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Keeping Pace with Science and Engineering. 1993 Pp. 91-140. Washington, DC: National Academy Press. Municipal Waste Combustion and New Source Performance Standards: Use of Scientific and Technical Information Suellen W. Pirages and Jason E. Johnston The release in 1992 of a U.S. Environmental Protection Agency report, Safeguarding the Future: Credible Science and Credible Decisions (EPA, 1992), signaled a renewed interest in and concern about application of sci- entific and technical information in the regulatory process. The develop- ment of scientifically based and technically sound regulations requires evaluation of a broad range of factors, including: Risks posed if an activity is unregulated; Benefits achieved if an activity is regulated; The feasibility of controlling risks; Costs incurred by a regulated community and the nation both with and without a specific regulatory program; and Ranking of risks and costs within national environmental priorities. Information regarding these factors is continually changing as research efforts within scientific, technical, and medical communities are completed and as national environmental priorities are reevaluated. This case study evaluates the use of technical and scientific information in the development of proposed and final new source performance standards for new municipal waste combustors. Promulgation of these standards was mandated by amendments to the Clean Air Act (42 U.S.C. 7411~. Although the focus is limited to performance standards developed for new (not existing), large facilities (i.e., greater than 250 tons per day unit capacity), we believe that the extent to which scientific and technical information was used by EPA is typical of many environmental regulatory programs. 91

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92 SUELLEN W. PIRAGES AND JASON E. JOHNSTON Municipal waste combustion (MWC) takes place both with and without energy recovery. Combustion with energy recovery, through generation of steam or electricity during incineration, is termed waste-to-energy (WTE) or resource recovery (RR). Combustion without energy recovery is termed incineration. In the past, both incineration and WTE facilities have been built in the United States. Currently, new MWC facilities almost always include energy recovery. FRAMEWORK FOR ANALYSIS There are two points in any regulatory decision-making process where scientific and technical information can be used. The first is during the initial debate about whether a regulatory program is necessary, technically feasible, and cost-effective. The second point is during the development of a rule. In an ideal world, determining the need for a regulatory program would depend strictly upon analysis of scientific and technical data and informa- tion. However, such a world does not exist. Instead, tensions develop between politics and science, both within regulatory agencies and among the different stakeholders in a regulatory outcome. Even once a decision about need has been made, tensions within agencies and among stakehold- ers continue until a final rule is promulgated, and these tensions may very well persist. In evaluating whether, and to what extent, EPA used scientific and technical information at these two points in the decision-making process, our analysis focused on the following questions: How did the regulatory system respond to scientific and technical understanding? What factors contributed to the acceptance (or lack of acceptance) of new information by the risk management and regulatory community? What incentives and disincentives existed in the risk management and regulatory system to seek new information? What differences, if any, exist in perspectives among federal, state and local levels of government when evaluating new information? We reviewed documentation available in EPA public dockets for the proposed and final rule and identified additional literature containing scien- tific and technical information about MWC. In addition, we interviewed representatives from the regulated industry, state and local governments, and EPA. We reached the following conclusions: Scientific and technical information was applied in developing par- ticular sections of the proposed and final new source performance standards . ^

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MUNICIPAL WASTE COMBUSTION AND NSPS 93 for municipal waste combustion. However, politics often influenced regula- tory decisions, resulting in neglect of available and relevant scientific and technical information. Such information was ignored in determining the need for a federal program specific to municipal waste combustion. Scien- tific and technical information was dismissed during EPA debates on whether a materials separation requirement should be included in operating permits for individual facilities. The perspectives of federal, state, and local governments vary. For example, the stringency of regulatory requirements depends upon the breadth of application in a regulatory program, that is, requirements for a single facility can be more stringent than those applied at a state or federal level with variable environmental conditions and waste management needs. . Incentives and disincentives for development of new technology are perceived differently among various stakeholders in any regulatory program. THE MWC INDUSTRY Municipal waste combustion facilities-with or without energy recov- ery are not a recent phenomenon. Nor did the development and imple- mentation of air pollution control technology occur only in response to congressional mandates or agency regulations. Historical Development Waste-to-energy and resource recovery facilities have been used as waste management options in the United States for several decades. The nation's first facility constructed with the intent to recover energy began operation in New York City in 1905 (Walsh, 1991~. It represented the first attempt at an integrated waste management system, incorporating incineration, recycling, and materials separation at a single facility. Municipal waste was burned in a hand-stoked furnace and energy was recovered with water-tube boilers. The electricity generated was used to light the Williamsburg Bridge. The plant operated for eight years, burning approximately one-fifth of the waste generated in Manhattan and the Bronx while achieving a 60 percent separa- tion and recycling rate. Despite economic success, the facility was closed in 1913 because of maintenance problems (Walsh, 1991~. Subsequent in- cineration facilities built in the 1920s did not include resource recovery and recycling. In the l950s, MWC became a recognized waste management tool and source of electricity in Europe. At this time, European vendors were begin- ning to apply pollution control technology to reduce potentially harmful stack emissions. By the 1960s, MWC reemerged in the United States with the installation of European-developed pollution control technologies. Pol

