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National Research Council (US) Committee on Health Effects of Waste Incineration. Waste Incineration & Public Health. Washington (DC): National Academies Press (US); 2000.

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6Regulation Related to Waste Incineration

In the 1960s, state and federal governments began to enact legislation and promulgate regulations calling for increasingly stringent environmental control for municipal solid-waste incinerators. Regulatory activity began with nuisance regulations (related to visible plumes and to odors) and then evolved to emission standards.

Today, waste incinerators must comply with a combination of federal, state, and local regulations that vary from place to place and time to time. In most states, it is also necessary to get permits from state or local governments. For example, a municipal-waste incinerator sited in California must comply with federal laws, as well as get a permit from the California Air Resources Board and one from the local air-pollution control district.

People who live near operating waste-incineration facilities and citizens who are asked to accept such facilities into their local area want assurance that the facilities will be operated safely and in compliance with regulations intended to protect the public health, safety, and the environment. Although the persons most directly affected by a proposed facility might be told much about the minimal hazards associated with new incineration facilities that are normally and efficiently operated, they are likely to be more anxious (perhaps overanxious) about the ability of the facility to be operated over an extended period in compliance with law. They may also be anxious about the risks that arise when equipment breaks down or operations go awry (Davis and Colglazier 1987).

The unintended and uncontrolled release of toxic substances into the environment from waste incineration can occur because of malfunctioning equipment, large changes in the waste feedstream, poor management of the incineration process, or inadequate maintenance or housekeeping. Off-normal operations (e.g., upsets and accidents) at various points in the incineration process might result in explosions; fires; the release of smoke, ash, or noxious odors into the atmosphere; and the spilling or leakage of contaminated or toxic substances. As discussed in Chapter 5, workers at incineration facilities are more at risk than nearby residents due to such occurrences.

Mishaps that are actually experienced by operating facilities that incinerate municipal wastes, hazardous wastes, or medical wastes form a concrete basis for the concerns of nearby residents and other concerned citizens about the safety of waste incineration and the efficacy of regulatory oversight. The fears and worries of residents and concerned citizens are not limited to worst-case scenarios, but extend to events that occur in the normal course of operations at what are otherwise considered properly run and maintained facilities (Curlee 1994). For example, the stream of waste flowing to a hazardous-waste incinerator might be automatically shut off for the purpose of minimizing emissions when operating conditions are outside permitted limits. Automatic waste-feed cutoffs might indicate that an incinerator is not being operated according to good combustion practices. The cutoffs might also affect emissions by leading to a quick shutdown and incomplete combustion. However, if properly managed, the emissions should be minimized. More serious is the use of an emergency bypass or vent stack. Such a stack allows an operator to bypass the air-pollution control equipment following a waste-feed cutoff to prevent the buildup of excessive pressure in an incinerator or to protect the emission control equipment from exceedingly hot flue gases. The frequency of occurrence of such emergency bypass venting by incineration facilities is unknown.

As a result of the possible dangers associated with waste incineration, potentially affected persons expect comprehensive, effective, and responsive regulation that prevents or deters uncontrolled emissions, upsets, and worker injuries, that punishes regulatory infractions, and that promotes decontamination, rectification, and compensation for any harm done.

This chapter examines the structure of waste-incineration regulations with regard to public and occupational health; regulatory oversight; and the policy concerns that are likely to affect future regulatory changes. Particular attention is paid to the different bases on which regulatory standards are formulated and to the extent to which regulations vary with the age and size of a facility. The chapter includes discussions of citizens' concerns regarding the reliability of incineration technology and operations and the effectiveness of regulation.


Direct federal regulation of facilities and federal oversight of state regulation are primarily the responsibility of the U.S. Environmental Protection Agency (EPA), whose authority arises under the Clean Air Act (CAA) (42 USC §7412), the Clean Water Act (CWA) (42 USC § 1365), the Resource Conservation and Recovery Act (RCRA) (42 USC §§ 6901-6992k), the Toxic Substances Control Act (TSCA) (15 USC §2601), and the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), referred to as Superfund (42 USC §9601). To some extent, regulation of facilities that incinerate municipal solid waste, medical waste, or hazardous waste has been effectively delegated to the states, with EPA performing an oversight role. Federal law sets minimal standards for the combustors that the states must implement and enforce, although they are free to impose more-stringent requirements if allowed to do so by state law (Organ 1995). EPA has exclusive jurisdiction, however, over incineration operations that handle polychlorinated biphenyls (PCBs) and hazardous wastes from Superfund cleanup sites.

Incineration regulations generally address emission limitations, good combustion practices, operator training and certification, facility-siting criteria, permit compliance and inspections, and record keeping and reporting requirements. There are wide variations across the country with regard to these subjects. Typically, incineration regulations vary with the type of waste being incinerated, the capacity of the facility, its age, and the overall regulatory environment. The remainder of this overview focuses on relevant requirements of the CAA and RCRA.

The Clean Air Act and Waste Incineration

The CAA requires EPA to establish new source performance standards (NSPS) for new incineration facilities and emission guidelines for existing facilities. Emission guidelines require states to develop plans for controlling emissions from facilities within their jurisdictions. Once EPA has approved the states' plans, they become federally enforceable. Standards and regulations are developed by EPA's Office of Air and Radiation for incinerators that burn municipal solid waste or medical waste. Regulations for hazardous-waste incinerators and cement kilns are developed by EPA's Office of Solid Waste and Emergency Response under the CAA and RCRA (as will be discussed below).

Regulations developed under the CAA are intended to limit atmospheric concentrations of the six criteria pollutants (i.e., carbon monoxide, lead, nitrogen dioxide, ozone, particulate matter, and sulfur dioxide) and control emissions of 188 air toxics (also known as hazardous air pollutants (HAPs)). 1

Prior to 1990, EPA's efforts to regulate HAPs on the basis of health risk were slowed by conflicts and litigation by interested or affected parties. As a result, EPA had developed standards for only seven of the original 189 HAPs. In response to the lack of progress, the 1990 amendments to the CAA shifted the regulatory tool from a risk-based emissions standard to a technology-based standard for the sources of air toxic emissions. The so called “MACT” (Maximum Achievable Control Technology) standards establish control requirements which assure that all major sources of toxic emissions (including waste incineration facilities) have the same level of control already attained by an average of the best performing (top 12%) sources in each pollutant category. The “residual risk” (i.e., the risk remaining) is to be determined in order to assess the risk remaining after the technology-based standard has been met. Section 122(f) stipulates that if an “ample margin of safety” is not reached, then taking into consideration “costs, energy, safety, and other relevant factors,” a standard more stringent than the MACT standards alone may be implemented. It is important to clarify that several of the requirements will not be in effect until several years later. In the meantime, for existing municipal solid-waste incinerators, there is a variety of permits of widely varied stringency governing emissions (for example, ranging from uncontrolled for some pollutants to state-of-the-art controls for others).

EPA is charged with measuring the risks that remain after MACT standards are implemented and reporting its measurements to Congress along with data on the methods used to calculate such risks, their health implications, commercially available methods for reducing them, and recommendations as to legislation regarding them (Steverson 1994). EPA has completed a residual risk report to Congress on the methods to be used to assess the residual risk after MACT standards have been promulgated and applied (EPA 1999). 2

As discussed later in this chapter, EPA has developed NSPS and emission guidelines for large municipal-waste incinerators (units with great than 250 tons per day capacity) of medical-waste incinerators as well as hazardous-waste incinerators, lightweight aggregate kilns, and cement kilns that burn hazardous waste.

