Sediments

Valence state: The combining capacity of an atom or radical determined by the number of electrons that it will lose, add, or share when it reacts with other atoms.

Source: The American Heritage™ Dictionary of the English Language, Fourth Edition
Copyright © 2000 by Houghton Mifflin Company.

free product: A NAPL found in the subsurface in sufficient quantity that it can be partially recovered by pumping or gravity drain.

aerobic: Direct aerobic metabolism involves microbial reactions that require oxygen to go forward. The bacteria uses a carbon substrate as the electron donor and oxygen as the electron acceptor. Degradation of contaminants that are susceptible to aerobic degradation but not anaerobic often ceases in the vicinity of the source zone because of oxygen depletion. This can sometimes be reversed by adding oxygen in the form of air (air sparging, bioventing), ozone, or slow oxygen release compound (e.g., ORC(r)).

Aerobic dechlorination may also occur via cometabolism where the dechlorination is incidental to the metabolic activities of the organisms. In this case, contaminants are degraded by microbial enzymes that are metabolizing other organic substrates. Cometabolic dechlorination does not appear to produce energy for the organism. At pilot- or full-scale treatment, cometabolic and direct dechlorination may be indistinguishable, and both processes may contribute to contaminant removal. For aerobic cometabolism to occur there must be sufficient oxygen and a suitable substrate which allows the microbe to produce the appropriate enzyme. These conditions may be present naturally but often in the presence of a source area oxygen and a substrate such as methane or propane will need to be introduced.

Adapted from US. EPA 2006 Engineering Issue: In Situ and Ex Situ Biodegradation Technologies for Remediation of Contaminated Sites

anaerobic: Direct anaerobic metabolism involves microbial reactions occurring in the absence of oxygen and encompasses many processes, including fermentation, methanogenesis, reductive dechlorination, sulfate-reducing activities, and denitrification. Depending on the contaminant of concern, a subset of these activities may be cultivated. In anaerobic metabolism, nitrate, sulfate, carbon dioxide, oxidized metals, or organic compounds may replace oxygen as the electron acceptor.

Anaerobic dechlorination also may occur via cometabolism where the dechlorination is incidental to the metabolic activities of the organisms. In this case, contaminants are degraded by microbial enzymes that are metabolizing other organic substrates. Cometabolic dechlorination does not appear to produce energy for the organism. At pilot- or full-scale treatment, cometabolic and direct dechlorination may be indistinguishable, and both processes may contribute to contaminant removal.

Quoted from US. EPA 2006 Engineering Issue: In Situ and Ex Situ Biodegradation Technologies for Remediation of Contaminated Sites

architecture: "Architecture" refers to the physical distribution of the contaminant in the subsurface. Residuals that take the form of long thin ganglia or small dispersed globules provide a larger surface area that will dissolve much faster than if the same amount of liquid were concentrated in a competent pool.

Sources: For purposes of this discussion, a DNAPL source zone includes the zone that encompasses the entire subsurface volume in which DNAPL is present either at residual saturation or as "pools" of accumulation above confining units. In addition, the DNAPL source zone includes regions that have come into contact with DNAPL that may be storing contaminant mass as a result of diffusion of DNAPL into the soil or rock matrix.

source zone: For purposes of this discussion, a DNAPL source zone includes the zone that encompasses the entire subsurface volume in which DNAPL is present either at residual saturation or as "pools" of accumulation above confining units. In addition, the DNAPL source zone includes regions that have come into contact with DNAPL that may be storing contaminant mass as a result of diffusion of DNAPL into the soil or rock matrix.

focal ulceration: The process or fact of a localized area being eroded away.

metaplasia of the glandular stomach: A change of cells to a form that does not normally occur in the tissue in which it is found.

hyperplasia of the glandular stomach: A condition in which there is an increase in the number of normal cells in a tissue or organ.

histiocytic: Degenerative.

duodenum: First part of the small intestine.

microcytic: Any abnormally small cell.

squamous cell papillomas: A small solid benign tumor with a clear-cut border that projects above the surrounding tissue.

squamous cell carcinomas: Cancer that begins in squamous cells-thin, flat cells that look under the microscope like fish scales. Squamous cells are found in the tissue that forms the surface of the skin, the lining of hollow organs of the body, and the passages of the respiratory and digestive tracts. Squamous cell carcinomas may arise in any of these tissues.