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94 SUELLEN W. PIRAGES AND JASON E. JOHNSTON lution controls were installed in response to particulate standards promul- gated in the late 1960s through air programs within the Department of Health, Education, and Welfare (DHEW) (personal communication with L. Hickman, Solid Waste Association of North America, 1992~. Because of a newly perceived solid waste management crisis in the early 1970s, MWC with pollution control regained a broader acceptance by U.S. communities as a waste management option. As illustrated in Figure 1, use of air pollution control devices predates the development of the 1990 comprehensive new source performance stan- dards. Pollution control devices were first installed in 1957 and became standard for new facilities by the early 1960s. The first energy-recovery plant to incorporate modern technology was constructed in Chicago, Illi- nois, in 1970. This facility followed European designs, featured a waterwall furnace for heat recovery and electrostatic precipitators for pollution con- trol, and provided all of its own operating energy. In 1975 a Massachusetts facility sold energy to outside users, initiating the commercial waste-to- energy industry. Also in 1975 an Iowa facility was retrofitted with electro- static precipitators and fabric filter technology (Waste Age, 1992~. Current Industry Status Figure 2 shows that the use of waste-to-energy as a municipal waste management option has increased dramatically over the past decade. One reason for this increase has been the growing endorsement by government officials of MWC as a legitimate component in national and local waste management plans. For example, in the 1989 EPA report The Solid Waste Dilemma: Agenda for Action, MWC was considered a desirable component of the solid waste management hierarchy (EPA, 1989a). The agency's 1993 goal for municipal waste management, as stated in this report, is to reduce the annual volume of waste generated by 25 percent through recycling and source reduction and to incinerate 20 percent, leaving only 55 percent to be landfilled (Porter, 1990~. These goals are not mandated by a federal regula- tory program. The volume of waste managed through MWC with energy recovery and the rate at which facilities have been constructed throughout the United States attest to local government's acceptance of this technology as a viable waste management option (Figure 3~. Currently, 17 percent of the 196 million tons of municipal waste generated annually is managed at 190 MWC processing and combustion plants (Kiser, 1992~. Of these, 142 facilities are waste-to-energy plants with a total capacity of 101,000 tons per day (t/d) (Kiser, 1992~. These facilities provide sufficient electricity to meet the needs of 1.3 million homes-equivalent to burning 31 million barrels of oil annually (Kiser and Burton, 1992~. _

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MUNICIPAL WASTE COMBUSTION AND NSPS Science and Engineering - First energy recovery facility with integrated - waste management activities in the United States (New York City, NY) _1 905 1955 _ - ESP installed on an incinerator (Euclid, Ohio) - ~ - _ _ 1 960 - ESP on a WTE facility (Queens, N.Y.) ~ ___ _ ~ Policy and Regulation _ - -CleanAirAct(CM) P.L.88-206 - Wet scrubber installed on an incinerator , _ - _ ~ (Sheboygan, Wis.) I ~ 1965 '~ - Particulate standard for all incinerators published $.__' by DHEW - Spray dryer/fabric controls installed on an ~ 1970 incinerator (Framingham, Mass.) - Waterwall heat recovery and ESP on a WTE facility (Chicago, III.) r-- _ - Recognition of ESP as replacement of wet ~ scrubbers for MWC, by replacement at WTE ~ - _ facility (Nashville, Tenn.) ~ 1 519 75 I_ _ - ~- CM Amendment mandating study of all dioxin/furan sources - ESP/fabric filter installed at a WTE facility (Ames, Iowa) - Odor problems at Hempstead, N.Y. facility led ~ - _ to detection of dioxin/furans 19 80 1 9185 - First use of selective noncatalytic reduction ~ for NOx control - Spray dryer/fabric filter and continuous monitoring required at a WTE facility (Marion County, Ore.) 95 -- CM Amendment requiring air emission standards - Formation of Environmental Protection Agency (EPA) I - Revised standards for particulate controls by EPA - Legal ruling about EPA authorities in PSD regulatory programs - EPA determines level of dioxin emissions at MWC are not a public health risk - NRDC, New York, and Florida petition for 1977 mandated study - NRDC, New York, Rhode Island, and Connecticut petition for determination of health effects - EPA Report to Congress on MWC - EPA advanced notice for rulemaking for MWC - EPA determines that acid gas scrubbers are best available technology 1 990~ L lintMA/ V^rl, one ~l~rirlo n~`titi~n tar r. alien en ~ vie vet v ivy van vet ~ ivy ~ us y vat ~ materials separation and lead-acid batteries; US Court of Appeals, D.C. Circuit ruling on petition - EPA proposes new source performance standards for MWC - EPA promulgates final new source performance standards for MOW FIGURE 1 Timeline of significant technical, legal, congressional, and regulatory events in combustion of municipal waste.

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96 SUELLEN W. PIRAGES AND JASON E. JOHNSTON 250 _ 225 200 <~ 1 75 150 125 100 75 50 25 o OWTE Incineration Recycling Landfills Reliance on WTE will increase dramatically an 1960 1980 1988 2000 FIGURE 2 Changing trends in managing muncipal waste. <~ ' , ' / Bin , . , ~ 3/0~ fib - 1/0 1/0 1 2/1----\ my> .~'-9i4 6/3 2/0 4/3 1/0 ~~ it= 1~ at) ~1 ~1 5/1 ~ so o [A 1/0 2/1 8/1 -\ \2~0r 2/0 ~ 1/1 by ~1 5/2 X = Number of operating MWC facilities Y = Number inactive, planned, and under construction FIGURE 3 Distribution of operating and projected municipal waste combustion facilities. . - ,

