Public Health Reviews of Hazardous Waste Thermal Treatment Technolosies
by
Betty C. Willis, M.S. MaxM. Howie, M.S. Robert C. Williams, P.E., DEE
A Guidance Manual for Public Health Assessors
Public Comment Draft March 2001 Comment Period Ends April 23, 2001
Send written comments to: Chief, Program Evaluation, Records, & Information Services Branch 1600 Clifton Road, NE (E-56) Atlanta, GA 30333 Agency for Toxic Substances and Disease Registry Division of Health Assessment and Consultation Atlanta, Georgia
Acknowledgments * The authors wish to acknowledge the invaluable review and comments on an earlier draft of this document by Dr. Allan Susten, Lynn Wilder, Brian Kaplan, Greg Zarus, Peter Kowalski, Dr. Paul ('harp. Theresa Kilgus. Dr. Jeff Lybarger. and Harvey Rogers of the National Center for Environmental Health. We want to especially thank Dr. Barry Johnson, former Assistant Administrator of the Agency for Toxic Substances and Disease Registry (ATSDR), for rccogni/ing the need to establish a Combustion Specialist position in the Division of Health Assessment and Consultation, encouraging the authors to write this document, and reviewing and commenting on an earlier draft. A special thanks to Dr. Henry Falk, Assistant Administrator of the agency, for supporting the preparation of this guidance document for ATSDR and state health assessors. The authors hope that public health partners worldwide will find this document helpful in their evaluations of thermal treatment technologies.
We also want to acknowledge the assistance of Eastern Research Group staff in preparing the electronic files for the figures and for summarizing several of the studies included in Chapter 8. A special thanks to Kathryn Harmsen for her editorial advice during the writing of this document, and to Pascale Knimm for the final editing of the manuscript before publication. We also want to acknowledge Laura Northern for her assistance in developing the cover design.
Disclaimer
Use of trade names and commercial sources is for identification purposes only and does not imply endorsement by the Agency for Toxic Substances and Disease Registry or the U.S. Department of Health and Human Services.
Foreword
This document states the views and policies of the Agency for Toxic Substances and Disease Registry (ATSDR) on the use of incinerators and desorbers to destroy hazardous wastes or decontaminate soil or debris from Superfund sites or other contaminated areas. In this document we will refer to incinerators and desorbers as thermal treatment devices. Others may include boilers and industrial furnaces, such as cement kilns, light-weight aggregate and lime kilns that burn hazardous waste derived fuels in the broad definition of hazardous waste ex-situ thermal treatment technologies. Our more limited definition addresses only the types of ex-situ technologies generally used for the treatment of hazardous wastes and polychlonnated biphenyls (PCBs) contaminated wastes or for decontamination of Superfund sites.
This document is intended to provide guidance to health assessors or other health professionals who have to provide an opinion on the public health implications of a thermal treatment facility. It is written specifically for health professionals who conduct technical reviews of thermal treatment technologies who have a technical background and are somewhat familiar with thermal treatment systems. This document should help U. S. Environmental Protection Agency (EPA) and thermal treatment facility staff to understand the concerns and information needs that public health officials will have if they become involved in reviewing the site. This document is not meant to replace or modify materials used by other government agencies charged with the responsibility of issuing permits to Resource Conservation and Recovery Act (RCRA) hazardous waste thermal treatment facilities or determine which technologies to use to manage Superfund wastes. Because health assessors need detailed technical guidance to ensure that agency staff evaluate thermal treatment facilities in a consistent manner, people without a technical background may find it difficult to understand this document. For a synopsis of ATSDR's policies regarding the use of thermal treatment devices, see Public Health O\>erview of Incineration as a Means to Destroy Hazardous Wastes - Guidance to ATSDR Health Assessors. ATSDR's acceptance of any thermal treatment technology is contingent on consideration of all remedial alternatives for a site. That is, each remedial alternative, including thermal treatment, must be evaluated for its potential to affect public health. ATSDR does not endorse or promote the use of any particular technology. The selection of a particular remedial action at a site resides with other federal and state regulatory agencies that must consider public health implications along with other risk management considerations. (.illkLilKX1 NLni'Kil :'.>] Put-11, Health .WexMH^ -I'.'-l' •• ••• •'• ..I >> !:.•.•/•.' ; .'• >'. \i Vv S ::!.-!-:;.il-.
ATSDR has public health authorities under both the Comprehensi\ c Hnvironmental Response. Compensation, and Liability Act (CERCLA) of 1980 (amended 198d). and the Resource Conservation and Recovery Act (RCRA) of 1976 (amended 1984), therefore this document will address issues related to both temporarily sited and RCRA permitted thermal treatment devices being used for the treatment of ha/ardous substances, pollutants, or contaminants. These may be regulated by FPA under CERCLA, RCRA. or the Toxic Substances Control Act (TSCA).
Robert C. Williams, P.E., PEE Director. Division of Health Assessment and Consultation (DHAC)
Table of Contents
Foreu ord
Table of Contents
List of Tables
List of Figures
Chapter 1 - Introduction Chapter 2-ATS PR Role
Chapter 3 - Background
Chapter 4 - Information Needs
4.1. Design and Operating Information Pertinent to Protect Public Health 4.2. Other Information Important to Public Health 4.3. Site Visit Chapter 5 - Review of Thermal Treatment Technologies 5.1. Thermal Treatment Facility Designs 5. /. /. Pretreatnient - Waste Preparation and Feed Systems 5.1.2. Combustion and Desorption Chambers 5.1.3. Gas Post Treatment - Air Pollution Control Equipment 5.1.4. Solids Post Treatment and Residuals Management 5.1.4.1. Liquids 5.1.4.2. Ash 5.1.4.2.1. Bottom Ash - Decontaminated Soil 5.1.4.2.2. Fly Ash - Particulate Matter 5.1.5. Other Design Features - Thermal Relief Vents 5.2. Emissions of Public Health Concern 5.2.1. Stack Emissions 5.2.1.1. Organics 5.2.1.2. Dioxins and Furans 5.2.1.3. Metals and Halogens 5.2.2. Fugitive Emissions 5.3. Design and Operating Considerations Important to Public Health
Chapter 0 - Public Health Evaluation
6.1. Pre-uperational Phase - Information to Review for Health Implications lltllll
Hft'eetueness ol'thc Technology
Chapter 8 - Health Studies at Thermal Treatment Facilities
8.1. ATSDR Funded Health Studies Related to Combustion 8.1.1. Cult At -ell Systems. Inc. (NO 8.1.2. Calilwcll Systems. Inc. (NO S.I.3. Culvert City Industrial Complex (KY) 8.1.4. Times Beach (MO) 8.1.5. V'ERTAC/Hercules Sire (AR) 8.1.6. Three Waste Incinerators (NC) 8.2. NIOSH Studies iV.J. /. The Caldwell Group (NO S.2.2. ENSCO(AR) 8.2.3. Allied Chemical (LA) •V._.-/. Rollins Environmental Services (LA) -S'.-..5. (rrosse Poinlcs-C'linton Refuse Disposal Authority (Ml) •V.-.6. fteltiMcre source Recovery Facility (PA) \_. 7 Monroe County fin inernior (FL) -S'.-.-V. Nort/nvesl Incinerator (PA) Ciuukince Manna! I'M; i'nbhc llcal;h hup \v\\\\ ..a^lr. ale uo\ NI-XVS tlicrnuil-uuidc yuidc.html
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('lianter ()_ - Reeojnineiided Restniree JJooks
M.I. ATS PR Resource Books °^2. \-.P\ Resource Books 9.3. Other Technical Resource Books
Appendix A - .Acronyms and Abbre\ iations
Appendix B - Tables
Appendix C - Figures
Appendix 1) - Public Health Assessment Process
Appendix F:. - Applicable or Relevant and Appropriate Requirements (ARARs)
List of Tables
Table 1 - Key Design and Operating Information to be Reviewed Table 2 - Applicability of Dcsorbers and Major Incinerator Types to Various Wastes Table 3 - Most Common Products of Incomplete Combustion from Ha/.ardous Waste Incinerators Table 4 - ARAR Identification Process Table 5 - Conservative Estimates of Metals Partitioning to Flue Gas as a Function of Solids Temperature and Chlorine Content Table 6 - Metal Volatility Temperatures Table 7 - Air Pollution Control Devices and their Conservatively Estimated Efficiencies for Controlling Metals Table 8 - Design Considerations Table 9 - Recommended Automatic Waste Feed Cut Off Conditions to be Continuously Monitored Table 10 - Issues Ambient Air Sampling and Monitoring Plans Should Address
List of Figures
Figure 1 - Incineration Subsystems and Typical Process Components Figure 2 - Thermal Desorption Systems
Chapter 1 - Introduction
The Agency for Toxic Substances and Disease Registry (ATSDR) receives questions from health professionals in state and local health agencies and from the public regarding human health implications of treating wastes in incinerators and desorbers. Agency staff who understand the characteristics of a well-designed and properly operated thermal treatment unit can provide informed advice about public health implications of such technologies. iuidunce Manual lor Public Health
This document describes current engineering practices, appropriate environmental monitoring, and their relationship to public health concerns about technical >'e\-iews of actual or potential contaminant releases from thermal ologies. It provides a treatment technologies. This document provides understanding of thermal treatment guidance that health assessors can use to evaluate a particular facility. However, because each facility is ecfinologtes so public hea-th professionals can different, health assessors must make site-specific tsk the appropriate questions and -nake fnore determinations on each facility as to what factors are njbr-ned judgements about f-iarards posed by important for protecting the public. Health assessors hese technologies. must not unilaterally apply all recommendations in this document to every facility. If health assessors do not have the expertise to determine the site-specific application of this guidance, they should seek assistance from technical experts at ATSDR in the Division of Health Assessment and Consultation (DHAC).
This document assumes the reader has a technical background and a familiarity with thermal treatment When developing the facility plans, EPA and systems. It does not replace or modify guidances or thermal treatment facility staff may want to materials used by other government agencies charged understand the types of concerns and with determining which technologies to use to manage information needs public health officials will Superfund wastes or those agencies issuing permits to thermal treatment facilities under the Resource have if they become involved in evaluating the Conservation and Recovery Act (RCRA) or Toxic public health implications of the site. If so. this Substances Control Act (TSCA). This document document may be helpful to them. provides detailed guidance to ensure that state health department and Agency staff evaluate thermal treatment facilities in a consistent manner. People without a technical background and knowledge of thermal technologies may find it difficult to understand this document. For a synopsis of ATSDR's policies regarding the use of thermal treatment devices, see Public Health Overview of Incineration as a Means to Destroy Hazardous Wastes - Guidance to ATSDR Health Assessors. This document will refer to incinerators and ex-situ desorbers as thermal treatment devices. EPA defines a desorber as "a thermal treatment device used to extract bound or mixed organic contaminants from a waste matrix. The thermal desorption system includes emission control devices to remove the extracted contaminants from the stack gas. This is meant to be just a useful technical description; the term 'desorber' has no regulatory significance.
How are Desorbers Regulated under RCRA? Desorbers are regulated under RCRA either as incinerators or miscellaneous treatment units if they are used to treat a RCRA hazardous waste. A desorber is regulated as an incinerator if it directly uses controlled flame combustion. Examples are: (1) use of a direct fired thermal desorption chamber; (2) injection of off-gas from direct flame combustion into the desorption chamber; and (3) use of an afterburner to destroy organic contaminants in off-gas from the desorption chamber. Other desorbers are regulated as miscellaneous treatment units. An example is a thermal desorption chamber that is indirectly heated (irrespective of whether controlled flame combustion is used to provide the heat to the heating device) followed by an emission control train comprised generally of condensers and an activated carbon bed. The Agency [EPA] specifies operating requirements for miscellaneous treatment units on a site-specific basis as necessary to ensure protection of human health and the environment. For desorbers that are classified as a miscellaneous treatment unit, it is agency policy to require compliance with those incinerator standards that are appropriate for the technology."
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hPA defines an incinerator as. "any enclosed device usitu: controlled llanie combustion that neither meets the criteria for classification as a boiler nor is listed as an industrial furnace." (4i> Code of Federal Regulations [CFR 260.10).
The American Academy of Hnviromnental Engineers (AAFF) monograph Innovative Site Remediation Technology - Thermal Desorption states that,
"thermal desorption is an ex situ means for physically separating organics from soils, sediments, sludges, filter cakes, and other solid media....Desorbcrs are physical separation facilities and are not specifically designed to decompose organics (organics denotes compounds, including volatiles. semivolatiles, polychlorinated hiphenyls [PCBs], and pesticides)....The separated contaminants, water vapor, and participates must be collected and treated. This is typically accomplished using conventional methods of condensation, adsorption, incineration, filtration, and the like....Regulations that govern thermal destruction processes may apply in some cases to some thermal desorption processes."
Figure 2 in Appendix C, taken from the monograph, presents the type of components that typically make up a thermal desorption system (AAEE 1993).
ATSDR considers an incinerator to be any technology The key public health concern must be to where flames come in contact with the waste being ensure that the facility is operated in a way treated. Incinerators destroy the organic contaminants in that prevents or, to the maximum extent the waste. ATSDR considers a desorber to be any device practicable, minimizes public exposure to that uses an external heat source to heat the waste material in order to drive contaminants out of the waste. contaminants of concern. Other differences and similarities between the two types of technologies are discussed in the relevant sections. In this document, desorber refers only to the unit that heats/desorbs the contaminated waste matrix, thermal desorption system refers to the entire process train, and incinerator and incineration system interchangeably refer to the entire process train.
We have included definitions of incinerators and desorbers for the benefit of health assessors and to make it easier to discuss the technical issues related to the operational differences between the two technologies. Health assessors should not get involved in controversies surrounding this matter. In site-specific documents, health assessors should use whatever name is generally used at that site. It does not matter to ATSDR what the facility is called, as long as sufficient sampling, monitoring, and operating controls are applied to protect the public.
As a matter of general public health policy, ATSDR supports waste minimization, recycling, and reuse as the preferred methods for reducing the volume of hazardous wastes and associated public health hazards. However, the agency recognizes that not all hazardous waste can be eliminated and that wastes need proper management, monitoring, and disposal. In some situations, such as the remediation of hazardous waste at Superfund sites, a review of all remedial technologies may indicate that thermal treatment is the preferred method of permanently eliminating or reducing potential public health hazards posed by those wastes.
Chapter 2 - ATSDR Role
ATSDR's mission is to prevent exposure and adverse human health ejjects and diminished quality of life associated with exposure to hazardous substancesfrom waste sites, unplanned releases, and other sources of pollution present in the environment. To accomplish that mission ATSDR makes recommendations targeted at preventing or minimizing public exposure to contaminants of health concern. [•.PA is the federal regulatory agency with primary responsibility under the (V*niprehensi\c Environmental Response. Compensation, and Liability Act of |9S(i (CHRCI.A, also known as Superfund, amended in I98(>), and the Resource Conservation and Recovery Act (RC'RA) of 1976 (amended in 1984). Those laws are aimed at protecting the public health and the environment at ha/.ardous waste sites. ATSDR provides an independent opinion on the facility's impact on public health. Both EPA and ATSDR have the same goal of protecting human health: therefore, their staff should be in general agreement on the plans, operating conditions, and monitoring requirements needed to ensure the protection of public health for a particular thermal treatment facility. However, differences of opinion between professionals can exist, even within one agency.
CERCLA requires ATSDR to assess the public health effects for every site proposed for the National Priorities List (NPL). RCRA expands ATSDR responsibilities by requiring the agency to consider petitions by the public to conduct a public health assessment of any facility or release.
This document provides detailed guidance on how to conduct a public health review of site-specific technical documents and information and how to evaluate the potential public health effects of thermal treatment (TT) facilities. To conduct a public health assessment at a TT facility readers should be familiar with ATSDR's Public Health Assessment Guidance Manual and health assessment policies (ATSDR 1992b). Appendix D contains a summary of the health assessment process.
This document recommends a public health review that is less rigorous than a RCRA permit review but sometimes more rigorous than a Superfund review. If ATSDR staff conclude that insufficient controls are in place to ensure the protection of public health, health assessors should discuss the technical issues with EPA or site managers and try to agree on necessary changes. Discussions during the review process and close coordination and cooperation between EPA, state regulatory agencies, ATSDR, and state health departments are especially important when communities are interested in the site.
If an agreement cannot be reached, ATSDR staff should explain in a health consultation the technical basis for and health concerns related to their recommendations. ATSDR suggests that health assessors generally only specify the type of conditions, controls, monitoring, and/or sampling that are recommended and let EPA or the state agency with regulatory authority and responsibility specify the actual operating limits and/or sampling requirements. For example, rather than recommending a specific minimum flue gas exit temperature for the primary combustion chamber, and the addition of this operating condition to the automatic waste feed shutoff system, health assessors could recommend that a minimum flue gas exit temperature condition be added to the automatic waste feed shutoff system. Health assessors should explain that the technical basis for the recommendation is to ensure that the waste is decontaminated when it exits the primary chamber and does not present a hazard to on-site workers or the public. Occasionally, health assessors may want to recommend a specific operating condition. An ATSDR review, conclusions, and recommendations regarding the use of a particular technology are usually ATSDR uses health consultations to address provided in a site-specific "public health consultation" specific and usually narrowly defined questions (consult). Appendix D summarizes the public health in a timely manner. assessment review process.
Chapter 3 - Background
3.1. ATSDR Guidance ATSDR believes that propcrlv designed and operated thermal treatment technologies can effectively and safely destrox or decontaminate certain types of ha/ardous wastes (primarily Ji* Jet^ndr on ko^v ?J:ey are ds&\ organic contaminated wastes). When asked to review a specific and or-erjtfd. treatment facility. ATSDR first reviews the site-specific design of the technology, the operating conditions, environmental monitoring, and on- and off-site contingency plans for the facility. ATSDR then assesses actual and potential contaminant releases from the facility and on-site operations in the past, present, and future. ATSDR evaluates this information to determine the possible public health implications of the site and the technology being used to remediate the site. Evaluations are done on a site-specific basis to address the differences in environmental and operating conditions at each site.
In 1992, ATSDR issued. Public Health Overview of Incineration as a Means to Destroy Hazardous Wastes - (iiiidance to ATSDR Health Assessors, which provides guidance on broad issues related to the use of Superfund incinerators. This document expands and updates the guidance to agency staff and other health professionals on how to evaluate the potential public health effects related to the use of thermal treatment devices used to treat hazardous wastes. The 1992 document, written in plain language, provides policy statements and general direction on the types of issues that health department staff should consider when evaluating incinerators. However, health assessors evaluating the actual operation of thermal treatment devices felt the document did not provide the level of detailed guidance they needed to properly evaluate these types of facilities. Furthermore, the evaluations of various thermal treatment sites were not consistent. The conclusions and recommendations regarding the site operations were, as one would expect, related to the experience and expertise of the health assessors. Therefore, the present document provides a more detailed, technical guidance and should promote more consistent reviews of thermal treatment facilities. 3.2. EPA Regulations
Some public health officials may find it difficult to determine which EPA regulations (and therefore which EPA program offices) apply to a facility. The EPA Air Program and the Clean Air Act regulations vary depending on the quantity of pollutants emitted by the facility, whether the facility existed when the regulations went into effect, but was later modified, or whether it is a new facility. The EPA air permitting program can be delegated in totality or in parts to state, county, or local air programs.
The Toxic Substances Control Act (TSCA), TSCA regulations, and permitting program apply to any facility that treats regulated PCB wastes, such as wastes containing more than 50 parts per million (ppm) PCBs or derived from those wastes. The TSCA program cannot be delegated to any state, county, or local agency.
If the waste contains any of the wastes defined as "hazardous wastes" in the RCRA regulations, Title 40 Code of Federal Regulations (40 CFR) Part 261, then the facility is subject to the hazardous waste regulations. The RCRA program can be delegated in whole or in parts to state environmental agencies, but not to county or local hazardous waste programs.
CERCLA exempts facilities from having to obtain permits from all the programs, but it requires them to comply with the technical standards of each applicable program. The CERCLA staff usually forward the site plans to each applicable program office for their input, but the CERCLA staff are ultimately responsible for assuring that the CERCLA facility complies with the applicable or relevant and appropriate standards, limitations, criteria, and requirements (ARARs). The EPA Web site provides the following description of ARARs: (see Appendix E for more details)
CERCLA §121(d) specifies that on-site Superfund remedial actions must attain federal standards, requirements, criteria, limitations, or more stringent state standards determined to be legally applicable or relevant and appropriate to the circumstances at a given site. Such ARARs are identified during the remedial investigation/feasibility study (RI/FS) and at other stages in the remedy selection process. For removal actions, ARARs are identified \\ hene\XT practicable, depending upon site circumstances. I o be applicable, a stale or federal requirement must directly and fully address the ha/ardous substance, the action being taken, or other circumstance at a site. A requirement which is not applicable may be relevant and appropriate if it addresses problems or pertains to circumstances similar to those encountered at a Superfund site. While legally applicable requirements must be attained, compliance with relevant and appropriate requirements is based on the discretion of the Remedial Project Manager (RPM), On-Scene Coordinator (C)SC'), or state official responsible for planning the response action (EPA 199Sa).
A number of federal and/or state program offices may be involved at a particular Superfund site. When there arc conflicting standards that apply to a site, the more stringent requirement usually applies.
Chapter 4 - Information Needs
This chapter lists the types of site-specific information that may be available for thermal treatment facilities. Every facility may not have all of the information listed. The information relevant to specific types of equipment will obviously not be applicable if the facility does not have that type of equipment. Public health officials may want to review the starred * items, but it is not essential. Table 1 (all tables are in Appendix B) summarizes the types of information public health staff need to review if they are conducting an in-depth evaluation of a thermal treatment facility.
4.1. Design and Operating Information Pertinent to Protect Public Health
• Waste analyses - concentration of organic and inorganic chemicals present in wastes • Treatability tests and protocols*
• Data on wastes, operating conditions, and environmental monitoring from previous sites where the unit has been operated*
• Projected fate of contaminants and ultimate fate/disposal of residuals and effluents
• Estimated time for volatile organic breakthrough of the carbon adsorption system
• Engineering design specifications* and detailed description of the following systems that affect emissions: o Waste feed handling, o Combustion/desorber chambers(s), o Treated waste handling, o Flue gas treatment/air pollution control system, o Monitoring equipment (thermocouples, pressure-drop indicators, flow-rate meters, continuous emission monitors [CEMs], etc.), o Stack height, and o Removal and handling of process residuals (i.e., fly ash, condensate, scrubber water, spent carbon, and spent filters).
• Permits or approvals to operate • Operation and maintenance plan (O&M plan) including: o Conditions to ensure effective treatment of waste, o Conditions to ensure effective flue gas treatment, o Conditions to ensure stack emissions are below levels of health concern, o Key conditions to be continuously monitored, o Key conditions for automatic waste feed cutoffs (AWFCOs), o Equipment shakedown/pretrial burn operating conditions. (iuukmce Manual tor Public lk\iith \w^M>r-, hup: \\ \\ u aK.ii cilc ;:i>\ \|-\\S ;:)•_•! m.ii-._u:K L- LUikle.html
o Post trial hum /pro-full operation operating conditions (if not shut do\\n). and o "fimcline covering shakedown of equipment through completion of thermal treatment, including dates for trial burn and submittal of a trial hum report.
• Performance test plan or trial burn plan including: o Target operating conditions, o Operating conditions to be recorded during the trial burn, o Waste sampling and analysis (S&A), o Stack emissions S&A, such as principal organic ha/ardous constituents (POHCs) or target compounds, products of incomplete combustion (PICs), tentatively identified compounds (TICs), and metals, o Continuous emission monitors (CEMs). o Residuals S&A - identify and quantify fate of contaminants, and o Quality assurance and quality control (QA/QC) plans.
• Trial burn or performance test report and data 4.2. Other Information Important to Public Health
• Ambient air sampling and monitoring plans, including: o Locations of monitoring and sampling stations on site and off site, o On-site action levels and response actions, o Fence-line action levels and response actions, and o Community action levels and response actions.
• Modeling of stack emissions such as: o Worst case 24-hour and 1-year dispersion coefficients, and o Average annual dispersion coefficient.
• Worker health and safety plan (There may be more than one per site if several contractors are involved.)
• Contingency or site safety plan, including on- and off-site actions in the event of an unplanned release
• Land use around the site
• Community demographics: This information is available from the ATSDR Geographic Information System (GIS) activity group
• Description of how waste materials will be excavated at CERCLA sites
• Description of how waste materials will be stored and any preprocessing to be done
• Description of operator training*
• Equipment inspection schedules*
• Reports of incidents or noncompliance that occur while treating waste materials • Additional reports of stack emissions testing completed after the trial burn*
• On- and off-site ambient air monitoring/sampling reports
• Risk assessment
4.3. Site Visit (iuidancc Maiuuii tor Public lleullii A Iitinl
ATSDR recommends that health assessors conduct a site visit of the thermal treatment facility to observe the waste and residuals handling practices, facility operation, and environmental sampling. Health assessors will find the site visit most productive if they first review the facility design and operating conditions, the environmental monitoring plan, and the health and safety plan. During site visits health assessors should also look at the potential for worker exposure and the presence of an adequate worker protection program. Health assessors should also note any worker safety issues that they observe while on site. If health assessors identify worker safety problems or are unsure whether the facility's program is adequate, they should discuss their findings with their supervisor and National Institute for Occupational Safety and Health (NIOSH). or Occupational Safety and Health Administration (OSHA) staff.
Chapter 5 - Review of Thermal Treatment Technologies
To evaluate the potential public health impacts of a thermal treatment technology, health assessors must be familiar with the design of incinerators and desorbers. This chapter discusses the common subsystems and explains the significant features of various types of equipment that may be used. 5.1. Thermal Treatment Facility Designs Thermal treatment units should be designed to handle the particular type(s) of waste which will be treated. Thermal An incinerator removes and destroys desorption units effectively remove volatile organic compounds the organic constituents in the waste. (VOCs), semi-volatile organic compounds (SVOCs), PCBs, pesticides, and petrochemicals from solid wastes such as A desorber removes and captures or contaminated soils. Some desorber designs can also decontaminate small amounts of sediments or liquid wastes in treats the organic constituents. conjunction with solid wastes. Incinerators may be designed to treat all types of wastes simultaneously or a single type. Table 2 lists desorbers, the major incinerator types, and the various physical forms of waste they can treat.
The four major subsystems in a thermal treatment facility are: (1) waste preparation and feed systems, or pretreatment, (2) combustion or desorption chambers, (3) air pollution control equipment or gas post treatment, and (4) liquids and ash handling or solids post treatment and residuals management systems. Figure 1, in Appendix C, shows the general orientation of the subsystems and typical process component options for incinerators. Figure 2, in Appendix C, shows the general orientation of thermal desorption systems. The desorber unit may be a rotary kiln/dryer, thermal screw, fluidized bed, distillation chamber, or belt conveyor system (EPA 1993). There are some design differences between a desorption system and an incinerator. A desorption system has a chamber operating at temperatures just high enough to effectively vaporize, but not combust, the organic compounds from the contaminated material and has condensers and/or carbon adsorption units in addition to or instead of any of the other air pollution control equipment (APCE) shown in Figure 1. An incinerator has one or two refractory lined combustion chambers operating at high enough temperatures to vaporize the organic compounds present and destroy them. 5.7.7. Pretreatment- Waste Preparation and Feed Systems
The type of waste preparation and feed system is determined by the physical form of the wastes, the type of contaminants, and the type of primary combustion chamber (PCC) or desorption chamber (DC). The physical forms of the wastes (gas, liquid, sludge, or solid) and the type of contaminants (flammable, VOCs, etc.) to be treated can also affect the design of the other three subsystems. jc Manual !t>i I'uhlu Hcailh .V.,.:-v. .. : -n.il ;:i,:.^
Liquid \\nstes are usually blended and. or agitated, then pumped through no/vies or atomi/mg burners into either one or both of the incinerator combustion chambers. Liquid wastes should be screened to avoid clogging the small no/./.le or atomi/er openings. Small quantities of liquids can be treated in desorbers by spraying the liquids on solid wastes during pretreatment or injecting them into the chamber while solid wastes are being fed.
Sludges are usually fed into the DC or PCC of the incinerator through water-cooled lances. The percentage of liquids is very important for desorbers because some desorption chamber designs cannot accommodate sludges or slurries; in that case any sludges or slurries should be dewatered or mixed in small amounts with the solid wastes to be fed to the DC.
Solid wastes are fed into the DC or PCC. Containerized wastes can only be incinerated and are typically- fed through an airlock ram feeder into the PCC, but they can also be gravity fed through a chute into the PCC. Bulk solid wastes such as debris or PCB capacitors usually need to be shredded before they are fed into the PCC, and are not normally treated in desorbers. Bulk solid wastes such as contaminated soil are typically fed to the desorber or incinerator via vibratory or screw feeders or conveyor belts. If the solid wastes are being fed to a fluidized bed incinerator or desorber, all solids generally must be screened, crushed, or shredded to be less than 2 to 2.5 inches in diameter. Some desorber designs (e.g., 4-inch screw conveyors) may require that the waste be 0.5 inches or smaller. If the screw conveyor is 12 inches in diameter or larger, the materials can be 2 inches or greater (Kulweic 1985).
Flammable or ignitable wastes require special nonsparking equipment to prepare and feed the waste. If the waste feed or preparation areas are enclosed, fire codes may require an automatic fire suppression system in addition to good ventilation to prevent vapors from accumulating and approaching the lower explosive limit (LEL). Good ventilation is also needed to prevent oxygen displacement and worker asphyxiation hazard if the pretreatment area is enclosed and the wastes contain VOCs. The air from enclosed pretreatment areas should be vented to the thermal treatment chamber or a carbon filter system. Waste piles containing VOCs should be covered to prevent volatilization of the VOCs.
