United States Office of Air Quality June 1985 Environmental Protection Planning and Standards Agency Research Triangle Park NC 27711 National Dioxin Study Tier 4 — Combustion Sources June 1985 Status Report ------- National Dioxin Study Tier 4 — Combustion Sources June 1985 Status Report By Air Management Technology Branch U.S. ENVIRONMENTAL PROTECTION AGENCY Office Of Air And Radiation Office Of Air Quality Planning And Standards Research Triangle Park, NC 27711 June 1985 ------- EXECUTIVE SUMMARY The National Dioxin Strategy directs Tier 4 to study combustion sources to determine what source categories, at what concentrations and at what risk to the public are 2,3,7,8 tetrachloridibenzo-p-dioxin and other chlorinated sources of dioxins and furans released into the environment. Tier 4 sample collection, from approximately three sources in each of twenty source categories, is on schedule with 85 percent of planned sampling completed by June 30, 1985. In addition to collecting samples, Tier 4 is coordinating with other local, State, Federal and international programs and agencies to gather additional information on dioxin from combustion sources. The remaining major Tier 4 efforts include two stack tests and several ash samples to be collected, receipt and analysis of Troika Tier 4 results, and drafting, review and completion of Tier 4 final reports. The most serious con- cern of Her 4 at this time has been delays in receiving results from Troika which may significantly impact the timeliness and content of final reports. Besides the delays in receiving results, all other Her 4 efforts are presently on schedule to provide input to the National Dioxin Study report to Congress in late 1985. ------- INTRODUCTION The Environmental Protection Agency (EPA) has undertaken the National Dioxin Strategy (Study) to identify more clearly the existence of chlorinated dioxin compounds in the environment. The study is divided into seven tiers, Tier 4 being directed toward combustion sources. The results of this effort will be sunmarized in a report to the U. S. Congress at the end of 1985. This document presents a summary of the plans and accomplishments under Tier 4 through June 1985. It is intended primarily for internal communication within the Agency but contains some background for others with interest in the study and its progress. The Office of Air and Radiation (OAR) has been delegated responsibility for planning and management of Tier 4. The Office of Research and Development (ORD) is responsible for sampling and analytical guidance and a major portion of the stack sampling program. ORD and the Office of Pesticides and Toxic Substances (OPTS) are also providing analytical support via an arrange- ment with three EPA laboratories (Duluth, MN, Bay St. Louis, MS, and Research Triangle Park, NC), collectively known as the Troika. EPA's Regional Offices are also responsible for Implementing various aspects of the Tier 4 effort. A Tier 4 Work Group, comprised of representatives from throughout the Agency, functions in an advisory role in the formulation of plans and the review and interpretation of data. Any comments or questions on the Tier 4 study should be sent to James H. Southerland, Mall Drop 14, Air Management Technology Branch, Office of Air Quality Planning and Standards, U. S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711. ------- TIER 4 - Combustion Sources The National Dloxln Strategy1 directs Her 4 to focus on "combustion sources, such as incineration of hazardous and municipal waste (including sewage sludge), wire reclamation facilities, internal combustion engines, home heating units (i. e., wood burning stoves), industrial fossil fuel-fired boilers, and inadvertent combustion sources." Since it would be economically and otherwise impractical to test each of the literally millions of sources covered by this mandate or even each source category, considerable thought and judgment have gone into planning how best to answer the following questions: 1. Which, if any, general combustion source categories likely emit 2,3,7,8-tetrachlorodibenzo-p-dioxin (2378-TCDD) and other chlorinated isomers of dloxins and furans? 2. At what concentrations are those compounds emitted to the environment? 