Superfund Remedy Report
16th Edition
o-EPA
United States
Environmental Protection
Agency
E PA-542- R-20-001
Office of Land and Emergency Management
July 2020
-------
Superfund Remedy Report, 16th Edition
Photo Credits:
Top left: Bird resting on boom at New Bedford Harbor Site in Massachusetts. Photo courtesy of
EPA Region 1, https://www.flickr.com/photos/usepagov/sets/7 215762545387 2678/
Top middle left: Soil sampling at Smokey Mountain Smelters in Tennessee. Photo courtesy of
EPA,
https://response.epa.gov/site/image zoom,aspx?site id=4643&xounter=133144&xategorv=&iRet
urnURL=image listview.aspx
Top middle right: Mechanical dredging at New Bedford Harbor Site in Massachusetts. Photo
courtesy of EPA Region 1,
https://www.flickr.com/photos/usepagov/31537773908/in/album-72157625453872678/
Top right: Filter press at New Bedford Harbor Site in Massachusetts. Photo courtesy of EPA
Region 1, https://www.flickr.com/photos/usepagov/sets/7 215762545387 2678/
Middle left: Treatment vessels at Fairfax St. Wood Treaters in Florida. Photo courtesy of EPA,
https://response.epa.gov/site/image zoom,aspx?site id=6253&xounter= 120810&xategorv=&LRet
urnURL=image listview.aspx
Middle center: Structure demolition at Savannah River Site in South Carolina. Photo courtesy of
EPA Region 4, https://www.epa.gov/superfund/superfund-success-stories-epa-region-4
Middle right: Treatment plant at Bunker Hill Mining and Metallurgical Complex in Idaho. Photo
courtesy of EPA Region 10, https://www.epa.gov/superfund/superfund-success-stories-epa-region-
10
Bottom left and right: Before and after photographs of the Milltown Reservoir Sediments Site in
Montana. Photos courtesy of EPA Region 8,
https://www.flickr.com/photos/ usepagov/14625061943/ in/album-7 2157 645 621495463/
JULY 2020
-------
EPA-542-R-20-001
,, . , _ Office of Land and Emergency Management
United States
Environmental Protection July 2020
Agency
xvEPA
Superfund Remedy Report
16th Edition
-------
Superfund Remedy Report, 16th Edition
Table of Contents
Table of Contents i
Figures ii
T ables ii
Notice and Disclaimer iii
Acronyms and Abbreviations iv
Executive Summary 1
I. Purpose and Introduction 1
Contents 2
II. Approach 3
III. Scope of this Report 6
IV. Overview of Remedies 8
V. Overview of Contaminants 11
VI. Source Remedies 13
Sediment Remedies 19
VII. Groundwater Remedies 23
Technical Impracticability Waivers 28
Optimization 29
Jones Road Ground Water Plume 30
Benfield Industries, Inc 30
VIII. Vapor Intrusion 31
IX. Conclusions 33
X. Sources and Electronic Versions 35
Sources 35
Electronic Versions 38
Appendix A: Definitions of Selected Remedies A-l
Table of Contents A-l
A. 1 Treatment Technologies A-3
A. 1.1 Biological Treatment A-3
A. 1.2 Chemical Treatment A-4
A. 1.3 Physical Treatment A-5
A. 1.4 Thermal Treatment A-8
A. 1.5 Pump and Treat (P&T) A-10
A. 2 On-Site Containment Technologies A-12
A.3 Monitored Natural Attenuation (MNA) A-13
A.4 Monitored Natural Recovery (MNR) for Sediment A-14
A.5 Enhanced Monitored Natural Recovery (EMNR) for Sediment A-14
A. 6 Vapor Intrusion Mitigation A-15
A. 7 Other or Unspecified Remedies A-16
Appendix B: Treatment Technologies by Fiscal Year B-l
Appendix C: Individual Contaminants and Assigned Contaminant Groups C-l
JULY 2020 i
-------
Superfund Remedy Report, 16th Edition
Figures
Figure 1: Example Remedial Approach at a Site 2
Figure 2: Total Number of Superfund Sites 6
Figure 3: Decision Documents per Fiscal Year (FY 1981-2017) 7
Figure 4: Treatment at Superfund Sites (FY 1981-2017) 8
Figure 5: Media Addressed at Superfund Sites with Remedies (FY 1981-2017) 10
Figure 6: COCs at Superfund Sites (FY 1981-2017) 12
Figure 7: COCs by Media at Superfund Sites (FY 1981-2017) 12
Figure 8: Selection Trends for Decision Documents with Source Remedies (FY 1982-2017) 14
Figure 9: Combinations of Recent Source Remedies (FY 2015-2017) 15
Figure 10: Detailed COCs in Decision Documents with Source Remedies (FY 2015-2017) 19
Figure 11: Detailed COCs in Decision Documents with Sediment Remedies (FY 2015-2017) 22
Figure 12: Superfund Sites with Groundwater Remedies (FY 1981-2017) 23
Figure 13: Selection Trends for Decision Documents with Groundwater Remedies
(FY 1982-2017) 24
Figure 14: Combinations of Recent Groundwater Remedies (FY 2015-2017) 25
Figure 15: Detailed COCs in Decision Documents with Groundwater Remedies
(FY 2015-2017) 28
Figure 16: Groundwater TI Waivers per Fiscal Year (FY 1988-2017) 29
Figure G2a: Detailed COCs in Groundwater at Superfund Sites (FY 1981-2017) C-17
Figure G2b: Detailed COCs in Soil at Superfund Sites (FY 1981-2017) C-18
Figure G2c: Detailed COCs in Sediment at Superfund Sites (FY 1981-2017) C-18
Tables
Table 1: Summary of Remedy Categories 3
Table 2: Source Remedies Selected in Recent Decision Documents (FY 2015-2017) 16
Table 3: Sediment Remedies Selected in Recent Decision Documents (FY 2015-2017) 20
Table 4: Groundwater Remedies Selected in Recent Decision Documents (FY 2015-2017) 26
Table 5: Vapor Intrusion Remedies Selected in Recent Decision Documents (FY 2015-2017) 32
JULY 2020 ii
-------
Superfund Remedy Report, 16th Edition
Notice and Disclaimer
Preparation of this report has been funded by the U.S. Environmental Protection Agency (EPA)
under contract number EP-W-14-001 with ICF. This report is not intended, nor can it be relied
upon, to create any rights enforceable by any party in litigation with the United States. Mention of
trade names or commercial products does not constitute endorsement or recommendation for use.
A portable document format version of Superfund Remedy Report (SRR) 16th Edition is available for
viewing or downloading from www.epa.gov/remedvtech/superfund-remedv-report. The data that
forms the basis of the analyses contained in SRR 16th Edition can be found at
https://www.epa.gov/superfund/superfund-data-and-reports by downloading Contaminant of
Concern Data for Decision Documents by Media, FY 1982-201 7 and Remedy Component Data for
Decision Documents by Media, FY 1982-201 7.
JULY 2020
-------
Superfund Remedy Report, 16th Edition
Acronyms and Abbreviations
ASR Annual Status Report
BTEX Benzene, toluene, ethyl-
benzene, xylenes
CERCLA Comprehensive Environmental
Response, Compensation, and
Liability Act
CFR Code of Federal Regulations
COC Contaminant of concern
DNAPL Dense non-aqueous phase
liquid
EK Electrokinetics
EMNR Enhanced monitored natural
recovery
EPA U.S. Environmental Protection
Agency
ESD Explanation of significant
differences
FY Fiscal year
IC Institutional control
ISCO In situ chemical oxidation
ISCR In situ chemical reduction
ISTT In situ thermal treatment
LNAPL Light non-aqueous phase liquid
MNA Monitored natural attenuation
MNR Monitored natural recovery
NAPL Non-aqueous phase liquid
NCP National Oil and Hazardous
Substances Pollution
Contingency Plan
NPL National Priorities List
OU Operable unit
P&T Pump and treat
PAH Polycyclic aromatic
hydrocarbon
PCB Polychlorinated biphenyl
PCE Tetrachloroethene
PRB Permeable reactive barrier
ROD Record of Decision
S/S Solidification/ stabilization
SRR Superfund Remedy Report
SVE Soil vapor extraction
SVOC Semivolatile organic
compound
TCE Trichloroethene
TI Technical impracticability
VOC Volatile organic compound
JULY 2020
iv
-------
Superfund Remedy Report, 16th Edition
Executive Summary
The U.S. Environmental Protection Agency (EPA) prepared the Superfund Remedy Report (SRR) 16th
Edition to provide information and analyses on remedies selected to address contamination at
Superfund sites. The statute authorizing EPA to clean up uncontrolled hazardous waste sites and
spills established a preference for remedial actions in which treatment permanently and
significantly reduces the volume, toxicity or mobility of the hazardous substances, pollutants, and
contaminants. Hence, EPA is particularly interested in documenting and disseminating
information on treatment technologies that advance its mission of protecting human health and
the environment at contaminated sites. This report is the latest in a series, prepared since 1991, on
Superfund remedy selection.
The SRR series provides historical trends of remedies selected in Superfund decision documents
and more detailed analyses of recent remedies. The previous edition, SRR 15th Edition, included
remedies selected in fiscal years (FYs) 1981 through 2014. The SRR 16th Edition updates remedy
trends and includes detailed analyses of remedies selected in FYs 2015, 2016, and 2017. Decision
documents include Records of Decision (RODs), ROD amendments, and explanations of
significant differences (ESDs) for National Priorities List (NPL) and Superfund Alternative
approach sites. From the inception of the Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA) through FY 2017, EPA has signed 5,601 decision
documents, including 3,867 RODs, 472 ROD amendments, and 1,262 ESDs, for 1,603
Superfund sites \ Data from these documents form the basis for the SRR remedy analysis. The
SRR compiles data on remedies and presents separate analyses for contaminants overall and
contaminants in select media (soil, sediment, and groundwater). This edition also provides a
discussion of groundwater technical impracticability (TI) waivers included in decision documents.
For the majority (78 percent) of the 1,595 Superfund sites with decision documents available,
treatment has been selected, often in combination with other remedies. Most of these sites have
more than one contaminated medium, most frequently groundwater and soil. Most sites also have
different types of contaminants of concern (COCs): more than half of sites address volatile organic
compounds (VOCs), semivolatile organic compounds (SVOCs) and metals, while a quarter of sites
address two of these groups.
For FYs 2015 to 2017, remedies were selected in 272 decision documents, including 174 RODs,
39 ROD amendments, and 59 ESDs with remedial components (out of a total of 140 ESDs). Of
the 272 decision documents, 175 (64 percent) include a remedy for source materials (such as soil
and sediment) and 110 (40 percent) for groundwater. Remedies were also selected for soil gas and
air related to vapor intrusion.
For this three-year period, more than 40 percent of decision documents with source remedies
include treatment. One-fifth of all source decision documents include in situ treatment. In situ
solidification/stabilization (S/S), soil vapor extraction, and in situ thermal treatment are the most
frequently selected in situ treatment technologies for sources with soil being the most common
source medium addressed. Physical separation is the most common ex situ treatment method.
1 There are eight sites with no documents available, leaving 1,595 sites with documents available for analysis.
JULY 2020
ES-I
-------
Superfund Remedy Report, 16th Edition
Metals, polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs) are the
COCs most commonly addressed.
Of the 175 recent source decision documents, 40 include a remedy for sediments. Most of the
sediment decision documents (88 percent) include dredging, excavation, off-site disposal, or on-site
containment as part of the selected remedy. Some treatment was also selected — for example,
physical separation, amendments, and in situ amended caps. Examples of other sediment remedies
include wetlands restoration and enhanced or monitored natural recovery. Nearly two-thirds of the
sediment decision documents include institutional controls (ICs). Metals, PCBs, and PAHs are the
COCs most frequently addressed.
For the 110 groundwater decision documents signed in FYs 2015 to 2017, the groundwater
remedies continue to be primarily a mix of in situ treatment, pump and treat (P&T), and
monitored natural attenuation (MNA); most also include ICs. The use of in situ groundwater
treatment is selected in over half of groundwater decision documents. Of these, bioremediation
and chemical treatment remain the most frequently selected. The majority of in situ
bioremediation remedies specify anaerobic bioremediation, and most chemical treatment remedies
specify in situ chemical oxidation. The selection of P&T in groundwater decision documents has
decreased significantly since the early 1990s and continues to decline, averaging approximately 20
percent for FYs 2015 to 2017. Groundwater MNA also decreased to 20 percent. Containment
technologies (vertical engineered barriers such as slurry walls) were selected at one site. By far,
halogenated VOCs (primarily chlorinated VOCs) are the most common type of groundwater
COC, addressed in 74 percent of recent groundwater decision documents.
This edition includes a new section summarizing groundwater TI waivers. From FYs 1988 to 2017,
105 decision documents have included TI waivers for groundwater at 96 sites.
In this report, EPA also discusses optimization reviews. The optimization highlights provide
examples of how optimization efforts have informed remedy selection in recent decision
documents.
In addition, vapor intrusion mitigation was selected for existing structures in 8 recent decision
documents, and ICs for either existing structures or future construction in 40. Some ICs restrict
the future use of structures to avoid vapor intrusion exposure and others require the installation of
mitigation systems as part of future construction. Active depressurization is the most common
mitigation method specified.
The remedy and site information provided in this report informs stakeholders in Superfund
communities about the program's remedy decisions and helps federal, state, and tribal remediation
professionals select future remedies. Analyzing the trends in remedy decisions provides an
indication of the future demand for remedial technologies, which helps technology developers and
consulting and engineering firms evaluate cleanup markets. The trends also indicate program
needs for expanded technical information and support related to specific technologies or site
cleanup challenges. For example, continued selection of in situ groundwater technologies suggests
an ongoing need for additional knowledge and support associated with those technologies.
JULY 2020
ES-2
-------
Superfund Remedy Report, 16th Edition
I. Purpose and Introduction
The U.S. Environmental Protection Agency's (EPA) Office of Superfund Remediation and
Technology Innovation prepared this Superfund Remedy Report (SRR) 16th Edition to share analysis of
remediation technologies selected to address contamination at Superfund sites. EPA is particularly
interested in documenting and disseminating information on treatment technologies to advance
its mission of protecting human health and the environment at contaminated sites. The report
focuses on treatment because the Comprehensive Environmental Response, Compensation, and
Liability Act (CERCLA) has a statutory preference for treatment.2
The SRR 16th Edition adds remedy information from decision documents issued during fiscal years
(FYs) 2015, 2016, and 2017. The data in this report build on the evaluations in the 12 editions of
Treatment Technologies for Site Cleanup: Annual Status Report (ASR), which covered the timeframe
from FY 1982 through a portion of FY 2005; SRR 13th Edition (FYs 2005 to 2008); SRR 14th Edition
(FYs 2009 to 2011); and SRR 15th Edition (FYs 2012 to 2014).
Selected remedial actions for Superfund sites, including National Priorities List (NPL) and
Superfund Alterative approach sites are recorded in a decision document, such as a Record of
Decision (ROD), ROD amendment, or explanation of significant differences (ESD). The
information in this report was extracted from these Superfund decision documents. This report
inventories all remedies selected, however, not all selected remedies are ultimately implemented.
Sometimes changes are made prior to implementation. For example, a different remedy may be
required 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. In addition, a
remedial technology may be added to the original remedy if additional contamination is
discovered during remedy implementation or a different approach can more efficiently address
residual contamination. Furthermore, a particular remedy may have been included in a ROD as a
contingent remedy, but subsequent site investigations reveal that implementation is not necessary.
Fundamental changes to remedies selected in a ROD are documented in a ROD amendment, and
significant changes are documented in an ESD.
A site can be divided into a number of operable units (OUs), which can result in multiple decision
documents. The National Oil and Hazardous Substances Pollution Contingency Plan (NCP)
defines an OU as "a discrete action that comprises an incremental step toward comprehensively
addressing site problems. This discrete portion of a remedial response manages migration, or
eliminates or mitigates a release, threat of a release, or pathway of exposure. The cleanup of a site
can be divided into a number of OUs, depending on the complexity of the problems associated
with the site. OUs may address geographical portions of a site, specific site problems, or initial
phases of an action, or may consist of any set of actions performed over time or any actions that
are concurrent but located in different parts of a site."3 Figure 1 illustrates an example of a
2 Comprehensive Environmental Response, Compensation, and Liability Act of 1980 and the amendments made by
subsequent enactments (42 U.S.C. 9601-9675).
3 Code of Federal Regulations (CFR), title 40, sec 300.5. www.gpo.gov/fdsvs/pkg/CFR-2001-title40-vol24/pdf/CFR-
200 l-title40-vol24-sec300-5 .pdf
JULY 2020
-------
Superfund Remedy Report, 16th Edition
remedial approach at a site with multiple OUs, decision documents, and remedies. In the example,
the site has been divided into three OUs, with two addressing separate sources and two addressing
groundwater. In the example, EPA has issued a ROD and ROD amendment for the OU1 source
area. The OU 1 ROD amendment made a fundamental change to the application of the selected
soil vapor extraction (SVE) technology by adding in situ bioremediation and discontinuing pump
and treat (P&T). OU2 has a ROD that addresses groundwater downgradient from OU 1 and
OU3. OU3 addresses a separate source area that is still under investigation and does not yet have a
decision document.
Figure I: Example Remedial Approach at a Site
ROD #1
In situ soil vapor extraction
for soil and pump and treat-
for groundwater
ROD Amendment #1
Adds in situ bioremediation
and discontinues pump
and treat
0U1: Disposal Area
(Soil and Groundwater)
0U2: Downgradient
Groundwater
No ROD
ROD #2
Monitored natural
attenuation and
institutional controls
for groundwater
Contents
The SRR 16th Edition includes 10 sections and 3 appendices.
¦ Section I discusses the purpose and introduces the report.
¦ Section II describes the approach used to collect and analyze data.
¦ Section III describes the scope of the report.
¦ Section IV analyzes types of remedies and media addressed at Superfund sites.
¦ Section V analyzes contaminants of concern (COC) included in decision documents.
¦ Section VI discusses source remedies, including a breakout of sediment remedies.
¦ Section VII discusses groundwater remedies, including technical impracticability (TI)
waivers and optimization highlights.
¦ Section VIII discusses vapor intrusion remedies.
¦ Section IX presents conclusions.
¦ Section X lists the data sources and provides information on how to access the electronic
version of this and previous editions of SRR.
¦ Appendix A provides the definitions of selected remedies.
¦ Appendix B lists treatment technologies by fiscal year.
¦ Appendix C lists individual contaminants and their assigned contaminant groups and
provides an analysis of detailed contaminant groups by media.
JULY 2020
2
-------
Superfund Remedy Report, 16th Edition
II. Approach
EPA used data from decision documents available as of November 2019 to compile information
about remedy selection for all years with a focus on the most recent three years (FYs 2015, 2016 and
2017).4 The data used include remedies selected in decision documents (RODs, ROD amendments,
and select ESDs). Only ESDs with additions or changes to remedy components were included in the
remedy analyses. ESDs were not included if they did not change a remedy component but instead
addressed another aspect of the remedy, such as quantity of material to be addressed, COCs, cost
information, or monitoring requirements.
The SRR remedy analysis distinguishes between remediation of contaminated source materials and
non-source materials such as groundwater. EPA defines "source material" as "material that
includes or contains hazardous substances, pollutants or contaminants that act as a reservoir for
migration of contamination to ground water to surface water, to air, or acts as a source for direct
exposure." This includes contaminated soil, sludge, sediment, solid waste, debris, drummed waste,
leachate, and any non-aqueous phase liquid both light (LNAPL) and dense (DNAPL) (EPA,
1991a). Groundwater is considered "non-source material" (EPA, 1991a).
The report groups remedies into major categories, indicated by the green bars in Table 1. It
discusses remedies as related to source, groundwater, or vapor intrusion based on the media
addressed. Appendix A provides definitions of all categories and corresponding remedy types
under each category.
Table I: Summary of Remedy Categories
Source Control
Treatment
• Alters the composition of a hazardous substance or pollutant or contaminant through chemical, biological, or
physical means to reduce toxicity, mobility, or volume of contaminated source media
• Can be either in situ or ex situ
• Examples include chemical treatment and in situ thermal treatment
On-site Containment
• Examples include the use of caps, liners, covers, and landfilling on site
Off-site Disposal
• Includes excavation and disposal at an off-site facility
Monitored Natural Attenuation (MNA)
Reliance on natural processes5
Natural recovery processes may include physical, chemical, and biological processes
Monitored Natural Recovery (MNR)
Reliance on natural processes to reduce risk from sediments
Natural recovery processes may include physical, chemical, and biological processes
4 The data that forms the basis for the analyses contained in SRR 16* Edition is available for download at
https:/ /www.epa.gov/superfund/ superfund-data-and-reports.