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MUNICIPAL WASTE COMBUSTION AND NSPS 50 45 40 2 o ~ 25 .O 35 30 20 15 10 5 o States in each EPA region Inactive, in planning, under construction Operational capacity l 1 l l I -CT, ME, MA, NH, Rl, VT 11 -NJ, NY, PR lil -DE, DC, MD, PA, VA, WV IV -AL, FL, GA, KY, MS, NC, SC, TN V -IL, IN, Ml, MN, OH, Wl Vl -AR, LA, NM, OK, TX VII-M, KS, MO, NE VIItCO, MT, ND, SD, UT, WY IX -AZ, CA, Hi, NV X -AK, ID, OR, WA _ = Vl11 111 IV V Vl Vl1 EPA Region IX X FIGURE 4 Total operating and projected MWC capacity by EPA region. 97 In addition, projects under construction or being planned could bring total waste volumes managed with MWC to 53 million tons per year (t/y) by the year 2000 (Kiser, 19911. Figure 4 indicates that operational and pro- jected MWC capacity is concentrated in the eastern portion of the United States (EPA Regions I, II, III, and portions of Region IV). For example, 34 percent of operational capacity and 38 percent of projected new capacity are located in EPA Regions I and II alone. Despite recent increases, however, the level of use in the United States is below that in other nations. Switzerland incinerates 80 percent of its municipal waste, Denmark 60 percent, and the Netherlands 40 percent. Ja- pan incinerates 72 percent of that volume of municipal waste remaining after separation for recycling (Integrated Waste Services Association, 1992a). The increased reliance on MWC in these countries is undoubtedly due to shortages of areas suitable for landfills. Technology Used Between 1975 and 1989 A major finding of this case study is that between 1975 and 1989, new facilities were being constructed with best available pollution control tech

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98 . w Q o E IS - U' c Cal m it' r - W I: I o ~ ~ Q s =5 W s _ w On W \ N \ o - \ O \ C) UJ ._ m _ ~ n ~3 ~ a) a' O ~ C' C7) UJ F C)C' ~ > - r \ - ~Ym _ On a, a) ~ ~ X W{15CL ~ W: c O 0< \ - ~ ~ \ '~ ~ ~W ~ ~! _ W ~ 1~.9 = 9- as ~ ~ ~n ~$ -' 311 ~ ~ CC _ - . _ _` oo . . o V) 4 - ._ ._ Cd . ~ ~ - > "D ~C~ _ ~Ct Cd o Cd ._

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MUNICIPAL WASTE COMBUSTION AND NSPS 99 nology and operated with sound combustion practices. These stringent pol- lution control and good combustion practices were required as part of the CAA Prevention of Significant Deterioration of Air Quality (PSD) program that was managed by state agencies and implemented by local (i.e., county or city) environmental agencies. With few exceptions, these early PSD requirements led to use of the same technologies used by EPA to establish the 1990 new source performance standards. Combustion Design Municipal waste combustors consist of three basic types: mass burn, modular, and refuse-derived fuel (EPA, 1989b; National Solid Waste Man- agement Association, 1991~. Combustion chambers are similar among these types, with major differences being size of a facility, combustion condi- tions, and degree of waste processing necessary before combustion. Figure 5 shows the design of a large, mass burn facility. Mass burn facilities handle mixed waste streams, generally without any precombustion processing other than removal of overly large items and those items included in local source separation programs. Individual units range in capacity from 50 to 1,000 t/d. Facilities can be constructed with more than one combustion unit. Combustion occurs at temperatures ranging from 1,800 to 2,000F. Typical mass burn technology uses hydraulic rams or pusher grate sections to move waste mechanically onto a grate. Combus- tion is enhanced by agitating the fuel bed; waterwalls are used to cool the combustion chamber and to recover heat for steam or generation of electric- ity. Modular facilities are similar to mass burn plants but are prefabricated and smaller. Individual units range in capacity from 5 to 120 t/d. A modu- lar facility can be constructed with two or more combustion chambers in either of two designs: modular excess-air or modular starved-air. These units are constructed with refractory walls, and most new facilities recover heat with waste-heat boilers. Refuse-derived fuel facilities use processed waste to ensure a uniform fuel during incineration. Waste processing involves removing materials that can be recycled or are not combustible; remaining wastes are shredded. In these units, shredded waste is generally fed by a stoker onto a moving grate and transported into the combustion chamber. These units range in capacity from 270 to 900 t/d. Virtually all plants are constructed with waterwalls and employ heat recovery systems. A fourth system under development employs fluidized bed combustion. In these units, waste is burned within a turbulent bed of heated noncombus- tible material, usually sand or limestone. These units generally burn pro- cessed waste, sometimes mixed with other fuels. Design plans generally

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100 SUELLEN W. PIRAGES AND JASON E. JOHNSTON range in size from 200 to 500 t/d. Heat recovery is generally a component of the design. Composition of Air Emissions Several different compounds can be generated and released to the air as a result of combustion activities, for example, operation of motor vehicles, wood-burning stoves, forest fires, and operation of municipal waste com- bustors. The composition of air emissions formed during combustion de- pends on the type of material being burned. In an MWC facility without any air pollution controls, the type of air emissions generated can vary (DePaul and Crowder, 19881. ~ ~ r ~ pounds may be formed during combustion: For example, the following types of com Particulate matter consisting of noncombustible material such as metals, light ash escaping through an exhaust system, or organic material that has not fully been incinerated. Sulfur dioxides formed from combustion of items such as paper, rub- ber, wallboard, and grasses. Nitrogen oxides resulting from the combustion of materials contain- ing nitrogen, for example, yard wastes and textile materials. Carbon monoxide as a product of incomplete combustion. Hydrogen chloride may result from combustion of materials contain- ing chlorides. Chlorinated organics can result from incomplete combustion. MWC Air Pollution Control Technology A major difference between facilities constructed after the 1970s and older existing facilities was the extent to which air pollution control was incorporated. In general, local or state environmental agencies have not always required older facilities to retrofit (i.e., to add more efficient air pollution controls). In some instances, agencies perceived retrofits as creat- ing major technical and economic problems that could result in closures of older facilities and disrupt an essential component of the locality's waste management plan. In contrast, new construction designs included require- ments for state-of-the-art combustion designs and air pollution controls. Figure 6 shows the increased use of add-on air pollution control devices over the past two decades. By the time EPA's new source performance standards were proposed for new MWC facilities in 1989, a substantial proportion of new facilities already included the proposed level of air pollu- tion control. The Appendix provides a brief description of the different control technologies. . . .

