Treatment Technologies
Annu
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tatus Report
TWELFTH EDITION
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Solid Waste and
Emergency Response
(5203P)
EPA-542-R-07-012
September 2007
www.epa.gov/tio
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i reatment Technologies for Site Cleanup:
Annual Status Report (Twelfth Edition)
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APPENDIX A - TREATMENT TECHNOLOGIES BY FISCAL YEAR
APPENDIX B - TREATMENT TECHNOLOGY SUMMARY MATRIX
APPENDIX C - DEFINITIONS OF SPECIFIC TREATMENT TECHNOLOGIES
APPENDIX D - TREATMENT TECHNOLOGIES: SUMMARY OF STATUS REPORT ADDITIONS,
CHANGES, AND DELETIONS
APPENDIX E - RODS SELECTING MONITORED NATURAL ATTENUATION
APPENDIX F - IDENTIFICATION OF REMEDY AND RECORD OF DECISION TYPES FOR
SUPERFUND REMEDIAL ACTIONS
APPENDIX G - REASONS FOR SHUT DOWN OF 73 GROUNDWATER PUMP AND TREAT
SYSTEMS
APPENDIX H - ON-SITE CONTAINMENT REMEDIES
INDEX
Boxes
Box 1. New in the Twelfth Edition 1-1
Box 2. In Situ and Ex Situ Treatment 1-2
Box 3. Summary of Source Control and Groundwater Remedy Types 1-3
Box 4. NPL Sites and RODS 1-4
Box 5. Evolution of Treatment Technologies 1-4
Box 6. Reporting of ROD and Project Data in the ASR 1-6
Box 7. Classifying the Status of Projects 2-4
Box 8. Definition of a Completed Project 2-4
Box 9. Source Control Remedy Types 3-1
Box 10. In Situ Chemical Treatment at Eastland Woolen Mill, Maine 3-6
Box 11. Innovative Technologies Selected From FY 2002 Through 2005 3-10
Box 12. Groundwater Remedy Types 4-1
Box 13. Sites with both Pump and Treat and Source Control Treatment Remedies .. 4-3
Box 14. Groundwater MNA 4-7
Box 15. P&T Optimization 4-14
Box 16. Information in ASR Search System 6-2
Figures
Figure 1. Actual Remedy Types at Sites on the NPL (FY 1982-2005) 2-1
Figure 2. Remedies Selected in RODs (FY 1982-2005) 2-2
Figure 3. Media Addressed in RODs (FY 1982-2005) 2-3
Figure 4. Completed Treatment Projects by Remedy Type (FY 1982 -2005).. .. 2-5
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Figures. Projects Completed for the Most Common Technologies
(FY 1982-2005) [[[ 2-6
Figure 6. Source Control RODS (FY 1982-2005) [[[ 3-2
Figure 7. Trends in Types of Source control RODS (FY 1982-2005) ............ . ............. 3-3
Figure 8. Source Control Treatment Projects (FY 1982 - 2005) ................................ 3-4
Figure 9. Source Control Treatment Projects (FY 2002 - 2005) ................................ 3-5
Figure 10. In Situ Technologies for Source Media (FY 1985-2005) ............................. 3-6
Figure 11. Status of in Situ and Ex Situ Source Treatment Projects -
Comparison Between Tenth, Eleventh and Twelfth Editions
Of the ASR (FY 1982-2005) [[[ 3-7
Figure 12. Innovative Applications of Source Treatment Technologies
(FY 1982-2005) [[[ 3-9
Figure 13. Established and innovative Source Treatment Projects
(FY 1982-2005) [[[ 3-10
Figure 14. NPL Sites with P&T, In Situ Treatment, or MNA Selected as Part
of a Croundwater Remedy (FY 1982 - 2005) ................................................ 4-2
Figure 15. RODS Selecting Croundwater Remedies (FY 1982-2005) .......................... 4-4
Figure 16. Trends in RODS Selecting Croundwater Remedies (FY 1986-2005) ......... 4-5
Figure 17. Trends in Croundwater RODS Selecting Pump and Treat
(FY 1986-2005) [[[ 4-6
Figure 18. Trends in Groundwater RODS Selecting in Situ Treatment
(FY 1986-2005) [[[ 4-7
Figure 19. In Situ Groundwater Treatment Projects (FY 1982-2005) ......................... 4-8
Figure 20. Contaminant Groups Treated by in Situ Groundwater Projects
(FY 1982-2005) [[[ 4-10
Figure 21. Status of In Situ Groundwater Treatment Projects - Comparison
Between Tenth, Eleventh and Twelfth Editions of the ASR
(FY 1982-2005) [[[ 4-11
Figure 22. Status of Groundwater Pump and Treat Projects (FY 1982-2005) ........ 4-13
Figure 23. Contaminants Most Commonly Treated by Pump and Treat
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Tables 2[
Table 1. Actual Source Control Remedy Types at NPL Sites (FY1982-2005) 3-1
Table 2. RODs Selecting Source Control Remedies
(FY 1982-2005) 3-1 Q
Table 3. Status of Source Treatment Projects by Technology
(FY 1982-2005) 3-8 §
Table 4. Contaminants Treated by Source Treatment Projects
(FY 1982-2005) 3-11
Table 5. Most Commonly Changed Source Control Technologies
(FY 1982 -2005) 3-13
Table 6. Actual Croundwater Remedy Types at NPL sites (FY 1982-2005) 4-2
Table 7. Sites with Groundwater Other Remedies (FY 1982-2005) 4-3
Table 8. RODs Selecting Croundwater Remedies
(FY 1982-2005) ..4-3
Table 9. In Situ Croundwater Treatment Projects 4-9
Table 10. Status of In Situ Croundwater Treatment Projects
by Technology (FY 1982-2005) 4-12
Table 11. Site Types for On-Site Containment Sites 5-2
Table 12. Types of Hydraulic Barriers for Conventional Caps at
Landfills/Disposal Units and Surface Contamination Sites 5-4
Table 13. Types of Vertical Engineered Barriers (FY 1982-2005) 5-8
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Notice
Preparation of this report has been funded wholly
or in part by the U.S. Environmental Protection
Agency (EPA) under contract number 68-W-02-
034. Mention of trade names or commercial
products does not constitute endorsement or
recommendation for use. A limited number of
printed copies of Treatment Technologies for Site
Cleanup: Annual Status Report (ASR), Twelfth
Edition (EPA 542-R-07-012) is available free of
charge from:
U.S. EPA/National Service Center for
Environmental Publications (NSCEP)
(800)490-9198
Fax: (301)604-3408
A portable document format (PDF) version of the
ASR is available for viewing or downloading from
the Hazardous Waste Cleanup Information (CLU-
IN) Web site at http://clu-in.orf/asr. Printed copies
of the ASR can also be ordered through that web
address, subject to availability.
The data for the ASR are available in a searchable
online database (the ASR Search System) at
htto://cft>ub. et>a. vovlasrl.
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List of Acronyms
ASR
BTEX
CC
CERCLA
CERCLIS
CFR
CLU-IN
DCE
DNAPL
ORE
EOU
EPA
ESD
FRTR
FY
LNAPL
MNA
MSW
NA/NFA
NAPL
NPL
NSCEP
Annual Status Report
Benzene, toluene, ethylbenzene, and
xylene
Construction completion
Comprehensive Environmental
Response, Compensation, and
Liability Act
Comprehensive Environmental
Response, Compensation, and
Liability Information System
Code of Federal Regulations
EPA's CLeanUp INformation system
Dichloroethene
Dense nonaqueous phase liquid
Destruction and removal efficiency
Excess, obsolete, or unserviceable
U.S. Environmental Protection
Agency
Explanation of significant differences
Federal Remediation Technologies
Roundtable
Fiscal year
Light nonaqueous phase liquid
Monitored natural attenuation
Municipal solid waste
No action/no further action
Nonaqueous phase liquid
National Priorities List
National Service Center for .
Environmental Publications
OD
S~~\ O f^~
osc
OSRTI
OSWER
OU
P&T
PAH
PCB
PCF
1 VjJ_i
PCOR
I V_>\^/I\
PDF
PRB
RA
RCRA
ROD
RPM
RSE
S/S
SARA
SVE
svoc
TCA
TCE
UV
VC
VEB
voc
Open detonation
On-Scene Coordinator
Office of Superfund Remediation
and Technology Innovation
Office of Solid Waste and Emergency
Response
Operable unit
Pump and treat
Polycyclic aromatic hydrocarbons
Polychlorinated biphenyls
Tetrachloroethene
Preliminary close-out report
Portable document format
Permeable reactive barrier
Remedial action
Resource Conservation and Recovery
Act
Record of Decision
Remedial Project Manager
Remediation System Evaluation
Solidification/stabilization
Superfund Amendments and
Reauthorization Act
Soil vapor extraction
Semivolatile organic compound
Trichloroethane
Trichloroethene
Ultraviolet
Vinyl chloride
Vertical engineered barrier
Volatile organic compound
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Executive Summary
The Twelfth Edition of Treatment Technologies for
Site Cleanup: Annual Status Report (ASR)
documents the status, achievements, and trends
associated with treatment technologies at National
Priorities List (NPL) sites for remedy decisions
between 1982 and 2005. Information collected
and analyzed for this report helps document the
progress and contributions of technologies
implemented at NPL sites. In addition to
presenting information about remedy decisions
based solely on records of decision (ROD), this
report provides data about projects that relate to
their operational status and treatment
accomplishments. The report includes information
about:
• Treatment technologies for source control: In
situ and ex situ treatment technologies for
sources of contamination (such as soil, sludge,
sediment, other solid matrix wastes, and
nonaqueous phase liquids [NAPL]).
• Treatment technologies and other remedies for
groundwater: In situ and ex situ (pump and
treat [P&T]) groundwater treatment
technologies and monitored natural attenuation
(MNA) remedies for groundwater.
• On-site containment remedies: Vertical
engineered barriers (VEB), caps, and liners used
to prevent the migration of contaminants or
contaminated media.
This edition of the ASR provides:
• Information about 192 treatment technologies
selected from fiscal year (FY) 2002 to 2005
("new" for the ASR Twelfth Edition)
• Updates to more than 1,200 projects from 1982
to 2002
• A total of 1,915 treatment technologies and 57
groundwater VEBs are included with updated
information
• Analysis of 133 on-site containment projects
("new" analysis for the ASR Twelfth Edition)
The data contained in the report were gathered
from the Comprehensive Environmental Response,
Compensation, and Liability Act Information
System (CERCLIS) for FY 1982 to 2005 (as
documented as of October 2006), from site-specific
decision documents, and online U.S.
Environmental Protection Agency (EPA) sources.
Major Findings
Use of Treatment Remedies at NPL Sites
The Superfund Amendments and Reauthorization
Act of 1986 (SARA) expressed a preference for
permanent remedies (that is, treatment) over
containment or removal and disposal in the
remediation of Superfund sites. As of September
2005, 1,536 sites had been listed on the NPL. Of
those, 307 sites, had been deleted, leaving 1,229
sites on the NPL. An additional 54 sites were
proposed for listing at that time.
• At nearly two-thirds of NPL sites (63 percent),
source control treatment, groundwater
treatment, or both, have been implemented or
are planned as a remedy for some portion of
the site.
• More than a quarter of the sites (28 percent)
selected treatment for both source control and
groundwater.
• The selected remedies do not include treatment
for 24 percent of sites.
• No ROD has been issued for 13 percent of all
NPL sites.
Some 56 percent (1,677) of all RODs analyzed for
the ASR (2,976) contained provisions for treatment
of source media or groundwater. EPA currently
tracks the status of 1,915 projects for application
of treatment technologies at Superfund sites,
including in situ and ex situ treatment projects for
both source control and groundwater. These
applications include:
• 515 ex situ source control treatment projects
(27 percent of all projects)
• 421 in situ source control treatment projects
(22 percent)
• 725 P&T projects (38 percent)
• 213 in situ groundwater treatment projects (11
percent)
• 41 in situ source control and in situ groundwater
treatment projects (2 percent)
Use of Treatment for Source Control
A total of 977 projects were planned or
implemented for the 1,104 source control
treatment RODs and ROD amendments. Those
projects include a wide range of in situ and ex situ
technologies used to address many types of
contaminants, and represent various stages of
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design and implementation. Trends and general
observations include:
• The selection of in situ treatment for source
control continues to increase. In situ source
control treatment projects represented 60
percent o( source treatment projects from FY
2002 to 2005. Cumulatively, from FY 1982
through 2005, in situ source control projects
make up 47 percent of the projects.
• From FY 2002 to 2005, projects that used in
situ technologies of multi-phase extraction and
chemical treatment are being selected at an
increasing rate compared with soil vapor
extraction (SVE) projects that are not being
selected as frequently as in past years.
• Historically, incineration projects have
represented a high percentage of ex situ source
treatment projects (29 percent reported in the
eleventh edition of the ASR for FY 1982 to
2005). During the period from FY 2002 to
2005, incineration represented only 6 percent
of ex situ treatment projects.
• In FY 2004, the percentage of projects that
selected innovative technologies reached 47
percent, nearly equaling the percentage for
established technologies. This trend continued
in FY 2005, with partial data indicating 48
percent of projects selected innovative
technologies.
• Nearly 80 percent of ex situ source control
projects are completed and 10 percent are
operational. Approximately 40 percent of in
situ source control projects are completed, while
another 40 percent are operational.
Use of Treatment for Groundwater
Of the RODs that select groundwater treatment,
18 percent (195) used in situ treatment remedies,
whereas more than 90 percent (958) used P&T
remedies. A total of 254 in situ treatment projects
and 725 P&T projects are planned or have been
implemented from those RODs. Trends and
general observations about groundwater treatment
RODs and projects include:
• RODs that select in situ groundwater treatment
have been generally increasing, from none in
FY 1982 through 1986 to a high of 31 percent
in FY 2005.
• RODs that select P&T alone have decreased
from about 80 percent before FY 1992 to an
average of 20 percent over the last 5 years (FY
2001 through 2005).
ES-
• RODs that select MNA experienced a decline
from FY 1999 to 2002, coinciding with
publication of EPA guidance on the use of
MNA in 1999. Since FY 2002, RODs that
select MNA have been increasing, with almost
half of all groundwater RODs selecting MNA
in FY 2005.
• The most common in situ technologies include
air sparging, bioremediation, chemical
treatment, permeable reactive barriers (PRB),
and multi-phase extraction. Cumulatively, air
sparging represents almost 30 percent of all in
situ groundwater treatment projects and
bioremediation represents 27 percent.
• In situ bioremediation and chemical treatment
have increased significantly in recent years, with
approximately 70 to 80 percent of these projects
selected in the past six years.
• More than 70 percent of P&T projects selected
are currently operational. Another 10 percent
have been shut down. Eighteen percent of in
situ groundwater projects have been completed,
and nearly 50 percent continue to operate.
Project Completion at NPL Sites
A total of 1,915 treatment remedies have been
planned or implemented at NPL sites. Of these
treatment remedies:
• 687 projects (36 percent) have been completed
or shut down
• 857 projects (45 percent) are operational
• 371 projects (19 percent) are being designed or
constructed
Trends and general observations about completed
projects include:
« Approximately 60 percent of all source control
projects are completed.
• Most of the completed projects are ex situ source
control treatments (57 percent) that usually
involve excavation of contaminated soil and
application of an aggressive treatment
technology in a controlled environment. Nearly
all incineration projects have been completed.
Approximately 80 percent of the solidification/
stabilization (S/S) and thermal desorption
projects have been completed.
• In situ treatments are applied to contaminated
media in place, without excavation. These
projects typically require longer treatment times
because they take place in a less controlled
environment, which may limit the treatment
rate. In situ treatment technologies represent
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those 216 projects being in situ source control
treatment only (with no groundwater
treatment).
More in situ source control projects have been
c completed than in situ groundwater projects.
For instance, approximately 65 percent of in
a) situ S/S projects and 45 percent of in situ SVE
projects have been completed. In contrast, less
o than 30 percent of air sparging for in situ
groundwater treatment have been completed.
P&T projects, which represent the largest
number of treatment projects (725), typically
r require long treatment times and represent only
;"; 11 percent of all completed and shut down
projects.
Ten percent of P&T projects have been
completed or shut down.
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Section 1: Introduction
In 1980, Congress enacted the Comprehensive
Environmental Response, Compensation, and
Liability Act (CERCLA, or Superfund) to address
the dangers of abandoned or uncontrolled
hazardous waste sites. CERCLA provides the U.S.
Environmental Protection Agency (EPA) and other
federal agencies the authority to respond to a release
or a substantial threat of a release of a hazardous
substance into the environment, or a release or
substantial threat of a release of "any pollutant or
contaminant, which may present an immediate and
substantial danger to public health or welfare."
Since the inception of the Superfund program, EPA
has responded to thousands of actual or potential
releases of hazardous substances through short-term
Or emergency removal actions and longer-term
cleanup efforts known as remedial actions. These
remedial actions, undertaken to provide more
permanent solutions to protect human health and
safety, may require years to design, implement, and
complete.
Although remedial options may include a variety
of possible remedies, ranging from containment of
wastes to treatment to institutional controls, the
Superfund Amendments and Reauthorization Act
of 1986 (SARA) expressed a preference for
permanent remedies (that is, treatment) over
containment or removal and disposal in
remediation of Superfund sites. EPA currently
tracks the status of projects where treatment
technologies are applied at National Priorities List
(NPL) sites to collect and analyze information
about the progress and contributions of
technologies that have been implemented. This
report documents the status, achievements, and
trends associated with treatment technologies at
NPL sites with remedy decisions from fiscal year
(FY) 1982 through 2005.
Reporting on the Status of
Treatment Technologies
The Twelfth Edition^of Treatment Technologies for
Site Cleanup: Annual Status Report (ASR)
documents treatment technology applications for
soil, other solid wastes, liquid wastes, and
groundwater at NPL sites. The report includes
information about:
Box 1. NEW IN THE TWELFTH EDITION
• Information about 192 treatment
technologies selected from FY 2002 to
2005 ("new" for the ASR Twelfth
Edition).
• Updates to more than 1,200 treatment
technologies selected from FY 1982 to
2002.
• A total of 1,915 treatment technologies
and 57 groundwater vertical engineered
barriers (VEBs) are included with
updated information.
• Analysis of 133 on-site containment
projects ("new" for the ASR Twelfth
Edition).
• Treatment Technologies for Source Control -
In situ and ex situ treatment technologies for
sources of contamination (such as soil, sludge,
sediment, other solid matrix wastes, and
nonaqueous phase liquids [NAPL]).
• Treatment Technologies and Other Remedies
for Groundwater - In situ and ex situ (pump
and treat [P&T]) groundwater treatment
technologies and monitored natural attenuation
(MNA) remedies for groundwater.
• Containment Remedies - Vertical engineered
barriers (VEB), caps, and liners used to prevent
the migration of contaminants or contaminated
media.
The Twelfth Edition of the ASR uses information
from the ASR Eleventh Edition (EPA 542-R-03-
009), published by EPA in February 2004, and
updated data from the following sources:
• FY 2002 decision documents (e.g., records of
decision [ROD], ROD amendments, and
Explanations of Significant Differences [ESD]).
Data includes the estimated 30 percent of
decision documents that were not included in
the ASR Eleventh Edition.
• FY 2003 decision documents.
• FY 2004 decision documents.
• FY 2005 decision documents available as of
October 2006 (an estimated 76 percent of the
total signed decision documents).
• Other sources of information, including 5-year
review reports, preliminary close-out reports
(PCOR), and online regional site summaries.
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Information about technologies and sites identified
in this report was obtained, in part, from the
CERCLA Information System (CERCLIS) as of
October 2006. Some data may differ from
information found in the CERCLIS database as a
result of review of individual decision documents,
site summaries, or other sources obtained while
preparing this report.
Treatment Technologies Included in this
Report
Remedies selected for NPL sites are documented
in RODs and ROD amendments. Throughout
the ASR, the term "RODs" is generally used
inclusively to mean both RODs and ROD
amendments. Many RODs for remedial actions
address the source of contamination, such as soil,
sludge, sediments, and solid-matrix wastes; these
"source control" RODs select "source control
remedies." A groundwater remedial action is also
known as "a non-source control action." These
actions are described in the report as "groundwater
remedies." The graphic at the right illustrates a
remedial site with source media contamination and
groundwater contamination. A ROD may include
both "source control" and "groundwater"
components. Appendix F to this document is a
detailed description of the methodology used to
classify RODs, including detailed definitions of
"source control remedies," "groundwater
remedies," and other remedy types. Box 3 provides
a summary of the remedy types presented in
Appendix F.
Box 2. IN SITU AND Ex SITU TREATMENT
In situ: In its original place; unmoved,
unexcavated; remaining at the site or in
the subsurface.
In situ treatment technologies treat or
remove the contaminant from source
media without excavation or removal of
the source media, or from groundwater
without extracting, pumping, or otherwise
removing the groundwater from the
aquifer.
Ex situ: Moved, excavated, or removed
from the site or subsurface.
Implementation of ex situ remedies
requires excavation or removal of the
contaminated source media or extraction
of groundwater from an aquifer before
treatment may occur above ground.
SITE WITH SOURCE MEDIA AND
GROUNDWATER CONTAMINATION
The term "treatment technology" means any unit
operation or series of unit operations that alters
the composition of a hazardous substance or
pollutant or contaminant through chemical,
biological, or physical means so as to reduce
toxicity, mobility, or volume of the contaminated
materials being treated. Treatment technologies
are an alternative to land disposal of hazardous
wastes without treatment (iMarch 8, 1990 Federal
Register [55 FR 8819], see Title 40 Code of Federal
Regulations [CFR] Part 300.5, "Definitions").