jejunum: The middle portion of the small intestine, between duodenum and ileum. It represents about 2/5 of the remaining portion of the small intestine below duodenum.

ileum: The distal and narrowest portion of the small intestine.

squamous: Flat cells that look like fish scales.

metaplasia: A condition in which there is a change of one adult cell type to another similar adult cell type.

ossification: The process of creating bone, that is of transforming cartilage (or fibrous tissue) into bone.

clastogenesis: Any process resulting in the breakage of chromosomes.

neoplastic: Abnormal and uncontrolled growth of cells.

ulceration: The process or fact of being eroded away.

leucocytosis: An elevation of the total number of white cells in blood.

neutrophils: A type of white blood cell.

chromodulin: A small protein that binds four trivalent chromium ions.

biomagnification: The increased accumulation and concentration of a contaminant at higher levels of the food chain; organisms higher on the food chain will have larger amounts of contaminants than those lower on the food chain, because the contaminants are not eliminated or broken down into other chemicals within the organisms.

exencephaly: Cerebral tissue herniation through a congenital or acquired defect in the skull.

everted viscera: Rotated body organs in the chest cavity.

To Be Considered: Documents, such as federal or state guidances, that are not legally binding but may be relevant to the topic in question.

gaining: A gaining surface water body is one where groundwater flows into it.

losing: A surface water body is losing when there is a permeable sediment bed that is not in contact with the groundwater allowing the surface water to seep through it.

fluvial: Of or pertaining to flow in rivers and streams.

lacustrine: Of or pertaining to a lake as in lacustrine sediments—sediments at the bottom of a lake.

lipid: Any class of fats that are insoluble in water.

lipophilic: Able to dissolve in lipids—in this case fatty tissue.

organelles: A part of a cell such as mitochondrion, vacuole, or chloroplast that plays a specific role in how the cell functions and membranes.

RfD: The RfD is an estimate of a daily exposure of the human population (including sensitive sub-groups) to a substance that is likely to be without "the appreciable risk of deleterious effects during a lifetime." An RfD is expressed in units of mg/kg-day.

autonomic: That part of the nervous system that controls non-conscious actions such as heart rate, perspiration and digestion.

ataxia: Lack of muscle coordination.

funnel-and-gate configuration: A system where low-permeability walls (the funnel) placed in the saturated zone direct contaminated ground-water toward a permeable treatment zone (the gate)

References: ATSDR (Agency for Toxic Substances and Disease Registry). 2015. Draft Toxicological Profile for Perfluoroalkyls. 574 pp.

EFSA (European Food Safety Authority). 2008. Opinion of the scientific panel on contaminants in the food chain on perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) and their salts. EFSA Journal 653:1-131.

Hekster, F.M., R.W.P.M. Laane, and P. de Voogt. 2003. Environmental and toxicity effects of perfluoroalkylated substances. Reviews of Environmental Contamination and Toxicology 179:99-121.

Higgins, C. and R. Luthy. 2006. Sorption of perfluorinated surfactants on sediments. Environmental Science & Technology 40(23):7251-7256.

HSDB (Hazardous Substances Data Bank). 2012 Update. Perfluorooctanoic acid.

Kaiser, M.A., B.S. Larsen, C-P.C. Kao, and R.C. Buck. 2005. Vapor pressures of perfluorooctanoic, -nonanoic, -decanoic, -undecanoic, and -dodecanoic acids. Journal of Chemical and Engineering Data 50(6):1841-1843.

Kauck, E.A. and A.R. Diesslin. 1951. Some properties of perfluorocarboxylic acids. Industrial and Engineering Chemical Research 43(10):2332-2334.

Lewis, R.J., Sr., ed. 2004. Sax's Dangerous Properties of Industrial Materials. 11th ed. Wiley-Interscience, Hoboken, NJ. V3:2860.

Lide, D.R. 2007. CRC Handbook of Chemistry and Physics. 88th ed. CRC Press, Boca Raton, FL. 3-412.

SRC (Syracuse Research Corporation). 2016. PHYSPROP Database. SRC Scientific Databases, Accessed May 2016.

UNEP (United Nations Environmental Program). 2015. Proposal to List Pentadecafluorooctanoic Acid (CAS No: 335-67-1, PFOA, Perfluorooctanoic Acid), Its Salts and PFOA-Related Compounds in Annexes A, B and/or C to the Stockholm Convention on Persistent Organic Pollutants. UNEP/POPS/POPRC.11/5.

