NETAC
National
Environmental
Technology
Applications
Corporation
TRENDS IN SUPERFUND SITE
REMEDY SELECTION
SEPTEMBER 1990
Prepared for
Office of Research and Development
U. S. Environmental Protection Agency
Washington, DC
UNIVERSITY OF PITTSBURGH APPLIED RESEARCH CENTER
615 William Pitt Way • Pittsburgh, PA 15238
Facsimile (412) 826-5552
(412)826-5511
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National Environmental Technology Applications Corporation
UNIVERSITY OF PITTSBURGH APPLIED RESEARCH CENTER
615 William Pitt Way • Pittsburgh, PA 15238
Facsimile (412) 826-3360
NETAC (412)826-5511
TRENDS IN SUPERFUND SITE REMEDY SELECTION
September 1990
Prepared for
Office of Research and Development
U.S. ENVIRONMENTAL PROTECTION AGENCY
Washington, DC
Prepared by
NATIONAL ENVIRONMENTAL TECHNOLOGY APPLICATIONS CORPORATION
University of Pittsburgh Trust
Pittsburgh, PA
APPROVED:
John W. Adams
Vice President
Technical and Business Programs
A subsidiary of the University of Pittsburgh Trust.
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DISCLAIMER
Development of the information contained in this document has been funded by
the U.S. Environmental Protection Agency (EPA) under assistance agreement
number CR-815286-01-0 with the National Environmental Technology Applications
Corporation (NETAC) at the University of Pittsburgh.
This document has not been subjected to the Agency's peer and administrative
review, nor does it necessarily represent the Agency's view on any of the
topics mentioned herein.
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ACKNOWLEDGMENTS
The National Environmental Technology Applications Corporation (NETAC) at the
University of Pittsburgh wishes to acknowledge the financial support and
encouragement received for the completion of this report from the Office of
Research and Development of the U.S. Environmental Protection Agency (U.S.
EPA). Special appreciation is extended to U.S. EPA's Project Officer, Mr.
Michael Mastracci.
NETAC would also like to thank the numerous individuals from the environmental
industry and from regulatory agencies who gave freely of their time to discuss
with NETAC the background and supporting data for this report.
This report was managed by NETAC Vice President of Technical and Business
Programs, John N. Adams. In addition, the following individuals made
significant contributions to the development and creation of this report.
William J. Aldridge, Business Analyst
Robb Lenhart, Director of Business Services
A. Thomas Merski, Regulatory Analyst
Ivy V. Schram, Vice President and Regulatory Counsel
Audrey G. Zelanko, Regulatory Analyst
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TABLE OF CONTENTS
Page
EXECUTIVE SUMMARY vi
1.0 INTRODUCTION 1
2.0 BACKGROUND 3
2.1 CERCLA 3
2.2 SARA 3
2.3 Steps of the Superfund Process 4
3.0 REGULATORY DISCUSSION 7
4.0 METHODOLOGY 9
5.0 TREND ANALYSIS 11
5.1 Contaminant Frequencies 11
5.2 General Trends in Remedy Selection 11
5.3 Trends in Remedy Selection by Contaminant 12
5.3.1 Solvents/VOCs 12
5.3.2 Metals 13
5.3.3 Organics 15
5.3.4 PCBs 15
5.3.5 Pesticides 16
5.3.6 Cyanide 16
5.3.7 Asbestos 17
5.3.8 Radionuclides 17
5.3.9 Acids/Alkalis 17
6.0 CONCLUSIONS 18
7.0 FUTURE TRENDS 19
Tables
Figures
References
Appendix A - Descriptions of Listed Contaminants and Remedies
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LIST OF TABLES
Table No. Title
1 Contaminant Categories
2 Remediation Methodologies
3 Frequencies of Remedies Selected for Solvents/VOCs Per Fiscal Year
4 Percentages of Remedy Groups Selected for Solvents/VOCs Per Fiscal
Year
5 Percentages of Specific Technologies Selected for Solvents/VOCs Per
Fiscal Year
6 Frequencies of Remedies Selected for Metals Per Fiscal Year
7 Percentages of Remedy Groups Selected for Metals Per Fiscal Year
8 Percentages of Specific Technologies Selected for Metals Per Fiscal
Year
9 Frequencies of Remedies Selected for Organics Per Fiscal Year
10 Percentages of Remedy Groups Selected for Organics Per Fiscal Year
11 Percentages of Specific Technologies Selected for Organics Per
Fiscal Year
12 Frequencies of Remedies Selected for PCBs Per Fiscal Year
13 Percentages of Remedy Groups Selected for PCBs Per Fiscal Year
14 Frequencies of Remedies Selected for Pesticides Per Fiscal Year
15 Percentages of Remedy Groups Selected for Pesticides Per Fiscal Year
16 Frequencies of Remedies Selected for Cyanide Per Fiscal Year
17 Percentages of Remedy Groups Selected for Cyanide Per Fiscal Year
18 Frequencies of Remedies Selected for Asbestos Per Fiscal Year
19 Percentages of Remedy Groups Selected for Asbestos Per Fiscal Year
20 Frequencies of Remedies Selected for Radionuclides Per Fiscal Year
21 Percentages of Remedy Groups Selected for Radionuclides Per Fiscal
Year
22 Frequencies of Remedies Selected for Adds/Alkalis Per Fiscal Year
23 Percentages of Remedy Groups Selected for Adds/Alkalis Per Fiscal
Year
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LIST OF FIGURES
Figure No. Title
1 Yearly Number of RODs Issued
2 Frequencies of Contaminant Occurrences Identified in RODs
3 Percentages of Contaminant Occurrences Identified in RODs Per
Fiscal Year
4 Percentages of Selected Remedies Identified in RODs Per Fiscal Year
5 Number of Technology Groups Identified in RODs Per Fiscal Year
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EXECUTIVE SUM4ARY
The National Environmental Technology Applications Corporation (NETAC),
through its cooperative agreement with the U.S. Environmental Protection
Agency (EPA), conducted this project to identify and analyze trends in the
selection of remediation technologies for application at federal Superfund
sites. The base data for this trend analysis is contained within the EPA's
Records of Decision (RODs) issued during the years 1982 through 1989.
N
The purpose of this report is to update past studies and determine the effec-
tiveness of SARA's directive for EPA to select permanent remedy alternatives.
This analysis alerts developers and suppliers of the types of technologies
which have been selected for use at federal Superfund sites. Further, NETAC1s
analysis of the trends in remedial technology selection, which is based upon
specific contaminant groupings, will result in an improved understanding of
the various incentives for technology selection as well as the barriers which
may be faced by technologies which have not been selected for use at Superfund
sites.
"-N
The findings of this report indicate that SARA has served to lessen the use of
land-based disposal remedies in Superfund cleanups and increase the use of
permanent remedies such as physical/chemical and thermal treatment methods.
In 1980, Congress passed the Comprehensive Environmental Response, Compensa-
tion and Liability Act (CERCLA). During the first 5 years of this program,
only 10 sites are reported to have been "cleaned up." This low number can be
at least partially attributed to a lack of available technology for permanent
waste destruction, lack of specific cleanup standards, and overall lack of
knowledge concerning the hazardous waste problem. The Superfund Amendments
and Reauthorization Act (SARA) was enacted in October 1986 to extend CERCLA
and to set more stringent remediation standards. SARA directiv.es included an
emphasis on utilization of permanent remedies rather than the traditionally
used land-based containment/disposal methods.
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EPA's traditional selection of land-based remedies is based largely upon the
fact that these technologies are well proven and inexpensive methods. The
enactment of SARA in 1986 directed EPA to utilize permanent remedies whenever
possible. This directive was, as this report will indicate, met with an
effort by EPA to reduce disposal and site containment land-based remedies.
The majority of remedies selected to replace these land-based technologies
consist of physical/chemical and thermal treatment methods. The selection of
biological and pump-and-treat methods play a lesser but still important role
among the alternative technologies selected by EPA.
The findings of this report further suggest that the impact from the SARA
directive in 1986 is apparent in the decrease of land-based, non-permanent
remedy selection and in the increase in thermal and physical/chemical remedy
selection. The impact of SARA is not as clear, however, for the selection of
specific technologies for specific site contaminants. These ambiguous trends
may be explained by:
o the likelihood that certain remedies, such as pumping and treating
of groundwater, and off-site treatment at POTHs, are utilized in
concert with primary remedies such as incineration, solidification/
stabilization, or air stripping;
o the increase in the total number of available alternative technolo-
gies dilutes apparent trends for any one technology; and
o a small number of occurrences in the examined RODs for contaminants
such as cyanide, asbestos, radionuclides, and acids/alkalis.
Based upon the findings of this report, there exists greater opportunities for
the application of alternative treatment technologies even though EPA has
continued to largely rely on site containment and disposal methods. A system
which provides greater incentive for the selection of alternative treatment
technologies is needed to fulfill the intent of SARA.
This report provides generators, environmental technology and service provid-
ers, and government agencies with an understanding of technology selection
trends within the Superfund program. This understanding will enable both the
generator and service industries to direct their resources to the development
and commercialization of environmental technology alternatives that can meet
the objectives of the remedy selection process mandated under SARA. More
vii
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specifically, firms will be able to focus on the development of permanent
treatment methods that can remediate solvent, VOC, metal, and organic contam-
inants in various waste matrices. This report also alerts waste handlers that
temporary alternatives such as site containment methods are less likely to be
used in the future. This may result in an increase in the transportation of
soils to permanent remediation technology sites. Thus, waste handlers could
begin to focus their marketing and technical capability efforts to meet this
projected need.
