United States General Accounting Office

GAO Report to Congressional Requesters

December 1995 SUPERFUND

EPA Has Identified

Limited Alternatives to

Incineration for

Cleaning up PCB and

Dioxin Contamination

GAO/RCED-96-13

GAO United States

General Accounting Office

Washington, D.C. 20548

Resources, Community, and

Economic Development Division

B-266331 

December 29, 1995

The Honorable Jerry Lewis

Chairman

The Honorable Louis Stokes

Ranking Minority Member

Subcommittee on VA, HUD,

 and Independent Agencies

Committee on Appropriations

House of Representatives

The Honorable James M. Talent

The Honorable Jim Chapman

The Honorable Barney Frank

House of Representatives

One of the most contentious environmental issues facing the

Environmental Protection Agency (EPA) today is the use of incineration to

clean up Superfund sites contaminated by polychlorinated biphenyls (PCB)

or dioxin. Across the country, local community groups are protesting the

choice of incineration as the treatment remedy. Many people believe that

incinerators have the potential to emit hazardous substances that could

lead to adverse health effects in their communities. Consequently, these

community groups want EPA to use technologies other than incineration to

clean up sites. However, EPA believes that the effectiveness and safety of

many alternative technologies remain unproven.

Because of the public’s concerns about the use of incineration at PCB- and

dioxin-contaminated sites, you asked us to identify (1) what EPA has done

to encourage the development and use of alternative or “innovative”

technologies at all contaminated sites, including those with PCBs and

dioxin;1

 (2) whether EPA has identified innovative technologies that can be

used at PCB- and dioxin-contaminated sites; and (3) what factors have

limited the use of innovative technologies at PCB- and dioxin-contaminated

sites. In addition, to provide an illustration of how EPA decides what

cleanup technology will be used, you asked us to conduct three case

studies at PCB- and dioxin-contaminated sites where EPA has proposed

incineration as the remedy. Our observations on these sites—Texarkana

1

EPA considers a technology to be innovative if it has not been used in a full-scale application or if it is

the first-time application of an existing technology to a new contaminant. More specifically, EPA

defines innovative treatment technologies as those that lack the cost and performance data necessary

to support their routine use.

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Wood Preserving Company, Texas; Times Beach, Missouri; and New

Bedford Harbor, Massachusetts—are described in appendix I.

Results in Brief Although EPA has taken a number of steps to encourage the development

and use of innovative technologies in general, it has not yet identified any

technologies it believes to be as effective as incineration for most PCB- or

dioxin-contaminated sites. As a result, EPA has relied on incineration for

many sites with PCB and dioxin contamination. Specifically, we found the

following:

• EPA has established programs and issued guidance to encourage the

development and use of innovative technologies for all types of

contaminants.2

 Overall, EPA has chosen innovative technologies in about

20 percent of its cleanup decisions at Superfund sites. However, EPA has

used innovative treatment technologies at only about 10 percent of the

PCB-contaminated sites and 3 percent of the dioxin-contaminated sites, and

then mostly at small, uncomplicated sites.3

• EPA has not identified any innovative technologies it believes to be as

effective as incineration for treating the waste at large, complex PCB- or

dioxin-contaminated Superfund sites. However, several innovative

technologies are being developed and tested that may someday prove as

effective, either alone or in combination, in cleaning most sites with these

contaminants. Accordingly, EPA has recognized that some of its previous

decisions on the cleanup technologies to be used should be reevaluated to

take advantage of recent technological advancements.

• EPA has identified a number of barriers that currently inhibit the further

development and routine use of innovative technologies at Superfund

sites. A primary barrier is the inability of current innovative technologies

to meet performance standards for incineration—the remedy on which

regulatory standards are based.4

 Other barriers include technical

limitations, limited cost and performance data, and the lack of incentives

to invest in the development of innovative technologies. Because of these

2

EPA’s innovative technology programs and guidance are focused on all types of contaminants, as

opposed to being focused on individual contaminants such as PCBs or dioxin. As requested, we

focused on PCBs and dioxin because they are difficult to treat and highly toxic. (See app. II for a

discussion of PCB and dioxin contamination.)

3

At other sites, large volumes of complex waste, such as those with multiple contaminants or high

levels of contamination, make the use of innovative technologies more difficult. However, sites with

small volumes of uniform waste, even those containing PCBs or dioxin, can more readily

accommodate the use of innovative technologies.

4

Performance standards are based on the level of effectiveness of a specific technology. Performance

standards generally are not based on the level of health risk associated with that level of effectiveness.

Page 2 GAO/RCED-96-13 EPA’s Encouragement of Innovative Technologies
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barriers, and of the proven effectiveness of incinerators, EPA has so far

relied on incineration to clean up most sites contaminated with PCBs or

dioxin.

Background With the enactment of the Comprehensive Environmental Response,

Compensation, and Liability Act (CERCLA) in 1980, the Congress created the

Superfund program to clean up the nation’s most severely contaminated

hazardous waste sites. The program was extended in 1986 and in 1990 and

is now being considered again for reauthorization. Under CERCLA, EPA

investigates contaminated areas and then places the nation’s most highly

contaminated sites on a priority list, called the National Priorities List

(NPL), for investigation and cleanup. As of September 1995, EPA had 1,238

sites on the NPL. Of these sites, approximately 190 had PCB contamination

and about 80 had dioxin contamination.5

After EPA puts a site on the NPL, the agency goes through an extensive

process to determine what remedy or remedies for cleanup would be

appropriate for that site. The remedy selected depends upon the

characteristics of the individual site, such as the types and levels of

contamination, the complexity of the site’s problem, the site’s risk

assessment, and the cleanup standards.

EPA weighs each potential remedy against a number of criteria set forth in

federal regulations. These criteria include the long-term protection of

human health and the environment; compliance with the applicable or

relevant and appropriate federal and state laws; and the community’s

acceptance of the remedy being considered. Using these criteria, EPA has

generally selected incineration as the remedy for many large, complex

Superfund sites contaminated with PCBs or dioxin—two compounds that

pose significant threats to human health and the environment. (See app. III

for a further discussion of incineration technology.)

Under CERCLA, incinerators at Superfund sites must comply with applicable

technical requirements contained in federal regulations. In particular, the

incineration of dioxins is governed by regulations issued under the

Resource Conservation and Recovery Act of 1976 (RCRA), as amended.

Similarly, the incineration of PCBs is governed by regulations issued under

the Toxic Substances Control Act (TSCA).

5

Because some sites may have both PCB and dioxin contamination, these numbers may not be added

together to yield a total number of PCB- and dioxin-contaminated sites.

Page 3 GAO/RCED-96-13 EPA’s Encouragement of Innovative Technologies
B-266331 

EPA’s Efforts to

Encourage the

Development and Use

of Innovative

Technologies

EPA has established two offices to encourage the development and use of

innovative technologies. One is the Superfund Innovative Technology

Evaluation (SITE) program, which evaluates cleanup or waste removal

technologies. The second is the Technology Innovation Office (TIO), which

acts as a clearinghouse for information on innovative cleanup

technologies. In addition, EPA has issued guidance that encourages the

consideration of innovative technologies for cleaning up Superfund sites.

These efforts do not focus on specific contaminants such as PCBs and

dioxin but are designed to promote the development and use of innovative

technologies for all types of contaminants. Overall, in 1994, EPA selected

innovative technologies in about 20 percent of its decisions on remedies

for all Superfund sites. For PCB- and dioxin-contaminated sites, EPA

selected innovative treatment technologies to a lesser extent than at other

Superfund sites.

