&EPA
United States
Environmental Protection
Agency
Office of Superfund Remediation and
Technology Innovation
Use of Amendments for In Situ
Remediation at Superfund Sediment Sites
OSWER Directive 9200.2-128FS
April 2013
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Contents
1. Introduction 1
2. Overview of Amendments for Sediments 3
3. Amendment Materials 5
4. Placement Methods 8
5. Design Considerations for Amendments 11
5.1 Fate and Transport/Migration Pathways 12
5.2 Amendment Characteristics 15
5.3 Computer Modeling 17
6. Remedial Action Monitoring 18
7. Recent Applications of Amendments for Sediments: Case Studies 20
7.1 Grasse River Site, Massena, New York 20
7.2 Spokane River, Upriver Dam PCBs Sediment Site,
Spokane, Washington 22
7.3 McCormick & Baxter Former Creosoting Company Superfund
Site, Portland, Oregon 23
8. Cost 25
9. Ongoing Research and Development 26
10. Summary 28
11. Glossary of Terms 30
12. References 35
Appendix: Summary of Sediment Sites Using Amendments for In Situ Remediation
This document has been prepared by the U.S. Environmental Protection Agency (EPA) Office of
Superfund Remediation and Technology Innovation. Technical support was provided under Contract
Number EP-W-07-078.
Mention of trade names or commercial products in this document does not constitute the U.S.
Environmental Protection Agency's endorsement or recommendation for use.
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1. Introduction
The in situ sequestering or destruction of contaminants has the potential to reduce risks at
Superfund sites. These technologies have successfully treated groundwater contamination, but
only recently have technologies been developed to treat contaminated sediments. These
technologies, referred to as amendments when applied to sediment remediation, are generally
placed into or onto the sediment surface layer, into a sand cap, or within a geotextile mat. They
can be used as a single remedial approach or in combination with other remedies. The most
common amendments, such as activated carbon, Organoclay , and apatite, are specialized
materials that decrease contaminant bioavailability by sorption. Other amendments being
considered promote the degradation of contaminants. The appropriate use of these amendments
has much potential to limit exposure to contaminants and, thus, to reduce risks.
Contaminated sediments are a significant, widespread environmental issue. As of December
2012, EPA's Superfund program has selected a remedy at 70 large sediment sites and is
evaluating another 50 sites for cleanup. Remedies currently available for addressing
contaminated sediments include Monitored Natural Recovery (MNR), enhanced MNR (EMNR),
in situ capping, dredging or excavation, and a combination of these approaches. These remedial
options all have advantages and limitations for controlling human health and ecological risks
associated with contaminated sediment. More information about these remedial approaches can
be found in EPA's Contaminated Sediment Remediation Guidance for Hazardous Waste Sites
(www.epa.gov/superfund/health/conmedia/sediment/guidance.htm).
Historically, most sediment remedies have included dredging or excavation as a significant
component of the remedy. They also typically rely on MNR to achieve long-term risk reduction,
even when not explicitly stated as part of the remedy. Recently, more sites are considering
combination remedies where MNR, capping, and dredging are being concurrently selected,
depending on conditions in different areas of the sites. Capping leaves contamination in place
and is generally intended to isolate the contaminants of concern (COCs). Although traditional
sand caps have effectively contained the COCs and prevented exposure of the benthic and
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pelagic communities, their large thickness can reduce the hydraulic capacity, flood storage, and
depth of the water body. They may also be compromised by physical disturbances, gas ebullition
(the transportation of contaminants via entrapment in migrating gas bubbles), non-aqueous phase
liquid (NAPL) transport, or groundwater advection.
The use of amendments to reduce bioavailability of contaminants by sorption or promote the
degradation of the contaminants is a relatively new option for in situ sediment remediation. This
innovative technology is being developed and implemented to improve the risk reduction and
cost-effectiveness of remedies at sediment sites. Amended caps have the potential to reduce the
thickness of traditional caps and to improve their resistance to erosional events and advective
transport of COCs by ebullition, NAPL, or groundwater flow. Amendments applied directly to
the contaminated sediment may be particularly useful in areas where MNR, caps, or dredging are
not likely to be effective in reducing risks.
The purpose of this document is to introduce the most promising amendments for in situ
remediation of sediments and summarize some of the information on contaminated sediment
sites that have already employed these amendments. This document is not a guidance or design
document. The U.S. Army Corps of Engineers (USAGE) Engineer Research Development
Center is developing a technical guidelines document to provide a detailed guide to
implementing in situ remedies, including amendments and a thorough discussion of their merits
and limitations (Technical Guidelines for In Situ Sediment Remediation). The main audience for
this document is Superfund Remedial Project Managers, but other stakeholders, such as federal,
state, and local regulators, site owners and operators, and consultants, may also find it useful.
This document provides information on the state of the practice of the use of amendments for in
situ remediation of contaminated sediments, as well as three case studies where these
amendments have been used. This document also focuses on the use of amendments either by
themselves or in conjunction with a conventional isolation cap or a thin layer cap and EMNR.
The amendments discussed are designed to treat hydrophobic organic contaminants, metals, or
both. Some of these amendments may also be effective in reducing risks from NAPL.
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Amendments for hydrophilic organics (for example: PCE, BTEX, or munitions) are not
discussed in this document. In situ technologies, such as in situ chemical oxidation and
permeable reactive barriers, are well established for treating groundwater and well documented
elsewhere. Additionally, there is less research on the effectiveness of using sediment
amendments to remediate such hydrophilic organic contaminants. Information on types of
amendments, placement methods, design considerations, modeling, monitoring, performance,
and cost are included below. The appendix contains a list of sediment sites where amendments
have been used as part of a remedy or as pilot studies, a brief description of the site remedies,
and monitoring results.
2. Overview of Amendments for Sediments
Amendments can be introduced in sediments either as part of a cap, or directly into or onto the
existing sediment. These two approaches are discussed separately below:
Amended caps. Where conditions preclude the use of a conventional cap, amendments show
promise, especially for hydrophobic organic contaminants (HOCs): polycyclic aromatic
hydrocarbons (PAHs), poly chlorinated biphenyls (PCBs), dioxins/furans, and chlorinated
pesticides. For example, the addition of amendments to a cap can increase the cap's effectiveness
by 1 to 2 orders of magnitude, as described in more detail later in this report. Amendments may
also better achieve design objectives, such as maintaining navigation depths, because these
approaches do not reduce water depths the way thicker, conventional caps do. Amended caps
work primarily by retarding contaminant transport through the cap and acting as a barrier
between the contaminated sediment and the new benthic layer, thus preventing exposure of the
benthic and pelagic communities to the contaminants. Amendments can be introduced to a
capping layer in a geotextile mat or added to capping materials before or during placement of
caps.
Direct sediment amendments. The primary exposure pathway for hydrophobic and
bioaccumulative pollutants often involves bioaccumulation in the benthic infauna and subsequent
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transfer into the aquatic food web. 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. The intent in direct application is to change the native sediment
geochemistry to reduce contaminant bioavailability without creating a new surface layer or cap.
Figure 1 shows examples of various placement methods.
Amendment
Mat Crane
Water
Barge
Rototiller
|
— $ -- — __^-"
Amendment
'—"" Layer
Figure 1: Placement Methods for Sediment Amendments
While amendments show promise, there are concerns and uncertainties that may limit their use in
some site conditions. One current concern with using bulk amendments is the difficulty in
placing some of these materials accurately in a dynamic, aqueous environment as a result of their
potential for entrainment and movement within the water column. The unknown treatment
capacity of some amendments, whether applied in bulk or in a mat, may also be a concern,
particularly with respect to multiple contaminants and interactions with the natural system. As
with other remedial alternatives (such as capping and dredging), the long-term permanence of
amendments and their ability to retain contaminants over time are not well understood. Although
laboratory tests and models can predict short- and long-term performance, there are few field
applications currently in place to evaluate the effectiveness of amendments and to validate the
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models used. The success of in situ amendments also depends on the level of contamination in
new sediment deposits that may form over time. Thus, ongoing source control is critical for the
success of any in situ remedy. Additional field applications will increase the understanding of
this technology and the key factors affecting its long-term effectiveness.
Currently, most of the amendment applications have been laboratory or pilot-scale (small scale,
intended as a test or demonstration of effectiveness) research projects; there are a small number
of sites where amendments have been used as demonstration projects or full scale in the field.
Site-specific information is provided in the report where available. Mention of trade names or
commercial products does not constitute EPA's endorsement or recommendation for use.
3. Amendment Materials
The type of amendment used is dictated by the type of contamination, sediment characteristics,
and site conditions. Activated carbon and other carbonaceous amendments are appropriate for
sorbing organic contamination, while phosphate additives are useful for binding metals. Properly
compounded Organoclays™™ are designed to capture NAPL while maintaining sufficient
permeability to permit groundwater advection and gas migration. The effectiveness of some of
the amendments, such as activated carbon and Organoclay™, has been demonstrated in a small
number of field applications, while other amendments, such as zero valent iron, phosphate
additives, and biopolymers, are still in the bench-scale or pilot-testing phase. Even though some
of these materials have been used in other environmental applications, such as groundwater and
off-gas treatments, there are a limited number of projects and available performance data on their
effectiveness for treating contaminated sediments. Table 1 presents examples of amendments,
the contaminant group targeted, and the developmental status of each as a sediment treatment
technology1. Additional information about the full-scale and pilot projects is provided in the
appendix.
1 For this document, the term "treatment technology" refers to any unit operation or series of unit operations that alters the
composition or behavior of a hazardous substance, pollutant, or contaminant through chemical, biological, or physical means so
as to reduce toxicity, mobility, or volume of the contaminated materials being treated.
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Activated carbon and other carbonaceous amendments are attractive amendments because of
their strong sorbent properties. PAHs, PCBs, dioxins/furans, and pesticides are strongly adsorbed
by activated carbon (often in a granular form), making them less bioavailable. Adsorption of
hydrophobic organic contaminants to activated carbon in sediments is often 10 to 100 times
greater than absorption to organic carbon (OC). Organic carbon is generally thought to be the
primary sorptive phase for hydrophobic organic contaminants in soils and sediment. Although
different parent materials used to create the activated carbon result in variable degrees of
sorption, activated carbon has a greater sorption capacity for hydrophobic organic contaminants
than other types of carbonaceous amendments under most environmental conditions. Coke
breeze, a carbonaceous material formed by heating coal in an oxygen-free environment, may be
an inexpensive alternative to activated carbon, but it is less effective at adsorbing organic
contaminants in sediments (Murphy and others 2006). Activated carbon, coal, and coke breeze
have been used in pilot- and full-scale applications for in situ sediment remediation. In most
capping applications, the placement difficulties have been overcome by containing the carbon in
a mat or delivering the amendment as a clay agglomerate, such as AquaBlok . Potential
limitations associated with activated carbon include difficulty with placement through the water
column (because of its low density and significant air entrapment), stability (it is easily
resuspended after bulk placement), and cost. Information regarding the negative effects of
activated carbon on benthic organisms is often contradictory, with some field and laboratory
studies reporting detrimental effects and others showing no observable detrimental effects.
Studies reporting detrimental effects typically note decreases in growth rates or in benthic
diversity, but they also report 10 to 100 fold reductions in bioaccumulation and generally
conclude that the amendment is a net benefit (for example: Millward and others 2005,
Kupryianchyk and others 2011, and Cornelissen and others 2011). Pilot studies for direct
sediment amendment applications have broadcast a slurry of activated carbon and water close to
the sediment surface (with and without tilling), injected activated carbon into sediment through
hollow tines, or delivered the amendment in a pelletized form that breaks up over time, such as
SediMite™. Activated carbon in a reactive core mat was selected as a full scale remedy at the St.
Louis River/Interlake/Duluth Tar Superfund site, where it was placed as part of a sediment cap.
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Organoclays™ are created by replacing the surface cation of bentonite or hectorite with an
organic molecule, such as tallow-based quaternary amines (Olsta and Darlington 2005). They are
hydrophobic, permeable, and effective at absorbing dissolved hydrophobic organics and
immobilizing metals (Knox 2008, Olsta and Darlington 2005). Organoclays have also been
formulated to create an impermeable layer, but these applications are less useful in sediments
because they are vulnerable to gas formation and may cause problems in areas of high
groundwater flow. Organoclays can potentially control NAPL migration, as they are capable of
absorbing two to four times their weight in free-phase product (Reible and Lampert 2008).
However, the absorption capacity in the field typically varies between 0.5 and 1.5 times their
weight (Reible and Lampert 2008). The absorption of the free-phase product or water, depending
on the surface cation replacement, causes the Organoclays™ to swell and can reduce
permeability. This loss of permeability must be accommodated in designing an amended cap
with Organoclays . An Organoclay with the appropriate surface cation can minimize swelling
and maintain high permeability (Olsta and Darlington 2005). Information on the detrimental
impacts of Organoclays on the benthos is limited. In some cases, Organoclays are used as a
layer in a cap and are separated from the benthos. However, the use of these clays as the
uppermost layer of a cap may greatly reduce the erosion potential of the cap. Organoclays™ may
be particularly beneficial when NAPL is present and have been used in both pilot- and full-scale
applications to address NAPL and HOCs and metals.
Phosphate additives reduce the bioavailability of metals through adsorption, ion exchange,
isomorphic substitution, and precipitation (Olsta and Darlington 2005). The phosphate mineral
apatite is most often used for sediment treatment. Apatite yields stable end products, can be
placed on contaminated sediment by existing technology, can be mixed with other additives, is
readily available, and is non-toxic. Similarly to carbonaceous amendments, there are multiple
types of apatite that exhibit different sorption characteristics. Another phosphate additive being
studied is phytic acid, a sugar additive (6-phosphate ester of inositol). This additive is applied in
a soluble form and precipitates metals in the same manner as apatite (Knox 2008). Although
effective at binding metals, phosphate additives do not treat organic contaminants. An important
limitation of these amendments is the potential for releasing soluble phosphate and increasing
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eutrophication. The effectiveness of phosphate additives has been tested with pilot-scale studies
but not with full-scale applications.
Bauxite is capable of sequestering many heavy metals, including mercury, arsenic, chromium,
cadmium, lead, zinc, and nickel. Its unique surface properties allow bauxite to sequester both
cationic and oxy-anionic forms of the metals through a combination of sorption, ion exchange,
and precipitation (EPA 2007). A bench-scale study was conducted to evaluate possible
effectiveness at the Dodge Pond Site in Connecticut to treat mercury (Gavaskar and others
2005). However, there have been no pilot- or full-scale applications.
Zero Valent Iron can reduce some organic contaminants to less toxic by-products and has been
used successfully in permeable reactive barriers (PRBs) for the dechlorination of chlorinated
hydrocarbons and the reductive precipitation of chromate in contaminated groundwater (Olsta
and Darlington 2005). Laboratory studies conducted at the University of New Hampshire
showed that micrometer-scale zero valent iron successfully promoted reductive dechlorination of
PCBs in sediments. However, the study also noted that the dechlorinated products may include
PCB congeners that are more toxic than the parent congeners and that dechlorination is slower
for the larger PCB congeners (Gardner 2004). Additional limitations with zero valent iron may
include alterations to sediment geochemistry, passivation of iron by the formation of a thin layer
of iron oxide, and the high cost of microscale and nanoscale supported iron. The use of zero
valent iron to treat sediments has been limited to bench-scale studies. There have been no pilot-
or full-scale applications for in situ sediment remediation.