USEPA (U.S. Environmental Protection Agency). 2016. Drinking Water Health Advisory for Perfluorooctanoic Acid (PFOA).#pdfsmall# Office of Water, EPA 822-R-16-005, 103 pp

• Overview
• Policy and Guidance
• Conceptual Site Models
• Fate and Transport of Contaminants
• Site Characterization
• Risk Assessment
• Remediation
  • Capping
  • Dredging
  • Excavation
  • Innovative
  • Institutional Controls
  • Monitored Natural Recovery
• Additional Resources

---

• Issue Areas Home
• Suggest Resource

Capping

Capping involves covering contaminated sediment, which remains in place, with clean material. Caps are generally constructed of clean sediment, sand, or gravel. A more complex cap can include geotextiles, liners, and other permeable or impermeable materials in multiple layers. Caps may also include additions of organic carbon or other in situ amendments to slow the movement of contaminants through the cap.

More recent innovative caps have organoclay or carbon encapsulated in geotextile mats. This configuration is generally delivered in rolls. It is placed on the contaminated sediments and covered with sand or other conventional cap material to provide suitable habitat and substrate.

Depending on the contaminants and the environment, a cap may reduce risk in the following ways:

• By physically isolating the contaminated sediment from the overlying water
• By stabilizing the contaminated sediment and protecting it from erosion and transport to other areas
• By chemically isolating the contaminants or reducing their movement into the water body (e.g. a reactive cap or one that prevents upwelling groundwater from flowing through the contaminated sediment).

Representative Capping Designs

• Conventional capping which places sand or other natural materials directly over the contaminated sediment area. The cap has to be at least as thick as the large populations of burrowing benthic organisms to keep them from becoming contaminated. Also, current velocity, availability of capping materials, and the type of contamination present determine cap thickness and the materials used. Typically, sand caps are used in low velocity waterways to protect them from scouring by strong (high energy) currents.
• Armored capping places an additional layer of stone or rip rap over a conventional cap to provide additional protection from high velocity currents.
• Composite capping places several layers of sand, rock, and geomembrane/ textile over the contaminated sediment to further isolate it. Geomembranes can be employed when there is a concern that advection by upward groundwater gradients or diffusion will carry contamination up into the clean cap area. Geomembranes are, however, problematic if anaerobic gas is generated from the underlying sediment.

General Site Conditions That are Appropriate for In-Situ Capping

• Suitable types and quantities of cap material are readily available
• Anticipated infrastructure needs (e.g., piers, pilings, buried cables) are compatible with the cap
• Water depth is adequate to accommodate the cap with anticipated uses (e.g., navigation, flood control)
• Incidence of cap-disrupting human behavior, such as large boat anchoring, is low or controllable
• Weight of the cap can be supported by the underlying sediment without slope failure
• Expected human exposure is substantial and not well-controlled by institutional controls
• Long-term risk reduction outweighs habitat disruption, and/or habitat improvements are provided by the cap
• Hydrodynamic conditions (e.g., floods, ice scour) are not likely to compromise the cap or can be accommodated in the cap design
• Rates of groundwater flow in the cap area are low and not likely to create unacceptable contaminant releases
• Sediment has sufficient strength to support the cap (e.g., has high density/low water content)
• Risk is moderate to high
• Contaminants have low rates of flux through the cap
• Contamination covers contiguous area

Placing Caps

When installing a granular cap, the major consideration is the accurate placement, density, and rate of application of the capping material. In general, the capping material should be placed so that it accumulates in a layer covering the contaminated material. Equipment and placement rates that cause the capping material to displace or mix with the contaminated sediment should be avoided.
View full description of cap placement

Text adapted directly from USEPA. 2004. Presenter's Manual for: Remediation of Contaminated Sediments. Office of Solid Waste and Emergency Response, 58 pp.

