Contaminated Sediment Research

Multi-Year Implementation Plan 2005

Office of Research and Development 

National Health and Environmental Effects Research Laboratory

U.S. Environmental Protection Agency

Research Triangle Park, NC 27711

EPA/600/R-05/033

May 2005
ii Contaminated Sediment Research Multi-Year Implementation Plan

Notice

The United States Environmental Protection Agency through its Office of Research and 

Development produced this multi-year implementation plan. It has been subjected to the 

Agency’s peer and administrative review and has been approved for publication as an EPA 

document. Mention of trade names or commercial products does not constitute endorsement or 

recommendation for use.
iii Contaminated Sediment Research Multi-Year Implementation Plan

Foreword

The National Health and Environmental Effects Research Laboratory (NHEERL), as part of the 

Environmental Protection Agency’s (EPA’s) Office of Research and Development (ORD), serves 

as EPA’s focal point for scientific research on the effects of contaminants and environmental 

stressors for both human health and ecosystem integrity. NHEERL’s research helps the Agency 

identify and understand the processes that affect our health and environment, thereby aiding in 

evaluation of the risks that pollution poses to humans and ecosystems. The research is intended 

to address key Agency problems in a timely and responsive manner. In this context, NHEERL 

develops research implementation plans to achieve the following objectives:

 • Optimizing responsiveness of research activities to Agency needs,

 • Sharpening the focus of research programs where needed,

 • Providing a forum for engagement of scientific staff on issues and approaches,

 • Focusing on multi-year planning explicitly linked to Agency performance goals, and

 • Providing a mechanism for prioritizing research.

NHEERL’s approach builds on the ORD planning process which identifies and prioritizes 

research needs. ORD’s research portfolio includes both core and problem-driven program areas. 

Currently, ORD has problem-driven research programs for air, water, waste, and pesticides 

and toxic substance, each of which addresses key problems faced by the respective regulatory 

program.

This implementation plan identifies the scientific problems and research that will be conducted 

by NHEERL concerning contaminated sediments, a key problem area for EPA’s waste regulatory 

program, specifically the Superfund office (Office of Superfund Remediation and Technology 

Innovation, or OSRTI). The goal of NHEERL’s research in this area is to help ORD address one 

of several long-term research goals in the waste program by improving the scientific foundation 

for selecting options to remedy contaminated sediments.

This document was developed by representatives from NHEERL research divisions, with 

significant engagement and peer review from OSRTI and other ORD laboratories and centers. 

In addition, the document has been reviewed by scientists external to the Agency. This 

implementation plan is intended to reflect research that will be conducted over the next several 

years. As progress is made in achieving the goals outlined in this document, it will be updated to 

address new and remaining challenges.

 

Lawrence W. Reiter, Ph.D.

Director National Health and Environmental Effects 

Research Laboratory
iv Contaminated Sediment Research Multi-Year Implementation Plan

NHEERL’s Contaminated Sediment Steering Committee

Barbara Bergen, Ph.D. ORD, NHEERL, AED

Robert Burgess, Ph.D. ORD, NHEERL, AED

Marilyn ten Brink, Ph.D. ORD, NHEERL, AED

Wayne Munns, Ph.D. ORD, NHEERL, AED

Robert Dyer, Ph.D. ORD, NHEERL, RPCS

Linda Birnbaum, Ph.D. ORD, NHEERL, ETD

Prasada Kodavanti, Ph.D. ORD, NHEERL, NTD

Dave Mount, Ph.D. ORD, NHEERL, MED

Lawrence Burkhard, Ph.D. ORD, NHEERL, MED

Philip Cook, Ph.D. ORD, NHEERL, MED

 

Dennis Timberlake, M.S. ORD, NRMRL, LRPCD

Dermont Bouchard, Ph.D. ORD, NERL

Keith Sappington, M.S. ORD, NCEA, Washington, DC

Steve Ells, M.S. OSWER, OSRTI

Peer Reviewers of NHEERL’s Contaminated Sediment 

Multi-Year Implementation Plan

Todd S. Bridges, Ph.D. 

US Army Engineer Research and Development Center, Army Corps of Engineers-Waterways 

Experiment Station (ACE-WES), EP-R, Vicksburg, MS 39180

Allison Hiltner, M.S. 

US-EPA Region 10, 1200 Sixth Avenue, Seattle, WA 98101

Kevin Farley, Ph.D.

Manhattan College, Environmental Engineering Department, Manhattan College Parkway, 

Riverdale, NY 10470

Ray Valente, M.S.

SeaRay Environmental, 902 Riverview Place, St. Marys, GA 31558
v Contaminated Sediment Research Multi-Year Implementation Plan

Table of Contents

Notice .......................................................................................................................................... ii

Foreword .................................................................................................................................... iii

NHEERL’s Contaminated Sediment Steering Committee ......................................................... iv

Peer Reviewers of NHEERL’s Contaminated Sediment Multi-Year Implementation Plan ...... iv

Executive Summary ................................................................................................................... vi

Acronyms .................................................................................................................................. vii

Introduction ..................................................................................................................................1

Purpose and Scope ...............................................................................................................1

Process for Developing this Implementation Plan ...............................................................1

Coordination Across ORD ...................................................................................................5

Research Questions for Projects I, II, III, and IV ........................................................................7

Project I : Integrative Assessment of Benthic Effects from Remedial Activities 

at Superfund Sites .........................................................................................8

Project II: Linking Residues to Effects in Aquatic and Aquatic-Dependent 

Wildlife .......................................................................................................17

Project III: Linking Chemical Concentrations in Water and Sediment with 

Residues in Aquatic and Aquatic-Dependent Wildlife ...............................24

Project IV: Research to Evaluate the Release and Bioavailability of Contaminants 

Associated with Resuspended Sediments and Post-Dredging 

Residuals at Superfund Sites ......................................................................40

Project Descriptions for Guidance Documents and for Research Dropped from Further 

Consideration in the Planning Process

Project V: Preparation of Equilibrium Partitioning Sediment Benchmark 

Documents for the Assessment of Contaminated Sediments 

at Superfund Sites .......................................................................................53

Project VI: Preparation of Whole Sediment and Interstitial Water Freshwater 

and Marine Toxicity Identification Evaluations (TIEs) Guidance 

Document for Use at Superfund Sites ........................................................55

Project VII: Development of Appropriate Remedial Goals for 

Non-Bioaccumulative Contaminants in Sediment .....................................56

Program Summary and Management .........................................................................................60

Appendices

Appendix A: Superfund Program Research Priorities .................................................. A-1

Appendix B: Expanded Descriptions of Ten Issues Resulting from 

May 2003 AED Meeting ..........................................................................B-1

Appendix C: Description of Science Tasks and Level of Effort for Eight 

Research Issues ........................................................................................C-1

Appendix D: Candidates for NHEERL Research in Contaminated Sediments ............ D-1

Appendix E: Commitments and Endorsements .............................................................E-1
vi Contaminated Sediment Research Multi-Year Implementation Plan

Executive Summary

This document describes the implementation plan for contaminated sediments research within 

the National Health and Environmental Effects Research Laboratory (NHEERL) for fiscal years 

2004 - 2008. Contaminated sediments research in the Office of Research and Development 

(ORD) of the Environmental Protection Agency (EPA) is based on needs identified by EPA’s 

Office of Superfund Remediation and Technology Innovation (OSRTI). 

ORD has developed a multi-year research plan (MYP) to address OSRTI’s needs for research. 

One of the long-term goals of the Contaminated Sites MYP is focused on contaminated 

sediments, and the NHEERL Implementation Plan provides the detailed approach that NHEERL 

will take to address mission-related scientific uncertainties identified in the MYP. This plan 

was developed in the context of the expected resource base for the program: an intramural 

research effort with about 8 full-time research FTEs (full-time equivalents) and associated 

research support resources. The Introduction provides a brief discussion of the process by which 

NHEERL developed this plan. 

The NHEERL contaminated sediments research program described in herein contains four 

projects: (1) assessing impact of remedial activities on benthic communities (benthic recovery 

project); (2) linking residues to effects in aquatic and aquatic-dependent wildlife (residues to 

effects project); (3) linking chemical concentrations in water and sediment with residues in 

aquatic and aquatic-dependent wildlife (water and sediment concentrations to residues project); 

and (4) evaluating the impact of resuspension events on contaminant release and bioavailability 

(resuspension project). This document describes each of these projects and includes a summary 

of the issue, state of the science, and research needs for each project. It also describes the 

projected activities, resource requirements, critical path, and key products.