National Ambient Air Quality Standards (NAAQS) are in place for the six criteria pollutants mentioned above. The NAAQS set nationwide limits on the atmospheric (ambient) concentrations. If it is determined that an area is not in attainment of any of the NAAQS, that state is expected to develop a State Implementation Plan (SIP) for achieving attainment of the NAAQS through state-selected and enforced controls on emissions. The state must satisfy the EPA that its SIP is adequate. Depending on location, it is possible that some incineration facilities may face additional, more-stringent controls as part of SIP requirements.

The Resource Conservation and Recovery Act (RCRA) and Waste Incineration

RCRA gave EPA the authority to control hazardous waste with respect to generation, transportation, treatment, storage, and disposal. RCRA focuses only on active and future facilities and does not address abandoned or historical sites (those are covered by CERCLA). RCRA requires EPA to establish performance, design, and operating standards for all hazardous-waste treatment, storage, and disposal facilities. The regulations developed in response apply to facilities that incinerate hazardous waste. The regulations restrict the emissions of organics, hydrogen chloride, and particulate matter, as well as fugitive emissions.


Federal Regulations

Section 111 of the CAA sets national emission standards for municipal solid-waste incinerators. It requires promulgation of performance standards for categories of new and existing stationary sources that might contribute to air pollution reasonably anticipated to endanger public health or welfare (Reitze and Davis 1993).

On December 20, 1989, EPA proposed new source performance standards for new municipal solid-waste incinerators and emission guidelines for existing ones on the basis of best demonstrated technology (BDT)(Subparts Ea and Ca of 40 CFR 60). On February 11, 1991, EPA promulgated those subparts as regulations applicable to municipal-waste incinerators reflecting BDT as determined by the EPA administrator at the time the guidelines were issued. Plants were divided into 3 categories: small (units burning up to 250 tons or Mg/day), large (units burning up to 2,200 Mg/day), and very large (units burning more than 2,200 Mg/day). The regulations included maximum levels that varied with the size of the unit for the following emissions: hydrochloric acid (HCl), oxides of nitrogen (NOx), opacity for particles, carbon monoxide (CO), sulfur dioxide (SO2), and dioxins and furans. They also include process parameters, such as load, and flue-gas temperature at the particulate-matter control-device inlet. The regulations also require provisional certification of the chief facility operator and shift supervisors by the American Society of Mechanical Engineers (ASME) or through a state certification program. A site-specific training manual to be used for training other incinerator personnel was required. Reporting is not required for emissions during process upsets, including startup and shutdown. Also, such data are not used to evaluate compliance with standards.

On November 15, 1990, as EPA was preparing final versions of the standards for new and existing municipal solid-waste incinerators, Congress passed the 1990 CAA Amendments; a new provision, section 129 (a)(2), required that emission standards for new incinerators and guidelines for existing ones reflect the maximal achievable degree of emission reduction, taking into consideration the cost and any non-air-quality health and environmental effects and energy requirements of the technology. The level of control was to be based on MACT. Section 129 also effectively added mercury, cadmium, lead, and fly-ash or bottom-ash fugitive emissions to the list of regulated pollutants, expanded the applicability of the standards to some of the smaller plants, and required recalculation of previously promulgated limits for the other pollutants according to a new method.

Municipal solid-waste incinerator “Standards of Performance for New Stationary Sources and Emission Guidelines for Existing Sources,” implementing sections 111 and 129 of the CAA, were promulgated on December 19, 1995, Fed. Regist. 60(243):65387-65436.

With regard to new sources, MACT emission standards (the so-called MACT floor) may not be less stringent than the emission control achieved in practice by the best-controlled similar units. As applied to existing incinerators, MACT emission standards may not be less stringent than the average emission limitation achieved in practice by the best-performing 12% of units. EPA has interpreted the former definition to mean the average performance level achieved at the uppermost 12th percentile of existing municipal solid-waste incinerators in the United States for which data were available, and the latter to mean the level corresponding to the average permit level for the uppermost 12th percentile of existing incinerators for each pollutant.

The data with which MACT floors were to be determined were the subject of some dispute. The MACT floor could have been based on permitted emission levels, levels achieved in practice by currently used technologies, or levels achievable with available technology. Some environmental groups interpreted MACT to mean, in the case of new plants, emission levels equivalent to the bestperforming plant's emission levels, and for existing plants, the average performance level achieved at the uppermost 12th percentile of existing municipal solid-waste incinerators both from a worldwide database of facilities. The difference between this interpretation and the permitted-emission-level interpretation is considerable, particularly in the case of existing incinerators, in that permit levels are usually considerably less stringent than the current state-of-the-art performance levels.

Section 129 also requires the setting of numerical emission limits based on MACT. That has been done for all required pollutants except mercury, HCl, and SO2, for which a dual standard—the less stringent of a numerical limit and a percentage reduction—is proposed. In practice, the percentage reduction usually applies.

Besides the MACT emission limitations, the December 1995 standards and guidelines required that all municipal solid-waste incinerators handling waste at over 35 Mg/day adhere to good combustion practices, which include the following requirements:

  • The incinerator load level and the flue-gas temperature at the particulatematter control-device inlet must be measured and not exceed the levels demonstrated during the most-recent dioxin or furan performance test. EPA did not propose any specific flue-gas temperature requirement for either new or existing plants. Each incinerator is to establish a sitespecific maximal flue-gas temperature based on the maximal 4-hr block average temperature measured during the most-recent dioxin and furan compliance test. The incinerator must then be operated in such a way that the flue-gas temperature does not exceed that maximum by more than 17°C (31°F).
  • The chief facility operator and shift supervisor must obtain provisional and then full operator certification from ASME, and a provisionally certified control-room operator may “stand in” for the chief facility operator or shift supervisor for an unspecified period.
  • All chief facility operators, shift supervisors, and control-room operators are required to complete an EPA or municipal solid-waste incinerator operator-training course. However, uniform course curricula or criteria are not specified in the law.

The rule requires control of flue-gas temperature and load level at the inlet of the particulate-matter control device. Flue-gas temperature at the inlet to the particulate-matter control device, activated-carbon and alkaline-reagent sorbent injection rates, waste-feed rates, and other characteristics are considered surrogates for continuous monitoring of mercury, HCl, and dioxins or furans; and EPA mandates measurement and monitoring of these pollutants under the standards and guidelines.

The CAA amendments of 1990 are being implemented to require the updating of antiquated technologies with more-modern control devices that are not, in the view of EPA, too expensive for both new and large old incinerators. For control of dioxins and furans and mercury, which are the types of the municipal solid-waste incinerator emissions that are most toxic and difficult to remove, and control of acid gases, such as SO2, NOx, and HCl, the MACT floors in both the NSPS and the guidelines for large plants are based on use of activated-carbon injection, spray-dryer absorbers with alkaline-reagent injection, fabric-filter particle-control devices, and selective noncatalytic reduction for NOx control.