Superfund Innovative

Technology Evaluation

Program

EPA established the Superfund Innovative Technology Evaluation program

in 1986 to accelerate the development and encourage the routine use of

innovative technologies.6

 Under the SITE program, EPA enters into

cooperative agreements with private technology developers who, after

refining their technologies on a small scale, may demonstrate them, with

support from EPA, at Superfund sites. The SITE program periodically

publishes reports containing engineering, cost, and performance

information for the technologies evaluated. For example, in fiscal year

1995, SITE spent about $12 million to demonstrate 11 technologies. None of

these treated a PCB- or dioxin-contaminated site.

Superfund officials involved in cleaning up sites stated that SITE’s reports

on demonstrations often focus on the science of the innovative

technologies and provide only limited information on potential

implementation problems. For example, the Superfund site manager at

one site we visited told us that SITE had initially been extremely positive

about the scientific potential for one of its demonstrated technologies at

that site. However, after learning about the site’s specific characteristics,

SITE officials decided the technology was inappropriate for that site.

These criticisms remain, although Superfund program officials stated that

they had begun to work with SITE in 1993 to make its information more

useful, and as a result, additional information has been added to SITE’s

6

The Superfund Amendments and Reauthorization Act of 1986 (SARA) directed EPA to establish a

research and development program for innovative treatment technologies.

Page 4 GAO/RCED-96-13 EPA’s Encouragement of Innovative Technologies
B-266331 

technology demonstration reports. SITE program officials noted that

resource constraints require them to set priorities for the scope of

demonstrations conducted and thus limit the information that can be

provided.

Technology Innovation

Office

In 1990, EPA established the Technology Innovation Office to increase the

use of innovative treatment technologies. TIO serves as an information

clearinghouse to provide (1) prospective technology vendors with

information on the extent and nature of sites needing cleanup and

(2) cleanup officials with information on the availability of innovative

technologies. In addition, TIO attempts to identify why innovative

technologies are not being used more frequently. In fiscal year 1995, TIO

spent about $2 million to carry out these responsibilities.

To serve as an information clearinghouse, TIO maintains several databases

containing information on innovative technologies and innovative

technology vendors. However, Superfund officials told us that the cost and

performance data contained in TIO’s database of innovative technology

vendors is vendor-supplied and TIO does not validate it. TIO officials stated

that these data are supposed to be only the starting point for identifying

potential innovative technologies and that TIO does not have the resources

to validate the data. In addition, TIO officials believe that requiring vendors

to supply independently validated data might exclude some innovative

technology vendors.

TIO officials, however, recognize that those responsible for cleaning up

hazardous waste sites need reliable cost and performance data and have

taken actions to address this problem. For example, working through the

Federal Remediation Technologies Roundtable, composed of major

federal agencies that carry out remediation research and projects, a guide

to documenting remediation projects’ cost and performance was

developed. This guide, which all member agencies have agreed to use,

provides project managers with standard procedures for collecting and

reporting project information.

TIO also attempts to encourage the use of innovative technologies by

identifying why innovative technologies are not being selected more often

at Superfund sites. For example, TIO published a study7

 in April 1995 which

showed that Superfund cleanup officials were often eliminating innovative

7

Feasibility Study Analysis, Volume 1: Findings and Analysis, prepared for the Technology Innovation

Office by Environmental Management Support, Inc., Silver Spring, MD, Apr. 21, 1995.

Page 5 GAO/RCED-96-13 EPA’s Encouragement of Innovative Technologies
B-266331 

technologies from the remedy selection process without fully considering

them. That study, based on 205 sites, found that EPA conducted tests to

assess the potential performance of innovative technologies at only 47

sites (less than 25 percent) of the 205 sites. When these tests were

conducted, however, innovative technologies were used in about

45 percent of the remedies selected. Superfund officials said that even

though guidance encourages the testing of innovative technologies, such

tests were not performed in a large number of cases because of time

constraints and funding limitations. TIO staff are now considering a number

of actions to address these and other problems identified in the report.

EPA’s Guidance on the Use

of Innovative Technologies

EPA has issued guidance encouraging greater use of innovative

technologies at all Superfund sites where such remedies can provide a

viable means for treatment. For example, in guidance issued in June 1991,

EPA urged staff responsible for selecting Superfund remedies to consider

innovative technologies in their technology evaluations for all sites

(including those contaminated with PCBs and dioxin), even when the cost

and performance of the innovative technologies were uncertain. The

guidance also encouraged EPA project managers to use on-site tests to

assess the potential performance of innovative technologies at sites.

Furthermore, it provided for expedited funding to facilitate early testing of

innovative remedies.

EPA officials told us that they are considering revising the guidance to

increase the use of on-site tests to determine the potential performance of

innovative technologies. However, the officials stated that they want to

avoid becoming too prescriptive because the testing of innovative

technologies may not be appropriate for all sites.

EPA’s Use of Innovative

Technologies

EPA’s most recent data show that EPA selected innovative technologies in

about 20 percent of all decisions on remedies made in 1994, up from

6 percent in 1986. However, EPA is using fewer innovative technologies at

PCB- and dioxin-contaminated sites than at Superfund sites overall. At sites

with PCB contamination, EPA selected innovative technologies that fully

treat the contamination at about 10 percent of the sites for which a

cleanup technology was selected. In addition, EPA selected innovative

technologies that extract the PCB contamination (but do not destroy it) at

another 20 percent of the sites for which decisions on cleanup

technologies have been made. For these sites, the PCB contamination will

have to be treated further with another remedy—such as incineration. For

Page 6 GAO/RCED-96-13 EPA’s Encouragement of Innovative Technologies
B-266331 

dioxin-contaminated sites, EPA selected innovative cleanup technologies

3 percent of the time.

EPA Has Identified

Limited Options for

Cleaning Up PCBs and

Dioxin

Even though EPA has generally not used innovative technologies for PCBand dioxin-contaminated sites, it has identified several technologies that

have the potential to clean up PCBs and dioxin in the future. However, to

be effective, some of these technologies may have to be used in

combination. Accordingly, EPA has recently recognized that for some sites,

previous decisions on cleanup technologies should be changed if new

technologies that provide more efficient and cost-effective cleanups have

been developed.

Innovative Technologies

for PCB and Dioxin

Contamination

EPA has identified technologies that have the potential to become

alternatives to incineration for PCB and dioxin contamination in the future.

However, EPA believes that these technologies are currently not viable

options for cleaning up most PCB- and dioxin-contaminated sites because

they are still at their early stages of development. Many of these

technologies have been used only in laboratory studies designed to

generate data on their potential. Other innovative technologies are

relatively more advanced; they have been tested, selected, or actually used

to treat PCBs or dioxin at some small, uncomplicated sites and have

generated some cost and performance data. However, these technologies

still lack the well-documented cost and performance data, under a variety

of site conditions, needed to expand their consideration and use.