To the extent feasible, projects in this implementation plan blend empirical and modeling 

approaches to resolve the key issues. The project on benthic effects is designed to evaluate the 

relative utility of two different approaches to assessing the recovery/reestablishment of benthic 

communities after remediation. The project addressing residues-to-effects linkages is a shortterm effort to assemble and evaluate existing polychlorinated biphenyl (PCB) residue-effects 

data for aquatic species. The project addressing water-concentrations-to-residues linkages is 

intended to produce a useful approach to extrapolating bioaccumulation data across ecosystems, 

species, and time for selected bioaccumulative toxicants. The resuspension project focuses on 

developing an empirical method and establishing linkages between empirical data and existing 

fate and transport models in order to better predict risks resulting from dredging activities.

The projects were developed with recognition that a key measure of success is the effectiveness 

with which critical information developed by NHEERL is transferred to the research client, 

i.e., to OSRTI and Superfund regional scientists and remedial project managers. Consequently, 

while the projects generally identify documents as the target products of the program, frequent 

communication between NHEERL and OSRTI will ensure timely and optimal transfer of new 

information.
vii Contaminated Sediment Research Multi-Year Implementation Plan

Acronyms

ACE Army Corps of Engineers 

AED Atlantic Ecology Division 

AhR aryl hydrocarbon receptor

APG annual performance goal 

AVS acid volatile sulfide

BAF bioaccumulation factor

BHQ benthic habitat quality 

B-IBI benthic index of biotic integrity

BSAF biota-sediment accumulation factor

CDA Coeur d’Alene River 

CFR Clark Fork River

DAMOS Disposal Area Monitoring System

DEA dermal exposure assessment 

DMU dredge management unit 

DNAPL dense, non-aqueous phase liquid 

DO dissolved oxygen 

EPA Environmental Protection Agency 

ERAF Environmental Risk Assessment Forum

ERDC Engineer Research and Development Center

ERED Environmental Residue-Effects Database

ESB equilibrium partitioning sediment benchmark 

EcoSSL ecological-soil screening level 

ETD Experimental Toxicology Division

FS feasibility study

FTE full-time equivalent 

HELP Hydrogeologic Evaluation of Landfill Performance

HSRC Hazardous Substances Research Center

LOAEL lowest-observed adverse effect level

LRPCD Land Remediation and Pollution Control Division 

LTG long-term goal

LUST CA Leaking Underground Storage Tank Corrective Action

MED Mid-Continent Ecology Division

MNA monitored natural attenuation 

MNR monitored natural recovery

MYIP multi-year implementation plan

MYP multi-year plan 

NBH New Bedford Harbor

NCEA National Center for Environmental Assessment

NERL National Exposure Research Laboratory

NHEERL National Health and Environmental Effects Research Laboratory 

NOAEL no-observed adverse effect level

NRMRL National Risk Management Research Laboratory
viii Contaminated Sediment Research Multi-Year Implementation Plan

NTD Neurotoxicology Division

ORD Office of Research and Development 

OSI organism-sediment index

OSP Office of Science Policy 

OSRTI Office of Superfund Remediation and Technology Innovation

OSWER Office of Solid Waste and Emergency Response

PAH polycyclic aromatic hydrocarbon 

PBT persistent bioaccumulative toxicant

PCB polychlorinated biphenyl 

PE polyethylene 

PES particle entrainment simulator 

PRB permeable reactive barrier

RAGS risk assessment guidance for Superfund 

RCRA Resource Conservation and Recovery Act 

RCT research coordination team

RI Remedial Investigation

RPCS research planning and coordination staff

RPD redox potential discontinuity 

SF Superfund

SPME solid-phase microextraction 

SPI sediment profile image 

SPMD semipermeable membrane device

SQG sediment quality guideline 

tbd to be determined

TEF toxicity equivalence factor

TEQ toxicity equivalents

TIE toxicity identification evaluation 

TRV toxicity reference value

USGS United States Geological Survey

WES Waterways Experiment Station

WOE weight of evidence 
1 Contaminated Sediment Research Multi-Year Implementation Plan

Introduction

Purpose and Scope

This document, the NHEERL Implementation Plan for Contaminated Sediments Research, 

describes the research that the National Health and Environmental Effects Research Laboratory 

(NHEERL) intends to perform in support of the Office of Research and Development’s 

(ORD’s) multi-year research plan (MYP) 

for contaminated sites research. ORD 

uses multi-year planning to chart the 

direction of ORD’s research programs 

in selected topic areas for time periods 

extending up to ten years. Within EPA’s 

Goal 3, Preserve and Restore the Land, 

two ORD multi-year plans (MYPs) have 

been developed: Contaminated Sites and 

Resource Conservation and Recovery Act 

(RCRA). The Contaminated Sites MYP

describes ORD’s research supporting three 

Office of Solid Waste and Emergency 

Response (OSWER) trust fund programs 

for which research is authorized: Superfund 

(SF), Leaking Underground Storage Tank 

Corrective Action (LUST CA), and the 

Oil Spills Program. The ORD Contaminated Sites MYP has four long-term goal (LTG) areas: 

Contaminated Sediments, Ground Water, Soil/Land, and Multimedia. 

To guide the implementation of strategic directions identified in the ORD MYPs, NHEERL 

develops multi-year implementation plans (MYIPs) for its major research programs. These plans 

are intended to ensure that NHEERL research addresses the key mission-related scientific issues 

that are raised in ORD MYPs in a way that maximizes benefit to the programmatic client, fully 

utilizes NHEERL capability, and integrates effectively with related ORD research programs. 

The scope of the NHEERL Contaminated Sites research program is limited to the Contaminated 

Sediments LTG in the ORD Contaminated Sites MYP. Consequently, this MYIP describes the 

NHEERL research program to support ORD’s Contaminated Sediments LTG. The full text of 

the ORD Contaminated Sediments LTG is provided in the text box.

The annual performance goals (APGs) and associated annual performance measures (APMs) for 

this MYIP are those listed under the Contaminated Sediments LTG. This MYIP will provide the 

background and project descriptions for NHEERL’s research program to achieve these APMs and 

APGs. 

Process for Developing this Implementation Plan

Prior to FY2001, NHEERL did not have a contaminated sediment research program supporting 

Superfund. In FY2000, a small number of ORD FTEs (7.8) were reassigned to establish a 

NHEERL research program on contaminated sediments to support Superfund.

ORD Contaminated Sediments 

Long-Term Goal

By 2010, improve the range and scientific 

foundation for contaminated sediment 

remedy selection options by improving 

risk characterization, site characterization 

and increasing understanding of different 

remedial options, in order to optimize the 

protectiveness to the environment and 

human health and the cost-effectiveness of 

remedial decisions.
2 Contaminated Sediment Research Multi-Year Implementation Plan

In the spring of 2003, an NHEERL contaminated sediment steering committee was created with 

the purpose of developing a focused NHEERL contaminated sediments research program, i.e., 

a program that was optimized in terms of responsiveness to client needs for ecological effects 

research related to contaminated sediments Superfund sites. The Steering Committee aims are as 

follows.

1. Establish a framework for NHEERL’s Superfund contaminated sediments research 

program that sets a context and goals for the research consistent with (a) the Contaminated 

Sediments LTG 1 in the ORD Contaminated Sites MYP; (b) the ORD contaminated 

sediments focus groups (an across ORD sediment planning group organized by EPA’s 

Office of Science Policy (OSP)); (c) the level of NHEERL effort available; and (d) the 

Laboratory’s capabilities.

2. Identify critical paths necessary to achieve the goals set in the framework.

3. Articulate an MYIP that follows the critical paths to achieve the goals.

4. Monitor and review program accomplishments for purposes of communicating progress 

and revising plans when necessary.

