average of the maximum hourly
rolling averages for each run
Average of the test run averages
Average of the test run averages
Average of the test run averages
Average of the test run averages
Average of manual sampling run
averages






Risk Burn Guidance for
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July 2001
    135

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r
                                                       TABLE 6-1



                            MACT CONTROL PARAMETERS ASSOCIATED WITH METALS EMISSIONS (Continued)

Control
Parameter
Limits From
r
Averaging
Period
How Limit Is
:. Established
Other Considerations
SEMIVOLATILE METAL CONTROL PARAMETERS (Pb, Cd)
Fabric Filter
Electrostatic Precipitator and
Ionizing Wet Scrubber
Maximum flue gas flow
rate or kiln production
rate
Minimum pressure drop
and maximum pressure
drop across each cell
Maximum flue gas flow
rate or kiln production
rate
Minimum power input
(kVA) based on secondary
voltage and current to
each field
Comprehensive
performance test
Manufacturer
specifications
Comprehensive
performance test
Comprehensive
performance test
1 hour
1 hour
1 hour
1 hour
Average of the maximum hourly
rolling averages for each run
N/A
Average of the maximum hourly
rolling averages for each run
Average of the test run averages




LOW-VOLATILE METAL CONTROL PARAMETERS (As, Be, Cr)
Feed Rate
Chlorine
Maximum total low-
volatile metal feed rates
from all feed streams '
Maximum total low-
volatile metal feed rates
from all pumpable feed
streams '
Same as semivolatile
metals
Comprehensive
performance test
Comprehensive
performance test

12 hour
12 hour

Average of the test run averages
Average of the test run averages


See Section 6.2.2

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136

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                                                               TABLE 6-1

                       MACT CONTROL PARAMETERS ASSOCIATED WITH METALS EMISSIONS (Continued)
1 J " 4
"\ „/ "', ,?\ , , * _1!
I Control * |
*" , Parameter
' '"Limits From
Averaging
Period
How Limit Is
, Established
Other Considerations
i '
LOW-VOLATILE METAL CONTROL PARAMETERS (As, Be, Cr)
Gas Flow Rate
Inlet Temperature to Dry
Particulate Matter Control Device
Wet Scrubber: High Energy and
Ionizing Scrubbers
All Wet Scrubbers
Fabric Filter
Electrostatic Precipitator and
Ionizing Wet Scrubber
Same as semivolatile
metals
Same as semivolatile
metals
Same as semivolatile
metals
Same as semivolatile
metals
Same as semivolatile
metals
Same as semivolatile
metals
























Notes:  As
       Be
       Cd
       Cr
=  arsenic
=  beryllium
=  cadmium
=  total chromium
ESP  .= electrostatic precipitator
IWS  = ionizing wet scrubber
kVA  = kilovolt-amperes
Pb    =  lead
MACT =  maximum achievable control technology
N/A   =  not applicable
              -  This limit applies to all feed streams except natural gas, process air, and feed streams from vapor recovery systems, provided that expected levels of
                 constituents in those feed streams are accounted for in documenting compliance with feed rate limits. See the MACT rule preamble (EPA 1999c) for further
                 information.                                                                                                     '
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6.3
RISK-BASED LIMITATIONS
The MACT control parameters discussed in Section 6.2, or similar parameters under the BIF rule, either
apply or will apply to most hazardous waste combustors. However, risk-based limitations beyond these
regulatory requirements may be necessary to protect human health and the environment for some facilities.
This section addresses potential site-specific risk-based controls beyond BIF or MACT, with emphasis on
metal feed rate and emissions restrictions. Since there is generally a strong relationship between metals
emissions and feed rates, feed rate reduction is expected to be the primary means of achieving a more
stringent risk-based metal emissions level if necessary.

Several topics are addressed in this section. Site-specific risk-based emissions and feed rate limitations for
regulated metals (i.e., metals specifically controlled under either BIF or MACT) are discussed in Section
6.3.1. Restrictions for other potentially toxic metals which are not specifically enumerated in the BIF or
MACT regulations, but which may be COPCs for site-specific risk assessments, are discussed in Section
6.3.2. Special considerations related to acute risks are discussed in Section 6.3.3. Finally, the use of
extrapolation and metals surrogates for establishing site-specific risk-based feed rate limits is discussed in
Sections 6.3.4 and 6.3.5, respectively.

Although the metal control parameters discussed in Section 6.2 were presented in terms of metal volatility
groups, this guidance does not recommend that risk-based permit limits be established for metal volatility
groups (rather than individual metals). The divisions between volatility groups are not absolute. More
importantly, EPA OS W has recommended that individual metals be modeled separately for risk assessments
using the fate and transport parameters and toxicity information specific to each metal (EPA 1998a and
 1999b). The use of volatility groupings for risk-based permitting should generally be limited to the metal
extrapolation and surrogate applications discussed later in Sections 6.3.4 and 6.3.5.
 6.3.1
 Regulated Metals
 As noted at the beginning of Section 6.2, the metals emissions standards that apply to hazardous waste
 combustors vary considerably, depending on the type of combustion device and the time frame being
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 considered. In assessing the need for risk-based controls, a permit writer will need to consider which
 regulatory standards apply to a particular facility for which metals, and whether the applicable standards are
 expected to change over time. Boilers, cement kilns and lightweight aggregate kilns are currently subject to
 standards for ten BIF metals (antimony, arsenic, barium, beryllium, cadmium, chromium, lead, mercury,
 silver, and thallium). Nickel and selenium have also been regulated at some facilities through omnibus
 authority of RCRA (EPA 1992a). For cement kilns and lightweight aggregate kilns, the BIF standards for
 mercury, lead, cadmium, arsenic, beryllium, and chromium will be superseded by MACT technology-based
 metals standards, and a MACT technology-based paniculate standard will serve as surrogate control for
 antimony, cobalt, manganese, nickel and selenium. The three remaining BIF metals (barium, silver and
 thallium) are not hazardous air pollutants under the Clean Air Act, and so do not have MACT limits. For
 hazardous waste incinerators, MACT standards for mercury, lead, cadmium, arsenic, beryllium, chromium
 and particulate matter will apply.  MACT standards for hazardous waste burning boilers have not yet been
 developed, and thus will not apply until a future rulemakinghas been completed.

 The particular regulatory standards which apply at a given facility will inform decisions regarding the need
 for supplemental risk-based permit conditions, as well as the type of supplemental risk-based permit
 conditions which may be appropriate. For example, it may be necessary to supplement the BIF standards to
 protect human health and the environment because the BIF standards may not sufficiently protect against
 risks via indirect exposure routes, or because the BIF standards may not reflect current lexicological
 information. Lower emissions and feed rate limits for mercury may be necessary to assure protection of
 human health and the environment because of its propensity to bioaccumulate, and for nickel, because of
 potential carcinogenic risks through the direct inhalation exposure route (EPA 1998a and 1999b). The
 MACT standards are viewed as more stringent than the RCRA 40 CFR Part 266 Subpart H standards for
 BIFs (EPA 1999c). However, risk-based controls to supplement the MACT standards may be appropriate
 on a site-specific basis.  Lower emissions and feed rate limits for certain metals may be appropriate at some
 sites to assure protection of human health and the environment. In addition, fewer metals are directly
 regulated under MACT (for some metals, a particulate matter standard serves as a surrogate control
 measure), and risk-based controls for the non-regulated metals and for the indirectly controlled metals may
 need to be considered, as discussed in Section 6.3.2. Finally, the MACT rule provides an option for
 alternative standards at cement kilns and lightweight aggregate kilns when the MACT metal emissions
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standards cannot be achieved because of metals in the raw materials. The alternative standards represent
another scenario where MACT may need to be supplemented with site-specific risk-based limits to ensure
that a facility does not pose an unacceptable risk (EPA 1999c).

A preliminary risk assessment can provide information to determine whether operation within regulatory
emissions limits (either BIF or MACT) may present a significant risk to human health and the environment.
As discussed in Section 3.2, EPA OSW recommends that the preliminary risk assessment be performed prior
to the risk burn to better define the risk burn data needs.  If a regulatory limit applies for a particular metal
and is sufficiently protective, additional risk-based limits should generally not be needed. However, if the
regulatory limit for a particular metal is not sufficiently protective, a lower, site-specific risk-based emissions
limit for that metal may need to be established in the RCRA permit to assure protection of human health and
the environment.

In addition to providing information on whether operation within a regulatory emissions limit may present a
significant risk to human health and the environment, the preliminary risk assessment can also indicate the
extent of emissions reduction necessary to assure protection of human health and the environment. After a
protective emissions limit has been defined, a correspondingly lower metal feed rate limit can be determined.
A variety of methodologies can be used to establish a risk-based feed rate limit from a risk-based emissions
limit. Several approaches are outlined below, and a combination of methodologies may be appropriate in
some cases:
               Zero SRE: A facility may choose to establish a risk-based feed rate limit from the risk-based
               emissions limit for a particular metal by assuming zero SRE (i.e., the feed rate limit is the
               same as the risk-based emissions rate limit).
               Existing SRE: A facility may have data from an existing SRE test performed for BIF or
               MACT documenting that the lower, risk-based emissions limit is already being achieved. In
               this case, the risk-based metal feed rate limit is the same as the feed rate during the SRE test
               where the risk-based emissions limit was demonstrated.
               New SRE: With careful planning, a future SRE test may serve as the vehicle for determining
               risk-based feed rate limits.  For example, a facility may be due for BIF re-certification testing,
               or may be about to perform the initial MACT performance test.  If the facility has performed
               a preliminary risk assessment which indicates the need for risk-based controls, the facility
               may be able to reduce (or eliminate) metals spiking, as well as perform sampling for
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              additional non-regulated metals, to meet the objectives of both the performance test and the
              risk burn. In this case, the risk-based metal feed rate limit is established as the feed rate
              during the SRE test where the risk-based emissions limit is demonstrated.

              Normal Test: Where appropriate (see Section 3.3.2.2), a separate test conducted at normal
              metal feed rates may be considered for establishing risk-based metal feed rate limits. When
              metals emissions data collected during a normal test are utilized for the site-specific risk
              assessment, a dual testing and permitting scheme such as the following is recommended:

              — An SRE test is performed to demonstrate that maximum emissions meet applicable BIF or
                MACT limits, and to establish maximum hourly or 12-hour feed rate limits

              - A normal test is performed to generate emissions data for evaluation in the site-specific
                risk assessment, and to establish long-term average feed rate limits

              Extrapolated Feed Rate: The use of extrapolation to establish risk-based feed rate limits is
              discussed further in Section 6.3.4.  Opportunities for using extrapolation to establish risk-
              based feed rate limits may be somewhat limited, since only upward extrapolation is
              recommended (whereas risk-based permitting involves lowering feed rates). However, some
              situations may be amenable to extrapolation. For example, a facility may have collected data
              for the  entire suite of metals during a previous SRE test (even though only a few metals were
              spiked). Upward extrapolation for the unspiked metals could be considered.

              Surrogate SRE: The use of surrogates to establish risk-based feed rate limits is discussed
              further in Section 6.3.5. If existing metals emissions data are available, but data on a certain
              metal were  not collected, or if the data for a particular metal are not useful (i.e., an SRE
              cannot be determined because of non-detects for the feed inputs), use of data for a surrogate
              metal based on volatility groupings may be considered.
The approach selected to establish risk-based metal feed rate limits from risk-based emissions limits will
affect the scope of the risk burn. For example, if a facility chooses the "Zero SRE" approach for all metals

where risk-based limits are needed, then metal emissions measurements may not be needed during the risk
burn. However, if a facility chooses the "Normal Test" approach, the risk burn may involve extra test

conditions.


Under any of these options, EPA OS W recommends that an averaging period for the risk-based feed rate

limit be specified. A facility may choose to comply using the same feed rate averaging periods as specified

by BIF or MACT (1 hour or 12 hours) to minimize need for extra monitoring. On the other hand, if these

averaging periods do not allow sufficient operating flexibility, a facility may choose to comply using a
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 longer-term averaging period. Long-term metal feed rate averaging periods should generally be adequate for
 controlling long-term, chronic risks, as discussed in Section 3.3.2.2.
 6.3.2
Other Toxic Metals
 In addition to the original ten BIF metals, other metals that EPA OS W has recommended be considered as
 COPCs for site-specific risk assessments include aluminum, cobalt, copper, manganese, nickel, selenium,
 vanadium, and zinc (EPA 1998a and 1999b). Summaries of specific human health and ecological concerns
 for these metals are found in Section 2.3 of this document.

 For these eight metals (if a facility is subject to BIF) and for twelve metals (if a facility is subject to MACT),
 specific regulatory restrictions on metal emissions or feed rates do not apply (although MACT does establish
 a particulate matter standard as a surrogate.control measure for antimony, cobalt, manganese, nickel, and
 selenium). EPA OSW recommends that the need for risk-based restrictions on these metals be determined on
 a site-specific basis, considering the potential risks associated with the metals. A preliminary risk assessment
 can provide an indication as to whether specific feed rate controls on these metals may be necessary. As
 discussed in Section 3.2, EPA OSW recommends that the preliminary risk assessment be performed prior to
 the risk burn to better define the risk burn data needs.

 To perform a preliminary risk assessment, initial emissions estimates for the non-BIF or non-MACT metals
 are needed.  Actual emissions data may not be available, since some of these metals have never been subject
 to specific regulatory emission or feed rate standards. In the absence of actual emissions data, a facility
 might consider performing the preliminary risk assessment based on the assumption that the non-regulated
 metals are fed  at normal feed rates (considering the composition of the wastes burned at the facility) and are
 completely emitted (i.e., zero SRE). If a preliminary risk assessment indicates that risks may be significant
 (for nickel, for example, which may be evaluated in the risk assessment as a carcinogen per the EPA OSW
 risk assessment guidance [EPA 1998a]), emissions sampling during the risk burn may be appropriate.

 The need for risk-based controls on the non-BIF/non-MACT metals will generally depend on whether
 emissions of these metals are predicted to present a significant risk to human health and the environment. If
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potential risks associated with the metals are insignificant, a permit writer may simply choose to document
the risk assessment feed and emissions assumptions in the administrative record instead of imposing specific
feed rate limits in the permit. As risks from non-BIF/non-MACT metals approach significant levels, feed
rate monitoring and tracking may be necessary for protection of human health and the environment by
ensuring that potentially significant changes in feed rates which could warrant re-evaluation in the risk
assessment are identified. Alternatively, risk-based emissions limits and long-term average feed rate limits
may be established in the permit.

As discussed in Section 6.3.1 for BIF/MACT metals, a variety of methodologies can be used to establish
risk-based feed rate limits from risk-based emissions limits. The same options listed in Section 6.3.1  may be
appropriate for the non-BIF/non-MACT metals. It is generally anticipated that feed rates of these metals will
not need to be limited on a short-term (i.e., 1 or 12 hour) basis, but that long-term average feed rate limits
will be sufficient. In addition, testing for these metals will not typically involve spiking.
 6.3.3
Acute Risks
 Sections 6.3.1 and 6.3.2 discuss establishing site-specific risk-based emissions limits and corresponding feed
 rate limits, with options involving testing at normal conditions and performing feed rate monitoring using
 long-term averaging periods. Testing at normal conditions and applying long-term averaging periods may be
 appropriate for the purpose of controlling long-term, chronic risk from metals. However, the EPA OS W risk
 assessment guidance (EPA 1998a) also recommends an evaluation of acute risk associated with short-term
 (maximum 1 hour) exposure through the inhalation pathway.  The acute evaluation is based on an estimate of
 maximum potential 1-hour metal emissions rates.  The normal test option mentioned in Sections 6.3.1 and
 6.3.2 would not be appropriate for generating maximum emissions estimates for an acute evaluation, and
 other options may need to be considered. Also, if acute risks at maximum emissions rates appear to be a
 concern for a particular metal, then a maximum 1-hour feed rate limit may need to be established in the
 permit (in addition to the longer-term feed rate limit which may be established per Sections 6.3.1 and 6.3.2 to
 control chronic risks).                              _
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 6.3.4
Extrapolation
 As discussed in Section 6.3.1, one option for establishing risk-based feed rate limits from risk-based
 emissions limits involves the use of extrapolation (subject to approval). Extrapolation involves using test
 data collected at one metals feed rate to project an emissions level at a different metals feed rate.  "Upward"
 extrapolation refers to projecting the emissions associated with a higher metals feed rate, whereas
 "downward" extrapolation refers to projecting the emissions associated with a lower metals feed rate.
 Extrapolation is of interest because: 1) it potentially eliminates the need to re-test at different metals feed
 rates to show compliance with more stringent risk-based emission limits; and 2) it can help to minimize the
 need for metals spiking.

 Trends in facility-specific data (EPA 1997e) support the following observations, as illustrated in Figure 6-1:

        •      Emissions tend to increase as feed rate increases;
        •      The relationship between emissions and feed rate for volatile and semivolatile metals tends to
               be stronger than that for low-volatile metals (i.e., there is a more proportional relationship
               between emissions and feed rates for volatile and semivolatile metals);
        •      The relationship between emissions rate and feed rate for low-volatile metals tends to be more
               flat (not a strong function of feed rate).  SRE strongly tends to increase with increasing feed
               rate for low-volatile metals.

 Given these trends, EPA has determined that upward extrapolation from the origin (i.e., from a metal feed
 rate and emissions rate of zero) is conservative for all metal types and volatilities, as illustrated in Figure 6-3
 (EPA  1997e). Upward extrapolation is conservative because the predicted emissions rates at higher feed
 rates are likely to be equal to or greater than actual emissions rates. SRE tends to stay the same or increase
 with increasing feed rate.  However, as also illustrated in Figure 6-3, downward extrapolation may not
 always be conservative. Downward extrapolation may result in predicted emissions that are less than actual
 emissions. Thus, downward extrapolation is generally not recommended.  Downward extrapolation for low-
 volatile metals can be particularly problematic, because there is not a strong linear relationship between
 emissions and feed (see Figure 6-1).
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                   I
                   EC
                   ID
                   
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Since only upward extrapolation is recommended as being conservative, the opportunities for using

extrapolation to establish risk-based feed rate limits may be somewhat limited. Risk-based permitting

generally involves lowering emissions and feed rates (i.e., downward extrapolation). However, some risk-

based permitting situations may be amenable to upward extrapolation.  For example, a facility may have

collected emissions data for unspiked metals during a previous SRE test. Upward extrapolation for the
unspiked metals could be considered. In reviewing a proposal to use extrapolation for establishing risk-based

feed rate limits, the permitting authority should generally consider information similar to the guidelines

specified in the hazardous waste combustor MACT rule and supporting documents (EPA 1999c and 1999e):


              Is there sufficient confidence in the test data being used for the extrapolation? Upward
              extrapolation to establish a risk-based metal feed rate limit is likely to involve the use of test
              data where spiking was not performed.  However, there may be a high degree of uncertainty
              associated with this type of data. At low concentrations, the error bounds on the sampling
              and analysis procedures tend to be more significant. Errors associated with sampling and
              analysis for heterogeneous feed streams can be particularly high.  In addition, it may not be
              possible to calculate an SRE at all if a metal is not detected in one or more of the feed
               streams. In determining whether there is sufficient confidence in the test data being used for
               the extrapolation, it is recommended that the permit writer consider the incidence and
               potential impact of non-detect data points, as well as the reproducibility between test runs.

               Are the requested feed rates warranted? A permit writer should generally not approve
               extrapolation to feed rates that are significantly higher than the historical range of feed rates,
               unless a facility documents that future operations will necessitate higher metals feed rate
               limits.
 A variety of metal extrapolation procedures have been proposed over the years (EPA 1992b, 1997d, 1997e,

 1999c and 1999e; Springsteen and others 1997).  It is recommended that available feed and emissions data be

 plotted graphically before a decision is made regarding the suitability of extrapolation and a specific

 extrapolation method. A graphical representation can assist in identifying non-linear behavior, high data

 variability, and potential outliers. It may also be useful to plot metals within the same volatility group on the

 same graph. A combined plot can support a determination of whether metals in the same volatility group

 behave similarly (as would theoretically be expected), and a wider range of feed rates for a particular

 volatility group may be represented when the data for several metals are grouped together.
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  The permit writer should generally ensure that a proposed extrapolation procedure will be appropriately
  conservative, considering the extent and quality of the metals feed rate and emissions data  Depending on a
  review of the actual data, a conservative extrapolation procedure might include:

                Extrapolation from the lowest observed SRE that is not an outlier. The lowest SRE can either
                be determined for an individual metal, or it might be selected based on the collective data for
                metals within a given volatility group. Provided that the grouped data confirm that the metals
                behave similarly, a wider range of feed rates may be represented when the data for several
                metals are grouped together.
                Extrapolation from the "Lower Confidence Limit" of the test condition average SRE for a
                particular metal, calculated based on the test condition average and the within-test-condition
                standard deviation at a particular confidence limit bound (such as 95 percent).
                For cases where data for a particular metal are more extensive (for example, if repeated tests
                have been conducted over the years), extrapolation from a statistically-based analysis of the
                entire database.

 A permit writer may choose to disapprove extrapolation if there is not a high degree of confidence that
 average emissions at the extrapolated feed rate will be at or below the risk-based emissions rate.
 Alternatively, a permit writer may choose to condition the extrapolation on performance of follow-up testing
 to confirm that the risk-based emissions levels are being achieved, or to limit the extent of extrapolation, or to
 limit the proximity of the extrapolation to the risk-based emissions limit.

 Section 6.2.3  explains that the MACT rule requires that separate feed rate  limits be established for low-
 volatile metals in total feed streams and for low-volatile metals in pumpable feed streams, since metals in the
 pumpable feed streams may partition at a higher rate to the combustion flue gas. When extrapolation is
 performed to establish a total risk-based feed rate limit for a low-volatile metal, the permit writer should also
 generally consider whether a separate feed rate limit is appropriate for pumpable feed streams and, if so, how
 to establish that  limit. One option is to maintain the pumpable and total feed rate ratio the same for the
 extrapolated feed rates as in the original data used for the extrapolation. Another, very conservative, option
 is to base the total extrapolated feed rate limit only on extrapolation from the feed rate of the pumpable feed
 stream. In this later case, separate feed rate limits for total and pumpable streams should not be needed.
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6.3.5
Surrogate SREs
As discussed in Section 6.3., another option for establishing risk-based feed rate limits from risk-based
emissions limits involves the use of SREs for surrogate metals. The use of an SRE for a surrogate metal may
be appropriate in several situations. For example, if existing metals emissions data are available, but data
were not collected for a particular metal, or if the data for a particular metal are not useful (i.e., an SRE
cannot be determined because of non-detects for feed inputs), the use of a surrogate SRE may be appropriate.
In addition, use of surrogate SREs may be considered to limit the need for spiking during a risk burn if
certain metals are not normally present in the feed streams at reliable levels.

In reviewing a proposal to use surrogate SREs for establishing risk-based feed rate limits from risk-based
emissions limits, EPA OSW recommends that the permitting authority consider whether one metal is an
appropriate surrogate for another. In general, metals within a volatility grouping can be used interchangeably
 for each other, and metals of a "higher" volatility grouping can be used as surrogates for metals in a lower
 grouping. Figure 6-2 depicts the relative volatility for sixteen of the potentially toxic metals discussed in
 Section 2.3.  Springsteen and others provide further analysis based specifically on trends in hazardous waste
 combustor data (Springsteen and others 1997). Springsteen categorizes mercury and selenium as "volatile"
 metals in hazardous waste combustor systems. This categorization compares favorably with the Group 3
 metals in Figure 6-2, reproduced from Clark and Sloss (Clark and Sloss 1992). These metals tend to
 vaporize completely at combustion temperatures. Mercury may remain volatile in the APCD, while selenium
 is more likely to condense. Because of its behavior in the APCD, selenium is often treated as a semivolatile
 metal (although it is the most volatile metal in that category, as indicated by Figure 6-2). Selenium may not
 completely fit within either category.

 Springsteen and others categorize cadmium, lead and thallium as "semivolatile" (Springsteen and others
  1997). This categorization compares favorably with the Group 2 metals identified in Figure 6-2, reproduced
 from Clark and Sloss (Clark and Sloss 1992).

  Springsteen and others categorize  barium, beryllium, chromium and nickel as "low-volatile" (Springsteen and
  others 1997).  Figure 6-2 also places these metals in the Group 1 low-volatile metal category. However, in
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 Figure 6-2, these metals fall in the area of the circle that overlaps with the Group 2 semivolatile metal
 category, indicating that partitioning behavior may vary for different combustion systems with different
 operating conditions. Facility-specific data should generally be reviewed to determine whether any of these
 metals exhibit semivolatile metal behavior (as evidenced by more enrichment of these metals in air pollution
 control residues than in bottom ash or clinker residues). Or, in the absence of site-specific information, these
 metals could be treated conservatively as semivolatile metals.

 Finally, Springsteen and others explain that three metals exhibit low-volatile behavior in cement kilns but
 may behave more like semivolatiles in incineration systems (Springsteen and others 1997).  These metals
 include arsenic, antimony, and silver.  Springsteen includes special recommendations for arsenic, antimony,
 and silver,  since their behavior can be dependent on combustion system type (Springsteen and others 1997).
 In cement and lightweight aggregate kilns, these metals are included within the low-volatile grouping, and all
 low-volatile metals can be used interchangeably as surrogates for each other. In incinerators and boilers,
 arsenic, antimony, and silver can conservatively be used as surrogates for low-volatile metals, but low-
 volatile metals generally should not be used as surrogates for arsenic, antimony, and silver. In addition,
 arsenic, antimony, and silver generally should not be used as surrogates for each other for incinerators and
 boilers.

 EPA OS W recommends that the general guidelines regarding specific metals and volatility groupings always
 be reviewed in conjunction with facility-specific data. Volatile metals will not be present in significant
 concentrations in either fly ash or bottom ash. Semivolatile metals are more likely to be enriched in air
 pollution control residues such as fly ash (or cement kiln dust), and low-volatile metals are more likely to be
 enriched in the bottom ash (or clinker).

 It is important to recognize that use of a surrogate SHE will often involve extrapolation, and the concepts
 presented in Section 6.3.4 apply. That is, "upward" extrapolation is usually conservative, but "downward"
 extrapolation may not be. Therefore, an SRE determined at a higher feed rate for one metal should generally
 not be used to calculate a lower feed rate for a surrogate metal.  In addition, the permit writer should feel
 comfortable that use of a surrogate SRE will be appropriately conservative, considering the extent and
 quality of the metals feed rate and emissions data. A conservative approach may involve:
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              Use of the lowest observed SRE that is not an outlier. The lowest SRE can either be
              determined for an individual metal, or it might be selected based on the collective data for
              metals within a given volatility group. Where the grouped data confirms that the metals
              behave similarly, a wider range of feed rates may be represented when the data for several
              metals are grouped together.
              Use of the "Lower Confidence Limit" of the test condition average SRE for a particular
              metal, calculated based on the test condition average and the within-test-conditionstandard
              deviation at a particular confidence limit bound (such as 95 percent).
              For cases where data are more extensive (for example, if repeated tests have been conducted
              over the years), it may be appropriate to perform a statistically-based analysis of the entire
              database to determine a conservative SRE.
6.4
METAL SPECIATION
The mobility, bioavailability and toxicity of a metal varies, depending on the specific chemical compound.
However, the ability to measure individual metal compounds and to assess the risks associated with those
compounds is currently limited. EPA OS W's human health and ecological risk assessment guidance
documents (EPA 1998a and 1999b) generally address metals in the elemental form, with the exception of
mercury, chromium, and nickel. For mercury, chromium and nickel, the guidance (EPA 1998a and 1999b)
provides recommended assumptions regarding valence stateor chemical form. Based on the conservative
nature of these assumptions, a facility may want to perform speciation sampling during the risk burn or
present other information to replace the recommended assumptions with site-specific data.
6.4.1
Mercury
As discussed in Section 6.2.1, mercury can be present in the divalent (oxidized) form or the elemental
(reduced) form. The form of mercury significantly influences its fate and transport in the environment. The
divalent form is water soluble and more likely to adsorb to particles.  Stack emissions can thus be removed
from the atmosphere by precipitation, which can lead to partitioning into methyl mercury in nearby surface
waters. This partitioning will tend to drive indirect ecological risks and food chain risks to humans.
Elemental mercury, on the other hand, is less prone to rapid atmospheric removal and deposition near the
source. The EPA OSW risk assessment guidance (EPA 1998a and 1999b) assumes that the vast majority
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(99 percent) of elemental mercury is diffused to the free atmosphere to become part of the global mercury
cycle (rather than being deposited near the source).

The recommended mercury emissions speciation assumptions provided in the EPA OSW risk assessment
guidance (EPA 1998a and 1999b) are: 60 percent divalent vapor phase, 20 percent divalent particle-bound
phase, and 20 percent elemental vapor phase. The rationale for these assumptions is discussed in greater
detail in the EPA OSW risk assessment guidance (EPA 1998a). A facility may wish to perform speciation
sampling for mercury during the risk burn to replace the recommended assumptions with site-specific data.
For example, some data suggest that the percentage of elemental mercury may be higher for certain units
equipped with wet scrubber systems (EPA 1999g).

Standard EPA sampling methods for mercury speciation are not currently available. However,
methodologies which have been evaluated for their.ability to provide mercury speciation information are
discussed in Appendix B of this document.  If mercury speciation sampling is performed, care should be
taken to avoid operating the unit in a manner which could result in a high bias for the elemental form of
mercury. Higher percentages of elemental mercury tend to decrease risks, because the EPA OSW risk
assessment guidance (EPA 1998a and 1999b) assumes that only 1 % of elemental mercury deposits near the
source.  As discussed in Section 6.2.1 of this document, elemental mercury can comprise a significant
fraction of the total mercury if chlorine levels are low or if sulfur levels are high. In addition, rapid
quenching may increase the percentage of elemental mercury because the elemental mercury (which is
favored at typical combustion temperatures) may not have sufficient residence time to shift to the divalent
form (which is favored at temperatures below approximately 600 °C in the presence of chlorine).
6.4.2
Chromium
Chromium exists in multiple valance states. The hexavalent form is most toxic and has been shown to be a
human carcinogen via the direct inhalation exposure route (EPA 1998a). The hexavalent form typically
occurs as either chromate or dichromate.  Trivalent chromium has not been shown to be carcinogenic in either
human or laboratory animals (EPA 1998a). EPA OSW has not recommended that other chromium valence
states be considered in risk assessments (EPA 1998a).
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Available information suggests that substantial quantities of chromium are not likely to be emitted in the
hexavalent form from combustion units.  Laboratory work by Linak and others indicates that the fraction of
hexavalent chromium emitted may be very small, typically ranging from less than one percent to
approximately two percent of the total chromium measured (Linak and others 1996; Linak and Wendt 1998).
The hexavalent fraction in the exhaust was found to be enhanced somewhat by high levels of chlorine, but
was reduced to below analytical detection limits by the addition of small quantities of sulfur. Additional
information indicating low percentages of hexavalent chromium from combustion units is provided by EPA
(EPA 1990) and Bailiff and Kelly (Bailiff arid Kelly 1990).  However, in limited situations and under certain
conditions, a high percentage of hexavalent chromium has been found in combustor emissions (EPA 1991).

The recommended chromium emissions speciation assumption provided in the EPA OSW risk assessment
guidance (EPA 1998a) is a worst-case assumption (i.e., that 100 percent of the chromium emissions are in
the hexavalent form). The basis for this assumption is that there is not sufficient evidence to reliably estimate
the partitioning of chromium between the two valence states. The recommended assumption is very
conservative.  Therefore, a facility may wish to sample for hexavalent chromium during the risk burn to
replace the recommended assumption with site-specific data. S W-846 (EPA 1996b) provides an in-stack
emissions method (Method 0061) for differentiating between trivalent and hexavalent chromium.
6.4.3
Nickel
Nickel can achieve several oxidation states (up to four), with the most common being +2. The most prevalent
forms of nickel are sulfides, oxides, chlorides, and silicates. Some forms of nickel (including nickel carbonyl,
nickel subsulfide, and nickel refinery dust) are considered to be carcinogenic. Previously under the BIF
regulations, EPA did not treat nickel as a carcinogen because of the presumption that nickel can only be
emitted from combustion units as nickel oxide (which, by itself, is not considered to be a carcinogen).

The recommended assumption provided in the EPA OSW risk assessment guidance (EPA 1998a) is that
nickel be evaluated as an inhalation carcinogen using the carcinogenic slope factor for nickel refinery dust.
This recommendation represents a change from the regulatory approach under the BIF rule.  The basis for the
revised approach is that nickel oxide is a major component of nickel refinery dust, and the component in
nickel refinery dust which causes it to be carcinogenic has not been established. For exposure pathways
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other than direct inhalation, EPA OS W has recommended that nickel be evaluated as a noncarcinogen using
the oral reference dose for soluble nickel salts (EPA 1998a). A similar approach was utilized in the risk
assessment conducted in support of the MACT rule (RTI1999).

Standard EPA sampling methods for nickel speciation do not exist at this time. Therefore, it is not possible
for a facility to generate site-specific stack emissions data to replace the recommended assumptions provided
in the EPA OS W risk assessment guidance (EPA 1998a). However, the risk assessment guidance discusses
an approach where a facility may present data at potential points of inhalation exposure indicating the
absence of carcinogenic nickel refinery dust components or the presence of noncarcinogenic species such as
soluble salts.
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                                  CHAPTER 7
                      HYDROGEN CHLORIDE/
                       CHLORINE EMISSIONS
           AND PARTICLE-SIZE DISTRIBUTION
EPA OSW has recommended that hydrogen chloride and chlorine be evaluated for potential risks in site-
specific risk assessments (EPA 1998a). Potential risks from HC1 and C^ are limited to the inhalation
pathway. Since most facilities are either controlling or will control HC1 and C^ emissions under the
hazardous waste combustor MACT rule, the primary consideration for the risk burn is whether additional
control beyond applicable regulatory standards may be warranted at a particular site (see also Sections 1.3.2
and 1.3.3). This chapter (Section 7.1) identifies risk burn data needs and control parameters related to HC1
and C12. Since HC1 and Clj have been discussed at length in other documents (EPA 1992b, 1999d and
1999e), they are only mentioned briefly here.

This' chapter (Section 7.2) also identifies risk bum data needs related to particle-size distribution.
Information on particle-size distribution is needed for the air dispersion and deposition modeling that supports
risk assessments (EPA 1998aand 1999b).
7.1
HYDROGEN CHLORIDE AND CHLORINE
The HCI and C12 emissions standards which apply to hazardous waste combustors vary, depending on the
type of combustion device and the time frame being considered. Technology-based limits for HC1 have
'applied to hazardous waste incinerators since 1981 (40 CFR Part 264.343). The technology-based standards
limit HCI emissions to the larger of 4 pounds per hour or 99% removal. The 40 CFR Part 264.343
provisions do not include an emission limit for C12. For hazardous waste burning boilers and industrial
furnaces, HCI and C12 emissions have been regulated since 1991 under the BIF rule (40 CFR Part 266,
Subpart H). The BIF standards are risk-based standards which consider exposure via the inhalation pathway

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 based on RACs specified in the regulations. However, updated toxicological information (instead of the
 RACs specified in 40 CFR Subpart H) may be available and may need to be considered for site-specific risk
 assessments at BIF facilities. Similar provisions to those prescribed by 40 CFR Subpart H have been applied
 at some hazardous waste incineration facilities through individual permit decisions pursuant to the omnibus
 authority of Section 3005(c)(3) of RCRA and 40 CFR 270.32(b)(2). More recently, technology-based
 MACT emission limits have been promulgated for hazardous waste burning incinerators, cement kilns, and
 lightweight aggregate kilns (EPA 1999c). The MACT standards establish limits on parts per million volume
 (ppmv) of HC1 and C12 emissions, expressed as HC1 equivalents (calculated as ppmv HC1 + 2*ppmv C1J.
 Facilities have three years from the MACT rule promulgation date (September 30,1999) to comply with the
 revised standards. Upon documentation of compliance with MACT, the RCRA incinerator and BIF emission
 standards are superseded (however, any RCRA permit requirements or conditions related to the combustor
 remain in effect until that permit is either modified to remove the conditions or the permit is terminated or
 expires). Technology-based standards for hazardous waste burning boilers are anticipated in a future MACT
 rulemaking.

 The particular regulatory standards which apply at a given facility will inform decisions regarding the need
 for supplemental risk-based controls on HC1 and C12 emissions, as well as the type of supplemental risk-
 based permit conditions which may be appropriate. For example, it may be necessary to supplement the 40
 CFR Part 264.343 incinerator standards to protect human health and the environment, because C^ emissions
 are not limited at all by 40 CFR Part 264.343, and because the HC1 removal efficiency standard does not
 equate to a specific emission limitation. It may be necessary to supplement the BIF standards when updated
 toxicological information (instead of the RACs specified in 40 CFR Subpart H) is available. Risk-based
 controls to supplement the MACT standards, including lower emissions and feed rate limits, may be
 appropriate to assure protection of human health and the environment on a site-specific basis.

 A preliminary risk assessment can provide information to determine whether operation within a regulatory
 emissions limit for HC1 and C12 (for example, BIF or MACT) may present a significant risk to human health
 and the environment. Both pollutants are noncarcinogens and pose risks only through the inhalation pathway.
As discussed in Section 3.2, EPA OS W recommends that the preliminary risk assessment be performed prior
to the risk burn to better define risk burn data needs. If a regulatory limit applies and is sufficiently
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protective, additional site-specific risk-based limits should generally not be needed. However, if the
regulatory limit is not sufficiently protective, a lower site-specific risk-based emissions limit for HCI or Clj,
may need to be established in the RCRA permit to assure protection of human health and the environment.

When it is appropriate to establish a lower, site-specific risk-based emission limit for HCI or Cl, in the
RCRA permit to supplement applicable regulatory standards, then EPA OS W recommends that stack
emission measurements for both HCI and C12 be performed to verify the feed and operating conditions
necessary for achieving compliance with the more stringent emission limits. HCI and CL, emission levels
cannot be predicted from feed rate information or from extrapolation of stack test data because of the
difficulty in predicting the partitioning between HCI and C^ at various operating conditions (additional
information on HCI and C^ partitioning is provided in a technical support document for the hazardous waste
combustor MACT rule, EPA 1999d). The use of existing test data may be appropriate in some cases,
particularly if the data already demonstrates compliance with the more stringent risk-based limits.
Otherwise, sampling during the risk burn may be appropriate.

EPA OSW recommends that the risk burn for HCI and Cl, generally be conducted while demonstrating
control parameters for chlorine feed rate and scrubber performance as identified in Table 7-1.  Table 7-1
summarizes the MACT control parameters related to HCI and C^ emissions. As suggested by the
information in Table 7-1, HCI and Ct emissions from hazardous waste combustors are primarily dependent
on chlorine feed rates and air pollution control efficiency for acid gases (wet or dry scrubbing). For cement
kilns, some dry scrubbing may occur within the process because of the highly alkaline limestone used in the
manufacture of cement. Additional information regarding the control parameters and their influence on HCI
and C12 emissions is available in other documents (EPA 1992b, 1999d, 1999e) and is not discussed at length
here. The MACT control parameters encompass the key control parameters influencing HCI and Cl,
emissions, and are similar to BIF control parameters. However, the MACT parameters have been reviewed
more recently against an extensive emissions database.

The purpose of summarizingthe MACT control parameters in Table 7-1 is not to suggest that MACT
emission standards should necessarily be imposed within the context of risk-based permitting, or to imply that
any facility will be required to achieve early compliance with MACT emissions standards. Rather, the
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purpose of reviewing the MACT control parameters in this guidance is to identify the feed and operating
conditions that influence HCI and C12 emissions, as well as to highlight the controls which will be
implemented at most hazardous waste combustors in accordance with the requirements of the MACT rule.
To the extent that risks from HCI and C12 emissions are already adequately controlled by regulatory limits on
key control parameters, then fewer site-specific risk-based limits may be needed in the RCRA permit.
However, if regulatory controls are not applicable or sufficiently comprehensive, then additional site-specific
risk-based limits may be warranted to ensure protection of human health and the environment.

Risk-based limits for chlorine feed rates, scrubber parameters, and maximum HCI and C12 emission rates
may be established in the RCRA permit based on the risk burn and risk assessment as necessary for
protection of human health and the environment.  Alternatively, the permit writer may determine that limits
imposed pursuant to MACT or other regulatory provisions are sufficient  Fewer permit limitations based on
the risk burn may be necessary when the risk burn can be performed in conjunction with a RCRA trial burn
or MACT performance test. A greater number of risk-based permit limitations may be necessary when the
risk burn and RCRA or MACT performance tests reflect different operating modes.
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                                           TABLE 7-1

      MACT CONTROL PARAMETERS ASSOCIATED WITH HYDROGEN CHLORIDE AND CHLORINE EMISSIONS
'
Chlorine Feed Rate
Wet Scrubbers
High Energy:
- venturi
• hydrosonic
- collision
- free jet
Low Energy:
- spray tower
- packed bed
- tray tower
Control
Parameter',
Maximum total chlorine
(organic and inorganic)
feed rate in all feed
streams '
Maximum flue gas flow
rate or kiln production '
High energy scrubbers:
minimum pressure drop
across scrubber
Low energy scrubbers:
minimum pressure drop
across scrubber
Low energy scrubbers:
minimum liquid feed
pressure
Minimum liquid pH
Minimum liquid scrubber
flow rate and maximum
flue gas flow rate or
minimum liquid/gas ratio
Limits From
Comprehensive
performance test
Comprehensive
performance test
Comprehensive
performance test
Manufacturer
specifications
Manufacturer
specifications
Comprehensive
performance test
Comprehensive
performance test
Averaging
Period
12 hour
1 hour
1 hour
1 hour
1 hour
1 hour
1 hour
How Limit Is
" Established
Average of the test run averages
Average of the maximum hourly
rolling averages for each run
Average of the test run averages
N/A
N/A
Average of the test run averages
Average of the test run averages
Otber Considerations
'
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                                                           TABLE 7-1

    MACT CONTROL PARAMETERS ASSOCIATED WITH HYDROGEN CHLORIDE AND CHLORINE EMISSIONS (continued)
' ^ "V j, " '•»• * «" * <•»> ' >
': >' ... -.'f.'.^''.''.'/ [
Dry Scrubber
r " Control
\.w- ^Parameter . /
Maximum flue gas flow
rate or kiln production
rate
Minimum sorbent feed
rate
Minimum carrier fluid
flow rate or nozzle
pressure drop
Identification of sorbent
brand and type or
adsorption properties
1 J Limits From
M * : -1 j "•
Comprehensive
performance test
Comprehensive
performance test
Manufacturer
specifications
Comprehensive
performance test
Av^ra|Wg
" PerioC
1 hour
1 hour
1 hour
N/A
i Bbw.Liraitfe
Established
Average of the maximum hourly
rolling averages for each run
Average of the test run averages
N/A.
Same properties based on
manufacturer specifications
* Other Considerations
, ! .- ,




Notes:
ESP =
IWS =
electrostatic precipitator
ionizing wet scrubber
                                                   MACT = maximum achievable control technology
                                                   N/A   = not applicable
             =  This limit applies to all feed streams except natural gas, process air, and feed streams from vapor recovery systems, provided that expected levels of
                constituents in those feed streams are accounted for in documenting compliance with feed rate limits. See the MACT rule preamble (EPA 1999c) for further
                information.
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 7.2
PARTICLE-SIZE DISTRIBUTION
Information on particle-size distribution and particle density are recommended for the air dispersion and
deposition modeling that supports risk assessments (EPA 1998aand 1999b). Particle size and particle
density directly affect particle terminal velocity. Large particles fall more rapidly than small particles and are
more easily removed from the atmosphere by precipitation. Smaller particles have lower terminal velocities,
and very small particles remain suspended in the air flow (EPA 1998a). For site-specific risk assessments,
EPA OS W has recommended that most metals and a few organics with very low volatility be assumed to
occur only in the particle phase (EPA 1998a). EPA OSW has recommended that mercury and more volatile
organics be assumed to partition between the particle and vapor phases. Very volatile organics are modeled
only in the vapor phase (EPA 1998a).

Because particle dispersion and deposition are directly related to particle size, predicted ambient impacts and
associated risks are also highly dependent on particle-size distribution. A particle-size distribution that is
more heavily weighted towards larger particles will result in higher deposition near the source, and  reduced
air concentration and deposition further away from the source. A particle-size distribution that is more
heavily weighted towards smaller particles will decrease deposition near the source, and increase air
concentrations and deposition away from the source. In general (but not necessarily in every case), higher
deposition near the source is expected to result in higher risks. However, the relationship between deposition
and risk will vary, depending on the size of the site and the location of potential receptors relative to
maximum deposition. In an air model sensitivity analysis (The Air Group 1997), the particle-size
distribution element was found to be a "moderately" sensitive parameter on a scale of "none" to "severe"
sensitivity. Moderate sensitivity meant that site-specific data could result in variations in the model outputs
of up to 50 percent from default assumptions.

In many cases, the APCD equipment is the primary determinant of particle size and total particle mass
emitted from hazardous waste combustion facilities. Advances in air pollution control technology have led to
improvements in particulate removal efficiency. Removal efficiencies typically decrease as particle size
decreases (i.e., smaller particles are more difficult to remove). According to the proposed MACT rule (EPA
1996a), cyclone separators have typical removal efficiencies of less than 20 percent for particles less than 1
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micron in diameter, and about 5 percent for particles less than 0.5 microns in diameter.  Fabric filters are
extremely efficient and have reported removal efficiencies of 99 to 99.99 percent for particles as low as 0.1
micron in diameter. ESPs are less efficient at capturing particles in the 0.1 to 1.0 micron range and have
reported removal efficiencies of 90 to 95 percent (EPA 1999 f).  Based on these observations, a well-operated
APCD greatly decreases the potential mass and mean particle size emitted from combustion facilities.

Some hazardous waste combustion facilities are not equipped with APCD devices. For these facilities,
particle-size distribution is driven strictly by combustor design, feed composition, combustion quality, and
flue gas cooling profile. In a comparison of particle-size distributions for two different types of combustion
equipment, Linak found significantly different distributions (Linak and others 1999) . A laboratory scale
refractory-lined combustor, which was shown to simulate the combustion conditions of a large utility residual
oil fired boiler with respect to parriculate emissions, produced very fine particulate with a mean diameter
around 0.1 micron. Conversely, a pilot scale fire-tube package boiler produced a small fraction
(approximately 0.2 percent) of mass with particle diameters less than 0.1 micron, and a very large fraction
(approximately 99.8 percent) of the mass with particle diameters between 0.5 and 100 microns. The larger
particles were shown to be porous, carbonaceous cenospheres resulting from poor carbon burnout.
7.2.1
Model Inputs
Particle-size inputs to the air dispersion and deposition model include: 1) particle density; 2) mass
distribution by particle-size category; and 3) surface area distribution by particle-size category. A minimum
of three particle-size categories (>10 microns, 2-10 microns, and <2 microns) are recommended (EPA
1998a). Because so many variables influence particle-size distribution, a representative distribution is very
difficult to predict. Therefore, the EPA OS W risk assessment guidance (EPA 1998a) has recommended that
existing facilities perform site-specific measurements to determine particle density and particle-size
distribution. Particle density and particle-size distribution measurements are discussed in Appendix B.

Detailed procedures for calculating mean particle diameters and mass and surface area distributions from
stack measurements are discussed in the EPA OSW risk assessment guidance (EPA 1998a).  When measured
mass is below the detection limit, it may be appropriate to use a mean particle-size diameter of 1.0 microns in
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the model to represent all particle mass (EPA 1998a). The use of a 1.0 micron particle-size results in the
particles behaving similar to a vapor in the air model.
7.2.2
Test Conditions for Measuring Particle-Size Distribution
EPA OSW recommends that particle-size data generally be collected under normal operating conditions
where ash spiking is not performed. Ash spiking will bias the particle-size distribution and is not likely to be
representative of ongoing emissions in terms of particle size.

In lieu of sampling during normal operating conditions, a facility may prefer to measure particle-size
distribution during the worst-case test conditions (when these tests do not involve ash spiking).  In this case,
EPA OSW recommends that the particle-size distribution measurement generally be performed during both
the high temperature and low temperature operating extremes.  Finer particles are likely to result from higher
combustion temperatures, good combustion conditions, and rapid flue gas cooling profiles. Larger particles
may be associated with poorer combustion situations or slower flue gas cooling profiles (such as through a
heat exchanger or waste heat boiler). Testing during both the high temperature and low temperature
operating extremes will allow potential variations in particle-size distribution to be determined and
subsequently reflected in the air modeling.

Finally, soot blowing practices at a boiler may affect particle-size distribution. Normal soot blowing
practices should generally be determined from the. facility's operating record and reflected during one run of
the particle-size determination. To the extent possible, EPA OSW recommends that the timing of the soot
blowing and particle-size testing be coordinated so that soot blowing is not over-represented or under-
represented in the sample, as compared to the number of hours per day that soot blowing normally occurs.
7.2.3
Alternatives When Site-Specific Measurements Are Not Available
In some cases, a site-specific particle-size distribution measurement will not be available. For example, a
proposed new facility that needs to develop a particle-size distribution estimate may decide to use a
representative distribution from a similar device as recommended by the EPA OSW risk assessment guidance
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(EPA 1998a).  Stack measurements from a similar unit equipped with similar APCD are preferred whenever
possible. However, in the event that stack data from a similar unit are not available, a facility may explore
several options. These include: 1) using literature estimates for similarly equipped facilities, 2) using APCD
vendor estimates, or 3) performing multiple air and risk modeling runs to bound the range of potential
impacts.  Each of these options is discussed further below.
7.2.3.1
Literature Estimates
If a particle-size distribution stack measurement is not available for the actual facility (or for a similar
facility), the use of a literature estimate may be considered. The literature estimate should generally match
the actual facility as closely as possible with respect to the types of fuels and wastes burned and APCD
equipment.

For sources equipped with ESPs or fabric filters, the EPA OS W risk assessment guidance (EPA 1998a)
recommends a nine-category particle-size assumption to be used for site-specific risk assessment modeling if
a more representative site-specific estimate cannot be obtained. The recommended assumptions are
reproduced here as Table 7-2. The assumed particle-size diameters range from less than 0.7 to greater than
15.0 microns, with a mass distribution approximately 48% < 2.5 microns and approximately 82% < 10
microns. The risk assessment guidance also recommends a value for particle density of 1 gram per cubic
centimeter (g/cm3).

For cement kilns equipped with ESPs or fabric filters, a technical support document to the hazardous waste
combustor MACT rule (EPA 1999g) uses a particle-size mass distribution estimate of 50% < 2.5 microns
and 85% < 10 microns. This distribution compares favorably with the distribution provided in Table 7-2 for
sources equipped with ESPs or fabric filters. The estimate is based on the distributions for Portland cement
kilns provided in AP-42 (EPA 1995b) of 45 to 64% < 2.5 microns and 85% < 10 microns, as well as
distribution data for three hazardous waste burning cement kilns ranging from 50 to 75% < 2.5 microns and
70 to 90% < 10 microns (EPA 1999g).

Particles from cement kilns may have a higher particle density than the density of 1 gm/cm3 provided in the
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                                         TABLE 7-2
       GENERALIZED PARTICLE-SIZE DISTRIBUTION TO BE USED AS A DEFAULT
        IN DEPOSITION MODELING IF SITE-SPECIFIC DATA ARE UNAVAILABLE
Mean Particle
Diameter*
(urn)
>15.0
12.5
8.1
5.5
3.6
2.0
1.1
0.7
0.7
Particle
Radius
(jim)
7.50
6.25
4.05
2.75
1.80
1.00
0.55
0.40
0.40
Surface
Area/Volume
(urn)
0.400
0.480
0.741
1.091
1.667
3.000
5.455
7.500
7.500
Fraction of
Total Mass"
0.128
0.105
0.104
0.073
0.103
0.105
0.082
0.076
0.224
Proportion of
Available
Surface Area
0.0512
0.0504
0.0771
0.0796
0.1717
0.3150
0.4473
0.5700
1.6800
Fraction of
Total Surface
Area
0.0149
0.0146
0.0224
0.0231
0.0499
0.0915
0.1290
0.1656
0.4880
Notes:
"Geometric mean diameter.
'The terms mass and weight are used interchangeably when using stack test data
EPA OSW risk assessment guidance (EPA 1998a). A higher density, for example 2 gm/cnf, may result in
up to 50 percent greater dry deposition near the source (The Air Group 1997). The use of a particle density
of 2 gm/cm3 is based on information from the cement kiln industry. Material Safety Data Sheets for cement
kiln dust (http://www.lafargecorp.com)list, among the physical and chemical properties, a specific gravity of
2.6 to 2.8 gm/cm3.  This value is for bulk cement kiln dust stored and shipped from a silo as a product. In
actuality, the density of stack dust emissions from a cement kiln will depend on the chemical composition and
size distribution, which is also a function of the APCD design and operation. Therefore, site-specific
measurements of particle density are preferred.
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Some hazardous waste burning incinerators and boilers are equipped with wet scrubbing devices to control

acid gas emissions. In a technical support document to the hazardous waste combustor MACT rule (EPA

1999g), EPA estimates mass particle-size distributions for incinerators equipped with wet APCD devices as
follows:
              Liquid injection units:

              Solids units:
95% < 2.5 microns and 100% < 10 microns

70% < 2.5 microns and 90% < 10 microns
These estimates are based on data from two hazardous waste burning incinerators, one equipped with an IWS

and one equipped with a wet ESP, as well as limited data from municipal and medical waste incinerators.

The liquid injection estimate compares favorably with the estimate available in AP-42 (EPA 1995b) for

residual oil burning utility boilers equipped with wet scrubbers (97% < 2.5 microns and 100% < 10 microns).


Some liquid injection incinerators and boilers burning low ash, low halogen wastes may not be equipped with

any APCD at all. A particle-size distribution is identified in AP-42 (EPA 1995b) for an uncontrolled utility
boiler firing residual oil. This mass distribution is 52% < 2.5 microns and 71 % < 10 microns.


Finally, AP-42 (EPA 1995b) identifies several particle-size distribution estimates for coal-fired boilers.
These distributions may be appropriate for hazardous waste burning boilers if coal is routinely co-fired as an
auxiliary fuel. Selected distributions are summarized here as follows:
       Bituminous and Sub-bituminous Coal
              Dry bottom boiler w/ ESP
              Dry bottom boiler w/ fabric filter
              Dry bottom boiler w/ scrubber
              Spreader stoker w/ ESP
              Spreader stoker w/ fabric filter
       Anthracite Coal
              Dry bottom boiler w/ fabric filter
% Mass < 2.5 microns

     29
     53
     51
     61
     26

     32
% Mass < 10 microns

       67
       92
       71
       90
       60

       67
It is important to emphasize that EPA OS W only recommends the use of literature estimates, such as those

summarized in this section, if site-specific data is unavailable. As documented by Linak (Linak and others
1999), particle-size distributions can vary significantly from unit to unit, and a site-specific determination is
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always preferred.
7.2.3.2
APCD Vendor Estimates
In some cases, a facility may be able to obtain particle-size distribution data from the APCD vendor if site-
specific data are not available. For example, vendor data for sources equipped with HEPA filters may be
sufficient for estimating mass distributions within the three particle-size categories (>10 microns, 2-10
microns, and <2 microns) because 100% of the particle mass would be expected to be below 2 microns in
diameter downstream of a HEPA filter.
7.2.3.3
Multiple Modeling Runs to Bound Potential Impacts
Another option when site-specific particle-size distribution data are not available is to perform multiple air
and risk modeling runs, using a range of assumed size distributions, to bound the range of potential impacts.
For this option, EPA OS W recommends that three different size distributions be modeled to determine the
highest impacts for site-specific receptors considering all exposure pathways:
        •      100% mass at 1 micron in diameter;
        •      100% mass at 5 to 7.5 microns in diameter;
        •      100% mass at 12 to 15 microns in diameter.
This approach may be very resource-intensive, but should assure that predicted impacts are conservatively
bounded by the risk assessment in the absence of site-specific particle-size data
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                                    CHAPTER 8
                               DATA ANALYSIS
Once the risk burn has been completed and emissions data are available, the data can be analyzed and the risk
assessment can be performed. This chapter (Section 8.1) discusses consolidation of the emissions data from
each risk burn test condition prior to evaluation in the risk assessment.  This chapter (Section 8.2) also
identifies various emissions scenarios that may be evaluated in the risk assessment. Since a risk burn can
involve multiple test conditions, EPA OSW recommends that the permit writer and facility give early
consideration to how the data from more than one test condition will be combined for subsequent evaluation.
In addition, EPA OSW recommends that the permit writer and facility consider whether the risk burn data
will be evaluated in conjunction with emissions estimates that may be based on information other than the
risk burn (for example, emissions corresponding to an applicable regulatory standard).
8.1
DATA REDUCTION AND COPC SELECTION
A large amount of data will be generated during the risk burn, and these data will need to be reduced prior to
evaluation in the risk assessment. Consolidation of data for each risk burn test condition, including treatment
of non-detects, is discussed in Section 8.1.1. Section 8.1.2 explains how constituents which are not detected
in any test run are addressed in the COPC selection process.
8.1.1
Data Reporting and Treatment of Non-Detects
Consolidation of risk burn emissions data prior to evaluation in a risk assessment is a multi-step process.
First, analytical results for the various fractions of a stack gas sampling train are summed to determine a
train total.  A train total is reported for each constituent and each test run.  Eventually, the reported results
for three test runs are consolidated to arrive at a test condition total.  At several points in the process,
questions arise regarding how to treat non-detects.  The EPA OSW risk assessment guidance (EPA 1998a)
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 provides a recommended procedure, and portions of that procedure are repeated here for the convenience of
 the reader.