Because of concerns about the bioaccumulation of mercury in the environment, EPA considers the incremental costs associated with adding activatedcarbon injection to control mercury emission reasonable for new and existing small plants, and it therefore requires the same mercury-emission standards for all municipal solid-waste incinerators—new and old, large and small. EPA considered activated-carbon injection to be the best of three mercury-control technologies but did not evaluate fixed activated-carbon filtration which is a technology that is used at a number of European facilities.

A siting analysis is required for new plants, as is a material-separation plan. The siting analysis is performed to consider “the impact of the affected facility on ambient air quality, visibility, soils and vegetation” and “air pollution control alternatives that minimize, on a site-specific basis, to the maximum extent practicable, potential risks to the public health or the environment” (40 CFR § 60.57b (b)(1), (2)). No other substantive requirements are stated. The requirements for the material-separation plans are largely procedural; EPA has not specified any particular minimum performance levels, separation-system design, or materials to be separated. To ensure proper siting of a landfill or incinerator, it is important to consider current and projected prevention, recycling, and composting levels and the effect of diversion on the character of the resulting waste stream that serves as the incinerator feedstock.

On April 8, 1997, the U.S. Court of Appeals for the District of Columbia Circuit vacated the emission guidelines and new source performance standards as they apply to municipal solid-waste incinerator units with the capacity to combust less than or equal to 250 tons per day of municipal solid waste, and all cement kilns combusting municipal solid waste. As a result the requirements described above apply only to municipal-waste combustor units with the capacity to burn more than 250 tons per day.

On August 25, 1997, EPA amended the emission guidelines and standards that were promulgated on December 19, 1995 (Fed. Regist. 62(164):4511645127) to make them consistent with the court decision. That amendment document also added supplemental emission guideline limits for four pollutants: hydrogen chloride, sulfur dioxide, nitrogen oxides, and lead. The amendments did not add any additional emission limits to the standards for new facilities. A summary of the emission limits for large municipal solid-waste incinerators is presented in Table 6-1. Proposed emission limits for new and existing small municipal solid waste incinerators are also shown in Table 6-1. Emission limits for carbon monoxide are presented in Table 6-2.

TABLE 6-1. Summary of Emissions Limits for Small and Large Municipal Solid-Waste Incinerators , .


Summary of Emissions Limits for Small and Large Municipal Solid-Waste Incinerators , .

TABLE 6-2. Summary of Carbon Monoxide Emission Limits for Small and Large Municipal-Waste Incinerators .


Summary of Carbon Monoxide Emission Limits for Small and Large Municipal-Waste Incinerators .

State and Local Regulations

Under the Resource Conservation and Recovery Act (RCRA), states must adopt regulations at least as strict as those required by the new municipal solidwaste incinerator performance standards and guidelines. States where greater stringency is allowed (Organ 1995) might have on the books provisions that are more stringent than those set forth in the new EPA regulations, or they might be writing more-stringent provisions into operating permits. The committee is uncertain as to the extent to which differences exist. There have been a number of calls by environmentalists for moratoriums on new waste incinerators (Ferris 1995). A few jurisdictions have enacted moratoriums on construction of new incinerators. Moratoriums are justified, in the view of their advocates not only because of concern for incineration-related health and environmental risks, but also because of concern that increased incineration capacity might interfere with greater use of waste-reduction strategies, including reuse and recycling, which they believe could reduce the quantity of all emissions and production of toxic byproducts and toxic emissions associated with incineration.

Criticisms of MACT-Standard Regulations

The MACT-standard regulations for municipal solid-waste incinerators might be considered controversial in some cases. Mercury, HCl, and SO2 have a dual standard: the less stringent of a numerical limit and a percentage reduction. That approach allows for the possibility of higher emissions when waste stream inlet concentrations of a pollutant are high. EPA's rationale is that low numerical limits might be difficult to achieve when waste-stream inlet concentrations of a pollutant are high. But the dual standard might effectively reduce the impetus for implementing waste-sorting methods (for example, separation of mercury batteries) to reduce pollutant precursors in the waste stream and reduce inlet pollutant concentrations.

Although research (e.g., Stieglitz and Vogg 1987) in the latter 1980s showed that flue-gas temperatures around 300°C are associated with peak secondary dioxin formation, and research by Environment Canada and others showed that lower emissions of mercury, dioxins, and acid gases occurred when flue-gas temperatures were around 150°C, EPA did not propose any specific flue-gas temperature requirement for either new or existing plants.

The technology on which MACT standards are based might have resulted in greater emissions reductions, but at higher costs if more-advanced technologies—such as activated-carbon filters or static beds for control of dioxin and mercury and selective catalytic reduction for NOx control—were considered.

The database on which MACT standards were calculated contained important omissions. For example, EPA chose not to include data from any incinerators in Europe in its database for determining the MACT floor.

Finally, environmental activists have called for siting criteria that take into account proximity to sensitive populations (e.g., the old, and the very young), sensitive land uses (e.g., schools and hospitals), facilities with long-term residents (e.g., prisons), and areas with multiple sources of pollution that impose a cumulative burden on residents. The MACT-based regulations do not reflect those concerns.


Incinerators and other combustors (e.g., light-weight aggregate kilns and cement kilns) that use hazardous wastes as fuels are regulated principally under RCRA and CAA. A hazardous waste is one that either exhibits specific characteristics of ignitability, corrosivity, reactivity, and toxicity or is specifically listed in 40 CFR §§ 261.31 through 261.33. Facilities that treat, store, and dispose of hazardous wastes are comprehensively regulated under RCRA. Operators of hazardous-waste incinerators must obtain an operating permit from either federal or state regulators under standards promulgated by EPA. The permitting process for a new hazardous-waste incinerator generally takes at least 3 years and entails the investment of $5-10 million (Steverson 1994).

Incinerators burning waste contaminated with PCBs, which fall under the Toxic Substances Control Act, must obtain a federal permit. Under Section 112 (d) of the CAA, EPA is required to develop national emission standards for hazardous air pollutants (NESHAP) for major source categories. EPA has determined that industrial/commercial/institutional boilers may be a major source of emissions of one or more HAPs. To the extent that an incinerator discharges pollutants into navigable waters, 3 the operator must also obtain a permit under the Clean Water Act.

The CAA of 1970 authorized a national program of air-pollution prevention and control and required nationwide uniform emission standards for major stationary sources. The act regulated three types of pollutants:

  • Criteria pollutants: particulate matter, SO2, NO2, hydrocarbons, photo-chemical oxidants, and CO.
  • Hazardous pollutants: under National Emission Standards for Hazardous Air Pollutants, which apply to both new and existing sources.
  • Designated pollutants: for pollutants that are neither criteria nor hazardous pollutants, a separate standard is established for existing sources by state agencies under state implementation plans (SIPs).

In the 1970s, the operation of hazardous-waste incinerators was regulated by the states under SIPs case by case. The focus was on emission limits for particles and acid gases (HCl, SOx, and NOx).