4. Placement Methods
Amendments can be contained in a mat, applied in bulk onto the sediment surface, mixed in the
sediment, added as part of a sand cap, or as a layer within a sand cap (Figure 1). Mats consist of
an amendment, or amendments, sandwiched between two geosynthetic layers. These mats allow
for accurate placement of amendments with high total organic content and low density that could
otherwise become suspended during placement. Synthetic geotextiles also provide a bioturbation
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barrier, prevent mixing of amendments with underlying sediments, allow a more uniform
application of amendments, and reduce erosion. As they are composed of synthetic fibers, they
do not easily biodegrade (Olsta and Darlington 2005). These mats are generally covered with
conventional capping materials and, if needed, armoring layers to provide physical stability and
further isolation. Such amendment mats are commercially available from a limited number of
vendors. One such vendor, CETCO, produces mats with typical thicknesses of 6 millimeters
(mm) and 11 mm. According to CETCO, typical material loadings are activated carbon - 0.4
pound per square foot (Ib/ft2), Organoclay™ - 0.8 Ib/ft2, and apatite - 0.8 Ib/ft2 (CETCO 2012).
Table 1: Examples of Amendments for In Situ Sediment Remediation
Amendment
Activated carbon (and other
carbon sources)
Organoclay1™
Phosphate additives (such as
apatite)
Bauxite
Zero valent iron
Biopolymers
Zeolite
Contaminant Group Targeted
PAHs, PCBs, dioxins/furans, pesticides1' 2' 3' 4' 5' 6
NAPLs, PAHs, PCBs, metals1' 3' '' 8
Metals (lead) T> 3' '
Metals (mercury, arsenic, chromium, cadmium,
lead, zinc, and nickel) n
Chlorinated hydrocarbons, chromate 3
Metals, organics 7
Nitrates, metals (copper, lead, zinc)3
Scale
Full2
Fully
Pilot10
Bench12
Bench1'
Bench7
Bench3
References:
1 CETCO 2012
r\
Olsta and Hornaday
3 Olsta and Darlington 2005
4 Murphy and others 2006
5 Cho and others 2011
6 Beckingham and Ghosh 2011
7 Knox 2008
Reible and Lampert 2008
Ecology and Environment 2008
Home 2007
EPA 2007
Gavaskar and others 2005
Gardner 2004
10
n
12
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Before a mat is installed, it is important to remove rocks, debris, and dead trees from the
sediment surface to minimize potential damage to the mat and provide a more even surface for
placement (Earth and Reible 2008). Additional factors that affect placement of mats include the
type of amendment used in the mat, shoreline accessibility, and the physical nature of the
sediment where the mat is placed. Differential settling of the mat could lead to ruptured seams
and contaminant migration through the seams. In addition, depending on the amendments and
components of the mat, they may not sink readily. Although some amendments enclosed in the
geotextiles are buoyant, it is possible to use geotextiles with a higher specific gravity or mix a
fraction of sand with the amendment to create a mat that is easier to sink (Olsta and Darlington
2005).
Amendments can be spread on the sediment in bulk using conventional equipment or equipment
that has been modified for aquatic use. At the Anacostia River demonstration, apatite was placed
using a clamshell bucket on a barge-mounted crane (see the appendix for more information). Silt
curtains were used to minimize the migration of cap material because of water movement.
Equipment such as submerged diffusers, energy dissipaters, submerged discharge points, and
tremies (specialized underwater pipes, typically used for pouring concrete) can be used to apply
amendments evenly to a required thickness. Amendments can also be applied in bulk with fine-
grained soil or sands to provide better dispersion, uniformity, placement controls, and contact
time when the required quantity of the amendment is small. AquaBlok™ and SediMite™ serve as
bulk delivery media for granular activated carbon by incorporating it in their formulation.
Although historically AquaBlok™ particles were clays designed to expand and create an
impermeable sediment cap, a permeable cap can also be designed using different AquaBlok
amendments (AquaBlok 2008). SediMite is designed to disintegrate, slowly releasing the
amendments, which can be mixed into the sediments by benthic organisms (Menzie and Davis
2009).
As with conventional caps, amendments placed in a slow and uniform manner will reduce the
potential for resuspension of the material or sediment into the water column, promote even
distribution, and allow the material to accumulate in layers that may minimize mixing with the
underlying contaminated sediment and contaminant dispersion. Using amendments with an equal
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or lower density than the underlying sediments may also minimize contaminant dispersion and
mixing during placement (USAGE 1998). When used as a direct sediment amendment, rather
than as an amended cap, mixing of amendments by benthic organisms is desired to incorporate
the amendment into the sediment. In such cases, mixing may be promoted by injecting the
amendment into the sediment with hollow tines or using equipment similar to a rototiller.
The current, energy, and depth of the waterway may also influence the type of placement
method, especially for bulk materials that may become entrained in the water column and
therefore be difficult to place accurately. Generally, a longer descent through the water column
results in a thinner layer of amendments over a larger area. Delivery may need to be directed
closer to the sediment surface in these situations. Slope of the waterway bottom may affect the
placement of bulk material, as flat bottom and shallow slopes allow material to be placed more
accurately. Currents can affect dispersion during amendment placement, while bottom currents
can generate shear stresses on the materials. Depending on the hydrodynamics of the water body,
the amendment may need to be protected from erosion. Protection may be accomplished by
placing a sand or gravel armoring layer on top of the amendment. The type of material selected
for this uppermost layer may also depend on habitat at the site (EPA 2005).
5. Design Considerations for Amendments
At Superfund sites, the most appropriate remedy is chosen after site-specific data and the nine
remedy selection criteria in the National Contingency Plan (NCP) have been considered. All
sediment remedies are designed to meet the remedial action objectives and cleanup levels
defined in final decision documents for the site. These objectives may include contaminant
concentrations in surficial sediment, pore water, surface water, and biota. As with all sediment
remedies, short-term and long-term monitoring plans are needed to evaluate how well the
remedy achieves these goals. It is also important to identify and adequately address the source of
sediment contamination for all remedial alternatives. If the sources are not adequately controlled,
they can limit the effectiveness of the remedy. Unlike other remedies, amendments applied to the
surface sediments have some potential to adsorb contamination from continuing sources as well
as from sediment sources. This ability to treat continuing sources is limited by the sorptive
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capacity of the amendment but may be useful for
reducing risk while continuing sources are being
addressed. Another unique benefit of amendments
applied in bulk is that, once they are applied to
and incorporated in the sediments, they will be
transported with the sediments and continue to
strongly sorb the contaminants. Erosion may
expose contaminated sediments that have not been
amended, but at sites where the contaminants are
concentrated in the surface sediments,
amendments may be useful for reducing risk.
There are numerous factors that affect both the
design and performance of a remedy that uses in
situ amendments. These factors include the fate
and transport mechanisms of sediments,
contaminants of concern, amendments,
geotechnical issues, and site-specific conditions
Information Box 1: Links to EPA Sediment
Resources
Clu-In Sediments Web Site:
www.cluin.org/issues/default.focus/sec/Sedim
ents/cat/Overview/
Superfund Sediment Resource Center:
www.epa.gov/superfund/health/conmedia/sed
iment/ssrc.htm
Guidance for In-Situ Subaqueous Capping
of Contaminated Sediments:
www.epa.gov/grtlakes/sediment/iscmain/inde
x.html
Contaminated Sediment Remediation
Guidance for Hazardous Waste Sites:
www.epa.gov/superfund/health/conmedia/sed
iment/guidance .htm
Principles for Managing Contaminated
Sediment Risks at Hazardous Waste Sites:
www.epa.gov/superfund/policv/remedy/pdfs/
92-85608-s.pdf
(including the potential for erosion and bioturbation). Many of these factors also apply to the
design of conventional caps. The USAGE is currently developing detailed technical guidelines
on the use, design, and performance of in situ caps, including amendments and amended caps
(Technical Guidelines for In Situ Sediment Remediation). Additional information regarding
design considerations can be found in several EPA resources provided in Information Box 1. The
most critical factors for selecting and applying amendments for in situ sediment remediation are
presented below.
5.1 Fate and Transport/Migration Pathways
Transport of contaminants at sediment sites is driven by physical movement of the contaminated
sediments and by movement of dissolved contaminants into or out of the sediment. While caps
may be effective at controlling the physical movement of sediments, amendments — either alone
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or in caps — may better control the movement of dissolved contaminants into the surface water
(for example, by contaminant migration via advection, diffusion, or gas migration). Advection
can be either (1) short-term, resulting from consolidation during or after cap placement and may
occur through or around the cap, or (2) long-term, if there is an upward hydraulic gradient
resulting from groundwater flow (upwelling), gas ebullition, or tidal fluctuation. Consolidation-
or groundwater-induced advective forces may mobilize contaminants from the sediments into
and possibly through the cap. Less consolidation, and thus less contaminant flux, may occur as a
result of mat or bulk amendment placement because mats and amendment layers are generally
thinner and lighter than conventional sand caps. When an amendment layer is used in a mat, it is
necessary to consider preferential seepage or flux through seams between mats in the fate and
transport analysis (Earth and Reible 2008). Another potential issue with using mats in locations
with significant groundwater flow or gas ebullition is the potential for the mat to be lifted. The
permeability of the mat and the method of anchoring the mat are important aspects of the remedy
design.
The available sorption capacity of an amendment can greatly reduce both the rate the chemicals
move through the cap and the bioavailability of chemicals in amended sediments (EPA 1998).
Laboratory studies indicate that a centimeter (cm) thick layer of activated carbon or other carbon
material beneath a sand cap can effectively mitigate contaminant flux of PCBs from sediment
(under laboratory-simulated diffusion and advection dominated conditions) and isolate them
from the bioactive region of the sand cap for decades to centuries (Murphy and others 2006).
Another laboratory study evaluated the effectiveness of apatite, Organoclay™, and biopolymers
in addressing metals, PAHs, and PCBs. The resulting models of amended caps predicted that
apatite and Organoclay would delay contaminant breakthrough into the overlying surface water
via diffusion by hundreds of years or more compared with sand caps (Knox 2008). In a
laboratory study of amended sediments, activated carbon was added to sediment samples with a
range of organic content and PCB concentrations. Results showed PCB concentrations in pore
water decreased by 69 to 97 percent, and bioaccumulation of PCBs in an oligochaete (a worm)
decreased by 42 to 85 percent after 28 days of exposure (Sun and Ghosh 2008).
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Data obtained from field studies also show similar performance. At the Grasse River site, where
activated carbon was used to amend the sediments and reduce the bioavailability of PCBs to
benthic organisms, results indicated that PCB concentrations in benthic worms decreased by
approximately 63 to 99 percent. Less hydrophobic congeners (Log KOW 2 less than 6) decreased
by more than 63 percent in the first year and remained low over 3 years. More hydrophobic
congeners decreased gradually, but reached similarly reduced levels 3 years after they were put
in place (Beckingham and Ghosh 2011). Similarly, results at the Hunters Point site, where
activated carbon was used as a sediment amendment, showed (1) reductions in the availability of
PCBs to water and biota, and (2) reductions in bioaccumulation without adversely affecting the
natural benthic community or releasing PCBs into the overlying water (ESTCP 2009). Five years
after activated carbon was applied to the sediment at Hunters Point, total PCB uptake in passive
samplers was reduced by 73 percent, with greater reductions in the bioavailability of the less
chlorinated congeners relative to the more chlorinated congeners (Cho and others 2011).
Additionally, analysis of the coke breeze mat-amended cap at the Anacostia River shows a 3 to 4
order of magnitude decrease in PAHs between the contaminated sediment and the sand overlying
the coke breeze mat, demonstrating that the coke efficiently isolated the PAHs from the surface
of the cap. Analysis of the AquaBlok -amended mat from the same study shows similar
efficiencies in isolating PAHs and also shows reductions of several orders of magnitude for a
variety of metals (Home Engineering Services 2007).
Gas migration, another potential contaminant transport pathway, can be a factor at sites with
sediments of high organic content and persistent anaerobic conditions. These gases can travel
through the sediment or sand cap via advective and diffusive transport (EPA 2005). Ebullition
enhances diffusive transport and provides preferential pathways for groundwater and NAPL
transport of contaminants. Gas can also generate significant uplift forces and affect the physical
stability of an amendment mat or layer (particularly one with low permeability) or carry
contaminants through the amendments and potentially into the overlying water column.
2 Log Kow = The octanoI/water partition coefficient, which is used as a measurement of a compound's bioaccumulation
potential.
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Amended cap designs may reduce the impact of gas migration by including vents with activated
carbon filters to treat contaminants transported by the gas.
5.2 Amendment Characteristics
The key characteristics of amendments to consider for in situ sediment remediation are the
sorption capacity, the sorption mechanism, and the contaminants targeted. It is also important to
know the grain size distribution, specific gravity, buoyancy, and porosity of the amendment. Key
properties of the contaminated sediments to be considered in designing the remedy, in addition to
those mentioned for the amendment, are the organic content and the hydraulic conductivity. It is
also critical to understand the potential for deposition onto and erosion of the sediment bed. The
USAGE is currently developing a technical guidance for assessing deposition and erosion in
sediments (Technical Guidelines on Performing a Sediment Erosion and Deposition Assessment
[SEDA] at Superfund Sites).
A study by Olsta and Darlington (2005), consisting of laboratory column testing and modeling,
shows that for PCBs the sorption capacity of a thin layer of activated carbon is more than 100
times greater than the sorption capacity of sand or soil, assuming the fraction of natural organic
carbon in the sand or soil equals 3.8 percent. Based on these results, a 1-cm-thick amendment
layer of activated carbon and a 1-meter-thick cap of sand have similar potentials for chemically
isolating contaminated sediments. However, project-specific conditions, such as bioturbation,
will require a thicker cap to guarantee isolation. In a study by Murphy and others (2006), the
physical properties of carbonaceous amendments were measured in the laboratory and then used
in a numerical model to predict migration of 2,4,5-PCB in a 50-cm contaminated sediment layer
capped by a 1.25-cm amendment layer and a 15-cm sand layer. The model predicted that sand
caps amended with a 1.25 cm thick layer of activated carbon, coal, or organic-rich soils would
isolate the PCBs for centuries when there was no groundwater advection. Estimated isolation
times decreased to decades for coke and soil in areas with groundwater advection of 1 cm/day,
while the activated carbon layer remained effective for centuries. Assuming a groundwater
velocity of approximately 10 cm/day, which may be too fast to allow equilibrium partitioning,
the numerical model predicted that activated carbon would isolate PCBs for about 200 years. The
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study also concluded that effective porosity, dispersivity, and bulk density had little effect on cap
performance; the sorption strength of the amendment was the primary determinant of cap
performance. Long isolation times afforded by sorbent-amended sediments could allow time for
inherently slow natural degradation processes to further mitigate PCB flux (Murphy and others
2006). Although laboratory and modeling studies can predict performance, their results often
vary from what actually occurs in a natural setting. Results from recent field studies, such as
those discussed in Section 7, show promising reductions in the bioavailability and biotic uptake
of sediment contaminants. Uncertainty in the long-term effectiveness of in situ amendments will
only be reduced as these early studies are monitored into the future.
If groundwater upwelling is expected to be significant (more than about 1 cm/day), the hydraulic
conductivity of the conventional or amendment materials to be placed on or in the sediment cap
impacts remedial design (EPA 2005). Amendment materials, particularly clay amendments, may
restrict groundwater and could result in uplift of the amendments or create preferential pathways
through the amendment layer (Mutch and Kearney 2003,). Groundwater may also be diverted
around the amendment layer and potentially lead to contaminant migration (Barm, Reible,
Bullard 2008). Migration is of particular concern for contaminants that are less hydrophobic (log
KQW below 3). Sediment amendments are unlikely to be effective in treating highly water soluble
contaminants. These factors will influence the effectiveness of the amendment and are important
considerations in areas with significant groundwater flow, uncontrolled sources, or NAPL (EPA
2005).