Government agencies will also benefit from this understanding of the selection
trends of Superfund technologies. From this understanding, government
agencies can work to enact policies and regulations that will enhance and
encourage the development and commercialization of needed innovative technolo-
gies to address the needs of the Superfund program.
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1.0 INTRODUCTION
In 1980, Congress passed the Comprehensive Environmental Response, Compensa-
tion and Liability Act (CERCLA). This legislation, often referred to as
Superfund, provided funding and federal authority for response actions at
hazardous abandoned and uncontrolled waste sites. During the first 5 years of
this program, only 10 sites are reported to have been "cleaned up." This low
number can be at least partially attributed to a lack of available technology
for permanent waste destruction, lack of specific cleanup standards, and
overall lack of knowledge concerning the hazardous waste problem.
The Superfund Amendments and Reauthorization Act (SARA) was enacted in October
1986 to extend CERCLA, increase funding, and set more stringent remediation
standards. SARA directives included an emphasis on utilization of permanent
remedies rather than the traditionally used land-based containment/disposal
methods.
Some reports suggest that, despite well intentioned efforts to heed SARA
directives, the U.S. Environmental Protection Agency (EPA) has predominantly
repeated pre-SARA cleanup remedy selection, i.e., on-site capping and contain-
ment techniques. The EPA has typically selected these land-based remedial
actions since they have tended to be more proven and less expensive than
alternative treatment techniques. Other studies, however, note that the use
of permanent treatment technologies has increased dramatically since SARA.
The purpose of this report is to update past studies and determine the effec-
tiveness of SARA's directive for EPA to select permanent remedy alternatives.
This analysis is conducted through a review of EPA's Records of Decision
(RODs) for the years 1982 through 1989. Further, this report provides an
understanding of the issues:
o summary of the regulatory history of Superfund;
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trends in the selection of various remediation technologies overall
and for specific contaminants;
relationship between regulatory directives and remediation methodol-
ogy trends; and
forecast of potential future trends.
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2.0 BACKGROUND
In order to most effectively determine whether SARA has impacted EPA's
selection of cleanup remedies, it is critical to understand the regulatory
directives of CERCLA and SARA and the steps of the Superfund decision process.
These are summarized below.
2.1 CERCLA
Authorized in 1980, CERCLA provided to U.S. EPA the federal authority for the
cleanup of abandoned and uncontrolled waste sites. Major provisions of CERCLA
are:
o identification of reporting requirements for current hazardous
substance releases;
o designation of liability on private parties for releases and Super-
fund site cleanups;
o development of a tax program for federally managed funds to be used
for the cleanups ($1.6 billion fund); and
o development of the National Contingency Plan (NCP) to establish
basic government procedures and standards for site cleanups.
2.2 SARA
In 1986, SARA extended CERCLA for 5 years and included the major revisions:
o enactment of strict cleanup standards that favor permanent solutions
(such as incineration)* and significantly reduce volume, toxicity,
and mobility of waste;
* The Superfund Innovative Technology Evaluation (SITE) program was estab-
lished by EPA in 1986 to aid in the achievement of this goal. The program
encourages private vendors to conduct full-scale demonstrations of promising
alternative technologies on applicable Superfund sites. Some technologies
that have been evaluated include chemical treatment by soil washing, vacuum
extraction, biological soil treatment, and various thermal treatment
technologies.
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o increase in public trust money and private funds to $8.5 billion;
o direction of stronger EPA control over Potentially Responsible Party
(PRP) settlements and other liability issues;
o development of mandatory schedules for investigations and remedial
actions;
o increase in state and public participation in the decision-making
process;
o codification of existing EPA practices (including CERCLA compliance
with other environmental laws, off-site disposal policy, applicable
or relevant and appropriate requirements [ARARs], and the evolving
settlement policy);
o development of a new regulatory program, Title III—Emergency
Planning and Community Right-to-Know Act of 1986 (includes notifica-
tion to communities, release information to EPA, and improvement of
emergency planning procedures);
o development of a tanks section which requires owners of underground
storage tanks (USTs) to take financial responsibility for leak
cleanup and compensation of third parties for property damage and
bodily injury with a $500 million trust fund established for cases
when no responsible owner/operator of tanks can be found; and
o requirement that the President revise the NCP and Hazard Ranking
System (HRS).
2.3 STEPS OF THE SUPERFUND PROCESS
The following steps are a summary of the Superfund process from the point of
site identification to completion of remediation.
Listing on NPL
Sites placed on the NPL are eligible for remedial action under CERCLA. In
order for a site to be placed on the NPL, it must first be listed on the
Comprehensive Environmental Response, Compensation and Liability Information
System (CERCLIS) list. The CERCLIS list is developed through general records
review and notifications to EPA. EPA then conducts a preliminary assessment
which includes a review of readily available Information. In most cases, the
EPA then conducts a site investigation, most often through private contrac-
tors. The site investigation typically consists of a visit to the site,
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visual observation, and some sampling. Finally, EPA evaluates the site under
Hazardous Ranking System (MRS) procedures. Under the MRS, scores are applied
for such characteristics as waste volumes, toxicity, distance to populations,
and presence of groundwater used for drinking water, etc. EPA policy has
provided that sites with scores equal to or above 28.5 would be included on
the NPL. Currently, however, the Office of Budget and Management is reviewing
a new ranking system. Until the new ranking system is made final, EPA may not
list any new hazardous waste sites on the NPL.
Remedial Investigation/Feasibility Study (RI/FS)
The RI is conducted by government agencies and/or Potentially Responsible
Parties (PRPs) to characterize site conditions. The nature and extent of
contamination is examined and criteria are established for site cleanup.
Preliminary alternatives are identified in the RI. The FS evaluates various
remedial solutions and makes recommendations for specific site remedial action
alternatives. Technical and environmental evaluations and cost effectiveness
are considered. Current EPA policy requires that a "work plan" be developed
prior to conducting an RI/FS. The site work plan may segregate the site into
several operable units (OUs) with different site remedies prescribed.
Record of Decision (ROD)
Issuance of a ROD follows the RI/FS and represents an actual remedial action
decision by EPA. The alternatives offered by the RI/FS may range from a "no
action" alternative to a total treatment alternative, e.g., incineration. EPA
bases its decision on the RI/FS, public and state comments, and other environ-
mental guidance and regulations. Once the ROD is completed, the PRPs are
notified and given the opportunity to conduct the remediation. If they do not
choose to remediate, the Agency will conduct the response action and later
seek to recover costs from the PRPs. For this report, EPA's RODs for fiscal
years 1982 through 1989 have been evaluated for this study.
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Remedial Design/Remedial Action
The remedial design phase provides for the development of engineering drawings
and specifications for the cleanup action selected in the ROD. The remedial
action phase follows the remedial design and consists of the actual implemen-
tation of the Superfund cleanup. Remedial action typically includes source
control (e.g., on-site land disposal, incineration, bioremediation) and
residual contamination management (e.g., adherence to ARARs).
Post-Remediation Requirements
Post-remediation action is often required at Superfund sites and operating
units that still contain hazardous substances after closure. Resource Conser-
vation and Recovery Act (RCRA) standards for land disposal, for example, apply
to Superfund land disposal actions. Further, the post-closure, 30-year
groundwater monitoring requirement can be extended by EPA. Sites that contain
no hazardous substances or groundwater contamination may avoid post remedia-
tion requirements.
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3.0 REGULATORY DISCUSSION
It has been well documented that, prior to Superfund's reauthorization by
SARA, the most common remedies identified in the RODs were in-situ source
containment and off-site disposal alternatives. This study will address the
trend in EPA's selection of remedies (i.e., EPA selected a greater number of
physical and chemical destruction technologies or bioremediation, etc.).
One study of Superfund remedy selection, completed jointly by a number of
leading environmental organizations and the Hazardous Waste Treatment Council,
was conducted in June 1988 (Greer, 1988). This study, the first comprehensive
analysis of EPA's remedy selection process, was conducted through a review of
the 75 RODs decided in 1987. The report's findings suggested that, although
SARA directed EPA to utilize permanent treatment remedies to the maximum
degree practicable, only 8 percent of the remedies selected were such treat-
ment technologies. Moreover, "68 percent of the remedies selected in fiscal
year 1987 failed to use any treatment whatsoever on the sources of contamina-
tion at Superfund sites" (Greer, 1988, p. 2).
A second study, completed in 1987, included an analysis of the treatment
technologies used at Superfund sites. This study consisted of a review of a
representative sample of actions occurring from 1980 through the beginning of
1987 (White, 1987). The authors reviewed RODs for sites that contain one of
the three most common waste types: (1) solid wastes, including soils and
sludges; (2) aqueous wastes, including leachate and groundwater; and (3) per-
chloroethylene. The authors reviewed the frequency of various remedies used
for each waste type. In general, it was found that only a small percentage of
Superfund actions utilized treatment technologies rather than land disposal
remedies. The authors noted, however, that a review of signed RODs in early
1987 of incomplete actions suggest that the use of treatment technologies was
expected to increase dramatically.
A third study included an analysis of the Superfund remedial action decision
process (Doty and Travis, 1989). The study consisted of a review of 50 RODs
signed during fiscal year 1987, applicable RI/FSs, and other available
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documents. One finding of this study indicated that EPA failed to follow the
SARA directive to select permanent remediation technologies during the fiscal
year 1987. It was reported that 19 percent of final source remedies selected
were permanent to the maximum degree practicable.
This report improves upon the previous studies through a comprehensive review
of remedy selection from 1982 through 1989. Moreover, the following factors
are expected to have more of an influence on EPA remedy selection than
decisions made prior to 1988:
o lessening landfill space available;
o expanding knowledge about alternative technologies (e.g., through
the SITE program); and
o more stringent "other environmental laws" (e.g., final land ban
legislation).