Innovative technologies that could potentially clean PCB and dioxin

contamination can generally be grouped into three categories: (1) those

that destroy the contamination, (2) those that extract the contamination

(which still must be treated), and (3) those that simply contain or

immobilize the contamination in place.8

 Innovative remedies that destroy

contamination, such as dechlorination, destroy PCB and dioxin molecules

by removing chlorine. Technologies that extract contamination may use,

for example, a chemical solvent or heat to remove the contaminants from

soil or other media. The remaining concentrated contaminants generally

require further treatment—such as incineration—but the extraction

process reduces the volume of waste that must be treated. Technologies

that immobilize hazardous waste may, for example, stabilize the

contaminant by using a substance, such as cement, that will bind with and

8

Each of these broad technological categories contains a number of individual technologies offered by

different technology developers and contractors. For example, each extraction technology developer

would have its own methods and equipment for extracting contamination.

Page 7 GAO/RCED-96-13 EPA’s Encouragement of Innovative Technologies
B-266331 

solidify the contaminated media. (See app. IV for a further explanation of

innovative technologies.)

Use of Innovative

Technologies in

Combination

For many of these innovative technologies to be effective at complex sites,

EPA must use a combination of different technologies, thus increasing the

complexity and uncertainty of the cleanup. For example, to fully clean a

site, an extraction technology, which removes and concentrates the

contaminant, would have to be used in combination with a destruction

technology, which destroys the concentrated contaminant. Also, because

some innovative technologies work only on specific contaminants, a site

with multiple contaminants would require the use of multiple innovative

technologies to address each contaminant. The TIO study cited earlier

found that innovative technologies were often being eliminated from

consideration at sites because of the need to use combinations of

technologies and the resulting uncertainty of success.

EPA’s Proposal to

Reevaluate Decisions

on Remedies

In October 1995, as part of its administrative reforms, EPA proposed that

the decisions on cleanup technologies at selected sites be reevaluated to

take advantage of the cost savings made possible by new technologies.

EPA’s proposal recognized that some remedies selected in the past, while

correct at the time, may not be the cleanup method the agency would

select now. In a September 1995 report, the Office of Technology

Assessment (OTA) also concluded that EPA should reexamine some of its

previous decisions on cleanup technologies on the basis of the availability

of new technologies.9

Barriers to the Use of

Innovative

Technologies

Several factors, often inherent in any unproven technologies, have

inhibited the further development and widespread use of innovative

technologies at PCB- and dioxin-contaminated sites. These factors include

(1) regulatory standards, (2) the technical limitations of technologies,

(3) the lack of sufficient cost and performance data, (4) the lack of

incentives for private industry to invest in innovative technologies, and

(5) EPA’s general preference for technologies it believes to be effective.

Regulatory Standards For the treatment of PCBs and dioxin, EPA sets standards that are based in

part on the performance of incinerators. These standards are based on the

9

This study, Cleaning Up Contaminated Wood-Treating Sites, OTA-BP-ENV-164, Sept. 1995, was done in

response to your request to examine the public safety effects of incineration.

Page 8 GAO/RCED-96-13 EPA’s Encouragement of Innovative Technologies
B-266331 

effectiveness of incineration, not necessarily the health risk associated

with the specified cleanup level. Generally, innovative technologies have

been successful in meeting these standards only at certain smaller PCB- or

dioxin-contaminated sites where the concentration levels of the

contaminant were low and under relatively controlled conditions.

Recognizing this barrier, EPA recently proposed amendments to its

regulations for PCBs to allow more flexibility in the cleanup standards.10

Specifically, the proposal would allow, in addition to performance-based

standards, other cleanup standards, including health-based ones, which

may be potentially easier for innovative technologies to meet. EPA is

currently reassessing the health risks from dioxin. EPA officials told us that

any regulatory changes will occur after that reassessment is complete.

Technical Barriers Technical barriers have also limited the application of innovative

technologies for PCBs and dioxin. Because most innovative technologies

are at their early stages of development, they generally are not yet suited

for cleaning up sites with highly toxic contaminants (such as PCBs or

dioxin), large amounts of contaminated materials, high concentrations of

the contaminants, or multiple contaminants. In addition, innovative

technologies’ performance generally depends on the physical and

chemical characteristics of the contaminated material, such as moisture

levels, clay and silt content, and the presence of other chemical

substances. As a result, EPA has generally used innovative technologies

only at PCB- and dioxin-contaminated sites with low levels of

contamination and uniform conditions. The use of innovative technologies

at dioxin-contaminated sites has been even more limited than at

PCB-contaminated sites because dioxin tends to be difficult to remove from

soil and is typically present in a variety of contamination settings (i.e.,

different types of soils and environmental conditions).

Limited Cost and

Performance Information

Many innovative technologies are still not fully developed or tested.

Because most of these technologies have not gone through full-scale

application, data on their cost, performance, and suitability under various

site conditions are generally not available. EPA officials told us that they

believe technologies must be used multiple times under a variety of

conditions before their cost and performance data are reliable.

10Disposal of Polychlorinated Biphenyls, Proposed Rule, 59 Federal Register 62788 (Dec. 6, 1994).

Page 9 GAO/RCED-96-13 EPA’s Encouragement of Innovative Technologies
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EPA found that one of the reasons why innovative technologies are not

selected more often is that the information necessary to make cleanup

decisions is not readily available. As a result, EPA and private industry

officials responsible for cleaning up PCB- and dioxin-contaminated

Superfund sites have been reluctant to choose unproven innovative

technologies. To overcome this reluctance, EPA entered into a cooperative

agreement with Clean Sites11 to demonstrate full-scale applications of

innovative technologies at several federal facilities. The goal of the

agreement is to demonstrate innovative technologies at real sites in order

to generate actual performance data. Seven demonstrations are currently

under way; however, data are not yet available on their outcomes.

Lack of Incentives to

Invest in Innovative

Technologies

Uncertainties about both the market for PCB and dioxin cleanups and

future regulatory standards for cleanups also create a disincentive for

private industry to invest in innovative technologies. The production of

PCBs stopped in 1977, and the number of sites known to be contaminated

with dioxin is relatively small. In addition, industry officials are uncertain

how clean EPA will require PCB- and dioxin-contaminated sites to be in the

future. Because the promulgation of new environmental standard often

takes many years, investors often choose to wait rather than invest in

innovative technology. They worry that if they invest money in a new

technology, by the time the new standards come into effect, the

technology might be obsolete.

EPA’s Reliance on

Incineration to Clean up

PCB and Dioxin

Contamination

EPA officials said that in light of the above barriers, they have chosen to

rely on incineration to clean up PCB-and dioxin-contaminated sites. EPA

officials told us that they have selected incineration because it meets EPA’s

existing regulatory standards, can perform under a variety of conditions,

and has been successfully demonstrated in full-scale applications. They

added that using a demonstrated technology becomes particularly

important for PCB- and dioxin-contaminated sites because these two

compounds are highly toxic and very difficult to treat.

Conclusions The existence of hazardous waste sites with threatening contaminants

such as PCBs and dioxin requires EPA to make tough choices about

appropriate remedies. EPA must attempt to clean up sites expeditiously

while protecting human health and the environment. Faced with this task,

11Clean Sites is a nonprofit corporation whose mission is to improve the cleanup of hazardous waste

sites.

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EPA officials have come to rely on incineration, a remedy they trust, to

clean up sites with contaminants as hazardous as PCBs and dioxin.

However, EPA also must convince communities that incineration is safe to

gain their acceptance of its use.

While EPA’s attempts to develop innovative technologies have not yet

identified any that can clean complex sites contaminated with PCBs and

dioxin, it has identified several that have the potential for future use.

