Superfund: EPA Has Identified Limited Alternatives To Incineration for
Cleaning Up PCB And Dioxin Contamination (Letter Report, 12/29/95,
GAO/RCED-96-13).

One of the most contentious issues facing the Environmental Protection
Agency (EPA) is the use of incineration to clean up Superfund sites
contaminated by polychlorinated biphenyls (PCB) or dioxin. Increasingly,
community groups are protesting the use of incineration as a treatment
remedy. Many people fear that the incinerators will emit hazardous
substances that could pose a health risk for neighboring communities.
Although EPA encourages the development of innovative technologies to
dispose of hazardous wastes, it has not identified any technologies it
believes to be as effective as incineration for most PCB- or
dioxin-contaminated sites. Several innovative technologies, however,
have the potential for future applications in treating complex sites
contaminated with PCBs and dioxin. Accordingly, GAO agrees with EPA's
recent proposal to revisit its decisions on remedies at some sites that
could benefit from significant technological advancements.

--------------------------- Indexing Terms -----------------------------

 REPORTNUM:  RCED-96-13
     TITLE:  Superfund: EPA Has Identified Limited Alternatives To 
             Incineration for Cleaning Up PCB And Dioxin
             Contamination
      DATE:  12/29/95
   SUBJECT:  Technology transfer
             Waste management
             Pollution control
             Environmental legislation
             Toxic substances
             Cost effectiveness analysis
             Safety standards
             Clearinghouses
IDENTIFIER:  Superfund Innovative Technology Evaluation Program
             EPA National Priorities List
             Superfund Program
             
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Cover
================================================================ COVER


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

EPA's Encouragement of Innovative Technologies

(160267)


Abbreviations
=============================================================== ABBREV

  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

Letter
=============================================================== LETTER


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 Wood Preserving
Company, Texas; Times Beach, Missouri; and New Bedford Harbor,
Massachusetts--are described in appendix I. 


--------------------
\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. 


   RESULTS IN BRIEF
------------------------------------------------------------ Letter :1

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
     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. 


--------------------
\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. 


   BACKGROUND
------------------------------------------------------------ Letter :2

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. 


   EPA'S EFFORTS TO ENCOURAGE THE
   DEVELOPMENT AND USE OF
   INNOVATIVE TECHNOLOGIES
------------------------------------------------------------ Letter :3

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
---------------------------------------------------------- Letter :3.1

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 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. 


--------------------
\6 The Superfund Amendments and Reauthorization Act of 1986 (SARA)
directed EPA to establish a research and development program for
innovative treatment technologies. 


      TECHNOLOGY INNOVATION OFFICE
---------------------------------------------------------- Letter :3.2

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 study\7 in
April 1995 which showed that Superfund cleanup officials were often
eliminating innovative 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. 


--------------------
\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. 


      EPA'S GUIDANCE ON THE USE OF
      INNOVATIVE TECHNOLOGIES
---------------------------------------------------------- Letter :3.3

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
---------------------------------------------------------- Letter :3.4

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
dioxin-contaminated sites, EPA selected innovative cleanup
technologies 3 percent of the time. 


   EPA HAS IDENTIFIED LIMITED
   OPTIONS FOR CLEANING UP PCBS
   AND DIOXIN
------------------------------------------------------------ Letter :4

Even though EPA has generally not used innovative technologies for
PCB- and 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
---------------------------------------------------------- Letter :4.1

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


--------------------
\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. 


      USE OF INNOVATIVE
      TECHNOLOGIES IN COMBINATION
---------------------------------------------------------- Letter :4.2

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
------------------------------------------------------------ Letter :5

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


--------------------
\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. 


   BARRIERS TO THE USE OF
   INNOVATIVE TECHNOLOGIES
------------------------------------------------------------ Letter :6

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
---------------------------------------------------------- Letter :6.1

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 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. 


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


      TECHNICAL BARRIERS
---------------------------------------------------------- Letter :6.2

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
---------------------------------------------------------- Letter :6.3

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. 

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 Sites\11 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. 


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


      LACK OF INCENTIVES TO INVEST
      IN INNOVATIVE TECHNOLOGIES
---------------------------------------------------------- Letter :6.4

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
---------------------------------------------------------- Letter :6.5

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
------------------------------------------------------------ Letter :7

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, 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
------------------------------------------------------------ Letter :8

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
------------------------------------------------------------ Letter :9

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. 


---------------------------------------------------------- Letter :9.1

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


THREE CASE STUDIES
=========================================================== Appendix I

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
--------------------------------------------------------- Appendix I:1

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. 

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

   (See figure in printed
   edition.)

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 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. 


   TIMES BEACH AND EASTERN
   MISSOURI SUPERFUND SITES
--------------------------------------------------------- Appendix I:2

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 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. 

   Figure I.2:  Storage Buildings
   Containing Dioxin-Contaminated
   Materials From One of the
   Eastern Missouri Sites

   (See figure in printed
   edition.)


   NEW BEDFORD HARBOR SUPERFUND
   SITE
--------------------------------------------------------- Appendix I:3

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. 

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 long- and 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. 

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

   (See figure in printed
   edition.)

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 agency expects to
issue its final decision on the cleanup for the hot spot in
approximately 3 years. 


DIOXIN AND POLYCHLORINATED
BIPHENYLS CONTAMINATION
========================================================== Appendix II

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
------------------------------------------------------ Appendix II:0.1

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 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
------------------------------------------------------ Appendix II:0.2

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. 

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. 


INCINERATION TECHNOLOGY
========================================================= Appendix III

Incineration is the burning of substances by controlled flame in an
enclosed area or compartment.  During the process of incineration,
hazardous organic wastes\12 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. 


--------------------
\12 Organic compounds are those that are composed of carbon,
hydrogen, and sometimes other elements. 


      THE INCINERATION PROCESS
----------------------------------------------------- Appendix III:0.1

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 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 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. 

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

   (See figure in printed
   edition.)

   Source:  EPA.

   (See figure in printed
   edition.)


      HAZARDOUS WASTE INCINERATOR
      REGULATIONS
----------------------------------------------------- Appendix III:0.2

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 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 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. 


INNOVATIVE TREATMENT TECHNOLOGIES
========================================================== Appendix IV

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
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 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. 


MAJOR CONTRIBUTORS TO THIS REPORT
=========================================================== Appendix V

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


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