Information on cost and performance is often
available for treatment technologies that are
considered "established." The most frequently used
established technologies are on- and off-site
incineration, solidification/stabilization (S/S), soil
vapor extraction (SVE), and thermal desorption
for source control, and P&T technologies for
groundwater. Treatment of groundwater after it
has been pumped to the surface usually involves
traditional water treatment; as such, groundwater
P&T remedies are considered established
technologies.
Innovative technologies are alternative treatment
technologies with a limited number of applications
and limited data on cost and performance. Often,
these technologies are established in other fields,
such as chemical manufacturing. In such cases, it
is the application of a technology or process at a
waste site (to soils, sediments, sludge, and solid-
matrix waste such as mining slag, or groundwater)
that is innovative, and not the technology itself.
Innovative technologies for source control are
discussed in Section 2. Innovative technologies
for in situ treatment of groundwater are discussed
in Section 3.
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Box 3. SUMMARY OF SOURCE CONTROL AND CROUNDWATER REMEDY TYPES
SOURCE CONTROL REMEDY TYPES*
Source Control Treatment
Treatment of a contaminant source in situ or ex situ.
Q.
Can include any of the source control treatment technologies described in this o
report, such as chemical treatment and thermal desorption.
Source Control Containment
• Containment of a contaminant source.
• Can include the use of caps, liners, covers, and landfilling, both on and off site.
Source Control Other
• Other remedies for contaminant sources.
• Can include institutional controls, monitoring, and population relocation.
CROUNDWATER REMEDY TYPES*
In Situ Treatment
• Treatment of groundwater in place without extracting it from an aquifer.
• Can include any of the in situ groundwater treatment technologies identified in this
report, such as air sparging and permeable reactive barriers.
Pump and Treat (P&T)
• Extraction of groundwater from an aquifer and treatment aboveground.
• Groundwater usually is extracted by pumping from a well or trench.
• Treatment can include any of the P&T technologies described in this report, such as
air stripping and ion exchange.
Monitored Natural Attenuation (MNA)
• The reliance on natural attenuation processes (within the context of a carefully
controlled and monitored approach to site cleanup) to achieve site-specific
remediation objectives on a schedule that is reasonable compared with other
alternatives.
• Natural attenuation processes include a variety of physical, chemical, and
biological processes.
Groundwater Containment
• Containment of groundwater through a vertical, engineered, subsurface,
impermeable barrier.
• Containment of groundwater through a hydraulic barrier created by pumping.
Groundwater Other
• Groundwater remedies that do not fall into the categories of groundwater in situ
treatment, P&T, MNA, or containment remedies.
• Can include a variety of remedies, such as water use restrictions and alternative
water supply.
* See Appendix F for further definitions of Source Control and Groundwater Remedies.
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In addition to the remedy types identified in Box
3 and the classifications of remedies discussed in
Appendix F, specific treatment technologies are
discussed throughout this report. Appendix C
defines 17 types of source control (primarily soil)
treatment technologies, 9 types of in situ
groundwater treatment technologies, 8 types of
groundwater P&T technologies, and 3 on-site
containment technologies.
Framework for Discussion of Treatment
Technology Data
From FY 1982 through 2005 (including an
estimated 76 percent of FY 2005 decision
documents), 2,976 RODs and ROD amendments
were signed. Multiple RODs may be prepared for
some sites to address different areas of the site
known as operable units (OU) and different media
within a site. In addition, each OU may require a
number of RODs to address different media or
contaminants, or ROD amendments to revise the
selected remedy. Box 4 identifies the numbers of
RODs and ROD amendments issued for NPL
sites. On average, 2.3 RODs are signed for each
NPL site. While a majority of sites (53 percent of
1,309 sites for which ROD data was available) have
a single ROD, and 95 percent have 5 or fewer
RODs and ROD amendments, some sites may
have a significant number of RODs and ROD
amendments. The majority of these sites are very
large and complex federal facilities (e.g., Savannah
River [68 RODs and ROD amendments], Oak
Ridge Reservation [29], Idaho National
Engineering Lab [25], Naval Air Engineering
Center [25fand Cecil Field [24]).
Box 4. NPL
Number
of Sites
697
360
111
46
33
12
7
5
8
25
4
1
SITES AND RODs
Number of RODs and
Amendments Per Site
1
2
3
4
5
6
7
8
9
10-18
24-29
68
Box 5. EVOLUTION OF TREATMENT
TECHNOLOGIES
Driven by the need for more effective, less
costly approaches (i.e., "smarter
solutions") to clean up contaminated sites,
new remediation technologies are
developed and deployed on a continual
basis. Since the inception of the
Superfund program, several treatment
technologies have evolved from
"innovative" bench- and pilot-scale
demonstrations to commonly used
"established" technologies. As
technologies mature, their applications
become better defined and cost and
performance are documented, enabling
them to become established. With the
ongoing use of these technologies, new
needs are identified and new technologies
emerge, continuing the cycle.
For example, in the early 1980s, SVE was
considered innovative and was used
infrequently. Since then, SVE has become
an established technology, representing
26 percent of the total source control
treatment projects planned or
implemented at NPL sites from 1982 to
2005. However, data in the ASR Twelfth
Edition now indicate that projects using
innovative in situ technologies like multi-
phase extraction and chemical treatment
are being selected at an increased rate
relative to SVE over the period from 2002
to 2005.
Each ROD or ROD amendment issued for a site
or OU may result in one or more projects
consisting of treatment, contaminant, or another
remedy. Alternatively, multiple RODs and ROD
amendments may be issued for a single project over
the duration of its operation. As such, the ratio of
RODs and ROD amendments to projects varies.
The graphic on the following page illustrates an
example of a remedial approach at a site with
multiple OUs, RODs, and projects.
The remedy selected in a ROD may not be the
remedy that is actually implemented at a site.
For example, a different remedy may be used when
a treatment technology that was selected in a ROD
based on bench-scale treatability testing proves
ineffective in pilot-scale tests conducted during the
design phase. Likewise, additional contamination
may be discovered at the site during the
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EXAMPLE REMEDIAL APPROACH AT A SITE
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Box 6. REPORTING OF ROD AND PROJECT DATA IN THE ASR
ROD Data:
ROD data (remedy selection data) are reported:
• By media (source control or groundwater), or
• Grouped using a hierarchy (each ROD being listed once) under the categories
of treatment, containment, and other.
ROD data for source control are reported:
• With each of the remedies selected in a ROD classified under a specific remedy
type* (with more than one remedy identified if appropriate), or
• With all remedies selected by a single ROD grouped using a hierarchy (each
ROD being listed only once) under the categories of treatment, containment,
and other.
ROD data for groundwater are reported:
• With each of the remedies selected in a ROD classified under a specific remedy
type* (with more than one remedy identified if appropriate), or
• With all remedies selected by a single ROD grouped using a hierarchy (each
ROD being listed only once) under the categories of treatment, MNA,
containment, and other.
Project Data:
Project data portrays information about actual projects planned or underway at
NPL sites.
Each remedy is considered a single project, for which technology, status,
contaminant, and other information is provided.
Site Data:
These data combine ROD data and project-level data for all remedies at a
particular site.
Site data are reported:
• With each of the remedies selected for a site classified under a specific remedy
type* (with more than one remedy identified if appropriate), or
• With all remedies selected for a site grouped using a hierarchy (each remedy
being listed only once) under the categories of treatment, MNA, containment,
and other. These groupings may be subdivided according to media (source
control and groundwater).
*See Box 3 and Appendix F for additional information about remedy types.
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(D
Organization of the ASR Twelfth
Edition 5
The ASR Twelfth Edition consists of the following
major sections:
• Executive Summary - Summarizes the major
findings of the report.
Section 1: Introduction - Provides an
introduction to the ASR, the types of data
contained in the report, and the framework used
for reporting data.
Section 2: Overview of Data - Presents an
overview of the remedies selected in decision
documents and status of projects planned or
underway at NPL sites.
Section 3: Treatment Technologies for Source
Control - Reports data and trends associated
with remedy decisions and projects to address
contaminated source media.
Section 4: Treatment Technologies for
Groundwater - Reports data and trends
associated with remedy decisions and projects
to address contaminated groundwater.
Section 5: Report Focus Area - On-Site
Containment Remedies - Provides data and
analysis for a limited sample of on-site
containment remedies.
Section 6: References and Sources of Additional
Information - Identifies references for data used
in the development of the ASR and sources of
additional data. Note: Section 6 contains
references to online sources of ASR data and
ASR appendices not included in the print
version of the report.
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Section 2: Overview of Data
As of September 2005, 1,536 sites had been listed
on the NPL. Of those, 307 sites had been deleted,
leaving 1,229 sites on the NPL. An additional 54
sites were proposed for listing at that time.
Updated information on site listings and deletions
is available at http://www.epa.gov/superfund.
Figure 1 provides a summary of the number of NPL
sites (both current and deleted) by type of remedial
action. The types of remedies planned or under
way at each site were identified and the sites were
classified based on the most recent information
about the implementation status of the remedies.
At nearly two-thirds of NPL sites (63 percent),
source control treatment, groundwater treatment,
or both, have been implemented or are planned as
a remedy for some portion of the site. More than
a quarter of the sites (28 percent) selected treatment
for both source control and groundwater. The
selected remedies do not include treatment for 24
percent of sites. No ROD has been issued for 13
percent of all NPL sites.
For the 1,536 sites that were listed on the NPL
from 1982 through 2005:
• 2,976 RODs and ROD amendments were signed
• 1,915 treatment projects have been
implemented or are planned
As discussed in the Introduction, each ROD and
ROD amendment, and the remedies they selected,
have been classified by the remedy types identified
in Appendix F. The following text presents a brief
overview of remedies selected in RODs and the
status of projects undertaken.
Figure 1: Actual Remedy Types at Sites on the NPL
(FY 1982 - 2005)*
Total Number of Sites = 1,536
Containment and
Other (370) 24%
No Action or
No Further Action (91)
6%
Non-Treatment
Groundwater
Remedy Only (47)
3%
Other Source
Control (46)
3%
Containment or Off-Site
Disposal of a Source (186)
12%
No Decision
(204) 13%
No Remedy Decision (204)
13%
Treatment (962) 63%
Treatment of a
Source Only (178)
12%
Treatment of Both
a Source and
Groundwater (427)
28%
Treatment of
Groundwater Only (357)
23%
Treatment remedies are planned or implemented at 63 percent of NPL sites.
^Includes final or deleted NPL sices as of September 2005. Also includes information from an estimated 74
percent of FY 2005 records of decision and amendments available as of October 2006 and project data available
in CERCLIS as of October 2006.
Each NPL site is'listed only once using the following hierarchy: treatment, containment, and other. Sires with
treatment remedies may also include containment and other non-treatment remedies. Sites with containment/
disposal may include other non-treatment remedies. Other source control (described in Appendix F) includes
institutional controls and other non-treatment/non-containment remedies. Non-treatment groundwater remedies
include MNA, containment, and other remedies defined in Appendix F.
Sources: 1,2,3, 4, 7. Data sources are listed in Section 6.
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Remedies Selected in RODs
Superfund remedy decisions are documented in
RODs. ROD amendments are used to document
changes to remedies that occur after a ROD has
been signed. Figure 2 presents remedy decisions
from FY 1982 to 2005. During that period, 2,976
RODs and ROD amendments were signed
documenting groundwater and source control
remedies (as well as no action and no further
action). Since FY 1991, the number of RODs
signed per year generally decreased. Recent years
indicate that the trend may be leveling off or
beginning to increase.
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Figure 2: Remedies Selected in RODs
(FY 1982-2005)*
Total Number of RODs = 2,976
Not Yet Available for FY 2005 - 24
Treatment - 1,677
MNA (with no treatment) - 139
Containment (with no treatment or MNA) - 503
Other remedies (with no treatment, MNA, or containment) - 224
No Action or No Further Action (with no other remedy) - 433
[Total 4 13 38 68 84 77 153145 170197 173190166 190 157169155 142 159 89 104 90 129138|
200
180
160
140
120
Number
of RODs 100
80
60
40
20
82 83 84 85 86 87
89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05*
Fiscal Year (FY)
The number of RODs signed each year peaked at 197 in FY 1991, 11 years after CERCLA was enacted.
MNA = Monitored natural a nenuacion
ROD = Record of Decision (Note: Data include ROD amendments)
*Includes information from an estimated 74 percent of FY 2005 RODs and amendments available as of October
2006. The following hierarchy was used tor this figure to count RODs only once: treatment, MNA, containment,
other non-treatment remedies, and no action/no fiirthcr action.
Sources: 3, 4, 7. Data sources are listed in Section 6.
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Using the previously described hierarchy for
classifying remedies selected, the 2,976 RODs and
ROD amendments signed between FY 1982 and
2005 may be classified as:
• Treatment remedies - 1,677 (56 percent)
• MNA for groundwater (widi no treatment) - 139
(5 percent)
• Containment remedies (without treatment) - 503
(17 percent)
• Other remedies such as institutional controls or
monitoring (with no treatment, MNA, or
containment) - 224 (7 percent)
• No action or no further action (with no
treatment, MNA, containment, or other remedy)
-433 (15 percent)
RODs may include a single remedy to address source
control or groundwater or may contain multiple
remedies for both sources and groundwater within
a single OU, for multiple OUs, or across the entire
site.
Figure 3 shows the number of RODs for each fiscal
year that selected:
• Only source control remedies
• Both groundwater and source control remedies
• Only groundwater remedies
• No action or no further action remedies
Figure 3: Media Addressed in RODs
(FY 1982-2005)*
Total Number of RODs = 2,976
• Not Yet Available for FY 2005 - 24
ED No Action or No Further Action - 433
S3 Source Control Remedy Only -1,034
•B Both a Source Control and a Groundwater Remedy - 960
B3 Groundwater Remedy Only - 549
[Total 4 13 38 68 84 77 153 145 170 197 173 190 166 190 157 169 155 142 159 89 104 90 129 1381
200n
Number 120
of RODs
82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05
Fiscal Year (FY)
In most years since FY 1998, many RODs include remedies that address
both source control and groundwater media.
ROD = Record of Decision (Noce: Data include ROD amendments)
*Includes information from an estimated 74 percent of FY 2005 RODs available as of October 2006. RODs are
counted only once in this figure as appropriate.
Sources: 3,4,7. Data sources are listed in Section 6.
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Status of Superfund Remediation
Projects
Information collected and analyzed for this report
helps document the progress and contributions of
technologies implemented at NPL sites.
In addition to presenting information about
remedy decisions based on RODs and ROD
amendments, this report provides project-related
data concerning operational status and treatment
applications. This section presents a brief overview
of the progress of treatment technologies at
Superfund remedial action sites. Box 7 explains
how the status of a project is classified.
Some 56 percent (1,677) of the 2,976 RODs
analyzed for the ASR contained provisions for
treatment of source media or groundwater. EPA
currently tracks the status of 1,915 treatment
projects at NPL sites, including in situ and ex situ
treatment projects for both source control and
groundwater. These applications include:
• 515 ex situ source control treatment projects
(27 percent of all projects)
• 421 in situ source control treatment projects (22
percent)
Box 7. CLASSIFYING THE STATUS OF
PROJECTS
The Superfund cleanup process begins
with Site Discovery followed by NPL
Listing, Remedial Investigation/Feasibility
Study, ROD, Remedial Design/Remedial
Action, Construction Completion, and
NPL Deletion. These stages are based
on the site as a whole, not individual
actions (or projects) at the site. In
contrast, the ASR evaluates projects
individually based on the following
classifications. After a remedy is
selected in a ROD, the project begins in
the "predesign/dssign" phase where the
project team is formed and the design of
the remedy is developed. Additional
data may be collected and bench-scale
or pilot-scale testing may also be
conducted during this phase, if
necessary. The next phase is called
"design complete/being installed" and
continues through installation until
construction is complete. The third
phase includes the "operational" phase
where the technology is operating and
treatment is being conducted. The final
phase, "completion," occurs when
operations are ceased and the treatment
system is shut down.
• 725 P&T projects (38 percent)
• 213 in situ groundwater treatment projects (11
percent)
• 41 in situ source control and in situ groundwater
treatment projects (2 percent)
Figure 4 presents data about 687 completed treatment
projects by media (i.e., projects where treatment is
no longer under way). The term "completed" does
not necessarily indicate that treatment goals have been
achieved. Although most source control treatment
projects that are completed have achieved their
treatment goals, groundwater projects may have been
completed or shut down because of issues with the
treatment technology. These issues can include
technical problems with the equipment, continuing
sources of contamination, or may result because
concentrations have been reduced significantly but
not to the point of cleanup goals. It may therefore be
more appropriate to describe diese projects as "shut
down" rather than "completed" in this report.
Appendix G lists die 73 P&T projects that are shut
down and the teasons that were identified for making
die decision. EPA is currently gathering additional
data to better understand, across the Superfund
program, the decisions that result in the shutdown of
P&T systems. In many cases, this decision appears
to be driven by a "treatment train" approach, where
P&T is supplemented by a different remedy such as
in situ treatment or MNA
For the 1,915 treatment projects:
• 687 projects (36 percent) have been completed
or shut down
• 857 projects (45 percent) are operational
• 371 projects (19 percent) are being designed or
constructed
Box 8. DEFINITION OF A COMPLETED
PROJECT
Project completion and construction
completion (CC) are different terms used
in defining progress in Superfund. The
first refers to a specific project (for
example, a soil vapor extraction system
that has been shut down after cieanup
levels have been achieved), whereas CC
refers to construction of all remedies for
an entire site (all remedial construction at
the site has been completed). Note that
project completion does not always
indicate that all cleanup goals have been
achieved, as projects may sometimes be
shut down for other reasons.
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Most of the completed projects are ex situ source
control treatments (57 percent). Ex situ source
control projects usually involve excavation of
contaminated soil and application of an aggressive
treatment technology in a controlled environment.
Therefore, this type of remedy typically requires a
shorter amount of time to complete. Additional
information on source control projects is presented
in Section 3.
In situ treatments are applied to contaminated
media in place, without excavation. These projects
typically require longer treatment times because
they take place in a less controlled environment,
which may limit the treatment rate. In situ
treatment technologies represent approximately 31
percent of completed projects, with 170 of those
216 projects addressing in situ source control
treatment only (with no groundwater treatment).
P&T projects, which represent the largest number
of treatment projects (725), also typically require
long treatment times, and in fact represent only
11 percent of all completed and shut down projects.
The application of P&T is often limited by
environmental factors, including the rate
contaminated groundwater can be extracted from
an aquifer and the presence of continuing sources
of groundwater contamination such as DNAPLs.
Additional information on groundwater projects
is provided in Section 4.
Figure 5 shows the number of completed and shut
down projects for the most commonly used
technologies for ex situ source control, in situ source
control, in situ groundwater, and P&T. Nearly all
incineration projects have been completed.
Additionally, nearly 80 percent of the S/S (ex situ)
and thermal desorption projects have been
completed.
Approximately 64 percent of S/S projects (in situ)
and 43 percent of SVE projects have been
completed. Fewer in s/ru groundwater projects
have been completed compared to source control
projects. However, these technologies tend to be
innovative and have been selected in more recent
RODs. Ten percent of P&T projects have been
shut down.
Figure 4: Completed Treatment Projects by Remedy Type
(FY 1982 - 2005)*
Total Projects Completed = 687
Ex Situ Groundwater
Treatment (P&T) (73)
11%
In Situ Groundwater
Treatment Only (35)
5%
In Situ Source Control
Treatment Only (170)
25%
In Situ Source Control and
Groundwater Treatment (11)
2%
Ex Situ Source Control
Treatment (398)
57%
Nearly one-third of completed treatment projects are in situ technologies.
^Includes information from an estimated 74 percent ofFY2005 records of decision and amendments available as
or October 2006 and project data available in CERCLIS as of October 2006. Completed does not always
indicate that cleanup goals have been met.
Sources: 3, 4, 7. Data sources are listed in Section 6.
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Figure 5: Projects Completed for the Most Common Technologies
(FY 1982 - 2005)*
to
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Not Completed
Number of
Projects
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Section 3: Treatment
Technologies for Source
Control
Source control remedies address soil, sediment,
sludge, solid-matrix wastes, or NAPL (in other
words, the source of contamination) and do not
address groundwater directly. Source control
remedies can be delineated by the general type of
remedy specified: (1) source control treatment that
is either in situ or ex situ, (2) source control
containment that uses caps or liners, or (3) other
actions (such as population relocation or
institutional controls). Box 9 delineates source
control remedies by remedy type and provides a
description for each category.
Box 9. SOURCE CONTROL REMEDY TYPES
Source Control Treatment
• Treatment of a contaminant source in situ
or ex situ.
• Includes any of the source control
treatment technologies described in this
report, such as chemical treatment and
thermal desorption.
Source Control Containment
• Containment of a contaminant source.
• Includes the use of caps, liners, covers,
and landfilling both on and off site.
Source Control Other
• Other remedies for contaminant sources.
• Includes institutional controls, monitoring,
and population relocation.
Beyond categorization by remedy type, source
control treatment projects may be classified as 1 of
17 specific technologies. Definitions for these
remedies are presented in Appendix C. Specific
key words in decision documents determine the
remedy classification into 1 of the 17 technologies.