5. Stimulate synergy between investigators and between divisions where appropriate.

6. Engage clients and collaborators to ensure responsiveness and linkages.

7. Suggest appropriate revisions to the ORD Contaminated Sites MYP when appropriate.

In May 2003, NHEERL’s Steering Committee met at NHEERL’s Atlantic Ecology Division 

(AED) in Narragansett, Rhode Island, with Mike Cook, director of the Superfund program 

(Office of Superfund Remediation and Technology Innovation (OSRTI)); Steve Ells, the OSRTI 

sediment team leader; and Leah Evison, the OSRTI member of the Waste RCT in order to 

start the development of NHEERL’s Contaminated Sediment MYIP. At this meeting, a list of 

Superfund research priorities for ORD in seven research categories (ground water, sediment, soil/

waste, multimedia and analytical, human health, and ecological research needs) was presented; 

and discussion of the research needs for the sediment category was initiated. The categorization 

of sediment research needs contained twenty-eight issues (Figure 1) grouped into three areas: (1) 

site characterization issues, (2) ecological and human health risk issues, and (3) development and 

evaluation of remedies. A complete listing of the entire Superfund program research priorities is 

provided in Appendix A. 

The discussions at the May 2003 meeting of the NHEERL Steering Committee resulted in a 

narrowing of the 28 sediment issues to 10 issues (Figure 1). Although no formal criteria were 

developed by the Steering Committee for eliminating a research issue, the decisions were 

based on the appropriateness of the research issue to the mission and capabilities of NHEERL. 

NHEERL’s research mission is centered on the effects of environmental pollutants and other 

anthropogenic stressors upon human and ecosystem health. Thus, research issues external to 

NHEERL’s mission such as fate and transport of chemical contaminants, sediment stability and 

erosion, design and engineering of remediation options, ground water-sediment interactions, 

and analytical methods were eliminated. For research issues within NHEERL’s mission, the 
3 Contaminated Sediment Research Multi-Year Implementation Plan

narrowing process considered whether the issue required new research or could be answered 

with available data. The narrowing process eliminated several research issues because they 

could be answered with available data, and tentative plans were made for the development 

of fact sheets for Superfund on these issues. For each of the remaining ten NHEERL-related 

contaminated sediment issues, expanded descriptions were developed (Appendix B). These 

descriptions were then reviewed by the steering committee members with particular attention to 

the accuracy in reflecting the OSRTI need, relation to NHEERL mission, clarity of the text, and 

division management support for these topics as focal points for the next 5-6 years of research. 

In addition, the committee considered whether additional issues should be added. 

Subsequently, in evaluating the expanded descriptions, the Steering Committee removed two of 

the ten remaining issues as possible focus areas (those related to dredging residuals and cleanup 

levels) because the issues were outside of NHEERL’s mission. For the remaining eight issues, 

descriptions of the science tasks and the level of effort and/or time required to complete the 

research effort were prepared (see Appendix C and Figure 1).

The task descriptions of the science proposed for NHEERL research were then evaluated by the 

Steering Committee (Figure 1). Three issues were identified as highest priority from among 

the eight candidates for NHEERL research, while two issues were identified as high priority 

candidates (Appendix D). 

The highest priority NHEERL research candidate issues were

• Residue-effect relationships: linking chemical residues in aquatic biota to levels of 

ecological risk to aquatic and aquatic-dependent wildlife;

• Non-Bioaccumulatives: development of appropriate remedial goals for nonbioaccumulative chemicals; and

• Resuspension: assessing the toxic and bioaccumulative effects of contaminated sediment 

resuspension.

The high priority NHEERL research candidate issues were

• Predicting rates of recovery following remedial action: short-term impacts and

• Monitoring methods and protocols.

The lower priority NHEERL research issues were

• Predicting rates of recovery following remedial actions: long-term impacts;

• Developing sediment contaminant screening levels;

• Delineation of appropriate uses of total PCBs, and Aroclor-based and congener-specific 

PCB concentrations as the basis for assessing and managing risks from PCBs; and

• Establishing guidance on sampling biota and surface sediments at Superfund sites. 
4 Contaminated Sediment Research Multi-Year Implementation Plan

Note that in the deliberation of the Steering Committee, the research on the issue of predicting 

rates of recovery was sub-divided into two sub-issues: short-term impacts and long-term 

impacts.

In November 2003, the Steering Committee had detailed discussions (meeting in Duluth, 

Minnesota) on the highest priority research candidate issues and on the high priority issue of 

predicting rates of recovery following remedial action: short-term impacts. At the meeting, 

a previously assigned lead person presented (1) a summary of the issue; (2) a proposed list of 

research targets (products if we successfully accomplished our goals); (3) a list of precursors to 

achievement of the target; (4) a gap analysis for the issue based upon the state of the science; 

and (5) a statement of research question(s) addressing the issue along with milestones and steps. 

The Steering Committee discussed each item, building towards a consensus on the approach (or 

approaches) required to meet the research needs of the proposed issues/projects successfully. 

These discussions also covered the products and their timing for each issue. 

Based upon the results from this meeting, project descriptions were prepared for the four highest 

priority sediment research issues (Figure 1) (also see “Research Project Descriptions” section). 

These projects are the following:

I. Integrative assessment of benthic effects from remedial activities at Superfund sites;

II. Linking residues to effects in aquatic and aquatic-dependent wildlife;

III. Linking chemical concentrations in water and sediment with residues in aquatic and 

aquatic-dependent wildlife; and

IV. Research to evaluate the release and bioavailability of contaminants associated with 

resuspended sediments and post-dredging residuals at Superfund sites.

Figure 1: NHEERL Contaminated Sediments Program

28 Superfund

Contaminated

Sediment Issues

• Research?

• Mission?

• Expertise?

Expanded descriptions prepared,

discussed, prioritized

Filtered to 8

issues

Prioritized to 4

issues

Defined 4 projects, Identified

key science questions,

research / products

proposed

Steering Committee Prioritization Process

• Research?

• Mission?

• Expertise?

• Internal review

• Revisions

• External review

• Revisions

Final review

process

Implementation Plan

Filtered to 10

issues

May-03

May-03

Aug-03

Sept- &

Oct-03

Nov-03

May-July-04

Aug-Nov-04

Dec-04

Science tasks and level of effort

descriptions prepared

Science tasks and level of effort

descriptions evaluated
5 Contaminated Sediment Research Multi-Year Implementation Plan

For each research issue, the project description summarizes the issue, the state of the science, 

and the research needs. In addition, a list of the research targets and a description of the actual 

research steps and tasks required to complete the research are included. The project description 

also includes a section on technology transfer that describes how the products and research will 

be provided to OSRTI and identifies the resources (FTE and project-specific extramural dollar 

needs) required to accomplish the research. The resource summary is used to both ensure that 

the Steering Committee does not design a program requiring more resources than are available 

and to identify explicitly what can be done with additional resources. Finally, the project 

descriptions are completed with a critical path diagram, a product timeline, and references.

After the individual project descriptions in this document, a Program Summary and Management 

section is provided. This section summarizes the research program outputs and discusses how 

the research program will be managed within NHEERL.

In addition to the research projects, this MYIP includes two additional projects (Projects V and 

VI) describing the preparation of technical documents. Project V describes the preparation 

of Equilibrium Partitioning Sediment Benchmark (ESB) documents for several sediment 

contaminants including polycyclic aromatic hydrocarbon (PAH) mixtures, metal mixtures, and 

pesticides. Project VI discusses the preparation of a sediment Toxicity Identification Evaluation 

(TIE) document for use in freshwater and saltwater systems. Neither project involves active 

research, but each seeks to provide guidance on determining the contaminants causing adverse 

ecological effects at contaminated sediment Superfund sites.

The MYIP was reviewed internally and subsequently reviewed externally (Figure 1). The 

internal review included sign-off by the Steering Committee and by AED, MED (Mid-Continent 

Ecology Division of NHEERL), and OSRTI division directors (Appendix E) on the proposed 

research. Additionally, AED and MED management agreed to provide the resources for the 

defined efforts. External review of the MYIP was performed by four reviewers: one EPA 

Regional Superfund site manager and three scientists external to the Agency. Their comments 

were addressed by the Steering Committee and project leads such that modifications to the MYIP 

were made where appropriate. A “Response to Comments” document is available upon request 

to NHEERL.

Coordination across ORD

This MYIP provides a description of NHEERL’s research program in support of ORD’s 

Contaminated Sites MYP under EPA’s Goal 3, Preserve and Restore the Land. The 

Contaminated Sites MYP for ORD is produced by the Waste Research Coordination Team (RCT) 

which consists of staff from ORD, OSWER, and EPA’s Regions. The Contaminated Sites MYP 

identifies the vision and strategic directions for ORD research and lays out how the research 

programs of NHEERL, National Exposure Research Laboratory (NERL), National Center for 

Environmental Assessment (NCEA), and National Risk Management Research Laboratory 

(NRMRL) coordinate to accomplish the overall research goals in support OSWER.