The contact time between the amendments and groundwater or pore water may be short because
mats or surface layers mixed with amendments are relatively thin. A short contact time is often
adequate because of the high hydrophobicity of the most common hydrophobic organic
contaminants in sediments, such as PCBs, PAHs, and dioxins. Depending on the solubility of the
contaminants, the flow rate of the groundwater, and the kinetic rate of sorption to the
amendment, the thickness of the amendment layer may need to be adjusted to ensure the
contaminants are adequately sequestered. Amendments also have finite sorption capacity;
understanding advective and diffusive fluxes is critical to ensure that treatment capacity is
adequate to address the risks posed by the COCs. Although the amendment layer or mat is
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designed to provide sufficient capacity, on-going sources may compromise the remedy. The
replenishment or replacement of the layer or mat may be necessary to ensure effectiveness of the
remedy, which may disturb the benthic community.
5.3 Computer Modeling
Computer modeling at sediment sites may assist in site characterization, risk assessment, and
evaluation of remedial alternatives. Models have various inputs and associated uncertainties.
EPA recommends use of a modeling expert to determine if a model should be used and which
models are most appropriate (EPA 2005). Additional information about the use of modeling at
sediment sites is available in the Sediment Assessment and Monitoring Sheet (SAMS) #2:
"Understanding the Use of Models in Predicting the Effectiveness of Proposed Remedial Actions
at Superfund Sediment Sites" at
www.epa.gov/superfund/health/conmedia/sediment/pdfs/Modeling Primer.pdf
Chemical isolation modeling can be used to predict expected changes associated with the
application of amendments, such as changes in chemical flux to the overlying water or into the
sediment surface layer. However, gas migration, factors relating to gas ebullition, and tidal
effects are not typically included. Models to evaluate the effectiveness of amendments range in
complexity but are typically vertically oriented, one-dimensional, and include transient and
steady state conditions (Earth and Reible 2008). Some of the input parameters and variables
include the thickness or mass of the amendment, sediment density, sediment organic content,
groundwater flow, and contaminant partitioning coefficients. Physical modeling is typically used
to predict the degree of (1) consolidation in capping materials and underlying sediments, and
(2) erosion potential in the capped or amended area (including erosion from flows, waves, and
vessel traffic). Three of the more commonly used models for documenting the effects of caps and
amendments are the USAGE Recovery Model, the USAGE CAP Model, and Dr. Reible's
Analytical Cap Active Layer Model (www.caee.utexas.edu/reiblegroup/downloads.html). The
USAGE models are available at
http://el.erdc.usace. army, mil/products. cfm?Topic=model&Tvpe=drgmat.
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6. Remedial Action Monitoring
i
EPA guidance recommends monitoring of short- and long-term remedy performance and risk
reduction for all Superfund sites where a remedy has been implemented. Monitoring of remedies
that involve amendments typically includes monitoring to evaluate (1) whether reductions in
chemical toxicity, bioavailability, or fluxes have been achieved and maintained, and (2) evidence
of contamination on the surface layer. Monitoring amended caps also should evaluate the long-
term integrity and stability of the mat or amended cap. The use of amendments may require an
intensive monitoring effort during and shortly after placement operations and immediately after
unusual events (for example, severe storms), with a declining level of effort in future years if the
remedy is performing as designed (EPA 2005). Examples of monitoring methods are listed in
Information Boxes 2 and 3. A database of sediment monitoring tools developed by the Space and
Naval Warfare Systems Center under the Navy's Environmental Sustainability Development to
Integration program is available at www.israp.org/.
Since amended sediments and amended caps are intended to have long design lives, periodic
maintenance, in addition to monitoring, may be necessary. Although studies of pilot- and full-
scale amendment based remedies indicate strong performance over 1 to 5 years, the performance
of amendments over decades has not been
evaluated. The lifetime of amendments may be
limited either by the sorption capacity of the
amendments or by their deterioration. The
amendments should be designed to allow
adequate time for natural recovery processes to
occur, limit maintenance needs, and minimize
benthic disruption.
Monitoring during placement of amendments
ensures design specifications and proper
installation are achieved and placement
operations do not cause unacceptable adverse
Information Box 2:
Construction Monitoring
Goal: Determine if cap or amendments are
placed properly and assess impacts to water
quality and downstream areas.
Methods:
Bathymetric surveys
Sediment coring
Sediment profiling camera
Contaminant resuspension
monitoring
Total suspended solids monitoring
Visual aids (viewing tube or diver
observations)
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Information Box 3: Performance Monitoring
Goal: Determine if the remedy is performing as
intended, and determine if the contaminant
exposures and corresponding risks are reduced to
acceptable levels. This is critical to determining if
RAOs have been, or are expected to be, achieved.
Methods:
For Amended Caps or Amended Sediments:
• Passive sampling of porewater
• Seepage meters
• Sediment coring
• Surface water quality monitoring
• Sediment traps
• Sediment profile imaging
• Tests of toxicity to invertebrates
• Tests of bioaccumulation in benthos
• Fish tissue concentrations
Specific to Caps:
• Gas flux chambers
• Inclinometers
• Bathymetric and side-scan sonar surveys
• Sedflume analysis
effects to the water body. Methods for
monitoring include bathymetric surveys,
sediment cores, sediment profiling
camera, and contaminant resuspension
monitoring. For some sites, visual
observation in shallow waters using a
viewing tube or diver observations can
also be useful. Bathymetric surveys and
coring were conducted at the Anacostia
River demonstration to measure cap and
mat thickness. Water column monitoring
of suspended sediments and COCs
during placement of amendments is
helpful in assessing sediment and
contaminant movement. Concentrations
of suspended solids can be measured
using grab samples from the water
column or using acoustic Doppler current
profilers. Total suspended solids
measurements may include capping
material stripped during placement in addition to contaminated sediments and do not necessarily
indicate resuspension of contaminated sediment (Lyons and others 2006). Total suspended solids
can be measured and used in conjunction with water samples analyzed for contaminants to
distinguish between the types of particles present.
As with conventional capping remedies, monitoring is typically conducted before and after
placement to evaluate whether sediment cleanup levels have been reached and whether remedial
action objectives are or are expected to be achieved. The type and extent of monitoring depend
on the objectives of the cap. More details on the monitoring of in situ amendments will be
provided in the USAGE technical guidelines document for in situ remedies currently in
development.
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7. Recent Applications of Amendments for
Sediments: Case Studies
The amendments discussed above are at various stages of development and implementation. The
appendix to this report summarizes the pilot- and full-scale applications that are under way or
completed. The most common types of amendments used are activated carbon and Organoclay .
Most of these applications address PCBs and PAHs, which are common contaminants in
sediment. Three sites where amendments have been applied either as a remedy or for a pilot
study are discussed below. The Grasse River, Spokane Upriver Dam PCB, and McCormick &
Baxter Sites were included here because of the availability of monitoring data and the
representative nature of the chosen amendments. Data on the effectiveness of amendments are
limited because of the small number of field applications, the length of time necessary to assess
long-term effectiveness, and, in some cases, the lack of monitoring data. Available information is
presented; also some of the data presented here were obtained from project managers, and were
not in the public record during development of this document.
7.1 Grasse River Site, Massena, New York
The Grasse River Superfund Site, located in New York State near the St. Lawrence River, was
contaminated with PCBs by the activities of a local aluminum smelter. In the early 1900s, the
lower Grasse River was dredged to accommodate the needs of a nearby hydro-power plant.
Today, the river is generally flat-bottomed and 10 to 25 feet deep. This section of the river is
deposit!onal, on average, and currently has a deposition rate of approximately 1 cm/year.
Consumption offish that have accumulated PCBs from these contaminated sediments is the
primary driver of risk for humans (Alcoa 2011).
A pilot study at this site used activated carbon to reduce the bioavailability of PCBs to benthic
organisms. In the fall of 2006, activated carbon, derived from both bituminous coal and coconut
shells, was applied to the sediment surface over a 0.5-acre pilot area (Oen and others 2012). The
activated carbon was either mixed mechanically into the sediments or left undisturbed, allowing
the benthic organisms to incorporate it into the sediment. The amendment was mixed using a
rototiller for one test area and a tine-sled at another. Water quality monitoring conducted during
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Grasse River Site Characteristics:
• COC: PCBs
• Amendment: granular activated carbon
• Placement Method: (1) Rototiller with rotors,
(2) Tine Sled, and (3) Rototiller without rotors
• Design: Addition of activated carbon dose of
2.5 percent of sediment. Placement methods 1
and 2, the sediments and activated carbon were
mixed; method 3 was unmixed.
• Construction Complete: Fall 2006
• Cost: Not Available
• Results: 1 year after construction,
approximately 72 to 94 percent reduction in
PCB concentrations in benthic worms and 63
to 99 percent reduction after 3 years of
treatment.
placement indicated no measurable
changes in water column PCB
concentrations, which remained below
detection limits (0.065 microgram per
liter [|ig/L] or part per billion [ppb]) at
locations upstream, local, and
downstream. A slight turbidity increase
was noted but concentrations remained
below the action level (25 nephlometric
turbidity units above background). Data
collected in 2006 (after placement) and
2007 showed that activated carbon was
applied at or above its target dose of 2.5
percent, with the exception of small-
scale variability. The applied activated
carbon remained in place over 3 years of monitoring. Biological monitoring conducted before
and 1 year after activated carbon placement included ex situ laboratory bioaccumulation studies
and in situ cage deployment. Those results showed PCB concentrations in benthic worms
decreased between 72 and 94 percent (Alcoa 2007, Beckingham and Ghosh 2011). Three years
after the activated carbon placement, aqueous equilibrium concentrations were 95 to 100 percent
lower than the reference contaminated site and more than 93 percent lower than the pre-treatment
concentrations. Bioaccumulation in benthic worms was reduced by 63 to 99 percent in laboratory
exposures and 62 to 93 percent in caged exposures. Measurements of individual PCB congeners
over 3 years indicate that activated carbon amendments decrease the bioavailable fraction of less
hydrophobic congeners (Log KOW below 6.0) by 90 percent within a year. Concentrations of the
more hydrophobic congeners decreased gradually and reached 90 percent reductions in benthic
worms after 3 years (Beckingham and Ghosh, 2011).
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7.2 Spokane River, Upriver Dam PCBs Sediment Site, Spokane, Washington
The Spokane River, Upriver Dam PCBs Sediment Site, located in eastern Washington State,
covers 3.5 acres directly behind the Upriver Dam in the City of Spokane and is a state-lead site.
Consumption of PCB-contaminated fish is the primary driver of risk. Measured sediment
concentrations of PCBs were as high as 1,430 ppb (micrograms per kilogram [jig/kg] dry
weight). The Washington State Department of Ecology issued a fish consumption advisory
recommending that no fish from this location be consumed (State of Washington 2011). An
amended cap, using coal as the carbonaceous amendment, was constructed in fall 2006 to
sequester PCB contamination. A minimum of 1,300 tons of coal was necessary to cover this area
with a 4-inch thick coal layer. An additional 780 tons was applied to compensate for uneven
distribution or losses from currents or placement techniques. Before coal was put in place at the
site, a pilot study was conducted on various placement methods. Results showed a more even
distribution was achieved when the coal was released just above the water surface rather than
just above the sediment surface. The
coal layer was covered with a 6-inch
sand layer followed by a 3-inch gravel
layer. Water quality was monitored
during amendment placement, and no
results that exceeded water quality
standards were observed during
construction. Piston core sampling and
bathymetric surveys were conducted
after placement. Coring verified that
the minimum thickness of 4 inches
was achieved for the coal layer; the
average was 6.3 inches (Anchor
2007). The first post-construction
monitoring event was conducted in
fall 2008 and included bathymetric
surveys, collection of sediment cores
Spokane River, Upriver Dam PCBs Sediment
Site Characteristics:
• COC: PCBs
• Amendment: Coal
• Placement Method: A long reach excavator
released the cap amendments above the water
surface and allowed them to settle through the
water column.
• Design: 4 inches of coal covering the
contaminated sediments, 6 inches of sand over
the coal, and 3 inches of gravel over the sand.
• Construction Complete: Fall 2006
• Cost: $1,578,000 (estimated in the draft Clean-
up Action Plan for the entire remedy)
• Results: By the fall of 2008, consolidation and
sediment deposition had occurred. Total PCBs
were below detection limits in the sand and
coal layers of the cap, indicating that the
contaminated sediments were effectively
isolated by the cap.
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and surficial sediment samples, and visual observations. Total PCBs were below detection limits
in the sand and coal layers, indicating that the cap is efficiently isolating the PCB contaminated
sediment (Anchor 2009). Additional information about this site and project is available at
https://fortress.wa.gov/ecy/gsp/Sitepage.aspx?csid=4213 and in the appendix.
7.3 McCormick & Baxter Former Creosoting Company Superfund Site,
Portland, Oregon
The McCormick & Baxter Superfund Site is located on the Willamette River, in Portland,
Oregon. Wood treatment operations between 1944 and 1991 have contaminated the sediments
with PAHs, creosote, diesel, pentachlorophenol, and a variety of heavy metals. PAH
contamination is extensive; the depth of contamination for PAHs is up to 80 feet below the
sediment surface. Direct contact with and ingestion of contaminated media (sediments,
groundwater, and soils) are the main drivers of risk at this site.
The sediment remedy at this site consists of (1) 23 acres of a 2- to 5-foot-thick sand cap with
armoring, including 600 tons of bulk granular Organoclay™ placed over the active creosote seep
areas, and (2) 25,000 square feet (0.6 acre) of Organoclay™ reactive core mat placed over
nearshore areas with ebullition-induced creosote sheens. The bulk Organoclay™ was placed in
2004, covering 20,000 ft2 (0.5 acre), and the Organoclay™ mats were deployed in 2005 to cover 3
areas of the sediment cap where ebullition-induced sheen was observed (GSI2007). Since fall
2005, post-construction monitoring has been conducted semi-annually (in spring and fall).
Monitoring included periodic multi-beam bathymetry and side-scan sonar surveys, visual and
diver inspection of the cap, crayfish tissue sampling, and monitoring of surface water, inter-
armoring water and sub-armoring water from 22 locations within the 23-acre footprint of the
sediment cap (ODEQ and EPA 2007). Additional activities to monitor the bulk Organoclay™ and
Organoclay™ mat were conducted between 2006 and 2008, including collection of sediment cap
and Organoclay cores, Organoclay mat samples, sheen, surface water, and pore water
samples. The samples of Organoclay and Organoclay mats (after they had been in place for 2
and 4 years) were tested for available sorption capacity, water content, permeability, and percent
hexane extractable material to determine to what extent the Organoclay had absorbed NAPL
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and the potential for further NAPL retention. In addition, flux chambers were placed over
ebullition pathways where gas and water were monitored to assess the significance of ebullition
as a contaminant pathway through the sediment cap. Strength of the bulk Organoclay™ was also
measured to assess structural integrity. Activities conducted since the mat was put in place in
2005 also included installation of additional mats as needed.
The mean pore water concentration of total carcinogenic PAHs in 2005, measured at the
interface of the contaminated sediment and the sand cap, was 0.2 |ig/L; in the surface water, the
mean concentration carcinogenic PAH was 0.04 |ig/L. Pore water concentrations at the bottom of
McCormick & Baxter Former Creosoting
Company Site Characteristics:
• COC: PAHs, creosote, and NAPL
• Amendment: Organoclay Reactive Core Mat along
the beach head and bulk Organoclay over the
NAPL hotspots.