5 For further information about MNA, refer to Use of Monitored Natural Attenuation at Superfund, RCRA
Corrective Action, and Underground Storage Tank Sites. Office of Solid Waste and Emergency Response. April 21,
1999. OSWER Directive No. 9200.4-17P. https://semspub.epa.gov/src/document/HO/159152.pdf
JULY 2020
3
-------
Superfund Remedy Report, 16th Edition
Source Control (continued)
Enhanced Monitored Natural Recovery (EMNR)
• Combines natural recovery with an engineered approach for sediments
• Typically includes placing a thin layer of clean sediment to accelerate the recovery process
Institutional Controls
• Non-engineered instruments, such as administrative and legal controls, that help minimize the potential for
human exposure to contamination and protect the integrity of the remedy
• Examples for source media include land use restrictions and access agreements
Other
• Source control remedies that do not fall into the categories of source control treatment, on-site containment,
off-site disposal, MNA, MNR, EMNR, or institutional controls
• Examples include wetlands replacement and shoreline stabilization
Groundwater
In Situ Treatment
Pump and Treat (P&T)
Monitored Natural Attenuation (MNA)
Containment
Containment of groundwater using a vertical, engineered, subsurface, impermeable barrier
Examples for groundwater include drilling restrictions and water supply use restrictions
Examples include installing new water supply wells, providing bottled water or extending a municipal water supply
Other
Institutional Controls
Alternative Water Supply
Treatment of groundwater in place without extraction from an aquifer
Examples include in situ chemical oxidation and in situ bioremediation
Pumping of groundwater from a well or trench, followed by aboveground treatment
Examples of aboveground treatment include air stripping and granular activated carbon
Reliance on natural attenuation processes6
Natural attenuation processes may include physical, chemical, and biological processes
• Groundwater remedies that do not fall into the categories of in situ treatment, P&T, MNA, containment,
institutional controls, or alternative water supply
• Examples include drainage/erosion control and wetlands restoration
Vapor Intrusion
Mitigation
• Mitigation of soil gas or indoor air to reduce exposure to vapor contamination in buildings
• Examples include active depressurization technologies and passive barriers
Institutional Controls
• Examples for vapor intrusion include land use restrictions and requirements for vapor intrusion mitigation for
new buildings
This report includes remedies selected in the Superfund remedial program, including treatment,
containment, and remedial components such as institutional controls (ICs); treatment
technologies are discussed in more detail. "Treatment technology means any unit operation or series
of unit operations that alters the composition of a hazardous substance or pollutant or
6 Ibid.
JULY 2020
4
-------
Superfund Remedy Report, 16th Edition
contaminant through chemical, biological or physical means so as to reduce toxicity, mobility or
volume of the contaminated materials being treated."7
In the analysis conducted for the SRR, monitoring is not included separately as a remedy.
According to EPA guidance, "[a]n alternative may include monitoring only and still be considered
'no action.'" (EPA, 1999a). Thus, monitoring is not considered itself a remedy. However, the
Superfund program recognizes the importance of effective monitoring and has implemented a
long-term monitoring optimization strategy.8
The report presents data in figures at the decision document-level or at the site-level, depending on
the objective of the figure. For some figures, decision documents that selected multiple remedies
are counted in each remedy category, as appropriate. For example, a single decision document that
selected both in situ treatment and a cap is listed in both remedy categories. For other figures, a
hierarchy is used to classify a decision document into a single category of remedy types. This
hierarchy has been established to represent the data consistent with the CERCLA statutory
preference for treatment. Notes on individual figures and tables indicate whether a hierarchy was
used. Additionally, some figures present historical or cumulative data, and others focus on recent
remedy selection.
7 CFR, title 40, sec 300.5. www.gpo.gov/fdsvs/pkg/CFR-200l-title40-vol24/pdf/CFR-200l-title40-vol24-sec300-5.pdf
8 For further information, please visit the Cleanup Optimization at Superfund Sites web page at
www.epa.gov/superfund/cleanup-optimization-superfund-sites
JULY 2020
5
-------
Superfund Remedy Report, 16th Edition
III. Scope of this Report
This report discusses decision documents for current and deleted NPL sites that had at least one
decision document as of the end of FY 2017. In addition, the SRR analysis includes 56 decision
documents for 52 Superfund Alternative approach sites (as of April 2019).9 The current analysis
does not include decision documents for other non-NPL sites or sites that were proposed for the
NPL but not yet on the final NPL. For the first time, the report includes information on TI
waivers at groundwater sites.
There are 1,603 sites that have at least one decision document. Of the 1,603 sites, 8 sites had no
electronic decision documents available, leaving 1,595 sites represented in this report. Further, 97
sites have selected only a no action or no further action decision for the site, leaving 1,498 sites
with remedies (Figure 2).
Figure 2: Total Number of Superfund Sites
r ^
1,603
Sites with at least one
decision document
Sites with no decision
document available
r ^
1,595
Sites with at least one
decision document
available
L. J
97
Sites with no action/no
further action only
1,498
Sites with remedies
The decision documents issued for these sites form the basis for the SRR and its analyses. A total
of 5,601 decision documents, including 3,867 RODs, 472 ROD amendments, and 1,262 ESDs
have been signed at the 1,603 sites. As discussed previously, most sites have multiple decision
documents. Figure 3 depicts the total number of RODs, ROD amendments and ESDs issued each
year through FY 2017. Only ESDs with a remedy component were included in the remedy analysis
(682). The first ESD was signed in 1988.
9 "One of EPA's non-NPL Superfund pathways is referred to as the Superfund Alternative (SA) approach. The SA
approach uses the same process and standards for investigation and cleanup as sites on the NPL. Sites using the SA
approach are not eligible for federal remedial cleanup funds. Cleanup funding for sites with SA agreements is
provided by the potentially responsible parties (PRPs)." (EPA, 2008b). To be considered an official Superfund
Alternative approach site, there needs to be a Superfund Alternative approach agreement per OECA policy (see:
www.epa.gov/enforcement/superfund-alternative-approach). The list of sites with a Superfund Alternative approach
agreement is as of April 1, 2019.
JULY 2020
6
-------
Superfund Remedy Report, 16th Edition
Figure 3: Decision Documents per Fiscal Year (FY 1981-2017)
10
200
180
w ISO
C
-------
Superfund Remedy Report, 16th Edition
IV. Overview of Remedies
Of the 1,595 sites with decision documents available as of the end of FY 2017, remedies were
selected at 1,498 sites and no action or no further action was specified at 97 sites. Figure 4 focuses
on treatment remedies and shows the proportion of Superfund remedies by remedy category
(including source and groundwater remedies). Sites are included once using the following
hierarchy: treatment, on-site containment or off-site disposal, other non-treatment remedies
(including ICs, monitored natural attenuation [MNA], enhanced or monitored natural recovery
[EMNR or MNR], and alternative water supply), and no action or no further action. At 78 percent
ol Superfund sites, at least one treatment remedy was selected for source, groundwater, or both.
Appendix B lists the type and number ot source and groundwater treatment technologies selected
by fiscal year.
Figure 4: Treatment at Superfund Sites (FY 1981-2017)
Non-Treatment, No Action or Treatment = 1,243 (78%)
No Further Action = 352 {22%)
Treatment of Both
Source and
Groundwater, 670,
42%
No Action or No Further
Action Only, 97,6%
Treatment of Source,
293,18%
On-site Containment or
Off-site Disposal of a
Source, 194,12%
Treatment of
Groundwater, 280,18%
Containment, ICs, MNA, or Alternative
Water Supply for Groundwater, 37,2%
ICs, MNA, MNR or
EMNR for a Source,
24, 2%
• Sites with remedies, no action or no further action, and available decision documents = 1,595.
• Sites counted in this figure using following hierarchy: (I) treatment, (2) on-site containment or off-site disposal of a source,
(3) other non-treatment remedies of a source, (4) containment or non-treatment remedies for groundwater, and (5) no
action or no further action only.
• Sites with treatment remedies include in situ or ex situ treatment, and may also include non-treatment remedies.
• Sites with only non-treatment remedies do not include treatment remedies in any decision document.
• Sites with only no action or no further action (97) do not have treatment or non-treatment remedies selected in any
decision document.
JULY 2020
8
-------
Superfund Remedy Report, 16th Edition
Hill Air Force Base11 in Utah is an example of a site that has selected treatment remedies for both
source and groundwater. Dating back to World War II, Hill Air Force Base has been the site for
maintenance and repair activities for numerous types of aircraft. Activities at Hill Air Force Base
generate various wastes including chlorinated and non-chlorinated solvents and degreasers, fuels,
other hydrocarbons, acids, bases, and metals. The site contains many contaminated source areas
such as landfills, chemical and waste pits, fire training areas, sludge drying beds, dumps, spill areas,
and groundwater contaminant plumes. Several recent documents (three FY 2015 RODs and one
FY 2017 ROD amendment) selected treatment remedies, including in situ bioremediation for
both soil and groundwater, P&T of groundwater, and free-product recovery of non-aqueous phase
liquid (NAPL). Numerous other remedies have been selected and implemented at the site since its
first ROD in 1991. Those remedies include excavation and disposal of soil, SVE, engineered caps
and soil covers for source media; ICs for both source and groundwater; and permeable reactive
barriers (PRBs) and MNA for groundwater.
EPA analyzed which types of media remedies target at Superfund sites (Figure 5). Groundwater is
addressed most frequently, followed by soil. Remedies also frequently target sediments and solid
waste. In this analysis, all media addressed within decision documents for the site are counted
once for each medium even if it was targeted at multiple OUs or in multiple decision documents.
Of the 1,498 sites with selected remedies, 85 percent have remedies for more than one medium. A
total of 1,093 sites have remedies for both source media and groundwater.
American Creosote Works Inc. (Pensacola Plant)12 in Florida illustrates a site that is addressing
several media. For example, in FY 2017 alone, remedies were selected for groundwater, NAPL, and
soil at this former wood-treating facility. Earlier decision documents addressed debris, sediment,
and sludge.
NAPL is considered a source medium when it contributes to groundwater contamination.
However, EPA does not have complete data on its presence at Superfund sites. NAPL is often
difficult to locate during a site investigation, and there may not be direct evidence of its presence
at the time EPA signs a decision document. In addition, EPA has only recently tracked NAPL as a
separate medium when reviewing remedy decisions. For these reasons, NAPL is not included in
Figure 5.
11 Hill Air Force Base: (1) ROD, OU4, 9/25/17, https://semspub.epa.gov/src/document/08/1000Q5817: (2) ROD,
OU9, 9/23/15, https://semspub.epa.gov/src/document/08/1574521: (3) ROD, OUIO, 9/23/15,
https://semspub.epa.gov/src/document/08/1574523: (4) ROD, OU11, 7/21/15,
https://semspub.epa.gov/src/document/08/1574587: and (5) Site profile,
https:/ /cumulis.epa.gov/supercpad/cursites/csitinfo.cfm? id=080075 3.
12 American Creosote Works (Pensacola Plant): (1) ROD, 9/7/17,
https://semspub.epa.gov/src/document/04/11070338: and (2) Site profile,
https://cumulis.epa.gov/supercpad/cursites/csitinfo.cfm?id=0400572.
JULY 2020
9
-------
Superfund Remedy Report, 16th Edition
Figure 5: Media Addressed at Superfund Sites with Remedies (FY 1981-2017)
in
-------
Superfund Remedy Report, 16th Edition
V. Overview of Contaminants
Decision documents typically identify COCs addressed by selected remedies. EPA evaluated the
types of COCs at Superfund sites based on decision documents with remedies and identified
COCs (1,494 sites). COC data were unavailable for 4 sites with remedies, less than one percent.
The contaminants may be in the same or different media and may be addressed by the same or
different remedies.
For this report, contaminants are categorized in three major groups based on general treatability:
metals, volatile organic compounds (VOCs), and semivolatile organic compounds (SVOCs). Any
contaminant that does not fit into one of those groups is categorized as "other."
The contaminant groups are defined below:
¦ Metals - Metals; metalloids; explosive metals; radioactive metals; and organometallic
pesticides and herbicides.
¦ VOCs - Halogenated VOCs (primarily chlorinated VOCs); benzene, toluene,
ethylbenzene, xylene (BTEX); and other nonhalogenated VOCs.
¦ SVOCs - Polychlorinated biphenyls (PCBs); polycyclic aromatic hydrocarbons (PAHs);
organic pesticides and herbicides; phenols; most fuels and distillates; most explosives;
dioxins and furans; and other halogenated and nonhalogenated SVOCs.
¦ Other - nonmetallic inorganics; asbestos; and unspecified organics or inorganics.
Contaminants are further grouped into more detailed categories. Appendix C lists contaminants
and their associated categories and provides an analysis of contaminants in detailed categories for
groundwater, soil, and sediment.
Over half of sites have COCs in all three groups: VOCs, SVOCs, and metals (Figure 6). Another
23 percent of sites have two types of contaminants, and 24 percent have one type. In Figure 6, any
of the groups shown may include "other" contaminants.
An example of a site that has all three types of contaminants groups is Barstow Marine Corps
Logistics Base13 in California. The base has two major functions: providing equipment
maintenance, repair, overhaul, and rebuilding; and receiving, storing, maintaining, and shipping
materials. Consequently, most of the contamination at this site resulted from vehicle-related
activities and war surplus materials. In the FY 2015 ROD, remedies addressed trichloroethene
(TCE), tetrachloroethene (PCE), aroclor 1016, aroclor 1254, dibenzo(a,h)anthracene, and
benzo[a]pyrene in soil and groundwater, and lead in soil.
13 Barstow Marine Corps Logistics Base: (1) ROD, OU7, 11/18/14,
https://semspub.epa.gov/src/document/09/1149112: and (2) Site profile,
https://cumulis.epa. gov/supercpad/cursites/csitinfo.cfm?id=0902790.
JULY 2020
-------
Superfund Remedy Report, 16th Edition
Figure 6: COCs at Superfund Sites (FY 1981-2017)
900
800
700
600
500
400
0)
on
o
£ 300
-Q
£
^ 200
100
0
Number of Sites
Metals:
1,172 (78%)
VOCs:
1,159 (78%)
SVOCs:
1,058 (71%)
Other:
422 (28%)
24%
I
23%
_l_
157
148
&
Qy
Np
4P
P>
121
112
116
52
rw
MOO
<1%
10
,^e
CP
0°
• Number of sites with identified COCs and a remedy = 1,494.
EPA analyzed COCs by the three media most frequently targeted (groundwater, soil, and
sediment) (Figure 7). On a site-wide basis, VOCs, metals, and SVOCs are all common in
groundwater and soil at Superfund sites with remedies- Metals and SVOCs are the most common
COCs in sediment.
Figure 7: COCs by Media at Superfund Sites (FY 1981 -2017)
100%
90%
80%
i/>
Cl)
+-»
70%
O)
M—
o
60%
Cl)
50%
ao
cu
c
Cl)
40%
(->
a;
30%
Q.
20%
10%
0%
86%
75%
77%
70%
31%
17%
116
| 187
1
I
I
Groundwater
Soil
Sediment
I VOCs 8 Metals ¦ SVOCs ¦ Other
Number of groundwater sites with identified COCs and a remedy = 1,187.
Number of soil sites with identified COCs and a remedy = i, I 17.
Number of sediment sites with identified COCs and a remedy = 380.
JULY 2020
12
-------
Superfund Remedy Report, 16th Edition
VI. Source Remedies
Source media include soil, sediment, solid waste, debris, buildings and structures, sludge, leachate,
liquid waste, and NAPL. The first figure in this section shows historical trends in source remedies.
Subsequent figures and tables provide additional information on remedies used to address sources
in recent decision documents. Descriptions of source remedies are included in Appendix A.
Sediments are included in the analysis of source remedies and are discussed in more detail in the
Sediment Remedies subsection.
To better understand the nature of the source remedies being selected in the Superfund program,
the source remedies are grouped into the following categories. See Table 1 for more detail on each
category:
¦ Treatment.
¦ On-site containment.
¦ Off-site disposal.
¦ MNA, EMNR, or MNR.
¦ ICs.
EPA has tracked use of these source remedies since EPA began issuing remedy decision documents
(FY 1981). EPA evaluated remedy selection trends from FY 1981 to 2017 for 3,235 source decision
documents with remedies (Figure 8). In the first few years of the program, the number of decision
documents issued was very low. After those early years, the selection of treatment, on-site
containment, and off-site disposal has remained relatively stable on average for source remedies
over the last 20 years. IC remedies increased somewhat in the early 2000s before leveling off.
JULY 2020
13
-------
Superfund Remedy Report, 16th Edition
Figure 8: Selection Trends for Decision Documents with Source Remedies (FY 1982-2017)
100%
C
OrHrNjfO'^-untDrxOO(j»(j>(j>cr>crj(j>crjcr)0^
-------
Superfund Remedy Report, 16th Edition
EPA evaluated remedies in more detail for the 272 FY 2015 to 2017 decision documents. Of
these documents, 175 (or 64 percent) address source contamination at 131 sites. The percentage
of decision documents addressing sources is consistent with the previous period evaluated (FYs
2012 to 2014).
Of the FY 2015 to 2017 source decision documents, 42 percent select source treatment, either by
itself or in combination with non-treatment remedies for sources (Figure 9). Overall, 56 percent
of decision documents with source remedies select multiple remedial approaches, including various
combinations of treatment, on-site containment or off-site disposal, MNR or EMNR (for
sediments), and ICs. An examination of the recent decision documents selecting ICs as the only
source remedy found that all were tor sites with previous remedial or removal actions. This finding
is consistent with the NOP, which includes the expectation that ICs should be used to
supplement engineering controls to prevent or limit exposure (EPA, 2012n).
Of the 131 sites with a source remedy from FY 2015 to 2017, 44 percent (57) also include a
groundwater remedy for that same timeframe. However, for all years, 73 percent of sites have a
remedy for both source and groundwater.
On-site source containment primarily includes caps and cover systems. Although some waste sent
for off-site disposal is treated prior to disposal in accordance with waste disposal regulations, if the
treatment is not specified in the decision document, it is not included as treatment, in this analysis.
Figure 9: Combinations of Recent Source Remedies (FY 2015-2017)
Non-Treatment - 102 (58%) Treatment - 73 (42%)
Source MNRor EMNR
Only, 1, 1%
Source Fencing, Signs
and Existing
Structures Only, 2,
Source ICs Only, 39,
22%
Source On-site
Containment or Off-
site Disposal Only, 24,
14%
Source On-site
Containment or Off-
site Disposal and ICs,
34,19%
Source Treatment,
On-site Containment
or Off-site Disposal,
ICs, and MNR or
EMNR, 3,2%
Source Treatment,
On-site Containment
or Off-site Disposal,
and ICs, 40, 23%
Source Treatment and
On-site Containment
or Off-site Disposal,
13, 8%
Source Treatment and
ICs, 6, 3%
Source Treatment
Only, 11, 6%
Source On-site Containment or
Off-site Disposal, ICs and MNR
or EMNR, 2, 1%
Number of source decision documents = 175.
JULY 2020
IS
-------
Superfund Remedy Report, 16th Edition
Table 2 summarizes the specific types of remedies selected in source decision documents for FYs
2015 to 2017. In situ treatment was selected in one-fifth of these documents. Of the 73 decision
documents with source treatment, 35 (or 48 percent) specified in situ treatment. The most
frequently selected in situ methods for sources are solidification/stabilization (S/S), SVE, in situ
thermal treatment (ISTT), bioremediation, and chemical treatment (including in situ chemical
oxidation [ISCO] and in situ chemical reduction [ISCR]).
Note that the number of decision documents selecting each type of technology within a category is
not additive to the total number of documents for the category. Frequently more than one type of
technology is selected to address source. For example, ISTT followed by flushing, ISCO and
enhanced in situ bioremediation, as necessary, was selected in the FY 2015 ROD amendment to
address NAPL contamination in the source area of Escambia Wood - Pensacola14 in Florida.
Treatment technologies will be finalized during the design phase. The selections of ISTT, flushing,
ISCO, and bioremediation at Escambia Wood - Pensacola are included in the number of
documents for each of those technologies, but the FY 2015 Escambia Wood - Pensacola
document is only counted once in the number of documents selecting in situ treatment.
Table 2: Source Remedies Selected in Recent Decision Documents (FY 2015-2017)
Number of Decision
Percent Source
Remedy
Documents
Decision
(FY15-17)
Documents
In Situ Treatment
35
20%
Solidification/Stabilization
9
5%
Soil Vapor Extraction
9
5%
Thermal Treatment
8
5%
Bioremediation
6
3%
Chemical Treatment
5
3%
Cap (amended, in situ sediment)
2
1%
Amendments (sediment)
2
1%
Multi-phase Extraction
2
1%
Electrokinetics
1
1%
Flushing
1
1%
Soil Amendments
1
1%
Ex Situ Treatment
50
29%
Physical Separation
22
13%
Source P&T
7
4%
Recycling
5
3%
Thermal Treatment
4
2%
Solidification/Stabilization
3
2%
Incineration (off-site)
2
1%
Soil Vapor Extraction
2
1%
Aeration
1
1%
14 Escambia Wood - Pensacola: (1) ROD Amendment, OU2, 9/25/15,
https://semspub.epa.gov/src/document/04/11014642: and (2) Site profile,
https://cumulis.epa.gov/supercpad/cursites/csitinfo.cfm?id=0400573.