 Detection limits are defined a number of ways, and terms are not always consistently applied.  For the
 purpose of combustion risk assessments, the EPA OSW risk assessment guidance (EPA 1998a) recommends
 that the following be reported when constituents are not detected in a stack gas emissions sample:

        Reliable detection limits (RDLs): RDLs should generally be reported when constituents are
        analyzed with non-isotope dilution methods, such as the methods for volatile and semivolatile
        organics, and are not detected.  The RDL is a total of 8 standard deviations above the Method
        Detection Limit (MDL) developmental test data, where the MDL is determined from analysis of at
        least seven replicate samples of a given matrix in accordance with 40 CFR Part 136, Appendix B.
        The reported RDL should be adjusted, as appropriate, to account for sample-specific volumetric
        treatments (e.g., splits and dilutions) that differ from those utilized in the Part 136 MDL
        determination.
        Estimated detection limits (EDLs):  EDLs should generally be reported when constituents are
        analyzed with isotope dilution methods, such as the method for D/Fs, and are not detected. EDLs are
        defined by the individual SW-846 (EPA 1996b) test method, such as Method 8290 for D/Fs, and
        represent an estimate by the laboratory of the concentration of a given analyte necessary to produce a
        signal with a peak height of at least 2.5 times the background signal level.

EPA OSW recommends that a facility inform the laboratory of these reporting conventions prior to
development of the risk burn QAPP and analysis of the risk burn samples. In particular, MDLs are specific
to each laboratory, and some laboratories may not have pre-determinedMDLs for all compounds that are
quantifiable by a particular method. MDLs determined per 40 CFR Part 13 6 may need to be explicitly
requested for all chemicals to be analyzed and subsequently reported in the risk bum report.

EPA OSW also recommends that a facility provide clear direction to the laboratory regarding how to report a
total sampling train mass for each constituent and each run if a constituent is not detected in certain of the
analytical determinations. For most of the stack gas sampling trains, separate analyses are performed on
various train fractions (for example, a resin fraction and a condensate fraction).  The MDLs (and therefore
the RDLs) are matrix-specific (i.e., separate MDLs are determined for the resin fraction and the condensate
fraction). For data reporting to support site-specific risk assessments at combustion facilities, the following
reporting convention is recommended when the results from each sampling train fraction have to be summed
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to arrive at a total train mass:

        •      If results for all fractions are non-detect, then the full RDLs (or EDLs) should be summed and
              the result reported with a "less than" sign;
        •      If a constituent is detected in some of the train fractions but not in others, then the data should
              be reported as a range (i.e., "greater than" the total detected amount, but "less than" the total
              detected amount plus the full RDLs or EDLs for the non-detects). For D/Fs, Method 0023A
              specifically allows a non-detect to be treated as zero if it is less than 10 percent of the total
              detected amount, subj ect to approval by the regulatory agency.

Blank results can also affect whether or not a constituent is considered to be detected. Blanks are not
addressed here, but are discussed in detail in Appendix B.

For D/F analysis by Method 8290, there is also the issue of how to report estimated maximum possible
concentrations (EMPCs). An EMPC is characterized by a response with a signal to noise ratio of at least
2.5 for both quantitation ions that meets all the relevant identification criteria except ion abundance ratio.
For an EMPC, the ion abundance ratio and quantitative ion signal may be affected by co-eluting
interferences. Therefore, an EMPC is a worst-case estimate of the concentration. The EPA OS W risk
assessment guidance (EPA 1998a) recommends that EMPCs be treated as full detections in the risk
assessment, and encourages application of techniques to minimize EMPCs.
8.1.2
COPC Selection and Treatment of Non-Detects
As discussed in Section 8.1.1, EPA OS W recommends that non-detects be fully carried through the risk burn
data reporting process. However, this does not necessarily mean that all non-detected constituents will be
evaluated in the risk assessment. Once the data is reported, decisions are needed as to whether the non-
detected constituents will be retained as COPCs for the risk assessment. The EPA OS W risk assessment
guidance (EPA 1998a) recommends a logical.process for making these decisions, and portions of that process
are repeated here for the convenience of the reader

EPA OS W has recommended that constituents that are not detected in the stack emissions during any test run
be re-evaluated for inclusion in the risk assessment using the final COPC selection process and flowchart
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found in the EPA OSW risk assessment guidance (EPA 1998a). A compound may be excluded from the
COPC list if: 1) it is not present in the waste being burned, and 2) it does not have a high potential to be
emitted as a PIC, and 3) it has no potential of being emitted and is not of concern due to other site-specific
factors (such as background concentrations and community or regulatory concern) (EPA 1998a). Based on
this COPC selection process, some constituents that are not detected during any of the test runs and which
meet the specified criteria will be eliminated from further consideration in the risk assessment.

In the COPC selection process, EPA OSW recommends that care be taken not to eliminate non-detected
constituents that may be limited quantitatively in the final permit, because compliance with an emission rate
limit of zero cannot be determined. Quantitative emission limits for certain toxic and bioaccumulative
constituents may be established in the final permit to ensure that emissions of those constituents do not
exceed the levels which were evaluated in the risk assessment and found  not to pose a significant risk to
human health and the environment. Constituents which may be candidates for risk-based emission limits in
the final permit include D/Fs, specific metals, HC1 and C^, and significant waste constituents (for example,
chemical warfare agents). Although emission limits for individual organics other than D/Fs may not be
routinely established, the permit writer may limit other organic contaminants that are found to be risk
drivers, as appropriate.

At the conclusion of the COPC selection process, the constituents retained as COPCs will include: .1)
constituents detected in at least one run of the risk burn, 2) constituents which are not detected during the risk
burn, but which cannot be excluded as COPCs because they have the potential to be emitted or are otherwise
of concern, and 3) constituents which may be limited by quantitative emission rates in the final RCRA
permit.  For constituents which are not detected but are retained as COPCs, EPA OSW has recommended
that the full RDL or EDL generally be used  in calculating an emission rate for each run and each test
condition for subsequent evaluation in the risk assessment (EPA 1998a).

The final step in the risk burn data consolidation process is calculation of a test condition emission rate from
the three test runs.  For each test condition, EPA OSW has recommended that the emission rate for each
constituent be calculated as the 95th percentile of the arithmetic test mean, or the maximum value from the
three test runs, whichever is lower (EPA 1998a). The EPA OSW risk assessment guidance (EPA 1998a and
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1999b) recommends that emissions data from the risk burn be evaluated in a site-specific risk assessment to
provide reasonable maximum exposure (RME) estimates of potential risks to human and ecological
receptors. Results from probabilistic risk assessments show that setting as few as two factors at RME levels
or high end (e.g., near the 90th percentile) while the remaining variables are set at less conservative, typical or
"central tendency" values (e.g., near the 50th percentile) results in a product of all input variables at an RME
level (e.g., 99th percentile value) (EPA 1998a). The EPA OS W risk assessment guidance identifies risk burn
emissions data as one of the variables that is recommended to be set at the RME level.
8.2
EMISSION SCENARIOS TO BE EVALUATED FOR RISK
Once the risk burn data have been consolidated for each test condition and COPCs have been selected as
discussed in Section 8.1, the risk assessment can be performed  When a risk burn involves multiple test
conditions, the permit writer and facility will need to decide whether the data from each test condition should
be evaluated separately, or whether the data will be combined in some manner.  In addition, decisions will be
needed regarding evaluation of emissions beyond those measured during the risk burn. For example, a
facility may prefer to evaluate risks associated with emissions at a regulatory standard or with an emissions
estimate (i.e., zero SRE) in the risk assessment.  This section identifies various emissions combinations that
may be evaluated for risk.

Consolidation of data from multiple test conditions can encompass a range of options, depending on how the
test conditions are structured and how the data will be presented for the risk management decision. EPA
OS W recommends that these options be considered carefully prior to establishing test conditions and
subsequent data collection.  As discussed in Chapter 3, EPA OSW recommends that the emissions scenarios
to be evaluated in the risk assessment be clearly identified in the risk burn plan, and that the test plan also
indicate whether the risk assessment will consider emissions estimates based on information other than the
risk burn.

Possible emissions scenarios to be evaluated for risk include: 1) calculation of risk ranges corresponding to
specific test  conditions (e.g., DRE and SRE); 2) consolidation of the highest emissions data from multiple
test conditions for calculation of a single high-end risk value; 3) combining test data with emission rate
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estimates; 4) combining test data with regulatory standards; 5) combining test data with emission rate
estimates for abated and unabated fugitive emissions and emission rate estimates for expected chemicals that
could not be incorporated into the test (i.e., due to lack of validated stack sampling methods, lack of available
waste quantities for the test, or an inability to represent waste diversity during the test); or 6) any
combination. Unless complete emissions determinations (for D/Fs, other organics, metals, and HCl/Cl,) are
conducted during every test condition, then consolidation of data from multiple conditions will need to be
considered. Examples of possible emission scenarios to be evaluated for risk are provided below and in
Appendix A.

Calculation of Risk Ranges Corresponding to Specific Test Conditions

A facility may choose to collect risk burn emissions data in conjunction with both the DRE and SRE tests.
The DRE and SRE tests typically bound the operating extremes of the combustion unit by representing the
lowest and highest combustion temperatures, as well as worst-case feed and APCD conditions. If complete
risk burn emissions data (D/Fs, other organics, metals, HCl/C^, and  particle size information) are collected
during both test conditions, then the facility may prefer to evaluate the emissions data set from each test
condition separately in a site-specific risk assessment to calculate risks corresponding to each end of the
operating envelope.

Consolidation of Multiple Tests for Calculation of a Single High-End Risk Value

It is more likely that the facility described above would not sample for metals during the DRE test, perhaps to
limit metals spiking.  In this case, complete data for all COPCs would not be available for both test
conditions, and the risk burn data would need to be consolidated to complete the site-specific risk assessment.
One option might involve combining the metals emissions from the SRE test with the higher of the D/F and
organic emissions from either the SRE or DRE tests to calculate a single RME risk estimate.

Combining Test Data with Emissions Estimates

For either of the above approaches, the facility may have preferred to estimate maximum mercury emissions
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by assuming zero SRE at a maximum mercury feed rale instead of spiking mercury during the SRE test.
This maximum mercury emissions estimate could be combined with the measured emissions data for
calculation of either a risk range or a single risk estimate.

Combining Test Data with Regulatory Standards

Finally, the facility described thus far may be planning for future compliance with the hazardous waste
combustor MACT standards. The facility may have determined that physical modifications to the
combustion system are not needed, but plans to reduce the feed rate of certain metals to meet the MACT
standards. The facility may decide to evaluate an extra scenario in the site-specific risk assessment to reflect
post-MACT operation.  In this scenario, the MACT emission rate limits for D/Fs, metals, and HC1/C1, might
be evaluated in the risk assessment, together with emissions data for the non-MACT metals collected during
the SRE test condition and the non-D/F organic emissions data from the DRE test condition of the  risk burn.

Obviously, if a facility collects emissions data under additional test conditions, then the data management and
analysis options become more complex. As explained in Chapter 3, EPA OSW recommends early
communication and coordination between the permit writer and facility.

Finally, EPA OSW recommends that recent EPA direction in characterizing and communicating risk (EPA
1995c) to the public be considered. The Guidance for Risk Characterization (EPA 1995c) recommends that
risk assessments include risks based on data reflecting both RME and central tendency (average) conditions.
As appropriate, site-specific risk assessments may be completed based on both RME and average emissions
data. This could assist in the risk communication process by allowing the facility and EPA to discuss a
broader risk range with the public and to consider effects of variations in operating conditions on potential
risks. However, RME conditions are generally expected to form the basis of permit conditions.
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                                    CHAPTER  9
              RISK-BASED PERMIT  CONDITIONS
After the site-specific risk assessment is performed and results are available, a final decision can be made
regarding inclusion of risk-based conditions in the RCRA permit. The final RCRA permit represents an
important and integral conclusion to the risk-based permitting process. The final permit identifies the
operational conditions that are necessary to protect human health and the environment, and how that will be
assured on an ongoing basis. This chapter concludes the ongoing dialogue provided throughout this
document regarding potential risk-based permit terms.

Risk-based permit terms may be appropriate when emissions are projected to present a significant risk to
human health and the environment. The EPA OSW risk assessment guidance (EPA 1998a) recommends
several options when a risk assessment indicates potentially significant risks, and these options are repeated
here for the convenience of the reader:
             Collecting additional site-specific information that is more representative of the exposure
             setting and performing additional iterations of the risk assessment based on the new
             information;
             Establishing permit terms (for example, waste feed limitations, process operating conditions,
             or environmental monitoring) to limit operations and performing additional iterations of the
             risk assessment to demonstrate that the resulting emissions are protective of human health and
             the environment;
             Denying the permit, if the initial risk assessment or subsequent iterations indicate potentially
             unacceptable risks.
However, even if the risk assessment indicates that projected risks will not be significant, risk-based permit
terms may still be necessary to protect human health and the environment by ensuring that emissions remain
below the levels which were measured during the risk burn and found to be protective. The risk burn and risk
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assessment are typically based on assumptions that include:
              Waste composition, physical form, and feed rates, with key considerations outlined in
              Chapters 4-7;
              Operating conditions and parameters, including those related to combustion conditions
              (temperature, turbulence, and residence time) and APCD operation (pressure drops, flow
              rates, liquid-to-gas ratios, inlet temperatures, and power) as identified in Chapters 4-7;
              Emission rates associated with specific feed and operating conditions.
Within the bounds of the conditions demonstrated during the risk burn, emissions are characterized and
evaluated in the risk assessment to determine whether they may present a significant risk to human health and
the environment.  Outside of those bounds (unless additional information is available), emissions and risks
are generally unknown. Therefore, in order to protect human health and the environment, it may be necessary
to limit operations to prevent higher emissions than those represented by the risk burn and risk assessment.

Site-specific factors will inform a decision regarding the need for, as well as the extent of, any risk-based
RCRA permit limits to assure that ongoing emissions do not present a significant risk to human health and
the environment.  Key factors generally include, but are not necessarily limited to: 1) the emissions scenarios
evaluated in risk assessment; 2) the feed and operating scenarios demonstrated during the risk burn; 3)
whether key feed and control parameters are already limited by another permit or regulatory mechanism; 4)
facility-specific operating practices; and 5) the potential for emissions to pose significant risks to human
health and the environment.

As discussed in Chapter 3, few (if any) risk-based permit limitations may be necessary when the risk bum
can be combined with a RCRA or MACT performance test, and when emissions and key control parameters
are already sufficiently addressed by regulatory limits.  A greater number of permit limitations may be
necessary when the risk burn and performance tests reflect different operating modes, or when emissions and
key control parameters are not limited by another mechanism.  EPA OS W recommends that expectations
regarding risk-based permit terms be clearly articulated in the risk burn plan, as discussed in Section 3.5.
The potential for emissions to pose significant risks to human health and the environment is an important
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consideration in determining appropriate permit terms. If the potential risks associated with all foreseeable
operating modes and operating extremes are insignificant, it may be appropriate for the permit writer to
conclude that risk-based permit conditions are not necessary to protect human health and the environment,
and to simply document the basis for the risk assessment emissions assumptions in the administrative record.
In some cases, it may be appropriate for the permit writer to incorporate general monitoring and reporting
provisions into the final permit to protect human health and the environment by ensuring that significant
changes that could affect emissions (including types of wastes treated or major changes to operating
parameters) are reported to EPA or the appropriate state agency. When potential risks are more significant, a
permit writer may conclude that specific permit limits are necessary to protect human health and the
environment. As identified in Chapter 3, risk-based permit terms may take the form of emission limits and
specifications for periodic stack testing, restrictions on feed or operating control parameters and associated
monitoring provisions, or some combination.

In summary, the emission rates (and related feed and operating conditions) that are demonstrated during the
risk burn and evaluated in the risk assessment should clearly correspond to potential permit terms and
conditions. The permit terms can ensure protection of human health and the environment by prohibiting
operations outside of the operating boundaries represented by a risk burn and risk assessment that
demonstrates emissions will not pose a significant risk. When a permit decision involves the use of a site-
specific risk assessment, final RCRA permit terms will ultimately depend on the operating practices, emission
levels, and risk results specific to each facility, and the permit writer should work closely with the facility to
determine appropriate conditions for the risk burn and a corresponding permit approach. Illustrations are
provided in Appendix A.
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Lemieux, P.M. and Ryan, J. V. 1998b.  "Enhanced Formation of Chlorinated PICs by the Addition of
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Lemieux, P.M., Lee, C.W., Kilgroe, J.D., and Ryan, J. V.  1999. "Emissions of Polychlorinated Biphenyls as
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  Risk Burn Guidance for
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July 2001
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EPA. 1989. "Guidance on Setting Permit Conditions and Reporting Trial Burn Results, Volume II of the
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EPA. 1994a. "Implementation Guidance for Conducting Indirect Exposure Analysis at RCRA Combustion
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EPA. 1994c. "Combustion Emissions Technical Resource Document." EPA530-R-94-014. May.

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EPA. 1997c. "Health Effects Assessment Summary Tables, F Y 1997 Update." Office of Solid Waste and
       Emergency Response. EPA-450-R-97-036. PB97-921199. July.

EPA. 1997d. "Revised Technical Standards for Hazardous Waste Combustion Facilities."  Proposed Rule.
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       Register 62:24211. May 2.

EPA. 1997e. "Draft Technical Support Document for HWC MACT Standards (NODA), Volume III:
       Evaluation of Metal Emissions Database to Investigate Extrapolation and Interpolation Issues."
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EPA. .1998a. "Human Health Risk Assessment Protocol for Hazardous Waste Combustion Facilities." Peer
       Review Draft. EPA530-D-98-001. Solid Waste and Emergency Response.  July.

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EPA. 1998c.  "EPA QA/R-5: EPA Requirements for Quality Assurance Project Plans." External Review
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       F., Zacharewski, T. 1998. "Toxic Equivalency Factors (TEFs) for PCBs, PCDDs, PCDFs for
       Humans and Wildlife." Environmental Health Perspectives.  106:775-792. December.
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Waterland,L.R. and Ghorishi, S.B. 1997. "Rapid High-Temperature Dioxin Formation: Pilot-Scale Test
       Results from the U.S. EPA Incineration Research Facility." Presented at the 1997 International
       Conference on Incineration and Thermal Treatment Technologies. Oakland, California May.

Wendt, J.O.L., Linak, W.P., Lemieux, P.M.  1990.  "Prediction of Transient Behavior During Batch
       Incineration of Liquid Wastes in Rotary Kilns." Hazardous Waste & Hazardous Materials. Volume
       7, Number 1.

Yonley, Carrie. 2000. Personal communication between Carrie Yonley, Schreiber, Yonley and Associates,
       and Beth Antley, EPA Region 4.
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                                     APPENDIX A
                    RISK BURN CONDITIONS AND PERMIT LIMITS
                              FOR EXAMPLE FACILITIES
      A.1   Risk Burn Conditions and Permit Limits for a Liquid Injection Incinerator (13 pages)


      A.2   Risk Burn Conditions and Permit Limits for a Rotary Kiln Incinerator Burning

            Containerized Wastes (16 pages)
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                                         APPENDIX A.1
                       RISK BURN CONDITIONS AND PERMIT LIMITS
                          FOR A LIQUID INJECTION INCINERATOR
         Note: This illustrative example does not represent the only approach to structuring a trial burn/risk
         bum/MACT performance test. Other regulatory and permitting options exist.  Test plans and final permit
         conditions should always be developed on a site-specific basis after close interaction between the regulator
         and facility.
Appendix A. 1 describes the risk burn and resulting permit limits for an example liquid injection incineration
facility (Facility Z). Facility Z burns organic liquid and aqueous wastes in a liquid injection combustion
chamber, followed by a heat recovery boiler and an air pollution control system consisting of a fabric filter
and venturi scrubber. Facility Z typically operates the combustion chamber within a 1,750 + 50 °F
temperature window, with exit gas temperatures from the heat recovery boiler in the range of 350 to 550 °F.
Gas exit temperatures from the heat recovery boiler generally increase and decrease with combustion
temperature.  A review of historical operating data indicates that Facility Z consistently maintains steady-
state operations, with very low carbon monoxide and few waste feed cutoffs.

Facility Z needs to complete performance testing and a risk burn for a Resource Conservation and Recovery
Act (RCRA) permit renewal. In addition, Facility Z anticipates complying with the hazardous waste
combustor Maximum Achievable Control Technology (MACT) standards in the future, and has already
added an activated carbon injection system to control dioxins. By carefully structuring the test plan, Facility
Z can satisfy the current RCRA permitting needs, as well as generate data that may be submitted at a later
date as "data in lieu of the initial performance test" for MACT.

Facility Z begins writing the test plan with the following test conditions (summarized in Table A. 1-1):

Destruction and Removal Efficiency Test Condition
A destruction and removal efficiency (DRE) demonstration will be conducted at a minimum combustion
temperature of 1,600 °F.  This combustion temperature corresponds to a fabric filter inlet temperature of
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350°F. Other control parameters to be demonstrated during the DRE test include: 1) maximum combustion
gas velocity, as an indicator of minimum gas residence time; 2) maximum waste feed rate to each feed
location; and 3) worst-case operating conditions for air pollution control parameters (to the extent possible).
Continuous carbon monoxide and total hydrocarbon monitoring is also planned for this test. Operating
parameters to ensure good operation of the waste firing system will be based on manufacturer's
specifications.

System Removal Efficiency Test Conditions

In anticipation of future MACT compliance, Facility Z adds test conditions to demonstrate system removal
efficiencies (SREs) for semivolatile and low-volatile metals (arsenic, beryllium, cadmium, chromium, and
lead). Stack determinations for particulate matter (PM) and hydrogen chloride (HC1) and chlorine (Cy are
also planned for the SRE tests.

The SRE demonstrations will be conducted at a maximum combustion temperature of 1,850 °F in order to
achieve a maximum inlet fabric filter temperature of 550 ° F.  Maximum semivolatile and low-volatile metal
feed rates will be achieved by spiking one metal from each of the two volatility groups. Since all of the feed
mechanisms at Facility Z are for liquid feeds, there is no distinction between total metal feed rates and
pumpable metal feed rates. Other control parameters to be demonstrated during the SRE test conditions
include:,!) maximum combustion gas velocity; 2) maximum chlorine feed rate; 3) maximum ash feed rate;
and 4) worst-case operating conditions for air pollution control parameters.

Two SRE test conditions are necessary to resolve conflicting parameters. Demonstration of the maximum
combustion gas velocity control parameter conflicts with demonstration of minimum pressure differential for '
the venturi scrubber. The two SRE test conditions are designated as SRE 1 and SRE 2 in Table A. 1-1.
During the SRE  1 test condition, maximum combustion gas velocity will be demonstrated. During the SRE 2
test condition, minimum pressure differential for the venturi scrubber will be demonstrated, and all other
control parameters will be maintained as close as possible to the SRE 1  conditions. Demonstration of the
maximum combustion gas velocity control parameter also conflicts with demonstration of minimum pressure
differential for the fabric filter.  However, Facility Z observes that the MACT rule allows minimum and
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maximum fabric filter pressure differential to be established based on manufacturer's specifications, and the
permit writer agrees with this approach.

For mercury, Facility Z wishes to avoid spiking and will not demonstrate a maximum mercury feed rate
during the SRE test. Facility Z plans to conservatively assume that 100% of the mercury fed to the unit is
emitted (even though some mercury control will be achieved from the carbon injection system).

Risk Burn Determinations and Addition of a Normal Test Condition

To complete a site-specific risk assessment, Facility Z recognizes that stack emissions determinations are
needed for: dioxins/furans (D/Fs); organics other than D/Fs; the eighteen toxic metals listed in Section 2.3;
particle-size distribution; and HC1/C12.  Facility Z incorporates these determinations into the test plan as
follows:
       D/Fs
       The primary operating parameters related to D/F formation for Facility Z are boiler exit temperature
       and fabric filter inlet temperature (both operating parameters are represented by the same
       measurement location for the Facility Z system configuration), as well as control parameters for the
       carbon injection system. D/Fs are expected to be maximized at the maximum fabric filter inlet
       temperature of 550 °F, and will therefore be measured in conjunction with the SRE tests.

       D/F testing will also be performed during the DRE test because of the permit writer's concern that
       the high combustion temperatures demonstrated during the SRE test might not adequately represent
       D/F precursors which could be formed during lower temperature combustion situations. In general,
       the formation of D/F precursors due to poor combustion should not be a significant concern for this
       system (because of the historical data indicating steady-state operation). Also, the 350°F fabric filter
       inlet temperature planned for the DRE test is outside of the critical D/F temperature range (400.- 750
       °F). However, the facility agrees that D/F sampling during DRE conditions will better represent the
       complete operating envelope, and will put Facility Z in a better position to potentially use the data for
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      future MACT compliance (control parameters for minimum combustion temperatures, maximum
      waste feed rates, and maximum gas flow rates are required to be demonstrated during D/F testing
      pursuant to MACT). Therefore, Facility Z adds a D/F determination to the ORE test

      Non-D/F Organics

      The feed and operating conditions that influence organic products of incomplete combustion (PICs)
      are already represented during the DRE test. Therefore, the facility plans to measure PICs and total
      organics in conjunction with the DRE performance demonstration. In addition, Facility Z arranges
      for the sampling contractor to operate a temporary total hydrocarbon continuous emissions monitor
      during the DRE/PIC testing.
      Metals
      The SRE tests already involve stack determinations for the five toxic metals identified in the MACT
      rule. However, Facility Z is concerned that the metals spiking during the SRE tests may result in
      emissions that exceed risk target values. Therefore, Facility Z proposes a separate test condition for
      the purpose of generating metals emissions data for the risk assessment. A normal test is proposed
      (as summarized in Table A. 1-1) since Facility Z is capable of defining and maintaining normal
      operating conditions for metals.

      The normal test for metals will be conducted at normal metal feed rates, at a combustion temperature
      of approximately 1,750 °F and a fabric filter inlet temperature of 450 °F. Emissions testing will be
      performed for eighteen metals.

      Particle-Size Distribution

      For Facility Z, the fabric filter will be the primary determinant of particle-size distribution.
      Therefore, significant variation in particle-size distribution between the different test conditions is not
      expected. A particle-size determination is added to the normal test, since this test does not include
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      ash spiking.


      HCI and Ct


      Determinations for HCI and C12 are already included in the SRE tests, and this data can also be used

      for the risk assessment
Risk Burn Guidance for
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July 2001
   A.l-5

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                                            TABLE A.l-1

                                 FACILITY Z TEST CONDITIONS
~ ~ { ' "- % J**
t ^
'*-',
!.<< r "
j-;i
Combustion temperature
Fabric filter inlet
temperature
Organic liquid feed rate
Aqueous liquid feed rate
Combustion gas velocity
Ash feed rate
Chlorine feed rate
Spiked metal feed rates
Other metal feed rates
Fabric filter differential
pressure
Venturi differential
pressure
Venturi liquid-to-gas ratio
Venturi scrubber liquid
exitpH
Scrubber blowdown rate
Carbon feed rate
'- " " "V " 's * -T-JE'STlQONJJrflONSr'T _V"'"* '/ *''
"- ' . AT^EMI^IONSDEfE^MINATlbNS- , 5 - ,\>
0>RE
PQHCs,PFCss D/Fs, TOE,
sTotaLlfydrocarbons, Carbon
Mondxidef ~ "~ * "
1,600 °F
350 °F
Maximum
Maximum
Maximum *
Above average
Maximum
N/A
N/A
Within manufacturer's
specifications
Minimum *
(or as close as possible)
Minimum
Minimum
Minimum
Minimum
SRE1 SRE2
MetaIs,JD/Fs, PM, "*
,HCyci, Carbon "
Monoxide - >
1,850 °F
550 °F
Maximum
Minimum
Maximum *
Maximum
Maximum
Maximum
Normal
Within
manufacturer's
specifications
Minimum *
Minimum
Minimum
Minimum
Minimum
NORMAL
Metals, Particle * '
Size
1,750 °F
450 °F
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Normal
Notes:
D/Fs
ORE
N/A
PICs
conflicting parameters

Dioxins/furans                      PM
Destruction and removal efficiency      POHCs
Not applicable                      SRE
Products of incomplete combustion      TOE
Particulate matter
Principal organic hazardous constituents
System removal efficiency
Total organic emissions
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                                                                                July 2001
                                                                                   A. 1-6

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Site-Specific Risk Assessment

Facility Z performs the tests according to the approved test plan. As expected, D/F emissions are highest
during the SRE test conditions. Emissions data are consolidated from all of the test conditions for evaluation
in a single multi-pathway human health and ecological site-specific risk assessment as follows:

       •      D/F emissions from the SRE test conditions are evaluated, together with...
       •      Organic PIC emissions from the DRE test condition, and...
       •      Metals emissions (18 metals) from the  normal test condition, and ...
       •      HC1 and C12 emissions from the SRE test conditions.


Total chronic risks from these consolidated emissions are determined to be below target levels.

An acute risk evaluation is also performed to assess inhalation risks associated with maximum potential one-
hour emissions.  Maximum one-hour emissions for the acute evaluation are estimated for D/Fs, other
organics, and HC1/C12 based on the test data listed above, with an upward adjustment to reflect upsets.
However, for metals, the test data are not representative of maximum potential one-hour emissions.  For the
metals represented by the spiked metals (arsenic, beryllium, cadmium, chromium, and lead), the facility uses
an approved extrapolation procedure to estimate maximum one-hour emission rates based on maximum
anticipated one-hour feed rates and the SREs demonstrated during the testing. The extrapolated emissions
estimates are then adjusted further to reflect upsets. For the remaining metals, the facility estimates
maximum emissions based on maximum anticipated one-hour feed rates and an assumption of zero SRE.
Further upward adjustment for these metals is not necessary, since the "zero SRE" assumption already
represents the most conservative estimate. Acute risks associated with these maximum emissions estimates
are determined to be below target levels.

Finally, Facility Z performs a "post-MACT scenario"  chronic risk evaluation. This evaluation is based on
emissions estimates for D/Fs, mercury, semivolatile metals, low-volatile metals, and HCl/Ck, where  the
emissions are determined assuming that Facility Z emits at the allowable MACT standard for these
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July 2001
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pollutants. These emission estimates are combined with the organic PIC emissions measured during the DRE
test, as well as the metals emissions for the non-MACT metals measured during the normal test. Total
chronic risks from these consolidated emissions are determined to be below target levels, with the exception
of mercury.

Final Permitted Emission Rates

As summarized in Table A. 1-2, maximum emission rate limits are established in the RCRA permit for D/Fs,
metals, and HC1/C12 based on the levels needed to achieve target risk levels. The limits are established for the
purpose of periodic verification testing to ensure that emissions remain below those evaluated in the risk
assessment.  If emissions increases occur above the permitted levels, then the permit calls for the risk
assessment to be repeated.  Since none of the non-D/F organics were found to be risk drivers, emission limits
for individual non-D/F organic compounds are not established in the permit

The "post-MACT scenario" risk evaluation showed that the MACT standards for D/Fs, arsenic, beryllium,
cadmium, chromium, lead, and HC1/C12 will be sufficiently protective. Therefore, the RCRA permit includes
"sunset" provisions on the emission limits for these pollutants in the RCRA permit.  In this instance, the
sunset provisions are structured so that the RCRA emission limits will no longer apply once the facility has
documented compliance with MACT, and once the regulatory agency has completed a finding of compliance.
For mercury, the MACT standard will not be sufficiently protective if one assumes that the source
continuously emits at the standard.  Therefore, the risk-based emission limits for mercury will remain in the
RCRA permit. Emission limits for the non-MACT metals (aluminum, antimony, barium, cobalt, copper,
manganese, nickel, selenium, silver, thallium, vanadium, and zinc) will also remain in the RCRA permit.

Final Permit Limits for Control Parameters

Table A. 1-2 provides the final permit limits on relevant control parameters for Facility Z. Total hydrocarbon
levels were negligible during the DRE test condition.  Therefore, the permit writer determines that there is no
need to specify continued total hydrocarbon monitoring as a condition of the RCRA permit.

For arsenic, beryllium, cadmium, chromium, lead, mercury, and nickel, acceptable risks were projected for at
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July 2001
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least one of the risk scenarios evaluated. However, since the projected risks came close to approaching target
risk levels, the permit writer determines that closer monitoring and control for these metals is warranted.
Therefore, quarterly average metals feed rate limits are established in the RCRA permit to ensure that these
metals are not fed at higher rates than those demonstrated. With the exception of mercury, the metals feed
rate limits are established in the RCRA permit based on feed rates demonstrated during the testing. For
mercury, a risk-based feed rate limit is conservatively calculated from the risk-based emissions limit by
assuming zero SRE (i.e., 100% of the mercury fed to the unit is emitted).

For the non-mercury metals, quarterly average feed rate limits are established based on two different test
scenarios. For arsenic, beryllium, cadmium, chromium and lead, the quarterly average feed rate limits are
established based on the SRE test (since the higher feed rates demonstrated during the SRE test were
demonstrated to achieve compliance with the MACT standards, and since the MACT standards were shown
to be sufficiently protective in the risk assessment). The RCRA permit is written with sunset provisions for
the feed rate limits on these five metals. For nickel, quarterly average feed rate limits are established based
on the normal test. The risk-based feed rate limits for nickel will remain in the RCRA permit after MACT.
Since risks from the remaining eleven metals were very far from target levels, and since target risk levels
could not possibly be exceeded based on the wastes burned at Facility Z, the permit writer decides to simply
document the risk assessment feed and emissions assumptions for the remaining metals in the administrative
record instead of imposing specific feed rate limits in the permit.

Short-term metal feed rate limits are not necessary for the RCRA permit, because acute risks were
determined to be negligible (considering the range of inputs for metals at Facility Z). Although the SRE tests
were performed for the purpose of establishing short-term metal feed rate limits for arsenic, beryllium,
cadmium, chromium, and lead, these limits will apply in the future pursuant to MACT and are not a RCRA
concern.

The RCRA permit is written with sunset provisions for all control parameters except for the quarterly
average feed rate limits for mercury and nickel.
 Risk Burn Guidance for
 Hazardous Waste Combustion Facilities
July 2001
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                                    TABLE A.l-2
                   FINAL RCRA PERMIT LIMITS FOR FACILITY Z
K ^ ~ X s
* ^° ~4
f ^
_ Paraipeier
> '""
' % ' **
-- H, », *"*• ^
Value -
• s**r ir - ,.' ',.BasVi. "/' *
..', Vv --' '' , ^ ?'
*"Test_
, Established As:
Summary of Performance Standards and Emission Limits
ORE
Maximum PM Emissions
HCi
Maximum HCI and C12
emissions
Maximum D/F emissions
Maximum emissions
(arsenic, beryllium,
cadmium, chromium,
lead)
Maximum emissions
(aluminum, antimony,
barium, cobalt, copper,
manganese, mercury,
nickel, selenium, silver,
thallium, vanadium, zinc)
99.99% for POHCs
0.08 gr/dscf
Larger of 99%
removal or 4 Ibs/hr
Inhalation risk-
based limits
Multi-pathway
risk-based limit
Multi-pathway
risk-based limits
Multi-pathway
risk-based limits
-N/A
N/A
N/A
N/A
N/A
N/A
N/A
Regulatory Limit
Regulatory Limit
Regulatory Limit
Target levels from risk
assessment
Target level from risk
assessment
Target levels from risk
assessment
Target levels from risk
assessment
Group A Control Parameters - Interlocked with AWFCO
Minimum combustion
temperature
Maximum combustion
gas velocity
Maximum organic liquid
feed rate
Maximum aqueous feed
rate
Maximum fabric filter
inlet temperature
1,600 °F, HRA
cfm, HRA
Ibs/hr, HRA
Ibs/hr, HRA
550 °F, HRA
ORE
SRE1/
DRE
DRE
DRE
SRE
Avg. of the test run
averages
Avg. of the test run
averages l
Avg. of the test run
averages '
Avg. of the test run
averages '
Avg. of the test run
averages
•^
J "
Sunset

Yes
Yes
Yes
Yes
Yes
Yes
No

Yes
Yes
Yes
Yes
Yes
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001
  A.l-10

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                                     TABLE A.l-2

               FINAL RCRA PERMIT LIMITS FOR FACILITY Z (continued)
Parameter
Minimum and maximum
fabric filter pressure
differential
Minimum venturi
scrubber differential
pressure
Minimum venturi liqujd-
to-gas ratio
Minimum venturi
scrubber liquid exit pH
Minimum carbon
injection feed rate
Maximum stack carbon
monoxide concentration
Maximum combustion
chamber pressure
$
*. * *&>***
~ - $
" * \ V
Value
inches water
column, HRA
inches water
column, HRA.
gal/cfm,HRA
pH,HRA
Ibs/hr, HRA
100ppmat7%.
oxygen, dry basis,
HRA
inches water
column, vacuum,
instantaneous limit
, ' 'Basis, ' " *"
": "- , ' '"^ ^t'fi.-* - .i
Test
1 * < ^f
N/A
SRE2
SRE
SRE
ORE/
SRE
N/A
N/A
^ Established As: t ^
- "I'Ssv^C * •»* > * *• „
Manufacturer's
specifications
Avg. of the test run
averages
Avg. of the test run
averages
Avg. of the test run
averages
Avg. of the test run
averages
Limit based on established
guidance
As necessary to maintain
negative pressure
Group B Control Parameters
Restrictions on "more
difficult-to-burnPOHCs"
Maximum chlorine feed
rate
Maximum ash feed rate
Maximum feed rates
(arsenic, beryllium,
cadmium, chromium, and
lead)
Allowable
Appendix VIII
constituents
lbs/hr,HRA2
lbs/hr,HRA3
Ibs/hr, quarterly
average 2
ORE
SRE
SRE
SRE
More difficult-to-burn
constituents than those
which achieved 99.99%
DRE are prohibited
Avg. of the test run
averages
Avg. of the test run
averages 3
Avg. of the test run
averages
'\l >"*
"• T
f !
t- ™ ^
Sunset ,
Yes
Yes
Yes
Yes
Yes
Yes
Yes

Yes
Yes
Yes
Yes
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001
  A.l-11

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                                              TABLE A.l-2
                    FINAL RCRA PERMIT LIMITS FOR FACILITY Z (continued)
* *
s &* *• ^ , g V
i ,"•*-' ./
1 ' > * i
, Parameter
Maximum nickel feed rate
Maximum mercury feed
rate
Minimum scrubber
blowdown
Carbon adsorption
properties
* * * s "^
^ i ^ j*
* A *x~ vS /"•*,, \^
fa ^ % HJ» ** t
j }" V i.gf >f. •* X
'l ~ , .**•
j'Valae 's "
Ibs/hr, quarterly
average
Ibs/hr, quarterly
average4
gpm, HRA
Manufactui'er's
brand
' \- ', ^v^,^;^
" I <» " * - r *' t i
^r«t "
Normal
N/A
SRE
N/A
Established As: "* >
* " '" - ^ "
Avg. of the test run
averages
Feed rate calculated from
the risk-based emission
limit assuming zero SRE4
Avg. of the test run
averages
Same as test
' > r
^ •" rs
Sunset ' ,
No
No
Yes
Yes
Group C Control Parameters
Maximum heat input
Burner/atomizer:
- Maximum viscosity
- Maximum turndown
- Maximum solids
- Minimum atomizing
pressure differential
Minimum venturi
scrubber nozzle
pressure
Minimum carbon carrier
fluid nozzle pressure drop
million Btu/hr
- centipoise
- gpm range
- percent solids
- psig (interlocked
withAWFCO)
psig (interlocked
withAWFCO)
psig (interlocked
withAWFCO)
N/A
N/A
N/A
N/A
Design basis
Manufacturer's
recommendations
Manufacturer's
recommendations
Manufacturer's
recommendations
Yes
Yes
Yes
Yes
Notes:

AWFCO
Avg.
Btu/hr
cfin
D/F
ORE
gal/cfin
gpm
gr/dscf
Automatic waste feed cutoff system         HRA
Average                              Ibs/hr
British thermal units per hour             N/A
Cubic feet per minute                    PM
Dioxin/furan                           ppm
Destruction and removal efficiency         psig
Gallons per cubic feet per minute          POHC
Gallons per minute
Grains per dry standard cubic foot          SRE
Hourly rolling average
Pounds per hour
Not applicable
Particulate matter
Parts per million
Pounds per square inch, gauge
Principle organic hazardous
  constituent
System removal efficiency
 Risk Burn Guidance for
 Hazardous Waste Combustion Facilities
                                                                             July 2001
                                                                               A.l-12

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                                              TABLE A.l-2

                    FINAL RCRA PERMIT LIMITS FOR FACILITY Z (continued)




1       Under MACT, the limit will be based on the average of the maximum hourly rolling averages for each run.

2       Under MACT, the averaging period will be 12 hours.

3       Under MACT, the averaging period will be 12 hours and the limit will be based on the average of the maximum hourly
        rolling averages for each run.

4       Under MACT, the averaging period will be 12 hours and the limit will be based on the maximum theoretical emission
        concentration assuming that all mercury from all feed streams is emitted.
  Risk Burn Guidance for
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July 2001
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                                         APPENDIX A.2
                       RISK BURN CONDITIONS AND PERMIT LIMITS
        FOR A ROTARY KILN INCINERATOR BURNING CONTAINERIZED WASTES
         Note: This illustrative example does not represent the only approach to structuring a trial burn/risk
         burn/MACT performance test. Other regulatory and permitting options exist. Test plans and final permit
         conditions should always be developed on a site-specific basis after close interaction between the regulator
         and facility.
Appendix A.2 describes the risk burn and resulting permit limits for an example rotary kiln incineration
facility (Facility Y). Facility Y burns a variety of waste streams including organic liquids, aqueous wastes,
organic sludges, bulk solids, and containerized wastes in a rotary kiln combustion chamber.  The rotary kiln
is followed by a secondary combustion chamber, where organic liquids and, aqueous wastes are fired. The
downstream air pollution control system consists of a spray dryer and fabric filter.  Facility Y is a
commercial facility, and the waste streams received at the facility can be highly variable. A review of
historical operating data indicates that Facility Y routinely experiences transient operations, with carbon
monoxide spikes that often correlate with charges of containerized wastes to the unit.

Facility Y needs to complete performance testing and a risk burn for a Resource Conservation and Recovery
Act (RCRA) permit renewal. In addition, Facility Y anticipates complying with the hazardous waste
combustor Maximum Achievable Control Technology (MACT) standards in the future. By carefully
structuring the test plan, Facility Y can satisfy the current RCRA permitting needs, as well as generate data
that may be submitted at a later date as "data in lieu of the initial performance test" for MACT (this facility
does not need to physically modify the combustion system to comply with MACT).

Facility Y begins writing the test plan with the following test conditions (summarized in Table A.2-1):

Destruction and Removal Efficiency Test Conditions

Destruction and removal efficiency (DRE) demonstrations will be conducted at minimum primary
combustion chamber (PCC) and secondary combustion chamber (SCC) combustion temperatures of
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July 2001
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1,400 °F and 1,800 °F, respectively. Other control parameters to be demonstrated during the DRE tests
include: 1) maximum combustion gas velocity, as an indicator of minimum gas residence time; 2) maximum
waste feed rate to each feed location; and 3) worst-case operating conditions for air pollution control
parameters (to the extent possible). Continuous carbon monoxide and total hydrocarbon monitoring is also
planned for the DRE tests. Operating parameters to ensure good operation of the waste firing system will be
based on manufacturer's specifications.

For the DRE determination, it is not possible to demonstrate maximum waste feed rates for all feed streams
simultaneously. Therefore, four (4) DRE test conditions are necessary. The four DRE test conditions are
designated as DRE 1, DRE 2, DRE 3, and DRE 4 in Table A.2-1. During each of the test conditions,
maximum feed rates for different individual waste streams will be demonstrated, while maintaining a
relatively constant maximum total thermal input to the PCC and total system (the unit is designed for 40
million (MM) Btu/hr thermal input to the PCC and 80 MM Btu/hr for the total system). Minimum
combustion temperatures and maximum combustion gas velocity will also be maintained throughout the four
test conditions. The maximum individual waste feed rate to be demonstrated during each condition follows:
              DRE 1 - Maximum organic liquid feed rate to the PCC
                    - Maximum bulk solids feed rate to the PCC
                    - Maximum container feed rate (mass basis) to the PCC
                    - Maximum organic liquid feed rate to the SCC
              DRE 2 - Maximum container feed rate (thermal input basis) to the PCC
              DRE 3 - Maximum aqueous feed rate to the PCC
                    - Maximum organic sludge feed rate to the PCC
              DRE 4 - Maximum aqueous feed rate to the SCC
The demonstration for containerized feeds encompasses two test conditions (DRE 1 and DRE 2). The
containerized wastes at Facility Y are fed in 55-gallon drums weighing 100 to 200 pounds each, and can be
highly variable. Containerized feeds can range from soil remediation waste (with high moisture and no
heating content) to high-heating-value, highly volatile organics sorbed onto a solid matrix.

In the DRE 1 test condition, Facility Y will demonstrate maximum containerized feed rate, as well as
  Risk Burn Guidance for
  Hazardous Waste Combustion Facilities
July 2001
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maximum total solids feed rate (for both the containerized and bulk feeds combined). Both feeds will consist
of contaminated, moist soils with no heating value (this type of material is representative of the bulk solids
which are normally burned, and is representative of materials which are sometimes burned in containers).
These conditions represent a challenging DRE test because of the heavy loading of solid material forming a
heat sink in the rotary kiln. The maximum containerized feed rate for the DRE 1 condition will be 9,000
Ibs/hr, and the maximum container size will be 200 Ib/hr, resulting in a feeding frequency of 45 drums per
hour.

A separate test condition, DRE 2, is necessary to represent containerized feeds consisting of high-heating-
value, highly volatile organics. For DRE 2, drums with a total heat content of 2 MM Btu each will be
prepared by adding a glass jar of highly volatile, high-heating-value liquid organics to a wood chip/plastic
pellet mixture. The drums will weigh 125 pounds each, and will be fed at the maximum rate allowed by the
thermal design capacity of the kiln (40 MM Btu/hr). This results in a feeding frequency of 20 drums per
hour. The DRE 2 test will be performed at a higher PCC temperature than the other DRE tests, because the
higher kiln temperature ensures a maximum volatilization rate. The higher PCC temperature, in combination
with the minimum SCC temperature, still represents a worst-case condition for organic destruction for
containerized feeds. In addition, combustion gas velocity for the DRE 2 condition will be slightly lower than
the other DRE conditions, since excess air to the PCC will be minimized in an attempt to minimize excess
oxygen at the location where the containers are fed.

Several batch/containerized feed parameters will not be demonstrated during the testing. Maximum batch
size (200 pounds) will be demonstrated during the DRE 1 condition, and maximum batch charge heat content
(which is the more important indicator of a situation that could overwhelm the combustion system) will be
demonstrated in the DRE 2 condition.  However, maximum container feeding frequency will not be
demonstrated in either test, because Facility Y cannot simultaneously demonstrate maximum size (or
maximum batch charge heat content) and maximum feeding frequency. Larger batches fed less frequently
are considered to be worse than smaller batches fed more frequently, within the total targeted feed rate limits
for the containerized feeds of 9,000 Ibs/hr and 40 MM Btu/hr for the DRE 1 and DRE 2 tests, respectively.
In addition, demonstration of maximum kiln rotation speed is not necessary, since the method of introducing
volatile liquids in glass jars will ensure a maximum rate of volatilization and puff intensity.
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During the DRE 1 and DRE 4 test conditions, maximum total ash feed rate and maximum atomized ash feed
rate will be demonstrated. Therefore, stack sampling for paniculate matter will be performed during these
test conditions.

System Removal Efficiency Test Condition

In anticipation of future MACT compliance, Facility Y adds a test condition to demonstrate system removal
efficiencies (SREs) for semivolatile and low-volatile metals (arsenic, beryllium, cadmium, chromium, and
lead). Stack determinations for hydrogen chloride (HC1) and chlorine (Clj) are also planned for the SRE test,
since chlorine will be maximized during this test and worst-case operating conditions for the spray dryer will
be demonstrated.

Maximum semivolatile and low-volatile metal feed rates will be achieved by spiking one metal from each of
the two volatility groups to the SCC organic liquid feed. Facility Y will base their total metal feed rate limits
only on metals in the SCC feed stream, so that separate feed rate limits on total and pumpable feed streams
will not be needed (metals fed as liquids to the SCC constitute a worst-case test).

The SRE demonstration will be conducted at a maximum SCC combustion temperature of 2,200 °F to
achieve a maximum inlet fabric filter inlet temperature of 400 ° F. Other control parameters to be
demonstrated during the SRE test condition include: 1) maximum combustion gas velocity; 2) maximum
chlorine feed rate; and 4) worst-case operating conditions for air pollution control parameters (to the extent
possible).

The permit writer and Facility Y discuss whether two SRE test conditions should be performed to resolve
conflicting parameters. Demonstration of the maximum combustion gas velocity control parameter conflicts
with demonstration of minimum pressure differential for the fabric filter.  (In fact, this conflict exists for all
of the DRE test conditions as well, including the DRE 1 and DRE 4 conditions where compliance with the
particulate matter standard will be demonstrated.)  Facility Y wishes to avoid duplicating multiple test
conditions, since the test program is already quite extensive, and observes that the MACT rule allows  limits
for minimum (and maximum) fabric filter pressure differential to be established based on manufacturer's
specifications.  The permit writer agrees with this approach in lieu of expanding the test program further.
  Risk Burn Guidance for
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July 2001
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For mercury, Facility Y wishes to avoid spiking and will not demonstrate a maximum mercury feed rate
during the SRE test. Facility Y plans to conservatively assume that 100% of the mercury fed to the unit is
emitted.

Risk Burn Determinations

To complete a site-specific risk assessment, Facility Y recognizes that stack emissions determinations are
needed for: dioxins/furans (D/Fs); organics other than D/Fs; the eighteen toxic metals listed in Section 2.3;
particle-size distribution; and HC1/C12  Facility Y incorporates these determinations into the test plan as
follows:
        D/Fs
        The primary operating parameters related to D/F formation for Facility Y are fabric filter inlet
        temperature and combustion parameters, including: 1) minimum PCC and SCC combustion
        temperatures; 2) maximum combustion gas velocity; 3) maximum waste feed rate for each location;
        4) limitations on waste feed composition and batch/containerized feeds; and 5) maximum flue gas
        carbon monoxide and/or total hydrocarbon concentrations.

        D/Fs can be expected to be maximized at the maximum fabric filter inlet temperature of 400 °F,
        which will be demonstrated during the SRE test. However, the SRE test is not designed to be a
        challenging test with respect to combustion of organics. Facility Y operates under challenging
        combustion scenarios which could promote D/F precursor formation, and which should be
        preferentially targeted for D/F testing, including: 1) transient conditions; 2) operation with
        containerized feeds; and 3) high carbon monoxide (greater than 100 ppm) situations.  These
        conditions are already represented by the DRE test scenarios. Therefore, Facility Y decides to adjust
        the spray dryer operation to demonstrate the maximum fabric filter inlet temperature of 400 °F
        during the DRE tests. D/F stack emissions determinations are added to those tests.

        Adjusting the DRE test conditions to demonstrate a maximum fabric filter inlet temperature causes
        another potential conflicting parameter situation with respect to operation of the spray dryer.  To
 Risk Burn Guidance for
 Hazardous Waste Combustion Facilities
July 2001
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       achieve the maximum 400 °F fabric filter inlet temperature at the lower SCC combustion
       temperatures planned for the DRE tests, the lime slurry feed rate will have to be lowered from the
       feed rate planned for the SRE test (which is supposed to represent the minimum). The permit writer
       and facility agree that this is acceptable, as long as the permit limit for minimum spray dryer slurry
       feed rate is based on the higher rate demonstrated during the SRE test.

       Non-D/F Organics

       The feed and operating conditions that influence organic products of incomplete combustion (PICs)
       are already represented during the DRE test conditions. Therefore, the facility adds PIC and total
       organic stack emissions determinations to the DRE test conditions.  In addition, Facility Y arranges
       for the sampling contractor to provide a temporary total hydrocarbon continuous emissions monitor
       during the DRE/PIC testing.
       Metals
       The SRE test already involves stack determinations for the five toxic metals identified in the MACT
       rule, and Facility Y has performed a preliminary risk assessment which indicates that the MACT
       emission standards for semivolatile and low-volatile metals should be sufficiently protective.
       Therefore, Facility Y simply expands the planned analytical determinations for the SRE test to
       encompass eighteen metals. The non-MACT metals will be fed at normal feed rates, since Facility Y
       is capable of defining and maintaining normal conditions for these metals.

       Particle-Size Distribution

       At Facility Y, the fabric filter will be the primary determinant of particle-size distribution.
       Therefore, significant variation in particle-size distribution between the different test conditions is not
       expected. Facility Y suggests that the particle-size distribution determination be performed during
       the SRE test condition. However, the permit writer is concerned that a particle-size determination
       during the SRE test could be biased due to the absence of solid feeds, as well as the high
       temperatures and metals spiking. Therefore, the parties agree that the particle-size determination will
Risk Burn Guidancefor
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July 2001
   A.2-6

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      be performed at the conclusion of the risk burn after the facility returns to normal operation.


      HCI and Cl,


      Determinations for HCI and C^ are already included in the SRE test, and this data can also be used

      for the risk assessment.
Risk Burn Guidance/or
Hazardous Waste Combustion Facilities
July2001
   A.2-7

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                                     TABLE A.2-1

                           FACILITY Y TEST CONDITIONS
; •- • - :.-..., . ;
PCC combustion
temperature
SCC combustion
temperature
Fabric filter inlet
temperature
PCC organic liquid feed rate
PCC aqueous liquid feed rate
PCC organic sludge feed rate
PCC bulk solids feed rate
PCC container feed rate
- total Ib/lir
- Ibs/drum
- drums/hr
-MM Btu/drum
-MMBtu/hr
SCC organic liquid feed rate
SCC aqueous liquid feed rate
Thermal input, MM Btu/hr
-PCC
-SCC
-Total
Combustion gas velocity
Ash feed rate
Chlorine feed rate
. ! v* ,-fisTjcoNbifioprs , -.% ,: " ^
._ . AND ESOSSI0NS DETERMINATIONS
. . , .POHCs^PICs^D^ToC, , , >-"
~ Tptal Hydrocarbons, Carbon Monoxide
r- -~ 4 , ,. ft '•**" <• < .> " p! ^ " !"5
- "~1- ^'\,^t~ *>
PM(pPlrlar^d4ordy)
j,1" i * -^ *"*( *,, f ^ ^ ** r -f
DRE1
1,400 °F
1,800 °F
400 °F
Maximum
Minimal
Normal
Maximum
Maximum
(mass input)
9,000
200
45
0
0
Maximum
Minimal
42
41
83
Maximum**
Maximum
total ash
Above
average
DRE2 -
1,800 °F
1,800 °F
400 °F
Minimal
Minimal
Minimal
Minimal
Maximum
(thermal input)
2,500
125
20
2
40
High
Minimal
45
33
78
High **
N/A
Above average
DRE3
1,400 °F
1,800 °F
. 400 °F
Minimal
Maximum
Maximum
Minimal
Minimal
High
Minimal
45
35
80
Maximum**
N/A
Above
average
DRE4
i V
1,400 °F
1,800 °F
400 °F
High
Minimal
Normal
Minimal
Minimal
High
Maximum
42
40
82
Maximum**
Maximum
atomized ash
Above
average
Metals,
HCI/C12/
Carbon
Monoxide
SRE
1,800 °F
2,200 °F *
400 °F *
Maximum
N/A
N/A
N/A
N/A
Maximum
N/A
N/A
Maximum**
N/A
Maximum
Risk Burn Guidance for
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July 2001
   A.2-8

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                                               TABLE A.2-1

                             FACILITY Y TEST CONDITIONS (continued)
rf fc ""' «S* ^ g. •?, *~ ^ yt ^ ^ '—
: ;>P^"'lr;
>, *"* K js ** * ^ „ v
1 ^J " - ". - «•>,'
- » ,>- . ,;„<&
v- ^ :\Vf'<-i -;*>3jr!">
i^A~->>t -* ,*•
<- V i <» * V. , '
* -\ > * * ^
Spiked metal feed rates
Other metal feed rates
Lime slurry feed rate
Lime slurry properties
(minimum percent lime
and lime absorbent
properties)
Fabric filter differential
pressure
- * s' A <::^~ ^ X . ^?^OTO)|fcrQNS _- ' v ' , 5'
".t ;f , AND EW5ISSIONS DETEgiaiNATtoNS
1 v',"t*'1. Tl^fQHCs&iCs^/Fs^O^ *-, ^«^'
? . -^\'tot^iTHydrocai:bons.,CafbonMono?cye - " ,
B 1-jJ- ^ K, >" r i ? / J ^^ -" •" *t*J_z i f ~ ..*
" ' , i I- '^ " * ""* "VnC -V^ i* V ' '
""^-f^ P^(DRfeTarid4^Myf"ii *> :
.- ^^ i. * '— ^^^ ~ rf > " 6-^- ' ^^J^i ,*/-'
* " "&_ ""•* „ *" "^ '
-,0BE1.\
•ii.il -• Nk" ,
N/A
N/A
Minimum
Minimum
Within
manufacturer
specifications
**
;'/i>RE2' •
•> » ' r "•»->!,
N/A
N/A
Minimum
Minimum
Within
manufacturer
specifications
**
* ^?,v .
DRE3
-f" ~ -v, ^ W--1-
N/A
N/A
Minimum
Minimum
Within
manufacturer
specifications
**
,JttRE4_ -
N/A
N/A
Minimum
Minimum
Within
manufacturer
specifications
**
, ^ ''-v.-jrf
Metals, ~
HC1/C12, ^
'Carbon ., ^
Monoxide ,
SRE
Maximum
Normal
As low as
possible *
Minimum
Within
manufacturer
specifications
**
Notes:

*       =
**      =

D/Fs
ORE
hr
Ib
MMBtu =
N/A
PCC
conflicting parameters related to spray dryer operation
conflicting parameters related to fabric filter operation

Dioxins/furans                       PICs
Destruction'and removal efficiency      PM      =
Hour                               POHCs   =
Pounds                             SCC
Million British thermal units           SRE     =
Not applicable                       TOE
Primary combustion chamber
Products of incomplete combustion
Particulate matter
Principal organic hazardous constituents
Secondary combustion chamber
System removal efficiency
Total organic emissions
 Risk Burn Guidance for
 Hazardous Waste Combustion Facilities
                                                                                  July 2001
                                                                                     A.2-9

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Site-Specific Risk Assessment

Facility Y performs the tests according to the approved test plan. Emissions data are consolidated from the
test conditions for evaluation in four (4) separate multi-pathway human health and ecological site-specific
risk assessment scenarios corresponding to each of the DRE 1, DRE 2, ORE 3 and ORE 4 test conditions as
follows:

       •      D/F emissions and organic PIC emissions from each DRE test condition are evaluated,
              together with...
       •      Metals emissions (18 metals) from the SRE test condition, and —
       •      HC1 and Clj emissions from the SRE test condition.