The RCRA Subpart O incineration regulations, promulgated on January 23, 1981, revolutionized the design and operation of all hazardous-waste incinerators in the United States. The regulation covered the complete operation, including the front-end waste-feed management, waste-feed sampling and analysis, waste-feed rate control and monitoring, combustion-zone operation control and monitoring, air-pollution equipment control and monitoring, and stack-emission testing and monitoring. Emission of particles and HCl, and efficiency of destruction of hazardous organic chemicals were tightly controlled. Stringent reporting and record-keeping requirements were imposed. There are also requirements on personnel training, inspection of equipment, contingency planning, financial responsibility, and closure plans.

The RCRA Subpart H BIF regulation was promulgated on February 21, 1991, and put all remaining hazardous-waste combustion facilities under the RCRA regulatory umbrella. In addition to the Subpart O incinerator requirement just discussed, several new pollutant-emission controls were included, such as products of incomplete combustion, toxic metals, chlorine gas (Cl2), and dioxin and furan (for facilities with potential to form dioxins and furans in the air-pollution control devices). There were also new and stringent quality-assurance (QA) and quality-control (QC) requirements for continuous flue-gas monitoring.

Since the implementation of Subpart H, EPA, under the RCRA omnibus authority, has imposed the emission standards applicable to BIFs on hazardous-waste incinerators that have high potential to emit the regulated pollutants (Steverson 1994).

As a result of the Subpart O and Subpart H regulations, all hazardous-waste combustion devices in the United States are required to have a detailed compliance-monitoring program. The requirements specify how the equipment can be operated and what levels of emissions are acceptable. Periodic trial-burn testing (for permitted facilities) or certification-of-compliance testing (for BIFs operating under interim status or before a final permit is issued) must be conducted to demonstrate that the stated operating conditions are appropriate and the maximal emission limits are not exceeded. An automatic waste-feed shutoff system is required for all hazardous-waste combustion devices to stop the feeding of hazardous wastes to the combustion chamber immediately if the combustion device does not perform as permitted.

All hazardous-waste incinerators must have four categories of continuousmonitoring devices to ensure that incinerators are operated within the safe operating range as established during the trial burn or certification-of-compliance test. Records of maintenance, calibration, and output of continuous-monitoring instruments must be kept for government regulatory agencies to inspect and ensure compliance.

  • The first category is for the waste-feed rate. Limits on ash, heavy metals, and chlorine (and other halogens) also are added to most permits. These must be tracked to ensure that feed rates will not exceed the design capacity of the incinerator and the associated air-pollution control devices.
  • The second category deals with the operating characteristics that affect the combustion or destruction of wastes in the incinerator combustion zones, including temperature, oxygen concentration, gas residence time, kiln rotation speed, and liquid-waste atomizing pressure. They must be monitored continuously to ensure that the incinerator is operating properly.
  • The third category includes characteristics that affect the control efficiency of the air-pollution control equipment, such as the pressure drop across a scrubber or the power supply to a precipitator. These must be monitored continuously to ensure that the air-pollution control devices are functioning properly.
  • The fourth category deals with the actual performance of the incinerator. Flue-gas CO is continuously monitored. CO is known as the most-stable and most-abundant product of incomplete combustion. If most of the CO is destroyed (as indicated by low concentrations in the flue gas), essentially all organic chemicals and products of incomplete combustion will be destroyed as well. Stack continuous emission-monitoring systems are also often required for NOx, SOx, HCl, total hydrocarbons, and opacity.

To demonstrate that an incineration facility can indeed perform as well as the designer and operator claim, federal regulations require that all hazardouswaste incinerator owners conduct a trial burn to confirm the incinerator's ability to perform as required. The trial burn is intended to demonstrate the limit of a facility's waste-feed rates under worst-case operating conditions. The demonstrated worst-case operating conditions become the operating limits, for example, the lowest allowable combustion-zone temperature and the maximal allowable waste-feed rate. These critical operating conditions and the associated waste-feed limits are listed in the facility's operating permit. The facility operator is allowed to operate the incinerator at conditions equal to or better than those worst-case conditions. To avoid permit violations and the associated fines, incinerator operators typically push the trial-burn test conditions to as close to the design limit as possible so that there is less likelihood that the operating permit will be violated, even though the facility might never operate under those extreme conditions.

In addition, owners or operators of incinerators must conduct training for people who operate the incinerator, must inspect and maintain the equipment, and must have plans that address emergency procedures. Detailed continuous monitoring, operating, and training records must be kept. Unannounced and periodic inspections are conducted by federal, state, and other agencies to see that incinerator operation is meeting all requirements and that violations are noted if they occur.

On April 19, 1996, EPA (1996b) proposed revised standards and guidelines for hazardous-waste incinerators and for hazardous-waste-burning cement kilns and lightweight-aggregate kilns (Revised Standards for Hazardous Waste Combustors, Part II, Fed. Regist. 61(April 19):17358). Since the proposal for the revised standards, EPA received comments identifying two general types of information that were not considered for the proposed standards: (1) errors in the emissions database used for the proposed standards and (2) new reports on trial burns and certification of compliance. EPA has revised its hazardous-waste combustor database based on those comments and other data collection efforts. EPA published a notice of data availability and request for comments on January 7, 1997 (Fed. Regist. 62(Jan. 7):960-962). In that notice, EPA indicated that changes in the proposed MACT floor levels could result from applying the alternative MACT methodologies discussed in the proposed standards to the updated database. See Table 6-3.

TABLE 6-3. Summary of Emission Limits for Existing and New Hazardous-Waste Incinerators (Final Rule) , .


Summary of Emission Limits for Existing and New Hazardous-Waste Incinerators (Final Rule) , .

The April 1996 proposed revisions, which were issued under both the CAA and RCRA, would establish MACT standards for dioxins and furans, mercury (Hg), semivolatile metals (cadmium and lead), low-volatility metals (arsenic, beryllium, chromium, and antimony), HCl and Cl2 combined, particulate matter (PM), CO, and hydrocarbons (HC). Large and small incinerators are held to the same standards, as are wet- and dry-process kilns. In the case of hazardous-waste incinerators, the minimal emission levels or MACT floors from which the MACT standards proceed were determined through analysis of data generated largely during trial burns undertaken to demonstrate compliance with RCRA standards. For kilns, the data came from certifications of compliance obtained under RCRA. MACT floors might not be sufficiently stringent, because data generated for the purpose of achieving flexible permit requirements or during compliance testing reflect worst-case performance and not normal, everyday operating conditions or emissions.

Continuous emission monitoring is required for CO, HC, O2, PM, and Cl2. Other requirements pertain to automatic waste-feed cutoffs. Monitoring must continue during cutoffs, and burning of hazardous wastes is not to be resumed until all conditions are within allowable limits. All cutoffs must be documented, and cutoffs in excess of a specified number will trigger increased inspections. Emergency safety-vent openings must be logged and reported to regulatory authorities. The committee was not aware of any operator certification and training requirements like those applicable to municipal solid-waste incinerators and medical-waste incinerators supervisors and operators.

On June 19, 1998, (Fed. Regist. 63(118):33782-33829), EPA finalized some parts of the standards that were proposed in April 1996. The final rule, “Hazardous Waste Combustors: Final Rule—Part I,” commonly referred to as the “MACT Fast Track Rule,” addresses the following four elements of the proposed standards:


An exclusion from RCRA Subtitle C jurisdiction for hazardous waste-derived fuels that are comparable to fossil fuels


Streamlined procedures to help facility owners and operators comply with their RCRA permits and with forthcoming MACT standards


Affected sources must prepare and submit for public comment a notification identifying the facility's intentions and strategy to comply with the final MACT rule


Waste minimization and pollution prevention criteria when one-year extensions are needed to install waste minimization measures that reduce the amount of hazardous waste entering combustion feedstreams.