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4.0 METHODOLOGY
In order to identify trends in the utilization of various remediation
technologies, RODs issued for federal Superfund sites for the fiscal years
1982 through 1989 were reviewed. EPA has issued a total of 566 RODs through
March 1990. Figure 1 illustrates the number of RODs issued in each year from
1982 through 1989. This number reflects the number of RODs issued for 455 of
the 1,219 sites currently on the NPL. The number of RODs exceeds the number
of Superfund sites with RODs due to the following reasons.
o New information or corrected data is incorporated into the original
RODs. .
o Previously selected technologies are replaced as a result of updated
research.
o Complex sites consist of multiple waste problems, or operating
units, which require multiple remediation methods.
In order to facilitate trend analysis, multiple RODs for a single site were
considered as separate decision-making events; that is, RODs, rather than
total site solutions, were studied.
The information sources for this study were Records of Decision and Record of
Decision abstracts accessed through the EPA ROD database. The technologies
prescribed by the RODs and ROD abstracts were matched with the specific site
contaminants, whenever possible. In cases where the contaminant(s) to be
treated was not identified, it was assumed that the remedies selected were
used for all contaminants. Sites that were identified only as collection and
treatment of ground or surface water were placed under the general category of
"pump and treat."
The "no action or non-technical solutions" category includes RODs that
indicated no action 1s to be taken at the site and also RODs that indicated
that the primary or secondary remediation method would be water supply
replacement only.
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Whenever possible, this report attempts to differentiate on-site versus off-
site technical solutions. If the treatment location was not identified in the
ROD, the technology was placed in the on-site treatment category.
Contaminant categories used in this report are listed in Table 1. Categories
of selected technologies are listed in Table 2 along with general methodology
groups for each technology. Descriptions of the contaminants, general remedy
method groups, and specific technologies are provided in Appendix A.
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5.0 TREND ANALYSIS
In this section, the ROD data are examined for trends in the types of remedies
selected by the EPA for the fiscal years 1982 through 1989. To evaluate these
trends, contaminant frequencies are reviewed and remedy selection trends are
analyzed at both an overall level and for each contaminant.
5.1 CONTAMINANT FREQUENCIES
An examination of the RODs for the years 1982 through 1989 indicate that
solvents/VOCs are the most frequent contaminant present at federal Superfund
sites. Metal and organic contaminants are the second and third greatest
contaminant categories, respectively. The frequencies of contaminant occur-
rences identified in RODs are shown in Figure 2. The contaminants are shown
in the following percentages over all the study years.
Solvents/VOCs 31.4
Metals 25.2
Organics 24.3
PCBs 9.7
Pesticides 4.8
Cyanide 1.4
Asbestos 1.2
Radionuclides 1.2
Acid/Alkalis 0.9
Figure 3 illustrates the percentages of contaminant occurrences identified in
RODs for each fiscal year from 1982 through 1989. Solvents/VOCs, metals, and
organics remain the top three contaminants for each year.
5.2 GENERAL TRENDS IN REMEDY SELECTION
The contaminant frequency data indicate that the selection of disposal and
site containment technologies has decreased by more than 50 percent from 1982
through 1989. In contrast, the use of physical/chemical and thermal methods
has increased by at least 50 percent. The frequency of the selection of
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biological and pump-and-treat methods, which began in 1984 and 1983, respec-
tively, varied over the remaining years. Figure 4 shows the percentages of
remedy selection frequencies for 1982 through 1989 for each technology group.
The impact of SARA'S directive to employ more permanent remedies can be
clearly seen through the decreased use of disposal and site containment
remedies from 1986 to 1989. It should be noted, however, that a more gradual
decrease in disposal remedy selection was under way pre-SARA. Site contain-
ment remedy selection experienced a dramatic decrease from 1982 to 1983, and
then a gradual increase until 1985, followed by a gradual decrease following
the passing of SARA. Containment methods may be decreasing at a gradual,
rather than dramatic, rate since these methods may often be used in conjunc-
tion with other methods.
The increase in the selection of physical/chemical and thermal remedies
appears to be directly linked to SARA'S enactment. Both categories show major
increases from 1986 to 1989. Trends in the selection of biological and pump-
and-treat remedies are not as clear. The frequencies of remedy selection per
contaminant are examined in the following sections.
Figure 5 illustrates the growth in the number of technology groups identified
in RODs per year. The general increase from 5 to 21 technology groups is most
likely a result of EPA's desire and ability to utilize a greater number of
permanent remedy methods.
5.3 TRENDS IN REMEDY SELECTION BY CONTAMINANT
The following sections describe trends in remedy selection for nine contamin-
ant categories.
5.3.1 Sol vents/VOCs
Table 3 shows the frequencies of specific remedies used during each fiscal
year for the contaminant category sol vents/VOCs. The percentages of remedy
groups utilized in each fiscal year is illustrated in Table 4. The following
trends are observed.
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o Selection of disposal remedies has decreased from 1982 to 1986 and
has dramatically decreased in the years 1987 to 1989.
o Selection of site containment methods has decreased overall from
1982 to 1989.
o Selection of physical/chemical remedies has increased from 1982 to
1989.
o Selection of thermal and biological remedies has gradually increased
from 1982 to 1989
o Selection of pump-and-treat remedies has decreased from 1987 to 1989.
Further details of these trends are provided in Table 5, which categorizes
specific technologies selected for each fiscal year. Major decreases are
shown for both on-site capping and off-site disposal methods. The in-situ
capping remedy experienced a decline from 1982 to 1985, but then increased
from 1986 to 1989 to the 1982 level of selection. Slurry wall remedy selec-
tion decreased from 1982 through 1989.
The fluctuations/decreases in the uses of specific physical/chemical remedies
(e.g., GAC, air stripping, solidification/stabilization), thermal remedies,
and biological remedies appear to be at least partly due to the increasing
numbers of new technologies that became available in the later study years.
These new technologies include on-site chemical precipitation, vacuum extrac-
tion, vitrification, and biological land treatment.
The "no action" alternative shows a decrease from 1983 to 1989.
5.3.2 Hetals
Percentages of remedy groups selected for metals for each fiscal year is
summarized in Table 6. Tables 7 and 8 provide further detail of the frequen-
cies and percentages, respectively, of specific remedies used for each fiscal
year for metals. The following trends are found.
o Selection of disposal remedies decreased dramatically from 1985 to
1986 and 1987, the beginning of SARA, and continued decreasing
through 1989.
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o Selection of site containment remedies decreased from 1982 to 1985,
increased from 1985 to 1988, and decreased again in 1989.
o Fluctuation in the use of physical/chemical and thermal remedies
existed until 1987, the beginning of SARA, when the increases became
generally steady and gradual through 1989.
o The trend in the selection of biological and pump-and-treat remedies
is not clear, although there is nearly a 50 percent increase in the
use of biological remedies from 1984 (the first year that biological
remedies are noted for treatment of metals in the RODs) to 1989.
Pump-and-treat technologies show an approximately 50 percent
decrease in use from 1983 to 1989.
Overall decreases are shown for both on-site capping and off-site disposal
methods. Capping selection fluctuated, with a gradual decrease from 1986
through 1989 (post-SARA). The selection of off-site disposal increased until
1985, decreased dramatically in 1986 and 1987, and increased again in 1989.
Although there is an overall decrease in the selection of containment methods,
no trends are apparent for use of either the in-situ capping or slurry wall
remedies.
Although overall selection of physical/chemical methods has increased, the
individual technology trends fluctuate. For example, new methods such as
on-site chemical precipitation were introduced for metals in the later study
years. The use of on-site and off-site thermal remedies fluctuated. The use
of on-site vitrification was selected for the first time in 1988.
The selection of individual biological remedies also fluctuated, with off-site
treatment at wastewater treatment facilities decreasing in 1987. Selection of
biological land treatment remedies increased from 1984 through 1987, then
decreased in 1988 and 1989. The selection of groundwater pump-and-treat
methods also fluctuated.
The lack of clear trends in the use of specific permanent remedy alternatives
is, again, probably due to the increase in the types of remedies available in
the later study years. The "no action" alternative remained relatively
constant over the study years.
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5.3.3 Organics
Table 9 shows percentages of remedy groups selected for each fiscal year.
Table 10 presents the frequencies of specific remedies selected for each
fiscal year for organics. The following trends are shown.
o Selection of disposal remedies decreased dramatically from 1985 to
1986 and 1987 and increased gradually from 1987 to 1989.
o Selection of site containment remedies generally decreased from 1982
to 1985 and increased from 1986 to 1989.
o In general, the selection of physical/chemical methods has increased
since the enactment of SARA (1986 through 1989).
o Selection of thermal, biological, and pump-and-treat technologies do
not appear to follow any clear trend.
The data show an increase in disposal activities prior to SARA and then a
marked decrease. The overall use of on-site capping methods has only slightly
decreased from 1982 to 1989. Off-site disposal method selection experienced
dramatic increases in 1983 and 1984 followed by dramatic decreases in 1985. A
continued decrease followed through 1989. The selection of site containment
methods has declined since 1982 with the observation of increases in 1987
followed by general decreases.
Physical/chemical, thermal, biological, and pump-and-treat method selection
fluctuated over the 1982 through 1989 period. This is most likely due to
increases in the numbers and types of alternative technologies available in
the later study years. Physical/chemical technologies first selected in 1985
and 1986 include solidification/stabilization, soil washing, and air-stripping
techniques. . Other new technologies—vitrification and biological land
treatment—were first selected in 1988. The "no action" alternative decreased
through 1987 but rose sharply and fluctuated in 1988 and 1989.