JULY 2020
16
-------
Superfund Remedy Report, 16th Edition
Number of Decision
Percent Source
Remedy
Documents
Decision
(FY15-17)
Documents
Ex Situ Treatment (continued)
Bioremediation
1
1%
Chemical Treatment
1
1%
Constructed Treatment Wetland
1
1%
Open Burn/Open Detonation
1
1%
Thermal Desorption
1
1%
Unspecified Ex Situ Treatment (off-site)
9
5%
Unspecified Ex Situ Treatment (on-site)
1
1%
Containment/Disposal
117
67%
Containment (on-site)
81
46%
Cap (engineered cap)
43
25%
Drainage/Erosion Control
37
21%
Cover (soil)
24
14%
Containment (other, onsite)
12
7%
Vertical Engineered Barrier
7
4%
Repair (pipe/sewer/tank/structure)
4
2%
Bottom Liner
2
1%
Building Sealant
2
1%
Leachate Control
2
1%
Containment (encapsulation)
1
1%
Disposal (off-site)
79
45%
MNR/EMNR
6
3%
Sediment EMNR
4
2%
Sediment MNR
4
2%
Institutional Controls
124
71%
Other
43
25%
Fencing, Signs, and Existing Structures
17
10%
Wetlands Restoration
13
7%
Revegetation
6
3%
Habitat Restoration
5
3%
Population Relocation
5
3%
Stream Realignment
3
2%
Shoreline Stabilization
2
1%
Wetlands Replacement
1
1%
• Number of source decision documents = 175.
• Number of source decision documents with treatment = 73.
• Decision documents with multiple remedies within a category counted once per category, documents may be
included in more than one remedy category.
• For unspecified on-site or off-site treatment, decision document indicates on- or off-site treatment but does not
specify a particular treatment technology.
Physical separation is the most commonly selected ex situ treatment. Consistent with CERCLA, all
types of physical separation are classified as treatment because they reduce the volume of
contaminated material. Physical separation processes include sifting, sieving, and sorting solid
JULY 2020
17
-------
Superfund Remedy Report, 16th Edition
media to separate components; dewatering; and decontamination (for example, cleaning
contaminated building surfaces). Of the 22 recent decision documents that selected physical
separation; 13 selected dewatering; 5 decontamination; and 8, other physical separation processes,
such as oil/water separation, sieving, and mechanical sorting. Four documents included more than
one type of physical separation.
Source P&T refers to extraction and ex situ treatment of leachate or liquid waste media. Ex situ
treatment technologies typically include carbon adsorption, neutralization, aeration, evaporation,
or bioremediation. Of the seven documents selecting source P&T in FYs 2015 to 2017, five are for
mining waste while two are for leachate.
Figure 10 shows the top COCs targeted by source remedies in FY 2015 to 2017 decision
documents. Sixty-four percent of these documents address metals; 40 percent, PAHs; and 32
percent, PCBs. More than half of recent documents with source remedies address more than one
contaminant group (72 of 137). For example, an FY 2015 ROD for Aerojet General Corp.15 in
California addresses a variety of contaminants resulting from the manufacture of various chemicals
and rocket propellants. Contaminants include chlorinated VOCs (TCE, PCE, and 1,1,2,2-
tetrachloroethane), metals (such as lead, cadmium, and chromium), nonhalogenated SVOCs (such
as bis(2-ethylhexyl)phthalate and n-nitrosodimethylamine), pesticides (such as dieldrin and
pendimethalin), PAHs (such as benzo(a)pyrene, naphthalene and phenanthrene), PCBs (aroclor
1248, aroclor 1254, and aroclor 1260), BTEX (toluene), halogenated SVOCs (phenol), other
organics (petroleum hydrocarbons), and other inorganics (perchlorate).
15 Aerojet General Corp.: (1) ROD, OU6, 7/22/15 https://semspub.epa.gov/src/document/09/1153972: and (2)
Site profile, https://cumulis.epa.gov/supercpad/cursites/csitinfo.cfm?id=0901718.
JULY 2020
18
-------
Superfund Remedy Report, 16th Edition
C
SO
03
C
r&
v
-------
Superfund Remedy Report, 16th Edition
treatment, as well as the need for adding amendments to the cap, will be determined during
remedial design.
Each individual technology selected in the decision documents are counted in Table 3, however,
the decision document is only counted once in the category total. For example, the Portland
Harbor decision document is counted in the number of decision documents selecting
dredging/excavation and cap (in situ), but it is only counted once in the category total for
dredging, disposal, and containment. Therefore, the individual technology numbers are not
additive to the category total.
Table 3: Sediment Remedies Selected in Recent Decision Documents
(FY 2015-2017)
Number of Decision
Percent
Remedy
Documents
Sediment Decision
(FY15-17)
Documents
Treatment
14
35%
Physical Separation
11
28%
Cap (amended, in situ sediment)
2
5%
Amendments (sediment)
2
5%
Aeration
1
3%
Incineration (off-site)
1
3%
Unspecified Ex Situ Treatment (off-site)
2
5%
Unspecified Ex Situ Treatment (on-site)
1
3%
Dredging, Disposal, and Containment
35
88%
Dredging/Excavation
29
73%
Disposal (off-site)
21
53%
Cap (in situ)
13
33%
Cap (ex situ)
5
13%
Drainage/Erosion Control
2
5%
Vertical Engineered Barrier
2
5%
Bottom Liner
1
3%
Containment (other, onsite)
1
3%
Repair (pipe/sewer/tank/structure)
1
3%
Enhanced Monitored Natural Recovery
4
10%
Monitored Natural Recovery
4
10%
Institutional Controls
25
63%
Other
19
48%
Wetlands Restoration
8
20%
Revegetation
6
15%
Habitat Restoration
5
13%
Stream Realignment
3
8%
JULY 2020
20
-------
Superfund Remedy Report, 16th Edition
Number of Decision
Percent
Remedy
Documents
Sediment Decision
(FY15-17)
Documents
Other (continued)
Fencing, Signs, and Existing Structures
2
5%
Shoreline Stabilization
2
5%
Wetlands Replacement
1
3%
• Number of decision documents with a sediment remedy = 40. (Does not include 13 decision documents
specifying no action or no further action only.)
• Decision documents with multiple remedies within a category counted once per category, and documents may
be included in more than one remedy category.
EPA analyzed COCs addressed by sediment remedies in recent decision documents (Figure 11).
Over 70 percent of these documents include metals. PCBs and PAHs are the next most frequent
categories of COCs with 55 percent and 32 percent, respectively. More than half of recent
sediment documents address multiple contaminant groups (17 of 31). For example, the FY 2015
ROD for Lower Duwamish Waterway17 in Washington selected capping and EMNR (both with
the option for addition of amendments, if appropriate), dredging with off-site disposal, MNR, and
ICs to address chlorinated dioxins and furans, halogenated SVOCs (such as phenol and 1,2,4-
trichlorobenzene), halogenated VOCs (1,2-dichlorobenzene and 1,4-dichlorobenzene), metals
(such as arsenic and lead), nonhalogenated SVOCs (such as bis(2-ethylhexyl)phthalate and
phenylmethanol), pesticides (pentachlorophenol and hexachlorobenzene), PCBs, and PAHs (such
as benzo(a)pyrene and phenanthrene).
17 Lower Duwamish Waterway: (1) ROD, OU1, 11/21/14, https://semspub.epa.gov/src/document/10/715975: and
(2) Site profile, https://cumulis.epa.gov/supercpad/cursites/csitinfo.cfm?id= 1002020.
JULY 2020
21
-------
Superfund Remedy Report, 16th Edition
Figure 11: Detailed COCs in Decision Documents with Sediment Remedies
(FY 2015-2017)
80%
| 70%
3
O 60%
| 50%
"u
Q 40%
HM
| 30%
-o
$ 20%
4—
o
& 10%
fD
¦*->
C
O
•N
-------
Superfund Remedy Report, 16th Edition
VII. Groundwater Remedies
Groundwater contamination occurs at most Superfund sites. Of the 1,498 Superfund sites with
remedies, 84 percent (1,251 sites) have groundwater remedies (Figure 12), which are documented
in 2,542 decision documents. The figures and tables in this section present additional information
on groundwater remedies and trends. Appendix A includes descriptions of groundwater remedies.
Figure 12: Superfund Sites with Groundwater Remedies (FY 1981-2017)
Sites with No
Groundwater
Remedy,
Sites with a Groundwater
Remedy, 1,251,84%
• Number of Superfund sites with a remedy = 1,498.
• Does not include 97 sites with only no action or no further action.
Figure 13 shows the selection trends for groundwater remedies in 2,541 decision documents from
FY 1982 to 2017. The selection of in situ groundwater treatment and the selection of P&T remain
consistent with the previous three years (FYs 2012 to 2014). In situ treatment has remained at an
average of 51 percent of groundwater decision documents in the most recent three years. The
percentage selecting P&T remains low, at an average of 20 percent, down from 23 percent in the
previous three years. Almost all recent groundwater decision documents include ICs18 with
percentages currently ranging from 64 to 7 8 percent. EPA determined that sites with groundwater
decision documents that did not include ICs had selected ICs for the groundwater in a previous
decision document or the decision was an interim remedy and ICs will likely be selected with the
final remedy in a later decision document.
18 Refer to Institutional Controls: A Guide to Planning, Implementing, Maintaining, and Enforcing Institutional
Controls at Contaminated Sites. OSWER. December 2012. EPA 540-R-09-001.
http:/ / semspub.epa.gov/src/document/11/175446
JULY 2020
23
-------
Superfund Remedy Report, 16th Edition
Figure 13: Selection Trends for Decision Documents with Groundwater Remedies (FY 1982-2017)
-
00
00
00
00
00
00
00
00
cn
cn
CTi
CTi
CTi
Cn
CTi
o
O
O
o o
o
O
o
o
o
rH
rH
rH
rH
rH
rH
rH
rH
on
en
~ • • Monitored Natural Attenuation
¦ In Situ Treatment
Vertical Engineered Barrier
Institutional Controls
Alternative Water Supply
• Number of groundwater decision documents with remedies: FY 1982-2017 = 2,541.
• One decision document from FY 1981 not included.
• Decision documents may be included in more than one category.
JULY 2020
24
-------
Superfund Remedy Report, 16th Edition
EPA evaluated remedies selected in 272 FY 2015 to 2017 decision documents. Of these, 40 percent
(110 documents) address groundwater contamination, and 71 (65 percent) of the 110 documents
included treatment, which consists of P&T or in situ treatment, selected by itself or in
combination with non-treatment remedies for groundwater (Figure 14). Overall, 52 percent of
decision documents with groundwater remedies select multiple remedial approaches, including
various combinations of treatment, vertical engineered barriers, MNA, and ICs.
Figure 14: Combinations of Recent Groundwater Remedies (FY 2015-2017)
Non-Treatment - 39 (35%)
Treatment - 71 (65%)
ICs and Alternative
MNA Only, 1,1% Water Supply, 1,1%
Alternative Water
Supply Only, 3, 3%
ICs and MNA, 9, 8%
ICs Only, 25, 23%
Treatment, Vertical
Engineered Barrier
and ICs, 1,1%
Treatment, ICs, and
Alternative Water
Supply, 1,1%
Treatment and MNA,
2, 2%
Treatment and ICs
31, 28%
Treatment, ICs and
MNA, 10, 9%
• Number of groundwater decision documents = 110.
• Treatment includes P&T or in situ treatment for groundwater.
® Percentage totals for treatment and non-treatment from chart off by I percent due to rounding.
In situ treatment was selected in over 50 percent (56) of the 110 groundwater decision documents
(Table 4). Of these 56 documents, bioremediation was selected in more than half (30) and nearly
half include chemical treatment (26). One-fifth of recent decision documents for groundwater
selected MNA.
JULY 2020
25
-------
Superfund Remedy Report, 16th Edition
One example of a combined remedy approach is at the Cristex Drum19 site in North Carolina.
Cristex Drum is a former fabric mill engaged in knitting, dyeing and finishing that operated from
1966 until 1986. During operations, the plant used an above-ground storage tank, oil-water
separator, a drum storage pad, and a small wastewater storage and treatment lagoon. Primary
sources of soil, sediment, surface water, and groundwater contamination include spills, leaks, and
facility operations. COCs in the groundwater include 1,4-dichlorobenzene, benzene,
benzo(a)pyrene, chloroethene, TCE, PCE, and cis-l,2-dichloroethene. The FY 2017 ROD selected
a combination of ISCO and electrokinetics (EK). A direct current applied to the subsurface
(electrokinetics) will enhance the transport of oxidant through the area to enhance contact of the
oxidant with COCs. The EK-ISCO approach will target the suspected source area and the most
contaminated portion of the saturated source zone where residual DNAPL and adsorbed phase
chlorinated VOCs may be present. Enhanced in situ bioremediation bio-barriers will be installed
down-gradient of the ISCO array to accelerate degradation of dissolved contamination in the
northern half of the saturated source zone, which has lower contaminant concentrations primarily
in the dissolved phase.
Each individual technology selected in the decision documents are counted in Table 4. As in
previous remedy tables, the decision document is only counted once in the total number of
decision documents for each category. For example, the Cristex Drum decision document is
counted in chemical oxidation (in situ), bioremediation (anaerobic, in situ), bioremediation
(bioaugmentation, in situ), and electrokinetics but is only counted once in the category total for in
situ treatment. Therefore, the individual technology numbers are not additive to the category total.
Table 4: Groundwater Remedies Selected in Recent Decision Documents
(FY 2015-2017)
Remedy
Number of Decision
Documents
(FY15-17)
Percent
Groundwater
Decision
Documents
Ex Situ Treatment (P&T)
22
20%
In Situ Treatment
56
51%
Bioremediation
30
27%
Bioremediation (anaerobic, in situ)
21
19%
Bioremediation (bioaugmentation, in situ)
11
10%
Bioremediation (aerobic, in situ)
5
5%
Bioremediation (unspecified, in situ)
4
4%
Chemical Treatment
26
24%
Chemical Oxidation (in situ)
19
17%
Chemical Reduction (in situ)
8
7%
Neutralization (in situ)
1
1%
Thermal Treatment
6
5%
19 Cristex Drum: (1) ROD, OU1, 9/29/17, https://semspub.epa.gov/src/document/04/11070129: and (2) Site
profile, https://cumulis.epa.gov/supercpad/cursites/csitinfo.cfm?id=0406597.
JULY 2020
26
-------
Superfund Remedy Report, 16th Edition
Remedy
Number of Decision
Documents
(FY15-17)
Percent
Groundwater
Decision
Documents
In Situ Treatment (continued)
Permeable Reactive Barrier
5
5%
Multi-phase Extraction
4
4%
Air Sparging
3
3%
Solidification/Stabilization
2
2%
Electrokinetics
1
1%
Flushing
1
1%
Phytoremediation
1
1%
Vapor Extraction
1
1%
Unspecified In Situ Treatment
3
3%
Monitored Natural Attenuation
22
20%
Containment (Vertical Engineered Barrier)
1
1%
Institutional Controls
78
71%
Alternative Water Supply
5
5%
• Number of groundwater decision documents = I 10.
• Number of groundwater decision documents with treatment = 71.
• Decision documents with multiple remedies within a category counted once per category, and documents may be
included in more than one remedy category.
For decision documents that selected bioremediation, 7 0 percent specify anaerobic bioremediation
(Table 4). Some bioremediation remedies also specify aerobic bioremediation or bioaugmentation
(addition of bacteria capable of degrading specific chemicals). About three-quarters of decision
documents that selected chemical treatment specify ISCO, while more than a quarter select ISCR.
Two documents selected both ISCO and ISCR. Appendix A includes descriptions of
bioremediation and chemical treatment remedies.
Figure 15 shows the COCs most frequently addressed in recent groundwater decision documents.
Nearly 75 percent of groundwater decision documents have remedies that target halogenated
(primarily chlorinated) VOCs. Metals and BTEX are the next most common contaminant
categories at 38 and 36 percent, respectively. Nearly 60 percent of recent groundwater decision
documents with COCs have more than one contaminant group (57 of 98).
JULY 2020
27
-------
Superfund Remedy Report, 16th Edition
At Standard Chlorine20 in New Jersey, various manufacturing activities conducted between 1916
and 1993, including the production, storage and packaging of moth balls and flakes; the
manufacture of lead-acid batteries; formulation of drain cleaners; production of dye carriers; and
distillation and purification of chlorinated benzenes, resulted in a variety of contaminants at the
site. In the FY 2016 ROD, groundwater remedies have been selected to address halogentated
VOCs (such as 1,2-dichlorobenzene and l,l'-biphenyl), halogenated SVOCs (1,2,4-
trichlorobenzene), BTEX (benzene, ethylbenzene and xylene), PAHs (such as benzo(a)pyrene and
naphthalene), and metals (such as lead and chromium).
Of the 21 decision documents with anaerobic bioremediation, 19 had COCs indicated and 17
included chlorinated VOCs. Of the 8 ISOR projects, 6 indicated COCs, as follows: organic COCs
only (2), metals and organic COCs (3), and metals only (1).
Figure 15: Detailed COCs in Decision Documents with Groundwater Remedies
(FY 2015-2017)
» 80%
c
CD
£ 70%
u
o 60%
c
o
50%
QJ
Q
5 40%
ra
| 30%
o
5 20%
4-
O
eio 10%
03
+-»
C
, V
&
<&
c/ °
\v
-------
Superfund Remedy Report, 16th Edition
CERCLA and the NCP..., including technical impracticability from an engineering perspective. TI
waivers generally will be applicable only for ARARs that are used to establish cleanup performance
standards or levels, such as chemical-specific MCLs [maximum contaminant levels] or State
ground-water quality criteria." (EPA, 1993).
When determined that groundwater restoration is technically impracticable from an engineering
perspective, a TI waiver may be included in a decision document. One hundred and five (105)
decision documents from FYs 1988 through 2017 specify TI waivers for groundwater (Figure 16).
These 105 documents are for 96 sites; sites may issue multiple TI waivers to address different
plumes or areas of the site.
Figure 16: Groundwater TI Waivers per Fiscal Year (FY 1988-2017)
12
10
10
r--ooa^o
OOOOOOOOOOrHrHrHrHrHrHrHrH
oooooooooooooooooo
(N(N(NfM(N(N(NN(N(NM(N(M(NN(N(NM
Number of groundwater TI waivers = 105.
Does not include surface water only TI waivers.
Only includes TI waivers at Superfund Alternative approach sites and final or deleted NPL sites.
Optimization
EPA has been conducting optimization reviews and providing technical support to specific projects
since 1997. Early in the program, optimization reviews focused on Fund-lead groundwater P&T
remedies and primarily addressed the remedy and long-term monitoring stages. EPA has since
issued the National Strategy to Expand Superfund Optimization Practices from Site Assessment to Site
Completion that expands and formalizes optimization practices from site assessment to site
completion for the Superfund program. The Strategy institutes changes to Superfund remedial
program business processes to take advantage of newer tools and strategies that promote more
effective and efficient cleanups. The Strategy identifies several objectives to achieve verifiably
protective site cleanups faster, cleaner, greener, and cheaper. Many of these approaches have been
JULY 2020
29
-------
Superfund Remedy Report, 16th Edition
applied for years at a subset of sites under the EPA's management as well as sites managed by other
federal and state programs. The body of knowledge on applied optimization techniques and their
use throughout the cleanup life cycle is substantial and growing rapidly (EPA, 2012o).
Two examples of recent decision documents informed by site optimization are summarized below.
Jones Road Ground Water Plume
OUOI, Optimization Review in August 2014, ROD Amendment issued September 29, 2017.
The Jones Road site is contaminated with chlorinated VOCs, including PCE, in soil and
groundwater. In 2013 during the design of two groundwater P&T systems, there were concerns
about their future implementation and effectiveness. The project was referred for an independent
optimization review of the preliminary remedy design. The review team found that addressing the
continuing sources for contaminants to the groundwater would be a more cost-effective approach
than first implementing P&T. The review focused on addressing the VOCs in soil contributing to
the contamination of both the shallow water-bearing zone and the Deep Chicot Aquifer.
Recommendations included using a phased remedial approach. To reduce VOC discharge to the
Lower Chicot water-bearing zone, the team recommended installing an SVE system in the deep
unsaturated Chicot sand unit. To address the shallow water-bearing zone, the recommendation
was to pilot test an SVE system and install a full system if successful. The need and possible design
for a P&T remedy to contain the migration of groundwater contaminants and restore the aquifer
could be better evaluated after the effectiveness of source treatment was known through continued
groundwater monitoring. Source mitigation of the two soil vapor sources in the Shallow Source
Area Soil and the Deep Unsaturated Chicot Sand is the focus of the 2017 ROD amendment.
Benfield Industries, Inc.
OUOI, Optimization Review in September 2007, ROD Amendment issued September 16, 2015.
The Benfield Industries site is contaminated with PAHs, SVOCs, VOCs, and metals in soil and
groundwater. A 2007 optimization review recommended, in part, assessment of in situ treatment,
particularly ISCO, of remaining soil hot spots. Additional characterization of the residual soil
contamination and groundwater confirmed that continuing elevated levels of PAHs in the
groundwater is the result of the PAHs dissolving into the groundwater from the smear zone. A
focused feasibility study conducted in 2014 resulted in the selection of ISCO followed by
enhanced in situ bioremediation, as needed, to address this source contamination. The selection
was documented in the 2015 ROD amendment.
JULY 2020
30
-------
Superfund Remedy Report, 16th Edition
VIII. Vapor Intrusion
Data for remedies that target air and soil gas media to address vapor intrusion have been tracked
since the SRR 14th Edition. Vapor intrusion mitigation technologies and ICs selected in FY 2015 to
2017 decision documents are included in Table 5. Descriptions of the mitigation technologies are
found in Appendix A.
Vapor intrusion is the term given to the migration of vapor-forming chemicals from any
underground source into a structure (for example, homes, businesses, schools). Contaminated
groundwater or soil is the most common subsurface vapor source, although contamination in
sewers, drain lines, and other conduits can also present a vapor intrusion threat in some settings.