Total chronic risks for all four risk scenarios are determined to be below target levels.
An acute risk evaluation is also performed to assess inhalation risks associated with maximum potential one-
hour emissions.  Maximum one-hour emissions for the acute evaluation are estimated for D/Fs , other
organics, and HC1/C12 based on the test data listed above, with an upward adjustment to reflect upsets.
However, for metals, the test data are not representative of maximum potential one-hour emissions. For the
metals represented by the spiked metals (arsenic, beryllium, cadmium, chromium, and lead), the facility uses
an approved extrapolation procedure to estimate maximum one-hour emission rates based on maximum
anticipated one-hour feed rates and the SREs demonstrated during the testing. The extrapolated emissions
estimates are then adjusted further to reflect upsets. For the remaining metals, the facility estimates
maximum emissions based on maximum anticipated one-hour feed rates and an assumption of zero SRE.
Further upward adjustment for these metals is not necessary, since the "zero SRE" assumption already
represents the most conservative estimate. Acute risks associated with these maximum emissions estimates
are determined to be below target levels.

Finally, Facility Y performs a "post-MACT scenario" chronic risk evaluation. This evaluation is based on
emissions estimates for D/Fs, mercury, semivolatile metals, low-volatile metals, and HCl/C^, where
emissions are determined assuming that Facility Y emits at the allowable MACT standard for these
pollutants. These emission estimates are combined with the organic PIC emissions measured during the DRE
  Risk Burn Guidance for
  Hazardous Waste Combustion Facilities
July 2001
  A.2-10

-------
tests, as well as the metals emissions for the non-MACT metals measured during the SRE test.  Total chronic
risks from these consolidated emissions are determined to be below target levels.

Final Permitted Emission Rates

As summarized in Table A.2-2, maximum emission rate limits are established in the RCRA permit for D/Fs,
metals, and HCl/Ct, based on the levels needed to achieve target risk levels.  The limits are established for the
purpose of periodic verification testing to ensure that emissions remain below those evaluated in the risk
assessment. If emissions increases occur above the permitted levels, then the permit calls for the risk
assessment to be repeated. Since none of the non-D/F organics were found to be risk drivers, emission limits
for individual non-D/F organic compounds are not established in the permit.

The "post-MACT scenario" risk evaluation showed that the MACT standards for D/Fs, metals, and HC1/C1,
will be sufficiently protective. Therefore, the RCRA permit includes "sunset" provisions on the emission
limits for these pollutants in the RCRA permit. In this instance, the sunset provisions are structured so that
the RCRA emission limits will no longer apply once the facility has documented compliance with MACT,
and once the regulatory agency has completed a finding of compliance. Emission limits for the non-MACT
metals (aluminum, antimony, barium, cobalt, copper, manganese, nickel, selenium, silver, thallium,
vanadium, and zinc) will remain in the RCRA permit

Final Permit Limits for Control Parameters

Table A.2-2 provides the final permit limits on relevant control parameters for Facility Y.  During the DRE
test conditions, carbon monoxide levels were greater than 100 ppm and total hydrocarbon levels were less
than 10 ppm on an hourly rolling average basis. The permit writer establishes the RCRA permit limit for
carbon monoxide as the average of the test run averages (i.e., a value greater than 100 ppm).  Since carbon
monoxide and total hydrocarbon spikes appeared to track pretty closely, the permit writer determines that
there is no need to specify continued total hydrocarbon monitoring as a RCRA permit condition prior to
MACT. However, after MACT, the facility will comply with a total hydrocarbon limit of 10 ppm instead of
with the limit on carbon monoxide.
 Risk Burn Guidance for
 Hazardous Waste Combustion Facilities
July 2001
  A.2-11

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With the exception of mercury, quarterly average metals feed rate limits are established in the RCRA permit
based on the feed rates demonstrated during the SRE test.  For mercury, a risk-based feed rate limit is
conservatively calculated from the risk-based emission limit by assuming zero SRE (i.e.,  100% of the
mercury fed to the unit is emitted).

Short-term metal feed rate limits are not necessary for the RCRA permit, because acute risks were
determined to be negligible (considering the range of inputs for metals at Facility Y). Although the SRE tests
were performed for the purpose of establishing short-term metal feed rate limits for arsenic, beryllium,
cadmium, chromium, and lead, these limits will apply in the future pursuant to MACT and are not a RCRA
concern.

The RCRA permit is written with sunset provisions for all control parameters except for the quarterly
average feed rate limits on the non-MACT metals, and except for limits on containerized feeds which are not
required to be established under the MACT rule.  Although MACT will limit total mass feed rate for
containers (as well as total hydrocarbons), the historical operating data for Facility Y suggests that
preventive controls are needed to preclude overcharging of highly volatile, high-Btu containers. Therefore,
the limits on "maximum Btu/drum" and "maximum total containerized thermal input" established based on
the DRB 2 test will be retained in the RCRA permit. The RCRA permit may be modified to delete these
provisions if similar limitations are placed in the Title V permit for this facility in the future.
 Risk Burn Guidance for
 Hazardous Waste Combustion Facilities
July 2001
  A.2-12

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                                     TABLE A.2-2

                    FINAL RCRA PERMIT LIMITS FOR FACILITY Y
' " -. V
, . * ^^ $,'» 4
J "-"• * * '
' "ParariifiW «
V -, <&, J, •> ft i
11 j> »
^ * r
-^VV ; '•?
t ,*i Talue f-v '
, l~ " -=,Basis-^* ', -
',>"", ^ ^ I"-", 4 , , v »
* r tB !• H 5? T
Test '
- Established As:
Summary of Performance Standards and Emission Limits
DRE
Maximum PM Emissions
HC1
Maximum HC1 and C12
emissions
Maximum D/F emissions
Maximum emissions
(arsenic, beryllium,
cadmium, chromium, lead
and mercury)
Maximum emissions
(aluminum, antimony,
barium, cobalt, copper,
manganese, nickel,
selenium, silver, thallium,
vanadium, zinc)
99.99% for POHCs
0.08 gr/dscf
Larger of 99%
removal or 4 Ibs/hr
Inhalation risk-
based limits
Multi-pathway
risk-based limit
Multi-pathway
risk-based limits
Multi-pathway
risk-based limits
N/A
N/A
N/A
N/A
N/A
N/A
N/A
Regulatory Limit
Regulatory Limit
Regulatory Limit
Target levels from risk
assessment
Target level from risk
assessment
Target levels from risk
assessment
Target levels from risk
assessment
Group A Control Parameters - Interlocked with AWFCO
Minimum PCC
combustion temperature
Minimum SCC
combustion temperature
Maximum combustion
gas velocity
Maximum PCC organic
liquid feed rate
Maximum PCC aqueous
feed rate
1,400 °F, HRA
1,800 °F, HRA
cfm,HRA
lbs/hr,HRA
Ibs/hr, HRA
DRE
DRE
DRE/
SRE
DRE 1
DRE 3
Avg. of the test run
averages
Avg. of the test run
averages
Avg. of the test run
averages '
Avg. of the test run
averages '
Avg. of the test run
averages '
•v
i •• r
Sunset

Yes
Yes
Yes
Yes
Yes
Yes
No

Yes
Yes
Yes
Yes
Yes
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 200.1
  A.2-13

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                                     TABLE A.2-2

               FINAL RCRA PERMIT LIMITS FOR FACILITY Y (continued)
Parameter
Maximum PCC organic
sludge feed rate
Maximum PCC bulk
solids feed rate
Maximum PCC container
feed rate
Maximum PCC container
heat content
Maximum total
containerized thermal
input
Maximum SCC organic
liquid feed rate
Maximum SCC aqueous
liquid feed rate
Maximum fabric filter
inlet temperature
Minimum and maximum
fabric filter pressure
differential
Minimum spray dryer
slurry feed rate
Maximum stack carbon
monoxide concentration
Maximum combustion
chamber pressure
SA *
ti
* falue k"
Ibs/hr, HRA
Ibs/hr, HRA
9,000 Ibs/hr, HRA
2 MM Btu/drum
40MMBtu/hr
Ibs/hr, HRA
Ibs/hr, HRA
400 °F, HRA
inches water
column, HRA
gpm,HRA
Site-specific limit
greater than 100
ppm at 7% oxygen,
dry basis, HRA
inches water
column, vacuum,
instantaneous limit
I - f ' Basis _>' '- -
•t T „- < * ^ "i ^
ft 5, *"•! av *%» s *
.Test
ORE 3
DRE1
DRE1
ORE 2
ORE 2
DRE1
ORE 4
DRE/
SRE
N/A
SRE
DRE
N/A
Established As:
,- £.^'"1"
Avg. of the test run
averages '
Avg. of the test run
averages '
Avg. of the test run
averages '
As demonstrated during
DRE 2
As demonstrated during
DRE 2
Avg. of the test run
averages '
Avg. of the test run
averages '
Avg. of the test run
averages
Manufacturer's
specifications
Avg. of the test run
averages
Avg. of the test run
averages 3
As necessary to maintain
negative pressure
* /
i
* r •* ~
Sunset
Yes
Yes
Yes
No/Yes 2
No/Yes 2
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001
  A.2-14

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                                      TABLE A.2-2
                FINAL RCRA PERMIT LIMITS FOR FACILITY Y (continued)
•;; v^W^^^iM
' \ ^r ' \* \ ^ Vi?*^ ^£-" "ift^*^
' V?* k' **•„"*" '% A f „_ t5 -ejLw'% s"^ tBS^C W^*
1 J ''". «••» "" Tr ri'.^TsK? ^.iVi »JS* *
•- •• ,. ' J?$rameter;;, " ^M-
vj .i)?*, 4\ Xii ,",."•]'• -i-;4,;
f "I**?''" y ^,- "• * '$Z'$*t {"- '-' ^
'-f?,^1* ? "*,* ^><5/^"°£^"'!.v° ; „'-
- f.sftKfy ",£ ,'^>5f»'-*~'',:
%.ir'? f^.r-^t^,-- ;•.
V-'^-'K-^jS-^^v-T'-'f'
f :-•:---'." ^mlue- A-;( v
g./.':^,-1 •.'.•'•#!* "-!'"^:^;%:f
'4"*" .-v -»'',;-" ' ^ --- ' "i.1",'-,". JfeS"', •'^VT'"
"Tt • - <'! -•>»'< - V* , --' -U-*' rv.--,t -- i
'•*,' h , ,'
M?v'
v'4, " Established Asf'lCv "^""
'/'$- "M?'Ct.^^P:
Group B Control Parameters
Limits on most difficult-
to-burnPOHCs
Maximum chlorine feed
rate
Maximum ash feed rate
-total
- atomized
Maximum feed rates
(arsenic, beryllium,
cadmium, chromium, and
lead)
Maximum mercury feed
rate
Maximum feed rates
(aluminum, antimony,
barium, cobalt, copper,
manganese, nickel,
selenium, silver, thallium,
vanadium, and zinc)
Lime slurry properties
(minimum percent lime
and lime absorbent
properties)
Allowable
Appendix VIII
constituents
lbs/hr,HRA4
Ibs/hr, HRA s
Ibs/hr, quarterly
average 4
Ibs/hr, quarterly
average6
Ibs/hr, quarterly
average
percent
ORE
SRE
DRE1
DRE4
SRE
N/A
SRE
SRE
Based on POHCs which
achieved
99.99% ORE
Avg. of the test run
averages
Avg. of the test run
averages 5
Avg. of the test run
averages
Feed rate calculated from
the risk-based emission
limit assuming zero SRE6
Avg. of the test run
averages
Avg. of the test run
averages
VlT'-V'"''?' '•"*•-
:--4:%v
i",' k"," •', !f- v'"1,"^
5^Sunset K

Yes
Yes
Yes
Yes
Yes
No
Yes
Group C Control Parameters
Maximum total heat input
80MMBtu/hr
N/A
Design basis
Yes
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001
  A.2-15

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                                                TABLE A.2-2

                     FINAL RCRA PERMIT LIMITS FOR FACILITY Y (continued)
*,"" ' . F*
Parameter >
Burner/atomizer:
- Maximum viscosity
- Maximum turndown
- Maximum solids
- Minimum atomizing
pressure differential
Minimum spray dryer
nozzle pressure
> 4-» Vf
' -* J1
Value
- centipoise
- gpm range
- percent solids
- psig (interlocked
with AWFCO)
psig, HRA
(interlocked with
AWFCO)
»; Basis f '> VT
' *' "* "*-> "*' lr^ '
Test
N/A
N/A
Established As:/*,
Manufacturer's
recommendations
Manufacturer's
recommendations
r >.
i Sunset
Yes
Yes
Notes:

AWFCO
Avg.
Btu/hr
cfin
D/F
ORE
gal/cfm
gpm
gr/dscf
HRA
Ibs/hr
Automatic waste feed cutoff system         MM Btu
Average                                N/A
British thermal units per hour              PCC
Cubic feet per minute                     PM
Dioxin/furan                            ppm
Destruction and removal efficiency          psig
Gallons per cubic feet per minute           POHC
Gallons per minute
Grains per dry standard cubic foot          SCC
Hourly rolling average                    SRE
Pounds per hour
Million British thermal units
Not applicable
Primary combustion chamber
Particulate matter
Parts per million
Pounds per square inch, gauge
Principle organic hazardous
  constituent
Secondary combustion chamber
System removal efficiency
1       Under MACT, the limit will be based on the average of the maximum hourly rolling averages for each run.

2       For some systems, these parameters may be critical to passing the DRE performance standard under MACT and would
        therefore be incorporated into the Title V permit.  If these limitations are placed in the Title V permit, then the
        provisions may be sunset or deleted from the RCRA permit.

3       Under MACT, total hydrocarbon monitoring to demonstrate compliance with a 10 ppmv limit will be performed instead
        of carbon monoxide monitoring.

4       Under MACT, the averaging period will be 12 hours.

5       Under MACT, the averaging period will be 12 hours and the limit will be based on the average of the maximum hourly
        rolling averages for each run.

6       Under MACT, the averaging period will be 12 hours and the limit will be based on the maximum theoretical emission
        concentration assuming that all mercury from all feed streams is emitted.
 Risk Bwn Guidance for
 Hazardous Waste Combustion Facilities
                                                                                July 2001
                                                                                   A.2-16

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                                     APPENDIX B

                              SAMPLING AND ANALYSIS

                                       (139 pages)
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001

-------
                                  CONTENTS
                                                                           Page
 ACRONYM LIST	vi

 B.I OVERVIEW OF SAMPLING AND ANALYSIS PROCEDURES	B-l
       B.I.I   EMISSIONS TESTING OBJECTIVES	B-2
       B.I.2  GENERATION OF USABLE DATA FOR RISK ASSESSMENTS.	B-5
             B.I.2.1 Detection Limits, Quantisation Limits, and the Range of Linearity	 B-8
             B. 1.2.2 Site-Specific Data Quality Objectives for Detection and
                  Quantitation Limits  	  B-10
             B.1.2.3 Use in the Risk Assessment of Data Reported as Non-Detect	B-15
             B.l.2.4 Treatment of Blanks for Risk Assessment	B-19
             B.I.2.5 General Description of Emissions Calculations	B-23
       B.1.3  METHOD SUMMARY	B-26
       B.1.4  QUALITY ASSURANCE/QUALITY CONTROL	B-32

 B.2 VOLATILE ORGANIC COMPOUNDS (VOCS)	B-34
       B.2.1  VOLATILE TARGET ANALYTE LISTS AND TENTATIVELY
             IDENTIFIED COMPOUNDS	B-37
       B.2.2  SIMPLE HYDROCARBONS	B-46

 B.3  SEMI VOLATILE AND CONDENSIBLE COMPOUNDS	B-48

 B.4 OTHER ORGANIC COMPOUNDS	B-62
       B.4.1   CHLOROBENZENES/CHLOROPHENOLS (CBS/CPS)	B-62
       B.4.2  POLYCYCLIC AROMATIC HYDROCARBONS (PAHS)	B-62

 B.5 POLYCHLORINATEDBIPHENYLS	,	B-67

 B.6 POLYCHLORINATEDDIBENZODIOXINS AND DIBENZOFURANS	B-73

 B.7 TOTAL ORGANIC EMISSIONS	B-78
       B.7.1   PREPARATION OF XAD-2*	B-87
             B.7.1.1 Quality Control Procedures for Cleaned XAD-2®  . ..:	B-89

 B.8 COMBINED MEASUREMENT TECHNIQUES	B-90
       B.8.1   EFFECT ON METHOD DETECTION LIMITS	B-91
       B.8.2  EFFECT ON SAMPLE PREPARATION PROCEDURES	B-91
       B.8.3   EFFECT ON THE SELECTION OF STANDARDS	B-92
       B.8.4  EXAMPLE OF A COMBINED MULTIPLE POLLUTANT
             SAMPLING/ANALYTICAL SCHEME	B-93
       B.8.5  USE OF TWO METHOD 0010 SAMPLING TRAINS	B-94
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001

-------
                                   CONTENTS
Section
     Page
       B.8.6  PAH ANALYSIS	B-95
       B.8.7  CLEANUP PROCEDURES	B-96
       B.8.8  MULTIPLE ANALYSES OF SINGLE EXTRACTS	B-96
       B .8.9  TOE DETERMINATION AND COMBINED MEASUREMENT
             TECHNIQUES		B-96

 B.9  ALDEHYDES AND KETONES	B-99

 B.10 FACILITY-SPECIFIC COMPOUNDS	B-101

 B.ll TENTATIVELY IDENTIFIED COMPOUNDS	B-105

 B.I2 TOTAL HYDROCARBON AND CARBON MONOXIDE CONTINUOUS EMISSIONS
       MONITORS (CEMS)	B-108

 B.13 METALS	B-110
       B.13.1  MERCURY	B-l 12
       B.13.2  CHROMIUM	;	B-117
       B.13.3  NICKEL	B-118

 B.14 PARTICLE-SIZE DISTRIBUTION	B-120

 B.15 HYDROGEN CHLORIDE AND CHLORINE	 B-125

 B.16 PROCESS SAMPLES	B-129

 REFERENCES	B-131


 Attachments

 1.     Method 0040 Clarifications
 2.     Information Available from Methods 98. Status of Stationary Source Methods for Air Toxics
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001

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                                 TABLES

 Table                                                               Page

 TABLE B. 1-1   REQUIREMENTS FOR CONFIDENT IDENTIFICATION AND
             QUANTITATION	  B-6
 TABLE B.l-2   ORGANIC COMPOUNDS THAT COULD BE IMPORTANT
             CONTRIBUTORS TO INDIRECT RISK	B-12
 TABLE B.l-3   COMMON LABORATORY CONTAMINANTS, CONCENTRATION
             REQUIREMENTS, AND RISK ASSESSMENT IMPLICATIONS	B-21
 TABLE B.I-4   RISK-BASED STACK EMISSION DETERMINATIONS	B-27

 TABLE B.2-1   VOLATILE ORGANIC COMPOUND TARGET LIST DERIVED FROM
             METHOD 8260B	B-38
 TABLE B.2-2   VOCS FOR WHICH FIELD METHOD EVALUATION DATA ARE
             AVAILABLE	B-40
 TABLE B.2-3   CANDIDATE ANALYTES FOR METHOD 0040	B-43
 TABLE B.2-4   CLEAN AIR ACT ANALYTES DEMONSTRATED TO BE
             INAPPROPRIATE FOR VOST IN LABORATORY TESTING	B-44
 TABLE B.2-5   POLAR WATER-SOLUBLE ANALYTES FOR WHICH DRAFT
             METHODS ARE AVAILABLE	B-46

 TABLE B.3-1   SEMIVOLATILE ORGANIC COMPOUND TARGET LIST -
             METHOD8270CANALYTES.	B-51
 TABLE B.3-2   FIELD METHOD EVALUATION DATA FOR SELECTED
             HALOGENATED SEMIVOLATILE ORGANIC COMPOUNDS	B-56
 TABLE B.3-3   FIELD METHOD EVALUATION DATA FOR SELECTED
             NON-HALOGENATED SEMI VOLATILE ORGANIC COMPOUNDS	B-58

 TABLE B.4-1   CHLOROBENZENES AND CHLOROPHENOLS	B-63
 TABLE B.4-2   TARGET ANALYTES FOR CARB METHOD 429	B-65

 TABLEB.5-1   POLYCHLORINATED BIPHENYLS	B-69

 TABLEB.6-1   2,3,7,8-SUBSTITUTED D/Fs	B-73
 TABLE B.6-2   COMPOUNDS THAT CAN BE DETERMINED BY METHOD 8290	 B-76

 TABLE B.7-1   GUIDELINES FOR CLEANLINESS OF XAD-2 RESIN	B-89

 TABLEB.10-1  ORGANOCHLORJNE PESTICIDES-METHOD 8081A ANALYTES	B-102
 TABLE B. 10-2  CHLORINATED HERBICIDES - METHOD 8151A ANALYTES	B-104

 TABLE B.13-1  TARGET LIST FOR METALS MEASUREMENT METHODS.	B-l 1.1
 TABLE B.13-2  COMPARISON OF IMPINGER CONTENTS FOR MERCURY
             SAMPLING TRAINS	B-114
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001

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                                   FIGURES
Figure
    Page
FIGURE B.l-1. RELATIONSHIP BETWEEN INSTRUMENT RESPONSE AND
             DETECTION LIMITS	B-9
FIGURE B.l-2. IMPACT OF DETECTION LIMIT AND CONCENTRATION OF
             CONCERN ON DATA PLANNING	  B-13
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001

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                                       ACRONYM LIST
 Hg            Microgram
 um           Micron
 ug/m3         Microgram per cubic meter
 ug/mL        Microgram per milliliter
 AED          Atomic emission detection
 A/K          Aldehyde/ketone
 AMS          Alkaline mercury speciation
 BaP          Benzo(a)pyrene
 BIF          Boiler and industrial furnace
 BP            Boiling point
 CARB        California Air Resources Board
 CAS          Chemical Abstract Services
 CB            Chlorobenzene
 CEM          Continuous emissions monitor
 CFR          Code of Federal Regulations
 C12            Chlorine
 COPC        Chemical of potential concern
 CP            Chlorophenol
 dscm          Dry standard cubic meters
 D/F          Dioxin and furan
 DQO          Data quality objective
 DNPH        2,4-dinitrophenylhydrazine
 ECD          Electron capture detector
 EDL          Estimated detection limit
 EDO          Environmental data operation
 EER          Energy and Environmental Research Corporation
 EMPC        Estimated maximum possible concentration
 EMTIC       Emissions Measurement Technical Information Center
 EPA          U.S. Environmental Protection Agency
 FGC          Field gas chromatography
 FID          Flame ionization detector
 FTIR          Fourier transform infrared
 g             Gram
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001

-------
                                ACRONYM LIST (Contiaued)
 GC           Gas chromatography
 GC/MS        Gas chromatography/mass spectrometry
 GFC          Gas filter correlation
 GRAY        Gravimetric
 HC1           Hydrogen chloride
 HPLC         High performance liquid chromatography
 HRGC        High resolution gas chromatography
 HRMS        High resolution mass spectrometry
 ICP           Inductively coupled plasma
 IDL           Instrument detection limit
 IR            Infrared
 L             Liters
 LC           Liquid chromatography
 LOL          Limit of linearity
 LOQ          Limit of quantitation
 LRMS        Low resolution mass spectrometry
 m3            Cubic meter
 MDL          Method detection limit
 MDGC        Multi-dimensional gas chromatography
 mg           Milligram
 mL           Milliliters
 MRI          Midwest Research Institute
 MS           Mass spectrometry
 ng            Nanogram
 OS W          Office of Solid Waste
 PAH          Polycyclic aromatic hydrocarbon
 PCB          Polychlorinated biphenyl
 PCDD        Polychlorinated dibenzodioxins
 PCDF         Polychlorinated dibenzofurans
 pg            Picogram
 POHC        Principal organic hazardous constituent
 ppb           Parts-per-billion
 ppm           Parts-per-million
 ppq           Parts-per-quadrillion
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                                ACRONYM LIST (Continued)
 QAPP        Quality assurance project plan
 RCRA        Resource Conservation and Recovery Act
 RDL          Reliable detection limit
 RSD          Relative standard deviation
 SEM          Scanning electron microscope
 SMVOC      Sampling method for volatile organic compounds
 SOP          Standard operating procedure
 SSSADIR     Stationary Source Sampling and Analysis Directory
 S VOC        Semivolatile organic compound
 TCO          Total chromatographable organic
 TEF          Toxicity equivalence factor
 TEQ          Toxic equivalent
 THC          Total hydrocarbon
 TIC           Tentatively identified compound
 TOE          Total organic emissions
 VOC          Volatile organic compound
 VOST        Volatile organic sampling train
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               B.1  OVERVIEW OF SAMPLING AND ANALYSIS PROCEDURES

 This appendix discusses procedures that are recommended by the U.S. Environmental Protection Agency
 (EPA) Office of Solid Waste (OSW) for collection of stationary source stack emissions data for evaluation
 in site-specific risk assessments. Site-specific risk assessment emissions data needs can generally be
 categorized as follows:

        •      .Dioxinsandfurans(D/Fs);
        •       Organics other than dioxins and furans;
        •       Metals;
        •       Particle-size distribution; and
        •       Hydrogen chloride aid chlorine.

 In Chapter 2 of Risk Burn Guidance for Hazardous Waste Combustion Facilities, the importance of
 characterizing the stack emissions as completely as possible, regardless of the availability of lexicological
 data for the compounds of potential concern, is stressed. EPA OSW recommends that all compounds
 initially be identified and quantified to the maximum extent achievable by currently available sampling and
 analytical methods.

 This appendix is intended to be a tool to assist permit writers and facility managers in making informed
 decisions regarding the emissions measurements necessary to meet their risk assessment data needs.  This
 appendix identifies recommended methodologies for stack sampling and analysis, as well as considerations
 which have an impact upon the usability of the analytical data. Where data are available from 40 Code of
 Federal Regulations (CFR) Part 63 Appendix A Method 301 field validation tests with dynamic spiking,
 the data are summarized in this appendix to assist in the selection of an appropriate sampling and analytical
 methodology. This appendix also provides clarifications and "lessons learned" for the stack sampling and
 analytical methods that have not been widely published elsewhere.

 In addition to the stack determinations to be performed as part of a risk burn, EPA OSW recommends that
 a comprehensive characterization of waste feeds, auxiliary fuels, and raw materials be performed to
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establish the basis for the risk burn and risk assessment. Characterization of process samples is discussed

briefly in this appendix.
B.1.1
EMISSIONS TESTING OBJECTIVES
EPA OS W recommends that the sampling and analytical procedures used to generate emissions data for

site-specific risk assessments be chosen to accomplish three primary objectives:


        •       Achieve the most comprehensive emissions characterization possible for toxic
               constituents;

               A comprehensive emissions characterization identifies and quantifies as many individual
               toxic constituents as possible to assess their contribution to the total risk posed by the
               facility.

        •       Identify and quantify as many other constituents as possible, regardless oftoxicity;

               This recommended objective involves determinations for constituents that are not typically
               included on target analyte lists, such as tentatively identified compounds (TICs) and simple
               hydrocarbons, to reduce the uncertainty associated with the risk assessment.

        •       Evaluate the completeness of the organic emissions characterization.

               The uncertainty of the risk assessment process depends upon the completeness of the
               characterization of the source. EPA OS W has recommended (EPA 1998a)that
               completeness be determined based on the difference between a Total Organic Emissions
               (TOE) measurement (EPA 1996a) and the total quantity of identified organics.


The first recommended objective, comprehensive characterization of emissions, is achieved by analyses for

specific target analytes.  The target list for an analytical method addresses known toxic compounds and, in

most cases, the target list for a method includes compounds for which the applicability of the method has
been demonstrated. EPA OS W recommends that analysis for the complete method target list for each

method generally be performed. Deletion of individual compounds a priori (e.g., because they are not

found in the waste feed stream, or because the compounds are not expected to be risk drivers) is not

recommended. Organic stack emissions cannot be predicted with certainty based upon waste feed

characteristics. Analyses performed for a modified method target list (a list generated by the deletion of
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certain compounds) generally do not cost significantly less than analyses performed for the complete target
list because the laboratory needs the same amount of time to prepare the samples and perform the analysis
for a modified method target list as for a complete method target list. Therefore, the a priori deletion of
individual compounds is not likely to significantly reduce analytical costs and could jeopardize the chances
of identifying the greatest possible percentage of organic compounds.

To support the second recommended objective, a comprehensive characterization of additional analytes
(regardless of toxicity) to reduce uncertainly for the risk assessment, EPA OSW recommends that
measurements for non-target compounds such as tentatively identified compounds and simple hydrocarbons
be performed. These measurements, especially for simple hydrocarbons, can significantly improve the
completeness of the overall emissions characterization.

For methods employing a mass spectrometric analysis, non-target compounds can be identified by means of
on-line library search or interpretation of mass spectra, and a quantitative estimate can be provided for
these additional compounds. Constituents identified in this manner are called tentatively identified
compounds, since there is no reference standard analyzed at the same time as the tentative identification.
Studies performed by Lemieux, Ryan, and Midwest Research Institute (MRI) have relied on comprehensive
evaluations for TICs to expand compound identifications beyond standard method target analyte lists
(Lemieux and Ryan 1997 and 1998; EPA  1997a; MRI 1997).  Identification of TICs has also played a key
role in full-scale research (Energy and Environmental Research Corporation [EER] 1997).

Uncertainty in the risk assessment can also be reduced by identifying and quantifying simple hydrocarbons,
such as methane. Determinations that specifically identify methane and other aliphatic compounds add
little cost to the analysis of emissions samples and can potentially alleviate concerns about the percentage
of organic mass that might represent toxic compounds. In studies emphasizing complete characterization
of emissions regardless of toxicity, MRI (MRI 1997) and EER (EER 1997) performed screening for C,
through C4 straight-chain alkanes, alkenes, and alkynes using an on-line gas chromatograph/flame
ionization detector (GC/FID) and specific analyses of S W-846 (EPA 1996b) Method 0040 bag samples for
C,  - C4 compounds. Simple hydrocarbons, especially methane, have been found to comprise a significant
percentage of the total stack organic compounds (MRI 1997; Johnson 1996a).
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 The third recommended objective, equally as important as the firsttwo, involves an assessment of the
 completeness of the organic emissions characterization. Organic compounds that cannot be identified by
 laboratory analysis will not be not addressed quantitatively in risk assessment calculations, and studies
 (EPA 1976; Pellizzari and others 1980) have shown that analyses based strictly on target analyte lists may
 account for less than 20 percent of the organic material in an environmental sample. However, the
 unidentified organic mass still may contribute to the overall risk, and EPA OS W has therefore
 recommended that the unidentified mass be considered in the uncertainty analysis for the risk assessment
 (DeCicco 1995; EPA 1998a).  An assessment of the completeness of an organic emissions characterization
 can be made by performing a mass balance for the organic stack emissions. In particular, EPA OSW has
 recommended that a Total Organic Emissions analysis (EPA 1996a) be performed to quantify the total
 recoverable organic mass emitted from the source, and that the quantity of unidentified organic compounds
 be estimated based on the difference between the TOE mass and the total quantity of identified organic
 compounds (EPA 1998a). Research has recently been performed to evaluate and clarify the analytical
 procedures for the TOE determination, and revised technical details for TOE analysis are included in this
 guidance. The revised technical details will be incorporated into an updated TOE guidance expected to be
 released later in 2001.

 EPA developed the TOE measurement to measure total recoverable organics (and therefore to provide an
 accounting of the total mass of unidentified organic compounds) because existing methods such as total
 hydrocarbon (THC) analyzers and analytical method target lists do not fully determine the total mass of
 organics present in stack gas emissions (Johnson 1996a). Several research studies have indicated that total
 hydrocarbon measurements may not be adequate or appropriate for supporting a mass balance of organic
 compounds (Ryan and others 1997a; MRI 1997). Total hydrocarbon monitors measure only gas phase
 organic compounds. Particulate material, including an indeterminate but sometimes significant fraction of
 the organic material, is filtered from the gas stream entering the THC analyzer and is discarded. This
 potential loss of non-volatile organic material is clearly unacceptable when a determination for total
 recoverable organic mass is desired (Johnson 1996a). The TOE analysis has been repeatedly cited as the
 preferred starting point for mass balance measurements (Lemieux and Ryan 1997 and 1998; EPA 1997a;
 Johnson 1996a; EPA  1996a). EPA OSW has recommended that the TOE result be used in conjunction
 with the total mass of identified organic compounds to calculate a TOE factor, which is then used to
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 support an evaluation of uncertainty associated with the risk assessment (EPA 1998a).  Permitting
 authorities can then evaluate .the TOE factor and assess to what extent actual risks may be greater than
 estimated risks (EPA 1998a).

 The methods and target analyte lists described in this appendix are generally commercially available, but
 recently developed methods for which limited actual field test data are available are also included when
 published EPA or other methods are limited. For the specific methods discussed in this appendix, available
 information is provided on method development and field evaluation studies for Clean Air Act analytes
 performed by EPA under contracts 68-D 1-0010 and 68-D4-0022 where both laboratory data and field data
 were generated at stationary sources using dynamic spiking procedures.

 Research by Ryan and others (Ryan and others 1997a and 1997b), Lemieux and Ryan (Lemieux and Ryan
 1997 and 1998; EPA 1997a), and Midwest Research Institute and A. T. Kearney (MRI1997) provides
 valuable insight into the limitations of standard methods for identifying and quantifying organics.
 Innovative techniques suggested by Lemieux and Ryan (e.g., multi-dimensional gas chromatography/mass
 spectrometry (MDGC/MS), gas chromatography/atomic emission detection (GC/AED), and liquid
 chromatography/mass spectrometry (LC/MS) are currently research methodologies and not generally
 available in the commercial laboratories performing analyses for risk burns. However, as alternative
 options for performing measurements become available, facilities may prefer to apply these new methods
 upon demonstration of acceptable performance. Until further method development and evaluation have
 been performed, EPA OS W recommends that comprehensive characterization of  organic emissions rely on
 correct application of the best available methods for specific target analytes and tentatively identified
 compounds, coupled with a TOE determination to indicate the portion of the organic mass that cannot be
 identified.

 B.1.2   GENERATION OF USABLE DATA FOR RISK ASSESSMENTS

 In selecting the specific sampling and analysis procedures to be .used, EPA OSW recommends that each
 facility carefully consider the data quality objectives that need to be met to demonstrate an acceptable level
 of risk. Risk burn data quality objectives may necessitate analyses near or below analytical detection or
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quantitation levels. Because measurements made below analytical detection and quantitation levels are

associated with increased measurement uncertainty, an understanding of these levels is important to the

comprehension of the effect they may have when applied.


Compounds included on a target list that are not detected in the environmental sample present two

questions:


        •       Is the compound really present?, and

        •       If the compound is present, at what concentration is the compound present?


Table B.l-1, reproduced from Guidance for Data Useability in Risk Assessment (EPA 1992) for the

convenience of the reader, summarizes recommended requirements for confident identification and

quantitation.
                                         TABLE B.l-1

       REQUIREMENTS FOR CONFIDENT IDENTIFICATION AND QUANTITATION
  Identification
  Quantitation
Analyte present above the instrument detection limit (IDL).

Organic - Retention time and/or mass spectra matches authentic
standards.

Inorganic- Spectral absorptions compared to authentic standards.

Knowledge of blank contamination (if any).
Instrument response known from analysis of an authentic standard.

Detected concentration above the limit of quantitation and within the
limit of linearity (instrument response not saturated).	
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 As indicated by the information in Table B.I. 1, the first objective of any analysis is confidence in the
 identification of chemicals of potential concern (COPCs). Identification requires that the chemical be
 present in an environmental sample above the detection limit, although it is possible to identify a chemical
 at a level lower than the level necessary for accurate quantitative analysis. Identification of inorganic
 chemicals is performed by comparison of their unique spectral absorption characteristics to authentic
 standards, with the certainty of the identification a function of the absence of interferences.

 To ensure the highest possible level of confidence in the identification of an organic chemical, an
 instrumental technique such as mass spectrometry is necessary to provide definitive results. Analytical
 techniques alternative to mass spectrometry are frequently available, but mass spectrometry coupled with
 gas chromatographic separation procedures provides the best option for confident identification to minimize
 the risk of error in the qualitative identification of organic analytes. Specific methods contain the criteria
 for compound identification. The two mass spectral methodologies that are used are full scan, in which the
 mass spectrometer is scanned repeatedly over a defined mass range, and selected ion monitoring, in which
 the mass spectrometer monitors only the masses specified in a given time window.

 Full-scan methods such as S W-846 Method 8260 (Volatile Organic Compounds by Gas
 Chromatography/Mass Spectrometry (GC/MS)) and S W-846 Method 8270  (Semivolatile Organic
 Compounds by Gas Chromatography/Mass Spectrometry (GC/MS)) specify criteria for the qualitative
 identification of compounds by comparison of chromatographic retention times to authentic standards for
 which the analytical system is calibrated and by comparison to reference mass spectra.  These methods
 also present guidelines  for tentative identification of sample components not associated with the calibration
 standards (TICs) using library search coupled with interpretation by an experienced analyst. Positive
 identification of TICs is confirmed by re-analysis of the sample with an authentic standard.

 Methods that use selected ion monitoring techniques such as S W-846 Method 8290 (Polychlorinated
 Dibenzodioxins (PCDDs) and Polychlorinated Dibenzofurans (PCDFs) by High Resolution Gas
 Chromatography/HighResolutionMass Spectrometry (HRGC/HRMS))rely upon correspondence of gas
 chromatographic retention times to authentic standards, high resolution mass measurements, and accurate
 ratios between specified isotopic peaks in the ion clusters. Because only specified masses are monitored in
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 a retention time window, methods that use selected ion monitoring procedures cannot be used to identify
 compounds other than the specified compounds.

 In addition to the identification of the chemicals, accurate quantitative data is typically desired. For
 quantitative analysis, an analytical instrument response has to be known from analysis of an authentic
 standard, and the concentration that is detected has to be above the limit of quantitationand within the limit
 of linearity (the instrument response cannot be saturated either chromatographically or in the detector).
 The existence of contamination in blanks and samples can impact both the identification of analytes and
 their quantitative analysis.
 B.l.2.1
Detection Limits, Quantitation Limits, and the Range of Linearity
 The relationship between analytical instrument response, detection limits, and a calibration curve is shown
 in Figure B.l-1, reproduced from Guidance for Data Useability in Risk Assessment (EPA 1992) for the
 convenience of the reader. The following information is also drawn from that guidance and is consistent
 with the approach discussed therein.

 Numerous terms are used to describe detection limits and the level at which a compound of potential
 concern can be quantitatively measured with the desired degree of confidence. The terms "detection limit"
 and "quantitation limit" are usually considered to be generic unless the specific types are defined. The
 general terms depicted in Figure B.l-1 are described below. Additional terms specific to combustion
 risk assessment applications are discussed later in Section B.1.2.3.
                Instrument detection limit (IDL) is the smallest signal above background that can be
                reliably detected (but not quantified) by an analytical instrument.  An IDL is generally
                described as a function of the signal-to-noise ratio. The IDL includes only the
                instrumental portion of detection, not sample preparation, concentration/dilution factors, or
                any method-specific parameters. Potentially significant matrix factors that may affect
                analyte recoveries are not addressed.
                The Method Detection Limit (MDL) is the minimum concentration of a material that can
                be routinely identified using a specific method. The MDL is determined based on analysis
                of replicate samples of a specific matrix type containing the compound of potential
                concern. The replicate samples are prepared and analyzed according to the complete
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         $
         I
         I
         •£
         01
I

I
c
o
I
I
              I
                       Less Certain
                       Quantitation
                     Less Certain
                     Identification
                                            Known Identification
                                               Quantitation
                                                                         Less Certain
                                                                         Quantitation
                 IDL
                             MDL   LOQ
                                                                LOL
             IDL = Instrument Detection Limit
             MDL = Method Detection Limit
             LOQ = Limit of Quantitation
             LOL = Limit of Linearity
  FIGURE B.l-1. RELATIONSHIP BETWEEN INSTRUMENT RESPONSE AND DETECTION
  LIMITS
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                method, and the MDL is based on statistical analysis of the data generated. Since the
                MDL includes sample preparation effects, the MDL is more representative than the IDL.
                However, since MDLs are typically determined by spiking clean matrices in the lab,
                potentially significant matrix effects from the actual environmental sample that may affect
                analyte recoveries are not addressed. For any given method, the MDL is laboratory- and
                compound-specific. Laboratories typically produce MDLs specific to each method
                performed by the laboratory on an annual basis.

                The Limit of Quantitation(LOQ) is the level above which quantitative results may be
                obtained with a specified degree of confidence. When analyte concentrations are close to
                but above the MDL, the uncertainty in the quantitative analysis is relatively high.
                Although the presence of the analyte is accepted, the quantitative results reported may be
                in the range of ± 30 percent.

                The Limit of Linearity (LOL) is the point at or above the upper end of the instrumental
                calibration curve where the relationship between the quantity present and instrumental
                response ceases to be linear (Taylor 1987). The instrument response is usually depressed
                at or above the LOL, and the concentration that is reported will be less than the amount
                actually present in the sample because the detector of the analytical instrument is
                saturated. When analyte concentrations are above the LOL, the sample should be diluted
                to perform a successful quantitative analysis.  However, dilutions correspondingly increase
                the MDL for a given sample.
 The area of known identification and quantitation is the area encompassed by the calibration curve. In the
 range above or below the calibration curve, either quantitation or identification or both become far less
 certain.  The wide range of chemical concentrations that may be present in the environmental matrix of

 interest may require multiple analyses of dilutions to obtain usable data.
 B.l.2.2
Site-Specific Data Quality Objectives for Detection and Quantitation Limits
 Prior to a risk burn, EPA OSW recommends that site-specific data quality objectives (DQOs) for detection

 and quantitation limits be established. DQOs define the quality and quantity of data needed to support

 decisions, considering the purpose of collecting the data. It is highly recommended that a facility perform a

 preliminary risk evaluation to determine target detection and quantitation limits. This information can then

 be used to determine whether modifications to the sampling and analytical procedures may be needed to

 achieve lower detection or quantitation limits.  Limits for D/Fs and bioaccumulative metals may be critical
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 for the indirect risk pathway. Other organic compounds that may warrant particular attention because they
 could be important contributors to indirect risk include the compounds shown in Table B. 1-2.

 The relationship between an MDL and a specific concentration of concern is introduced in Figure B. 1-2,
 reproduced from Guidance for Data Useability in Risk Assessment (EPA 1992) for the convenience of the
 reader. When the concentration of concern for an analyte is greater than the MDL, to the extent that the
 confidence limits of both the MDL and concentration of concern do not overlap, then both "non-detect" and
 "detect" results can be used with confidence. If the confidence limits of the MDL and concentration of
 concern overlap, there will be a possibility of false positives (i.e., the chemical may be misidentified as
 present at the concentration of concern) and false negatives (i.e., the chemical may be misidentified as being
 below the concentration of concern). When the concentration of concern is sufficiently less than the MDL
 that the confidence limits do not overlap, only "detect" results are useful. Reported "non-detect" values are
 not meaningful (because, at the MDL, the compound cannot be confirmed to be below the concentration of
 concern).

 This guidance, as well as the references cited, provides limited information regarding detection limits that
 can generally be expected from the various combinations of sampling train and analytical methods. In
 some cases, for draft methods or modified methods, method detection limits may not be established.
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                                                  TABLE B.l-2

        ORGANIC COMPOUNDS THAT COULD BE IMPORTANT CONTRIBUTORS TO
                                            INDIRECT RISK
   Dioxins/Furans (D/Fs)
   2,3,7,8-tetrachlorodibenzodioxin
   Total tetrachlorodibenzodioxins
   1,2,3,7,8-pentachlorodibenzodioxin
   Total pentachlorodibenzodioxins
   1,2,3,6,7,8-hexachlorodibenzodioxin
   1,2,3,4,7,8-hexachlorodibenzodioxin
   1,2,3,7,8,9-hexachlorodibenzodioxin
   Total hexachlorodibenzodioxins
   1,2,3,4,6.7,8-heptachlorodibenzodioxin
   Total heptachlorodibenzodixoins
   Octachlorodibenzodioxin
2,3,7,8-tetrachlorodibenzofuran
Total tetrachlorodibenzofurans
1,2,3,7,8-pentachlorodibenzofiiran
2,3,4,7,8-pentachlorodibenzofuran
Total pentachlorodibenzofurans
1,2,3,6,7,8-hexachlorodibenzofuran
1,2,3,7,8,9-hexachlorodibenzofuran
1,2,3,4,7,8-hexachlorodibenzofuran
2,3,4,6,7,8-hexachIorodibenzofuran
Total hexachlorodibenzofurans
1,2,3,4,6,7,8-heptachlorodibenzofuran
1,2,34,7,8,9-heptachlorodibenzofuran
Total heptachlorodibenzofurans
Octachlorodibenzofuran
   Polycyclic Aromatic Hydrocarbons (PAHs)
   benzo(a)pyrene
   benz(a)anthracene
   benzo(b)fluoranthene
   benzo(k)fluoranthene
   chrysene
   dibenz(a,h)anthracene
   indeno(l,2,3-cd)pyrene
Nitroaromatics
1,3-dinitrobenzene
2,4-dinitrotoluene
2,6-dinitrotoluene
nitrobenzene
pentachloronitrobenzene
  Polychlorinated Biphenyls (PCBs)
  Total PCBs
  Dioxin-Like CoplanarPCBs (12 compounds):

    IUPAC Number               Name
        77                S.S'A^-tetrachlorobiphenyl
        81                3,4,4',5-tetrachlorobiphenyl
       105                2,3,3',4,4'-pentachlorobiphenyl
       114                2,3,4,4',5-pentachlorobiphenyl
       118                2,3',4,4',5-pentachlorobiphenyl
       123                2',3,4,4',5-pentachlorobiphenyl
       126                3,3',4,4',5-pentachlorobiphenyl
       156                2,3,3',4,4',5-hexachlorobiphenyl
       157                2,3,3')4,41,5'-hexachlorobiphenyl
       167                2,31,4,4')5,51-hexachlorobipheny 1
       169                3,3',4,4',5,5'-hexachlorobiphenyl
       189                2,3J3r)4,4',5,5'-heptachlorobiphenyl
Other Chlorinated Organics
hexachlorobenzene
pentachlorophenol
Phthalate Esters
6w(2-ethylhexyl) phthalate
di-«-octyl phthalate
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            Relationship Between
            Method Detection Limit (MDL) and
            Concentration of Concern (COC)
                         Result
                    MDL
                                      COC
      Confidence
      Limits
Confidence
Limits
Detects and
Non-Detects
Usable
       Concentration
                     MDL
                                       COC
                                                                    False Positives and
                                                                    False Negatives
                                                                    Possible
       Concentration
                                       COC
                                                       MDL
                                                                   Non-Detects Not Usable
                                                                   Detects Usable
                                                                   False Negatives
                                                                   Possible
       Concentration
   FIGURE B.l-2. IMPACT OF DETECTION LIMIT AND CONCENTRATION OF CONCERN
   ON DATA PLANNING
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 Detection and quantisation limits are best assigned with input from the qualified analytical chemist who will

 oversee the analysis for the specific application.  In conferring with the analytical chemist regarding

 detection and quantitation limits, EPA OSW recommends that the following issues be addressed:


         •      How does the laboratory define "detection limit" and "quantitation limit"?

         •      What medium or matrix (i.e., adsorbent resin, filter, condensate) is used to determine
                method detection limits? If the method provides options regarding volumetric treatments,
                which specific volumetric treatments are used?

         •      What final sample or extract volume corresponds to the reported detection or quantitation
                limit (in micrograms, ug)?

         •      Will anticipated detection/quantitationlimits need to be adjusted to reflect sample-specific
                volumetric treatments, such as splits and dilutions, that may differ from the method?

         •      How will non-detects for individual sampling train fractions be treated in the summation to
                determine a total mass for the sampling train? (EPA OSW recommends the following data
                reporting convention for non-detects: If all of the train fractions are non-detect, then the
                non-detects should be summed and reported with a "less than" sign. If the analyte is
                detected in some of the train  fractions but not in others, then the data should be reported as
                a range (i.e., "greater than" the total detected amount, but "less than" the total detected
                amount plus the non-detects)).

         •      In summary, what are the detection/quantitationlimits (in \ig)per sample train?


 With information on the anticipated detection/quantitationlimits for a given sampling train (in ug) and

 information on the volume of stack gas to be sampled (in cubic meters, m3), the facility can evaluate the

 limits in terms of analyte mass per volume of stack gas sampled (in ug/m3). This value will be the

 detection/quantitationlimit in the stack, and may or may not meet the data quality objectives for the risk

 bum and risk assessment.
 If a stack or quantitation limit does not meet risk burn data quality objectives, it may be appropriate for a

 facility to evaluate modifications to the sampling/analytical methodology that will allow the risk burn data

 quality objectives to be met.  When lower detection or quantitation limits are necessary, it may be possible

 to collect a larger sample (i.e., sample at a higher flow rate or for a longer period of time), or the final

 sample volume may be concentrated.  However, either of these procedures has potential disadvantages.
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Sampling for a longer period of time may saturate the collection medium or may saturate an analytical

instrument in the presence of matrix interferences. Concentration of a sample may result in evaporative

loss of more volatile analytes from the sample.


EPA OS W also recommends that the facility confer with the laboratory regarding the meaning of any data

qualifiers that may accompany the final results.  Examples of data qualifiers which are sometimes used and

which may have particular relevance in the final risk calculations include:


        U  -   This flag may indicate that the compound was analyzed for, but not detected.


        J -    This flag may indicate that the compound is present, but that the quantity is estimated. It
               is often used for an organic chemical where the spectral identification criteria have been
               met, but the concentration is less than the quantitation limit.


        E  -   This flag may indicate that the quantity is estimated (e.g., for an organic compound where
               the concentration exceeds the upper level of the calibration range, or for an inorganic
               compound because matrix interferences are present). For organic compounds where the
               concentrations exceed the upper level of the calibration range, the sample should be diluted
               and re-analyzed if possible.

        B  -   This flag may be used when the analyte is found in a blank associated with the sample to
               indicate possible blank contamination.

The types and definitions of data qualifiers are likely to vary among different laboratories and different

applications. Thus, EPA OS W recommends that the specific definitions for data qualifiers be reported

with each data set.
 B. 1.2.3
Use in the Risk Assessment of Data Reported as Non-Detect
 EPA OS W's recommendations regarding treatment of non-detect results in risk assessment calculations are

 dependent upon the analytical method used to produce the data. To increase consistency and

 reproducibility in dealing with non-detects, EPA OS W has recommended application of the MDL-derived

 reliable detection limit (RDL) to quantify non-detects for COPCs analyzed with non-isotope dilution
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 analytical methods, and application of the method-defined estimated detection limit (EDL) to quantify non-
 detects for COPCs analyzed with isotope dilution methods (EPA 1998a).

 Non-Isotope Dilution Methods (SW-846 Methods 8260, 8270):  To quantify non-detects for non-isotope
 dilution methods such as Methods 8260 and 8270, EPA OSW has recommended that an MDL-derived
 RDL for each COPC non-detect be calculated from the developmental test data used to generate the MDL
 (derived according to procedures consistent with 40 CFR Part 136, Appendix B).  The RDL is a total of 8
 times the standard deviation of the replicate measurements performed to generate the MDL for a given
 constituent.

 The MDL procedure was promulgated in 1984 and is incorporated in more than 130 EPA analytical
 methods for the determination of several hundred analytes. To determine the MDL as specified in 40 CFR
 Part 136, Appendix B, at least seven replicate samples with the compound of interest spiked at a level near
 the estimated MDL are analyzed. The standard deviation among these analyses is calculated and multiplied
 by 3.14 (this factor is based on a t-test with six degrees of freedom and provides a 99 percent confidence
 that the analyte concentration is greater than zero).  The result of the calculation becomes the MDL (EPA
 1995).  The RDL is a total of 8 times the standard deviation of the MDL developmental test data, or 2.55
 times the MDL when the MDL  is based on seven replicate samples (i.e., standard deviation x 3.14 x 2.55).
 It is appropriate to adjust the RDL as necessary to account for sample-specific volumetric treatments (such
 as splits and dilutions) that differ from those utilized in the Part  136 MDL determinations. The 40 CFR
 Part 136, Appendix B MDL procedure is specific to the Clean Water Act and therefore specifies the use of
 water as the matrix for MDL determination. Using  spiked sorbent media, the methodology has been
 adapted to the determination of MDLs for stationary source methods that collect analytes on a sorbent
 matrix. For stationary source samples, MDLs have historically been determined by spiking a clean matrix
 that is representative of each sample train fraction (i.e., adsorbent resin, condensate) rather than the actual
 stationary source matrix. Unless the actual stationary source matrix is used, potentially significant matrix
 factors that may affect analyte recoveries are not addressed. For example, SW-846 Method 8260B notes
 that matrix effects in actual volatile organic sampling train (VOST) samples can cause MDLs to be larger
 than the MDLs determined on clean VOST sorbent tubes by a factor of 500-1000. Laboratories typically
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 produce MDLs specific to each non-isotope dilution method performed by the laboratory on an annual
 basis.

 Isotope Dilution Methods (SW-846 Methods 8290, Method 0023A; Office of Water Method 1668A;
 California Air Resources Board (CARS) Method 429, etc.): The Estimated Detection Limit (EDL) is a
 quantitation level defined in SW-846 (EPA 1996b) that is applied to isotope dilution analytical methods
 such as SW-846 Method 8290. The EDL is defined in various methods as the estimate made by the
 laboratory of the concentration of a given analyte necessary to produce a signal with a peak height of at
 least 2.5 times the background signal level. As generally reported by commercial laboratories, the EDL is
 the detection limit reported for a target analyte that is not detected, or presents an analyte response that is
 less than 2.5 times the background level. The EDL is specific to a particular analysis of the sample and
 will be affected by sample size, dilution, etc. EPA OSW has recommended that non-detects for COPCs
 analyzed,using isotope dilution analytical methods be quantified for use in the risk assessment using the
 EDL as defined by the analytical method without the use of empirical factors or other mathematical
 manipulations specific to the laboratory (EPA 1998a).

 For isotope dilution methods, there is also the issue of how to report Estimated Maximum Possible
 Concentrations (EMPCs). An EMPC, as defined in SW-846 Methods 8280A and 8290, may be calculated
 for D/F congeners that are characterized by an analytical instrument response with a signal-to-noise ratio of
 at least 2.5 for both the ions used in the quantitative analysis, and that meet all the relevant identification
 criteria specified in the method except the ion abundance ratio. The ion abundance ratio may be affected
 by chromatographically co-eluting interferences that contribute to the quantitative ion signals and produce a
 positive bias for one or both of the ion signals.  The EMPC is a worst-case estimate of the concentration.
 EPA OSW (EPA 1998a) has recommended that EMPC values be used as full detections in the risk
 assessment without any further manipulations (such as dividing by 2).  Because EMPCs are worst case
 estimates of stack gas concentrations, EPA OSW has recommended that permitting authorities and
 facilities consider techniques to minimize EMPCs when reporting trial and risk burn results, especially
 when EMPC values result in risk estimates above regulatory levels of concern (EPA 1998a). Some
 procedures that may be used to minimize EMPCs include additional cleanup procedures (as defined by the
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analytical method) for the sample or archived extract and/or re-analysis of the sample under different
chromatographic conditions.