Waste analysis is another important part of waste preparation, to ensure that it does not contain any chemicals that should not be treated in that particular treatment facility, e.g., PCBs, dioxins, certain metals, etc. Analysis also provides information needed to properly manage the waste, e.g., pH, viscosity, water content, concentrations of various metals and certain organics, solids, compatibility with other wastes stored on site, etc. The list of parameters to be analyzed for at each facility is determined on a site-specific basis, depending on the type of equipment and permit conditions. 5.1.2. Combustion and Desorption Chambers
Incinerators with PCB and hazardous waste permits typically have two combustion chambers in order to meet the EPA regulatory requirement to destroy or remove 99.9999% of the PCBs and dioxins present in the wastes, and 99.99% of the other designated hazardous organic constituents. If sludges or solids are to be incinerated, the PCC may be a rotary kiln, fixed hearth, infrared, or fluidized bed, which can handle solids and sludges as well as liquid and gaseous wastes. If only liquid wastes will be treated, a liquid injection incinerator is typically used. Most PCB and hazardous waste incinerators also have a fired secondary combustion chamber (SCC) or afterburner to provide the temperatures (1800F-2200F) and residence time (2 seconds) necessary to effectively destroy the wastes. Incinerator combustion chambers are refractory lined because of the high temperatures. The lining can be firebrick or a sprayed-on insulation. Under the CERCLA program the chambers' design may depend on whether TSCA or RCRA regulations are ARARs for the site. Desorbers are used to clean up PCB contaminated soils and other Superfund, petroleum, and hazardous wastes. EPA has not specified performance standards for desorbers. If they treat wastes classified as hazardous waste they are regulated under 40 CFR Part 264 Subpart X, Miscellaneous Units. Site-specific operating conditions are set for each desorption facility based on the contaminants present in the waste (see Chapter 2 for further discussion). There are currently no fixed commercial desorber facilities treating hazardous wastes under a RCRA permit. The most commonly used desorption chambers (DCs) are rotary dryers (rotary kilns), thermal screws, indirect calciners, and belt desorbers.
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1'ypical desorber operating temperatures are 200F-1000F (HPA. 1W3). However, they may operate as high as 1 500F depending on the contaminant, waste matrix, and desorber construction materials. The air pollution control equipment train immediately follows the DC. DCs are not usually refractory lined because the flame usually is not be in contact with the metals or wastes in the chamber. However if the DC' must be run at higher operating temperatures to effectively decontaminate the soil being treated, it may need to be refractory lined.
5.1.3. (.his Post Treatment - Air Pollution Control Equipment
The types of wastes to be treated will also dictate the type of APCE needed to protect the public from exposure to harmful Acid gases are revioved by eit.ber concentrations of stack emissions. All incinerators treating wastes \vc'. or drv scrubbing svstems. containing halogens, such as chlorinated solvents, PCBs, or metal halides, need APCE designed to remove acid gases, since these generate acid gases, such as hydrogen chloride (HCI) when they are combusted. Desorbers sometimes are run at high enough temperatures that acid gases are produced from decomposition of halogenated compounds.
A typical wet scrubbing system consists of a quench (to reduce the gas temperature and to remove some particulate and acid gases), a venturi scrubber (to control particulate and to remove acid gases), a packed bed or tray tower (to remove acid gas and additional particulate), and a demister (to reduce the visibility of the vapor plume). Generally, caustic soda or lime is added to the water circulating through the venturi scrubber and packed bed or tray tower for acid absorption and neutralization.
A typical dry scrubbing system uses a waste heat boiler after the SCC or thermal oxidizer to cool the off-gas to 400F-600F before it flows into an absorber. Lime in the form of calcium hydroxide slurry is injected as a finely atomized spray into the absorber, in the 5 %-50 % slurry to water range. The temperature of the gases exiting the absorber are normally maintained in the 250F-300F range. The flue gases next flow into a particulate collection device, such as an electrostatic precipitator (ESP) or a baghouse (also called a fabric filter).
Desorbers typically have a wet or dry scrubbing system for It is very important to have a particulate removal followed by a series of condensers, then hydrocarbon monitor after a activated carbon adsorption units to remove the organic carbon adsorption unit, in order contaminants volatilized from the wastes. If the condensers are not ULI detect organic bi-.^.. operated at temperatures well below the lowest boiling organic expected in the flue gas, the carbon adsorption units may become as quickly as possible. quickly saturated and ineffective. Carbon adsorption units also have difficulty removing very low boiling VOCs. It is very important to have a CEM designed to detect hydrocarbons (HCs) after a carbon adsorption unit in order to detect organic "breakthrough" as quickly as possible. The facility should have procedures in place to change out the carbon units when that happens.
High efficiency particulate air (HEPA) filters are usually only used on TT systems treating radioactive or extremely toxic wastes. A problem with carbon adsorption units and HEPA filters is that "channeling" can occur, which allows some of the flue gas to pass straight through the unit without being filtered. CEM flue gas monitors (HC, radioactivity and/or monitors for specific extremely toxic chemicals) should be installed after all APCE to document whether the equipment is functioning properly. CEMs are typically placed in the stack. The final piece of equipment for all TT systems is a stack or exhaust pipe, which should be designed to meet or exceed the EPA Air Program's "Good Engineering Practice" (GEP) standards to adequately disperse the stack emissions and to minimize public exposure. Minimum GEP is defined as follows:
GEP = H + 1.5L H = height of a nearby structure, and L = the lesser dimension of the height or projected width of the nearby structure. oj NLiiHial |nr I'ulMic I kvi::i A-.v^M>i> MUP '.\ \\ -.- L\:-.,\] ^u ,M\ \l-\\ S ii:.ji uial-uuuk uuuk' lunil
I he maximum GHP physical slack height that EPA will give the facilit\ credit tor \\hen it conducts stack emissions modeling is defined as the greater of 65 meters or II - 1.51.. If the stack is taller than the maximum (iEP stack height, the facility will have better dispersion of their plume, so ATSDR should encourage the use of tall stacks or exhaust pipes.
\1.4. Solids Post Treatment and Residuals Management
The types of residuals generated by a thermal treatment facility depend on the types of waste feeds and APCE. The quality of the residuals depends on the treatment temperature, moisture content, residence time, and whether additional chemicals are added to the treatment chamber or APCE. Under RCRA, any process residuals from treating a listed hazardous waste is still a listed ha/ardous waste and must be handled accordingly.
5.1.4.1. Liquids
Liquid waste streams/residuals are generated at thermal treatment facilities by washing down the equipment and the waste processing and unloading areas, and by wet scrubbers, if they are included in the APCE design. The facility may dispose of the waste waters by:
• Injecting them into the incinerator combustion chamber,
• Discharging them through the sewer system to the publicly owned treatment works (POTW),
. Discharging them to a nearby body of water, such as a stream, lake, or surface impoundment, or
• Spraying them on the hot soil/ash to cool it as it is discharged from the PCC or DC. Injecting waste waters into desorbers is not economical.
A permit is required to discharge waste waters. Depending on the facility location and the constituents present in the waste waters, the local POTW may require the facility to pretreat the waste waters. When health assessors evaluate a facility that discharges to a POTW, they should also evaluate the impact of the thermal treatment facility on the POTW's sludge if the facility's waste water stream has significant concentrations of metals or organics. Contaminants of concern may concentrate in POTW sludge. Sludges from POTWs are often used as fertilizers by farmers and homeowners, and may therefore be a completed exposure pathway that needs evaluation. EPA regulations require all facilities, except CERCLA ones (see section 3.2.), to obtain a National Pollution Discharge Elimination System (NPDES) permit for all discharges into certain water bodies. The permit will specify such items as pH, biological oxygen demand, which chemicals and at which concentration can be discharged, and may require treatment before discharging the waste water. The discharge may still contaminate the local surface water, sediments, and food chain pathways because all toxic chemicals which may be in hazardous waste are not regulated under the NPDES program.
The waste water generated by cleaning/washing of the facility and equipment may contain small concentrations of any of the hazardous constituents that are present in the wastes being handled. The waste waters from the wet scrubbing system may contain higher concentrations of some of the metals than were in the original wastes, but they usually contain low concentrations of only a few organic chemicals. Waste waters (also called process waters) need to be analyzed before being sprayed on hot soil/ash to make sure they will not recontaminate the treated materials. TSCA requires the process water to contain less than 3 parts per billion (ppb) PCBs.
Desorbers that have condensers as a part of their APCE generate a liquid waste containing the organic chemicals desorbed from the waste and liquified in the condensers. Because the organic contaminants will be concentrated in this waste stream, employees need training in how to safely manage this waste.
5.1.4.2. Ash
1001 1:08 PM High ash content liquid wastes, sludges, or solid wastes ted to a thermal treatment facility generate bottom ash and fly ash. Bottom ash is generated in and discharged from the PCX' or DC If the unit is used to decontaminate soil, the bottom ash is usually referred to as the decontaminated soil rather than ash. Fly ash are the solid particles that are entrained in the flue gas and metals, or the organics that are volatili/ed and later condense in the air pollution control equipment when the Hue gases are cooled. The bulk of the fly ash is captured and removed by the APCE to keep the facility in compliance with its participate emission limitation.
5.1.4.2.1. Bottom Ash - Decontaminated Soil
Bottom ash or decontaminated soil (if soil is being treated) discharged from the PCC or DC should contain only very low concentrations of organic contaminants. It may be a fine material that has metals concentrated in it and is easily blown around. Some facilities discharge the ash soil into a water quench to cool the ash/soil and prevent it from blowing. Other facilities have a water spray directed on the ash/soil conveyor, while others have a shroud around the conveyor where water is being sprayed on the hot ash/soil. Sometimes the bottom ash from a high temperature incinerator is a molten slag material that does not contribute to fugitive emissions.
5.1.4.2.2. Fly Ash - Particulate Matter Thermal treatment facilities which have a dry scrubber system or treat contaminated soil or high solids waste Particles rang? in diameter, but those that are generate fly ash, also called particulate matter (PM), that 2.5 microns or less have the greatest is entrained in the flue gas. The fly ash can be removed respiratory effect on humans. However, even from the flue gas by cyclones, scrubbers, bag houses, or particles up to 10 microns are respirable and ESPs. Some facilities discharge the fly ash removed by the APCE directly into drums or other containers for can cause respiratory problems. disposal which is usually fairly effective in preventing fugitive dust emissions. Some facilities convey the fly ash and the bottom ash to a residuals' management area where they are analyzed before being mixed or disposed. To prevent fugitive dust emissions these conveyors should be enclosed, shrouded, and/or kept moist. 5.7.5. Other Design Features - Thermal Relief Vents Most incinerators and some desorbers that treat solid wastes have a thermal relief vent (TRV), also called The activation of the TRV must be tied into the an emergency relief vent or "dump stack," AWFCO system to prevent additional -wastes immediately after the combustion or desorption jrom beingjed to the unit -while the TRVis open. chamber(s). The hot gases can be diverted through ______this TRV if downstream equipment malfunctions. TRVs are necessary on certain facility designs to prevent equipment fires that cause the hot combustion gases to vent at ground level because this would be hazardous to facility workers as well as nearby residents. A TRV is not necessary if the desorber operates at temperatures low enough that the APCE can withstand them in an emergency situation. Because the emergency vent allows the flue gases to bypasses the APCE when the stack is opened, the public may be exposed to metals, particulates, acid gases, and possibly organic chemicals if the emergency relief vent is opened while waste is still in the combustion or desorption chamber(s). A TRV is not needed and should not be allowed if solids are not being treated. Now TRV openings are infrequent, however, prior to RCRA permitting TRV openings occurred frequently. According to a recent EPA survey of RCRA permit writers, a facility may not have a TRV opening for several months, then have an equipment malfunction and have several openings in a short time. Historically, 30 TRV openings a year were common. Facilities should try to minimize or eliminate TRV openings.
5.2. Emissions of Public Health Concern 1 he two categories ol "emissions that may be of public health concern are stack emissions and fugitive emissions.
5.2.1. Stack Emissions
5.2.1.1. Organics
Even though thermal treatment units can efficiently destroy or remove organic chemicals in wastes, they emit low concentrations of some organics. The organics in incinerator stack emissions are called products of incomplete combustion (PICs). Various definitions of a PIC exist, but this document will use the term loosely to refer to any organic compound found in incinerator stack emissions. This section discusses PICs that are generally found in most waste incinerators' emissions. During the 1980s EPA analyzed the stack emissions of a number of hazardous waste incinerators for PICs. Table 3 shows the emission rates of the nine chemicals that EPA found most frequently (most common PICs) in the stack emissions of hazardous waste incinerators.
Thermal desorption stacks may emit small concentrations of the organic chemicals and volatile metals that are present in the wastes being treated. Partial degradation or pyrolytic breakdown byproducts (carbon monoxide and light hydrocarbons) may also be emitted. Thermal desorber (TD) stack emissions have not been characterized as extensively as incinerator emissions.
5.2.1.2. Dioxins and Furans
Test data from some TT facilities show low concentrations of polychlorinated dibenzyl dioxins (dioxins or PCDDs) and polychlorinated dibenzyl fiirans (furans or PCDFs) in the stack emissions of PCB and RCRA incinerators and thermal desorption facilities. The test data suggest that incomplete destruction of organic material in the combustion zone and adsorption of this material on entrained fly ash significantly increases the possibility of formation of PCDD and PCDF in the APCE if the gas temperature or downstream surfaces are in the 400F-650F (200C-340C) range (EPA 1989). PCDD and PCDF emissions can also be reduced by reducing the dioxin/furan precursors. Research has shown that good operating practices can minimize the formation of chlorinated dioxins and furans.
Good operating practices include • Maintaining tow carbon monoxide (less than I OOppm), • Maintaining low total hydrocarbon (less !?:.?n lOppm) levels in the stack gas, and • Quickly cooling post combustionfdesorption gases to below 400 °F (200 °C).
The data EPA used to establish the maximum achievable control technology (MACT) standards for hazardous waste incinerators showed that when the particulate matter control device is operating at or below 400F, dioxin/furan emissions are below 0.4 nanograms toxicity equivalency quotient per dry standard cubic meter (ng TEQ/dscm) unless the incinerator is equipped with a waste heat recovery boiler. For such incinerators, activated carbon injection may be needed to lower the emissions below 0.4 ng TEQ/dscm. Chlorinated dioxins and furans can be controlled through • Minimizing their formation by conducting good operating practices or using dioxin and furan formation inhibitors, or
• Using APCE control equipment, such as carbon adsorption or catalytic oxidation, for either the destruction or removal of the dioxins and furans.
Research on the formation of dioxins and furans has primarily been conduced on combustion sources, however, using the same good operating practices at desorbers should help reduce any potential dioxin and furan formation. 5.2.1.3. Metals and Halogens
If activated carbon is used for effective mercury control, the Hue gas temperature needs to be below 400F (204C). The temperature should also be maintained below 4uOF to avoid carbon tires. Arsenic, beryllium, cadmium, and chromium are carcinogenic metals that are sometimes found in wastes and stack emissions. Other toxic metals which may be present are antimony, barium, lead, mercury, nickel, selenium, silver, and thallium.
Because metals are elements, they cannot be destroyed by incineration or any other treatment technology, and may Concentrations ofmetois in stack gases therefore remain in the bottom ash, be carried into the APCE ca>i be affected fy: and removed there as fly ash or in the scrubber liquor, or be • Solids ternpe emitted in the stack gases. The concentration of metals present in stack gases can be affected by the following: Volatility offnetals, a>xt Typv ofAPCK • Solids temperatures—As the temperature of solids increases, the concentration of some metals (e.g., barium and silver) in the flue gases also increases (see Table 5). • Chlorine—With a few exceptions, chlorine generally increases the volatility of metals (see Table 6).
• Volatility of metals—Table 6 provides the volatility temperatures of 12 metals with and without chlorine. These metals volatilize at normal incineration temperatures, however, a few may not volatilize in desorbers depending on their operating temperature.
• Type of APCE-Table 7 shows conservative metals removal efficiencies of different types of APCE. Performance burns almost always demonstrate that a facility's APCE has better removal efficiencies than those shown in the table, so the values in Table 7 could be used to estimate potential health impacts when health assessors do not have facility stack emission data. There is little data for TD stack emissions because stack sampling and monitoring requirements for TDs have not been as stringent as those for incineration, except under the PCB program. EPA requires identical monitoring for PCB TDs and PCB incinerators during performance tests. 5.2.2. Fugitive Emissions Fugitive emissions from the waste processing/feed area can be volatilized organics or contaminated particulate. The two primary sources of fugitive Particulates contain organics and metals that are blown off emissions at any thermal treatment facility waste piles or waste transfer equipment or emitted through are the \vaste processing/Jeed area and the cracks in conveyor systems and storage and waste residuals handling/management area. processing buildings. Fugitive emissions from the waste processing/feed area can be effectively prevented by a number of different methods or combinations, such as (1) covering the waste with tarps or plastic, (2) spraying it with water, (3) spraying it with foam or other To ensure effective jugitive emissions coating materials, or (4) unloading and processing the management, ambient air monitoring is waste inside a building that is maintained under negative recommended at TTfacilities. If the facility pressure. The air drawn from the building should bt_ piped does not have fixed monitoring stations, directly to the incinerator or desorber for disposal, or vented through a carbon filter system to remove the hand-held monitors should be used to organics before the air is released to the atmosphere. If screen during spills or other releases and to bulk liquids are received and stored in tanks, the tanks periodically screen the area. should be vented through pipes to a carbon filter system or piped directly to the incinerator combustion chamber. Fugitive emissions from the solid residuals (fly ash, bottom ash. or decontaminated soil) handling area are generally tine particulatc matter that may easily become airborne if not managed properly. At most facilities the fly ash and bottom ash are stored separately, at least until they are analy/ed. but some CERCLA facilities combine them within the treatment system.
5.3. Design and Operating Considerations Important to Public Health
The following thermal treatment facility design considerations are important in minimi/ing or preventing public exposure:
• Controlling fugitive emissions can be done by physical/mechanical means, operating conditions, or enclosures/buildings. A company may also design the facility with a large buffer zone so that the fugitive emissions do not go off site. In this case health assessors should determine if access to the site is restricted to prevent exposure of people and pets, or animals which may become a part of the food chain.
• Venting waste feed tanks to the combustion chamber(s) or through a carbon filter system.
• Installing an AWFCO system that is connected to the key desorption, combustion, and APCE operating conditions to prevent continued operation under poor operating conditions which may cause excess stack emissions.
• Triggering the opening of a TRY, if there is one, but only under extremely critical operating conditions. If health assessors are not experienced enough with the design of incinerators to evaluate what parameters trigger the opening of the TRV, they should contact ATSDR combustion specialists. They should also ask how often the TRV is used, how long it stays open, and if any stack or ambient monitoring has been done during its use.
• Designing and operating the ash handling equipment to prevent blowing fugitive participates, if the facility generates solid residuals.
• Installing CEMs that monitor the stack emissions. ATSDR recommends that all TT facilities have a total hydrocarbon (HC) monitor. However, if a carbon monoxide (CO) monitor at a combustion facility has historically run well below 100 ppm on volume basis (ppmv) CO, then an HC monitor may not be needed. Desorbers which include condensers and/or carbon adsorption units need an HC monitor to monitor VOC emissions.
• Locating the facility and stack high enough in relation to the surrounding terrain and buildings to comply with GEP, will provide good dispersion of the plume. This will also minimize the likelihood of a plume "down draft" or fumigation, and minimize exposure of the public and workers from the stack emissions. The following operating limits are key to preventing poor combustion, desorption, or APCE operation (see section 6.1.1.4. for more on recommended operating conditions). As appropriate on a site-specific basis, these operating limits should trigger the facility's AWFCO system. • Minimum temperature in the DC and each combustion chamber • Maximum pressure in the DC or PCC
• Maximum feed rate of each waste type to the DC and each combustion chamber • Maximum chlorine and metals feed rates • Maximum size of batches or containerized wastes (iuulaiK'e Manual loi Public Health A
• Maximum CO and'or 11C stack emissions
• APCH inlet gas temperature
. Critical APC'E operating parameters specific for each type of equipment at the facility
• Maximum Hue gas flowrate or velocity
Chapter 6 - Public Health Evaluation
A team approach is recommended to thoroughly evaluate a thermal treatment facility's potential impact on the community. Someone familiar with the design and operation of thermal treatment technologies should evaluate the following:
• Design and operating conditions • Trial burn or performance test plan • Test report • Inspection schedules • Operator training • Contingency plans Someone experienced in air modeling should review the A site visit is necessary to understand the modeling. A toxicologist, physician, industrial hygienist, configuration and operation of the facility, it's or other health specialist should evaluate the potential relationship to the community, susceptible for health effects due to the ambient air and stack populations, and any topographic jeatures in emissions. An industrial hygienist or environmental scientist should evaluate the ambient air sampling and the area that may offset tiie dispersion of the monitoring plans for stack and fugitive emissions, action facility emissions. levels and associated response actions, health and safety and contingency plans, and demographics of the community. Some experienced health assessors may be able to do several or all of these tasks. After the thermal treatment facility is constructed, the person reviewing the thermal treatment design, if not all the members of the site team, should tour the facility, the community, and the locations of any on- and off-site ambient air monitoring stations. As discussed in Chapter 4, the mention anywhere in this document of items such as modeling, ambient monitoring stations, risk assessments, etc., does not imply that every facility will or should have all of these items. This chapter discusses how to evaluate different items or information if they are available for the site being evaluated. If ATSDR is involved early in the planning stage of the project, the following 3-phase review can be conducted: the pre-operational phase, the testing phase, and the operational phase. This chapter discusses the types of information that are normally available in each of these phases and how to evaluate the information. This chapter also explains terms and acronyms that are normally used in the thermal treatment industry. If ATSDR becomes involved late in the process, such as after the facility is operational, staff should still obtain and review the information discussed in each phase below. 6.1. Pre-operational Phase - Information to Review for Health Implications
Several stages of design drawings may be The pre-operational phase covers the design through available. However, ATSDR may not have the the construction of the thermal treatment facility. resources to review and comment on each level of design before plans are finalized, even though EPA and the facility may want the agency's input early in the process. Public health officials should at least review the final design or "as built" drawings and description if the agency becomes involved after the facility is already constructed. If EPA and the facility staff understand ATSDR's public health concerns as outlined in this document, they should be able to address all our technical concerns, so c Manual :.;> 1'uNic Ik'alth ASMJSM>,"> ;;;ip >.\ '.\ u at^ii ,^;L ,L:M\ \I.\\S liicrmal-Liiiiuc tv.iule.lltml
ATSDR's involvement late in the process should not he too disruptive.
6.1. /. Design and Operating Considerations Pertinent to Protecting I'uhlic Health
(>. 1.1.1. Effectiveness of the Technology
If the technology does not effectively decontaminate the waste on the first pass through the unit, worker exposure to tne tecfmoiogy Joes >:o? etfscin'ely contaminants may he increased when handling the partially coxtawsn&s I he \vjste o>! the first treated wastes prior to having the treated waste analysis back. ISS through the unit, public exposure Reprocessing and additional handling of partially treated waste e ncrease. may also increase off-site exposure because of the greater potential for fugitive emissions. Although the partially treated waste may not be an acute hazard, the cumulative dose should be considered. While the cost of waste treatment is not a major consideration for ATSDR, it may be more economical to run the TT unit a few degrees hotter to ensure that wastes do not have to be reprocessed, rather than try to run the unit at a lower temperature and have to reprocess a substantial portion ( i.e., more than 10%) of the batches.
Data from treatability tests and waste analysis, or data from previous sites where the unit was operated will help address these issues at a pre-operational facility. For example, has the unit (or a similarly designed unit) treated a similar waste? If so, what were the concentrations of the contaminants, the operating conditions, and performance test and environmental monitoring results? Do the current plans indicate that the design will remain the same and that the facility will be operated under the same conditions? If the only data available are from treatability tests, do the plans indicate that the proposed operating conditions are at least as conservative as, if not more conservative than, the conditions demonstrated in a successful treatability test? Have problems identified during the treatability test been addressed? To ensure effective treatment of the waste, a minimum flue gas exit temperature in the DC or PCC or minimum bottom ash discharge temperature should be specified and be a part of the AWFCO system.
To ensure effective treatment of the flue gas, the state or EPA should establish operating conditions for the APCE and monitoring of the stack gas. The APCE operating conditions should be specified for each air pollution control device (APCD) based on the operating conditions during the successfully completed performance test. See section 6.1.1.4. for recommendations on APCE operating conditions. 6.1.1.2. Fate of Contaminants of Health Concern
ATSDR staff should evaluate the potential for public exposure to process residuals and effluents. Therefore, health assessors need to know the fate of any contaminants of concern that are present in the waste, or created by the treatment process. For example, VOCs in TD stack gas may include vinyl chloride or trichloroethylene depending on temperatures or whether base catalyzed dechlorination is conducted simultaneously in the TD. If metals are present in the wastes, where will they ultimately end up? Tables 5 and 6 show the boiling points of some of the metals found in hazardous wastes and the effect chlorine (if present in the waste streams) may have on the metals. Table 7 shows the contaminant removal efficiency of different air pollution control systems. Using these tables and the proposed operating conditions, health assessors should be able to estimate whether the metals will be left in the treated waste, captured in the air pollution control system effluent(s), or exit through the stack. Mercury is a highly volatile metal that is difficult to capture in APCE, so the amount of mercury in the total waste feed to thermal treatment units should be limited, if it is present in wastes at the site. The design estimate of the fate of the contaminants should be verified by analyzing all residuals during the performance test.
Any halogens present in the wastes may be converted to acid gases (e.g., hydrogen chloride, hydrogen bromide) in incinerators or high temperature desorbers, but may or may not be decomposed in low temperature thermal desorbers (LTTDs). Acid gases can be removed and/or neutralized in the APCE \1-\VS the: null-made iuiulc.html
(sec section 5.1.3). .Acid gases in the concentrations typically found in uncontrolled Hue gases he lore the APC'I- of incinerators burning halogenated compounds can cause :icute respirator} problems and initiate asthma attacks (see sections 8.1.1. and 8.1.2.). A well-designed and operated thermal treatment facility can easily remove acid gases and participates.
Incinerators can destroy or remove 99.99",, to 99.9999% of the e ate o organic cefrxca organic chemicals present in the waste streams. The fate of far incinerators and for desorbers. organic chemicals in desorbers depends on the type of air pollution control equipment. Most desorbers are designed to vapori/c (volatili/.e), but not destroy, the organic chemicals present in the waste(s). Their primary chamber is usually operated at low temperatures (relative to incinerators). Most desorbers use condensers to liquefy the organics volatilized in the primary chamber and remove them from the Hue gas, the flue gas then passes through carbon filters to remove any remaining organics not removed by the condensers/chillers. TD stack emissions should be analyzed to see if decomposition products like vinyl chloride are blowing through (not being adsorbed by) the carbon filter. Depending on the concentration of organic solvents present in the original waste(s), a sufficient quantity of organics may be removed in the condensers, making it possible to recycle the condensed solvent(s).
The operating conditions for the APCE for TDs are extremely important for protecting the public, because the organic contaminants present in the waste or soil are transferred to the flue gases and emitted from the stack if not captured in the air pollution control system. Most TDs have carbon filters as their last APCD to remove any organics in the flue gas after the condenser. To ensure that the organics are removed from the flue gases, ATSDR strongly recommends that all TDs have the stack effluent continuously monitored for HCs, and an interlock system, which shuts off the waste feed to the desorber if the HC reading exceeds 10 ppm (the hazardous waste incinerator and industrial furnace standard [64 Federal Register [FR] 52869-52870]). On a site-specific basis other CEMs may be used to monitor for hydrocarbon break through. Health assessors should carefully evaluate the CEM's ability to detect small changes in hydrocarbon emissions. An increase of HC in the stack gases indicates that either organics are breaking through the desorber's carbon filter and it The toxicological review should be needs to be changed, or poor combustion is occurring in an based on the orgpnics detected in incinerator. The recommended 10 ppm HC limit is based on jitgitives and stack gys samples during what EPA deems to be technically feasible for incinerators to the performance test. meet; it is not a health-based standard per se. According to the FP A preamble to the Final Standards for Hazardous Air Pollutants for Hazardous Waste Combustors (64 FR 52869), "More than 85 percent of test conditions in our data base have hydrocarbon levels below 10 ppmv, and nearly 75 percent have levels below 5 ppmv." Although desorbers are not likely to have been included in the EPA combustors data base, ATSDR recommends that any alternative thermal technology used in lieu of an incinerator be at least as protective of public health as an incinerator would be.
ATSDR's mission is to prevent or minimize public exposure, and therefore the agency endorses EPA's technology-based standard. If an HC limit lower than 10 ppm is deemed necessary based on a site-specific toxicological and modeling review of the contaminants present in the waste and their decomposition products, ATSDR staff should discuss with the facility operators and EPA or the state regulatory agency the feasibility of continuously achieving a lower HC emission rate or of monitoring the stack gas for the specific organic contaminant that needs to be limited. It is anticipated that monitoring the stack for specific organic chemicals will rarely be appropriate, unless an extremely toxic chemical is being treated, such as nerve agents. If a site-specific evaluation determines that the facility needs a higher than 10 ppm HC limit to be able to operate continuously, a toxicological evaluation of the hydrocarbons being emitted during the performance test should be conducted. 6.1.1.3. Engineering Design Considerations Affecting Stack Emissions The only way to prevent the release of stack emissions from any thermal treatment technology at levels that would be a public health hazard is to properly design the unit for the waste to be treated and to have S^-SMM^ hup operating controls. I'hc control conditions should ensure that the lacility is operated the same as. or more conservatively than, it \\as during the performance and or risk hums that were passed (see section 6.1.1.5. for a discussion on performance test burns). Some facility operators may argue that operating controls are not necessary, and that their staff would not operate the facility improperly because they are concerned about their own safety. Some operators argue that if public health officials feel they need assurances, they should rely on the CEMs to ensure that the emissions are not a health ha/ard. because C'EMs measure what is actually being released out of the stack. While ATSDR agrees that CEMs are an important part of monitoring and controlling the system, there are two problems with relying only on stack CEMs:
• CEMs usually only measure indicators of the quality of stack emissions. For example, opacity or PM monitors are indicators of respirable participates and metal emissions; CO monitors are indicators of good combustion in incinerators; HC monitors are indicators of good combustion and low PICs in incinerators and effective operation of the air pollution control or treatment system in desorbers; and oxygen (<>>) and stack gas flow meters are indicators of favorable combustion conditions. However, none of these monitors measure specific chemicals or metals of health concern. A flame ionization detector (FID) HC monitor does not report the full mass of chlorinated compounds (e.g., a FID may report the mass of a highly chlorinated compound as a negative value) and therefore may be a poor indicator of organic emissions at a particular site. Stack gas monitors may be available in the near future to measure specific metals, and some facilities can measure on a fairly frequent, but not continuous, basis a few organic chemicals in stack gases using a gas chromatograph with a mass spectrometer detector (GC/MS). High moisture and/or particulate loadings may make chemical-specific measurements in the stack gases impossible at some facilities.