3. What Is the risk to the public exposed to the ambient air concen- trations resulting from these emissions? To date, about 85 percent of the samples we, planned to collect have been collected and sent to the laboratory for analysis. The results from Tier 4 will be svmmarlzed in a report to Congress, scheduled for December 1985. The results will also be used in making a decision to list dioxin under Section 112 of the Clean Air Act (for hazardous air pollutants). ------- -2- Basls For Investigation Of Combustion Sources There are several unproven hypotheses concerning chlorinated dioxin emis- sions from combustion processes. Dow Chemical's "Chemistries Of Fire" theory^ proposes that the dioxins are a natural byproduct of fire and will be formed at some quantities in all combustion processes. However, experimental results by others^ suggest that dioxins may only be emitted only under limited conditions. The most prevalent theories^ involve the incomplete combustion of polychlori- nated dibenzo-p-dioxin (PCDDs) or the formation of PCDD from precursors. More data are needed to determine the magnitude and extent of exposure to dioxins from combustion sources. Current evidence does not suggest that an unreason- able risk exists. However, there are uncertainties, and the Dioxin Strategy^ provides an opportunity to perform an orderly investigation of the potential of combustion sources to emit dioxin. Project Approach There are many data gaps in the available information concerning emissions of dioxins from combustion sources, and a nuaber of different approaches could be taken to fill these data gaps. After considering various alternatives, the Agency has focused Tier 4 efforts on the collection of source data from a number of combustion source categories which are reasonably believed to have the highest potential to emit 2378-TCDD.* Thus, the primary objective of the Tier 4 project is one of problem definition (i.e., what source categories emit dioxin and at *However, source categories for which three or more tests have already been completed (e. g., municipal incinerators) will not be tested under Tier 4. ------- -3- what concentration). Detailed stack, ash and other media samples are being col- lected and analyzed for 2378-TCDD, 2,3,7,8-tetrachlorodibenzofuran (2378-TCDF), and the higher dioxin and furan homologues (i.e., tetra, pent a, hexa, hepta, and octa). A parametric study of dioxin formation was not possible within the time and resource limits of this study. Two levels of source sampling are being carried out in Tier 4. First, relatively inexpensive ash samples (screening) are being collected from the com- bustion source categories listed in Table 1, from approximately three sources in each source category. These samples are generally fly ash or slurries from con- trol devices or "bottom" ash and are being analyzed by Troika for 2378-TCDD, and the higher chlorinated dioxin and furan homologues. The resulting data can only be used to provide a qualitative indication of the likely presence of dioxins in the flue gas emissions, not to estimate the magnitude of dioxin and furan emissions. The second level of testing involves stack testing. A limited number of combustion source categories has been selected for detailed source testing (i. e., stack sampling), as also shown in Table 1. Because of the costs involved with stack testing, only 13 individual sources could be tested within the avail- able budget. These tests have been, and continue to be, perforated using proce- dures consistent with those described by the American Society of Machanical Engineers (ASME) in its sampling protocol for energy recovery facilities (now pending publication as a proposed American Society for Testing and Materials [ASTM] method). ------- -4- TABLE 1. COMBUSTION SOURCE CATEGORIES WHERE ASH AND STACK SAMPLES HAVE BEEN OR ARE BEING COLLECTED Source Categories Samples To Be Collected Ash Stack Sewage Sludge Incinerators X X (3) Black Liquor Recovery Boilers X X (3) Industrial Incinerator X X (1) Wire Reclamation Incinerator X X (I) Secondary Metals - Blast Furnace X X (1) Industrial Carbon Regeneration Units X X (1) Drum and Barrel Reclamation Facilities X X (1) Wood Stoves X X (1) PCP Treated and Salt Laden Wood-Fired Boilers X X (1) Charcoal Manufacturing Oven X Utility Boilers X Small Spreader-Stoker Coal-Fired Boilers X Industrial Boilers X Kilns Burning Hazardous Wastes X Open Burning/Accidental Fires X Sulfite Liquor Incinerator X Apartment House Flue-Fed Incinerators X Hazardous Waste Incinerators X Hospital Incinerators X Residential Contaminated Oil Combustion X ------- -5- Samples collected for the stack testing program include stack emission samples (both before and after controls), ash or slurry from the control device and firebox ash hoppers, the feed and/or fuel, precombustion air (in some cases) and soils. Samples are being analyzed for the 2378-TCDD isomer and for each of the higher homologues of dioxins (i.e., tetra, penta, hexa, hepta, octa) and furans. A sunmary of the samples typically collected during stack testing and the analyses being performed under Tier 4 is shown in Table 2. At the conclusion of the Tier 4 study, the Agency will have collected either ash samples or detailed stack samples from a number of combustion source cate- gories. Also, the available results of studies conducted by others will be sum- marized in the final Tier 4 report. For example, stack test data collected