Accordingly, we agree with EPA’s recent proposal to revisit its decisions on

remedies at certain sites that could benefit from significant technological

advancements.

Agency Comments We provided copies of a draft of this report to EPA for its review and

comment. On November 21, 1995, we met with EPA officials, including a

Senior Process Manager from EPA’s Office of Emergency and Remedial

Response and officials from EPA’s offices of Pollution Prevention and

Toxics, Research and Development, and Solid Waste and Emergency

Response, to obtain their comments on our draft. These officials generally

agreed with the facts and findings in the report. They also suggested a

number of technical corrections, which we incorporated into the report.

Scope and

Methodology

You asked us to identify (1) what EPA has done to encourage the

development and use of alternative, or “innovative,” technologies at all

contaminated sites, including those contaminated with PCBs and dioxin;

(2) whether EPA has identified innovative technologies that can be used at

PCB-and dioxin-contaminated sites; and (3) what factors have limited the

use of innovative technologies at PCB- and dioxin-contaminated sites. To

address the three objectives, we interviewed EPA officials at SITE and TIO,

Risk Reduction Engineering Laboratory, Air and Environmental Research,

Regions I, VI, and VII, and the Offices of Solid Waste, Emergency and

Remedial Response, Research and Development, and Pollution Prevention

and Toxics. We contacted representatives of three major industry groups,

environmental consulting firms, and academia. Also, as you requested, we

visited three Superfund sites with PCB or dioxin contamination and their

applicable EPA regional office in order to provide an illustration of EPA’s

process for making decisions on remedies. In addition, we obtained and

analyzed documents and data from EPA and the other individuals we

contacted. Our work was performed in accordance with generally

accepted government auditing standards between October 1994 and

December 1995.

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As arranged with your offices, unless you publicly announce its contents

earlier, we will make no further distribution of this report until 10 days

after the date of this letter. At that time, we will send copies of the report

to other appropriate congressional committees; the Administrator, EPA; the

Director, Office of Management and Budget; and other interested parties.

We will also make copies available to others upon request. Should you

need further information, please call me at (202) 512-6112. Major

contributors to this report are listed in appendix V.

Peter F. Guerrero

Director, Environmental

 Protection Issues

Page 12 GAO/RCED-96-13 EPA’s Encouragement of Innovative Technologies
Page 13 GAO/RCED-96-13 EPA’s Encouragement of Innovative Technologies
Contents

Letter 1

Appendix I 

Three Case Studies

16

The Texarkana Wood Preserving Company Site 16

Times Beach and Eastern Missouri Superfund Sites 19

New Bedford Harbor Superfund Site 21

Appendix II 

Dioxin and

Polychlorinated

Biphenyls

Contamination

25

Appendix III 

Incineration

Technology

28

Appendix IV 

Innovative Treatment

Technologies

34

Appendix V 

Major Contributors to

This Report

37

Figures Figure I.1: Remaining Structures of the Wood Treating Operations

at Texarkana

17

Figure I.2: Storage Buildings Containing Dioxin-Contaminated

Materials From One of the Eastern Missouri Sites

21

Figure I.3: Dredging Facility at New Bedford Hot Spot 23

Figure III.1: Typical Incinerator Processes 31

Page 14 GAO/RCED-96-13 EPA’s Encouragement of Innovative Technologies
Contents

Abbreviations

ATSDR Agency for Toxic Substances and Disease Registry

BCD base catalyzed decomposition

CERCLA Comprehensive Environmental Response, Compensation,

and Liability Act

DRE destruction and removal efficiency

EPA Environmental Protection Agency

NCP National Contingency Plan

NPL National Priorities List

OSWER Office of Solid Waste and Emergency Response

OTA Office of Technology Assessment

PCB polychlorinated biphenyls

PICs products of incomplete combustion

POHC principal organic hazardous constituents

ppb parts per billion

ppm parts per million

RCRA Resource Conservation and Recovery Act

SARA Superfund Amendments and Reauthorization Act

SITE Superfund Innovative Technology Evaluation program

S/S solidification and stabilization technologies

TIO Technology Innovation Office

TSCA Toxic Substances Control Act

Page 15 GAO/RCED-96-13 EPA’s Encouragement of Innovative Technologies
Appendix I 

Three Case Studies

We visited three sites where both incineration and innovative technologies

were considered during the remedy selection process. The Environmental

Protection Agency (EPA) plans on using incineration at two of these

sites—Texarkana, Texas, and Times Beach, Missouri. EPA had initially

selected incineration at New Bedford, Massachusetts, but yielded to public

pressure and is now searching for an alternative remedy. We did not

evaluate whether EPA made the correct decisions, but we did discuss with

the EPA regional officials responsible for each site why they, at least

initially, chose incineration rather than an alternative technology.

The Texarkana Wood

Preserving Company

Site

The Texarkana Wood Preserving Company Superfund site is a 25-acre

abandoned wood preserving facility in Texarkana, Texas. (See fig. I.1.) EPA

placed the site on its National Priorities List in 1986. The cleanup effort at

Texarkana is led by the state of Texas and is primarily federally funded.

The site is contaminated with chemicals that are commonly found at wood

preserving sites. The contamination occurred when wood preserving

chemicals were dumped into storage ponds used for the wood treating

operations. Approximately 77,000 cubic yards of soil, sludge, and sediment

and 16 million gallons of groundwater are contaminated primarily with

dioxin, polynuclear aromatic hydrocarbons, and pentachlorophenol. The

site contains some areas of heavy contamination, particularly in the

sludge. Further complicating the cleanup efforts, the Texarkana site is in a

floodplain. The site lies in a mixed-use residential, industrial, and

agricultural area.

Page 16 GAO/RCED-96-13 EPA’s Encouragement of Innovative Technologies
Appendix I 

Three Case Studies

Figure I.1: Remaining Structures of the

Wood Treating Operations at

Texarkana

Although there are no immediate risks, the site presents potential health

risks in the future if left untreated. EPA determined that nearby residents

are not currently at risk of adverse health affects—a residential

community lies about one-third of a mile from the site. However,

groundwater contamination is continuing to spread at the site. The spread

could threaten drinking water if contamination reaches a deeper aquifer.

In addition, surface run-off and leachate from the soil could potentially

contaminate a nearby creek. EPA has estimated increased cancer risks for

potential trespassers and for other persons if the site is used for other

purposes in the future.

In 1990, EPA chose incineration on the basis of its assessment that it would

be the most effective remedy for the type and combination of

contaminants at the Texarkana site. Although EPA analyzed other options,

it believed that incineration was the only technology that would reduce the

contaminants to a level below health-based standards. According to EPA

regional officials, to reach the cleanup standards using other technologies

would require combining two or more technologies. They added that using

Page 17 GAO/RCED-96-13 EPA’s Encouragement of Innovative Technologies
Appendix I 

Three Case Studies

multiple innovative technologies would raise the uncertainty level

associated with new technologies even further. These standards are based

on ensuring the safety of future industrial workers on the site. In addition,

EPA officials judged that incineration was the best remedy for high levels of

dioxin and for wood treating chemicals in general.