• Controlling the waste treatment facility using only CEMs is not likely to prevent exposure from occurring. Stack CEMs indicate in general terms what may be released, unless the automatic waste feed shutoff (AWFSO) conditions are tied to CEMs that measure specific chemicals of concern. Traditional CEM levels that trigger AWFSOs (like HC) would have to be set well below levels of public health concern to try to prevent emissions of the chemicals of concern from reaching levels of public health concern.
EPA regulations do not set specific standards for desorbers like they do for incinerators. Instead, EPA relies on the permit writer to set whatever conditions are necessary to protect human health and the environment. Even though EPA guidance recommends that the incinerator standards be considered when permitting a TD, many facility operators argue against having to analyze their stack emissions and having CEMs.
Health assessors do not have the engineering expertise to review design calculations and detailed engineering specifications to ensure that the thermal treatment system is designed properly to meet the projected operating conditions and performance standards. However, health assessors should look for several key design and operational features when reviewing the information available during the pre-operational phase. The following sections discuss the major equipment subsystems and suggest specific items that affect emissions and ultimately the level of public exposure to site contaminants and by-products.
6.1.1.3.1. Waste Feed Handling The more homogeneous the waste feed material is, the easier it is to ensure consistent operation of the treatment j emissions from the waste feed unit as a whole and consistent levels of stack emissions. handling area may be the source of the Therefore, facility operators often have a waste feed highest public exposure to contaminants. preparation area where front-end loaders or other equipment mix contaminated soils or other wastes together to blend wastes with high organic, moisture, or metals content with less contaminated wastes. The wastes may also be crushed or sorted by size, or other debris may have to be removed for further pretreatment or treatment by another technology. The solid waste materials to be thermally treated are then placed on conveyor(s) or in augers or ram feeders X1 Manual lui I'uhlic Health A^C^M>I^ litlp: A >,\ \\ .atMlraL.L;O\ Nh'AS thcrmal-L'uuIc ^u
and fed into the PCC or DC. If the waste material is relatively dry and Nous easily or if some of the contaminants are fairly volatile, fugitive emissions from the waste feed handling area may he the souree of the highest public exposure to contaminants from the site.
Liquid wastes should he stored in tanks with agitators, mixers, or recirculatmg pumps to keep the liquid waste feed homogeneous. Open top tanks should not be used if the wastes contain VOCs. Feed lines should have screens to remove objects that might clog the injection no//le(s). Leaks of ha/ardous wastes from pipes, pumps, and valves can also be sources of fugitive emissions.
If the community is close to the waste handling area, and/or excavation areas at a CER.CLA site, the operator ir may erect a waste feed handling building, tent, or wind hand-held fnomtors to e>ssurs thai screen to control airborne emissions, and install water controls are effec'T\v and to alert staff tr.< runoff control devices such as berms or fabric fencing take corrective action if fugitive evssFioxs and/or hay bales around the excavation area. Waste feed handling enclosures may also be needed in cold or wet exceed a predetermined level. climates to ensure a more consistent waste feed and economical operation. Feed conveyors should be enclosed in a building or by shrouds or other enclosures to minimize worker and community exposure to fugitive emissions. During site visits, health assessors should evaluate whether fugitive emissions from the waste excavation, handling, and storage areas are being controlled.
6.1.1.3.2. Combustion/Desorber Chambers
Numerous designs of thermal treatment chambers (e.g., rotary kilns, fixed or moving hearths, hollow augers, conveyor belts, cylinders) exist. Incinerators normally have two combustion chambers, referred to as primary and secondary combustion chambers (PCC and SCC), while desorbers usually have only one chamber (DC). The function of the PCC and the DC is essentially to volatilize the contaminants that are in the waste. In an incinerator the combustion or decomposition of the organic chemicals present in the waste also begins in the PCC. The amount of time a waste needs to remain in the DC/PCC depends on the size of waste particles, the volatility and concentration of the contaminants, the operating temperature, and the effectiveness of heat transfer. Typically, solid wastes spend between 15 and 45 minutes in this chamber. The treatment time and minimum bottom ash temperature actually needed to ensure that the waste consistently meets the site-specific treatment standards are determined during the system testing phase (see discussion in sections 6.1.1.1. and 6.2.). Desorbers—The externally heated carrier gas, air or an inert gas such as nitrogen, flows through the desorption system to convey the contaminants removed from the waste through the post-desorption treatment system. The volume of carrier gas used in a desorption system is generally much less than the volume used in an incinerator. To prevent an explosion from occurring if air is the carrier gas in a desorber, the operator must make sure sufficient dilution air is present to ensure that 25 % of the lower explosion limit (LEL) is not exceeded. The American Academy of Environmental Engineers also warns that, "In gas post treatment, a potential fire hazard exists in the baghouse if hydrocarbons or other combustible materials are allowed to collect on the filters. This presents a potential problem especially in the countercurrent rotary desorber configuration when used to treat material contaminated with heavier organics" (AAEE 1993). The carrier gas flow can be co-current (flow in the same direction as the waste), or counter-current (flow in the opposite direction). The carrier gas is also called the flue gas. Incinerators—An incinerator uses air as the carrier gas in order to supply oxygen foi the flame in the burners and to support combustion of the VOCs. Some incinerators also add oxygen gas through the burner block to improve the oxidation of the volatilized organics while maintaining a lower air flow through the system. In most thermal treatment systems the carrier gas is drawn through the entire system by an induced draft fan after the air pollution control system. The flow should be sufficient to create a negative pressure at the "face" of the PCC/DC where the waste is fed into the system, or the system should be sealed to prevent the escape of the contaminants being volatilized in the chamber and to carry them through the air LTIIUI-L:UK;C -.mute
pollution control equipment.
6.1.1.3.3. 'Created Waste Handling The treated waste (bottom ash or decontaminated soil) exiting the PCC DC is hot (typically 400F-1000F) and usually dusty because all the moisture and organic chemicals have been volatili/ed from the waste. The bottom ash can be cooled by (1) dropping into a water chamber from which it is usually removed via an ash drag type conveyor or (2) being sprayed with water through no//les in the shroud conveyor cover as it is being conveyed to the treated waste storage area. Some facilities recycle water by using the water from their wet scrubber to cool the bottom ash. If VOCs have condensed in the wet scrubber they can be re-volatili/ed when the scrubber water is sprayed on the hot treated waste. Because the conveyor shrouds/covers are not typically sealed, the VOCs can be emitted as fugitive emissions through cracks and openings in the conveyor system; for example, at one desorber facility this practice caused acute health problems for people off site (ATSDR 1997a). An explosion can also occur if the LEL is reached in the conveyor equipment. This is only a problem with desorbers, not incinerators, since the VOCs are destroyed in the incinerator combustion chambers.
If the waste is not treated sufficiently, i.e., if it does not get hot enough in the PCC/DC to volatilize all the organic chemicals, the steam generated by the hot ash falling into the water chamber or by spraying water on the conveyor may strip additional organic chemicals out of the waste. Those organics will then be emitted with the steam and could pose a hazard to workers or nearby residents. Because this can be a problem with both incinerators and desorbers, a minimum bottom ash exit temperature should be specified to ensure that the waste is properly decontaminated on the first pass through the treatment system, unless there is a system problem.
6.1.1.3.4. Flue Gas Treatment/Air Pollution Control System
Different types of equipment exist for treating the flue gases that exit the PCC/DC. Incinerators almost always have a SCC, also called a thermal oxidizer, where additional burners complete the combustion of the organic chemicals volatilized from the waste. The flue gases from the SCC and the DC contain entrained particulate matter and volatilized metals (if metals are present in the waste).
If halogens are in the waste, desorber flue gases may, but not necessarily, contain acid gases. Incinerator A major difference bet\veen desorbers and flue gases contain acid gases if halogens are present in incinerators is that desorbers 'flue gas contain the waste, except when a fluidized-bed incinerator is ^11 the organic chemicals volatilized from the used. If halogens are present in the waste, caustic waste. material is often used in the bed material to neutralize the acid as soon as it is generated.
The flue gas treatment system is called the air pollution control system. It should contain a series of APCE that will remove the contaminants to below levels of health concern before the gas is vented through the stack. Health assessors should review site documents and the information in Tables 5-7 to determine if the facility has sufficient APCE to treat the flue gases. See also sections 5.1.3. and 6.1.1.4. 6.1.1.3.5. Process Monitoring Equipment EPA or state regulatory staff should conduct an in-depth review of the monitoring equipment specifications to Process monitoring equipment examples: ensure that the equipment is appropriate for the thermocouples, manometers, pressure drop operating conditions it will be monitoring. The facility's indicators, jlow rate meters, pH meters, inspection schedule should include calibration of the continuous emission monitors [CEMsj. various monitors with National Institute of Standards and Technology (NIST) traceable gases on an appropriate schedule. Facility operators also often install duplicate monitors on some of the key operating conditions (e.g. thermocouples). Manual tor t'uolic Heal M-AVS
Health assessors mav not have the expertise to do an in-depth review: however, if they do and they are ••>;onif,ofi.ng equipment connected io a data involved during the design phase, they should review loT?er Lkaf cc'nte.nttouslv lo?s 'hose operating the equipment descriptions for the items helow. If health assessors become involved after the monitors are already installed, they should only rarely recommend replacing the monitors. Assessors should look for the following items:
• Is the operating condition to be monitored in the middle of the monitor's operating range'.' The monitor's range should not be too large or it will not be very accurate in the range the facility will be operating.
• When calculating "rolling averages," what number does the equipment use in the calculation when the monitor is "pegged out" at the bottom or top of the range'.' Typically, the monitor uses the value where the unit is "pegged-out" (the maximum or minimum reading available). If the monitor has a narrow operating range, it will not register the true high or low value that the facility reached, causing the rolling average to "recover" or come back into range more quickly.
• Does the equipment have a dual operating range that automatically expands if the readings exceed the normal operating range? A narrow range should only be used if the monitor has a dual operating range that automatically expands when the narrow range is exceeded. This is particularly important on CO monitors since CO concentrations are typically less then 10 ppm, but spikes go into the thousands (2,000-5,000 ppm).
During the operating phase health assessors should review the following items:
• Monitoring equipment should be calibrated in accordance with manufacturer's instructions and a written calibration protocol. Calibration should occur at a minimum of 2 points that bracket the normal facility operating range; however, 3-point calibrations are preferred (top, middle, and bottom of monitor's range).
• CEMs should be calibrated daily with NIST traceable gases. Thermocouples, flowrate meters, pressure drop indicators, and other monitoring equipment that are sealed or cannot readily be calibrated may be calibrated monthly, quarterly, or annually. During the operational phase, health assessors should verify that the equipment is installed, inspected, and calibrated on schedule. • If a CEM that is tied to an AWFCO cannot be nroperly calibrated within 15-20 minutes, the waste feed should be shut off until the CEM calibration is completed. 6.1.1.3.6. Stack Height
Proper stack height lowers the potential for public exposure to The taller the stack, the better contaminants at levels of health concern. The stack should be taller than the plume dispersion. any nearby buildings, so the plume won't directly impact the building's windows or air intakes. Some facility operators want to have a short stack so their facility will not be noticed, but this potentially increases the exposure of on-site workers and nearby residents or businesses. The EPA Air Program requires that stacks meet GEP standards, which ensure good plume dispersion and help prevent plume downwash or fumigation of nearby buildings and personnel. See section 5.1.3. for further discussion of GEP. The EPA CERCLA program commented that it does not consider GEP an ARAR. If the stack height is below GEP or site documents do not address this issue, health assessors should pay particular attention to the stack height and the distance from and height of nearby buildings to evaluate the potential for downwash or fumigation of nearby buildings and personnel. 6.1.1.3.7. Handling of Process Residuals ce Manual tor Public Health A^essms hup: \\\\u .aistlr.cdc.iiov NT\VS tlK'imai-auhie Luudc.html
Health assessors should observe the handling of process residuals (fly ash. comlensate, scrubber water, spent carbon, spent filters, etc.) during site visits to determine if fugitive emissions from these areas could impact the public. They should also investigate whether the ultimate disposal of the residuals and any off-site transportation of process residuals could cause additional public exposure. If the facility operator has to reprocess a sub..'.antial portion of the batches, health assessors should note the potential exposure routes that will be impacted. See sections 5.1.4., 5.2.2.. and 6.1.1.1. for further discussion.
6.1.1.4. Operation and Maintenance Plan (O&M Plan)
The O&M plan, or permit application, should specify the operating conditions for each piece of equipment at the facility. It should also state that the operating conditions will be modified after the performance test, based on the operating conditions actually demonstrated during the fully successful test(s). Key conditions to be continuously monitored should be interlocked with the AWFCO system. Waste feed should automatically be cut off when the starred (*) conditions below are exceeded. The O&M plan should specify the following conditions to ensure effective treatment of the waste:
• Minimum PCC flue gas exit temperature for incinerators, and minimum bottom ash temperature for desorbers and incinerators treating contaminated soil*
• Minimum SCC flue gas exit temperature for incinerators* • Solids residence time in the PCC or DC
• Maximum size of solid materials to be fed to the unit (usually 2 inches or less)
• Maximum waste feed rate for each waste type to each chamber* • Maximum viscosity of pumpable wastes • Maximum burner turndown
• Minimum atomization fluid pressure
• Maximum size and frequency of addition of batches or containerized waste
The plan should specify the following conditions for APCE, as applicable to the facility, to ensure the effective flue gas treatment: • Maximum inlet temperature to APCE
• Minimum pressure differential across a venturi scrubber* • Minimum/maximum nozzle pressure to scrubber • Minimum pressure differential across a baghouse* • Minimum liquid-to-gas ratio and pH to a wet scrubber* • Minimum caustic feed to dry scrubber* • Minimum kilovolt-amperes (kVA) settings for electrostatic precipitators (wet/dry)* • Minimum kilovolt (kV) and minimum liquid flowrate to ionized wet scrubber (IWS)* • Minimum exit temperature from condensers* The plan should specify the following operating conditions to ensure that stack and fugitive emissions 1-jmt.laiicc Manual l'<>i Public Health \^sc^^^ll•^ hup. w\v\\ .al^lr.ulc.uov \1-.\VS thcmial-^uulc iunde.html
are maintained hclovx levels of health concern:
. Maximum total halides and ash feed rate to the system.
• Maximum CO emissions or maximum total hydrocarbon emissions measured at the stack or other appropriate location*
• Maximum Hue gas flow rate or velocity measured at the stack or appropriate location*
. Maximum pressure in the DC or PCC* • Maximum metals feed rate of each metal of concern
• Maximum of 25% of LEL in desorber gases using a combustible gas monitor in the stack or PCE (if air is the carrier gas)* • Maximum gas exit temperature of PCC and DC* • Maximum air monitoring values allowable at facility fence line. There should be more than one number, i.e., one set of numbers for particulate matter and contaminants of concern (or VOCs) that triggers on-site measures to control emissions, and a higher number for each to trigger shut down of excavation and/or facility operations. 6.1.1.5. Performance Test Plans Performance tests are called trial burns for RCRA incinerators, but may be called proof of process or performance tests at CERCLA incinerator or desorber facilities. In this document the term performance test means any of these tests. The operating conditions during the performance test are used to set the facility operating conditions. If a risk assessment is conducted, the thermal treatment facility may also do a separate risk burn. The risk burn measures the stack emissions during normal operation of the facility as contrasted with the performance test emissions which should be the worst stack emissions that should occur during routine fluctuations in operating conditions of the thermal treatment system. Some facility operators combine the risk bum with the performance test rather than doing two separate tests. To give the facility maximum operating flexibility, the Performance tests should be conducted at performance tests for thermal treatment facilities are worst-case operating conditions, i.e., at the usually conducted at worst-case operating conditions. minimum temperatures in the PCC/DC and However, at some sites the operator's contract may SCO for organic chemicals, but at the require the performance test to be run at the facility's proposed operating conditions (normal conditions rather maximum temperatures during normal than worst-case). Because the operating conditions are operations for metals. set from the performance test, the performance test is the de facto worst case operating condition. The stack emissions during normal operation should not be worse than those measured during the test since the AWFCOs are set at the operating conditions used during the performance test. Worst-case operating conditions for organic chemical emissions include maximum feed and flue gas flow rate; minimum temperature in DC or PCC and SCC; maximum halides, metals, ash, and water feed rates; and the minimum or maximum (as appropriate) operating conditions for all the starred operating conditions in the previous section. Unless the operator is willing to accept a narrow range of operating temperatures, it is impossible to do worst-case operating conditions for organic chemicals and for metals at the same time. Therefore, two performance tests are usually conducted if metals are a health concern at that site. Worst-case operating conditions for metals emissions include maximum feed rate, maximum halides and metals feed rates, maximum PCC or DC exit gas temperatures, but the same minimum or maximum APCE operating conditions. RCRA stack sampling requirements differ for incinerators and for TDs. EPA does not have specific (itiuhince Manual I'ur Public Health Assessors hup: u\v\v.Litsdr.c\ic.^o\. \1-V\S ihcii'.ial-uuulc '_Hiule.html
remilations for TDs. lioue\cr RX'RA permit writers usually use the incinerator regulations as guidelines for TDs. 1 he TD performance test plan should include stack emissions sampling and analysis (S&A) for destruction and removal efficiency (ORE), PICs, TICs. and metals (if they are a health concern at the site). Some TD operators may object to the DRE and PiC requirements, arguing that the standards are not applicable because they are not combusting or destroying the waste. However, at the temperatures used in TDs some decomposition of organics will occur and/or the condensers and carbon units may not capture all the organics in the Hue gas, so the identity and concentration of the organics in the stack emissions must be evaluated. The DRE test primarily measures the removal efficiency of the desorption facility, and can thus be called the "removal efficiency" (RE) test. To provide maximum protection of the public, the REs for RCRA TDs should be numerically the same as incinerator DREs. i.e., 99.99",, for the POHCs in the waste and 99.9999% for dioxins, furans. and PCBs (if over 50 ppm PCBs) in the waste. At CERCLA sites, site-specific concentrations are set for stack emissions and site clean-up concentrations based on ARARs or a risk assessment (see section 3.2 or Appendix E for additional discussion of ARARs). If the stack emissions and clean-up criteria are protective of public health, health assessors do not need to consider REs for CERCLA incinerators or TDs, how ever the stack emissions do need to be characterized during the performance test. To ensure normal-to-vvorst case emissions during testing of TDs, the performance tests should be conducted during the middle-to-end of the carbon adsorption units change-out cycle rather than immediately after changing the carbon. Condensers should operate at the maximum temperature allowed during normal operations. At CERCLA sites, EPA often requires the performance test to be conducted as soon as possible. If the unit has few operating problems during shakedown, the performance test should not be delayed for long just to accommodate this recommendation. To show compliance with RCRA incinerator emissions regulations under their preferred operating conditions, operators often spike the waste feed with organic and/or metal compounds. The organic spikes are selected from lists of difficult to destroy compounds and are called POHCs, or target compounds. If POHCs or metals are spiked into the waste feed to demonstrate worst-case feed rates and compliance with the performance standards, the spiked waste feed should be fed to the thermal treatment unit before stack sampling begins. The minimum amount of time in advance of stack sampling that the spiked waste feed should be fed equals the solids retention time, so the thermal treatment unit is operating at steady operating conditions when sampling begins.
Each performance test should consist of three runs under the same operating conditions. Some facilities do an additional run so they have backup data in case some of the samples are lost or broken. Performance test plans should cover the following topics: • Operating conditions for each piece of equipment . Waste feed S&A • Stack emissions S&A - POHCs/target compounds, PICs, products of contaminant degradation or reformation (i.e., organics not removed in the APCE), TICs, and metals, . CEMs • Residuals (including treated waste) S&A - to identify and quantify fate of contaminants • Treated waste S&A at CERCLA sites - to verify decontamination • Quality assurance and quality control (QA/QC) - chain of custody for samples, field and method blanks, and laboratory spikes If EPA approved stack sampling, analytical, and QA/QC procedures are followed, the data should be adequate for making public health determinations. EPA approved methods are in the EPA Publication ' Manual tor Public llcallh Asse.-»nr-> hup: \\w\v.utMlr.ale.iio\ \1 'AS thermal-'j.UKic uukle.html
SW-S46. '/'CM Methods for l-'valiuitin^ Solid Wastes. Physical.-'!, 'lie/nit ul Mcilioils and the HPA Air Program regulations in 40 CFR Part 60 (see www.epa.gov). There may he other state approved sampling and analytical methods or modifications of the EPA QA QC procedures that may provide data of adequate quality tor making health determinations, but they will be evaluated on a case-by-case basis.
6.1.2. Additional Considerations Important to Public Health
ATSDR staff should also consider the items addressed below.
6.1.2.1. Ambient Air Sampling and Monitoring Plan
Health assessors should recommend that all thermal treatment facilities whose stack data or risk assessment indicates the potential to have air releases of contaminants at concentrations which may cause adverse health effects have an ambient air sampling and monitoring plan. In addition if the public is concerned, health assessors should consider recommending that the facility or EPA conduct ambient air monitoring and sampling to provide data that will document the level of public exposure, even though in theory the contaminants are not likely to be at concentrations expected to cause adverse health effects. Health assessors should know that, under RCRA, ambient air sampling can only be required on a site-specific basis through the omnibus provision, so it must be deemed necessary to ensure protection of human health or the environment.
Ambient air monitors are direct reading instruments that continuously, or frequently (<15-minutes turnaround Ambient air monitors continuously sample time), sample the ambient air and provide real-time data the ambient air and provide real-time data. on levels of airborne contaminants (specific compounds or Ambient air samples are time-integrated groups of compounds). Monitors should be located at the samples that are analyzed in a laboratory at fence line of the facility, and where air dispersion modeling indicates that people may be exposed to fugitive the end of the sampling period. or stack emissions from the thermal treatment facility at levels that would be of health concern. Examples of air monitors include: photo ionization detectors (PIDs), flame ionization detectors (FIDs), oxygen meters, combustible gas monitors, colorimetric tubes, and remote optical sensors (ATSDR/EPA 1997) and gas chromatographs. If the site is large, such as a military base, the monitors should be at the borders or fence line of the thermal treatment site, not the fence line of the base. Modeling should be done to determine other locations where ambient air monitors or sampling may be needed such as on-site housing, schools, oay-care centers, and Hospitals, as well as off-site locations where susceptible populations and the maximum exposed receptor are located. For worker protection, on-site monitoring should also be conducted in the excavation and waste handling areas. One to four chemicals should be chosen as indicators of exposure to site contaminants. Following are criteria for the selection of such compounds: • Easily and quickly quantified, preferably on a continuous basis, or at least a frequent basis (not greater than 15 minutes between sampling and report of results), • Present in sufficient concentration on site to be detectable if migrating off site as a fugitive or stack emission, • Present in the highest concentrations on site, • Representative of the various classes of chemicals present, and/or • Present on site in concentrations that could cause acute or chronic health effects.
The contingency or site-safety plan(s) should specify "on-site action levels" and/or "fence-line action levels," as Action levels should be specified that will appropriate, depending on the toxicity of the contaminants trigger specific actions to reduce emissions. and the distance to the nearest off-site population. Action levels are the concentration of the chemicals being monitored that will trigger specific actions by facility staff to reduce emissions. Usually several action levels will be set. For example, when the lowest on-site :e Manual lor Public 1 Icaltli Assessors hup v-. \\ \\ .atsilr.cilc.L'o^ NI'AVS
threshold is exceeded in the work or excavation area, hand-held monitors should be used to try to identify the source of the release. Actions can then be initiated to reduce emissions and or to signal an increased level of protective equipment being worn by on-site personnel. If concentrations continue to increase and exceed the second on-site action level or exceed a fence-line action level, work may be stopped, and waste materials covered or wetted down, or other appropriate actions may he initiated depending on the source of the release. If the fence-line monitors then exceed a third specified concentration (the second fence-line action level), the thermal treatment unit may be shut down and monitoring and sampling in the community may be initiated. If contaminants are present on site that could foreseeably cause acute health effects off site, the community first-responders should be notified to stand by in case the evacuation or "shelter-in-place" action level is reached. Some sites have fewer action levels; they may choose to directly shut down the facility, determine the source of the release) s). and fix the problem. If there are multiple contractors working on the site, health assessors should make sure everyone is using the site's action levels, not different contractors using different numbers and signals.
In addition to ambient air monitoring, time-weighted Action levels should be set, based on air ambient air samples (8-hour, 24-hour, etc.) should be monitoring data rather than air sampling data. taken. Air sampling consists of analytical techniques that require either on- or off-site laboratory analysis. Components commonly used in sampling and analysis include filters, tubes, cartridges, impingers, bubblers, badges, bags, and canisters (ATSDR/EPA 1997). In addition to fence-line ambient air monitoring, ambient air samples should be taken in the community at locations likely to be impacted by fugitive or stack emissions as shown by air dispersion modeling. Air sampling and air monitoring are often used interchangeably, but they are not the same. Air monitors are direct reading instruments that provide analytical data within seconds or minutes. Perimeter or fence-line sampling is conducted to verify the monitoring results. Air samples must be analyzed in a laboratory. If the samples are not fed directly into an on-site gas chromatograph (GC), it may take several days or weeks to get the analytical data back. Therefore, action levels should be set based on air monitoring data rather than air sampling data. Ambient air samplers take samples periodically. The samples may or may not be composited over several days or weeks, depending on the toxicity and reactivity of the chemical, the quantity of sample necessary to achieve a detection limit at or below the level of health concern, and other factors. For example, a sample may be collected and composited every 15 minutes for 24 hours and sampling may be repeated every 5th day, or a sample may be collected every half-hour for 3 days. Local meteorologic conditions should be recorded during each sampling period. Air monitoring and air sampling programs should begin before Continuous air monitoring should site operations begin to establish baseline chemical le\""10 'n the occur -whenever there is activity on community. These samples can be used to look at the site (excavation or facility operation). background exposure of the community and to evaluate the ______impact of the facility on the overall contaminant level in the air and the community's exposure. Air monitoring and air sampling should occur when the facility is operating to the maximum extent possible. If excavation or treatment unit operations occur only from 7 am to 5 pm, doing a 24-hour composite sample will bias the sample low because the samples of presumably clean air taken between 5 pm and 7 am will dilute the contaminated samples taken during operating hours. ATSDR recommends that perimeter and community air sampling occur daily during shakedown, the performance test, and the first weeks of full operation, i.e., any time the thermal treatment facility is operating ou hazardous wastes from start-up until the data is reviewed by EPA and ATSDR staff. When the contaminant air concentrations are consistently well below levels of health concern, sampling frequency may be reduced to once every 3 to 6 days or be collected for a 3-7 day period.
In summary, the ambient air sampling and monitoring plan should provide: Data necessary to access episodic and chronic exposures, Assurance of worker protection, On-site action levels and response actions,
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6.1.2.2. Contingency and Site Safety Plans
ERA requires every RCRA and CERCLA site have a site safety plan that contains an on- and off-site contingency plan, which should be a part of the health and safety plan (H&S plan). In addition to the action levels and on- and off-site responses discussed in section 6.1.2.1., RCRA requires the contingency plan to describe the safety equipment and it's location. It should describe emergency situations such as chemical spill, fire, explosion, and flooding (if in flood zone), and emergency procedures that the facility staff will carry out to prevent or minimize exposure or danger to the community and on-site workers. The plan(s) should specify who will respond and list the names and phone numbers of the site safety officer(s), hospital(s), and emergency personnel who have agreed to provide additional services, such as the fire department, Chemtrec, or Poison Control Center. The plan should contain Material Safety Data Sheets (MSDSs) for all the hazardous chemicals present on site. If several contractors are working on site, they may have their own site safety plan. All site safety and There should be one overall health and safety contingency plans should be reviewed to ensure that plan, even at sites with multiple contractors. they are in agreement on action levels and response actions and that all important items are included. Sites with multiple contractors should have one overall H&S plan that includes all contractor specific duties, safety items, and monitoring requirements. The contingency plan often addresses only on-site activities. The H&S plan should also address off-site action levels and activities, and it should integrate with the local emergency response plan.
The ambient air monitoring and sampling plan should be a part of the H&S plan. If not, health assessors should make sure that action levels and response actions specified in each plan are consistent with each other and are logical. 6.1.2.3. Maintaining Good Performance
The key to maintaining good performance is having well trained, experienced, skilled, dedicated, and conscientious employees. Routine operator and facility staff training is mandatory at RCRA and CERCLA facilities. Because thermal treatment units are only temporarily at CERCLA sites, the contractor typically brings only a few key personnel to the site and hires temporary workers locally. While these temporary employees can be trained on safety and OSHA requirements and leam to do their specific jobs, they will lack experience and will need close supervision by technical staff who possess the appropriate educational background, experience, and training. l] Operators should understand the principles of good Even with all the proper design combustion and/or desorption and be thoroughly familiar with features, skilled operators are essential all major and support systems at their plants. Careful attention for a safe, effective treatment program. to proper waste treatment rates and waste blending, as needed, helps to ensure that the systems are not overloaded and that the AWFCOs are not activated excessively. Routine maintenance, inspection, and instrument calibrations should be conducted and recorded. Safety and emergency response plans that thoroughly address likely failure scenarios (including loss of power and operational failures) should be in place, documented, and shared with local officials. Emergency "release" drills should be conducted periodically with the knowledge and involvement of local emergency response personnel. Additionally, all employees should be adequately trained in appropriate health and safety procedures for the safe day-to-day operation of the facility. While ATSDR recognizes that having well trained staff who are vigilant in their inspection and maintenance of the plant are critical for the good performance of thermal treatment facilities and the ct- Manual t<>r Public Health AV^C-MMN hup: \\ \v \v .at-ilr.alc.um \1 'vVS thi'rmal-iuiklc Ljiinle.html
protection of the public, most health assessors are not trained to critically review the adequacy o! traimnu plans and inspection schedules. Health assessors should at least ensure that these program areas are addressed by the site and that knowledgeable EPA staff ha\e reviewed and approved the plans.