The Office of Science Policy (OSP) coordinates, communicates, and tracks research by ORD that 
6 Contaminated Sediment Research Multi-Year Implementation Plan

supports the program offices. For the Contaminated Sediments research area, OSP established 

eight (now reduced to five) Focus Groups for specific sediment issue areas; the Focus Groups 

are composed of OSP, ORD, and Superfund staff. These Focus Groups provide coordination 

and communication among ORD’s laboratories. Additionally, the waste RCT allocates targeted 

funding (above base/infrastructure) via the Focus Groups for research on specific issues that are 

key to having ORD fulfill the vision and strategic directions identified in ORD’s Contaminated 

Sites MYP.

The Superfund Program developed a list of research issues and needs (see Appendix A) that 

includes a series of non-sediment related research areas. These non-sediment research needs 

have been considered, evaluated, and addressed in the other three LTGs in ORD’s Contaminated 

Sites MYP, i.e., Ground Water, Soil/Land, and Multimedia. For non-NHEERL aspects of the 

research needs for contaminated sediments, the NHEERL Contaminated Sediment Steering 

Committee includes representatives from ORD’s other two laboratories (NERL and HRMRL) 

and NCEA. The research missions of these organizations cover non-NHEERL aspects of the 

research needs for contaminated sediments. 
7 Contaminated Sediment Research Multi-Year Implementation Plan

Research Project Descriptions

Research Questions for Projects I, II, III, and IV

In the process of writing the research project descriptions, the description for the research 

on residue-effect relationships was divided into two research project descriptions: Linking 

Residues to Effects in Aquatic and Aquatic-dependent Wildlife (Project II) and Linking Chemical 

Concentrations in Water and Sediment with Residues in Aquatic and Aquatic-Dependent Wildlife 

(Project III). The table below summarizes the research questions for each of the projects; 

detailed descriptions are provided on the following pages.

Research Questions

I. Evaluating benthic recovery monitoring methods

 For assessing/predicting recovery of benthic communities at contaminated sediment sites:

• Will sediment profile image (SPI) data be more cost-effective than benthic enumeration 

techniques?

• Will SPI data be as accurate as benthic enumeration techniques?

• Does understanding near-bottom dissolved oxygen conditions increase prediction 

accuracy?

II. Predicting effects based on chemical residues

 For estimating ecological risk at contaminated sediment sites:

• Do major gaps exist in PCB residue-effect data for aquatic and aquatic dependent wildlife?

• Will risk estimates be altered significantly by the manner in which PCB is expressed 

(e.g.total PCB, Aroclors, congeners, and dioxin-like congeners)?

III. Predicting residues based on chemical concentrations

 For predicting bioaccumulation at contaminated sediment sites:

• Can bioaccumulation data, i.e.,biota-sediment accumulation factors (BSAFs) and 

bioaccumulation factors (BAFs), be extrapolated across ecosystems, species, and/or time 

using a hybrid empirical modeling approach?

• Will the accuracies and uncertainties of the hybrid predictions be similar to those obtained 

with dynamic time-variant bioaccumulation food web models?

IV. Evaluating off-site impacts from dredging

 For resuspension of sediments during dredging at contaminated sediment sites:

• Do existing fate and transport models accurately predict dissolved concentrations?

• Will dissolved contaminants be released and transported?

• Will bioavailability of contaminants be increased temporarily?
8 Contaminated Sediment Research Multi-Year Implementation Plan

Project I : Integrative Assessment of Benthic Effects 

from Remedial Activities at Superfund Sites

Summary of Issue

At contaminated sediment sites, the Superfund program must decide whether to leave the site 

alone or select a remedial option. These decisions are based in part on the relative risks to the 

environment and health posed by each alternative. Whatever decision is made at a site, the 

Superfund program must have an understanding of the potential risks to the ecosystem posed by 

the remedial action itself. Consequently, Superfund needs cost-effective, rapid methods to assess 

benthic effects before and after remedial actions (both spatially and temporally) and means to 

separate the effects of chemical contamination from other stressors on the benthic community. 

The objectives of the research are to (1) evaluate the sediment profile image (SPI) camera as 

a rapid and cost-effective tool to assess the short-term effects on and recovery of the benthic 

community after dredging at a Superfund site; (2) to evaluate and compare SPI data for benthic 

communities with more traditional grab/sieve metrics (e.g., benthic species enumeration); and 

(3) to investigate interactions between sediment contaminants and near-bottom dissolved oxygen 

concentrations and their relative influence on benthic community recovery. 

Summary of the State of the Science

Two methods have been commonly used to assess the status of the benthic community, 

each with it’s own advantages and disadvantages. The most traditional method, benthic 

organism enumeration, involves sediment collection and sieving after which the collected 

benthic organisms are identified and counted. This information has been used in many ways, 

including producing indices such as the benthic index of biotic integrity (B-IBI) developed 

for Chesapeake Bay (Weisberg et al. 1997). While sieving and counting benthic animals 

yields significant detailed information on species richness and biomass, it requires sediment 

collection and handling, is labor intensive, and is comparatively expensive and slow. Several 

of these characteristics present special problems at Superfund sites (e.g., extensive handling of 

contaminated sediment, cost). 

Another method involves remote sensing of the benthos using SPI cameras (Rhoads and Cande 

1971). This approach has also led to the calculation of several indices based on information 

taken from sediment profile images, such as benthic habitat quality (BHQ) (Nilsson and 

Rosenberg 1997) and the Organism-Sediment Index (OSI) (Rhoads and Germano 1982; 1986). 

Sediment profile imagery provides a rapid spatial assessment of the benthic community in situ

and is relatively inexpensive after initial instrument acquisition costs. While these attributes 

can be very beneficial at Superfund sites, the camera images do not provide quantitative, 

comprehensive species counts.

The bulk of the existing studies utilizing SPI methods focus on benthic community recovery 

(“recolonization”) following disposal of uncontaminated, fine-grained dredged material in 

estuarine or marine environments. Such disposal is quite comparable, in terms of benthic 

disturbance, to remedial actions such as dredging or capping: both essentially involve replacing 
9 Contaminated Sediment Research Multi-Year Implementation Plan

an existing benthic substrate and associated biota with a new substrate that is initially devoid 

of organisms but that can become colonized over time. Therefore, literature is available that 

describes benthic successional patterns and responses following physical sea floor disturbance 

(see review by Hall 1994); and a significant number of studies specifically examined 

recolonization following dredging or dredged material disposal (see reviews by Newell et al. 

1998; Bolam and Rees 2003).

Most past studies have utilized the traditional grab/sieving approach to evaluate benthic impacts 

and recovery following disposal or capping; but there are also some that have utilized SPI, either 

alone or in combination with grab/sieving (e.g., Valente et al. 2000; Valente and Fredette 2002). 

Most notably, the Corps of Engineers Disposal Area Monitoring System (DAMOS) has utilized 

SPI extensively for over 25 years as a cost-effective alternative to grab sampling in monitoring 

benthic impacts and recovery at dredged material disposal sites throughout New England (see 

Fredette and French 2004 and references therein). That being said, comparatively few studies 

have attempted to make a direct, explicit comparison between grab/sieving and SPI results 

obtained simultaneously to calibrate and validate the correlation, and even fewer have been 

conducted at Superfund sites (Fredette et al. 2002).

Diaz et al. (2002) compared the two methods directly in Chesapeake Bay and demonstrated that 

there were significant differences between them when classifying a particular station as having 

“stressed” or “good” habitat quality. The B-IBI, calculated with species enumeration data, was 

community-structure orientated with an emphasis on species identity and richness. The BHQ, 

calculated from image analysis of SPI data, was process oriented; the images recorded the end 

products of biological and physical processes that impact and structure the benthos (e.g., the 

presence of tubes, redox depth). Despite a large body of knowledge about both methods, there 

is still considerable debate over which metrics/indices to calculate from the data and how to 

best utilize both methods (e.g., alone or in combination) and their metrics. In addition, there 

are questions about the standardization and quality assurance of SPI images and their most 

appropriate use at Superfund sites.

Research Needs

Superfund needs rapid and cost effective tools that provide data appropriate for identifying 

and evaluating benthic quality. The question is whether the SPI approach provides enough 

information to adequately assess remedial effects and effectiveness as compared to the traditional 

enumeration procedures. We also recognize that both methods may be needed in combination 

(e.g., SPI for spatial coverage and sieving/counting for ground-truthing). Therefore, a study to 

directly compare the two methods at a Superfund sediment site would be useful. 