EPA considered the following alternative remedies for the Texarkana site:

biological and chemical treatment, solidification, placing a protective

cover over the site to reduce the spread of contaminants (capping), and

off-site incineration. (See app. IV for a discussion of the innovative

technologies.) EPA officials believed that chemical or biological remedies

would not work successfully on all contaminants or achieve the agency’s

cleanup goals. They were also concerned about the possibility that

biological or chemical degradation could produce a more toxic form of

dioxin. EPA eliminated solidification because the technology was not

expected to reduce the volume or toxicity of the waste to the same degree

as the other treatments and because of the difficulty in solidifying the type

of contaminants present at the site. EPA eliminated capping because it

would not provide a permanent treatment, and the site’s location on a

flood plain increased the risk of continued release of contaminants.

According to the EPA project manager, a cap at this site could be

guaranteed only for about 6 years. In addition, the local community

wanted the land usable for future industry, making solidification and

capping inappropriate options because the contamination would still be on

site. EPA decided against off-site incineration because of its high cost—the

estimated cost was more than four times greater than on-site incineration.

EPA estimates that the planned incineration project will cost approximately

$43 million and take approximately 2-1/2 years to fully clean the site.

According to the project manager, EPA is in the process of conducting an

analysis of incineration at the site to determine the potential health risk of

the cleanup to nearby residents.

Currently, EPA is planning to take some measures to enhance safety at the

site and to prevent the spread of contamination, in advance of full-scale

cleanup efforts. According to the project manager, EPA plans to remove the

structures on the site—the remnant of the wood preserving operation. It

also plans to build a berm along the side of the site that borders a creek to

prevent run-off from spreading, if necessary. These efforts by themselves,

however, will not stem the spread of groundwater contamination.

Page 18 GAO/RCED-96-13 EPA’s Encouragement of Innovative Technologies
Appendix I 

Three Case Studies

Times Beach and

Eastern Missouri

Superfund Sites

The Times Beach Superfund site is a 0.8 square mile area located

approximately 20 miles southwest of St. Louis, Missouri, in a mixed-use

residential and agricultural area. The contamination at Times Beach, a

formerly incorporated town, resulted from spraying unpaved roads for

dust control with waste oil contaminated with dioxin in the early 1970s. In

1982, after severe flooding of the adjacent Meramec River, EPA discovered

elevated dioxin concentrations on the surface of the former town’s

roadways. EPA paid approximately $30 million to buy the town and

relocate its 2,240 residents. EPA placed Times Beach on the National

Priorities List in 1983. In 1988, EPA estimated that dioxin levels in

approximately 13,600 cubic yards of soil exceeded standards of 20 parts

per billion (ppb) or less. Currently, the site is completely vacant and

fenced.

EPA decided to address Times Beach and 26 other sites in eastern Missouri

with similar dioxin contamination as a single response action in its

cleanup plans. The waste oil hauler who sprayed Times Beach with

dioxin-contaminated waste oil also sprayed the other 26 sites, which

included streets, parking lots, and horse arenas. Because the dioxin

contamination at each of these locations originated from the same source,

EPA decided that it can be destroyed effectively by the same treatment. In

addition, all but 3 of the 27 sites lie in the St. Louis metropolitan area. As a

result, EPA determined that a combined response action for all 27 sites

would be cost-effective and protective of human health and the

environment. EPA estimated that a total of approximately 100 thousand

cubic yards of contaminated material from all 27 sites will require

treatment.

After analyzing several permanent cleanup options, EPA decided to

excavate and incinerate the dioxin-contaminated material at Times Beach

and the 26 eastern Missouri sites. For several years, EPA evaluated the

effectiveness and safety of several different options and treatment

technologies, including chemical and biological treatment. In 1988, EPA

concluded that excavating and treating dioxin-contaminated material in a

temporary incinerator at Times Beach was the most acceptable remedy of

the various alternatives. EPA believed incineration would be protective of

human health and the environment, cost-effective, attain applicable or

relevant and appropriate requirements, and utilize permanent solutions to

the maximum extent practicable. In addition, EPA believed incineration

was the only method with the demonstrated ability to clean the large

quantities of soil, storage bags, and other types of contaminated material

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Appendix I 

Three Case Studies

found at the 27 dioxin-contaminated sites and reach the specified

residential cleanup levels.

In 1990, a consent decree signed by EPA, the state of Missouri, and Syntex,

the corporation responsible for the cleanup, implemented EPA’s 1988

cleanup choice. The decree dictated cleanup responsibilities for each

party involved. Under its terms, EPA had to excavate and transport

dioxin-contaminated material from the 26 eastern Missouri sites to Times

Beach, the site of the temporary incinerator. Syntex had to excavate and

incinerate dioxin soil from Times Beach and to incinerate

dioxin-contaminated material from the other eastern Missouri sites.

Several stages in the cleanup process for the 27 eastern Missouri sites have

already been completed. EPA has excavated contaminated material at 10 of

the eastern Missouri sites and placed approximately 67 thousand cubic

yards of material in temporary storage buildings until completion of the

incinerator. (See fig. I.2.) In addition, Syntex has completed several

components of the work required by the consent decree, including

demolition and disposal of structures and debris in Times Beach,

construction of a ring levee to protect the incinerator subsite from floods,

construction of an interim storage facility at Times Beach, and excavation

and storage of approximately 21,000 cubic yards of dioxin-contaminated

soil. Currently, Syntex subcontractors at the site have completed

construction of the temporary incinerator. EPA expects that testing of the

incinerator will begin in October or November of 1995 and full-scale

operation will begin early 1996.

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Appendix I 

Three Case Studies

Figure I.2: Storage Buildings

Containing Dioxin-Contaminated

Materials From One of the Eastern

Missouri Sites

New Bedford Harbor

Superfund Site

The 18,000-acre New Bedford Harbor Superfund site in Massachusetts is

an urban tidal estuary consisting of a harbor and bay that are highly

contaminated with PCBs and heavy metals. Manufacturers in the area used

PCBs while producing electric capacitors from 1940 to 1978 and discharged

PCB-containing waste into the harbor. The contamination of the sediments

in the harbor and bay areas has resulted in closing the area to lobstering

and fishing and has limited recreational activities and harbor development.

EPA placed New Bedford Harbor on the National Priorities List in 1983.

EPA planned to address the cleanup of New Bedford Harbor in two stages,

starting with the cleanup of the “hot spot” area. EPA defined the hot spot as

the area where the concentration of PCBs in the sediment was 4,000 parts

per million (ppm) or greater. The PCB concentrations in the hot spot, an

area of approximately five acres, ranged between 4,000 ppm and over

200,000 ppm. The volume of hot spot sediments that required treatment

represented approximately 45 percent of the total PCB mass in the

sediment in the entire New Bedford Harbor site.

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Appendix I 

Three Case Studies

EPA identified over 90 potential technologies for cleaning New Bedford

Harbor. After EPA narrowed its list, it conducted detailed studies on several

innovative technologies to assess their potential for success at the New

Bedford hot spot. After evaluating the alternatives it believed feasible, EPA

decided in 1990 to use dredging and on-site incineration to clean up the

hot spot.

EPA believed that dredging and on-site incineration was the preferred

option to protect public health and the environment and to permanently

reduce the migration of contaminants throughout the site. (See fig. I.3.) On

the basis of its analyses, EPA determined that incineration, considered a

proven technology, would achieve the best balance among the criteria

used by EPA to evaluate the alternatives. These criteria included both longand short-term effectiveness, implementability, overall protection of

human health and the environment, and compliance with federal and state

applicable or relevant and appropriate requirements. On the other hand,

the many uncertainties about the performance of innovative technologies

at the New Bedford hot spot sediments made these technologies unlikely

candidates for the site. For example, EPA was uncertain about the

performance and adequacy of innovative technologies given the silt/clay

composition and high water content of the New Bedford sediments. Soil

composition and water content are factors that could compromise the

performance of innovative technologies.