5.3.4 PCBs
Tables 12 and 13 present, respectively, the percentages of remedy groups and
the frequency of specific remedies selected for each fiscal year for PCBs.
The following trends are observed from this data.
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Selection of disposal remedies decreased by more than 50 percent
from 1985 to 1986 (post-SARA).
Selection of site containment, physical/chemical, and thermal
remedies showed increases from 1985 to 1989.
Pump-and-treat remedies were higher in 1985 and 1986 then fluctuated
and decreased through 1989.
There is an insufficient number of selections of biological treat-
ment remedies to determine trends.
Specific technology trends are not analyzed due to the limited number of PCB
contaminant occurrences.
5.3.5 Pesticides
Tables 14 and 15 present, respectively, the percentage of remedy groups and
the frequencies for pesticides. The following trends are observed.
o Selection of disposal and containment remedies decreased from 1985
through 1988 and increased in 1989.
o An overall trend exists in the use of alternative treatment tech-
nologies with no specific treatment method preferred.
Specific technology trends are not analyzed due to the limited number of
pesticide contaminant occurrences.
5.3.6 Cyanide
Tables 16 and 17 present, respectively, the percentages of remedy groups and
the frequencies of specific remedies selected for each fiscal year for
cyanide. The following observations are made.
o The majority of remedies selected during 1983 through 1989 were
disposal and containment.
o Other major technology selections included oxidation and
solidification/stabilization.
Specific technology trends are not analyzed due to the limited number of
cyanide contaminant occurrences.
16
-------
5.3.7 Asbestos
Tables 18 and 19 present, respectively, the percentages of remedy groups and
the frequencies of specific remedies selected for each fiscal year for
asbestos. The following observation is made.
o Most of the remedies selected were disposal and site containment.
Specific technology trends are not analyzed due to the limited number of
asbestos contaminant occurrences.
5.3.8 Radionuclides
Tables 20 and 21 present, respectively, the percentages of remedy groups and
the frequencies of specific remedies selected for each fiscal year for radio-
nuclides. The following observations are made.
o Disposal remedies only were selected (1985 through 1989) except for
one pump-and-treat method reported in 1988.
o No thermal or biological remedies were selected.
Specific technology trends are not analyzed due to the limited number of
radionuclide contaminant occurrences.
5.3.9 Adds/Alkalis
Tables 22 and 23 present, respectively, the percentages of remedy groups and
the frequencies of specific remedies selected for each fiscal year for acid/
alkalis. The following observations are made.
o The majority of remedies selected were disposal and site containment.
o A limited number of physical/chemical and pump-and-treat remedies
were selected
o No thermal or biological remedies were selected.
Specific technology trends are not analyzed due to the limited number of acid/
alkali contaminant occurrences.
17
-------
6.0 CONCLUSIONS
As previously noted, EPA has traditionally selected land-based remedies on the
basis that they are well proven and inexpensive methods. The enactment of
SARA in 1986 included a directive that EPA utilize permanent remedies whenever
possible. This directive was, as the report data indicate, met with an effort
by EPA to reduce disposal and site containment land-based remedies. The
majority of remedies selected to replace these land-based technologies consist
mainly of physical/chemical and thermal methods. The selection of biological
and pump-and-treat methods plays a lesser but still important role among the
alternative technologies selected by EPA.
The data further suggest that the impact from the SARA directive in 1986 is
apparent in the decrease of land-based, non-permanent remedy selection and in
the increase in thermal and physical/chemical remedy selection. The impact of
SARA is not as clear, however, for the selection of specific technologies for
specific site contaminants. These ambiguous trends may be explained by:
o the likelihood that certain remedies, such as pumping and treating
of groundwater and off-site treatment at POTWs, are utilized in
concert with primary remedies such as incineration, solidification/
stabilization, or air stripping;
o the increase in the total number of available alternative technolo-
gies dilutes apparent trends for any one technology; and
o a small number of occurrences in the examined RODs for contaminants
such as cyanide, asbestos, radionuclides, and acids/alkalis.
In summary, SARA has served to lessen the use of land-based disposal remedies
in Superfund cleanups and to increase the use of permanent remedies such as
physical/chemical and thermal treatment methods. Greater opportunities for
the application of alternative treatment technologies exist even though EPA
has continued to largely rely on site containment and disposal methods. A
system which provides greater incentive for the selection of alternative
treatment technologies is needed to fulfill the intent of SARA.
18
-------
7.0 FUTURE TRENDS
It is clear from the trends identified in this report that the increased
availability of permanent remedies will be important to the overall success of
the Superfund cleanup program. The following trends are anticipated to occur.
o The high cost of proven permanent treatment technologies, such as
incineration along with the increasingly strict regulatory environ-
ment (e.g., land ban, more stringent cleanup standards), will most
likely lead to a greater economic incentive for industry to develop
viable alternative waste technologies.
o The SITE program, a cooperative effort between EPA and private
industry, will continue to provide an important vehicle for
technology development and demonstration.
o Technology development will concentrate on permanent treatment
methods that have the ability to remediate solvents/VOCs, metals,
and organics.
o The use of land disposal remedies will continue to decline due to
the impact of SARA and, probably more significantly, the RCRA land
ban, but will still remain an important alternative for residual
waste management.
o Site containment methods will continue to be used, most likely as a
secondary remedy on sites with multiple contaminants and/or residual
wastes.
The trends described above indicate that EPA and industry are expected to
continue working to meet the goals of SARA and other environmental directives.
The expected result is a greater success rate in the cleanup of this nation's
hazardous waste sites.
19
-------
Table 1
CONTAMINANT CATEGORIES
o Sol vents/VOCs
o Metals
o Organics/Petrochemicals
o Pesticides
o PCBs
o Cyanide
o Asbestos
o Radionuclides
o Acids/Alkalis
-------
Table 2
REMEDIATION METHODOLOGIES
General Method
Disposal
Containment
Physical/Chemical
Thermal
Biological
Pump and Treat
Technology Categories
Off-Site Containment
On-Site Containment
RCRA Cap
Slurry Wall
Air Strip-Water Only
Air Strip/GAC Polish (liquid and vapor phase)
Oxidation
Granular Activated Carbon
Soil Washing
On-Site Chemical Precipitation
Off-Site Chemical Precipitation
Critical Fluid Extraction
Vacuum Extraction/Volatile Soil Aeration
Vacuum Extraction/Volatile Soil Aeration/GAC
Polish
Solidification/Stabilization
On-Site Thermal
Off-Site Thermal
Vitrification
Biological Land Treatment
POTW
Groundwater Pump and Treat
-------
TABLE 3 - FREQUENCIES OF REMEDIES SELECTED FOR SOLVENTS/VOCS PER FISCAL YEAR
::::l;?rREMEDY;::i:GRQDPS::;f;:,:-'
DISPOSAL
SITE CONTAINMENT
PHYS ICAL/CHEMICAL
THERMAL
BIOLOGICAL
PUMP & TREAT
::;;m;;7:":M-'::. •.' TECHNOLOGY '•• - -, ; :.- •
DISPOSAL CAP ON-SITE
DISPOSAL OFF-SITE CONTAINMENT
IN-SITU/CONSOLIDATING RCRA CAP
SLURRY WALL
GAC ONLY IN LIQUID PHASE
CRITICAL FLUID EXTRACTION
AIR STRIP ONLY
OFF-SITE CHEMICAL PRECIPITATION
AIR STRIP/GAC POLISH (VAPOR PHASE)
ON-SITE CHEMICAL PRECIPITATION
OXIDATION (INCLUDES .UV AND KPEG)
VAPOR EXTRACTION/VSA ONLY
AIR STRIP/GAC POLISH (LIQUID PHASE)
SOLIDIFICATION/STABILIZATION
SOIL WASH
VACUUM EXTRACTION/VSA WITH GAC POLISH
ON-SITE THERMAL (MOBILE, FIXED)
OFF-SITE THERMAL
VITRIFICATION
OFF-SITE TREATMENT AT POTW OR PRIVATE
BIOLOGICAL LAND TREATMENT
GROUND WATER PUMP AND TREAT
NO ACTION OR NON-TECHNICAL SOLUTIONS
; TOTALS
1982
2
3
1
1
1
8
1983
4
2
1
1
2
1
11
1984
7
15
4
2
2
3
1
3
1
3
4
45
FISCAL YEAR
1985
17
21
4
2
2
7
1
2
1
1
1
4
5
10
5
83
1986
19
12
6
2
5
7
1
2
3
1
7
3
8
15
6
97
1987
11
3
10
3
5
9
2
5
5
5
2
2
1
11
5
79
1988
16
11
27
7
13
14
13
1
2
8
8
9
3
4
8
6
1
8
3
15
7
184
1989
15
14
24
1
10
12
11
1
2
5
11
7
6
8
13
9
2
5
6
16
10
188
TOTALS
87
83
76
18
38
54
26
2
5
19
25
25
11
12
35
27
3
29
10
72
38
695
-------
TABLE 4 - PERCENTAGES OF REMEDY GROUPS SELECTED FOR SOLVENTS/VOCS PER FISCAL YEAR
FISCAL TEAR
1982
1983
1984
1985
1986
1987
1988
1989
DlSEOSALi
62.5
36.4
48.9
45.8
32.0
17.7
14.7
15.4
leONTA IN .
25.0
13.3
7.2
8.2
16.4
18.5
13.3
REMEDY GROUPS
PHYS./CHEM.