The standards were made final in 1999 (see Table 6-3). Phase II of the Hazardous Waste Combustor rule will control emissions form hazardous-waste boilers and halogen-acid furnaces.


In 1980, Congress enacted the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), which created the Superfund program to clean up the nation's most-contaminated hazardous-waste sites. The most highly contaminated sites are placed on a priority list. Their cleanup has entailed or will entail incineration, including the use of temporarily sited units. Incineration is the nearly exclusive means of destroying PCB- and dioxin-contaminated wastes (GAO 1995a). Under CERCLA, incinerators at Superfund sites must comply with applicable federal regulations. Incineration of PCBs is governed by the Toxic Substances Control Act (TSCA), and incineration of dioxins falls within RCRA.

The Agency for Toxic Substances and Disease Registry (ATSDR) was created under CERCLA in 1980 to assess, among other things, the public-health effects of Superfund sites, including the impact of incineration in the remediation process. ATSDR has undertaken health assessments in communities near incinerators used to burn hazardous substances. (See Chapter 5.)


Medical-waste incinerators (MWIs) are used primarily to destroy regulated medical waste that is potentially contaminated with pathogens (also referred to as “hospital/medical/infectious waste”). EPA does not regulate infectious medical waste as hazardous waste (Battle 1994).

EPA has produced final MACT regulations for MWIs under the mandate of the 1990 CAA amendments. On February 27, 1995, EPA proposed new sourceperformance standards for new MWIs and emission guidelines for existing MWIs to fulfill the requirements of section 129 of the CAA (EPA Proposed Rules of Medical Waste Incinerators, Fed. Regist. 60(38):10653-10691 (proposed Feb. 27, 1995). On June 20, 1996, EPA issued a notice of availability of supplemental information and reopening of public comment period (Fed. Regist. 61(Jun. 20):31736-31779). The notice presented an assessment of the supplemental information submitted following the proposed standards and it solicited public comment on that assessment. Virtually every aspect of the 1995 proposal was changed significantly by the 1996 notice. Final rule-making took place on September 15, 1997 (Fed. Regist. 62(178):48348- 48391).

Medical/infectious waste is defined as any waste generated in the diagnosis, treatment, or immunization of human beings or animals, in research pertaining thereto, or in production or testing of biologicals, including cultures and stocks of infectious agents, human pathological waste, and sharps that have been used in animal or human patient care or treatment. Hospital waste is defined as discards generated at a hospital, except unused items returned to the manufacture. The definition does not include human corpses, remains, and anatomical parts that are intended for internment or cremation. For the purpose of this discussion, all of the above types of waste are referred to as “medical waste.”

Incineration facilities that burn medical waste are divided into three source categories based on waste burning capacity: small (less than or equal to 200 lb/hr), medium (greater the 200 to 500 lb/hr), and large (greater than 500 lb/hr). Separate emission standards apply to each subcategory. A summary of the emission limits for new and existing facilities are shown in Table 6-4. Emission limitations have been set for particulate matter, carbon monoxide, dioxins and furans, hydrogen chloride, sulfur dioxide, nitrogen oxides, lead, cadmium, and mercury. In addition, new or modified large incinerators are subject to a 5% visible emission limit for fugitive emissions generated during ash handling and all existing, new, or modified incinerators are subject to a 10% stack opacity limit. The emission guidelines for existing facilities contain alternative emission limits for small facilities that meet the “rural criteria.” Those criteria are based on the MACT levels for small existing medical-waste incinerators that are located at least 50 miles from the nearest Standard Metropolitan Statistical Area and burns no more than 2,000 pounds of hospital waste and medical/infectious waste per week.

TABLE 6-4. Summary of Emission Limits for Hospital/Medical/Infectious Waste Incinerators (Final Rule) .


Summary of Emission Limits for Hospital/Medical/Infectious Waste Incinerators (Final Rule) .

In its final rule, EPA estimates that emission limits for existing units are expected to produce reductions of 96-97% for dioxins and furans; 80-87% for lead; 88-92% for particulate matter; 75-82% for CO; 98% for HCl; 75-84% for cadmium; 93-95% for mercury; and 0-30% for SO2 and NOx. EPA estimates that in the fifth year after implementation of the standards, there would be nationwide emission reductions of 74-87% for dioxins and furans; 85-92% for particulate matter; 0-52% for CO; 95-98% for HCI; 85-92% for lead; 83-91% for cadmium; 45-74% for mercury; and 0-52% for SO2 and NOx. A range of emission reductions is presented to account for the emissions that could occur under a scenario for which no small or medium medical-waste incineration facilities are installed and many of the existing facilities cease operation.

In addition to the medical-waste incineration emission standards and guidelines, EPA includes the requirements listed in Table 6-5, Table 6-6, Table 6-7, Table 6-8 through Table 6-9.

TABLE 6-5. Summary of Additional Requirements Under the Emission Guidelines for Existing Medical-waste Incinerators.


Summary of Additional Requirements Under the Emission Guidelines for Existing Medical-waste Incinerators.

TABLE 6-6. Summary of Additional Requirements Under the Emission Guidelines for Existing Medical-Waste Incinerators that Meet the Rural Criteria.


Summary of Additional Requirements Under the Emission Guidelines for Existing Medical-Waste Incinerators that Meet the Rural Criteria.

TABLE 6-7. Summary of Additional Requirements Under Standards for New Medical-Waste Incinerators.


Summary of Additional Requirements Under Standards for New Medical-Waste Incinerators.

TABLE 6-8. Compliance Times Under the Emission Guidelines for Existing Medical-Waste Incinerators.


Compliance Times Under the Emission Guidelines for Existing Medical-Waste Incinerators.

TABLE 6-9. Compliance Times Under the Standard for New Medical-Waste Incinerators.


Compliance Times Under the Standard for New Medical-Waste Incinerators.

On March 2, 1999, a U.S. Circuit Court of Appeals in the District of Columbia (case no. 97-1686) remanded the 1997 rule asking EPA for further justification of its methodology for setting MACT emission limits for new and existing medical-waste incinerators.


In its MWC rules, EPA (Fed. Regist. 61(Jun. 20):31736-31779) left NOx and lead emissions uncontrolled for plants of specified sizes and ages. Also, there are different CO standards, depending on the size, type, and age of plant (see Table 6-2). But that is not the case for hazardous-waste incinerators, which by their nature are at least as diverse in feedstock and combustor design as municipal solid-waste incinerators or medical-waste incinerators. Unlike hazardous-waste combustors under the proposed rules, all municipal solid-waste incinerators and medical-waste incinerators are not regulated within their own categories according to MACT with single numerical emission limits for each pollutant irrespective of plant size, design, age, or feedstock. However, the same types of air-pollution controls (as discussed in Chapter 3) can be applied to large and small facilities. Although there may be other legitimate reasons for doing so, allowing weaker limitations for some designs or sizes provides little incentive for smaller facilities to pursue further achievable emission reductions. Also, having multiple emission standards for similar devices is inconsistent with minimizing risks of health effects.