Keywords used to classify source control treatment
remedies are listed in Appendix F. Some of these
technologies may also be used in other applications,
such as to treat contaminated groundwater.
Technology definitions are based on the
Remediation Technologies Screening Matrix and
Reference Guide, Version 4.0, which can be viewed
at the Federal Remediation Technologies
Roundtable (FRTR) Web site at http://www. tnr.gov.
Of the 1,104 source control treatment RODs, a
total of 977 projects were planned or implemented
at 605 sites. Tables 1 and 2 provide breakdowns
of the source control remedies by sites and RODs,
respectively. The following section of this report
discusses the latest data and historical trends
associated with these RODs and source control
treatment projects.
Table 1. Actual Source Control
Remedy Types at NPL Sites
(FY 1982 - 2005)*
Total Number of Sites with a
Source Control Remedy = 1,055
Remedy Type
Treatment of a Source
Number of
Sites
605
Containment or Off-Site
Disposal of a Source
632
Other Source Control
682
*Includes final or deleted NPL sices as of September
2005. Also includes information from an estimated
74 percent of FY2005 records of decision and
amendments available as of October 2006 and project
data available in CERCLIS as of October 2006.
No hierarchy is used for this table; sites maybe
included in more than one category.
Sources: 1, 2, 3, 4, 7. Data sources are listed in
Section 6.
Table 2. RODs Selecting Source
Control Remedies
(FY 1982-2005)*
Total Number of RODs with a
Source Control Remedy = 1,994
Remedy Type
Treatment of a Source
Number of
RODs
1,104
Containment or Off-Site Disposal
of a Source
953
Other Source Control
507
ROD = Record of Decision (Note: Date include ROD
amendments)
"Includes information from an estimated 74 percent of
FY2005 RODs and amendments available as of
October 2006.
No hierarchy is used for this table; RODs and
amendments may be counted in more than one
category.
Sources: 3, 4, 7. Data sources are listed in Section 6.
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The following subsections provide information
about (1) the selection of source control remedies
and (2) technologies, status, and contaminants
treated for source control treatment projects.
Source Control RODs
Of the 2,976 RODs and amendments signed between
FY 1982 and 2005, 67 percent (1,994) addressed the
source of contamination. Figure 6 delineates source
control RODs, showing annual totals for treatment,
containment and disposal, and other categories. The
trends exhibited for all source control remedies and
source control treatment generally track with the trends
for RODs overall, with the number of source treatment
RODs ranging from 23 to 42 annually over the last 5
years. Figure 7 shows the percentage of source control
RODs of each type for each fiscal year. For Figures 6
and 7, each ROD, which may select multiple remedies,
is assigned a single remedy type based on the
classification hierarchy discussed in the Introduction
(i.e., source control treatment, source control
containment, and other). For example, RODs that
select treatment are considered "source control
treatment RODs" even though they may also have
selected additional remedies including containment or
other remedies. ''Source control containment" includes
those using containment but no treatment.
Containment RODs may also have selected other non-
treatment source control remedies. Other source
Figure 6: Source Control RODs
(FY 1982 - 2005)*
Total Number of RODs = 1,994
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180
160
140
120
Number
of RODs 10o
• Other (Institutional Controls, Monitoring, Relocation) -159
Q Containment/Disposal - 731
Treatment-1,104
Total Number of RODs
82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05*
Fiscal Year (FY)
For most years, the majority of source control RODs selected treatment.
ROD = Record of Decision (Note: Dan include ROD amendments)
"Includes information from an estimated 74percent of FY2005 RODs available as of Octoher 2006. RODs are
only counted once in this figure using the following hierarchy: source control treatment, source control
containment or disposal with no treatment, then source control other remedies only.
Sources: 3, 4, 7. Data sources are listed in Section 6.
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Figure 7: Trends in Types of Source Control RODS
(FY 1982 - 2005)*
Total Number of RODs = 1,994
100%
Percentage
of Source 50%
Control
RODs
40%
Treatment
Containment or Disposal Only
Other (Institutional Controls, Monitoring, Relocation)
V5%
82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05*
Fiscal Year (FY)
Since 1986, the percentage of source control RODs selecting treatment usually has been greater
than those for containment/disposal without treatment; however, the gap appears to be closing.
ROD = Record of Decision (Nocc: Data include ROD amendments)
"Includes information from an estimated 74 percent of FY 200$ RODs available as of October 2006.
RODs are only counted once in this figure using the following hierarchy: source control treatment, source control
containment or disposal with no treatment, then source control otlieronly.
Sources: 3, 4, 7. Data sources are listed in Section 6.
control remedies (such as institutional controls,
relocation, and others) are the only remedy type
represented in the other column.
As shown in Figure 7, from FY 1987 to 2003 (widi
the exception of FY 1997 and 2000), the percentage of
RODs including a source control treatment remedy
has equaled or exceeded the percentage of RODs with
source control containment (and no treatment). Over
the last two years, the percentage of source control
containment RODs has slightly exceeded those with
some treatment. Cumulatively:
• 55 percent of source control RODs use some
form of "treatment"
• 37 percent are "containment or disposal" RODs
that do not include "treatment"
• 8 percent are "other source remedy" and use
remedies such as institutional controls,
monitoring, or population relocation (with no
treatment or containment)
From FY 2002 to 2005, the percentage of each
type of source control remedy has remained
consistent with the cumulative percentages, with
approximate values of 51 percent treatment, 37
percent containment, and 12 percent other. The
percentage of source control treatment RODs was
generally higher from FY 1988 through 1996,
ranging from 51 percent to 73 percent, while the
percentages of containment and other source
control remedies were generally lower.
Source Control Treatment Projects
From FY 1982 through 2005, 977 treatment
projects were selected for source control. Figure 8
provides a cumulative overview of these treatment
technologies.
3-3
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Figure 8: Source Control Treatment Projects
(FY 1982-2005)*
Total Number of Projects = 977
Ex Situ Technologies (515) 53%
Physical Separation (21)
2%
Incineration (on-site) (42)
4%
Bioremediation (60)
6%
Thermal
Desorption (71)
7%
Incineration (off-site)
(105)
11%
Solidification/
Stabilization (173)
18%
In Situ Technologies (462) 47%
Soil Vapor Extraction (248)
26%
Other Ex Situ (43)
4%
Chemical Treatment - 9
Neutralization - 7
Soil Vapor Extraction - 7
Soil Washing - 6
Mechanical Soil Aeration - 4
Open Burn/Open Detonation - 4
Solvent Extraction - 4
Phytorernediation -1
Vitrification -1
Bioremediation
(53)
5%
Multi-Phase
Extraction (46)
5%
Solidification/
Stabilization (44)
5%
Chemical
Treatment (20)
2%
Flushing (17)
2%
^Thermal Treatment (14)
1%
Other In Situ (20)
2%
Neutralization - 8
Phytoremediation - 6
Mechanical Soil Aeration - 3
Vitrification - 2
Electrical Separation -1
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Cumulatively, more than half of source control treatment projects have been ex situ, although the
single most common treatment technology has been in situ soil vapor extraction.
*Includes information from an estimated 74 percent of FY 2005 records of decision and amendments available as
of October 2006 and project data available in CERCLIS as of October 2006.
Sources: 3, 4, 7. Data sources are listed in Section 6.
In Situ Versus Ex Situ Technologies
In situ treatment technologies for source control
treat or remove the contaminated medium without
excavating, pumping, or otherwise moving the
contaminated medium to the surface.
Implementation of ex situ technologies requires
excavation, dredging, or other processes to remove
the contaminated medium before treatment either
on site or off site.
As Figure 8 indicates, the most common in situ
technologies, together making up 85 percent of all
in situ source control treatment projects, are:
• SVE (248 projects, 26 percent of all source
control treatment projects)
• Bioremediation (53 projects, 5 percent)
• Multi-phase extraction (46 projects, 5 percent)
• S/S (44 projects, 5 percent)
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Figure 10: In Situ Technologies for Source Media
(FY 1985-2005)*
90%
Percentage
of Source 40% 438%
Treatment
30%
Percentage of Source Treatment
Technologies that are In Situ
Linear Trendline (In Situ Source
Treatment Projects)
78%
to
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T I I 1 I I I I I
85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05*
Fiscal Year (FY)
On average, the number of in situ treatment projects has gradually increased.
In situ remedies can reduce potential risks from waste because there is no excavation,
and can be more cost effective than ex situ technologies.
"Includes information from an estimated 74 percent of FY 2005 records of decision and amendmen r.v available ax
of October 2006 and project data available in CERCLISas of October 2006.
Sources: 3, 4, 7. Data sources are listed in Section 6.
Box 10. IN SITU CHEMICAL TREATMENT AT EASTLAND WOOLEN MILL, MAINE
In situ chemical treatment is being used to treat soil, DNAPL, and grpundwater
contamination at the Eastland Woolen Mill site in Maine. This site served as a textile mill
from 1909 to 1996 and related activities led to chlorobenzene (mono, di, tri, and tetra)
contamination in soil, groundwater, and nearby surface water. DNAPL has also been
observed at the site. A non-time critical removal action (NTCRA) was conducted between
1999 and 2003. This action removed all soil contamination above the water table and
most soil contamination, including the DNAPL, below the water table, and resulted in
decreasing groundwater contamination levels. However, since contamination would
remain in a few areas that were inaccessible to excavation, a ROD was signed in 2002,
which selected in situ chemical treatment to reduce the mass of contamination in the soil
and bedrock fractures to achieve groundwater restoration. Based on pilot studies that
were conducted as part of the NTCRA, iron-catalyzed sodium persulfate was determined
to be the optimal oxidant for use at this site. The in situ chemical treatment system was
constructed in September 2006 and is currently operational. Following chemical
oxidation, bioremediation may be conducted if cleanup levels are not achieved. A ROD
Amendment was issued in 2006, which eliminated two components of the original ROD
(P&T to limit the migration of contaminated groundwater and in situ flushing), because it
was determined these actions were no longer necessary following the success of the
removal action.
-------
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Figure 11: Status of In Situ and Ex Situ Source Treatment Projects - Comparison
Between Tenth, Eleventh and Twelfth Editions of the ASR
(FY 1982-2005)***
In Situ Source Treatment
Technologies
100%
60%-
Percentage
of Source
Treatment
Projects
Completed
Operational
Design Complete/
Being Installed
IPredesign/
Design
10th
Edition
(314
projects)*
11th
Edition
(364
projects)*
12th
Edition
(462
projects)***
Ex Situ Source Treatment
Technologies
10th
Edition
(425
projects)*
11th
Edition
(499
projects)*
12th
Edition
. (515
projects)**
The percentage of projects at the end of the Superfund pipeline, those completed,
has increased while the percentage of projects at the beginning of the pipeline,
in predesign/design,has decreased.
ROD = Record of Decision (Noce: Data include ROD amendment*)
""Includes information from RODs through FY 1999 available as of summer 2000.
**Includes information from an estimated 70 percent of FY 2002 RODs available as of March 2003.
***lncludcs information from an estimated 74 percent of FY 2005 RODs available as of October 2006 and
project data available in CERCLIS as of October 2006.
Sources: 3, 4, 7. Data sources are listed in Section 6.
• In situ technologies are often more cost-effective
at large sites where excavation and materials
handling for ex situ technologies can be
expensive.
• As in situ treatment technologies are used more
frequently, site managers, regulators, and other
remediation professionals are coming to accept
them as a reliable technology.
Status of Source Control Treatment Projects
Figure 11 shows the status of in situ and ex 5/ru
source control treatment projects, comparing the
projects in the Tenth Edition of the ASR (data
collected through FY 1999) and the Eleventh
Edition (data collected through March 2003) with
the Twelfth Edition (data collected through
October 2006). Based on the data in Figure 11,
in this 3-year period:
The number of completed in situ source control
projects increased from 123 to 181 (a 47 percent
increase), while completed ex situ source control
projects increased from 341 to 398 (a 17 percent
increase).
In situ source control projects completed since
the Eleventh Edition included 33 SVE, 10
bioremediation, 6 S/S, 6 multi-phase extraction,
4 chemical treatment, 3 neutralization, 2
flushing, 1 thermal treatment, 1
phytoremediation, and 1 electrical separation
project.
Ex situ source control projects completed since
the Eleventh Edition included 20 S/S, 7
bioremediation, 7 incineration (off-site), 7
physical separation, 4 thermal desorption, 2
solvent extraction, and 1 soil washing project.
-------
Table 3. Status of Source Treatment Projects by Technology
(FY 1982-2005)*
Predesign/
Technology Design
Design Complete/
Being Installed Operational
Completed Total
In Situ
Soil Vapor Extraction
Bioremediation
Multi-Phase Extraction
Solidification/Stabilization
Chemical Treatment
Flushing
Thermal Treatment
Neutralization
Phytoremediation
Mechanical Soil Aeration
Vitrification
Electrical Separation
Total
Percentage of In Situ Technologies
Percentage of All Source
Treatment Technologies
23
8
8
13
9
1
5
0
2
2
1
0
72
16%
7%
9
1
2
1
3
2
2
1
0
0
0
0
21
5%
2%
110
25
30
2
3
9
3
3
3
0
0
0
188
41%
19%
106
19
6
28
5
5
4
4
1
1
1
1
181
39%
19%
248
53
46
44
20
17
14
8
3
2
1
462
—
47%
Ex Situ
Solidification/Stabilization
Incineration (off-site)
Thermal Desorption
Bioremediation
Incineration (on-site)
Physical Separation
Chemical Treatment
Neutralization
Soil Vapor Extraction
Soil Washing
Mechanical Soil Aeration
Open Burn/Open Detonation
Solvent Extraction
Phytoremediation
Vitrification
Total
Percentage of Ex Situ Technologies
Percentage of All Source
Treatment Technologies
23
4
10
9
0
3
0
1
0
2
0
2
1
1
56
11%
6%
4
0
1
1
1
2
1
0
1
0
1
1
0
0
0
13
3%
1%
10
6
4
16
1
6
1
1
2
1
0
0
0
0
0
48
9%
5%
136
95
56
34
40
10
7
5
4
3
3
1
3
1
0
398
77%
41%
173
105
71
60
42
21
9
7
7
6
4
4
4
1
1
515
53%
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* Includes information from an estimated 74 percent ofFY 2005 records of decision and amendments available as
of October 2006 and project data available in CERCLIS as of October 2006.
Sources: 3, 4, 7. Data sources are listed in Section 6.
Please note that a comparison of the numbers in
Figure 11 may not be consistent with the ASR
Eleventh and Twelfth Editions because of projects diat
were reclassified during the collection and analysis of
data for the most recent edition.
Table 3 provides a summary of project status for each
technology type. Of the most commonly selected
(20 or more selected projects), the highest percentage
of completed projects of in situ technologies was for
S/S, while the highest completion percentage for ex
situ technologies involved incineration (on site). The
completion percentages for these technologies, along
with incineration (offsite), S/S (exsitu), and thermal
desorption, are high (above 75 percent) because they
often can be completed within months, in contrast
to in situ technologies such as SVE, which may require
years to complete remediation. In general, ex situ
projects, which can be implemented more quickly
dian in situ projects, represent a greater percentage of
completed projects.
3-8)
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Figure 12: innovative Applications of Source Treatment Technologies
(FY 1982 - 2005)*
Total Number of Projects = 240
Multi-Phase Extraction (46)
19%
Bioremediation (113)
47%
Chemical Treatment (29)
12%
Flushing (17)
7%
In Situ Thermal Treatment(14)
6%
Other InnovativeTechnologies (21)
9%
Phytoremediation - 7
Soil Washing - 6
Solvent Extraction - 4
Vitrification - 3
Electrical Separation -1
Bioremediation remains the most common innovative technology for source control treatment,
making up nearly half of all innovative technologies. In recent years, multi-phase extraction and
chemical treatment projects have been increasing (see Figure 9).
Tnc/lK/es information from an estimated 74 percent ofFY2005 records of decision and amendments available as
of October 2006 and project data available in CERCLIS as of October 2006.
Sources: 3, 4, 7. Data sources are listed in Section 6.
Innovative Applications
Innovative technologies are defined as alternative
treatment technologies that have a limited number
of applications and limited data on cost and
performance. Innovative technologies have the
potential for providing more cost-effective and reliable
alternatives for cleanup, or may offer a solution' to an
environmental problem historically considered
impossible to treat.
For example, DNAPLs historically have been difficult
to treat because of their physical and chemical
properties (relatively low solubility, high specific
gravity, and tendency to remain sorbed to organic
materials in an aquifer). They tend to sink in the
subsurface and continue to release dissolved
contaminants to surrounding media. In addition,
DNAPLs may not contact soil vapor, and therefore
are not effectively treated by technologies that
extract and treat soil vapor, such as in situ SVE.
However, innovative technologies such as in sitii
thermal treatment or in situ flushing have been
found to effectively treat DNAPLs. In other cases,
an innovative technology may be less expensive
than an established technology. It may be expensive
to treat soils deep below the ground surface by
incineration because of the amount of excavation
required to reach the soil. However, an in situ
chemical oxidation process may work effectively
at that depth, while avoiding the cost of excavation
to reach the source zone. Other reasons for
selecting innovative technologies can include a
reduction in exposure of workers to contaminated
media; and community concern about off-site
releases of contaminants, noise, or odor.
Figure 12 depicts the number and types of
innovative technologies used for source control
treatment. Innovative treatment technologies
currently account for 25 percent of all source
treatment technologies compared with the
Eleventh Edition of the ASR, where innovative
technologies made up only 21 percent. As with
the Eleventh Edition, bioremediation still
contributes nearly one half of the innovative
applications (113 projects, 47 percent). Multi-
phase extraction accounts for nearly 20 percent of
innovative technologies. This is a significant
increase in applications compared with the
Eleventh Edition, up from 8 applications to 46.
However, of the 38 projects added since the
Eleventh Edition, only 8 projects were newly
selected between FY 2002 and 2005. The
remaining 30 projects were selected prior to FY
2002 and were either reclassified because of a
revision in the categorization of this technology or
identified as a result of a more refined analysis
conducted for this edition of the report.
-------
As shown in Figure 12, some innovative
technologies, such as solvent extraction,
vitrification, and electrical separation, have been
applied few times at NPL sites. A low number of
applications of a technology does not necessarily
indicate its lack of effectiveness. In some cases,
the technology may have only recently become
available and has not had time to become widely
accepted and used at NPL sites. In other cases,
the technology may be designed for specific types
of applications, such as certain contaminants or
media. For example, energy costs for vitrification
typically are higher than for other technologies.
However, vitrification is often capable of destroying
hazardous chemicals in addition to immobilizing
radioactive contaminants when radioactive
contaminants are mixed with other hazardous
chemicals. The contaminants treated for one of
the three vitrification applications included a
mixture of radioactive and other contaminants.
Figure 13 depicts the percentage of projects selected
for innovative and established technologies for
source control by fiscal year. The figure shows that
although established technologies historically have
been the most frequently used, the frequency of
their use when compared with innovative
technologies has been gradually decreasing since
the early 1990s. The use of innovative
Box 11. INNOVATIVE TECHNOLOGIES
SELECTED FROM FY 2002 THROUGH 2005
• Bioremediation - 13 projects
• Chemical treatment - 13 projects
• Multi-phase extraction - 13 projects
• In situ thermal treatment - 5 projects
• Phytoremediation - 2 projects
• Flushing - 1 project
technologies has generally increased during that
time, with the percentage of projects that used
innovative technologies becoming nearly equal
to the percentage for established technologies for
the first time in 2004. This trend has continued
into FY 2005.
The FRTR case studies Web site (htrp://
www.frtr.gov/costpert.htm) provides detailed
information on the cost and performance of both
innovative and established technologies applied at
NPL sites. As of October 2006, the FRTR
included 383 case studies covering a wide range of
treatment technologies that are available for
viewing on line or for downloading from the FRTR
to
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Figure 13: Established and Innovative Source Treatment Projects
(FY 1982 - 2005)*
90%
80%
70%
Percentage 60%
of Source 50%
Treatment
Projects 40% "I
30%
20%
10%
0%
Established
Innovative
82 84 86 88 90 92 94 96 98 00 02 04
Fiscal Year (FY)
Recently, the percentage of projects using innovative treatment has become nearly
equal to those using more established treatment approaches.
^Includes information from an estimated 74 percent ofFY2005 records of decision and amendments available as
of October 2006 and project data available in CERCL1S as of October 2006.
Sources: 3, 4, 7. Data sources are listed in Section 6.
3-10,
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Web site. The case studies wete developed by EPA,
the U.S. Department of Defense, the U.S.
Department of Energy, the U.S. Department of
the Interior, and the National Aeronautics and
Space Administration for Superfund and non-
Superfund sites. They present available cost and
performance information for full-scale remediation
efforts and large-scale demonstration projects.
They also provide information about site
background and setting, contaminants and media
treated, technology, cost and performance, and
points of contact for the technology application.
Additional information on innovative technologies
can be found at EPA's Hazardous Waste Cleanup
Information (CLU-IN) Technology Focus area
(hfrp;//vvww.clu-in.org/techfocus/), which bundles
information for particular technologies that may
be used in a variety of applications.