The EPA OS W risk assessment guidance (EPA 1998a) also notes that statistical distribution techniques are
available for calculating a range of standard deviations to quantify non-detect concentrations of COPCs.
These techniques include random replacement scenarios, such as the procedures found in journal articles by
Cohen and Rao (Cohen 1989; Rao 1991) including:
               The uniform fill-in method, where each Limit of Detection value is replaced with a
               randomly generated data point by using a uniform distribution;
               The log fill-in method, where each Limit of Detection value is replaced with a randomly
               generated data point by using a logarithmic distribution;
               The normal fill-in method, where each Limit of Detection value is replaced with a
               randomly generated data point by using a log-normal distribution; and
               The maximum likelihood estimation techniques.
 EPA OS W has explained that a Monte Carlo simulation may be used to determine a "statistical" value for
 each non-detect concentration if the permitting authority determines the methodology to be applicable (EPA
 I998a). However, EPA OSW has recommended that, in most cases, emission rates for undetected COPCs
 be estimated by assuming that COPCs are present at a concentration equivalent to the MDL-derived RDL
 for non-isotope dilution methods, or the method-defined EDL for isotope dilution methods (EPA 1998a).
 EPA OSW has articulated the belief that these methods are reasonable and conservative, and that they
 represent a scientifically sound approach that supports maximum protection of human health and the
 environment while recognizing the uncertainty associated with analytical measurements at very low
 concentrations in an actual sample matrix (EPA 1998a). There are necessarily subjective components and
 limitations to each of the non-detect methodologies presented in the EPA OSW risk assessment guidance,
 including the recommended methods.

 Some state permitting authorities have expressed the desire to obtain and use non-routine data
 (e.g., uncensored data) of defensible quality in risk assessment as a way to deal with non-detect issues.
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 EPA OS W has stated that the decision to use non-routine data in a risk assessment is not precluded just

 because the data are different: a permitting authority that chooses to use non-routine data should carefully

 identify and evaluate the limitations associated with non-routine data and clearly document this discussion

 in the uncertainty section of the risk assessment report (EPA 1998a).
 B.l.2.4
Treatment of Blanks for Risk Assessment
 Blanks are used to monitor the presence of contamination introduced into a sample during collection,

 transportation, or preparation and analysis. Blank samples are analyzed in the same manner as site

 samples. To prevent the inclusion of contaminants in the risk assessment process, EPA OS W has

 recommended that the identities and concentrations of compounds detected in the blanks be compared to the

 identities and concentrations of the compounds detected in the field samples (EPA 1998a). Four types of

 blanks are defined in the Risk Assessment Guidance for Superfund(EPA. 1989) and discussed in Human

 Health Risk Assessment Protocol for Hazardous Waste Combustion Facilities (EPA 1998a):
                Trip Blank - A trip blank is used to indicate potential contamination due to conditions
                occurring during transport of sampling media to the field and collected samples to the
                laboratory. The trip blank accompanies the sampling media to the field as well as the
                collected samples returning to the laboratory for analysis.  The trip blank is not opened
                until it is prepared/analyzed in the laboratory.

                Field Blank - A field blank is used to determine if field sampling or cleaning procedures
                (e.g., insufficient cleaning of sampling equipment) result in contamination of field samples.
                Like the trip blank, the field blank is transported to the field with sampling media and
                analyzed in the laboratory together with the field samples. However, unlike the trip blank,
                a field blank consisting of sorbent, for example, is opened in the field and placed in a
                sampling train (which does not collect an actual sample) for the duration of a sampling run
                and recovered in the same manner as the field samples.

                Method Blank - A method blank results from the treatment of clean sampling media or
                distilled, deionized water with all of the reagents and manipulations (e.g., extractions,
                cleanups, extract concentration) to which field samples will be subjected. Positive results
                in the reagent blank may indicate either contamination of the chemical reagents or the
                glassware and implements used to store or prepare the sample and resulting solutions.
                Although a laboratory following Good Laboratory Practices will have its analytical
                processes under control, in some instances method blank contaminants cannot be entirely
                eliminated.
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               Reagent Blank - A reagent blank consists of a separate analysis of any of the reagents
               used in the field recovery or laboratory preparation of the samples. In practice, aliquots of
               all solvents used in the field or laboratory are archived and analyzed individually in the
               event contamination is observed in one of the other blank samples in order to eliminate
               individual solvents as a source of contamination.
 EPA OS W recommends that data generated in the analysis of blanks be compared to the specific analytical
 results with which the blanks are associated. However, even if the specific association between blanks and
 the field data cannot be made, blank data can be compared to the results from the entire sample data set.
 EPA OSW recommends that all data be reported without blank correction.

 In the Guidance for Data Useability in Risk Assessment (EPA 1992), EPA makes a distinction between
 blanks containing common laboratory contaminants and blanks containing contaminants not frequently
 used in laboratories. Compounds considered to be common laboratory contaminants that frequently appear
 on method target lists include acetone, 2-butanone (methyl ethyl ketone), methylene chloride, toluene, and
 the phthalate esters. If compounds considered to be common laboratory contaminants are detected in the
 blanks, then the 1992 guidance recommends that sample results not be considered to be detected unless the
 concentrations in the sample are equal to or exceed ten times the maximum amount detected in the
 applicable blanks. If the concentration of a common laboratory contaminant in a sample is less than ten
 times the blank concentration, then the 1992 guidance recommends that the compound be treated as a non-
 detect in that particular sample. Common laboratory contaminants are summarized in Table B. 1-3, which
 has been reproduced from the 1992 guidance for the convenience of the reader.

 In some cases, blanks may contain compounds that are not considered by EPA to be common laboratory
 contaminants as identified above. In these cases, the 1992 guidance recommends that sample results not be
 considered to be detected unless the concentrations in the sample exceed five times the maximum amount
 detected in the applicable blanks. If the concentration in a sample is less than five times the blank
 concentration, then the 1992 guidance recommends that the compound be treated as a non-detect in that
 particular sample.
 EPA OSW recommends that permitting authorities carefully consider the evaluation of blank data in the
 overall context of the risk assessment and permitting process. Risk burn data should be carefully evaluated
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                                          TABLE B.l-3
  COMMON LABORATORY CONTAMINANTS, CONCENTRATION REQUIREMENTS, AND
                             RISK ASSESSMENT IMPLICATIONS
  Common Laboratory
  Contaminants
Concentration Requirements
Risk Assessment Implications
  Target Compounds
  methylene chloride
Sample concentrations
< 10 x Blank are reported as
non-detect or flagged (B)
   Include the analyte if
   concentration is > 10 x Blank
   Include the analyte if
   concentration is < 10 x Blank and
   multiple volatile chlorinated
   analytes are detected; exclude
   analyte in all other situations
  acetone
Sample concentrations
< 10 x Blank are reported as
non-detect or flagged (B)
   Include analyte if concentration is
   > 10 x Blank
   Include analyte if concentration is
   < 10 x Blank and multiple ketones
   are detected; exclude analyte in all
   other situations
  toluene
Sample concentrations
< 10 x Blank are reported as
non-detect or flagged (B)
   Include analyte if concentration is
   > 10 x Blank
   Include analyte if concentration is
   < 10 x Blank and multiple
   aromatic or fuel hydrocarbons are
   detected; exclude analyte in all
   other situations.
  2-butanone
  (methyl ethyl ketone)
Sample concentrations
< 10 x Blank are reported as
non-detect or flagged (B)
   Include analyte if concentration is
   > 10 x Blank
   Include analyte if concentration is
   < 10 x Blank and multiple ketones
   are detected; exclude analyte in all
   other situations.
  phthalate esters
  (i.e., dimethyl, diethyl,
  di-tt-butyl, butylbenzyl,
  bis (2-ethylhexyl), and/or di-
  n octyl phthalate)
Sample concentrations
< 10 x Blank are reported as
non-detect or flagged (B)
   Include analyte if concentration is
   > 10 x Blank
   Exclude analyte in all other
   situations.
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                                         TABLE B.l-3

 COMMON LABORATORY CONTAMINANTS, CONCENTRATION REQUIREMENTS, AND
                      RISK ASSESSMENT IMPLICATIONS? (Continued)
 Common Laboratory
 Contaminants
Concentration Requirements
Risk Assessment Implications
 Tentatively Identified Compounds
 carbon dioxide
Not reported if present in the
Method Blank.
-  Exclude analyte in all situations.
 diethyl ether
Not reported if present in the
Method Blank.
   Include analyte if concentration is
   > 10 x Method Blank.
   Exclude analyte in all other
   situations.
  hexanes
Not reported if present in the
Method Blank.
   Exclude if analyte concentration is
   not 10 x Method Blank
   Exclude if analyte is not
   10 x Field Blank
   Exclude if sample is not analyzed
   within 7 days
  Freons
  (i.e., l,l,2-trichloro-l,2,2-
  trifluoroethane,
  fluorotrichloromethane)
Not reported if present in the
Method Blank.
   Exclude if analyte concentration is
   not 10 x Method Blank
   Exclude if analyte concentration is
   not 10 x Field Blank
   Exclude if sample is not analyzed
   within 7 days
  solvent preservative
  (e.g., cyclohexanone,
  cyclohexenone,
  cyclohexanol, cyclohexanol,
  chlorocyclohexene,
  chlorocyclohexanol)
Not reported if present in the
Method Blank.
   Exclude if artifact concentration is
   not 10 x Method Blank
   Exclude if artifact concentration is
   not 10 x Field Blank
   Exclude if sample is not analyzed
   within 7 days
  Aldol reaction products of
  acetone
  (e.g., 4-hydroxy-4-methyl-2-
  pentanone,
  4-methylpenten-2-one,
  5,5-dimethyl-2(5H>
  furanone)
Not reported if present in the
Method Blank.
   Include analyte if concentration is
   > 10 x Blank
   Include analyte if concentration is
   < 10 x Blank and multiple ketones
   are detected
   Exclude analyte in all other
   situations
 Table is presented in Guidance for Data Useability in Risk Assessment (EPA 1992).
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 to ensure that the level of contamination present in the blanks does not compromise the integrity of the data

 for purposes of the risk assessment, or result in a need for re-testing in order to properly address data

 quality issues.  When considering blank contamination in the selection of COPCs, EPA OS W recommends

 that permitting authorities ensure:


         1.      The facility or data generator has made every reasonable attempt to ensure good data
                quality and has rigorously implemented the quality assurance project plan (QAPP) and
                good industry/laboratory sampling and testing practices.

         2.      Trial and risk burn data have not been submitted to the permitting authority as  "blank
                corrected." The permitting authority should have the full opportunity to review the data
                without additional manipulation by the data generator.

         3.      The effect of the blank correction on the overall risk estimates, if such an effort is
                considered, is clearly described in the uncertainty section of the risk assessment report.

         4.      The risk assessment reports emission rates both as measured and as blank corrected in
                situations where there is a significant difference between the two values.


 EPA OS W recommends that caution be exercised in applying blank results to correct or qualify sample

 results.  Blanks are usually provided in minimal quantities, usually only one blank of any type per set of

 samples, due to cost considerations associated with collection and analysis of samples. The blank is
 therefore not statistically representative, and blank results are at best only qualitative indicators of the
 validity of a data set.
 B. 1.2.5
General Description of Emissions Calculations
 This appendix is concerned with methods for collecting stationary source emissions samples, with
 subsequent analysis of those samples in the laboratory.  Two sets of calculations will be performed:
         1.      One set of calculations involves the sampling train and the sampling parameters, ultimately
                resulting in a value (expressed as m3) for volume of gaseous emissions sampled; and

        2.      A second set of calculations is performed in the laboratory for calibration of instruments
                and calculation of analytical results. The results generated in the laboratory are usually
                either a weight of material or a weight of material/volume of solvent.  If the laboratory
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               results are weight of material per volume of solvent, the results need to be multiplied by
               the total volume of solvent in order to obtain a weight of material per sampling train.
Once laboratory results are available as weight of material per sampling train (usually ug) and the volume

of gaseous emissions sampled (expressed as m3) is known, the material collected can be related to the

volume of emissions from which it was collected (ng/nf ). This ultimate calculation is usually not

performed by the laboratory, because the laboratory is usually not associated with the sampling effort and

does not know the volume of gaseous emissions sampled by a given sampling train.


For stationary source emissions testing, the units in which the results are reported have meaning only in the

context of the stationary source at which the samples were taken and in relation to the specific sampling

parameters. The following specific results may be reported:
        Volatile organic compound (VOC) results are typically obtained from the laboratory as a weight of
        material (nanograms, ng, for VOST, or ug/nf for S W-846 Method 0040). The VOST values need
        to be related to the actual volume sampled. Since VOST sampling volumes are usually measured
        in liters (L), the units will be ng/L. These units can readily be converted to ug/m3, if desired, since
        1000 L = 1 m3 and 1 p.g = 1000 ng. If tentatively identified compounds are identified in
        association with the VOST determination, a relative instrument response factor of 1 is assumed
        and the quantitative analysis is performed relative to the nearest-eluting internal standard to obtain
        an estimated quantity for the tentatively identified compounds. The same procedure for
        characterization of tentatively identified compounds can be followed for the S W-846 Method 0040
        analysis when the analytical procedure involves mass spectrometry in the full scan mode.

        The results for the semivolatile organic compounds (S VOCs) are reported as (ig/milliliter (mL)
        directly from the analytical instrument, with three sets of values typically generated for each
        sampling train. Since the volume of solvent used in each of the three fractions is known, the total
        ug per train fraction can be calculated and summed. The ultimate value reported by the laboratory
        is the total ug per sampling train. The volume of gaseous emissions sampled by each sampling
        train (expressed as m3) is known, and the value of the total weight of material per sampling train is
        related to the total volume sampled and expressed as ug/m3.  Tentatively identified compounds, if
        characterized, can be quantified using an instrument response factor of 1, with the quantitative
        analysis performed relative to the nearest-eluting internal standard to obtain an estimated quantity
        for the tentatively identified compounds.

        Chlorobenzenes/chlorophenols(CBs/CPs) and polycyclic aromatic hydrocarbons (PAHs) are also
        semivolatile organic compounds, which are reported as total  ug per sampling train, with ug/m?
        calculated using the actual volume sampled in the field.
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         Polychlorinated biphenyls (PCBs) are likewise semivolatile organic compounds, with the quantity
         calculated by the laboratory as nanograms (or ug) per sampling train.  The goal of the analysis is
         to report accurate quantitative values for the coplanar polychlorinated biphenyls, with the non-
         coplanar compounds reported as "Other PCBs" at a specific chlorination level. Calculations
         involving polychlorinated biphenyls are complicated by the consideration that the coplanar
         polychlorinated biphenyls are considered to exhibit dioxin-like toxic effects, and are assigned
         toxicity equivalence factors (TEFs) accordingly.  Thus, for the coplanar PCBs, an additional step
         involving a toxic equivalence (TEQ) determination is involved in the calculation (Section B.5).
         The ultimate reported values for the polychlorinated biphenyls also have to be related to the volume
         of gaseous emissions sampled in the field (expressed as m3).  Polychlorinated biphenyls are
         analyzed using selected ion monitoring mass spectrometric procedures, so no information is
         available to determine tentatively identified compounds from this analysis.

         Polychlorinated dibenzodioxins and dibenzofurans are also semivolatile organic compounds, which
         are calculated by the laboratory as picograms (pg) or nanograms (ng) per sampling train. The goal
         of the analysis is to report accurate quantitative values for the 2,3,7,8-substituteddioxins and
         furans, with the non-2,3,7,8-substitutedcompounds reported as "Other Dioxins/Furans" at a
         specific chlorination level. Calculations involving dioxins and furans are complicated by the
         consideration that each 2,3,7,8-substitutedcongener is assigned a TEF which corresponds to its
         toxicity in relation to 2,3,7,8-tetrachlorodibenzodioxin(Section B.6). The ultimate values for the
         polychlorinated dibenzodioxins and dibenzofurans also have to be related to the volume sampled in
         the field (expressed as m3). Polychlorinated dioxins and furans are analyzed using selected ion
         monitoring mass spectrometric procedures, so no information is available to determine tentatively
         identified compounds from this analysis.

         Combined measurement techniques likewise have the goal of determining the weight of analyzed
         material per sampling train, so that this quantity can be related to the volume sampled. Since no
         two laboratories follow exactly the same scheme of dividing/combining fractions, a very careful
         tracking of division/combination of extracted fractions should be performed in order to be sure that
         accurate values are obtained for the quantity of material collected by the sampling train. For
         example, if the "standard method uses extraction of an entire fraction to perform the analysis but the
         combined method divides the fraction in half for different analyses, the chemist should be aware
         that the analytical values have to be multiplied by two to obtain the total weight of material per
         sampling train. The ultimate reported values for the compounds of interest also have to be related
         to the volume of gaseous emissions sampled in the field (expressed as m3).  Any fractions of a
         combined method that are analyzed using mass spectrometric procedures in the full scan mode can
         produce information for characterizing tentatively identified compounds, which can then be
         quantified using the procedures described above.

         In the application of SW-846 Method 0011 to the measurement of aldehydes and ketones (A/Ks),
         the final value reported by the laboratory should be total weight of material per sampling train.
         This value of total weight of material per sampling tram can be related to the volume of gaseous
         emissions sampled (expressed as m3).
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        Facility-specific compounds may be either volatile or semivolatile organic compounds, which are
        treated as described above. If the analytical methodology involves full scan mass spectrometry,
        tentatively identified compounds can be characterized and quantified.
        Metals analysis frequently involves the summation of metals analyzed in several fractions of the
        sampling train to obtain a total weight of metal per sampling train.  The scheme of combination of
        fractions to determine the total weight of a given metal is quite complicated and is described
        thoroughly in SW-846 Method 0060. The weight of metal per sampling train is related to the
        volume of gaseous emissions sampled in the field (expressed as m3).
        Hydrogen chloride (HC1) and chlorine (Cy determinations involve quantifying results from
        multiple impingers as described in the sampling/analytical method to obtain a total weight per
        sampling train. The weight of HCl/Clj per sampling train is related to the volume of gaseous
        emissions sampled in the field (expressed as m3).
 In summary, all of the analytes are reported as a total weight of material collected by the sampling train,
 related to the volume of stack gas sampled in the field (expressed as m3).
 B.1.3
METHOD SUMMARY
 Table B. 1-4 provides a summary of source sampling and analysis procedures which are recommended for
 collection of stationary source emissions data for evaluation in site-specific risk assessments. Specific
 information regarding each determination is provided in subsequent sections.

 The recommended determinations rely on methods from the SW-846 Compendium (EPA I996b), where
 available. The most recent versions of the SW-846 methods are available at SW-846 On-line
 (http://www.epa.gov/sw-846/main.htm). When revisions are made to any of the SW-846 sampling or
 analytical methods, EPA OS W recommends that the facility use the latest revised method, as available on-
 line. Additional test methods are also available through the EPA Emission Measurement Center
 (http://www.epa.gov/ttn/emc/tmethods.html). Methods available through this site include Promulgated,
 Proposed, Approved Alternative, Conditional, and Preliminary stationary source test methods. The
 Emission Measurement Center has recently completed the development of a 24-hour automated telephone
 infonnationhotline known as the "SOURCE." The SOURCE, at (919) 541-0200, provides callers with a
 variety of technical emissions testing information.  The SOURCE includes connections to technical
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fcc tv
ff 5'
I?
              TABLE B.l-4

RISK-BASED STACK EMISSION DETERMINATIONS
!*S£1.'
Dioxins/Furans

























Sampling '
* IVfethlTd \ -
M0023A

























•^ Analysis
8290
HRGC/HRMS
























" Constituents To Be
Determined _
2,3,7,8-tetrachlorodibenzodioxin
Total tetrachlorodibenzodioxins
1 ,2,3,7,8-pentachlorodibenzodioxin
Total pentachlorodibenzodioxins
1 ,2,3 ,6,7,8-hexachlorodibenzodioxin
1,2,3,4,7,8-hexachlorodibenzodioxin
1 ,2,3 ,7,8,9-hexachlorodibenzodioxin
Total hexachiorodibenzodioxins
1,2,3,4,6,7,8-
heptachlorodibenzodioxin
Total heptachlorodibenzodixoins
Octachlorodibenzodioxin
2,3 ,7,8-tetrachlorodibenzofuran
Total tetrachlorodibenzofurans
1,2,3,7,8-pentachlorodibenzofuran
2,3,4,7,8-pentachlorodibenzofuran
Total pentachlorodibenzofurans
1 ,2,3 ,6,7,8-hexachlorodibenzofuran
1,2,3,7,8,9-hexachlorodibenzofuran
1 ,2,3,4,7,8-hexachlorodibenzofuran
2,3,4,6,7,8-hexachlorodibenzofuran
Total hexachlorodibenzofurans
1,2,3,4,6,7,8-heptachlor.odibenzofuran
1,2,34,7,8,9-heptachlorodibenzoruran
Total heptachlorodibenzofurans
Octachlorodibenzofuran
^Applicability
Generally
applicable
























% , , Comments, „ , ,
Method 0023A may be modified to
allow simultaneous sampling and
analysis of PCBs, PAHs, or SVOCs.
However, specific approval should be
obtained for this modification, a
detailed description of the proposed
methodology should be provided, and
demonstration of method performance
should be provided, including how the
modification affects detection limits
for all compounds in the combined
method.














  I

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                   TABLE B.l-4
RISK-BASED STACK EMISSION DETERMINATIONS (Continued)
a?
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(U s
o s
1*
i
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&
&
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A
x
m ^
• S
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Pollutant
Category
Sampling
Method ,1;-
Analysis
Method1 .•".'
Constituents To Be
: ; '- - ^Determined •

: Applicability

Comments:
Non-D/F Organics:
Volatile Organics













Semivolatile
Organics



Chlorobenzenes/
Chlorophenols
PAHs


VOST
M0030/0031
for Low
Concentration
Organics in
Specified BP
Ranges
(<121 °C)
Tedlar®Bag
M0040
for
&High
Concentration
Organics

M0010
for
Organics
withBP
>100 °C
M0010

M0010



5041A/8260B
GC/MS




8260B
GC/MS

GC/FID
GC/ECD


3542/8270C
GC/MS



GC/MS

CARB 4292



• Volatile target analyte list, per
Table B.2-1
• TICs, 'per Section B. 11



• Volatile target analyte list, per
Table B.2-1
• TICs, per Sections. 11
Alkanes, alkenes, alkynes, volatile
halogenated organics


• Semivolatile target analyte list, per
Table B.3-1
• TICs, per Sections. 11


• CBs/CPs in Table B.4-1

• PAHs in Table B.4-2



Generally
applicable




Generally
applicable

Highly
recommended


Generally
applicable



Generally
applicable
Generally
applicable


Condensate collected during Method
0030/0031 sampling is analyzed using
Method 8260B.

Section B.2 identifies BP ranges for
each method.
Condensate collected during Tedlar®
bag sampling is analyzed using
Method 8260B.
Examples: Methane, ethane, ethene,
acetylene, propane, propene, and
propyne may be identified and
quantified by this method.





Analysis of the MOO 10 extract for
CBs/CPs is recommended.
Separate cleanup of the M0010 extract
and analysis for PAHs by
HRGC/HRMS is recommended.

-------




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-------
Risk Burn Guidance for July 2001
Hazardous Waste Combustion Facilities B-30
TABLE B.l-4
RISK-BASED STACK EMISSION DETERMINATIONS (Continued)
Pollutant
,.,:, • Category .
Total Organic
Mass4
I THC/CO
Metals
Particle-Size
[Distribution
Hydrogen
Chloride and
(Chlorine
Sampling
Method1
Tedlar*Bag
M0040
Tedlar(DBag
M0040
(Condensate
Fraction)
M0010
Analysis,
Metftoa :»
GC/FID
Purge and Trap
GC/FID
GC/FID
Gravimetric
CEMs-40CFRPart266
Appendix IX Section 2.0
M0060/
0061
CARB 5012
M0050/0051
6010B/6020
7000-series
Gravimetric
M9057/9056
Constituents To Be
.Determined
Total organic mass (ug) for
organics boiling between (-)160to
100 °C
Total organic mass (ug) for
water soluble organics
Total organic mass (fig) for
organics boiling between
100-300 °C
Total organic mass (ug) for organics
boiling at temperatures > 300 °C
THC/CO, corrected to 7% oxygen, dry
basis
Al, Co, Cu, Mn, Ni, Se, V, and Zn, in
addition to As, Be, Cd, Cr, Ag, Ba,
Hg,Pb,Sb,Tl
Site-specific particle-size distribution
Hydrogen chloride and chlorine
Applicability
Generally
applicable
Generally
•applicable
Generally
applicable
See discussion
in Section B.14
Generally
applicable
,',..'.' •-,'•' ••••,, •. ; Comments •'/ ., .••

The result for the condensate is
combined with the result for the
Tedlar® bag fraction to give total
organic mass for organics boiling
between (-)160to 100 °C.
A separate MOO 10 train is generally
necessary for the total organic mass
determination unless procedures in
Section B.8.9 are followed.
Baseline may be needed for continuous
performance assurance.
Metals may be excluded if the facility
assumes that 100 percent of the metal
which is fed is emitted
(i.e., assumption of no partitioning/
removal).
Particle density also needs to be
determined.
See Section B.15 for additional
methods.


-------
                                           TABLE B.l-3
               RISK-BASED STACK EMISSION DETERMINATIONS (Continued)
Notes:
 1   Sampling and analysis methods are from "Test Methods for Evaluating Solid Waste," SW-846 or EPA's
    Emission Measurement Center. The latest revision, available from SW-846 on-line (http://www.epa.gov/sw-
    846/main.htm) should be used.  If detection limits are not low enough to achieve target risk levels, then
    modifications to the sampling and analytical procedures may need to be considered.  Other methods may be
    considered provided that the user can demonstrate the methods meet the data quality objectives for the
    particular application.

 2   California Environmental Protection Agency, Air Resources Board, Sacramento, CA,
    (http://www.arb.ca.gOV/testmeth/vol3/vol3.htma/irfhttp://arbis.arb.ca.gov/testmeth/voll/voll.htm).

 3   EPA "Method 1668, Revision A: Chlorinated Biphenyl Congeners in Water, Soil, Sediment, and Tissue by
    High Resolution Gas Chromatography/High Resolution Mass Spectrometty," EPA-821-R-00-002, Office of
    Science and Technology, Office of Water, December 1999.

 4   "Guidance for Total Organics - Final Report," prepared for EPA by Radian Corporation, EPA/600/R-96/033,
    March 1996, as updated considering the technical recommendations discussed in Section B.7 of this document.
    See also "Determination of Total Organic Emissions from Hazardous Waste Combustors," Larry D. Johnson,
    Analytical Chemistry, Vol. 68, No.l, January 1, 1996.

 See the Appendix B Acronym List for acronym definitions.
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001
     B-31

-------
 material through an automatic facsimile link and with technical staff during working hours.  Other
 locations for stationary source test methods are the California Air Resources Board sites, Test Methods for
 Determining Emissions of Toxic Air Contaminants from Stationary Sources
 (http://www.arb.ca.gov/testmeth/vol3/vol3.htm)md Stationary Source Criteria Pollutant Test Methods
 (http://arbis.arb.ca.gov/testmeth/voll/voll.htm). Additional information for selection and field evaluation
 of sampling and analytical methods is available through EPA's Stationary Source Sampling and Analysis
 Directory, Version 2.1 (SSSADIR) (Jackson 1995a).

 The numbered methods as written are intended as guidance, and EPA OS W recommends that the numbered
 methods generally be used as starting points for the preparation of standard operating procedures (SOPs)
 for the methods that will actually be used. The S W-846 Compendium provides guidance on individual
 method modifications. Methods other than the methods in the S W-846 Compendium may be appropriate
 for generation of risk bum emissions data, and EPA OS W recommends that all methods and method
 modifications proposed for a specific application be discussed in detail in the risk bum plan and QAPP.
 Detailed information regarding the actual methods should be described in the plans, and the plans should
 define data quality objectives (DQOs) for the particular application. For all test methods, EPA OS W
 recommends that the user demonstrate and document that the proposed methods meet the DQOs for the
 particular application.  Additional modifications to standard methods may be appropriate in  order to meet
 site-specific objectives (e.g., the need for reduced analytical detection limits or a desire to use a single
 sampling train for  multiple pollutant determinations).
 B.1.4
QUALITY ASSURANCE/QUALITY CONTROL
 EPA OS W recommends establishing DQOs for risk burn measurements and defining detailed quality
 assurance objectives in a project-specific QAPP as a critical component of the risk burn planning process.
 Although a thorough treatment of the DQO process and specific quality assurance/quality control
 provisions is beyond the scope of this guidance, there are other sources of information that may be
 consulted. EPA QA/G-4: "Guidance for the Data Quality Objectives Process" provides a standard
 working tool for project managers and planners to develop DQOs for determining the type, quantity;, and
 quality of data needed to reach defensible decisions.  Since 1997, EPA has recommended that a QAPP be
Risk Bum Guidance for
Hazardous Waste Combustion Facilities
                                                                      July 2001
                                                                           B-32

-------
 written for any activity that involves an environmental data operation (EDO), as documented in EPA
 QA/R-5: "EPA Requirements for Quality Assurance Project Plans for Environmental Data Operations."
 An additional source of information provided by the EPA Quality Assurance Division to assist with writing
 a QAPP is the document EPA QA/G-5: "EPA Guidance for Quality Assurance Project Plans." All of these
 documents are available on the web (http://www.epagov/ncerqa/qa/qa_docs.html).

 The documents available from the EPA Quality Assurance Division offer broad guidelines regarding the
 DQO planning process and QAPP development. Information specific to stationary source measurements is
 also available and should be consulted. Individual test methods, such as those in S W-846, outline quality
 assurance/quality control procedures to be followed to assure acceptable performance of the method. In
 addition, the following documents focus on quality assurance/quality control procedures for the source
 measurements commonly performed at hazardous waste combustion facilities:

 •      U.S. EPA Region 6. Hazardous Waste Combustion Unit Permitting Manual. Component 2 -
        How to Review a Quality Assurance Project Plan. Center for Combustion Science and
        Engineering, Multi Media Planning Division. January 1998.
        (Includes a generic trial burn quality assurance project plan as Attachment A.)
        http://www.epagov/earthlr6/6pd/rcra_c/manual/manual.htm#A.
 •      U.S. EPA. Handbook: Quality Assurance/Quality Control (QA/QC) Procedures for Hazardous
        Waste Incineration.  Office of Research and Development. EPA/625/6-89/023. January 1990.
 •      U.S. EPA. Handbook: Hazardous Waste Incineration Measurement Guidance Manual. Volume
        III of the Hazardous Waste Incineration Guidance Series. Office of Solid Waste and Emergency
        Response. EPA/625/6-89/021. June 1989.

 The Emission Measurement Center provides guidance on test plan and final report preparation on the web
 (http://www.epa.gov/ttn/emc/guidlnd.html). In addition, the Emission Measurement Center currently
 operates the Stationary Source Compliance Audit Program, through which compliance audit samples may
 be requested by Regional Offices, State Agencies, and Local Agencies for stack tests.  Information on the
 Stationary Source Compliance Audit Program is available on the Emission Measurement Center web site:
 http://www.epagov/ttn/emc/email.html#audit.
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001
     B-33

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                      B.2 VOLATILE ORGANIC COMPOUNDS (VOCs)


 There are two EPA methods available for the determination of volatile organic compounds (VOCs), and

 numerous methods in draft stages for a variety of specific volatile organic analytes. The two EPA methods

 include:
               The Volatile Organic Sampling Train (VOST) is actually a combination of sampling and
               analytical methods from the SW-846 Compendium.  Sample collection is performed using
               either Method 0030 or 0031, desorptioh of the sorbent cartridges is performed using
               Method 5041 A, and analysis is achieved via GC/MS (Method 8260).

                      Method 0030 (Volatile Organic Sampling Train)

                      VOST describes the collection of volatile principal organic hazardous constituents
                      (POHCs) from the stack gas effluents on paired sorbent resin and sorbent
                      resin/charcoal cartridges. Method 0030 may be used to collect volatile POHCs
                      with boiling points (BPs) between 30° C and 100°C, although performance may be
                      adequate for compounds with boiling points up to 121 °C. If the boiling point of a
                      POHC of interest is less than 30° C, the POHC may break through the sorbent
                      under the conditions of the sample collection procedure. Many compounds that
                      boil above 100°C (such as chlorobenzene) may also be efficiently collected and
                      analyzed using the VOST, but VOST collection and desorption efficiency for
                      these compounds should be demonstrated.

               -      Method 0031 (Sampling Method for Volatile Organic Compounds (SM VOC))

                      Method 0031 is a modified version of Method 0030 whereby two sorbent resin
                      cartridges are employed prior to the sorbent resin/charcoal cartridge, for a total of
                      three cartridges. Method 0031 may be used to collect VOCs that have a boiling
                      point between -15°C and 121 °C. Field application for VOCs with boiling points
                      less than 0°C should be supported by data obtained from laboratory gaseous
                      dynamic spiking of the sampling train with gas chromatography/mass
                      spectrometry (GC/MS) analysis according to Methods 5041/8260 to demonstrate
                      the efficiency of the sampling and analysis methods.

               -      Method 5041A (Analysis for Desorption of Sorbent Cartridges from Volatile
                      Organic Sampling Train (VOST))

                      Method 5041A describes the desorption of POHCs collected from  stack gas
                      effluents of hazardous waste incinerators using the VOST methodology with
                      analysis by GC/MS (Method 8260).
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001
     B-34

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               Method 0040 (Sampling of Principal Organic Hazardous Constituents from Combustion
               Sources Using Tedlar® Bags

                       Method 0040 establishes standardized test conditions and sample handling
                       procedures for the collection of VOCs from effluent gas samples from stationary
                       sources using time-integrated evacuated Tedlar® bags. Method 0040 may
                       generally be used to collect VOCs with boiling points less than 121 °C, although
                       actual performance will depend on analyte concentration and condensation point.
                       Method 0040 is a sample collection method and does not directly address the
                       analysis of these samples other than to recommend the application of GC/MS
                       procedures because of the ability of GC/MS to provide positive identification of
                       compounds in complex mixtures such as stack gas.  In some cases, the samples
                       may be analyzed in the field using GC/FID or GC with an electron capture
                       detector (BCD).
 Method 0030, the VOST sampling method, specifies the use of SKC Lot 104 charcoal in the sorbent tube

 used for sample collection. The specified sorbent has not been commercially available for many years, and

 EPA has done several studies to identify and specify a sorbent (Anasorb®-747) that is technically

 equivalent and commercially available (Johnson 1996b).  Use of Anasorb®-747 is recommended for both

 Method 0030 and Method 0031.


 In the application of the sampling methods, Methods 0030 and 0031 involve time-integrated collection of
 VOCs on sorbent and, therefore, typically can achieve lower detection limits than the Tedlar® bag method

 (Method 0040).  However, the upper range of analyte concentrations for the sorbent sampling methods is

 limited by the capacity of the sorbent and the capacity of the chromatographic analytical column and the

 mass spectrometric detection system.  Methods 0030/0031 were developed for the collection/analysis of

 trace levels of specific analytes at parts-per-billion (ppb) levels in the stack gas stream (or 500-1000 ng on

 the analytical column, depending upon the specific compound). Non-polar, relatively stable, hydrophobic
 compounds typically perform well in Methods 0030/0031. Because these methods involve purging the

 sorbent tubes through water, they are generally very poorly applicable (or not applicable at all) to volatile,
 polar water-soluble compounds.


 Method 0040 is a whole-gas sampling technique developed initially to provide an alternative to Methods

 0030/0031 for sources where the emission concentrations were higher than the Method 0030/0031 limits

 (i.e., levels ranging from parts-per-million(ppm) to hundreds of ppm in the emission stream).  Method
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001
     B-35

-------
 0040 allows aliquots of the sample to be analyzed and the aliquot can be pre-concentrated. Non-polar,
 relatively stable, hydrophobic compounds that can be shown to be stable in a Tedlar® bag for at least 72
 hours typically perform well in Method 0040. Attachment 1 of this appendix provides a memorandum
 clarifying certain aspects of the Method 0040 Tedlar® bag method.

 EPA OSW recommends that project-specific measurement objectives for volatile organic compounds be
 established in the QAPP and used to select appropriate sampling and analytical methods for the range of
 volatile compounds that may be emitted.  Pre-testing can provide valuable information. For example, pre-
 testing can reveal whether certain compounds are present at concentrations which exceed the operating
 range for Methods 0030/0031. If high concentration volatile organic compounds are present, a Method
 0040 Tedlar® bag determination with GC/MS analysis may be needed to achieve accurate quantitative
 results for the higher concentration organics. Volatility of the organic compounds should also be
 considered. Although the Method 8260B analytical conditions can and do obtain quantitative
 measurements for the very volatile halogenated compounds (such as chloromethane, chloroethane, etc.),
 these compounds cannot be sampled reliably using Method 0030. Thus, either Method 0031 or Method
 0040 would be needed to sample the very volatile compounds (with boiling points'less than 30 °C),
 followed by GC/MS analysis. For trace levels of the very volatile halogenated compounds, analysis of a
 Method 0040 Tedlar® bag sample by GC/ECD may be considered in some cases to increase sensitivity.
 However, compound identification is less certain with GC/ECD.

 To capture the complete range of constituent concentrations and volatility, it is likely that two sampling
 methods will be needed. Methods 0030/0031 can typically achieve lower detection limits than the Method
 0040 Tedlar® bag (ppb versus ppm levels).  However, Method 0030 will not reliably capture very volatile
 compounds (i.e., those boiling below 30 °C), and neither of the VOST/SMVOC methods (Methods
 0030/0031) will reliably capture compounds present in high concentrations (i.e.,  ppm levels).  Thus, a
 Method 0040 Tedlar® bag sample may be needed to augment the Method 0030/0031 results for very
 volatile and high concentration compounds. EPA OSW recommends that all samples (VOST, Tedlai® bag,
 and condensates) be analyzed by GC/MS for the target analytes appropriate to the sampling method as
 discussed in Section B.2.1, and for TICs as described in Section B.I 1.  Analysis of Tedlai® bag samples
 for simple hydrocarbons is also recommended, as discussed in Section B.2.2. When both Method
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001
     B-36

-------
 0030/0031 and Method 0040 procedures are applied at a given source and a VOC is detected using both
 methods, EPA OSW recommends that the higher of the two results generally be used for the risk
 assessment and in the summation of total identified organics. If a compound is not detected, EPA OSW
 recommends that the lower of the two detection limits generally be used.

 EPA OSW also recommends that condensate samples from both Methods 0030/0031 and Method 0040 be
 analyzed. These samples can be introduced into the analytical system by direct aqueous injection, or
 Method 8260 analytical procedures can be applied.
 B.2.1
VOLATILE TARGET ANALYTE LISTS AND TENTATIVELY IDENTIFIED
COMPOUNDS
 Individual laboratories are very likely to use a target list for VOCs, in conjunction with both Methods
 0030/0031 and Method 0040, that is the same as or derived from the Volatile Organic Compound Target
 List shown in Table B.2-1, based on analytical Method 8260B. However, all of the compounds listed in
 Table B.2-1 are not appropriate analytes for Methods 0030/0031 and Method 0040. Table B.2-2 lists
 VOCs for which field method evaluation data, using quadruple sampling trains with dynamic spiking
 according to the procedures of EPA Method 301 (Field Validation of Pollutant Measurement Methods from
 Various Waste Media, 40 CFR Part 63 Appendix A), are available. [If EPA currently recognizes an
 appropriate test method or considers the analyst's test method to be satisfactory for a particular analyte at a
 particular source, the Administrator may waive use of the method validation protocol or may specify a less
 rigorous validation procedure.]  A list of validated methods may be obtained by contacting the Emissions
 Measurement Technical Information Center (EMTIC), U. S. Environmental Protection Agency, Research
 Triangle Park, NC 27711 (919)541-0200; or through the Emissions Measurement Center web  site
 (http://www.epa.gov/ttn/emc). Table B.2-3 lists analytes for Method 0040, including compounds that met
 acceptance criteria in a field method evaluation study, compounds that failed to meet acceptance criteria,
 and appropriate candidates not tested. Table B.2-4 lists analytes which preliminary laboratory testing has
 demonstrated to be inappropriate candidates for VOST sampling and analytical methodology.
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
                                                                      July-2001
                                                                           B-37

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                                    TABLE B.2-1
                  VOLATILE ORGANIC COMPOUND TARGET LIST
                          DERIVED FROM METHOD 8260B
Volatile Organic Compound
acetone2
acrylonitrile2
benzene
bromodichloromethane
bromoform3
bromomethane1
2-butanone (methyl ethyl ketone)4
carbon disulfide
carbon tetrachloride
chlorobenzene3
chlorodibromomethane3
chloroethane1
chloroform
chloromethane1
dibromomethane
dichlorodifluoromethane4
1,1-dichJoroethane
1,2-dichloroethane
1 , 1 -dichloroethene
cis- 1,2-dichloroethene
trans- 1,2-dichloroethene
1 ,2-dichloropropane
cis- 1,3-dichloropropene3
trans- 1,3-dichloropropene3
ethylbenzene3
iodomethane2
methylene chloride
styrene3
1 , 1 ,2,2-tetrachloroethane3
CAS Number
67-64-1
107-13-1
71-43-2
75-27-4
75-25-2
74-83-9
78-93-3
75-15-0
56-23-5
108-90-7
124-48-1
75-00-3
67-66-3
74-87-3
74-95-3
75-34-3
75-34-3
107-06-2
75-35-4
156-59-2
156-60-5
78-87-5
10061-01-5
10061-02-6
100-41-4
74-88-4
75-09-2
100-42-5
79-34-5
Boiling Point, °C'
56
78
80
87
149
4
80
46
77
132
119
12
62
-24
97
57
57
83
32
48
48
95
108
107
136
43
40
145
146
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001
    B-38

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                                         TABLE B.2-1
                     VOLATILE ORGANIC COMPOUND TARGET LIST
                         DERIVED FROM METHOD 8260B (Continued)
Volatile Organic Compound
tetrachloroethene3
toluene3
1,1,1 -trichloroethane
1 , 1 ,2-trichloroethane3
trichloroethene
trichlorofluoromethane1
1 ,2,3-trichloropropane3
vinyl chloride1
xylenes (total)3
CAS Number
127-18-4
108-88-3
71-55-6
79-00-5
79-01-6
75-69-4
96-18-4
75-01-4
1330-02-7
Boiling Point, °C'
121
110
74
114
87
24
157
-13
137
 Notes:
        Existing sampling methods for VOCs are boiling-point specific. The appropriate sampling
        methods should be considered to achieve results for the entire VOC target analyte list. For
        example, compounds with boiling points less than 30°C cannot be reliably sampled using Method
        0030, and should be sampled using Methods 0031 and/or 0040.

        Certain compounds, including acetone, acrylonitrile, and iodomethane, cannot be reliably
        determined using the VOST methodology (either Method 0030 or Method 0031). VOST results
        obtained for these compounds should be considered semi-quantitative, at best. However, the
        compounds have been retained on the target analyte list to provide the most complete emissions
        characterizationpossible using currently available analytical methods.

        These constituents have a boiling point greater than 100°C, as specified in Method 0030.
        Although these compounds are listed as Method 8260B target analytes, the reliability of the VOST
        sampling methodology for these compounds should be demonstrated or the analytes should be
        added to the S VOC target analyte list.

        Two constituents, 2-butanone and dichlorodifluoromethane, have been retained from the former
        Method 8240 target list because these compounds are regularly observed in stack emissions.
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001
     B-39

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                      TABLE B.2-2




VO Cs FOR WHICH FIELD METHOD EVALUATION DATA ARE AVAILABLE
*l
Ȥ
H
1
§
?
1
8
1
ro£
§s
Results for Method 0030 halogenated compounds laboratory study and four field tests.
Compound
methyl chloride (chloromethane)
ethylidene dichloride
(1,1-dichloroethane)
chlorobenzene
vinyl chloride
vinylidene chloride
(1 ,1-dichloroethylene)
chloroform
propylene dichloride
(1 ,2-dichloropropane)
methyl bromide (bromomethane)
ethyl chloride (chloroethane)
methylene chloride
methyl chloroform
(1,1,1 -trichloroethane)
carbon tetrachloride
ethylene dichloride (1,2-dichloroethane)
trichloroethylene
cis-l ,3-dichloropropene
/rara-l,3-dichloropropene
1 , 1 ,2-tri chloroethane
First Field Test"
Percent
Recovery
937
75.7
88.2
110.4
88.0
81.8
67.2
53.7
50.3
77.7
110
107
76.6
126
137
135
98.0
Percent
RSD
53.8
13.7
22.0
27.3
31.3
14.8
9.6
20.2
28.7
27.1
43.5
47.2
33.0
15.6
26.0
38.1
22.1
Second Field Testb
Percent
Recovery
243
82.2
81.2
41.8
77.8
91.3
121
54.8
33.7
89.9
91.1
81.2
72.3
119
79.5
52.3
79.7
Percent
RSD
62.8
23.3
22.1
44.6
24.2
24.6
24.8
26.2
36.9
14.3
31.1
23.6
37.5
26.2
27.6
35.4
27.2
Third Field Test'
Percent
Recovery
255.3
86.0
84.8
37.3
77.8
95.3
117.7
52.8
31.4
90.8
96.8
85.7
78.6
124.0
83.5
47.9
81.4
Percent
RSD
58.1
13.2
27.9
39.5
25.1
14.3
30.0
27.8
37.6
11.7
19.4
13.8
27.7
16.8
16.1
35.0
14.4
Laboratory Studies'1
Percent
Recovery
101.2
108.8
94.2
90.4
123.0
117.4
98.0
97.4
95.8
101.6
103.4
108.4
95.8
110.0
109.0
96.6
106.4
Percent
RSD
8.10
3.97
14.56
12.01
4.56
4.92
9.52
9.78
11.2
2.84
12.28
14.97
6.19
6.88
14.59
18.00
13.71
Fuerst, et al.
Field Test1
Percent
Recovery





127





108





Percent
RSD





12





8







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Risk Burn Guidance for
Hazardous Waste Combustion Facilities
TABLE B.2-Z
VOCs FOR WHICH FIELD METHOD EVALUATION DATA ARE AVAILABLE (Continued)
Compound
tetrachloroethene
methyl iodide (iodomethane)
allyl chloride (3-chloropropene)
ethylene dibromide (1,2-dibromoethane)
chloroprene
vinyl bromide
trichlorofluoromethane (freon 1 1)
First Field Test"
Percent
Recovery
97.7
72.8
29.9
34.9
40.1
60.7
Percent
RSD
21.9
37.6
19.5
31.6
22.4
34.3
not tested
Second Field Testb
Percent
Recovery
60.1
79.5
35.6
79.6
72.4
29.8
Percent
RSD
27.9
63.1
33.3
37.4
23.0
29.7
not tested
Third Field Testc
Percent
Recovery
57.5
77.8
36.4
81.6
76.4
28.4
Percent
RSD
12.5
20.4
29.6
31.0
12.3
30.9
not tested
Laboratory Studies'1
Percent
Recovery
111.6
108.4
127.2
97.0
104.2
110.8
Percent
RSD
6.72
5.28
5.43
14.86
4.31
9.30
not tested
Fuerst, et al.
Field Test3
Percent
Recovery
122





93
Percent
RSD
8





10
   * Mean of six replicate quadruple sampling train runs, with dynamic spiking.  Coal fired power plant. (McGaughey 1993; McGaughey 1994a)
   b Mean of eight replicate quadruple sampling train runs, with dynamic spiking. Organic chemical manufacturing facility.
           (McGaughey 1994a; McGaughey 1994c).
   c Mean of six replicate quadruple sampling train runs, with dynamic spiking.  Organic chemical manufacturing facility.
           (McGaughey 1994d; McGaughey 1994b; Jackson 1994; McGaughey 1994c).
   d Mean of five  replicate  quadruple sampling train runs. Full scale sampling train, dynamic spike, stack simulator.
           (Bursey 1993; McGaughey 1994a)
    Mean of 11-16 replicate quadruple sampling train runs, with dynamic spiking. Hazardous waste combustor. (Fuerst 1987)

   Note: References gathered and results summarized by Larry D. Johnson, in "Methods 98.  Status of Stationary Source Methods for Air Toxics" available at
   http://www.epa.gov/ttnemc01/news.html.
I

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If
§
I
£*.'
I'
Compound
2,2,4-trimethylpentane
carbon disulfide
w-hexane
benzene
toluene
First Field
Test"
Percent
Recovery
63.1
63.8
79.2
106.3
77.9
Percent
RSD
18.3
23.6
22.6
25.6
17.5
Second Field Testb
Percent
Recovery
75.9
42.0
92.9
100.1
98.8
Percent
RSD
27.7
27.7
23.5
23.6
30.3
Laboratory
Test'
Percent
Recovery
69/83
54/60
88/105
66/99
60/*
Percent
RSD
13/11
21/15
13/8
7/6
21/*
Fuerst, et al.
Field Testd
Percent
Recovery



106

Percent
RSD



6

                                                               TABLE B.2-2

                         VOCs FOR WHICH FEELD METHOD EVALUATION DATA ARE AVAILABLE (Continued)


     Results for Method 0030 nonhalogenated organic compounds, laboratory study and three field tests
      Mean of 9 replicate quadruple sampling train runs, with dynamic spiking. Coal-fired power plant. (Bursey 1997a; Jackson 1996a)
     " Mean of 11 replicate.quadruple sampling train runs, with dynamic spiking. Chemical manufacturing facility waste burner.  (Bursey 1997a; Jackson 1997a)
     0 Mean of 10 replicate quadruple sampling train runs, with dynamic spiking at two concentration levels. Source simulator. (Jackson 1996a; Bursey 1997a)
     d Mean of 16 replicate quadruple sampling train runs, with dynamic spiking. Hazardous waste combustor. (Fuerst 1987)

       Invalid results due to laboratory contamination.

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                                      TABLE B.2-3

                      CANDIDATE ANALYTES FOR METHOD 0040
Compounds that Met Method 301 Acceptance Criteria in a Field Method Evaluation
1,1,1 -tr ichloroethane
trichloroethene
1, 1-dichloroethane
1,1-dichloroethene
2,2,4-trimethylpentane
allyl chloride
benzene
carbon tetrachloride
methyl chloride (chloromethane)
hexane
methylene chloride
toluene
trichlorofluoromethane
vinyl bromide
vinyl chloride
71-55-6
79-01-6
75-34-3
75-35-4
540-84-1
107-05-1
71-43-2
56-23-5
74-87-3
1 10-54-3
75-09-2
108-88-3
353-54-8
593-60-2
75-01-4
Compounds that Failed to Meet Method Acceptance Criteria in a Field Method Evaluation
methyl bromide
1,3-butadiene
dichlorodifluoromethane
74-83-9
106-99-0
75-71-8
Appropriate Candidates for Method 0040 Not Tested
1 ,2-dichloro- 1 , 1 ,2,2-tetrafluoroethane
1 , 1 ,2-trichlorofluoroethane
chloroform
1 ,2-dichloropropane
tetrachloroethene
76-14-2
76-13-1
67-66-3
78-87-5
127-18-1
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                                       TABLE B.2-4

  CLEAN AIR ACT ANALYTES DEMONSTRATED TO BE INAPPROPRIATE FOR VOST IN
                                LABORATORY TESTING1
Volatile Organic Compound
acetaldehyde
acetonitrile
acrolein
acrylonitrile
allyl chloride
6/XchIoromethyl) ether
1,3-butadiene
carbonyl sulflde
chloromethyl methyl ether
1,4-dioxahe
epichlorohydrin
ethyl acrylate
ethylene imine
ethylene oxide
formaldehyde
methanol
methyl hydrazine
methyl isocyanate
methyl methacrylate
methyl tert-butyl ether
phosgene
triethylamine
vinyl acetate
CAS Number
75-07-0
75-05-8
107-02-8
107-13-1
107-05-1
92-87-5
106-99-0
463-58-1
107-30-2
123-39-11
106-89-8
140-88-5
151-56-4
75-21-8
50-00-0
67-56-1
60-34-4
624-83-9
80-61-6
1634-04-4
.75-44-5
121-44-8
108-05-4
Comment
Polar, water-soluble, reactive
Polar, water-soluble
Polar, water-soluble, reactive
Polar; purges poorly
Reactive
Reactive
Reactive
Too highly volatile; quantitative collection
questionable
Reactive; may decompose during sampling
Polar, water-soluble; low analytical system
response in laboratory testing
Reactive
Polymerizes easily
Water-soluble; polymerizes
Reactive
Polar; water-soluble; reactive
Polar; water-soluble
Polar; water-soluble; reactive
Polar; water-soluble; reactive
Polar; water-soluble; may polymerize during
sampling
Polar; water-soluble; low. analytical system
response during laboratory testing
Reactive
Polar; water-soluble
Polar; water-soluble; low analytical system
response during laboratory testing
   Note:       References gathered and results summarized by Larry D. Johnson, in "Methods 98. Status of
              Stationary Source Methods for Air Toxics" available at http://www.epa.gov/ttnemc01/news.html.
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For all of the VOC sampling and analytical methods, laboratories generally base their analytical target list
upon Method 8260B (or the most current version of the analytical purge and trap GC/MS method). Some
laboratories have eliminated from their target lists compounds known to be inappropriate analytes or
compounds that cannot be analyzed successfully. The permit writer should be aware which of the
compounds from Table B.2-1 are not appropriate for the sampling and analytical methodology and should
request demonstration of the effectiveness of the methodology for compounds where appropriateness of the
methodology has not been demonstrated. Some laboratories may also have eliminated compounds from
their target lists that have  not historically been found in stack emissions. Documents which can be
reviewed to identify compounds which have historically been found in stack emissions include the EPA
OSW risk assessment guidance (EPA 1998a) and various studies that attempt to identify products of
incomplete combustion (Lemieuxand Ryan 1997 and 1998; EPA 1997a; MRI 1997; EER 1997).

In addition to the complete target analyte list for the method, EPA OSW recommends that non-target
compounds (i.e., TICs) be characterized. Since the Method 8260B  analytical methodology uses GC/MS
(usually in the full scan mode), the methodology is amenable to the characterization of tentatively identified
compounds, according to  the criteria for identification presented in Method 8260 and summarized in
Section B. 11, in order to make the characterization of the source as complete as possible. For the Total
Organics Emissions (TOE) analysis discussed later in Section B.7, total organic mass in the volatile range
is one of the components  of the total recoverable organic mass that can be calculated. All organic
compounds that are identified and quantified are ultimately subtracted from the total organic emissions
mass value. It is, therefore, beneficial for the laboratory to identify and quantify the maximum number of
compounds when the analysis is performed. Although it is  in the facility's interest to characterize as many
TICs as possible, extensive characterization of TICs involves a significant commitment of time and
expertise and can reach a point of diminishing returns.  Therefore, it is recommended that TICs be
characterized when the peak intensity is 10 percent or more of full chromatographic scale, and that a
quantitative estimate of the value be obtained using the nearest-eluting internal standard and a response
factor of 1. Unless the identification of the TIC is confirmed by the analysis of an authentic standard, the
quantitative value should be qualified as "estimated."
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 None of the methods for VOCs described above are appropriate for polar water-soluble compounds.  There
 are some methods available in draft versions for specific VOCs; extended applicability of these methods to
 VOCs other than the specific analyte has not been demonstrated, but in some cases, field method validation
 data are available for the compound specified in the method. These polar water-soluble analytes are shown
 in Table B.2-5.  It is possible that these methods have a wider application, but the extended application
 remains to be demonstrated if these methods are used.
                                         TABLE B.2-5
 POLAR WATER-SOLUBLE ANALYTES FOR WHICH DRAFT METHODS ARE AVAILABLE
Volatile Organic Compound
methyl isocyanate
acetonitrile
methanol
Method
Sampling and Analysis of Isocyanates (McGaughey 1995)
Draft Method 207.1
Draft Method 207.2
Sampling and Analysis for Acetonitrile Emissions from Stationary
Sources (Steger 1997)
Test Method for the Measurement of Methanol Emissions from
Stationary Sources (Pate 1994; Peterson 1995)
 B.2.2
SIMPLE HYDROCARBONS
 Analysis of samples using the Method 8260B GC/MS target analyte list and Method 8260B analytical
 conditions will not provide analytical results for the more volatile alkanes, alkenes, and alkynes such as
 methane, ethane, ethene, acetylene, propene, and propyne. Methane and other aliphatics can comprise a
 significant percentage of total stack organics, and specific determinations for methane, ethane, propane,
 and other short-chain aliphatics are recommended to increase the completeness of the emissions
 characterization and potentially alleviate concerns about the percentage of the total organic mass that might
 be toxic. To achieve accurate measurements for these more volatile compounds, a Method 0040 Tedlar®
 bag determination with GC/FID analysis for the appropriate compounds will generally be necessary.
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 One simple way to quantify simple hydrocarbons without expanding the sampling effort is to utilize
 information already available as part of the Total Organic Emissions determination (Section B.7). The
 TOE determination involves measurements of volatile organics by field gas chromatography (FGC), and an
 initial calibration is performed using methane, ethane, propane, butane, pentane, hexane, and heptane. If
 the analysis shows that a stack gas constituent has the same retention time as one or more of the calibration
 standards, then that constituent can be quantified and included in the "identified" portion of the stack
 emissions.  A facility may also choose to calibrate the field gas chromatograph with additional compounds
 to identify more volatile hydrocarbons, thereby moving those compounds from the "unknown" to the
 "identified" portion of the stack emissions. Additional information is provided in Section B.7.
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                B.3  SEMIVOLATILE AND CONDENSIBLE COMPOUNDS

 The SW-846 Method 0010 sampling train provides the technical foundation for the sampling methods
 pertaining to the following groups of semivolatile organic compounds, defined as organic compounds with
 boiling points >100°C:

        •      Dioxins/Furans(D/Fs);
        •      Polynuclear Aromatic Hydrocarbons (PAHs);
        •      Polychlorinatedbiphenyls(PCBs);
        •      Chlorobenzenes (CBs) and chlorophenols (CPs); and
        •      All other semivolatile organic compounds (SVOCs) with boiling points above 100°C.