• Placement Method: The reactive core mat was
deployed using a barge and crane, while the bulk
Organoclay was placed from shore using a
backhoe.
• Design: 1 foot of sand above the contaminated
sediments, 1 foot of Organoclay over the sand, 4
inches of gravel over the Organoclay, and 10
inches of rock armor over the gravel.
• Construction Complete: Bulk placement - 2004,
reactive core mat placement - 2005.
• Cost: The total cost is not available. The reactive
core mat cost was $2 per square foot.
• Results: Monitoring in 2006 indicated that the
Organoclay had similar sorptive capacity as fresh
Organoclay. No significant signs of NAPL
migration and no decrease in permeability were
observed. Bubble migration was observed but no
NAPL was associated with the gas bubbles.
the cap decreased steadily through
2010 when the mean pore water
concentration of carcinogenic PAHs
was 0.02 |ig/L. In 2010, all PAH
concentrations in the cap were below
the National Recommended Water
Quality Criteria (NRWQC), with the
exception of chrysene. At one
sampling location, the chrysene
concentration was 0.035 |ig/L
compared with an NRWQC of 0.018
|ig/L, but was below the NRWQC at
all other sampling stations (Hart
Crowser and GSI2011). Sheen,
surface water, and pore water
samples, as well as sediment cap
cores, collected in 2007 and 2008,
were used to determine whether the
sheen observed in the summer/fall
periods were potentially caused by
NAPL penetrating the sediment cap
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(Ecology and Environment 2008, GSI and Hart Crowser 2008). The sheen samples did not differ
significantly from nearby surface water samples (approximately 5 feet away from collocated
sheen samples). Pore water and sediment cap cores showed no evidence of NAPL entering or
penetrating the sediment cap and total petroleum hydrocarbons were only detected in one of six
samples in a location where PAHs were not detected. The Organoclay™ at this site continues to
have similar sorption capacity to water-saturated fresh Organoclay™ and retains sufficient
permeability to allow for groundwater transport through the sediment cap. Using flux chambers,
the calculated rate of ebullition over the top of the Organoclay was 2.9 liters per square meter
per day (liters/m /day), while the rate outside of the Organoclay footprint where residual
creosote is known to be present in the native sediment was calculated to be between 0.02 to 0.09
Iiters/m2/day (Hart Crowser and GSI 2009). While the high rate of ebullition over the bulk
Organoclay™ was not expected, it does not appear to be a significant contaminant pathway
affecting the sediment cap performance.
8. Cost
Available cost data for amendments are limited and often do not include installation costs. Table
2 shows total material cost estimates for several amendments based on the Anacostia River
demonstration. According to the reactive core mat vendor, CETCO, costs are approximately
$2.50 per square foot for mats with activated carbon and $2.00 per square foot for Organoclay .
In addition, based on the Anacostia River demonstration, construction costs for the large-scale
application (1,000 acres) were estimated to be $2.80 per square foot plus the cost of materials.
The principal costs within this estimate include monitoring costs ($1.10 per square foot) and
construction costs for cap placement ($1.10 per square foot). The costs of bulk activated carbon
is about $1.00 per square foot, assuming a typical application of 5 percent activated carbon dry
weight to the top 10 cm of sediment. For activated carbon applied using SediMite , the price is
about $2.00 per square foot (Menzie-Cura and Associates).
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Table 2: Estimated Material Costs for In Situ Sediment Amendments
Cap Type (thickness)
Apatite (6")
Sand (6")
AquaBlok'"(4-6")
Reactive Core Mat with coke breeze (0.5")
Reactive Core Mat with activated carbon (0.5")
Reactive Core Mat with bulk iron (0.5")
Reactive Core Mat with 10% nano-iron (0.5")
Bulk Activated Carbon+
SediMite Activated Carbon+
Material cost
($ per square foot in 2005)
$3.10*
$0.45*
$3.00*
$1.11
$2.00
$1.25
$3.62
$1.00
$2.00
References: Reible, Constant and Zhu 2005; Menzie and Cura Associates
RCM: Reactive Core Mat
*Excludes shipping costs
+Assumes a typical dose of 5 percent AC dry weight to the top 10 cm of sediment, which is about
1 pound per square foot.
9. Ongoing Research and Development
The EPA, Navy, USAGE, Department of Defense's Environmental Security Technology
Certification Program (ESTCP)/Strategic Environmental Research and Development Program
(SERDP), and many others are actively involved in developing and testing amendments and
placement processes. Several universities are conducting research with amendments or
application techniques through the Superfund Research Program under the National Institute of
Environmental Health Sciences - National Institutes of Health.
In addition to the amendments discussed above, there are a variety of amendments used for
treating other contaminated media (soil and groundwater) that may also be applicable for
contaminated sediments. These materials include manganese and iron oxides, alumina, magnetite
and substrates containing reactive thiol groups for the removal of mercury from liquid media,
and silica for removal of heavy metals from liquid media (Dong and others 2000, Melamed and
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Benvindo da Luz 2006, Pacific Northwest Laboratory 2009, Spark and others 2005). In addition,
activated carbon can be impregnated with various compounds to enhance its treatment
capabilities. For example, activated carbon mixed with zero valent iron and palladium has the
potential to degrade PCBs through dechlorination, thereby reducing their bioavailability, but this
mixture has been tested on PCBs in sediments only in the laboratory (Choi 2009). There have
been no studies on using impregnated activated carbon materials for sediment remediation.
Some additional amendments being developed or adapted to sediments include biopolymers and
zeolites. Biopolymers are naturally occurring materials that can bind metals and organics. When
the polymers are cross-linked, they resist biodegradation. They have a plugging effect
(increasing the shear strength of porous media to resist erosion), can be injected into sediments,
and are economical and non-toxic. One biopolymer evaluated in bench-scale studies is chitosan
(Knox 2008). Zeolites are porous crystalline aluminosilicates that can be natural or synthetic.
They are used commercially for their adsorption, ion exchange, molecular sieve, and catalytic
properties. They have been used in water treatment for the removal of nitrates and metals (Olsta
and Darlington 2005). However, their applicability for use as in situ sediment capping material is
speculative. There have been no pilot- or full-scale applications to test the longevity and
efficiency of biopolymers or zeolites as amendments.
A new method for placing amendments into contaminated sediments is being investigated by
researchers at the Missouri University of Science and Technology. This method adapts existing
water jet technology to inject the amendment into the sediment. Under laboratory controlled
conditions, powdered activated carbon was injected into columns of PAH-contaminated
sediment. By varying the pressure and nozzle diameter of the water jet and the duration of the
injection, this study was able to place the powdered activated carbon at a specified depth in the
sediment column up to 30 cm, with minimal resuspension of the contaminated sediment.
Injections of 9.5-seconds duration placed 3 percent powdered activated carbon at a maximum
depth of 30.5 cm, with an average powdered activated carbon concentration of 14 percent
between 0 and 27 cm. Solid-phase microextraction (SPME) measurements of phenanthrene
indicated more than 95 percent reduction in the pore water concentrations after the injection.
This method may be useful at locations where the contaminated sediment is buried by cleaner
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sediment or where resuspension caused by rototillers or tine sleds would be unacceptable.
However, this method has been tested only in the laboratory, and challenges remain to adapting
the commercially-available equipment to this method (Redell and others 2011).
Available data suggest that the use of in situ amendments is a feasible remedial option at some
sites. However, limited data are available on the long-term effectiveness and stability of
amendments because of the low number of installed projects and the lengthy timeframe required
for monitoring. As more data become available, it will be easier to assess the long-term
effectiveness of amendments at future sites under a range of site conditions. In addition, limited
field information is available about potential threats to mat integrity, such as gas ebullition, ice,
and benthic organisms. There are also limited pilot-scale applications or field studies in high-
energy waterways, marine sediments, and colder environments that experience freeze/thaw
cycles (Earth and Reible 2008). These issues are potential topics for future research and
development.
10. Summary
Contaminated sediments are a continuing concern for regulatory agencies and the public. An
emerging alternative in sediment remediation is the use of in situ amendments. These specialized
materials can be applied in different ways to the sediment surface, within a cap, or within a mat
to minimize contaminant flux via sequestration and degradation. A variety of amendments, such
as activated carbon, Organoclay™, and apatite, are being used or studied that can serve this
purpose. Some of the better developed amendments have shown large reductions in the
bioavailability of contaminants over months to several years with minimal impacts to benthic
communities. Although uncertainty remains regarding the long-term effectiveness of these
amendments, ongoing studies will continuously improve our understanding.
There are several factors to consider in selecting, designing, and implementing a sediment
remedy using amendments. Sediment characteristics, contaminant fate and transport
mechanisms, amendment characteristics, and placement methods are four of the most critical
design considerations. Modeling is often used to predict the performance associated with these
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applications, while monitoring (both short-term and long-term) is conducted to ensure proper
placement and performance are achieved. Institutional controls may be required to ensure long-
term effectiveness. In addition, periodic maintenance or replacement of the layer or mat may be
necessary.
This document highlights three field projects across the country using amendments for in situ
sediment remediation and provides a compendium of pilot and full-scale in situ remediation
projects in the appendix. The field projects, including some addressing large areas of
contamination, show excess amendment capacity remaining several years after remedy
construction and significant reductions in pore water concentrations. Studies and monitoring are
ongoing to evaluate the long-term effectiveness of these amendments. As more of these
applications are implemented and their performance is evaluated, there will be a greater
understanding and information to gauge the effectiveness and applicability of these technologies
under different site conditions. Further information about in situ amendments, as well as other
sediment remedies, is available at www.cluin.org/sediments.
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11. Glossary of Terms
Absorption
Process by which chemicals penetrate into a three-dimensional matrix.
Activated Carbon
(AC)
A highly reduced and recalcitrant form of organic carbon, typically
formed by the incomplete combustion of carbon, such as wood, coal, or
oil. Particles or granules of Activated Carbon are highly adsorptive for
organic molecules and have a high capacity to selectively remove certain
trace and soluble materials from water.
Adsorption
Process by which chemicals adhere to the surface of particles.
Advective Transport The transport of particles or dissolved material resulting from the motion
or velocity of a fluid.
Amendment
A remediation method that reduces the toxicity of the contaminants using
biological, chemical, or physical processes to treat the contaminated
sediments in place.
Apatite
Phosphate mineral that sorbs metals through a surface precipitation
reaction.
Bathymetric analysis Bathymetric analysis involves the measurement of the water depths in a
water body and modeling of the depth to the sediment surface.
Bauxite
A clay like mineral and a primary ore of aluminum consisting of
aluminum oxides and aluminum hydroxides.
Benthic Layer
Surface layer of sediment where benthic organisms are active.
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Benthic Organism The biota living on the bottom of the water body or very near the bottom
of the water body, including the surface layer of sediment.
Bioavailable
Available for uptake by living organisms.
Biopolymer
Naturally occurring material that can bind metals and organics.
Bulk density
Mass of sediment and pore water per unit volume of soil or bed material.
Capping
Covering of contaminated sediment with clean sediment with the intention
of isolating the contaminants.
Thin Layer Cap
The placement of a thin layer of clean sediment (on the order of a few
inches thick) over contaminated sediment with the intention of enhancing
natural recovery processes, such as deposition and burial.
Carbonaceous
amendment
An amendment rich in organic carbon.
Dredging
An excavation activity or operation usually carried out underwater for the
purpose of removing bottom sediments and disposing of them at a
different location.
Diffusive
Transport
Movement across a concentration gradient from Brownian or random
thermal motion.
Dispersivity
Tendency or ability to scatter or spread widely.
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Excavation
The removal of contaminated sediment using conventional dry land
equipment. This requires the isolation of contaminated sediment from the
overlying body of water by pumping or diverting water from the area and
managing any continuing inflow prior to beginning the excavation.
Enhanced MNR
(See Monitored Natural Recovery for a definition of MNR.) MNR
combined with thin-layer placement of clean sediment at sites where the
natural rate of sedimentation is insufficient to bury contaminants in a
reasonable time frame, but where thin-layer placement can accelerate
reductions in surface sediment concentrations
Gas Ebullition
The transportation of contaminants via entrapment in migrating gas
bubbles.
Hydraulic
conductivity
A coefficient describing the rate at which water can move through
a permeable medium. Hydraulic conductivity is a function of both the
intrinsic permeability of the porous medium and the kinematic viscosity of
the water which flows through it.
Hydrophilic
The property of attracting or associating with water molecules;
characteristic of polar or charged molecules.
Hydrophobic
With regard to a molecule or sub-group of a molecule, tending to dissolve
readily in organic solvents, but not in water, resisting wetting, not
containing polar groups or sub-groups.
In Situ
Amendment
(See Amendment.)
In Situ Capping (See Capping.)
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Institutional Control Non-engineered instruments, such as administrative and legal controls,
that help minimize the potential for human exposure to contamination or
protect the integrity of the remedy.
Log KQW
The octanol/water partition coefficient, which is used as a measurement of
a compound's bioaccumulation potential.
Monitored A remedy for contaminated sediment that typically uses ongoing, naturally
Natural Recovery occurring processes to contain, destroy, or reduce the bioavailability or
toxicity of contaminants in sediment.
Organoclay™
A hydrophobic and permeable clay in which the surface molecules are
modified to include an organic carbon molecule.
Pelagic
The area of a water body that is neither near the bottom of the water body
nor near the shore, such as the open water column where there is less
interaction with the sediments.
Phytic acid
A sugar additive (6-phosphate ester of inositol); it may be used as an
amendment to bind metals in sediments.
Porosity
Ratio of the volume of void space (i.e., pores) to the total volume of an
undisturbed sediment or soil sample.
Sediment
Particles derived from rocks, biological material, or both that is
transported, suspended, and deposited by flowing water.
Sorption
Process in which chemicals become associated with solid phases; this
process includes both absorption and adsorption.
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Specific gravity The dimensionless ratio of the density of a substance with respect to the
density of water. The specific gravity of water is equal to 1.0 by definition.
Turbidity
Measure of the extent to which light passing through water is reduced due
to suspended matter in the water column.
Zero-valent iron
(ZVI) Elemental metallic iron typically used in granular form to reduce
metals or reductively dechlorinate organic solvents such as PCE or TCE.
Zeolite
Porous crystalline aluminosilicates (natural or synthetic) that are used
commercially for their adsorption, ion exchange, molecular sieve, and
catalytic properties.
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12. References
Alcoa Inc. 2007. Grasse River Activated Carbon Pilot Study. Construction Documentation
Report. November.
Alcoa. 2011. The Grasse River Project, website: www.thegrasseriver.com. Accessed August 17,
2011.
Anchor QEA (formerly Anchor Environmental, LLC). 2007. Cleanup Action Completion
Report, Upriver Dam PCBs Sediment Site. April.
Anchor QEA. 2009. Memorandum to Brendan Dowling, Washington State Department of
Ecology. Year 2 Upriver Dam Cap Monitoring Results, Project 080306-01. April 16.
AquaBlok Ltd. 2008. Expanded Range of Proven Remediation Treatment Materials Can be
Delivered to Contaminated Sediments with AquaBlok Composite Particle System. Press
Release. August 18.
Barm, E. and D. Reible. 2008. Design Consideration Involving Active Sediment Caps.
Proceedings: First International Conference, Hazardous Waste Management. Chania - Crete,
Greece. October 1 through 3.
http://cfpub.epa.gov/si/sijublic file download.cfm?p download id=484974
Earth, E.F., D. Reible, and A. Bullard. 2008. Evaluation of the Physical Stability, Ground Water
Seepage Control, and Faunal Changes Associated with an AquaBlok Sediment Cap.