from on going testing of various municipal incinerators in New York State and the a major program by Environment Canada will be of particular interest. Since the initiation of the Dioxin Strategy, the Resource Conservation and Recovery Act (RCRA) has been ammended to require EPA to prepare a report to Congress on dioxin emissions from energy recovery, municipal incinerators. The National Dioxin Strategy report to Congress will also cover the topic to a degree since these specific incinerators are combustion sources. In view of the requirement for this separate EPA effort focusing on waste-to-energy inciner- ators, Tier 4 will minimize discussion of this specific source subcategory in the final report. Tier 4 will still use the available data on municipal incinerators as it applies generally to emissions of dioxins from combustion sources. Careful coordination is being carried out within the Agency to coordinate these two ------- -6- TABLE 2. EXAMPLE DIOXIN SAMPLE PRIORITIZATION Sample Location Sample Type Samples Collected Analysis Priority Sludge Feed Grab Sample Composite 3 2a Ambient Combustion Air XAD-2 Trap 3 2 Fuel Oil Grab Sample Composite 3 3 Incinerator Outlet** MM5 Component 3 la Incinerator Bottom Ash Grab Sample Composite 3 1 Scrubber Slurry Blowdown Aqueous Grab Sample Composite 3 la Stack Outlet^ MM5 Components 3 la Soil Grab Sample Composite 1 3 Blank Train MM5 Components 2 1/2*.c aAqueou8 phase sample or components and should be extracted within 14 days of sample collection. ^Incinerator outlet is before controls. Stack outlet is after controls. cTwo blank trains collected. One is designed priority one. The second will be analyzed only if the first blank train has detectable background levels of dioxin/furans. NOTE: Priority 1 indicates analyses should be performed for 2378-TCDD plus higher (tetra-octa) homologues of dioxins and furans. If there is a detectable concentration, Priority 2 samples are to be analyzed. Pri- ority 3 samples may be analyzed on a - case-by-case basis if Priority 1 and 2 results are significantly high. ------- -7- reports to provide Che Congress with the most timely, accurate, and complete information available. Schedule And Status Of Tier 4 Tier 4 has been operating under a fairly tight schedule from the beginning. Figure 1 outlines the discrete components of the Tier 4 plan and the schedule for each. The schedule has remained basically unchanged throughout the project, and as of this date, is on schedule. The major question of schedule is whether the Troika can provide all the analytical results in time for the data to be assessed and Included in the report to Congress by the date desired. A number of specific objectives have been accomplished during the first 18 months of this two-year project. These are listed and discussed below: °The stack testing program is nearing completion. Eleven (11) sources have been tested between October 1984 and June 1985 with two additional tests scheduled before completion of the program. The sources were categorized in Tkble 1. The program suamary as of June 30, 1985: Total tests planned - 13 Sites selected - 13 Tests completed - 11 (85%) Test results received - 1 ( 8%) "The ash sampling program Is also nearing completion. The program status as of June 30, 1985: Total samples planned - 65 Sites selected * 65 (100%) Tests completed - 60 ( 922) Test results received - 0 ------- ACTIVITIES FIGURE 1. SCHEDULE: NATIONAL DIOXIN STUDY - TIER 4 - COMBUSTION SOURCES 1983 1984 1985 1986 NDJFMAMJJASONDJFMAMJJASONDJFMAMJ Begin project Tier 4 Work Group Meeting* Perform literature review Develop Tier 4 work plan Select sources for ash screening Select individual sources for stack testing. Ash and stack sanqtle collection and analysis Prepare individual source test plans; conduct source testing and prepare source test reports. Prepare draft Tier 4 reports Draft o Final -o—o Complete - Distributed Draft Final -o—o Complete - Distributed O" o Draft Final _o o I *Tier 4 Work Group will »eet periodically throughout the study period. ------- -9- °A Tier 4 Work Group comprised of representatives has been formed to assist in formulation and review of plans and results. This group has been very helpful in providing review of the Tier 4 Work Plan and their comments are reflected on the final published plan (National Dioxin Study, Tier 4 - Combus- tion Sources: Project Plan, EPA-450/4-84-014a). "Regional Contacts representing all ten EPA Regional Offices have been established. These contacts have collected significant information on candidate test sites and have participated significantly in collecting the samples or coordinating their collection by contractors or other Federal, State and local agencies. "A literature review and data assessment of available dioxin related information from combustion sources has been completed (National