 The Method 0010 sampling train consists of a heated filter, a solid sorbent (XAD-2®) collection module,
 and a number of impingers. The chief difference in the applicability of the Method 0010 sampling train to
 each of the different groups of analytes lies in the standards used to spike the sorbent resin prior to
 collecting the semivolatile organic compounds, and the sample recovery procedures and analytical finish.
 Appendix B of Method 0010 includes procedures for preparation of the Method 0010 sampling train
 components for Total Chromatographable Organic Material analysis, but the Appendix B procedures have
 been superseded by SW-846 Method 3542 (Extraction of Semivolatile Analytes Collected Using Modified
 Methods (Method 0010) Sampling Train). The components of the Method 0010 sampling train are
 recovered in the field with subsequent preparation (according to Method 3 542) in the analytical laboratory.
 The field recovery procedures generate six sets of train components to be snipped to the laboratory:
               A particulate matter filter (prepared by Soxhlet extraction; dried, and concentrated for
               analysis);
               A front half rinse (filtered; filtrate added to Soxhlet extraction of the filter);
               A condenser rinse and rinse of all sampling train components located between the filter and
               the sorbent module (methylene chloride extraction with water separation; combined with
               filter extract, dried, and concentrated for analysis);
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                A sorbent trap section (combined with both filter holder back half rinse and condenser.
                rinse after water separation; Soxhlet extraction; dried; concentrated for analysis);
                Condensate and condensate rinse (methylene chloride extraction with water separation;
                dried; concentrated for analysis); and
                Silica gel (weighed to determine moisture content).
 The rinse used to recover the Method 0010 sampling train in the field consists of a 1:1 mixture of
 methylene chloride and methanol. Thus, any of the train components that include a rinse will contain
 methanol. If any methanol is retained in extracts when they are concentrated for analysis, the resulting
 concentrate will consist of all or mostly methanol and cannot be analyzed successfully. It is therefore
 essential that any steps of Method 3542 that include a rinse component include a water separation step to
 ensure removal of all of the methanol prior to concentration and analysis of the extract.

 Application of Method 3542 to the preparation of Method 0010 train components ultimately produces three
 5-mL extracts for analysis: the filter/front half rinse, the XAD-2® resin/back half rinse, and the
 condensate/condensate rinse. A final extract volume of 5 mL ensures that the more volatile of the
 semivolatile components (i.e., boiling points of 100-150°C) will be recovered quantitatively in the sample
 concentration step. Several laboratories have demonstrated extensive losses of these types of compounds
 when an extract is concentrated below 5 mL.  This area of concern becomes especially important if
 additional constituents from the Method 8260B target list are included in the semivolatile target list.  At
 present, because of the surrogate spiking scheme  used in the current version of Method 3542, the three
 extracts cannot be combined and analyzed. Research efforts are currently in progress to identify a
 surrogate spiking scheme that will allow combination of the extracts.

 An additional area of concern for the operation of the Method 0010 sampling train is sufficient cleanliness
 of the XAD-2* resin used to collect the semivolatile organic compounds. The XAD-2® resin as supplied by
 the manufacturer is impregnated with a bicarbonate solution to inhibit microbial growth during storage.
 The salt solution, any residual extractable. monomer and polymer species, and any residual organic
 chemicals used in the synthesis of the resin has to be removed before use of the resin in a Method 0010
 sampling train. There is no guarantee that "pre-cleaned" XAD-2® purchased from a commercial vendor
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 will be sufficiently clean to be used for its intended purpose. Furthermore, cleaned XAD-2® in storage at
 room temperature for more than 30 days should be re-cleaned in order to remove contaminants collected in
 storage. Appendix A of Method 0010 includes a procedure for the preparation of XAD-2® sorbent resin
 that uses extraction with a sequence of solvents (water, methyl alcohol, methylene chloride) followed by
 careful drying of the resin to prevent breaking the resin particles in the drying process. Method 0010 also
 provides quality control procedures for determination of residual methylene chloride in the cleaned, dried
 resin, as well as for determination of residual extractable organics. A standard procedure in many
 laboratories has been to use a cleanliness criterion of <10 ug/g of Total Chromatographable Organics
 extracted from a 20±0.1 gram (g) sample of dried resin, as specified in Method 0010. These standard
 procedures and quality criteria were developed to achieve environmental assessment screening studies of
 combustion sources (EPA 1978). However, this criterion for cleanliness is not sufficient to ensure adequate
 resin cleanliness for all Method 0010 applications. To ensure adequate cleanliness for all applications, the
 following procedures are recommended:
                Extract an aliquot of resin equal to the size resin sampling module that will be used in the
                Method 0010 sampling train (a 40 gram resin sample is usually used);
                Concentrate the extract to the same volume that will be used for the samples in the
                ultimate analysis; and
                Screen the resin blank according to the analysis that will be performed, at the Method
                Detection Limit for each compound of interest.
 The standard analytical procedures for semivolatile organic compounds collected in the Method 0010
 sampling train are found in Method 8270 (Method 8270C is the current version from SW-84.6 On-Line).
 Individual laboratories may have target analyte lists that differ slightly from Method 8270C and
 Table B.3-1. If a laboratory does not include all of the Table B.3-1 compounds on their standard
 semivolatile target analyte list, EPA OS W recommends that the laboratory identify the excluded
 compounds and explain the reason for the exclusion.  The permit writer can then review the laboratory's
 proposed list considering the laboratory's rationale for exclusion of certain compounds, as well as a review
 to ensure that the excluded compounds have not historically been found in stack emissions based on
 Appendix A-l of Has Human Health Risk Assessment Protocol for Hazardous Waste Combustion
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July 2001
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                                    TABLE B.3-1

   SEMIVOLATILE ORGANIC COMPOUND TARGET LIST - METHOD 8270C ANALYTES
Semivolatile Organic Compound
acenapththene
acenaphthylene
acetophenone
4-aminobiphenyl
aniline
anthracene
benzidine
benzoic acid1
benzo(a)anthracene
benzo(b)fluoranthene
benzo(k)fluoranthene
benzo(g,h,i)perylene
benzo(a)pyrene
benzyl alcohol1
&/s(2-chloroethoxy)methane
Z>/s(2-chloroethyl) ether
fe(2-ethylhexyl) phthalate2
4-bromophenyl phenyl ether
butylbenzyl phthalate2
4-chloroaniline
4-chloro-3-methylphenol
1 -chloronaphthalene
2-chloronaphthalene
2-chlorophenol
4-chlorophenyl phenyl ether
chrysene
dibenz(aj)acridine
dibenzo(a,h)anthracene
dibenzofiiran
CAS Number
83-32-9
208-96-8
98-86-2
92-67-1
62-53-3
120-12-7
92-87-5
65-85-0
56-55-3
205-99-2
207-08-9
191-24-2
50-32-8
100-51-6
111-91-1
111-44-4
117-81-7
101-55-3
85-68-7
106-47-8
59-50-7
90-13-1
91-58-7
95-57-8
7005-72-3
218-01-9
224-42-0
53-70-3
132-64-9
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July 2001
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                                    TABLE B.3-1
   SEMIVOLATILE ORGANIC COMPOUND TARGET LIST - METHOD 8270C ANALYTES
                                     (Continued)
Sem {volatile Organic Compound
di-«-butyl phthalate2
1 ,2-dichlorobenzene3
1,3-dichlorobenzene3
1 ,4-dichlorobenzene3
3,3'-dichlorobenzidine
2,4-dichlorophenol
2,6-dichlorophenol
diethyl phthalate?
j3-dimethylaminoazobenzene
7,12-dimethylbenz(a)anthracene
a, a-dimethylphenethylamine
2,4-dimethylphenol
dimethyl phthalate2
4,6-dinitro-2-methylphenol
2,4-dinitrophenol
2,4-dinitrotoluene
2,6-dinitrotoluene
di-n-octyl phthalate2
diphenylamine
ethyl methane sulfonate
fluoranthene
fluorene
hexachlorobenzene
hexachlorobutadiene3
hexachlorocyclopentadiene
hexachloroethane
indeno(l ,2,3-cd)pyrene
isophorone
3-methylcholanthrene
CAS Number
84-74-2
95-50-1
541-73-1
106-46-7
91-94-1
120-83-2
87-65-0
84-66-2
60-11-7
57-97-6
122-09-8
105-67-9
131-11-3
534-52-1
51-28-5
121-14-2
606-20-2
117-84-0
122-39-7
62-50-0
206-44-0
86-73-7
118-74:1
87-68-3
77-47-4
67-72-1
193-39-5
78-59-1
56-49-5
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                                    TABLE B.3-1
  SEMIVOLATILE ORGANIC COMPOUND TARGET LIST - METHOD 8270C ANALYTES
                                     (Continued)
Semivolatile Organic Compound
methyl methane sulfonate
2-methymaphthalene
2-methylphenol
4-methylphenol
naphthalene
1-naphthylamine
2-naphthylamine
2-nitroaniline
3-nitroaniline
4-nitroaniline
nitrobenzene
2-nitrophenol
4-nitrophenol
N-nitrosodi-w-butylamine
N-nitrosodimethylamine
N-nitrosodiphenylamine
N-nitroso-di-rt-propylamine
N-nitrosopiperidine
2,2'-oxy 6zs(l-chloropropane)
&X2-chloroisopropyl) ether
pentachlorobenzene
pentachloronitrobenzene
pentachlorophenol
phenacetin
phenanthrene
phenol
2-picoline
pronamide
pyrene
CAS Number
66-27-3
91-57-6
95-48-7
106-44-5
91-20-3
134-32-7
91-59-8
88-74-4
99-09-2
100-01-6
98-95-3
88-75-5
100-02-7
924-16-3
62-75-9
86-30-6
621-64-7
100-75-4
108-60-1
608-93-5
82-68-8
87-86-5
62-44-2
85-01-8
108-95-2
109-06-8
23950-58-5
129-00-0
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                                        TABLE B.3-1

   SEMIVOLATILE ORGANIC COMPOUND TARGET LIST - METHOD 82JOC ANALYTES
                                         (Continued)
Semivolatile Organic Compound
1 ,2,4,5-tetrachlorobenzene
2,3,4,6-tetrachlorophenol
1 ,2,4-trichlorobenzene
2,4,5-trichlorophenol
2,4,6-tnchlomphenol
CAS Number
95-94-3
58-90-2
120-82-1
95-95-4
88-06-2
Additional Constituents from the Method 8260B Target List with Boiling Points >10(f C
bromoform3
chlorobenzene3
ethylbenzene3
styrene3
1 , 1 ,2,2-tetrachloroethane3
toluene3
1,2,3-trichloropropane3
xylenes (total)3
75-25-2
108-90-7
100-41-4
100-42-5
79-34-5
108-88-3
96-18-4
1330-02-7
 Notes:

 'Common oxidation products of XAD-2® resin either due to the presence of ozone in ambient air or in the
 oxidizing stationary source matrix. When these compounds are reported, they should be qualified so the
 evaluator of the data can consider the possibility that these compounds are artifacts of the sampling
 process.

 2The phthalate esters are common laboratory contaminants. The presence and concentrations of these
 compounds in the laboratory and field blanks should be monitored carefully.

 3These compounds have boiling points between 100°C and 150°C and can easily be lost if an extract is
 concentrated below 5 mL prior to analysis.
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 Facilities (EPA 1998a) and various studies that attempt to identify products of incomplete combustion
 (Lemieux and Ryan 1997 and 1998; EPA 1997a; MRI 1997; EER 1997).

 A further consideration in selection of a target list for the analytical method is the data that are available
 from several field method evaluation studies using quadruple Method 0010 sampling trains, dynamic
 spiking, and EPA Method 301 (40 CFR Part 63 Appendix A) statistical data evaluation procedures. Data
 for the halogenated semivolatile organic compounds tested are included in Table B.3-2, and for non-
 halogenated semivolatile organic compounds in Table B.3-3. The collected data demonstrate that
 successful performance in the methodology is compound- and source-dependent and that, in general, non-
 polar, hydrophobic compounds tend to perform more successfully in the methodology than polar, water-
 soluble compounds. Data and information included in Attachment 2 describe the compounds listed in the
 Clean Air Act Amendments of 1990, with status relative to sampling and analytical methods. Comments
 and suggestions are also included, with references.  This information was gathered by Dr. Larry D. Johnson
 (EPA, retired) and is available on-line in the document "Methods 98.  Status of Stationary Source Methods
 for Air Toxics" (http://www.epa/gov/ttnemc01/news.html).

 In addition to the complete target list for the method, EPA OS W recommends that non-target compounds
 (i.e., TICs) be characterized. Since the Method 8270C analytical methodology uses GC/MS (usually in the
 full scan mode), the methodology is amenable to the characterization of tentatively identified compounds,
 according to the criteria for identification presented in Method 8270 and summarized in Section B. 11, in
 order to make the characterization of the source as complete as possible. In the Total Organics Emissions
 (TOE) analysis, total organic mass in the  semivolatile range is one of the components of the total
 recoverable organic mass that can be calculated. All organic compounds that are identified and quantified
 are ultimately subtracted from the total recoverable organic mass value. It is therefore beneficial for the
 laboratory to identify and quantify the maximum number of compounds when the analysis is performed.
 Although it is in the facility's interest to characterize as many TICs as possible, extensive characterization
 of TICs involves a significant commitment of time and expertise and can reach a point of diminishing
 returns. Therefore, EPA OSW recommends that TICs be characterized when the peak intensity is
 10 percent or more of full chromatographic scale, and that a quantitative estimate of the value be  obtained
 using the nearest-eluting internal standard and a response factor of 1.  Unless the identification of the TIC
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001
     B-55

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-
                                         TABLE B.3-2



      FIELD METHOD EVALUATION DATA FOR SELECTED HALOGENATED SEMIVOLATILE ORGANIC COMPOUNDS
Guidancefor
y Waste Combustion Facilities
Results for Method 0010 halogenated semivolatile organic compounds, laboratory study and five field tests.
Compound
i/Xchloromethyl) ether
epichlorohydrin
cis-l ,3-dichloropropene
/ra«s-l,3-dichloropropene
1 , 1 ,2-trichloroethane
1,2-dibromoethane
tetrachloroethene
chlorobenzene
bromoform
1 , 1 ,2,2-tetrachloroethane
dichloroethyl ether
1 ,4-dichlorobenzene
benzyl chloride
hexachloroethane
1 ,2-dibromo-3-chloropropane
1 ,2,4-trichlorobenzene
hexachlorobutadiene
benzotrichloride
First Field
Test"
Percent
Recovery
0.0
6.0
49.1
52.0
56.4
58.9
53.2
62.3
59.8
64.0
60.9
56.2
67.4
74.0
44.8
59.5
65.4
60.1
Percent
RSD
0.0
128.1
37.5
35.2
37.7
36.9
37.2
43.2
37.6
35.3
34.7
35.2
33.4
36.9
36.0
35.7
43.1
36.5
Second Field Testb
Percent
Recovery
0.0
13.4
50.3
79.8
60.3
62.5
49.4
65.1
69.3
73.9
77.0
73.5
73.9
70.9
73.8
76.1
77.1
72.4
Percent
RSD
0.0
44.2
48.3
63.4
38.2
40.4
52.5
40.7
35.7
34.5
34.3
35.7
. 34.9
35.6
35.7
34.5
34.3
38.0
Third Field
Test"
Percent
Recovery
36.4
58.5
73.8
79.4
79.8
85.3
73.8
76.4
87.0
81.7
80.3
84.2
82.1
83.6
84.3
86.8
84.7
75.2
Percent
RSD
44.9
39.7
25.1
21.9
17.6
19.4
30.7
18.2
17.3
18.5
17.4
15.9
20.9
15.5
16.8
14.2
16.6
20.5
Laboratory Test4
Percent
Recovery
80.7
187.0
51.9
29.3
84.4
83.9
78.7
86.2
123.0
79.7
82.5
78.7
77.9
84.6
69.8
67.7
68.1
85.7
Percent
RSD
23.2
11.7
12.9
13.1
13.5
12.7
17.6
11.9
14.2
10.5
10.5
12.5
11.7
13.3
11.4
13.3
14.0
16.8
Margeson, et al.
Two Field Tests'
Percent
Recovery







86/86

81.5








Percent
RSD







22/14

32.9









-------
So
s
                                                   TABLE B.3-2

FIELD METHOD EVALUATION DATA FOR SELECTED HALOGENATED SEMIVOLATILE ORGANIC COMPOUNDS
                                                    (Continued)
Guidance for
s Waste Combustion Facilities

Compound
2-chloroacetophenone
hexachlorocyclopentadiene
2,4,6-trichlorophenol
12,4,5-trichlorophenol
hexachlorobenzene
pentachlorophenol
pentachloronitrobenzene
chlorobenzilate
|3,3'-dichlorobenzidine
First Field
Test"
Percent
Recovery
56.0
42.3
49.8
62.7
44.6
42.4
43.4
40.7
4.4
Percent
RSD
40.7
61.8
47.0
35.3
33.9
41.5
37.9
50.6
164.9
Second Field Test"
Percent
Recovery
79.5
59.6
75.4
76.6
56.5
60.3
58.5
61.8
0.6
Percent
RSD
32.7
37.7
35.2
34.5
31.0
25.6
28.9
33.1
264.6
Third Field
Test1
Percent
Recovery
66.1
68.5
77.1
80.7
82.6
64.3
87.5
78.0
10.0
Percent
RSD
44.6
35.1
15.8
16.1
12.7
49.2
15.8
17.0
78.8
Laboratory Testd
Percent
Recovery
89.1
975.5
72.8
76.1
. 73.3
57.5
79.2
131.6
1352.4
Percent
RSD
11.7
24.8
26.2
23.8
10.0
60.3
10.1
32.0
43.4
Margeson, et al.
Two Field Tests'
Percent
Recovery





124



Percent
RSD





46.3



    Mean of 12 replicate quadruple sampling train runs. Coal fired power plant. (McGaughey 1993; McGaughey 1994a)
    Mean of 4 replicate quadruple sampling train runs. Organic chemical manufacturing facility. (McGaughey 1994b; Jackson 1996b; McGaughey 1996a)
    Mean of 10 replicate quadruple sampling train runs. Organic agricultural chemical manufacturing facility.  (Jackson 1995c; Bursey 1997a)
    Mean of 7 replicate quadruple sampling train runs. Full scale sampling train, dynamic spike, stack simulator.  (McGaughey 1994a)
   e Mean of 13-39 replicate quadruple sampling train runs, with dynamic spiking.  Two hazardous waste incinerators.  (Margeson 1987)
I

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                                     TABLE B.3-3




FIELD METHOD EVALUATION DATA FOR SELECTED NON-HALOGENATED SEMIVOLATILE ORGANIC COMPOUNDS
•n Guidancefor July 2001
nis Waste Combustion Facilities B-58
Results for Method 001 0 nonhalogenated semivolatile organic compounds, laboratory study and four field tests.
| Compound
[di-H-butyl phthalate
pw(2-ethylhexyl) phthalate
(m-Xp-cresol
[dimethyl phthalate
[phenol
|o-cresol
|J2,4-dinitrophenol
||4-nitrophenol
|[4,6-dinitro-o-cresol
(quinone
[hexamethylphosphoramide
jtrifluralin
jdimethylaminoazobenzene
|3,3'-dimethoxybenzidine
||o-anisidine
|jo-toluidine
[penzidine
JN,N,-dimethylaniline
[aniline
|4,4'-methyleneiw(2-chloroaniline)
|3,3'-dimethylbenzidine
First Field
Test4
Percent
Recovery
46
48
69
82
89
90
111
114
122
2
14
27
31
37
39
56
65
67
70
89
92
Percent
RSD
54
23
14
17
9
15
31
31
14
438
118
41
51
38
39
30
119
24
24
36
44
Second Field Testb
Percent
Recovery
107
65
65
123
56
71
24
59
53
Percent
RSD
14
93
49
7
22
34
87
18
34
not tested
not tested
not tested
17
6
4
24
8
54
35
25
6
67
129
149
70
95
31
45
49
129
Laboratory
Test0
Percent
Recovery
118
110
105
105
96
100
5
38
44
28
49
149
106
20
67
80
8
97
67
75
28
Percent
RSD
10
32
5
9
7
5
155
33
44
97
74
11
16
50
17
22
81
12
11
27
51
Margeson, et al.
Two Field Tests'1
Percent
Recovery




96
















Percent
RSD




14

















-------
Risk Burn Guidance for July 2001
Hazardous Waste Combustion Facilities B-59
1 ADLiL, B. J-J
FIELD METHOD EVALUATION DATA FOR SELECTED NON-HALOGENATED SEMIVOLATILE ORGANIC COMPOUNDS
(Continued)
t Compound
I-diethylaniline
jaryl
^1 carbamate
rolactam
litrosomorpholine
litrosodimethylamine
poxur
setylaminofluorene
•ene oxide
halic anhydride
methoxychlor
toluene
m-/p-xylene
quinoline
styrene
o-xylene
1,4-dioxane
cumene
phylbenzene
[parathion
|isophorone
First Field
Test"
Percent
Recovery
95
99
103
114
116
117
123
147
0.5
5
73
76
79
80
84
85
87
88
89
89
93
Percent
RSD
19
19
14
12
12
13
12
23
1481
144
19
11
12
19
10
11
11
11
12
28
12
Second Field Testb
Percent
Recovery
54
125
27
22
81
81
75
49
Percent
RSD
31
51
33
107
26
27
61
45
not.tested
not tested
75
97
79
82
39
97
79
95
93
76
96
51 '
11
12
30
81
9
21
9
9
28
13
Laboratory
Testc
Percent
Recovery
104
94
69
91
85
96
97
106
49
2
73
340
104
99
104
103
92
102
94
96
106
Percent
RSD
'16
22
21
18
23
9
20
17
66
136
30
45
9
8
8
8
8
9
10
11
13
Margeson, et al
Two Field Tests'1
Percent
Recovery











75/85



99
86.




Percent
RSD











26/15



8
17






-------
                                                       TABLE B.3-3

  FIELD METHOD EVALUATION DATA FOR SELECTED NON-HALOGENATED SEMTVOLATILE ORGANIC COMPOUNDS
irn Guidance for
rous Waste Combustion Facilities
(Continued)
Compound
acetbphenone
naphthalene
dibenzofuran
dichlorvos
DDE
4-nitrobiphenyl
iieptachlor
biphenyl
lindane
nitrobenzene
2,4-dinitrotoluene
methyl isobutyl ketone
chlordane
pyridine
First Field
Test"
Percent
Recovery
96
96
100
101
102
102
103
103
104
109
109
112
142
Percent
RSD
12
11
12
18
15
14
12
12
12
12
12
11
16
not tested
Second Field Testb
Percent
Recovery
98
94
103
57
93
104
35
105
104
100
102
101
85
Percent
RSD
13
10
12
•27
24
10
107
12
8
10
21
11
25
not tested
Laboratory
Test'
Percent
Recovery
132
107
110
68
120
104
95
106
107
97
110
103
93
Percent
RSD
12
8
11
30
10
12
9
9
9
9
24
9
14
not tested
Margeson, et al,
Two Field Tests'1
Percent
Recovery

106







117



82/71
Percent
RSD

16







17



24/18
 Mean of 10-20 replicate quadruple sampling train runs, with dynamic spiking. Coal-fired power plant. (Jackson 1996b; Bursey 1997b)
 Mean of 8-19 replicate quadruple sampling train runs, with dynamic spiking. Chemical manufacturing facility waste burner. (Jackson 1997b; Bursey 1997c)
c Mean of 6-14 replicate quadruple sampling train runs, with dynamic spiking. Source simulator.  (Jackson 1995b; Bursey 1993)
J Mean of 13-39 replicate quadruple sampling train runs, with dynamic spiking. Two hazardous waste incinerators.  (Margeson 1987)

-------
is confirmed by the analysis of an authentic standard, the quantitative value should be qualified as
"estimated."
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001
     B-61

-------
                             B.4 OTHER ORGANIC COMPOUNDS

 There is considerable variability in the analyses offered by commercial laboratories. EPA OSW
 recommends that specialized analyses to address specific groups of semivolatile organic compounds be
 utilized to the extent possible. Examples of specialized analyses for semivolatile compounds are discussed
 below.
 B.4.1
CHLOROBENZENES/CHLOROPHENOLS(CBS/CPS)
 Some commercial laboratories offer an expanded GC/MS target list for CBs/CPs, with a specialized target
 list as shown in Table B.4-1. There is some overlap with the semivolatile organic analytes on the SW-846
 Method 8270C target list, but the specialized CB/CP list is more extensive and use of the extended target
 list is recommended. Since the CB/CP analysis uses the same extracts that have been prepared for analysis
 using Method 8270C procedures, there is no technical reason why the additional compounds cannot be
 added to the calibration compounds for Method 8270C and determined in a single analysis. If a dual
 analysis is performed for Method 8270C analytes and CB/CPs, there should be no adverse impact upon
 Method Detection Limits for either determination. If a CB/CP compound is detected in both the Method
 8270C SVOC analysis and in the CB/CP analysis, EPA OSW recommends that the higher of the two
 results (if there is a difference) be used for the risk assessment and in the summation of the total identified
 organics. If a compound is not detected, EPA OSW recommends that the lower of the two detection limits
 (if there is a difference) be used.
 B.4.2
POLYCYCLIC AROMATIC HYDROCARBONS (PAHS)
Consistent with current EPA OSW guidance (EPA 1998a), PAHs are recommended for evaluation as
COPCs in site-specific risk assessments. The following PAHs are commonly detected: benzo(a)pyrene
(BaP); benzo(a)anthracene; benzo(b)fluoranthene; benzo(k)fluoranthene; chrysene; dibenz(a,h)anthracene;
and indeno(l,2,3-cd)pyrene.  EPA considers all of these compounds to be carcinogenic; all except chrysene
are known to be animal carcinogens. However, an oral cancer slope factor is available for only one PAH,
BaP. Although the analyte list for Method 8270C includes most PAHs, the detection limits for PAHs have
Risk Bum Guidance for
Hazardous Waste Combustion Facilities
                                                                     July 2001
                                                                         B-62

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                                        TABLE B.4-1

                       CHLOROBENZENES AND CHLOROPHENOLS
Chlorobenzenes
1 ,2-dichlorobenzene1
1 ,3-dichlorobenzene1
1,4-dichlorobenzene1
1,3,5-trichlorobenzene
1 ,2,4-trichlorobenzene1
1 ,2,3-trichlorobenzene
1 ,2,3,5-tetrachlorobenzene2
1 ,2,4,5-tetrachlorobenzene1-2
1 ,2,3,4-tetrachlorobenzene
pentachlorobenzene1
hexachlorobenzene1






CAS
Number
95-50-1
541-73-1
106-46-7
108-70-3
120-82-1
87-61-6
634-90-2
95-94-3
634-66-2
608-93-5
118-74-1






Chlorophenols
2-chlorophenol1
3-chlorophenol3
4-chlorophenol3
2,4-dichlorophenol1
2,5-dichlorophenol
2,3-dichlorophenol
2,6-dichlorophenol1
3,5-dichlorophenol
3,4-dichlorophenol
2,3,5-trichlorophenol
2,4,6-trichlorophenol1
2,4,5-trichlorophenol1
2,3,4-trichlorophenol
2,3,6-trichlorophenol
2,3 ,5,6-tetrachlorophenol4
2,3 ,4,5-tetrachlorophenol4-5
pentachlorophenol '
CAS Number
95-57-8
108-43-0
106-48-9
120-83-2
583-78-8
576-24-9
87-65-0
591-35-5
95-77-2
933-78-8
88-06-2
95-95-4
15950-66-0
933-75-5
935-95-5
490-151-3
87-86-5
Notes:

'This compound is also included on the list of Method 8270C analytes.

2Co-elute; reported as totals.

3Co-elute; reported as totals.

4Co-elute; reported as totals.

5The analyte list for CB/CPs does not include 2,3,4,6-tetrachlorophenol(58-90-2), which is included on the
list of Method 8270C analytes.
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001
     B-63

-------
been found to be critical for the indirect risk pathway. Using selected ion monitoring mass spectrometric
techniques in the Method 8270C analysis will improve the detection limits for the PAHs, but this
improvement may not be sufficient for the risk assessment. It is therefore recommended that, for the lowest
possible method detection limits, PAHs be determined by a separate analysis using HRGC coupled with
HRMS or possibly low resolution mass spectrometry (LRMS) in the selected ion monitoring mode after the
application of chromatographic cleanup procedures designed to remove interfering organic compounds. If a
PAH is detected in both the SVOC (Method 8270C) analysis  and in a specialized PAH analysis, EPA OS W
recommends that the higher of the two results be used for the risk assessment and in the summation of total
identified organic compounds. If a PAH is not detected in either of the two analyses, EPA OSW
recommends that the lower of the two detection limits be used.

GARB Method 429 (Determination of Polycyclic Aromatic Hydrocarbon (PAH) Emissions from Stationary
Sources) [http://www.arb.ca.gov/testmeth/vol3/vol3.htmjappliesto the determination of 19 PAHs listed in
Table B.4-2. In this method, particulate and gas phase PAH are extracted isokinetically from the stack and
collected by a Method 0010 sampling train. The analytical methodology used is isotope dilution mass
spectrometry combined with HRGC.  Isotope dilution entails the addition of internal standards to all samples
in known quantities, matrix-specific extraction of the sample with appropriate organic solvents, preliminary
fractionationand cleanup of extracts, and analysis of the processed extract for PAH using HRGC coupled
with either HRMS or LRMS operated in the selected ion monitoring mode.

EPA OSW recommends that the decision regarding specific analytical procedures for the PAHs be made
considering the detection limits which are determined to be necessary for PAHs based upon a preliminary
risk evaluation. PAHs analyzed by LRMS have detection limits in the range of 1-5 ug/fraction; PAHs
analyzed by HRMS typically have detection limits in the range of 10-50 ng/fraction. The actual detection
limits that can be achieved are limited by interferences remaining in the extract and the background level of
PAHs observed in the XAD-2® resin used to collect the PAH.

It may be possible to combine CARB Method 429 analytical procedures with SW-846 Method 0023A D/F
analytical procedures or with SW-846 Method 0010/3542 SVOC analysis using careful planning. An
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001
     B-64

-------
                                      TABLE B.4-2

                      TARGET ANALYTES FOR CARS METHOD 429
Polycyclic Aromatic Hydrocarbons
acenaphthene
acenaphthylene
anthracene
benzo(a)anthracene
benzo(a)pyrene
benzo(b)fluoranthene
benzo(e)pyrene
benzo(ghi)perylene
benzo(k)fluoranthene
chrysene
dibenz(a,h)anthracene
fluoranthene
fluorene
indeno(l ,2,3-cd)pyrene
2-methylnaphthalene
naphthalene
perylene
phenanthrene
pyrene
CAS Number
83-32-9
208-96-8
120-12-7
56-55-3
50-32-8
205-99-2
192-97-2
191-24-2
207-08-9
218-01-9
53-70-3
206-44-0
86-73-7
193-39-5
91-57-6
91-20-3
198-55-0
85-01-8
129-00-0
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001
     B-65

-------
extract that has been subjected to the specialized cleanup procedures for PAHs cannot be used for any other
semivolatile determination. However, without the final cleanup step, sample preparation and extraction can
be designed to achieve multiple types of determinations for semivolatile organic compounds. The user
should be aware that one effect of a scheme that involves splitting the sample for different analyses may be
an unacceptable increase in the detection limits that the methodology is capable of achieving. There are
presently several laboratories that are performing combined methodologies. There is, however, no numbered
EPA method that has been evaluated and is accepted for its ability to perform combined analyses on a single
sample.  Laboratories that perform combined analytical procedures regard their specific procedure as
proprietary and have not published any data to support their specific analysis to demonstrate compound
recoveries and effects upon method detection limits. Potential implications of combined methodologies are
discussed further in Section B.8.
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001
     B-66

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                           B.5 POLYCHLORINATEDBIPHENYLS

Stack determinations for polychlorinatedbiphenyls (PCBs) are recommended during risk burns, based on
evidence that PCBs can be emitted from combustion sources regardless of PCB contamination in the feed.
An increasing body of information supports the likelihood that PCBs may be formed as by-products of the
combustion process, similar to D/Fs.

The need for sampling and analysis of polychlorinatedbiphenyls (PCBs) was first discussed in detail in the
Human Health Risk Assessment Protocol for Hazardous Waste Combustion Facilities (EPA 1998a). That
guidance cites limited laboratory and field studies showing that PCBs can be formed during the combustion
of hazardous waste. Stack tests performed in U. S. EPA Region 10 on a boiler and an incinerator burning
waste with 0.07 and 1.4 percent chlorine, respectively, confirmed the presence of PCBs in the stack gases
(Kalama Chemical, Inc. 1996; Idaho National Engineering Laboratory 1997). The concentration of total
PCBs detected in the incinerator stack gas was 211 ng per dry standard cubic meter (dscm) @ 7% oxygen at
low temperature conditions (1,750 °F) and 205 ng/dscm @ 7% oxygen at high temperature conditions
(2,075 °F). For the incinerator test, PCBs with more than four chlorine atoms in the molecule comprised
51 percent of the total PCBs in the low temperature test and 59 percent of the total PCBs in the high
temperature test.  The EPA OS W risk assessment guidance (EPA 1998a) also references laboratory studies
suggesting the possibility of formation of PCBs as products of incomplete combustion from hazardous
waste with a high chlorine content. When chlorinated paraffins (such as pesticides) were heated under
conditions similar to incinerator conditions, the combustion of highly chlorinated (60 percent or higher)
wastes was demonstrated to produce PCBs (Bergmann 1984). The EPA OSW risk assessment guidance
(EPA 1998a) provides the following general recommendations with regard to the testing of PCBs:
              PCBs should be tested at combustion units that burn PCB-contaminated wastes or waste
              oils;
              PCBs should be tested at combustion units that burn variable waste streams such as
              municipal and commercial wastes for which it is reasonable to suspect PCB contamination;
              and
              PCBs should be tested at facilities that burn highly chlorinated waste streams.
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001
     B-67

-------
Concerning testing for PCBs at facilities other than the facilities described above, the guidance states: "Due
to the toxicity and uncertainties associated with combustion chemistries, the permitting authority may
choose to confirm the absence of these compounds from stack emissions via stack gas testing for units
burning hazardous wastes" (EPA 1998a).

Since the time that the EPA OSW risk assessment guidance (EPA 1998a) was released, an increasing body
of information has been developed which supports the likelihood that PCBs may be formed as by-products
of the combustion process, similar to D/Fs.  Lemieux hypothesized that, if PCBs and D/Fs are formed by
similar mechanisms, then emissions of PCBs should correlate with emissions of D/Fs (Lemieux and others
1999). This hypothesis was tested by reviewing data where both PCBs and D/Fs were measured. In most
cases, PCBs were found in the stack even when there were no PCBs in the feed.  Overall, PCB emissions
exceeded D/F emissions by approximately a factor of 20, and this trend appeared to hold over five orders of
magnitude in D/F emissions. In addition, Alcock has established that waste combustion units contribute
significantly to total emission inventories of PCBs, and that PCBs can be important from a risk standpoint
(Alcock and others 1999). In the United Kingdom, where a TEQ is used to assess the potential toxicity of
complex mixtures of D/Fs and PCBs, the PCBs contributed up to 60 percent of the TEQ for a cement kiln
facility.  For other sources, the PCB contribution was more minimal (Alcock and others 1999).

Based on evidence that PCBs can be emitted from combustion sources regardless of PCB contamination in
the feed, EPA OSW now recommends stack determinations for polychlorinatedbiphenyls (PCBs) during
risk bums even if the facility does not burn PCB-contaminated, highly variable, or highly chlorinated waste
streams. With proper planning, the PCB determination can be made using portions of the D/F sampling
train extracts. Combined measurement methodologies are discussed further in Section B.8.

The current toxicity approach for PCBs (EPA 1996c; Van den Berg and others 1998) calls for data on:

       •       The total PCB concentration; and
       •       Congener-specific analyses for the 12 toxic dioxin-like coplanar and mono-ortho-substituted
               PCBs listed in Table B.5-1.
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001
     B-68

-------
                                    TABLE B.5-1

                          POLYCHLORINATED BIPHENYLS
Dioxin-Like Coplanar PCBs
3,3',4,4'-tetrachlorobiphenyl
3,4,4',5-tetrachlorobiphenyl
2,3,3',4,4'-pentachlorobiphenyl
2,3,4,4' ,5-pentachIorobiphenyl
2,3',4,4',5-pentachlorobiphenyl
2',3,4,4',5-pentachlorobiphenyl
3,3',4,4',5-pentachlorobiphenyl
2,3 ,3',4,4',5-hexachlorobiphenyl

2,3,3',4,4',5-hexachlorobiphenyl

2,3',4,4',5,5'-hexachlorobiphenyl

3,3',4,4',5,5'-hexachlorobiphenyl
2,3,3',4,4',5,5'-heptachlorobiphenyl

IUPAC Number
77
81
105
114
118
123
126
156
157
167
169
189
CAS Number
32598-13-3
70362-50-4
32598-14-4
74472-37-0
31508-00-6
65510-44-3
57465-28-8
38380-08-4
69782-90-7
52663-72-6
32774-16-6
39635-31-9
Total Homolog Groups Summed to Determine Total PCBs
monochlorobiphenyls
dichlorobiphenyls "
trichlorobiphenyls
tetrachlorobiphenyls
pentachlorobiphenyls
hexachlorobiphenyls
heptachlorobiphenyls
octachlorobiphenyls
nonachlorobiphenyls
decachlorobiphenyl
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TEFs are applied to the congener-specific concentrations to evaluate dioxin-like toxicity. Risks from the
dioxin-like congeners (evaluated using the slope factor for dioxin) are then added to risks from the rest of the
mixture (evaluated using the slope factor for PCBs, applied to total PCBs reduced by the amount of dioxin-
like congeners).

Earlier EPA OS W guidance (EPA 1994a, 1994b, 1994c and 1994d) recommended that all PCB congeners
(209 different chemicals) be treated in a risk assessment as a mixture having a single carcinogenic potency.
Additional research on PCBs has been reported since the original compilation of PCB data by EPA
(ATSDR1995; EPA 1996c; Van den Berg and others 1998). The most important result of this additional
research is the demonstration that some of the moderately chlorinated PCB congeners can have dioxin-like
effects (EPA 1996c; ATSDR 1995; Van den Berg and others 1998). The following PCB congeners have
been identified as  dioxin-like or coplanar PCBs (EPA 1996c; Van den berg and others 1998) because when
the rings rotate into the same plane, the shape of the PCB molecule is  very similar to the shape of a
polychlorinated dibenzofuran molecule:

       •      3,3 A,4'-tetrachlorobiphenyl(Chemical Abstracts Services (CAS) Number 32598-13-3)
               3,4,4',5-tetrachlorobiphenyl(CAS 70362-50-4)
               2,3,3'4,4'-pentachlorobiphenyl(CAS 32598-14-4)
               2,3 A4',5-pentachlorobiphenyl(CAS 74472-37-0)
               2,3',4,4',5-pentachlorobiphenyKCAS 31508-00-6)
               2',3,4,4',5-pentachlorobiphenyl(CAS 65510-44-3)
               3,3',4,4',5-pentachlorobiphenyl(CAS 57465-28-8)
               2,3,3',4,4',5-hexachlorobiphenyl(CAS 38380-08-4)
               2,3,3',4,4',51-hexachlorobiphenyl(CAS 69782-90-7)
               2,3',4,4',5,5'-hexachlorobiphenyI(CAS 52663-72-6)
               3,3A,4\5,5'-hexachlorobiphenyl(CAS 32774-16-6)
               2,3,3',4,4',5,5I-heptachlorobiphenyl(CAS 39635-31-9).

 The World Health Organization has derived interim toxicity equivalency factors for these coplanar PCBs
 (Van den Berg and others 1998). Additional congeners are suspected of producing similar biochemical
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responses, but there are not sufficient data to derive toxicity equivalency factors for these additional
congeners. EPA OS W has recommended that permitting authorities estimate risks from coplanar PCBs by
applying a toxicity equivalency factor (TEF) to each coplanar PCB and then applying a slope factor for
dioxin (EPA 1998a).  Risks from the rest of the mixture are calculated by applying a slope factor for total
PCBs.

PCBs were originally prepared and used commercially as mixtures of compounds called Aroclors. Several
analytical methods using gas chromatography focus on the identification and quantitative analysis of PCBs
as Aroclors. This type of analytical methodology is inappropriate for site-specific risk assessments at
combustion facilities because the Aroclor mixtures of PCBs are altered both in the combustion process and
in weathering, and because the PCBs which may be formed in a combustion process would not be expected
to resemble a commercial mixture. PCBs as analyzed in stationary source emissions are therefore not
recognizable as Aroclors, and these types of analytical methods therefore cannot generally be used to
identify individual PCB congeners. A sampling and analytical method specific for the identification and
quantitative analysis of both the coplanar PCBs and total PCBs in stationary sources at each chlorination
level is being developed and is not currently available even in draft form. Currently available analytical
methodology includes:

               S W-846 Method 8082: Polychlorinated Biphenyls (PCBs) by Gas Chromatography
               Method 8082 is used to determine the concentrations of PCBs as Aroclors or as specific
               individual PCB congeners (not specifically the coplanar PCBs) in extracts from solid and
               aqueous matrices. No sampling procedures for stationary sources are included, and no
               sample spiking/preparation procedures for a solid sorbent matrix are included. This method
               is not applicable to the determination of PCBs in a stationary source matrix.
       •       Office of Water Method 1668A: Chlorinated Biphenyl Congeners in Water, Soil, Sediment,
               and Tissue by High Resolution Gas Chromatography/HighResolutionMass Spectrometry
               Method 1668A applies to determination of the toxic PCBs in water, soil, sediment, sludge,
               tissue, and other sample matrices by HRGC/HRMS. The coplanar PCBs and other specific
               congeners, as well as homolog totals, may be determined by this method. The Method
               Detection.Limit for a specific compound in water has been determined experimentally at the
               parts per quadrillion (ppq) level. There is no sampling procedure for stationary sources
               included in the method, nor are sample preparation procedures included for stationary
               source matrices.  However, the analytical methodology should be applicable for the analysis
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              of the coplanar PCBs and other specific congeners, as well as the determination of total
              PCBs at each chlorination level, and can be combined with a semivolatile sampling
              procedure (such as Method 0023 A or CARS 428) with appropriate sample recovery and
              preparation steps.

              CARB Method 428; Determination of Polychlorinated Dibenzo^-Dioxin (PCDD),
              Polychlorinated Dibenzofuran(PCDF), and Polychlorinated Biphenyl Emissions from
              Stationary Sources (http://www.arb.ca.gov/testmeth/vol3/vol3.htm).

              CARB Method 428 applies to the determination of D/Fs and PCBs in emissions from
              stationary sources at nanogram to picogram levels, with the sensitivity ultimately
              achievable for a given sample dependent upon the types and concentrations of potentially
              interfering compounds present, the original sample size, and the instrument sensitivity. The
              analytical methodology uses HRGC/LRMS or HRGC/HRMS. CARB Method 428 is
              intended to determine PCBs as homolog groups (by level of chlorination) in samples
              containing PCBs as single congeners or as complex mixtures. CARB Method 428 without
              modification calls for analysis of PCBs using HRGC/LRMS, with detection limits ranging
              from 0.1 to  1.0 fig/sample per homolog group when both D/F and PCBs are determined
              from the same sample. Since PCBs can be risk drivers, EPA OS W recommends that
              CARB 428 be used with HRMS to provide PCB homolog group concentrations at lower
              detection limits. CARB Method 428, as written, does not specifically provide information
              on the 12 coplanar PCBs. However, if CARB Method 428 procedures are combined with
              appropriate analytical procedures, such as those described by EPA Office of Water
              Method 1668A for spiking standards, calibration standards, and subsequent analysis by
              HRMS, then specific characterization of the 12 coplanar PCBs as well as each homolog
              group should be achieved at the highest possible sensitivity.
In summary, a combination of methodologies may be needed for determination of both coplanar and total

PCBs. A semivolatile sampling procedure, such as Method 0023 A or CARB 428, can be combined with

appropriate sample recovery and preparation steps, similar to those described in CARB 428, and followed

by HRGC/HRMS analytical determinations such as those described in Method 1668A for coplanar PCBs

and homolog totals. Whenever a combined or modified sampling and analytical method is used, EPA OS W

recommends that the user demonstrate performance for the analytes of interest at the stationary source of

interest. Combined methodologies are discussed further in Section B.8.
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           B.6 POLYCHLORINATED DIBENZODIOXINS AND DIBENZOFURANS

Consistent with current EPA OS W guidance (EPA 1998a), EPA OS W recommends that polychlorinated
dibenzodioxins and polychlorinated dibenzofurans (D/Fs) be addressed in site-specific risk assessments for
combustion facilities. There are 210 individual polychlorinated dibenzodioxin and dibenzofuran compounds
or congeners; all of these compounds do not have equivalent toxic properties. The most toxic dioxin is
2,3,7,8-tetrachlorodibenzodioxin(TCDD) (EPA 1994e). The D/F congeners with chlorine atoms
substituted in the 2,3,7 and 8 positions, a total of 17 compounds, are assigned a value, referred to as a
toxicity equivalency factor (TEF), which relates the toxicity to that of 2,3,7,8-TCDD, which has a TEF
value of 1.  Since 2,3,7,8-TCDD is the most toxic, all other D/F congeners have decimal TEF values.
Current analytical methodology is designed to focus on obtaining accurate values for the 17 specific D/Fs
listed in Table B.6-1, as well as total quantities for other remaining congeners at each level of chlorination.
                                        TABLE B.6-1
                                 2,3,7,8-SUBSTITUTED D/Fs
Dioxin Congener
2,3,7,8-tetrachlorodibenzo-/?-dioxin
l,2,3,7,8-pentachlorodibenzo-/7-dioxin
1 ,2,3,4,7, 8-hexachlorodibenzo-/7-dioxin
1,2,3,6, 7,8-hexachlorodibenzo-p-dioxin

1,2,3,7,8,9-hexachlorodibenzo-p-dioxin

1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin
octachlorodibenzo-p-dioxin




Furan Congener
2,3,7,8-tetrachloro dibenzofuran
1 ,2,3 ,7,8-pentachlorodibenzofuran
2,3,4,7,8-pentachlorodibenzofuran
1 ,2,3,4,7,8-hexachlorodibenzofuran

1 ,2,3 ,6,7,8-hexachlorodibenzofuran

1,2,3,7,8,9-hexachlorodibenzofuran
2,3 ,4,6,7,8-hexachlorodibenzofuran
1 ,2,3 ,4,6,7,8-heptachlorodibenzofuran

1,2,3,4,7,8,9-heptachlorodibenzofuran
octachlorodibenzofuran
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As indicated in Table B.l-4, SW-846 Method 0023A is recommended for stack sampling and sample
preparation to determine D/Fs, with analytical procedures performed according to SW-846 Method 8290.
Method 8290 is an isotope dilution HRGC/HRMS analytical method. The sampling methodology for
Method 0023A is basically Method 0010, modified by the use of specific isotopically-labeledD/F standards
to spike the sorbent prior to use in the field and specific sampling train recovery procedures to be used in the
field. Since this sampling train will collect all S VOCs, including D/Fs, PAHs, PCBs, CB/CPs, it is possible
to modify the sample preparation and analytical methodology to encompass one or more of these additional
compound classes. However, EPA OSW recommends that any modification of the methodology be
described to the regulatory authority in detail, and that the user demonstrate acceptable detection limits and
performance for the modified methodology. Combined methodologies, are discussed further in Section B.8.

Method 0023A supersedes Method 23 (40 CFR Part 60 Appendix A) for Resource Conservation and
Recovery Act (RCRA) testing (EPA 1997b).  Procedures for addition of isotopically-labeled standards to
both the XAD-2® sorbent trap and filter, as well as separate extraction and analysis of the sorbent and filter,
have been added in order to quantify recoveries from each fraction.  The isotopically-labeled surrogate
standards are spiked onto the XAD-2® sorbent prior to sampling, and onto the filter prior to extraction.
Use of Method 0023A entails additional analysis, which can increase cost as well as detection limits.
However, there is an important tradeoff from a quality assurance perspective. Specifically, Method 0023A
provides surrogate compound recovery data for each train fraction, whereas Method 23 does not. For this
reason, EPA OSW continues to recommend use of Method 0023 A.

Target detection limits for D/Fs should be considered very carefully. Section 6.2.3 of Method 0023 A
provides guidance on determining a minimum sampling time based upon desired D/F detection limits. EPA
OSW recommends that the desired D/F detection limits be determined prior to testing by performing a
preliminary risk assessment. If lower method detection limits are desired, it may be possible to  sample for a
longer time: D/F testing for periods as long as 6-8 hours has been performed.

Field sample recovery and laboratory sample preparation steps determine whether Method 0023 A can be
modified to provide simultaneous determination of PAHs, PCBs, SVOCs, or CB/CPs.  Method 0023A
specifies sequential acetone, methylene chloride, and toluene rinses of the front half and back half portions
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of the sampling train to recover the train, with all of the solvents combined in one container for the front half
rinse and another for the back half rinse. If SVOCs and CB/CPs are being determined simultaneously with
the D/Fs, it is appropriate to separate the toluene rinse from the acetone and methylene chloride because
SVOCs could be lost in subsequent laboratory sample preparation steps.  If the sampling train is to be
analyzed exclusively for D/Fs, the impinger liquid may be discarded after weight or volume is recorded
because D/Fs will not be found dissolved in the aqueous impingers. However, if other SVOCs are being
determined, SVOCs that are sufficiently volatile and water-soluble may be found in the impingers, so the
condensate and the impinger solutions should be retained and analyzed.

In the laboratory, surrogate standards are added to the filter and internal standards are added to both the
filter/front half and XAD-2® resin/back half fractions. The two fractions are then extracted separately using
Soxhlet extraction with toluene, then each fraction is concentrated. One half of each fraction is archived,
and the other half is solvent-exchanged to hexane and then subjected to cleanup procedures using three
different chromatographic columns according to the procedures described in Method 8290, after addition of
isotopically-labeled standards to monitor recovery through cleanup.  Additional isotopically-labeled
standards are added to each fraction prior to analysis by Method 8290 HRGC/HRMS techniques (target
compounds for Method 8290 are shown in Table B.6-2).  SW-846 Method 8280 is available with a
HRGC/LRMS analytical methodology, but detection limits achieved with the LRMS analytical method are
an order of magnitude higher than the detection limits that can be achieved with HRMS. Use of
Method 8280 is therefore not appropriate for the generation of risk burn data without modification of the
methodology.  For data reporting, the results from each sampling train fraction will need to be added
together to arrive at a total mass for each sampling train. If all of the fractions are non-detects, then EPA
OSW recommends that the sum of the non-detects should be reported with a "less than" sign.  If D/Fs are
detected in some of the train fractions but not in others, then EPA OSW recommends that the data be
reported as a range (i.e., "greater than" the total detected amount, but "less than" the total detected amount
plus the non-detects). Also, Section 7.4 of Method 0023 A allows a "non-detect"to be treated as zero if it is
less than 10 percent of the total detected amount, subject to approval by the regulatory agency.
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                                    TABLE B.6-2

             COMPOUNDS THAT CAN BE DETERMINED BY METHOD 8290
Dioxins
2,3,7,8-tetrachlorodibenzo-p-dioxin
1,2,3,7,8-pentachlorodibenzo-p-dioxin
1,2,3,6,7,8-hexachIorodibenzo-p-dioxin
lAS.^y.S-hexachlorodibenzo-p-dioxin
1,2,3,7,8,9-hexachlorodibenzo-p-dioxin
1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin
octachlorodibenzo-/7-dioxin



CAS
Number
1746-01-6
40321-76-4
57635-85-7
39227-28-6
19408-74-3
35822-39-4
3268-87-9



Furans
2,3,7,8-tetrachlorodibenzofuran
1,2,3,7,8-pentachlorodibenzofuran
2,3,4,7,8-pentachlorodibenzofuran
1,2,3,6,7,8-hexachlorodibenzofuran
1,2,3,7,8,9-hexachlorodibenzofuran
1,2,3,4,7,8-hexachlorodibenzofuran
2,3,4,6,7,8-hexachlorodibenzofuran
1,2,3,4,6,7,8-
heptachlorodibenzofuran
1,2,3,4,7,8,9-
heptachlorodibenzofuran
octachlorodibenzofuran
CAS
Number
51207-31-9
57117-41-6
57117-31-4
57117-44-9
72918-21-9
70648-26-9
60851-34-5
67562-39-4
55673-89-7
39001-02-0
Totals for Each Congener Group
tetrachlorodibenzo-/7-dioxins
pentachlorodibenzo-p-dioxins
hexachlorodibenzo-p-dioxins
heptachlorodibenzo-p-dioxins
tetrachlorodibenzofurans
pentachlorodibenzofurans
hexachlorodibenzofurans
heptachlorodibenzofiarans
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EPA is currently evaluating the potential for formation of fluorine- and bromine-substitutedD/Fs, as well as
sulfur-analogs of D/Fs, but analysis of stack samples for these types of compounds is not anticipated at this
time (EPA 1996d and 1996e).  Few calibration standards are commercially available to perform the
analysis, and analytical methods are not yet developed. EPA has conducted preliminary studies of
chlorinated, brominated, and mixed bromochloro-D/Fs in stack emissions (Lemieux and Ryan 1997 and
1998), but further research is necessary to provide better quantitative analysis for these compounds and to
develop and validate the appropriate sampling and analytical methodologies. The Human Health Risk
Assessment Protocol for Hazardous Waste Combustion Facilities (EPA 1998a) recommends that these
compounds be addressed in the uncertainty section of the risk assessment.

Even though the primary focus in this document and in the EPA OS W risk assessment guidance is on the
tetra- through octa- D/F congeners, EPA has developed analytical standards for certain mono- through tri-
congeners.  EPA OSW encourages stack gas analysis for these mono- through tri-congeners whenever
possible. The analysis can be performed at very little increased cost, and the results may support
development of a database to determine which (if any) of the mono- through tri-chloro congeners can act as
surrogates for the tetra- through octa-congeners. Identification of an easily measurable surrogate may
support future development of a continuous emissions monitoring system to indicate D/F emissions (see
http://www.epagov/appcdwww/crb/empact/index.htm).
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                              B.7 TOTAL ORGANIC EMISSIONS

The Human Health Risk Assessment Protocol for Hazardous Waste Combustion Facilities.  Volume One
(EPA 1998a) states:

         "Although U. S. EPA OSW will not require a risk assessment for every possible metal or
         PIC from a combustion unit, this does not imply that U. S. EPA OSW will allow only
         targeted sampling for COPCs during trial burn tests. Based on regional permitting
         experience and discussions with regional analytical laboratories, U. S. EPA OSW
         maintains that complete target analyte list analyses conducted when using U. S. EPA
         standard sampling methods (e.g., 0010 or 0030) do not subject facilities to significant
         additional costs or burdens during the trial burn process. Facilities conducting stack
         emission sampling should strive to collect as much information as possible which
         characterizes the stack gases generated from the combustion of hazardous waste.
         Therefore, every trial burn or "risk burn" should include, at a minimum, the following
         tests: Method 0010, Method 0030 or 0031 (as appropriate), total organic compounds
         (using the Guidance for Total Organics, including Method 0040), Method 23A, and the
         multiple metals train. Other test methods may be approved by the permitting authority for
         use in the trial burn to address detection limit or other site-specific issues."

To determine the potential risk from a hazardous waste combustor, EPA OSW recommends that emissions
be identified and quantified to the maximum extent practicable. However, the numbered methods listed
above are not sufficientto characterize all organic emissions from waste combustion. Studies (Harris 1982;
EPA 1984) have shown that standard analyses will often account for less than 20 percent of the total
organic material in an emission sample. To evaluate the uncertainty associated with a risk assessment, EPA
OSW has recommended that a measure of the completeness of the emissions characterization be developed
based on a Total Organic Emissions (TOE) analysis quantifying the total recoverable organic mass emitted
from the source (EPA 1998a).  The quantity of unidentified organic compounds can then be estimated based
on the difference between the TOE mass and the total quantity of identified organic compounds.