12.5
27.3
13.3
16.9
19.6
32.9
40.8
38.8
THERMAL
9.1
6.7
6.0
10.3
8.9
8.2
12.8
B 1 0'LV;< •:::•;
2.2
6.0
8.2
3.8
6.0
5.8
POMP&TREAT
27.3
15.6
18.0
21.6
20.2
12.0
13.8
-------
TABLE 5 - PERCENTAGES OF SPECIFIC TECHNOLOGIES SELECTED FOR SOLVENTS/VOCS PER FISCAL YEAR
* .: :; 1* REMEDY: GROUPS ! ;\;:; :? :'
DISPOSAL
SITE CONTAINMENT
PHYSICAL/CHEMICAL
/•
THERMAL
BIOLOGICAL
PUMP & TREAT
" ; . : :•;: . "': • >;.: : : . • ; ;i' -v ; " TECHNOLOGY' - , • • : ' ' • ' . v ; :. ;
DISPOSAL CAP ON-SITE
DISPOSAL OFF-SITE CONTAINMENT
IN-SITU/CONSOLIDATING RCRA CAP
SLURRY WALL
GAC ONLY IN LIQUID PHASE
CRITICAL FLUID EXTRACTION
AIR STRIP ONLY
OFF-SITE CHEMICAL PRECIPITATION
AIR STRIP/GAC POLISH (VAPOR PHASE)
ON-SITE CHEMICAL PRECIPITATION
OXIDATION (INCLUDES UV AND KPEG)
VAPOR EXTRACTION/VSA ONLY
AIR STRIP/GAC POLISH (LIQUID PHASE)
SOLIDIFICATION/STABILIZATION
SOIL WASH
VACUUM EXTRACTION/VSA WITH GAC POLISH
ON-SITE THERMAL (MOBILE, FIXED)
OFF-SITE THERMAL
VITRIFICATION
OFF-SITE TREATMENT AT POTW OR PRIVATE
BIOLOGICAL LAND TREATMENT
GROUND WATER PUMP AND TREAT
NO ACTION OR NON-TECHNICAL SOLUTIONS
1982
25.0
37.5
12.5
12.5
12.5
1983
36.4
18.2
9.1
9.1
18.2
9.1
1984
15.6
33.3
8.9
4.4
4.4
6.7
2.2
6.7
2.2
6.7
8.9
FISCAL YEAR
1985
20.5
25.3
4.8
2.4
2.4
8.4
1.2
2.4
1.2
1.2
1.2
4.8
6.0
12.0
6.0
1986
19.6
12.4
6.2
2.1
5.1
7.2
1.0
2.1
3.1
1.0
7.2
3.1
8.2
15.5
6.2
1987
13.9
3.8
12.6
3.8
6.3
11.4
2.5
6.3
6.3
6.3
2.5
2.5
1.3
13.9
6.3
1988
8.7
6.0
14.7
3.8
7.1
7.6
7.1
0.5
1.1
4.3
4.3
4.9
1.6
2.2
4.3
3.3
0.5
4.3
1.6
8.2
3.8
1989
8.0
7.4
12.8
0.5
5.3
6.4
5.8
0.5
1.2
2.6
5.8
3.7
3.2
4.2
6.9
4.8
1.1
2.6
3.2
8.5
5.3
-------
TABLE 6 - FREQUENCIES OF REMEDIES SELECTED FOR METALS PER FISCAL YEAR
: ; REMEDt; GROUPS
DISPOSAL
SITE CONTAINMENT
PHYSICAL/CHEMICAL
THERMAL
BIOLOGICAL
PUMP & TREAT
TECHNOLOGY
DISPOSAL CAP ON-SITE
DISPOSAL OFF-SITE CONTAINMENT
IN-SITU/CONSOLIDATING RCRA CAP
SLURRY WALL
GAC ONLY IN LIQUID PHASE
CRITICAL FLUID EXTRACTION
AIR STRIP ONLY
OFF-SITE CHEMICAL PRECIPITATION
AIR STRIP/GAC POLISH (VAPOR PHASE)
ON-SITE CHEMICAL PRECIPITATION
OXIDATION (INCLUDES UV AND KPEG)
VAPOR EXTRACTION/VSA ONLY
AIR STRIP/GAC POLISH (LIQUID PHASE)
SOLIDIFICATION/STABILIZATION
SOIL WASH
VACUUM EXTRACTION/VSA WITH GAC POLISH
ON-SITE THERMAL (MOBILE, FIXED)
OFF-SITE THERMAL
VITRIFICATION
OFF-SITE TREATMENT AT POTW OR PRIVATE
BIOLOGICAL LAND TREATMENT
GROUND WATER PUMP AND TREAT
NO ACTION OR NON-TECHNICAL SOLUTIONS
TOTALS
1982
2
3
3
2
1
11
1983
1
2
1
1
2
7
1984
4
10
3
1
2
2
1
3
2
28
FISCAL YEAR
1985
16
17
5
2
2
1
1
2
1
4
6
6
1
64
1986
13
7
11
4
5
1
1
1
1
6
2
4
2
9
5
72
1987
10
2
14
3
3
2
4
4
8
2
1
1
10
6
70
1988
22
7
31
8
13
4
3
2
2
3
2
7
3
11
7
1
4
6
14
7
157
1989
16
13
24
1
7
1
3
3
1
2
3
7
10
6
4
13
9
2
2
9
11
11
158
TOTALS
84
61
91
21
30
1
13
6
3
5
9
13
24
11
4
39
26
3
18
18
55
32
567
-------
TABLE 7 - PERCENTAGES OF REMEDY GROUPS SELECTED FOR METALS PER FISCAL YEAR
FISCAL, YEAR
1982
1983
1984
1985
1986
1987
1988
1989
PISPQSAI,
45.4
42.6
50.0
51.6
27.8
17.1
18.5
18.4
: CONTAIN .
45.4
0
14.3
10.9
20.8
24.3
24.8
15.8
REMEDY GROUPS
PHYS ; /CHEM .
9.1
14.3
7.1
10.9
12.5
18.6
24.8
29.7
THERMAL
0
14.3
7.1
6.2
11.1
14.3
12.1
15.2
BIOL.
0
0
3.6
9.4
8.3
2.8
6.4
7.0
PUMP&TREAT
0
28.6
17.8
10.9
19.4
22.8
13.4
13.9
-------
TABLE 8 - PERCENTAGES OF SPECIFIC TECHNOLOGIES SELECTED FOR METALS PER FISCAL YEAR
;l;:;i;;;REMjSW::;(GROUPS
DISPOSAL
SITE CONTAINMENT
PHYSICAL/CHEMICAL
THERMAL
BIOLOGICAL
PUMP & TREAT
TECHNOLOGY ! .;.:• 'X^^.^;* :•: •;
DISPOSAL CAP ON-SITE
DISPOSAL OFF-SITE CONTAINMENT
IN-SITU/CONSOLIDATING RCRA CAP
SLURRY WALL
GAC ONLY IN LIQUID PHASE
CRITICAL FLUID EXTRACTION
AIR STRIP ONLY
OFF-SITE CHEMICAL PRECIPITATION
AIR STRIP/GAC POLISH (VAPOR PHASE)
ON-SITE CHEMICAL PRECIPITATION
OXIDATION (INCLUDES UV AND KPEG)
VAPOR EXTRACTION/VSA ONLY
AIR STRIP/GAC POLISH (LIQUID PHASE)
SOLIDIFICATION/STABILIZATION
SOIL WASH
VACUUM EXTRACTION/VSA WITH GAC POLISH
ON-SITE THERMAL (MOBILE, FIXED)
OFF-SITE THERMAL
VITRIFICATION
OFF-SITE TREATMENT AT POTW OR PRIVATE
BIOLOGICAL LAND TREATMENT
GROUND WATER PUMP AND TREAT
NO ACTION OR NON-TECHNICAL SOLUTIONS
1982
18.2
27.3
27.3
18.2
9.1
1983
14.3
28.6
14.3
14.3
28.6
1984
14.3
35.7
10.7
3.6
7.1
7.1
3.6
10.7
7.1
FISCAL YEAR
1985
25.0
26.6
7.8
3.1
3.1
1.6
1.6
3.1
1.6
6.2
9.4
9.4
1986
18.0
9.7
15.3
5.6
6.9
1.4
1.4
1.4
1.4
8.3
2.8
5.6
2.8
12.5
6.9
1987
14.3
2.8
20.0
4.3
4.3
2.8
5.7
5.7
-
11.4
2.8
1.4
1.4
14.3
8.6
1988
14.0
4.4
19.7
5.1
8.3
2.5
1.9
1.3
1.3
1.9
1.3
4.4
1.9
7.0
4.4
0.6
2.5
3.8
8.9
4.4
1989
10.1
8.2
15.2
0.6
4.4
0.6
1.9
1.9
0.6
1.3
1.9
4.4
6.3
3.8
2.5
8.2
5.7
1.3
1.3
5.7
7.0
7.0
-------
TABLE 9 - FREQUENCIES OF REMEDIES SELECTED FOR ORGANICS PER FISCAL YEAR
; ;•;;: v;;;; : REMEDY GROUPS! ; :;V:
DISPOSAL
SITE CONTAINMENT
PHYSICAL/CHEMICAL
THERMAL
BIOLOGICAL
PUMP & TREAT
•;£:mi-'^?:-.- •"•:-:" TECHNOLOGY •••;• : :v,v; :i ^'-
DISPOSAL CAP ON-SITE
DISPOSAL OFF-SITE CONTAINMENT
IN-SITU/CONSOLIDATING RCRA CAP
SLURRY WALL
GAC ONLY IN LIQUID PHASE
CRITICAL FLUID EXTRACTION
AIR STRIP ONLY
OFF-SITE CHEMICAL PRECIPITATION
AIR STRIP/GAC POLISH (VAPOR PHASE)
ON-SITE CHEMICAL PRECIPITATION
OXIDATION (INCLUDES UV AND KPEG)
VAPOR EXTRACTION/VSA ONLY
AIR STRIP/GAC POLISH (LIQUID PHASE)