The source and extent of regulation protecting the health and safety of incineration workers depend on the nature of the waste handled by the facility, its location, and the nature of the entity operating the facility. Incineration facilities that are operated by government entities and do not handle hazardous waste are exempt from the federal Occupational Safety and Health Act but might be subject to state and local regulation. Thus, municipal solid-waste incinerators operated by government bodies are not subject to the authority of the Occupational Safety and Health Administration (OSHA), whereas such incinerators operated by private companies or contractors might be. The act that created OSHA also enables states to establish their own programs with federal approval if their standards are at least as stringent as OSHA's. Thus, all municipal solid-waste incinerators not operated by government entities must be operated in compliance with OSHA regulations, although some fall under the jurisdiction of OSHA and some come under approved state plans.

The Superfund Amendments and Reauthorization Act of 1986 requires that OSHA and EPA promulgate regulations to protect workers employed in hazardous-waste operations. OSHA requires that employers develop and implement written programs that cover information and training, personal protective equipment, monitoring, medical surveillance, decontamination, engineering controls and work practices, handling and labeling of drums and containers, exposure and medical-treatment record keeping, and other subjects (29 CFR §1910.120). EPA has extended these requirements to state and local employees who are involved in hazardous-waste operations but do not fall within OSHA's jurisdiction or the jurisdiction of an approved state plan (40 CFR §311).

In November 1990, EPA and OSHA entered into a Memorandum of Understanding on Minimizing Workplace and Environmental Hazards whereby the agencies agreed to coordinate their regulatory efforts on the local, regional, and national levels. The agreement was fleshed out in March 1991. In July 1991, a joint task force formed by the two agencies issued a report summarizing the results of the inspection of 29 hazardous-waste incinerators and made a number of recommendations to EPA and OSHA. On January 25, 1995, the General Accounting Office (GAO) reported that several of the recommendations had not been fully implemented. At that time, EPA had not conducted research on the cause and effects of the use of automatic waste-feed cutoffs and emergency safety vents or vent stacks. Moreover, it had not implemented changes in its inspection protocol to test the effectiveness of worker training, contingency plans, and emergency preparedness (GAO 1995b). OSHA had not improved its inspection expertise, nor had it increased the priority ranking accorded the refuse industry in such a way as to subject a single hazardous-waste incineration to a programmed inspection. Because OSHA considers other industries more dangerous than hazardous-waste incineration, incinerators are inspected on a random basis or in response to complaints, referrals, or accidents. GAO acknowledged that EPA and OSHA were undertaking initiatives not recommended by the task force. For example, EPA and the states targeted combustion facilities for enforcement activities and assessed fines in excess of $9 million. OSHA proposed to require accredited training programs for workers, although it would have no means of ensuring that the accreditation is actually received. GAO suggested that EPA inspections might assist OSHA in assessing the extent of compliance with an accreditation requirement.

MACT-based standards and guidelines applicable to waste combustors required under section 129 of the CAA do not address occupational health and safety directly, although they might affect the well-being of incinerator workers indirectly. For example, it has been estimated that retrofitting incinerators with lime-injection scrubbers will reduce the toxicity of ash. The municipal solid-waste regulations limit visible fugitive emissions from ash-handling and ash-transfer points to no more than 5% of the time, although maintenance and repair activities are exempted from the requirement. Plant operating manuals, operator training, and ASME or equivalent certification of facility operators and shift supervisors might also reduce the likelihood that an incinerator will be run in ways that pose a hazard to its workforce (W. Stevenson, EPA, pers. commun., May 21, 1996).


In 1988, a committee of the American Society of Mechanical Engineers (ASME) Codes and Standards Division developed a voluntary standard for municipal solid-waste incinerator plant-operator certification. Since then, subcommittees of the Qualification of Resource Recovery Operators Committee (QRO)—some containing members who train operators for firms that design, operate, or construct municipal-waste incinerators—have developed tests for chief facility operators (CFOs) and shift supervisors. In the 1991 New Source Performance Standards, EPA required that CFOs and shift supervisors be certified at the first level of the ASME operator-certification program. EPA's 1991 standards also required that each municipal solid-waste incinerator have a plant-operations manual that each employee was to review. No standards of uniformity were given for preparation of the operations manuals, and no uniform guidelines were proposed to facilitate the review of the manuals by operators.

In the subsequent revision of the municipal solid-waste incinerator emission standards, EPA has proposed requiring that CFOs and shift supervisors be certified at the second, site-specific, level of ASME's operator-certification program. Provisionally certified operators take the site-specific, oral examinations for full certification. In its promulgated municipal solid-waste incinerator standards, EPA requires that a control-room operator who can substitute for a CFO or shift supervisor should also be certified at the first level (on an optional basis). However, there is no stipulated limit on the amount of time that a control-room operator may substitute for a shift supervisor or CFO. With regard to operator training, the standard requires that all CFOs, shift supervisors, and control-room operators complete an municipal solid-waste incinerator operator-training course approved by EPA within 2 years.

The ASME QRO's stipulated minimal qualifications for eligibility to take the first-level operator-certification examinations do not specify any formal academic training, such as college credits in physical science and engineering. Persons with a high-school diploma are permitted to take the examination and receive certification. Furthermore, the requirements proposed by QRO and EPA do not involve demonstration that certified operators have kept up with design changes or are knowledgeable about advances in pollution prevention, combustion efficiency, or emission-control technologies and regulations. The main requirement for renewal of certification is continuation of employment as a CFO or shift supervisor. No periodic testing is required in the operator-certification standard to ensure that the hundreds of operators who received certification in the first few years of credentialing are well versed in the newer technologies or regulations. The ASME created a sister committee to the QRO to develop operator certification for medical-waste incinerator operators.


The effectiveness of the panoply of regulations governing waste incineration depends on compliance by incineration facility operators and enforcement of the regulations by federal and state environmental regulators. In general, greater regulatory attention has been paid to securing initial compliance with technologic requirements than with monitoring and ensuring continuing operational compliance (Russell 1990). Audits and assessments of regulatory activity in waste incineration may be rare. Accordingly, it is difficult to assess the full extent of operator noncompliance with regulations or the efficacy of regulatory oversight in policing incineration activity. The absence of data is important. According to Reitze and Davis (1993), “the yet unproven ability of our regulators to effectively control emissions over the life of a facility” is a weakness that undercuts the conclusion that incineration “is a rational option for managing solid waste.”

Siting, Startup, and Initial Compliance

Regulations concerning the siting and permitting of new facilities are elaborate. Much regulatory attention is directed toward ensuring that the requisite technology is incorporated and operational in new facilities and that standards are satisfied. Nonetheless, among grassroots environmental activists and mainstream environmentalists there is a high level of dissatisfaction with the regulatory process regarding the siting and permitting of waste incineration. The points that follow do not constitute a complete catalog of the complaints but are among the most-often voiced. Also, it is important to keep in mind that all local residents do not necessarily share these concerns.