Table 4. Contaminants Treated
(FY1982
Contaminants Addressed
Nine major groups of contaminants targeted by
specific technologies were analyzed for this report,
as summarized in Table 4. Compounds were
categorized (with the exceptions noted in Table 4)
as:
• Volatile organic compounds (VOC) - either
halogenated or non-halogenated
• Semivolatile organic compounds (SVOC) -
either halogenated or non-halogenated
• Polycyclic aromatic hydrocarbons (PAH)
• Benzene, toluene, ethylbenzene, and xylene
(BTEX)
• Polychlorinated biphenyls (PCS)
• Organic pesticides/herbicides
• Metals and metalloids
by Source Treatment Projects
2005)*
Bioremediation
113
51
33
33
24
17
22
Chemical Treatment 29
12
13
Multi-Phase Extraction 46
11
18
Electrical Separation
1
Flushing
17
11
Incineration
147
27
41
33
23
36
34
52
36
Mechanical Soil Aeration 7
Neutralization
Open Burn/
Open Detonation
Physical Separation
15
4
21
2
0
4
0
1
2
0
0
1
0
0
0
0
0
3
0
0
0
0
0
0
0
0
4
6
0
5
Phytoremediation
1
Soil Vapor Extraction 255 15
31
107
51
33
217
Soil Washing
Solidification/
Stabilization
Solvent Extraction
Thermal Desorption
In Situ
Thermal Treatment
Vitrification
6
217
4
71
14
3
1
17
2
21
5
0
1
18
1
17
0
g
0
13
0
24
2
I
0
13
1
15
u
1
2
16
1
8
3
0
0
7
0
12
3
1
0
20
2
33
8
3
1
35
2
16
0
2
2
180
1
0
0
1
Total Projects
977 145
175
238
155
103 124
410
104
229
The contaminants most often addressed by source control treatment are
halogenated VOCs followed by BTEX and metals.
•' Each project may treat more than one contaminant group. h Does not include PAHs.
' Docs not include BTEX. ll Does not include organic pesticides and herbicides.
* Includes information from an estimated 74 percent ofFY2005 records of decision and amendments available as of
October 2006 and project data available in CERCLIS as of October 2006.
Sources: 3,4,7. Data sources are listed in Section 6.
-------
It should be noted that projects are listed in Table 4
multiple times, once for each contaminant type
(resulting in a total number of projects that is greater
than the actual number of projects). Overall, 42
percent of the source control treatment projects
address halogenated VOCs; while 24 percent address
BTEX; and 23 percent address metals and metalloids.
The selection of treatment technologies for a site often
depends on the physical and chemical properties of
the contaminants. For example, VOCs are amenable
to treatment by certain technologies, such as SVE or
thermal desporption, because of their volatility.
Conversely, metals, which are not volatile and do not
degrade, are not usually amenable to treatment by
those technologies. S/S is most often used for
treatment of diese contaminants because metals form
insoluble compounds when combined with
appropriate additives, such as Portland cement. Some
of the more common uses of technologies for
contaminant groups are identified below.
• Halogenated VOCs, BTEX, and other non-
halogenated VOCs are treated most often by SVE.
• Non-halogenated SVOCs and PAHs are treated
most often by bioremediation.
• PCBs, organic pesticides and herbicides, and
halogenated SVOCs are treated most often by
incineration.
• Metals are treated almost exclusively by S/S. An
interesting exception is the use of bioremediation
in five projects to treat metals. Three of these
projects are in the predesign or design phase. The
odier two are operational ex situ projects.
EPA has developed the CLU-IN Contaminant Focus
area (http://www.du-in.org/concamina.ntfocus/). which
bundles information associated with cleanup of
individual contaminants and contaminant groups.
This information is presented in categories that
include Overview, Policy and Guidance, Chemistry
and Behavior, Environmental Occurrence,
Toxicology, Detection and Site Characterization,
Treatment Technologies, Conferences and Seminars,
and Other Resources. Contaminant Focus will be
continuously updated with information from federal
cleanup programs, state sources, universities,
nonprofit organizations, peer-reviewed publications,
and public-private partnerships. New contaminants
will be added on a periodic basis.
Remedy Changes
As discussed earlier, remedies selected at NPL sites
are documented in a ROD, and changes to the
original remedies can be either formally
documented or executed through clauses in the
original ROD. Remedies most often change during
the pre-design or design phase of a project when
new information about site characteristics is
discovered or when treatability studies for the
selected technologies are completed. Remedies also
may change throughout the implementation and
operation of the remedy. Source control treatment
remedies have been changed to non-treatment
remedies at approximately 130 sites. These
remedies are most often changed to excavation with
off-site disposal (and no treatment), containment,
or institutional controls. The most commonly
cited reason for changing source control treatment
to another remedy was that further site
investigation revealed that the concentration or
extent of contamination was less than expected.
Other frequently cited reasons included rising
groundwater levels that made soil treatment
impracticable, community concerns about on-site
remedies, and high costs. The Superfund program
allows EPA and state regulators the flexibility to
modify remedies as site conditions change. The
ASR tracks 977 source control treatment projects,
not including the 130 that have been changed to
non-treatment remedies. Based on a total of 1,107
source control treatment remedies (977 active plus
130 changed), 12 percent have been changed.
In 94 instances, one source control treatment
technology was replaced with a different treatment
technology. Table 5 provides information about
the most frequently changed treatment
technologies and the technologies that replaced
them, as indicated by cumulative data from FY
1982 to 2005. The source control treatment
technologies that were most frequently changed
to another treatment technology were incineration,
bioremediation, and thermal desorption. These
technologies are the second, fourth, and third most
frequently selected ex situ treatment technologies,
respectively (see Figure 8). The most common
technologies selected to replace incineration,
bioremediation, and thermal desorption were
thermal desorption (replacing incineration and
bioremediation), S/S, SVE, and incineration
(replacing bioremediation and thermal desorption).
Previous editions of the ASR included an appendix
(Appendix D) that listed all the technology changes,
additions, and deletions since the previous edition
of the ASR. Because the appendix has expanded
over time, it is now available online at http://clu-
in.org/nsr. For additional information about
remedy updates, see Updating Remedy Decisions at
Superfund sites - Summary Report FY2004 and FY
2005, February 2007 (EPA 540-R-06-074).
to
-------
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Table 5. Most Commonly Changed Source Contol Technologies
(FY 1982 - 2005)*
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Technology Initially Selected
New Treatment Technology Incineration
Thermal Desorption
Solidification/Stabilization
Soil Vapor Extraction
Incineration
Bioremediation
Chemical Treatment
Pump and Treat
Solvent Extraction
Air Sparging
Soil Washing
Physical Separation
In Situ Thermal Treatment
Total Number of Remedy Revisions
9
7
3
_
5
1
0
1
0
0
0
0
26
Bioremediation
4
3
2
5
_
0
2
0
1
0
0
1
18
Thermal Oesorption
_
1
5
5
0
1
0
0
0
1
1
0
14
Total
13
11
10
10
5
2
2
1
1
1
1
1
58
The most commonly changed source control technologies are incineration, bioremediation, and
thermal desorption. Thermal desorption also is the most frequently used "replacement" technology.
"Includes information from an estimated 74 percent of FY2005 records of decision and amendments available as
of October 2006and project data available in CERCLISas of October 2006.
Sources: 3, 4, 7. Data sources are listed in Section 6.
Conclusion
A total of 977 projects were initiated from the 1,104
source control treatment RODs. Those projects
consist of a wide range of in situ and ex situ
technologies at various stages in design and
implementation, being used to address a broad
spectrum of contaminants. Although annual
fluctuations occur, some trends and general
observations can be noted:
• The selection of in situ source control projects
continues to increase. In situ source control
treatment projects represented 60 percent of
source treatment projects from FY 2002 to
2005. Cumulatively, from FY 1982 through
2005, in situ source control projects made up
nearly 50 percent of the projects.
• From FY 2002 to 2005, in situ technologies of
multi-phase extraction and chemical treatment
are being selected at an increasing rate compared
with SVE, which is not being selected as
frequently as in previous years.
• Historically, incineration projects have
represented a high percentage of ex situ source
treatment projects (29 percent reported in the
eleventh edition of the ASR for FY 1982 to
2002). During the period from FY 2002 to
2005, incineration represented only 6 percent
of ex situ treatment projects.
• In FY 2004, the percentage of projects that
selected innovative technologies reached 47
percent, nearly equaling the percentage for
established technologies. This trend continued
in FY 2005, with available data indicating 48
percent of projects selected innovative
technologies.
-------
Section 4: Treatment
Technologies for
Groundwater
Groundwater remedies are delineated by the type
of remedy specified: (1) in situ treatment, (2)
extraction of groundwater followed by
aboveground treatment (P&T), (3) MNA, (4)
containment using subsurface VEBs, or (5) other
actions (such as alternative drinking water supplies
or drilling prohibitions). Box 12 delineates
groundwater remedies by type and provides a
description for each category. Remedies for source
media (such as soil, sediment, solids, and NAPL),
discussed in a previous section, fall into similar
categories.
Beyond categorization by remedy type,
groundwater treatment projects may be classified
as 1 of 17 specific technologies. Definitions for
these remedies are presented in Appendix C.
Specific key words in decision documents
determine classification into 1 of the 17
technologies (9 in situ technologies and 8 P&T
technologies). Key words used to classify
groundwater treatment remedies are listed in
Appendix F. Definitions are based on the
Remediation Technologies Screening Matrix and
Reference Guide, Version 4.0, which can be viewed
at the FRTR Web site at h ttp://www. fnr.gov.
This section focuses on updated information for
in situ and ex situ (P&T) groundwater treatment
by documenting the status, achievements, and
trends associated with applications of these
treatment technologies at NPL sites from 1982 to
2005. The following subsections provide
information about (1) the selection of groundwater
remedies, (2) the technologies and status of in situ
groundwater treatment projects, and (3) the status
of P&T projects and the most frequently treated
contaminants.
Groundwater Remedy Decisions
Groundwater remedies have been implemented or
are currently planned at 1,072 sites, nearly 70
percent of sites on the NPL. As shown in Table 6,
P&T remedies have been implemented or are
planned at 728 of the sites. More than one type of
groundwater remedy has been implemented at
many sites. These sites are counted in Table 6 once
for each type of groundwater remedy.
Approximately 900 sites with groundwater
remedies also have source control remedies.
When different types of groundwater remedies are
applied to the same contaminant plume, they may
be used to treat different parts of the plume. For
example, an in situ groundwater treatment
technology may be used for areas that are difficult
to treat using P&T, such as hot spots, NAPL source
zones, tight clays, fractured rock, and areas with
heterogeneous hydrogeology. P&T, in turn, may
be used to control migration of the plume and
Box 12. GROUNDWATER REMEDY TYPES
In Situ Treatment
• Treatment of groundwater in place
without extracting it from an aquifer.
• Includes any of the in situ groundwater
treatment technologies described in this
report, such as air sparging and
permeable reactive barriers.
Pump and Treat (P&T)
• Extraction of groundwater from an aquifer
and treatment aboveground.
• Groundwater usually is extracted by
pumping groundwater from a well or
trench.
• Treatment can include any of the P&T
technologies described in this report,
such as air stripping and ion exchange.
Monitored Natural Attenuation (MNA)
• The reliance on natural attenuation
processes (within the context of a
carefully controlled and monitored
approach to site cleanup) to achieve site-
specific remediation objectives within a
time frame that is reasonable compared
to other alternatives.
• Natural attenuation includes a variety of
physical, chemical, and biological
processes.
Groundwater Containment
• Containment of groundwater through a
vertical, engineered, subsurface,
impermeable barrier, or;
• Containment of groundwater through a
hydraulic barrier created by pumping.
Groundwater Other
• Groundwater remedies that do not fall
into the categories above.
• Can include a variety of remedies, such
as restrictions on water use.
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while only MNA was selected for 11 percent (93)
of the sites. The remedy at many of the sites shown
in Figure 14 also includes source control treatment.
For example, source control treatment is part of
the remedy at 45 percent of the 485 sites with P&T
only. Source control treatment is also part of the
remedy at 41 percent of the 93 sites with MNA
only, though this information is not displayed in
Figure 14.
Although other groundwater remedies, such as
monitoring and institutional controls, are not the
focus of this report, analysis indicates they have
been selected in about 95 percent of RODs in
recent years at NPL sites. These remedies, although
they are protective, typically do not directly reduce
contaminant concentrations or decrease
contaminant mobility and are therefore not
considered treatment. Table 7 shows the number
of sites where these other groundwater remedies
have been selected. By far, the most common other
groundwater remedy is monitoring, which has been
selected at 727 sites (68 percent of sites with a
groundwater remedy) followed by institutional
controls, which has been selected at 437 sites (41
percent of sites with a groundwater remedy).
RODs That Select Groundwater Treatment
More than 1,500 RODs included at least one
groundwater remedy. Table 8 shows the number
of RODs that selected these remedies. P&T was
selected most frequently (958 RODs), while
containment using VEBs was selected the least (60
RODs). Each ROD may be counted in more than
one category.
Table 7. Sites with Groundwater
Other Remedies
(FY 1982 - 2005)*
Total Number of Sites with
Groundwater Other Remedies = 786
Remedy Type
Engineering Control
Number of Sites
45
Groundwater Monitoring
727
Institutional Control
437
Water Supply Remedies
106
"Includes final or deleted NPL sites as ot September
2005. Also includes information from an estimated
74 percent ofFY2005 records of decision and
amendments available as of October 2006.
No hierarchy is used for this table; sites may be
included in more than one category.
Sources: 1,2,7. Data sources are listed in Section 6.
Box 13. SITES WITH BOTH PUMP AND
TREAT AND SOURCE CONTROL
TREATMENT REMEDIES
At 45 percent of sites with P&T (and
no in situ groundwater treatment or
MNA), source control treatment has
also been selected. One example is
ABC One Hour Cleaners in North
Carolina. This site is an active dry
cleaning facility where chlorinated
solvents have contaminated both soil
and groundwater. RODs were signed
for groundwater (OU 1) in 1993 and
soils (OU 2) in 1994. Remediation
currently is being conducted using
P&T for groundwater and SVE for
soils. In this case, although different
media are being treated, both
technologies are addressing the same
contaminants at the same area of the
site. At other sites with P&T and
source control treatment, it is possible
that these technologies are being used
to address different contaminants or
different areas of the site.
Table 8. RODs Selecting
Groundwater Remedies
(FY 1982-2005)*
Total Number of RODs with a
Groundwater Remedy = 1,509
Remedy Type
Number of RODs
Groundwater Pump and Treat
958
In Situ Treatment of Groundwater 195
MNA of Groundwater
303
Groundwater Containment
60
Other Groundwater
579
MNA = Monitored natural attenuation
ROD -- Record of Decision (Note: Data include
ROD amendments)
*Includes information from an estimated 74percent of
FY 2005 RODs and amendments available as of
October 2006.
No hierarchy is used for this table; RODs may be
counted in more than one category.
Sources: 3, 4, 7. Data sources are listed in Section 6.
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may also have selected other remedies. Other
groundwater remedies (such as institutional
controls, engineering controls, and others) are the
only remedy type represented in the "Groundwater
other" column. Figure 15 indicates that:
• The number of groundwater treatment RODs
(including in situ and ex situ remedy types)
peaked in FY 1991 at 114 and has been
generally decreasing in line with the overall
number of RODs. This peak matches the crest
in the total number of RODs in FY 1991.
• From FY 1988 through 1995, the number of
groundwater treatment RODs ranged from 55
to 114, while the number ranged from 19 to
42 from FY 1996 through 2005.
The relative perceritages of remedies selected in
RODs from FY 1986 through 2005 are presented
in Figures 16, 17, and 18. These figures do not
include FY 1982 through 1985 because of the small
number of RODs that were signed during these
years. Figure 16 shows the percentages of RODs
that selected groundwater remedies. RODs are
counted in each category as appropriate (for each
remedy selected) in the figure. The combined
percentages for all remedies in a given year total
more than 100 percent because a ROD may select
multiple remedies and may be counted in more
than one category. Figure 16 shows:
• Nearly 90 percent of RODs selected P&T from
FY 1987 through 1992. This percentage
decreased to 30 percent in FY 1998 and has since
averaged approximately 35 percent.
• MNA was selected in less than 10 percent of
RODs from FY 1986 through 1991, but then
increased every year until it peaked at 48 percent
in FY 1998. After a decline to 10 percent in FY
2002, RODs that select MNA have increased
steadily and reached 49 percent in FY 2005.
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• RODs that select /n s/ru groundwater treatment
have been generally increasing, from none in FY
1986 to 31 percent in FY 2005.
• The percentage of RODs that select groundwater
treatment using VEBs has remained consistent,
less than 10 percent for all years.
• RODs that select other remedies were less than
25 percent from FY 1986 through 1997, but then
increased rapidly. While some of this increase
may be attributed to changes in program
guidance, it should be noted that data reporting
methods used prior to FY 1998 may have resulted
in under reporting of other remedies in Figure
16 for those years. About 90 percent of RODs
selected other groundwater remedies from FY
2000 through 2005.
RODs that select P&T alone have decreased from
about 80 percent before FY 1992 to an average of
20 percent over the last 5 years (FY 2001 through
2005), as shown in Figure 17. In contrast, P&T is
being used increasingly with in situ treatment or
MNA, or not at all. RODs that select P&T with
another remedy generally ranged from 5 to 10
percent through FY 1995, but increased to an
average of 17 percent from FY 2001 through 2005.
Similarly, RODs that select in situ treatment or
MNA and not P&T generally ranged from 5 to
10 percent through FY 1993. However, these
RODs then increased to a peak of 43 percent in
FY 1998 and again in 2005 after the percentage
dipped to 16 percent in FY 2002.
The general decrease in the selection of P&T
remedies may be a result of a variety of factors,
including:
• More widespread acceptance of innovative in
situ groundwater treatment remedies
• Reduced operation and maintenance costs from
use of in situ treatment technologies
• Reduced time to address risk and quicker return
of sites to beneficial uses by using active in situ
treatment remedies
• Reduced costs by using MNA
Figure 17: Trends in Ground water RODs Selecting Pump and Treat
(FY 1986-2005)*
Total Number of Groundwater RODs = 1,458
Percentage
of All
Groundwater 40%
RODs
RODs Selecting Only P&T
(and no In Situ treatment or MNA)
RODs Selecting P&T and Another
Groundwater Remedy
(MNA or In Situ Treatment)
RODs Selecting In Situ Treatment or MNA
but Not Selecting P&T
87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 OS*
Fiscal Year (FY)
Since 1995, RODs selecting pump and treat alone have dropped, while RODs selecting in situ
treatment or MNA, with or without pump and treat, have increased.
MNA = Monitored natural attenuation
P&T = Pump and treat
ROD = Record of Decision (Note: Data include ROD amendments)
includes information from an estimated 74 percent of FY 2005 RODs available as of October 2006. RODs are
coun ted only once in this figure as appropriate.
Sources: 3, 4, 7. Data sources are listed in Section 6.
-------
The general increase in the selection of P&T with
MNA or in situ treatment may in turn be a result
of a variety of factors, including:
• More active in situ treatments can reduce P&T
treatment times by remediating hot spots and
contaminant sources
• MNA can reduce P&T treatment times by
allowing P&T systems to be shut down when
contaminants reach levels that can effectively
be treated by MNA
• MNA can treat areas of a contaminant plume
with low concentrations, reducing the amount
of the contaminant plume treated by P&T
Figure 18 counts all RODs that selected in situ
groundwater treatment (regardless of whether
additional remedies were selected). The percentage
of groundwater RODs that select in situ treatment
peaked in FY 2005 at 31 percent. The gradual
upward trend in selection of in situ treatment may
be a result of several factors:
Box 14. GROUNDWATER MNA
Groundwater MNA includes a variety of
physical, chemical, or biological processes
that, under favorable conditions, act without
human intervention to reduce the mass,
toxicity, mobility, volume, or concentration
of contaminants in soil or groundwater.
These in situ processes include
biodegradation; dispersion; dilution;
sorption; volatilization; radioactive decay;
and chemical or biological stabilization,
transformation, or destruction of
contaminants.
Development of these technologies is growing
rapidly
They have been more frequently used in recent
years to treat some media and contaminants,
which are difficult to remediate, such as NAPL,
chlorinated solvents, and fractured bedrock
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Figure 18: Trends in Ground water RODs Selecting in Situ Treatment
(FY 1986 -2005)*
Total Number of Groundwater RODs = 1,458
30%
25%
20%
Percentage
of All
Groundwater 15%
RODs
10%
50/
/a
-«— RODs Selecting In Situ
Treatment for Groundwater
Linear Trend
(RODs Selecting In Situ
Treatment for Groundwater)
31
9%X/
**
86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05*
Fiscal Year (FY)
The selection of in situ treatment remedies has generally increased since 1986.
ROD = Record of Decision (Note: Data include ROD amendments)
'Includes information from an estimated 74 percent of FY 2005 RODs and amendments available as of
October2006.
Sources: 3, 4, 7. Data sources are listed in Section (•>.
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The number of in situ groundwater treatment
projects selected in RODs from FY 2002 to 2005
is presented in Table 9. The table shows that
selection and use of bioremediation and chemical
treatment for in situ groundwater continue to
increase. Although air sparging represents the most
projects cumulatively, its use is beginning to
decrease. Bioremediation and chemical treatment
have increased significantly, with approximately 70
and 80 percent of projects, selected in the past six
years.