SOLIDIFICATION/STABILIZATION
SOIL WASH
VACUUM EXTRACTION/VSA WITH GAC POLISH
ON-SITE THERMAL (MOBILE, FIXED)
OFF-SITE THERMAL
VITRIFICATION
OFF-SITE TREATMENT AT POTW OR PRIVATE
BIOLOGICAL LAND TREATMENT
GROUND WATER PUMP AND TREAT
NO ACTION OR NON-TECHNICAL SOLUTIONS
y : TOTALS
1982
1
1
2
2
6
1983
1
1
1
1
1
5
1984
5
13
3
2
1
1
1
2
2
2
32
FISCAL YEAR
1985
13
14
5
1
1
3
4
5
2
48
1986
16
15
10
1
3
1
2
1
6
1
4
2
6
13
6
87
1987
9
3
15
3
2
3
3
1
6
1
4
1
10
1
62
1988
20
12
21
6
5
1
10
4
10
2
1"
3
. 3
1
8
4
15
14
140
1989
22
13
26
1
10
1
3
7
6
15
4
2
8
4
1
5
10
6
144
TOTALS
87
72
82
16
21
5
4
24
1
11
38
8
3
19
13
2
26
4
56
32
524
-------
TABLE 10 - PERCENTAGES OF REMEDY GROUPS SELECTED FOR ORGANICS PER FISCAL YEAR
FISCAL YEAR
1982
1983
1984
1985
1986
1987
1988
1989
DISPOSAL
33.3
40.0
56.2
56.2
35.6
19.4
22.6
24.3
CONTAIN,
66.7
15.6
12.5
12.6
29.0
19.3
18.8
REMEPY GROUPS
PHYS./CHEM,
20.0
6.2
2.1
16.1
25.8
23.6
33.3
/THERMAL
3.1
6.2
6.9
6.4
5.0
9.0
;-.v:BIQL'.x;r
6.2
8.3
6.9
1.6
8.6
3.5
PUMP&TREAT
40.0
12.5
14.6
21.8
17.7
20.7
11.1
-------
TABLE 11 - PERCENTAGES OF SPECIFIC TECHNOLOGIES SELECTED FOR ORGANICS PER FISCAL YEAR
REMEDY GROUPS
DISPOSAL
SITE CONTAINMENT
PHYSICAL/CHEMICAL
THERMAL
BIOLOGICAL
PUMP & TREAT
TECHNOLOGY ;
DISPOSAL CAP ON-SITE
DISPOSAL OFF-SITE CONTAINMENT
IN-SITU/CONSOLIDATING RCRA CAP
SLURRY WALL
GAC. ONLY IN LIQUID PHASE
CRITICAL FLUID EXTRACTION
AIR STRIP ONLY
OFF-SITE CHEMICAL PRECIPITATION
AIR STRIP/GAC POLISH (VAPOR PHASE)
ON-SITE CHEMICAL PRECIPITATION
OXIDATION (INCLUDES UV AND KPEG)
VAPOR EXTRACTION/VSA ONLY
AIR STRIP/GAC POLISH (LIQUID PHASE)
SOLIDIFICATION/STABILIZATION
SOIL WASH
VACUUM EXTRACTION/VSA WITH GAC POLISH
ON-SITE THERMAL (MOBILE, FIXED)
OFF-SITE THERMAL
VITRIFICATION
OFF-SITE TREATMENT AT POTW OR PRIVATE
BIOLOGICAL LAND TREATMENT
GROUND WATER PUMP AND TREAT
NO ACTION OR NON-TECHNICAL SOLUTIONS
1982
16.7
16.7
33.3
33.3
1983
20.0
20.0
20.0
20.0
20.0
1984
15.6
40.6
9.4
6.2
3.1
3.1
3.1
6.2
6.2
6.2
FISCAL YEAR
1985
27.1
29.2
10.4
2.1
2.1
6.2
8.3
10.4
4.2
1986
18.4
17.2
11.5
1.1
3.4
1.1
2.3
1.1
6.9
1.1
4.6
2.3
6.9
14.9
6.9
1987
14.5
4.8
24.2
4.8
3.2
4.8
4.8
1.6
9.7
1.6
6.4
1.6
16.1
1.6
1988
14.3
8.6
15.0
4.3
3.6
0.7
7.1
2.8
7.1
1.4
0.7
2. 1
2.1
0.7
5.7
2.8
10.7
10.0
1989
15.3
9.0
18.0
0.7
6.9
0.7
2.1
4.9
4.2
10.4
2.8
0.7
5.6
2.8
0.7
3.5
6.9
4.2
-------
TABLE 12 - FREQUENCIES OF REMEDIES SELECTED FOR PCBS PER FISCAL YEAR
; REMEDY:; GROUPS
DISPOSAL
SITE CONTAINMENT
PHYSICAL/CHEMICAL
THERMAL
BIOLOGICAL
PUMP & TREAT
TECHNOLOGY :
DISPOSAL CAP ON-SITE
DISPOSAL OFF-SITE CONTAINMENT
IN-SITU/CONSOLIDATING RCRA CAP
SLURRY WALL
GAC ONLY IN LIQUID PHASE
CRITICAL FLUID EXTRACTION
AIR STRIP ONLY
OFF-SITE CHEMICAL PRECIPITATION
AIR STRIP/GAC POLISH (VAPOR PHASE)
ON-SITE CHEMICAL PRECIPITATION
OXIDATION (INCLUDES UV AND KPEG)
VAPOR EXTRACTION/VSA ONLY
AIR STRIP/GAC POLISH (LIQUID PHASE)
SOLIDIFICATION/STABILIZATION
SOIL WASH
VACUUM EXTRACTION/VSA WITH GAC POLISH
ON-SITE THERMAL (MOBILE, FIXED)
OFF-SITE THERMAL
VITRIFICATION
OFF-SITE TREATMENT AT POTW OR PRIVATE
BIOLOGICAL LAND TREATMENT
GROUND WATER PUMP AND TREAT
NO ACTION OR NON-TECHNICAL SOLUTIONS
•'•:::-::.'--O: -;•- ^••*- 1--- '•' -•• .-• - ' .TOTALS
1982
1
1
2
1983
2
2
1984
3
6
3
2
1
1
16
FISCAL YEAR
1985
4
12
2
1
1
1
1
1
3
2
4
32
1986
3
3
4
1
2
2
4
1
4
24
1987
3
2
4
1
1
1
2
5
2
21
1988
10
6
8
2
3
1
3
5
5
1
3
47
1989
6
6
13
1
2
1
1
5
3
1
7
6
1
1
3
2
50
TOTALS
29
38
35
5
5
1
6
1
1
13
4
1
22
17
1
3
1
17
3
203
-------
TABLE 13 - PERCENTAGES OF REMEDY GROUPS SELECTED FOR PCBS PER FISCAL YEAR
FISCAL YEAR
1982
1983
1984
1985
1986
1987
1988
1989
DISPOSAL
50.0
100.0
56.2
50.0
25.0
23.8
34.0
20.3
J CONTAIN.
50.0
18.8
6.2
20.8
23.8
21.3
23.7
REMEDY GROUPS
PHYS./CHEM.
12.5
16.7
19.0
14.9
22.0
THERMAL
12.5
12.5
20.8
23.8
21.3
23.7
BIOL,
6.2
2.1
1.7
PUMP&TREAT
12.5
12.5
16.7
9.5
6.4
8.5
-------
TABLE 14 - FREQUENCIES OF REMEDIES SELECTED FOR PESTICIDES PER FISCAL YEAR
; REMEDY GROUPS:
DISPOSAL
SITE CONTAINMENT
PHYSICAL/CHEMICAL
THERMAL
BIOLOGICAL
PUMP & TREAT
•:::::,v;:--';:-: ;-'•-. /• ^ '""'.:,' TECHNOLOGY ••'•.•'-. - -•• ,;,
DISPOSAL CAP ON-SITE
DISPOSAL OFF-SITE CONTAINMENT
IN-SITU/CONSOLIDATING RCRA CAP
SLURRY WALL
GAC ONLY IN LIQUID PHASE
CRITICAL FLUID EXTRACTION
AIR STRIP ONLY
OFF-SITE CHEMICAL PRECIPITATION
AIR STRIP/GAC POLISH (VAPOR PHASE)
ON-SITE CHEMICAL PRECIPITATION
OXIDATION (INCLUDES UV AND KPEG)
VAPOR EXTRACTION/VSA ONLY
AIR STRIP/GAC POLISH (LIQUID PHASE)
SOLIDIFICATION/STABILIZATION
SOIL WASH
VACUUM EXTRACTION/VSA WITH GAC POLISH
ON-SITE THERMAL (MOBILE, FIXED)
OFF-SITE THERMAL
VITRIFICATION
OFF-SITE TREATMENT AT POTW OR PRIVATE
BIOLOGICAL LAND TREATMENT
GROUND WATER PUMP AND TREAT
NO ACTION OR NON-TECHNICAL SOLUTIONS
f'>'r:l:.;:v- • .:::\, . ,. • • ' :: ::': ..,-.,•• ' TOTALS
1982
1
1
2
1983
1
3
4
1984
3
5
2
1
2
1
2
2
18
FISCAL YEAR
1985
1
3
2
1
1
8
1986
1
2
2
1
1
2
1
10
1987
3
1
2
1
1
1
1
1
1
4
16
1988
1
2
1
1
1
1
1
1
1
1
1
1
2
15
1989
1
5
4
1
1
2
1
1
1
1
2
2
3
2
27
TOTALS
11
19
15
6
4
3
2
1
2
2
2
2
4
4
1
4
2
13
3
100
-------
TABLE 15 - PERCENTAGES OF REMEDY GROUPS SELECTED FOR PESTICIDES PER FISCAL YEAR
FISCAL YEAR
1982
1983
1984
1985
1986
1987
1988
1989
PISPQSAti:
100.0
44.4
50.0
30.0
25.5
6.7
22.2
ICQNTAIN.