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MUNICIPAL WASTE COMBUSTION AND NSPS 80 70 60 50 40 E 20 10 101 MWCs with APC APC type not available MWCs without APC : I. ~ ~ l Date N/A t50-'55 t56-~60 '61-~65 '66-'70 71-'75 '76-~80 .81-~85 '86-'90 '91 + Year of Start-Up FIGURE 6 Use of air pollution control technology by year of start-up. Initially, wet scrubber technology was used to control particulates, but this technology soon became obsolete because it could not achieve the par- ticulate standards of the late 1960s and early 1970s. For example, low- energy, wet scrubbers at a Nashville, Tennessee, facility were replaced in the mid-1970s with electrostatic precipitators (ESP) because of the increased removal efficiency and enhanced ability to function at high temperatures (Gaige and Halil, 1992~. This change at a large existing commercial facility signaled the end of wet scrubber installations at new units. Later, industry switched to fabric filters and large multifield ESPs for even greater effi- ciency in pollution control. In addition to particulates, acid gases (i.e., sulfur oxides and hydrogen chloride) are found in MWC flue gas. Sulfur dioxide (SO2) removal tech- nology was in its second generation at coal-fired plants during the 1970s; therefore, based on operational information from these plants, this removal technology was easily installed at MWC facilities. For example, in the 1970s, following three PSD permit remands concerned with appropriate acid gas controls, EPA declared that acid gas scrubbers used in conjunction with fabric filters were to be considered "available" control technology in the PSD permit program. By 1987, most new plants were being constructed

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130 SUELLEN W. PIRAGES AND JASON E. JOHNSTON essary. Given the extent of public scrutiny of MWC activities, it is unlikely that minimal health and environmental protection will be imposed in host communities. Incentives for Seeking New Information Incentives for seeking new information vary throughout the regulatory process and among the various stakeholders. The basis of the Clean Air Act, that is, implementation of technological and operational standards, should provide maximum incentives for EPA to seek out the best available informa- tion. To a limited extent, the agency did seek new information during the initial stages of evaluating MWC by commissioning a large multifaceted study. However, once political factors begin to intrude, new information either was not sought or was ignored. For example, the risk evaluations performed in 1987 and 1989 suggested that MWC did not pose major risks at either a national or local level. The EPA did not use this information as a means of balancing political pressure and, thus, had little influence on the decision about the need for a regulatory program. A major incentive for regulators in seeking comprehensive and new information is to enhance their credibility and the enforceability of a regula- tory program. The materials separation requirement in the proposed rule is an excellent example of the influence of limited and less credible data. Acceptance by state and local governments and industry was not forthcom- ing because inclusion of this provision was not based on sufficient support- ing data. If the agency had used scientific and technical information in reaching its decision about the advisability of the provision, a major contro- versy in the development of the NSPS rule might have been avoided. Un- fortunately, political pressures forced it to ignore such information. Should the agency desire to revisit a materials separation requirement in other rules or in future revisions to this rule, it will be necessary to seek appropriate data to support assumptions about the reduction in air emissions associated with materials separation and the impact on public health and the environ- ment. The CAA itself inhibits to some extent the incentive to identify new data about new and cutting-edge technological innovations. The act specifi- cally requires a standard of performance that is defined as the best system of emission reduction which (taking into account the cost of achieving such reduction . . .) the Administrator determines has been ade quately demonstrated BAA 42 USC 7411, Section lllta)]. If a technology has not been used sufficiently to demonstrate consistent emission reductions, it is unlikely to be considered "demonstrated" because there is no opportunity for the agency to search beyond systems currently in -

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MUNICIPAL WASTE COMBUSTION AND NSPS 131 operation. Statutes such as the CAA result in the development of techno- logically driven regulations. By specifying consistent achievements as the definition of performance, EPA can only look at those technologies used at existing facilities. The agency cannot promulgate technology-forcing regu- lations those that force development of new technologies capable of achieving emissions standards beyond what is possible with current technology un- der the CAA. To some extent the agency does attempt to force new tech- nologies by setting standards at the upper bound of margins of achievability. However, the definition of BDT limits this option. Industry also has limited incentives to develop new technology. In conversations with industry representatives, it was emphasized that indus- trial incentives for technological improvements in air pollution or opera- tional control systems are to reduce operation and compliance costs.6 Re- duced emissions may be an added benefit of any cost reduction, but they are not the primary goal of new technical research. If a new technology can reduce emissions but is more costly to operate, industry would be less likely to implement it voluntarily. Until all facility operators are required through rulemaking to install the same, more costly equipment, such voluntary ac- tions place operators with more advanced thinking at an economic disad- vantage. The main reason that there was so little opposition to most of the provisions in the proposed new source performance standards is that most new facilities were already being required to implement the equipment and practices recognized as BDT in the proposed rule. Thus, the rule simply equalized the playing field within the regulated community. Environmental groups probably have the greatest incentive to seek new information. In general, the agenda of these groups is to drive regulations to ever more stringent levels in a desire to maximize protection of public health and the environment. These groups often are not constrained by concerns for technical feasibility or economic factors. Therefore, they can identify new developments before a technology is considered to be techni- cally or economically viable. Unfortunately, these groups may become so focused on a perceived need for more stringent requirements that they may not support their allegations about technical feasibility or risks posed by unregulated facilities with sound scientific and technical information. CONCLUSIONS The environmental regulatory agenda has always been shaped by politi- cal forces. Since the inception of EPA in 1970, Congress, industry, and public interest groups have identified various industrial activities thought to require a regulatory program. For example, in the early 1970s, Congress seemed to identify a different pollutant every year, which, in its opinion (or the opinion of a few members), would lead to dire public health and envi