Vapor-forming chemicals may include VOCs, select SVOCs, some pesticides, some PCBs, and
some inorganic contaminants, such as elemental mercury. Concentrations of vapor-forming
chemicals in indoor air may pose an unacceptable health risk to building occupants. EPA issued
two technical guides for assessing and mitigating vapor intrusion (EPA, 2015a and 2015b).
Forty FY 2015 to 2017 decision documents address vapor intrusion (Table 5). Eight of these
documents select vapor intrusion mitigation for existing structures. Six specify active
depressurization or positive building pressurization. Fourteen decision documents select ICs for
vapor intrusion at existing structures. Thirty-eight recent decision documents include ICs related
to building design and construction of future structures in areas with subsurface contamination
that does not allow unlimited land use and unrestricted exposure.
A total of 100 decision documents from FYs 2009 to 2017 have addressed vapor intrusion since
the data began being tracked for SRR 14th Edition. Of these documents, 31 documents select vapor
intrusion mitigation for existing structures, with 17 decision documents selecting active
depressurization. Thirty-seven decision documents select ICs for vapor intrusion at existing
structures, while seventy-nine decision documents include ICs related to building design and
construction of future structures.
At the Raymark Industries, Inc.21 site in Connecticut, liquid manufacturing wastes were
discharged to the facility's drainage system, which led to extensive VOC contamination in the
groundwater. Groundwater in the source area also contains DNAPL. To address vapor intrusion
resulting from volatile contaminants in the groundwater, the FY 2016 ROD includes the
continued operation and maintenance of active depressurization technologies (sub-slab
depressurization systems) at 106 homes, in addition to installing and operating similar systems at
20 additional buildings.
21 Raymark Industries, Inc.: (1) ROD, OU2, 9/9/16, https://semspub.epa.gov/src/document/01/592492: and (2)
Site profile, https://cumulis.epa.gov/supercpad/cursites/csitinfo.cfm?id=Q 100094.
JULY 2020
31
-------
Superfund Remedy Report, 16th Edition
Table 5: Vapor Intrusion Remedies Selected in Recent Decision Documents
(FY 2015-2017)
Remedy
2015
2016
2017
Total
Vapor Intrusion Mitigation at Existing Structures
3
4
1
8
Active Depressurization Technology
0
4
1
5
Positive Building Pressurization (commercial/industrial)
1
0
0
1
Vapor Intrusion Mitigation (unspecified)
3
0
0
3
Institutional Controls
13
12
15
40
ICs for Future Construction
13
10
15
38
ICs for Existing Buildings
5
6
3
14
• Number of decision documents selecting vapor intrusion remedies = 40.
• Existing buildings may continue to require ICs for future use changes or modifications.
• Decision documents with multiple remedies within a category are counted once per category, and documents
may be included in more than one remedy category.
The OSWER Technical Guide for Assessing and Mitigating the Vapor Intrusion Pathway from Subsurface
Vapor Sources to Indoor Air (EPA, 2015a) states that "the preferred long-term response to the
intrusion of vapors into buildings is to eliminate or substantially reduce the level of contamination
in the subsurface vapor source (e.g., groundwater, subsurface soil, sewer lines) by vapor-forming
chemicals to acceptable-risk levels, thereby achieving a permanent remedy." For sites with vapor
intrusion remedies, source or groundwater remedies may have been selected to address subsurface
contamination or such remedies may be planned. Selected remedies are included in the source and
groundwater sections (Section VI and Section VII, respectively). Building mitigation for vapor
intrusion should "be regarded as an interim action that can provide effective human health
protection, which may become part of a final cleanup plan" (EPA, 2015a).
JULY 2020
32
-------
Superfund Remedy Report, 16th Edition
IX. Conclusions
Based on EPA's analysis of recently selected remedies (FYs 2015 to 2017) and trends over the life
of the Superfund program, treatment continues to be selected frequently and remains selected at
78 percent of Superfund sites with decision documents. Superfund also continues to address
complex sites involving multiple media and contaminants. In addition, optimization studies have
led to remedy changes in recent decision documents.
With respect to recent source remedies:
¦ The Superfund remedial program continued to select treatment for a large number of
source remedies.
¦ Source remedies continued to include a combination of treatment, on-site containment,
off-site disposal, and ICs.
¦ One-fifth of recent source decision documents selected in situ treatment.
¦ S/S, SVE, and ISTT were the most frequently selected remedies for in situ treatment.
¦ Physical separation and recycling were recently selected most often for ex situ treatment.
¦ Remedies in more than 60 percent of recent source decision documents addressed metals.
¦ Almost all sediment decision documents included excavation or dredging. One-third of
sediment decision documents included either in situ or ex situ treatment (primarily
dewatering).
Pertaining to recent groundwater remedies:
¦ The selection of in situ treatment for groundwater remains at over 50 percent of recent
groundwater decision documents.
¦ The selection of P&T in groundwater decision documents has decreased significantly since
the early 1990s and is hovering near 20 percent. By comparison, P&T selection was above
80% as late as 1992.
¦ Seventy percent of recent groundwater decision documents included ICs.
¦ The selection of alternative water supply remedies and vertical engineered barriers are both
down slightly.
¦ Bioremediation and chemical treatment were the most frequently selected in situ remedies
for groundwater.
¦ The majority of in situ bioremediation remedies specified anaerobic bioremediation. Most
of the chemical treatment remedies specified ISCO.
¦ The most common COCs addressed by groundwater remedies were halogenated VOCs,
primarily chlorinated VOCs.
¦ One hundred and five (105) decision documents from FYs 1988 through 2017 have TI
waivers for groundwater.
¦ Since FY 2007, five or fewer TI waivers have been approved annually.
JULY 2020
33
-------
Superfund Remedy Report, 16th Edition
Regarding vapor intrusion remedies:
¦ Active depressurization was the most frequently selected technology for vapor intrusion
mitigation.
¦ ICs were frequently selected to reduce the risk of exposure to vapor intrusion in current
buildings and to require mitigation for future structures constructed in areas with
subsurface contamination that does not support unlimited land use and unrestricted
exposure.
The remedy and site information provided in this report informs stakeholders in Superfund
communities about the program's remedy decisions, and helps federal, state, and tribal
remediation professionals select future remedies. Analyzing the trends in remedy decisions
provides an indication of the future demand for remedial technologies, which helps technology
developers, and consulting and engineering firms, evaluate cleanup markets. The trends also
indicate program needs for expanded technical information and support related to specific
technologies or site cleanup challenges. For example, continued selection of in situ groundwater
technologies suggests an ongoing need for additional knowledge and support associated with those
technologies.
JULY 2020
34
-------
Superfund Remedy Report, 16th Edition
X. Sources and Electronic Versions
This section lists the sources of information used in this report and provides information on how
to access the electronic version of this report and previous versions of the ASR and SRR.
Sources
EPA. 199 la. A Guide to Principal Threat and Low Level Threat Wastes. Office of Solid Waste and
Emergency Response (OSWER). November. Publication 9380.3-06FS.
https:/ / semspub.epa.gov/src/document/05/382007,pdf
EPA. 199 lb. Remediation of Contaminated Sediments. Office of Research and Development.
April. EPA/625/6-91/028, https://semspub.epa.gov/src/document/HO/189668,pdf
EPA. 1993. Guidance for Evaluating the Technical Impracticability of Ground-Water Restoration.
OSWER. September. EPA 540-R-93-080.
https:/ / semspub.epa.gov/ src/document/HQ/17 53 87 .pdf
EPA. 1996. A Citizen's Guide to Soil Washing. OSWER. April. EPA 542-F-96-002.
https:/ / nepis.epa.gov/Exe/ZvPDF.cgi/10002SYY.PDF?Dockev= 10002SYY.PDF
EPA. 1997 a. Analysis of Selected Enhancements for Soil Vapor Extraction. OSWER. September.
EPA 542-R-97-007. https://semspub.epa.gov/src/document/HO/134629.pdf
EPA. 1997b. Presumptive Remedy: Supplemental Bulletin Multi-Phase Extraction (MPE)
Technology for VOCs in Soil and Groundwater. OSWER. April. EPA 540-F-97-004.
https:/ / semspub.epa.gov/ src/document/HQ/ 174624.pdf
EPA. 1998. Field Applications of In Situ Remediation Technologies: Ground-Water Circulation
Wells. OSWER. October. EPA 542-R-98-009.
https:/ / semspub.epa.gov/ src/document/HO/134593,pdf
EPA. 1999a. A Guide to Preparing Superfund Proposed Plans, Records of Decision, and Other
Remedy Selection Decision Documents. OSWER. July. EPA 540-R-98-031.
https://www.epa.gov/sites/production/files/2015-02/documents/rod guidance.pdf
EPA. 1999b. Use of Monitored Natural Attenuation at Superfund, RCRA Corrective Action, and
Underground Storage Tank Sites. OSWER. April 21. OSWER Directive No. 9200.4-17P.
https://nepis,epa,gov/Exe/ZvPDF,cgi/2000ISUG,PDF?Dockev=2000ISUG.PDF
EPA. 2000. Engineered Approaches to In Situ Bioremediation of Chlorinated Solvents. OSWER.
July. EPA 542-R-00-008. https://semspub.epa.gov/src/document/HO/134557.pdf
EPA. 2001. Use of Bioremediation at Superfund Sites. OSWER. September. EPA 542-R-01-019.
www.epa.gov/sites/production/files/2015-08/documents/bioremediation 542r01019.pdf
EPA. 2005. Contaminated Sediment Remediation Guidance for Hazardous Waste Sites. OSWER.
December. EPA 540-R-05-012. https://semspub.epa.gov/src/document/HQ/17447 l.pdf
JULY 2020
35
-------
Superfund Remedy Report, 16th Edition
EPA. 2006. In Situ Treatment Technologies for Contaminated Soil: Engineering Forum Issue
Paper. OSWER. November. EPA 542-F-06-013. www.epa.gov/sites/production/files/2015-
04/documents/tsp issue paper 542f06013.pdf
EPA. 2007. The Use of Soil Amendments for Remediation, Revitalization, and Reuse. OSWER.
December. EPA 542-R-07-013. https://semspub.epa.gov/src/document/11/176023,pdf
EPA. 2008a. Engineering Issue: Indoor Air Vapor Intrusion Mitigation Approaches. National Risk
Management Research Laboratory; Office of Research and Development. October. EPA
600-R-08-115. www.epa.gov/sites/production/files/2015-09/documents/600r08115.pdf
EPA. 2008b. Understanding the Superfund Alternative Approach. OSWER. April. EPA 330-R-08-
001. https://semspub.epa.gov/src/document/HQ/189821.pdf
EPA. 2008c. Wetlands Compensatory Mitigation. Office of Wetlands, Oceans and Watersheds.
EPA 843-F-08-002. www.epa.gov/sites/production/files/2015-
08/documents/compensatory mitigation factsheet.pdf
EPA. 2010. Update on Providing Alternative Water Supply as Part of Superfund Response
Actions. OSWER. September. OSWER Directive No. 9355.3-22.
https:/ / semspub.epa.gov/ src/document/HQ/175 200.pdf
EPA. 2011. Fact Sheet on Evapotranspiration Cover Systems for Waste Containment. OSWER.
February. EPA 542-F-l 1-001. https://semspub.epa.gov/src/document/HO/153848,pdf
EPA. 2012a. A Citizen's Guide to Activated Carbon Treatment. OSWER. September. EPA 542-F-
12-001. https://clu-in.org/products/citguide/
EPA. 2012b. A Citizen's Guide to Air Stripping. OSWER. September. EPA 542-F-l2-002.
https:/ / clu-in.org/ products/citguide/
EPA. 2012c. A Citizen's Guide to Capping. OSWER. September. EPA 542-F-l2-004. https://clu-
in.org/ products/citguide/
EPA. 2012d. A Citizen's Guide to Fracturing for Site Cleanup. OSWER. September. EPA 542-F-
12-008. https://clu-in.org/products/citguide/
EPA. 2012e. A Citizen's Guide to In Situ Chemical Reduction. OSWER. September. EPA 542-F-
12-012. https://clu-in.org/products/citguide/
EPA. 2012f. A Citizen's Guide to In Situ Thermal Treatment. OSWER. September. EPA 542-F-12-
013. https://clu-in.org/products/citguide/
EPA. 2012g. A Citizen's Guide to Incineration. OSWER. September. EPA 542-F-l2-020.
https:/ / clu-in.org/ products/citguide/
EPA. 2012h. A Citizen's Guide to Pump and Treat. OSWER. September. EPA 542-F-12-017.
https:/ / clu-in.org/ products/citguide/
JULY 2020
36
-------
Superfund Remedy Report, 16th Edition
EPA. 2012i. A Citizen's Guide to Soil Vapor Extraction and Air Sparging. OSWER. September.
EPA 542-F-12-018. https://clu-in.org/products/citguide/
EPA. 2012j. A Citizen's Guide to Solidification and Stabilization. OSWER. September. EPA 542-
F-12-019. https://clu-in.org/products/citguide/
EPA. 2012k. A Citizen's Guide to Thermal Desorption. OSWER. September. EPA 542-F-12-020.
https:/ / clu-in.org/ products/citguide/
EPA. 20121. A Citizen's Guide to Vapor Intrusion Mitigation. OSWER. September. EPA 542-F-12-
022. https://clu-in.org/products/citguide/
EPA. 2012m. A Citizen's Guide to Vertical Engineered Barriers. OSWER. September. EPA 542-F-
12-022. https://clu-in.org/products/citguide/
EPA. 2012n. Institutional Controls: A Guide to Planning, Implementing, Maintaining, and
Enforcing Institutional Controls at Contaminated Sites. OSWER. December. EPA 540-R-
09-001. https://semspub.epa.gov/src/document/HQ/175446.pdf
EPA. 2012o. National Strategy to Expand Superfund Optimization Practices from Site Assessment
to Site Completion. OSWER. September. OSWER Directive No. 9200.3-75.
https:/ / semspub.epa.gov/ src/document/HQ/174096.pdf
EPA. 2013a. In Situ Amendments. OLEM. April. Infographic.
http:/ / semspub.epa.gov/ src/document/HQ/100000673
EPA. 2013b. Use of Amendments for In Situ Remediation at Superfund Sediment Sites. OSWER
April. OSWER Directive 9200.2-128FS.
https:/ / semspub.epa.gov/ src/document/HQ/196704.pdf
EPA. 2015a. OSWER Technical Guide for Assessing and Mitigating the Vapor Intrusion Pathway
from Subsurface Vapor Sources to Indoor Air. OSWER. June. Publication 9200.2-154.
https:/ / semspub.epa.gov/ src/document/HQ/ 190145.pdf
EPA. 2015b. Technical Guide for Assessing Petroleum Vapor Intrusion at Leaking Underground
Storage Tank Sites. Office of Underground Storage Tanks. June. EPA 510-R-15-001.
https://www.epa.gov/ sites/ production/files/2015-06/documents/ pvi-guide-final-6-10-
15.pdf
Federal Remediation Technologies Roundtable (FRTR). 2007. Remediation Technologies
Screening Matrix and Reference Guide, 4th Edition. January, www.frtr.gov
Interstate Technology & Regulatory Council (ITRC). 1997. Technical and Regulatory Guidelines
for Soil Washing. Metals in Soil Workgroup. Washington, D.C. December. MIS-1.
http://www.environmentalrestoration.wiki/images/3/3c/ITRC-1997-
Tech %26 Reg Guidelines for Soil Washing.pdf
JULY 2020
37
-------
Superfund Remedy Report, 16th Edition
ITRC. 2003. Technical and Regulatory Guidance Document for Constructed Treatment
Wetlands. Wetlands Work Group. Washington, D.C. December. WTLND-1.
www.itrcweb.org/GuidanceDocuments/WTLND-l.pdf
ITRC. 2007. Technical and Regulatory Guidance Document for Vapor Intrusion Pathway: A
Practical Guideline. Washington, D.C. January. VI-1.
https://semspub.epa.gov/work/01/533755.pdf
ITRC. 2011. Permeable Reactive Barrier: Technology Update. Permeable Reactive Barrier Work
Group. Washington, D.C. June. PRB-5-1.
https:/ / semspub.epa.gov/ src/document/09/114223 l.pdf
Karn, Barbara; Kuiken, Todd; and Otto, Martha. 2009. Nanotechnology and in Situ Remediation:
A Review of the Benefits and Potential Risks. Environmental Health Perspectives.
December. Volume 117, Number 12. pp. 1823-1831.
https://www.ncbi.nlm.nih.gov/ pmc/articles/PMC2799454
Nielsen, K.B. and B. Hvidberg. 2017. Remediation techniques for mitigating vapor intrusion from
sewer systems to indoor air. Remediation. Volume 27, Issue 3. Pages 67-73.
https:/ / doi.org/10,1002/rem. 215 20
Electronic Versions
SRR 16th Edition is available electronically at https://www.epa.gov/remedvtech/superfund-remedv-
report.The body of the report and its appendices can be downloaded from the website. The list
below describes the appendices for the SRR 16th Edition.
Appendix A: Definitions of Selected Remedies. This appendix defines the specific remedies
selected as part of remedial actions.
Appendix B: Treatment Technologies by Fiscal Year. This appendix lists the ex situ and in situ
source treatment technologies, groundwater in situ treatment technologies, and groundwater
pump and treat remedies by FY from 1982 to 2017.
Appendix C: Individual Contaminants and Assigned Contaminant Groups. This appendix lists
the individual contaminants from decision documents and identifies which contaminant groups
the individual contaminants were assigned.
The data that forms the basis of the analyses contained in SRR 16th Edition can be found at
https://www.epa.gov/superfund/superfund-data-and-reports by downloading Contaminant of
Concern Data for Decision Documents by Media, FY 1982-201 7 and Remedy Component Data for
Decision Documents by Media, FY 1982-201 7.
In addition, previous editions of ASR and SRR can be downloaded from
https://www.epa.gov/ remedvtech/superfund-remedv-report.
JULY 2020
38
-------
Appendix A
Definitions of Selected Remedies
-------
Superfund Remedy Report, 16th Edition
Appendix A: Definitions of Selected Remedies
Table of Contents
Table of Contents A-l
A. 1 Treatment Technologies A-3
A. 1.1 Biological Treatment A-3
Bioaugmentation A-3
Bioremediation A-3
Constructed Treatment Wetlands A-3
Phytoremediation A-3
A. 1.2 Chemical Treatment A-4
Amendments A-4
Cap (amended, in situ) A-4
Chemical Fixation A-4
Chemical Oxidation A-4
Chemical Reduction A-4
In Situ Chemical Oxidation (ISCO) A-5
In Situ Chemical Reduction (ISCR) A-5
Nanoremediation A-5
Neutralization A-5
Permeable Reactive Barriers (PRB) A-5
A. 1.3 Physical Treatment A-5
Air Sparging A-5
Electrokinetic Separation A-6
Flushing A-6
In Situ Geochemical Stabilization A-6
In-Well Air Stripping A-6
Mechanical Soil Aeration A-6
Multi-Phase Extraction (MPE) A-6
Physical Separation A-7
Recycling A-7
Soil Vapor Extraction (SVE) A-7
Soil Washing A-7
Solidification and Stabilization (S/S) A-7
Solvent Extraction A-8
A. 1.4 Thermal Treatment A-8
Electrical Resistance Heating (ERH) A-8
Incineration A-8
In Situ Thermal Treatment (ISTT) A-9
In Situ Thermal Desorption A-9
Open Burn (OB) and Open Detonation (OD) A-9
Steam Enhanced Extraction (SEE) A-9
Thermal Conduction Heating (TCH) A-9
Thermal Desorption A-9
JULY 2020 A-l
-------
Superfund Remedy Report, 16th Edition
Thermally-Enhanced SVE A-10
Vitrification A-10
A. 1.5 Pump and Treat (P&T) A-10
Activated Carbon Treatment A-10
Air Stripping A-l 1
Filtration A-l 1
Ion Exchange A-l 1
Metals Precipitation A-l2
A. 2 On-Site Containment Technologies A-12
Building Sealant A-l2
Caps and Cover Systems A-12
Cap (In situ) A-12
Containment Cell (subaqueous) A-12
Containment Cell (upland, adjacent) A-13
Evapotranspiration (ET) Covers A-13
Repair (pipe/sewer/tank/structure) A-13
Vertical Engineered Barriers (VEB) A-13
A.3 Monitored Natural Attenuation (MNA) A-13
A.4 Monitored Natural Recovery (MNR) for Sediment A-14
A.5 Enhanced Monitored Natural Recovery (EMNR) for Sediment A-14
A. 6 Vapor Intrusion Mitigation A-15
Active Depressurization Technology A-15
Interior Ventilation A-15
Passive Barrier (Impermeable Membrane) Installation A-15
Passive Soil Depressurization A-16
Positive Building Pressurization A-16
Sealing Cracks and Openings A-16
Soil Pressurization A-16
Sub-slab Ventilation A-16
A. 7 Other or Unspecified Remedies A-16
Alternative Water Supply Remedy A-16
Fracturing for Site Cleanup A-17
Institutional Controls (ICs) A-l7
Soil Amendments A-l7
Wetlands Replacement A-17
Wetlands Restoration A-18
JULY 2020 A-2
-------
Superfund Remedy Report, 16th Edition
A. I Treatment Technologies
Most treatment technologies were grouped into one of the four main treatment categories:
biological, chemical, physical or thermal treatment. Ex situ treatment technologies associated with
pump and treat (P&T) systems are included separately as its own treatment category.