Benthic community metrics, including but not limited to indices such as IBI and BHQ, will be 

comparatively evaluated to determine not necessarily which method is “best” (i.e., in a perfect 

world of unlimited resources and personnel, benthic enumeration is most comprehensive), 

but whether the SPI approach provides enough information to fill Superfund’s requirement to 

document remedial effects and recovery at sediment sites given the realities of limited budgets 

and the need for timely decisions, etc.
10 Contaminated Sediment Research Multi-Year Implementation Plan

In addition to evaluating the utility of the SPI camera, the proposed study will also address the 

question of what each benthic community indicator is reflecting or measuring. One advantage of 

any integrative indicator, such as benthic community, is that it incorporates the effects of multiple 

environmental conditions. In most aquatic systems, including those contaminated enough to be 

classified as Superfund sites, there is rarely only one stressor (e.g., contaminants) that affects 

the benthic condition. Contaminant stress to the benthos can be confounded by other processes, 

both anthropogenic (e.g., low dissolved oxygen from eutrophication) and natural (e.g., salinity 

gradients in estuaries, depositional/erosional processes in rivers). In the context of a regulatory 

program such as Superfund, it is especially important to understand exactly what an indicator is 

reflecting so that scientific and management assessments of remedial effects can be accurate and 

expectations about remedial recovery can be realistic. A drawback to both benthic assessment 

methods described above is the lack of a direct link between what they measure and the ability to 

partition observed effects among multiple stressors. Research is needed to elucidate these links 

and potentially confounding effects. 

Proposed Research Targets

The specific objective of this research is to compare and evaluate the traditional grab/sieving 

method and the SPI camera method of benthic community assessment at a Superfund site. The 

research program will use traditional and innovative tools to understand the relationship between 

these metrics and sediment variables present at the site, both anthropogenic (i.e., PCBs, low 

dissolved oxygen) and natural (i.e., grain size, salinity, organic carbon). In addition, this research 

will evaluate the SPI camera as a rapid and cost-effective tool to assess the short-term effects on 

and the recovery of the benthic community after dredging. This effort will contribute towards 

our long-term goal to develop a predictive capability so that the timeframe to benthic recovery 

after dredging can be more accurately estimated.

Research Steps/Approaches

This research program will have three related tasks. 

Task 1

SPI sampling will be conducted concurrently with benthic sampling that is already planned as 

part of the long-term monitoring program (Nelson et al. 1996) at the New Bedford Harbor (NBH) 

Superfund site. The purpose of the program is to document physical, chemical, and biological 

changes before, during, and after remediation. The study area encompasses large gradients of 

water depth, sediment type, and contamination level. One aspect of this monitoring program 

involves collecting sediment at 72 stations located throughout the upper, lower, and outer harbor 

areas (Figure 2). Three sediment collections have occurred to date: a baseline in 1993, after 

the Hot Spot remediation in 1995, and prior to planned remediation in 1999. These sediment 

samples were analyzed for 18 PCB congeners, 8 metals, sediment toxicity, organic carbon, acid 

volatile sulfide (AVS), grain size, and benthic species enumeration. Because the upper harbor 

remediation was delayed from 1999 to 2004, another round of sampling was conducted in Fall 

2004. 

Although SPI has been in continuous routine use as a benthic sampling technique for almost 25 
11 Contaminated Sediment Research Multi-Year Implementation Plan

years, one of the impediments to its more widespread acceptance has been skepticism on the part 

of many benthic ecologists who conduct studies that use the traditional grab/sieving approach. A 

SPI survey at each of these 72 stations will allow a direct comparison between SPI metrics and 

a suite of individual analyses that characterize benthic condition, including benthic enumeration 

data, sediment toxicity, and chemical and physical parameters. Traditional information from 

SPI images (depth of apparent redox potential discontinuity [RPD] layer, presence/absence of 

burrows) will be assessed as well as metrics such as color change. In addition, live video of the 

sediment surface during SPI sampling will be examined to augment SPI analyses. This data set 

should provide a sound basis for testing and validating the applicability of SPI to Superfund’s 

need to assess the long-term recovery of a site over a large spatial area. 

Due to fiscal constraints, the upper harbor dredging has been segmented into a number of dredge 

management units (DMUs). The first DMU is scheduled for dredging in Fall 2004. The longterm monitoring sediment sampling and initial SPI survey should be conducted prior to the start 

of dredging. The value of this research lies in the side-by-side comparison of the SPI and benthic 

enumeration for evaluating benthic impacts. It is our intention to repeatedly sample these sites to 

assess both temporal and spatial variability within a station.

Task 2

A second task will focus on determining how useful SPI technology is for examining the shortterm effects of dredging on the benthos, as well as how fast the area is recolonized. The first 

DMU is scheduled to be dredged in Fall 2004. The EPA investigation on biological aspects 

will be complemented by the Army Corps of Engineers (ACE) extensive investigation in this 

DMU which will examine the physical and chemical aspects of the dredging (e.g., efficiency of 

the dredge, recontamination of the dredged area). Using the SPI camera, we will document the 

benthic recovery by collecting a specified number of SPI images in the DMU (in coordination 

with ACE’s physical and chemical sampling) immediately before and after dredging. Because 

the dredging should end sometime in December and the upper harbor freezes over occasionally, 

it is difficult to specify the sampling frequency at this time. We propose to sample every two 

weeks initially as the literature indicates that estuarine recolonization should be rapid; however, 

sampling intervals may be modified depending on the results, degree of icing, and weather. 

The spatial design of the SPI sampling will also attempt to evaluate whether there are “edge 

effects” (i.e., benthic recovery beginning first at the dredge area boundaries). We will conduct 

a parallel assessment in an adjacent un-dredged DMU to quantify any redeposition of sediment 

from the dredging operation and to compare the benthic community in the remediated and 

unremediated areas. Because of the projected lengthy time to completely remediate the site, we 

are cooperating with Region 1 in designing the sampling plan to also evaluate the deposition 

of residual contamination from dredging outside the dredge area. We will be sharing pre- and 

post-dredge chemistry data to correlate (if possible) with SPI images. This task should confirm 

hypotheses about recolonization rates, specifically at contaminated sediment sites. 

Task 3

The final task is designed to investigate the effects of various stressors, primarily dissolved 

oxygen (DO), on the SPI metrics. Initially, three stations will be selected in New Bedford 
12 Contaminated Sediment Research Multi-Year Implementation Plan

Harbor for monthly monitoring beginning in early Spring 2005 and continuing until ice over. 

Monitoring will consist of a deployed hydrolab that records continuous water column salinity, 

temperature, and DO, as well as discrete benthic data collections using SPI camera images, video 

images, some benthic enumeration data, and sediment analysis for natural and anthropogenic 

chemicals and physical characteristics (e.g., excess molybdenum (Mo), grain size, organic 

carbon, toxic and crustal metals, PCBs, PAHs). Excess Mo accumulation in surface sediments 

will be investigated as a tool for determining the duration of any low DO events. Data on low 

DO extent and potential toxicant concentrations will be used to evaluate whether contaminant 

stress is the dominant cause of benthic community impairment in NBH. If a benthic community 

is primarily stressed by low DO, benthic recovery will differ in response to reducing contaminant 

concentrations from that in an area with adequate DO. 

Experiments will be conducted in AED’s DO system to further elucidate the relationship between 

the duration of low DO conditions and the formation of excess Mo under controlled conditions. 

In addition, we plan to calibrate the apparent RPD (using color change) measured by the SPI 

camera to actual RPD (using Eh). These laboratory measurements will be compared to similar 

field data that will be collected in cores at the three NBH monitoring stations. Task 3 (and 

associated products) will be refined based on examination of the first year’s data collection. 

Resources

It should be noted that the successful completion of 

Tasks 1 and 2 will be dependent upon the New Bedford 

Harbor long-term monitoring sampling and first 

DMU dredging occurring as currently scheduled. It is 

expected that future work will involve evaluating the 

applicability of methods developed in this research to 

additional Superfund sites to ascertain how consistently 

SPI metrics can be used to describe benthic condition. 

If the results are widely applicable, it would be 

advantageous to attempt to develop the ability to predict benthic recovery at dredging sites. 