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32 SUELLEN W. PIRAGES AND JASON E. JOHNSTON ronmental problems without the immediate and rigorous attention of EPA. Industry and environmental groups often were sources of information that supported such urgency. Environmental and other public interest groups also have used specific environmental issues to further membership drives or to force a change in national policy, for example, the recent Alar contro- versy. Likewise, industry has lobbied Congress and EPA for regulatory programs that would provide more uniform regulations across the country, thus preventing uneven economic advantages or enhancing the ability to implement better technology. In all such instances, regardless of the origination of an initiative, we are left with the impression that scientific and technical information rarely plays a determining role in the debates. Unfortunately, all stakeholders attempt to limit full use of scientific and technical information in the regu- latory decision-making process, particularly if the information is counter to the stakeholder's agenda. The outcome of this political struggle is an increased likelihood that significant problems, and important scientific data, are ignored. This point has been emphasized by the Expert Panel on the Role of Science at EPA (EPA, 19921. The panel stated in its report: Science is also key to determining which environmental problems pose the greatest risks to human health, ecosystems, and the economy. In the ab- sence of sound scientific information, it is likely that high-profile but low risk problems will be targeted, while more significant threats are ignored. . . . Strong science provides the foundation for credible environmental deci- sionmaking (EPA, 1992, p. 15-25~. There is no question that politics both shaped the decision about whether a federal regulatory program was necessary for MWC and influenced provi- sions in the proposed and final new source performance standards. Whether, and how, such political forces can be curbed is questionable and may not be altogether desirable. However, based on the findings of this case study, certain suggestions emerge that may facilitate a better balance between po- litical considerations and use of scientific, technical, and economic infor- mation in the regulatory decision-making process. First, politics should be balanced with scientific, economic and tech- nical information. In this case study, EPA evaluated such information related to MWC and published its findings in the 1987 report to Congress. However, the agency evaluated MWC as a single issue divorced from the broader national environmental context. Thus, while the agency estimated emissions from existing and projected facilities, it is not apparent that these emissions were compared with other industrial sources to determine their significance from a national perspective. Similarly, when the risks from exposure to these emissions were calculated, they were not compared - .

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MUNICIPAL WASTE COMBUSTION AND NSPS 133 with risks associated with other sources of these same chemicals and met- als. The EPA's economic analysis also failed to put the MWC issue into a national context The agency considered costs for controlling emissions only. There was no attempt to compare costs of the federal program in broad terms with national environmental and public health benefits. The EPA should conduct a cost-benefit analysis using several competing envi- ronmental issues to determine if a specific problem (i.e., MWC) merits a federal program or whether there are alternative and less costly regulatory options. Analysis of the relative national priority, evaluating consequences of not having a federal program, the cost of a federal program, and other problems competing for limited resources may result in a more effective balance of political pressure. A stronger foundation for balancing political influences might have been achieved if EPA had conducted such analyses when reaching a decision about the need for a federal MWC regulatory program. As it turned out, EPA staff had little real information with which to counter effectively the political pressures being brought to the MWC debate. A second recommendation concerns a mechanism to enhance the qual- ity of information available to the agency for use in developing regulatory requirements. Both government and industry agree that, for the most part, EPA used available information in formulating the proposed and final rules for new source performance standards. As indicated in an earlier discus- sion, the standards are largely based on the technological capability of the best demonstrated technology. However, conversations with EPA officials indicate that the information-gathering process might be enhanced (per- sonal communication with R. Brenner and J. Democker, EPA Office of Air and Radiation, 19921. At present, EPA believes that stakeholders are play- ing a passive role in the agency's search for necessary information. Only in limited instances do stakeholders voluntarily provide information before a rule is proposed. Much information often appears to be withheld until the public comment period for a proposed rule. Furthermore, state and local governments, environmental groups, and industry often complain that information used by the agency is not always of the highest quality. This complaint is supported by an observation of the Expert Panel on the Role of Science in EPA: EPA program offices often conduct scoping studies or other preliminary assessments in the early stages of regulatory development. These studies are frequently carried out without benefit of peer review or quality assur- ance. They sometimes escalate into regulatory proposals with no further science input, leaving EPA initiatives on shaky scientific ground and af- fecting the credibility of the Agency (EPA, 1992; p. 371.

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34 SUELLEN W. PIRAGES AND JASON E. JOHNSTON The EPA did conduct a large-scale study of MWC. However, to our knowledge, with the exception of an EPA Science Advisory Board review of only the methodology used in the risk assessment work, it was not peer reviewed (Hartung and Nelson, 1987~. During development of a proposed standard, the only opportunity for any interested party to provide EPA with better information is to provide data informally and voluntarily. The extent and quality of information provided in this manner depends on the aware- ness of different stakeholders about directions the agency may take, or is taking, in developing a proposed rule. In general, EPA provides limited information about policy choices while a proposed rule is being developed, thus stakeholders are not always aware of gaps in the agency data base. Once a rule is published for public comment, additional information can be forthcoming, and EPA can apply it in revisions for the final rule. This seems to be an inefficient process that fosters adversarial positions rather than constructive comments. A more effective mechanism is needed through which the agency can request and receive new information during development of a proposed rule, rather than waiting to receive information submitted voluntarily or during the public comment period. The Expert Panel on the Role of Science has provided extensive suggestions for enhancing the use of better information (EPA, 1992~. An additional recommendation is to employ regulatory negotiations or some version of these negotiations to enhance acquisition of better informa- tion. Regulatory negotiations have been used by EPA over the past five years in selected rulemaking to reduce adversarial reactions to proposed rules. The concept is to bring together representatives of all major interest groups for a specific rule and to develop a proposal to which all representa- tives can agree. Some of these negotiating attempts have been successful, resulting in proposed rules that enjoyed the consensus of all stakeholders. However, even when an acceptable proposal is not negotiated, there is still some success in terms of the amount of scientific and technical information that is brought into the negotiation process early. To illustrate, a regulatory negotiation was attempted in developing RCRA regulations for deep-well injection of hazardous wastes.7 Because of philo- sophical differences among the various interests at the negotiation table, consensus on a proposed rule was not achieved. ' However, most partici- pants in this particular process acknowledged that a wealth of information was brought to the agency's attention. In the absence of these regulatory negotiations, it is questionable whether the full extent of pertinent informa- tion would have been presented through the normal voluntary mechanisms. One reason that there is an increase in the volume of new information provided during such negotiations is that all participants are able to learn firsthand the basis for any opposing views. Thus, new information relevant _