Thermal treatment facilities are complex industrial plants uld ha\v datails which need constant inspection, maintenance, and thai jacihiy s'qff are properly adjustment. To ensure that employees check all the rssr^i.w.g and waimaiKixg iksjaeihiy. necessary monitors, gauges, valves, or equipment, RCRA requires that inspection schedules be approved and detailed checklists be prepared. Documentation of inspections, including problems found and repaired, must be kept at the facility. CERCLA facilities should also have detailed checklists to ensure that facility- staff are properly inspecting and maintaining the facility.
To ensure that the system operates in a manner consistent with the operating conditions specified in the RCRA permit or CERCLA documents, ATSDR recommends that EPA or state environmental staff conduct frequent, random, unannounced inspections and make the results available to the public. Under some circumstances, a few state environmental programs have assigned permanent on-site inspectors at thermal treatment facilities.
Another way to ensure continued satisfactory operation is to retest the thermal treatment system periodically. This would Each tme a CERCLA thermal treatment be appropriate for all RCRA and CERCLA facilities if they system is relocated, it should be retested. operate at the site for an extended period of time, if there are other indications that it may not be operating properly, or if the waste feed changes. RCRA regulations allow for a less rigorous performance test if the unit or a similarly designed incinerator successfully passed a performance test on similar wastes at another site. 6.1.2.4. Transportation of Wastes
If the facility treats wastes transported from other sites, the transportation aspects should be carefully considered. Routes of access should be selected to minimize accident (release) potential, narrow or winding roads and residential, school, and play areas should be avoided if possible. For remediation of Superfund sites, for which no over-the-road hauling is required, care is still needed to avoid spills, blowing soil, or other types of releases when transporting the wastes on site.
When waste is hauled off site, trucks should be decontaminated before leaving the hazardous waste site. The Department of Transportation regulations require hazardous wastes to be hauled in containers or tightly covered and properly placarded trucks to prevent blowing of the wastes during transit. Residuals or treated soils being transported off site should also be transported in a way to minimize fugitive emissions during transit. Even though the residuals should not contain contaminants at levels of health concern, excessive fugitive particulate could cause respiratory problems for those living along the transportation routes.
6.1.2.5. Location of the Unit Another consideration relevant to public health is the location of the thermal treatment facility with respect to the community. Community members want to know the possible health impacts associated with living or working in the path of stack or fugitive emissions fallout. To address those concerns, when reviewing the location of a treatment facility with stack and potential fugitive emissions, regulatory agencies combine air dispersion models and local meteorologic data to determine the conditions necessary to protect human health and the environment. Such modeling results are helpful in identifying prevailing wind transport patterns and their effect on downwind pollutant concentrations.
Ideally, the site should not be where modeled high ground-level concentrations of stack or fugitive emissions coincide with population centers. Dispersion models can also help evaluate the need for, and the location of, off-site air monitors used to detect fugitive emissions associated with excavation, waste handling and storage facilities, process equipment, and residuals management areas. If there is concern Manual tor Public Health ahoul the impact of the facility on a specific food source, such as a fish hatcherx, and ATSDR has data regarding the uptake of the contaminants of concern by the particular food chain species, dispersion modeling can he used to estimate the deposition of contaminants that would he available for food chain uptake.
Little flexibility exists in selecting a site for a Superfund treatment facility, except with regard to where it is placed within the boundaries of the actual site. When EPA is conducting the feasibility study, if the site is surrounded by residential areas, modeling should be used to determine whether thermal treatment is a feasible technology for cleanup of that particular site. Health assessors should tour the area to determine the land use and get an idea of the demographic structure of any nearby residential areas and areas that modeling has indicated are likely to be impacted by the facility. A detailed demographic analysis can he obtained from the ATSDR GIS Activity Group in the Program Evaluation. Records, and Information Services Branch.
6.1.2.6. Community Involvement ATSDR strongly recommends that information and data The better ike public understands the concerning a thermal treatment facility's design, testing, facility's design and safety features, the operation, and monitoring be made public. Technical staff roles of different equipment in assuring from the regulatory agencies, the facility, and/or the public emissions will be controlled, and hew the health agencies involved should make a special effort to explain the information in plain language that a lay person facility \vill operate, be tested, etc., the can understand and relate to. After the facility is built, but less fear they will have of the facility. before any waste is fed to it (to avoid the risk of public exposure), local officials and the public should be allowed to tour the facility's equipment and control room, and be provided an explanation of the design and operation of the facility. Afterwards, the facility operator may want to have open houses periodically.
The more open discussions the public can have in small groups, or one-on-one in public availability type meetings with site personnel and agency staff, the more confidence and trust the public will have in the staff and the safety of the facility. If all the data that goes into the air modeling, such as 5 years of meteorological data, topography, and land use are explained to the public, they will feel more comfortable with modeling being used to project potential public exposure.
Several sites have set up advisory committees comprised of representatives from a number of local organizations as another way to disseminate information to the community and to allow the community to bring its concerns to the facility staff and regulators. 6.2. Testing Phase - Operating Conditions to Protect Public Health The testing phase covers, (1) "shaking down" or testing the The testing phase starts at the completion equipment to make sure everything is working properly, (2) of construction and continues until the unit the performance test, and, (3) the posttest, pre-operational is approved to begin full operation. period when the data is being reviewed, and the final operating conditions are being set.
6.2.1. Pre-Performance Test Period - Equipment Shakedown Phase
Initially, the treatment system will be heated to ensure that all the mechanical systems, monitoring and control equipment, and automatic waste feed shutoff systems are functioning properly. After the entire thermal treatment system has been checked and determined to be operating properly, the facility operator will then process clean materials or soils to further test all the systems. After clean materials have been successfully processed, EPA or the state will allow contaminated waste to be processed at reduced feed rates and conservative operating conditions to further test the system to ensure everything is working properly and to prepare for the trial burn. For incinerators, the pre-performance test burn operating period is usually limited to a maximum of 720 hours of operating time actually treating contaminated materials. During the pretest period the operator should be allowed a limited number of hours (perhaps (iuidance Manual for Public Health .VMJSMH^ http:'''w\v\\ .atM.tr.ale.uov \T\VS thermal-guide LHi
40 hours) to operate at the maximum feed rate and worst-case operating conditions to ensure that all systems will function properly during the performance test. Otherwise, conservative operating conditions should he set for all operating periods prior to the review of the performance test data and setting of the full operating conditions based on that data. The HPA requirements for desorbers are not as extensive as for incinerators, b.u EPA usually applies the same standards to both types of facilities.
6.2.1.1. Conservative Operating Conditions
During the pretest period, when equipment malfunctions are more likely to occur, the waste feed rates and the The waste feed rates and the operating operating temperatures should be set conservatively to tefnperatures should bs set conservatively. minimize the potential for public exposure. As operating experience is gained and the unit is fully tested, waste feed rates should be gradually increased until feed rates are around 75%-80% of maximum to be demonstrated during the performance test. These rates should be exceeded only for the limited time period when the facility is allowed to operate at maximum test conditions. However, at no time should the facility be allowed to exceed the manufacturer's specifications. The temperatures in the PCC, SCC, and DC should be maintained 10%-20% higher than proposed for normal operating conditions. Condenser and chiller temperatures on desorbers should be maintained at lower temperatures then proposed full operation temperatures to help ensure that any extra loading of organics which may occur due to process upsets during start-up are condensed. 6.2.1.2. Site-specific Needs Considerations
Health assessors should evaluate the site-specific need for increased stack monitoring during the pre-performance test period. If the thermal treatment unit was approved to have neither CO nor HC CEMs during full operation, ATSDR strongly recommends that all units have one or both CEMs monitoring the stack emissions during the testing phase. The CO and/or HC monitors will help ensure that good combustion and/or adsorption of desorbed organics occurs. Depending on the type of desorber unit, a CO monitor may not be appropriate. CO monitors are almost always required by EPA on incinerators. An HC monitor or some other CEM should monitor the TD stack emissions to assure that the volatilized organics are adsorbed.
If EPA does not require the unit to have a sulfur dioxide (SO2) monitor, but the wastes contain sulfur in sufficient concentrations to theoretically generate SO2 at levels of health concern if APCE malfunctioned, then health assessors should consider recommending an SO2 monitor, at least during the testing phase. Factors to be considered when evaluating the need for increased stack monitoring during this period include: • Proximity of the community to the unit • Past performance and operating experience of the thermal treatment unit company • Level of protective equipment routinely worn by on-site personnel • Presence of and type of ambient air monitors in continuous operation on site 6.2.1.3. On-site and Community Ambient Air Monitoring and Sampling If the facility has an ambient air monitoring program, health Consider the need to sample for assessors should determine if the frequency should be additional or different contaminants increased during operational changes such as when starting-up, when different wastes are processed. increasing the feed rate, processing different wastes, or during the performance test, to determine if worker and/or community exposure rates are affected by the process change. More frequent monitoring should continue until the analytical sampling data indicates that levels are below health concern. Health assessors should also consider the need to sample for additional or different contaminants during start-up and when different wastes are processed. The evaluation should include compounds that may be formed during the treatment process. See Section 6.1.2.1. for a more extensive discussion of ambient air sampling and monitoring. 1 Manual tor Public Health \l V\'S jhcinial-miklc iuiklc.html
6.2.2. Performance Test Period
While the facility staff should have some operating time to As soon as tJie thermal freat.me>-;.t system gain experience on how to operate the equipment in the can operate at a steady state, the most efficient and protective manner, stack emission data performance, test should b? conducted. should also be obtained as quickly as possible to determine what the potential public health impact is from a new facility. This is particularly important at Superfund sites. Some CERCLA facility operators have proposed testing phase feed rates and time periods used at RCRA type sites, which would allow the operators to process more than half the contaminated soils and wastes on site before the performance test is even conducted, the test report and environmental data reviewed, and before the agency could determine if the unit performs in a manner that is protective of public health.
6.2.2.1. Worst-case Operating Conditions
ATSDR recommends that performance tests for thermal treatment facilities be conducted at worst-case operating conditions, so the stack emissions will be the worst that are likely to occur during normal operation. However, at facilities where only one waste stream will be burned, such as CERCLA sites, the performance test may be conducted at their proposed operating conditions. This should be a site-specific determination. Worst-case operating conditions include:
• Maximum feed rate • Maximum concentration of minimum Btu wastes • Maximum flue gas flow rate • Minimum temperature in DC or PCC and SCC • Maximum halides, metals, ash, and water feed rates • Minimum or maximum (as appropriate) operating conditions for all the starred operating conditions in section 6.1.1.4
If metals are a health concern at the site, it is difficult to do worst-case operating conditions for organic chemicals and worst-case operating conditions for metals at the same time; two performance tests are usually needed. The primary difference is that, to be worst-case for organic chemicals, performance tests should be done at the minimum temperatures in the PCC/DC and SCC, but should be the maximum temperatures allowed during normal operations for metals. See sections 6.1.1.4. and 6.1.1.5. for additional discussion. 6.2.2.2. Stack Testing Thermal treatment stack sampling should be conducted, at a minimum, for POHCs, PICs, VOCs, SVOCs, metals, acid gases, particulate, HC, C>2, dioxins, and furans. If contaminants containing sulphur or nitrogen are present in the wastes to be treated, the stack emissions also should be sampled and analyzed for sulfur oxides (SOX) or nitrous oxides (NOx) during the performance test.
If the incinerator operates at temperatures greater than 2200F, the nitrogen in the combustion air may form NOx so stack sampling Desorbers should have an HC CEM for NOx snould be required. Incinerator stack emissions should as a standard operating condition. also be analyzed for carbon monoxide using a CEM. If an HC monitor is not required on the incinerator or TD as an operating condition, it should be required during the performance test. Each performance test should consist of three stack sampling runs. Some facilities do a fourth run so they have backup data in case some of the samples are lost or broken. Representatives from the EPA or state environmental protection department knowledgeable in stack sampling procedures should be present during all the runs to ensure that the performance test is conducted according to the approved plan.
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6.2.2.3. Consider Site-specific Need for Additional OEMs
If the thermal treatment facility is not required to continuously monitor the stack for HC. ATSDR strongly recommends that an HC OEM be in place at least during the performance test. Health assessors and the environmental oversight agency staff should discuss the site-specific need to have other OEMs monitoring stack emissions during the performance test if they are not already required for operation, such as carbon monoxide, carbon dioxide (CC^), SOi, or opacity. See sections 6.1.1.2., 6.2.1.2., and 6.2.2.2. for further discussion. 6.2.2.4. On-site, Fence Line, and Community Sampling and Monitoring If the facility has an ambient air monitoring system, health assessors should consider the need to have the frequency increased during the performance test to determine if worker and/or community exposure rates are affected since the thermal treatment unit may be operating at maximum capacity and worst-case operating conditions, which may cause increased fugitive and/or stack emissions. Health assessors should also consider the need to sample for additional or different contaminants during the performance test if the waste will be spiked with additional chemicals or if different chemicals (PICs) may be formed during treatment of the spiked waste. See sections 6.1.2.1. and 6.2.1.3. for further discussion. 6.2.3. Posttest Period to Operational Phase
ATSDR recommends that CERCLA and new RCRA thermal treatment facilities be shut down after the performance test and not be allowed to operate until the test report is reviewed and the final operating conditions are set based on the operating conditions demonstrated during the performance test. Public exposure to stack emissions should be minimized until data demonstrate that the emissions will not pose a health risk to the community. EPA regulations allow RCRA incinerators (new and existing interim status facilities) to continue operating at conservative operating conditions that the permit writer believes to be protective of public health during the posttest period. RCRA permits have often required one-half the facility's proposed feed rate and higher operating temperatures. RCRA regulations for desorbers (40 CFR 264 Subpart X) are silent on this issue, but permit writers usually apply the RCRA incinerator regulations to desorbers that are relevant to the desorber's design. However, CERCLA and new RCRA facilities do not have a long operating history to base posttest period operating conditions on, so ATSDR strongly recommends that these units be shut down during this period. If existing facilities have an operating history of low CO and HC (CO < 100 ppm and HC < 10 ppm) and stable operations (few TRY openings and/or AWFCOs), then stack emissions will not likely be a health threat if ^""'•ations continue H'-^ng the posttest period. ATSDR staff should not routinely oppose continued operation at these facilities during this period. Facility staff usually collect at least one stack sample during shakedown to see if the facility is ready to be tested. The facility may submit the analysis of the "pretest samples" (usually without QA/QC data) as justification for continued operation after the performance test. A minimum of three data points are needed to determine the reliability of a measurement, ATSDR staff should therefore carefully consider on a site-specific basis the advisability of continued posttest operation based on pretest data. At a minimum posttest operations should (1) be for a limited time period and/or maximum amount of waste ATSDR strongly recommends that CERCLA and that can be processed at CERCLA sites, and (2) new RCRA thermal treatment facilities be shut require that the unit be immediately shut down if the down ifter the performance test and not allowed stack data shows any of the performance criteria were to operate until the test report is reviewed and not met. The limit on the amount of waste that is allowed to be processed at a CERCLA site before the the final operating conditions are set performance-test data is reviewed and final operating conditions set should be set on a site-specific basis, but should generally be limited to less than 25% of the amount of waste to be treated at the site. Agency staff should expedite their review of performance test results to ensure the public is not unduly exposed and the agency does not cause unnecessary delays.
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6.2.3.1. Modeling of Stack Emissions Data
The stack emissions should he modeled using EPA approved air dispersion models to determine the maximum ground level Maxiwxjfn annual, 24-hour, and concentrations that may occur from stack emissions during full hourly concentrations should be operation. Five years of meteorologic data from a National calculated to evaluate possible Weather Station or one year of cm-site meteorologic data should chrome as well as acute exposures. be input into the model to ensure that realistic worst-case exposures are considered.
When identifying the maximum exposed individual (MEI) or maximum exposed receptor (IV1ER) that may be impacted by the site, ATSDR staff should use realistic assumptions about how that individual may be impacted. This is called the reasonable maximum exposure (RME) (EPA 1994, EPA 1998b). The RME is not necessarily a house, it can be any location that is frequently used, such as a business, commercial or industrial area, or schools, recreational areas, parks, or a farm, ranch, or hatchery. For RCRA facilities, where there is a potential for future residential development around the facility, health assessors should consider in their evaluation any area that might become inhabited. For a Superfund site where the thermal treatment unit will only be temporarily located, only currently habitable areas should be considered in the modeling and exposure evaluation. Unhabitable areas, such as swamps, deserts, cliffs or rugged terrain, lakes, forest preserves, or areas of national or state parks that are only infrequently accessed, should not be considered when evaluating the RME. The models and assumptions used in the model should be reviewed by an ATSDR meteorologist or other staff or contractor experienced in modeling to ensure that the modeling done is appropriate to use in evaluating public health implications of the thermal treatment facility. Modeling can be used to evaluate future and past exposure pathways. Ambient air monitoring and sampling data, along with modeling data, can be used to evaluate the public's current exposure. See section 6.1.2.1. for a detailed discussion of ambient air monitoring and sampling plans. In addition to inhalation exposure, health assessors should consider indirect exposure through the food chain if farms, ranches, hatcheries, or other food sources may be impacted by deposition of stack or fugitive emissions. EPA risk assessments have shown that the majority of potential risk from combustion facilities is through the indirect pathways rather than direct inhalation of their emissions (EPA 1998b). 6.2.3.2. Evaluating Reports During the posttest period, prior to the facility resuming operation, in addition to the performance test report, health assessors should review the on- and off-site ambient air monitoring and sampling reports and any worker personal monitoring data that was collected until that time. A toxicologist or health professional should review the concentrations of contaminants in the ambient air and render an opinion on whether the facility operations under those conditions are likely to cause adverse health effects if it is allowed to complete the proposed operational period. While ambient air data are the best data to use in making health calls, only a limited number of constituents are typically available, so modeled performance and risk burn data should also be considered. Often the contaminant levels measured in the stack gases are sufficiently low that a toxicologist can eliminate all but a few contaminants for which modeling may be needed to evaluate the potential public exposure. If EPA or the facility conducted a pre-operational, cumulative risk assessment, they usually revise it after me performance test, based on the stack emissions data. Health assessors should obtain and review a copy of any risk assessment which has been conducted. 6.2.3.3. Evaluating Operating Conditions
EPA or the state regulatory agency staff are responsible for reviewing all the data collected during the performance test and for specifying how the thermal treatment facility must be operated (if the data
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supports allowing the facility to operate). If the EPA permit writer, remedial proiect manager (RPM), or on-seene coordinator (OSC) follows the EPA incineration guidance on how to set operating conditions based on test hum results (see section 9.0) and sets the operating conditions listed in section 6.1.1.4., the facility's operation should not cause public health impacts. However, all of the incineration conditions and guidance may not be applicable to some desorbers. Appropriate operating conditions have to be determined on a site-specific basis. ATSDR staff should also review the
. CEM data; • S&A data for the feed materials, residuals, and stack emissions; • QA/QC report; (4) operating conditions during the performance test; and . data from any risk burns that are used to set operating conditions.
Health assessors should determine if the EPA specified facility operating conditions ensure that normal stack emissions will not exceed those measured during the performance test. Generally maximum and minimum operating conditions should be set by first discarding any "spike values" Frequent waste feed shutof/s and restarts (outliers) which are excessively higher or lower than the create unstable operating conditions and can readings during the balance of the run, and then increase stack and/or fegitive emissions. averaging the lowest (or highest) value in each run of the test. Some facilities have a computerized data logger which records the individual readings and also calculates a rolling average for each operating condition. A more stable operation will be achieved if rolling average operating conditions are used. However, rolling averages mask the full range of operating conditions that occur. If instantaneous readings are used to set operating conditions that are tied to the automatic waste feed cutoff system, then the facility should set an alarm point at a slightly higher (or lower) reading so that facility operators are notified of a pending shutoff and can take action to quickly correct that condition and avert an AWFCO, which will provide more stable operations. The method used to record the operating conditions during the performance test (rolling average or instantaneous) should be used to set the final operating conditions. 6.3. Operational Phase - Information to Review to Protect Public Health The thermal treatment facility can be brought back on line, after the performance test data has been reviewed, the decision has been made to allow the thermal treatment unit to begin operating again, and the operating conditions have been specified for full operation. Depending on the availability of agency resources and priorities, ATSDR staff may only occasionally review facility reports during the operating phase or they may be asked to review all CERCLA site reports. It would be too resource inten::, c for ATSDR staff to review all RCRA reports. This section discusses the types of reports and information that may be available during the operational phase and their relevancy to public health. 6.3.1. Equipment Operation Protective of Public Health An important key to preventing public exposure to hazardous emissions is to have a well-operated thermal treatment facility. The more stable the facility operator can maintain the operating conditions the lower the overall emissions will be. 6.3.1.1. Incident Reports EPA often requires the operator to submit incident or noncompliance reports whenever there is a TRY opening (see section 5.1.5. for more details), noncompliance with operating conditions, or there are excedences of the on- or off-site ambient air action levels. ATSDR should look at any available ambient air monitoring and sampling data for the time period covered by the incident to see if there was an increase in the potential public exposure to site contaminants. 6.3.1.2. Inspection Reports Reports prepared by EPA or state environmental department compliance inspectors will list any Guidance Manual ft>r Public Health Assessors http: \v\\w.aiMlr.alc.;.M>\ Nl'AVS thcnnal-guKleguide.httn!
violations discovered during inspections of RCRA permitted facilities. Most Superfund facilities are not inspected by the RC'RA compliance inspectors. Their operations are overseen by the RPM, OSC, or the EPA oversight contractor on a very frequent basis. Inspectors or overseers who have completed the RCRA Incinerator Inspection or Incineration Permit Writers training course or have experience with thermal treatment facilities will provide the best oversight of the facility operations.
Inspection reports, notices of deficiencies (NODs), and notices of violations (NOVs) are good sources of information on the past operation of RCRA facilities. These documents may also contain data on releases that exceed permitted limits if they have occurred, and give ATSDR staff an indication of how well the facility has been operated in the past in order to estimate past exposure pathways. If enforcement actions are pending, the most recent inspection report may not be available for some time after the inspection.
6.3.1.3. Continuous Monitoring Reports
RCRA facilities must maintain on-site records of all of the operating conditions that are continuously monitored. The types of conditions that usually are continuously monitored are listed in section 6.1.1.4., which includes all of the stack continuous emission monitors. These data may be in electronic or hard copy format. Because data are continuously recorded, the volume of data is extensive, making it impractical to look at all the available data to see how well the facility has been operated. However, if there are questions about a particular time in the past when there may have been releases, this could be a good data source if health assessors are familiar with the permit conditions and know how to interpret monitoring data and operating conditions.
Superfund sites should also keep the records of all their continuously monitored operating conditions on site. Likewise, if questions about the potential for releases during a particular time period arise, ATSDR staff familiar with this type of data should visit the site and examine the data. If ATSDR staff want to look at just the CEM data for a few hours on a particular day it may be possible for the facility staff to send it, otherwise ATSDR staff should look at the data on site.
ATSDR staff should primarily review the CEM data for signs of fluctuations in the emissions or operating conditions that may indicate the potential for stack or fugitive emissions releases during and around the time period in question. If there is the possibility that emissions did increase, health assessors should also look at any on- and off-site ambient air data available for that time period. Health assessors may lack the expertise to evaluate the facility operating conditions and thus may be unable to judge the potential for past exposure. If that level of review is necessary, and EPA compliance inspection reports that address the issue(s) are not available, the assistance of a DHAC or contractor combustion specialist may be requested. 6.3.1.4. Additional Stack Emissions Testing Reports EPA requires all RCRA and some CERCLA thermal treatment facilities, depending on the length of time they will be operating, to retest their stack emissions periodically. Health assessors should review all emission test reports to understand the potential for public exposure in the past as well as the current operating status of the facility. New modeling will need to be done if there have been • Modifications to the thermal treatment unit or air pollution control equipment that would change the stack height, stack gas temperature, or exit velocity, • Significant changes in waste feed, • Construction or other modifications of nearby buildings that could affect the plume, or • Development of the area within a 1-mile radius of the site. The emissions test report should include the stack gas temperature and velocity which health assessors can compare to the numbers used in the original modeling for the facility. If there are only minor differences in the stack gas temperature or velocity and they are within normal site fluctuations, the dispersion coefficients from the original modeling can be used to estimate maximum potential acute and/or chronic public exposure. Guidance Manual for Public Health Assessor lutp: \\ \v\v.aNdr.alc.yov Nl-AVS theiinal-uuide yuide.html
6.3.2. Overall l-'ucility Conditions Protective ofPuhlic Health
6.3.2.1. Ambient Air Reports - Fence Line and Community
Whenever good quality ambient air monitoring and sampling data are available for a facility. ATSDR staff should rely on that as the main source of data which characterizes the community's potential exposure. Because ambient air monitors and samplers measure the total impact on the residents from the facility and other sources in the area emitting the chemicals being measured in the ambient air, the ambient air data are a better indicator of whether residents can be exposed to contaminants at levels of health concern. Modeling of the facility's stack emissions and information from the EPA Toxic Release Inventory (TRI) database for that area can also be used to evaluate the community's potential total exposure. See section 6.1.2.1. for more details on ambient air monitoring and sampling.
6.3.2.2. Residuals Analysis Reports
All thermal treatment facilities should routinely analyze their process residuals (bottom ash, fly ash, condensate, scrubber water, spent carbon, spent filters, etc.). Superfund sites are normally required to analyze each batch or day's run of solids or soils processed. Other process residuals are typically — analyzed less frequently. See sections 5.1.4., 6.1.1.1., 6.1.1.2., and 6.1.1.3.g. for additional discussion on process residuals. If there is a potential for the public to be exposed to process residuals, the reports on the analysis of those residuals will be an important data source.
Chapter 7 - Toxicologic Evaluation of Air Pathway
ATSDR Public Health Assessment Guidance Manual, Chapter 7 provides guidance on determining public health implications of exposure to contaminants of concern (ATSDR 1992b). The present chapter only addresses key issues for evaluating air pathways related to thermal treatment facilities. The hierarchy of comparison values to use and the latest values can be found in the ATSDR Air Comparison Values table. Because inhalation studies have not been conducted on many chemicals, toxicologists often have to look at oral (and/or dermal) studies and the health effects found in those studies and use their professional judgement to evaluate the potential public health implications of the air exposure pathway.
^ Key issues that health assessors should consider when evaluating air pathways at thermal treatment facilities are: • Ambient air monitoring and sampling data are preferable to stack data. However, detection levels of most chemicals make it advantageous to sample at the stack where concentrations should be the highest. Also, not as many compounds are analyzed for in ambient air, so health assessors should look at both sets of data. • If stack emissions are below or barely above comparison values, no further analysis is needed. In general, the hourly maximum dispersed ground level concentrations can be estimated to be a 100 times lower than the stack concentrations, and the maximum annual MEI concentration can typically be estimated to be a 1,000 times less than the stack concentration. If the stack concentrations of any chemicals are substantially above their comparison value, then toxicologists should use modeled values~NOT the estimated values. • Dioxins and furans are always an issue with both incinerators and desorbers. RCRA combustion regulations specify a toxicity equivalency quotient (TEQ) stack emission concentration less than or equal to 0.4 nanograms per dry standard cubic meter (ng/dscm) for existing facilities or 0.2 ng/dscm for new facilities (64 FR 52828). ATSDR toxicologists should evaluate on a case-by-case basis the dioxins/furans congener-specific, stack-emission data or ARAR set for the site. iuulanco Manual tor Public Health .Wc^ois imp: \\\\\\ at^di.cclc.yuv M V\ S thermal-tinkle uuidc
• It'dioxins, furans, or metals arc detected in the staek gases, health assessors should also evaluate the potential for indirect exposure of the public through food chain contamination from deposition of the stack emissions.
• The life of the facility should be used when looking at chronic exposures. RCRA facility life expectancy may be over 30 years. CERCLA sites usually operate less than 2 years. Health assessors should use the maximum projected operating life in making public health determinations. • If the unit has a TRY and is at an operating RCRA facility or a CERCLA unit which has been operated at other sites, information should be obtained on the frequency and number of TRY openings and length of each opening. If no data exists, toxicologists should assume at least 12 TRY openings per year, lasting 30 minutes each (or at least as long as the solids residence time), and add this dose to the normal stack emissions when evaluating chronic exposure. Health assessors should assume that during TRY events all acid gases, particulate matter, and metals are emitted from the TRY. If the TRY is after the SCC, assume all halogens are converted to acid gases, the metals are vaporized (if the SCC temperature is greater than the temperatures specified in Table 6 for each metal), then assume the DRE to initially be 99.99%, but to rapidly decrease to 99% by the end of the event.
• If fence-line or community ambient air data or observations during a site visit indicate that nearby residents may be exposed to fugitive particulate, health assessors should consider potential exposure (particularly of small children) to contaminants that may be deposited on surface soils and indoor dust.
Chapter 8 - Health Studies at Thermal Treatment Facilities
ATSDR has funded several health studies in communities near hazardous waste combustion facilities. Summaries of those studies are included so health assessors know of the research findings and status of studies still in progress at publication of this document. The National Institute for Occupational Safety and Health (NIOSH) conducts health hazard evaluations (HHEs) at work sites. This chapter includes summaries of HHEs NIOSH staff have conducted at incineration facilities. No HHEs were found for thermal desorption facilities. Summaries of all types of incineration facilities have been included because hazardous wastes may be occasionally mixed with other wastes and health assessors must consider the combined waste stream in their evaluation. Included are all HHEs conducted at facilities combusting hazardous wastes and several HHEs at municipal solid waste (MSW) and medical waste combustion (MWC) facilities, also called biological waste incinerators (BWIs). 8.1. ATSDR Funded Health Studies Related to Combustion 5.7.7. Caldwell Systems, Inc. (NC)
Name of Study Study of Symptom and Disease Prevalence Caldwell Systems, Inc. Hazardous Waste Incinerator Caldwell County, North Carolina September 1993 Type of Waste Hazardous waste, predominantly lacquer chips and dust from the furniture industry and waste torpedo fuel from the U.S. Navy, as well as pipeline industry wastes. Facility Description (niidimce Manual for Public Health Assessors litlp: \\v-v. .audr.cdc.gov \h\VS thermal-guide guide.html
From 1976 to September 1987 the Caldwell incinerator consisted of a combustion chamber and short stack. Flames and smoke were frequently seen coming out of the stack, an indication of poor combustion. A few months before it was shut down, the incinerator was upgraded to include air pollution control equipment and automated operating controls. The Caldwell Systems, Inc. incinerator (CSI) is not representative of hazardous waste combustion facilities operating today. Currently, most hazardous waste incinerators have received final RCRA permits and are subject to performance standards, emissions testing requirements, and operating restrictions to ensure attainment of emissions limits. The facility was also a waste blending, bulking, and storage facility.