As shown in Figure 20, in situ groundwater
technologies treat eight major groups of
contaminants categorized for this report as follows,
with the exceptions listed in the figure notes:
• VOCs - either halogenated or non-halogenated
• SVOCs - either halogenated or non-halogenated
• PAHs
• BTEX
• Organic pesticides/herbicides
• Metals and metalloids
Table 9. in Situ Croundwater
Treatment Projects
ASR 11th Edition ASR 12th Edition
Number of New Number of New
Projects Selected Projects Selected
Technology in FY 2000-2002* in FY 2002-2005"
Bioremediation
21
26
Chemical
Treatment
15
17
Permeable Reactive
Barrier
Air Sparging
Phvtoremediation
Multi-Phase
Extraction
In-Well Air
Stripping
Flushinq
Total
7
10
3
4
3
2
65
6
6
5
5
2
0
67
In situ groundwater treatment applications of
bioremediation and chemical treatment are being
selected more frequently than in prior years.
*Includes information from an estimated 70percent ot
FY2002 records of decision (ROD) and amendmen ts
available as of March 2003.
**Indudes information from an estimated 74percent
of FY 2005 RODs and amendments available as of
October 2006 and project data available in CERCL1S
as of October 2006.
Sources: 3, 4, 7. Data sources are listed in Section 6.
Overall, VOCs — including BTEX and halogenated
VOCs — are the contaminants most commonly
treated in groundwater using in situ technologies.
Halogenated SVOCs (including organic pesticides
and herbicides) and metalloids and metals in
groundwater are treated least frequently with in situ
remedies. The number of projects in Figure 20
exceeds the total number of in situ groundwater
projects because some projects involve more than
one type of contaminant. These projects, therefore,
are repeated in Figure 20 under each contaminant
type treated by the remedy.
The selection of a treatment technology for a site
depends on the physical and chemical properties of
the contaminants. For example, VOCs are amenable
to air sparging and in-well air stripping because of
their volatility. Conversely, metals, which are not
volatile and do not degrade, are nor amenable to
these technologies, and are most often treated using
chemical treatment and PRBs. As Figure 20 shows,
BTEX and halogenated VOCs are treated most
frequently using air sparging. PAHs and other non-
halogenated SVOCs, which are not as volatile as
BTEX and halogenated VOCs but can be destroyed
through microbial processes, are treated most
frequently by bioremediation. Metalloids and metals
are typically not amenable to bioremediation; one
exception is the use of in situ bioremediation to
reduce hexavalent chromium to its less toxic trivalent
form. This technology, which uses biological activity
to create conditions that result in chemical reduction
of chromium, is being applied at one NPL site.
Bioremediation to treat arsenic is currently planned
at two additional sites. Metals and metalloids may
undergo chemical reactions widi certain substances
to form compounds that are less toxic or mobile.
The PRBs were used most often to treat halogenated
VOCs, BTEX, and metals and metalloids.
The selection of groundwater treatment technologies
may also depend on site-specific factors, such as soil
type and hydrogeology. For example, air sparging
may be an effective treatment for VOCs at a site
with sandy soil but may not be effective at a site
with tightly packed clay soil. In addition, chemical
treatment may be ineffective at sites with low-
permeability soils because of the resulting uneven
or limited chemical distribution in the subsurface.
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Figure 20: Contaminant Croups Treated by In Situ Croundwater Projects
(FY 1982 - 2005)*
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Number of
Projects
33
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45
40
•MB
30
25
20-
•15-
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• Air Sparging - 72 Projects
D Bioremediation - 70 Pr
E3 Chemical Treatment - C
D Multi-Phase Extraction
a Permeable Reactive B<
D Phytoremediation - 14
ojects
!9 Projects
- 26 Projects
jrrier - 24 Projects
Projects
35
20
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loon
*1VU1 1
Polycyclic Other
aromatic non-
hydrocarbons halogenated e
(PAH) semivolatiles3 x
2
6
66
14
g[3
^ 1
6 '< 0 sffll
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40
7
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25
;
•
: 16
'
:'
H '•' ' ~ ^
':-.. ,* ^§ •.
t: I jfill
Benzene, Other Organic Other Halogenated Metals and
toluene, non pesticides/ halogenated volatiles metalloids
thylbenzene, halogenated herbicides semi-
ylene (BTEX) volatiles'' volatiles0
In situ treatment technologies are usually selected to address halogenated voiatiles
and BTEX. Fewer in situ methods are available for other types of contaminants.
* Does- nor include PAHs.
h Does nor include BTEX.
c Does noc include organic pesticides Mid herbicides.
^Includes information from an estimated 74 percent of FY 2005 records ot decision and amendments available as
of October 2006 and project data available in CERCLISas of October 2006.
Data for in-well air stripping and Hushing are not included.
Projects may treat more than one contaminant group.
Sources: 3, 4, 7. Data sources are listed in Section 6.
4-10
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Status of In Situ Groundwater Projects
A snapshot of the status of in situ groundwater
treatment technologies is presented in Figure 21.
The data in Figure 21 show:
• The total number of in situ groundwater
treatment projects increased by 50 percent,
from 169 to 254, between the Eleventh and
Twelfth Editions.
• An additional 27 in situ groundwater projects
were completed, increasing the percentage of
completed in situ groundwater projects from
11 percent to 18 percent. These completed
projects included 14 air sparging, 5
bioremediation, 4 chemical treatment, 2 multi-
phase extraction, and 2 PRBs.
Nearly half (47 percent) of in situ groundwater
treatment projects are operational.
Although the percentage of in situ groundwater
projects that are operational decreased, the total
number of operational projects increased from
91 to 119. The technologies that exhibited the
largest increase in the number of operational
projects were phytoremediation (6 projects),
bioremediation (6 projects), multi-phase
extraction (5 projects) and PRBs (5 projects).
The number of in situ groundwater treatment
projects in the design phase increased. The
technologies with the largest increase in the
number of projects in the design phase were
bioremediation (11 projects) and chemical
treatment (9 projects).
Figure 21: Status of In Situ Groundwater Treatment Projects - Comparison
Between Tenth, Eleventh and Twelfth Editions of the ASR
(FY 1982-2005)***
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100%
90%
80%
70%
60%
Percentage
of In Situ
Groundwater 50%
Projects
40%
30%
20%
10%
0%
6% (6)
65%
(68).
5% (5)
24% (25)
In Situ Groundwater
Technologies (104)
Tenth Edition*
11% (19)
54%
(91)
3% (5)
32% (54)
In Situ Groundwater
Technologies (169)
Eleventh Edition**
18% (46)
47%
(119)
29% (73)
D Completed
•Operational
• Design Complete/
Being Installed
• Predesign/Design
In Situ Groundwater
Technologies (254)
Twelfth Edition***
As with source control treatment projects (see Figure 11), projects addressing contaminated
groundwater have progressed. The percentage of completed in situ groundwater
treatment projects has increased by 13 percent since the ASR Tenth Edition.
damcndmcn
** Includes in formation from an estimated 70 percent of FY 2002 RODs and amendments available as of March 2003.
*** Includes information from an estimated 74 percent of FY2005 RODs and amendments available as of October 2006
and project data available in CERCLIS as of October 2006.
Sources: 3,4, 10. Data sources are listed in Section 6.
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Between FY 2002 and 2005, 82 in situ treatment
technology projects for groundwater were selected.
Of those, 67 have been added since the Eleventh
Edition of the ASR (see Table 9). Technologies most
frequently selected include bioremediation (26
projects), chemical treatment (17 projects), PRBs (6
projects), and air sparging (6 projects). The status of
in situ groundwater treatment projects selected in F.Y
2002 through 2005 at NPL remedial action sites
includes:
• One bioremediation project selected in the period
has been completed
• Eighteen projects selected in the period became
operational
• An additional five projects have progressed beyond
the design phase, and the remedies are being
installed
The specific types of in sini treatment technologies
and their status are listed in Table 10. In s/tu treatment
of groundwater has been selected 254 times at 190
sites. Among these technologies, air sparging and
bioremediation have been the technologies most
frequently selected; although recent trends indicate
that bioremediation has been increasing while air
sparging is decreasing. A large number of projects in
the operational phase use these technologies. The
treatment rate of these technologies is typically limited
by site-specific factors. For example, air sparging may
require long treatment times when continuing sources
of contaminants, such as light nonaqueous phase
liquids (LNAPL) and DNAPL, are present. Likewise,
bioremediation may be limited by the rate the
microbes can break down contaminants, which can
depend on a variety of factors such as climate, soil
conditions, contaminant concentrations, and
solubility.
The third most frequently selected technology is
chemical treatment. Chemical treatment is typically
applied as an aggressive technology that requires a
relatively short treatment time to achieve cleanup
goals. It may also be effective in treating small
amounts of DNAPL and LNAPL. The number of
chemical treatment projects has nearly doubled from
21 to 39 since the ASR Eleventh Edition. PRBs are a
passive technology that relies on natural groundwater
flow to carry contaminants into a reactive zone, where
they are treated; therefore, diis technology does not
treat contaminants upgradient of the reactive zone.
Most PRBs (15 of 24) are in the operational phase,
and two are completed.
Groundwater Pump and Treat
Projects
This section presents information about P&T
projects. P&T extracts groundwater from an
aquifer and treats it aboveground. The extraction
step usually is conducted by pumping groundwater
from a well or trench. The treatment step can
Table 10. Status of in Situ Croundwater Treatment Projects by Technology
(FY 1982-2005)*
Technology Predesign/ Design Complete/
Design Being Installed
Air Sparging
Bioremediation
Chemical Treatment
Permeable Reactive Barrier
Multi-Phase Extraction
Phvtoremediation
In-Well Air Stripping
Flushing
Total
Percentage of In Situ
Groundwater Technologies
9
29
19
6
6
3
1
0
73
29%
5
4
2
1
1
1
1
1
16
6%
Operational
38
27
9
15
14
10
6
0
119
47%
Completed
20
10
9
2
5
0
0
0
46
1 8%
Total
72
70
39
24
26
14
8
1
254
Almost half of in situ groundwater treatment projects are operational.
includes information from ait estimated 74 percent of FY 2005 records of decision and amendments available :ts
of October 2006 and project data available in CERCLIS as of October 2006.
Sources: 5, 4, 7. Data sources are listed in Section 6.
-------
include a variety of technologies, with the most
common being air stripping and carbon adsorption
(refer to Appendix C for all technology
descriptions).
Status of Pump and Treat Projects
This report contains information about 725 P&T
projects at NPL sites. Figure 22 shows the status
of these projects and allows for the following
conclusions:
• Most P&T projects (72 percent) are
operational.
• Fifteen percent are in the predesign or design
phase.
• 73 P&T projects (10 percent) have been shut
down (no longer operational).
The status "shut down" does not indicate that goals
were met for these projects. Although 38 percent (28
projects) had met the goal of either restoration or
hydraulic containment of groundwater, others were
shut down for various reasons: replaced with another
remedy, such as in situ treatment or MNA; for
monitoring to evaluate whether goals have been
achieved; or because of technical issues, such as well
fouling or limited pumping capacity. Appendix G lists
73 P&T projects along with their reasons for shutdown.
Figure 22: Status of Groundwater
Pump and Treat Projects
(FY 1982 - 2005)*
Total Number of Projects = 725
i
1 Operational (521)
72%
Shut Down (73)
10%
Predesign/Design (107)
15%
Design Complete/
Being Installed (24)
3%
Nearly 75 percent of pump and treat projects
are operational, presenting a continuing
challenge and opportunity for optimization
efforts (see Box 15).
includesinformation from 011 estimated 74 percent of FY
2005 records of decision and amendmen K available as of
Occober 2006 and project data available in CERCLlSas
ofOaolxr2006.
Sources: 3,4, 7. Data sources are listed in Section 6.
Contaminants Treated by Pump and Treat
Projects
The contaminants treated by 514 P&T projects were
identified, and the 10 most frequently treated
contaminants are shown in Figure 23. (Note that
contaminant infotmation was available for 70 percent
of projects.) Chlorinated VOCs are the most
commonly treated group of contaminants. The
contaminant treated most often is trichloroethene
(TCE). Other frequendy treated chlorinated VOCs
include tetrachloroethene (PCE); 1,1,1 -trichloroethane
(TCA); vinyl chloride (VC); 1,2-dichloroethene
(DCE); and 1,1 -DCE. Frequently treated
nonchlorinated VOCs include benzene, toluene, and
xylene. P&T systems also are frequently used to treat
metals and metalloids, including chromium. Projects
that treat more than one contaminant are counted once
for each contaminant listed in Figure 23.
Pump and Treat Remedy Changes
One goal of this report is to compile a current list of all
P&T projects. As discussed earlier, remedies selected
for remedial actions at NPL sites are documented
through a ROD, and changes to the original remedies
may be formally documented. Remedies often change
during the pre-design or design phase of a project when
new information about site characteristics is discovered
or treatability studies for the selected technologies are
completed.
EPA updated the status of 725 P&T projects, primarily
by reviewing site documents, such as 5-year review
reports and PCORs. In addition to these 725 P&T
projects, nearly 100 additional P&T projects were
changed to other groundwater remedies.
These remedies were most often changed to in situ
groundwater treatment or non-treatment remedies,
such as institutional controls and MNA The most
commonly cited reason for changing a P&T remedy
was that further site investigation revealed that the
concentration or extent of contamination was less than
expected. Other frequendy cited reasons included
problems in implementing the remedy because of site
conditions such as hydrogeology, implementation of a
more effective in situ treatment remedy, and high costs.
For additional information about remedy updates, see
Updating RemedyDecisions atSuperiundsites -Summary
Report FY2004 and FY 2005, February 2007 (EPA
540-R-06-074).
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Figure 23: Contaminants Most Commonly Treated by Pump and Treat Systems
(FY 1982-2005)*
300
250 -
Number of
Projects
150
100 -|
50
0
pQO
161
131
99
i — -
98 90 90 78 77 72
Contaminant
Volatile organic compounds, such as TCE and PCE, are the contaminants
treated most commonly by pump and treat systems.
"Includes information from an estimated 74 percent of FY2005 records of decision and amendmen ts available as
of October 2006 and project data available in CERCLIS as of October 2006.
Only the most common contaminants have been included for the 514projects with contaminant data.
Sources: 3, 4, 7. Data sources arc listed in Section 6.
Box 15. P&T OPTIMIZATION
Once remediation systems have been
functioning for a period of time, opportunities
may exist to optimize the system, particularly if
they are long-term remedies. The purpose of
optimization is to identify potential changes
that will improve the effectiveness of a system
and reduce operating costs without
compromising the effectiveness of the remedy
or the achievement of other cleanup
objectives.
EPA recognizes that long-term remedial
approaches should not remain static, that
conditions change over time, and that better
technologies, tools, and strategies evolve,
which allow for continuous improvement of
remedy performance. In OSWER Directive No.
9200.0-33, Transmittal of Final FYOO - FY01
Superfund Reforms Strategy, dated July 7,
2000, EPA outlined a commitment to optimize
Superfund-lead P&T systems at Superfund
sites. Superfund-lead P&T systems include
systems that are either EPA-lead or state-lead
that are funded from the Superfund Program.
Initially, EPA performed a Remediation System
Evaluation (RSE) on 20 Superfund-lead
groundwater P&T systems during 2000 and
2001. The results of this initiative are
documented in two reports: (1) Groundwater
Pump and Treat Systems: Summary of
Selected Cost and Performance Information at
Superfund-Financed Sites and (2) Pilot Project
to Optimize Superfund-financed Pump and
Treat Systems: Summary Report and Lessons
Learned. Since the initial set of RSEs, EPA
has prepared 17 RSEs for Superfund-lead
P&T systems and 1 for a responsible-party
site. EPA is also preparing additional RSEs for
Superfund-financed sites. The summary
reports, RSEs, and other reports are
available at http://clu-in.org/rse. Additional
information on RSE and optimization of
remedies is available at http://www.frtr.gov/
optimization. This site includes information on
optimization tools and techniques, including
checklists that can be used to identify
optimization opportunities for specific
groundwater treatment technologies.
4-I4
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Conclusion
Several conclusions can be drawn from the analysis
of the latest data and historical trends associated
with in situ and ex situ groundwater treatment
projects. Of the RODs that select groundwater
treatment, 18 per.cent (195) used in situ treatment
remedies, whereas more than 90 percent (958) used
P&T remedies. A total of 254 in situ treatment
projects and 725 P&T projects were implemented
or planned from those RODs. Those projects
consist of a wide range of technologies used to
address a broad spectrum of contaminants at
various stages in design and implementation.
Although annual fluctuations occur, some trends
and general observations can be noted:
• RODs that select in situ groundwater treatment
have been generally increasing, from none in
1986 to a high of 31 percent in FY 2005.
• RODs that select P&T alone have decreased
from about 80 percent before FY 1992 to an
average of 20 percent over the last 5 years (FY
2001 through 2005).
• RODs that select only MNA (with no
groundwater treatment) experienced a decline
from FY 1999 to 2002, coinciding with
publication of EPA guidance on the use of
MNA in 1999. Since FY 2002, RODs that
select MNA have been increasing.
• The most common in situ technologies include
air sparging, bioremediation, chemical
treatment, PRBs, and multi-phase extraction.
• Cumulatively, air sparging represents almost 30
percent of all in situ groundwater treatment
projects, with bioremediation representing 27
percent.
• In situ bioremediation and chemical treatment
have increased significantly in recent years, with
approximately 70 to 80 percent of these projects
selected in the past 6 years.
• More than 70 percent of P&T projects selected
are currently operational. Another 10 percent
have been shut down. Eighteen percent of in
situ groundwater projects have been completed,
and nearly 50 percent continue to operate.
Selection and implementation of in situ
groundwater treatment technologies have been
increasing and may continue to do so as their
applicability and performance are demonstrated at
a larger number of sites and a wider variety of
conditions. Site owners, remedial project
managers, and other stakeholders may look more
favorably to these options when they consider
groundwater cleanup alternatives because these
systems do not require extraction of contaminated
groundwater. Additionally, they generally have
shorter operating periods than P&T remedies.
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Section 5: Report Focus
Area On-Site Containment
Remedies
The ASR focuses on the documentation and analysis
of treatment technology applications for Superfund
remedial action sites. Given the prevalence of on-
site containment remedies, EPA expanded the scope
of the report beyond treatment technologies to
include information on groundwater containment
remedies, specifically VEBs, in the Tenth Edition.
With this Twelfth Edition, the scope was expanded
further in an effort to understand the state of the
practice of on-site containment remedies, such as
final cover systems (commonly refetred to as caps),
to prevent the migration of contaminants or
contaminated media. An initial analysis has been
conducted for source control cover systems. These
details are provided for a limited subset of cover
systems at surface contamination sites, landfills, and
disposal units. In total, information and analysis
are presented for 112 cover system remedies at 89
NPL sites and 57 VEB remedies at 55 NPL sites.
The information provided in this section, therefore,
only suggests the state of the practice, and is not a
"status report" on these remedies. This section
provides an overview of the data collected about on-
site containment remedies and presents the findings
derived. Specific types of containment remedies are
identified in Appendix F.
From FY 1982 to 2005, 17 percent (503) of RODs
selected containment without treatment and an
additional 16 percent (475) of RODs selected
containment in conjunction with a treatment
remedy. Trends associated with selection of on-site
containment remedies are presented in Figure 24.
Overwhelmingly, the most common type of on-site
containment remedy is a cover system. Although
RODs selecting other on-site containment remedies,
such as VEBs, have remained constant over time —
with less than 10 selected per year — RODs that
select a cover system as a remedy surged in FY 1990
and reached a peak of 57 in FY 1993. Since then,
the number of RODs that have selected cover
systems has been steadily declining but still
represents the majority of on-site containment
remedies selected.
While other sections of the ASR focus on treatment
remedies, information about containment remedies
has also been included (see Figures 1, 2, 6, 7, 15,
and 16 and Tables 1, 2, 6, 7, and 8). The remainder
of this section focuses on the analysis performed on
a limited sample of on-site containment remedies.
Figure 24: RODs Selecting On-Site Containment
(FY 1984-2005)*
60
Number
of RODs 30
20
52
£57
53
55
'" K1 i -' '^ ^ -^
\ ^' \ / \
\/47 \ / \
0
42
39
535
84 ' 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05*
Fiscal Year (FY)
The number of RODs selecting capping generally tracked the total number of RODs since 1984
(see Figure 6).
"Includes information from a/i estimated 74 percent of FY 2005 records of decision (ROD) and amendments
available as of October 2006 and project data available in CERCLIS as of October 2006.
Sources: 3, 4. 7. Data sources are listed in Section (i.
-------
Collection of Data about On-Site
Containment Projects
Detailed project-level information about on-site
containment remedies was collected for a limited
number of sites for this edition of the ASR.
Sites identified for the survey included:
• Sites classified as "Fund-Lead," that is, funded
and implemented by EPA, and
• Sites in the remedial action (RA) phase
These sites were selected because it was expected
that implementation data would be more readily
available. The application of these two criteria
narrowed the list of prospective sites with on-site
containment from 656 to 91 (based on CERCLIS
data as of September 2006).
The breakdown of sites with RODs that select
containment remedies and the relative proportion
of cover systems are as follows:
• Of 656 sites with on-site containment remedies,
634 included a cover system
• Of 439 sites with on-site containment remedies
in the RA phase, 417 included a cover system
• Of 228 sites with on-site containment remedies
and EPA funding, 222 included a cover system
• Of 91 sites with on-site containment remedies
in the RA phase and EPA funding, 89 included
a cover system
As discussed in previous sections, more than one
treatment remedy can be specified for a site.