100.0
16.7
25.0
30. 0
18.6
20.0
18.5
REMEDY GROUPS
PHYS;/CHEMv
11. i
18.8
40.0
25.9
THERMAL
5.6
12.5
6.2
13.3
14.8
BIOL.
11.1
12.5
10.0
6.2
6.7
PUMP&TREAT
il.l
30.0
25.0
13.3
18.5
-------
TABLE 16 - FREQUENCIES OF REMEDIES SELECTED FOR CYANIDE PER FISCAL YEAR
REMEDY GROUPS
DISPOSAL
SITE CONTAINMENT
PHYSICAL/CHEMICAL
THERMAL
BIOLOGICAL
PUMP 6 TREAT
TECHNOLOGY
DISPOSAL CAP ON-SITE
DISPOSAL OFF-SITE CONTAINMENT
IN-SITU/CONSOLIDATING RCRA CAP
SLURRY WALL
GAC ONLY IN LIQUID PHASE
CRITICAL FLUID EXTRACTION
AIR STRIP ONLY
OFF-SITE CHEMICAL PRECIPITATION
AIR STRIP/GAC POLISH (VAPOR PHASE)
ON-SITE CHEMICAL PRECIPITATION
OXIDATION (INCLUDES UV AND KPEG)
VAPOR EXTRACTION/VSA ONLY
AIR STRIP/GAC POLISH (LIQUID PHASE)
SOLIDIFICATION/STABILIZATION
SOIL WASH
VACUUM EXTRACTION/VSA WITH GAC POLISH
ON-SITE THERMAL (MOBILE, FIXED)
OFF-SITE THERMAL
VITRIFICATION
OFF-SITE TREATMENT AT POTW OR PRIVATE
BIOLOGICAL LAND TREATMENT
GROUND WATER PUMP AND TREAT
NO ACTION OR NON-TECHNICAL SOLUTIONS
TOTALS
1982
0
1983
1
1
1984
2
1
3
FISCAL YEAR
1985
1
1
1
3
1986
1
1
1
3
1987
0
1988
1
3
2
1
1
2
2
1
13
1989
1
1
1
3
TOTALS
3
8
2
2
2
3
1
3
2
26
-------
TABLE 17 - PERCENTAGES OF REMEDY GROUPS SELECTED FOR CYANIDE PER FISCAL YEAR
FISCAL YEAR
1982
1983
1984
1985
1986
1987
1988
1989
.DISPOSAL
100.0
66.7
33.3
33.3
30.8
66.7
CONTAIN.
15.4
REMEDY GROUPS
PHYS./CHEM.
66.7
33.3
30.8
THERMAL
33.3
BIOLV
PUMP&TREAT
33.3
23.1
33.3
-------
TABLE 18 - FREQUENCIES OF REMEDIES SELECTED FOR ASBESTOS PER FISCAL YEAR
i: jREMEDT GROUPS
DISPOSAL
SITE CONTAINMENT
PHYSICAL/CHEMICAL
THERMAL
BIOLOGICAL
PUMP & TREAT
TECHNOLOGY-
DISPOSAL CAP ON-SITE
DISPOSAL OFF-SITE CONTAINMENT
IN-SITU/CONSOLIDATING RCRA CAP
SLURRY WALL
GAC ONLY IN LIQUID PHASE
CRITICAL FLUID EXTRACTION
AIR STRIP ONLY
OFF-SITE CHEMICAL PRECIPITATION
AIR STRIP/GAC POLISH (VAPOR PHASE)
ON-SITE CHEMICAL PRECIPITATION
OXIDATION (INCLUDES UV AND KPEG)
VAPOR EXTRACTION/VSA ONLY
AIR STRIP/GAC POLISH (LIQUID PHASE)
SOLIDIFICATION/STABILIZATION
SOIL WASH
VACUUM EXTRACTION/VSA WITH GAC POLISH
ON-SITE THERMAL (MOBILE, FIXED)
OFF-SITE THERMAL
VITRIFICATION
OFF-SITE TREATMENT AT POTW OR PRIVATE
BIOLOGICAL LAND TREATMENT
GROUND WATER PUMP AND TREAT
NO ACTION OR NON-TECHNICAL SOLUTIONS
TOTALS
1982
0
1983
1
1
2
1984
0
FISCAL YEAR
1985
1
1
1986
0
1987
1
1
2
1988
2
1
2
1
2
1
9
1989
1
1
3
-5
TOTALS
5
3
7
1
2
1
19
-------
TABLE 19 - PERCENTAGES OF REMEDY GROUPS SELECTED FOR ASBESTOS PER FISCAL YEAR
FISCAL YEAR
1982
1983
1984
1985
1986
1987
1988
1989
DISPOSAL
50.0
100.0
50.0
33.3
40.0
CONTAIN.
50.0
50.0
22.2
60.0
REMEDY GROUPS
PHYS./CHEM.
11. 1
THERMAL
BIQL.
PUMP&TREAT
33.3
-------
TABLE 20 - FREQUENCIES OF REMEDIES SELECTED FOR RADIONUCLIDES PER FISCAL YEAR
REMEDY: GROUPS
DISPOSAL
SITE CONTAINMENT
PHYSICAL/CHEMICAL
THERMAL
BIOLOGICAL
PUMP & TREAT
TECHNOLOGY
DISPOSAL CAP ON-SITE
DISPOSAL OFF-SITE CONTAINMENT
IN-SITU/CONSOLIDATING RCRA CAP
SLURRY WALL
GAC ONLY IN LIQUID PHASE
CRITICAL FLUID EXTRACTION
AIR STRIP ONLY
OFF-SITE CHEMICAL PRECIPITATION
AIR STRIP/GAC POLISH (VAPOR PHASE)
ON-SITE CHEMICAL PRECIPITATION
OXIDATION (INCLUDES UV AND KPEG)
VAPOR EXTRACTION/VSA ONLY
AIR STRIP/GAC POLISH (LIQUID PHASE)
SOLIDIFICATION/STABILIZATION
SOIL WASH
VACUUM EXTRACTION/VSA WITH GAC POLISH
ON-SITE THERMAL (MOBILE, FIXED)
OFF-SITE THERMAL
VITRIFICATION
OFF-SITE TREATMENT AT POTW OR PRIVATE
BIOLOGICAL LAND TREATMENT
GROUND WATER PUMP AND TREAT
NO ACTION OR NON-TECHNICAL SOLUTIONS
TOTALS
1982
0
1983
0
1984
0
FISCAL YEAR
1985
1
1
1986
3
3
1987
5
5
1988
1
1
1989
4
4
TOTALS
13
1
14
-------
TABLE 21 - PERCENTAGES OF REMEDY GROUPS SELECTED FOR RADIONUCLIDES PER FISCAL YEAR
FISCAL YEAR
1982
1983
1984
1985
1986
1987
1988
1989
DISPOSAL
100.0
100.0
100.0
100.0
• CONTAIN;
REMEDY GROUPS
PHYS . /CHEM .
THERMAL
: BIOL.
PUMP&TREAT
100.0
-------
TABLE 22 - FREQUENCIES OF REMEDIES SELECTED FOR ACIDS/ALKALIS PER FISCAL YEAR
-REMEDY ; GROUPS
DISPOSAL
SITE CONTAINMENT
PHYSICAL/CHEMICAL
THERMAL
BIOLOGICAL
PUMP & TREAT
w;,v •;:;•: •:,:*•••;.. ,'v: TECHNOLOGY" • - ; - ; "...i;- -:•.".
DISPOSAL CAP ON-SITE
DISPOSAL OFF-SITE CONTAINMENT
IN-SITU/CONSOLIDATING RCRA CAP
SLURRY WALL
GAC ONLY IN LIQUID PHASE
CRITICAL FLUID EXTRACTION
AIR STRIP ONLY
OFF-SITE CHEMICAL PRECIPITATION
AIR STRIP/GAC POLISH (VAPOR PHASE)
ON-SITE CHEMICAL PRECIPITATION
OXIDATION (INCLUDES UV AND KPEG)
VAPOR EXTRACTION/VSA ONLY
AIR STRIP/GAC POLISH (LIQUID PHASE)
SOLIDIFICATION/STABILIZATION
SOIL WASH
VACUUM EXTRACTION/VSA WITH GAC POLISH
ON-SITE THERMAL (MOBILE, FIXED)
OFF-SITE THERMAL
VITRIFICATION
OFF-SITE TREATMENT AT POTW OR PRIVATE
BIOLOGICAL LAND TREATMENT
GROUND WATER PUMP AND TREAT
NO ACTION OR NON-TECHNICAL SOLUTIONS
TOTALS
1982
1
1
1983
1
1
1984
1
1
1
1
1
5
FISCAL YEAR
1985
1
1
2
1986
2
1
1
4
1987
0
1988
1
1
2
1989
1
1
TOTALS
4
4
2
1
1
1
3
16
-------
TABLE 23 - PERCENTAGES OF REMEDY GROUPS SELECTED FOR ACIDS/ALKALIS PER FISCAL YEAR
FISCAL YEAR
1982
1983
1984
1985
1986
1987
1988
1989
DISPOSAL
100.0
40.0
100.0
50.0
50.0
CONTAIN.