Dioxin Study: Tier 4 - Combustion Sources - Initial Literature Review and Testing Options, EPA-450/4-84-014b). "Sampling protocols have been developed, reviewed and adopted for Tier 4 stack sampling and ash sampling programs (National Dioxin Study: Tier 4 - Combustion Sources; Sampling Procedures, EPA-450/4-84-014c, and National Dioxin Study: Tier 4 - Combustion Sources; Ash Sampling Program, EPA-450/4-84-014d). "Arrangements have been made with EPA's Troika dioxin analysis labora- tories for approximately 700 analyses for 2378-TCDD and tetra through octa dioxin and furan homologues. Through use of a prioritization scheme developed by Tier 4, more tests have been possible initially than envisioned but with a lessened load on Troika. ------- -10- "Community relation plans and press releases as well as Tier 4 fact sheets have been coordinated and distributed in conjunction with the Office of External Affairs. "Contact and continued coordination has been established with Canadian authorities resulting in their agreement to provide data from studies they have underway. Results from one of three tests should be available in time for use by Tier 4. "Coordination with State/local and other groups has been established to gain access to data under development as soon as they are able to be released (e. g., N.Y. state). "Provided considerable input to EDF petition response and coordination with the listing decision process for dixoin under Section 112 of the Clean Air Act. "Assistance has been provided to external groups and other EPA offices on the collection and interpretation of data in conjunction with risk analyses. "Remaining major work to be done includes the following: -completion of two remaining stack tests In July -completion of collection of remaining ash samples in June and July -receipt of analytical data from Troika (July through September) -completion of final reports (September through December) ------- -11- Issues/Recommendatlons °Tier 4 samples have been collected since October 1984, however only one partial set has been analyzed by the Troika. Original Dioxin Strategy plans called for samples to be analyzed for higher priority Tiers first (i. e., Tier 3 before 4-7, Tier 4 before 5-7, etc.). In considering laboratory efficiency, the Troika decided to process similar types of sauries in batches (i. e., soils, animal tissues, combustion ashes, etc.). March and April were to be devoted to analysis of Tier 4 of samples, but due to other priorites, this date was slipped to May and June. In May, a major power failure at Troika/RTF along with serious health problems with the chief analyst caused continued delays. Consequently, samples from the first eight stack sample sites will be analyzed in mid to late July. We have been advised by the Troika that all analyses, including those for the ash samples, should be available by September 30. Tier 4 Management is concerned with the continued slippage of Tier 4 laboratory analyses schedules. The laboratory results must be in hand for any meaningful data interpretation at least six weeks before a draft technical report is issued. If the results from the first eight tests are not available until July 30, then a report including only partial data will not be issued until at least September 15 ^ and a final draft with all the data may not be possible by November 15, even with reduced time for peer review and coordination. While not absolutely necessary, it would be prudent to have the detailed technical report nearly completed by the time of the report to Congress. Some discussion and con- clusions will not be Included if sufficient time is not available to evaluate data prior to preparing the input to the report to Gongress by November 1, as ------- -12- requested by the Office of Solid Waste (OSW). Obtaining timely results from the Troika is the most serious concern of Tier 4 at this time. It is recommended that the overall status and progress of the Troika be reviewed by the Dixoin Management Task Force (DMTF) to determine what steps should be taken to assure the most complete and timely data base possible. References 1. Dioxin Strategy, the Office of Water Regulations and Standards and the Office of Solid Waste and Emergency Response, U. S. Environmental Protection Agency, Washington, DC, November 28, 1983. 2. The Trace Chemistries Of Fire - A Source Of And Routes For The Entry Of Chlorinated Dioxlns Into The Environment, Dow Chemical, U.S.A., Midland, Michigan, 1978. 3. National Dioxin Study: Tier 4 - Combustion Sources: Literature Reviews And Testing Options, EPA-450/4-84-014b, U.S. Environmental Protection Agency, Research Triangle Park, NC, December 1984. 4. M. P. Esposito et al., Dioxlns: Volume 1 - Sources, Exposure, Trans- port And Control, EPA-600/2-80-156, U.S. Environmental Protection Agency, Cincinnati, OH, June 1980. ------- |