Active sediment capping for pollutant mixtures: control of biogenic gas production under highly intermittent flows
Viana, Priscilla, Ke Yin, Xiuhong Zhao and Karl Rockne
Land Contamination & Reclamation, 15 (4), 13 pp, 2007

Adsorption and Simultaneous Dechlorination of PCBs on GAC/Fe/Pd: Mechanistic Aspects and Reactive Capping Barrier Concept
Hyeok Choi, Shirish Agarwal and Souhail R. Al-Abed
Environ. Sci. Technol., 2009, 43 (2), pp 488-493

Declaration for the Explanation of Significant Differences: Pine Street Canal Superfund Site, Burlington, Vermont
U.S. EPA Region 1, 31 pp, 2009

At this MGP site, EPA completed construction of a cap over the canal's contaminated sediments in 2004, but the 2006 5-year review found that portions of the cap were leaking oil and coal tar. Where contaminant seepage is occurring, this ESD provides that the existing cap will be redesigned and reconfigured to intercept and sequester the NAPL, likely following the "Alternative 2" design in the June 2008 Final NAPL Controls Report. Alternative 2 would modify the existing cap with the addition of two new layers. The first would comprise a high-permeability, lightweight material (e.g., pumice) in which slotted pipes would be laid to facilitate NAPL capture and removal. This layer would be covered with a reactive core mat in which an absorbent material (e.g., organoclay) binds with the contaminant and prevents its release. See Also: Final NAPL Controls Report, Pine Street Canal Superfund Site, Burlington, Vermont

Design Consideration Involving Active Sediment Caps
Barth, E. and D. Reible.
1st International Conference In Hazardous Waste Management, Chania-Crete, Greece, October 01 - 03, 2008.

Effects of Bentonite Clay on Sediment Erosion Rates
U.S. Army Corps of Engineers, ERDC TN-DOER-N9, 25 pp, 2001

Equipment and Placement Techniques for Subaqueous Capping
U.S. Army Corps of Engineers, ERDC TN-DOER-R9, 23 pp, 2005

The Evaluation of Sorbent Containing Geotextiles for the Remediation of PAH and NAPL Contaminated Sediment
Trejo, Gabriel, Master's thesis, University of Texas at Austin, 149 pp, 2009

Two active capping methods were evaluated and compared for their effectiveness, capacity, and lifespan in the presence of dissolved- and separate-phase contaminants (naphthalene, phenanthrene, and pyrene). The two active capping materials evaluated were Aqua Technology's ET-1 Organoclay, which was deployed in bulk at the McCormick & Baxter Creosoting Company Superfund Site in Portland, OR, and a powdered activated-carbon impregnated geotextile produced by Huesker, Inc. In 2008, sampling was performed at the McCormick & Baxter site to determine the continued effectiveness of bulk sand and 1-ft-thick organoclay sediment caps as well as that of laminated mats containing ~1 cm of organoclay (CETCO PM-200) from the pilot-test section of the Tank Farm Area in the Willamette River. Despite their significantly greater specific sorption capacity, the geotextiles could not offer the same protection for an extended period of time as the bulk organoclay. Over 60 stacked layers of the evaluated geotextiles would be needed to achieve the same capacity for dissolved-phase contaminants as the 1-ft organoclay cap; however, it should be noted that no significant penetration of NAPL into the bulk organoclay has been observed, which suggests that even the thin layer within a geotextile might be sufficient to inhibit upward seepage of contaminants, despite its significantly lower overall capacity.

Guidance for In Situ Subaqueous Capping of Contaminated Sediments
Palermo, M., S. Maynord, J. Miller, and D. Reible
USEPA, Great Lakes National Program Office, EPA 905-B96-004, 1998

This document provides descriptions of the processes involved with in-situ capping, identification of the design requirements of an in-situ capping project, and a recommended sequence for design. Detailed guidance is provided on site and sediment characterization, cap design, equipment and placement techniques, and monitoring and management considerations.

In-Situ Capping of Contaminated Sediments
Jersak, J., G. Goeransson, Y. Ohlsson, L. Larsson, P. Flyhammar, and P. Lindh.
Swedish Geotechnical Institute, Linkoeping. 7 separate files (30-1E - 30-7E), 2016

This publication was developed to serve as a basis for the design and assessment of remediation alternatives to dredging by providing a technology overview of various capping-based techniques and describing their possibilities and limitations. The guide consists of a main text plus several supporting but stand-alone appendices: a preliminary review of contaminated sediments in Sweden; a general overview of established ex situ and in situ sediment remediation technologies; a preliminary overview of remedial sediment capping projects worldwide; a short discussion on anticipated challenges with capping Sweden's fiberbank sediments; an extensive bibliography of international technical references; and an overall summary.