NHEERL Category D Needs

In addition to the personnel costs, benefits, supplies, equipment, etc., that are specifically 

associated by ORD with 

FTE and considered 

intramural resources, 

NHEERL uses ORD 

planning resources to pay 

laboratory indirect costs 

(called “ABC costs”) 

and project-specific costs 

(called “Category D 

costs”). Listed above are 

the kinds of Category D needs associated with this project. Annual budget planning documents 

determine the dollar amounts needed.

Year Division FTEs

2004 AED 2.50

2005 AED 2.50

2006 AED 2.50

2007 AED 2.50

2008 AED 2.50

Year Division Analytical 

Chemistry GIS Statistics Field Support

Image 

Analysis

2004 AED

2005 AED yes yes yes

2006 AED yes yes yes yes yes

2007 AED yes yes yes yes yes

2008 AED tbda tbd tbd tbd tbd

 a tbd = to be determined
13 Contaminated Sediment Research Multi-Year Implementation Plan

Critical Paths

Task #1: Application of SPI to assess 

benthic community at Superfund sites

Peer-reviewed paper on direct 

comparison of SPI/sieving methods

at a sediment Superfund site

Compare/contrast/analyze SPI and 

traditional sieving methods, spatially 

and temporally

Collect SPI, sieve, and chemical/physical

data at a Superfund sediment site

Recommendation (fact sheet) for OSRTI 

on SPI data use in Superfund sediment

monitoring programs

Task #2: Application of SPI to assess the short-term

effects of dredging on the benthic community 

Collect SPI and chemical/physical data 

before/after dredging

Determine how accurately SPI metrics 

Reflect effects and document recovery by 

comparing dredged and not dredged data

Peer-reviewed paper on use of 

SPI to document benthic community 

Effects and recovery from remedial dredging

Task #3: Methods to apportion benthic effects among multiple stressors

Peer-reviewed paper on methods to 

assess the magnitude and duration 

of low DO stress to benthos

Comparison of controlled lab

And field data for DO, Mo, SPI

Collect continuous DO, Mo, 

and SPI field data, both

spatially/temporally

Conduct controlled lab 

Experiments with known

DO and measured excess Mo

Use data from Task#1 and #2, with DO method

to apportion relative effect on benthos of multiple

stressors including salinity, grainsize, organic carbon

Identify next research steps
14 Contaminated Sediment Research Multi-Year Implementation Plan

Products

By 2008, provide assessment of the applicability of sediment profile 

imagery for monitoring effects of and recovery from dredging at a 

Superfund sediment site.*

FY08 NHEERL

Report to OSRTI on the direct comparison of SPI/

sieving methods at a sediment Superfund site FY06* NHEERL-AED Barbara Bergen

Peer-reviewed paper on direct comparison of SPI/

sieving methods at a sediment Superfund site FY07* NHEERL-AED Barbara Bergen

Recommendation (fact sheet) for OSRTI on SPI data 

use in Superfund sediment monitoring programs FY06* NHEERL-AEDSkip Nelson

Report to OSRTI on the relationship between SPI and 

other environmental variables, particularly dissolved 

oxygen

FY06

NHEERL-AED

Warren Boothman 

Laura Coiro

Peer-reviewed paper on the relationship between 

SPI and other environmental variables, particularly 

dissolved oxygen

FY07

NHEERL-AED

Warren Boothman 

Laura Coiro

Peer-reviewed paper on use of SPI to document 

benthic community effects and recovery from remedial 

dredging

FY08* NHEERL-AED 

Barbara Bergen

* Due dates dependent on NBH dredging occurring as currently scheduled

References

Bolam, S.G. and H.L. Rees. 2003. Minimizing impacts of maintenance dredge material disposal 

in the coastal environment: a habitat approach. Environ Manage 32(2):171-188.

Diaz, R.J., G.R. Cutter Jr., and D.M. Dauer. 2002. A comparison of two methods for estimating 

the status of benthic habitat quality in the Virginia Chesapeake Bay. J Exp Mar Biol Ecol

285/286:371-381.

Fredette, T.J. and G.T. French. 2004. Understanding the physical and environmental 

consequences of dredged material disposal: history in New England and current 

perspectives. Mar Poll Bull 49:93-102.

Fredette et al. 2002. Field Pilot Study of In Situ Capping of Palos Verdes Shelf Contaminated 

Sediments. U.S. Army Corps of Engineers, Engineer Research and Development Center 

(ERDC), Technical Report TR-02-5.

Grizzle, R.E. and C.A. Penniman. 1991. Effects of organic enrichment on estuarine 

macrofaunal benthos: a comparison of sediment profile imaging and traditional methods. 

Marine Ecology Progress Series 74:249-262.

Hall, S.J. 1994. Physical disturbance and marine benthic communities: life in unconsolidated 

sediments. Oceanogr Mar Biol Ann Rev 32:179-239.

Newell, R.C., L.J. Seiderer, and D.R. Hitchcock. 1998. The impact of dredging works in coastal 

waters: a review of the sensitivity to disturbance and subsequent recovery of biological 

resources on the sea bed. Oceanogr Mar Biol Ann Rev 36:127-178.

Nelson, W.G., B.J. Bergen, S.J. Benyi, G. Morrison, R.A. Voyer, C.J. Strobel, S. Rego, 

G. Thursby, and C.E. Pesch. 1996. New Bedford Harbor Long-Term Monitoring and 

Assessment Report: Baseline Sampling. U.S. Environmental Protection Agency, National 
15 Contaminated Sediment Research Multi-Year Implementation Plan

Health and Environmental Effects Research Laboratory, Atlantic Ecology Division, 

Narragansett, RI. EPA/600/R-96/097. 

Nilsson, H.C. and R. Rosenberg. 1997. Benthic habitat quality assessment of an oxygen 

stressed fjord by surface and sediment profile images. J Mar Sys 11:249-264.

Rhoads, D.C. and S. Cande. 1971. Sediment profile camera for in situ study of organismsediment relations. Limnol Oceanogr 16:110-114.

Rhoads, D.C. and J.D. Germano. 1982. Characterization of organism-sediment relations 

using sediment profile imaging: an efficient method of remote ecological monitoring of the 

seafloor (REMOTSTM system). Marine Ecology Progress Series 8:115-128.

Rhoads, D.C. and Germano, J.D. 1986. Interpreting long-term changes in benthic community 

structure: a new protocol. Hydrobiologia 142:291-308.

Valente, R.M. and T. Fredette. 2002. Benthic recolonization of a capped dredged material 

mound at an open water disposal site in Long Island Sound. Proceedings of Dredging 2002: 

Third Specialty Conference on Dredging and Dredged Material Disposal, May 5-8, Orlando, 

Florida. American Society of Civil Engineers, Reston, VA. 

Valente, R.M., S.M. McChesney, and G. Hodgson. 2000. Benthic recolonization following 

cessation of dredged material disposal in Mirs Bay, Hong Kong. J Mar Env Eng 5:257-288.

Weisberg, S.B., J.A. Ranasinghe, D.M. Dauer, L.C. Schaffner, R.J. Diaz, and J.B. Frithsen. 

1997. An estuarine benthic index of biotic integrity (B-IBI) for Chesapeake Bay. Estuaries

20:149-158.
16 Contaminated Sediment Research Multi-Year Implementation Plan

Figure 2

LOWER HARBOR OUTER HARBOR

Coggeshall St. 

Bridge

Upper Harbor

Lower Harbor

Outer Harbor

Hurricane Barrier

Coggeshall St.

Rt. I Bridge -195

Bridge

Rt. 6

Bridge

Hurricane

Barrier

Popes

Island

(a)

(c) (d)

UPPER HARBOR

Hot Spot

CDF

Coggeshall St.

Bridge

(b)

Hurricane

Barrier
17 Contaminated Sediment Research Multi-Year Implementation Plan

Project II: Linking Residues to Effects in 

Aquatic and Aquatic-Dependent Wildlife

Summary of Issue

At contaminated sediment sites, the Superfund program must decide whether to leave the site 

alone (i.e., allow for natural recovery to occur), cap it, or dredge it. These decisions are based in 

part upon the relative risks to the environment and human health posed by each option. These 

risks, in turn, depend upon a variety of factors, including the toxicity of the chemicals of concern 

and the concentration of toxic chemicals likely to be found in the tissues of aquatic wildlife and 

aquatic-dependent wildlife. Based on an understanding of these factors, the Superfund program 

needs to develop critical residue values in target species for the chemicals of concern with the 

presumption that when the critical value or lower is achieved in the target species, the risks posed 

by contaminant releases from the site are acceptable. This project is focused on the first of these 

two factors. 