Background
In 1976, Caldwell County built the CSI incinerator next to the county landfill. The semi-rural area was about 7 miles south of Lenoir, NC. The county operated the facility until 1977, when it leased the incinerator to CSI, who operated the incinerator until September 1987 without any air pollution control equipment and few waste feed restrictions. From November 1980 until it closed in 1987, CSI operated the hazardous waste incinerator as an interim status facility, under the RCRA regulations. Regulations for interim status facilities are less stringent than those for fully permitted facilities and do not place restrictions on feed rates, waste characteristics, or stack emissions. According to the Air Program permit granted by North Carolina in 1977, CSI was allowed to bum 4,100 pounds per hour, more than twice as much waste as the specified design rate of 1,800 pounds per hour. Furthermore, former CSI employees told ATSDR investigators that the licensed rate was frequently exceeded. Caldwell County ordered the incinerator to cease operations on May 31,1988, but the plant continued to operate as a waste blending, bulking, and storage facility until December 1989. On September 13, 1989, a fire in a roll-off container emitted smoke and irritant fumes, and nearby residents had to evacuate the area. This incident led the Caldwell County Superior Court to issue an order on September 28, 1989, for CSI to cease operations completely and remove all waste by December 1, 1989. In April 1990, EPA Region IV asked ATSDR to perform a health consultation to evaluate health complaints of residents living near the incinerator as well as those of former CSI employees and their families. ATSDR concluded that workplace conditions during the years of incinerator operation at CSI presented a threat to human health for some former CSI employees and the members of their households, as well as pulmonary health problems for residents living near the former CSI incinerator. ATSDR issued a public health advisory in July 1990 which indicated that a significant threat to human health was associated with past work practices at CSI. The advisory further recommended a study of the population living near the site and of household contacts of the former CSI workers. NIOSH performed a health study of former CSI workers during the fall of 1991 (see section 8.2.1. or NIOSH 1992b). In July 1991, ATSDR conducted a retrospective cross-sectional symptom and disease prevalence study of 713 residents living within a 1.5-mile radius of the CSI site. Study Objective To determine whether the prevalence of specific symptoms or disease in persons living within a 1.5-mile radius of the former CSI site differed from the symptoms and diseases in similar people not living near the site. Study Design Retrospective cross-sectional symptom and disease prevalence study. Type of Data Collected Guidance Manna] tor I'lihlK llcaltii .Vs.j.-.u^ hup u \\\v.atsdi aL.gov NTAVS thermal-ymde guide.html
Symptom and disease questionnaire data, including a detailed respiratory section adapted from the American Thoracic DLD-7S questionnaire. The questionnaire covered 14 self-reported symptoms and 26 self-reported, physician-diagnosed diseases.
Study Group
To select the study group, investigators sampled all residents living within a 0.9-mile radius of the facility and half of all residents (every other household) living from 0.9 to 1.5 miles from the facility. The comparison group was drawn from the village of Gamewell in Lenoir Township, approximately 8 miles west of the site. Ninety-six percent (713) of eligible participants from the target area and 91% (588) of eligible participants from the comparison area were included in the study. To be eligible for the study residents had to (1) be aged 3 through 79 years, (2) have resided in one of the two study areas for at least 6 months prior to May 1988, and (3) not be a former worker at CSI or a family member of a former worker.
Summary
In comparison to the control group, study group participants had an increased prevalence of self-reported respiratory symptoms, but not respiratory or other diseases, since the onset of incinerator operation (adjusting for age, sex, and cigarette smoking). Residents of the target area were almost nine times more likely than residents of the control area to report symptoms of recurrent wheezing or cough following a respiratory insult (Respiratory Symptom Complex A), adjusting for cigarette smoking, asthma, and environmental concern. Furthermore, residents living within 0.9 miles of the site were almost twice as likely as those living from 0.9 to 1.5 miles of the site to report symptoms consistent with Respiratory Symptom Complex A (adjusting for smoking, asthma, and environmental concern). Residents of the target area were approximately one and a half times more likely to report neurologic symptoms than residents of the comparison area and almost two and a half times as likely to report the diagnosis of selected neurologic diseases when smoking, sex, diabetes, alcohol ingestion, and environmental concern were adjusted for. Within the target area, statistically significant odds ratios (ORs) were found for irritative and neurologic symptoms (dizziness and poor coordination) in the areas north and south of the incinerator compared with areas east and west of the incinerator. Among people living less than 0.9 miles from the incinerator compared with those living farther away in the target area, using stratified analysis, there were statistically significant increased ORs for chest pain, poor coordination, dizziness, and irritative symptoms. Multiple logistic regression analysis demonstrated that neither distance nor direction played an important role for respiratory symptoms among target area residents, but that people living within 0.9 miles of the incinerator were more likely to report the occurrence of respiratory symptoms (Complexes A and B) than if they lived further away. Conclusions
The prevalence of self-reported irritant, respiratory, and neurologic symptoms was significantly increased in the target area versus the comparison area. Neither self-reported, physician diagnosed respiratory diseases nor hospital admissions for these diseases differed in prevalence between the target and comparison areas when all participants were compared. However, the prevalence of self-reported physician-diagnosed respiratory diseases (bronchitis and pneumonia) was higher in the comparison area among participants who reported no health problems attributed to environmental causation.
Within the target area, self-reported irritant, respiratory, and neurologic symptoms were more prevalent among participants living 0.9 miles or less versus those living between 0.9 and 1.5 miles from the CSI incinerator. Neurologic symptoms were also consistent with the prevailing winds (north-south) among the study group participants. The increased prevalence rates of irritant, respiratory, and neurologic symptoms within the target area
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remained statistically significant after adjusting for smoking, sex. employment in the furniture industry, and environmental concern.
Although the study was not designed to determine a causal association between environmental exposures and health outcomes, significant differences were found between the target and comparison areas.
Further examination of the residents living near the incinerator is indicated based on the results of the symptom and disease prevalence study because of the increased prevalence of respiratory, neurologic, and irritant symptoms.
Public Health Assessment Implications The target area participants living closest to the CSI incinerator reported irritant, respiratory, and neurologic symptoms more often than participants living more than 0.9 miles from the CSI facility. However, no differences were found in self-reported physician-diagnosed respiratory diseases. Although the study was not designed to determine a causal association between environmental exposures and health outcomes, significant differences were found between the target and comparison areas. The implication is that people living closer to the hazardous waste facility are more likely to occasionally have acute symptoms, but so far there is no indication of chronic illnesses developing. The CSI incinerator is not representative of hazardous combustion facilities currently in operation. Currently, most hazardous waste incinerators have received final RCRA permits and are subject to performance standards, emissions testing requirements, and operating restriction to ensure attainment of emissions limits. The CSI incinerator likely produced more hazardous emissions than incinerators operating today.
5.7.2. Caldwell Systems. Inc. (NC)
Name of Study Health Outcome Follow-up Study of Residents Living Near the Caldwell Systems, Inc. Site Caldwell County, North Carolina August 1998
Type of Waste ~~ Hazardous waste, predominantly lacquer chips and dust 1. „.,, the furniture inu.._..y and waste torpedo fuel from the U.S. Navy, and pipeline industry wastes
Facility Description From 1976 to September 1987 the incinerator consisted of a combustion chamber and short stack. Flames and smoke were frequently seen coming out the stack, an indication of poor combustion. A few months before it was shut down, the incinerator was upgraded to include air pollution control equipment and automated operating controls. The CSI incinerator is not representative of hazardous waste combustion facilities operating today. Currently, most hazardous waste incinerators have received final RCRA permits and are subject to performance standards, emissions testing requirements, and operating restrictions to ensure attainment of emissions limits. The facility was also a waste blending, bulking, and storage facility. Background This study is a followup to ATSDR's 1993 study on the prevalence of symptoms and diseases among residents living with 1.5 miles of the CSI incinerator. Because ATSDR's initial study demonstrated higher prevalence of respiratory, neurologic, and irritant symptoms among target area residents, ATSDR
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conducted a follow-up study in 1993 to further compare the respirator}, neurologic, and immune systems of residents within the target area to residents in the comparison area.
See section 8.1.1. or the Stiuly ofSvmptom and Disease Prevalence, C 'aldwell Systems Inc. for further background information (ATSDR 1993).
Study Objective
• To compare the prevalence of abnormalities in pulmonary and neurobehavioral functioning and immune biomarkers among three groups selected from participants in the original study—the original symptomatic group, the original asymptomatic group, and the comparison group
• To evaluate the extent to which pulmonary and neurologic symptoms reported in the follow-up study reflected actual organ-system effects that could be demonstrated using biomarker panels
• To determine the extent to which participants who reported pulmonary symptoms in the first study reported the same symptoms again 2 years later
Study Design
Cross-sectional follow-up study Type of Data Collected • Pulmonary function tests (PFTs) performed on all participants • Forced vital capacity (FVC)
• Forced expiratory flow (25-75%)
• Forced expiratory volume in 1 second (FEV1)
• Forced expiratory volume in 1 second to forced vital capacity (FEV1/FVC)
• ATSDR basic immune test battery (total lymphocyte count, T-cells count, B-cells count, cluster designation 4+ (CD4+) lymphocytes count, CD8+ lymphocytes count, CD4/CD8 ratio, level of immunoglobins A, G, and M, and C reactive protein) • Adult environmental neurobehavioral test battery • Questionnaire data, using the same questionnaire from the original study Study Group The study group contained 3 subgroups: • 52 of 77 target area participants who were symptomatic in the original study • 112 of 150 selected target area participants who were asymptomatic in the original study • 96 of 150 selected comparison area participants from the original study The overall participation rate was 69%. Summary The prevalence of existing respiratory symptoms was related to study group status. The original
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symptomatic group reported significantly more respiratory symptoms than the original asymptomatic group: 53.8% versus 28.6% for cough, 51.9% versus 23.2% for phlegm production, 50% versus 31.3% for shortness of breath, and 61.5% versus 32.1% for whee/ing. After adjusting for the effect of smoking, only phlegm production and whee/.ing remained statistically significant.
Pulmonary function test results were worse in the original symptomatic group. Abnormal PFTs were uniformly more prevalent in the original symptomatic group than in the other two groups; however, these differences were not significant after controlling for smoking status. Pulmonary function test results were significantly worse among target area participants who had respiratory symptoms at follovvup than among those who did not.
There were no statistically significant differences in the mean values for various immune biomarkers between the study groups. Women from the original symptomatic group demonstrated significantly lower sensitivity to vibration (vibrotactile threshold test), worse coordination (Santa Ana test), and lower strength (dynamometer test) compared with women from the original asymptomatic group or from the comparison group. The reason for the differences in the neurobehavioral tests and the clinical significance of the finding are unknown.
There were no significant differences in the neurobehavioral test results among the three groups of men. Conclusions Self-reported respiratory symptoms were more prevalent in the original symptomatic group than in the original asymptomatic group. However, after adjusting for the effect of smoking, only phlegm production and wheezing remained statistically significant. Differences in pulmonary function test results were not statistically significant after controlling for smoking status. Mean PFT results were significantly lower among target area participants who reported respiratory symptoms than among target area participants who did not. However, abnormal PFT results were not significant after controlling for smoking status. The results of the immune test battery were similar for the three groups. Some differences in neurobehavioral test results were observed among women in the original symptomatic study group in comparison to women in the other two groups. Women from the original symptomatic group demonstrated significantly lower sensitivity to vibration (vibrotactile threshold test), — worse coordination (Santa Ana test), and lower strength (dynamometer test) compared with women from the original asymptomatic group or from the comparison group. The clinical significance of this finding is unknown. Public Health Assessment Implications The authors concluded that the original symptomatic group had worse pulmonary function test results in comparison to the original asymptomatic and comparison groups. Furthermore, they concluded that target area participants who had respiratory symptoms at followup had worse pulmonary function test results in comparison to target area participants without them. However, the fact that the differences were not statistically significant after controlling for smoking implies that the abnormal PFTs measured were more likely due to smoking than the CSI incinerator. After adjusting for the effect of smoking, phlegm production, and wheezing, some neurobehavioral test results in women were statistically significant, so one cannot rule oat the possibility that some effects may be related to proximity to the CSI facility. Although this study cannot prove what caused the measured health effects, public health officials should work with state and federal regulatory officials to prevent stack and fugitive emissions to the maximum extent practical from hazardous waste thermal treatment facilities. No thermal treatment unit should operate without air pollution control equipment. Ambient air monitoring should be conducted in communities near facilities with known air releases to
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evaluate the residents' exposure.
The CSl incinerator is not representative of hazardous waste combustion facilities currently in operation. Currently, most hazardous waste incinerators have received final RC'RA permits and are subject to performance standards, emissions testing requirements, and operating restrictions to ensure attainment of emission limits. The CSl incinerator likely produced more ha/ardous emissions than incinerators operating today.
8.1.3. Culvert City Industrial Complex (KY)
Name of Study Symptom and Illness Prevalence with Biomarkers Health Study for Culvert City and Southern Livingston County. Kentucky^ May 1995
Type of Waste
Hazardous waste and chemical manufacturing emissions Facility Description Seventeen companies, many involved in manufacturing and handling of chemical compounds, occupy the Calvert City Industrial Complex (CCIC), including LWD, Inc., a commercial hazardous waste incineration and treatment facility that has been operating waste incinerators since 1978. Information was not provided on the incinerator design. Background The CCIC started in the late 1940s. In addition to the hazardous waste incinerator, the CCIC contains two EPA National Priorities List sites.
In response to a petition request filed in May 1987 by a resident of Livingston County, ATSDR initiated a public health assessment at the site. ATSDR completed the health assessment in 1992 and recommended that the agency consider Calvert City and the southern Livingston County area for future health studies. In 1993, ATSDR initiated this health study. "~ Meetings held between ATSDR staff and the local community elicited three general areas of concerns: (1) exposure to toxic substances, (2) increased prevalence of various symptoms and illnesses, and (3) excess cancer deaths. Chemicals of concern included heavy metals, dioxin, various organic chemicals, such as vinyl chloride, neurotoxic chemicals, and others. Some members of the community stated that there was a high rate of birth defects in the Calvert City area. Other symptoms and illnesses of concern were infertility, miscarriages, low birth weight, skin rashes, chronic obstructive pulmonary disease, respiratory problems, asthma, eye irritation, neurologic disease, lupus erythematosus, and silicosis. Study Objective • To compare the prevalence of certain self-reported diseases and symptoms of participants in the target group with prevalence in the comparison group • To characterize the distribution of selected biomedical, pulmonary function, and volatile organic compound (VOC) exposure test values in the target study group • To compare them with both standard reference ranges for these tests and the distribution of biomedical test values in the comparison study group
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• To examine the effect of other factors, such as age. sex. smoking history, and occupation, on hiomedical test results and symptom and disease prevalence
Study Design
Cross-sectional symptom and illness prevalence study
Study Group
The study group was comprised of 357 target area residents and 363 comparison area residents. Blood specimens for the VOC exposure test were collected from 100 of the target area residents and from 107 of the comparison group. The participation rates for the target and comparison areas were 48% and 55%, respectively.
The target area residents were drawn from two areas thought to have the greatest potential for exposure to hazardous substances emanating from the CCIC: Target Area A included all residents living within defined city limits of Calvert City (most of these residents live within 3 miles of CCIC), Target Area B included all residents living in the southern region of Livingston County just across the Tennessee River from the CCIC.
Based on location and socio-demographic factors, ATSDR selected Cadiz, a city 40 to 50 miles southeast of Calvert City, for the comparison community.
ATSDR defined the target and comparison areas, then conducted a census of randomly selected residences in each area to generate a list of eligible residents. The sample size for the study was then selected to allow 80% or greater power to detect realistic differences over a spectrum of background symptoms and disease prevalence. Type of Data Collected • Questionnaire data (to assess symptoms, illnesses, and confounding factors)
• Pulmonary function tests
• Biologic specimens to test for organ function and recent exposure to VOCs Summary The study was conducted in two phases. The first phase was the census of randomly selected residences to generate a list of eligible residents. The census also included a well water survey. The second phase consisted of administering a standardized symptom and disease prevalence questionnaire, conducting pulmonary function tests, and collecting biological specimens. Target and comparison area study participants had similar age, sex, race, education, income, and length of residency distributions. However, target area participants were more likely to have worked in a position that may have exposed them to chemicals than were comparison area participants. The self reporting of two illnesses was statistically significantly higher in the target area—weakness or paralysis of limbs and gallbladder disease (odds ratios of 3.3 and 2.6, respectively). The odds ratios for these two diseases remained statistically significant after adjusting for confounding factors. Breast cancer was the only cancer with enough cases for making a statistical comparison between the two groups, and there was no significant difference in occurrence between the target and comparison area women.
There were no statistical differences in the reproductive histories between women in the target and comparison areas. Odds ratios for miscarriages, stillbirths, and birth defects were less than 1.0, indicating less occurrence in the target area, but none were statistically significant.
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Odds ratios were calculated to determine whether there were differences between target and comparison area groups when comparing biomarker results. Serum total protein results (to assess liver function) of target area study participants were more frequently outside the established reference range than results of comparison area participants (odds ratio 2.3, 95% confidence interval 1.2-4.5). No odds ratios comparing renal or immune system biomarkers were statistically significant.
There were no statistical differences in the pulmonary function test results between target and comparison area participants.
Of the 16 compounds with detectable levels, nine were significantly higher (though not statistically) in comparison area participants and six were significantly higher (though not statistically) in target area participants.
Conclusions • Target area study participants reported illnesses slightly more often and symptoms less often than comparison area study participants; however, no clear pattern of symptoms or illness was observed. • There were no statistically significant differences in reproductive histories between target and comparison area women. • Biologic test results of the hepatobiliary, renal, immune, and hematopoietic systems revealed no clear differences between the target population and established reference levels.
• There were no statistically significant differences in pulmonary function tests between target and comparison area participants. • There was no association between area of residence and VOC exposure, nor excessive recent exposure occurring in either study or community.
• Of the 31 chemicals tested for in the VOC exposure testing, only acetone was found at a statistically significantly higher mean concentration in target area participants than in comparison area participants. However, both target and comparison levels were below the national reference level. Public Health Assessment Implications
Even though this study found no association between the area of residence and any adverse health effects measured, the same may not be true for other industrial parks or hazardous waste incinerators. The potential for public exposure at each hazardous waste facility must be evaluated on a case-by-case basis. This study adds to the growing database indicating that adverse health effects are not usually found at the chemical concentrations found in the environment, even in communities near industrial parks that have been there for 50 years. 8.1.4. Times Beach (MO)
Name of Study Dioxin Incinerator Emissions Exposure Study Times Beach, Missouri July 1999
Type of Waste Hazardous waste contaminated soil containing 2,3,7,8-tetrachlorodibenzo-/?-dioxin (TCDD)
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Facility Description
A transportable incinerator was constructed on the Times Beach Supertund site. The incinerator consisted of an indirect-tired rotary kiln operated around I650F with oxygen enrichment and a secondary combustion chamber operated around 21 OOF followed by an emergency vent with two propane burners that fired automatically to provide extra combustion of the emissions if the vent opened in the case of a flame out (lose uf flame) in one or both of the combustion chambers.
The primary and the secondary combustion chambers (PCC and SCC) were fired with natural gas and operated under negative pressure. The air pollution control chain consisted of a quench, an ultrasonic scrubber, a wet ESP, a carbon adsorption bed, and the stack. All material handling occurred inside structures (portable buildings) that were under negative pressure. Trucks bringing contaminated soil to the facility entered the buildings through an air lock, dumped their load, and went through a decontamination chamber before exiting the building (ATSDR 2000).
Background
The 1988 EPA Record of Decision for 27 dioxin sites in eastern Missouri called for thermal destruction of contaminated soils and other materials. Approximately 265,000 tons of soil and other materials containing TCDD from these sites were burned at the Times Beach, Missouri Superfund site between March 17, 1996 and June 20, 1997. TCDD concentrations in the soil materials ranged from one part per billion (ppb) to approximately 3,000 ppb.
Times Beach, formerly an incorporated city in southwest St. Louis County, is approximately 20 miles from St. Louis. Times Beach and the 26 other eastern Missouri sites were contaminated in the early 1970s when waste oil contaminated with TCDD was sprayed on roadways and other areas for dust suppression. Study Objective To determine if serum concentrations of TCDD, and other related compounds, significantly increased in persons living in the vicinity of the Times Beach site during the time frame of the incineration operation compared with persons who lived farther away from the site Study Design Prospective cohort Study Group The study group consisted of 76 of 245 randomly selected people from the survey census of the target area. The comparison group consisted of 74 of 245 randomly selected people from the survey census of the comparison area. To be eligible for the study, participants had to be between 18 and 64 years of age, and could not be employed in occupations likely to have exposure to TCDD and other related compounds. Pregnant or nursing mothers were also excluded from the study. The target area was within a 4-kilometer radius of the incinerator. To determine the most likely neighborhoods for exposure, the location of the incinerator was compared to air-dispersion modeling maps prepared by an EPA contractor. The comparison area was selected using the following criteria: (1) the area needed to be in St. Louis, but approximately 16 kilometers from the incinerator, (2) no industries likely to produce TCDD or related compounds could be present in the area, and (3) no known TCDD site could exist in the area. Furthermore, no comparison area participant could be exposed in the target area vicinity on a daily basis. After defining the target and comparison areas, ATSDR conducted a census of each household in the two areas, randomly selected 245 names from each area census, and recruited study participants from these lists of names.
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Type of Data Collected
• Questionnaire data • Serum TCDD levels (reported on a lipid-adjlisted basis).
Summary Blood samples were collected in September 1995 (before incineration), July 1996 (shortly after incineration began), and June 1997 (just before the conclusion of the incineration). The blood levels of most analytes decreased from pre-incineration to the end of the incineration. There were no differences in the mean blood levels between the target and comparison areas for any analysis, except log-transformed polychlorinated biphenyl (PCB), which was slightly higher in the comparison area. After controlling for age, gender, participant's weight and height, head of household income and head of household education level, there were still no differences in the levels of analytes between the target and comparison areas. TCDD levels decreased from a mean of 1.79 parts per trillion (ppt) to 1.23 ppt in the target area, and from 1.46 ppt to 1.23 ppt in the comparison area. The TEQ showed a similar decrease over time.
The maximum and minimum levels of most analytes tested fell within the Centers for Disease Control and Prevention (CDC) reference ranges normally seen for these chemicals.
Most demographic, socio-economic, and behavioral characteristics did not differ significantly between the two groups. However, more participants in the comparison group smoked cigarettes, used lawn-care services, and weighed more. TCDD levels for the target and comparison area were combined and stratified on a number of participant characteristics. None of the comparisons resulted in statistically significant differences. ATSDR conducted the same analysis for TEQ and the only significant difference was for living in a home with smokers. The average TEQ for participants living in a home with smokers was 12.77 ppt compared to 9.36 ppt in homes without smokers.
Conclusions
ATSDR concluded that incineration of TCDD-contaminated soil and other material at the Times Beach incinerator did not result in any measurable exposure to the population surrounding the incinerator, as indicated by serum TCDD levels. There was no evidence of any changes in serum levels of analytes between pre- and post-incineration. Public Health Assessment Implications The study's findings support the use of incineration for similar materials that are contaminated with dioxin-like compounds, as long as the incineration is conducted in a similarly controlled manner with appropriate state and federal health, and RCRA and Superfund oversight, and with extensive citizen input and involvement. 8.1.5. VERTAC/Hercules Site (AR)
Name of Study Adverse Reproductive Outcomes in Pulaski County for Years 1980 Through 1990 March 1998
Type of Waste Although this study did not involve a hazardous waste incinerator, it involved exposure to dioxins and
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other ha/ardous substances from the production of phenoxy herhieides. On-site incineration of lov. dioxin 2,4-Dichlorophenoxy acetic acid (2,4-D) wastes and high dioxin 2.4,5-Trichlorophcnoxy acetic acid (2,4,5-T) wastes was planned for the future.
Facility Description
A herbicide manufacturing facility surrounded by homes in close proximity to the site. The site was later remediated using a transportable hazardous waste incinerator.
Background
The Jacksonville community in Pulaski County, Arkansas, has documented exposures to dioxin and possible exposures to chlorophenol and chlorophenoxyacid potentially related to multi year production of phenoxy herbicides at the Vertac site. The planned incineration of 2,4-D and 2.4,5-T wastes created an additional potential for further environmental exposure. As reported in the 1986 Report to the Policy Advisory Commission by the Arkansas Reproductive Health Monitoring System (ARHMS), an apparent increase in fetal loss (20%) was noted for Jacksonville births from 1980 to 1982 when compared to the remainder of Pulaski County rate (5.9% compared to 4.5%). This difference was statistically significant for all races combined and for whites. However, the difference was not statistically significant for African-Americans. The fetal loss ratio studies were for those fetuses known to be at least 8 weeks or older in gestational age, (old enough to minimize the potential for over- or under-counting very early losses.)
In this study, ATSDR and the Arkansas Department of Health sought to extend the time period studied from 1980 through 1990, and to examine a broader range of adverse pregnancy and developmental outcomes, including birth defects, low birth weight, and specific developmental disabilities occurring in early childhood—in addition to fetal loss. Study Objective To examine an 11-year data series of reproductive outcomes for evidence of possible association with the Vertac Superfund site of Jacksonville, Arkansas, and to provide pre-incineration baseline data regarding these health outcomes, which could be compared to future post-incineration data. Specific objectives included (1) ascertaining all Pulaski County resident's cases of birth defects and fetal loss occurring in the 1980-1990 birth cohort, and all cases of developmental disabilities occurring in the 1985-1990 birth cohort, (2) investigating whether prevalence rates of adverse pi^nancy outcomes differed between Jacksonville and the rest of Pulaski County, (3) performing extensive mapping studies and cluster analyses to search for possible local aggregations of cases and their potential relationship with the Vertac site, and (4) estimating baseline birth prevalence rates of these reproductive outcomes for possible later comparison to post-incineration rates. Study Design Retrospective analysis of prevalence rates Type of Data Collected • Birth defects and other adverse birth outcome cases collected by the ARHMS. Cases are sought from hospitals, clinics, diagnostic centers, Head Start programs, community programs, vital records and other sources. • Births, deaths, and fetal deaths data collected by the Arkansas Department of Health Study Group
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The study group included all birth outcomes for Jacksonville residents, considered potentially exposed to the Vertac site. The comparison group included all birth outcomes for non-Jacksonville residents of Pulaski County. Over the 1 1-year period there were 67,545 (64% white) births in all of Pulaski County and 9,602 (82% white) births in Jacksonville. Because Little Roek Air Force Base abutted Jacksonville, the study group differed significantly from the comparison group with respect to military employment (48.7% of births vs. 3.1%). Other differences between the two groups included maternal race. socioeconomic status, and birth weight. To avoid the expected large bias of military out-migration prior to diagnosis, the authors limited many analyses to nonmilitary births only.
Summary The excess of fetal loss in Jacksonville in the early 1980s reported earlier by ARHMS was confirmed. Trend analysis indicated a decrease to the lower rates of the balance of Pulaski County, followed by a rapid increase in fetal loss county-wide. The analyses suggest that the excess fetal loss in the early 1980s occurred among military families who were stationed at the Little Rock Air Force Base abutting Jacksonville. No evidence was found to link this reproductive outcome to the Vertac site. No evidence was found between occurrence rate of birth defects and the Vertac site, considering time trends, prevalence rates, and spatial analyses. Isopleth mapping identified clustering of low birth weight (1985-1990) between 1 and 2 miles southeast of the Vertac site. The analyses suggested a possible association between the prevalence of neonatal seizures and seizure disorders and proximity to the Vertac site (1985-1990), although case numbers were very low. The identified clusters of children diagnosed with seizure disorders, neonatal seizures, mental retardation, and low birth weight around and to the southeast of the Vertac site suggests the possibility of a common factor which may or may not be associated with the site. The predicted under-ascertainment of diagnosed cases of birth defects and especially of developmental disabilities among military families was shown. Inability to link study records of 1980-1984 to birth certificates restricted the analysis of nonmilitary events to the 1985-1990 time period.
Because of the conversion of rural route addresses to road addresses during the study decade, 100% geocoding of data was not attained. Geocoding failures among Jacksonville residents primarily occurred for addresses to the north and west of Jacksonville; potential clusters in those areas may have been missed. Racial differences in prevalence rates of adverse outcomes and different racial distribution in the study and control group both required race-specific analyses that further reduced the statistical power of the study. Conclusions • The increased fetal loss rates observed in the Jacksonville area in the early 1980s were not associated with spatial proximity to the Vertac site. • No indication of an excess in birth defects related to the Vertac site was observed. • Weak associations were found for a few developmental problems, such as seizures and neonatal seizures, and the Vertac site. • Several clusters of low birth weight were noted in Pulaski county, including one to the southeast of the Vertac site. • No indication of an association of fetal loss, birth defects or developmental disabilities with the passage of time was demonstrated.
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The localized excess in low birth weight may account for the weak clusters of developmental disabilities. There is no direct evidence relating the low birth weight cluster to the southeast of the Vertac site to site activities. ATSDR and the Arkansas Department of Health recommended further spatial study of low birth weight and developmental disabilities, including evaluating possible relationships to body burdens and environmental data.
Public Health Assessment Implications
This study did not find any associations between fetal loss, birth defects, or low birth weight and proximity to the production of phenoxy herbicides that contained dioxins at the Vertac site. Weak associations were found between a few developmental problems and proximity to the site. While this study documents the status of the community's health prior to incineration for potential comparisons to any health effects measured after the site is remediated, it does not document the exposure (if any) of the pregnant mothers to dioxins or the herbicides manufactured at the Vertac site.