In Situ Sediment Remediation Through Capping: Status and Research Needs
Reible, D.D.
Invited Paper/Presentation for SERDP Workshop on Research Needs in Contaminated Sediments, 20 pp, 2004

Measuring Contaminant Resuspension Resulting from Sediment Capping
EPA 600-S-08-013, 8 pp, 2008

Studies to evaluate solids resuspension before, during, and after the capping of contaminated sediments were conducted at 2 marine sites: the Boston Harbor/Mystic River site and the Wyckoff/Eagle Harbor Superfund site off Bainbridge Island, WA. The study results indicate that resuspension during capping can be reduced by placing cap material in lifts (in which the first lift provides a uniform layer of clean material) using techniques that minimize potential disturbance.

Operation and Maintenance Report (January 2007 through December 2007), McCormick and Baxter Creosoting Company Site
Ecology and Environment, Inc. 2008.

Organoclay Laboratory Study McCormick and Baxter Creosoting Company Portland, Oregon
Reible, D
Oregon State Department of Environmental Quality, 39 pp, 2005

Provides the results of laboratory studies on the ability of two commercially available organoclays potential to contain a creosote DNAPL plume surfacing in the Willamette River.

Predicting the Performance of Activated Carbon-, Coke-, and Soil-Amended Thin Layer Sediment Caps
Murphy, P. et al
Journal of Environmental Engineering, pp 787-794. 2006

SAMMS® Technical Summary
Pacific Northwest National Laboratory, 12 pp, 2009.

Discusses SAMMS—Self-Assembled Monolayers on Mesoporous Supports which are created by attaching a monolayer of molecules to mesoporous ceramic supports. They are used to bind metals in solution.

Subaqueous Cap Design: Selection of Bioturbation Profiles, Depths, and Process Rates
U.S. Army Corps of Engineers, ERDC TN-DOER-C21, 14 pp, 2001

Subaqueous Capping and Natural Recovery: Understanding the Hydrogeologic Setting at Contaminated Sediment Sites
U.S. Army Corps of Engineers, ERDC TN-DOER-C26, 16 pp, 2002

Case Studies

Anacostia River Innovative Capping Demonstration Project
Materials demonstrated in this project include AquaBlok™, zero valent iron, apatite barrier, BioSoil™, and organoclay sorbent caps.

• Anacostia Active Capping Demonstration Status
  Reible, D. 31 slides, NATO CCMS-Ljubljana, Slovenia , June 19, 2007
• Active Capping Demonstration in the Anacostia River, Washington, D.C. (Abstract)
  Reible, D., D. Lampert, D. Constant, R.D. Mutch Jr., and Y. Zhu.
  Remediation Journal 17(1):39-53(2006)
• Development and Placement of a Sorbent-amended Thin Layer Sediment Cap in the Anacostia River
  McDonough, Kathleen M., Paul Murphy, Jim Olsta, Yuewei Zhu, Danny Reible, and Gregory V. Lowry
  International Journal of Soil and Sediment Contamination, 24 pp, 2006
• Demonstration of the Aquablok® Sediment Capping Technology: Innovative Technology Evaluation Report
  EPA 540-R-07-008, 145 pp, 2007

Demonstration and Validation of Enhanced Monitored Natural Recovery at DoD Sites
Kirtay, V., G. Rosen, M. Colvin, J. Guerrero, C. Katz, B. Chadwick, K. Fetters, V. Magar, et al.
ESTCP Project ER-201368, 2079 pp, 2017

The performance of enhanced monitored natural recovery (EMNR) was evaluated under field conditions at Site 99, Quantico Marine Corps Base, Virginia, on sediments containing DDX (i.e., the sum of the pesticide DDT and it derivatives DDD and DDE). A thin-layer cap (TLC, commonly <30 cm, also referred to as a "habitat enhancement cap") of clean sand was emplaced to enhance natural recovery and reduce contaminant bioavailability to benthic organisms. This demonstration was designed to evaluate the performance and effectiveness of the EMNR remedy and the utility of available monitoring tools to address EMNR performance, short-term TLC implementation success, and projection of long-term remedy success as well as to gain understanding of the mechanisms and processes that regulate EMNR effectiveness. Additional resources: 2018 ESTCP Cost and Performance Report

Ebullition and Sheen Investigation Work Plan for McCormick & Baxter Superfund Site
GSI Water Solutions, Inc. and Hart Crowser, 2008.