Citizens have several kinds of objections to risk assessments. Citizens complain that the data used are hypothetical, that they are not necessarily related to the potentially affected community and the particular facility. To the extent that the facility's risk is assessed in terms of increments to background risk, populations already subject to cumulative risks from other pollution sources are disadvantaged; poor and minority-group communities often feel especially vulnerable in this regard. Moreover, a risk assessment is not a public-health assessment. After a risk assessment has been done and a facility is sited and begins operation, there often is no follow-up to determine whether the assumptions on which the risk assessment was based are true. Community advocates argue that there should be health monitoring in the affected community before a waste-disposal facility opens, during its active operation, and after it closes or is closed. Furthermore, the environmental assessments that precede a siting decision should not be limited to health risks. The risks to the economic and social environment if the facility opens should also be assessed. These concerns are discussed further in Chapter 7 of this report.

Moreover, some citizens doubt that the possibility of upsets, malfunctions, leaks, releases, mishandling, and explosions, whether or not caused by regulatory violations, is taken into account in risk-assessment calculations.

Some citizens believe that they receive notice that their community is a potential site for a waste-disposal facility too late in the siting process. They believe that risk assessments are done to support decisions that have already been made. They do not believe that regulators are impartial decision-makers who will give them a fair chance to present their opposing views and make a fair and impartial decision based on all the evidence. These concerns are addressed in Chapter 7 of this report.

Some citizens believe that stack tests are conducted under ideal or optimally efficient operating conditions when the facilities are in the control of the mostqualified and most-experienced operators and not under ordinary operating conditions, which are likely to be less controlled and therefore more dangerous to the environment and affected populations (Connett and Connett 1994).

Regulators and operators, in contrast, assert that an operator would have little reason to conduct a trial burn at a facility under the best conditions because the limits on emissions in its operating permit are based on conditions determined during that burn, and ordinary operations under less-favorable conditions than the test burn would give rise to permit violations. The operator has an incentive to conduct the trial burn under conditions as close to the design limits of the facility as possible so that there is more latitude in conducting ordinary operations (U.S. Congress 1994). Making it clear to the residents living in the vicinity of a facility being tested, that, contrary to their assumptions, trial burns are conducted under conditions that push (if not exceed) the limits of a facility's design capacity might prompt strong objections from residents.

Continuing Compliance

Regulators engaged in enforcement receive data about ongoing incineration operations through reporting requirements, operator self-monitoring, electronic monitoring, inspections, and citizen complaints.

The inspections of incineration facilities are performed largely by the states with grants from the federal government pursuant to memoranda of agreement that set forth inspection priorities. The priorities are a matter of negotiation between the states and EPA and therefore differ from region to region. Inspectors in the air programs focus on emissions. Inspectors in the waste program (RCRA) consider combustion and other operations, including the handling of wastes coming into the facility and leaving it. RCRA inspections accordingly will cover personnel training, waste storage, and ash disposal.

A principal goal of an inspection is to determine whether a facility is operating in conformity with the applicable permits or certificates. Logs, strip charts, and data from continuous emission-monitoring systems (CEMS) are important sources of data regarding emissions and cases in which they exceed limits. Data from strip charts and CEMS are particularly reliable because they appear not to be subject to alteration or fraud. CEMS do not exist for all important toxicants though EPA does not require use of all CEMS that are commercially available. The operating conditions set during trial burns are used as surrogate measures of some emissions of substances for which CEMS are not required or for which continuous-monitoring technology has not yet been developed and validated. If the surrogate measures are within compliance ranges, it is assumed that the unmeasured substances are also within compliance ranges. Modems connected to CEMS make it possible for regulators to obtain contemporaneous data on a facility's operations. Such an approach would allow regulators to quickly know about process upsets or bypassing of emission control devices due to emergencies or equipment malfunctions. In Pennsylvania, data from CEMS sent directly and contemporaneously to regulators are used to produce computer-generated records of conditions that exceed limits and the resulting fines that are assessed against a facility, although extenuating circumstances might be the basis for a reduction in fines (Francine Carlini, Air Quality Inspector, Pennsylvania EPA, pers. commun., Nov. 1995). Continuous emission monitoring need not necessarily foreclose the exercise of regulatory discretion. For example, data revealing limit violations that do not appear to be caused by identifiable engineering problems or by technical conditions that can be fixed might not trigger enforcement action (James Topsale, U.S. EPA Region III, pers. commun., Oct. 31, 1995).

Although continuous emission and process monitoring will be required for some pollutants on some incinerators as a result of the CAA, a municipal-waste incinerator will be allowed to exclude data from 25% of its daily operating time and from 10% of the calendar days per quarter when the plant is operating. Furthermore, the proposed standards and guidelines do not indicate which data may or may not be excluded. Separate from the allowable exclusions mentioned above, emissions during startup, shutdown, and upsets are specifically excluded from consideration with respect to compliance. These data exclusions seem to confirm citizen complaints that they do not have access to a full picture of the safety of incinerators.

The timing and frequency of inspections are matters of some criticism by environmentalists. Some jurisdictions conduct inspections without advance notice to the operator; others do not. Environmental activists are concerned that advance notice of an inspection allows an operator to clean up a facility, remove contaminants from the feedstock, hide unfavorable data, and make sure that the most-experienced operators are on duty paying special attention to optimizing combustion and emission controls when the regulators are on site. Regulators respond that announced inspections can be just as effective at turning up violations as unannounced visits. Inspections are undertaken on very short notice; given that the frequency of inspections is mandated by regulations, complete surprise is impossible. Notice facilitates the inspection by ensuring that records and key personnel will be readily available when the inspectors arrive. The inspections depend heavily on data that cannot be concealed or altered (EPA Regulatory Enforcement and Compliance personnel, pers. commun., Feb. 15, 1996).

Incinerator-inspection data are kept at the state, regional, and national levels. Data pertaining to compliance monitoring and enforcement, as well as corrective action, regarding hazardous-waste incineration are supposed to become part of the RCRA Information System (RCRIS). GAO, however, has concluded that RCRIS is difficult to use, does not satisfy the needs of individual states and EPA regions, and fails to serve as a mechanism for maintaining highly reliable data. By and large, RCRIS is not a good basis on which to determine how well incinerators are performing (GAO 1995c).

In the absence of contemporaneous, direct reporting via computerized continuous emission monitoring or the presence of an on-site inspector, regulatory oversight between inspections might depend on reporting by the incinerator operator or complaints from local residents.

The standards and guidelines for municipal solid-waste incinerators require annual testing for dioxin and furan emissions; but to increase the incentive “to optimize performance and achieve emission levels significantly lower” than prescribed limits, less-frequently reporting will be demanded of facilities that meet specified dioxin and furan emission limits for two years. Moreover, reporting requirements have been changed from quarterly to annual to reduce their cost. Such less-frequent testing makes it difficult to determine whether operators have maintained optimal performance.

Violations need not be reported immediately under current EPA proposals. Residents suggest that their complaints are not always accorded the reception that they deserve. Some residents who have lived close to waste combustors complain that their knowledge of the harm that such facilities might produce has been undervalued and ignored. Moreover, although facilities are generating more and more information about their operations, some of it is unavailable to the public and some of it is available but not in a form that is readily usable by laypersons or government officials. It has been suggested that if maintenance and operation records must be kept and made available to the public in a form that is accessible to a lay reader, it would increase the likelihood that incinerators are being operated in compliance with regulations (Reitze and Davis 1993).