The fundamental research for the TOE analysis was performed by EPA's Office of Research and
Development between 1976 and 1985 as part of the environmental assessment of stationary sources (EPA
1976).  Gas sample analysis (compounds with boiling point less than 100°C) was performed using a gas
chromatograph in the field, with calibration performed using a series of hydrocarbon standards as well as
individual organic compounds of interest due to toxicity or potential response in the analysis methods. The
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result of that research was a guidance manual for performing base level characterization of emission sources
(EPA 1978).   From 1990 to 1997, EPA Office of Research and Development validated RCRA methods
including S W-846 Method 0010, Method 3542, and Method 8270 on a variety of hazardous waste
combustion sources (Johnson 1998). To date, the methods recommended in EPA's TOE guidance (EPA
1996a) are the best suited for general characterization of the recoverable organic mass from stationary
sources.  Mass balance between identified compounds and the TOE analysis has shown anywhere from a 20
percent to 80 percent agreement Combustion sources that emit higher concentrations of non-volatile
material (as determined gravimetrically) tend also to be the sources that are not characterized well by target
compound methods. Sources that have more volatile organic emissions where the compounds can be
analyzed by a combination of GC and GC/MS tend to have better agreement and closure with the TOE
methods. These results lead EPA to conclude that a procedure that provides information on gravimetric
(GRAY) material is important to assess the uncertainty associated with the measurement methods that are
used to identify specific target compounds in hazardous waste combustion samples. Until and unless more
compounds can be identified, TOE analysis continues to be the best scientific measure currently available to
cost-effectively direct resources and regulatory action to the highest potential for risk of organic material
from affected facilities.

TOE analysis, as determined by the published methodology (EPA 1996a ), means the total amount of
organic material which is recoverable by means of analysis of gaseous components, solvent extraction or
other preparatory steps, and gravimetric analysis. The TOE analysis is not suitable for collection/analysis
of polar water-soluble compounds or highly reactive compounds.  Results are reported as a sum of "ug total
organics  per m3"; these results can be compared directly to the summed mass of all of the identified
constituents. In order to determine the unidentified organic mass, the masses of the specific quantified toxic
organic compounds, including D/Fs, VOCs, S VOCs, PAHs, PCBs, and TICs, are subtracted from the
results of the TOE determination. The mass of organic material remaining after correction for identified
compounds is referred to as the "unspeciated (or unidentified) organic mass" (EPA 1998a).
Two separate sampling procedures are needed to generate the samples for TOE analysis:
               A VOC fraction is collected using SW-846 Method 0040 sampling procedures with a
               Tedlar® bag. Condensate collected during the Method 0040 sampling is returned to the
               laboratory for analysis. The VOCs in the Tedlar® bag are analyzed by field gas
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               chromatography (FGC).  The VOCs in the condensate are determined by purge and trap
               GC. The VOC fraction determines organics in the boiling point range <100°C.

               Total chromatographable organic (TCO) and gravimetric (GRAY) fractions are collected
               using a SW-846 Method 0010 sampling train, operated during the same sampling period as
               the Method 0040 train. The Method 0010 sampling train operates in the same mode for
               TOE as for S VOC collection, but the present TOE guidance recommends the operation of a
               separate Method 0010 train.  With careful attention to procedures to avoid bias as
               discussed in Section B.8.9, it  may be possible to use a single train for the S VOC and TOE
               determinations in some cases. The TCO fraction determines organics in the boiling point
               range between 100°C and 300°C, and the GRAV fraction determines organics with boiling
               points >300°C.
Research has recently been performed to evaluate and clarify the analytical procedures for the TOE

determination. Revised technical details for TOE analysis are included in this guidance, and will be

incorporated in a revised TOE guidance expected to be released later in 2001. Analysis of the three TOE

fractions, including the updated technical details, is described below:


        •      FGC Fraction (Organic Compounds with Boiling Points < 100°C)

               The FGC fraction is collected by Method 0040, using a Tedlar® bag for the gaseous
               component, and the collected condensate fraction is transferred to a zero-headspacevial.
               Analysis of the gaseous component is performed in the field using a gas chromatograph
               with a flame ionization detector.  The field GC is calibrated with a gaseous hydrocarbon
               mixture containing methane, ethane, propane, w-butane, «-pentane, «-hexane, and K-heptane
               (C, - C7).  The chromatographic column used in the field GC should be capable of
               resolving the C,  - C7 hydrocarbons at baseline level.  A minimum of three multi-component
               standards at different concentration levels spanning the expected sample concentration
               range is analyzed in triplicate to calibrate the gas chromatograph; more concentrations may
               be used, if desired. The additional concentrations can be prepared by dilution of the stock
               standard. Gaseous standards in cylinders are usually sold in ppm concentrations.
               However, the gas chromatograph should be calibrated in specific units of (ig/m3 to provide
               results compatible with the other parts of the TOE analysis. To convert the units for each
               component of the multi-component standard from the cylinder concentration (ppm) to
               u.g/m3, the following equation (based on the Ideal Gas Law at Standard Temperature and
               Pressure) is used:
= C
                                                GMW
                                                       x 1000
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               where:
GMW =

24.04  =
                                     concentration of each hydrocarbon expressed in ug/m3;

                                     concentration of each hydrocarbon expressed in ppm;

                                     gram molecular weight of each hydrocarbon.

                                     liters/gram-mole ideal gas @ 293 °K; 760 mm Hg
               The following steps are applied to each component of the multi-component standard:
                      Step 1. Determine the concentration of each component of the standard in ppm.

                      Step 2. Using the equation above, convert the concentration of each component to
                             ug/m3.

                      Step 3. Sum the concentrations of each of the components in ug/m3 to obtain a
                             total concentration, which can then be related to the sum of the
                             chromatographic peak areas at each concentration level.
               To determine total mass of the hydrocarbons for the calibration curve, the concentrations of
               each of the hydrocarbons (in ug/m3) are summed, and total mass (OC vs/aa for each of the
               components of the standard) is plotted vs. area counts. The calibration procedure is
               conducted using a mean response factor (relative standard deviation of 20 percent or better)
               or a linear regression^ = 0.995 or better, b«y). The sample is analyzed using duplicate
               injections, and integrated from a retention time of zero to the end of the C7 peak.  A total
               mass in ug/m3 is calculated for the entire integrated area from zero through the end of C7 to
               yield the value for the gaseous volatile portion of the TOE analysis.

               The aqueous portion of the TOE sample generated from the condensate of the Method 0040
               sampling train is analyzed in the laboratory using purge-and-trap gas  chromatography with
               flame ionization detection, with the gas chromatograph calibrated from C4 through Q in
               micrograms. The sample is  integrated from zero through the end of C,, and the answer is
               expressed in terms of total number of ug/volume of condensate (ug/mL). The total volume
               of condensate has been measured, so the answer can be expressed as a total number of ug
               per sampling train. The stack gas volume sampled in the field (expressed as m3) is known
               from the Method 0010 sample volume, and the value is expressed as ug/volume sampled
               (expressed as m3)  to make the result compatible with the values determined for the other
               portions of TOE.
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              Determination of Qualitative/Quantitative Values for Specific FGC Components

              Compounds such as methane, ethane, and propane may constitute major components of the
              emissions sample. In performing the risk assessment calculation, it may be highly desirable
              to subtract the mass of these compounds from the TOE value as part of the determination
              for unspeciated organic compounds, if these specific compounds are indeed major
              components of the emissions. Since the field gas chromatograph is calibrated with a
              standard that contains the specific C, through C7 w-alkanes, and it is therefore possible to
              determine retention times and compound-specific response factors for these compounds. If
              data from the FGC calibration are collected as peak areas for individual compounds in the
              original FGC calibration, a retention time and a response factor for each compound may be
              calculated from the original FGC calibration data. Alternatively, an additional multipoint
              calibration series can be analyzed to determine retention times and response factors for the
              individual compounds. In the analysis of the emission sample, the #-alkanes from C,
              through C7 can then be identified and a specific quantitative analysis performed for these
              compounds. When the ultimate risk assessment calculation is performed, the concentrations
              of the identified compounds can then be subtracted from the unspeciated mass to reduce the
              uncertainty associated with the TOE value. However, no subtraction of specifically
              identified and quantified compounds should be performed in determining the TOE value
              itself; the TOE value should be reported as  the summation of the individual components:
              FGC + TCO + GRAY.  The use of additional gas standards to aid in the speciation of FGC
              compounds is encouraged, particularly standards containing compounds that may not be
              amenable to identification and quantitation by the target-analyte-specific volatile organic
              GC/MS approaches.  Gas mixtures containing hydrocarbons such as C2 through C4 alkanes,
              alkenes, and alkynes may also be useful in characterizing the composition of the FGC TOE
              fraction.

              TCO Fraction (Boiling Point between 100°C and 300°C)

              TCO and GRAY fractions are both collected using the SW-846 Method 0010 sampling
              train, with samples prepared using Method 3542. There are several changes to
              Method 3542 which are recommended to ensure complete removal of water and inorganic
              interferents:

              -     All three sample fractions should be reverse-extracted in a separatory funnel with
                      dichloromethane and water under base and acid conditions. Surrogate or internal
                      standard compounds are not added to any of the fractions. The XAD-2® resin is
                      initially Soxhlet extracted according to Method 3542 and then extracted with
                     dichloromethane and water under base and acid conditions. Acid/base extractions
                      follow the procedures in Method 3542.  The extraction removes any soluble
                      inorganic salts that might provide a high bias to the GRAY results.

              -     After extraction, components are combined into a single pooled extract. The
                     Method 3542 extract is dried by filtration through sodium sulfate as specified in the
                      method. The drying/filtration step is performed using pre-washed cellulose filter
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                     medium (Whatman #1 filter paper or equivalent) rather than the glass wool
                     specified in the extraction procedure. As in Method 3542, the extract may be taken
                     to a final volume of 5 mL for TCO and GRAY analysis.

              -      At no time should any of the extracts be reduced to volumes less than 3 mL, or loss
                     of semivolatile compounds may occur.  As a final step, the extract is filtered
                     through a 0.45 micron (urn) Teflon® syringe filter, then diluted to 5.0 mL.

              After the three methylene chloride extracts resulting from Method 3542 are combined and
              concentrated, the TCO and GRAY analyses are performed. TCO analysis is performed by
              GC/FID, with a total mass between boiling points 100°C and 300°C calculated by
              integrating the entire area under the response curve from C7 through the C17 range. The
              analysis window is established by injecting H-heptane (C7) and «-heptadecane (C17) during
              calibration to establish the retention time reference peaks between which the TCO
              determination will occur. The calibration curve is generated with hydrocarbon standards
              which fall within the TCO range, specifically decane (C10), dodecane (C12), and tetradecane
              (C14). A multipoint calibration of at least three points (in triplicate) is generated in units of
              ug/mL. The response factor for TCO is calculated based on the total area of the three
              calibration standards. For analysis of the  stack sample, integration of detector response
              beginning immediately after the C7 retention maxima and terminating immediately before
              the C17 maxima constitutes the TCO response. The response factor for the entire TCO
              range, as determined during calibration, is then used to calculate compound mass in this
              boiling point range.  The TCO concentration is initially expressed as |J.g/mL based on the
              chromatographarea and the TCO calibration curve. The final TCO value, in units of
              ug/m3, is calculated by multiplying the ug/mL value by the volume of the original Method
              0010 extract and dividing by the stack gas volume sampled in the field (in m3). The use of
              both TCO and GRAY does not duplicate the assessment of the quantity of extractable
              organic material in a sample. Recent research results demonstrate that the C,7  cutoff point
              for TCO provides a reasonable and consistent measure of semivolatile versus nonvolatile
              organic material in Method 0010 samples (Ryan and others 1999).

              GRAY Fraction (Boiling Point > 300°C)

              The GRAY procedure is carried out by analysis of an aliquot of the same methylene
              chloride extract that was used for the TCO determination. The aliquot is placed in a
              weighing pan, allowed to dry, and weighed.  The mass of the residue (ug) is recorded. The
              total ug per sampling train divided by the  gaseous volume sampled (m3) is the GRAY
              value.  EPA OSW is aware of technical issues that affect results of the GRAY analysis.
              The  issues of inorganic salts, as well as contamination of the samples by microfragments of
              XAD-2® and other fine particulate matter, have been known since the development of these
              procedures. EPA OSW continues to recommend preparation of Method 0010 samples
              using Method 3542 with the modifications described previously. Method 3542 procedures
              for removal of water/methanol by pH-adjusted back-extraction with water will solve the
              water-soluble inorganic salts problems incurred by the presence of water, methanol, and
              methylene chloride in the sample extract.  Fine solid particles may cause interferences with
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               the condensible fraction analysis and, since filtration of the samples is a critical part of the
               preparation step, EPA OS W in this guidance encourages laboratories to filter XAD-2®
               extracts with an inert pre-washed cellulose filter medium that is capable of removing fine
               solid particles that could interfere with analysis of condensibles.

               Because high field blank results for the GRAY fraction have been reported, trouble-
               shooting measures have been identified to minimize potential sources of contamination
               (EPA 1997c). In order to obtain the most accurate results possible for the GRAY fraction,
               the XAD-2® resins used in the Method 0010 sampling train have to be clean.  High field
               blank results have been attributed to the use of old and contaminated XAD-2® resin in the
               Method 0010 sampling train. Only recently-cleaned (within 14 days of the sample analysis)
               XAD-2® resin should be used in the Method 0010 sampling train. A summary of "lessons
               learned" is provided below:

               -      Assure that all glassware and field and laboratory equipment have been cleaned
                      thoroughly with high quality reagents.

               —      Use high quality reagents for performing procedures (extractions, rinses, etc.)
                      "Ultrapure" reagents are recommended.

               -      Cover the weighing pan to which composite extracts are transferred for drying by
                      building a tent with aluminum foil, shiny side out.

               —      Run control pans: pan blank (dust blank) and solvent blank.  Blank weighing pans
                      without solvent or sample should be carried through the evaporation and drying
                      process as a quality control check for each set of samples. Solvent blank samples
                      consisting of concentrated reagent solvent should be analyzed in duplicate for each
                      batch of samples.  Sample weights should be corrected for blank weighing pan
                      mass gain using the dust blank.

               —      Check balance calibration prior to each weighing.

               —      Use a balance precise to at least  10 ug.

               —      Handle XAD-2® resin with extra care: make sure that resin particles do not float
                      out of extraction thimble.

               —      Confirm that the XAD-2® used in the laboratory and in the field meets appropriate
                      cleanliness standards and has been cleaned within two weeks of analysis.

               —      For samples where there can be significant sources of sulfur in the fuels or wastes,
                      reconstitute the GRAY sample and analyze for rhombic sulfur using GC/MS. Also
                      analyze the TCO fraction by GC/M S for rhombic sulfur. Significant quantities of
                      rhombic sulfur, if present, can be dissolved in methylene chloride.
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The TOE measurement is an estimate. For fractions where GC/FID is used for the analysis, there are
discrepancies in detector response for various hydrocarbons, including halogenated compounds, and
oxygenated compounds. However, the TOE measurements are strongly believed to be the best currently
available procedure for generation of a TOE value to indicate uncertainty due to the organic compounds that
have not been quantified. The final calculated TOE value is the sum of the values for each component:

                             TOE=TOFGC + TOCON + TOTCO * TOGRAV
where:
TOE
TOFGC   =
TO
   CON
TOG
                      stack concentration of Total Organic Emissions, including identified and
                      unidentified compounds (ug/m3)
                      stack concentration of Total Organic Emissions, including identified and
                      unidentified compounds (ug/m3), as determined by FGC
                      stack concentration of Total Organic Emissions, including identified and
                      unidentified compounds (fig/m3), as determined by analysis of the Method 0040
                      condensate
                      stack concentration of Total Organic Emissions, including identified and
                      unidentified compounds (ug/m3), as determined by TCO analysis
                      stack concentration of Total Organic Emissions, including identified and
                      unidentified compounds (ug/m3), as determined by gravimetric analysis
EPA OSW recommends that values for the individual components of the TOE determination also be
reported, since this information may be useful during later interpretation of the results. For example,
unidentified mass in the GRAY range cannot be due to vinyl chloride, just as unidentified material in the
FGC analysis cannot be dioxin or PAH (Johnson 1996a). EPA OSW has recommended that the TOE data
be used in conjunction with the data for positively identified compounds to compute a TOE factor, defined
as the ratio of the TOE mass to the mass of identified organic compounds:
                                                 TOE
                                         rTOE
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where:
       FTOE
       TOE
       Q
TOE factor (unitless)
total organic emissions (ug/m3)
stack concentration of the Ith identified organic compound (ug/m3)
(EPA 1998a). A critical component in the calculation of the TOE factor is the identification of the organic
compounds for the denominator of the calculation. Although the permitting authority may not ask a facility
to analyze the organic compounds with all possible analytical methods, gaps in the compound identification
can have a dramatic effect upon the TOE factor. EPA OS W recommends that permitting authorities include
TICs in the denominator when computing the TOE factor to ensure that appropriate credit is given to
defensible efforts to identify the maximum number of organic compounds (EPA 1998a). The TOE factor is
used in the uncertainty section of the risk assessment report to evaluate the risks from the unknown fraction
of organic compounds. Permitting authorities can evaluate the TOE factor and assess to what extent actual
risks may be greater than estimated risks (EPA 1998a).

Estimates of compounds that are potentially associated with the three TOE fractions are summarized below
(MRI1997):

       •       The FGC fraction would be expected to contain lighter hydrocarbons and halogenated
               alkanes and alkenes such as methane, and halogenated ethanes, ethenes, and propanes.
       •       The TCO fraction would be expected to contain a wide range of semivolatile compounds
               such as D/Fs, phthalates, phenols, halogenated aromatic compounds, and nitrogenated and
               sulfonated compounds.
       •       The GRAY portion has been very difficult to characterize, but would be expected to contain
               high molecular weight organic compounds such as hydrocarbons of C17 or greater, D/Fs,
               PAHs, and high molecular weight organic acids and salts.

One attempt to characterize the GRAY fraction of reaction products from D/Fs sorbed on a calcium-based
sorbent used thin-layer chromatography followed by multiple analytical techniques (Gullett  1997). The
analytical results showed that the GRAY portion consisted of higher molecular weight chlorinated
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compounds with both aromatic and aliphatic components, most likely not detectable by conventional
GC/MS analysis. Application of non-routine analytical methods such as High Performance Liquid
Chromatography(HPLC)/MassSpectrometry would probably be necessary to perform significant amounts
of characterization of the non-volatile compounds to be found in the GRAY fraction.
B.7.1
PREPARATION OF XAD-2®
XAD-2® is a macroreticulate porous polymer synthesized from styrene (vinylbenzene) and divinylbenzene.
The emulsion block co-polymerization used to crosslink the resin gives it a pore structure and chemical
stability that are ideally suited for the sampling and recovery of semivolatile organic compounds from the
Method 0010 sampling train.  The synthesis process for preparing the polymer also exposes the raw resin to
high concentrations of naphthalene, styrene (vinylbenzene), divinylbenzene, and low molecular weight
byproducts of these reagents and the polymerization reaction. The typical amount of resin used in the
sampling module of the Method 0010 sampling train is 40 grams and, especially for the TOE determination,
it is essential that this resin be clean and free of fines and contaminants that could contribute a positive bias
to the TCO and GRAY determinations. Some forms of "pre-cleaned" resin are commercially available, but
all XAD-2® used for TCO and GRAY analysis should be analyzed before use using the TCO and GRAY
preparation/analysis procedures in order to ensure that the background of extractable semivolatile organic
compounds meets the appropriate quality standards. Preparation of the XAD-2® resin within two weeks of
the sampling episode where it is to be used provides sufficient time for the cleaning and drying processes and
avoids extended storage, which may result in contamination and elevated levels of semivolatile organic
compounds in the blanks. The cleaning method described below has proven to be a cost-effective and high
quality procedure for obtaining XAD-2® resin.

The procedures for cleaning XAD-2® are derived from EPA's Level 1 Procedures Manual (EPA 1978). The
original methodology has been improved to provide a reproducible method for preparation of sorbent
material clean enough for low level organic compound capture and analysis. The complete cleaning cycle
takes approximately five working days to complete. Typical background values of blank total organic
concentrations from XAD-2® prepared according to these procedures are on the order of 1 ug/g sorbent
medium. The recommended cleaning procedures include the following steps:
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               Obtain resin, either directly from the manufacturer or supplier, or recycled from previous
               use. Resin that has been cleaned by a secondary vendor should be treated like recycled
               resin.  Recycled and re-cleaned resin usually contain less organic contamination and are
               preferred over raw material straight from the manufacturer.

               Soak the resin and wash several times with deionized water if the resin is new from the
               manufacturer. Resin "fines" float to the surface of the water and are removed before the
               next cleaning step.

               Load washed or recycled resin directly into the extractor for solvent cleaning. The entire
               cleaning procedure is done "wet" with final drying taking place only at the end of the
               process.

               Use an extractor capable of holding 900 grams of resin to extract the resin sequentially with
               methanol, methylene chloride, and methylene chloride again.  Solvents used in this step
               should be chromatographic grade. Solvent is drained after each extraction sequence, and
               the extractor is pre-rinsed with the solvent to be used in the next step.

               After the final extraction, drain the methylene chloride and remove the extractor body to a
               hood where the resin is dried. Drying is accomplished using a gentle stream of nitrogen
               generated by a heat exchanger attached to the gas output of a liquid nitrogen tank to avoid
               introducing contaminants through the nitrogen.

               Transfer dried resin to a clean, dry glass jar with a screw-cap lid. For quality control of a
               blank,  at least one portion of the dried sorbent equal to the contents of a typical
               Method 0010 sampling module (usually 40 grams) is extracted, prepared, and analyzed
               according to the method that will be used for the field samples.

               If the analysis of the clean XAD-2® meets method acceptance criteria, label the jar with a
               laboratory identification number and store at room temperature in a clean, solvent-free
               cabinet for use in sampling activity. Clean resin is stable and can be  stored for 2-3 weeks.
               Longer storage times are possible if the material is refrigerated in a solvent-free
               refrigerator, but a blank sample should be checked before material stored for longer than
               three weeks is used for field sampling.
EPA OS W recommends that a sufficient quantity of clean resin be prepared to collect the number of

samples indicated in the QAPP, to provide one or two spares in case of breakage, to provide a field blank,

and to allow resin from the same batch to be available in the laboratory for use as method spikes/method

spike duplicates.
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Analytical interferences are generally contaminants that appear in the resin after storage and may cause the
cleaned resin to fail the quality control specifications for the analytical method used in sample analysis or
oxidation products from exposing the resin to an oxidizing stationary source matrix. Contaminants originate
from both external contamination and internal "bleeding" of manufacturing chemicals or other entrained
chemicals (possibly from a previous use) from very small or inaccessible pores in the resin. Subsequent re-
cleaning and reuse reduces the internal contributions to organic compound contamination during storage.
Contaminant levels in the XAD-2® resin may also increase if the XAD-2® has been exposed to high
concentrations of oxidizing agents such as ozone or oxides of nitrogen.
B.7.1.1
Quality Control Procedures for Cleaned XAD-251
The cleaned XAD-2® resin can be checked for contamination by extracting a quantity of resin equivalent to
the amount used during sampling, typically 40 grams. The resin is prepared for analysis using the same
volumes of solvent and preparation procedures that will be used for the field samples following the
procedures in SW-846 Method 3542 for Method 0010 samples. Extracts are analyzed for TCO and GRAY
and should meet the quality control criteria shown in Table B.7-1 in order to be used for sampling. If the
extracted resin fails to meet acceptance criteria, the resin should be re-cleaned by Soxhlet extraction with
methanol and methylene chloride. A sample of resin failing to meet acceptance criteria after re-cleaning
should be discarded and no further attempts made to clean that batch.

                                         TABLE B.7-1
                    GUIDELINES FOR CLEANLINESS OF XAD-f RESIN
Analysis
TCO
GRAY
Maximum Blank Concentration/g Resin
1 |ig/g resin
10 ug/g resin
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                       B.8 COMBINED MEASUREMENT TECHNIQUES

The S W-846 Method 0010 sampling train simultaneously collects all semivolatile organic compounds,
including SVOCs, D/Fs, CB/CPs, PAHs, and PCBs, with adaptations for specific groups of analytes. In
some cases (e.g., to increase sampling efficiency, to cut costs), it may be necessary or desirable to analyze a
single Method 0010 sample for multiple pollutant classes encompassing all of the groups of compounds
listed above. For these situations, EPA OSW recommends that all aspects of the sampling and analysis be
considered carefully to ensure that the resulting data will be acceptable for risk assessment. Modifications
to the sample preparation methodology may invalidate the data for one or more of the compound classes. If
extracts are divided to be used for different purposes, EPA OSW recommends that the effect upon the
method detection limits be carefully evaluated to ensure that appropriate detection limits can be achieved.

EPA OSW recommends that procedures for combined measurements be described in detail in the QAPP for
the risk burn and approved by the regulatory agency prior to sampling.  The documentation provided should
include detailed information on sampling, recovery, spiking, analysis, quality assurance and quality control
procedures, and anticipated effect on detection limits for all of the compound groups analyzed. In addition,
the facility should demonstrate that the modified methodology performs acceptably.  Providing an
appropriate level of description may be difficult, since laboratories that have developed these combined
methods consider the exact procedures and standard spiking schemes to be proprietary information and have
not published the procedures and supporting data in the open literature. There is also no recognized
numbered EPA method that combines measurement procedures for all possible groups of semivolatile
analytes, so no data are available to demonstrate performance of this type of methodology.  Thus, combined
analysis schemes can be described only in general outlines, and detailed procedures are not generally
available.

The potential liabilities that are associated with combination of analytical methodology for various groups of
semivolatile analytes have been discussed (Johnson 1995); a brief summary of key information is presented
below for the convenience of the reader.
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B.8.1
EFFECT ON METHOD DETECTION LIMITS
One effect of combining analytical procedures for multiple groups of analytes may be an elevation of the
detection limit.  If it is necessary to split a sample or an extract to allow two different extraction or cleanup
procedures, each part of the sample or extract may have its detection limit increased proportionally to the
size of the sample or extract used. If, on the other hand, a second analysis is performed on one extract, there
will be no effect on the detection limits. EPA OS W recommends that assistance be obtained from a well-
qualified and experienced analytical chemist who understands the methods and calculations involved, as well
as the detection limits needed for the risk assessment.
B.8.2
EFFECT ON SAMPLE PREPARATION PROCEDURES
Sample preparation procedures for semi volatile organic compounds ultimately involve concentration of an
extract prior to analysis.  If solvents are combined in the preparation process (i.e., methylene chloride and
toluene), the more volatile solvent and the more volatile analytes will be lost when the extract is
concentrated.

Cleanup procedures are an integral part of most semivolatile organic compound sample preparation
procedures. Because many of the analyses for semivolatile components are performed using high resolution
mass spectrometry, cleanup procedures typically involve the use of column chromatography and/or gel
permeation chromatography to remove the potentially interfering compounds with minimal effect on target
analytes. When sample preparation procedures are used for multiple classes of analytes, it is important to
verify that compounds of interest are not removed in sample cleanup. A judicious selection of appropriate
isotopically labeled standards added to the extract prior to cleanup can be used to demonstrate recoveries of
the appropriate analytes. The methods for D/Fs, PAHs, and PCBs each designate specific extract cleanup
procedures intended to remove two of the groups of analytes as potential analytical interferences; the
resulting extract is thus unsuitable for any other determinations. Splitting the sample after recovery and
extraction may be necessary to allow unique cleanup procedures to be used for specific analytical targets,
and splitting samples may have an effect on detection limits. EPA OS W recommends that assistance be
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obtained from a well-qualified and experienced analytical chemist who understands the methods and
calculations involved, as well as the detection limits needed for the risk assessment.
B.8.3
EFFECT ON THE SELECTION OF STANDARDS
Each of the isotope dilution methods discussed (D/Fs, PAHs, PCBs) involves the use .of internal standards,
pre-sampling surrogate standards, and recovery standards. SW-846 Method 8270, the generic semivolatile
organic compound analytical method, involves the use of pre-extraction surrogate standards and internal
standards. The isotope dilution methods typically involve the use of high resolution mass spectrometry in
the selected ion monitoring mode and correspondingly lower levels of standards spiked at all stages of the
preparation and analytical procedures. Method 8270 is generally applied to low resolution mass
spectrometry in the full scan mode, and involves correspondingly higher levels of all standards. The two
different standard spiking schemes could be a source of incompatibility between methods.

A judicious selection of isotopically-labeledstandards can be used to demonstrate acceptable measurement
performance of the combined methodologies when they are spiked at various stages of the sampling and
analytical procedures:
               Standards (pre-sampling surrogates) can be added to the sorbent in the sampling module
               prior to sampling, to estimate potential losses during sampling.
               Standards (pre-extraction surrogates/internal standards) can be added to the different
               Method 0010 train components (i.e., filter, sorbent, impinger contents) to provide an
               estimate of compound loss through extraction, concentration, and cleanup.
               Standards (internal standards/recovery standards) can be added immediately before analysis
               to perform quantitative calculations and to provide a final check on the effects of the sample
               matrix.
The standards described above constitute the minimum for the semivolatile organic compound sampling,
preparation, and analytical methods. EPA OS W recommends that additional standards be added as
necessary to address specific concerns with combined methodologies, and that assistance be obtained from a
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well-qualified and experienced analytical chemist who understands the methods and calculations involved, as
well as the detection limits needed for the risk assessment.
B.8.4
EXAMPLE OF A COMBINED MULTIPLE POLLUTANT SAMPLING/
ANALYTICAL SCHEME
It is possible to make all semivolatile determinations (D/Fs, S VOCs, CB/CPs, PAHs, and PCBs) from a
single S W-846 Method 0010 sampling train that has been spiked with the S W-846 Method 0023 A
standards. However, toluene train rinses from the D/F recovery have to be stored separately from other
train rinses, the condensate and impinger contents and rinses have to be retained and analyzed, and two
separate Soxhlet extractions using different solvents are necessary.

The general combined process used by one laboratory is described below:
               Perform a first Soxhlet extraction of Method 0010 train components with methylene
               chloride.
               Remove the methylene chloride from the extraction flask. Split the methylene chloride
               extract in half, one half for the D/F analysis and the other half for everything else.
               Add the toluene rinse to the remaining contents of the Soxhlet extractor, and perform a
               second extraction with toluene.
               Remove the toluene extract from the extraction flask.  Combine half of the toluene extract
               with half of the methylene chloride extract and subject the combined extract to D/F cleanup
               and analysis; archive the other half of the toluene extract.
               Divide the remaining methylene chloride extract into three portions: perform PAH cleanup
               and analysis on one portion, PCB cleanup and analysis on a second portion, and analyze the
               third portion directly for SVOCs and/or CB/CPs.
The detection limit for D/F analysis is not compromised by combining the methodologies because
Method 0023 A already specifies archiving half of the extract. Depending upon the exact scheme followed
for the additional analyses, the S VOC detection limits may be doubled or tripled because of a 1:1 or 1:2 split
of the methylene chloride extract.  The detection limits for the PCBs and PAHs may or may not be affected,
depending upon the cleanup procedures and the final volume to which the extracts are concentrated before
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analysis. EPA OS W recommends that assistance should be obtained from a well-qualified and experienced
analytical chemist who understands the methods and calculations involved, as well as the detection limits
needed for the risk assessment.

The scheme described above is used in one laboratory; other laboratories have developed their own schemes.
The methodology is presented only in general outline because the laboratory considers the exact procedure
and the standard spiking scheme to be proprietary information, as well as any supporting data developed by
the laboratory. There are numerous alternatives to the scheme described above. CARB Method 428
describes the analysis of Method 0010 samples for D/Fs and PCBs. CARB 429 describes the analysis of
PAHs. The combination of CARB Methods 428 and 429 and comparison of this combined methodology
with the individual sampling trains and individual analysis has been discussed (Steiner 1994). Results for
triplicate tests of combined vs. individual sampling trains and analyses show correspondence for the two
groups of analytes ranging from 14-32 relative percent difference.  Standard recoveries were closely
comparable between the individual trains and the combined train on a compound-by-compound basis. The
effect of the combined scheme on detection limits was not discussed.
B.8.5
USE OF TWO METHOD 0010 SAMPLING TRAINS
If two Method 0010 sampling trains can be used, use of one train for Method 0023 A and CARB Method
428 (D/Fs and PCBs) is reasonable since both analyte groups are amenable to toluene extraction. The other
Method 0010 sampling train could then be used for all other semivolatile organic analytes. IF PCBs and
D/Fs are determined in combination from a single sampling train, EPA OS W recommends that at least four
isotopically-labeledPCB surrogate compounds be spiked onto the XAD-2® resin together with the
designated D/F surrogate compounds before sampling.  The amount of the surrogate compounds and
internal standards added to the XAD-2® and the sample extracts should be adjusted to compensate for the
additional analysis (Ryan 1998). The two Method 0023 A sampling train fractions should be processed
separately as outlined in that method.  Each fraction would be extracted with toluene, and the resulting
extracts would be split: one portion for D/F cleanup and analysis, and another portion for PCB cleanup and
analysis.  Since Method 0023A procedures call for archiving one half of the toluene extract, the D/F
detection limits would not be compromised. The impact on the PCB detection limits would depend upon the
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size of the portion of the extract used and the final volume to which the extract is concentrated before
analysis.

The components of the second Method 0010 sampling train would be extracted as per Method 3 542 with
methylene chloride.  One analytical scheme might be to divide the extracts from Method 3542 and subject
one portion to PAH cleanup and analysis and analyze another portion directly for S VOCs and/or CB/CPs.
In this scheme, the impact upon the detection limits would depend upon the sizes of the portions used for
each part of the scheme and the final volume of the extract before analysis. Alternatively, general SVOC,
CB/CP, and PAH analyses could all be done using the same extract, subject to the following limitations:
               Additional standards to encompass the additional CB/CP compounds (if desired) should be
               added to the Method 8270 SVOC calibration mixture.
               An appropriate spiking scheme for isotopically-labeledPAHs should be developed to allow
               concentration of the extract with subsequent analysis of PAHs using selected ion monitoring
               mass spectrometry.
               The standard spiking scheme for Method 3542 should be modified to allow
               combination/concentration of the three extracts generated in the methodology, and the
               standards should be carefully selected to ensure that the standards for one analytical scheme
               do not interfere with the standards needed for another analytical scheme.
               The impact of every step of the process on the method detection limits should be carefully
               evaluated.
Research is currently in progress to modify the standard spiking scheme for Method 3542 in order to allow
combination/concentration of the three extracts.
B.8.6
PAH ANALYSIS
It may be possible to determine PAHs with the D/F extract because both groups of compounds can be
extracted with toluene (Johnson 1995). However, D/F cleanup procedures are specifically designed to
remove PAHs from the extract used to analyze D/Fs, because PAHs are interferences in this analysis: the
presence of high levels of PAHs in the extract analyzed for D/Fs will compromise the D/F analysis and may
prevent quantitative analysis of some of the D/F isomers. In any extract to be analyzed for PAHs, care
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should be taken not to take the extract to dryness in a concentration step because the more volatile PAHs
(i.e., naphthalene, methylnaphthalene, acenaphthene, acenaphthylene, fluorene) could incur significant losses
with complete evaporation of the extract. If a single toluene extract is divided into thirds for separate D/F
cleanup and analysis, PCS cleanup and analysis, and PAH cleanup and analysis, detection limits for each of
the analytes would be raised, depending upon the final volume of the extract used for analysis.
B.8.7
CLEANUP PROCEDURES
Extract cleanup procedures are optional for Method 8270; methods for D/Fs, PAHs, and PCBs each specify
cleanup procedures designed to remove potential interferents from the extract ultimately analyzed. An
extract that has been subjected to any one of these specialized cleanup procedures should not be analyzed for
other S VOCs. It should be possible, however, to design cleanup steps that allow extraction and preparation
of a combined extract. EPA OS W recommends that assistance be obtained from a well-qualified and
experienced analytical chemist who understands the methods and calculations involved, as well as the
detection limits needed for the risk assessment.
B.8.S
MULTIPLE ANALYSES OF SINGLE EXTRACTS
For any determinations that involve multiple injections of a single extract (for example, S VOCs and CB/CPs
if analyzed separately), there is no compromise in detection limits.  It is also possible to perform one
analysis of a given extract for one compound group and then to concentrate the extract to perform another
analysis without affecting detection limits.
B.8.9
TOE DETERMINATION AND COMBINED MEASUREMENT TECHNIQUES
Historically, a separate Method 0010 sampling train has been needed for the TOE determination to avoid
potential biases associated with the use of surrogate and internal standards used by other measurement
methods, the primary concern being that compounds in these standards would add a positive bias to the TOE
measurement. This concern is only partially valid, because the surrogates and internal standards themselves
are accurately measured in the same manner as target analytes, or are of known mass (some internal
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standards are added at the time of analysis), and therefore can be subtracted from the TOE mass just as
would be done for an identified analyte. A greater concern is whether the diluent solvent that the surrogate
or internal standard is contained in or prepared in is compatible with the TCO measurement. Analytical
standards are commonly prepared as solutions with solvents such as dichloromethane, methanol, hexane,
nonane, isooctane, and toluene. Of these, only dichloromethane and methanol would not be measured by
TCO.

A major benefit of being able to combine the Method 0010 portion of the TOE measurement with a target-
analyte-specific S VOC method is that measurement quality assurance/quality control information would
then be available for the TOE data. The target-analyte-specificS VOC methods make use of pre-sampling
and pre-extraction surrogates to define and assess measurement performance through recovery efficiencies.
This option has not been employed for the TOE methodology for the reasons discussed above. However, it
is indeed possible to incorporate these highly valuable data quality indicators into the TOE measurement.
Another benefit of combining the Method 0010 portion of the TOE measurement with a target-analyte-
specific SVOC method is that compounds identified and quantified by the target-analyte-specificSVOC
method would then be subtracted directly from the same sample used for the TOE determination, thereby
reducing the uncertainty of subtracting mass of one sample from a sample that has little or no quality
assurance/quality control information.

It is possible to use a single sampling train for both the TOE determination and for target analyte SVOC
determinations, provided that all procedural compatibility issues for the combined methods can be achieved.
This is only possible in limited situations. The most compatible measurement with potential for combination
is the Method 0010/8270 train. The surrogate and internal standard solutions typically use dichloromethane
and/or methanol as the solvent Care should be taken to ensure that any standards used during sampling and
common analysis do not contain compounds that can bias the TCO and/or GRA V measurement. For
example, D/F, PCB and PAH standard solutions commonly use nonane as the solvent, precluding them from
use with simultaneous TOE measurement. While the benefit of generating TOE data of known quality is
obvious, the use of combined measurement techniques involving the TCO and GRAV fractions of the TOE
determination should be implemented with caution. EPA OS W recommends that assistance be obtained
from a well-qualified and experienced analytical chemist. Should the Method 0010 portion of the TOE
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measurement and a target-analyte-specificSVOC method be combined, the above issues should be discussed
in detail in the test plan to ensure data of acceptable quality.
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                              B.9 ALDEHYDES AND KETONES

Stack determinations for aldehydes and ketones (A/Ks) involve a separate sampling and analytical
methodology, although some of these compounds are included on the volatile target list (acetone, 2-
butanone) and the S VOC (Method 8270) target list (acetophenone, isophorone). A/Ks are generally polar
water-soluble compounds; many of the compounds in the class exhibit a high level of reactivity as well.
The quantitative nature of the VOST determination for these type of compounds is questionable because
VOST tubes are purged through water and significant amounts of the volatile A/Ks will not be purged from
the water used in the VOST analytical determination. If A/Ks are sampled using the Method 0040 train,
these types of compounds would be found mostly in the condensate of the train. If any A/Ks are collected in
the Tedlar® bag, the stability of A/Ks in this medium is questionable and the likelihood of wall effects is
very high. VOST and Method 0040 can, at best, provide qualitative information for A/Ks. SVOC analysis
will provide accurate and quantitative information for the semivolatile A/Ks with a significant amount of
hydrocarbon character.  For the most polar A/Ks, the quantitative recovery from XAD-2®becomes
progressively more questionable as the compounds become more polar.

To provide a reliable measurement for A/Ks, specific sampling and analytical procedures are necessary.
S W-846 Method 0011 (Sampling for Selected Aldehyde and Ketone Emissions from Stationary Sources) is
used to withdraw gaseous and particulate pollutants isokinetically from an emission source and collect these
emissions in aqueous acidic 2,4-dinitrophenylhydrazine(DNPH). A/Ks present in the emissions react with
the DNPH to form a dinitrophenylhydrazone derivative to stabilize the reactive A/Ks. The field samples are
returned to the laboratory where the derivatized A/Ks are extracted, solvent-exchanged, concentrated, and
then analyzed using HPLC according to SW-846 Method 8315 (Determination of Carbonyl Compounds by
High Performance Liquid Chromatography (HPLC)). The analytical methodology is applicable to far more
analytes than the sampling methodology because of the kinetics of formation of,the derivatives under stack
sampling conditions.  For some A/Ks, the derivative as it is formed under stack sampling conditions is not
stable and decomposition occurs. If the A/K is sufficiently volatile, the compound may be lost from the
sampling train and the methodology will be biased low. Because the derivatization reaction is based on the
formation of an equilibrium state between reactants and products, for some compounds quantitative
recoveries may not be achieved until the concentration exceeds 200 parts-per-billion volume.  Field method
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evaluation data are available to support the applicability of Method 001 I/Method 8315 to the following
A/Ks(Stegerl996):

              Formaldehyde (CAS Number 50-00-0);
              Acetaldehyde (CAS 75-07-0);
              Acetophenone (CAS 980-86-2);
              Isophorone (CAS 78-59-1);
              Propionaldehyde (CAS 123-38-6).

Method 001 I/Method 8315 has been applied specifically to the above analytes. The methodology is
possibly applicable to other A/Ks from stationary sources, but performance should be demonstrated for
other compounds. The method has been shown not to be applicable to quinone (CAS 106-51 -4), acrolein
(CAS 107-02-8), methyl ethyl ketone (CAS 78-93-3), and methyl isobutyl ketone (CAS 108-10-1).,

Method 0011 is particularly sensitive to oxidizing agents such as NO2.  If strong oxidizing agents are
present in the flue gas emissions, then special care should be taken to guarantee an excess of derivatizing
agent, or another technique should be used.  Formaldehyde is often the highest concentration carbonyl
compound from a combustion source, and measurement of formaldehyde in relatively high NO2 gas streams
have been demonstrated successfully using EPA Method 320 (40 CFR Part 63 Appendix A).

EPA OSW recommends that the need for Method 0011 A/K sampling be considered carefully. In some
cases, a facility may wish to submit a justification for use of A/K data from a similar facility or for A/K
data collected previously at the same facility, unless the facility burns large quantities of A/K wastes. Also,
as stated previously, at least some qualitative data may be provided by the VOST and Method 0040,
although the data for the compounds listed above would not be of the same quality (quantitative analysis
would be biased low) as the data generated by Methods 0011/8315. For the semivolatile A/Ks listed above,
Method 0010/3542/8270 should generate accurate quantitative data.
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                           B.10  FACILITY-SPECIFIC COMPOUNDS

Previous sections have identified methods with target analyte lists applicable to numbers of compounds and
generally applicable to most facilities. However, it may also be appropriate for individual facilities to
sample and analyze for additional compounds based upon the constituents contained in their waste feed.
Potential candidates for additional facility-specificdetermination include any highly toxic, persistent, or
bioaccumulative constituents burned in large quantities. Section 5.2.2 of Risk Burn Guidance for
Hazardous Waste Combustion Facilities lists examples of historical waste feed information that EPA OSW
recommends be compiled to determine which constituents may be burned in large quantities, as well as to
identify highly toxic, persistent, or bioaccumulative constituents. If a constituent ranks prominently on one
or both of these rankings, then EPA OSW recommends that the constituent also be considered a candidate
for sampling and analysis during the risk burn. Facility-specific constituents to be considered for sampling
and analysis during the risk burn include compounds such as pesticides, herbicides, nitroaromatics,
cyanides, and isocyanates, as well as other groups/families of compounds and/or individual compounds.
Sampling and analysis for these constituents is recommended as an addition to, not as a substitute for, the
target analytes described previously in this appendix.

Table B. 10-1 lists organochlorine pesticides that can be determined by S W-846 Method 8081A
(Organochlorine Pesticides by Gas Chromatography) using GC/ECD, together with the waste codes that
might contain these types of compounds. However, including these compounds in Table B. 10-1 as analytes
for Method 8081A  DOES NOT ADDRESS the issues associated with removing these compounds from the
source emissions and preparing them for analysis. Pesticides are generally semivolatile organic compounds
that would be collected by the Method 0010 sampling train and prepared for analysis using Method 3542.
Pesticides are also highly reactive compounds that may decompose in the hot and reactive stationary source
emissions matrix, react with other compounds present in the stationary source matrix, or fail to be recovered
quantitatively from the XAD-2® sorbent resin of the Method 0010 sampling train. Table B.10-1 indicates
which analytes on the target list for Method 8081A have been evaluated using quadruple Method 0010
sampling trains with dynamic spiking, Method 3542 sample preparation procedures, and Method 8270
analytical procedures. Not all of the compounds tested performed successfully. EPA OSW recommends
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                                        TABLE B.10-1

              ORGANOCHLORINE PESTICIDES - METHOD 8081A ANALYTES
Compound
Aldrin
a-BHC
S-BHC
3-BHC (Lindane)1
S-BHC
Chlorobenzilate2
d-Chlordane1
a-Chlordane1
Chlordane - mixed isomers1
l^-Dibromo-S-chloropropane2
4,4'-DDD
4,4'-DDE'
4,4'-DDT
Diallate
Dieldrin
Endosulfan I
Endosulfan II
Endosulfan sulfate
Endrin
Endrin aldehyde
Endrin ketone
Heptachlor1
Heptachlor epoxide
Hexachlorobenzene2
Hexachlorocyclopentadiene2
Isodrin
Methoxychlor'
Toxaphene
CAS Number
309-00-2
319-84-6
319-85-7
58-89-9
319-86-8
510-15-6
5103-71-9
5103-74-2
57-74-9
96-12-8
72-54-8
72-55-9
50-29-3
2303-16-4
60-57-1
959-98-8
33213-65-9
1031-07-8
72-20-8
7421-93-4
53494-70-5
76-44-8
1024-57-3
118-74-1
77-47-4
465-73-6
72-43-5
8001-35-2
Waste Codes
P004
D013,U129
D013,U129
D013,U129
D013.U129
U038
D020, K097, U036
D020, K097, U036
D020, K097, U036
U066
U060,U061
U060,U061
U060,U061
U062
P037
P050
P050
P050
D012,P051
D012,P051
D012,P051
D031,K097,P059
D031,K097,P059
D032
U130
P060
D014.U247
D015, K041, K098, P123
Notes:

'Acceptable recovery/reproducibility in field validation studies with Method 0010/3542/8270.
2Marginal to poor recovery/reproducibility in field validation studies with Method 0010/3542/8270.
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that, for any of the facility-specific compounds to be tested, acceptable performance of the sampling and
analytical methodology be demonstrated for the data to be accepted as valid.

Other waste streams and specific compounds that may be considered for sampling on a site-specific basis
include D017 waste (2,4,5-TP [Silvex]), D016 and U240 wastes (2,4-D), K025 waste (1,3-dinitrobenzene),
and cyanide wastes (F007-F012, F019, KOI 1, K013, K027, K060, K088, and U246). SW-846 Method
8151A (Chlorinated Herbicides by GC Using Methylationor PentafluorobenzylationDerivatization)
provides analytical procedures for the chlorinated herbicides shown in Table B.I0-2, with the same
constraints on the analytical methodology due to the sampling and sample preparation methodology and the
same need to demonstrate sampling and analytical method performance. SW-846 Method 8270C can
provide data on some nitroaromatics, but the Method 8270 list is not exhaustive for nitroaromatics and
performance of the Method 0010/Method 3542/Method 8270 sampling and analytical methodology should
be demonstrated. CARB Method 426 (Determination of Cyanide Emissions from Stationary Sources) is
potentially applicable to the determination of cyanide emissions from stationary sources.  The method is
listed as "NYA (Not Yet Available)" on the CARB web site, but directions for obtaining hard copies of the
method are provided on the web site. A critical feature of CARB Method 426 is collection in an alkaline
impinger. If the pH of the impinger is not monitored and controlled during sampling, the hydrogen cyanide
will not be collected quantitatively.

Paint and foam rubber (polyurethane foam) incineration may warrant sampling for a facility-specific
compound class called isocyanates. Draft Method 207-1 (Draft Sampling Method for Isocyanates) and
Method 207-2 (Analysis for Isocyanatesby High Performance Liquid Chromatography (HPLC)) have been
validated for 2,4-toluene diisocyanate (CAS Number 584-84-9), l,6-hexamethylenediisocyanate(CAS  822-
06-0), methylene diphenyl diisocyanate (CAS 101-68-8) and methyl isocyanate (CAS 624-83-9) at several
stationary sources (Attachment 2).   Attachment 2 lists the analytes of the Clean Air Act Amendments of
1990, together with applicable or potentially applicable sampling and analytical methods, and the status  of
these methods relative to field evaluation.
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                                      TABLE B.10-2

                CHLORINATED HERBICIDES - METHOD 8151A ANALYTES
Compound
2,4-D
2,4-DB
2,4,5-TP(Silvex)
2,4,5-T
Dalapon
Dicamba
Dichloroprop
Dinoseb
MCPA
MCPP
4-Nitrophenol'
Pentachlorophenol2
CAS Number
94-75-7
94-82-6
93-72-1
93-76-5
75-99-0
1918-00-9
120-36-5
88-85-7
94-74-6
93-65-2
100-02-1
87-86-5
Notes:

'Performance in field evaluation using Method 0010/3542/8270 ranged from acceptable to poor.
Consistently poor recovery in field evaluation using Method 0010/3542/8270.
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                       B.ll TENTATIVELY IDENTIFIED COMPOUNDS


For all methods using mass spectrometry for detection in the full scan mode (i.e., SW-846 Method 8260,

Method 8270, Method 0040), EPA OSW recommends that analysis for the specific target analytes listed in

the method be accompanied by an evaluation of the Tentatively Identified Compounds (TICs).


The Human Health Risk Assessment Protocol for Hazardous Waste  Combustion Facilities.  Volume One
(EPA 1998a) states:


        "Although U. S. EPA OSW will not require a risk assessment for every possible metal or
        PIC from a combustion unit, this does not imply that U. S. EPA OSW will allow only
        targeted sampling for COPCs during trial burn tests.  Based on regional permitting
        experience and discussions with regional analytical laboratories, U. S. EPA OSW maintains
        that complete target analyte list analyses conducted when using U. S. EPA standard
        sampling methods (e.g., 0010 or 0030) do not subject facilities to significant additional
        costs or burdens during the trial burn process. Facilities conducting stack emission
        sampling should strive to collect as much information as possible which characterizes the
        stack gases generated from the combustion of hazardous waste. Therefore, every trial burn
        or "risk burn" should include, at a minimum, the following tests: Method 0010, Method
        0030 or 0031 (as appropriate), total organic compounds (using the Guidance for Total
        Organics, including Method 0040), Method 23A, and the multiple metals train.  Other test
        methods may be approved by the permitting authority for use in the trial burn to address
        detection limit or other site-specific issues."

In addition to the target analytes listed in the methods, there are generally a number of non-target

components observed in the chromatograrn. Attempts to identify and quantify these unknown

chromatographic peaks can improve the percentage of identified organic compounds and reduce overall

uncertainty. However, because the instrument is not calibrated for these unknown compounds, the

identification and quantitative analysis is tentative until the identification is confirmed by the analysis of a

standard. The EPA OSW risk assessment guidance (EPA 1998a) recommends that TICs be considered

"identified" compounds for purposes of site-specific risk assessments to ensure that appropriate credit is

given to defensible efforts to identify the maximum number of organic compounds.


To identify non-target TICs, the mass spectrum can be searched against a computerized library of reference

mass spectra. A forward library search selects the largest mass spectral peaks from the unknown mass
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spectrum and looks for reference spectra in the library that contain the peaks of the unknown.  A reverse
library search looks for the peaks in the reference spectrum that occur in the unknown mass spectrum. Data
system library search routines should not use normalization routines that would misrepresent the library or
unknown spectra when compared to each other. Only after visual comparison of sample spectra with the
nearest library matches should the analyst assign a tentative identification. Any components that are
identified are referred to as TICs, since no reference standard was analyzed at the same time as the
unknown. Without calibration of the instrument with the actual compound, TICs are quantified using the
nearest-eluting internal standard with a relative instrument response factor of 1.00. The resulting
concentration is considered "estimated," because the response factor is not compound-specific. An unknown
level of error in the quantitation is introduced using the response factor of 1.00; this level of error will vary
from compound to compound. Methods 8260/8270 present guidelines for identification of TICs, and these
guidelines are summarized below for the convenience of the reader:

       «       Relative intensities of major ions in the reference mass spectrum (ions greater than 10
               percent of the most abundant ion) should be present in the sample mass spectrum.
       «       The relative intensities of the major ions should agree within ±20 percent. Example: for an
               ion with an abundance of 50 percent in the standard spectrum, the corresponding sample ion
               abundance should lie between 30 and 70 percent.
       «       Molecular ions present in the reference mass spectrum should be present in  the sample mass
               spectrum.
       «       Ions present in the sample mass spectrum but not in the reference mass spectrum should be
               reviewed for possible background contamination or presence of co-eluting compounds.
       •       Ions present in the reference mass spectrum but not in the sample mass spectrum should be
               reviewed for possible subtraction from the sample spectrum because of background
               contamination or co-eluting peaks. Data system library programs can sometimes create
               these discrepancies.

If, in the judgment of the experienced mass spectral interpreter, no valid tentative identification can be made,
the compound should be reported as "unknown." The mass spectral interpreter should give additional
classification of the unknown compound, if possible (i.e., unknown aromatic compound, unknown
hydrocarbon, unknown chlorinated compound). If a probable molecular weight can be distinguished, this
molecular weight should also be reported. The experienced interpreter should apply this experience and
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judgment to the mass spectral interpretations supplied by the computerized library search. For example, if a
hydrocarbon occurring 40 minutes into the chromatographic analysis is identified by the computer as
"octane," analytical judgment dictates that this identification is scientifically illogical and the compound
should be reported as "unknown hydrocarbon."  By no means should the computer identifications be
accepted uncritically.

It may be possible to prepare and analyze additional standards containing TICs to confirm the
identifications, although this process is time-consuming and costly. A multi-concentration calibration curve
containing the additional compounds can be used to establish relative response factors for the specific
compounds. The semivolatile extracts can then be re-analyzed to improve quantitative accuracy. For
VOCs, the sample generally cannot be re-analyzed, but the relative response factors can be used to re-
quantify prior analyses to improve quantitative accuracy.  In some cases, an authentic standard for
confirmation of compound identification may not be available. Many of the mass spectral libraries were
assembled using mass spectra contributed by laboratories around the world, including compounds
synthesized in individual laboratories or obtained by isolation from a variety of sources. Thus, it may not
always be possible to confirm a compound identification.

In the Total Organics Emissions (TOE) analysis, organic mass in both the volatile and semivolatile ranges is
one of the components of the total recoverable organic mass that is calculated. All organic compounds that
are identified and quantified are ultimately subtracted from the total organic emissions mass value. It is,
therefore, beneficial for the laboratory to identify and quantify the maximum number of compounds when
the analysis is performed, including TICs.  Although it is in the facility's interest to characterize as many
TICs as possible, extensive characterization of TICs involves a significant commitment of time and
expertise and can reach a point of diminishing returns. Therefore, EPA OS W recommends that TICs be
characterized when the peak intensity is 10  percent or more of full chromatographic scale, and a that
quantitative estimate of the value be obtained using the nearest-eluting internal standard and a response
factor of 1. Unless the identification of the TIC is confirmed by the analysis of an authentic standard, the
quantitative value should be qualified as "estimated."
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    B.12 TOTAL HYDROCARBON AND CARBON MONOXIDE CONTINUOUS EMISSIONS
                                      MONITORS (CEMs)
 EPA OS W has recommended (EPA 1998a) that the Total Organics Emission (TOE) measurement be
 performed during the risk burn to obtain the best measure of total recoverable organic mass (as indicated in
 Section B. 1.1, a THC monitor is not appropriate for determining total organic mass). However, the TOE
 determination involves manual measurements, and therefore cannot be used on an ongoing, continuous basis
 to quantify the level of organic emissions. Continuous emissions monitors (CEMs) provide a continuing
 indication of source performance.  CEMs for THC and carbon monoxide can both indicate whether good
 combustion practice is being maintained, and whether or not organics emissions have changed from the
 baseline determined during the risk burn.

 EPA OS W recommends that THC and carbon monoxide monitoring be performed during the risk bum in
 conjunction with the manual organic emissions determinations. Even if THC monitoring is not required by
 current regulations at a facility, it can be accomplished by having a temporary monitor brought in during the
 testing, if necessary.  The monitoring serves several purposes. One purpose is to ensure that targeted
 operating conditions are being maintained during the risk burn. Chapters 4 and 5 of Risk Burn Guidance
for Hazardous Waste Combustion Facilities recommend operating scenarios to be preferentially targeted
 for D/F and non-D/F  organic testing, including:

        •       Transient conditions;
        •       Operation with containerized or batch waste feeds; and
        •       High carbon monoxide (greater than 100 ppm) situations.