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Appendix I 

Three Case Studies

Figure I.3: Dredging Facility at New Bedford Hot Spot

As EPA proceeded with its plans to incinerate hot spot sediments,

opposition from environmental and local community groups to EPA’s plans

to incinerate grew. The public’s main concern was the potential health risk

from dioxin emissions coming from the incinerator. In response to the

community’s growing opposition, in 1994 EPA canceled the incineration

part of the Corps of Engineers’ contract to clean the hot spot. The

cancellation costs of the incineration contract were approximately

$5 million dollars, and there may be additional costs.

After the cancellation of EPA’s incineration plans, the agency started new

efforts to identify alternative cleanup technologies for the site. With public

participation, EPA narrowed candidate cleanup options to

(1) solidification/stabilization, (2) chemical destruction, and (3) a

separation technology such as thermal desorption followed by chemical

destruction. EPA plans to conduct detailed studies on at least two chemical

destruction technologies and at least two solidification technologies. The

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Appendix I 

Three Case Studies

agency expects to issue its final decision on the cleanup for the hot spot in

approximately 3 years.

Page 24 GAO/RCED-96-13 EPA’s Encouragement of Innovative Technologies
Appendix II 

Dioxin and Polychlorinated Biphenyls

Contamination

Dioxin and PCBs (polychlorinated biphenyls) are highly toxic contaminants

of particular concern because of their potentially adverse effects on

human health and their degree of permanence in the environment. EPA

classifies dioxin as a probable human carcinogen. Dioxin has the potential

to invoke a wide range of harmful effects in relatively small doses, as

compared with other toxic compounds. Some PCBs, having a chemical

makeup similar to dioxin’s, have the potential for many of the same

effects.

Dioxin Dioxin and dioxin-like substances are not purposely manufactured but are

unintentional by-products of combustion and chemical processes. The

four main sources of dioxin are (1) the formation during incineration of

materials that contain chlorine (such as the incineration of municipal and

medical waste); (2) industrial and other processes that employ chlorine

(such as chlorinated bleaching of wood pulp for paper manufacturing);

(3) chemical manufacturing and related processes, including the

manufacture of chlorine and chlorinated substances; and (4) redistribution

of existing contamination—because dioxin tends to accumulate in soil and

sediment, dioxin contamination may become redistributed through

contaminated dust. In addition, dioxin emissions may also result from the

incineration of materials already contaminated with dioxin. In this

scenario, some of the dioxin-contaminated material remains intact through

the incineration process and is emitted from the stack.

Exposure to dioxin occurs daily, mainly through dietary intake of meat,

dairy products, fish, and shellfish. Dioxin is present in all media,

particularly in soil and sediment, which transfer the contaminant to plants

and animals. Researchers believe that the presence of dioxin in the food

chain is primarily the result of dioxin air emissions depositing from the

atmosphere on soil, plants, and bodies of water. In addition, some

individuals may be exposed to even higher dioxin levels from other

sources; these include occupational exposures, exposure to a distinct local

source (for example, a chemical manufacturing plant, or a municipal or

medical incinerator), exposure of nursing infants from mothers’ milk, or

frequent consumption of dioxin-contaminated fish from a particular

source.

Health effects have been associated with exposure to dioxin. Dioxin is

considered a probable human carcinogen, according to laboratory studies

on animals and observation of humans beings exposed to dioxin. In

addition, it has been associated with other adverse effects, including

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Appendix II 

Dioxin and Polychlorinated Biphenyls

Contamination

reproductive, developmental, immunological, and endocrine changes. In

high doses, dioxin causes chloracne, a serious skin condition. The adverse

effects of dioxin are contingent upon dose and length of exposure. Dioxin

is present in humans at birth in small concentrations and accumulates,

increasing as individuals age. The exact level at which health effects will

occur is uncertain.

EPA began a scientific reassessment of dioxin and dioxin-related

compounds in 1991. The reassessment summarizes and evaluates available

research to provide a comprehensive survey of the sources of dioxin, the

levels of exposure, and the potential health effects. It also identifies gaps

in dioxin research. The preliminary conclusions of the reassessment

strengthen the evidence that dioxin can cause human health effects even

at low levels of environmental exposure. In September 1994, EPA issued

two draft reports based on this work which have been released for public

comment: Estimating Exposure to Dioxin-Like Compounds and Health

Assessment Document for 2,3,7,8 Tetrachlorodibenzo-p-Dioxin (TCDD)

and Related Compounds.

PCBs Polychlorinated biphenyls (PCB) are similar to dioxin as they are in the

same class of chemicals. However, unlike dioxin, PCBs were intentionally

manufactured (from the 1920s to the 1970s in the United States), mainly

for use as an insulating fluid in electrical equipment. The production and

use of PCBs was widespread, causing large amounts to be released into the

environment. They were used primarily because of their stability and

resistance to decomposition, which have caused them to persist in the

environment even though they are no longer manufactured.

Because of the stability of PCBs, many routes of exposure are possible. The

primary source of human intake of PCBs is through food—mainly fish, but

also meat and dairy products. Other sources of exposure include

inhalation and dermal contact. As with dioxin, exposure to PCBs may cause

health effects. In its most toxic forms, PCBs are carcinogenic in laboratory

animals and are considered a probable human carcinogen. Some forms of

PCBs can have the same toxicity as dioxin (known as dioxin-like PCBs). PCBs

are also associated with reproductive and immunologic changes in some

people who are exposed to the contaminant. According to EPA researchers,

the incomplete destruction of PCBs during incineration of the contaminant

may pose the most significant of health threats because of the potential

dioxin formation and emissions.

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Appendix II 

Dioxin and Polychlorinated Biphenyls

Contamination

In 1993, the Agency for Toxic Substances and Disease Registry (ATSDR)

convened an expert panel to evaluate the public health implications of

treating and disposing of PCB-contaminated waste. The panel concluded

that although the safety of incinerating PCB-contaminated waste is not

certain, information on the safety and effectiveness of alternative

technologies is also limited. The panel affirmed that no single type of

alternative technology can remediate all PCB-contaminated wastes. In

addition, it recommended that further research is needed to study the

health effects of PCBs.

Page 27 GAO/RCED-96-13 EPA’s Encouragement of Innovative Technologies
Appendix III 

Incineration Technology

Incineration is the burning of substances by controlled flame in an

enclosed area or compartment. During the process of incineration,

hazardous organic wastes12 fed into an incinerator are converted to

simpler forms, principally carbon dioxide and water, reducing their

volume and toxic qualities. EPA regulates incineration under its authority to

regulate hazardous waste.

Pursuant to the Resource Conservation and Recovery Act (RCRA), as

amended by the Hazardous and Solid Waste Amendments of 1984, EPA in

the late 1980s and early 1990s promulgated land disposal restrictions to

bar the disposal—except under very restrictive conditions—of untreated

hazardous waste. As land disposal became increasingly expensive due to

the restrictions, other disposal options, such as incineration, became

increasingly attractive. In many cases, the disposal of waste through

incineration has become the most economical and, in some cases, the only

option for certain hazardous wastes. EPA has encouraged regulated

burning as a treatment option and considers incineration to be the best

demonstrated available technology for many wastes. By the late 1980s,

incineration was also playing an important role in the cleanup of many

Superfund sites, where it has been used for treating contaminated soils

and other wastes removed from the site.