Once an environmental protection agency learns of a regulatory infraction or permit violation, a number of options are open to it, including informal responses (site visits or warning letters), administrative remedies (including penalties and compliance orders), and judicial actions (including injunctions and criminal prosecutions). The number of inspections that an agency conducts, the number of facilities shut down or fined, the dollar amount of fines, and the length of time between notice of an infraction and final administrative action with regard to it are all measures of an agency's competence and efficiency in punishing violators and deterring future infractions (Lavelle and Coyle 1992).

Enforcement typically involves the exercise of discretion. Many agencies have enforcement or compliance guidance documents that assist regulators in determining appropriate responses to regulatory infractions (Kuehn 1994). In 1987, EPA revised its Enforcement Response Policy in a way that proved to be problematic. Some industry sources found the policy to be inflexible, insensitive to risk-based concerns, and too harsh in its treatment of minor infractions. But GAO criticized EPA and state regulators operating under EPA oversight for failing to pursue the dictates of the civil-penalty policy, which required penalties stiff enough to deprive violators of the economic benefit of their infractions (GAO 1991). According to GAO, “penalties play a key role in environmental enforcement by acting as a deterrent to violators and by ensuring that regulated entities are treated fairly and consistently with no one gaining a competitive advantage by violating environmental regulations.” The size of the penalties was affected by budgetary resources, program targets that favored settlement, regulatory limits on monetary penalties, and the belief of some regulators that working with a violator to achieve voluntary compliance was more effective than imposing heavy fines in deterring future violations.

EPA has issued revised Hazardous Waste Civil Enforcement Response Policy that became effective April 5, 1996. The policy focuses on facilities that pose the greatest risk of exposure to hazardous waste or that are chronic, recalcitrant, or substantial violators of regulatory requirements (EPA 1996c). According to the policy, “an appropriate [enforcement] response will achieve a timely return to compliance and serve as a deterrent to future noncompliance by eliminating any economic advantage received by the violator.” The policy indicates that formal proceedings are appropriate in the case of substantial noncompliers; smaller penalties may be assessed against facilities that are unable to pay the full penalty or that discover violations during self-evaluations and audits and promptly disclose and correct them. The policy also sets forth response-time guidelines with allowances for violations under specified circumstances. The policy also specifies the circumstances in which EPA will initiate independent enforcement actions in authorized states.

Persons calling for environmental justice have spawned some reviews of the effectiveness of regulatory activity in areas populated by poor or minority-group citizens. For example, in 1992, the National Law Journal published the results of a comprehensive study of completed lawsuits brought by EPA under RCRA and under many other laws, over a seven-year period (Lavelle and Coyle 1992). The study concluded that the average fines were substantially higher in areas with the highest proportion of white people than in areas with the highest proportion of minority-group people (506% higher in RCRA actions and 306% higher in actions based on violations of multiple laws). The method used by the study for designating white and minority-group communities has been criticized, and later studies, including several undertaken by EPA, have contradicted its findings (Kuehn 1994). EPA recognizes a need for more data with regard to the racial impact of its enforcement activities (Kuehn 1994). Environmental justice issues are discussed further in Chapter 7.



  • MACT-based regulations vary for incinerators of municipal waste, hazardous waste, and medical waste. There are three to five CO standards, depending on the size, type, and age of municipal solid-waste incinerator. But that is not the case for hazardous-waste incinerators or medical-waste incinerators, which by their nature are at least as diverse in feedstock and combustor design as municipal solid-waste combustors. Within the municipal-waste incinerator rules and medical-waste incinerator rules, several types of emissions (e.g., lead, NOx, and dioxins and furans) are lessstringently controlled for facilities of specified size (generally smaller) and ages (generally older).
  • Workers at incineration facilities tend to be subject to greater risk than other people from exposure to pollutants from normal incinerator operations and from accidents and upset conditions. Ensuring worker safety requires effective coordination of enforcement activities between EPA and OSHA.
  • Assessment of both regulatory compliance and the efficacy of regulatory oversight are important to ensure that existing standards are being met in all cases and to satisfy citizens' needs for information concerning incinerator safety.


  • In future regulatory decision-making, greater consideration should be given to emission levels achieved in actual performance of incinerators, including process upset conditions. EPA should routinely seek out and use the best and most appropriate data including foreign plant-emission data, and other sources, as well as domestic data, in proposing new standards. In addition, any combustion, emission-control, and continuous emission-monitoring, telemetering and bill boarding technologies and optimum operating practices used in foreign plants should be actively studied and considered for adoption in the United States. In order to give appropriate consideration to combustor and air-pollution control technology and operating techniques used in foreign countries, EPA should develop methods for characterizing the uncertainty of relevant information.
  • All regulated medical-waste incinerators and municipal solid-waste incinerators should have uniform limits for each pollutant, irrespective of plant size, design, age, or feedstock, as is the case for hazardous-waste incinerators. The same technology for air-pollution control is applicable to small and large facilities. Although there may be other legitimate reasons for doing so, allowing less-stringent limitations for some designs or sizes is inconsistent with the principle of minimizing risks of health effects.
  • Government agencies should encourage research, development, and demonstration of continuous emission monitors (CEMs), telemetering, bill boarding, and computer programs that automatically analyze, summarize, and report CEM data for all types of incineration facilities. In addition to the CEMs already required in the municipal solid-waste incinerator rules, requirement of HCl and particulate-matter CEMs should be considered on all municipal solid-waste incinerators. Also, as soon as a mercury monitor that measures both ionic and metallic forms of mercury emissions has been proven reliable, EPA should consider its use for domestic incinerators. The same approach should be used for other monitors, including those for other heavy metals and the dioxins and furans. EPA should also explore the utility of telemetering and bill boarding of CEM data to regulatory authorities and the public. Providing such data and data summaries on the Internet should be considered.
  • In monitoring for compliance, or other purposes, data generated during the intervals in which a facility is in startup, shutdown, and upset conditions should be included in the hourly emissions data recorded and published. It is during those times that the highest emissions are expected to occur, and omitting them systematically from monitoring data records does not allow for a full characterization of the actual emissions from an incineration facility.
  • Because operators need to be trained to handle new technologies and follow new requirements, periodic renewal of operator certification for all types of waste incineration should require retesting on new technologies, practices, and regulations. Both provisional and onsite certification should apply to all control room operators, because they can stand in for certified individuals for indeterminate periods of time.
  • Government agencies and incineration equipment manufacturers should continue to undertake research to determine how to optimize incineration facility performance for different types of incinerators and how to prevent and mitigate upsets. Detailed guidance should be provided based on the results of this research to state and local regulatory jurisdictions and plant operators, and to the public via the Internet.
  • EPA and OSHA should continue striving to improve coordination of enforcement activities between the two agencies to protect the health of incineration workers.



The original list of HAPs included 189 chemicals, but caprolactam was removed from the list in 1996.


EPA's (1999) residual risk report was not available until after the committee completed its deliberations.


Traditionally, navigable waters refers to waters that are sufficiently deep and wide for navigation by all, or specified vessels.

Copyright 2000 by the National Academy of Sciences. All rights reserved.
Bookshelf ID: NBK233621