 These scenarios are recommended to be targeted for the risk burn because of the increased potential for
 localized oxygen deficiencies and carbon monoxide/THC spikes. Numerous test programs have established
 that D/Fs can be high when oxygen is insufficient or when carbon monoxide/THC concentrations are high.
 CEMs for THC and carbon monoxide provide an indication that the targeted scenarios are being maintained
 during the test  As appropriate, permit limits for appropriate combustion parameters, including THC and
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carbon monoxide, may be established based on the risk burn to protect human health and the environment by
continually indicating that D/F and other organic emissions are being maintained below the levels measured
during the risk burn on an ongoing basis. Thus, THC and carbon monoxide monitoring may also serve the
purpose of providing ongoing compliance assurance. Finally, THC and carbon monoxide monitoring can
indicate whether ongoing organic emissions may have changed from the baseline measured during the risk
burn.  Performance specifications for THC and carbon monoxide monitoring are provided in 40 CFR Part
266, Appendix IX, Section 2.0.
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                                        B.13 METALS

Metals that may be measured during the risk burn and subsequently evaluated in site-specific risk
assessments include antimony, arsenic, barium, beryllium, cadmium, chromium, lead, mercury, silver, and
thallium, as well as aluminum, copper, cobalt, manganese, nickel, selenium, vanadium, and zinc (EPA
1998a and 2000). There are two methods available for the determination of metals emissions: S W-846
Method 0060 (Determination of Metals in Stack Emissions) and EPA Method 29 (Determinationof Metals
Emissions from Stationary Sources, 40 CFR Part 60 Appendix A). Both methods state that they are
applicable to the determination of metals emissions from stationary sources. In both of these methods, a
stack sample is withdrawn isokinetically from the source.  Particulate emissions are collected in the probe
and on a heated filter and gaseous emissions are collected in a series of chilled impingers: two impingers are
empty, two impingers contain an aqueous solution of dilute nitric acid combined with dilute hydrogen
peroxide, two other impingers contain acidic potassium permanganate solution, and the last impinger
contains a desiccant. Method 0060 is paired with the S W-846 6000 and 7000 series of methods for
preparation and analysis. Preparation and analysis procedures are included in Method 29.  The target lists
for the two methods are the same and are shown in Table B.13-1. CARS Method 436 (Determinationof
Multiple Metals Emissions from Stationary Sources) is also available as a sampling and analytical method
for metals in stationary source emissions that uses basically the same collection of impingers for collection
of metals in stationary source emissions.  It should be noted that aluminum (Al) and vanadium (V) are not
included on the target list of analytes for Method 0060 and Method 29, but the sampling methodology
should be amenable.  CARB Method 436, using the same sampling and analytical methodology, includes
aluminum (Al) and vanadium (V) on the method target list.

Iron can be a spectral interference during the analysis of arsenic, chromium, and cadmium by inductively
coupled plasma (ICP) spectroscopy. Aluminum can be a spectral interference during the analysis of arsenic
and lead using ICP. These interferences can generally be reduced by diluting the sample, but dilution
increases the method detection limit. There are three metals (mercury, chromium, and nickel) for which
speciationis an issue. These metals are discussed individually.
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TABLE B.13-1
TARGET LIST FOR METALS MEASUREMENT METHODS
Analyte
antimony (Sb)
arsenic (As)
t

barium (Ba)
beryllium (Be)
cadmium (Cd)
total chromium (Cr)
cobalt (Co)

copper (Cu)
lead (Pb)
manganese (Mn)
mercury (Hg)



nickel (Ni)
phosphorus (P)
selenium (Se)
thallium (Tl)

zinc (Zn)
CAS Number
7440-36-0
7440-38-2
7440-39-3
7440-41-7
7440-43-9
7440-47-3
7440-48-4
7440-50-8
7439-92-1
7439-96-5
7439-97-6
7440-02-0
7723-14-0
7782-49-2
7440-28-0
7440-66-6
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B.13.1
MERCURY
Stack emissions containing mercury include both vapor and particulate forms of mercury. Vapor mercury
emissions are thought to include both elemental (Hg°) and oxidized (Hg+2) chemical species, while
particulate mercury emissions are thought to be composed primarily of oxidized compounds due to the
relatively high vapor pressure of elemental mercury (EPA 1997d).  While coal combustion is responsible
for more than half of all emissions of mercury in the United States due to anthropogenic sources, the fraction
of coal combustion emissions in oxidized form is thought to be less than from waste incineration and
combustion (EPA 1997d).

There is no generally accepted numbered EPA method for accurate and reproducible speciation of mercury
from exit vapors and emission plumes.  Development and evaluation of sampling and analytical methods to
provide reliable speciation of mercury is currently an active area of research.  The exit stream is thought to
range from almost all divalent mercury to nearly all elemental mercury, with true speciation of mercury from
the various source types still uncertain and thought to vary,  not only among source types but also for
individual plants as feed stocks and operating conditions change (EPA 1997d). Data on mercury speciation
in emissions exiting the stack are very limited, and the behavior of mercury close to the point of release has
not been extensively studied.  This lack of information results in a significant degree of uncertainty in
modeling of mercury emissions. Additional areas of uncertainty include precision of measurement
techniques, estimates of pollution control efficiency, and limited availability of data specific to source class
and activity level.

The Human Health Risk Assessment Protocol for Hazardous Waste Combustion Facilities (EPA 1998a)
provides recommended mercury speciation assumptions for  site-specific risk assessments of 20 percent
divalent particulate mercury, 60 percent divalent mercury vapor, and 20 percent elemental mercury vapor
consistent with the latest scientific literature on the subject (EPA 1997d). A facility may prefer to perform
speciation sampling for mercury during the risk burn to replace the recommended assumptions with site-
specific data. For example, some data suggest that the percentage of elemental mercury may be higher for
certain units equipped with wet scrubber systems.
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A review of design and operating parameters affecting mercury emissions has been performed (EPA 1999).
For incinerators, mercury speciation in the flue gas depends upon factors such as waste composition (in
particular, chlorine and sulfur levels), flue gas temperature profile, and type of air pollution control. If
chlorine is not present or sulfur levels are high, elemental mercury can comprise a significant fraction of the
total mercury. Elemental mercury is not soluble in water and is usually not well controlled by wet
scrubbers. Control of elemental mercury may involve use of carbon injection or carbon beds.

In the presence of chlorine, formation of divalent mercury is thermodynamically favored in combustion
systems. Mercuric chloride is soluble in water and is readily captured by wet scrubbers.  Slow gas cooling
(instead of rapid quenching) has been shown to maximize the levels of soluble mercuric chloride and
increase wet scrubber performance.

Among the measurement methods which have been evaluated for their ability to provide information on
speciated mercury emissions from stationary sources are:

               EPA Method 29 (or EPA SW-846 Method 0060);
               EPA Draft Method 101B (Research Triangle Institute);
               Ontario Hydro method (Ontario Hydro); and
               Alkaline Mercury Speciation (AMS) method (Research Triangle Institute).
The sampling train configuration of the impingers for all of these methods is based on the Method 29/0060
train, but different impinger solutions are utilized as shown in Table B. 13-2. All of the methods rely on
acidified potassium permanganate solution (H2SO4/KMnO4) in the final impinger of the sampling train for
the ultimate collection of elemental mercury.  The methods differ with respect to the chemistry of the
impingers located upstream of the potassium permanganate impingers.  The upstream impingers collect
divalent mercury. The use of various upstream impinger solutions has been proposed in an attempt to
minimize potential interferences (most notably SO2 and Cy known to cause oxidation of elemental mercury
in the Method 29 nitric acid/hydrogen peroxide (HNO3/H2O2) impingers (thus resulting in over-reporting
divalent mercury and under-reporting elemental mercury). Much of the research and method development to
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                                        TABLE B.13-2
      COMPARISON OF IMPINGER CONTENTS FOR MERCURY SAMPLING TRAINS
Impinger
1
2
3
4
5
6
7
8
Method 29
Empty
(optional)
5% HNO3
10%H2O2
5% HNO3
10%H2O2
Empty
10% H2S04
4°/oKMnO4
10%H2SO4
4%KMnO4
Silica Gel
—
Method 101B
Empty
(optional)
H2O
H2O
5%HNO3
10%H2O2
Empty
10% H2SO4 4%KMnO4
10% H2S04 4%KMn04
Silica Gel
Ontario Hydro
KC1 (IN)
KC1 (IN)
KC1 (IN)
5% HNO3
10% H2O2
10% H2SO4 4%KMnO4
10% H2SO4
4% KMnO4
10% H2SO4
4% KMnO4
Silica Gel
AMS
NaOH (IN)
NaOH(lN)
H2O
Empty
10%H2SO4
4%KMnO4
10% H2SO4
4%KMnO4
Silica Gel
-
date has focused on coal-fired utility sources, where higher SCI, emissions are a concern. All of the more
recent methods (Method 101B, Ontario Hydro, and AMS) are less prone to SO, interference than Method
29. Less research is available for hazardous waste combustor applications, where higher C12 concentrations
from combustion of highly chlorinated waste streams may exist. Each of the methods is discussed below in
more detail.

Method 29:  The Method 29 (and Method 0060) sampling trains were developed and validated only for
total mercury (including both elemental and ionized forms). Method 29 was not developed with the intent of
speciating mercury emissions. However, due to the manner in which the mercury is captured and
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subsequently analyzed in the Method 29 train, it has been suggested (Krivanek 1993) that the results can be
used to estimate speciation for three forms of mercury:

       •       Condensed solid particulate mercury (primarily HsO) — Captured on the filter and in the
               front half sample nozzle and probe wash (up to the filter).
       •       Soluble divalent mercury vapors (HsCl-,, etc.) — Captured in the aqueous nitric acid and
               hydrogen peroxide (5% HNOj/10% H2O2) impingers located downstream of the filter.
       •       Elemental mercury (Hs?) — Captured in the final two impingers of sulfuric acid/potassium
               permanganate (10% H2SO4/4% KMnO4).

Pilot-scale work has shown that Method 29 does not properly speciate mercury under conditions of high
SO2, with the method overstating the divalent mercury up to 50%.  The high bias for the ionic form of
mercury has also been confirmed in field tests for utility sources (EPA 1997d). In other studies, high
concentrations of SO2 (approximately 1000 ppm) caused 23 percent of the elemental mercury to be oxidized
to divalent mercury (Giglio 1998).  For hazardous waste combustion sources, trace levels (in excess of 1
ppm) of C12 may result in oxidation of elemental mercury in the nitric acid impingers, thus overstating the
divalent mercury and under-reporting the elemental mercury (Giglio 1998).
Draft Method 101B: EPA Draft Method 101B was developed in an attempt to reduce SQ interference.
Because of the high solubility of SO2 in the Method 29 nitric acid/hydrogen peroxide impingers, the first
acidified peroxide impinger was replaced with two deionized water impingers. The water impingers capture
divalent mercury, while the acidified peroxide solution absorbs SO2. Draft Method 10 IB has been formally
evaluated for utility sources using the validation protocol established in EPA Method 301. Since there is no
reference method for comparison, only the precision and bias associated with the sampling procedures were
evaluated based on dynamic spiking of the flue gas stream. Method 101B passed the Method 301 criteria,
but showed more variability than the Ontario Hydro method (EPA 1997d). Method 101B has also been
evaluated for C12 interference, to determine applicability to hazardous waste combustion sources.  At C12
levels of approximately 18 ppm C12, up to 93 % of elemental mercury was oxidized to divalent mercury in
the water impingers. This result was not surprising, considering that the solubility of C12 in water may have
resulted in conditions conducive to a liquid-phase reaction between C12 and elemental mercury.  For
hazardous waste combustion sources, trace levels (in excess of 1 ppm) of C12 may result in oxidation of
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elemental mercury in the water impingers, thus overstating the divalent mercury and under-reporting the
elemental mercury (Giglio 1998).

Ontario Hydro:  The Ontario Hydro method (Curtis 1995) was also developed to address SOj interference.
The Ontario Hydro method has been formally evaluated for utility sources using the validation protocol
established in EPA Method 301.  Since there is no reference method for comparison, only the precision and
bias associated with the sampling procedures were evaluated based on dynamic spiking of the flue gas
stream. The Ontario Hydro method passed the Method 301 acceptance criteria, and showed less variability
than EPA Draft Method 101B. Ontario Hydro has been recommended by the U.S. Department of Energy as
the best method for speciating mercury in coal-fired systems (EPA 1997d).  For hazardous waste
combustion sources, CI2 may result in oxidation of elemental mercury in the KC1 impingers, thus overstating
the ionic mercury and under-reporting the elemental mercury. The C12 interference appears to be more
pronounced at increased C12 concentrations (Giglio 1998).

AMS Method: The AMS method was developed in an attempt to reduce C\ interference. The method was
developed considering the principle of Method 26 (40 CFR Part 60 Appendix A), which employs sodium
hydroxide (NaOH) impingers for collection of C12, resulting in the formation of the chloride (Cl~) and
hypochlorite (OCf) ions. A later modification (Method 26A) incorporates sodium thiosulfate (Na2S2O8) to
convert C12 entirely to Cl\ The AMS method uses a NaOH medium in place of the Draft Method 101B
water impingers to collect water-soluble ionic mercury while preventing oxidation by C12.  Bench and pilot-
scale tests have showed that the AMS method effectively speciates elemental and divalent mercury emissions
in the presence of SO2 levels exceeding 1500 ppm. However, mixed results have been observed when C12 is
introduced as an interferent (Giglio 1998).

Speciated mercury measurements continue to be an active research area within EPA. Potential
modifications to the Ontario Hydro method are currently being investigated, including the addition of sodium
thiosulfate to the KC1 impingers to reduce C12 interference (Ryan 2000).

At present, EPA Method 29 (or Method 0060)  is the only field-tested methodology which can provide valid
data on the entire list of total metals as well as limited data on speciated mercury, recognizing that, at worst,
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Method 29 may over-report the divalent form of mercury in the presence of SO2 or C12. Over-reporting of
divalent mercury should generally be conservative for multi-pathway risk assessments, in that risks will
generally be over-estimated. Higher percentages of divalent mercury tend to increase risk, because the risk
methodology assumes that 68 percent of divalent mercury vapor deposits near the source, whereas only 1
percent of elemental mercury vapor is presumed to deposit near the source.
B.13.2
CHROMIUM
The oxidation state of chromium (Cr) is a crucial issue in evaluating the toxicity of this metal and the risks
associated with exposure. Hexavalent chromium (Cr*) is the most toxic valence state of chromium and has
been demonstrated to be a human carcinogen (EPA 1996f).  Trivalent chromium (Cr+3), a commonly found,
less oxidized form of chromium, has not been shown to be carcinogenic in either humans or laboratory
animals (EPA 2000). EPA has indicated that chromium emitted from a combustion source is not likely to be
in the hexavalent form (EPA 1990a and 1990b). However, there are not sufficient data to reliably estimate
the partitioning of chromium emissions between the two valence states. Therefore, unless site-specific
process or sampling information is  provided, a worst-case assumption—that 100 percent of the facility
chromium emissions are in the hexavalent form—has been recommended for risk assessments (EPA 1998a).

Because medium-specific chromium speciation information is difficult to obtain, EPA OS W has
recommended that risk assessments generally be prepared following the conservative initial assumption that
all exposure is to hexavalent chromium (EPA 1998a). However, EPA OSW recognizes that chromium may
exist partially or in some cases entirely as trivalent chromium in various media. For example, in biological
materials, chromium is probably always trivalent. Therefore, in the event risks or hazards associated with
chromium exceed target levels based on the initial conservative assumption that exposure is entirely to
hexavalent chromium, EPA OSW has recommended that risks and hazards be re-calculated assuming
potential receptors are exposed through indirect exposure pathways (e.g., ingestion offish, beef, pork,
chicken, dairy products, and produce) to trivalent chromium  (EPA 1998a). These additional risk estimates
can then be presented in the report with the hexavalent chromium estimates, and discussed in the uncertainty
section of the risk assessment report (EPA 1998a).
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Based on the conservative nature of the assumptions for chromium recommended in the EPA OSW risk
assessment guidance, a facility may prefer to perform speciation sampling during the risk burn and utilize
site-specific data in the risk assessment. It should be noted that Method 0060 and Method 29 measure total
chromium only, since the acidic conditions associated with the sampling train would reduce Crrt to Cr+3, and
all chromium is measured in the reduced form. Specialized sampling trains that stabilize the Cr*6 species in
base are available for sampling the hexavalent form: SW-846 Method 0061 (Determination of Hexavalent
Chromium Emissions from Stationary Sources) and C ARE Method 425 (Determination of Total Chromium
and Hexavalent Chromium Emissions from Stationary Sources). Method 0061 provides procedures for the
determination of hexavalent chromium emissions from hazardous waste incinerators, municipal waste
incinerators, municipal waste combustors, and sewage sludge incinerators using a sampling train
constructed of Teflon® (evaluated only at temperatures less than 300°C). Emission samples are collected
with a recirculating train where the impinger reagent is continuously recirculated to the nozzle of the
sampling train.  The pH of the recirculating fluid should be monitored during sampling to maintain basic
conditions; recovery procedures include a post-sampling purge and filtration. Analysis involves the use of
an ion chromatograph equipped with a post-column reactor and a visible wavelength detector. The CARB
425 method collects sample for hexavalent chromium in impinger solutions of 0.1M sodium hydroxide, with
direct sample injection and post-column derivatization with a colorimetric reagent and photometric detection.
B.13.3
NICKEL
EPA OSW (EPA 1998a) has recommended that permitting authorities evaluate nickel as an inhalation
carcinogen in site-specific risk assessments because some forms of nickel—including nickel carbonyl, nickel
subsulfide, and nickel refinery dust—are considered to be carcinogens (EPA 2000).  Previously under the
boiler/industrial furnace (BIF) regulations, nickel was not treated as a carcinogen because the BIF
regulations assumed that nickel can only be emitted as nickel oxide, which, by itself, is not considered to be
a carcinogen (EPA 1991). However, because nickel oxide is a major component of nickel refinery dust, and
because the component of nickel refinery dust causing it to be carcinogenic has not been established, EPA
OSW now recommends that nickel emissions be evaluated as a potential carcinogen (EPA 1998a). Also,
nickel oxides can be reduced to nickel sulfates (which are carcinogenic) in the presence of sulfuric acid
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(Weast 1986). Hazardous waste combustion units that burn wet wastes containing significant amounts of
nickel and sulfur may need to be especially concerned with nickel emissions.

The standard metals sampling methods (S W-846 EPA Method 0060,40 CFR Part 60 Appendix A Method
29, and CARS Method 436) all include nickel on their target lists.  However, these methods detect nickel
only and do not speciate nickel (i.e., differentiate the carcinogenic forms from non-carcinogenic forms).
There are currently no methods available to detect, for example, nickel carbonyl or nickel sulfate as a
distinct species.  EPA OSW therefore recommends (EPA 1998a) that nickel be evaluated as an inhalation
carcinogen using the inhalation unit risk factor for nickel refinery dust. However, if the permitting authority
has information at points of potential inhalation exposure that demonstrate the absence of nickel refinery
dust components or the presence of non-carcinogenic nickel species such as soluble salts, EPA OSW has
recommended that this information be used as the basis for supplemental non-carcinogenic calculations
(EPA 1998a).
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                            B.14  PARTICLE-SIZE DISTRIBUTION

Information on particle-size distribution and particle density of emissions are utilized in the air dispersion
and deposition modelingthat supports risk assessments (EPA 1998a).  Inputs to the air models include: 1)
particle density; 2) mass distribution by particle-size category; and 3) surface area distribution by particle-
size category. A minimum of three particle-size categories (>  10 microns, 2-10 microns, and < 2 microns)
are recommended (EPA 1998a).  A representative particle-size distribution can be difficult to predict, and
EPA OS W has therefore indicated that site-specific measurements are preferred whenever possible (EPA
1998a). However, a site-specific particle-size distribution measurement may not be possible for all
situations. Other alternatives, such as use of literature estimates or vendor information, are described in
Chapter? of Risk Burn Guidance for Hazardous Waste Combustion Facilities.

To perform particle-size distribution measurements, CARB Method 501 (Determination of Size Distribution
of Particulate Matter Emissions from  Stationary Sources) is recommended.  In operation of CARB 501,
particulate matter is withdrawn isokinetically from the source and segregated by size in a cascade impactor
at the sampling point exhaust conditions of temperature, pressure, etc.  Cascade impactors use inertial
separation to size-segregate particle samples from a particle-laden gas stream.  The mass of each size
fraction is determined gravimetrically. CARB Method 501 recommends stage configurations representing a
range of 0.25 to 10 microns, with five to eight cuts and a total sample size of 50 milligrams (mg).  For
hazardous waste combustion facilities with very low particulate emissions, a very long sampling period may
be needed to achieve resolution for the smaller sizes. In some casesj the weight gain on the filter may be
negligible or zero.. Hazardous waste combustion facilities with wet stacks may experience a problem with
particle agglomeration.

High temperature environments (temperatures above 1300°F) are difficult to test because of the need for
sampling equipment that can withstand high temperatures.  High moisture environments are also difficult to
test.  In a high moisture environment,  the moisture promotes the formation of droplets that can overload the
system or wash the sample off the collection surfaces.  Modifications to the CARB 501 cascade impactor
methodology for sizing of particles have been developed to address sampling of both high-temperature and
high-moisture gas  streams. The modifications are described by McCain and Fowler (McCain and Fowler
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1994). For both types of gas streams, large drops and/or particles are collected in adaptations of a right-
angle pre-collector.. In wet stream sampling, the remaining droplets are passed to the impactor through a
heated inlet tube, where they are evaporated to dryness.  In the high temperature case, the sampled gases are
passed through an air-cooled tube until they are cool enough for collection in a standard impactor.

The high moisture particle-size measurement apparatus is the same as the apparatus used for CARB Method
501, with additions. In the modified method, a Pilat Mark V cascade impactor is used, with a liquid droplet
pre-collector, a heated interconnecting tube, a heating jacket for the impactor body, thermocouples, and
temperature controllers. The liquid droplet pre-collector is an EPA right-angle pre-collector modified to
include greater internal volume, permitting collection of relatively large amounts of water. Prior to
sampling, heaters are all brought to optimum operating temperatures. The high temperature modification of
CARB Method 501 likewise uses a Pilat Mark V cascade impactor, with a Hayes high temperature "super
alloy" that allows operation up to 2000 °F, a sheathed air-cooled probe, a heating jacket for the impactor
body, thermocouples with braided ceramic insulation, temperature controllers, and a blower to provide
cooling air for the probe. Before fabricating the new sampling equipment, the investigators produced a
review of the fundamentals of basic particle sizing techniques, including optical and inertial methods
(McCain and Fowler 1994). In sampling at a wet stack, stack temperatures averaged about 160°F and the
moisture content ranged from 30 to 35 percent. Most of the fine dry particulate matter collected was smaller
than one micrometer in diameter and the evaporative residues from the pre-collector were all quite small (a
few micrograms). The method appeared to perform well (McCain and Fowler 1994).

In the application of CARB Method 501 for the determination of particle-size distribution, a determination
of fip, the particle density, is necessary. CARB Method 501 specifies the use of a helium pycnometer to
perform the determination of particle density. There is no recognized numbered EPA, American Society for
Testing and Materials, or CARB method available for performing this determination, but a number of
commercial laboratories have procedures for performing the measurement. In the use of a helium
pycnometer, after properly preparing the collected particle sample with heat or vacuum, helium gas fills all
spaces and all but the smallest micropores open to the atmosphere. Knowing the volume of the container
and the volume of the gas at standard temperature and pressure, the volume of the sample is easily
determined, the weight of the sample is available, and the density is then calculated.
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Additional information regarding source test cascade impactors may be found at the cascade impactor web
site (http://www.cascadeimpactor.com/)- This site describes the Source Test Cascade Impactors developed
at the University of Washington (Seattle, Washington) Department of Civil Engineering by Professor M. J.
Pilat and his graduate students specifically for measuring the particle-size distribution in stacks and ducts at
air pollution sources. The web site describes at least one cascade impactor that includes multi-jet stages and
a number 1 inlet sampling nozzle stage that can be arranged in at least four different jet stage configurations
depending upon the desired aerodynamic cut diameters.  The site also includes an Operations Manual for
Pilat (University of Washington) Mark 3 and Mark 5 Source Test Cascade Impactors which presents
sampling procedures for stationary source testing, and reference literature.

Numerous tests have been performed to determine particle-size distributions from a variety of stationary
sources using cyclones, but there is no formal written method or a numbered EPA method describing a
specific procedure. Cyclones are better suited than impactors for sampling large particles because particle
bounce and re-entrainmentare less severe. Also, cyclones have the practical advantage that the inlet is at
right angles to the axis of the cyclone proper.  Hence, the nozzle can be pointed directly into the gas stream
and the problem of transporting large particles around bends is absent. Although the flow in cyclones is
complicated and no theory exists to predict their behavior adequately, several experimental investigations
have been performed demonstratingtheir utility for separating and sizing small particles (Rusanov 1969;
Hochstrasser 1976). The curves of collection efficiency vs. particle diameter for small cyclones can be as
steep as those of impactors, and significant re-entrainment has not been observed (Smith 1979; John 1980).
One study reports using Standard EPA Method 5 with a cyclone and Method 0060 sampling and analytical
procedures to determine total particulate and metal concentrations. Particle-size distributions were
determined by electrical mobility and inertial impaction for sampled  aerosols and light scattering for in situ
in-stack analyses (Linak 1999). Another study describes a system consisting of two cyclones and a filter in
series to  be used as the primary system for measuring the total particulate concentration and the inhalable
particulate concentration in two size fractions. The cyclones were specially designed to encompass the size
regions of interest (Smith 1982). Another study used the three cyclones from the High-Volume Source
Assessment Sampling System train to collect particulate in four size fractions (Mann 1978), while another
paper describes the development and evaluation of a five-stage cyclone sampler, using a series of cyclones
with progressively decreasing cut points which performed similarly to impactors (Wilson 1979). There are
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thus numerous reported applications of cyclones in particle sizing, although there is no specific written
method that will produce the particle-size distribution test results needed for use in the ISCST3 model. EPA
OSW recommends that the potential user of the cyclone methodology write a procedure for review by the
regulating agency and demonstrate that the procedure works effectively for his application.


Without consideration of the method used to collect the particulate matter, there are several methods
available to determine particle-size distribution. The cascade impactor and the cyclone estimate the
aerodynamic diameter of the particle, whereas the physical measurement methods estimate physical
diameter. The particle-size distributions produced by the two methods are not equivalent; one measure
cannot be translated into the other without additional information on factors such as particle density and
particle shape. However, the ISCST3 model used to perform the risk assessment calculations is not overly
sensitive to the difference between aerodynamic diameter and physical diameter. Some examples of
analytical instrumentation that can perform particle sizing are:
               The Scanning Mobility Particle Sizer is used for measuring high-resolution size
               distributions of ultrafine particles in the range from 3 to 1000 nanometers in diameter. The
               Scanning Mobility Particle Sizer employs an Electrostatic Classifier to determine particle
               size and a Condensation Particle Counter to determine particle concentrations. The
               Scanning Mobility Particle Sizer uses an electrical mobility detection technique.  During
               operation, the aerosol sample first passes through a single-stage inertial impactor to remove
               large particles outside the measurement range. The aerosol next passes through a bipolar
               ion neutralizer to impart a high level of positive and negative ions. The charged particles
               then enter a Differential Mobility Analyzer that separates particles according to their
               electrical mobility. After exiting the Differential Mobility Analyzer, the classified particles
               enter a Condensation Particle Counter which provides a measure of particle concentration.

               A Coulter Counter is used for rapid, accurate particle counting and sizing.  The Coulter
               Counter provides number, volume, and surface area distributions in one measurement, with
               an overall range of 0.4 um - 1200 um. The Coulter Counter can provide accurate particle
               counting and size distribution determination on dilute samples, so a dilution system would
               be necessary to sample a stationary source.  The Coulter Method of sizing and counting
               particles is based on measurable changes in electrical resistance produced by non-
               conductive particles suspended in an electrolyte. An aperture between electrodes is the
               sensing zone through which suspended particles pass. In the sensing zone each particle
               displaces its own volume of electrolyte. Volume displaced is measured as a voltage pulse,
               with the height of each pulse being proportional to the volume of the particle. Several
               thousand particles per second are individually counted and sized with great accuracy.
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               The Aerodynamic Particle Sizer spectrometer provides aerodynamic size and relative light
               scattering intensity. The Aerodynamic Particle Sizer spectrometer detects particles in the
               range from 0.37 to 20 uro, with high-resolution sizing from 0.5 to 20 um aerodynamic
               diameter. Time-of-flight particle sizing technology involves measuring the acceleration of
               aerosol particles in response to the accelerating flow field of a nozzle.  The aerodynamic
               size of a particle determines its' rate of acceleration, with larger particles accelerating more
               slowly due to increased inertia As particles exit the nozzle, their flight time between two
               laser beams is recorded and, using a calibration curve, converted to aerodynamic diameter.

               The Scanning Electron Microscope (SEM) focuses a beam of electrons and scans across the
               sample.  The signal from the detected scattered and emitted electrons is used to form a
               magnified image with better resolution and depth of view than an optical microscope could
               give.  Filter samples are photographed at magnification, and diameter measurements of the
               individual particles are made.  The data can then be processed to produce particle-size
               distributions. The SEM analysis approach should not be used for particles collected on a
               glass fiber or quartz filter. A polycarbonate filter has been used successfully in a number
               of applications. It is important that the filter has sufficient, but not excess, mass. Particle
               agglomeration can be a problem with SEM.  The SEM provides physical particle-size
               information rather than aerodynamic diameter.
With the exception of the application of SEM and research papers describing applications of the other
techniques, the instrumentation described above has not been generally applied to the determination of

particle-size distribution in stationary sources.  EPA OSW recommends that a facility planning to use this
type of instrumentation to perform particle-size distribution determinations supply detailed procedures in the
QAPP for the risk burn, so the procedures can be reviewed prior to use, and demonstrate that the procedure

works effectively to perform the determination indicated.    ,
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                       B.15 HYDROGEN CHLORIDE AND CHLORINE


EPA OSW has recommended that hydrogen chloride and chlorine be evaluated for potential risks in site-

specific risk assessments (EPA 1998a). As part of the risk burn, facilities may need to characterize their

stack emissions for HC1 and C12.


The following methods are applicable to the determination of hydrogen chloride and chlorine:
               SW-846 Method 0050 (Isokinetic HCl/C^ Emission Sampling Train)
               EPA Method 26 A (Determination of Hydrogen Halide and Halogen Emissions from
               Stationary Sources Isokinetic Method, 40 CFR Part 60 Appendix A)

               Method 0050/26A collects the emission sample isokinetically and is therefore particularly
               suited for sampling at sources such as those controlled by wet scrubbers that emit acid
               particulate matter (i.e., HC1 dissolved in water droplets).  Gaseous and particulate
               pollutants are withdrawn from an emission source and are collected in an optional cyclone,
               on a filter, and in absorbing solutions..  The cyclone collects any liquid droplets and is not
               necessary if the source emissions do not contain liquid droplets. Acidic and alkaline
               absorbing solutions collect gaseous HC1 and C12, respectively. The method has potential for
               collection of all halogens and halogen acids but has not yet been fully evaluated for that
               application. For analytical determination of HCl/Cl,, SW-846 Method 9057
               (Determination of Chloride from HC1/C12 Emission Sampling Train (Methods 0050 and
               0051) by Anion Chromatography) is used. For analytical determination of additional
               halides, SW-846 Method 9056 (Determination of Inorganic Anions by Ion
               Chromatography) is used.

               SW-846 Method 0051 (Midget Impinger HCl/C^ Emission Sampling Train)
               EPA Method 26 (Determination of Hydrogen Halide and Halogen Emissions from
               Stationary Sources Non-Isokinetic Method, 40 CFR Part 60 Appendix A)

               Method 0051/26 is designed to collect HCl/CIj in their gaseous forms from hazardous waste
               incinerators and municipal waste combustors.  Use of Method 0051 is limited to the
               sampling of relatively dry, particulate-freegas streams. Sample collection is similar to
               Method 0050. The method has potential for collection of all halogens and halogen acids but
               has not yet been fully evaluated for that application. For analytical determination of
               HC1/C12, SW-846 Method 9057 (Determination of Chloride from HCI/C1, Emission
               Sampling Train (Methods 0050 and 0051) by Anion Chromatography) is used. For
               analytical determination of additional halides, SW-846 Method 9056 (Determination of
               Inorganic Anions by Ion Chromatography) is used.
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               EPA Method 320 (Measurement of Vapor Phase Organic and Inorganic Emissions by
               Extractive Fourier Transform Infrared (FTIR) Spectroscopy, 40 CFR Part 63 Appendix A)
               Method 320 applies to the analysis of vapor phase organic or inorganic compounds which
               absorb energy in the mid-infrared spectral region. The method is used to determine
               compound-specific concentrations in a multi-component vapor phase sample.  Spectra of
               gaseous emission samples are collected using double beam infrared absorption
               spectroscopy, and a computer program is used to analyze spectra and determine compound
               concentrations. Range and sensitivity of the technique are compound-dependent and the
               ability of FTIR to attain the detection limits needed for risk assessment should be carefully
               evaluated for each application.
Johnson has summarized research evaluating the use of Methods 0050/0051 for hydrogen chloride and
chlorine determinations (Johnson 1996c). Methods 0050/0051 are very sensitive to train operating
temperature. If the train is maintained at temperatures below those specified in the method, HCI may
condense in the probe/filter assembly and not be reported.  Several studies found that operating the
sampling train at higher temperatures (170 °C [338°F]) increased the precision of the HCI measurement and
reduced the loss of HCI in the cyclone. Additional data are also available to show that operating the train at
200°C (400°F) eliminates the negative bias reported when sampling sources containing less than 20 ppmv
HCI.  However, operating the sampling train at higher temperatures significantly increases the positive bias
in the HCI measurement when ammonium chloride is present in the source sample, because breakthrough of
ammonium chloride may be enhanced. There are compromises that will be made in the operation of the
method on a source-specific basis in order to obtain optimum results using the manual train.

An area of concern repeatedly noted by cement kiln representatives is that HCI determinations based on
Methods 0050/0051 or 26/26A could be biased high because volatile particulate chloride salts, such as
ammonium chloride, could penetrate the filter and be converted to HCI within the sampling train (Gossman
1997).  Industry has proposed correcting the HCI results based upon ion chromatographic analysis of the
impinger solutions for cations (Na*, Ca+2, K+, and NH/).  EPA has considered this issue and, on the basis
of the study results summarized by Johnson (Johnson 1996c) and revised standards (EPA 1996f), does not
believe that the presence of salts will significantly bias the results. Johnson emphasizes that the correction
of HCI results for the presence of other salts is not appropriate, because the ion chromatographic analysis
that detects the cations cannot determine in what form the ionic material entered the impingers (Johnson
1996c). The filter specified for use in the sampling train will not pass significant quantities of solid halide
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salts such as sodium chloride (NaCl), calcium chloride (CaCl2), or potassium chloride (KC1). The presence
of sodium, calcium or potassium ions in the impingers could reflect contamination during handling, a torn
filter, or operation with a wet filter. These problems can be addressed by use of a cyclone and adequate
heating in the sampling train, coupled with careful handling of the sampling train components to minimize
contamination.

There is some evidence that it may be possible for ammonium chloride to penetrate the filter in the vapor
phase. Under all conditions tested in the laboratory (EPA 1993), the presence of ammonium chloride in the
sampled gas introduced a positive bias into the HC1 measurement. The positive bias increased when the
temperatures of the probe and filter were increased and as the amount of moisture in the sampled stream
decreased, and appeared to be independent of the type of filter used in the sampling train. When both HC1
and ammonium chloride were present in the sampled gas, a synergistic effect increased the positive bias in .
the HC1 measurement. If ammonium chloride is believed to be the cause of significant bias, then application
of an FTIR or infrared (IR) gas-filter correlation (GFC) method for HC1 measurement may be considered.

Test Method 321 (Measurement of Gaseous Hydrogen Chloride Emissions at Portland Cement Kilns by
Fourier Transform Infrared (FTIR) Spectroscopy, 40 CFR Part 63 Appendix A) and Proposed Test Method
322 (Measurement of Hydrogen Chloride Emissions from Portland Cement Kilns by GFCIR, 40 CFR Part
63 Appendix A) are specifically applicable to the determination of HC1 concentrations in emissions from
Portland cement kilns. Method 321 relies on Method 320 procedures but is specifically designed for the
application of FTIR spectrometry in extractive measurements of gaseous HC1 concentrations in Portland
cement kiln emissions. Method 322 is an instrumental method for the measurement of HC1 using an
extractive sampling system and an infrared (IR) gas-filter correlation (GFC) analyzer, and is intended to
provide the cement industry with a direct interface instrumental method. Method 322 is considered self-
validating provided that the methods for sample collection, preservation, and storage are followed. In the
application of Method 322, kiln gas is continuously extracted from the stack or duct using either a source
level, hot/wet extractive system or an in-situ dilution probe or heated out-of-stack dilution system. The
sample is then directed by a heated sample line maintained above 350°F to a GFC analyzer having a range
appropriate to the type of sampling system. The gas filter correlation analyzer incorporates a gas cell filled
with HC1. This gas cell is periodically moved into the path of an infrared measurement .beam of the
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instrument to filter out essentially all of the HCI absorption wavelengths. Spectral filtering provides a
reference from which the HCI concentration of the sample can be determined. Interferences are minimized
in the analyzer by choosing a spectral band over which compounds such as CO2 and H2O either do not
absorb significantly or do not match the spectral pattern of the HCI infrared absorption.
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                                   B.16 PROCESS SAMPLES


 EPA OSW recommends that risk burn protocols address analytical procedures for complete characterization

 of materials to be burned during the risk burn, including wastes, fuels, raw materials, and spike materials.

 These data define a baseline for the facility with respect to long-term impacts and potential effects on human

 health and the environment.  If there are significant changes to the baseline of the facility, additional risk-

 based data collection and/or risk analyses may be appropriate.


 EPA OSW recommends that the following types of data typically be generated for process samples in the
 characterization of the stationary source:


        •      Proximate analysis, or a comparable evaluation, to determine physical properties including
               moisture, percent solids, heating value, ash, and viscosity or physical form, as well as
               chemical properties including total organic carbon, total chlorine, total organic halogens,
               and elemental composition;

        •      Quantitative analysis of total metals feed rates for the following metals: aluminum,
               antimony, arsenic, barium, beryllium, cadmium, chromium, cobalt, copper, lead,
               manganese, mercury, nickel, selenium, silver, thallium, vanadium, and zinc;

        •      Survey analysis or a comparable evaluation to provide an overall description of the
               chemistry of the sample in terms of the major types and quantities of organic compounds
               that are present, as well as identification and quantitation of trace levels of persistent,
               bioaccumulativeand toxic constituents based on GC/MS analysis for VOCs, SVOCS,
               PCBs and PAHs. As warranted (based on the wastes handled by a particular facility),
               analysis for pesticides, herbicides, and other facility-specific toxic compounds using
               standard analytical methods may also be appropriate.


 Standard methods for performing inorganic and  organic analysis are available in S W-846 (EPA 1996b).
 For organic analysis, the sample preparation procedures usually involve dilution of the sample with an

 appropriate solvent (i.e., methanol for VOCs, methylene chloride for S VOCs) until the diluted sample can

 be subjected to the appropriate analytical procedure using a capillary gas chromatographic column coupled

 with mass spectrometry (Method 8260 for VOCs, Method 8270 for S VOCs). Standard VOC or S VOC

analytical procedures may not be adequate for determining trace components in the presence of very large

quantities of major components.  If complete characterization of constituents of a process sample is
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necessary, a sample preparation and analysis scheme will need to be carefully designed by an experienced
analytical chemist and approved by the regulating agency.

Another difficulty in application of standard methods lies in the preparation of the waste feed samples for
analysis. The chemical and physical nature of process samples is so variable from facility to facility that
development of a generic method appropriate for all process samples is not straightforward.  The nature of
process samples may range from nearly pure organic solvent to oils to tars (both viscous and solidified), and
the major analytical problems may arise from handling the samples in the laboratory to produce a
diluted/extracted/digested medium which can be subjected to the standard laboratory analytical procedures.

Once the sample has been prepared for analysis, analytical problems can arise from the presence of
interferences in the sample. A process sample that contains significant amounts of an organic solvent will
need to be diluted until an analysis of the major component can be performed using the calibration range for
the analytical instrument. The result of the necessary dilution will be to dilute trace constituents of the
process sample below the level at which they can be detected in the analysis. EPA OSW recommends that
assistance should be obtained from a well-qualified and experienced analytical chemist who understands the
methods involved, as well as the objectives for the risk assessment.
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       of Organic Emissions from Hazardous Waste Incineration Processes Under the New EPA Draft
       Risk Burn Guidance: Measurement Issues." Presented at the 1999 International Conference on
       Incineration and Thermal Treatment Technologies. Orlando, FL.

Ryan, J. V. 2000. Personal communication with Beth Antley of EPA Region 4, Atlanta, Georgia

Smith, W.B., Wilson, R.R., and Harris D.B.  1979. "A Five-Stage Cyclone System for in Situ Sampling."
       Environ. Sci. Technol.  13:  1387-1391.

Smith, W. B., Gushing, K. M., and Wilson, R.R. 1982. "Cyclone Samplers for Measuring the
       Concentration of Inhalable Particles in Process Streams. J. Aerosol Sci. Volume 13, No. 3.
       pp 259-267. November.

Steger, J. L. and Workman, G. S.  1996. "Field Validation of the DNPH Method for Aldehydes and
       Ketones." EPA/600/R96/050. NTIS PB96-168398. U. S. Environmental Protection Agency,
       Research Triangle Park, NC. April.

Steger, J. L., Bursey, J. T., and Epperson, D. 1997. "Acetonitrile Field Test." EPA-600/R-97/140. NTIS
       PB98-133143, U. S. Environmental Protection Agency, Research Triangle Park, NC. October.

Steiner, J. and Mitzel, M.  1994. Presented at Stationary Source Sampling Conference. Palm Coast, FL.
       April.

Taylor, J. H.  1987. "Quality Assurance of Chemical Measurements." Lewis Publishers, Inc.  Ann Arbor,
       ML
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 U. S. Environmental Protection Agency (EPA).  1976. "Environmental Assessment Sampling and
       Analytical Strategy Program." EPA-600/2-76-093a. U. S. Environmental Protection Agency.
       May.

 EPA. 1978. "IERL-RTP Procedures Manual: Level 1 Environmental Assessment (Second Edition)."  EPA-
       600/7-78-201. NTIS PB29-395. U. S. Environmental Protection Agency.

 EPA. 1984. "Summary of Activity on SATS Technical Assistance Work Assignment." Arthur D. Little,
       Inc., EPA Contract No. 68-02-3627.

 EPA. 1989. "Risk Assessment Guidance for Superfund: Volume I. Human Health Evaluation Manual
       (Part A)." Office of Emergency and Remedial Response. Washington, DC. Office of Emergency
       and Remedial Response 9200 6-303-894.

 EPA. 1990a. "Operations and Research at the U. S. EPA Incineration Research Facility. Annual Report
       for FY 89." Risk Reduction Engineering Laboratory. Office of Research and Development.
       Cincinnati, OH.  EPA/600/9-90/012.

 EPA. 1990b. "Standards for Owners and Operators of Hazardous Waste Incinerators and Burning of
       Hazardous Wastes in Boilers and Industrial Furnaces." Federal Register. 55:17862-17921.

 EPA. 1991. "Burning of Hazardous Waste in Boilers and Industrial Furnaces: Final Rule." Federal
       Register. 56: 7134-7240.

 EPA. 1992. " Guidance for Data Useability in Risk Assessment (Part A). Final." U.S. Environmental
       Protection Agency, Washington, DC. EPA 9285.7-09A. April.

 EPA. 1993. "Evaluation of Method 0050 for Hydrogen Chloride, Task C. Studies of Sampling
       Atmospheres Containing Ammonium Chloride." Contract No. 68-D1-0010. Draft Report.

 EPA. 1994a.  "Draft Revision, Implementation Guidance for Conducting Indirect Exposure Analysis at
       RCRA Combustion Units. Attachment, Draft Exposure Assessment Guidance for RCRA
       Hazardous Waste Combustion Facilities." April.

 EPA. 1994b.  "Draft Guidance on Trial Burns. Attachment B, Draft Exposure Assessment Guidance for
       RCRA Hazardous Waste Combustion Facilities." May.

 EPA. 1994c.  "Draft Guidance for Performing Screening Level Risk Analyses at Combustion Facilities
       Burning Hazardous Wastes^  Attachment C, Draft Exposure Assessment Guidance for RCRA
       Hazardous Waste Combustion Facilities." Office of Solid Waste and Emergency Response. United
       States Environmental Protection Agency. April.
Risk Burn Guidance for
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EPA. 1994d.  "Revised Draft Guidance for Performing Screening Level Risk Analyses at Combustion
       Facilities Burning Hazardous Wastes. Attachment C, Draft Exposure Assessment Guidance for
       RCRA Hazardous Waste Combustion Facilities." Office of Emergency and Remedial Response.
       Office of Solid Waste. December.

EPA. 1994e.  "Estimating Exposure to Dioxin-Like Compounds. Volume II: Properties, Sources,
       Occurrence, and Background Exposures. Review Draft." Office of Research and Development. U.
       S. Environmental Protection Agency. EPA/600/6-88/005Cb. Washington, D.C. June

EPA. 1995. "Development of Compliance Levels from Analytical Detection and Quantitation Levels." U.
       S. EPA, Washington, DC. NTISPB95-216321.

EPA. 1996a.  "Guidance for Total Organics." EPA/600/R-96/033. National Exposure Research
       Laboratory. U. S. Environmental Protection Agency. Research Triangle Park, NC. March.

EPA. 1996b.  "Test Methods for Evaluating Solid Waste, Physical/Chemical Methods." EPA Publication
       SW-846 [Third Edition (November 1986), as amended by Updates I (July 1992), II  (September
       1994), IIA (August 1993), IIB (January 1995), III (December 1996), and IV (January 1998)]. The
       most recent versions of the SW-846 methods are also available at SW-846 On-line
       (http^/www.epa.gov/sw-846/main.htm)

EPA. 1996c.  "PCBs: Cancer Dose-Response Assessment and Application to Environmental Mixtures."
       EPA/600/P-96/001. National Center for Environmental Assessment, Office of Research and
       Development. September.

EPA. 1996d.  "Formation of Dioxin-Like PICs During Incineration of Hazardous Wastes." Memorandum
       to the Record. Dorothy Canter. June 21.

EPA. 1996e.  Internal Memorandum Regarding JACADS Risk-Related Issues. From Timothy Fields, Jr.,
       Deputy Assistant Administrator, Office of Solid Waste and Emergency Response. To Julie
       Anderson, Director, Waste Management Division. October 2.

EPA. 1996f.  "Revised Standards for Hazardous Waste Combustors." Proposed Rule. Title 40 of the
       Code of Federal Regulations Parts 60,63,260, 261,264,265, 266,270, and 271. Federal Register
       61:17358. April.

EPA. 1997a.  "Development of a Hazardous Waste Incinerator Target Analyte List of Products of
       Incomplete Combustion." Final Report. Prepared by EPA National Risk Management Research
       Laboratory, Research Triangle Park, NC, for the Office of Solid Waste. July.

EPA. 1997b. "Hazardous Waste Management Systems: Testing and Monitoring Activities." Final Rule.
       Federal Register 62:32452. June 13.

EPA. 1997c. "TOC Gravimetric Lab Procedures Troubleshooting Options to Minimize and Identify
       Sources of Contamination." Memorandum from Catherine Massimino, EPA Region 10.  May 1.
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EPA. 1997d.  "Mercury Study Report to Congress, Volumes I through VIII." Office of Air Quality
       Planning and Standards and Office of Research and Development. U. S. Environmental Protection
       Agency. EPA/452/R-97-001. December.

EPA. 1998a.  "Human Health Risk Assessment Protocol for Hazardous Waste Combustion Facilities.
       Volume One." Peer Review Draft. EPA530-D-98-001. Prepared for EPA Office of Solid Waste.
       July.

EPA. 1999. "Final Technical Support Document for HWCMACT Standards. Volume III."  July.

EPA. 2000. Integrated Risk Information System (IRIS). On-line Database (http://www.epa.gov/iris).

Van den Berg, M., Birnbaum, L., Bosveld, A., Brunstrom, B., Cook, P., Feeley, M., Giesy, J.P., Hanberg,
       A., Hasegawa, R., Kennedy, S., Kubiak, T., Larsen, J.C., van Leeuwen, F., Liem, A., Nolt, C.,
       Peterson, R.E., Poellinger, L., Safe, S., Schrenk, D., Tillitt, D., Tysklind, M., Younes, M., Waern,
       F., Zacharewski, T. 1998. "Toxic Equivalency Factors (TEFs) for PCBs, PCDDs, PCDFs for
       Humans and Wildlife." Environmental Health Perspectives.  106:775-792.  December.

Weast, R. C.  1986. Handbook of Chemistry and Physics. 66th edition. Cleveland, OH. CRC Press.

Wilson, R. R., Jr., Smith,  W. B., and Harris, D. B.  1979. "A Five-Stage Cyclone System for In-Situ
       Sampling." Environmental Science and Technology. 13:1387-1392.
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                                   ATTACHMENT 1

                           METHOD 0040 CLARIFICATIONS

                                       (3 pages)
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                        UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                               NATIONAL EXPOSURE RESEARCH LABORATORY
                                       Research Triangle Park, NC 27711
                                                                                   Office of
                                                                            Research and Development
MEMORANDUM:

DATE: April 3, 1998

SUBJECT:    Method 0040 Questions

FROM:       Larry D. Johnson
              Source Apportionment and Characterization Branch (MD-47)

TO:          Catherine Massimino, U.S. EPA Region 10

This memo is to transmit clarifications to the passages of Method 0040 about which you asked questions. I'm
also sending it to Beth Antley so she can include the explanations in her new Trial Burn Guidance. Other
interested parties are also receiving copies. The appropriate section of M0040 is reproduced below in Arial
type. Your question, as understood by me, follows in italics.  The answer follows in regular GC Times type.
If I misinterpreted or omitted any of the questions, or if the explanations aren't clear, please let me know. Thank
you very much for bringing these confusing instructions to our attention.

       7.4.3.4        Draw at least eight times the sample volume of flue gas, or purge for at least
10 minutes, whichever is greater.

Isn't eight times the sample volume an unreasonably large amount of purge volume, it takes a long
time to carry this out in the field.

You certainly have a good point. The confusion here is that "sample volume" refers to the volume contained
in the part of the train being purged (the probe and lines, typically less than a liter) rather than the bag volume
of 30-40 liters.  Purging 40 liters times 8 at 0.5 liters per minute would take 640 minutes. The 10 minute purge
mentioned in the method would give an 8 fold volume exchange for a 0.6 liter train volume (at 0.5 liters per
minute). If the train volume is estimated to be larger than 0.6 liters, then the purge time needs to be increased
accordingly.
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       7.6.5.2       Rinse the condenser, the condensate trap and the sample line three times
with 10 mL of HPLC grade waterand add the rinsings to the measuring cylinder containing the
condensate.  Record the final volume of the condensate and rinse mixture on the field sampling
data form. High moisture sources (such as those with wet control devices) may require a 150-mL
or200-mL measuring cylinder while low moisture sources (such as some rotary kilns and pyrolytic
incinerators) may require only a 100-mL size.

Does the method mean 3 rinses of 10 mL each, or three rinses totaling 10 mL?

Three rinses of 10 mL each was the intended instruction. The contractor who wrote and field tested the method,
feels that it is difficult to achieve an adequate rinse with much less than 10 mL.

       7.6.5.3       Pourthe contents of the measuring cylinder into a 20- or40-ml_ amber glass
VOA vial with a Teflon® septum screw cap.  Fill the vial until the liquid level rises above the top of
the vial and cap tightly.  The vial should contain zero void volume (i.e., no air bubbles).  Discard any
excess condensate into a separate container for storage and transport for proper disposal.

If three rinses of 10 mL each are carried out, there will always be a minimum of 30 mL of condensate.  Why
is a 20 mL vial an option? Do you throw out the extra liquid?

The section above does instruct the sampler to discard any excess condensate, so the 20 mL vial would be an
option, but not necessarily the best one. If more than 10 mL of actual condensate is collected, even the 40 mL
vial would not hold the combined volume.  If the analytical method is to use purge-and-trap technology (it
usually does), then it is best to discard as little of the liquid as possible. The detection limit may be minimized
by purging the target compound from as much of the original volume as possible.

This question also brings up another important point which is inadequately addressed in the method. In Section
7.6.5.2 above, the sampler is instructed to record the final volume of condensate and rinse mixture on the field
sampling data form (shown in Figure 6). This volume is called "Total condensate volume" on the form in Fig.6,
and becomes V|C as defined (Total volume of liquid collected in the condensate knockout trap) in Section 7.8.2.
Vk is used in equation 15 in Section 7.8.9.2 to calculate the amount of target compound collected in the
condensate. This whole sequence is all well and good, as long as there is excess condensate, or exactly enough
to fill a vial. However, in the case where the condensate and rinses do not completely fill the vial and the vial
must be "topped off with rinse water as described in Section 7.6.5.3, then the vial volume should be used as
Vk rather than using the volume measured with the measuring cylinder (and recorded as "Total condensate
volume" on the form in Fig. 6).

Example:

Given that the condensate plus rinses makes up 30 mL. If a 20 mL vial is used to ship the sample, then V,c
should be 30 mL, since the sample concentration determined in the lab was contained in 30 mL of liquid. If a
40 mL vial was used, then the sample was diluted with 10 mL of water, so V,c must be 40. The lab determined
concentration was contained in 40 mL rather than the original 30. In this example, the use of the  wrong volume
would introduce a negative bias of 25% into the condensate result. The magnitude in actual cases would depend
on the dilution ratio. Since 30 mL is pretty much the minimum total volume, as discussed above, the example
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is likely to be a worst case. Of course, most of the target compound will usually be collected in the bag rather
than the condensate, so even a 25% bias in the condensate value might have little effect on the overall results.
This just demonstrates, once again, that no matter how many highly competent people write and review a method
(and there were quite a few in this case), it takes years of use to discover all the ambiguities and oversights.
cc     Beth Antley, Region 4
       Bob Fuerst, ORD
       Barry Lesnik, OSW
       Jeff Ryan, ORD
       Gene Riley, OAQPS
       Joan Bursey, Eastern Research Group
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                               ATTACHMENT 2

 INFORMATION AVAILABLE FROM METHODS 98. STATUS OF STATIONARY SOURCE
                          METHODS FOR AIR TOXICS

                                   (22 pages)
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                                        ATTACHMENT 2

   INFORMATION AVAILABLE FROM METHODS 98.  STATUS OF STATIONARY SOURCE
                                  METHODS FOR AIR TOXICS

                                Comments and Suggestions
 The following information is included to give the user of this document perspective on the information contained
 therein and to aid in decisions regarding its use.

 1.      The status table contains a summary of the methods type and status for stack sampling and analysis of
        eachofthe 189 airtoxics listed in the 1990 CleanAir Act Amendments. The table and its attachments
        have no direct regulatory standing, and therefore do not constitute approval of the use of the methods
        to satisfyregulatorvrequirements. Such approvalmust always be obtained from the regulatory agency
        or group involved in the individual project. Hopefully this compilation will aid both the regulator and
        the regulated community in making planning decisions for air toxics source testing.

 2.      Methods98 isaMay 1998 update and expansionof the 12/14/89 version of the status table, which was
        originally produced primarily from memory or opinion with the use of only a very few reference texts.
        An intermediate partial update was produced in 1994, but was not circulated widely.  A large amount
        of field evaluation data has been produced by EPA and its contractors since 1989, and an attempt has
        been made to utilize all of it in Methods 98.  The 1998 status table, therefore, is based much more on
        field and laboratory test information than were its predecessors. No attempt has been made to perform
        a comprehensive literature survey and to include field test information from sources outside EPA.  It
        is the author's opinion, however, that very little data from outside sources exist that would meet the
        criteria needed for useful inclusion in this table. The scope of Methods 98 has been expanded in order
        to give the user easy access to the papers and reports which contain the information behind the Status
        Table entries, and compilation tables are included which contain much of the field and laboratory data.
        Footnotes for each column on the compilation tables lead the reader to a corresponding item on the
        Reference List. The reference list contains at least one source, usually a report and a paper, for all of
        the recently generated data and for some of the older studies. The information in the attached tables
        and the referenced papers is more compact, and is usually much easier to use than that in the reports.
        The reports provide much more detail. Some, but not all, of the Status Table entries include suggested
        references. Other references may be identified by scanning the Reference List for appropriate topics.

        Methods such as  0010 (MM5), 0030 (VOST sampling), 5041/8260 (VOST analysis), and 8270
        (GC/MS) are from the SW-846 Methods Manual used by OSW and the Regions for RCRA related
        work.  Method 5, Method 15,and Method 106 are examples of Federal Register Methods historically
        related to OAQPS air programs. Some of the methods have been promulgated by both groups under
        different method numbers. Methods and other useful material can be obtained from sources given later
        in this document.  The  SW-846 methods listed are the most recent versions, for example 8270C and
       5041 A. In the future, later versions of the same method should functionjust as well, or better. In most
       cases, data obtained with earlier versions of the same method will also be sound, but new tests should
       always utilize the most recent rendering of the procedure. Methods such as XHCN and XACN are
3.
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       Office of Research and Development produced methods which have been cleared for publication, but
       which have not yet been promulgated by one of the program offices. Copies of the "X" methods are
       included in the corresponding research reports listed in the references.