A. I. I Biological Treatment
Biological treatment involves 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 in the definition of biological treatment.
Bioaugmentation is "[the] addition of microbes to the subsurface where organisms able to degrade
specific contaminants are deficient. Microbes may be 'seeded' from populations already present at
a site and grown in aboveground reactors or from specially cultivated strains of bacteria having
known capabilities to degrade specific contaminants" (EPA, 2000).
Bioremediation "is a technology that uses microorganisms to treat contaminants through natural
biodegradation mechanisms (intrinsic bioremediation) or by enhancing natural biodegradation
mechanisms through the addition of microbes, nutrients, electron donors, and/or electron
acceptors (enhanced bioremediation). This technology, performed in situ (below ground or in
place) or ex situ (above ground), is capable of degrading organic compounds to less toxic materials
such as carbon dioxide (CO2), methane, and water through aerobic or anaerobic processes" (EPA,
2001).
Constructed Treatment Wetlands are "manmade wetlands built to remove various types of
pollutants that may be present in water that flows through them. They are constructed to recreate,
to the extent possible, the structure and function of natural wetlands...They possess a rich
microbial community in the sediment to effect the biochemical transformation of pollutants, they
are biologically productive, and...they are self-sustaining....[Constructed wetlands] utilize many of
the mechanisms of phytoremediation" (ITRC, 2003). Note that the term "constructed wetlands" is
used to refer only to wetlands constructed for the purposes of treatment, and not to wetlands
constructed to compensate for wetlands destroyed by a remedy (such as placement of a cap in a
marsh). Such "compensatory wetlands" are considered as "Wetlands Replacement."
Phytoremediation "uses [macroscopic] plants to extract, degrade, contain, or immobilize
contaminants in soil, groundwater, and other contaminated media. The phytoremediation
mechanisms used to treat contaminated [media]...are phytoextraction, rhizodegradation,
phytodegradation, phytovolatilization, and phytostabilization" (EPA, 2006). Phytoremediation may
be applied in situ or ex situ.
Note that while phytoremediation may include the use of microorganisms in conjunction with
plants, it is distinguished from bioremediation in that bioremediation does not use macroscopic
plants or trees. For purposes of this report, the use of plants to control surface water drainage, to
influence groundwater movement, or to adjust the water table are not considered
phytoremediation since the purpose is not to extract the contaminants from the media. Such
remedies are classified as engineering controls.
JULY 2020
A-3
-------
Superfund Remedy Report, 16th Edition
A. 1.2 Chemical Treatment
Chemical treatment chemically converts hazardous contaminants to non-hazardous or less toxic
compounds or compounds that are more stable, less mobile, inert, or all three. Even though a
chemical reaction is not always involved in chemical precipitation, chemical precipitation is
typically included in this category.
Amendments are "specialized materials used to reduce risk through in situ sequestering or
destruction of contaminants in sediment" (EPA, 2013a). Examples include activated carbon,
organoclay, and phosphate additives. "Direct amendment of surficial sediment with sorbents can
reduce pollutant bioavailability to the food chain and flux of pollutants into the water column.
Amendments can be spread on the surface of the contaminated sediment as a thin layer, intended to
be mixed with the sediments through natural processes, or mixed into the surface using equipment
similar to a rototiller" (EPA, 2013b).
Cap (amended, in situ) for sediment refers to a subaqueous cover in which "[specialized] materials
[are] used to enhance the chemical isolation capacity...compared to sand caps. Examples
include...reactive/adsorptive materials such as activated carbon, apatite, coke, organoclay, zero-
valent iron and zeolite. Composite geotextile mats containing one or more of these materials (i.e.,
reactive core mats) are becoming available commercially" (EPA, 2005).
Chemical Fixation or Chemical Stabilization— See Solidification and Stabilization.
Chemical Oxidation "typically involves reduction/oxidation (redox) reactions that chemically
convert hazardous contaminants to nonhazardous or less toxic compounds that are more stable,
less mobile, or inert. Redox reactions involve the transfer of electrons from one chemical to
another. Specifically, one reactant is oxidized (loses electrons) and one is reduced (gains electrons).
There are several oxidants capable of degrading contaminants. Commonly used oxidants include
potassium or sodium permanganate, Fenton's catalyzed hydrogen peroxide, hydrogen peroxide,
ozone, and sodium persulfate. Each oxidant has advantages and limitations, and while applicable
to soil contamination and some source zone contamination, they have been applied primarily
toward remediating groundwater" (EPA, 2006). Chemical oxidation can be conducted either in
situ or ex situ.
Chemical Reduction "uses chemicals called 'reducing agents' to help change contaminants into
less toxic or less mobile forms....[Chemical reduction] can clean up several types of contaminants
dissolved in groundwater. It can also be used to clean up contaminants known as 'dense non-
aqueous phase liquids' or 'DNAPLs,' which do not dissolve easily in groundwater and can be a
source of contamination for a long time. [Chemical reduction] is most often used to clean up the
metal chromium and the industrial solvent trichloroethene, or 'TCE,' which is a DNAPL.
"Common reducing agents include zero valent metals, which are metals in their pure form. The
most common metal used in [in situ chemical reduction (ISCR)] is zero valent iron, or 'ZVI.' ZVI
must be ground up into small granules for use in ISCR. In some cases, micro- or nano-scale
(extremely small) particles are used. The smaller particle size increases the amount of iron available
to react with contaminants. Other common reducing agents include polysulfides, sodium
dithionite, ferrous iron, and bimetallic materials, which are made up of two different metals. The
JULY 2020
A-4
-------
Superfund Remedy Report, 16th Edition
most common bimetallic material used in ISCR is iron coated with a thin layer of palladium or
silver" (EPA, 2012e).
In Situ Chemical Oxidation (ISCO) — See Chemical Oxidation.
In Situ Chemical Reduction (ISCR) — See Chemical Reduction.
Nanoremediation "methods entail the application of reactive nanomaterials for transformation
and detoxification of pollutants. These nanomaterials have properties that enable both chemical
reduction and catalysis to mitigate the pollutants of concern....Because of their minute size and
innovative surface coatings, nanoparticles may be able to pervade very small spaces in the
subsurface and remain suspended in groundwater, allowing the particles to travel farther than
larger, macro-sized particles and achieve wider distribution....
"Many different nanoscale materials have been explored for remediation...Of these, nanoscale zero-
valent iron (nZVI) is currently the most widely used....nZVI particles range from 10 to 100
[nanometers (nm)] in diameter....The high reactivity of nZVI particles is in part a direct result of
their high specific surface area....nZVI's small particle size also allows more of the material to
penetrate into soil pores, and it can be more easily injected into shallow and deep aquifers, a
property that is particularly beneficial when contamination lies underneath a building" (Karn,
Kuiken, & Otto, 2009).
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.
Permeable Reactive Barriers (PRB) are "in situ, permeable treatment zone[s] designed to intercept
and remediate a contaminant plume. The term 'barrier' is intended to convey the idea that
contaminant migration is impeded; however, the PRB is designed to be more permeable than the
surrounding aquifer media so that groundwater can easily flow through the structure without
significantly altering groundwater hydrology. The treatment zone may be created directly using
reactive materials such as ZVI, or indirectly using materials designed to stimulate secondary
processes (e.g., adding carbon substrate and nutrients to enhance microbial activity). In this way,
contaminant treatment may occur through physical, chemical, or biological processes" (ITRC,
2011).
A. 1.3 Physical Treatment
Physical treatment uses the physical properties of the contaminants or the contaminated medium
to separate or immobilize the contamination.
Air Sparging "involves drilling one or more injection wells into the soil below the water table. An
air compressor at the surface pumps air underground through the wells. As air bubbles flow
through the groundwater, it carries contaminant vapors upward into the soil above the water table.
The mixture of air and vapors is then pulled out of the ground for treatment using [soil vapor
extraction (SVE)]" (EPA, 2012i). Oxygen added to the contaminated groundwater and vadose-zone
soils also can enhance biodegradation of contaminants below and above the water table. The
injection of ozone into the aquifer is referred to as ozone sparging and is a form of chemical
treatment.
JULY 2020
A-5
-------
Superfund Remedy Report, 16th Edition
Electrokinetic Separation is "an emerging technology that relies on the application of a low-
intensity, direct current through the soil to separate and extract heavy metals, radionuclides, and
organic contaminants from unsaturated soil, sludge, and sediment. The current is applied across
electrode pairs that have been implanted in the ground on each side of the contaminated soil
mass. During electromigration, positively charged chemical species, such as metals, ammonium
ions, and some organic compounds, move toward the cathode, and negatively charged chemicals,
such as chloride, cyanide, fluoride, nitrate, and negatively-charged organic species, migrate toward
the anode....The target compounds are either extracted to a recovery system or deposited at the
electrode" (EPA, 2006).
Flushing "involves flooding a zone of contamination with an appropriate solution to remove the
contaminant from the soil. Water or liquid solution is injected or infiltrated into the area of
contamination. The contaminants are mobilized by solubilization, formation of emulsions, or a
chemical reaction with the flushing solutions. After passing through the contamination zone, the
contaminant-bearing fluid is collected and brought to the surface for disposal, recirculation, or on-
site treatment and reinjection.... Flushing solutions may be water, acidic aqueous solutions, basic
solutions, chelating or complexing agents, reducing agents, cosolvents, or surfactants" (EPA, 2006).
In Situ Geochemical Stabilization — See Solidification and Stabilization.
In-Well Air Stripping systems "create a circulation pattern in the aquifer by drawing water into and
pumping it through the wells, and then reintroducing the water into the aquifer without bringing
it above ground....The well is double-cased with hydraulically separated upper and lower screened
intervals within the aquifer....The system can be configured with an upward in-well flow or a
downward in-well flow. The most common configurations involve the injection of air into the
inner casing, decreasing the density of the groundwater and allowing it to rise....Through this
system, volatile contaminants in the ground water are transferred from the dissolved phase to the
vapor phase by the rising air bubbles. Contaminated vapors can be drawn off and treated above
ground or discharged into the vadose zone" (EPA, 1998).
Mechanical Soil Aeration agitates contaminated soil, using tilling or other means to volatilize
contaminants.
Multi-Phase Extraction (MPE) "is an enhancement of the traditional SVE system. Unlike SVE,
MPE simultaneously extracts both groundwater and soil vapor. The groundwater table is lowered
in order to dewater the saturated zone so that the SVE process can be applied to the newly exposed
soil. This allows the volatile compounds sorbed on the previously saturated soil to be stripped by
the induced vapor flow and extracted. In addition, soluble VOCs present in the extracted
groundwater are also removed" (EPA, 1997b). "[MPE] systems can be implemented to target all
phases of contamination associated with a typical NAPL spill site. These systems remove residual
vadose zone soil contamination residing in soil gas, dissolved in soil pore-space moisture, and
adsorbed to soil particles. [MPE] also effectively removes dissolved and free-phase (both light and
dense NAPL [LNAPL and DNAPL]) contamination in groundwater" (EPA, 1997a). Dual-phase
extraction and bioslurping are types of MPE.
JULY 2020
A-6
-------
Superfund Remedy Report, 16th Edition
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. Physical
separation is included as treatment because it reduces the volume of contaminated material.
Recycling is the process of collecting and processing materials that would otherwise require
disposal and turning them into new products. Examples include recycling recovered oil and
solvents.
Soil Vapor Extraction (SVE) "extracts vapors from the soil above the water table by applying a
vacuum to pull the vapors out...SVE involves drilling one or more extraction wells into the
contaminated soil to a depth above the water table, which must be deeper than 3 feet below the
ground surface. Attached to the wells is equipment (such as a blower or vacuum pump) that creates
a vacuum. The vacuum pulls air and vapors through the soil and up the well to the ground surface
for treatment" (EPA, 2012i). SVE usually is performed in situ; however, in some cases, it can be
used as an ex situ technology.
Soil Washing "is a process that uses physical and/or chemical techniques to separate contaminants
from soil and sediments. Contaminants are concentrated into a much smaller volume of
contaminated residue, which is either recycled or disposed. Washwater can consist of water only or
can include additives such as acids, bases, surfactants, solvents, chelating or sequestering agents
which are utilized to enhance the separation of contaminants from soils or sediments" (ITRC,
1997). "Hazardous contaminants tend to bind, chemically or physically, to silt and clay. Silt and
clay, in turn, bind to sand and gravel particles. The soil washing process separates the
contaminated fine soil (silt and clay) from the coarse soil (sand and gravel). When completed, the
smaller volume of soil, which contains the majority of the fine silt and clay particles, can be further
treated by other methods (such as incineration or bioremediation) or disposed of according to
state and federal regulations" (EPA, 1996).
Solidification and Stabilization (SIS) "refer[s] to a group of cleanup methods that prevent or slow
the release of harmful chemicals from wastes, such as contaminated soil, sediment, and sludge.
These methods usually do not destroy the contaminants. Instead, they keep them from 'leaching'
above safe levels into the surrounding environment...[Solidification and stabilization] are often
used together to prevent people and wildlife from being exposed to contaminants, particularly
metals and radioactive contaminants....
"Solidification involves mixing a waste with a binding agent, which is a substance that makes loose
materials stick together. Common binding agents include cement, asphalt, fly ash, and clay. Water
must be added to most mixtures for binding to occur; then the mixture is allowed to dry and
harden to form a solid block.
"Similar to solidification, stabilization also involves mixing wastes with binding agents. However,
the binding agents also cause a chemical reaction with contaminants to make them less likely to be
released into the environment. For example, when soil contaminated with metals is mixed with
water and lime — a white powder produced from limestone — a reaction changes the metals into a
JULY 2020
A-7
-------
Superfund Remedy Report, 16th Edition
form that will not dissolve in water" (EPA, 2012j). Stabilization remedies are classified as S/S
whether or not they ultimately involve solidification.
S/S may be performed either ex situ or in situ. Note that chemical agents added in situ for the
purpose of binding with contaminants in groundwater is classified as in situ S/S.
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.
A. 1.4 Thermal Treatment
Thermal treatment uses heat to separate contaminants from contaminated media by increasing
their mobility. Thermal treatment includes volatility; destroying contaminants or contaminated
media by burning, decomposing, or detonating the contaminants or the contaminated media; or
immobilizing contaminants by melting and solidifying the contaminated media.
Electrical Resistance Heating (ERH) "delivers an electrical current between metal rods called
'electrodes' installed underground. The heat generated as movement of the current meets
resistance from soil converts groundwater and water in soil into steam, vaporizing contaminants"
(EPA, 2012f). A low-energy ERH approach raises the subsurface temperatures to approximately 30
to 60°C to enhance the rate of biotic and abiotic contaminant dechlorination, respectively.
(ESTCP Project ER-200719, Combining Low-Energy Electrical Resistance Heating with Biotic and
Abiotic Reactions for Treatment of Chlorinated Solvent DNAPL Source Areas). A type of In Situ
Thermal Treatment.
Incineration "is the process of burning hazardous materials at temperatures high enough to destroy
contaminants. Incineration is conducted in an 'incinerator,' which is a type of furnace designed
for burning hazardous materials in a combustion chamber...Hazardous materials must be
excavated or pumped into containers before incineration. They may require further preparation,
such as grinding or removing large rocks and debris, or removing excess water. The materials are
then placed in the combustion chamber of an incinerator where they are heated to an extremely
high temperature for a specified period of time. The temperature and length of time depend on
the types of wastes and contaminants present. Air or pure oxygen may be added to the chamber to
supply the oxygen needed for burning...Depending on the contaminants present, the target
temperature may range from 1,600 to 2,500°F [870 to 1,370 °C]....
"As the wastes heat up, the contaminants volatilize (change into gases) and most are destroyed.
Gases that are not destroyed pass through a secondary combustion chamber for further heating
and destruction. The resulting gases then pass though air pollution control equipment....
"Incinerators can be constructed for temporary use at the site. However, in recent years, it has
been more common for the wastes to be loaded onto trucks for transport to a permanent offsite
facility. EPA requires that an incinerator can destroy and remove at least 99.99 percent of each
harmful chemical in the waste it processes. When some extremely harmful chemicals are present,
EPA requires that an incinerator show it can destroy and remove at least 99.9999 percent of
contaminants in the waste" (EPA, 2012g).
JULY 2020
A-8
-------
Superfund Remedy Report, 16th Edition
In Situ Thermal Treatment (ISTT) "methods heat contaminated soil, and sometimes nearby
groundwater, to very high temperatures. The heat vaporizes (evaporates) the chemicals and water
changing them into gases... [which] can move more easily through soil. The heating process can
make it easier to remove NAPLs from both soil and groundwater. High temperatures also can
destroy some chemicals in the area being heated...The chemical and water vapors are pulled to
collection wells and brought to the ground surface by applying a vacuum [that is, SVE]" (EPA,
2012f). Lower energy ISTT (see ERH) can enhance biotic or abiotic contaminant destruction.
Specific types of ISTT techniques include conductive heating, electrical resistive heating, radio
frequency heating, hot air injection, hot water injection, and steam enhanced extraction.
In Situ Thermal Desorption — See In Situ Thermal Treatment.
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, detonatable explosives and
munitions are destroyed by detonation, which is generally initiated by the detonation of an
energetic charge" (FRTR, 2007).
Steam Enhanced Extraction (SEE) "injects steam underground by pumping it through wells drilled
in the contaminated area. The steam heats the area and mobilizes and evaporates contaminants"
(EPA, 2012f). SEE is a type of In Situ Thermal Treatment.
Thermal Conduction Heating (TCH) "uses heaters placed in underground steel pipes. TCH can
heat the contaminated area hot enough to destroy some chemicals" (EPA, 2012f). TCH is a type of
In Situ Thermal Treatment.
Thermal Desorption "removes organic contaminants from soil, sludge or sediment by heating
them in a machine called a 'thermal desorber' to evaporate the contaminants. Evaporation changes
the contaminants into vapors (gases) and separates them from the solid material... A thermal
desorber is not the same as an incinerator, which heats contaminated materials to temperatures
high enough to destroy the contaminants.... Thermal desorption involves excavating soil or other
contaminated material for treatment in a thermal desorber. The desorber may be assembled at the
site for onsite treatment, or the material may be loaded into trucks and transported to an offsite
thermal desorption facility. To prepare the soil for treatment, large rocks or debris first must be
removed or crushed....If the material is very wet, the water may need to be removed to improve
treatment....
"The prepared soil is placed in the thermal desorber to be heated. Low-temperature thermal
desorption is used to heat the solid material to 200-600°F [90 to 320°C] to treat VOCs. If SVOCs
are present, then high-temperature thermal desorption is used to heat the soil to 600-1000°F [320
to 540°C].
"Gas collection equipment captures the contaminated vapors. Vapors often require further
treatment, such as removing dust particles. The remaining organic vapors are usually destroyed
using a thermal oxidizer, which heats the vapors to temperatures high enough to convert them to
carbon dioxide and water vapor...
JULY 2020
A-9
-------
Superfund Remedy Report, 16th Edition
"Often, treated soil can be used to fill in the excavation at the site. If the treated soil contains
contaminants that do not evaporate, such as most metals, they may be disposed of and capped
onsite, or transported offsite to an appropriate landfill" (EPA, 2012k). Thermal desorption is an ex
situ treatment process. In situ thermal desorption processes are previously discussed as In Situ
Thermal Treatment.
Thermally-Enhanced SVE — See In Situ Thermal Treatment.
Vitrification is a thermal treatment process that converts contaminated soil to stable glass and
crystalline solids. There are two methods for producing heat for melting the contaminated soil.
The older method uses electrodes and electrical resistance to vitrify materials, while the emerging
technique uses plasma arc technology.
"In the electrical resistance method, high voltage is applied to electrodes (typically four) placed in
the soil. Starter frit (generally graphite) is placed on the soil surface and electrical current heats the
soil from the top down to temperatures between 1,400 and 2,000°C [2,550 to 3,650°F].... If the
silica content of the soil is sufficiently high, contaminated soil can be converted into glass. Heating
vaporizes or pyrolyzes organic contaminants. Most inorganic contaminants are encased in the glass-
like monolith that results when the soil cools after treatment" (EPA, 2006). Vitrification may be
conducted in situ or ex situ.
A. 1.5 Pump and Treat (P&T)
Pump and treat "is a common method for cleaning up groundwater [and other aqueous media]
contaminated with dissolved chemicals, including industrial solvents, metals, and fuel oil. [Water
is extracted and conveyed] to an above-ground treatment system that removes the contaminants.
(P&T) systems also are used to 'contain' the contaminant plume. Containment of the plume keeps
[the plume] from spreading by pumping contaminated water toward the wells. This pumping helps
keep contaminants from reaching drinking water wells, wetlands, streams, and other natural
resources" (EPA, 2012h). For the purpose of this report, all P&T systems are considered
treatment, even if designed to only contain, rather than restore, a contaminated plume.
Activated Carbon Treatment — "Activated carbon is a material used to filter harmful chemicals
from contaminated water and air. It is composed of black granules of coal, wood, nutshells or
other carbon-rich materials. As contaminated water or air flows through activated carbon, the
contaminants sorb (stick) to the surface of the granules and are removed from the water or air.