Potential adverse health outcomes related to current or past site exposures should be taken into account when evaluating the safety of proposed on-site incineration of hazardous wastes. On-going Study - Incinerator Exposure Assessment Purpose: To help determine if remediation activities associated with the Vertac site cleanup, particularly handling and incineration of drummed wastes, result in increases in body burdens of site-related chemicals by conducting pre- and post-incineration biomonitoring activities for estimating blood lipid concentrations and urine concentrations of site contaminants in nearby residents. Biological samples were taken and analyzed. Preliminary reports indicate that there was no increase in dioxin body burdens in residents living near the site attributable to the incineration of Vertac wastes. Two residents' dioxin blood levels were higher during the post-incineration testing so ATSDR conducted an exposure investigation and found residential sources of exposure which EPA remediated (ATSDR 1997b). 8.1.6. Three Waste Incinerators (NC)
Name of Article Do Waste Incinerators Induce Adverse Respiratory Effects? An Air Quality and Epidemiological Study of Six Communities (Shy 1995)
Type of Waste
One incinerator bums municipal solid waste (garbage) and one burns medical waste. The industrial furnace burns coal and liquid hazardous wastes. Facility Description The biomedical waste facility was a commercial facility with two continuous-feed incinerators. The combined capacity of the two units was 35 metric tons per day. No air pollution controls were in use during the first year of the study. The incinerators burned boxed medical wastes containing microbiological wastes, pathological tissue, needles, discarded instalments and utensils, plastics, paper, pigments, and discarded biologicals and chemicals used in laboratc/ies. No radioactive wastes were incinerated.
The municipal waste facility was a publicly owned facility with two incinerators and a total capacity of 224 metric tons per day. The units operated continuously, burning paper, plastics, and other household wastes to generate steam. The incinerators had an electrostatic precipitator and a 73-meter stack.
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The third facility had four rotary kilns which heated crushed slate to produce lightweight aggregate for use in construction materials. The kilns normally bum coal, but during the second and third years of the study one of the kilns also burned liquid hazardous wastes at a maximum rate of 1.220 liters per hour. The maximum heat input to each kiln was 35 million British thermal units per hour.
Background
ATSDR and EPA provided funding and support to the University of North Carolina (UNC) at Chapel Hill for this 3-year study. UNC conducted an epidemiological study of the prevalence and incidence of respiratory effects among residents of communities surrounding three types of waste combustion facilities (a biomedical incinerator, a municipal waste incinerator, and a liquid hazardous waste-burning industrial furnace), and three matched comparison communities.
Twelve-hour ambient air sampling was conducted (day and night samples) for 35 days each year in each of the six study communities for particulate matter (PM2 s and PMi0), aluminum, iron, sulfur, silicon, zinc, sulfur dioxide (SO2), hydrogen chloride (HC1), nitrous acid (HNO2), and nitric acid (HNO^,). Simultaneously, the cohorts in that community recorded twice daily in a diary any respiratory symptoms they experienced, and a subgroup performed baseline spirometry at the beginning of the month, and peak expiratory flow rates twice daily. A second subgroup performed spirometry and provided a sample of nasal washings once each year.
Study Objective • To compare the prevalence of chronic respiratory symptoms, respiratory hypersensitivity, diminished lung function, upper respiratory tract inflammatory reactions, and upper and lower respiratory tract diseases in exposed and nonexposed communities, adjusting for the distribution of known risk factors for these conditions
• To select subcohorts of normal and of hypersensitive adults in these exposed and control communities and to obtain daily measurements of lung function and respiratory symptoms in these persons over a one month period, annually, for 3 years, with simultaneous daily measurements of air quality in each community
• To identify whether subgroups of the population are at higher risk of lung and respiratory disease from exposure to fugitive or stack emissions from incinerators Study Design Longitudinal prospective cohort study of prevalence and incidence of respiratory effects Study Group The cohort consisted of 3,479 persons living in three communities within a 2 by 5 kilometer (km) elliptical area around the three facilities. The controls were 3,392 persons matched to the cohort by socioeconomic characteristics who lived in three communities upwind of and no closer than 5 km to the facilities. Each person (or an adult in the household) participated in a 20-25 minute telephone survey. Questions were drawn from the respiratory disease questionnaire of the American Thoracic Society with additional questions on household characteristics and demographics, smoking, chemical exposures at work and home, type of heating and cooking appliances, and perceived quality of the outdoor air in the immediate neighborhood.
Based on these responses, UNC recruited 80 persons from each community for the longitudinal component of the study. Forty subjects in each community were selected because they had asthma or asthma-like symptoms during the past 12 months. The other 40 were selected because they gave negative responses to all questions regarding chronic or acute respiratory symptoms. All subjects were
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nonsmokers aiul were not regularly exposed to cigarette smoke in their home. An additional 25 subjects from each community were recruited to participate in a once yearly collection of nasal lavage samples and to perform spirometric lung function tests.
Type of Data Collected
• Questionnaire data
• Daily diaries of respiratory symptoms (35 days each year)
• Peak How measurements (twice daily same 35 days each year)
• Ambient air environmental samples (day and night samples same 35 days each year)
• Spirometry (once a year)
• Nasal washings (once a year)
Summary The data from the first year failed to show any pattern of excess chronic or acute respiratory symptoms in any of the incinerator communities. Among "normals," mean forced expiratory volume in 1 second (FEVj) and peak expiratory flow rate (PEFR) values were consistently higher in incinerator than in comparison communities. Among the "sensitives," mean PEFR values were higher in the municipal and hazardous waste incinerator communities than in their paired comparisons, whereas these values were slightly lower in the biological waste incinerator community than in it's comparison community. FEVj results did not show a consistent difference between community pairs among the sensitive subgroup. In the nasal lavage analysis neither cell counts nor biochemical indices of inflammation suggested an inflammatory effect of residence in the incinerator versus comparison communities. There were no important differences in average peak flows or in the diurnal change in peak flows between incinerator and comparison communities.
No differences in concentrations of particulate matter were detected among any of the three pairs of study communities. Average fine particulate (PM2 5) concentrations measured for 35 days varied across study communities from 16 to 32 micrograms per cubic meter (g/m3). Within the same community, daily concentrations of the fine particulate varied by as much as eightfold, from 10 to 80 g/m3, and were nearly identical within each pair of communities. Direct measurements of air quality and estimates based on a chemical mass balance receptor model showed that incinerator emissions did not have a major or even a modest impact on routinely monitored air pollutants. During the first year of this 3-year study, the industrial furnace was burning coal, not hazardous wastes. A one-time baseline descriptive survey (n = 6,963) did not reveal consistent community differences in the prevalence of chronic or acute respiratory symptoms between incinerator and comparison communities, nor were differences seen in baseline lung function tests or in the average peak expiratory flow rate measured over a period of 35 days. Conclusions Based on this analysis of the first year of the study, investigators concluded that they had no evidence of acute or chronic respiratory effects or lung function abnormalities associated with residence in any of the three incinerator communities. However, they stated that their "failure to reject the null hypothesis does not warrant acceptance of the null as fact., .to the degree that other incinerators bum different wastes or operate under different conditions, our conclusions are only applicable to the three specific incinerators in our study communities."
The 3-year study was completed in 1994, but UNC has not completed the study report at this time.
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Preliminary indications are that findings from the second and third year were the same as for the first year, and that there were no differences in the measured values between the three incinerator communities when compared to the three comparison communities.
Public Health Assessment Implications
This study is important for public health officials who evaluate incineration facilities, because it was the first study to obtain simultaneously direct measurements of both air quality and respiratory function and symptoms in incinerator and comparison communities. The study included cohorts with pre-existing respiratory problems, "sensitive" population, as well as "normal" individuals. It combined environmental sampling concurrently with respiratory symptoms daily diaries (to eliminate recall bias) and objective biomedical testing.
The differences (if any) between year 1 and years 2 and 3 in the ha/.ardous waste industrial furnace community will provide for comparisons of health effects when an industrial furnace was and was not burning hazardous wastes. Preliminary reports indicate that there were no differences. 8.2. NIOSH Studies On-site workers involved with the operation or maintenance of a facility often experience the greatest exposure to contaminants from the facility. Review of the literature identified several NIOSH health hazard evaluations (HHEs) that evaluated health implications associated with occupational exposures at incineration facilities. Only four HHEs involved hazardous waste facilities. These studies will be presented first. Summaries of several NIOSH studies at municipal waste combustors (MWCs) and medical/biological waste incinerators (BWIs) are included because the types of problems identified could also be found often at hazardous waste thermal treatment facilities. The MWCs and BWIs are also included because occasionally health assessors may be asked to evaluate those types of facilities or hazardous wastes may sometimes be co-treated with those wastes. Sometimes more information on the facility design and background has been included then was in the NIOSH report because of ATSDR staffs familiarity with the facility. The Public Health Assessment Implications section will discuss the application of the study to the public health assessment process, which will help the reader apply the study to other sites. 5.2.7. The Caldwell Group (NC)
Name of Report Health Hazard Evaluation Report The Caldwell Group North Carolina HETA 90-240-2259
Type of Waste Hazardous waste, mostly liquid and solid wastes from furniture industry and wastes containing Otto Fuel II (torpedo propellant from U.S. Navy) Facility Description The Caldwell Group consisted of 3 companies, Caldwell Systems, Inc. (CSI), Mitchell Systems, Inc. (MSI) and Caldwell Industrial Services, Inc. (CIS). CIS provided hazardous waste (HW) transportation services. CSI in Lenoir, NC, and MSI, in Spruce Pines, NC, were interim status commercial hazardous waste facilities, each with an incinerator, storage tanks, a drum storage area, and blending tanks. The incinerators had similar designs, primarily for burning liquid wastes, however, solid or slurried wastes were also fed to them. Neither of the incinerators had any air pollution control equipment until 1987, when CSI was remodeled and air pollution control equipment added. Wastes were often fed to the incinerators far in excess of their design capacity. Prior to 1987, flames and smoke (indicating poor combustion conditions) were often seen coming out of their relatively short stacks.
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Background
The 2-acre CSI site is adjacent to the Caldwell County landfill. The incinerator was originally built in 1976 by the county, who operated it until March 1977, when it was leased to CSI. In September 1987, CSI upgraded the facility by adding air pollution control equipment. The Caldwell County Health Department ordered the incinerator closed on May 31, 1988. However, the plant continued to operate as a waste blending, bulking, and storage facility until September 13, 1989. when a fire in a roll-off container emitted smoke and irritant fumes, causing the evacuation of residents in the area. On September 28, 1989, the Caldwell Superior Court issued an order requiring CSI to cease operations and remove all waste from the facility by December 1, 1989.
The MSI facility was built by the Caldwell Group and began operation in 1980. It was closed in 1985, and later dismantled. In 1983, a local waste transportation and clean-up firm was purchased by Caldwell and renamed CIS. CIS was sold after both incinerators were closed.
In 1987, the NC Division of Occupational Safety and Health (NC-DOSH) investigated the CSI facility and found no excessive exposures to HW during the time of their investigation. In 1989, NIOSH received reports of neurologic problems in former Caldwell workers. In October 1989, NC-DOSH investigated CIS in response to reports of work-related illnesses; however, they found no evidence of — hazardous chemical exposures. In August 1990, NIOSH investigators made an unannounced visit to CIS. At the time of the visit, activities with potential for exposure were not being performed, and no HW were seen on site. NIOSH investigators later collected personnel records, and the HW manifests for waste Otto Fuel II. Summary
In September 1990, NIOSH investigators medically evaluated 14 former Caldwell Group employees to independently assess the workers' neurologic conditions, and to develop a case definition for an epidemiologic study to determine whether the reported neurologic disorders could be associated with work at Caldwell. NIOSH staff confirmed the finding of disabling movement disorders (myoclonus and tremor) in two of the 14 former employees evaluated. Because there was not a high prevalence of an objectively quantifiable finding that could be used as part of a specific case definition, a valid epidemiologic study was not feasible. However, screening examinations, were offered to the 313 other current and former Caldwell employees to address concerns that other employees might have undetected or unreported neurologic disorders. In November 1991, 54 current and former Caldwell Group employees participated in the screening exams conducted by NIOSH. No additional cases of disabling movement disorders characterized by myoclonus and tremor were found. The most frequent neurologic finding was a mild postural tremor in eight participants. Some former employees' descriptions of environmental conditions and work practices at the Caldwell facilities suggest that substantial exposures, especially before 1987, might have occurred, although NC-DOSH investigations in 1987 and 1989 found no evidence of hazardous chemical exposures during their visits. The disabled and other former employees reported that their acute symptoms were worst when they handled wastes containing the Otto Fuel II. waste torpedo propellant. The disabled employees reported heavy direct skin contact and inhalation exposures. The principal component in Otto Fuel II is propylene glycol dinitrate. Conclusions NIOSH concluded that these results did not represent the entire Caldwell workforce or HW workers in general because only 17% of 313 eligible employees participated. NIOSH also concluded that the question of whether or not the symptoms or movement disorders are related to the HW exposures during work at the Caldwell Group facilities remains unanswered; and that the absence of an indisputable medical explanation for the symptoms could increase the employees' anxiety, which in turn may
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exacerbate their symptoms.
Public Health Assessment Implications
Because of the inherent potential for adverse health effects related to HW exposures, health assessors should evaluate the potential for exposures to occur during waste unloading and handling. If HW unloading and handling frequently occurs in open areas, i.e., not in buildings under negative pressure, activities that cause worker exposure will likely result in fugitive emissions that may also affect nearby residents. Employers should use engineering controls, wear personal protective equipment and clothing, and get worker education to reduce their exposure to organic solvents. When an indisputable medical explanation for a worker's or community's symptoms does not exist, supportive counseling may be needed, not on the basis that the medical problem is "all in the patient's head," but rather, as a way to increase coping mechanisms for dealing with something that cannot be understood. 8.2.2. ENSCO (AR)
Name of Report Health Hazard Evaluation Report ENSCO El Dorado, Arkansas HETA 86-519-1874
Type of Waste PCBs and hazardous wastes (HWs) Facility Description
The ENSCO incineration facility is a commercial facility that disposed of PCBs and HWs in El Dorado, Arkansas at the time of this NIOSH evaluation. In 1991, ENSCO ceased combusting PCBs. As a part of their RCRA permit ENSCO has been required to fund an Arkansas Department of Environmental Quality (ADEQ) on-site inspection program since 1990. ENSCO employed about 275 workers, including 50 truck drivers. NIOSH described the incinerator as a rotary kiln (PCC) followed by a liquid injection thermal oxidation unit (SCC). The flue gas goes through a scrubber before being discarded through a tall stack. The solids and ash from the lain discharge into 55-gallon drums.
Wastes are transported to ENSCO by truck or rail, tested by the on-site laboratory, and stored in warehouses prior to incineration. The old PCB warehouse stores liquid PCBs. Drums are opened and the liquids pumped into a holding tank. Solids and sludges are packaged in 10-gallon plastic drums for subsequent shredding and incineration. Some capacitors and PCB-contaminated solids were stored in the North warehouse, located several miles from the main site, prior to being transported to the main site for incineration. ENSCO was phasing out this warehouse at the time of the NIOSH visits. The new PCB warehouse is on site and is designed for storage of PCB-contaminated solids and capacitors prior to incineration. Capacitors, other solids, and drummed wastes are hauled by truck from the warehouses to the kiln dock, where they are unloaded onto the dock and then fed by lift truck into a shredder which feeds directly into the rotary kiln. A ram feeder injects plastic drums of flammable liquid organic wastes into the kiln. Liquid PCB and HW are pumped from storage tanks and injected through nozzles in the SCC in a closed system. Background In December 1986, the Arkansas Department of Health asked NIOSH to evaluate worker exposure to
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PCBs at ENSCO. NIOSH personnel conducted an initial inspection on January 27. 1987, and then an in-depth environmental and medical survey March 23-26. 1987. A review of the ENSCO environmental sampling and hlood PCB data from May 1985 through December 1986 indicated that the kiln dock area was the highest exposure area and that the old PCB warehouse and North warehouse were intermediate exposure areas. The wipe sampling at ENSCO documented surface contamination in the warehouses and kiln dock areas, as expected. NIOSH also found significant surface contamination in the break rooms, lunch room, and shower area.
NIOSH's environmental sampling consisted of area air samples, personal air samples, and surface wipe samples. The medical survey included, for each participant, (1) an interview regarding work history and potential exposure to PCB, (2) an examination of the skin of the head and neck for signs of chloracne, and (3) measurement of serum PCB concentration.
Summary Forty of the 41 air samples contained PCB concentrations greater than the NIOSH recommended exposure limit of 1 g/m3. The air concentrations ranged from 0.85 to 40 g/m3 with the highest levels in the kiln dock area. None of the air samples exceeded the OSHA permissible exposure limit (PEL) for PCBs.
Twenty-five of the 28 low-contact surface wipe samples (floors) exceeded the 100 micrograms per square meter (g/m2) guideline for PCB levels. That guideline is based on the background level in non-industrial buildings. Only 12 of the 20 samples from high-contact surfaces, such as control panels and desk and table tops were greater than 100 g/m2. All five surface wipe samples analyzed for PCDDs and PCDFs exceeded the 1 nanogram per square meter (ng/m2) guideline for total 2,3,7,8-TCDD TEQ. The concentrations ranged from 4-40 ng TCDD TEQ/m2; however, 2,3,7,8-TCDD was not found in any of the samples. Forty of the 81 serum PCB levels were greater than the general population background level of 20 ppb. Ten PCB blood samples were in the 20-50 ppb range, 14 in the 51-100 ppb range, 10 in the 101-200 ppb range, 1 in the 201-300 ppb range, and 5 were greater than 300 ppb. The serum PCB levels ranged from 2 to 385 ppb. Employees in the production department (which included the kiln dock) had the highest PCB levels with a median concentration of 98 ppb. Warehouse and maintenance workers also had elevated PCB levels with medians of 52 and 46 ppb, respectively. Nine workers had skin findings suggestive of chloracne, but only four of the nine had PCB serum levels greater than 20 ppb, and none of the workers in the 201-385 ppb serum PCB level had sign., ^~ chloracne.
Conclusions NIOSH concluded that the lack of a consistent association between skin findings suggestive of chloracne and serum PCB levels suggests that either the skin findings were not due to chloracne or the cause was something other than PCBs, perhaps PCDD or PCDF. The environmental and medical data documented excessive exposure to PCBs. The environmental data also documented the presence of PCDD and PCDF, though not 2,3,7,8-TCDD, on environmental surfaces at ENSCO. NIOSH concluded that additional engineering and administrative controls, work practices, personal protective equipment (PPE), and exposure monitoring were needed at ENSCO to reduce employee exposures. Public Health Assessment Implications
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When ATSDR health assessors are conducting site visits they should (1) wear appropriate PPE for the chemicals present at the site, (2) minimize contact with surfaces in a facility. (3) follow site decontamination procedures, and (4) always wash their hands before eating and before and after using the restroom to prevent exposure and/or carrying contamination off site.
Waste handling and feed areas are usually the areas with the highest air concentrations of contaminants. The potential for fugitive emissions from these areas reaching the community should be carefully evaluated during site visits.
8.2.3. Allied Chemical (LA)
Name of Report Health Hazard Evaluation Report Allied Chemical Baton Rouge. Louisiana HETA 80-232-1055
Type of Waste Hazardous waste
Facility Description
The Allied Chemical plant (Allied) is a polyolefin manufacturing plant located next door to Rollins Environmental Services, Inc. (Rollins), a commercial HW treatment, storage, and disposal facility. See section 8.2.4. for a description of the Rollins facility.
Background In October 1980, NIOSH investigated complaints by 10 Allied employees of health problems they attributed to chemical wastes migrating from the Rollins facility, which was located immediately north of the Allied plant. NIOSH staff inspected the Allied plant for potential workplace exposure due to Allied's manufacturing activities and administered questionnaires to 108 of Allied's 233 employees. The questionnaire collected information on work history, medical history, and symptoms. Summary
No industrial hygiene samples were collected based on outdoor workers at Allied reporting a significantly higher frequency of symptoms and the complaints being plant-wide, rather than associated with any particular process or operation at Allied. Outdoor workers reported a higher incidence of watery burning eyes, dry mouth, sore throat, cough, chest tightness, chest pain, suffocating feeling, h^^ache, weakness, a..-'. ..«asea than indoor workers. However, no chronic medical problems were significantly elevated in this study. Fence-line ambient air sampling data collected by the state environmental agency and EPA throughout 1980 were used to evaluate the potential exposures of Allied employees. Conclusions Because the measured concentrations of volatile organic vapors did not approach an occupational health standard either singly or in combination, NIOSH concluded that "airborne chemical waste which may migrate to the Allied plant from Rollins does not constitute a serious occupational health hazard." Public Health Assessment Implications • Low level concentrations of VOCs migrating from a HW facility may result in complaints of eye and respiratory symptoms. • Ambient air sampling data may be available from other agencies for nearby industries that can be
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used to evaluate off-site exposures.
• Even though the concentrations of chemicals in the air are not at levels expected to cause health effects, some people may experience symptoms that can cause alarm in the community.
• Ambient air sampling at the fence line and/or in the community should he conducted for an extended period of time to effectively evaluate the public' exposure.
8.2.4. Rollins Environmental Services (LA)
Name of Report Health Hazard Evaluation Rollins Environmental Services Baton Rou^e, Louisiana HETA 81-037-1055
Type of Waste Hazardous wastes
Facility Description
Rollins Environmental Services (Rollins) is a commercial hazardous waste treatment, storage, and disposal facility located on approximately 160 acres in an industrial area of East Baton Rouge Parish. The site has an incinerator, biological stabilization and treatment, landfill, land farm, surface impoundments, drum storage area and crusher, and chemistry laboratory. The plant had about 50 employees at that time on three shifts, who handled approximately 193,000 tons of HW per year. Rollins was later purchased by Safety-Kleen who closed the former Rollins Baton Rouge incineration facility in 1997.
Background In response to a request from 34 Rollins employees, NIOSH medical and industrial hygiene staff inspected the plant on November 5-6, 1980, conducting 45 medical interviews and collecting 49 screening air samples which were analyzed for VOCs, metals, pesticides, polynuclear aromatics (PNAs), PCBs, hydrogen sulfide, and acid anions. Samples were collected in the unloading pump pad, landfill, land farm, biosystem, oil/water separator ponds, and the drum crusher. Grab samples were taken from the liquid in the land farm holding pit and the cement kiln dust. NIOSH conducted a follow-up visit March 17-20, 1981, and gathered personal air sampling to evaluate the magnitude of employee exposure to the ubiquitous chemicals (benzene, toluene, and xylene) found in the samples taken in November 1980. NIOSH staff took two samples in the breathing zone of1 ° workers. Silica, respirable and total dust, and noise monitoring were also conducted because of the earth moving operations. Summary All job categories were exposed to cyclohexane solubles, benzene, toluene, and xylene; however, the exposures did not exceed recognized health standards either singly or when identical target organs and additivity of effect were assumed. Operations personnel were exposed to naphthalene, indan, indene, and anthracene. Maintenance workers were exposed only to anthracene. Transportation workers had naphthalene and indan exposure. Laboratory personnel were not exposed to any of the specific PNAs measured. Because of the sampling technique used, NIOSH staff felt that the PNAs and arenes detected were in a vapor state. Eighteen samples for total and respirable dust were collected on the terrigator and grader and one personal respirable dust sample was obtained. Two samples exceeded the OSHA total dust standard and two samples exceeded the 10-hour NIOSH recommended time-weighted average (TWA) of 50 g/m3 for
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rcspirable tree silica. All rcspirable samples exceeded 50 g/m-; before allowing for nonexposure during nonworking hours.
The eight.noise dosimeter measurements taken indicated that high noise exposure occurred during grading operations at the land farm. The incinerator was not operating during the N1OSFI visits. Conclusions
NIOSH concluded that Rollins personnel are exposed to solvents. PNAs. and arenes which were very similar to those compounds measured in the bulk land farm holding pit samples. Excess respiratory and eye irritation among Rollins employees, complaints of eye and lung irritation among Allied workers who worked outdoors, and excess eye irritation complaints from citizens of Alsen may be attributed to dust-bearing PNA materials blowing throughout the Rollins site and off site. The cyclohexane-soluble fraction of airborne participate concentrations measured at Rollins are known to produce eye irritation. Land farm workers are overexposed to noise and silica. The landfill personnel may have similar exposures, but were not included in this study.