The Incineration Process Incineration involves four basic steps: (1) wastes are prepared and fed into

the incinerator; (2) wastes are burned, converting organic compounds into

residual products in the form of ash and gases;(3) ash is collected, cooled,

and removed from the incinerator; and, (4) gases are cooled, cleaned, and

released to the atmosphere through the incinerator stack.

During incinerator operations, wastes are fed into the incinerator in

batches or in a continuous stream. This flow of wastes is generally

referred to as the waste feed. The wastes are then burned in the

combustion chamber, which is designed to maintain and withstand

extremely high temperatures. As the wastes are heated, they are converted

from solids or liquids into gases. The gases are mixed with air and passed

through a hot flame. As the temperature of the gases rises, the organic

compounds in the gases begin to break down and recombine with oxygen

from the air to form stable inorganic compounds, such as carbon dioxide

and water. Depending on the waste composition, other inorganic

12Organic compounds are those that are composed of carbon, hydrogen, and sometimes other

elements.

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Appendix III 

Incineration Technology

compounds, such as the acid gas hydrogen chloride, may form. This entire

process is called combustion.

In many incinerators, combustion occurs in two combustion chambers.

The combustion of more easily burned organics is completed in the first

chamber. For compounds that are difficult to burn, combustion is

completed in a secondary combustion chamber, or afterburner, after the

compounds have been converted to gases and partially combusted in the

first chamber.

Combustion yields two residual products: solids, in the form of ash, and

gases. Ash is an inert inorganic material composed primarily of carbon,

salts, and metals. During combustion, most ash collects at the bottom of

the combustion chamber; some ash, however, is carried along with the

gases as small particles, or particulate matter. Ash removed from the

bottom of the combustion chamber is considered, by regulation, a

hazardous waste. Combustion gases are composed primarily of carbon

dioxide and water, plus small quantities of other gases such as carbon

monoxide and nitrogen oxides. Following combustion, the combustion

gases move through various devices that cool and cleanse the gases before

they are released to the atmosphere through the incinerator stack.

A well-designed and operated hazardous waste incinerator will destroy all

but a small fraction of the organic compounds contained in the waste.

Complete combustion, however, is only a theoretical concept since the

development of a 100-percent efficient incinerator is not possible. The

three critical factors that determine the completeness of combustion in an

incinerator are (1) the temperature in the combustion chamber; (2) the

length of time wastes are maintained at high temperatures; and (3) the

turbulence, or degree of mixing, of the wastes and the air.

Because combustion is never complete, incinerator emissions gases may

also contain small quantities of organic and inorganic compounds from

both the original waste and compounds formed during the combustion.

These “new” organic compounds form from the breakdown and

recombination of the original compounds and are called products of

incomplete combustion or PICs. PICs are formed during the combustion of

any organic material, such as when wood is burned in a wood stove or

when gasoline is burned in an automobile engine. Among the types of

compounds found in analyses of PICs are very small quantities of dioxins

and dibenzofurans. Among the inorganic compounds not present in the

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Appendix III 

Incineration Technology

original waste are carbon monoxide and nitrogen oxides, both of which

are always formed as a result of combustion.

Among the most common types of hazardous waste incinerators is the

rotary kiln incinerator. Rotary kiln incinerators are versatile and can

accept gases, liquids, sludges, slurries, and solids either separately or

simultaneously, either in bulk or in containers. Because of this versatility,

rotary kilns are commonly used to treat a variety of wastes. The kiln is a

cylindrical shell mounted on its side at a slight angle to the horizontal. As

the kiln rotates and the wastes travel down the slope, the organic

chemicals in the waste convert into gases and partially combust. The gases

then pass into the afterburner or secondary combustion chamber where

further combustion takes place. Ash residue is removed from the lower

end of the kiln. (See fig III.1.) Mobile incineration systems are generally

constructed using the rotary kiln incinerator design. These systems are

hauled to a site on flat-bed trucks, then assembled and tested. Although

smaller than most stationary facilities, they operate on identical principals.

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Appendix III 

Incineration Technology

Figure III.1: Typical Incinerator Processes (Rotary Kiln)



Rotary Kiln (First


Combustion Chamber)

Waste


Feed

Waste (Ash)


Disposal

Secondary Combustion


Chamber


Stack


Emissions

Quench


Chamber


(Cools Gases)

Air Pollution


Control Devices


(Remove Acid 


Gases)

Fan


(Maintains Proper


Pressure and


Draw Rate)

Source: EPA.

Hazardous Waste

Incinerator Regulations

EPA developed performance standards for the incineration of hazardous

wastes on the basis of research on incinerator air emissions and health

and environmental risk studies. All incinerators emit gases through a stack

as the final step in the incineration process. The quantity of pollutants in

these emissions is the major determinant of the risk of incineration. The

performance standards thus address and attempt to control the various

emissions from the stack. Under EPA’s regulations, an incinerator must be

able to burn wastes and cleanse combustion gases so that only very small

quantities of pollutants are emitted through the stack. EPA’s principal

measure of incinerator performance is destruction and removal efficiency

(DRE). Destruction refers to the combustion of waste, while removal refers

to the cleansing of the pollutants from the combustion gases before they

are released from the stack. For most organic wastes, a DRE of 99.99

percent is required; however, for PCBs and dioxins, a DRE of 99.9999

percent is required, which means that no more than one molecule of the

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Appendix III 

Incineration Technology

compound is released to the air for every 1 million molecules entering the

incinerator.

Because it is not technically feasible to monitor DRE results for all organic

compounds that may be contained in a waste feed, an incinerator must

demonstrate that it can achieve the performance standards for selected

hazardous compounds, called principal organic hazardous constituents

(POHC), which the permitting agency designates in the permit. These POHCs

generally are selected from among the wastes the applicant is seeking

approval to burn on the basis of their high concentration in the waste feed

and their difficulty to burn in comparison with other organic compounds

in the waste feed. According to the theory of incineration followed by EPA,

if the incinerator achieves the required destruction and removal efficiency

for the POHCs, then the incinerator should achieve the same or better

destruction and removal efficiencies for organic compounds that are

easier to incinerate.

The incinerator performance standards in EPA’s RCRA regulations include

emissions of the designated organic compounds, hydrogen chloride, and

particulate matter. Specifically, those performance standards for the

incineration of dioxin require (1) a minimum DRE of 99.9999 percent;

(2) generally, removal of 99 percent of hydrogen chloride gas from the

incinerator’s emissions; and (3) a limit of 180 milligrams of particulate

matter per dry standard cubic meter of gas emitted through the stack.

Before a final permit to operate the incinerator is issued, a trial burn

generally is required. The trial burn tests the incinerator’s ability to meet

all applicable performance standards when burning a waste under specific

operating conditions. The operating conditions include such things as the

rate and composition of the waste feed, the temperature that must be

maintained in various areas of the incinerator, and the gas flow rate. To

obtain a final operating permit, the trial burn results must demonstrate

that the incinerator can meet the performance standards contained in its

permit.