Granular activated carbon or 'GAC' can treat a wide range of contaminant vapors including radon
and contaminants dissolved in groundwater, such as fuel oil, solvents, polychlorinated biphenyls
(PCBs), dioxins, and other industrial chemicals, as well as radon and other radioactive materials. It
even removes low levels of some types of metals from groundwater.
"Activated carbon treatment generally consists of one or more columns or tanks filled with GAC.
Contaminated water or vapors are usually pumped through a column from the top down, but
upward flow is possible. As the contaminated water or air flows through the GAC, the
contaminants sorb to the outer and inner surfaces of the granules. The water and air exiting the
container will be cleaner. Regular testing of exiting water or air is conducted to check contaminant
JULY 2020
A-10
-------
Superfund Remedy Report, 16th Edition
levels. If testing shows that some contaminants remain, the water or air may need to be treated
again to meet the treatment levels.
"The GAC will need to be replaced when the available surfaces on the granules are taken up by
contaminants and additional contaminants can no longer sorb to them. The 'spent' GAC may be
replaced with fresh GAC or 'regenerated' to remove the sorbed contaminants. To regenerate spent
GAC, it is usually sent to an offsite facility where it is heated to very high temperatures to destroy
the contaminants. If a lot of GAC needs to be regenerated, equipment to heat the GAC and
remove the sorbed contaminants can be brought to the site.
"Depending on the site, treated groundwater may be pumped into a nearby stream or river or back
underground through injection wells or trenches. At some sites, a sprinkler system can distribute
the water over the ground surface so that it seeps into soil. The water also may be discharged to the
public sewer system for further treatment at a sewage treatment plant" (EPA, 2012a).
Air Stripping "is the process of moving air through contaminated groundwater or surface water in
an above-ground treatment system. Air stripping removes chemicals called 'volatile organic
compounds' or 'VOCs.' VOCs are chemicals that easily evaporate, which means they can change
from a liquid to a vapor (a gas). The air passing through contaminated water helps evaporate
VOCs faster. After treating the water, the air and chemical vapors are collected, and the vapors are
either removed or vented outside if VOC levels are low enough. Air stripping is commonly used to
treat groundwater as part of the 'pump and treat' cleanup method....
"Air stripping uses either an air stripper or aeration tank to force air through contaminated water
and evaporate VOCs. The most common type of air stripper is a packed-column air stripper, which
is a tall tank filled with pieces of plastic, steel, or ceramic packing material.
"Contaminated water is pumped above ground and into the top of the tank and sprayed over the
top of the packing material. The water trickles downward through the spaces between the packing
material, forming a thin film of water that increases its exposure to air blown in at the bottom of
the tank. A sieve-tray air stripper is similar in design but contains several trays with small holes. As
water flows across the trays, a fan at the bottom blows air upwards through the holes, increasing air
exposure. Aeration tanks are another type of design that remove VOCs by bubbling air into a tank
of contaminated water" (EPA, 2012b).
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. Ultrafiltration/microfiltration occurs when particles are separated
by forcing fluid through a semipermeable membrane. Only the particles whose size are smaller
than the openings of the membrane are allowed to flow through" (FRTR, 2007). Other filtration
methods include nanofiltration and reverse osmosis.
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
JULY 2020
-------
Superfund Remedy Report, 16th Edition
are attached. They also may be inorganic and natural polymeric materials. After the resin capacity
has been exhausted, resins can be regenerated for re-use" (FRTR, 2007).
Metals Precipitation "from contaminated water involves the conversion of soluble heavy metal
salts to insoluble salts that will precipitate. The precipitate can then be removed from the treated
water by physical methods such as clarification (settling) and/or filtration. The process usually uses
pH adjustment, addition of a chemical precipitant, and flocculation. Typically, metals precipitate
from the solution as hydroxides, sulfides, or carbonates. The solubilities of the specific metal
contaminants and the required cleanup standards will dictate the process used. In some cases,
process design will allow for the generation of sludges that can be sent to recyclers for metal
recovery" (FRTR, 2007).
A.2 On-Site Containment Technologies
For the purpose of this report, containment includes several containment technologies, including
caps, covers, and vertical engineered barriers (VEBs).
Building Sealant refers to "in-place sealing and covering of accessible contaminated building
materials with a high performance coating to prevent release of [contaminants] into the indoor air
of residential, commercial, and industrial structures...The common method of applying an
encapsulant is by brush, roller, or airless sprayer."
Caps and Cover Systems — "Capping involves placing a cover over contaminated material such as
landfill waste or contaminated soil.... Caps do not destroy or remove contaminants. Instead, they
isolate them and keep them in place to avoid the spread of contamination....The cap design
selected for a site will depend on several factors, including the types and concentrations of
contaminants present, the size of the site, the amount of rainfall the area receives, and the future
use of the property. Construction of a cap can be as simple as placing a single layer of a material
over lightly contaminated soil to placing several layers of different materials to isolate more highly
contaminated wastes. For example, an asphalt cap might be selected to cover low levels of soil
contamination on a property whose future reuse requires a parking lot. A cap for a hazardous
waste landfill, however, might require several layers, including a vegetative layer, drainage layer,
geomembrane, and clay layer" (EPA, 2012c).
Cap (In situ) for sediment refers to "the placement of a subaqueous covering or cap of clean
material over contaminated sediment that remains in place. Caps are generally constructed of
granular material, such as clean sediment, sand, or gravel" (EPA, 2005).
Containment Cell (subaqueous) for sediment, also referred to as contained aquatic disposal
(CAD), "is a type of subaqueous capping in which the dredged sediment is placed into a natural or
excavated depression elsewhere in the water body. A related form of disposal, known as level
bottom capping, places the dredged sediment on a level bottom elsewhere in the water body,
where it is capped. [CAD] has been used for navigational dredging projects (e.g., Boston Harbor,
Providence River), but has been rarely considered for environmental dredging projects. However,
there may be instances when neither dredging with land disposal nor capping contaminated
sediment in-situ is feasible, and it may be appropriate to evaluate CADs. The depression used in
the case of a CAD should provide lateral containment of the contaminated material, and also
JULY 2020
A-12
-------
Superfund Remedy Report, 16th Edition
should have the advantage of requiring less maintenance and being more resistant to erosion than
level-bottom capping" (EPA, 2005).
Containment Cell (upland, adjacent) for sediment refers to containment in a confined disposal
facility (CDF) either upland or adjacent to the water body. "CDFs are engineered structures
enclosed by dikes and designed to retain dredged material. They may be located upland (above the
water table), partially in the water near shore, or completely surrounded by water. A CDF may
have a large cell for material disposal, and adjoining cells for retention and decantation of turbid,
supernatant water. A variety of linings have been used to prevent seepage through the dike walls.
The most effective are clay or bentonite-cement slurries, but sand, soil, and sediment linings have
also been used... Caps are the most effective way to minimize contaminant loss from CDFs, but
selection of proper liner material is also an important control in CDFs. Finally, CDFs require
continuous monitoring to ensure structural integrity." (EPA, 1991b).
Evapotranspiration (ET) Covers are alternatives to conventional cap and cover systems. "ET cover
systems are designed to rely on the ability of a soil layer to store the precipitation until it is
naturally evaporated or is transpired by the vegetative cover. In this respect they differ from more
conventional cover designs in that they rely on obtaining an appropriate water storage capacity in
the soil rather than...engineered low hydraulic conductivity [barrier components]. ET cover system
designs are based on using the hydrological processes (water balance components) at a site, which
include the water storage capacity of the soil, precipitation, surface runoff, evapotranspiration, and
infiltration. The greater the storage capacity and evapotranspirative properties are, the lower the
potential for percolation through the cover system" (EPA, 2011).
Repair (pipe/sewer/tank/structure) involves the repair of subsurface structures, such as pipes,
sewer lines, and tanks, to control a source of contamination.
Vertical Engineered Barriers (VEB) are "[walls] built below ground to control the flow of
groundwater. VEBs may be used to divert the direction of contaminated groundwater flow to keep
it from reaching drinking water wells, wetlands, or streams. They also may be used to contain and
isolate contaminated soil and groundwater to keep them from mixing with clean groundwater.
VEBs differ from permeable reactive barriers in that they do not clean up contaminated
groundwater" (EPA, 2012m). Common types of VEBs include slurry walls and sheet pile walls.
A.3 Monitored Natural Attenuation (MNA)
MNA is "the reliance on natural attenuation processes (within the context of a carefully controlled
and monitored site cleanup approach) to achieve site-specific remediation objectives within a
timeframe that is reasonable compared to 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. When relying on natural attenuation processes for site remediation,
EPA prefers those processes that degrade or destroy contaminants. Also, EPA generally expects
JULY 2020
A-13
-------
Superfund Remedy Report, 16th Edition
that MNA will only be appropriate for sites that have a low potential for contaminant migration"
(EPA, 1999b).
A.4 Monitored Natural Recovery (MNR) for Sediment
Sediment MNR "[relies] on a wide range of naturally occurring processes to reduce risk [from
contaminated sediments] to human and/or ecological receptors. These processes may include
physical, biological, and chemical mechanisms that act together to reduce the risk posed by the
contaminants....Natural processes that reduce toxicity through transformation or reduce
bioavailability through increased sorption are usually preferable as a basis for remedy selection to
mechanisms that reduce exposure through natural burial or mixing-in-place because the
destructive/sorptive mechanisms generally have a higher degree of permanence. However, many
contaminants that remain in sediment are not easily transformed or destroyed. For this reason,
risk reduction due to natural burial through sedimentation is more common and can be an
acceptable sediment management option. Dispersion is the least preferable basis for remedy
selection based on MNR. While dispersion may reduce risk in the source area, it generally
increases exposure to contaminants and may result in unacceptable risks to downstream areas or
other receiving water bodies....
"The key difference between MNA for ground water and MNR for sediment is in the type of
processes most often being relied upon to reduce risk. Transformation of contaminants is usually
the major attenuating process for contaminated groundwater; however, these processes are
frequently too slow for the persistent contaminants of concern in sediment to provide for
remediation in a reasonable timeframe. Therefore, isolation and mixing of contaminants through
natural sedimentation is the process most frequently relied upon for contaminated sediment"
(EPA, 2005).
A.5 Enhanced Monitored Natural Recovery (EMNR) for Sediment
Natural recovery combined with an engineering approach is called Enhanced Monitored Natural
Recovery. "In some areas, natural recovery may appear to be the most appropriate remedy, yet the
rate of sedimentation or other natural processes is insufficient to reduce risks within an acceptable
timeframe. Where this is the case, project managers may consider accelerating the recovery process
by engineering means, for example by the addition of a thin layer of clean sediment. This approach
is sometimes referred to as 'thin-layer placement' or 'particle broadcasting.' Thin-layer placement
normally accelerates natural recovery by adding a layer of clean sediment over contaminated
sediment. The acceleration can occur through several processes, including increased dilution
through bioturbation of clean sediment mixed with underlying contaminants. Thin-layer
placement is typically different than...isolation caps...because it is not designed to provide long-
term isolation of contaminants from benthic organisms. While thickness of an isolation cap can
range up to several feet, the thickness of the material used in thin layer placement could be as little
as a few inches....Clean sediment can be placed in a uniform thin layer over the contaminated area
or it can be placed in berms or windrows, allowing natural sediment transport processes to
distribute the clean sediment to the desired areas.
"Project managers might also consider the addition of flow control structures to enhance
deposition in certain areas of a site" (EPA, 2005).
JULY 2020
A-14
-------
Superfund Remedy Report, 16th Edition
Note that a layer of clean sediment placed as backfill following dredging or excavation is not
considered EMNR.
A.6 Vapor Intrusion Mitigation
Vapor intrusion is the term given to migration of vapor-forming chemicals from any underground
source into a structure (e.g., homes, businesses, schools) (EPA, 2015a). For example, vapors can
enter buildings as a component of soil gas by migrating through cracks, seams, interstices, and gaps
in basement floors, walls, or foundations ("adventitious openings") or through intentional
openings (e.g., perforations due to utility conduits, sump pits) (EPA, 2015a).
As used in this document, mitigation refers to "interim actions taken to reduce or eliminate
human exposure to vapor-forming chemicals in a specific building arising from the vapor intrusion
pathway" (EPA, 2015a). Functionally, mitigation methods can be categorized into two basic
strategies: (i) those that seek to prevent or reduce vapor entry into a building (e.g., active
depressurization technologies, positive building pressurization, sealing cracks and openings); and
(ii) those that seek to reduce or eliminate vapors that have entered into a building (e.g., indoor air
treatment, interior ventilation). Neither strategy entails reducing the level of vapor-forming
contamination in the subsurface source, which refers to remediation.
Active Depressurization Technology "creates a driving force for air flow from the building into
the subsurface by lowering the pressure below the slab, thereby reducing vapor intrusion (soil gas
entry into a building)" (EPA, 2015a). This approach is the most thoroughly studied and
demonstrated approach for mitigating vapor intrusion. This approach consists of a group of
methods that site teams can customize to treat different construction features of a building,
including sub-slab depressurization (SSD), drain tile depressurization, wall depressurization,
baseboard depressurization, and sub-membrane depressurization (EPA, 2015a). Another active
depressurization method involves depressurization of a sewer system. This approach may be
effective when the sewer is determined to be a major intrusion pathway (Nielsen and Hvidberg,
2017).
Interior Ventilation — Increasing building ventilation (i.e., increasing the rate at which
indoor air is replaced with outdoor air) can reduce the buildup of vapor-forming chemicals
within a structure. "Natural ventilation may be accomplished by opening windows, doors,
and vents. Forced or mechanical ventilation may be accomplished by using a fan to blow
air into or out of the building" (EPA, 2015a). Exhausting air from the building will
generally contribute to under-pressurization of the building, relative to the subsurface,
thereby potentially resulting in an increased rate of soil gas entry (i.e., vapor intrusion),
which could lead to higher levels of vapors in indoor air unless ambient air entry into the
building is increased disproportionately.
Passive Barrier (Impermeable Membrane) Installation involves "placing sheets of
'geomembrane' or strong plastic beneath a building to prevent vapor entry. Vapor barriers
are best installed during building construction, but can be installed in existing buildings
that have crawl spaces" (EPA, 20121). Spray-on vapor barriers (rubberized asphalt emulsions
or epoxy) may also be used (EPA, 2008a).
JULY 2020
A-15
-------
Superfund Remedy Report, 16th Edition
Passive Soil Depressurization is designed to achieve lower sub-slab air pressure relative to
indoor air pressure by use of a vent pipe routed through the conditioned space of a
building and venting to the outdoor air, thereby relying solely on the convective flow of air
upward in the vent to draw air from beneath the slab" (EPA, 2008a).
Positive Building Pressurization "involves adjusting the building's heating, ventilation, and
air-conditioning [HVAC] system to increase the pressure indoors relative to the sub-slab
area. This method is typically used for office buildings and other large structures" (EPA,
20121).
Sealing Cracks and Openings involves filling in adventitious and intentional openings in
the building foundation using products such as synthetic rubbers, acrylics, oil-based
sealants, asphalt/bituminous products, swelling cement, silicon, epoxy or elastomeric
polymers (EPA, 2015a). In addition, "[c]oncrete can be poured over unfinished dirt floors"
(EPA, 20121).
Soil Pressurization systems "are used to push air into the soil or venting layer below the
slab instead of pulling it out. The intention is to increase the sub-slab air pressure above
ambient levels, forcing soil gas from the subsurface to the sides of the building." (ITRC,
2007)
Sub-slab Ventilation refers to engineered controls that function by diluting the vapor
concentrations beneath the slab and foundation (EPA, 2008a) by drawing outside air into
and through the sub-slab area. When installed during building construction, sub-slab
ventilation systems "typically consist of: a venting layer (e.g., filled with porous media such
as sand or pea gravel; or suitably fabricated with continuous voids) below a floor slab to
allow soil gas to move laterally to a collection piping system for discharge to the
atmosphere; and a sub-slab liner that is installed on top of the venting layer to reduce entry
points for vapor intrusion" (EPA, 2015a).
A.7 Other or Unspecified Remedies
Alternative Water Supply Remedy - "In CERCLA, section 101(34) states that '[t]he term
'alternative water supplies' includes, but is not limited to, drinking water and household water
supplies.' Also, CERCLA section 118 states that in taking response actions, the President [EPA]
shall 'give a high priority to facilities where the release of hazardous substances or pollutants or
contaminants has resulted in the closing of drinking water wells or has contaminated a principal
drinking water supply.'... Providing an alternative supply of water to affected users generally is
designed to prevent residents from being exposed to contaminated groundwater...Providing an
alternative water supply may involve furnishing clean, drinkable water on a permanent or
temporary basis. For example, providing a permanent supply of drinking water may include
installing a private well, connecting to a municipal water system, drilling of a new community
water supply well, or reinstating a previously contaminated water supply well once the groundwater
has been cleaned up. Examples of providing a temporary supply of water may involve installing
individual treatment units or delivering bottled water. When a [Superfund] response action that
provides an alternative water supply involves connecting hundreds of homes to a municipal system
JULY 2020
A-16
-------
Superfund Remedy Report, 16th Edition
(i.e., a residential connection to a water purveyor), it generally means that [residents are connected]
to a water supply line that is located relatively close by" (EPA, 2010).
Fracturing for Site Cleanup — "Fracturing creates or enlarges openings in bedrock or dense soil,
such as clay, to help soil and groundwater cleanup methods work better. The openings, called
"fractures," become pathways through which contaminants in soil and groundwater can be treated
in situ (in place, underground) or removed for above-ground treatment. Although fractures can
occur naturally in soil and rock, they are not always wide or long enough to easily reach
underground contamination using cleanup methods. Fracturing can enlarge the cracks and create
new ones to improve the speed and effectiveness of the cleanup" (EPA, 2012d).
Fracturing for site cleanup is different from fracturing to recover oil and gas. "Oil and gas
hydraulic fracturing is used to stimulate the recovery of oil or natural gas from underground
geologic formations. Oil and gas hydraulic fracturing works by pumping a mixture of fluids and
other substances into the target formation to create and enlarge fractures. Such operations are
much larger, use different equipment and chemical additives, occur at greater depths, and use
higher volumes of fluid than fracturing for site cleanup. Fracturing to clean up a contaminated site
rarely exceeds a depth of 100 feet, and the affected area around the fracturing well usually is less
than 100 feet in any direction. However, wells to extract oil and gas often are drilled hundreds or
thousands of feet downward and sometimes horizontally into the oil- or gas-bearing rock. Fractures
may extend over 500 feet from these wells" (EPA, 2012d).
Institutional Controls (ICs) are defined by EPA as "non-engineered instruments, such as
administrative and legal controls, that help to minimize the potential for human exposure to
contamination and/or protect the integrity of a response action. ICs typically are designed to work
by limiting land and/or resource use or by providing information that helps modify or guide
human behavior at a site. ICs are a subset of Land Use Controls (LUCs). LUCs include
engineering and physical barriers, such as fences and security guards, as well as ICs" (EPA, 2012n).
Some common examples of ICs include zoning restrictions, building or excavation permits, well
drilling prohibitions, easements, and covenants.
Soil Amendments — "Many soils, particularly those found in urban, industrial, mining, and other
disturbed areas, suffer from a range of physical, chemical, and biological limitations. They include
soil toxicity, too high or too low pH, lack of sufficient organic matter, reduced water-holding
capacity, reduced microbial communities, and compaction. Appropriate soil amendments may be
inorganic (e.g., liming materials), organic (e.g., composts) or mixtures (e.g., lime-stabilized
biosolids). When specified and applied properly, these beneficial soil amendments may limit many
of the exposure pathways and reduce soil phytotoxicity. Soil amendments also can restore
appropriate soil conditions for plant growth by balancing pH, adding organic matter, restoring soil
microbial activity, increasing moisture retention, and reducing compaction." (EPA, 2007).
Wetlands Replacement — "Compensatory mitigation is required to replace the loss of wetland and
aquatic resource functions in [a] watershed. Compensatory mitigation refers to the restoration,
establishment, enhancement, or in certain circumstances preservation of wetlands, streams or
other aquatic resources for the purpose of offsetting unavoidable adverse impacts [from a specific
project (EPA, 2008c). For the purposes of this report, mitigation performed at the site of the
JULY 2020
A-17
-------
Superfund Remedy Report, 16th Edition
adverse impacts is excluded from the definition of wetlands replacement. For mitigation
performed at the site of adverse impacts, see Wetlands Restoration. For wetlands constructed as a
form of treatment, see Constructed Treatment Wetlands.
Wetlands Restoration is defined as "[r]e-establishment or rehabilitation of a wetland or other
aquatic resource with a goal of returning natural or historic functions and characteristics to a
former or degraded wetland" (EPA, 2008c). For the purposes of this report, restoration conducted
at a location other than the impacted site is excluded from the definition of wetlands restoration
and is instead considered Wetlands Replacement. For wetlands constructed as a form of
treatment, see Constructed Treatment Wetlands.