Similarly, more than one on-site containment
remedy can be specified. The 91 sites included in
this analysis yielded 128 on-site containment
remedies, of which 112 were cover systems at 89
NPL sites. These cover systems are the focus of this
section. Appendix H presents a list that includes
each containment remedy and details of the projects
that were identified during this update.
Data sources used to obtain information about on-
site containment remedies included PCORs and
5-year reviews. These sources provided the most
readily available and up-to-date information about
the status of containment remedies and their
effectiveness at sites. In addition, decision
documents, site summaries, and fact sheets also
were reviewed for background information.
Decision documents, which contain pre-design
information, were less reliable than PCORs and
5-year reviews, which often provide actual
construction and "as-built" information. Based on
these sources, a variety of data was collected on
the remedies and associated sites.
Overview of Sites with On-Site
Containment
Site types were identified based on activities
conducted at the site, which are the likely sources
of contamination. Applicable types for each site
were established according to the data sources
described above. (An NPL site could be classified
as more than one site type if appropriate.) Table
11 shows the site types that were identified for the
NPL sites with containment remedies. The Other
Site Types category consists of site types with only
a small number of NPL sites each and includes
agricultural applications; chemical distributors;
pesticide manufacturing, use, or storage; and textile
dye manufacturing.
Each remedy also was categorized according to the
source of contaminants contained by the barrier.
(More than one source was selected if appropriate.)
The 220 sources identified for all remedies and
sites include:
• 72 (33 percent) contaminated soil
• 55 (25 percent) hazardous waste
• 30 (14 percent) municipal solid waste
• 16 (7 percent) other
• 12 (5 percent) NAPL
• 35(16 percent) all other sources (each category
represented less than 10 sources)
Table 11. Site Types for On-Site
Containment Sites*
Total Number of Sites = 91
Site Types
Municipal Landfills
Number
of Sites
25
Industrial Landfills
21
Wood Preserving
18
Metal Ore Mining and Smelting
16
Other Site Types'*
64
Total
144
*Sites can have more than one type of classification.
* *Categoiy includes such sire types as agriculniral
applications, chemical distributors, pesticide
manufacturing, and textile dye manufacturing.
Data included tor a limited sample of Fund-Lead,
remedial action phase sites selected from CERCLIS as
of October 2006. Includes information obtained from
preliminary close-out reports, five-year reviews, and
outer site documcn ts.
Sources: 3,4,7. Data sources are listed in Section 6.
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The 91 sites with on-site containment were
grouped into four general classifications based on
the results of the site type and source of
contamination analyses:
1. Landfills/Disposal units — Sites that are municipal
or industrial landfills or where the contamination
was caused by disposal of waste (44 sites).
2. Surface contamination sites — Sites where
dumped waste contaminated the surface medium
of the site or where an industrial process
contaminated the site. Examples of surface
contamination sites are chemical manufacturing
facilities and wood treating and preserving facilities
(37 sites).
3. Sediment sites—Sites where sediments are capped
in situ (4 sites).
4. Mine sites — Sites where mining activities
contaminated on-site media (11 sites).
Because of the diverse nature of some NPL sites, a
site could have multiple site classifications for the
purpose of the review and be counted more than
once, as appropriate. One example is Wyckoff Co./
Eagle Harbor, which is classified as both a surface
contamination site and a sediment site.
Subsequent analysis focuses on cover systems
associated with landfills/disposal units and surface
contamination sites. The majority of cover systems
are associated with these site classifications: 89 cover
systems at 77 sites. Data collected include details
about the cover system, such as: type, layer
components, and size; goals and status; and remedies
used in conjunction with those cover systems.
Cover Designs and Layer
Components
Most cover systems employ a hydraulic barrier layer
to prevent infiltration of water into the contained
material. Typical materials used for hydraulic barriers
include compacted clay liners, geosynthetic clay liners,
geomembranes, and combinations of these materials.
A hydraulic barrier is generally used with additional
components of the cover system, such as a surface
protection layer, a biointrusion layer, a drainage layer,
a gas collection layer, and a foundation layer. Cover
systems may include some or all of these layers
depending on factors such as site type, regulations,
goal of the cover, and planned reuse of the site.
Additional information about the design of cover
systems can be found in the EPA report, Design and
construction ofRCRA/CERCLA Final Covers. This
evaluation of on-site containment remedies classified
Example of a Conventional Cap
Surface
Protection Layer
Internal
Drainage
Layer
Hydraulic
Barrier
_ Waste
P= Precipitation
ET= Evapotranspiration
R= Runoff
L= Lateral Drainage
cover systems according to the general type of cover
design and layer components. The three cover system
classifications are as follows:
1. Conventional caps -- Cover systems that
include a hydraulic barrier and a surface
protection layer. Types of conventional caps
include Resource Conservation and Recovery
Act (RCRA) C and D (or similar type caps),
Toxic Substances Control Act caps, clay caps,
and other multilayer caps that include a
hydraulic barrier. The graphic above illustrates
a multilayer cap with a hydraulic barrier.
2. Soil caps -— Cover systems with a single layer
of soil covering the waste and no hydraulic
barrier.
3. Asphalt/concrete caps — Cover systems with
an asphalt or concrete surface layer but no
hydraulic barrier underneath.
Soil and conventional caps constitute the most
common cover system types (71 of 89 cover
systems). Figure 25 shows the percentages of each
cover system type for the landfills and disposal units
and surface contamination sites, the two most
common site classifications.
For the landfills/disposal units (48 cover systems):
• Conventional caps represented 86 percent of
the cap remedies
• Soil caps represented 10 percent
For surface contamination sites (41 cover systems):
• Conventional caps represented 46 percent of
the cap remedies
• Soil caps represented 15 percent
• Asphalt/concrete caps represented 27 percent
-------
Figure 25: Cover System Types for
Landfills/Disposal Units and
Surface Contamination Sites*
Landfills/Disposal
Unit Covers
(48 Cover Systems)
Surface Contamination
Covers
(41 Cover Systems)
Soil (5)
10%
Not Specified (2
Soil (6)
15%
Conventional (41)
86%
Not Specified (5)
12%
Asphat,
Concrete (11)
27%
Conventional (19)
46%
Conventional covers are the most common cover type at both landfills/disposal units and surface
contamination sites reviewed (see section on Cover Designs and Layer Components).
*Data included for a limited sample ofFund-Lead, remedial action phase sices selected from CERCL1S as of October
2006. Includes information obtained from preliminary close-out reports, five-year reviews, and other site documents.
Sources: 3, 4, 7. Data sources are listed in Section 6.
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Whereas landfills/disposal units relied more
frequently on conventional caps, surface
contamination sites employed other cover designs,
primarily asphalt/concrete as an alternative. A
possible explanation for this condition might include
the ongoing industrial use of surface contamination
sites mat requires the use of asphalt/concrete surfaces.
Also, surface contamination sites may be more
amenable to excavation and disposal. When less
contamination remains, an asphalt/concrete cap,
with no hydraulic barrier, may be appropriate.
Table 12 lists the numbers and types of hydraulic
barriers at landfills/disposal units and surface
contamination sites. The most frequently used
hydraulic barrier at landfills/disposal units and surface
contamination sites is a compact clay liner, which has
been used for 17 of 60 cover systems (28 percent).
Thirteen of 41 conventional caps (32 percent) at
landfills/disposal units used compact cky liners, while
4 of 19 conventional caps (25 percent) at surface
contamination sites used them.
Table 12. Types of Hydraulic Barriers
for Conventional Caps at Landfills/
Disposal Units and Surface
Contamination Sites*
Type(s) of Landfills/disposal
Hydraulic Sites
Barriers (41 projects)
Surface
Contamination
Sites (19 projects)
Compact Clay
13
Geomembrane
Composite
Geosynthetic Clay
Not Documented
10
"Composite harriers are hydraulic harriers with
multiple types of components (e.g., compact clay and
geomembrane).
Data included fora limited sample of Fund-Lead,
remedial action phase sites selected from CERCLIS as
of October 2006. Includes information obtained from
preliminary close-out reports, five-year reviews, and
other sice documents.
Sources: 3, 4, 7. Data sources are listed in Section 6.
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Figure 26: Cover System Sizes
by Site Type
Total Number of Caps = 26
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Figure 27: Secondary Coals for Conventional and Soil Caps at
Landfills/Disposal Units and Surface Contamination Sites*
Secondary Goals of Conventional Caps
(60 Caps)
Secondary Goals of Soil Caps
(11 Caps)
Prevent source migration
(including DNAPL or LNAPL) (18) 1
14%
Prevent migration of
contaminated groundwater (7)
5%
Collect Leachate (6)
5%
Provide erosion control (5)
4%
Minimize gas
migration (5)
4%
Minimize
- infiltration (34)
27%
Prevent direct —\
contact (7)
46%
Not identified - 4
Allow future land use - 2
Other - 2
Collect DNAPL/LNAPL -1
Prevent direct
contact (44)
34%
Not identified (3)
20%
Minimize
infiltration (1)
7%
Provide erosion
control (2)
13%
Collect DNAPU
LNAPL (1)
7%
Allow future
land use (1)
7%
For both conventional and soil caps reviewed, the most
common secondary goal is preventing direct contact.
*Data included for a limited sample of Fund-Lead, remedial action phase sites selected from CERCLIS as of
Ocmber2006.
Includes information obtained from preliminary closeout reports, five-year reviews, and other site documents.
Each cap may have more than one secondary goal.
Sources: 3, 4, 7. Data sources are listed in Section 6.
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Figure 27 shows secondary goals for conventional
and soil caps at landfills/disposal units and surface
containment sites. The most common secondary
goal for both types of cover system is to prevent
direct contact with the contamination or waste
contained. This is consistent with the primary
purpose of a cover system to act as a barrier between
contamination and human and ecological
receptors.
Gas management and monitoring can be a critical
aspect of cover design and performance and often
depends on the age and type of waste or media
being contained. Of the total 112 cover systems:
• Gas monitoring was confirmed at 24 sites
• Of the 24 sites, 16 can be classified as municipal
solid waste (MSW) landfills.
In addition to monitoring, these remedies also
employed gas management technologies. The two
most common types of gas management at these
sites were open vents and flares. Eight other sites
in the study can also be classified as MSW landfills,
but it is unclear if gas was being monitored. For
these eight sites, there was either an open vent or
no gas management.
Another goal of a cover system may be to allow for
reuse and redevelopment of a site. Of the
information available for all the cover systems, the
most common planned reuse for a site was
recreational at 14 sites (10 percent). Additional
information about reuse of Superfund sites is
available at EPA?s Superfund Redevelopment Web site
(http://www.epa.gov/superfund/programs/recyde/).
Rarely is on-site containment the only remedy
selected for a site. Additional remedies also are
implemented at these sites in conjunction with
containment to provide additional protection or
to expedite treatment of the contaminated media.
The selection of other remedies in RODs is
discussed in the introduction to this section. The
two most common additional remedies for
landfills/disposal units and surface contamination
sites are institutional controls and groundwater
monitoring (at 27 percent and 20 percent of
landfills/disposal units and 24 percent and 15
percent of surface contamination sites,
respectively). Figure 28 shows the additional
remedies used with cover systems at landfills/
disposal units and surface contamination sites.
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Figure 28: Additional Remedies Used with Cover Systems*
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Number of
Projects
Landfills/Disposal Units
Surface Contamination
For landfills/disposal units and surface contamination sites reviewed, the remedies most commonly
used with cover systems were institutional controls and groundwater monitoring.
*Data included fora limited sample of Fund-Lead, remedial action phase sites selected from CERCLISasof
October 2006. Includes in forma tion obtained rrom preliminary close-out reports, five-year reviews, and other
site documents.
A coversystem can have multiple additional remedies.
Additional remedies are those remedies used in addition of the cover system to remediate the source ma terial.
Sources: 3,4, 7. Data sources are listed in Section 6.
Vertical Engineered Barriers
VEBs are subsurface barriers made of an
impermeable material designed to contain or divert
groundwater. VEBs can be used to contain
groundwater, divert uncontaminated groundwater,
or divert contaminated groundwater from reaching
resources, such as surface water bodies or drinking
water intakes. In addition, VEBs are an integral
part of many PRBs. The following information
presents updates and additions to information first
reported in the ASR Tenth Edition. Four VEBs
were selected in RODs from FY 2002 through
2005.
VEBs for groundwater containment were selected
at 55 Superfund remedial action sites, for a total
of 57 projects. (Some sites have more than one
VEB.) Nearly 90 percent of the VEBs have been
installed (50 of 57). Table 13 indicates the numbers
and types of VEBs. The types of barriers are:
• Slurry wall — Consists of a vertical trench that
is filled with a low-permeability slurry of
bentonite, soil, or cement.
• Sheet pile — A series of overlapping sheets of
impermeable material, such as metal.
• Geosynthetic wall — Constructed by placing a
geosynthetic liner into a trench.
-------
• Grout — Constructed by injecting a high-
pressure grout mixture into the subsurface. The
grout used is typically cement or a mixture of
cement and bentonite.
• Deep soil mixing — Overlapping columns
created by a series of large-diameter, counter-
rotating augers that mix in situ soils with an
additive, usually bentonite, cement, or grout,
that is injected through the augers.
Slurry walls are the most frequently planned or
initiated type of VEB. There are five or fewer
applications at Superfund remedial action sites for
each of the other types of VEBs. Some VEBs
incorporate more than one type of barrier.
Additional information on VEBs is available in
Evaluation of Subsurface Engineered Barriers at Waste
Sites (EPA-542-R-98-005), which is available
online at http://clu-in.org.
Table 13. Types of Vertical Engineered
Barriers (FY 1982 - 2005)*
Total Number of Sites = 55
Vertical Engineered
Barrier Type
Slurry Wall
Number of
Barriers**
54
Sheet Pile
Grout
Geosynthetic Wall
Deep Soil Mixing
Other
TOTAL
67
'Includes information from an estimated 74percent of
FY2005 records of decision and amendments.
Sources: 5, 4, 7. Data sources are listed in Section 6.
""Some VEBs incorporate more than one type ot
barrier.
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Section 6: References and
Sources of Additional
Information
Listed below are references and sources of
additional information. The references identify
sources of data and other information presented
in the ASR Twelfth Edition. Online resources also
are identified to download ASR spreadsheets or
search ASR databases.
References
1. List of Superfund National Priorities List
(NPL) sites that are final, www.epa.sov/
super'fund/'sites/query/queryhtm/'nplfina.txt.
September 2005.
2. List of Superfund NPL sites that have been
deleted. www.epa.gov/supertund/sites/query/
queryhtm/npldela.txt. September 2005.
3. Records of Decision (RODs), ROD
Amendments, and Explanations of Significant
Difference from FY 1982 - 2005.
4. Innovative Treatment Technologies: Annual
Status Report (ASR) Eleventh Edition (EPA-
542-R-03-009). EPA. Office of Solid Waste
and Emergency Response (OSWER).
February 2004.
5. Groundwater Remedies Selected at Superfund
Sites (EPA-542-R-01 -022). EPA. OSWER.
January 2002.
6. Use of Monitored Natural Attenuation at
Superfund, RCRA Corrective Action, and
Underground Storage Tank Sites. OSWER
Directive 9200.4-17P. EPA. April 21, 1999.
7. Comprehensive Environmental Response,
Compensation, and Liability Information
System (CERCLIS). http://cfpub.ep-d.sov/
supercpad/cursites/srclisites.cfni.
8. The Role of Cost in the Superfund Remedy
Selection Process (EPA 540-F-96-018). EPA.
OSWER. September 1996.
9. Design and Construction of RCRA/CERCLA
Final Covers (EPA/625/4-91/025). EPA.
Office of Research and Development. May
1991.
Online ASR Resources
EPA maintains several resources online to allow
users of the ASR access to additional information,
including:
• ASR spreadsheets that can be downloaded from
http://clu-in. org/asr.
o Table 1. Source Control Remedy Types at
NPL Sites
o Table 3. Status of Source Treatment Projects
by Technology
o Table 6. Groundwater Remedy Types at NPL
Sites
o Table 10. Status of In Situ Groundwater
Treatment Projects by Technology
o Figure 22. Status of Groundwater Pump and
Treat Projects
For these tables and figures, EPA prepared
spreadsheets listing the specific sites names,
locations, CERCLIS identification numbers, and
types of remedies selected in RODs for the sites.
• Appendices available online at http://clu-in.org/asr:
o Appendix A. Treatment Technologies by
Fiscal Year
o Appendix B. Treatment Technology
Summary Matrix
o Appendix C. Definitions of Specific
Treatment Technologies
o Appendix D. Treatment Technologies:
Summary of Status Report Additions,
Changes, and Deletions
o Appendix E. RODs Selecting Natural
Attenuation
o Appendix F. Identification of Remedy and
Record of Decision Types for Superfund
Remedial Actions
o Appendix G. Reasons tor Shut Down of 73
Groundwater Pump and Treat Systems
o Appendix H. On-Site Containment
Remedies
Some appendices (B, D, E, and H) have
expanded over time and are not available in the
printed version of this report.
-------
ASR Search System — EPA created a searchable,
online system to allow access to the data that form
the basis for this report. See Box 16 for a list of
the types of information available from the ASR
Search System. This system is available at
http://cfpub. epa. eov/asr/.
Box 16. INFORMATION IN ASR SEARCH
SYSTEM
Site Information
• Site name and location (city and state)
• CERCLIS ID
• Description
Project-Specific Information
• Operable unit name
• Cleanup type
• ROD date
• Lead agency and funding information
Contact Information
• Contact name and affiliation
• Address, phone number, and e-mail
Technology Information
Technology and type (in situ or ex situ)
• Description of technology
Treatment of residuals, if applicable
• Details (such as type of additives)
• Indicate whether part of a treatment train
Media and Quantity Information
• Media and quantity
Contaminant Information
• Contaminants treated
• Contaminants not treated
Status Information
• Status
• Date began operation
• Date completion is planned
Completed Project Information
• Cost
• Contaminant concentrations before and
after treatment
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-------
Appendicies B, D, E and H
Appendix B: Treatment Technology Summary Matrix
Appendix D:
Treatment Technologies:
Summary of Status Report Additions,
Changes, and Deletions
Appendix E: RODs Selecting Monitorec
Natural Attenuation
Appendix H: On-Site Containment Remedies
These appendices do not appear in the printed version of
Treatment Technologies for Site Cleanup: Annual Status
Report (Twelfth Edition). The appendices are available ir
the online version of this report at http://clu-in.org/asr.
-------
-------
Appendix C
Definitions of Specific Treatment Technologies
-------
This appendix provides definitions of 17 types of
source control (primarily soil) treatment
technologies, 9 types of in situ groundwater
treatment technologies, 8 types of groundwater
P&T technologies, and 3 containment
technologies. Technologies that are applicable to
both source control and groundwater treatment are
described only once under the source control
treatment section. For P&T technologies, the
descriptions focus on the treatment portion of the
technology. Groundwater pumping technologies
are not addressed in this report. Definitions are
based on the Remediation Technologies Screening
Matrix and Reference Guide, Version 4.0, which
can be viewed at the Federal Remediation
Technologies Roundtable (FRTR) web site at http:/
/ivww.frtr.yov.
SOURCE CONTROL TREATMENT
TECHNOLOGIES
BIOREMEDIATION uses microorganisms to
degrade organic contaminants in soil, sludge, solids,
and groundwater either in situ or ex situ. It can also
be used to make metals or metalloids less toxic or
mobile. When treating organic contaminants, the
microorganisms break down contaminants by using
them as a food source or cometabolizing them with
a food source. Aerobic processes require an oxygen
source, and the end-products typically are carbon
dioxide and warer. Anaerobic processes are
conducted in the absence of oxygen, and the end-
products can include methane, hydrogen gas, sulfide,
elemental sulfur, and dinitrogen gas. Ex situ
bioremediation technologies for groundwater
typically involve treating extracted groundwater in a
bioreactor or constructed wedand. In situ techniques
stimulate and create a favorable environment for
microorganisms to grow and use contaminants as a
food and energy source, or to cometabolize them.
Generally, this process involves providing some
combination of oxygen, nutrients, and moisture, and
controlling the temperature and pH.
Microorganisms that have been adapted for
degradation of specific contaminants are sometimes
applied to enhance the process. For the treatment
of metals and metalloids, it involves biological activity
that promotes the formation of less toxic or mobile
species, by either creating ambient conditions that
will cause such species to form, or changing the
chemical form of the contaminant directly. The
treatment may result in oxidation, reducrion,
precipitation, coprecipitation, or another
transformation of the contaminant.
CHEMICAL TREATMENT, also known as
chemical reduction/oxidation, typically involves
reduction/oxidation (redox) reactions that
chemically convert hazardous contaminants to
compounds that are nonhazardous, less toxic, more
stable, less mobile, or inert. Redox reactions involve
the transfer of electrons from one compound to
another. Specifically, one reactant is oxidized (loses
electrons) and one is reduced (gains electrons). The
oxidizing agents used for treatment of hazardous
contaminants in soil include ozone, hydrogen
peroxide, hypochlorites, potassium permanganate,
Fenton's reagent (hydrogen peroxide and iron),
chlorine, and chlorine dioxide. This method may
be applied in situ or ex situ to soils, sludges,
sediments, and odier solids, and may also be applied
to groundwater in situ or ex situ (P&T). P&T
chemical treatment may also include the use of
ultraviolet (UV) light in a process known as UV
oxidation.