The trial burn results are also used to establish the final operating

conditions that will be included as part of the facility’s permit. Because the

trial burn involves the measurement of the incinerator’s performance

under different sets of operating conditions, the trial burn results verify

the incinerator’s ability to meet the performance standards under one or

more of these conditions and thus can be used to determine what is an

acceptable range of operating conditions for the final permit. The final

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Incineration Technology

operating permit specifies only those operating conditions under which

the incinerator has proven it can meet the performance standards.

These operating conditions are important because it is not technically

feasible to directly and continuously measure certain aspects of

performance, such as destruction and removal efficiency, and certain

emissions. On the basis of the results of the trial burn, the permit may

specify different operating conditions for different types of waste feeds or

specify ranges or minimum or maximum levels for different parameters,

such as temperature. Under EPA’s regulatory approach, as long as the

incinerator operates within these ranges, it is assumed to be operating

under the same conditions as during the successful trial burn and thus to

be in compliance with the environmental performance standards. Toxic

Substances Control Act (TSCA) regulations have comparable requirements

for the incineration of PCBs.

Page 33 GAO/RCED-96-13 EPA’s Encouragement of Innovative Technologies
Appendix IV 

Innovative Treatment Technologies

While incineration is the only established technology for the treatment of

most PCB- and dioxin-contaminated sites, EPA and the industry are

developing and testing several innovative technologies that could become

viable alternatives to incineration, particularly after further development.

Some of these innovative technologies, like incineration, destroy the

waste; some of them change its chemical composition so that it is no

longer hazardous; and some of them immobilize the waste so that although

it may still be hazardous, it will be less likely to move into the air, soil, or

water or other waste. The following are the most recognized alternatives

to incineration for PCBs and dioxin.

Bioremediation: Bioremediation refers to the breakdown of contaminants

into less harmful and usually less toxic forms by natural microorganisms.

It can be performed at a higher rate in the presence of oxygen, or more

slowly under near oxygen-free conditions. Historically, PCBs have been

considered resistant to biodegradation. However, the results of lab studies

and environmental monitoring studies indicate that PCBs biodegrade in the

environment but at a very slow rate. In addition, bioremediation of highly

chlorinated substances can result in highly toxic forms of dioxin. To date,

EPA has not found a bioremediation process that can accelerate the

biodegradation of PCBs to rates necessary to make such a process

commercially viable for use in site cleanups. Similarly, limited information

from field work on the biodegradation of dioxin has shown that the

process can be significantly lengthy.

Chemical Dechlorination: This process destroys or detoxifies certain

contaminants, such as PCBs and dioxin, by gradually removing chlorine

atoms. The conditions that most commonly determine the efficacy and

cost of dechlorination methods include the size of soil particles, the soil’s

moisture content, the organic carbon contents of the soil, and the cleanup

level required. In addition, under certain circumstances, dechlorination

can generate highly toxic dioxin. A well-known dechlorination technology

is base catalyzed decomposition (BCD). EPA developed BCD to detoxify

chlorinated organics such as PCBs and dioxin. It uses two different

technologies—thermal desorption (described later in this appendix)

followed by a chemical process to separate and detoxify organic

contaminants. It is an efficient, relatively inexpensive treatment process

for PCBs and potentially capable of treating PCBs at virtually any

concentration. However, the process can be expensive for high PCB

concentrations because it requires a larger dose of the chemicals

necessary to neutralize the chlorine. Field data on the performance and

cost of BCD for PCBs and dioxin are very limited. In addition, EPA officials

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Appendix IV 

Innovative Treatment Technologies

responsible for administering the Toxic Substances Control Act

regulations have not yet had an opportunity to assess whether BCD is

acceptable as a remedy for PCBs.

Soil Washing: Soil washing mixes, washes, and rinses the soil to separate

contaminants, such as PCBs, adhering to soil particles. Because it is not a

destruction technique, this technology does not present a final solution for

the disposition of toxic and hazardous materials. The technology is

designed for volume reduction of contaminated material. Its effectiveness

depends on factors such as the size of soil particles and humic and silt or

clay content of the soil. Multiple washings may be necessary to achieve

acceptable contamination levels. In addition, there is need for further

management of the concentrated contaminant. While limited work has

been done on the effectiveness of soil washing for PCBs, no work has been

done for dioxin.

Solidification/Stabilization: Solidification and stabilization technologies

focus primarily on limiting the solubility or mobility of contaminants,

generally by physical means rather than by chemical reaction. Waste

solidification technologies encapsulate the contaminants in a solid

material—such as portland cement or asphalt. Waste stabilization

technologies convert the contaminants into a less soluble, mobile, or toxic

form by adding a binder to the waste, such as cement kiln dust or fly ash.

Historically, solidification and stabilization technologies have been used to

treat metals and other inorganic compounds. With currently available

technology, it is generally easier to successfully solidify or stabilize

inorganic compounds than organic compounds, such as PCBs and dioxin.

More recently, some work has been done on the applicability of

solidification and stabilization to organics, such as PCBs. Although no

solidification or stabilization treatment currently offered is considered by

EPA to be an acceptable alternative incineration for PCBs and dioxin, EPA

believes the technology has potential.

Solvent Extraction: Using a solvent, such as propane, solvent extraction

separates hazardous contaminants from soil and sediment. This process

reduces the volume of the hazardous waste that requires treatment. The

application of this technology represents only a transfer of the

contaminant from one medium (soil) to another (solvent) but does not

provide for the contaminant’s ultimate destruction. The ultimate removal

of PCBs depends on the number of stages employed and the feed

concentration. Many variables, such as soil type and moisture content,

influence the system’s performance. For example, water and fine-grained

Page 35 GAO/RCED-96-13 EPA’s Encouragement of Innovative Technologies
Appendix IV 

Innovative Treatment Technologies

materials inhibit some solvent extraction processes. In addition, after

extraction is complete, some solvent remains in the treated sediment. This

residual solvent may pose a separate problem if the solvent is toxic or

highly explosive.

Thermal Desorption: Thermal desorption treats contaminated soils by

heating the soil at relatively low temperatures between 300 and 1,000

degrees fahrenheit. The heat separates the contaminants from the soil. The

contaminants then require further treatment. The effectiveness and cost of

this technology vary and depend on site characteristics such as the

moisture content of the soil and the concentration and distribution of the

contaminants. In addition, thermal desorption can generate residual that

should be monitored and may require further treatment.

Vitrification: All existing vitrification technologies use heat to melt the

contaminated soil or sediment, which forms a rigid, glassy product when it

cools. The volume of the end product is typically 20 to 45 percent less than

the volume of the untreated soil or sediment. Organic compounds,

including PCBs, are destroyed by the high temperature during vitrification.

Vitrification may also have application to special types of dioxin

contamination if current developments can be successfully tested.

However, the effectiveness of vitrification for both PCBs and dioxin is

difficult to assess at this point.1

1

On October 31, 1995, EPA issued an operating permit to the Geosafe Corporation to use in-situ

vitrification for treating PCB-contaminated soil.

Page 36 GAO/RCED-96-13 EPA’s Encouragement of Innovative Technologies
Appendix V 

Major Contributors to This Report

Jacqueline M. Garza, Staff Evaluator

Richard P. Johnson, Attorney Advisor

Gerald E. Killian, Assistant Director

Pauline Seretakis Lichtenfeld, Staff Evaluator

James B. Musial, Senior Evaluator

William H. Roach, Jr., Senior Evaluator

Paul J. Schmidt, Senior Evaluator

(160267) Page 37 GAO/RCED-96-13 EPA’s Encouragement of Innovative Technologies
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