Remediation. Autumn. Pages 63 through 70.
www3.interscience.wilev.com/journal/121459444/abstract
Beckingham, B and U. Ghosh. 2011. Field-scale reduction of PCB bioavailability with activated
carbon amendment to river sediments. Environmental Science & Technology. Volume 45,
Number 24. Pages 10567 to 74. December 15. http://pubs.acs.org/doi/abs/10.1021/es202218p
CETCO Remediation Technologies. 2012. Company Website, www.cetco.com. Accessed on
November 7, 2012.
United States Environmental Office of Superfund Remediation OSWER Directive 9200.2-128FS
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Use of Amendments for In Situ Remediation at Superfund Sediment Sites
Cho, Y.M., D. Werner, Y. Choi and R.G. Luthy. 2011. Long-term monitoring and modeling of
the mass transfer of polychlorinated biphenyls in sediment following pilot-scale in-situ
amendment with activated carbon. J. Contam. Hydrol. doi:10.1016/j.jconhyd.2011.09.009.
www.researchgate.net/publicati on/5177167 ^Long-
term monitoring and modeling ofjthe mass transferof_polychlorinated biphenyls in se
diment following_pilot-scale in-situ amendment with activated carbon
Choi, H., S. Agarwal, and S.R. Al-Abed. 2009. Adsorption and Simultaneous Dechlorination of
PCBs on GAC/Fe/Pd: Mechanistic Aspects and Reactive Capping Barrier Concept.
Environmental Science & Technology. Volume 43, Number 2. Pages 488 through 493.
http://pubs.acs.org/doi/abs/10.1021/es8015815
Cornelissen, G.; M.E. Krusa; G.D. Breedveld; E. Eek; A.M.P Oen; H.P.H Arp; C. Raymond; G.
Samuelsson; I.E. Hedman; O. Stokland; and J.S. Gunnarsson. 2011. Remediation of
Contaminated Marine Sediment Using Thin-layer Capping with Activated Carbon - A Field
Experiment in Trondheim Harbor, Norway. Env.Sci.Tech., 45(14), 6110 - 6116.
Dong. D., Y.M. Nelson, L.W. Lion, M.L. Shuler, and W.C. Ghiorse. 2000. Adsorption of Pb and
Cd onto metal oxides and organic material in natural surface coatings as determined by
selective extractions: new evidence for the importance of Mn and Fe oxides. Water Research.
Volume 34, Issue 2. Pages 427 through 436. February.
www. sci encedirect.com/sci ence?_ob=Articl eURL&_udi=B6V73-402CN57-
8& user=930810& rdoc=l& fmt=& orig=search& sort=d&view=c& acct=C000048423&
version=l& urlVersion=0& Userid=930810&md5=ba77544bd2c7882c86c7el06c3c524bl
Ecology and Environment, Inc. 2008. Operation and Maintenance Report (January 2007 through
December 2007), McCormick and Baxter Creosoting Company Site. Prepared for Oregon
Department of Environmental Quality. May. www.mandbsuperfund.com
Environmental Security Technology Certification Program (ESTCP). 2009. Field Testing of
Activated Carbon Mixing and In Situ Stabilization of PCBs in Sediment. Final Report.
ESTCP Project ER-0510. May. http://serdp-estcp.org/content/download/4895/70429/file/ER-
0510-FR.pdf
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Gardner, K. 2004. In-situ Treatment of PCBs in Marine and Freshwater Sediments using
Colloidal Zero-Valent Iron. A Final Report Submitted to the NOAA/UNH Cooperative
Institute for Coastal and Estuarine Environmental Technology. February 17.
http://rfp.ciceet.unh.edu/display/report.php?chosen=51
Gavaskar, A., S. Chattopadhyay, M. Hackworth, V. Lai, B. Sugiyama, and P. Randall. 2005. A
Reactive Cap for Contaminated Sediments at the Navy's Dodge Pond Site. Technology
Innovation News Survey, www.clu-in.org/products/tins/tinsone.cfm?id=47254881
GSI Water Solutions, Inc. 2007. Post Remedial Action Conceptual Site Model for NAPL
Transport, McCormick and Baxter Superfund Site, Portland, Oregon. Prepared for Oregon
Department of Environmental Quality. August, www.mandbsuperfund.com
GSI Water Solutions, Inc. and Hart Crowser. 2008. Ebullition and Sheen Investigation Work
Plan for McCormick & Baxter Superfund Site. Prepared for Oregon Department of
Environmental Quality. August, www.mandbsuperfund.com
Hart Crowser and GSI Water Solutions, Inc. 2011. Operations and Maintenance Report, January
2010 through December 2010, McCormick & Baxter Creosoting Company, Portland,
Oregon. Prepared for Oregon Department of Environmental Quality. June
www.mandbsuperfund.com
Hart Crowser and GSI Water Solutions, Inc. 2009. Operations and Maintenance Report, January
2008 through December 2008, McCormick & Baxter Creosoting Company, Portland,
Oregon. Prepared for Oregon Department of Environmental Quality. May.
www.mandbsuperfund.com
Home Engineering Services, LLC. 2007. Final Month 30 Monitoring Report, Comparative
Validation of Innovative "Active Capping" Technologies. Anacostia River, Washington, DC.
September.
Knox, A. 2008. Active Caps for the Remediation of Mixtures of Contaminants and Resistance to
Erosion. Federal Remediation Technologies Roundtable (FRTR) Meeting. Arlington,
Virginia. PowerPoint presentation. June 5.
www.frtr.gov/pdf/meetings/jun08/knox_presentation.pdf
Kupryianchyk, D.; E.P. Reichman; M.I. Rakowska; E.T.H.M. Peeters; J.T.C. Grotenhuis; and
A. A. Koelmans. 2011 Ecotoxicological Effects of Activated Carbon Amendments on
Macroinvertebrates in Nonpolluted and Polluted Sediments. Env.Sci.Tech., 45, 8567 - 8574.
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Use of Amendments for In Situ Remediation at Superfund Sediment Sites
Lyons, T., J.A. Ickes, V.S. Magar, C.S. Albro, L. Cumming, B. Bachman, T. Fredette, M.
Keegan, K. Marcy, and O. Guza. 2006. Evaluation of Contaminant Resuspension Potential
during Cap Placement at Two Dissimilar Sites. Journal of Environmental Engineering. Pages
505 through 514. April. http://cedb.asce.org/cgiAVWWdisplav.cgi70601833
Melamed, R. and A. Benvindo da Luz. 2006. Efficiency of industrial minerals on the removal of
mercury species from liquid effluents. Science of the Total Environment. Volume 368, Issue
1. Pages 403 through 406. September 1.
www. sci encedirect.com/sci ence?_ob=Articl eURL&_udi=B6V78-4HH819M-
4& user=10& rdoc=l& fmt=& orig=search& sort=d&view=c& acct=C000050221& vers
ion=l& urlVersion=0& userid=10&md5=9f28cdd920783efcc72a28b5dlf381eb.
Menzie-Cura and Associates. SediMite™ Information Sheet.
Menzie, C. and J. Davis. Evaluating the Efficacy of a Low-Impact Delivery System for In Situ
Treatment of Sediments Contaminated with Methylmercury and Other Hydrophobic
Chemicals (ER-0835) Fact Sheet. http://serdp-estcp.org/Program-Areas/Environmental-
Restoration/Contaminated-Sediments/ER-200835/ER-200835. Accessed on October 10,
2009.
Millward, R.N.; T.S. Bridges; U. Ghosh; J.R. Zimmerman; and R.G. Luthy. 2005. Addition of
Activated Carbon to Sediments to Reduce PCB Bioaccumulation by a Polychaete (Neanthes
arenaceodentata) and an Amphipod (Leptocheirus plumulosus). Env.Sci.Tech., 39, 2880 -
2887.
Murphy, P., A. Marquette, D. Reible, and G. V. Lowry. 2006. Predicting the Performance of
Activated Carbon-, Coke-, and Soil-Amended Thin Layer Sediment Caps. Journal of
Environmental Engineering. Pages 787 through 794. July.
http://cedb.asce.org/cgi/WWWdisplav.cgi70604350.
Mutch Jr., R.D. and D.K. Kearney. 2003. Geotechnical/Hydrogeologic Factors in In-Situ
Contaminated Sediment Capping. Proceedings: In Situ Contaminated Sediment Capping
Workshop. Cincinnati, Ohio. May 12 through 14. www.epri.com
Oen, A.M.P, B. Beckingham, U. Ghosh, M.E. Krusa, R.G. Luthy, T. Hartnik, T. Henriksen, and
G. Cornelissen. 2012. Sorption of Organic Compounds to Fresh and Field-Aged Activated
Carbons in Soils and Sediments. Environmental Science & Technology. Volume 46. Pages
810-817.
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Olsta, J.T. and J. Darlington. 2005. Innovative Systems for Dredging, Dewatering, or for In-situ
Capping of Contaminated Sediments. The 21st Annual International Conference on Soils,
Sediments, and Water. University of Massachusetts at Amherst. October 17 through 20.
http://scholarworks.umass.edu/soilsproceedings/volll/issl/20/
Olsta, J.T. and C. Hornaday. 2007. Installation of an In-Situ Cap at a Superfund Site.
Proceedings of the Fourth International Conference on Remediation of Contaminated
Sediments. Savannah, Georgia. January.
http://remediation.cetco.com/DesktopModules/Bring2mind/DMX/Download.aspx?EntryId=4
96&Command=Core Download&PortalId=9&TabId=1381
Oregon Department of Environmental Quality and U.S. Environmental Protection Agency (U.S.
EPA). 2007. Draft Operation and Maintenance Plan for McCormick and Baxter Creosoting
Company Superfund Site, Portland, Oregon, ORD00020603. October.
Pacific Northwest National Laboratory. 2009. SAMMS Technical Summary.
http://samms.pnl.gov/sammstech summary.pdf.
Redell, C.J., A.C. Elmore, J.G. Burken, andR.D. Stringer. 2011. Waterjet injection of powdered
activated carbon for sediment remediation. Journal of Soils Sediments. Volume 11, pages
1115-1124.
Reible, D.D., W.D. Constant, and Y. Zhu. 2005. The Active Capping Demonstration Project in
the Anacostia River, Washington, D.C. PowerPoint presentation. June.
Reible, D and D. Lampert. 2008. Effectively Managing Risks of Contaminated Sediments. Waste
Management Conference. Phoenix, Arizona. February 24 to 28.
www.wmsvm.org/archives/2008/pdfs/8309.pdf
Spark, K.M., B.B Johnson, and J.D. Wells. 2005. Characterizing heavy-metal adsorption on
oxides and oxyhydroxides. European Journal of Soil Science. Volume 46, Issue 4. Pages 621
through 631. August 10. http://onlinelibrary.wilev.com/doi/10. Ill 1/j.1365-
2389.1995.tb01358.x/abstract
State of Washington, Department of Ecology. 2011. Spokane River Upriver Dam and Donkey
Island website: https://fortress.wa.gov/ecy/gsp/Sitepage.aspx?csid=4213. Accessed 18
August 2011.
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Strategic Environmental Research and Development Program (SERDP) and ESTCP. 2004.
SERDP and ESTCP Expert Panel Workshop on Research and Development Needs for the In
Situ Management of Contaminated Sediments. Final Report. October. http://serdp-
estcp.org/content/download/8048/99399/versi on/1/file/SedimentsFinalReport.pdf
Sun, X. and U. Ghosh. 2008. The Effect of Activated Carbon on Partitioning, Desorption, and
Biouptake of Native Polychlorinated Biphenyls in Four Freshwater Sediments.
Environmental Toxicology and Chemistry. Volume 27, Number 11. Pages 2287 through
2295.
U.S. Army Corps of Engineers. 1998. Guidance for Subaqueous Dredged Material Capping.
Technical Report DOER-1. June, http://el.erdc.usace.armv.mil/dots/doer/pdf/trdoerl.pdf
U.S. Environmental Protecton Agency (U.S. EPA). 1998. Contaminated Sediments Program.
Sediment Assessment and Remediation Report. Guidance for In-Situ Subaqueous Capping of
Contaminated Sediments. EPA 905-B96-004.
www.epa.gov/grtlakes/sediment/iscmain/index.html. Accessed on July 28, 2008.
U.S. EPA. 2005. Contaminated Sediment Remediation Guidance for Hazardous Waste Sites.
EPA-540-R-05-012. December.
www.epa.gov/superfund/health/conmedia/sediment/pdfs/guidance.pdf
U.S. EPA. 2007. Land Research Program Multi-Year Plan: Fiscal Years 2007-2012. Office of
Research and Development. Final Report.
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Appendix: Summary of Sediment Sites Using Amendments for In Situ Remediation
EPA Region and Site Name Page Number
EPA Region 1 A-3
1. Cocheco River, Dover, New Hampshire A-3
2. Former industrial site, Silver Lake, Massachusetts A-3
3. Former manufactured gas plant, Everett, Massachusetts A-4
4. Pine Street Barge Canal Superfund Site, Burlington, Vermont A-4
5. Salem Manufactured Gas Plant, Salem, Massachusetts A-5
EPA Region 2 A-6
1. Berry's Creek, Bergen County, New Jersey A-6
2. Central Hudson Gas & Electric Corp, North Water Street Manufactured Gas Plant Site, Poughkeepsie, New York A-6
3. Grasse River, Massena, New York A-7
EPA Region 3 A-8
1. Anacostia River Demonstration Project, Washington DC A-8
2. Bailey Creek, Fort Eustis, Virginia A-9
3. Canal Creek, Aberdeen Proving Ground, Maryland A-9
EPA Region 4 A-10
1. Chattanooga Creek, Tennessee Products Superfund Site, OU 1, Chattanooga, Tennessee A-10
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EPA Region and Site Name Page Number
EPA Region 5 A-ll
1. Former creosoting wood treating site, Escanaba, Michigan A-ll
2. St. Louis River/lnterlake/Duluth Tar Superfund Site (Stryker Bay), Duluth, Minnesota A-12
EPA Region 6 A-12
1. Cottonwood Bay, Grand Prairie, Texas A-12
EPA Region 9 A-13
1. Hunters Point Shipyard Superfund Site, Parcel F, San Francisco, California A-13
EPA Region 10 A-14
1. Gasco, Portland, Oregon A-14
2. McCormick & Baxter Creosoting Co. (Portland Plant) Superfund Site, Portland, Oregon A-15
3. Spokane River Upriver Dam PCB Site (Deposit 1), Spokane, Washington A-16
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EPA Region 1
Cocheco River, Dover, New Hampshire [Howe 2008, University of New Hampshire 2008]
Design of
Amendment Layer
COCs/ Extent of
Contamination
Site Conditions/
Physical Setting
Goal of Amendment
Scale/ Status
Placement Method
Performance
Monitoring
Cost
Comments
Contact
Information
8 mats (2 m x 2 m) with a mixture of 0.23 1 lb/ft2 activated carbon. 0.284 lb/ft2 Organoclav'". and 0.284 lb/ft2 apatite. Mats were constructed of a non- 1
woven geotextile as the bottom layer and a woven 40-mesh geotextile as the top layer.
PAHs (low levels)
Tidal river
Determine how technology performs in the field compared with laboratory results.
Pilot (32 m2)/ Installed (spring 2008)
Mats were unrolled and placed manually with the non-woven geotextile face down in contact with the sediment. Each mat was secured with eight
anodized steel stakes.
Amendment mats will be monitored over a period of 2 years. Monitoring techniques will include peepers, SPME, sediment
sampling, and biological monitoring.
sampling, push point
N/A
Cocheco River was selected for demonstration because of its characteristics and proximity to University of New Hampshire
contaminated. The mats with amendments are being compared with mats containing sand.