ELECTROKINETICS is based on the theory that
a low-density current will mobilize contaminants
in the form of charged species. A current passed
between electrodes is intended to cause aqueous
media, ions, and particulates to move through the
soil, waste, and water. Contaminants arriving at
the electrodes can be removed by means of
electroplating or electrodeposition, precipitation or
coprecipitation, adsorption, complexing with ion
exchange resins, or by the pumping of water (or
other fluid) near the electrode.
For FLUSHING, a solution of water, surfactants,
or cosolvents is applied to the soil or injected into
the subsurface to treat contaminated soil or
groundwater. When treating soil, the injection is
often designed to raise the water table into the
contaminated soil zone. Injected water and
treatment agents are recovered together with flushed
contaminants.
Both on-site and off-site INCINERATION use
high temperatures (870 to 1,200°C or 1,600 to
2,200°F) to volatilize and combust (in the presence
of oxygen) organics in hazardous wastes. Auxiliary
fuels are often employed to initiate and sustain
combustion. The destruction and removal
efficiency (DRE) for properly operated incinerators
exceeds the 99.99% requirement for hazardous
waste and can be operated to meet the 99.9999%
requirement for polychlorinated biphenyls (PCB)
and dioxins. Off-gases and combustion residuals
generally require treatment. On-site incineration
typically uses a transportable unit; for off-site
-------
incineration, waste is transported to a central
facility.
MECHANICAL SOIL AERATION agitates
contaminated soil, using tilling or other means to
volatilize contaminants.
MULTI-PHASE EXTRACTION uses a vacuum
system to remove various combinations of
contaminated groundwater, separate-phase
petroleum product, and vapors from die subsurface.
The system typically lowers the water table around
the well, exposing more of the formation.
Contaminants in the newly exposed vadose zone
are then accessible to vapor extraction. Once above
ground, the extracted vapors or liquid-phase
organics and groundwater are separated and treated.
NEUTRALIZATION is a chemical reaction
between an acid and a base. The reaction involves
acidic or caustic wastes that are neutralized (pH is
adjusted toward 7.0) using caustic or acid additives.
OPEN BURN (OB) and OPEN DETONATION
(OD) operations are conducted to destroy excess,
obsolete, or unserviceable (EOU) munitions and
energetic materials. In OB operations, energetics
or munitions are destroyed by self-sustained
combustion, which is ignited by an external source,
such as a flame, heat, or a detonation wave. In OD
operations, explosives and munitions are destroyed
by detonation, which generally is initiated by an
energetic charge.
PHYSICAL SEPARATION processes use physical
properties to separate contaminated and
uncontaminated media, or separate different types
of media. For example, different-sized sieves and
screens can be used to separate contaminated soil
from relatively uncontaminated debris. Another
application of physical separation is the dewatering
of sediments or sludge.
PHYTOREMEDIATION is a process that uses
plants to remove, transfer, stabilize, or destroy
contaminants in soil, sediment, or groundwater. The
mechanisms of phytoremediation include enhanced
rhizosphere biodegradation (takes place in soil or
groundwater immediately surrounding plant roots),
phytoextraction (also known as phytoaccumulation,
the uptake of contaminants by plant roots and the
translocation/accumulation of contaminants into
plant shoots and leaves), phytodegradation
(metabolism of contaminants within plant tissues),
and phytostabilization (production of chemical
compounds by plants to immobilize contaminants
at the interface of roots and soil). Phytoremediation
applies to all biological, chemical, and physical
processes that are influenced by plants (including
the rhizosphere) and that aid in the cleanup of
contaminated substances. Phytoremediation may be
applied in situ or ex situ to soils, sludges, sediments,
other solids, or groundwater.
SOIL VAPOR EXTRACTION (SVE) is used to
remediate unsaturated (vadose) zone soil. A vacuum
is applied to the soil to induce the controlled flow
of air and remove volatile and some semivolatile
organic contaminants from the soil. SVE usually
is performed in situ; however, in some cases, it can
be used as an ex situ technology.
For SOIL WASHING, contaminants sorbed onto
fine soil particles are separated from bulk soil in a
water-based system on the basis of particle size. The
wash water may be augmented with a basic leaching
agent, surfactant, or chelating agent, or by adjusting
the pH to help remove contaminants. Soils and wash
water are mixed ex situ in a tank or other treatment
unit. The wash water and various soil fractions are
usually separated using gravity settling.
SOLIDIFICATION/STABILIZATION (S/S)
reduces the mobility of hazardous substances and
contaminants in the environment through both
physical and chemical means. The S/S process
physically binds or encloses contaminants within a
stabilized mass. S/S is performed both ex situ and
in situ. Ex situ S/S requires excavation of the
material to be treated, and the resultant material
must be disposed. In situ S/S uses auger/caisson
systems and injector head systems to add binders
to the contaminated soil or waste without
excavation, leaving the resultant material in place.
SOLVENT EXTRACTION uses an organic
solvent as an extractant to separate contaminants
from soil. The organic solvent is mixed with
contaminated soil in an extraction unit. The
extracted solution then is passed through a
separator, where the contaminants and extractant
are separated from the soil.
For THERMAL DESORPTION, wastes are
heated so that organic contaminants and water
volatilize. Typically, a carrier gas or vacuum system
transports the volatilized water and organics to a
gas treatment system, typically a thermal oxidation
or recovery system. Based on the operating
temperature of the desorber, thermal desorption
processes can be categorized into two groups: high
temperature thetmal desorption (320 to 560°C or
600 to 1000°F) and low temperature thermal
desorption (90 to 320°C or 200 to 600°F). Thermal
desorption is an ex situ treatment process. In situ
C-2)
-------
thermal desorption processes are discussed below
as in situ thermal treatment.
IN SITU THERMAL TREATMENT is a
treatment process that uses heat to facilitate
extraction through volatilization and other
mechanisms or to destroy contaminants in situ.
Volatilized contaminants are typically removed from
the vadose zone using SVE. Specific types of in
situ thermal treatment techniques include
conductive heating, electrical resistive heating, radio
frequency heating, hot air injection, hot water
injection, and steam enhanced extraction.
VITRIFICATION uses an electric current to melt
contaminated soil at elevated temperatures (1,600
to 2,000°C or 2,900 to 3,650°F). Upon cooling,
the vitrification product is a chemically stable,
leach-resistant, glass and crystalline material similar
to obsidian or basalt rock. The high temperature
component of the process destroys or removes
organic materials. Radionuclides and heavy metals
are retained within the vitrified product.
Vitrification may be conducted in situ or ex situ.
'lN 'SITU GROUND WATER TREATMENT
TECHNOLOGIES
AIR SPARGING involves the injection of air or
oxygen into a contaminated aquifer. Injected air
traverses horizontally and vertically in channels
through the soil column, creating an underground
stripper that removes volatile and semivolatile
organic contaminants by volatilization. The
injected air helps to flush the contaminants into
the unsaturated zone. SVE usually is implemented
in conjunction with air sparging to remove the
generated vapor-phase contamination from the
vadose zone. Oxygen added to the contaminated
groundwater and vadose-zone soils also can enhance
biodegradation of contaminants below and above
the water table.
BIOREMEDIATION See Source Control
Treatment Technologies.
CHEMICAL TREATMENT - See Source Control
Treatment Technologies.
ELECTROKINETICS - See Source Control
Treatment Technologies.
FLUSHING - See Source Control Treatment
Technologies.
For IN-WELL AIR STRIPPING, air is injected
into a double-screened well, causing the volatile
organic compounds (VOC) in the contaminated
groundwater to transfer from the dissolved phase
to the vapor phase in air bubbles. As the air bubbles
rise to the surface of the water, the vapors are drawn
off and treated by a SVE system.
MULTI-PHASE EXTRACTION - See Source
Control Treatment Technologies.
PERMEABLE REACTIVE BARRIERS (PRB),
also known as passive trearment walls, are installed
across the flow path of a contaminated groundwater
plume, allowing the water portion of the plume to
flow through the wall. These barriers allow the
passage of water while prohibiting the movement
of contaminants by employing treatment agents
within the wall such as zero-valent metals (usually
zero-valent iron), chelators, sorbents, compost, and
microbes. The contaminants are either degraded
or retained in a concentrated form by the barrier
material, which may need to be replaced
periodically.
PHYTOREMEDIATION See Source Control
Treatment Technologies.
PUMP AND TREAT TECHNOLOGIES
(EX SITU TREATMENT)
In ADSORPTION, contaminants concentrate at
the surface of a sorbent, thereby reducing their
concentration in the bulk liquid phase. This
technology is typically applied by passing extracted
groundwater through a column containing granular
adsorbent. The most common adsorbent is
granulated activated carbon. Other natural and
synthetic adsorbents include activated alumina,
lignin adsorption, sorption clays, and synthetic
resins.
AIR STRIPPING partitions volatile organics from
extracted groundwater by increasing the surface area
of the contaminated water exposed to air. Aeration
methods include packed towers, diffused aeration,
tray aeration, and spray aeration.
BIOREMEDIATION - See Source Control
Treatment Technologies.
CHEMICAL TREATMENT - See Source Control
Treatment Technologies.
FILTRATION is the physical process of mechanical
separation based on particle size, whereby particles
suspended in a fluid are separated by forcing the
fluid through a porous medium. As fluid passes
through the medium, the suspended particles are
trapped on the surface of the medium and/or within
the body of the medium.
-------
ION EXCHANGE removes ions from the aqueous
phase by the exchange of cations or anions between
the contaminants and the exchange medium. Ion
exchange materials may consist of resins made from
synthetic organic materials that contain ionic
functional groups to which exchangeable ions are
attached.
METALS PRECIPITATION transforms dissolved
contaminants into an insoluble solid, facilitating
the contaminant's subsequent removal from the
liquid phase by sedimentation or filtration. The
process usually uses pH adjustment, addition of a
chemical precipitant, and flocculation.
MEMBRANE FILTRATION separates
contaminants from water by passing it through a
semipermeable barrier or membrane. The membrane
allows water and other low molecular weight
chemicals to pass, while blocking contaminants with
a higher molecular weight. Membrane filtration
processes include microfiltration, ultrafiltration,
nanofiltration, and reverse osmosis.
MONITORED NATURAL ATTENUATION
(MNA) FOR GROUNDWATER
Groundwater MNA is the reliance on natural
attenuation processes (within the context of a
carefully controlled and monitored approach to site
cleanup) to achieve site-specific remediation
objectives within a time frame that is reasonable,
compared with that offered by other, more active
methods. The "natural attenuation processes"
include a variety of physical, chemical, or biological
processes that, under favorable conditions, act
without human intervention to reduce the mass,
toxicity, mobility, volume, or concentration of
contaminants in soil or groundwater. These in situ
processes include biodegradation; dispersion;
dilution; sorption; volatilization; radioactive decay;
and chemical or biological stabilization,
transformation, or destruction of contaminants.
Guidance on MNA is available from the document
"Use of Monitored Natural Attenuation at
Superfund, RCRA Corrective Action, and
Underground Storage Tank Sites (OSWER
Directive 9200.4-17P, EPA, April 21, 1999.").
CONTAINMENT TECHNOLOGIES
COVER SYSTEMS, also known as caps or covers,
are surface barriers composed of one of more layers
of impermeable material designed to contain
contaminated source material. COVER SYSTEMS
can be used to prevent direct contact with the source
material or minimize leachate creation by
preventing surface water infiltration into the
contained source material.
A BOTTOM LINER is a subsurface impermeable
barrier designed to prevent the spread of leachate
from contaminated source material. They are often
used in conjunction with COVER SYSTEMS in
the containment of source material.
VERTICAL ENGINEERED BARRIERS (VEB)
are subsurface barriers made of an impermeable
material designed to contain or divert groundwater.
VEBs can be used to contain contaminated
groundwater, divert uncontaminated groundwater
from a contaminated area, or divert contaminated
groundwater from a drinking water intake or other
protected resource. VEBs can also be used for the
containment of source material.
C-J)
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-------
Append
Identification of Remedy and Record of Decision
Types for Superfund Remedial Actions
-------
f. 7 BACKGROUND
On December 11, 1980, Congress passed the
Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA),
which is known as the "Superfund" act. The act
created the Superfund program, which was
established to clean up abandoned hazardous waste
sites around the United States. Section 105(a)(8)(B)
of CERCLA, as amended, requires that the U.S.
Environmental Protection Agency (EPA) prepare a
list of national priorities among the known sites
throughout the United States at which releases or
threatened releases of hazardous substances,
pollutants, or contaminants may occur. This list is
known as the National Priorities List (NPL).
The remedies selected for an NPL site are
documented in a record of decision (ROD).
Remedies implemented at NPL sites or NPL
equivalent sites in accordance with RODs are known
as Superfund remedial actions, and such sites are
known as Superfund remedial action sites. Because
selected remedies vary in the type of media addressed
and the methods used to address those media,
confusion can arise when assigning a type to a
particular remedy. Categorizing remedies by types
can facilitate the transfer of experience and
technology by making it easier to identify sites at
which similar remedies are applicable. Establishing
and applying a methodology for classifying remedy
types can provide a consistent and comprehensive
approach for reviewing and comparing remedies used
in RODs. In addition, use of such an approach can
lead to more consistent data collection and reporting
and assist remedial project managers (RPMs), On-
Scene Coordinators (OSCs), and other regulatory
and remediation professionals in the transfer of
experience and technology among Superfund sites
and in identifying sites implementing similar
remedies. This Appendix describes the approach used
to classify remedies and RODs for the ASR.
Remedies were classified by reviewing the remedies
selected in RODs. Although RODs are written
using an overall format that is consistent, RODs
are prepared by individual RPMs and other staff of
the 10 EPA regions. In addition, the management
practices and techniques used to remediate sites
have evolved over time and continue to evolve.
Therefore, the words, phrases, and descriptions
applied to the same or similar remedies may differ
from ROD to ROD. To facilitate the identification
of remedy types, this appendix includes both
descriptive definitions of remedy types and lists of
key words and phrases that may be used to refer to
each remedy type.
The definitions of remedy types provided in this
document are based on a review of definitions and
lists of media, remedies, and technologies provided
in the following resources:
• The CERCLA Information System (CERCLIS
3) database
• ROD Annual Reports for fiscal years (FY) 1989
through 2005
• The Federal Remediation Technologies
Roundtable (FRTR) Technology Screening
Matrix
• Treatment Technologies for Site Cleanup:
Annual Status Report (Twelfth Edition) (ASR)
The remedy type definitions were reviewed and
augmented by a working group of personnel of the
EPA Office of Solid Waste and Emergency
Response (OSWER) who are experienced in site
remediation and ROD preparation and review.
F.2' CLASSIFYING REMEDIES AND RODs
Remedy types were identified by first dividing
remedies into three categories (source control,
groundwater, and no action) based on the media
treated and the type of action. Within each of these
categories, the remedies were then further divided
into the following 10 specific remedy types:
Source Control Remedies:
1. Source control treatment
2. Source control containment
3. Source control other
4. Source control monitored natural attenuation
Groundwater Remedies:
5. Groundwater in situ treatment
6. Groundwater pump and treat
7. Groundwater containment barriers
8. Groundwater other
9. Groundwater monitored natural attenuation
No Action Remedies:
10. No action or no further action (NA/NFA)
RODs were classified using the 10 remedy types
listed above. When more than one remedy type
was selected in the same ROD, the ROD was
assigned all of the remedy types that are identified.
-------
The definitions that were used to identify each
remedy type are provided in the "Definitions"
section below. When definitions include specific
technologies and those technologies commonly are
referred to by more than one word or phrase, the
most commonly used word or phrase is listed first,
followed by synonyms in parentheses.
F.3* 'DEFINITIONS USED TO IDENTIFY
REMEDY TYPES
F.3.1 General Definitions
The definitions of treatment technology and the
different types of treatment technologies (physical,
chemical, thermal, and biological treatment) apply
to both source control and groundwater remedies.
Treatment Technology - Any unit operation or series
of unit operations that alters the composition of a
hazardous substance, pollutant or contaminant
through chemical, biological, or physical means so
as to reduce toxicity, mobility, or volume of the
contaminated materials being treated. Treatment
technologies are an alternative to land disposal of
hazardous wastes without treatment (Federal
Register, volume 55, page 8819, 40 CFR 300.5:
Definitions). Treatment technologies are grouped
into five categories. The definitions for four of the
categories (physical treatment, chemical treatment,
thermal treatment, and biological treatment) are
based on definitions provided in the FRTR
Technology Screening Matrix. The fifth category,
other or unspecified treatment, includes those
technologies that do not fit into the first four
categories. The five treatment technology categories
are:
Physical Treatment - Uses the physical properties of
the contaminants or the contaminated medium to
separate or immobilize the contamination.
Chemical Treatment - Chemically converts
hazardous contaminants to non-hazardous or less
toxic compounds or compounds that are more
stable, less mobile, and/or inert. Even though a
chemical reaction is not always involved in chemical
precipitation, chemical precipitation is typically
included in this category.
Thermal Treatment - Uses heat to: separate
contaminants from contaminated media by
increasing their volatility; destroy contaminants or
contaminated media by burning, decomposing, or
detonating the contaminants or the contaminated
media; or immobilize contaminants by melting and
solidifying the contaminated media.
Biological Treatment - Includes adding or
stimulating the growth of microorganisms, which
metabolize contaminants or create conditions under
which contaminants will chemically convert to non-
hazardous or less toxic compounds or compounds
that are more stable, less mobile, and/or inert.
Phytoremediation, the use of plants to remove,
stabilize, or destroy contaminants, is included
within the definition of biological treatment.
Other or Unspecified Treatment - Treatment that
cannot be classified as physical treatment, chemical
treatment, thermal treatment, or biological
treatment. For example, some RODs select
physical/chemical treatment of a source without
specifying the particular physical/chemical
treatment. In such cases, the ROD was not
definitively classified as physical or chemical
treatment and was classified as other or unspecified
treatment, unspecified physical/chemical treatment.
F.3.2 Source Control Remedies
Source Media - A source medium is defined as a
material that acts as a reservoir, either stationary or
mobile, for hazardous substances. Source media
include or contain hazardous substances, pollutants,
ot contaminants that may migrate to the
groundwater, to surface water, to air, (or to other
environmental media) or act as a source for direct
exposure. Contaminated groundwater generally is
not considered to be a source material although
nonaqueous phase liquids (NAPLs [occurring either
as residual- or free-phase]) may be viewed as source
materials. (A Guide to Principal Threat and Low
Level Threat Wastes, Superfund publication
9355.3-02FS, USEPA OSWER 1991). Source
media include soil, sediment, sludge, debris, solid-
matrix wastes, surface water, NAPLs, equipment,
drums, storage tanks, leachate, landfill gas, and any
other contaminated media other than groundwater
that can act as a potential source of contamination.
Source Control Remedy - any removal, treatment,
containment, or management of any contaminant
source or contaminated medium other than
groundwater.
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1. Source Control Treatment
Any process meant to separate and remove, destroy, or bind contaminants in a source medium. Key
words used in RODs to identify these processes are listed below. Additional detail about these technologies
can be found in the ASR at http:lldu-in.org/asr or on the Federal Remediation Technologies Roundtable
Web site at http://www.frtr.yov.
Physical Treatment
Acid extraction
Air stripping
Carbon adsorption (liquid-phase carbon
adsorption)
Clarification (sedimentation)
Decontamination
Dewatering
Electrical separation (electrokinetic separation)
Evaporation
Filtration
Flushing (soil flushing and surfactant flushing)
Ion exchange
Magnetic separation
Membrane filtration (microfiltration,
nanofiltration, reverse osmosis, ultrafiltration)
Multi-phase extraction (free product recovery)
Oil/water separation (free product recovery)
Physical separation (component separation and
materials handling)
Soil vapor extraction (vacuum extraction and
vapor extraction)
Soil washing
Solidification/stabilization (asphalt batching,
immobilization, and microencapsulation)
Solid-phase extraction
Solvent extraction (chemical stripping)
Steam stripping
Super-critical fluid extraction
Volatilization (aeration, mechanical soil
aeration, and tilling)
Chemical Treatment
Chemical oxidation (cyanide oxidation,
oxidation, and peroxidation)
Chemical reduction (reduction)
Chemical treatment (chemical reduction/
oxidation and remedy type not further
specified)
Dehalogenation (dechlorination)
Flocculation
Metals precipitation
Neutralization (pH neutralization)
Permeable reactive barrier (chemical reactive
barrier, chemical reactive wall, leachate
reactive wall, and passive treatment wall)
Ultraviolet (UV) oxidation
Thermal Treatment
Flaring (gas flaring)
High energy corona
Open burning/open detonation
Plasma high-temperature recovery (fuming
gasification and high-temperature metals
recovery)
Thermal clesorption
Thermal destruction (incineration and
pyrolysis)
Thermal treatment (remedy type not further
specified)
In situ thermal treatment (conductive heating,
Contained Recovery of Oily Wastes [CROWcr
dynamic underground stripping, electrical
resistance heating, hot air injection, in situ
thermal desorption, microwave heating, radio
frequency heating, steam injection, and
diermally enhanced soil vapor extraction)
Vitrification (slagging)
Biological Treatment
Aeration (for purpose of bioremediation, tilling)
Biopile
Bioreactor
Bioremediation (biological treatment, remedy
type not further specified)
Bioslurping
Bioventing
Co-metabolic treatment
Composting
Controlled solid phase
Fixed film reactors
Landfarming
Microbial injection (addition of
microorganisms)
Nitrate enhancement
Nutrient injection
Oxygen enhancement with air sparging
(biosparging)
-------
Biological Treatment (continued)
Oxygen enhancement with hydrogen peroxide
(H202)
Permeable treatment bed (for purpose of
bioremediation)
Phyto remediation
Slurry-phase bioremediation (bioslurry,
activated sludge)
White rot fungus
Other or unspecified Treatment
Air emission treatment
Fracturing (pneumatic fracturing, hydraulic
fracturing)
Gas collection and treatment (off-gas treatment)
Hot gas decontamination
Leachate treatment
Publicly owned treatment works (POTW)
Recycling
Surface water treatment
Treatment of residuals
Unspecified physical/chemical treatment
Unspecified treatment
2. Source Control Containment
Any process or structure designed to prevent contaminants from migrating from a source media into
groundwater, to surface water, to air, (or to other environmental media) or acting as a source for direct
exposure. Key words used in RODs to identify source control containment remedies are listed below:
Capping and Cover
Cap (impermeable barrier)
Cover material
Bottom Liner
Clay
Geosynthetic material
Evapotranspiration cover
Liner (impermeable barrier)
Drainage and Erosion Control
Engineering control (remedy type not further
specified)
Hydraulic control
Impermeable barrier
Revegetation
Slope stabilization
Subsurface drain (leachate control)
Surface water control (dike, berm, drainage
controls, drainage ditch, erosion control,
flood protection, and levee)
On-Site Landfilling
On-site consolidation
On-site disposal
On-site landfilling (remedy type not further
specified)
Off-Site Landfilling
Off-site consolidation
Off-site disposal
Off-site landfilling (remedy type not further
specified)
Vertical Engineered Barrier
(When used as a remedy for a source medium [including subsurface NAPLs]. Vertical subsurface
engineered barriers used to control or contain groundwater should not be considered source control
containment.)