NIOSH recommended:
• Basit "hygiene facilities and storage facilities for protective equipment must be improved • Gloves and aprons should be selected to protect against carcinogenic skin hazards • If crushing drums with residual contents is necessary, the process should be Name of Report Health Hazard Evaluation Report Grosse Pointes-Clinton Refuse Disposal Authority Mount Clemens, Michigan HETA 90-348-2135 Type of Waste Municipal solid wastes Facility Design The incinerator is a continuous feed/mass burner design with two parallel PCCs. The floor of each PCC is an inclined reciprocating grate approximately 12 feet wide by 40 feet long. Refuse is dumped from the 64 of 94 7/10/01 1:08 PM (iuHlance Manual lor 1'uhlic Health Assessor-; hup: \v\\ \v .al^lr.^L' jn\ \i 'A > iiu-iuial-uuult.1 Liiiide.litnil garbage trucks into a storage pit, an overhead crane then transfers the refuse to a continuous teed hopper which drops the refuse into the PCC at a controlled rate. The reciprocating grate slowly pushes refuse from the top of the chamber toward a water-filled ash-collection system. When refuse first enters the PCC the heat drives off the water and may pyrolyze some of the more volatile materials. The solids and the pyroly/ed gases ignite as the refuse moves down the grate. After about 20 minutes the unburned materials and bottom ash reach the end of the PCC grate and fall into a water-filled channel. The 1500F gases and fly ash are carried into a SCC and then into a conditioning and cooling tower. The cooling tower has water sprays to cool the exhaust gases and capture some of the participate matter. An induced draft fan downstream of the electrostatic precipitator next draws the gases through the electrostatic precipitator which traps most of the remaining fly ash before exiting the stack. The induced draft fan maintains the system under negative pressure to minimize the escape of gases and fly ash. After the refuse is lit, it burns continuously all week without needing auxiliary fuel burners. The bottom ash, unburned refuse, and fly ash are all collected in the water-filled conveyor channel located under the incinerator and air pollution control equipment. The fly ash collected in the electrostatic precipitator is carried to the water channel in an enclosed mechanical conveyor. Eventually, all the materials collected in the water channel are removed by a continuous drag conveyor which carries it up a ramp and dumps it into a truck for disposal. • Friday evenings, the furnaces are shut down to allow them to cool overnight. On Saturdays, the PCCs are opened and two to four workers enter them to clean the grates with push brooms. Any slag which may have built up is broken off with a pick axe. After the PCCs are cleaned, the access doors to the under-fire air chamber below the reciprocal grates are opened to remove, if necessary, any built-up ash or debris. One worker climbs in to perform the cleanup. Background In July 1990, NIOSH received a request from employees to evaluate possible employee exposures to silica, lead, cadmium, and mercury from inhalation of ash, particularly during the once-a-week furnace cleanout. The only personal protection equipment employees wear while cleaning the furnace are disposable dust masks. NIOSH investigators visited the incinerator facility in November 1990 and March 1991, to observe the operations and to collect air and ash samples. The Refuse Authority was formed in the early 1960s. The report did not state when the incinerator was constructed. Summary Because the highest exposures were expected to occur during the furnace cleanout, air sampling was conducted at that time, and 25 air samples were collected. Some samples were collected in a worker's breathing zone using a battery-powered pump attached to the employee's belt, and some area samplers were suspended from pipes on the inside wall of the PCC at a height of about 5 feet. Ten samples were analyzed for respirable dust (<10 microns in diameter) and crystalline silica, ten samples for total dust and elements, and five samples for mercury. Four bulk samples of ash were analyzed for arsenic, beryllium, cadmium, chromium, lead, nickel, and zinc. No beryllium or arsenic was detected. While the number of bulk ash samples is too limited to allow for conclusions, the data seem to suggest that fly ash collected in the electrostatic precipitator may have higher metal content than the bottom ash from the PCC. Employees are exposed to the bottom ash when cleaning out the PCC, a task that takes 1 to 2 hours every week. Two of the four area samplers and one of the six personal samplers indicated average dust concentrations that were well above the limits specified by OSHA and American Conference of Governmental Industrial Hygienists (ACGIH), if one assumes that those exposures continued for 8 hours each day. Since the furnace cleanout lasts less than 2 hours, the 8-hour TWA must be used. Only two of 65 of 94 7/10/01 1:08 PM (.iuulancc Manual lor Public Health A>seNsm- littp: \\\\ w .al^lr *.\L' ui». M-'i\S the; nui'i-^uidc ^uidc.html the samples, the area sample taken under the burner grate and one of the personal samples worn by an employee involved in the furnace cleanout, indicated an OS HA violation for total dust. Respirable dust levels were close to, but did not exceed, the OSHA standard. The concentrations of metals in the dust samples were highly variable, but none of them exceeded OSHA or NIOSH recommended limits. One personal sample slightly exceeded the NIOSH standard for crystalline silica. Conclusions A dense cloud of ash and other particles became airborne during the incinerator cleanout. Because of the constantly changing composition of municipal refuse from week to week it is likely that the elemental content of the ash will also vary. NIOSH recommended that exposures to dust be minimi/ed by • Spraying water on the ash before employees enter the furnace to sweep the grates. • Controlling the direction of air movement inside the furnace, if possible, to carry the dust away from the employees, • Requiring workers to wear full-face piece respirators in a pressure-demand or positive-pressure mode, • Not allowing workers to enter the under-fire area until the upper chamber is completely cleaned, • Providing workers with goggles and disposable coveralls and requiring them to shower and change before leaving the work site, and • Requiring workers entering the under-fire area to wear a safety line and not allowing them to work alone. Public Health Assessment Implications This study concludes that workers who enter incinerators to clean them out may be exposed to dust and other particulates (metals, silica, etc.) at levels of health concern if they do not wear appropriate protective equipment. Because the content of the wastes being burned is highly variable at municipal incinerators, as well as at hazardous waste incinerators and desorbers, workers entering thermal treatment units should wear full-face piece respirators and coveralls, and change and shower before leaving the work site. The public's exposure to dust generated when cleaning out incinerators is not likely to cause off-site exposure. 5.2.6. Delaware source Recovery Facility (PA) Name of Report Delaware County Resource Recovery Facility Chester, Pennsylvania HETA 91-0366-2453 Type of Waste Municipal Facility Design The Delaware County Resource Recovery Facility (DCRRF) is a waste-to-energy incinerator that began burning waste on March 6, 1991. The facility incinerates MSW and refuse derived fuel (RDF), a shredded form of MSW, to produce energy. MSW contains primarily paper products, yard and food wastes, metals, rubber, and glass. The facility has six combustor-boiler trains that use proprietary design water-walled rotary combustors engineered to burn approximately 448 tons of MSW per day. Each combustor consists of a 13.3-foot diameter rotating inclined cylinder using induced draft fans to provide combustion air to the burners. 66 of 94 7:10/01 1:08 PM Guidance Manual Im l'i;i>iK I lea 1th Assessors ;'''P; 'A ''•'• '•'• -:l ">'; '-'•'- - ' - '•' •• ^ u -'-•••• '.'-'>••* . :.>.c.html After an operator sorts the MSW at the plant, the MSW is moved by conveyor to an inclined feed chute leading into the combustor. Air pollution is controlled using spray dryers and baghouses for each unit. Pulveri/.ed lime slurry is injected into a reaction vessel where acid gases (mainly sulfur dioxide and hydrochloric acid) are absorbed. The system design incorporates flue gas evaporation in an atomi/ed lime slurry to produce a dry calcium salt. A baghouse is Uoed downstream of the spray dryer to collect the spray dryer reactant products, imreacted sorbent, and fly ash. Background On August 8, 1991, NIOSH received a request for a health hazard evaluation of the DCRRF. The request was submitted on behalf of the contractors regarding conditions during construction and initial operation of the facility. It specifically identified complaints of eye irritation; ear, nose, and throat problems; skin rash; heat stress; and concern about exposure to the lead-containing dust of incinerator ash. In December 1991, NIOSH conducted a site visit and interviewed employees, collected medical monitoring records and bulk samples of incinerator ash and settled dust samples. Based on the results of this initial walk through, NIOSH returned in June 1992, to conduct full-shift personal monitoring for lead and other metals, silica, and respirable dust. Summary NIOSH collected 34 personal breathing zone (PBZ) and general area air samples. Employees wore two sampling trains: one was configured to sample for respirable dust and silica, and the other was configured to sample for metals. Because NIOSH suspected that workers were transporting ash on their boots to a carpeted administrative area at the DCRRF, investigators collected dust samples from the carpet and from a chair. Wipe samples were also collected from workers' hands and from the tops of tables in the contractor's break/lunch trailer. No metals were detected at elevated levels in the air samples. None of the PBZ samples for lead exceeded the OSHA PEL of 50 g/m3 for an 8-hour TWA. Chromium and cadmium samples did not exceed their respective OSHA PELs, ACGIH Threshold Limit values (TLVs), or NIOSH Recommended Exposure Limits (RELs). Nickel was not detected. Although PBZ and area samples for respirable dust were all below the OSHA PEL of 5 mg/m3, NIOSH concluded that this criteria may not be appropriate because exposure to these dusts also involves a potential exposure to toxic metals. Neither respirable quartz nor cristobalite were detected in the respirable dust samples. Lead, chromium, cadmium, and nickel were present on the wipe samples from workers' hands and from the tops of lunch tables. Lead was found in greatest abundance. The presence of metals in the wipe samples indicated an increased risk of ingestion of toxic metals for workers in contact with incinerator ash. Although NIOSH did not cite the results of its bulk analysis, it reported that, according to the DCRRF Municipal Incinerator Ash Residue Monitoring Report dated March 20, 1991, the lead content of the ash was 6.44% lead on a dry-weight basis. Conclusions NIOSH concluded that inhalation exposure to lead was not an occupational hazard at the DCRRF. Although lead was found in bulk and wipe samples, the PBZ samples ranged from nondetectable to 4.6 g/m3. However, NIOSH concluded that a potential occupational exposure to toxic metals via ingestion existed. Lead, chromium, cadmium, and nickel were detected in wipe samples collected from lunch tables and the hands of employees. Although PBZ samples for respirable dust did not exceed the OSHA 67 of 94 7'10/01 1:08 PM C Manual ;o: i'ir>lit- llcallh Assessor Intp: v. ^ \valsdr.o.lc.uc^ M-\VS thcmial-guklc yuide.html PHL. N1OSH concluded that this PEL is probably insufficiently protective because of the presence of toxic elements in the incinerator ash. Respirable silica was not detected. N1OSH recommended improvements in workplace hygienic practices—specifically hand washing. NIIOSH also recommended characterizing the fugitive ash emissions from the residue building. During the second N1OSH visit, investigators noted that airborne fly ash was escaping from the residue building and blowing towards neighborhoods in nearby Chester, Pennsylvania. The situation appeared to be compounded by the wind coming off the Delaware River. NIOSH noted that the layout and construction of the residue building, with large doors opened at either end, favored wind funneling through the building as the scrap trucks were loaded. Public Health Assessment Implications NIOSH investigators did not find any workplace inhalation exposures to metals, respirable dust, or silica in excess of occupational standards. However, NIOSH noted that fugitive ash emissions from the residue building were blowing towards neighborhoods. Residents of these neighborhoods may have a small risk of inhalation or dermal exposure to the toxic metals in these dusts. 8.2.7. Monroe County Incinerator (FL) Name of Report Health Hazard Evaluation Report Monroe County Incinerator, Key Largo, Florida HETA 82-056-1186 Type of Waste Municipal solid wastes and medical wastes Facility Design The facility has three reciprocating grate furnaces with combined capacity of 300,000 pounds per 24-hour period. Each incinerator is batch-charged every 8 minutes with 560 pounds of mixed municipal and hospital wastes, or municipal wastes alone. Each batch typically includes about 180 to 200 pounds of hospital waste. The grate is designed to retain the ash and cinders, however, part of the ash falls through the grate into an ash hopper. An employee must go beneath the incinerator periodically and remove an iron cover allowing ash to fall on the floor, then scrape the balance out by hand or by water spray. Most of the ash is conveyed from the incinerator in a quenched ash conveyor channel. The conveyor channel lacks guard rails at several points. Rain water from the incinerator building roof drains into a cistern. If the temperature goes above 1800F, the collected rain water is used to cool the combustion chamber. Auxiliary water is fed to the cistern from the county drinking water system. The type of connection used creates the potential for contaminated cistern water to backflow into the drinking water system. News reports in 1982 indicated a continual low-pressure problem in the county water system. Background On November 24, 1981, NIOSH received a request to evaluate the Monroe County Incinerator, North Key Largo Plant #1 in Key Largo, FL. The employees were concerned about biohazards and exposure to "fly ash from the incinerated hospital waste." The facility was evaluated on January 6-7, 1982, by the UNC's Occupational Health Studies Group. The facility began operation in September 1981, and initially burned only household wastes. Private haulers pick up the hospital wastes and bring them to the incinerator. The driver typically backs his truck into the incinerator building and unloads the bagged hospital wastes by hand from the truck into the 68 of 94 7/10/01 1:08 PM Guidance Manual t'oi i\ihlic Health Assessors hup: \\ \v\\ .jtsdr.i\k'.i:o'. \1-\VS fnemul-iuude uiiHle.html front-end loader bucket. Summary Investigators observed the transferring of hospital waste from trucks to the charging hopper, one employee was observed while he was removing the ash from the ash hopper under the grate, and samples of the grate siftings (ash) were analyzed. Several employees were interviewed, but none complained of adverse health effects. Employees reported that occasionally the plastic bags of hospital waste break during handling or transport in the truck. One employee reported seeing human body parts and blood being spilled from the truck onto the incinerator building floor. Other employees had not seen body parts but had seen blood leaking from bags onto truckbeds and the incinerator floor. All the hospital wastes appeared to be double-bagged and none were broken or leaking during the site visit. The employee cleaning out the grate siftings wore monogoggles but no dust respirator. The procedure took about 30 minutes. Samples of the ash contained 0.08 to 0.12 % volatile material when ignited to 1000F. The percent of volatile material was consistent with or less than the concentration expected. There was no indication that hospital wastes are leaving the incinerator partly unburned. Conclusions • Guard rails are needed along the ash conveyor channel to prevent workers from falling into the channel and being mangled or drowned. • The backflow connection between the cistern and the county water line needs to be inspected and replaced if needed to prevent contamination of the county drinking water system. • Equipment and procedures to remove and convey hopper ash with minimal worker exposure should be provided. In the meantime, disposable NIOSH approved dust masks and eye protection should be worn by employees while cleaning ash hoppers. • No immediate biohazard was identified during the site visit; however, worker exposure to infectious wastes due to breakage of the bags is possible. Public Health Assessment Implications Workers at facilities handling infectious or medical waste should wear PPE to prevent exposure to infectious wastes or particulates. The public's off-site exposure to infectious wastes is unlikely. The only potential public exposure identified by this study is the potential for backflow of water from the cistern into the public drinking water supply. At industrial sites, all tanks that are connected to a public water system should have a valve to prevent backflow. 8.2.8. Northwest Incinerator (PA) Name of Report Northwest Incinerator Philadelphia, Pennsylvania HETA 88-207-2195 Type of Waste Municipal Facility Description Built in 1959, the Northwest Incinerator consists of two furnaces. The furnaces operate at 1650F to 1900F, and can each burn approximately 700 tons of garbage per day. Crane operators in enclosed cabs dump the garbage into hoppers leading to the inclined stoker and horizontal conveyor belt inside of each 69 of 94 7/10/01 1:08 PM uudance Manual for Public Health Assessor hup. -.\u.v. atsilr.alc.uuv N1-\\'S thermal-guide guide.html furnace. The emission control system for each furnace consists of a cooling tower, drying tower, and an electrostatic precipitator which are fed by an induced draft. Fly ash from the emission system and the incinerator are quenched with water and then cooled in a residue tank. The ash is then dumped into a truck and transported to a landfill. Background In March 1988, NIOSH received a joint request from Philadelphia and the American Federation of State, County, and Municipal Employees, District 33, Local 427 to evaluate potential employee exposures at the city's Northwest Incinerator. The request was submitted in response to a March 1988 report issued by EPA and ATSDR, evaluating potential community exposures from the incinerator. Although the report concluded that no significant health hazard existed for the community, it indicated that incinerator workers were the "potentially exposed population of most concern," and recommended that the city request NIOSH to evaluate potential worker exposures. NIOSH conducted an initial site visit on June 9, 1988, and returned for environmental sampling on June 22-26, 1988. Summary NIOSH focused its investigation on evaluating potential employee exposure to PCDDs, PCDFs, metals, silica, total dust, and respirable dust. NIOSH collected 12 general air area and 15 PBZs for dust, metals and silica. For the PBZs, employees were asked to wear two personal sampling pumps; one evaluated potential exposures to respirable dust and silica, the other evaluated potential exposure to total dust and metals. NIOSH collected six general air samples for PCDDs and PCDFs; however, PBZs for PCDDs and PCDFs were not possible due to the size of the sampling media. The PCDDs and PCDFs samples were expressed as 2,3,7,8-TCDD equivalents, using both EPA 1987 toxicity equivalency factors (TEFs) and the 1989 International TEFs. Using the 1987 criteria, the six air samples ranged from 0.01 to 12.8 picograms per cubic meter (pg/m3), while using the 1989 criteria the samples ranged from less than 0.001 to 24.2 pg/m3. The only sample exceeding the National Research Council (NRC) guideline of 10 pg/m3 was collected during furnace cleaning. Five wipe samples were collected for PCDDs and PCDFs at the main office, lunchroom, change room, incinerator floor and a hotel room (for a background sample). Only the sample collected from the incinerator floor was at the NRC acceptable limit for dioxin. However, the results showed that PCDDs and PCDFs were being transported to the office, lunchroom, and change room via air or on the clothes of employees. Airborne concentrations of respirable nuisance dust (27 samples) were all well below the OSHA Permissible Exposure Limit (PEL) of 5 mg/m3. Two of the 27 samples contained trace amounts of silica. Of the 27 total dust samples collected, one exceeded the OSHA PEL of 15 mg/m3 and two exceeded the lower ACGIH TLV of 10 mg/m3. One PBZ sample exceeded the OSHA PEL for lead and the ACGIH TLV (but not the OSHA PEL) for cadmium. One PBZ and one area air sample exceeded the NIOSH REL for nickel (0.026 mg/m3). Seven surface wipe samples collected for metals indicated that the major constituents of the surface dust were metals with relatively low toxicity. However, one sample contained a significant amount of lead. The results suggested that incinerator ash was being transported on the clothes and shoes of employees from the work areas to other areas of the facility. Conclusions The environmental sampling data indicated that the potential existed for employee overexposure to PCDDs, PCDFs, and metals via inhalation and surface contact from the incinerator ash. Because the Northwest incinerator closed immediately following the NIOSH survey, NIOSH's recommendations 70 of 94 7/10/01 1:08 PM Guidance Manual for Public Health Assessors hup:. v\ \\ \\.atsdr ctic go\ M:\VS. thermal-guide guide.html focused on remediation or reopening of the site. NIOSH recommended that remediation or reopening of the site should follow all requirements of RCRA and CERC'LA to ensure that personnel entering the site are adequately protected. NIOSH also recommended that competent industrial hygiene and safety- professional should he used to help establish an adequate health and safety program should the facility- reopen. Public Health Assessment Implications Although the environmental sampling data indicated the potential for employee overexposure to both PCDDs and PCDFs via inhalation and dermal contact with the ash, it is unlikely that the public would have been impacted by fugitive emissions from the plant. Because the incinerator closed after NIOSH's investigations, no current public exposures are possible. 5.2.9. Lutheran Medical Center (NY) Name of Report Lutheran Medical center Brooklvn, New York HETA88-314-2152 Type of Waste Medical, infectious, pathological, biological Facility Description The pathological waste incinerator was located in a partial 6th floor that covered a portion of the roof. Licensed to bum 175 pounds of infectious waste per hour, the incinerator was manually loaded and employed two stage combustion followed by a scrubber for final control of emissions. Incinerator emissions passed through the scrubber located in the penthouse above the incinerator room before being released to the outside atmosphere. The scrubber stack extended beyond the roof of the penthouse by approximately 8 feet and the top of the stack was estimated to be approximately 35 feet above the roof of the medical center building. Air handling units (AHUs) were contained within fan enclosures on the roof of the 5th floor at varying distances from the incinerator/scrubber stack. Background On July 12, 1988, NIOSH received a request from employees at the Lutheran Medical Center concerning a variety of noxious odors in the hospital that were potentially originating from the medical center's pathological waste incinerator. They were concerned that exposures to incineration products could be affecting their health. On November 29, 1988, NIOSH investigators conducted a preliminary evaluation of conditions at the hospital and interviewed workers to determine the extent of their work-related health complaints. Employees reported headaches, nausea, hair loss, and dermatitis. Several workers indicated that the Neonatal Intensive Care Unit was affected by intermittent episodes of noxious odors, and that patients had been evacuated due to the odors on one occasion. Based on this initial investigation, NIOSH returned in April 1989, to conduct an industrial hygiene survey and tracer gas study to evaluate the potential for reentry of incinerator exhaust emissions into the hospital's ventilation systems. Summary NIOSH focused its investigation on assessing the potential for the hospital's ventilation system to entrain emissions from the hospital's pathological waste incinerator. In addition to obtaining and reviewing drawings of the hospital's ventilation system, NIOSH investigators conducted a tracer gas study and collected environmental samples. Collecting both general-area air and PBZ samples, NIOSH sampled (iuidance Manual tor Public Health Assessors http: \\v.\\ .atsdr.cdc.gov \li\VS thermal-guide guide.html for total and rcspirahlc participates, metals, and VOCs. N1OSH also monitored carbon dioxide levels throughout the hospital. The highest detectable airborne concentrations of total and respirable participates were less than 5% of the NIOSH REL of 10 mg/m-' and 5 mg/'m3, respectively. General-area air samples collected for qualitative screening for VOCs showed that all samples contained toluene, xylenes, isopropanol, some alkanes, and a series of various aliphatic hydrocarbons. Based on the results of the qualitative screenings for VOCs, 23 quantitative samples were analyzed for the compounds detected qualitatively. Toluene, xylene, isopropanol, trichloroethylene, and 1,1,1-trichloroethane were detected in some samples but all detected levels were less than 1% of NIOSH RELs. Carbon dioxide levels inside the hospital ranged from 575 ppm to 850 ppm. As the indoor concentration approaches and exceeds 1,000 ppm there is an indication that inadequate amounts of fresh air are being delivered to those areas. Tracer-gas sampling in rooms served by AHUs #1 and #4 showed that entry of incinerator stack emissions occurred under certain meteorological conditions. In the afternoon, prevailing winds blew the incinerator emissions towards the AHUs fresh-air intakes. However, the calculated dilution factors were large, and emissions were greatly diluted. Conclusions The tracer-gas evaluation showed that entrainment of incinerator stack emissions was possible under certain meteorological conditions; however, there were no documented over-exposures to any of the chemical substances evaluated. NIOSH recommended evaluating the effect of stack height and/or modifying the air handling unit fresh air intakes in the event the pathological waste incinerator was restarted. Public Health Assessment Implications When evaluating thermal treatment facilities, public health officials should evaluate whether stack emissions will enter the fresh air intake units for nearby buildings. Chapter 9 - Recommended Resource Books 9.1. ATSDR Resource Books The following ATSDR documents are available through ATSDR or the National Technical Information Services (NTIS). Many of them are also on ATSDR's Web site at http://atsdr.cdc.gov/HAC. • Public Health Overview of Incineration as a Means to Destroy Hazardous Waste - Guidance to A TSDR Health Assessors • Environmental Data Needed for Public Health Assessments - A Guidance Manual • Public Health Assessment Guidance Manual • Toxicological Profiles (for different chemicals) 9.2. EPA Resource Books Copies of the following EPA documents can be obtained from NTIS. Copies of the EPA hazardous waste regulations, including the preamble and background documents, as well as a number of memos, Guidance Manual lor Public Health Assessois Imp: \v\v\\.atsdr.cdc.govNK\VS thermal-guide uuule.html and letters regarding incineration, industrial furnaces, and thermal desorption can be found on HPA's Web site nt ::i. -. :'...;.••. ,-p <>•-•.•..•• I1;:.-"A ;•-!,•'•••;•"': : i • •. EPA also has two combustion training modules on their web site under the heading "RCRA Hotline Training Modules"; one is called Introduction to Hazardous Waste Incineration and the other one is Introduction to Strategy for Hazardous Waste Minimization and Combustion. • Guidance Manual for Hazardous Waste Incinerator Permits. Volume I of the Hazardous Waste Incineration Guidance Series. Office of Solid Waste and Emergency Response. SW966. July 1983. • 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. • Handbook: Hazardous Waste Incineration Measurement Guidance Manual. Volume III of the Hazardous Waste Incineration Guidance Series. Office of Solid Waste and Emergency Response. EPA/625/6-89/02 I.June 1989. -_ • Handbook: Quality Assurance/Quality Control (QA/QC) Procedures for Hazardous Waste Incineration. Office of Research and Development. EPA/625/6-89/023. January 1990. • 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. • 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. • Engineering Handbook for Hazardous Waste Incineration. Office of Solid Waste. SW-889. September 1981. • Background Information Document for the Development of Regulations for PIC Emissions from Hazardous Waste Incinerators. Office of Solid Waste. October 1989. 9.3. Other Technical Resource Books Numerous books and journal articles are available on the various aspects of incineration as a technology and on the permitting of hazardous waste incinerators. However, references regarding thermal desorption are limited. Following is a list of books on the topic. ATSDR staff may borrow a copy from DHAC. • Hazardous Waste Incineration - a Resource Document. The American Society of Mechanical Engineers. New York: ASME. January 1988. • Innovative Site Remediation Technology - Thermal Desorption. American Academy of Environmental Engineers. Anderson WC, editor. Annapolis, MD: AAEE copyright; 1993. • Innovative Site Remediation Technology - Thermal Destruction. American Academy of Environmental Engineers. Anderson WC, editor. Annapolis, MD: AAEE copyright; 1994. • Hazardous Waste Incineration: Evaluating the Human Health and Environmental Risks. Roberts, Teaf, Bean, ed. Lewis Publishers. Baco Raton, FL:1999. • Hazardous Waste Incineration and Human Health. Travis CC, Cook SC. CRC Press, Inc. Boca Raton, FL: 1989. • Health Effects of Municipal Waste Incineration. Hattemer-Frey HA, Travis CC, ed. CRC Press, (iuidancc Manual I'm Public Health Asicssor> http: \\u\\.atsilr.cdc.go\. Nl-AVS thermal-guide gun.lf.html Inc. Boca Raton, FL: 1991. • Waste Incineration and Public Health. National Research Council. National Academy Press. Washington, DC: Sep 1999. • Proceedings - International Conference on Incineration and Thermal Treatment Technologies for years: 1991, 1993, 1995, 1998, '1999, 2000. Copyright: The Regents of the University of California. Irvine. References AAEE 1993 American Academy of Environmental Engineers. 1993. Innovative site remediation technology - thermal desorption. Anderson WC, editor. Annapolis: AAEE. ATSDR 1992a Agency for Toxic Substances and Disease Registry. Public health overview of incineration as a means to destroy hazardous wastes - guidance to ATSDR health assessors. Atlanta: US Department of Health and Human Services. Feb 1992a. ATSDR 1992b Agency for Toxic Substances and Disease Registry. Public health assessment guidance manual. Atlanta: US Department of Health and Human Services. 1992b. ATSDR 1993 Agency for Toxic Substances and Disease Registry. Study of symptom and disease prevalence Caldwell Systems, Inc. hazardous waste incinerator, Caldwell County, North Carolina. Atlanta: US Department of Health and Human Services. Sep 1993. ATSDR 1995 Agency for Toxic Substances and Disease Registry. Symptom and illness prevalence with biomarkers health study for Calvert City and Southern Livingston County, Kentucky. Atlanta: US Department of Health and Human Services. May 1995. ATSDR 1997a Agency for Toxic Substances and Disease Registry. ATSDR record of activity for telephone communication with Bob Montione of New York State Department of Health. Atlanta: US Department of Health and Human Services. 1997 Feb 13. ATSDR 1997b Agency for Toxic Substances and Disease Registry. Exposure investigation - Vertac, Incorporated. Atlanta: US Department of Health and Human Services. 1997 Aug 11. ATSDR 1998a Agency for Toxic Substances and Disease Registry. Adverse reproductive outcomes in Pulaski County for years 1980 through 1990. Atlanta: US Department of Health and Human Services. Mar 1998a. ATSDR 1998b Agency for Toxic Substances and Disease Registry. Health outcome follow-up study of residents living near the Caldwell Systems, Inc. site, Caldwell County, North Carolina. Atlanta: US Department of Health and Human Services. Aug 1998b. ATSDR 1999a Agency for Toxic Substances and Disease Registry. Dioxin incinerator emissions exposure study, Times Beach, Missouri. Atlanta: US Department of Health and Human Services. July 1999a. ATSDR 1999b Agency for Toxic Substances and Disease Registry. Follow-up investigation of B-cell abnormalities identified in previous ATSDR health studies. Atlanta: US Department of Health and Human Services. July 1999b. (iuidaiKe Manual tin Punlic Health Assessors http: \\ v,v\ ats \1-\VS theimal-uuidegmde.html ATSDR 2<)00 Agency for Toxic Substances and Disease Registry. A FSDR record of activity for telephone communication with Robert Field of HP A Region VII.. Atlanta: I'S Department of Health and Human Services. 2000 July 11. ATSDR EPA EPA designs for air impact assessments at ha/ardous waste sites. Manual containing 1997 lectures by ATSDR and EPA/ERT for course at ATSDR. Atlanta: US Department of Health and Human Services. Feb 1997. EPA 1989 US Environmental Protection Agency. Guidance on setting permit conditions and reporting trial burn results, Vol II of the ha/ardous waste incineration guidance series. EPA/625/6-89/019. Washington, DC: EPA. Jan 1989. EPA 1993 US Environmental Protection Agency. Engineering bulletin - thermal desorption treatment. Vol. 2. EPA/540/0-00/000. OERR, Washington, DC and ORD, Cincinnati, OH. EPA 1994 US Environmental Protection Agency. Exposure assessment guidance for RCRA hazardous waste combustion facilities. EPA530-R-94-021. Washington, DC: EPA. April 1994. EPA 1998a US Environmental Protection Agency. RCRA, Superfund & EPCRA hotline training module - introduction to: applicable or relevant and appropriate requirements. EPA540-R-98-020 OSWER9205.5-10A. Washington, DC: EPA. June 1998. EPA 1998b US Environmental Protection Agency. Human health risk assessment protocol for hazardous waste combustion facilities. EPA530-D-98-001 A, B & C, peer review draft. Washington, DC: EPA. July 1998. 64 FR 52869-70 NESHAPS: Final standards for hazardous air pollutants for hazardous waste combustors. Federal Register 1999 Sep 30; 64:52828-53077. Kulwiec 1985 Kulwiec, RA, editor. 