, not because it was highly
Lead Investigator: Kevin Gardner, University of New Hampshire, 603-862-4334, kevin. gardnertgiunh. edu
Vendor: James Olsta, CETCO, 847-818-7912, Jim.Olsta@cetco.com
Former industrial site, Silver Lake, Massachusetts [CETCO 2008 and 2009]
Design of
Amendment Layer
COCs/ Extent of
Contamination
Site Conditions/
Physical Setting
Goal of Amendment
Scale/ Status
Placement Method
Reactive core mat with 8 percent Organoclav™ and 92 percent sand (7-mm thick over 13,500 ft2)
PCBs
Lake sediment
Control PCB transport
Pilot (13,500 ft2)/ Installed (2006)
Deployed off the back of a barge. Three rolls on racks were sewn side-to-side, and rebar was attached every 30 feet to stabilize the 45-foot-wide panel.
United States
Environmental Protection Agency
Office of Superfund Remediation and
Technology Innovation
A-3
OSWER Directive 9200.2-128FS
April 2013
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Use of Amendments for In Situ Remediation at Superfund Sediment Sites
1 1
Former industrial site, Silver Lake, Massachusetts [CETCO 2008 and 2009] (Continued)
Performance
Monitoring
Cost
Comments
Contact
Information
N/A
Approximately $2/ft2 for reactive core mat materials
None
Vendor: James Olsta, CETCO, 847-818-7912, Jim.Olsta@cetco.com
Former manufactured gas plant, Everett, Massachusetts [CETCO 2008]
Design of
Amendment Layer
COCs/ Extent of
Contamination
Site Conditions/
Physical Setting
Goal of
Amendment
Scale/ Status
Placement Method
Performance
Monitoring
Cost
Comments
Contact
Information
Reactive core mat with Organoclav™ (7 -mm thick over 33,000 ft2)
NAPL
Bay sediment
Control NAPL seepage
Full (33,000 ft2) /Installed (2008)
Mat attached to bottom of Tensar Marine Mattress, deployed by crane.
Visual inspection for sheen
Approximately $2/ft2 for RCM materials
None
Vendor: James Olsta, CETCO, 847-818-7912, Jim.Olsta@cetco.com
Pine Street Barge Canal Superfund Site, Burlington, Vermont [Arcadis 2010 and 2011; USEPA 2011b]
Design of
Amendment Layer
COCs/ Extent of
Contamination
Site Conditions/
Physical Setting
Reactive core mat with Organoclay (3 layers overall, with up to 6 layers near west bank); underlain by geotextile mat; overlain by turf reinforcement
mat
NAPL
Canal sediment
United States
Environmental Protection Agency
Office of Superfund Remediation and
Technology Innovation
A-4
OSWER Directive 9200.2-128FS
April 2013
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Use of Amendments for In Situ Remediation at Superfund Sediment Sites
Pine Street Barge Canal Superfund Site, Burlington, Vermont [Arcadis 2010 and 2011; USEPA 2011b] (Continued)
Goal of
Amendment
Scale/ Status
Placement Method
Performance
Monitoring
Cost
Comments
Contact
Information
Salem Manufactu
Design of
Amendment Layer
COCs/ Extent of
Contamination
Site Conditions/
Physical Setting
Goal of
Amendment
Scale/ Status
Placement Method
Performance
Monitoring
Cost
Comments
Contact
Information
Control NAPL seepage
Full (27,000 ft2)/ Installed (2011)
Deployed from a barge and the banks of the canal. Secured on the west bank by an anchor trench and on the east bank by epoxy -coated rebar anchors.
Secured in canal by concrete pavers.
Visual inspection and settlement plate monitoring
N/A
Partially replaced a 1.5- to 2-foot-thick sand cap installed in 2003. Supplemented by 10 passive NAPL recovery wells (five on each bank).
EPARPM: Karen Lumino, 617- 918-1348, lumino . karentgiepa. gov
red Gas Plant Salem Massachusetts fCETCO 2008 and 20091
Tensar marine mattresses (for armoring) reactive core mat with Organoclav™ (7 -mm thick over 36,000 ft2) over gravel-filled geoweb
NAPL / Two distinct NAPL types in beach and intertidal sediments
Beach and intertidal sediment
Control NAPL seepage
Full (36,000 ft2) / Installed (2007)
Backhoe from the shore used for deployment.
Monitoring will be conducted, and reactive core mat to be replaced as needed.
Approximately $2/ft2 for reactive core mat materials
None
Vendor: James Olsta, CETCO, 847-818-7912, Jim.Olsta@cetco.com
United States
Environmental Protection Agency
Office of Superfund Remediation and
Technology Innovation
A-5
OSWER Directive 9200.2-128FS
April 2013
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Use of Amendments for In Situ Remediation at Superfund Sediment Sites
EPA Region 2
Berry's Creek, Bergen County, New Jersey
Design of
Amendment Layer
COCs/ Extent of
Contamination
Site Conditions/
Physical Setting
Goal of
Amendment
Scale/ Status
Placement Method
Performance
Monitoring
Cost
Comments
Contact
Information
Activated carbon was placed on the surface of a phragmites marsh using three approaches: 1) granular carbon only, 2) granular carbon with a 2 inch
coarse sand cap, and 3) fine granular carbon in the form of SediMite™. Activated carbon dose was 5 percent by dry weight of sediment in the top 10
cm. SediMite™ application rate was 5 kg/m2
PCBs, Hg and other metals
Tidal marsh covered with phragmites
Determine how technology performs in the field compared with laboratory treatability results.
Pilot scale with 30 feet by 30 feet plots for each treatment and control. Installed in Fall 2012.
Granular activated carbon was placed in a slurry form using a hydroseeder. Coarse sand was delivered to plot using a telebelt and manually layered over
the treatment area. SediMite™ was applied using a Vortex TR Aquatic spreader.
Treatment performance will be monitored over 2 years. Monitoring plan includes 1) assessment of activated carbon levels in sediment core sections to
assess persistence and mixing, 2) measurement of porewater PCBs using passive samplers and porewater Hg/MeHg using seepers, 3) PCB/Hg/MeHg
bioaccumulation in native and field caged invertebrates, and 4) PCB/Hg/MeHg bioaccumulation in intact cores transported to the laboratory.
N/A
N/A
Lead Investigator: Dr. Charles A. Menzie, Exponent, camenzietgiexponent.com
Central Hudson Gas & Electric Corp, North Water Street Manufactured Gas Plant Site, Poughkeepsie, New York [Bessingpas and others
2008, Clock 2009, EPRI 2011]
Design of
Amendment Layer
COCs/ Extent of
Contamination
Site Conditions/
Physical Setting
Goal of
Amendment
Scale/ Status
Three Tensar Triton mattress configurations: (1)6 inches of stone with an Organoclav -filled RCM layer below; (2) 3 inches of stone and 3 inches of
sand wrapped in a geotextile; and (3) 3 inches of stone, 3 inches of sand/Organoclav™ (at a ratio of 5: 1) wrapped in a geotextile with an Organoclav™-
filled reactive core mat layer below. Each configuration comprises 25 mattresses measuring 6.5 feet by 20 feet and covers approximately one-third of the
10,000-ft2 test area.
NAPL, PAHs / Near-surface coal tar NAPL-impacted sediments. Sheens have been observed on the water surface.
Hudson River
Control NAPL migration, primarily as PAH. This project is a performance and implementability study.
Pilot (10,000 ft2) / Installed (May 2009)
United States
Environmental Protection Agency
Office of Superfund Remediation and
Technology Innovation
A-6
OSWER Directive 9200.2-128FS
April 2013
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Use of Amendments for In Situ Remediation at Superfund Sediment Sites
Central Hudson Gas & Electric Corp, North Water Street Manufactured Gas Plant Site, Poughkeepsie, New York [Bessingpas and others
2008, Clock 2009, EPRI 2011] (Continued)
Placement Method
Placed by a crane on barge with assistance from divers. Sonar system also used to minimize gaps between adjacent mat sections. Oil booms were posted
around the work area to control NAPL/sheen migration.
Performance
Monitoring
Turbidity monitoring and sheen observations were conducted during placement. First round of post-construction monitoring was performed in June and
July 2009 and included diver and video inspections, assessment of PAHs and NAPL within the cap, and monitoring of sediment deposition above cap.
Diver inspections reported no NAPL breakthrough, significant (approximately 5 inches) sediment deposition, and some debris accumulation. Video
monitoring was not useful because of turbidity in the river. NAPL was found in two locations but was determined to be likely from adjacent sediments
rather than through the cap. Staining/spotting from organic material was observed in surface sediments.
Cost
N/A
Comments
The mattresses were removed in November 2010 after 18 months in place and analyzed for NAPL and PAH distribution. The Type 1 (6 inches of stone
with an Organoclav™-filled reactive core mat layer below) caps had the highest levels of success.
Contact
Information
Project Manager: Jeff Clock, EPRI, 845-608-0642. jclocktgiepri.com
Vendor: Tensar International Corp., 888-828-5126. www.tensarcorp.com and James Olsta, CETCO, 847-818-7912. Jim.Olsta(@,cetco.com
Grasse River, Massena, New York [Alcoa 2006, 2007 and 2011; Beckingham and Ghosh 2011; Oen and others 2012]
Design of
Amendment Layer
Activated carbon (75 x 300 microns) derived from either bituminous coal or coconut shells over 0.5-acre test area
COCs/ Extent of
Contamination
PCBs
Site Conditions/
Physical Setting
Shallow and wide part of the river, contiguous fine sediment
Goal of
Amendment
Reduce bioavailability of PCBs
Scale/ Status
Pilot (0.5 acre) / Installed (2006)
Placement Method
Different placement methods were used to mix the carbon into the upper layer of sediment. The three application techniques tested included: (1) rototiller
with rotors, (2) rototiller without rotors, and (3) tine sled alone.
Performance
Monitoring
A 2-year post-treatment physiochemical and biological assessment was conducted. A third year may be added based on results. Data collected in 2006
and 2007 showed that activated carbon was applied at or above its target dose of 2.5 percent with the exception of small-scale variability. Where
activated carbon doses equaled native TOC levels, reductions in aqueous equilibrium PCB concentrations approached 100 percent. Water quality
monitoring conducted during placement activities indicated no measurable changes in water column PCB concentrations, which remained below
detection limits (0.065 ug/L) at all locations (upstream, local, and downstream). A slight turbidity increase was noted but concentrations remained below
the action level (25 NTUs above background). In addition, biological monitoring conducted before and one year after activated carbon placement
included ex situ laboratory bioaccumulation studies and in situ cage deployment. Those results showed PCB concentrations in benthic worms decreased
by approximately 72 percent to 94 percent.
United States
Environmental Protection Agency
Office of Superfund Remediation and
Technology Innovation
A-7
OSWER Directive 9200.2-128FS
April 2013
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Use of Amendments for In Situ Remediation at Superfund Sediment Sites
Grasse River, Massena, New York [Alcoa 2007, Beckingham and Ghosh 2011, Oen and others 2012] (Continued)
Cost
Comments
Contact
Information
N/A
Fish consumption advisory is in place in the lower Grasse River because of elevated PCB levels.
EPARPM: Young Chang, (212) 637-4253, chang. youngtgiepa. gov
Lead Investigator: Larry McShea, ALCOA, (724) 337-5458, Larry.McSheatgialcoa.com
Vendor: Calgon Carbon Corporation, 800-4CARBON, www.calgoncarbon.com
EPA Region 3
Anacostia River Demonstration Project, Washington DC [Arcadis and Hart Crowser 2008, Home 2007, McDonough 2007, Reible and
others 2005]
Design of
Amendment Layer
COCs/ Extent of
Contamination
Site Conditions/
Physical Setting
Goal of
Amendment
Scale/ Status
Placement Method
Performance
Monitoring
Cost
Comments
Contact
Information
Apatite applied in bulk (6 inches) over 8,000 ft2.
Coke breeze (less than 1 inch) contained within reactive core mat over 1 1,840 ft2. RCM was constructed of polyester fabric and covered with 6 inches of
sand.
PAHs, PCBs, coal tarNAPL, metals
Sediment hydrocarbon concentrations ranged from 5,000 to 60,000 mg/kg. PAHs detected at levels up to 82,360 ug/kg to depths of 7 feet.
Tidal river with silty clay to silty, fine sand
Apatite to promote sorption and reaction of metals
Coke breeze to promote sequestration of contaminants
Pilot (19,840 ft2) / Installed (spring 2004)
Apatite was placed using a clamshell bucket of a crane on a barge.
Reactive core mat with coke breeze was submerged, and a diver and barge-mounted crane unrolled the reactive core mat underwater. Each mat was
anchored with a bucketful of sand.
The following monitoring was conducted at Months 1,6, 18, and 30 after placement: bathymetric, sub-bottom profiling, and sediment profile imaging
surveys; surface water quality monitoring and groundwater movement studies; chemical analyses of cap and sediment samples; and biological
monitoring. In 2006, analysis of the cap samples indicated that contaminants of interest (PAHs, PCBs, and metals) had not migrated upward into the cap.
However, some contamination was noted at the sediment surface because of re-deposition of sediments. Cores of the cap material also showed that
placement methods minimized mixing of sediments and cap materials.
Total material costs: Apatite - $3. I/ft2; Coke - $l.l/ft2 ; Sand - $0.45/ft2
None
Lead Investigator: Danny Reible, reibletgjmail.utexas.edu
Vendor: James Olsta, CETCO, 847-818-7912, Jim.Olsta(@,cetco.com
United States
Environmental Protection Agency
Office of Superfund Remediation and
Technology Innovation
A-8
OSWER Directive 9200.2-128FS
April 2013
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Use of Amendments for In Situ Remediation at Superfund Sediment Sites
Bailey Creek, Fort Eustis, Virginia
Design of
Amendment Layer
COCs/ Extent of
Contamination
Site Conditions/
Physical Setting
Goal of
Amendment
Scale/ Status
Placement Method
Performance
Monitoring
Cost
Comments
Contact
Information
Activated carbon was placed on sediment surface in the form of SediMite™. Dose of activated carbon was 5 percent by dry weight of sediment in the
top 10 cm plus a 25 percent safety factor. SediMite™ application rate was 3.4 kg/m2. Total treatment area was 225 m2. The treatment area included
part of a marsh and adjacent creek. A similar upstream area was used as a control plot for monitoring.
PCBs
Tidal estuary/shallow wetland. Application performed over water from a boat at high tide.
Determine how technology performs in the field compared with laboratory treatability results.
Pilot scale (225 m2). Installed in Summer 2009.
SediMite™ was applied using a Vortex TR Aquatic spreader mounted on a shallow-draft boat.
Post application monitoring conducted 2 months and 15 months after application. Monitoring included: 1) assessment of activated carbon levels in
sediment core sections to assess persistence and mixing, 2) measurement of porewater PCBs using passive samplers, 3) laboratory biouptake studies to
assess changes in PCB bioavailability in sediments, and 4) benthic community changes in treated and control plots.
N/A
Project was funded by the NIEHS Superfund Research Program. Samples were collected and examined before treatment, two months, and 15 months
after treatment. Activated carbon measurement in sediment cores demonstrated that the applied activated carbon remained in sediment after application
and was found in the top 5 cm of sediment. A greater lateral dispersion of the carbon was observed in the creek compared to the marsh possibly due to
tidal action. Bioaccumulation studies using the benthic organism Leptocheirus plumulosus as well as aqueous concentration measurement using a passive
sampler showed reductions in PCB bioavailability at the treatment sites after deployment. The percent reduction in total PCB bioaccumulation after 2
months of treatment in the field was 90 percent which reduced to 50 percent after 1 5 months. The lower bioaccumulation reduction seen in 1 5 months
compared to 2 month is likely due to the ongoing influence of contaminated sediment movement and deposition within the large contaminated area of
which the treatment plot was a very small fraction. Benthic community sampling after application demonstrated no significant impact of the application
on native biota.