Grout (grout curtain)
Impermeable barrier
Sheet piling
Slurry wall
Subsurface barrier
Vertical barrier
F-4
-------
Repair (pipe repair, sewer repair, .and tank
repair)
Surface water management (surface water
collection, surface water discharge, surface
water recovery wells, surface water
reinjection)
Other or unspecified Containment
Containment (consolidation, disposal,
landfilling, and removal)
Encapsulation (overpacking)
Leachate control (leachate collection, leachate
discharge, leachate recovery wells, leachate
reinjection)
Liquid waste management (liquid waste
collection, liquid waste discharge, liquid
waste recovery wells, liquid waste reinjection)
Permanent storage
3. Source Control Other
Source control remedies that do not fall into the categories Source Control Treatment or Source Control
Containment,
institutional Control
The classification of institutional controls has been revised based on Institutional Controls: A Site
Manager's Guide to Identifying, Evaluating, and Selecting Institutional Controls at Superfund and RCRA
Corrective Action Cleanups, OSWER9355.0-74FS-P, EPA 540-F-00-005, September 2000. The remedy
definitions outlined in this guidance differ from those historically used to classify institutional control
remedies. This classification system groups institutional controls into 4 categories. Listed below are
these tour categories. Beneath each category, the terms historically applied to institutional controls that
are most likely to fall under the categories are listed. The list below also adds a fifth category, "Institutional
control (remedy type not further specified)" for cases where the particular institutional control selected
is not recorded in a ROD.
1. Governmental control
Access restriction
Drilling restriction
Fishing restriction
Guard (security)
Recreational restriction
Surface water restriction
Swimming restriction
Water supply use restriction
2. Proprietary control
Deed notification
Deed restriction
Land use restriction
3. Enforceable agreement
Access agreement
4. Informational device
5. Institutional control (remedy type not
further specified)
Engineering Control
Dust suppression
Engineering control (remedy type not further
specified)
Fencing
Water table adjustment
Wetland replacement
Source Monitoring
Monitoring
Sampling
Population Relocation
Population relocation
Surface water Supply Remedies
Alternate water supply (alternate drinking
water and bottled water)
Carbon at tap
Well-head treatment
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4. Source Control Monitored Natural Attenuation (MNA)
The reliance on natural attenuation processes (within the context of a carefully controlled and monitored
approach to site cleanup) to achieve site-specific remediation objectives within a timeframe that is
reasonable, compared with that offered by other, more active methods. The "natural attenuation processes"
that are at work in such a remediation approach include a variety of physical, chemical, or biological
processes that, under favorable conditions, act without human intervention to reduce the mass, toxicity,
mobility, volume, or concentration of contaminants in soil or groundwater. These in situ processes
include biodegradation; dispersion; dilution; sorption; volatilization; radioactive decay; and chemical or
biological stabilization, transformation, or destruction of contaminants (Use of Monitored Natural
Attenuation at Superfund, RCRA Corrective Action, and Underground Storage Tank Sites, USEPA,
Office of Solid Waste and Emergency Response, Directive Number 9200.4-17P, 1999).
A remedy should be considered source control MNA if it includes "natural attenuation" or "monitored
natural attenuation" for a source (e.g., contaminated soil).
F.3.3. Groundwater Remedies
Groundwater Remedy - Management of groundwater.
Groundwater remedies can include in situ treatment,
pump and treat, containment using vertical
Groundwater Media - One or more aquifers beneath
or proximal to a source medium, contaminated by
migration of contaminants, such as leachate, or by
engineered barriers, MNA, and other measures to other sources.
address groundwater.
5. Groundwater In Situ Treatment
Treatment of groundwater without extracting it from the ground. Key words used in RODs to identify
groundwater in situ treatment remedies are listed below:
Physical Treatment
Air sparging Multi-phase extraction (free product recovery)
Electrical separation (electrokinetic separation) Surfactant flushing
In-well air stripping (well aeration and air Vapor extraction
stripping)
Chemical Treatment
Chemical oxidation (cyanide oxidation, Dehalogenation (dechlorination)
oxidation, and peroxidation) Permeable reactive barrier (chemical reactive
Chemical reduction (reduction) barrier, chemical reactive wall, and passive
Chemical treatment (chemical reduction/ treatment wall)
oxidation and remedy type not further
specified)
Biological Treatment
Aeration (for purpose of bioremediation)
Bioremediation (biological treatment, remedy
type not further specified)
Bioslurping
Bioventing
Co-metabolic treatment
Microbial injection (addition of
microorganisms)
Nitrate enhancement
Nutrient injection
Oxygen enhancement with air sparging
(biosparging)
Oxygen enhancement with hydrogen peroxide
(HA)
Phytoremediation
Other or Unspecified Treatment
Fracturing (pneumatic fracturing, hydraulic
fracturing)
Treatment of residuals
Unspecified physical/chemical treatment
Unspecified treatment
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6. Groundwater Pump and Treat
Extraction of groundwater from an aquifer followed by treatment above ground. Key words used in
RODs to identify groundwater pump and treat remedies are listed below:
Physical Treatment
Aeration (air stripping)
Carbon adsorption (liquid phase carbon
adsorption)
Clarification (sedimentation)
Coagulation
Component separation
Equalization
Evaporation
Filtration
Ion exchange
Membrane filtration (microfiltration,
nanofiltration, reverse osmosis,
ultrafiltration)
Oil/water separation (free product recovery)
Chemical Treatment
Chemical oxidation (cyanide oxidation,
oxidation, and peroxidation)
Chemical reduction
Chemical treatment (chemical reduction/
oxidation and remedy type not further
specified)
Flocculation
Metals precipitation
Neutralization (pH neutralization)
Ultraviolet (UV) oxidation
Biological Treatment
Biological treatment (remedy type not further
specified)
Bioreactors
Fixed film reactors
Oxygen enhancement with hydrogen peroxide
(HA)
Wetlands treatment
Other or unspecified Treatment
Centralized waste treatment facility
Fracturing (pneumatic fracturing, hydraulic
fracturing)
Publicly owned treatment works (POTW)
Pumping and unspecified ex-situ treatment
Treatment of residuals
Unspecified ex-situ physical/chemical treatment
Unspecified treatment
Groundwater Extraction
The process of removing groundwater from beneath the ground surface, including the following methods
of groundwater extraction:
Directional well (horizontal well) Recovery trench (horizontal drain)
Pumping (recovery well, vertical well) Subsurface drain
Croundwater Discharge and Management
A method of discharging or otherwise managing extracted groundwater, including the following discharge
methods and receptors:
Deep well injection (Class 1 well) Surface drain reinjection (infiltration basin,
Recycling infiltration trench)
Reuse as drinking water Surface water discharge (National Pollutant
Discharge Elimination System [NPDES1
Reuse as irrigation water
discharge)
Reuse as process water ., . .......
Vertical well reinjection (into contaminated
aquifer)
-------
7. Groundwater Containment
Containment of groundwater, typically through the use of vertical engineered barriers. Key words used
in RODs to identify groundwater containment remedies are listed below:
Vertical Engineered Barrier
Deep soil mixing (barrier installation Impermeable barrier
technique) Sheet piling
Geosynthetic wall Slurry wall
Grout (grout curtain) Subsurface vertical engineered barrier
High-density polyethylene (HOPE) wall (subsurface barrier, subsurface vertical barrier)
Other or Unspecified Containment
Plume containment (hydraulic containment of plume, plume management, plume migration control)
8. Groundwater Other
Groundwater remedies that do not fall into the categories Groundwater In situ Treatment, Groundwater
Pump and Treat, Groundwater Containment, or Groundwater Monitored Natural Attenuation.
Institutional Control
The classification of institutional controls has been revised based on Institutional Controls: A Site
Manager's Guide to Identifying, Evaluating, and Selecting Institutional Controls at Superfund and RCRA
Corrective Action Cleanups, OSWER 9355.0-74FS-P, EPA 540-F-00-005, September 2000. The remedy
definitions outlined in this guidance differ from those historically used to classify institutional control
remedies. This classification system groups institutional controls into 4 categories. Listed below are
these four categories. Beneath each category, the terms historically applied to institutional controls that
are most likely to fall under the categories are listed. The list below also adds a fifth category, "Institutional
control (remedy type not further specified)" for cases where the particular institutional control selected
is not recorded in a ROD.
1. Governmental control
Access restriction
Drilling restriction
Fishing restriction
Groundwater restriction
Guard (security)
Recreational restriction
Surface water restriction
Swimming restriction
Water supply use restriction
2. Proprietary control
Deed notification
Deed restriction
Land use restriction
3. Enforceable agreement
Access agreement
4. Informational device
5. Institutional control (remedy type not
further specified)
Engineering Control
Engineering control (berm, dike, drainage
ditch, levee)
Water table adjustment
Wetland replacement
Groundwater Monitoring
Monitoring
Sampling
Population Relocation
Population Relocation
Water Supply Remedies
Alternate water supply (alternate drinking
water and bottled water)
Carbon at tap
Extend piping to existing water main
Install new surface water intake
Install new water supply wells
Seal well (close well)
Treat at use location
Well-head treatment
-------
9. Groundwater MNA
The reliance on natural attenuation processes (within the context of a carefully controlled and monitored
approach to site cleanup) to achieve site-specific remediation objectives within a time frame that is
reasonable, compared with that offered by other, more active methods. The "natural attenuation processes"
that are at work in such a remediation approach include a variety of physical, chemical, or biological
processes that, under favorable conditions, act without human intervention to reduce the mass, toxicity,
mobility, volume, or concentration of contaminants in soil or groundwater. These in situ processes
include biodegradation; dispersion; dilution; sorption; volatilization; radioactive decay; and chemical or
biological stabilization, transformation, or destruction of contaminants (Use of Monitored Natural
Attenuation at Superfund, RCRA Corrective Action, and Underground Storage Tank Sites, USEPA,
Office of Solid Waste and Emergency Response, Directive Number 9200.4-17P, 1999).
A remedy should be considered groundwater MNA if it includes "natural attenuation" or "monitored
natural attenuation" of groundwater.
F.3.4 No Action Remedies
10. NA/NFA
The designation used for remedies that indicate no action or no further action will be taken. When
determining overall ROD type, the designation was used only for RODs under which NA/NFA is the
only remedy selected. If a ROD selected NA/NFA for only part of a site and another remedy for another
part of a site, the ROD was given the classification corresponding to that selected remedy and was not
given an NA/NFA designation.
F.4 SPECIAL CASES
This subsection provides a list of some special cases
and descriptions of how remedy types should be
assigned in those cases:
Decon tamination
* The remedy type for decontamination of
buildings, equipment, tanks, debris, boulders,
rocks, or other objects was considered source
control treatment. For example, abrasive
blasting or scarifying a concrete pad to remove
the contaminated surface layer of the pad was
identified as source control treatment.
• Decontamination of equipment used to clean
up a Superfund site is a normal activity that
occurs at many Superfund sites and was not
considered a remedy. For example, high-
pressure water washing of a front end loader used
to excavate contaminated soil was not considered
a remedy and was not given a remedy type.
Phytoremediation
* Phytoremediation involves che use of
macroscopic plants to destroy, remove,
immobilize, or otherwise treat contaminants.
While this technology may include the use of
microorganisms in conjunction with plants, it
is distinguished from bioremediation in that
bioremediation does not use macroscopic plants.
Remedies that used microorganisms without
macroscopic plants were identified as
bioremediation.
• The use of plants to control surface water
drainage at a site is not phytoremediation. Such
remedies were identified as engineering controls
(source control other or groundwater other).
Remedies Based on Site Characteristics - It a ROD
indicates that a certain remedy be implemented
based on certain site characteristics, the ROD
should be considered to have selected the remedy.
For example, a ROD may specify that if soils exceed
a certain level of contamination they will be
incinerated, but if they do not exceed that level, no
further action will be taken. In such a case, the
ROD was considered to have selected incineration
and therefore was considered a source control
treatment ROD.
Vertical Engineered Barriers - Some of the
technologies used tor vertical engineered barriers
are also used to control surface water and surface
drainage (for example, slurry walls and sheet piles).
Where these remedies were used to contain
groundwater, they were identified as groundwater
containment.
•9
-------
Solidification/Stabilization - Some of the
technologies used for solidification/stabilization can
be used for either treatment or containment. For
example, "encapsulation" of a waste in plastic drums
is source control containment. "Encapsulation" of
a waste by mixing with a monomer and then
causing it to polymerize, resulting in
microencapsulation, is source control.treatment. In
general, containment involves isolating bulk wastes,
while solidification/stabilization involves
incorporating the contaminants into a matrix so
that their leachability is reduced.
Water Table Adjustment - Where water table
adjustment is used to prevent the groundwater from
coming into contact with a contaminated source
medium, it was identified as source control other,
engineering control. Where water table adjustment
was used to treat groundwater, it was classified as
groundwater other, engineering control.
Subsurface Drain - When a subsurface drain was
used in order to prevent contact of precipitation
runoff with a source or to prevent erosion, it was
considered source control containment, drainage
and erosion control. When a subsurface drain was
used to extract groundwater prior to treatment of
the groundwater, it was classified as groundwater
pump and treat, groundwater extraction.
Treatment of Residuals- Residuals are the matter that
results from a treatment process. For example, the
residuals from incineration of soil can include ash,
off-gasses, and scrubber blowdown from off-gas
treatment. In the preceding example, treatment of
off-gasses using a scrubber was classified as treatment
of residuals. Where treatment of residuals was
specified in a ROD, the existence of residuals
treatment was identified, but additional information
on the treatment of residuals was not collected.
Air Media - Air media include sources that are in a
gaseous form, such as landfill gas or hazardous gasses
stored in compressed gas cylinders. When remedies
for air media were selected in a ROD they were
identified as source control remedies. For example,
collection and treatment of landfill gas was classified
as source control treatment. Air emissions from
equipment used to treat sources or groundwater
are not air media. For example, a ROD may specify
that groundwater will be extracted and treated by
air stripping, and the off-gas generated by the air
stripping must be treated by activated carbon
adsorption. In such a case, the ROD was classified
as groundwater pump-and-treat (both physical
treatment, aeration [air stripping]; and other or
unspecified treatment, treatment of residuals), but
was not classified as a source control treatment
ROD.
-------
-------
Appendix
Reasons for Shut Down of 73 Groundwater
Pump and Treat Systems
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Index
Air sparging 1-3, 1-5,4-2,4-8,4-9,4-11,
4-12,4-15
B
Bioremediation 1-5, 3-4, 3-5, 3-6, 3-7, 3-8,
3-9, 3-10, 3-11, 3-12, 3-13,4-8,4-9,4-11,
4-12,4-15
c
Chemical treatment 1-3, 1-4, 1-5, 3-2, 3-5.
3-6, 3-7, 3-8, 3-10, 3-11, 3-13, 4-8, 4-9, 4-11,
4-12,4-15
Comprehensive Environmental Response,
Compensation, and Liability Act
(CERCLA) 1-2, 2-2, 5-3, 6-1
CERCLA Information System (CERCLIS) 1-2,
1-5,3-2,3-11,3-13,4-1,4-9,4-11, 5-1, 5-2,
5-3,6-1,6-2
Contaminants 1-2, 1-4, 1-5, 3-2, 3-9, 3-10,
3-11, 3-12, 3-13, 4-1,4-3, 4-7, 4-8, 4-9, 4-12,
4-13,4-15, 5-1, 5-2, 6-2
N
National Priorities List (NPL) .... 1-2, 1-4, 1-5, 1-6,
1-7, 2-2, 2-4, 3-2, 3-10, 3-12, 4-1,4-3, 4-9,
4-12,4-13, 5-1, 5-2,5-3,6-1
Neutralization ; 3-7, 3-8, 3-11
o
On-site containment 1-2, 1-4, 1-7, 5-1, 5-2,
5-3,5-6,6-1
Open burn/open detonation 3-8
P
Permeable reactive barrier (PRB 4-9, 4-1 1,
4-12,4-15, 5-8
Physical separation 3-7, 3-8, 3-11, 3-13
Phytoremediation ... 3-7, 3-8, 3-10, 3-11,4-9, 4-11
Preliminary close-out report (PCOR) 1-2, 1-5,
4-13,5-1,5-2,5-3
Pump and treat (P&T) 1-2, 1-3, 1-4, 1-5, 2-4,
2-5, 3-6, 4-1,4-2, 4-3, 4-4, 4-5, 4-6, 4-7, 4-8,
4-12,4-13,4-14,4-15
Dense nonaqueous-phase liquid (DNAPL) 2-5,
3-6, 3-9, 4-12
Electrical separation 3-7, 3-8, 3-10, 3-11
F
Federal Remediation Technologies
Roundtable (FRTR) 3-1, 3-10, 4-1
Flushing... 3-6, 3-7, 3-8, 3-9, 3-10, 3-11, 4-9, 4-11
Groundwater 1-1, 1-2, 1-3, 1-4, 1-5, 1-6,
1-7, 2-2, 2-3, 2-4, 2-5, 3-1, 3-6, 3-12, 4-1,4-2,
4.3, 4-4, 4-5, 4-6, 4-7, 4-8, 4-9, 4-11, 4-12,
4-13, 4-14, 4-15, 5-1, 5-5, 5-6, 5-8, 6-1
H
Hazardous Waste Cleanup Information
(CLU-1N) 3-11, 3-12
I
In situ thermal treatment 3-9, 3-10, 3-13
In-well air stripping 4-9, 4-11
Incineration 1-2, 2-5, 3-5, 3-7, 3-8, 3-9,
3-12,3-13
Innovative 1-2, 1-4, 3-9, 3-10, 3-11, 3-13
M
Mechanical soil aeration 3-8, 3-11
Monitored natural attenuation (MNA) 1-2,
1-3, 1-6, 2-3, 2-4, 4-1,4-2, 4-3, 4-4, 4-5, 4-6,
4-7,4-8, 4-13, 4-15
Multi-phase extraction 1-4, 3-4, 3-5, 3-7, 3-8,
3-9, 3-10, 3-11, 3-13, 4-8, 4-11,4-15
Record of Decision (ROD) 1-2, 1-4, 1-5, 1-6,
2-2, 2-3, 2-4, 2-5, 3-1, 3-2, 3-3, 3-5, 3-6, 3-11,
3-12, 3-13, 4-3, 4-4, 4-5, 4-6, 4-7, 4-8, 4-9,
4-13,4-15, 5-1, 5-2, 5-6, 5-8,6-1
Remedial action 1-2, 2-2, 2-4, 4-12, 4-13, 5-1,
5-2, 5-3, 5-8, 6-1
s
Soil vapor extraction (SVE) 1-2, 1-4, 2-5, 3-4,
3-5, 3-7, 3-8, 3-9, 3-12, 3-13, 4-3
Soil washing .' 3-7, 3-8, 3-11,3-13
Solidification/stabilization (S/S) 1-2, 2-5, 3-4,
3-5, 3-7, 3-8, 3-12
Solvent extraction 3-7, 3-8, 3-10,3-11,3-13
Source control 1-2, 1-3, 1-4, 1-6, 1-7, 2-2, 2-3,
2-4, 2-5, 3-1, 3-2, 3-3, 3-4, 3-5, 3-7, 3-10,
3-11, 3-12, 3-13,4-1,4-3, 5-1, 6-1
Status 1-2, 1-5, 1-6, 2-2, 2-4, 3-2, 3-7, 3-8,
4-1, 4-11,4-12,4-13, 5-1, 5-2, 5-3, 6-1, 6-2
Thermal desorption 1-2, 2-5, 3-2, 3-5, 3-7,
3-8,3-11,3-12,3-13
Vertical engineered barrier (VEB) 1-2, 4-1,
4-2,4-3,4-4,4-6, 5-1, 5-8
Vitrification... .. 3-8, 3-10,3-11
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