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MUNICIPAL WASTE COMBUSTION AND NSPS 135 to specific issues can be brought to the negotiating table as a counter to such objections. If negotiations were to become a standard component of a regulatory process, stakeholders would have a more controlled and focused opportunity to provide EPA with information in an atmosphere of coopera- tion. In addition, the quality and direct relevance of the scientific and technical information might be substantially enhanced. The ultimate result would be a stronger foundation for the development of scientifically and technically sound regulations. As our findings suggest, EPA can benefit from implementing a process that enhances not only the quality of data collected but also the range of information. If informed regulatory decisions are to be made, current scien- tific and technical information is needed to balance political influences. At the first stage of the regulatory process, this information must be evaluated in a national context. At the second stage of regulatory development, the scope of information must be sufficiently broad to allow development of sound, achievable, and enforceable regulatory standards. While these recommended options offer other mechanisms for enhanc- ing the availability of new scientific and technical information to the agency, they do not address the underlying and extremely critical problem inherent in a regulatory process: the influence of political factions to the exclusion of scientific and technical information. The MWC rule for new source performance standards is not unique in the role that politics played in deter- mining the need for and the scope of the regulatory program. Politics have "interfered" in many of the agency's activities. Such political pressure arises externally and internally to EPA. Until political factors are placed on an equal, rather than superior, footing with scientific, economic, and techni- cal factors, EPA and all regulatory agencies will not be able to function effectively. Unfortunately, the resolution of this problem is not simple and will require a commitment on the part of all stakeholders to allow such information to play a more prominent role. APPENDIX: DESCRIPTIONS OF AIR POLLUTION CONTROLS Electrostatic Precipitators Electrostatic precipitators (ESPs) are used to remove particulate matter from flue gas streams. A typical ESP consists of an alternating array of negatively charged grids of wires and positively charged collection plates. Incoming particles are given an electrical charge through contact with gas ions. Charged particles pass through a strong electronic field, which causes these particles to migrate to a collection electrode with an opposite charge. .

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36 SUELLEN W. PIRAGES AND JASON E. JOHNSTON The precipitators are divided into sections called fields; adding fields in- creases the collection efficiency (Frillici and Schwartz, 1991~. Fabric Filters Fabric filters (FFs) mechanically separate particles from flue gas streams, greater than 99 percent removal (Gaige and Halil, 1992~. They . . ac sieving consist of a filter medium, (i.e., tubular bag), a cage to support the bags, a gas-tight enclosure, and a mechanism to remove accumulated particles peri- odically. As the particulate-laden gas passes through the filter medium, collected material forms a porous cake, which acts as an additional filtration medium. Fabric filters are categorized according to how they are-cleaned: shaker, reverse-air, and pulsejet. The fabric of the filters may either be woven or felled and may consist of fiberglass, Teflon or Nomex, which will withstand entering flue gas temperatures of up to 300F (Frillici and Schwarz, 1991). Acid Gas Scrubbers Acid gas scrubbers operate by bringing acid gases into contact with alkali reagents, forming a neutralized salt solid that can be removed by ESPs or FFs. Acid gas scrubbers are categorized as wet scrubbers, dry scrubbers, or wet-dry scrubbers. Wet scrubbers use lime, limestone, or an alkali reagent and produce a wet bottom catch; their design might include venturi, spray, baffle, or packed tower. Dry scrubbers inject dry sorbent into the flue duct, resulting in a dry catch (Frillici and Schwartz, 1991~. In wet-dry scrubbers, commonly referred to as spray dryer absorbers (SD), flue gas enters the reaction vessel, where it is dispersed and put into spiral motion. A water-based slurry of alkali reagent is sprayed into the flue gas stream; the water evaporates and the reagent reacts with SO2 and HCl to form salts. Use of FFs in conjunction with an SD results in a cake where the reagent and gases can react further, increasing efficiency (Frillici and Schwartz, 1991; Gaige and Halil, 1992~. Although acid gas scrubbers are intended primarily to remove HC1 and SO2, they also remove some organic and heavy metal pollutants (Brna and Kilgore, 1991~. Reduced flue gas temperatures associated with scrubbers cause many volatilized metals and organics to condense, thus increasing removal efficiencies in the ESP or FF (Gaige and Halil, 1992~. Nitrogen Oxide Controls Two main add-on technologies are currently in use across the world: selective catalytic reduction (SCR) and selective noncatalytic reduction (SNCR). . ~ ,