For purposes of predicting toxicity for persistent bioaccumulative toxicants (PBTs)1

, chemical 

doses are best expressed in terms of chemical residues in tissues because chemical residues in 

tissues integrate doses received from all environmental exposure pathways (e.g., food, water, 

sediment) (McCarty and Mackay 1993). To provide well-informed projections of risk, the 

Superfund program must be able to assess the effects of chemical residues in the wildlife of 

interest based upon an understanding of the dose-response relationship for the chemical and 

organism. For aquatic and aquatic-dependent wildlife, species’ sensitivities vary for a given 

chemical; in general, the dose-response relationships have similar shapes for organisms of the 

same family. To make remediation decisions, the Superfund program needs to be able to assess 

the survival, growth, and reproduction toxicity effects of chemical residues in aquatic and 

aquatic-dependent wildlife.

When Superfund assesses the relative risk of remediation options (i.e., to leave a site alone, 

cap it, or dredge it), inaccuracies in the assessment of the effects for chemical residues in 

organisms (and thus, populations and communities) will directly influence the decisions made 

concerning the remedial options. If the assessment of effects is based on inaccurate doseresponse predictions, Superfund might select options which require too much or too little 

remediation as compared to the option which would have been chosen if the actual risks posed 

to the environment and human health were more accurately understood. Because remediation 

of contaminated sediments is often very expensive, Superfund wants and needs the assessment 

of effects on human health and on aquatic wildlife and aquatic-dependent wildlife to be highly 

accurate and precise so that contaminated sites can be remediated most cost effectively. 

Superfund contaminated sediment sites are often physically and chemically complex ecosystems 

characterized by a variety of species, sediment types, and contaminants. In the face of this 

complexity, Superfund strives to be consistent in the manner in which it assesses risk and 

1 The term “Persistent Bioaccumulative Toxicants (PBTs)” is used in a generic sense in the text. 
18 Contaminated Sediment Research Multi-Year Implementation Plan

evaluates risk management options. Such consistency can most readily be achieved when 

the determining variables and parameters are understood. From the perspective of providing 

consistency, the most problematic chemicals at Superfund contaminated sediments sites are PBTs 

because of their prevalence, toxicity, persistence, and bioaccumulative behavior. An additional 

challenge exists when the individuals responsible for making difficult decisions at Superfund 

sites do not have the opportunity to develop a detailed understanding of all the factors involved. 

When this is the case, the factors that affect the residue-effect assessment must be clearly and 

understandably delineated to on-site decision makers.

Summary of the State of the Science

Historically, aquatic toxicology has focused on understanding the relationship between waterbased exposures and effects expressed using acute and chronic toxicity endpoints (e.g., for 

acute toxicity, see MED’s fathead minnow database (ECOTOX 2003)). For most PBTs, there 

has been a historical under appreciation of the importance of dietary and maternal transfer (i.e., 

transfer of contaminants from the adult female to its eggs) exposure routes when performing 

laboratory tests. These additional exposure routes make it difficult to produce exposures (and 

resulting effects) which are truly representative of conditions occurring in the environment in the 

laboratory using water-only based exposures. Thus, measurements of acute and chronic toxicity 

for PBTs that are based on water-only exposures have provided less than satisfactory results 

because the chemical dose, when expressed as the concentration of chemical in water, does not 

represent the actual dose for the organism. In the last decade, our understanding of appropriate 

dose measures and effects endpoints for PBTs has increased greatly; and it is now recognized 

that for PBTs, the chemical residue in the organism (or one of its tissues) is the best measure of 

dose for predicting chronic toxicity (generally, reproductive endpoints) (McCarty and Mackay 

1993). 

We know how to develop the linkage between the concentration of chemicals in the organism 

(or one of its tissues) and the biological effects caused by the chemical residue when proper 

data exist for single chemicals and for mixtures of chemicals with common modes of action. 

The best examples of this linkage for PBTs are the chlorinated dibenzo-p-dioxins, chlorinated 

dibenzofurans, and planar PCBs (which all have the same mode of action). Toxicity equivalence 

factors (TEFs) have been developed for these chemicals and applied for fish, wildlife, and 

humans (Van den Berg et al. 1998). To properly develop these linkages, toxicity data with 

species specificity, end-point specificity, and dose-exposure consistency are required; and all 

three of these requirements must be consistent with the mode of action. Unfortunately, these 

requirements are fairly challenging to fulfill.

The scientific literature for toxicological data is composed of studies with an assortment of 

species, endpoints, and dosing regimes for individual chemicals. The variability and gaps in the 

available data result in large uncertainties in our understanding of residue-effects relationships 

and in the subsequent predictions made with them. An additional difficulty, beyond the issues 

associated with extrapolation and the filling of data gaps, is the lack of having data from 

the literature assembled and available so that one can develop and evaluate residue-effects 

relationships. Databases are being developed, e.g., the effect-residue database of Jarvinen and 

Ankley (1999) and the Environmental Residue-Effects Database (ERED) of US-Army Corps of 
19 Contaminated Sediment Research Multi-Year Implementation Plan

Engineers (accessible at www.wes.army.mil/el/dots); but additional data still need to be evaluated 

and incorporated into databases to facilitate the development and evaluation of residue-effects 

relationships.

Key gaps in our understanding of the linkage between the chemical residues in tissues (or 

organisms) and their resulting biological effects include the following:

1. Critical toxicity endpoints for single chemicals and mixtures of chemicals;

2. High quality residue-effects data for most PBTs;

3. For complex mixtures with numerous chemicals (e.g., toxaphene), how to quantify the 

residue in a toxicologically meaningful way across laboratory tests and ecosystems;

4. Techniques for extrapolating laboratory test data from one toxicological endpoint to 

another (e.g., from a growth endpoint to a fecundity endpoint);

5. Techniques for extrapolating endpoints for test species to Superfund receptor species; and

6. Translating biological effects on individuals to those manifested in populations. 

Research Needs

The steering committee identified the following key scientific challenges upon reviewing the 

issue summary, state of the science, and gap analysis:

1. Consolidate existing toxicological knowledge and clarify data gaps;

2. Develop methods to establish biological effects with varying amounts and types of 

laboratory-derived toxicological data;

3. Extrapolate toxicological endpoints for laboratory test species to Superfund receptor 

species; and

4. Extrapolate from effects on individuals to effects on populations.

Proposed Research Targets

After assessing the research needs relative to the level of effort required to achieve them and 

the expertise and resources available, the steering committee concluded that the research needs 

required more resources than are available. Additionally, the steering committee concluded 

that research needs were sufficiently general in nature that ongoing research elsewhere may 

provide significant insights for specific chemicals and issues. Given this assessment, the steering 

committee identified the following research target for this project:

Consolidate existing knowledge and clarify data gaps by assembling and evaluating a 

database of up-to-date PCB residue-effects data for aquatic and aquatic-dependent species. 

The rationale for selecting this target included the following considerations:

1. PCBs are chemicals of high concern and interest for Superfund;

2. There is much discussion and controversy existing about how to evaluate or express PCB 

mixtures, e.g., total PCB, total Aroclors, homologs, and sum of the dioxin-like PCBs 

(toxicity equivalents, or TEQs);
20 Contaminated Sediment Research Multi-Year Implementation Plan

3. Given the limited resources for NHEERL’s Goal 3 effort, this target would not require 

laboratory toxicity testing and analytical chemistry support which, if done, would require 

more resources than available;

4. This effort would build upon the existing residue-effects database of Jarvinen and Ankley 

(1999), a database assembled at MED, and US-Army Corps of Engineers’ ERED database;

5. MED has expertise in similar data compilation and evaluation efforts, e.g., the 

development of EcoSSL (ecological soil screening levels) for Superfund; and

6. Supplemental resources via ORD’s Contaminated Sediment Focus Group 1: Fate and 

Transport Modeling and Bioaccumulation are potentially available; and MED via its 

AQUIRE and ECOTOX database efforts has the ability to contract out the assembling of 

the PCB database with these funds.

Research Steps/Approaches

To achieve the above target, two steps must be taken: (1) assemble a database of PCB residueeffects data for aquatic and aquatic-dependent species and (2) evaluate assembled data on PCB 

residue-effects for aquatic and aquatic-dependent species.