JULY 2020
A-18
-------
Appendix B
TREATMENT TECHNOLOGIES BY FISCAL YEAR
-------
Superfund Remedy Report, 16th Edition
Appendix B: Treatment Technologies by Fiscal Year
Type
Remedy
82
83
84
85
86
87
88 89
90
91
92
93
94
95
96
97
98
99
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
Total
C
aj
E
1
CD
2
0
1
Acid Extraction
0
0
0
0
0
0
0
0
1
0
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
3
Aeration
0
0
0
1
2
2
2
3
1
4
0
0
0
0
0
0
2
3
1
0
1
0
0
1
0
0
0
0
0
0
0
0
0
1
0
0
24
Bioremediation
0
0
1
0
3
2
6
9
4
5
9
8
6
6
6
1
4
9
3
0
3
2
3
1
0
2
0
2
1
1
0
0
1
0
1
0
99
Chemical Treatment
0
0
0
1
0
0
1
5
0
4
2
4
0
3
2
1
2
2
1
2
1
0
1
3
1
0
0
1
0
1
0
1
1
1
0
0
41
Constructed Treatment Wetland
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
2
0
0
1
1
0
0
7
Incineration
0
0
0
2
2
1
2
4
0
0
0
5
1
2
3
1
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
24
Incineration (off-site)
0
0
7
5
8
3
9
10
9
16
7
14
7
10
7
5
5
6
1
2
3
0
1
0
1
0
1
0
1
0
5
0
0
0
2
0
145
Incineration (on-site)
0
0
1
2
5
8
12
12
18
6
4
5
2
4
3
1
0
0
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
85
Neutralization
0
1
0
0
0
0
0
0
1
0
4
0
0
1
2
0
0
0
1
0
1
0
0
0
1
0
0
0
0
0
0
1
0
0
0
0
13
Open Burn/Open Detonation
0
0
0
0
0
0
0
0
0
0
1
0
0
1
0
0
0
1
0
0
2
0
0
0
0
0
1
0
0
0
0
0
0
0
0
1
7
Physical Separation
0
1
3
11
9
7
20
19
20
33
24
20
7
17
16
11
18
14
8
8
9
12
9
9
8
4
5
14
9
10
11
6
12
6
8
8
406
Recycling
0
1
0
0
2
2
7
4
9
9
12
12
5
4
9
3
4
5
3
1
5
2
5
6
5
2
0
4
2
3
3
5
5
2
2
1
144
Soil Vapor Extraction
0
0
0
1
0
1
3
0
2
0
0
0
10
2
3
1
0
2
0
1
0
0
1
1
0
1
0
0
0
0
0
1
0
0
1
1
32
Soil Washing
0
0
0
0
1
1
2
3
9
2
4
2
0
3
1
1
2
0
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
33
Solidification/Stabilization
0
0
2
0
8
10
16
17
15
26
31
23
8
11
10
9
12
10
8
1
10
8
11
4
15
5
10
9
5
5
3
1
2
1
0
2
308
Source P&T
2
0
2
8
6
4
18
5
7
12
13
8
4
6
3
2
4
4
1
2
5
1
3
1
1
1
1
1
2
1
2
1
0
3
4
0
138
Thermal Desorption
0
0
0
0
0
0
1
1
5
8
1
4
3
6
8
1
7
5
1
1
2
1
1
2
0
0
0
1
0
0
0
1
0
1
0
0
61
Thermal Treatment
0
0
0
0
2
3
8
6
5
4
2
3
2
4
2
1
2
2
5
0
1
1
0
0
1
0
0
0
1
0
2
0
0
1
0
3
61
Unspecified Ex Situ Treatment
0
0
0
0
0
0
0
0
0
0
1
1
0
1
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
4
Unspecified Ex Situ Treatment (off-site)
0
1
0
3
2
1
0
5
8
4
2
2
5
4
3
3
2
4
5
1
6
1
5
3
2
1
4
3
3
6
2
1
5
1
1
7
106
Unspecified Ex Situ Treatment (on-site)
0
0
0
2
2
2
2
4
1
1
1
6
1
3
2
2
1
2
0
0
1
1
2
2
0
1
0
0
0
0
4
0
2
0
0
1
46
Total
2
4
16
36
52
47
109
107
115
135
119
118
61
88
80
43
66
69
40
22
50
29
42
33
35
17
22
36
25
29
32
18
29
18
19
24
1,787
In Situ Source Treatment
Amendments (sediment)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
1
2
Bioremediation
0
0
0
0
0
1
4
2
2
2
7
4
6
9
11
4
12
9
3
3
3
1
1
3
5
3
1
2
2
2
1
2
4
4
1
1
115
Cap (amended, in situ sediment)
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
2
0
0
0
2
1
1
0
1
7
Chemical Treatment
0
0
0
0
0
0
0
0
1
1
0
0
0
0
0
0
0
1
1
0
0
0
0
1
2
2
1
4
7
4
3
3
7
2
1
2
43
Constructed Treatment Wetland
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
1
Electrokinetics
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
Flushing
0
0
0
1
0
2
4
6
3
6
3
3
2
0
1
1
0
2
2
1
0
0
0
0
0
0
2
0
1
0
0
0
0
1
0
0
41
Fracturing
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
1
0
0
1
0
0
0
0
0
3
Multi-phase Extraction
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
1
0
0
0
0
1
0
0
2
0
5
Phytoremediation
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
3
0
0
0
0
0
0
2
0
0
0
0
0
0
0
1
0
0
0
7
Soil Amendments
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
1
1
0
1
0
1
2
1
0
1
1
1
0
0
12
Soil Vapor Extraction
0
0
0
0
0
3
9
16
15
31
18
18
7
11
22
17
12
11
7
8
11
12
8
7
7
7
7
6
7
10
2
6
6
3
2
4
310
Solidification/Stabilization
1
0
1
2
0
3
5
5
6
7
12
9
4
6
11
10
18
5
6
4
5
3
3
5
6
2
5
3
4
3
2
3
2
2
3
4
170
Thermal Treatment
0
0
0
0
1
2
1
5
6
5
2
11
5
6
3
6
1
5
5
1
0
0
1
4
3
2
2
3
4
0
5
3
3
2
3
3
103
Unspecified In Situ Treatment
0
0
0
1
0
1
2
0
3
1
0
1
2
3
0
0
0
1
1
1
3
0
1
2
0
1
1
0
0
1
0
0
0
0
0
0
26
Total
1
0
1
4
1
13
25
34
36
53
42
46
26
35
48
38
45
37
26
18
22
16
15
23
25
19
20
23
27
21
14
21
25
17
12
17
846
Source
Treatment
(Unspecified)
Unspecified Source Treatment
0
0
0
0
0
0
1
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
3
Unspecified Treatment (on-site)
1
1
0
6
3
3
8
2
5
6
8
4
2
3
0
3
5
4
4
2
3
2
5
1
2
0
1
1
1
1
0
0
0
0
0
0
87
Total
1
1
0
6
3
3
9
2
5
6
9
4
2
3
0
3
5
4
4
2
3
2
5
2
2
0
1
1
1
1
0
0
0
0
0
0
90
In Situ Groundwater Treatment
Air Sparging
0
0
0
0
0
0
0
0
0
1
0
4
3
6
6
12
8
10
7
5
6
2
2
5
2
1
1
6
3
1
1
2
2
0
0
3
99
Bioremediation
0
0
0
1
1
1
1
6
5
5
6
4
6
5
5
2
3
4
5
9
6
3
5
11
21
14
13
22
20
10
13
17
17
10
10
10
271
Chemical Treatment
0
0
0
0
0
1
0
1
2
2
2
0
0
3
0
0
1
0
3
0
0
0
0
7
10
13
5
6
10
10
15
9
15
11
8
7
141
Electrokinetics
0
0
0
0
1
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
3
Flushing
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
1
0
1
0
0
4
Fracturing
0
0
0
0
0
0
0
0
0
1
0
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
0
0
0
5
In-well Air Stripping
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
1
1
0
1
1
0
0
0
0
2
0
0
0
1
1
0
0
0
9
Multi-phase Extraction
0
0
0
0
0
0
0
1
0
0
0
0
1
0
0
1
1
0
2
0
2
0
1
1
1
1
1
1
1
1
0
2
0
1
1
2
22
Permeable Reactive Barrier
0
0
0
0
0
0
0
0
0
0
2
0
1
1
0
1
4
0
2
3
1
2
5
3
4
1
1
1
3
4
0
4
3
0
4
1
51
Phytoremediation
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
0
1
2
1
0
1
2
0
2
0
0
0
0
0
0
0
2
0
1
0
13
Solidification/Stabilization
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
2
Thermal Treatment
0
0
0
0
0
0
0
2
0
0
0
0
0
0
0
0
0
0
0
0
1
0
0
0
0
0
0
0
0
0
1
2
1
2
1
3
13
Unspecified In Situ Treatment
0
1
0
0
0
0
0
1
2
4
1
1
1
0
1
1
2
1
4
1
5
3
6
2
1
4
0
0
0
0
0
1
2
1
1
1
48
Vapor Extraction
0
0
0
0
0
0
0
0
0
3
1
1
1
3
2
9
4
5
1
0
0
1
0
0
0
2
2
0
1
2
0
0
0
0
0
1
39
Total
0
1
0
1
2
2
2
11
9
17
12
10
14
18
15
27
23
21
27
20
21
13
22
30
41
36
23
38
38
28
31
40
44
26
27
30
720
Groundwater
Pump and
Treat
Pump and Treat
3
5
13
27
43
37
77
67
92
114
75
76
74
62
57
50
34
40
46
32
31
13
23
32
23
28
21
19
13
14
15
13
9
9
7
6
1,300
Data in Appendix B may vary from data presented in the SRR 15th Edition. EPA has updated the dataset to add remedy components for decision documents from the early years of the program that had
not previously been recorded and has updated older data to conform more readily to recently updated media and remedy categories.
JULY 2020
B-1
-------
Appendix C
Individual Contaminants and Assigned
Contaminant Groups
-------
Appendix C-l: Individual Contaminants and Assigned Contaminant Groups
High Level Group
Detailed Category
u
o
>
to
-a
QJ
u
o
>
"a
QJ
QJ
c
TO
3
u
o
>
"ro
o
1—
CO
Q
03
X
I
O
o
O
O
QJ
Q_
<
Q_
(2-METHYL-2-PROPANYL)BENZENE
X
X
(2Z)-2-BUTENEDIOIC ACID
X
X
(3R)-l-AZABICYCLO[2.2.2]OCTAN-3-YL HYDR0XY(DIPHENYL)ACETATE
X
X
(4-CHLORO-2-METHYLPHENOXY)ACETIC ACID
X
X
(E)-l,3-DICHLORO-l-PROPENE
X
X
(Z)-l,3-DICHLORO-l-PROPENE
X
X
[(E)-PROP-l-ENYL] BENZENE
X
X
1,1,1,2-TETRACHLOROETHANE
X
X
1,1,1-TRICHLOROETHANE
X
X
1,1,2,2-TETRABROMOETHANE
X
X
l,l,2,2-TETRACHLORO-l,2-DIFLUOROETHANE
X
X
1,1,2,2-TETRACH LOROETHAN E
X
X
l,l,2-TRICHLORO-l,2,2-TRIFLUOROETHANE
X
X
1,1,2-TRICH LOROETHAN E
X
X
1,1'-BIPHENYL
X
X
1,1-DICH LOROETHAN E
X
X
1,1-DICHLOROETHENE
X
X
l,2,3,4,6,7,8,9-OCTACHLORODIBENZO[b,e][l,4]DIOXIN (OCDD)
X
X
1,2,3,4,6,7,8,9-OCTACHLORODIBENZOFURAN
X
X
l,2,3,4,6,7,8-HEPTACHLORODIBENZO[b,e][l,4]DIOXIN (HpCDD)
X
X
l,2,3,4,7,8-HEXACHLORODIBENZO[b,e][l,4]DIOXIN (HxCDD)
X
X
1,2,3,4,7,8-HEXACHLORODIBENZOFURAN (HxCDF)
X
X
1,2,3,4-TETRACHLOROBENZENE
X
X
l,2,3,6,7,8-HEXACHLORODIBENZO[b,e][l,4]DIOXIN (HxCDD)
X
X
1,2,3,6,7,8-HEXACHLORODIBENZOFURAN (HxCDF)
X
X
l,2,3,7,8-PENTACHLORODIBENZO[b,e][l,4]DIOXIN (PeCDD)
X
X
1,2,3,7,8-PENTACHLORODIBENZOFURAN
X
X
1,2,3-TRICHLOROBENZENE
X
X
1,2,3-TRICHLOROPROPANE
X
X
1,2,3-TRIMETHYLBENZENE
X
X
1,2,4,5-TETRACHLOROBENZENE
X
X
1,2,4-TRICHLOROBENZENE
X
X
1,2,4-TRIMETHYLBENZENE
X
X
l,2-DIBROMO-3-CHLOROPROPANE
X
X
1,2-DIBROMOETHANE
X
X
l,2-DICHLORO-l,l,2,2-TETRAFLUOROETHANE
X
X
1,2-DICHLOROBENZENE
X
X
1,2-DICH LOROETHAN E
X
X
1,2-DICHLOROETHENE (CIS AND TRANS MIXTURE)
X
X
1,2-DICHLOROPROPANE
X
X
1,2-DIHYDROACENAPHTHYLENE
X
X
1,2-DIMETHYLBENZENE (O-XYLENE)
X
X
1,2-DIPHENYLHYDRAZINE
X
X
1,2-ETHANEDIOL (ETHYLENE GLYCOL)
X
X
1,2-PROPANEDIOL
X
X
1,3 (OR 1,4)-DIMETHYLBENZENE (M (OR P)-XYLENE)
X
X
July 2020
C-l
-------
Appendix C-l: Individual Contaminants and Assigned Contaminant Groups
High Level Group
Detailed Category
u
o
>
to
-a
QJ
u
o
>
¦a
QJ
QJ
c
TO
3
u
o
>
"ro
o
1—
CO
Q
03
X
I
o
O
O
O
QJ
Q_
<
Q_
l,3,5,7-TETRANITRO-l,3,5,7-TETRAZOCANE (HMX)
X
X
1,3,5-TRICHLOROBENZENE
X
X
1,3,5-TRIMETHYLBENZENE
X
X
1,3,5-TRI NITROBENZENE
X
X
1,3-BENZENEDIOL
X
X
1,3-BUTADIENE
X
X
1,3-DICHLOROBENZENE
X
X
1,3-DICHLOROPROPENE (EZ MIXTURE)
X
X
1,3-DIMETHYLBENZENE (M-XYLENE)
X
X
1,3-DI NITROBENZENE
X
X
l,3-DIOXO-l,3-DIHYDRO-2-BENZOFURAN-5-CARBOXYLIC ACID
X
X
1,4-BENZENEDICARBOXYLIC ACID
X
X
1,4-DICHLOROBENZENE
X
X
1,4-DIMETHYLBENZENE (P-XYLENE)
X
X
1,4-DI NITROBENZENE
X
X
1,4-DIOXANE
X
X
1,4-DITHIANE
X
X
10-CHLORO-5H-PHENARSAZININE
X
X
10H-PHENOTHIAZINE
X
X
l-BROMO-4-PHENOXYBENZENE
X
X
1-BUTANOL (N-BUTANOL)
X
X
1-BUTOXYBUTANE
X
X
l-CHLORO-2-[(2-CHLOROETHYL)SULFANYL]ETHANE
X
X
l-CHLORO-2-ETHENOXY ETHANE
X
X
l-CHLORO-2-METHYLBENZENE (O-CHLOROTOLUENE)
X
X
l-CHLORO-4-PHENOXYBENZENE
X
X
1H-INDENE
X
X
l-METHYL-2-NITROBENZENE
X
X
l-METHYL-3-NITROBENZENE
X
X
l-METHYL-4-NITROBENZENE
X
X
1-METHYL-4-PROPAN-2-YLBENZENE
X
X
1-METHYLNAPHTHALENE
X
X
1-NITROSOPYRROLIDINE
X
X
1-PHENYLETHANONE
X
X
1-PROPENE
X
X
2-(l-METHYLPROPYL)-4,6-DINITROPHENOL (DINOSEB)
X
X
2-(2,4,5-TRICHLOROPHENOXY)PROPANOIC ACID
X
X
2-(2,4-DICHLOROPHENOXY)PROPANOIC ACID
X
X
2,2',2"-NITRILOTRIETHANOL
X
X
2,2,2-TRICHLORO-l,l-BIS(4-CHLOROPHENYL)ETHANOL
X
X
2,2,4-TRIMETHYLPENTANE
X
X
2,2-DICHLOROETHENYL DIMETHYL PHOSPHATE
X
X
2,2'-OXYDIETHANOL
X
X
2,3,4,7,8-PENTACHLORODIBENZOFURAN (PeCDF)
X
X
2,3,5,6-TETRACHLOROPHENOL
X
X
2,3,7,8-TETRACHLORODIBENZOFURAN
X
X
July 2020
C-2
-------
Appendix C-l: Individual Contaminants and Assigned Contaminant Groups
High Level Group
Detailed Category
u
o
>
to
-a
QJ
u
o
>
¦a
QJ
QJ
c
TO
3
u
o
>
"ro
o
1—
CO
Q
03
X
I
o
O
O
O
QJ
Q_
<
Q_
2,3,7,8-TETRACHLORODIBENZO-p-DIOXIN (TCDD)
X
X
2,3,7,8-TETRACHLORODIBENZO-p-DIOXIN (TCDD) TOXICITY EQUIVALENTS (TEq)
X
X
2,4,5-TRICHLOROPHENOL
X
X
2,4,5-TRICHLOROPHENOXYACETIC ACID
X
X
2,4,6-TRICHLOROPHENOL
X
X
2,4,6-TRINITROPHENOL
X
X
2,4,6-TRINITROTOLUENE
X
X
2,4-DICHLOROPHENOL
X
X
2,4-DICHLOROPHENOXYACETIC ACID
X
X
2,4-DIMETHYLPHENOL
X
X
2,4-DINITROPHENOL
X
X
2,4-DINITROTOLUENE
X
X
2,6-DINITROTOLUENE
X
X
2-[FLUORO(METHYL)PHOSPHORYL]OXYPROPANE (SARIN)
X
X
2-AMINO-4,6-DINITROTOLUENE
X
X
2-AMINOPYRIDINE
X
X
2-BENZOFURAN-l,3-DIONE
X
X
2-BUTANONE (METHYL ETHYL KETONE)
X
X
2-BUTOXYETHANOL
X
X
2-CHLORO-l-PHENYLETHANONE
X
X
2-CHLOROANILINE
X
X
2-CHLORONAPHTHALENE
X
X
2-CHLOROPHENOL
X
X
2-ETHOXYETHANOL
X
X
2-FLUOROACETIC ACID
X
X
2-HEXANONE
X
X
2-HYDROXY-2,2-DIPHENYLACETIC ACID
X
X
2-METHOXY-2-METHYLPROPANE (MTBE)
X
X
2-METHYL-2-PROPANOL
X
X
2-METHYL-4,6-DINITROPHENOL (4,6-DINITRO-O-CRESOL)
X
X
2-METHYLANILINE
X
X
2-METHYLNAPHTHALENE
X
X
2-METHYLOXIRANE
X
X
2-METHYLPHENOL (O-CRESOL)
X
X
2-METHYLPROP-2-ENENITRILE
X
X
2-NAPHTHALENAMINE
X
X
2-NITROANILINE
X
X
2-NITROPHENOL
X
X
2-PROPAN-2-YLOXYPROPANE
X
X
2-PROPANOL
X
X
2-PROPENENITRILE (ACRYLONITRILE)
X
X
3-(3,4-DICHLOROPHENYL)-l,l-DIMETHYLUREA(DIURON)
X
X
3-(4-CHLOROPHENYL)-l,l-DIMETHYLUREA
X
X
3,5,5-TRIMETHYLCYCLOHEX-2-EN-l-ONE
X
X
3,6-DICHLORO-2-METHOXYBENZOIC ACID
X
X
3-CHLOROANILINE
X
X
July 2020
C-3
-------
Appendix C-l: Individual Contaminants and Assigned Contaminant Groups
High Level Group
Detailed Category
u
o
>
to
-a
QJ
u
o
>
¦a
QJ
QJ
c
TO
=5
¦a
c
03
U
O
>
"a
qj
TO
c
"ro
o
1—
CO
Q
03
X
I
O
O
O
O
QJ
Q_
<
Q_
3-CHL0R0PR0P-1-ENE
X
X
3-METHYLPHENOL (M-CRESOL)
X
X
3-METHYLPHENOL (MIXED MONOCHLORINATED ISOMERS)
X
X
3-NITROANILINE
X
X
4-(2,4-DICHLOROPHENOXY)BUTANOIC ACID
X
X
4-(4-AMI NO-3-CH LOROPH ENYL)-2-CHLOROAN 1 LI NE
X
X
4-(4-AMINO-3-METHYLPHENYL)-2-METHYLANILINE
X
X
4,4'-METHYLENEBIS(2-CHLOROANILINE)
X
X
4-AMINO-2,6-DINITROTOLUENE
X
X
4-CHLORO-3-METHYLPHENOL
X
X
4-CHLOROANILINE
X
X
4-CYANO-l,2,3,4-TETRAHYDRO-l-NAPHTHALENE-PROPIONITRILE
X
X