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MUNICIPAL WASTE COMBUSTION AND NSPS 137 SCR has been used on coal- and oil-fired power plants in Japan and Europe. Ammonia is injected into the flue gas stream and the mixture is then passed through a catalyst (molybdenum, vanadium, titanium) bed where NOX are converted to nitrogen gas. SCR operates at temperatures ranging from 500 to 800F. Fouling caused by high particulate loading limits the potential for application of this technology (Frillici and Schwartz, l991~. SNCR involves postcombustion injection of ammonia or urea to contact the flue gas. SNCR is most effective between 1600 and 2000F, so the injectors are located in the upper portion of the furnace. The gas phase reaction between the NOX and the injected ammonia or urea results in the production of nitrogen gas and water. Potential disadvantages include the difficulty of maintaining the optimal flue gas temperature in the injection zone. Also, ammonia may react with acid gases to form ammonia salts, which may corrode and foul downstream equipment or exit the stack as a visible plume (Frillici and Schwartz, 19914. NOTES 1. We interviewed staff of particular MWC companies and the Integrated Waste Services Association, the trade association for the industry. Discussions were held with representatives of the U.S. Conference of Mayors and the Association of State and Territorial Solid Waste Management Officials. Staff of the EPA Office of Air and Radiation and Office of Air Quality Planning and Standards were interviewed. 2. The first legislative action for Clean Air occurred in December 1963 (P.L. 88-206), and was amended eighteen times between 1963 and 1990. 3. An acceptable risk range of 10-6 to 10-4 was established by the Office of Solid Waste and Emergency Response for use in the Superfund Program during the mid-1980s. 4. The following health parameters were used in Morrison (1989) for comparison with MWC emissions. HCl: EPA reference dose (RfD) of 7 ,ug/m3; fig: National Emission Stan- dards for Hazardous Air Pollutants guideline of 1 ,ug/m3; and Pb: National Ambient Air Qual- ity Standards of 1.5 ,ug/m3 (quarterly average). 5. The conflict between Congress and EPA over the initial proposal to develop health- based treatment standards for the 1984 HSWA provisions for land disposal restrictions un- doubtedly set a precedent for EPA's decision about a basis for requesting MWC emissions. 6. Personal conversations with representatives of Integrated Waste Services Association, Ogden Martin Systems, and ABB Resource Recovery Systems. 7. Dr. Pirages was a participant in this regulatory negotiation. REFERENCES Abrams, R., H. G. Williams, A. Violet, and J. I. Lieberman. 1986. lion regarding health effects for the establishment of emission regulations under 112 of the United States Clean Air Act. States of New York, Rhode Island, and Connecticut. Brna, T. G., and J. D. Kilgore. 1991. The impact of particulate emissions control on the control of other MWC air emissions. Journal of the Air Waste Management Association 40(9): 1324-1330. Cheremisinoff, P. 1987. Resource recovery: A special report. Pollution Engineering, Novem- ber:52-59. Petition for a determina

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38 SUELLEN W. PIRAGES AND JASON E. JOHNSTON Curling, D. S. 1990. Comments on the proposed NSPS for MWCs from the Southeastern Public Service Authority of Virginia, Chesapeake, Va., dated January 29, 1990. EPA Air Docket No. A-89-08, IV-D-77. DePaul, F. T., and J. W. Crowder. 1988. Control of emissions from municipal solid waste incinerators. Prepared for Illinois Department of Energy and Natural Resources, Energy and Environmental Affairs Division, Springfield, Ill. ILENR RE-AQ-88/14. Doniger, D. 1990. Letter from David Doniger, Senior Attorney, NRDC to George Bush, President, dated December 27, 1990. Frillici, P. W., and S. C. Schwartz. 1991. BACT, MACT, and the act: What's going on? Waste Age 22(11):65-72. Gaige, C. D., and R. T. Halil, Jr. 1992. Clearing the air about municipal waste combustors. Solid Waste & Power, January-February:12-17. Goldstein, E. A., D. D. Doniger, A. K. Ahmed and M. D. Uva. 1986. Petition to the United States Environmental Protection Agency for the Regulation of Emissions from Municipal Solid Waste Incinerators. Washington, D.C.: Natural Resources Defense Council. Greim, H. 1990. Toxicological evaluation of emissions from modern municipal waste incin- erators. Chemosphere 20(3/4):317-331. Gruenspecht, H. 1990. Memo from Howard Gruenspecht, Council of Economic Advisers, to James McRae, Office of Management and Budget, dated December 7, 1990. Hartung, R., and N. Nelson. 1987. Letter to Mr. L. M. Thomas, U.S. EPA Administrator. Science Advisory Board, Washington, D.C. Hershkowitz, A. 1990. Letter from A. Hershkowitz, Natural Resources Defense Council, to William K. Reilly, U.S. EPA Administrator, dated December 20, 1990. Institute of Resource Recovery. 1990. Written statement of the Institute of Resource Recov- ery regarding the U.S. EPA's proposed rules fur municipal waste combustors, dated March 1, 1990. Integrated Waste Services Association. 1992a. Waste-to-energy. Washington, D.C. Integrated Waste Services Association (IWSA). 1992b. Survey of recycling and waste-to- energy activities. Washington, D.C. Kiser, J. V. L. 1991. Municipal waste combustion in the United States: An overview. Waste Age 22(11) :27-30. Kiser, J. V. L., and D. B. Sussman. 1991. Municipal waste combustion & mercury: The real story. Waste Age 22(11):41~4. Kiser, J. V. L. 1992. Municipal waste combustion in North America: 1992 update. Waste Age 23(11):26-36. Kiser, J. V. L., and B. K. Burton. 1992. Energy from municipal waste: Picking up where recycling leaves off. Waste Age 23(11):39~6. Martineau, R. J., Jr. 1990a. Memo from Martineau, Attorney, U.S. EPA Air and Radiation Division re: September 12, 1990 meeting of EPA Officials and National Association of Counties. Martineau, R. J., Jr. 1990b. Memo from Martineau, Attorney, U.S. EPA Air and Radiation Division re: September 10, 1990 meeting between EPA officials and representatives of Natural Resources Defense Council. Martineau, R. J., Jr. 1990c. Memo from Martineau, Attorney, U.S. EPA Air and Radiation Division re: November 6, 1990 meeting with representatives of Waste Management Inc. and EPA representatives on proposed MWC rule. Morrison, R. M. 1989. Baseline risk analysis to support municipal waste combustor new source Performance standard and emission guideline development. Memorandum to file. U.S. EPA Office of Air Quality Planning and Standards, Research Triangle Park, N.C. EPA Air Docket #A-89-08. National Association of Counties. 1990. Comments of the National Association of Counties