1985. Materials handling handbook. New York: John Wiley & Sons. NIOSH 1982a National Institute of Occupational Safety and Health. Health hazard evaluation report HETA 80-232-1055 Allied Chemical, Baton Rouge, Louisiana. Cincinnati: US Department of Health and Human Services. Feb 1982a. NIOSH 1982b National Institute of Occupational Safety and Health. Health hazard evaluation report HETA 81-037-1055 Rollins Environmental Services, Baton Rouge, Louisiana. Cincinnati: US Department of Health and Human Services. Feb 1982b. NIOSH 1982c National Institute of Occupational Safety and Health. Health hazard evaluation report HETA 82-056-1186 Monroe County incinerator, Key Largo, Florida. Cincinnati: US Department of Health and Human Services. Sep 1982c. NIOSH 1988 National Institute of Occupational Safety and Health. Health hazard evaluation report HETA 86-519-1874 ENSCO, El Dorado, Arkansas. Cincinnati: US Department of Health and Human Services. Feb 1988. NIOSH 199 la National Institute of Occupational Safety and Health. Health hazard evaluation report HETA 90-348-2135 Grosse Pointes-Clinton Refuse Disposal Authority, Mount Clemens, Michigan. Cincinnati: US Department of Health and Human Services. Sep \ i » . r\ o n A Cimdance Manual lor Public Health Assessors littp: \\w\v.atsdi ale.yo\ N l:\VS.1 thermal-guideguide.html 199 la. NIOSH 1991b National Institute of Occupational Safety and Health. Health ha/ard evaluation report HETA 88-314-2151 Lutheran Medical Center. Brooklyn, New York. Cincinnati: US Department of Health and Human Services. Oet 1991b. NIOSH 1992a National Institute of Occupational Safety and Health. Health ha/ard evaluation report HETA 88-207-2195 Northwest incinerator, Philadelphia. Pennsylvania. Cincinnati: US Department of Health and Human Services. Mar 1992. NIOSH 1992b National Institute of Occupational Safety and Health. Health hazard evaluation report HETA 90-240-2259 the Caldwell Group, North Carolina. Cincinnati: US Department of Health and Human Services. Oct 1992. NIOSH 1994 National Institute of Occupational Safety and Health. Health ha/ard evaluation report HETA 91-0366-2453 Delaware County Resource Recovery Facility, Chester, Pennsylvania. Cincinnati: US Department of Health and Human Services. Sep 1994. NIOSH 1995 National Institute of Occupational Safety and Health. Health hazard evaluation report HETA 90-0329-2482 New York City Department of Sanitation, New York, New York. Cincinnati: US Department of Health and Human Services. Jan 1995. PittsD 1998 Pitts D. Metals: control, compliance and monitoring-advanced tutorial. Presented at: International Conference on Incineration and Thermal Treatment Technologies Meeting; 1998 May 11-15, Salt Lake City. Shyetal. 1995 Shy CM et al. 1995. Do waste incinerators induce adverse respiratory effects? An air quality and epidemiology study of six communities. Env Health Perspectives 103(7-8):714-724. Appendix A - Acronyms and Abbreviations AAEE - American Academy of Environmental Engineers ACGIH - American Conference of Governmental Industrial Hygienists AHUs - Air handling units APCD - Air pollution control device APCE - Air pollution control equipment ARAR - Applicable or relevant and appropriate (standards, limitations, criteria, and) requirements ARHMS - Arkansas Reproductive Health Monitoring System ATSDR - Agency for Toxic Substances and Disease Registry AWFCO - Automatic waste feed cutoff system [pronounced "off- co"] AWFSO - Automatic waste feed shutoff system in m i ns PM iuidance Manual for Public Health Assessors http: w\v\v.atM.li-.cilc.L:ov Nl \VS ihermal-guule guide.htnil BVVI - Biological waste incinerator C - Centigrade CCIC - Culvert City Industrial Complex CD - Cluster designation CDC - Centers for Disease Control and Prevention CEM - Continuous emissions monitor CERCLA - Comprehensive Environmental Response, Compensation, and Liability Act of 1980 CFR - Code of Federal Regulations CIS - Caldwell Industrial Services, Inc. CO - Carbon monoxide CO2 - Carbon dioxide CSI - Caldwell Systems, Inc. 2,4-D - 2,4-Dichlorophenoxy acetic acid DC - Desorption chamber DCRRF - Delaware County Resource Recovery Facility DHAC - Division of Health Assessment and Consultation (ATSDR) DRE - Destruction and removal efficiency DS - Dry scrubber EPA - Environmental Protection Agency ESP - Electrostatic precipitator F - Fahrenheit FEV - Forced expiratory volume FF - Fabric filter (baghouse) FID - Flame ionization detector FR - Federal Register FS - Feasibility study FVC - Forced vital capacity GEP - Good engineering practice GIS - Geographic information system "7''10/01 1:08 PM (iuiduncc Manual tor Public Health Assessors hup: \\ww.atsdr.cdc.gov, Nl-AVS thermal-guule guide.litml GC/MS - Gas chromatograph (with) mass spectrometer (detector) HC - Hydrocarbon HC1 - Hydrogen chloride HEPA - High efficiency particulate air (filter) HHE - Health hazard evaluation H&S - Health and safety HVV - Hazardous waste IWS - Ionizing wet scrubber kV - Kilovolt kVA - Kilovolt-amperes LDR - Land disposal restrictions LEL - Lower explosion limit LTTD - Low temperature thermal desorber MACT - Maximum achievable control technology MCL - Maximum contaminant level MEI - Maximum exposed individual MER - Maximum exposed receptor mg/m3 - Milligrams per cubic meter mg/min - Milligrams per minute MSDS - Material safety data sheet MSI - Mitchell Systems, Inc. MSW - Municipal solid waste MWC - Municipal waste combustor NC-DOSH - North Carolina Division of Occupational Safety and Health ND - Not Detected or nondetect ng/dscm - Nanogram(s) per dry standard cubic meter ng/m2 - Nanogram(s) per square meter NIOSH - National Institute for Occupational Safety and Health •7 in 01 i -OR PM Guidance Manual tor Public Health Assessors http: uv\\\ .atsdi.cdc.gov, NK\VS thermal-guide uuide.html MIST - National Institute of Standards and Technology NOD - Notice of deficiency NOV - Notice of violation NOX - Nitrogen oxides [pronounced "knocks"] NPDES - National Pollution Discharge Elimination System NPL - National Priorities List (EPA Superfund) NRC - National Research Council NTIS - National Technical Information Services O2 - Oxygen O&M - Operation and maintenance (plan) OR - Odds Ratio OSC - On-scene coordinator OSHA - Occupational Safety and Health Administration PBZ - Personal breathing zone PCB - Polychlorinated biphenyl PCC - Primary combustion chamber PCDD - Polychlorinated dibenzodioxin (dioxin) PCDF - Polychlorinated dibenzofuran (furan) PEFR - Peak expiratory flow rate PEL - Permissible exposure limit (OSHA standard) PFT - Pulmonary function test pg/m3 - Picogram(s) per cubic meter PIC - Product of incomplete combustion PID - Photo ionization detector PM - Particulate matter PNA - Polynuclear aromatic hydrocarbon POHC - Principal organic hazardous constituent POTW - Publicly owned treatment works Til 1 09 PVf (iuuiance Manual In i" 1'uhlic Health Assessors hup: \v\\\\ .atsih .cdc.yov Nh\VS thermal-gunk1 guule.html pph - Part(s) per billion PPK - Personal protective equipment ppm - Part(s) per million ppmv - Part(s) per million by volume PS - Packed scrubber ppt - Part(s) per trillion QA/QC - Quality assurance/quality control RCRA - Resource Conservation and Recovery Act of 1976 (amended 1984) RDF - Refuse derived fuel RE - Removal efficiency REL - Recommended exposure limit (NIOSH guideline) RI/FS - Remedial investigation/feasibility study RME - Reasonable maximum exposure ROD - Record of decision RPM - Remedial project manager S&A - Sampling and analysis SCC - Secondary combustion chamber SD - Spray dryer SO2 - Sulfur dioxide SOX - Sulfur oxides [pronounced "socks"] SVOC - Semivolatile organic compound 2,4,5-T - 2,4,5-Trichlorophenoxy acetic acid TBC - To-be-considered TCDD - Tetrachlorodibenzodioxin TCDF - Tetrachloro dibenzofuran TD - Thermal Desorber or desorption TEF - Toxicity equivalency factor TEQ - Toxicity equivalency quotient (iuiilance Manual I'm Public Health Assew>rs hup. \v\\ \v.atsilr.cdc.gov NHWS thermal-gunk- yun.le.html TIC - Tentatively identified compound TLV - Threshold limit value (ACGIH guideline) TRI - Toxic release inventory TRV - Thermal relief vent (or valve) TSCA - Toxic Substances Control Act TT - Thermal treatment TVVA - Time-weighted average g/m2 - Micrograms per square meter g/m^ - Micrograms per cubic meter UNC - University of North Carolina VOC - Volatile organic compound VS - Venturi scrubber WESP - Wet electrostatic precipitator WS - Wet scrubber Appendix B - Tables Table 1 - Key Design and Operating Information to be Reviewed Guidance Manual lor Public Health Assessor Imp: v. u w.atsdi.cdc. iiov Nl-WS thermal-yuule iuiule.html Waste analyses--concentration of organic and inorganie chemicals present in wastes Projected fate of contaminants and ultimate fate/disposal of residuals and effluents Estimated time for volatile organic breakthrough of the carbon adsorption system (if the facility- has a carbon adsorption system) Detailed description of the facility systems that affect emissions, i.e., o Waste feed handling o Combustion desorber chamber(s) o Treated waste handling o Flue gas treatment/air pollution control system o Monitoring equipment (thermocouples, pressure drop indicators, flow-rate meters, continuous emission monitors [CEMs], etc.) o Stack or vent height o Removal and handling of process residuals (bottom ash, fly ash, condensate. scrubber water, spent carbon, spent filters, etc.) Permits or approvals to operate and the operation and maintenance plan (O&M Plan) Performance test plan or trial burn plan Trial burn or performance test report and data Ambient air sampling and monitoring plans (if the facility has an ambient air sampling or monitoring system) Ambient air monitoring and sampling reports (on- and off-site) Modeling of stack emissions (if stack concentrations are at levels of health concern) Land use around the site Demographics of community Description of how materials will be excavated at CERCLA sites Description of how waste materials will be stored and any preprocessing to be done Contingency and/or site safety plan including action levels for unplanned releases Reports of incidents or noncompliance Table 2 - Applicability of Desorbers and Major Incinerator Types to Various Wastes Waste Type Liquid Rotary Fixed Fluidized Desorber Injection Kiln Hearth Bed j8lWar.''^^'vv^,:.. • ' -•••;• "; ->•• • .•• . • ~'i- tf ••-Vf.;.^"'>>:.*'!%^; ,____ x Granular, screened x r~^~r Bulky, large, irregular (pallets, etc.) X X Low melting point (tars, etc.) •\T X X x X* Containers (pails, drums, etc.) X X Organic compounds with fusible ash X X x X &I*P^^'-<: ••"•:•. -'^v$mmm ,'}-:;V-"; •'•.:.• • -'- •" l ; ^'- *',:'.•;-' •.-' •• •;<--.n^$?^! Organic vapors X ~\r X X X •••.:;•>:•>• •&?>•":}?•#£$$? Liquids•*- '"•;• ••"'*r.-.,:]: :-'... - •- . . .. '••''•'•• • <•- ,• '^$aM, &«wSiraIaHlalHiM HBBI*£I ^ x Organic liquids X X x r -x— r * Aqueous wastes X X X X X* v ; ; : •• ' ''"'i ;/ •••-.-: ;- *-•; " • ' .. *• < -•" >.- • . StSi^U--.-.:,- -' Kfei^'y; i .-V- •''->"•..- v .;•,•,*;•'' * "&': '., ,/*Aj5^i«S*»'-;Ril^ir* Halogenated aromatics requiring >2200F X X X Aqueous/organic sludge X X X* Source of data: EPA 1981 Guidance Manual tor Public Health Assessors p: \\\\.\v.al.sdr.cdc i;m Nl-AVS. thernul-mude uuide.html * In limited quantities simultaneously with solids "able 3 - Most Common Products oflncomplete Combustion from Hazardous Waste Incinerators (m»minlt PIC Range Mean Median Benzene 0.17-590 34 1.5 Toluene 0.12-95 17 5.0 Carbon tetrachloride NDJ-140 : 10 0.49 Chloroform 0.04-2,800 110 0.73 ; Methylene chloride ND-14 : 3.2 1.1 Trichloroethylene ND-99 i n 0.92 - _ Tetrachloroethylene ND 16 ' Y "" 1.4 -•••;•'" 0.76 Chlorobenzene ND-160 i 12 ! 0.27 Naphthalene 0.07-55 I 8.1 | 1.6 | t mg/min - milligrams per minute J ND - Not detected Source of data: EPA 1989 Table 4 - ARAR Identification Process 1. Scoping of the Remedial Investigation/Site Characterization List all chemicals present and location characteristics Identify potential chemical- and location-specific ARARs and TBCs Determine applicability and relevance and appropriateness of potential chemical and location specific ARAR 2. Screening and Development of Alternatives/Feasibility Study (FS) Identify all potential action-specific ARARs and TBCs for alternatives that pass through initial screening Determine applicability or relevance and appropriateness of potential action-specific ARAR 3. Detailed Analysis of Alternatives//Proposed Plans (FS) List preferred alternatives and all associated ARARs and TBCs identified Document and justify proposed ARAR waiver 4. Record of Decision Document reason for selecting final remedial alternative and how ARARs and TBCs will be attained Document and justify final ARAR waive ARAR = Applicable or relevant and appropriate requirements TBC = To-be-considered Source: EPA Web Page Tin ni i -n« r>vt Guidance Manual tor i'uhhc Health As.-,e.-,M>i s ctlj tiov NH\VS thermal-guide guide.html Table 5 - Conservative Estimates of Metals Partitioning to Flue Gas as a Function of Solids Temperature and Chlorine Content* Metal 1600 °F 200 0"F Clt = 0% ~ C1 = T% Cl = 0% Cl= 1% Antimony 100% --— • 100% : 1 00% 100% Arsenic ; ioo%"""~ ~~~ 100% " .' 100% 1 00% .., ...... 5f)% Barium —•-- 30%- ••"••[•" 100% 1 00% 'Beryllium 5% 5% i 5% 5% Cadmium 100% 100% ; 100% 1 00% ___... _5.%.. ;. jChromium 5% 5% 5% jLead : 100% 100% ; 100% 100% 1 Mercury 100% 100% | 100% 100% pSilver 1 8% 100% i 100% 100% jThallium 1 100% 100% | 100% 100% * The remaining percentage of metal is contained in the bottom ash. Partitioning for liquids is estimated at 100% for all metals. The combustion gas temperature is expected to be 100F-1000F higher than the solids temperature. t Cl = Chlorine. Source of data: EPA 1989 Table 6 - Metal Volatility Temperatures Metal WITHOUT CHLORINE WITH 10% CHLORINE Volatility Principle Volatility Principle Temperature Species Temperature Species (°C) (°C) Chromium 1613 CrO2/CrO3 1611 CrO2/CrO3 Nickel 1210 Ni (OH)2 693 NiCl2 Beryllium 1054 Be (OH)2 1054 Be (OH)2 Silver 904 Ag 627 AgCl Barium 849 Ba (OH)2 904 BaCl2 Thallium 721 T1203 138 TIOH Antimony 660 Sb203 660 Sb2O3 Lead 627 Pb -15 PbCl4 Selenium 318 SeO2 318 SeO2 Cadmium 2 1 4 Cd 214 Cd Arsenic 32 As203 32 As2O3 Mercury i 14 | Hg 14 [ Hg •7 in m i P\I Guidance Manual for Public Health Assessors http: •\\\\\\ .atsilr.cdc.w. NEWS thermal-guide yun.le.html Source of data: Original data by Dr. Randy Seeker of HER Corporation, under contract to ERA (used with permission). Table 7 - Air Pollution Control Devices and their Conservatively Estimated Efficiencies for Controlling Metals POLLUTANT APCD |Ba, Be Ag Cr As, Sb, Cd. Hg Pb, Tl Wet scrubber (WS)* [~so 50 50 40 30 jVenturi scrubber, 20-30 in. 90 90 90 20 20 [Water gauge pressure (WGP) :Ventun scrubber, 98 98 98 40 40 |>60in. WGP(VS-60) Electrostatic precipitator, •~95~ 95 95 80 0 1 stage ( ESP- 1) Electrostatic precipitator, 97 97 85 0 2 stage (ESP-2) " Electrostatic precipitator, 99 99 90 0 4 stage (ESP-4) " Wet ESP (WESP) 97 97 96 95 60 Baghouse or fabric filter (FF) 95 95 95 90 50 Proprietary wet scrubber (PS)| 95 95 95 95 80 Spray dryer/FF (SD/FF) or 99 99 99 95 90 Spray dryer/Cyclone/FF Dry scrubber/FF (DS/FF) 98 98 98 98 50 FF/WS 95 95 95 90 50 ESP- 1/WS or ESP- I/PS 96 96 96 90 80 ESP-4/WS or ESP-4/PS 99 99 99 95 85 VS-20/WS 97 97 97 96 80 WS/Ionizing wet scrubber (IWS)J 95 95 95 95 85 WESP/VS-20/IWS 99 99 98 97 90 Cyclone/DS/ESP/FF 99 99 99 99 98 Cyclone/DS/Cyclone/ESP/FF SD/Cyclone/ESP-1 99 99 98 95 85 * Wet scrubber includes Sieve Tray Tower, Packed Tower, and Bubble Cap Tower. t It is assumed that flue gases have been pre-cooled in a quench before the PS. If gases are not cooled adequately, mercury recoveries will diminish, as will cadmium and arsenic to a lesser extent. A number of proprietary wet scrubbers have come on the market in recent years that are highly efficient on both particulates and corrosive gases. Two such units are offered by Calvert Environmental Equipment Co. and by Hydro-Sonic Systems, Inc. J An IWS is nearly always used with an upstream quench and packed horizontal scrubber. Source of data: EPA 1989 Table 8 - Design Considerations ni i n Design Considerations Important in Minimizing or Preventing Public Exposure: Unloading and processing wastes in enclosed areas that are under negat iv e pressure \Tf.Renting waste feedtanks to the corrbustion chambet\s) cr through a carbon filter system Connecting an autornatic waste feed cutoff system (AWFCO) to the key cperating conditions Tnggering the opening of an emergency relief vent only when extremely critical operating conditions are exceeded Designing the ash handling equipment to prevent blowing fugitive participates Installing continuous emissions monitors (CEMs) that monitor the stack emissions. Desorbers which nave condensers and/or carbon adsorption units need a CEM hydrocarbon monitor to monitor for volatile organic compounds (VOCs) breakthrough. Building stacks in accordance with good engineering practice (GEP) to provide good dispersion of the plume Table 9 - Recommended Automatic Waste Feed Cut Off Conditions to be Continuously Monitored 7/10/01 1:08 PM Guidance Manual tor Public Health Assessors hup: \\A\\v.alMli.cJ.c.uu\ NTAVS thermal-guide guide.litml Conditions to assure effective treatment of the waste: • Minimum PCC flue gas exit temperature for incinerators, and minimum bottom ash temperature for desorbers and incinerators treating contaminated soil • Minimum SCC Hue gas exit temperature for incinerators • Maximum waste feed rate for each waste type to each chamber Conditions for APCE as applicable to the facility to assure the effective Hue gas treatment: i • Minimum pressure differential across a venturi scrubber ; • Minimum pressure differential across a baghouse ! • Minimum liquid-to-gas ratio and pH to a wet scrubber • Minimum caustic feed to dry scrubber ; • Minimum kVA settings for electrostatic percipitators (wet/dry) | • Minimum kV and minimum liquid flowrate to ionized wet scrubber (IWS) i • Maximum exit temperature from condensers I I Conditions to ensure that stack and fugitive emissions are maintained below levels of health concern: I • Maximum CO or HC emissions measured at the stack or other appropriate location • Maximum flue gas flow rate or velocity measured at the stack or appropriate location • Maximum pressure in the DC or PCC • Maximum total hydrocarbon emissions measured at the stack or other appropriate location • Maximum of 25% of LEL in desorber gases using a combustible gas monitor (if air used as carrier gas) • Maximum gas exit temperature of PCC and DC Table 10 - Issues Ambient Air Sampling and Monitoring Plans Should Address Data necessary to access episodic and chrome exposures Assurance of woiker protection levels On-site action levels and response actions Fence-line action levels and response actions Community action levels and response actions Relationship of contaminants to be sampled or monitored to contaminants of concern Relationship of sampling frequency to facility operations Appendix C - Figures Ciuidance Manual tor Public Health Assessors http: \\\\ u .atMlr.cdc.uov \1:\VS thermal-guide guide.html Waste Preparation Combustfon Air Pollution Control u.ml hiliU •l>icnth *:in, Kiln • PAS' • I lui«l>/cJBcit • t.ihiK CcmbuSlkxi Waste Waste Combustion Pa • . Ash RwjdmWi Disposal 4 —————— Tre«rtrfwot Handling ^ Rehiirn to • NV-ulrali/jiiun Pro»•• -t •hcmical Subiltmion • C'hcmjcal trvulniCTir • Sixure Lamlfitl WMt* • 1 WS = loncing WM ScruMwr ESP - Electrostatic Prscrpdaioi ThHtnwnt Figure I. Incineration Subsystems and Typical Process Components. a. Organic Co«««iorV destruction b. Paniculate coBectwo c. Acid gas removal Pre- Thermal treatment Desorber a. Excavation a. Oired-fired rotonr desorber a. Discharge material b. Storage handling system c Sizing 0- lndtf«cl-fH«d rotary d. Crushing, dewatenng. OW Figure 2. Thermal Dcsorption Systems (AAEE Appendix D - Public Health Assessment Process V'1001 1:08 PM ( iuulunee Manual for Public Health Assessors hup: \v\\\v atsilr.alc.uov \'HWS IherniLil-yuule yuule.htnii The public health review process is covered extensively in the ATSDR Puhlic Health Assessment (niidance Manual and other agency policies and procedures. This appendix summarizes the public health review process for readers who may not be familiar with ATSDR policies and procedures. This document does not replace other ATSDR guidance or imply that matters not specifically covered in it are not important. ATSDR PUBLIC HEALTH ASSESSMENT PROCESS ATSDR's mission is to prevent exposure and adverse human health effects and diminished quality of life associated with exposure to hazardous substances from waste sites, unplanned releases, and other sources of pollution present in the environment. Under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), also known as Superfund, ATSDR is charged with evaluating potential public health hazards resulting from exposure to toxic substances found at National Priorities List (NPL) sites, federal hazardous waste sites, sites of unplanned releases, and sites where ATSDR has been petitioned by concerned individuals or organizations, such as Tribal Nations or other federal, state, and local government agencies. ATSDR's public health assessment process encompasses many key elements of the Agency's mission. The purpose of a public health assessment is to determine whether people have been, are being, or will be exposed to hazardous substances and, if so, whether that exposure is harmful and what actions need to occur to stop or reduce exposures. In conducting public health assessments, ATSDR obtains and evaluates information on the releases of toxic substances into the environment, the media contaminated, the concentration of contaminants, the routes of exposure, and the public health implications of exposures. This initial step of data collection involves numerous organizations such as EPA, US Geological Survey, state health and environmental agencies, county and local health offices, and communities. ATSDR evaluates available health outcome data, and community health concerns in determining the threat caused by the site. After assessing the information available, ATSDR draws conclusions about the health concern posed by the site and makes recommendations for follow-up actions that address those concerns. The Agency strives to address health issues associated with all exposed populations, including those who may be uniquely vulnerable such as children, tribal populations, or those in compromised health conditions. The primary steps in the health assessment process include: • Collecting site information, including environmental and health data and community concerns • Identifying and evaluating exposures, based on environmental contamination data, exposure pathway (e.g., air, water, soil, food) information, and any available health outcome (e.g., health studies) data • Determining public health implications for exposed populations • Drawing conclusions and making recommendations • Formulating a public health action plan A public health assessment generally does not generate new information, but rather involves a review of already existing health and environmental data. However, based on the data needs, ATSDR sometimes recommends that an exposure investigation be conducted to fill the data needs. Exposure investigations may be environmental sampling, biological sampling, or dose-reconstruction activities. The results of an exposure investigation are incorporated into the public health assessment document. Community outreach is another important part of the public health assessment process, with three primary purposes: to obtain information for the health assessment process; to collect and respond to the specific concerns expressed by community members; and to inform the community about ATSDR's progress, findings, and relevant health-related measures. ATSDR engages the public early and maintains communication throughout the public health assessment process. ATSDR community outreach activities niidance Manual tor Public Health Assessing hup \\ \vu .atsJr cdc.gov NI-\VS thcniul-^UKle ^u include: Holding public meetings and availability sessions. Distributing tact sheets. Establishing and maintaining information repositories. Issuing press releases. Conducting mailings. Posting information on its Web site. Responding to public comments. The findings of the public health assessment process may be reported in a variety of different types of reports, including: • A health advisory- is a statement from ATSDR Administrator to the Administrator of the EPA containing a finding that a release of a hazardous substance or physical conditions poses a significant risk to human health and recommending measures to be taken to reduce exposure and eliminate or substantially mitigate the significant risk to human health. • A public health assessment provides an evaluation of data and information on the release of hazardous substances into the environment in order to assess any past, current, or future impact on public health, makes recommendations, and identify studies or actions needed to evaluate and mitigate or prevent human health effects. All public health assessments contain five essential elements. They are: 1) nature and extent of contamination, 2) pathways of human exposure, 3) demographics, 4) public health implications, and 5) comparison of morbidity and mortality statistics—if appropriate. • A health consultation, which provides advice or addresses specific requests for information about site-specific health risks related to a particular exposure pathway or substance. These consultations are intended to focus on a specific issue and recommend specific actions as needed. The Public Health Assessment Guidance Manual provides additional detail in the steps necessary for conducting a comprehensive assessment of hazardous waste sites and the preparation of a report that documents the agency's actions, conclusions and recommendations. The guidance manual is available on the ATSDR web site at wvvw.atsdr.cdc.gov. Appendix E - Applicable or Relevant and Appropriate Requirements (ARARs) ARARs Selection Process The RCRA, Superfund & EPCRA Hotline Training Module - Introduction to: Applicable or Relevant and Appropriate Requirements provides the following discussion of ARARs (EPA 1998a). Table 4 shows the ARAR identification process. CERCLA §121(d) specifies that on-site Superfund remedial actions must attain federal standards, requirements, criteria, limitations, or more stringent state standards determined to be legally applicable or relevant and appropriate to the circumstances at a given site. Such ARARs are identified during the remedial investigation/feasibil-ity study (RJ/FS) and at other stages in the remedy selection process. For removal actions, ARARs are identified whenever practicable depending upon site circumstances. To be applicable, a state or federal requirement must directly and fully address the hazardous substance, the action being taken, or other circumstance at a site. A requirement which is not applicable may be relevant and appropriate if it addresses problems or pertains to circumstances similar to those encountered at a Superfund site. While legally applicable requirements must be attained, compliance with relevant and appropriate requirements is based on the discretion of the Remedial Project Manager (RPM), On-Scene Coordinator (OSC), or state official 7 Id'01 1:08 PM ljuidancc Manual tor Public Health Assessors htip: \\v\\\.atsdr.edc.go\ NHXVS thermal-guide gmde.html responsible for planning the response action (p. 3). The scope and extent of ARARs that may apply to a Superfund response action will vary depending on where remedial activities take place. For on-site response activities, CERCLA does not require compliance with administrative requirements, of other laws. CERCLA requires compliance with only the substantive elements of other laws, such as chemical concentration limits, monitoring requirements, or design and operating standards for waste management units for on-site activities. Administrative requirements, such as permits, reports, and records, along with substantive requirements, apply only to hazardous substances sent off site for further management. The extent to which any type of ARAR will apply also depends upon where response activities take place. Applicable requirements are universally applicable, while relevant and appropriate requirements only affect on-site response activities (p. 3). During on-site response actions, ARARs may be waived under certain circumstances. In other cases, the response may incorporate environmental policies or proposals that are not applicable or relevant and appropriate, but do address site-specific concerns. Such to-be-considered (TBC) standards may be used in determining the cleanup levels necessary for protection of human health and the environment (p. 4). ARARs must be identified on a site-by-site basis. Features such as the chemicals present, the location, the physical features, and the actions being considered as remedies at a given site will determine which standards must be heeded (p. 4). ARARs are used in conjunction with risk-based goals to govern Superfund response activities and to establish cleanup goals. EPA used ARARs as the starting point for determining protectiveness. When ARARs are absent or are not sufficiently protective, EPA uses data collected from the baseline risk assessment to determine cleanup levels. ARARs thus lend structure to the Superfund response process, but do not supplant EPA's responsibility to reduce the risk posed by a Superfund site to an acceptable level (p. 4). ...[F]or on-site activities, CERCLA requires compliance with both directly applicable requirements (i.e., those that would apply to a given circumstance at any site or facility) and those that EPA deems to be relevant and appropriate (even though they do not apply directly), based on the unique conditions at a Superfund site (p. 4). Environmental laws and regulations fit (more or less) into three categories: 1) those that pertain to the management of certain chemicals; 2) those that restrict activities at a given location; and 3) those that control specific actions. There are therefore three primary types of ARARs. Chemical-specific ARARs are usually health- or risk-based restrictions on the amount or concentration of a chemical that may be found in or discharges to the environment. Examples include RCRA land disposal restrictions (LDR) treatment standards and SDWA [Safe Drinking Water Act] maximum contaminant levels (MCLs). Location-specific ARARs prevent damage to unique or sensitive areas, such as flood plains, historic places, wetlands, and fragile ecosystems, and restrict other activities that are potentially harmful because of where they take place.... Action-specific ARARs are activity or technology based. These ARARs control remedial activities involving the design or use 7;10'01 1:08 PM uidance Manual for Public Health Assessors http: \\\v\v.ntM.lr.cJc.y,t>\ \! \VS ihemial-uuidc guide.html of certain equipment, or regulate discrete actions (p. 5-6). The types of legal requirements applying to Superfund responses will differ to some extent depending upon whether the activity in question takes place on site or off site (the term "on site" includes not only the contaminated area at the site, but also all areas in very elose proximity to the contamination necessary for implementation or the response action). Superfund responses must comply with all substantive requirements that are "applicable" or "relevant and appropriate." Off site, compliance is required only with applicable requirements, but both substantive and administrative compliance are necessary (p. 6). Congress limited the scope of EPA's obligation to attain administrative ARARs through CERCLA §121 (e), which states that no federal, state, or local permits are required for on-site Superfund response actions. This permit exemption allows the response action to proceed in an expeditious manner, free from potentially lengthy delays associated with the permit process.... Only the substantive elements of other laws affect on-site responses. Examples of substantive requirements include concentration limits for chemical emissions or discharges and specifications for the design and operation of remediation equipment (p. 7). Removal actions must attain ARARs to the extent practicable, considering site-specific circumstances, including the urgency of the situation, the scope of the removal action, and the impact of ARARs on the cost and duration of the removal action (§300.415(j)). The OSC would not, for example, have to stop to identify ARARs prior to removing potentially explosive munitions discovered in a residential area, or comply with an ARAR that would cause the removal action to exceed the statutory 12 month, $2 million limits. OSCs must document why certain ARARs are not practicable for emergency removal actions, but should strive to implement those ARARs that are most crucial to the protection of human health and the environment (p. 8). Since conditions vary widely from Superfund site to Superfund site, ARARs alone may not adequately protect human health and the environment. When ARARs are not fully protective, EPA may implement other federal or state policies, guidelines, or proposed rules capable of reducing the risks posed by a site. Such TBC standards, while not legally binding (since they have not been promulgated), may be used in conjunction with ARARs to achieve an acceptable level of risk.... Because TBCs are not potential ARARs, their identification is not mandatory (p. 8). When ARARs and TBCs do not specity a particular remedy, EPA has the discretion to choose the best remedial alternatives. EPA prefers to use active control measures, such as treatment, to eliminate the principal threats posed by a Superfund site. If active measures are not practicable or cost-effective, institutional controls, such as restrictions on site use or access, or engineering controls, such as waste containment, may be used to prevent exposure to hazardous substances (§300.430(a)(iii)) (p. 8). ARAR WAIVERS 7M001 1:08 PM 'iiiclance Manual for Public Health ASSCSMM^ hup: \v\v\v .atsdr.alc.LKH MA s liiemul-iundc iiuidc.htnil Congress also identified certain circumstances under which a law or regulation that would normally be an ARAR may be waived in favor of another protective remedy (CERCLA §121(d)(4) and 40 CFR $300.430(f)(l)(ii)(B)). The following six types of "ARARs waivers" may be invoked during a remedial action (p. 19). INTERIM MEASURES An ARAR may be temporarily waived to implement a short-term alternative, or interim measure, provided that the final remedy will, within a reasonable time, attain all ARARs without causing additional releases, complicating the response process, presenting an immediate threat to public health or the environment, or interfering with the final remedy (p. 20). GREATER RISK TO HUMAN HEALTH AND THE ENVIRONMENT An ARAR may be waived if compliance with the requirement will result in greater risk to human health and the environment than noncompliance. It might, for example, be riskier to meet an ARAR calling for dredging of a riverbed to remove PCB-contaminated sediments, and in so doing release PCBs into the river, than to leave the contaminated sediments in place (p. 20). TECHNICAL IMPRACTICABILITY An ARAR may be waived if it is technically impracticable from an engineering standpoint, based on the feasibility, reliability, and cost of the engineering methods required. It is, for example, often technically impracticable to remove from a drinking water aquifer dense, nonaqueous phase liquids (DNAPLs) trapped in deep bedrock fractures (p. 20). EQUIVALENT STANDARD OF PERFORMANCE An ARAR may be waived if an alternative design or method of operation can produce equivalent or superior results, in terms of the degree of protection afforded, the level of performance achieved, long-term protectiveness, and the time required to achieve beneficial results (p. 20). INCONSISTENT APPLICATION OF STATE STANDARD A state ARAR may be waived if evidence exists that the requirement has not been applied to other sites (NPL or non-NPL) or has been applied variably or inconsistently. This waiver is intended to prevent unjustified or unreasonable state restrictions from being imposed at CERCLA sites (p. 20). FUND-BALANCING An ARAR may be waived if compliance would be costly relative to the degree of protection or risk reduction likely to be attained and the expenditure would jeopardize remedial actions at other sites. The lead Agency should consider the fund-balancing waiver when the cost of attaining an ARAR is 20 percent or more of the annual remedial action budget or $100 7,10/01 1:08 PM Guidance Manual tor Public Health Assessors htlp: \vw\v.atsdr.cdc:.yo\ Nl-AVS thernial-umde yuidc mini million, whichever is greater (p. 21). DOCUMENTATION OF ARAR WAIVERS When an alternative that does not attain an ARAR is chosen, the basis for waiving the requirement must be fully documented and explained in the ROD [Record of Decision].... The lead Agency may therefore include a contingent ARAR waiver(s) in the ROD, by specifying specific contaminant levels or circumstances that will trigger the waiver (p. 21). 1001 1:08 PM