Lead Investigator: Upal Ghosh, University of Maryland Baltimore County, ughosh(@,umbc.edu.
SediMite™ technology being commercialized by startup company Sediment Solutions: www.sedimite.com
Canal Creek, Aberdeen Proving Ground, Maryland
Design of
Amendment Layer
COCs/ Extent of
Contamination
Site Conditions/
Physical Setting
Activated carbon placed in a marsh and a creek in the contaminated site. SediMite™ application rate was 4.5 kg/m2 in the Lower Canal Creek area and
4.3 kg/m2 in the Upper Canal Creek area. (A parallel study performed by AECOM evaluated alternative placement methods of activated carbon)
PCBs and mercury
Tidal estuary/shallow wetland.
United States
Environmental Protection Agency
Office of Superfund Remediation and
Technology Innovation
A-9
OSWER Directive 9200.2-128FS
April 2013
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Use of Amendments for In Situ Remediation at Superfund Sediment Sites
1 1
Canal Creek, Aberdeen Proving Ground, Maryland (Continued)
Goal of
Amendment
Scale/ Status
Placement Method
Performance
Monitoring
Cost
Comments
Contact
Information
Determine how technology performs in the field compared with laboratory treatability results.
Pilot scale, 0.25 acres total area, installed in Winter 2010.
Activated carbon was placed in two areas: 1) in the creek using a spreader mounted on a barge, and 2) in the marsh using a Vortex TR Aquatic
during low tide.
spreader
Treatment performance monitored over 2 years. Monitoring plan included 1) assessment of activated carbon levels in sediment core sections to assess
persistence and mixing, 2) measurement of porewater PCBs using passive samplers and porewater Hg/MeHg using seepers, 3) PCB/Hg/MeHg
bioaccumulation in intact cores transported to the laboratory.
N/A
Project was funded by the DoD ESTCP program. Pilot study work plan was jointly evaluated and approved by EPA Region 3, Army Corps, and
Maryland Department of the Environment. Results of the study will be available in 2013.
Lead Investigator: Charles A. Menzie, Exponent, camenzietgiexponent.com
SediMite™ technology being commercialized by startup company Sediment Solutions: www.sedimite.com
EPA Region 4
Chattanooga Creek, Tennessee Products Superfund Site, OU 1, Chattanooga, Tennessee [USEPA 201 la]
Design of
Amendment Layer
To address NAPL:
1) Placement of a minimum of 12 inches of sub-grade soil over the excavated creek bed and banks to
highest point of observed NAPL and then hydrated.
2) A 6-inch layer of AquaBlok™ 3070 FW (blended 50:50 on a volume basis with AASHTO
layer and hydrated as well.
3) A minimum of 6 inches of clay rich soil was placed over the AquaBlok layer.
To address coal tar-contaminated sediments:
1) 6 inches of AquaBlok™ was placed over the excavated creek bed and then hydrated.
2) 6 inches of native clay material were placed on the AquaBlok™.
XT APT mal tar PAT-Tc PPRc Hinvinc unH fiirunc mptalc npctiHHpc
a level that is a minimum of 3 feet above the
#8 aggregate or equivalent) was placed on top of the soil
COCs/ Extent of
Contamination
NAPL, coal tar, PAHs, PCBs, dioxins and furans, metals, pesticides, VOCs
The capping remedy covers 5,750 linear feet of the creek for a total of 7.1 acres addressed by the sediment cap.
Site Conditions/
Physical Setting
2.5-mile section of the Chattanooga Creek. It is a small, forested creek and is adjacent to industrial, residential, and undeveloped areas.
Goal of
Amendment
To provide a protective barrier to prevent recontamination from sub-surface NAPL.
Scale/ Status
Full (308,878 ft2 cap) / Installed (September 2007)
United States
Environmental Protection Agency
Office of Superfund Remediation and
Technology Innovation
A-10
OSWER Directive 9200.2-128FS
April 2013
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Use of Amendments for In Situ Remediation at Superfund Sediment Sites
Chattanooga Creek, Tennessee Products Superfund Site, OU 1, Chattanooga, Tennessee [USEPA 201 la] (Continued)
Placement Method
Performance
Monitoring
Cost
Comments
Contact
Information
Water flow in the creek was diverted around the contaminated area, contaminated sediments were excavated from the dried creek bed, and the cap was
placed using an excavator and construction personnel raking the cap to achieve a uniform distribution.
SPME monitoring of the cap was conducted in 2009 and 2010, and was scheduled again for 201 1. SPME results in 2009 and 2010 showed very low
(parts per trillion-range) concentrations in cap pore water. Moreover, the concentration of PAHs in the cap materials changed very little between 2009
and 2010. Therefore, EPA has concluded that the cap is effectively isolating residual NAPL. EPA suggested that additional inspections and monitoring
of the cap be included in the RCRA Post-Closure Permit issued by the state. However, the permit had not been finalized at the time of the 5-year review
(September 20 11).
N/A
None
EPA RPM: Craig Zeller, 404-562-8827, zeller.craigtgiepa.gov
EPA Region 5
Former creosoting wood treating site, Escanaba, Michigan [CETCO 2008]
Design of
Amendment Layer
COCs/ Extent of
Contamination
Site Conditions/
Physical Setting
Goal of
Amendment
Scale/ Status
Placement Method
Performance
Monitoring
Cost
Comments
Contact
Information
Reactive core mat with Organoclav'" (7 -mm thick over 6,000 ft2) on beach head and in PRB upgradient of RCM 1
Covered with 6 inches of 0.75 in stone and 2 feet of rip rap
NAPL / Further delineation ongoing
Groundwater contaminated with NAPL threatening nearby fresh water bay, which had a re-occurring sheen.
Control NAPL seepage
Full (6,000 ft2) / Installed (2005)
Backhoe from the shore used for deployment.
Visual inspection for sheen
Approximately $2/ft2 for reactive core mat materials
None
Vendor: James Olsta, CETCO, 847-818-7912, Jim.Olstatgicetco.com
United States
Environmental Protection Agency
Office of Superfund Remediation and
Technology Innovation
A-11
OSWER Directive 9200.2-128FS
April 2013
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Use of Amendments for In Situ Remediation at Superfund Sediment Sites
St. Louis River/Interlake/Duluth Tar Superfund Site (Stryker Bay), Duluth, Minnesota [Arcadis and Hart Crowser 2008, CETCO 2008,
Olsta and Hornaday 2007]
Design of
Amendment Layer
COCs/ Extent of
Contamination
Site Conditions/
Physical Setting
Goal of
Amendment
Scale/ Status
Placement Method
Performance
Monitoring
Cost
Comments
Contact
Information
Reactive core mat with 60 percent activated carbon and 40 percent sand was constructed of polypropylene seotextiles at a loading of 0.4 lb/ft2. Mat
thickness was typically 1 1 mm.
1 1 acres: 6 in of sand, 1 1-mm thick reactive core mat (60 percent activated carbon and 40 percent sand), 36 in of sand, and 6.5 to 8 ft temporary
surcharge.
PAHs (including naphthalene) and metals
1 1-acre area contaminated with naphthalene (greater than 1,000 mg/kg).
135,000 cubic yards contaminated with NAPL.
3 5 -acre shallow water embay ment (3 to 5 feet depth)
Reactive core mat was added to help adsorb contamination from the consolidation water. Dredging was not an option for areas with naphthalene greater
than 1,000 mg/kg because it would result in failure to achieve ambient air quality standards at the site.
Full (11 acres) /Installed (2006)
Mats were unrolled and floated to allow panels to be attached and then sunk as they absorbed water (see Olsta and Hornaday 2007 for additional details).
Reactive core mat placed with temporary surcharge of sand, which was placed by either backhoe bucket (near shore) or from a barge (off shore).
Coring and settlement monitoring. Compliance monitoring every 5 years.
Approximately $2/ft2 for reactive core mat materials
Pre-remediation migration pathway: NAPL migration via gas ebullition, groundwater advection, and pore water migration caused by consolidation.
Sheet pile was installed along the area to be capped.
EPARPM: James Hahnenberg, 312- 353-4213 hahnenberg.j ames(@,epa. gov
Vendor: James Olsta, CETCO, 847-818-7912, Jim.Olsta(@,cetco.com
EPA Region 6
Cottonwood Bay, Grand Prairie, Texas [SAIC 2008a, 2008b, 2009]
Design of
Amendment Layer
COCs/ Extent of
Contamination
Site Conditions/
Physical Setting
Mats consisted of AOS 80 (8 oz/yd3) polypropylene non-woven geotextile, a woven backing geotextile and a mixed amendment core made up of 0.23
lb/ft2 crushed apatite. 0.28 lb/ft2 coconut shell activated carbon and 0.28 lb/ft2 Organoclay™. Each individual "mat" consisted of two 25-foot x 15-foot
panels to be placed with a 5-foot overlap for an overall footprint of 25 feet x 25 feet.
PCBs, PAHs, some metals
N/A
United States
Environmental Protection Agency
Office of Superfund Remediation and
Technology Innovation
A-12
OSWER Directive 9200.2-128FS
April 2013
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Use of Amendments for In Situ Remediation at Superfund Sediment Sites
Cottonwood Bay, Grand Prairie, Texas [SAIC 2008a, 2008b, 2009] (Continued)
Goal of
Amendment
Scale/ Status
Placement Method
Performance
Monitoring
Cost
Comments
Contact
Information
Study compares four designs with an undisturbed, uncapped area:
(1) single layer geotextile
(2) double layer geotextile
(3) single layer geotextile with sand cover
(4) sand cover only
Pilot / Installed (spring 2008)
Mats were transported using jet skis and placed by commercial divers. The mats were unrolled at the surface and pinned to the sediment using 36-inch
screw anchors. Within minutes, air escaped from the mats, and they rested flat on the sediment surface.
Monitoring is being conducted to assess contaminant adsorption and flux properties by passive sampling and groundwater seepage surveys. Passive
samplers (SPMD, SPME fibers, and peepers) were placed at each of the test areas in October 2008 and retrieved in December 2008. Peeper data
(concentrations of nickel and zinc) suggest effective sequestration of metals, and results indicate the single-layer mat with sand and the double-layer mat
are most successful. SPMD data show sequestration of PAHs was 5 to 6 times greater in the single-layer mat with sand and the double-layer mat than the
single mat with no sand. SPME data were inconclusive, as all concentrations were below detection levels. Bathymetric, sub-bottom, side-scan sonar, and
sediment profiling imaging surveys were also conducted.
N/A
This demonstration is a continuation of a smaller-scale study at the site conducted in 2007 where mats were smaller (6 feet x 6 feet) than the 25 feet x 25
feet mats in this field demonstration. Modeling was conducted to determine whether sediment deformation caused by the weight of the mat and capping
materials compromises groundwater flow and reactivity of the amendments.
Lead Investigator: Amy Hawkins, Navy, 805-982-4890, amy. Hawkins (@,naw. mil
Vendor: James Olsta, CETCO, 847-818-7912, Jim.Olsta(@,cetco.com
EPA Region 9
"dut^*™ Ca"for"ia |Ch° 2°11' ESTCP 20C"' °e" a"d °"iers 2°H a"d 2°12'
Design of
Amendment Layer
COCs/ Extent of
Contamination
Site Conditions/
Physical Setting
3.4 percent by weight activated carbon (virgin) mixed to a depth of 1 foot at two test plots (370 ft2 each). 1,250 pounds of activated carbon applied pe
plot.
Four plots (370 ft2 each) are included in the demonstration:
( 1 ) activated carbon mixed with a rotovator
(2) mixed with the rotovator (no activated carbon)
(3) activated carbon mixed with injection slurry
(4) control plot (no activated carbon and no mixing)
a-
PCB concentrations ranged from approximately 1 to 2 mg/kg in the test area.
The tests plots are located in a tidal mudflat. The top 4 inches of sediment consist of small gravel, shells, and clay particles with a homogeneous clay
layer underneath. The top foot of sediment has a bulk density of 1.3 to 1.4 g/cm3.
United States
Environmental Protection Agency
Office of Superfund Remediation and
Technology Innovation
A-13
OSWER Directive 9200.2-128FS
April 2013
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Use of Amendments for In Situ Remediation at Superfund Sediment Sites
Hunters Point Shipyard Superfund Site, Parcel F, San Francisco, California [Cho 2011, ESTCP 2009, Oen and others 2011 and 2012,
Stanford University 2005, Tomaszewski and Luthy 2008] (Continued)
Goal of
Amendment
Scale/ Status
Placement Method
Performance
Monitoring
Cost
Comments
Contact
Information
Stabilize PCBs and reduce bioavailability
Pilot (1,480 ft2) / Installed (2006)
Activated carbon was mixed into the sediment using two available large-scale equipment technologies (slurry injector and rotovator).
Baseline samples were collected before activated carbon was applied. Sediment core and overlying water samples were collected at 6 and 18 months
post-treatment, and biological monitoring was conducted at 6, 18, and 24 months post-treatment. Results showed (1) 60 percent reductions in the freely
dissolved pore water concentrations of PCBs relative to the reference site after 18 months, (2) 80 percent reductions in the freely dissolved pore water
concentrations after 30 months, and (3) reductions in bioaccumulation without impairing the natural benthic community or releasing PCBs into the
overlying water. After 5 years, total PCB uptake in passive samplers was reduced by 73 percent, with greater reductions in the bioavailability of the less
chlorinated congeners relative to the more chlorinated congeners.
Total cost for the demonstration is approximately $1 million. Breakdown of costs is available in Table 5-1 of Stanford University 2005.
None
Lead Investigator: Ryan Ahlersmeyer, Southwest Division Naval Facilities Engineering Command, 619-532-0960, ryan. ahlersmevertginaw. mil
EPA Region 10
Gasco, Portland, Oregon [Anchor 2006, 2009a, and 2012; CETCO 2008]
Design of
Amendment Layer
COCs/ Extent of
Contamination
Site Conditions/
Physical Setting
Goal of
Amendment
Scale/ Status
Placement Method
Performance
Monitoring
Cost
Reactive core mat with Organoclav™ (7 -mm thick over 3,000 ft2) installed over 6 inches of sand to protect from underlying rip-rap; covered with 6
inches of sand plus 2 feet of quarry spalls
NAPL
River shore intertidal sediment
Control NAPL seepage
Pilot (3,000 ft2) / Installed (2005)
Barge and crane
Visual inspections have been conducted monthly (approximately) since late 2005. Results show that the mat has remained in place and controlled the
release of potential sheen from the underlying sediment, although some portions have become exposed.
Approximately $2/ft2 for RCM materials
United States
Environmental Protection Agency
Office of Superfund Remediation and
Technology Innovation
A-14
OSWER Directive 9200.2-128FS
April 2013
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Use of Amendments for In Situ Remediation at Superfund Sediment Sites
1 1
Gasco, Portland, Oregon [Anchor 2006, 2009a, and 2012; CETCO 2008] (Continued)
Comments
Contact
Information
None
EPA RPM: Eric Blischke, 503-326-4006, Blischke.Erictgiepa.gov
Vendor: James Olsta, CETCO, 847-818-7912
McCormick & Baxter Creosoting Co. (Portland Plant) Superfund Site, Portland, Oregon [Arcadis and Hart Crowser 2008, CETCO 2008,
Ecology & Environment 2008, GSI and Hart Crowser 2008, Hart Crowser and GSI 2009 and 2011]
Design of
Amendment Layer
COCs/ Extent of
Contamination
Site Conditions/
Physical Setting
Goal of
Amendment
Scale/ Status
Placement Method
Performance
Monitoring
Cost
Comments
Contact
Information
Organoclav reactive core mat installed along beach head and bulk Organoclav media deployed over NAPL hot spots. 600 tons of bulk Organoclav
(20,000 ft2 total) added to three areas of sand cap: sand (1 foot), Organoclav™ (1 foot), gravel (4 inches), rock armor (10 inches). Three 7-mm thick
Orsanoclav™ mats over 25,000 ft2.