100.0
20.0
50.0
v REMEDY GROUPS
PHYS./CHEM.
25.0
THERMAL
BIOL.
PUMPfcTREAT
40.0
25.5
100.0
-------
200 1
M
o
o
DC
3
150-
100 -
1982 1983 1984 1985 1986 1987 1988 1989
Fiscal Year
Figure 1
Yearly Number of RODs Issued
-------
Solvents
Metals
Organlcs
PCBs
Pesticides
Cyanide
Asbestos
Radio Nuc.
Acids/Alks.
369
100
200
300
400
Figure 2
Frequencies of Contaminant Occurrences Identified
-------
40.0% n
«
u
30.0% H
20.0%-
10.0% H
0.0%
• Solvents/VOCs
D Metals
H Organics
0 PCBs
m Pesticides
• Cyanide
El Asbestos
H Radlonuclldes
m Acids/Alkalis
1982 1983 1984 1985 1986 1987 1988 1989
Fiscal Year
Figure 3
Percentages of Contaminant Occurences
Identified in ROD's per Fiscal Year
-------
Year
1989
1300
1007
IQflfi
1985
1984
1983
1982
DISPOSAL
<\^ i i , * , i n >* J 27
r ,v,v,vJ26
f, , i , , , >••>>>!>>>>>>>& 37
(v////////A-,v,v/,v////J49
< 4 48
^ d8 5
yx^y^/x/y/x/^y////^x/xx//x/ ,^9f
10 20 30 40 SO
% of Time Remedy Was Selected
60
Year
10 20 30
% ol Time Remedy Was Selected
Year
PHYSICAL/CHEMICAL
34
10 20 30
% ol Time Remedy Was Selected
Year
1989
1988
1987
1986
1985
1984
1983
1982
THERMAL
10
11
11
¥
14
10
% ol Time Remedy Was Selected
20
Year
PUMP & TREAT
2468
% of Time Remedy Was Selected
10
Year
% ol Time Remedy Was Selected
Figure 4
Percentages of Selected Remedies Identified in RODs per Fiscal Year
-------
•o
0)
0)
(0
Q.^
O «
2
3 >» k.
O) O 0)
JZ O 0.
"5 M
C Q
O
*_
O
I
JB3A
-------
REFERENCES
Arbuckle, J. G., et al., Environmental Law Handbook - Tenth Edition. Govern-
ment Institutes, Inc., Rockville, Maryland, 1989.
Doty, C. B., and C. C. Travis, "The Superfund Remedial Action Decision
Process: A Review of Fifty Records of Decision," The Journal of the Air &
Haste Management Association. Volume 39, No. 12, 1989.
ERT, Inc. and Sidley & Austin, Suoerfund Handbook. Concord, Massachusetts, and
Chicago, Illinois, 1987.
Hazardous Waste Treatment Council et al., Right Train. Wrong Track: Failed
Leadership in the Superfund Cleanup Program. A Comprehensive Environmental
Industry Report of Recent Cleanup Decisions. 1988.
JRB Associates et al., Guidance Document for Feasibility Studies Under CERCLA.
prepared for U.S. Environmental Protection Agency and Office of Emergency and
Remedial Response, McLean, Virginia, 1984.
McKinney, J. A., et al., PRP Organization Handbook. A Guide for Potentially
Responsible Parties At Superfund Sites. Morgan, Lewis & Bockius, Washington,
DC, 1989.
White, D. C., et al., "Summary of Hazardous Waste Treatment at Superfund
Sites," Special Analysis, Environment Reporter. Washington, DC, 1987.
-------
APPENDIX A
-------
DESCRIPTIONS OF LISTED CONTAMINANTS AND REMEDIES
CONTAMINANTS
1. Solvents/VOCs
Group of chemicals that represent commonly found aromatics and short-chain
aliphatic hydrocarbons used primarily for solvent purposes. This group
includes benzene, xylene, toluene, trichloroethylene, dichloroethylene,
dichloroethane, tetrachloroethylene, trichloroethane, etc.
2. Metals
Compounds containing metallic elements including arsenic, barium, cadmium,
chromium, lead, mercury, nickel, and nitrates.
3. Oroani cs/Petrochemi cals
Organic chemicals that are not solvents, pesticides, or polychlorinated
biphenyl including references made to oils and petroleum products.
4. PCBs
Family of chemicals known collectively as polychlorinated biphenyls in its
various forms.
5. Pesticides
Chemicals identified either specifically or generally as insecticides, herbi-
cides, or pesticides, e.g., DDT, 2,4,T, etc.
6. Cyanide
Cyanide-bearing wastes.
7. Asbestos
Asbestos-bearing wastes.
8. Radionuclides
Wastes that contain any radioactive material.
9. Acids/Alkalis
Waste products noted as having a strong acidic or alkaline content.
-------
REMEDIES
General Methods
1. Disposal
On-site or off-site disposal of waste material or treated residue in a land-
based unit that meets RCRA standards.
2. Containment
Methods to contain residue on site from further off-site migration by means of
preventing surface water or groundwater from penetrating the current disposal
unit, e.g., RCRA cap and slurry wall.
3. Physical/Chemical
Technical methods of removing or concentrating contaminants from soil or water
except thermal methods.
4. Thermal
Method that uses heat energy to destroy contaminants or to encapsulate them in
liquid or solid forms.
5. Biological
Standard biological treatment methods such as disposal in wastewater treatment
facilities (public or privately owned treatment works [POTN]), and on- or
off-site biodegradation methods.
6. Pump and Treat
General methods of treating groundwater or leachate by pumping the liquid and
using an as yet undefined means of treating the material.
Technologies
1. Disposal Off-Site Containment
Disposal of hazardous waste or treated waste residue at an off-site facility
that complies with RCRA disposal requirements.
2. Disposal On-Site Containment
Disposal of hazardous waste or treated waste residue at an on-site waste
treatment facility that complies with RCRA disposal requirements.
3. RCRA Cap
Methods used to prevent the percolation of surface water through the soil and
waste material into the subsurface environment, by managing the surface water
flow and making the overburden impermeable to rain water.
-------
4. Slurry Hall
Methods used to prevent subsurface waters from penetrating a cell that con-
tains waste materials or treated residues, usually used in conjunction with a
RCRA cap.
5. Groundwater Pump and Treat
General methods of treating groundwater or leachate by pumping the liquid and
using an as yet undefined means of treating the material.
6. Air Strip Only
Methods used to introduce large quantities of air into water contaminated with
VOCs in order to remove them through volatilization.
7. Air Strio/GAC Polish (Liquid Phase)
Air stripping method tied into a granular activated carbon (GAC) bed for the
purpose of'reducing VOCs to a level where the treated water may be introduced
into a water system or water body requiring low levels of VOCs.
8. Air Strip/GAC Polish (Vapor Phase)
Air stripping method where off-gas discharge is tied into a GAC bed for the
purpose of reducing any VOCs from impacting ambient air quality.
9, Granular Activated Carbon (GAC)
Method used to absorb organic compounds from liquids or vapors through the use
of a filtering bed.
10. Off-Site Treatment at a PQTN
Method used to collect groundwater or leachate at a site and to discharge it
to a sewage treatment plant where it will undergo standard biological treat-
ment.
11. Solidi fi cation/Stablllzation
Methods used to combine wastes with chemicals and/or concrete to create a
matrix that prevents contaminants from leaching into the surrounding soil or
water.
12. On-Site Thermal
Methods where heat is applied to vaporize or incinerate waste materials at an
on-site unit (either mobile or fixed). Residue from this process may be
disposed either on site or off site in a properly designed facility.
-------
13. Off-Site Thermal
Methods where high heat is applied to incinerate waste materials at a fixed
off-site unit. Residue from this process is typically disposed off-site in a
properly designed facility.
14. Vitrification
A high-thermal technology used to vitrify materials either in situ or at a
fixed facility in order to immobilize and/or detoxify the material for in-
place disposal or possible re-use.
15. Vacuum Extraction/Volatile Soil Aeration
Physical means of aerating soil media to remove volatile contaminants.
16. Vacuum Extraction/Volatile Soil Aeration/GAC Polish
Physical means of aerating soil media to remove volatile contaminants accom-
panied by GAC treatment of the off-gases.
17. Soil Hashing
Process that utilizes water or some other type of solvent to remove soluble
contaminants from the soil.
18. Biological Land Treatment
Methods that utilize microorganisms to enhance the natural degradation of
organic contaminants.
19. On-Site Chemical Precipitation
Methods that utilize chemical coagulants to precipitate metals from contamin-
ated liquids at an on-site facility.
20. Off-Site Chemical Precipitation
Methods that utilize chemical coagulants to precipitate metals from contamin-
ated liquids at an off-site facility.
21. Oxidation
Technologies (including UV/ozone and chemical dechlorination—KPEG process)
that are used to oxidize a contaminant to a lower chemical state that is
deemed to be less toxic.
22. Critical Fluid Extraction
Process where contaminants are removed from a media through the use of
solvents and controlled pressure.
-------
23. No-Action ROD or Non-Technical Solutions
This category was used to stipulate the RODs that selected the "no-action"
alternative subsequent to the RI/FS process. It was also used to count non-
technical solutions such as the replacement of a water system.
------- |