4-CYANO-l,2,3,4-TETRAHYDRO-ALPHA-METHYL-l-NAPHTHALENEACETONITRILE
X
X
4-METHOXYPHENOL
X
X
4-METHYL-2-PENTANONE (METHYL ISOBUTYL KETONE)
X
X
4-METHYLCHRYSENE
X
X
4-METHYLHEPTYL 2-(2,4,5-TRICHLOROPHENOXY)PROPANOATE
X
X
4-METHYLPHENOL (P-CRESOL)
X
X
4-NITROANILINE
X
X
4-NITROPHENOL
X
X
4-NITROSODIPHENYLAMINE
X
X
4-PHENYLANILINE
X
X
9H-CARBAZOLE
X
X
9H-FLUORENE
X
X
ACENAPHTHYLENE
X
X
ACETONE
X
X
ACETONITRILE
X
X
ACROLEIN
X
X
ACRYLAMIDE
X
X
ACTINIUM-227
X
X
ACTINIUM-228
X
X
ALACHLOR
X
X
ALDRIN
X
X
ALPHA GROSS
X
X
ALPHA-CHLORDANE
X
X
ALPHA-HEXACHLOROCYCLOHEXANE
X
X
ALUMINUM
X
X
ALUMINUM OXIDE
X
X
AMERICIUM
X
X
AMERICIUM-241
X
X
AMMONIA
X
X
AMMONIUM HYDROXIDE
X
X
AMMONIUM NITRATE
X
X
AMMONIUM TETRACHLOROZINCATE
X
X
ANILINE
X
X
ANTHANTHRENE
X
X
July 2020
C-4
-------
Appendix C-l: Individual Contaminants and Assigned Contaminant Groups
High Level Group
Detailed Category
Contaminant
ANTHRACENE
ANTIMONY
ANTIMONY COMPOUNDS
AROCLOR1016
AROCLOR1221
AROCLOR1232
AROCLOR1242
AROCLOR1248
AROCLOR1254
AROCLOR 1260
AROCLOR 1268
ARSENIC
ARSENIC COMPOUNDS
ASBESTOS
ATRAZINE
AZEPAN-2-ONE
AZOBENZENE
AZULENE
BARIUM
BARIUM CHLORIDE
BARIUM COMPOUNDS
BENZALDEHYDE
BENZENE
BENZIDINE
BENZIDINE AND ITS SALTS
BENZO(B)FLUORANTHENE
BENZO(GHI)PERYLENE
BENZO(K)FLUORANTHENE
BENZOfAlACEANTHRYLENE
BENZOfAlANTHRACENE
BENZOfAlPYRENE
BENZOfAlPYRENE EQUIVALENTS (BaPEq)
BENZOfEl PYRENE
BENZOfJIFLUORANTHENE
BENZOIC ACID
BENZONITRILE
BENZOPHENONE
BENZOYL BENZENECARBOPEROXOATE
BENZOYL CHLORIDE
BERYLLIUM
BERYLLIUM COMPOUNDS
BETA GROSS
BETA-HEXACHLOROCYCLOHEXANE
BIS(2-CHLOROETHOXY) METHANE
BIS(2-CHLOROETHYL)ETHER
BIS(2-CHLOROISOPROPYL) ETHER
July 2020
C-5
-------
Appendix C-l: Individual Contaminants and Assigned Contaminant Groups
High Level Group
Detailed Category
Contaminant
BIS(2-ETHYLHEXYL) ADIPATE
BIS(2-ETHYLHEXYL)PHTHALATE
BIS(CHLOROMETHYL) ETHER
BISMUTH
BISMUTH TEILLURIDE
BORON
BORON OXIDE
BROMACIL
BROMINE (BR2)
BROMINE-CONTAINING INORGANIC COMPOUNDS
BROMOCHLOROMETHANE
BROMODICHLOROMETHANE
BROMOFORM
BROMOMETHANE
BUTAN-2-YLBENZENE
BUTYL ACETATE
BUTYL BENZYL PHTHALATE
BUTYLATE
BUTYLBENZENE
C.I. ACID GREEN 3
C.I. BASIC VIOLET 1
C11-C22 AROMATIC HYDROCARBONS
C13-C18 ALIPHATIC HYDROCARBONS
C19-C36 ALIPHATIC HYDROCARBONS
C5-C8 ALIPHATIC HYDROCARBONS
C9-C10 AROMATIC HYDROCARBONS
C9-C12 ALIPHATIC HYDROCARBONS
C9-C18 ALIPHATIC HYDROCARBONS
CADMIUM
CALCIUM
CALCIUM CARBONATE
CALCIUM OXIDE
CAMPHOR
CARBARYL
CARBOFURAN
CARBON DISULFIDE
CARBON TETRACHLORIDE
CARBON-14
CARBONYL DICHLORIDE (PHOSGENE)
CARBOPHENOTHION
CARCINOGENIC POLYCYCLIC AROMATIC HYDROCARBONS (cPAH)
CESIUM
CESIUM-134
CESIUM-137
CHLORDANE
CHLORDECONE
July 2020
C-6
-------
Appendix C-l: Individual Contaminants and Assigned Contaminant Groups
High Level Group
Detailed Category
Contaminant
CHLORENDIC ACID
CHLORIDE
CHLORINATED DIOXINS AND FURANS
CHLORINE (CL2)
CHLOROACETIC ACID
CHLOROBENZENE
CHLOROBENZILATE
CHLOROBENZOIC ACID
CHLOROETHANE
CHLOROETHENE (VINYL CHLORIDE)
CHLOROFORM
CHLOROMETHANE
CHLOROMETHYLBENZENE
CHLOROPHENOXY HERBICIDES
CHLORPYRIFOS
CHROMIC ACID
CHROMIUM
CHROMIUM (HEXAVALENT COMPOUNDS)
CHROMIUM (III)
CHROMIUM COMPOUNDS
CHROMIUM(III) CHLORIDE
CHROMIUM(III) SULFATE
CHROMIUM(VI)
CHRYSENE
CIS-l,2-DICHLOROETHENE
COBALT
COBALT-57
COBALT-60
COPPER
COPPER COMPOUNDS
COUMAPHOS
CREOSOTE
CRESOL (MIXED ISOMERS)
CUMENE
CURIUM
CYANIDE
CYANIDE COMPOUNDS
CYANIDES, INORGANIC SALTS
CYCLOHEXANE
CYCLOHEXANOL
CYCLOHEXANONE
DDT AND METABOLITES
DELTA-HEXACHLOROCYCLOHEXANE
DEMEPHION-S
DIAMINOTOLUENE (MIXED ISOMERS)
DIAZINON
July 2020
C-7
-------
Appendix C-l: Individual Contaminants and Assigned Contaminant Groups
High Level Group
Detailed Category
u
o
>
to
-a
QJ
u
o
>
¦a
QJ
QJ
c
TO
=5
"a
c
03
u
o
>
"a
qj
TO
c
"ro
o
1—
CO
Q
03
X
I
O
O
O
O
QJ
Q_
<
Q_
DIBENZ[A,H]ACRIDINE
X
X
DIBENZ[A,J] ANTHRACENE
X
X
DIBENZO(A,H)ANTHRACENE
X
X
DIBENZO[A,E]PYRENE
X
X
DIBENZO[A,H]PYRENE
X
X
DIBENZOFURAN
X
X
DIBROMOCHLOROMETHANE
X
X
DIBROMOMETHANE
X
X
DIBUTYLPHTHALATE
X
X
DICHLORO-[(E)-2-CHLOROETHENYL]ARSANE (LEWISITE)
X
X
DICHLOROBENZENE (MIXED ISOMERS)
X
X
DICHLORODIFLUOROMETHANE
X
X
DICHLOROMETHANE (METHYLENE CHLORIDE)
X
X
DICHLOROPROPANE (MIXED ISOMERS)
X
X
DICYCLOPENTADIENE
X
X
DIELDRIN
X
X
DIESEL FUEL
X
X
DIESEL RANGE ORGANICS
X
X
DIETHYL ETHER
X
X
DIETHYL PHTHALATE
X
X
DIETHYLBENZENE (MIXED ISOMERS)
X
X
DIMETHOXYMETHANE
X
X
DIMETHYL PHENOL (MIXED ISOMERS)
X
X
DIMETHYL PHTHALATE
X
X
DIMETHYL SULFIDE
X
X
DIMETHYLFORMAMIDE
X
X
DIMETHYLMERCURY
X
X
DINITROTOLUENE (MIXED ISOMERS)
X
X
DI-N-OCTYL PHTHALATE
X
X
DIOXINS (CHLORINATED DIBENZODIOXINS)
X
X
DIOXINS AND DIBENZOFURANS
X
X
DIPHENAMID
X
X
DIPHENYLAMINE
X
X
DISULFOTON
X
X
ENDOSULFAN (1 OR II)
X
X
ENDOSULFAN 1
X
X
ENDOSULFAN II
X
X
ENDOSULFAN SULFATE
X
X
ENDRIN
X
X
ENDRIN ALDEHYDE
X
X
ENDRIN KETONE
X
X
ETHANE
X
X
ETHANE-1,2-DIAMINE
X
X
ETHANETHIOL
X
X
ETHANOL
X
X
ETHION
X
X
July 2020
C-8
-------
Appendix C-l: Individual Contaminants and Assigned Contaminant Groups
High Level Group
Detailed Category
Contaminant
ETHYL ACETATE
ETHYL CARBONOCHLORIDATE
ETHYL PR0P-2-EN0ATE
ETHYLBENZENE
EUROPIUM
EUROPIUM-152
EUROPIUM-155
FENSULFOTHION
FLUORANTHENE
FLUORIDE
FLUORINE (F2)
FONOFOS
FORMALDEHYDE
FORMIC ACID
FORMOTHION
FURAN
GAMMA RADIOACTIVITY EMITTERS
GAMMA-CHLORDANE
GAMMA-HEXACH LOROCYCLOH EXANE (LI N DAN E)
GASOLINE
GUTHION
HALOGENATED VOCs
HEAVY METALS
HEPTACHLOR
HEPTACHLOR EPOXIDE
HEPTACHLORODIBENZOfb,elfl,41DIOXIN (HpCDD) (MIXED ISOMERS)
HEPTANE
HEXACHLORO-1.3-BUTADIENE
HEXACHLOROBENZENE
HEXACHLOROCYCLOPENTADIENE
HEXACHLORODIBENZOfb,elfl,41DIOXIN (HxCDD) (MIXED ISOMERS)
HEXACHLOROETHANE
HEXAHYDRO-l,3,5-TRINITRO-l,3,5-TRIAZINE (RDX)
H EXANE
HYDRAZINE
HYDROCARBONS
HYDROGEN (H2)
HYDROGEN CARBONATE
HYDROGEN CHLORIDE
HYDROGEN CYANIDE
HYDROGEN SULFIDE
INDENO(l,2,3-CD)PYRENE
INDIUM
INORGANICS
IODINE (12)
IODINE-129
July 2020
C-9
-------
Appendix C-l: Individual Contaminants and Assigned Contaminant Groups
High Level Group
Detailed Category
Contaminant
IRON
ISODRIN
KEROSENE
LEAD
LEAD COMPOUNDS
LEAD COMPOUNDS (INORGANIC)
LEAD(II) ACETATE
LEAD-210
LEAD-212
LINURON
LITHIUM
MAGNESIUM
MALATHION
MANGANESE
MANGANESE COMPOUNDS
MANGANESE-54
MECOPROP
MERCURY
MERCURY COMPOUNDS
METALS
METHANE
METHANETHIOL
METHANOL
METHIOCARB
METHOXYCHLOR
METHYL 2-METHYLPROP-2-ENOATE
METHYL ACETATE
METHYL MERCURY
METHYL PARATHION
METHYL PROP-2-ENOATE
METHYLCYCLOHEXANE
METHYLCYCLOHEXANOL (MIXED ISOMERS)
METHYLMERCURY DICYANDIAMIDE
METHYLPHOSPHONIC ACID
MEVINPHOS
MINERAL OILS
MIREX
MOLINATE
MOLYBDENUM
MONOCROTOPHOS
N,N-DIBUTYLNITROUS AMIDE
N.N-DIETHYLNITROUS AMIDE
N,N-DIMETHYLANILINE
N.N-DIPHENYLNITROUS AMIDE
N,N-DIPROPYLNITROUS AMIDE
NAPHTHALENE
July 2020
C-10
-------
Appendix C-l: Individual Contaminants and Assigned Contaminant Groups
High Level Group
Detailed Category
Contaminant
NAPHTHENIC ACIDS
NEODYMIUM
NEPTUNIUM
NICKEL
NICKEL-63
NITRATE
NITRATE/NITRITE
NITRITE
NITROAROMATICS
NITROBENZENE
NITROGEN
NITROGLYCERIN
NITROTOLUENE (MIXED ISOMERS)
N-METHYL-N,2,4,6-TETRAN ITROANI LI NE (TETRYL)
N-NITROSODIMETHYLAMINE
NONANE
0,0,0,0-TETRAETHYL DITHIODIPHOSPHATE
OCTANE
O-DI NITROBENZENE
0-ETHYL 0-(4-NITR0PHENYL) PHENYLPHOSPHONOTHIOATE
O-ETHYL S,S-DIPROPYL PHOSPHORODITHIOATE (ETHOPROP)
ORGANICS
OXAMYL
P.P'-DDD
P,P'-DDE
P.P'-DDT
PARATHION
p-CYMENE
PEBULATE
PENDIMETHALIN
PENTACHLOROBENZENE
PENTACHL0R0DIBENZ0fb,elfl,41DI0XIN (PECDD) (MIXED ISOMERS)
PENTACHLORODIBENZOFURAN (PeCDF)
PENTACHLOROETHANE
PENTACHLORONITROBENZENE
PENTACHLOROPHENOL
PENTAERYTHRITOLTETRANITRATE (PETN)
PENTANE
PERCHLORATE
PERFLUOROOCTANE SULFONIC ACID
PERFLUOROOCTANOIC ACID (PFOA)
PESTICIDES
PHENACETIN
PHENANTHRENE
PHENOL
PHENYLMETHANOL
July 2020
C-ll
-------
Appendix C-l: Individual Contaminants and Assigned Contaminant Groups
High Level Group
Detailed Category
Contaminant
PHORATE
PHOSPHORIC ACID
PHOSPHORUS
PHOSPHORUS (P4)
PHOTOMIREX
PLATINUM
PLUTONIUM
PLUTONIUM-238
PLUTONIUM-239
PLUTQNIUM-239/240
PLUTONIUM-240
PLUTONIUM-241
PLUTONIUM-242
PLUTONIUM-244
POLONIUM-210
POLYBROMINATED BIPHENYLS (FIREMASTER FF 1)
POLYCHLORINATED BIPHENYLS (CONTAINING 60 OR MOREPERCENT CHLORINE BY MOLECULAR WEIGHT)
POLYCHLORINATED BIPHENYLS (PCBs)
POLYCHLORINATED TERPHENYLS
POLYCYCLIC AROMATIC HYDROCARBONS (PAHS)
POLYCYCLIC AROMATIC HYDROCARBONS, HIGH MOLECULAR WEIGHT (HPAHS)
POLYCYCLIC AROMATIC HYDROCARBONS, LOW MOLECULAR WEIGHT (LPAHS)
POTASSIUM
POTASSIUM CYANIDE
POTASSIUM HYDROXIDE
POTASSIUM NITRATE
POTASSIUM PERMANGANATE
PROMETHIUM-147
PROMETON
PROMETRYN
PROPANEDINITRILE
PROPYLBENZENE
PYRENE
PYRIDINE
QUINOLINE
RADIOACTIVE
RADIONUCLIDES
RADIUM
RADIUM-224
RADIUM-226
RADIUM-228
RADON
RADON AND ITS DECAY PRODUCTS
RADON-222
RESIDUAL RANGE ORGANICS (RRO)
RONNEL
July 2020
C-12
-------
Appendix C-l: Individual Contaminants and Assigned Contaminant Groups
High Level Group
Detailed Category
Contaminant
RUTHENIUM-106
SELENIUM
S-ETHYL N,N-DIPROPYLCARBAMOTHIOATE (EPTC)
SILICON
SILICON DIOXIDE (AMORPHOUS SILICA)
SILICONE
SILVER
SIMAZINE
SODIUM
SODIUM CYANIDE
SODIUM HYDROXIDE
SODIUM NITRATE
SODIUM NITRITE
SODIUM-22
STODDARD SOLVENT
STRONTIUM
STRONTIUM-90
STYRENE
SULFATE
SULFIDE
SULFUR
SULFUR DIOXIDE
SULFURIC ACID
TANTALUM
TECHNETIUM-99
TETRACHLORODIBENZOfb,elfl,41DIOXIN (TCDD) (MIXED ISOMERS)
TETRACHLORODIBENZOFURAN (TCDF)
TETRACHLOROETHENE
TETRAETHYL LEAD
TETRAHYDROFURAN
THALLIUM
THALLIUM CHLORIDE
THALLIUM COMPOUNDS
THALLIUM(I) CARBONATE
THALLIUM-204
THORIUM-228
THORIUM-230
THORIUM-232
THORIUM-234
TIN
TITANIUM
TITANIUM DIOXIDE
TOLUENE
TOLUENE DIISOCYANATE (MIXED ISOMERS)
TOTAL BENZOFLUORANTHENES
TOTAL EXTRACTABLE PETROLEUM HYDROCARBONS (TEPH)
July 2020
C-13
-------
Appendix C-l: Individual Contaminants and Assigned Contaminant Groups
High Level Group
Detailed Category
u
o
>
to
-a
QJ
u
o
>
"a
QJ
QJ
c
TO
=5
¦a
c
03
U
O
>
"a
qj
TO
c
"ro
o
1—
CO
Q
03
X
I
O
O
O
o
QJ
Q_
<
Q_
TOTAL PETROLEUM HYDROCARBON -DIESEL
X
X
TOTAL PETROLEUM HYDROCARBON -GASOLINE
X
X
TOTAL PETROLEUM HYDROCARBONS (TPH)
X
X
TOTAL RECOVERABLE PETROLEUM HYDROCARBONS (TRPH)
X
X
TOTAL TRIHALOMETHANES
X
X
TOXAPHENE
X
X
TRANS-l,2-DICHLOROETHENE
X
X
TRANS-NONACHLOR
X
X
TRIBUTYL PHOSPHATE
X
X
TRI BUTYLfCH LORO)STAN NAN E
X
X
TRIBUTYLSTANNANYLIUM
X
X
TRIBUTYLSTANNYL BENZOATE
X
X
TRICHLORO(NITRO)METHANE
X
X
TRICHLOROETHANE (MIXED ISOMERS)
X
X
TRICHLOROETHENE
X
X
TRICHLOROFLUOROMETHANE
X
X
TRICHLOROPHENOL (MIXED ISOMERS)
X
X
TRIFLURALIN
X
X
TRIMETHYLBENZENE (MIXED ISOMERS)
X
X
TRIPHENYL PHOSPHATE
X
X
TRIS(2,3-DIBROMOPROPYL) PHOSPHATE
X
X
TRIS(CHLOROPROPYL)PHOSPHATE
X
X
TRITIUM
X
X
TUNGSTEN
X
X
URANIUM
X
X
URANIUM-233
X
X
URANIUM-234
X
X
URANIUM-234/235/238
X
X
URANIUM-235
X
X
URANIUM-238
X
X
VANADIUM
X
X
VANADIUM PENTOXIDE
X
X
VANADIUM, METAL AND/OR ALLOY
X
X
VERNOLATE
X
X
VINYL ACETATE
X
X
VX
X
X
XYLENE (MIXED ISOMERS)
X
X
ZINC
X
X
ZIRCONIUM
X
X
July 2020
C-14
-------
Superfund Remedy Report, 16th Edition
Appendix C-2: Analysis of Detailed Contaminant Categories by Media
In addition to the contaminant groups discussed in Section V, EPA classified contaminants into
more detailed categories and analyzed how frequently remedies target them in groundwater, soil,
and sediment (Figures C-2a, C-2b, and C-2c). Remedies frequently address metals in all media. A
more detailed look at organic COCs shows halogenated VOCs (primarily chlorinated VOCs) and
BTEX to be the most common in groundwater (Figure Q2a); and halogenated VOCs and PAHs in
soil (Figure C-2b). For sediment, PAHs and PCBs are the most frequently targeted organics (Figure
C-2c).
Figure C-2a: Detailed COCs in Groundwater at Superfund Sites (FY 1981-2017)
90%
80% 78%
• Number of groundwater sites with identified COCs and a remedy = 1,187.
JULY 2020
C-17
-------
Superfund Remedy Report, 16th Edition
Figure C-2b: Detailed COCs in Soil at Superfund Sites (FY 1981-2017)
80% 75%
70%
60%
to
CD
50%
U~l
~ 40%
U~l
m- 30%
& 20%
ro
£ 10%
Cl)
£ 0%
(D
CL
49% 47%
0 32% 32%
19% is%
0 1 ^0/
lb/o 12%
6%
*
J? No^
¦$> S& x ,\0 . xO vO vO
¦.ft
•xf
F f ^ ^ X
J~ J?
^ x<* vtf
>rsr ;>y ^ v
* i>° ^ _eT
o*
^ O0 J?
0 <6*
^ 4? V
» Number of soil sites with identified COCs and a remedy = I, I 17.
Figure C-2c: Detailed COCs in Sediment at Superfund Sites (FY 1981-2017)
£ 70%
"S 40%
" 0%
22% 21% 19%
14/° 13% 3%
«*' ^ J5*
^ A«/
5%
[il
Ml Bfifl LZfl Ez9 ETi*
*> /¦ / J
j> y y / v-
^ J #
Number of sediment sites with identified COCs and a remedy = 380.
,x>
cr
JULY 2020
C-18
------- |