PAHs, creosote, NAPL / PAHs detected up to 35 feet below sediment surface, NAPL in upper 7 feet of sediment.
Willamette River with poorly graded fine to medium grained, clean to slightly silty sand
Organoclav'" applied in bulk to control NAPL seeps and in mats to control gas migration.
Specific cleanup goals are listed in the 2007 operations and maintenance report (Ecology & Environment 2008).
Full (bulk: 20,000 ft2; mats: 25,000 ft2) / Installed (bulk in 2004 and mats in 2005)
Bulk Organoclav™ deployed by backhoe on shore and reactive core mat deployed by barge and crane.
Diver inspection, along with collection of Organoclay '" cores, samples from the mat, and water quality samples were conducted in October 2006. Results
indicated that Organoclay™ had an available sorption capacity similar to freshly placed Organoclay™, no significant changes were measured in
permeability, and minimal evidence of NAPL (less than 1 cm thick) was noted at the sediment-Organoclay™ interface. Observations noted the migration
of gas bubbles, but the bubbles contained no NAPL. Evidence suggested that Organoclay™ is absorbing NAPL prior to gas bubbles breaking the surface
of the cap.
Cap pore water concentrations were also measured. In 2005, total carcinogenic PAH concentrations was 0.2 ug/L. In 2010, PAH concentrations in the
pore water were all below the NRWQC, with the exception of chrysene at one location. Sheen, surface water, and pore water samples, as well as
sediment cores, were collected in 2007 and 2008.
Sheen samples did not differ significantly from nearby surface water samples, and pore water and sediment core concentrations showed no evidence of
NAPL entering or penetrating the sediment cap. Results confirm that Organoclay continues to have sufficient sorption capacity and permeability.
Additional information about the monitoring of this cap is available at www.mandbsuDerfund.com.
Approximately $2/ft2 for reactive core mat materials
Pre-remediation migration pathway: Methane-mediated NAPL migration observed. Before capping, a sheet pile wall was installed to minimize the flow
of NAPL to the river.
State RPM: Scott Manzano, ODEQ, 503-229-6748, manzano . scotttgideq. state . or. us
EPA RPM: Nancy Harney, 206-553-6635, harnev.nancv(@,epamail.epa. gov
Vendor: James Olsta, CETCO, 847-818-7912, Jim.Olsta(@,cetco.com
United States
Environmental Protection Agency
Office of Superfund Remediation and
Technology Innovation
A-15
OSWER Directive 9200.2-128FS
April 2013
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Use of Amendments for In Situ Remediation at Superfund Sediment Sites
Spokane River Upriver Dam PCB Site (Deposit 1), Spokane, Washington [Anchor 2007 and 2009b, Washington State Department of
Ecology 2005]
Design of
Amendment Layer
COCs/ Extent of
Contamination
Site Conditions/
Physical Setting
Goal of
Amendment
Scale/ Status
Placement Method
Performance
Monitoring
Cost
Comments
Contact
Information
3.5 acres of coal (4 inches minimum), sand (6 inches), gravel (3 inches) applied in bulk. Modeling predicted that a 1-inch-thick cover would ensure PCB
pore water concentrations remain below cleanup goals at 10 cm below mudline for 500 years (below 1 picogram per liter). Washington Department of
Ecology required a minimum 4-inch-thick cap, based on a safety factor of 4.
PCBs up to 1,430 ug/kg dry weight.
Fine-grained (silty sand) sediments, low energy area behind a dam
Control and minimize benthic exposure to contaminated sediments, reduce potential remobilization of sediments by hydraulic or other processes, and
reduce the potential transport of PCBs into overlying water column and groundwater.
Full (3.5 acres) / Installed (fall 2006)
Based on results from a placement demonstration, a long reach excavator released amendments above the water surface and allowed them to settle
through the water column.
Water quality monitoring was conducted during placement, and no turbidity or dissolved oxygen impacts were observed. Piston core sampling and
bathymetric surveys verified that the minimum thickness of the coal layer was achieved (average was 6.3 inches).
First round of post-construction monitoring was conducted in fall 2008 and included bathymetric surveys, collection of sediment cores and surficial
sediment samples, and visual observations. Results showed consolidation and sediment deposition had occurred in some areas, and the cap and its layers
were intact in all locations. Total PCBs were not detected in the sand isolation layer or coal layer, indicating the cap is functioning as designed.
Unscheduled monitoring will be conducted after the occurrence of a 50-year or higher flood event in the Spokane River.
$1,578,000 (estimate in draft Cleanup Action Plan [Washington State Department of Ecology 2005] for entire remedy at Deposit 1)
Sediment cleanup level is 62 ug/kg (dry weight) for PCBs.
State RPM: Brendan Dowling, WA Dept. of Ecology, 509-329-3611, bdow46 1 (giecv. wa. gov
Vendor: Palmer Coking Coal Company, 425-432-4700, www.Dalmercc.com
Notes:
Underlined text indicates amendment types to allow for easier identification.
AASHTO - American Association of State Highway lb/ft2 - pound per square foot
and Transportation Officials m - meter
AOS - apparent opening size nig/kg - milligram per kilogram
COCs - contaminants of concern mm - millimeter
cm - centimeter MeHg -Methylmercury
ft - foot N/A - Not available
ft2 - square foot NAPL - non-aqueuse phase liquid
g/cm3 - gram per cubic centimeter NTU - Nephelometric Turbidity Units
in - inch oz/yd3 - ounce per square yard
PAH - polycyclic aromatic hydrocarbon
PCB - polychlorinated biphenyl
PRB - permeable reactive barrier
RCM™ - Reactive Core Mat™
SPMD - Semi-permeable membrane device
SPME - Solid phase microextraction
TOC - Total organic carbon
ug/kg - microgram per kilogram
u.g/L - microgram per liter
United States
Environmental Protection Agency
Office of Superfund Remediation and
Technology Innovation
A-16
OSWER Directive 9200.2-128FS
April 2013
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Appendix References:
Alcoa Inc. 2006. In-Situ PCB Bioavailability Reduction in Grasse River Sediments. Final Work Plan. August. wwwthegrasseriver.com/pdf/ACPS_FinalWorkPlan_080906.pdf
ALCOA Inc. 2007. Grasse River Activated Carbon Pilot Study. Construction Documentation Report. November.
Alcoa. 2011. The Grasse River Project, website: www.thegrasseriver.com. Accessed 17 August 2011.
Achor Environmental L.L.C. 2006. Draft Removal Action Completion Report. NW Natural "Gasco" Site. January.
Anchor QEA (formerly Anchor Environmental, LLC). 2007. Cleanup Action Completion Report, Upriver Dam PCBs Sediment Site. April.
Anchor QEA. 2009a. Annual Data Evaluation Monitoring Report, Year 2 Long-Term Pilot Cap Monitoring, Removal Action NW Natural "Gasco" Site. July.
www.epa.gov/regionlO/pdf/ph/gasco/v2_eval_mon_rpt_0709.pdf
Anchor QEA. 2009b. Memorandum to Brendan Dowling, Washington State Department of Ecology. Year 2 Upriver Dam Cap Monitoring Results, Project 080306-01. April 16.
Anchor QEA. 2012. Draft Engineering Evaluation/Cost Estimate for the Gasco Sediments Cleanup Site. May.
www.epa.gov/regionlO/pdf/ph/gasco/anchor_OEA_gasco_sediments_engineering_evaluation_cost_analvsis_mav_2012.pdf
ARCADIS. 2010. Design Report, Pine Street Canal Superfund Site, Burlington, Vermont. Submitted to Green Mountain Power. Project 69852. August 6. Superfund Document
Management System (SDMS) document number 470808.
ARCADIS. 2011. Amended Cap Operation, Maintenance, and Monitoring Plan, Pine Street Canal Superfund Site, Burlington, Vermont. Submitted to Green Mountain Power.
Project 69852. November 14. SDMS document number 501378.
ARCADIS and Hart Crowser, Inc. 2008. Final NAPL Controls Report, Pine Street Canal Superfund Site, Burlington, Vermont. Appendix A: Review of Engineering Capping at
NAPL-Impacted Sediment Sites. Submitted to Green Mountain Power. Project 69852. June 20.
Beckingham, B and U. Ghosh. 2011. Field-scale reduction of PCB bioavailability with activated carbon amendment to river sediments. Environmental Science & Technology.
Volume 45, Number 24. Pages 10567 to 74. December 15.
Bessingpas, D., N. Gensky, A. Coleman, D. Reible, and J. Clock. 2008. Reactive Sediment Capping Pilot Study. Poster presented at Remediation of Chlorinated and Recalcitrant
Compounds: The Sixth International Conference. Monterey, California. May 19 to 22.
CETCO Remediation Technologies. 2008. E-Mail Regarding Project Information. From Jim Olsta, PhD. To Danielle Wohler, Tetra Tech EM Inc. October 7.
CETCO Remediation Technologies. 2009. E-Mail Regarding Project Information. From Jim Olsta, PhD. To Danielle Wohler, Tetra Tech EM Inc. February 12.
Cho, Y.M., D. Werner, Y. Choi and R.G. Luthy. 2011. Long-term monitoring and modeling of the mass transfer of poly chlorinated biphenyls in sediment following pilot-scale in-
situ amendment with activated carbon. J. Contam. Hydrol. doi:10.1016/j.jconhyd.2011.09.009
United States Office of Superfund Remediation and OSWER Directive 9200.2-128FS
Environmental Protection Agency Technology Innovation April 2013
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Clock, J. 2009. Hudson River Reactive Sediment Capping Demonstration Project. Sediment Management Work Group. Fall Meeting. September 30 through October 1.
Ecology and Environment, Inc. 2008. Operation and Maintenance Report (January 2007 through December 2007), McCormick and Baxter Creosoting Company Site. Prepared for
Oregon Department of Environmental Quality. May. www.mandbsuperfund.com
Electric Power Research Institute (EPRI). 2011. "Reactive Cap Shows Potential to Remediate Coal Tar." EPRI Journal. Summer. Page 32.
http://mvdocs.epri.com/docs/CorporateDocuments/EPRI_ Journal/2011-Summer/l 023458_InTheField.pdf
Environmental Security Technology Certification Program (ESTCP). 2009. Field Testing of Activated Carbon Mixing and In Situ Stabilization of PCBs in Sediment. Final Report.
ESTCP Project ER-0510. May. www.estcp.org/Technology/upload/ER-0510-FR.pdf
GSI Water Solutions, Inc. and Hart Crowser. 2008. Ebullition and Sheen Investigation Work Plan for McCormick & Baxter Superfund Site. Prepared for Oregon Department of
Environmental Quality. August, www.mandbsuperfund.com
Hart Crowser and GSI Water Solutions, Inc. 2009. Operations and Maintenance Report, January 2008 through December 2008, McCormick & Baxter Creosoting Company,
Portland, Oregon. Prepared for Oregon Department of Environmental Quality. May. www.mandbsuperfund.com
Hart Crowser and GSI Water Solutions, Inc. 2011. Operations and Maintenance Report, January 2010 through December 2010, McCormick & Baxter Creosoting Company,
Portland, Oregon. Prepared for Oregon Department of Environmental Quality. June, www.mandbsuperfund.com
Home Engineering Services, LLC. 2007. Final Month 30 Monitoring Report, Comparative Validation of Innovative "Active Capping" Technologies. Anacostia River,
Washington, DC. September.
Howe, J.G. 2008. River bed mats filter, cap pollution: Dredging alternative is less expensive, disruptive. Foster's Daily Democrat. June 23.
www.fosters.com/apps/pbcs.dll/article?AID=/20080623/GJNEWS_01/855093481
McDonough, K.M., P. Murphy, J. Olsta, Z. Yuewei, D. Reible, and G. V. Lowry. 2007. Development and Placement of a Sorbent-amended Thin Layer Sediment Cap in the
Anacostia River. Soil and Sediment Contamination, an International Journal. May 1. Pages 313 through 322. www.informaworld.com/smpp/300091052-
99120016/content~db=all~content=a7765 3 3 574
Oen, A.M.P, E.M.L. Janssen, G. Comelissen, G.D. Breedveld, E. Eek, and R.G. Luthy. 2011. In Situ Measurement of PCB Pore Water Concentration Profiles in Activated Carbon-
Amended Sediment Using Passive Samplers. Environmental Science & Technology. Volume 45. Pages 4053-4059.
Oen, A.M.P, B. Beckingham, U. Ghosh, M.E. Krusa, R.G. Luthy, T. Hartnik, T. Henriksen, and G. Comelissen. 2012. Sorption of Organic Compounds to Fresh and Field-Aged
Activated Carbons in Soils and Sediments. Environmental Science & Technology. Volume 46. Pages 810-817.
Olsta, J.T. and C. Homaday. 2007. Installation of an In-Situ Cap at a Superfund Site. Proceedings of the Fourth International Conference on Remediation of Contaminated
Sediments. Savannah, Georgia. January.
http://remediation.cetco.eom/DesktopModules/B ring2mind/DMX/Download.aspx?EntrvId=496&Command=Core_Download&PortalId=9&TabId=1381
United States Office of Superfund Remediation and OSWER Directive 9200.2-128FS
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Reible, D.D., W.D. Constant, and Y. Zhu. 2005. Monitoring of the Active Capping Demonstration Project in the Anacostia River, Washington, DC, USA. June.
www.caee.utexas.edu/reiblegroup/reible-materials/SETAC2006final.pdf
Science Applications International Corporation (SAIC). 2008a. SERDP Project ER-1493 Quarterly Progress Report (01 April - 31 June 2008). July 14.
SAIC. 2008b. SERDP Project ER-1493 Quarterly Progress Report (01 October - 31 December 2007). January 9.
SAIC. 2009. SERDP Project ER-1493 Quarterly Progress Report (01 January - 31 March 2009). April 16.
Stanford University. 2005. ESTCP Demonstration Plan for Field Testing of Activated Carbon Mixing and In Situ Stabilization of PCBs in Sediment at Hunters Point Shipyard,
Parcel F, San Francisco, California. December 5. www.stanford.edu/group/luthvgroup/download/ESTCP%20Demonstration%20Plan.pdf
Tomaszewski, J.E. and R.G. Luthy. 2008. Field Deployment of Polyethylene Devices to Measure PCB Concentrations in Pore Water of Contaminated Sediment. Environmental
Science & Technology. Volume 42. Pages 6086-6091.
U.S. Environmental Protection Agency (EPA). 201 la. First Five-Year Review Report for Tennessee Products Superfund Site. September 27.
U.S. EPA. 201 Ib. Second Five-Year Review Report for Pine Street Barge Canal Superfund Site, Burlington, Chittenden County, Vermont. December 22. SDMS document number
501469.
University of New Hampshire. 2008. CICEET Progress Report for the Period 3/1/08 through 9/1/08.
Washington State Department of Ecology. 2005. Spokane River Upriver Dam PCB Site. Draft Cleanup Action Plan. March.
United States Office of Superfund Remediation and OSWER Directive 9200.2-128FS
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