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MUNICIPAL WASTE COMBUSTION AND NSPS 139 regarding the Environmental Protection Agency's New Source Performance Standards for Municipal Waste Combustors, Washington, D.C., dated February 28, 1990. EPA Air Docket No. A-89-08, IV-D-116. National Solid Waste Management Association. 1991. Resource recovery in North America. Washington, D.C. Nosenchuck, N. H. 1992. Personal communication. Director, Division of Solid Waste, New York Department of Environmental Conservation, Albany, N.Y. Nosenchuck, N. H., and D. Bruckner. 1990. Comments on the proposed NSPS for MWCs from the Association of State and Territorial Solid Waste Management Officials, dated March 1, 1990. EPA Air Docket No. A-89-08, IV-D-71. Pederson, W. F., Jr. 1987. Air pollution control. Chapter 6 in Environmental Law Handbook, 9th ea., Arbuckle et al., eds. Rockville, Md.: Government Institute, Inc. Porter, J. W. 1990. Municipal Solid Waste Recycling: The Big Picture, speech before the U.S. Conference of Mayors Recycling Conference, March 29. (Reported in IWSA, 1992a) President's Council on Competitiveness. 1990. Fact Sheet re: Recycling Requirement in the Municipal Waste Combustor Rule, dated December 19, 1990. Reisch, M. S. 1992. SO2 emissions trading rights: A model for other pollutants. Chemical and Engineering News 70(27):21-22. Roffman, A., and H. K. Roffman. 1991. Air emissions from municipal waste combustion and their environmental effects. The Science of Total Environment 104:87-96. Ruston, J. F. 1990. Comments of the Environmental Defense Fund on the U.S. Environmental Protection Agency's Proposed Standards of Performance for New Stationary Sources; Municipal Waste Combustors, Washington, D.C., dated March 1, 1990. EPA Air Docket No. A-89-08, IV-D- 173. Thomas, L. M. 1985. Statement before the Subcommittee on Health and the Environment and Commerce, U.S. House of Representatives. Washington, D.C. U.S. Court of Appeals for the D.C. Circuit. 1992. No. 91 - 1168, State of New York and State of Florida v. W. K. Reilly, Administrator, U.S. Environmental Protection Agency, and No. 9101170, Natural Resources Defense Council v. W. K. Reilly, Administrator, U.S. Environmental Protection Agency. U.S. Environmental Protection Agency (EPA). 1985. A strategy to reduce risks to public health from air tonics. Research Triangle Park, N.C.: Office of Air Quality Planning and Standards. U.S. Environmental Protection Agency. 1987a. Municipal Waste Combustion Study: Report to Congress. Washington, D.C.: Office of Solid Waste and Emergency Response, Office of Air and Radiation and Office of Research and Development. EPA/530-SW-87-021a. U.S. Environmental Protection Agency. 1987b. Response to petition for rulemaking and advance notice of proposed rulemaking. Federal Register 52(129):25399-25409. U.S. Environmental Protection Agency. 1987c. Operational Guidance on Control Technology for New and Modified Municipal Waste Combustors. Research Triangle Park, N.C.: Office of Air Quality Planning and Standards. U.S. Environmental Protection Agency. 1987d. Municipal waste combustion study: Assess- ment of health risks associated with municipal waste combustion emissions. Washington, D.C.: Office of Solid Waste and Emergency Response, Office of Air and Radiation and Office of Research and Development. EPA/530-SY`T-87-021g. U.S. Environmental Protection Agency. 1989a. The Solid Waste Dilemma: An Agenda for Action. Final report of the Municipal Solid Waste Task Force. Washington? D.C.: Office of Solid Waste. EPA/530-SW-89-019. U.S. Environmental Protection Agency. 1989b. Standards of performance for new stationary sources; municipal waste combustors; proposed rule. Federal Register 54(243):52251- 52304.

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140 SUELLEN W. PIRAGES AND JASON E. JOHNSTON U.S. Environmental Protection Agency. 1989c. Interim Procedures for Estimating Risks Associated with Exposures to Mixtures of Chlorinated Dibenzo-p-Dioxins and -Dibenzofurans (CDDs and CDFs) and 1989 Update. Washington, D.C.: Risk Assessment Forum. EPA/ 625/3-89/016. U.S. Environmental Protection Agency. 1990. Municipal Waste Combustion: Background Information for Materials Separation. Research Triangle Park, N.C.: Office of Air Qual- ity Planning and Standards. EPA-450/3-90-021. U.S. Environmental Protection Agency. 1991a. Standards of performance for new stationary sources; municipal waste combustors; final rule. Federal Register 56(28):5488-5527. U.S. Environmental Protection Agency. 1991b. Municipal Waste Combustion: Background Information for Promulgated Standards and Guidelines Summary of Public Comments and Responses. Research Triangle Park, N.C.: Office of Air Quality Planning and Stan- dards. EPA/450/3-91 -004. U.S. Environmental Protection Agency. 1992. Safeguarding the Future: Credible Science, Credible Decisions. Expert Panel on the Role of Science at EPA. EPA/600/9-91/050. Walsh, D. C. 1991. The nation's first resource recovery plant. Waste Age 22(11):62-64. Walsh, M. W., Jr. 1990. Comments on the proposed NSPS for MWCs from the Maryland Department of the Environment, Baltimore, Md., dated April 2, 1990. EPA Air Docket No. A-89-08, IV-D-277. Waste Age. 1992. The 1992 municipal waste combustion guide. Waste Age 23(11):99-117.