4      The sampling methods listed are generally intended for relatively low concentrations of materials in
       stack gases. Alternate methods may be necessary for process streams or flue gases with no control
       devices. Not all methods that might be effective are included on the table. The Tedlar® bag version of
       M18 would probably be effective for the same compounds that 0040 sampled well, provided that the
       source did not emit sorptive particulate matter or condensable water vapor, and that sorption losses in
       the lines were minimal. The performance of the sorbent tube version of Method 18 would be less easy
       to predict, and would have little relation to 0040 performance.

5.     Priority has been given in this table to methods such as 0010 (a.k.a Modified Method Five, a.k.a.
       SemiVOST) or Method 297 Method 0060 (a.k.a. the Multiple Metals Train)  which have the most
       potential for determination of many compounds or metals simultaneously. Alternate single pollutant
       methods are often given in the comments column. Exclusion of a method from the Status Table does
       not necessarily imply that it will not perform adequately.

6.     Many of the compounds on this list are also on RCRA Appendix 8 but listed under a different name.
       In cases where common,  alternate identities have been identified, these are given in the comments
       column. No attempthas been made to HstaU alternatechemical names. In some cases, two inconsistent
       chemical names or an inconsistent pairing of a name with a CAS number has been given on the CAAA
       list Cases such as these have been noted in the Status Table, and the CAS number has been assumed
       to be the primary reference (i.e. the correct CAS number for the compound intended to be regulated).
       The author has no idea, whatever, what the legal ramifications are of such mistakes in the CAAA.

7.      In general the compounds that have identical listings in the sampling column and in the analysis column
        can be determined simultaneously. Some of the analyses may require more than one GC or HPLC run
       to accomplish this end.

9.      Unless otherwise stated, metals methods produce total Cr, total Pb, etc.  Metals oxidation state or
        compound speciationis always difficult, often impossible, and requires special S&A.

 10.    EventhoughmuchlessfielddataisavailableforMethod0031thanforMethod0030,theformershould
        always perform at least as well as the latter, and often times better.  The limited comparison data
        generally,  but not always, supports this position.  The  author believes that 0031 can always be
        successfully substituted for M0030, and usually should be chosen for new projects.

 11.    The field and laboratory recovery tables have not been included for all compounds or all methods on
        the Status Table, but there should be at least one reference in the Reference List to support each "f" or
        "1" listing in the table. The "m" and "s" listings are more conjectural, and may or may not have direct
        support in the references.

 12.    Only CAAA toxics are included on the Status Table, but data for a few additional compounds may be
        found on the results tables.
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13.     Poor performance of one of the basic methods such as MOO 10 is often a result of reactivity of the target
       compound. The relatively non-reactive compounds will consistently show good recoveries, the highly
       reactive compounds will consistently exhibit very poor recoveries, but the marginally  reactive
       compounds may show variability as a function of the reactivity of the stack gas matrix being sampled.
       Chloroprene, for example, yielded field test results of f2 and f4 along with 11 laboratory recoveries.
       Caprolactam actually showed fl, f4, and 11 results. When sampling compounds with a history of mixed
       performance, it is probably a good idea to spike the sorbent resin (for sorbent methods) with an
       isotopically labeled recovery standard before sampling.  Carbon or chlorine labels are the least likely
       to exchange to another compound. Method 23 uses a form of this technique, as does M0040.

14.     Laboratory recoveries are not usually shown on the Summary Table unless field results were poor, or
       the laboratory results are at odds with the field results.  The code does not indicate how many field
       results of a given category were obtained, see the compilation tables or the reference documents for that
       type of information.

15.     A number of the CA AA compounds were eliminated from further testing with Methods 0030 and 0010
       when they failed initial laboratory studies.  This was usually an analytical problem rather than a
       sampling deficiency. In the major studies which produced the data in the compilation tables, no effort
       was made to utilizealternateanalysis methods. In some cases, potential alternates have beensuggested
       in the Status Table. Method 0010 will collect any organic compound with a boiling point above 100°C
       If the compound is not altered by chemical reaction during sampling, field recovery, transport or
       storage, then identification of a successful quantification scheme becomes a matter of finding effective
       extraction and determinative analytical methods. The researcher investigatinga problem of this nature,
       should find References 32, 33,42, 56, 57, and 58 especially helpful.
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                     Status and Recovery Table Code Definitions

R     %Recovery of spiked standard.

C     Method 301 bias correction factor

_     An underlined method is not recommended for the listed air toxic.

?      Effectiveness of the method for the listed air toxic is questionable or showed mixed results.

fl     Data are available from at least one Method 301 field test where 143%>R >76.9% (equivalentto
       0.70<;Cs 1.30) and the relative standard deviation (RSD) of R was <;50%.

£2     Data are available from at least one Method 301 field test where 150%> R ^ 50% (equivalent to
       0.67<;Cs2.00) and the RSD of R was <;50%.

f3     Data are available from at least one field test not fully qualifying as Method 301 where 150%> R
       £50% (equivalentto 0.67=;C<;2.00) and the RSD of R was <;50%. Some of the recovery data may
       be better than the minimum shown, and the test may only have failed to meet minimum replicate
       criteria for full Method 301 statistical analysis.

f4     Data are available from at least one Method 301 field test where R<;50% or R> 150% or the RSD of
       R was ;>50%.

f5     Data are available from at least one field test not fully qualifying as Method 301 where R^50% or
       Rs 150% or the RSD of R was ;>50%.

11     Laboratory test data are available where full scale sampling equipment, dynamic spiking, and a
       stack simulator were utilized.  The  RSD of R was <;50%, and 143%sR :>76.9% (equivalentto
       0.70^C^1.30). This is essentially a successful Method 301 test in the laboratory.

12     Laboratory test data are available where full scale sampling equipment, dynamic spiking, and a
       stack simulator were utilized.  The  RSD of R was <;50%, and 150%>R ;>50% (equivalentto
       0.67<;C<;2.00).

13     Laboratory test data are available where full scale sampling equipment, dynamic spiking, and a
       stack simulator were utilized.  R<50% or R;> 150% or the RSD  of R was > 50% or unknown.

14     Other laboratory test data are available, where 143%sR S;76.9% (equivalentto 0.70
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16     Other laboratory test data are available, where R<50% or R^ 150% or the RSD of R was ;>50% or
       unknown. The data from tests in this category may be insufficient to yield a credible RSD.

17     Laboratory tests showed no response in VOST analytical system (5041A & 8260B). See
       References 5,1,11, and 16.

18     Laboratory tests showed weak response in VOST analytical system (5041A & 8260B). See
       References 5, 7,11,'and 16. Special attention or modification necessary for reliable operation.

s      Should work. For sampling methods, no confirmatory field or laboratory data have been identified,
       but the structure of the compound or its similarity to validated compounds makes the prognosis
       optimistic.

m     Might work. This designation usually implies that the technique given should work if the compound
       survives the sampling and analysis process, but that we have strong reservations about its ability to
       do so.  This status is usually linked with reactivity/instability. Many compounds are stable enough
       to analyze, but will not tolerate prolonged exposure to water, NO2, or other materials during
       sampling.

n      No known adequate method.  This always means we know of no reliable method for this pollutant.
       We usually have identified a number of unreliable methods for the pollutant. If negative data are
       available, the sampling method will be underlined

sp     Suspected problems.  The suspected problem is given in the comments, and is often related to
       reactivity.

kp     Known problems. This is similar to the suspected problem except that our fears have been
       confirmed by data. If data indicate questionable or inconsistent performance, the sampling
       method will be followed by a question mark.
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CAS No.
7S-07-0
60-35-5
75-05-8
98-86-2
53-96-3
107-02-8
79-06-1
79-10-7
107-13-1
107-05-1
92-67-1
62-53-3
90-04-0
1332-21-4
71-43-2
92-87-5
98-07-7
100-44-7
92-52-4
117-81-7
542-88-1
75-25-2
106-99-0
Chemical Name
Acetaldehyde
Acetamide
Acetonitrile
Acetophenone
2-Acetylaminofluorene
Acrolein
Aciylamide
Aciy lie Acid
Acrylonitrile
AHyl Chloride
4-Aminobiphenyl
Aniline
o-Anisidine
Asbestos
Benzene
Benzidine
Benzotrichloride
Benzyl Chloride
Biphenyl
bis(2-EthylhexyI)phthalate
bis(Chloromethyl)ether
Bromoform
1,3-Butadiene
Sampling
Method
0011
0010
XACN
0010
•0011
0010?
0011?
PFBHA
0010
0010
sorbent
XACN
00300031
0030 kp
003 Ikp
0040
0010
acid liquid
0010?kp
acid liquid
0010 kp
acid liquid

0030
0040
0010?kp
acid liquid
0010
0010
0010
0010
n,kp0010
kpOOSO
0010
0040? kp
s.
Code
fl
m,sp
n
n
n
f2, f4,
n
12, kp
14
m,sp
m, sp
14
s
s!8
f4,ll
f4
n
m,sp
s
f2,f4,
12
14
f4,12
s
-
n
n
f2,f4,
13
s
a
fl,f2
n
f2, f4,'
11
f4,Il
17
n G
f4
Analysis
Method
83 ISA
8032
8015B8033
3542 8270C
83 ISA
3542 8270C
83 ISA
GC/MSorECD
GC/MSor
8316
8316
GC/F1D
8015B 8033
5041A8260B
5041A 8260B
5041A8260B
8260B
GC/MS
HPLC/PDA
3542 8270C
HPLC/PDA
3542 8270C
HPLC/PDA
microscopy
5041A 8260B
8260B
3542 8270C
HPLC/PDA
3542 8270C
3542 8270C
3542 8270C
3542 8270C
3542 8270C
3542 8270C
8260B
Comments
Simultaneous aldehydes possible. Refs. 23, 40
May be reactive
See Refs. 24 & 26.
See References 23 & 40 for 00 11 .

Stability/reactivity problems, even in DNPH
See references 45 & 50 for PFBHA approach.
Polar, water soluble. Poor GC, needs work.
Suspect polymerization may be problem
Ref 50&54, prototype needs to be isokinetic.
See Refs. 24 & 26.
Purges poorly, needs special attention.
0030 recoveries good in lab., 30% from field test
(suspect reactivity)
Ref50&51.
Extraction and reactivity problems.
Ref 50&51, prototype needs to be isokinetic.
Ref 50&51, prototype needs to be isokinetic.
Separate S&A
Make sure that the Tenax is clean.
May react during sampling.
Ref 50&51, prototype needs to be isokinetic.



a.k.a. DEHP; common contaminant
Reacts quickly with water

Reactive, borderline results.
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001

-------
CAS No.
156-62-7
105-60-2
133-06-2
63-25-2
'75-15-0
463-58-1
463-58-1
120-80-9
133-90-4
57-74-9
7782-50-5
79-11-8
532-27-4
108-90-7
510-15-6
67-66-3
107-30-2
126-99-8
1319-77-3
95-48-7
108-39-4
Chemical Name
Calcium cyanamide
Caprolactam
Captan
Carbaryl
Carbon Disulfide
Carbon Tetrachloride
Carbonyl Sulfide
Catechol
Chloramben
Chlordane
Chlorine
Chloroacetic Acid
2-Chloroacetophenone
Chlorobenzene
Chlorobenzilate
Chloroform
Chloromethyl Methyl Ether
Chloroprene
Cresols/Cresylic Acid
o-Cresol
m-Cresol
Sampling
Method
0010
M5
0010?
0010
0010?
0030?
0030/0031
M15
0040
0010
acid liquid
0010
M26/26A
00500051
n,sp
0010
0010
0030?
0031?
0010
0030
0031
0040
nkpOOSO
0030?
0031
-
0010
NaOH
0010
NaOH
S.
Code
s
fl,f4,
11
m
fl, f4,
11
f2, f4,
12
fl
s
m
14
fl
fl
n
fl, £2
fl,r2
n
n
fl.G,
f4
n
n
s
17
£2, f4,
11
n
-
n, f2
n
£2
n
Analysis
Method
?
3542 8270C
3542 8270C
HPLC
3542 8270C
5041A8260B
5041A8260B
GC/FPD
CG/FPD
3542 8270C
HPLC/PDA
3542 8270C
9056 9057
HPLC
3542 8270C
3542 8270C
5041A8260B
5041B8260B
3542 8270C
5041A8260B
5041A8260B
8260B
5041A8260B
5041A8260B
5041A8260B
-
3542 8270C
HPLC
3542 827QC
HPLC
Comments
Should be able to collect salt as paniculate.
Analysis is problematic, low solubility without
decomposition.
Mixed results, suspect hydrolysis.
Can be reactive.
Mixed results.
Mixed results.


Careful pH control during extraction mandatory.
Recovery may be difficult.
Ref 50&5 1 , prototype needs to be isokinetic

Halogens & halo-acids can be done
simultaneously


Above recommended bp limit for 0030/0031,
and for 0040.


May decompose during s&a
Recoveries good in lab., mixed in field. Suspect
reactivity.
Determine as individual cresols by methods
following.
NaOH impinger collection for emissions in the
20-100 ppm range. Refs. 46, 64, & 65.
NaOH impinger collection for emissions in the
20-100 ppm range. Refs. 46, 64, & 65.
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001

-------
CAS No
106-44-5
98-82-8
94-75-7
3547-04-4
334-88-3
132-64-9
84-74-2
84-74-2
106-46-7
91-94-1
111-44-4
542-75-6
62-73-7
111-42-2
91-66-7
64-67-5
119-90-4
60-11-7
121-69-7
119-93-7
79-44-7
68-12-2
Chcmicsl Name
p-Cresol
Cumene
2,4-D
DDE
Diazomethane
Dibenzofurans
1 ,2-Dibromo-3-Chloro-
propane
Dibutyl phthalate
1 ,4-Dichlorobenzene(p)
3,3'-Dichlorobenzidine
Dichloroethyl Ether
1 ,3-DichIoropropene
Dichlorvos
Diethanolamine
N,N-Diethyl aniline
Diethyl Sulfate
3,3*-Dimethoxybenzidine
Dimethyl- aminoazobenzene
N,N-DimethyIaniline
3,3-Dimethylbenzidine
Dimethyl Carbamoyl
Chloride
N,N-Dimethylformamide
Sampling
Method
0010
NaOH
0010
0010
0010
n, kp
0010
0010
0010
0010
0010
acid liquid
0010
0030/0031
0010
0010
n,kp
acid liquid
0010
acid liquid
n, kp
•kpOOlO
acid liquid
0010?
acid liquid
0010
acid liquid
0010?kp
acid liquid
0010
0010
S.
Code
f2
n
fi
s
n
-
n
n,f4
fl,f4
fl,f2
f4,f5
s
fl,£2
fl,E
fl,f2
fl,G
s
fl,f2
s
-
f4,!3
S
f4,ll
s
f2,ll
14
fl,f4,
13
14
m, sp
m,sp
Analysis
Method
3542 8270C
HPLC
3542 8270C
8151A.8321A
3542 8270C
-
3542 8270C
3542 8270C
3542 8270C
3542 8270C
3542 8270C
, HPLC/PDA
3542 8270C
5041A8260B
3542 8270C
3542 8270C
8270
HPLC should
work
3542 8270C
HPLC/PDA
-
3542 8270C
HPLC/PDA
3542 8270C
HPLC/PDA
3542 8270C
HPLC/PDA
3542 8270C
HPLC/PDA
8321A
8260B, 8141A

NaOH impinger collection for emissions in the
20-100 ppm range. Refs. 46, 64, & 65.


CAS #3547-04-4 is on CAAA, The large volume
pesticide is 72-55-9. The two are similar Almost
congeners) and should behave comparably.
Very reactive. Derivative method should be
developed.
For PCDF, use Method 0023A or Method 23

Common contaminant

Reactive, no good with 0010.
Ref 50&51, prototype needs to be isokinetic.
Same as bis(2-chloroethyl)ether
Mixed results. May be source sensitive.

The method of Ref. 50&5 1 should collect OK if
made isokinetic. No benzene ring, so alternate
detector may be needed
Compound confused with Dimethylaniline on
CAAA, wrong CAS number listed. Ref. 50&51 ,
prototype needs to be isokinetic.
Probably special S&A. a.k.a. sulfuric acid,
diethyl ester
Likely reactive.
Ref 50&51, prototype needs to be isokinetic.
Suspect reactivity.
Ref 50&5 1, prototype needs to be isokinetic.
Incorrectly called diethylaniline on CAAA
Ref 50&51, prototype needs to be isokinetic
Mixed results probably due to reactivity.
Ref 50&51, prototype needs to be isokinetic


Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001

-------
CAS No.
57-14-7
131-11-3
77-78-1
534-52-1
51-28-5
121-14-2
123-39-1 1
122-66-7
106-89-8
106-88-7
140-88-5
100-41-4
51-79-6
75-00-3
106-93-4
107-06-2
107-21-1
151-56-4
75-21-8
96-45-7
Chemical Name
1 , 1-Dimethy Ihydrazine
Dimethyl Phthalate
Dimethyl Sulfate
4,6-Dinitro-o-Cresol, and
salts
2,4-Dinitrophenol
2,4-Dinitrotoluene
1,4-Dioxane
1 ,2-Diphenylhydrazine
Epichlorohydrin
1,2-Epoxybutane
Ethyl Aciylate
Ethylbenzene
Ethyl Carbamate
Ethyl Chloride
(Chloroethane)
Ethylene Dibromide
Ethylene Dichloride
Ethylene Glycol
Ethylene Imine (Aziridine)
Ethylene Oxide
Ethylene Thiourea
Sampling
Method
0030?
0010
special
0010
0010?
0010
0010
0030
0010
acid liquid
0010 kp
0030 ko
0030
kpOOSO?
0010
sorbent
0010
0010?
0030?kp
0031?kp
0010
0030?
0031?
0030
0031
0010
nkpOOJO
Tedla^bag
CARS 431
0010
S.
Code
kp, 17
fl
s
fi,£z,
13
flf4I3
n
fl
17
m
s
f2,f4,
13
17
m, sp
18
m, sp
14
fl
fi,f4,
12
a, f4,
u
f4
fl, a
fl,f4,
u
n
fl,f2
fl
s
17
O
m
Analysis
Method

3542 8270C
special
3542 8270C
3542 8270C
3542 8270C
3542 8270C
GC/MS
HPLC/PDA
3542 8270C
5040,(GCMS)
GC/MS
GC/FID
3542 8270C
3542 8270C
5041A8260B
5041A8260B
3542 8270C
5041A8260B
5041A8260B
5041A8260B
5041A8260B
80158,8430

GC/MS
GC/FID
HPLC/UV
8325
Comments
Stability problems. Probably needs derivatization
method.
Common contaminant

Bad lab results are puzzling. This test was for
the cresol only, not salts.
Mixed results, very good to very bad.

a.k.a. 1,4-Diethyleneoxide. Easily lost during
extraction and concentration. Labeled lab.
recovery standard is mandatory. Water soluble.
Reactive.
Ref 50&51, prototype needs to be isokinetic.
Mostly poor with 0010, worse with 0030. New
method needed.
Suspect reactivity problems
Polymerizes easily
Ref50&54.

a.k.a. urethane
Low bp, 003 1 should have done better.
a.k.a. dibromoethane. Above recommended bp
for 0030/0031.
a.k.a. 1,2-Dichloroethane

Water soluble & polymerizes
Reactivity can cause problems in some matrices
Reactive and water soluble. See Ref. 56 & 57 for
HPLC/UV.
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
July 2001

-------
CAS No
75-34-3
SO-00-0
76-44-8
118-74-1
87-68-3
77-47-4
67-72-1
822-06-0
680-31-9
1 10-54-3
302-01-2
7647-01-0
7664-39-3
123-31-9
78-59-1
58-89-9
108-31-6
67-56-1
72-43-5
74-83-9
74-87-3
71-55-6
Chemical Name
1,1-Dichloroethane
[misnamed Ethylidene
Dichloride on CAAA)
Formaldehyde
Heptachlor
Hexachlorobenzene
Hexachlorobutadiene
Hexachlorocyclopentadiene
Hexachloroethane
Hexamethylene-1,6-
diisocyanate
Hexamethylphosphoramide
Hexane
Hydrazine
Hydrochloric Acid
Hydrogen Fluoride
Hydroqutnone
Isophorone
Lindane (all isomers)
Maleic Anhydride
Metlianol
Methoxychlor
Methyl Bromide
Methyl Chloride
(Chloromethane)
Methyl Chloroform
Sampling
Method
0030
0031
0040
0011
0010
0010
0010
0010
0010
M207-1
0010
0030
0040
0010
M26/26A
00500051
M26/26A
0010
0010
0011
0010
0010
0030?
M308
MST
0010'
0030?kp
0031?kp
0040?kp
0030 kp
003 Ikp
0040
0030/0031
0040
S.
Code
fl.E
fl
fl
fl
n,f4,
11
fl,f2
f4
n,f2'
f2f4
fl
fl
f413
n
fl
kp
n
14
m,sp
n
n
n
s, kp
m,sp
fl
n
€2
f2
f4
f4
f4
f4
fl
fl
fl
Analysis
Method
5041A8260B
5041A8260B
8260B
83 ISA
3542 8270C
3542 8270C
3542 8270C
3542 8270C
3542 8270C
M207-2
3542 8270C
5041A8260B
8260B
GC/MS
9056 9057
9057
GC/MS
3542 8270C
83 ISA
3542 8270C
HPLC
5041A8260B
GC/FID
GC/FID
3542 8270C
5041A8260B
5041A8260B
8260B
5041 A 8260B
5041B 8260B
8260B
5041A8260B
8260B
Comments
75-34-3 is really 1,1-Dichloroethane. Ethylidene
dichloride is 75-35-4
Simultaneous aldehydes possible, ref. 23&40

Recovery increased greatly with each field test.
Last one was 82.6%

Good to mediocre field tests, poor in the lab.

Reactive, a.k.a. 1,6-Diisocyanatohexane
a.k.a. HDI
Suspect reactivity

Water soluble & unstable, probably requires
special S&A
Halogens & halo-acids can be done
simultaneously
Methods 13A,13B,14 for total fluoride
Reactive, solubility problems.

a.k.a. hexachlorocyclohexane
Reacts with water, must quantitate the acid &
report as parent compound
Highly water soluble, may purge poorly
See References 59, 60, & 61 for evaluation of
M308 and MST.

a.k.a. bromomethane. 0030 barely met f2, 0031
should be better, but was worse. Low bp. 0040
results high.
Artifact problems with Tenax*.
a.k.a. 1,1,1-trichloroethane
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
10
                                     July 2001

-------
CAS No.
78-93-3
60-34-4
74-88-4
108-10-1
624-83-9
80-61-6
1634-04-4
101-14-4
75-09-2
101-68-8
101-77-9
91-20-3
98-95-3
92-93-3
100-02-7
79-46-9
684-93-5
62-75-9
59-89-2
56-38-2
82-68-8
87-86-5
108-95-2
Chemical Name
Methyl Ethyl Ketone
(2-Butanone)
Methyl Hydrazine
Methyl iodide
Methyl Isobutyl Ketone
(Hexone)
Methyl Isocyanate
Methyl Methacrylate
Methyl Ten Butyl Ether
4,4'-Methylene
bis(2-Chloroaniline)
Methylene Chloride
(dichloromethane)
Methylene Diphenyl
Diisocyanate
4,4'-Methylenedianiline
Naphthalene
Nitrobenzene
4-Nitrobiphenyl
4-Nitrophenol
2-Nitropropane
N-Nitroso-N-Methylurea
N-Nitrosodimethylamine
N-Nitrosomorpholine
Parathion
Pentachloronitrobenzene
Pentachlorophenol
Phenol
Sampling
Method
0011
0030?
PFHBA
0030
0030/0031
0010
0011
PFBHA
kp 0030?
M 207-1
0010
kp0030?
sorbent
kp 0030?
0010
acid liquid
0030/0031
0040
M207-1
0010
acid liquid
0010
0010
0010
0010
0010,0030
0010
0010
0010
0010
0010
0010
0010
NaOH
S.
Code
f4
18
14
kp
fl
fl
f4
14
18
fl
m, sp
18
14
18
m, sp
s
' fl
fl
fl
m,sp
s
fl
fl
fl
fl,o,
13
s
m, sp
fl
fl
fl.G
n,o,
f4
fl.D,
f4
fl,f2
fl
Analysis
Method
83 ISA
5041A8260B
GC/MSorECD
5040
5041A8260B
3542 8270C
83 ISA
GC/MSorECD
M207-2
5040,(GC/MS)
GC/FID

GC/MS
HPLC/PDA
5041A8260B
8260B
M207-2
GC/MS
HPLC/PDA
3542 8270C
3542 8270C
3542 8270C
3542 8270C
GC/MS
HPLC
3542 8270C
3542 8270C
3542 8270C
GC/MS
3542 8270C
3542 8270C
HPLC
Comments
Water solubility causes problems with 5041 A
purge. See References 45 & 50 for PFBHA
approach.
Reactive, probably requires special S&A
a.k.a. lodomethane
See references 45 & 50 for PFBHA approach, 23
&40forDNPH(0011).
a.k.a. isocyanic acid, methyl ester, a.k.a. ML See
Ref. 18.
May polymerize
Ref50&54.
a.k.a. tert-butyl methyl ether
Suspect reactivity problems during sampling.
Ref 50&51, prototype needs to be isokinetic.
a.k.a. dichloromethane
Reactive, See Ref. 18. a.k.a. MDI,a.k.a.
4,4'-bis(Carbonylamino)diphenylmethane.
Reactive?
Ref 50&5 1 , prototype needs to be isokinetic.



Bad lab results are puzzling.

Unstable





NaOH impinger collection for emissions in the
20-100 ppm range. Refs. 46, 64, & 65.
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
11
                                      July 2001

-------
|| CAS No.
106-50-3
75-44-5
7803-51-2
7723-14-0
85-44-9
1336-36-3
1120-71-4
57-57-8
123-38-6
114-26-1
78-87-5
75-56-9
75-55-8
91-25-5
106-51-4
100-42-5
96-09-3
1746-01-6
79-34-5
127-18-4
7550-45-0
108-88-3
Chemical Name
p-Phenylenediamine
Phosgene
Phosphine
Phosphorus
Phthalic anhydride
Polychlorinated Biphenyls
(Aroclors)
1,3-Propane Sultone
3-Propiolactone
Propionaldehyde
Propoxur
Propylene Dichloride
Propylene Oxide
1 ,2-Propylenimine
Quinoline
Quinone
Styrene
Styrene Oxide
2,3,7,8-Tetrachlorodibenzo-
p-Dioxin
1 , 1 ,2,2-Tetrachloroethane
Tetrachloroethylene
Titanium Tetrachloride
Toluene
Sampling
Method
0010
acid liquid
XPHS
M29 0060
M290060 •
0010
0010 kp
0010
CARB428
0010
0010
0011
0010
0030
0031
kp0030
0040
nkpOQ30
0010
acid liquid
0010
0011?
0010?
OOlOkp
M23
0023A
0010
0010
0030/0031
M290060
0010
0030
0040
S.
Code
m,sp
s
11
s
s
s
f4,13
s
m
m, sp
n
fl,f2
fl,f2
fl
17
m, sp
17
fl
14
f4, 13,
kp
C,kp
fl,f4,
11
f4, 13
fl
n
£2
fl,f2
s
fl,f2
n
n
Analysis
Method
GC/MS
HPLC/PDA
GC/MS
60106020
7000
60106020
7000
HPLC
3542 8270C
3542 GC/MS
CARB 428
GC/MS
GC/MS
83 ISA
3542 8270C
5041A8260B
5041A8260B


3542 8270C
HPLC/PDA
3542 8270C
83 ISA
3542 8270C
3542 8270C
M23
8290
3542 8270C
3542 8270C
5041A8260B
60106020
7000
3542 8270C
5041A8260B
8260B
Comments
Reactive, polar, water soluble.
Ref 50&51, prototype needs to be isokinetic.
Reactive, must be derivatized as collected. See
Refs.52&53.
Yields total P value
Yields total P value
Reacts with water, must quantitate the acid &
report as parent compound
Combustion destroys Aroclor patterns.
Determine isomer groups or individuals.
Polar and reactive.
May be too reactive
Simultaneous aldehydes possible. Ref.23&40
a.k.a. Baygon
a.k.a. 1 ,2 dichloropropane
Reactive, water soluble, a.k.a. 1,2-Propylene
oxide
May be reactive
Ref 50&51, prototype needs to be isokinetic
May be reactive,a,k.a. l,4-benzoquinone,a.k.a.
p-benzoquinone
Low f4 results puzzling. Reactivity?
Reactive. a.k.a. 1,2-epoxyethylbenzene
Special care needed during recovery and analysis.

a.k.a. tetrachloroethene,.a.k.a perchloroethylene
For total titanium

Risk Burn Guidance for
Hazardous Waste Combustion Facilities
12
                                      July 2001

-------
II
| CAS No.
95-80-7
584-84-9
95-53-4
8001-35-2
120-82-1
79-00-5
79-01-6
95-95-4
88-06-2
121-44-8
1582-09-8
540-84-1
108-05-4
593-60-2
75-01-4
75-35-4
1330-20-7
95-47-6
108-38-3
106-42-3
Chemical Name
2,4-ToIuene Diamine
2,4-ToIuene Diisocyanate
o-Toluidine
Toxaphene (Chlorinated
Camphene)
1 ,2,4-Trichlorobenzene
1,1,2-Trichloroethane
Trichloroethylene
2,4,5-Trichlorophenol
2,4,6-TrichIorophenol
Triethylamine
Trifluralin
2,2,4-Trimethylpentane
Vinyl Acetate
Vinyl Bromide
Vinyl Chloride
Vinylidene Chloride
Xylenes(mixture)
o-Xylene
m-Xylene
p-Xylene
Sampling
Method
0010
acid liquid
M207-1
0010?
acid liquid
0010
0010
0010
0030/0031
0040
0030/0031
0010
0010
nkpOOSO
acid liquid
0010
acid liquid
0030
0040
kp 0030?
sorbent
0030?kp
0031?kp
0040
M106
0030 kp
0031?kp
0040
M106
0030/0031
0040
M106
0010
0010
0010
0010
s.
Code
m, sp
14
n
f2,f4,
11
14
s
n,(2
n,£2
n
n
n
n
fl.E
17
s
f4, 12, .
kp
m, kp
f2
n
18
14
f2, f4,
11
f4
n
fl,f4,
11
f411
n
15
fl/fl
fl
15
n
n
n
n
Analysis
Method
GC/MS
HPLC/PDA
M207-2
3542 8270C
HPLC/PDA
GC/MS.8250
3542 8270C
3542 8270C
5041A 8260B
8260B
5041 A 8260B
3542 8270C
3542 8270C
HPLC should
work
3542 8270C
HPLC/PDA
5041 A 8260B
8260B
GC/FID
5041A8260B
5041A8260B
8260B
GC/MS
5041A8260B
5041A8260B
8260B
GC/MS
5041A 8260B
8260B
GC/MS
3542 8270C
3542 8270C
3542 8270C
3542 8270C
Comments
Reactive
Ref 50&51, prototype needs to be isokinetic.
Reacts with water,a.k.a. TDI
Mixed results, may be reactive.
Ref 50&51, prototype needs to be isokinetic.



a.k.a. trichloroethene


a.k.a. N,N-Diethylethanimine. Suspect
reactivity. The method of Ref. 50&51 should
collect OK. No benzene ring, so alternate
detector may be needed
Suspect reactivity, a.k.a. Treflan
Ref 50&51, prototype needs to be isokinetic.
Analysis method needs modification.
a.k.a isooctane
Ref50&54.

Mixed results, 0030 is questionable. Poor field
results for 003 1 are puzzling, may be due to
reactivity.
a.k.a. 1,1-dichloroethene.
a.k.a. 1,1-dichloroethylene
Determine individual xylenes, not total.



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CAS No.
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
Chemical Name
Antimony Compounds
Arsenic Compounds
Beryllium Compounds
Cadmium Compounds
Chromium Compounds
Cobalt Compounds
Coke Oven Emissions
Cyanide Compounds
Glycol Ethers
Lead Compounds
Manganese Compounds
Mercury Compounds
Mineral Fibers
Nickel Compounds
Polycyclic Organic Matter
Radionuclides (including
radon)
Selenium Compounds
Sampling
Method
M29 0060
M29 0060
M29 0060
M29 0060
M29 0060
M29 0060
Method
109
XHCN
n
0010
M29 0060
M29 0060
M29 0060

M29 0060
0010
CARS 429
Mill
M114
M115
M29 0060
S.
Code
n
n
n
n
n
s
-
11
s
n
n
n

n
B

n
Analysis
Method
60106020
7000
60106020
7000
60106020
7000
60106020
7000
60106020
7000
60106020
7000
-
XHCN
8430,80158
60106020
7000
60106020
7000
7470

60106020
7000
3542 8270C
CARB 429

60107000
Comments

Also Method 108 &108A
Also Method 103 & 104

M29 or 0060 for total chromium, 006 1 for
hexavalent Cr.


XHCN for HCN, CARB426 for total cyanide.
Category too general, however a method is
possible for individual compounds. Should be
isokinetic, probably 0010.
Also Method 12

Also Methods 101,101 A, 102. For speciation
research see references 50 & 55.


Individual compounds are determined, not total
POM, more or less synonymous with PNA, PAH,
pac.


References

1.     McGaughey, J.F., Bursey, J.T., Merrill, R.G., Field Evaluation of EPA Method 0040
       (Volatiles Using Sags), EPA-600/R-98/030, PB98-133085, U.S. Environmental Protection
       Agency, Research Triangle Park, NC, January 1998.
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
                                    July 2001
14

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2.     McGaughey, J.F., Bursey, J.T., Merrill, R.,G., Fuerst, R.G. and Jackson, M.D., "Field
       Evaluation of EPA Proposed Method 0040 (Sampling and Analysis of Volatile Compounds
       Using Tedlar Bags)," Proceedings of the EPA/A&WMA International Symposium:
       Measurement of Toxic and Related Air Pollutants, Research Triangle Park, NC, April
       1997, VIP-74, Air & Waste Management Association, Pittsburgh, PA, 1997, pp 159-165.

3.     Johnson, L.D.,"Research and Evaluation of Organic Hazardous Air Pollutant Source
       Emission Test Methods," J. Air & Waste Manage. Assoc., 46, pp. 1135-1148, December
       1996.

4.     Margeson, J.H., Knoll, J.E., Midgett, M.R., Wagoner, D.E., Rice, J., and Homolya,
       J.B.,"An Evaluation of The Semi-VOST Method for Determining Emissions from
       Hazardous Waste Incinerators,"/. Air Pollut. Control Assoc., 37:(9)1067 (1987).

5.     Jackson, M.D., Knoll, J.E., Midgett, M.R., Bursey, J.T., McAllister R.A., Merrill, R.G,
       "Evaluation of VOST and SemiVOST Methods for Halogenated Compounds in the Clean
       Air Act Amendments Title III, Bench and Laboratory Studies," Proceedings of the
       National A&WMA Meeting,  Kansas City, June 1992, Air & Waste Management
       Association, Pittsburgh, PA, 1992.

6.     Jackson, M.D., Knoll, J.E., Midgett, M.R., Bursey, J.T., McGaughey, J.F., Merrill, R.G.
       "Evaluation of VOST and Semi-VOST Methods for Halogenated Compounds in the Clean
       Air Act Amendments Title III, Validation Study at Fossil Fuel Plant," Proceedings of the
       National A&WMA Meeting, Denver, CO, June 1993, Air & Waste Management
       Association, Pittsburgh, PA, 1993.

7.     Bursey, J.T., Merrill, R.G., McAllister, R.A., McGaughey, J.F., Laboratory Validation of
       VOST and SemiVOST for Halogenated Hydrocarbons from the Clean Air Act Amendments
       List, Volumes 1 & 2, EPA-600/R-93/123a, EPA-600/R-93/123b, PB93-227163, PB93-
       227171, U.S. Environmental Protection Agency, Research Triangle Park, NC, July 1993.

8.     McGaughey, J.F., Bursey, J.T., Merrill, R.G., Field Test of a Generic Method for
       Halogenated Hydrocarbons, EPA-600/R-93/101, PB93-212181AS, U.S. Environmental
       Protection Agency, Research Triangle Park, NC, September 1993.

9.     McGaughey, J.F., Bursey, J.T., Merrill, R.G., Jackson, M.D.,"Field Test of a Generic
       Method for The Sampling and Analysis of Halogenated Hydrocarbons Listed in Title III of
       The Clean Air Act Amendments of 1990," Proceedings of the  13th Annual International
       Incineration Conference, Houston, TX, May 1994, University of California, Irvine, CA,
       1994.
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
15
                                   July 200 J

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10.    Jackson, M.D., Bursey, J.T., McGaughey, J.F., Merrill, R.G.," An Evaluation of the
       SemiVOST Method for Halogenated Compounds at a Chemical Manufacturing Facility,"
       Proceedings of the EPA/A&WMA International Symposium on Measurement of Toxic and
       Related Air Pollutants, Research Triangle Park, NC, May 1995, VIP-50, Air & Waste
       Management Association, Pittsburgh, PA, 1995, pp 227-232.

11.    Jackson, M.D., Bursey, J.T., McGaughey, J.F., Merrill, R.G.,"Application of VOST and
       SemiVOST to Nonhalogenated CAAA Compounds," Proceedings of the EPA/A&WMA
       International Symposium on Measurement of Toxic and Related Air Pollutants, Research
       Triangle Park, NC, May 1995, VIP-50, Air & Waste Management Association, Pittsburgh,
       PA, 1995, pp 233-238.

12.    Jackson, M.D.y Johnson, L.D., McGaughey, J.F., Wagoner, D.E.,  Bursey, J.T., Merrill,
       R.G., "Improvements in Preparation of Samples Generated by SW-846 Method 0010,"
       Proceedings of the EPA/A&WMA International Symposium on Measurement of Toxic and
       Related Air Pollutants, Durham, NC, May 1994, VIP-39, Air & Waste Management
       Association, Pittsburgh, PA, 1994, pp 331-338.

13.    Jackson, M.D., Bursey, J.T.,McGaughey, J.F. and Merrill, R. G., "An Evaluation of the
       SemiVOST Method for non-Halogenated Compounds at a Agricultural Chemical
       Manufacturing Facility", Proceedings of the EPA/A&WMA International Symposium:
       Measurement of Toxic and Related Air Pollutants, Research Triangle Park, NC, April
       1997, VIP-74, Air & Waste Management Association, Pittsburgh, PA, 1997, pp 134-141.

14.    Bursey, J.T.,McGaughey, J.F.  and Merrill, R. G., Field Evaluation at an Agricultural
       Manufacturing Facility of VOST and SemiVOST Methods for Selected CAAA Organic
       Compounds, EPA/600-R-97/037, PB97-174585, U.S. Environmental Protection Agency,
       Research Triangle Park, NC, March 1997.

15.    Jackson, M.D.,McGaughey, J.F., Merrill, R. G., and Bursey, J.T., "Method Evaluation
       Study: The Application of Semi-VOST to the Nonhalogenated Semivolatile Organic
       Compounds from the Clean Air Act Amendments", Proceedings of the EPA/A&WMA
       International Symposium: Measurement of Toxic and Related Air Pollutants, Research
       Triangle Park, NC, May 1996, VIP-64, Air & Waste Management Association, Pittsburgh,
       PA, 1996 pp 620-625.

16.    Bursey, J.T.,McGaughey, J.F.  and Merrill, R. G., Field Evaluation (First) of VOST and
       Semi-VOST Methods for Selected CAAA Organic Compounds at a Coal Fired Plant,
       EPA/600-R-97/076, PB97-196117, U.S. Environmental Protection Agency, Research
       Triangle Park, NC, February 1997.
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
16
                                  July 2001

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17.    Bursey, J.T., McGaughey, J.F. and Merrill, R. G., Field Test of a Generic Method for
       Halogenated Hydrocarbons: SemiVOST at an Agricultural Chemical Manufacturing
       Facility, EPA/600-R-97/033, PB97-162499, U.S. Environmental Protection Agency,
       Research Triangle Park, NC, February 1997.

18.    McGaughey, J.F., Foster, S.C., Merrill, R.G., Laboratory Development and Field
       Evaluation of A Generic Method for Sampling and Analysis ofIsocyanates, EPA-600/R-
       95/144, PB95-273801, U.S. Environmental Protection Agency, Research Triangle Park,
       NC, August 1995.

19.    Jackson, M.D.; Johnson, L.D.; McGaughey, J.F.; Wagoner, D.E.; Bursey, J.T.; Merrill,
       R.G., "Improvements in Preparation of Samples Generated by SW-846 Method 0010,"
       Proceedings of the EPA/A&WMA International Symposium on Measurement of Toxic and
       Related Air Pollutants,  Durham, NC, May 1994, VIP-39, Air & Waste Management
       Association, Pittsburgh, PA, 1994, pp 331-338.

20.    Johnson, L.D., Fuerst, R.G., Foster, A.L. and Bursey, J.T.,"Replacement of Charcoal
       Sorbent In The Sampling of Volatile Organics from Stationary Sources," Intern. J.
       Environ. Anal. Chem.,Vol 62,  pp. 231-244, (1996).

21.    Eaton, W.C.; Jaffe, L.B.; Rickman, E.E.; Jayanty, R.K.M., Field Tests of Chloroform
       Collection/Analysis Methods, EPA-600/R-94/082, PB94-176948, U.S. Environmental
       Protection Agency, Research Triangle Park, NC, July 1994.

22.    Eaton, W.C.; Jaffe, L.B.; Rickman, E.E.; Jayanty, R.K.M.; Wilshire, F.W.; Knoll, J.E.,
       "Validation of a Test Method for Collection and Analysis of Chloroform Emissions from
       Stationary Sources," J. Air & Waste Manage. Assoc., 46, pp 66-71, 1996.
23.    Steger, J.L., Knoll, J.E., "Dynamic Spiking Studies Using the DNPH Sampling Train,"
       presented at EPA/A&WMA International Symposium: Measurement of Toxic and Related
       Air Pollutants, Research Triangle Park, NC, May 1996.

24.    Steger, J.L., Bursey, J.T., and Epperson, D., Acetonitrile Field Test, EPA-600/R-97/140,
       PB98-133143, U.S. Environmental Protection Agency, Research Triangle Park, NC,
       October 1997.

25.    R.G. Fuerst, T.J. Logan, M.R. Midgett and J. Prohaska, "Validation Studies of the
       Protocol for the Volatile Organic Sampling Train," J. Air Pollut. Control Assoc.,
       37:(4)388 (1987).

26.    Johnson, L.D., Fuerst, R.G., Steger, J.L., and  Bursey, J.T., "Evaluation of a Sampling
       Method for Acetonitrile Emissions from Stationary Sources," Proceedings of the
       EPA/A&WMA International Symposium: Measurement of Toxic and Related Air
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
                                   July 2001
17

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       Pollutants, Research Triangle Park, NC, April 1997, VIP-74, Air & Waste Management
       Association, Pittsburgh, PA, 1997, pp 149-158.

27.    McGaughey, J.F., Bursey, J.T., Merrill, R.G., Jackson, M.D., Johnson, L.D., Fuerst, R.G.,
       "Comparison of a Modified VOST Sampling Method with SW-846 Method 0030 at a
       Chemical Manufacturing Facility," Proceedings of the 13th Annual International
       Incineration Conference, Houston, TX, May 1994, University of California, Irvine, CA,
       1994.

28.    Jackson, M.D., Johnson, L.D., Fuerst, R.G., McGaughey, J.F., Bursey, J.T., Merrill, R.G.,
       "Field Evaluation of a Modified VOST Sampling Method," Proceedings of the
       EPA/A&WMA International Symposium on Measurement of Toxic and Related Air
       Pollutants, Durham, NC, May 1994, VIP-39, Air & Waste Management Association,
       Pittsburgh, PA, 1994, pp 354-360.

29.    McGaughey, J.F., Bursey, J.T., Merrill, R.G., Field Test of a Generic Method for
       Halogenated Hydrocarbons: A VOST Test at a Chemical Manufacturing Facility Using a
       Modified VOST Sampling Method,  EPA-600/R-94/130, PB95-142055, U.S.
       Environmental Protection Agency, Research Triangle Park, NC, July 1994.

30.    McGaughey, J.F., Bursey, J.T., Merrill, R.G., Field Test of a Generic Method for
       Halogenated Hydrocarbons: SemiVOST Test at a Chemical Manufacturing Facility, EPA-
       600/R-96/133, PB97-115349, U.S. Environmental Protection Agency, Research Triangle
       Park, NC, November 1996.

31.    McGaughey, J.F., Bursey, J.T., Merrill, R.G., Field Test of a Generic Method for
       Halogenated Hydrocarbons: A VOST Test at a Chemical Manufacturing Facility, EPA-
       600/R-94/113, PB95-129144, U.S. Environmental Protection Agency,  Research Triangle
       Park, NC, June 1994.

32.    Rice, J., McGaughey, J.F., Bursey, J.T., Merrill, R.G., Harvan, D., Handbook ofGC/MS
       Data and Information for Selected Clean Air Act Amendments Compounds, EPA-600/R-
       94/021, PB94-155884, U.S. Environmental Protection Agency, Research Triangle Park,
       NC, January 1994.

33.    Wagoner, D.E., Merrill, R.G., McGaughey, J.F., Bursey, J.T., Evaluation ofCAAA
       Compounds: Approaches for Stationary Source Method Development, EPA-600/R-
       96/091, PB96-193206, U.S. Environmental Protection Agency, Research Triangle Park,
       NC, 1996.

34.    Jackson, M.D.,McGaughey, J.F., Merrill, R. G., and Bursey, J.T., "Method Evaluation
       Study: The Application of VOST to the Nonhalogenated Volatile Organic Compounds
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
18
                                   July 2001

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       from the Clean Air Act Amendments", Proceedings of the EPA/A&WMA International
       Symposium: Measurement of Toxic and Related Air Pollutants, Research Triangle Park,
       NC, May 1996, VIP-64, Air & Waste Management Association, Pittsburgh, PA, 1996 pp
       613-619.

35.    Jackson, M.D., Bursey, J.T.,McGaughey, J.F. and Merrill, R. G., "An Evaluation of the
       VOST Method for non-Halogenated Compounds at a Agricultural Chemical Manufacturing
       Facility", Proceedings of the EPA/A&WMA International Symposium: Measurement of
       Toxic and Related Air Pollutants, Research Triangle Park, NC, April 1997, VIP-74, Air &
       Waste Management Association, Pittsburgh, PA, 1997, pp 129-133.

36.    Prohaska, J., T.J. Logan, R.G. Fuerst, M.R. Midgett, Validation of the Volatile Organic
       Sampling Train (VOST) Protocol, Volume 1, Laboratory Validation Phase, PB86-145547,
       U.S. Environmental Protection Agency, Research Triangle Park, NC, January 1986.

37.    Prohaska, J., T.J. Logan, R.G. Fuerst, M.R. Midgett, Validation of the Volatile Organic
       Sampling Train (VOST) Protocol, Volume 2, Field Validation Phase, PB86-145554, U.S.
       Environmental Protection Agency, Research Triangle Park, NC, January 1986.

38.    Wilshire, F.W., Knoll, J.E., Foster, S.C. and McGaughey, J.F., "Development and
       Validation of a Source Test Method for 2,4-Toluene Diisocyanate," in Proceedings of the
       1993 EPA/A&WMA International Symposium on Measurement of Toxic and Related Air
       Pollutants, VIP-34, Air & Waste Management Association, Pittsburgh, PA, 1993, pp 399-
       407.

39.    Wilshire, F.W., Knoll, J.E., Foster, S.C. and McGaughey, J.F., "Field Test and Validation
       of a Source Test Method for Methylene Diphenyl Diisocyanate," Proceedings of the 87th
       Annual National A&WMA Meeting, Cincinnati, OH, June 1994, Air & Waste
       Management Association, Pittsburgh, PA, 1994.

40.    Steger, J.L. and Workman, G.S., Field Validation of the DNPH Method for Aldehydes and
       Ketones, EPA/600/R96/050, PB96-168398, U.S. Environmental Protection Agency,
       Research Triangle Park, NC, April 1996.

41.    Jackson, M.D., Johnson, L.D., "Sampling and Analysis Information Aids for Stationary
       Source Personnel," Proceedings of the EPA/A&WMA International Symposium on
       Measurement of Toxic and Related Air Pollutants, Durham, NC, May 1994, VIP-39, Air
       & Waste Management Association, Pittsburgh, PA, 1994, pp 315-318.

42.    Jackson, M.D., Johnson, L.D., Stationary Source Sampling and Analysis Directory,
       Version 2.1, U.S. Environmental Protection Agency, Research Triangle Park, NC, 1995,
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
19
                                   July 2001

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       EPA/600/R-97/028, PB98-120033 (Report/Manual) and PB-500598 (Database on floppy
       disk) February 1997.

43.    Steger, J.L., Merrill, R.G., Parrish, C.R., and Johnson, L.D., Development and Evaluation
       of a Source Sampling and Analysis Method for Hydrogen Cyanide, EPA/600/R-98/xxx,
       PB98-XXXXXX, U.S: Environmental Protection Agency, Research Triangle Park, NC,
       February 1998.

44.    Steger, J.L., Merrill, R.G., Fuerst, R.G., Johnson, L.D., Jackson, M.D. and Parrish, C.R.,
       "Development and Evaluation of a Source Sampling and Analysis Method for Hydrogen
       Cyanide," Proceedings of the EPA/A&WMA International Symposium: Measurement of
       Toxic and Related Air Pollutants, Research Triangle Park, NC, April 1997, VIP-74, Air &
       Waste Management Association, Pittsburgh, PA, 1997, pp 114-122.

45.    Fan, Z., Peterson, M.R., Jayanty, R.K.M., "Development of a Test Method for Carbonyl
       Compounds from Stationary Source Emissions," Proceedings of the EPA/A&WMA
       International Symposium: Measurement of Toxic and Related Air Pollutants, Research
       Triangle Park, NC, April 1997, VIP-74, Air & Waste Management Association,
       Pittsburgh, PA, 1997, pp 92-97.

46.    Bursey, J.T., McGaughey, J.F., Merrill, R. G., Knoll, J.E., Ward, T.E., and Jackson, M.D.,
       "Field Testing to Complete Validation of a Manual Method for High Levels of Phenolic
       Compounds," Proceedings of the EPA/A&WMA International Symposium: Measurement
       of Toxic and Related Air Pollutants, Research Triangle Park, NC, April 1997, VIP-74, Air
       & Waste Management Association, Pittsburgh, PA, 1997, pp 142-149.

47.    Pau, J.C., Romeu, A.A., Whitacre, M., and Coates, J.T., Validation of Emission Sampling
       and Analysis Test Method for PCDDs andPCDFs II, EPA-600/R3 -90/047, PB90-
       235847/AS, U.S. Environmental Protection Agency, Research Triangle Park, NC, August
       1990.

48.    Cooke, M., DeRoos, F., Rising,  B., Jackson, M.D., Johnson, L.D., and Merrill, R.G.,
       "Dioxin Collection from Hot Stack Gas Using Source Assessment Sampling System and
       Modified Method 5 Trains - An Evaluation," presented at Ninth Annual Research
       Symposium on Land Disposal, Incineration, and Treatment of Hazardous Waste, Ft.
       Mitchell, KY, May 1983.

49.    Fan, Z., Peterson, M.R., Jayanty, R.K.M., Wilshire, F.W., "Measurement of Carbonyl
       Compounds from Stationary Source Emissions by a PFBHA-ECD Method," presented at
       the 91st Annual National Meeting of the Air & Waste Management Association, San
       Diego, CA, June 1998.
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
20
                                   July 2001

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 50.
51.
52.
53.
54.
55.
56.
57.
 Peterson, M.R., Fan, Z., Jaffe, L.B., Albritton, J.R., Grohse, P.M., Jayanty, R.K.M.,
 Research, Development, and Evaluation of Stationary Source Emission Test Methods for
 Air Toxics, Letter Report, Research Triangle Institute to U.S. Environmental Protection
 Agency, Research Triangle Park, NC, March 1998.

 Peterson, M.R., Pate, B.A., Wright, R.S.,Jayanty, R.K.M., Wilshire, F.W., "A Test Method
 for the Measurement of Arylamines in Stationary Source Emissions," Proceedings of the
 EPA/A&WMA International Symposium: Measurement of Toxic and Related Air
 Pollutants, Research Triangle Park, NC, May 1996, VIP-64, Air & Waste Management
 Association, Pittsburgh, PA, 1996 pp 577-582.

 Steger, J.L., Coppedge, E.A. and Johnson, L.D., "Research and Development of A Source
 Method for Phosgene," Proceedings of the EPA/A&WMA International Symposium:
 Measurement of Toxic and Related Air Pollutants, Research Triangle Park, NC, May
 1996, VIP-64, Air & Waste Management Association, Pittsburgh, PA, 1996, pp 285-289.

 Steger, J.L., Bursey, J.T., Merrill, R.G., and Epperson, D., Research and Development of
 a Field-Ready Protocol for Sampling of Phosgene from Stationary Source Emissions:
 Diethylamine Reagent Studies, EPA/600/R-98/xxx, PB98-xxxxxx, U.S. Environmental
 Protection Agency, Research Triangle Park, NC, May 1998.

 Peterson, M.R., Jaffe, L.B., Jayanty, R.K.M., Wilshire, F.W., "A Test Method for the
 Measurement of Acrylics in Stationary Source Emissions," presented at the 90th Annual
 National Meeting of the Air & Waste Management Association, Toronto, Ontario, Canada,
 June 1997.

 Giglio, J.J., O'Rourke, J.J., Grohse, P.M., Wilshire, F.W., Ryan, J., Linak, W., The
 Development of a Method for the Speciation of Source Mercury Emissions," Presented at
 the International Conference on Incineration and Thermal treatment Technologies, Salt
 Lake City, UT, May, 1998.

 James, R.H., Adams, R.E., Finkel, J.M., Miller, H.C., and Johnson, L.D., "Evaluation of
 Analytical Methods for the Determination of POHC in Combustion Products," J. Air
Pollution Control Association, 35, 959 (1985).

James, R.H., Adams, R.E., Finkel, J.M.,  Miller, H.C., POHC Analysis Methods for
Hazardous Waste Incineration, Vol. l,Parts 1 & 2, Vol. 2, EPA/600/8-87-037 a, b & c,
PB87-227286/AS, PB87-227294/AS, PB87-227302/AS, U.S. Environmental Protection
Agency, Research Triangle Park, NC, December 1987.
Risk Burn Guidance for
Hazardous Waste Combustion Facilities
                                   21
                                                                       July 2001

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58.    James, R.H., Adams, R.E., Farr, L.B., Miller, H.C., PIC Analysis Methods, EPA-600/9-87-
       011, PB87-208955/AS, U.S-. Environmental Protection Agency, Research Triangle Park,
       NC, June 1987.

59.    Pate, B.A., Peterson, M.R., Rickman, E.E., Jayanty, R.K.M., Test Method for the
       Measurement ofMethanol Emissions from Stationary Sources, EPA-600/R-94/080, PB94-
       170297, U.S. Environmental Protection Agency, Research Triangle Park, NC, July 1994.

60.    Pate, B.A., Peterson, M.R., Jayanty, R.K.M., Wilshire, F.W., Knoll, J.E., "Development of
       a Test Method for the Measurement of Gaseous Methanol Emissions from Stationary
       Sources," in Proceedings of the 1993 EPA/A&WMA International Symposium on
       Measurement of Toxic and Related Air Pollutants, VIP-34, Air & Waste Management
       Association, Pittsburgh, PA, 1993, pp 393-398.

61.    Peterson, M.R.,Pate, B.A., Rickman, E.E., Jayanty, R.K.M., Wilshire, F.W., "Validation of
       a Test Method for the Measurement of Methanol Emissions from Stationary Sources," J.
       Air & Waste Manage. Assoc., 45, pp. 3-11, 1995.

62.    Eaton, W.C., Jaffe, L.B., Rickman, E.E., Jayanty, R.K.M., Field Tests of Chloroform
       Collection/Analysis Methods, EPA-600/R-94/082, PB94-176948, U.S. Environmental
       Protection Agency, Research Triangle Park, NC, July 1994.

63.    Eaton, W.C., Jaffe, L.B., Rickman, E.E., Jayanty, R.K.M., Wilshire, F.W., Knoll, J.E.,
       "Validation of a Test Method for Collection and Analysis of Chloroform Emissions from
       Stationary Sources," J. Air & Waste Manage. Assoc., 46, pp 66-71, 1996.

64.    Bursey, J.T., McGaughey, J.F., Steger, J.L., Merrill, R. G., Field Testing to Complete
       Validation of a Manual Method for High Levels of Phenolic Compounds, Draft Final
       Report, U.S. Environmental Protection Agency, Research Triangle Park, NC.

65.    U.S. EPA Tentative Method 317, Phenol, Manual Method, U.S. Environmental Protection
       Agency, Research Triangle Park, NC.
 Risk Barn Guidance for
 Hazardous Waste Combustion Facilities
                                   July 2001
22

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