Field Experiment on Thin-Layer Capping in Ormefjorden and Eidangerfjorden, Telemark: Functional Response and Bioavailability of Dioxins, 2009-2011
Schaanning, M.T. and I. Allan.
Norwegian Institute for Water Research, REPORT SNO 6285-2012, 92 pp, 2012

A large-scale field study of in situ thin-layer capping was carried out at four sites in the dioxins-contaminated Grenlandfjord, Norway, to test and compare the effectiveness of active caps (2.5 cm thickness) consisting of powdered activated carbon (AC) mixed into clean clay, and nonactive caps (5 cm thickness) of clay without AC and of crushed limestone. Fields with areas of 10,000 to 40,000 sq m were established at 30 to 100 m water depth. With clay and AC treatments, bioaccumulation and leakage of dioxins was 67-91% lower than at the uncapped reference fields. At the two fields treated with limestone gravel and dredged clay without activated carbon, cap efficiencies declined to less than 46% over a 2-year period. The use of AC decreased both the bioavailability of dioxins present below the cap and the bioaccumulation and leakage of dioxins entering the cap after placement.

Evaluation of Contaminant Resuspension Potential During Cap Placement at Two Dissimilar Sites
Lyons, T. et al.
Journal of Environmental Engineering. pp 505-514. 2006

Innovative In-Situ Remediation of Contaminated Sediments for Simultaneous Control of Contamination and Erosion
Knox, A. et al.
SERDP Project ER-1501, 303 pp (pt.1) & 68 pp (pt.2), 2011

Project ER-1501 investigated how to develop/select active capping materials and cap designs for contaminant sequestration under a range of aquatic sediment conditions in the lab, and then assessed the ability of multiple-amendment active caps (MAACs) to immobilize a variety of organic and inorganic contaminants and resist erosion in field pilot plots at the Savannah River Site. The field MAACs consisted of in situ placement of phosphate materials, organoclays, and biopolymer products. The project also tested diffusion gradients in thin-films (DGT) for evaluating active caps in the field. A numerical model was developed to evaluate the long-term effectiveness of various amendments and to help estimate the amendment thickness needed to delay contaminant breakthrough for a given period of time. Phosphate, zeolite, bentonite, and organoclays individually or mixed with other active or neutral materials were shown to stabilize metals and nonpolar pollutants (e.g., PAHs). Addition of a small amount of bentonite (~10%) to MAACs can improve erosion resistance and metal sequestration capacity. Part I; Part II

Innovative Systems for Dredging, Dewatering, or for In-situ Capping of Contaminated Sediments
Olsta, J.T. and J. Darlington
Third International Conference on Remediation of Contaminated Sediments, New Orleans, Louisiana; Jan 24�27, 2005

In Situ Remediation of Contaminated Sediments: Active Capping Technology
Knox, A.S., J. Roberts, M.H. Paller, and D.D. Reible.
15th International Conference on Heavy Metals in the Environment, 4 pp, 2010

A 12-month field demonstration of a selected set of active capping treatment technologies was conducted at the Savannah River Site to address sediments containing As, Cd, Cr, Mo, Pb, and Zn. Pilot-scale active caps were installed in Steel Creek, comprising 8 plots with 4 treatments: 2 controls consisting of uncapped sediments; 2 caps composed of apatite and sand; 2 caps composed of a layer of biopolymer/sand slurry over a layer of apatite and sand; and 2 caps composed of a top layer of biopolymer/sand slurry, a middle layer of apatite and sand, and a bottom layer of organoclay and sand. 2012 Update

Installation of an In-Situ Cap at a Superfund Site
Olsta, J.T. and C. Hornaday
Proceedings of the Fourth International Conference on Remediation of Contaminated Sediments Savannah, Georgia, 2007

A Reactive Cap for Contaminated Sediments at the Navy's Dodge Pond Site
Gavaskar, A. et al.
Technology Innovation News Survey.

Use of Amendments for In Situ Remediation at Superfund Sediment Sites
U.S. EPA, Office of Superfund Remediation and Technology Innovation.
OSWER Directive 9200.2-128FS, 61 pp, 2013

This document introduces the most promising amendments for in situ remediation of sediments and summarizes information from three case studies of sites where activated carbon, organoclay, phosphates, bauxite, and/or ZVI have been employed for sediments contaminated with PCBs or PAHs.

Top of Page