Step 1: Assemble/consolidate a database of PCB residue-effects data for aquatic and aquaticdependent species

The following tasks are needed in order to assemble a PCB residue-effects database for aquatic 

and aquatic-dependent species. First, a literature search strategy must be developed. The 

search strategy will be built from existing literature search strategies used for the Eco-SSLs 

effort performed at MED. Second, the actual search needs to be conducted and the citations 

downloaded. Third, the citations/abstracts from searches need to be skimmed through so they 

can be ranked according to their potential usefulness based upon a checklist for minimum data 

needs. Fourth, selected data must be abstracted and entered into the database. This process 

will build upon the existing residue-effects database of Jarvinen and Ankley (1999) and ERED. 

Thus, in the third task, the checklist process would determine if a citation is already included 

in one of these databases. In assembling and consolidating the database, multiple measures of 

PCBs will be included; e.g., total PCB, total Aroclors, sum of the dioxin-like PCBs (TEQs), etc., 

In addition, the type of analytical method used for PCB quantification will be recorded. The 

database effort will be focused on freshwater and marine species which respond to dioxin-like 

toxicity, i.e., aryl-hydrocarbon-receptor-(AhR-)mediated toxicity, because PCB toxicity occurs 

via this receptor. Invertebrate species, in general, do not appear to have this receptor (Hahn 

et al. 1994) and are considered to be much less susceptible to AhR-mediated toxicity. Thus, 

invertebrate species will not be considered in the current data compilation effort.

To stimulate this effort, we obtained FY04 funds via ORD’s Focus Group 1. These funds were 

placed onto a MED contract which supports the database efforts for AQUIRE and ECOTOX 

databases. Because this effort is similar to those being performed by the contract for AQUIRE 

and ECOTOX, this effort should move forward quite quickly.
21 Contaminated Sediment Research Multi-Year Implementation Plan

Step 2: Evaluate assembled PCB residue-effects data for aquatic and aquatic dependent species 

To evaluate the PCB residue-effects data, a number of approaches will be taken. First, we will 

determine the overall consistency within and among species for the data. We propose assembling 

no observed adverse effect levels (NOAELs) and lowest observed adverse effect levels 

(LOAELs) for biochemical, behavior, physiology, pathology, reproduction, growth, and mortality 

endpoints. These values will be compared for individual species where adequate data exist 

and across species to assist in evaluating data quality and variability. We also plan to examine 

the dose-response curves by comparing the shape, steepness, etc., of the curves. The prior 

comparisons are similar to those used by Superfund in developing EcoSSLs (see http://www.

epa.gov/ ecotox/ecossl/SOPs.htm). Second, we will perform PCB ecological risk predictions 

using congener-specific, dioxin-like PCBs (TEQ), total PCB, homolog, and Aroclor exposure/

dose measurements or predictions to determine comparability of the eco-risk predictions. These 

comparisons will help us evaluate how divergent estimates of risks are for different expressions 

of PCBs. It is anticipated that these assessments would be performed for Superfund sites where 

the appropriate data are available, and expressions of risk would be evaluated on a variety of 

endpoints such as critical residues in fishes and other organisms or sediment clean-up levels. 

Further definition of the assessment, comparison tools, and techniques will occur as the data are 

assembled and consolidated because these tools and techniques will be somewhat dependent 

upon the actual data available. Third, we will clearly define data gaps and deficiencies for PCBs 

so that future research activities can be optimally focused.

Among the outcomes from the evaluation effort on the PCB residue-effect data are the methods, 

tools, and techniques developed for screening and evaluating the toxicity data as well as for 

deriving residue-effect relationships with varying amounts and types of laboratory-derived 

toxicological data. These techniques and tools will provide a starting point from which to move 

beyond the PCBs to other PBTs and derivation of their residue-effects relationships for aquatic 

and aquatic-dependent species.

Technology Transfer

Transfer of research results from this effort will occur through a variety of mechanisms. First, 

peer reviewed report(s) on the evaluations of the PCB residue-effects data will be written and 

published. These reports will cover the (1) overall consistency within and among species for 

the PCB data, (2) data gaps and deficiencies for the PCBs, (3) comparisons of residue-effects 

relationships based on different measures of PCB, (4) comparability of eco-risk predictions 

using different expressions for PCBs, and (5) possibly, methods and techniques for screening 

and evaluating toxicity data for residue-effect relationships. Second, the PCB residue-effects 

database will be made available to Superfund. Additionally, after consultation with Superfund, 

processed outputs or tables of data from the database will be developed for use by Superfund. 

Third, educational seminars will be provided in consultation with Superfund about their format 

and content. The content of the seminars will cover the overall consistency of the PCB residueeffects data, data gaps and deficiencies, and comparability of eco-risk predictions. These 

seminars could be held within the ORD-OSRTI seminar series, Superfund’s Environmental Risk 

Assessment Forum (ERAF) semi-annual meetings, or through some other to-be-determined 

forum. Fourth, in cooperation with Superfund, appropriate fact sheets will be written.
22 Contaminated Sediment Research Multi-Year Implementation Plan

Resources

Year Division FTEs

2004 MED 0.25

2005 MED 0.25

2006 MED 0.25

2007 MED 0

2008 MED 0

NHEERL Category D Needs

In addition to the personnel costs, benefits, supplies, equipment, etc., that are specifically 

associated by ORD with FTE and considered intramural resources, NHEERL uses ORD planning 

resources to pay laboratory indirect costs (called “ABC costs”) and project-specific costs (called 

“Category D costs”). Listed below are the kinds of Category D needs associated with this 

project. Annual budget planning documents determine the dollar amounts needed.

Year Division Supplemental 

Funding ECOTOX

2004 MED yes yes

2005 MED yes

2006 MED yes

2007 MED

2008 MED
23 Contaminated Sediment Research Multi-Year Implementation Plan

Critical Path

Products

By 2008, provide hybrid modeling approaches using empirical field 

data and bioaccumulation models to extrapolate BAFs and BSAFs 

for PBTs across ecosystems, species, and time.

FY08 NHEERL

Provide report on the evaluation of the PCB residueeffects database FY06 NHEERL

Lawrence Burkhard 

References

ECOTOX Database. 2003. Version 3. U.S. Environmental Protection Agency, Office 

of Research and Development, National Health and Environmental Effects Research 

Laboratory, Mid-Continent Ecology Division, MN [www.epa.gov/ecoxtox].

Hahn, M.E., A. Poland, E. Glover, and J.J. Stegeman. 1994. Photoaffinity labeling of the Ah 

receptor: phylogenetic survey of diverse vertebrates and invertebrate species. Arch Biochem 

Biophys. 310:218-228.

Jarvinen, A.J. and G.T. Ankley. 1999. Linkage of Effects to Tissue Residues: Development 

of a Comprehensive Database for Aquatic Organisms Exposed to Inorganic and Organic 

Chemicals. SETAC Press, Pensacola, FL. 358 p.

McCarty, L.S. and D. Mackay. 1993. Enhancing ecotoxicological modeling and assessment: 

body residues and modes of toxic action. Environ Sci Technol 27:1719-1728.

Van den Berg, M., et al., 1998. Toxic Equivalency Factors (TEFs) for PCBs, PCDDs, PCDFs for 

humans and wildlife. Environmental Health Perspectives 106:775-792.

Focus Group Supplemental

Funding for development of

PCB residue-effects data base

Development of Effects Data

Develop literature search strategy

Perform literature search

Develop checklist and skim

through citations/abstracts

Abstract and enter data into

residue-effects database

Development of residue-effects

database for PCBs

Evaluation of toxicity residue

database for PCBs

Evaluate PCB residue-effects data

for overall consistency among

species and endpoints

Perform comparisons ecological

risk predictions using

exposure/dose expressions for

total PCB, dioxin-like PCBs

(TEQ), and total Aroclors.

Define data gaps and deficiencies D for PCBs ata from existing residue-effects

databases

Report on evaluation of PCB

residue-effects database

Report on methods and

techniques for screening and

evaluating toxicity data for

residue-effects relationships

Comparison of eco-risk

predictions using different

expressions for PCB toxicity
24 Contaminated Sediment Research Multi-Year Implementation Plan

Project III: Linking Chemical Concentrations in Water and 

Sediment with Residues in Aquatic and 

Aquatic-Dependent Wildlife

Summary of Issue

At contaminated sediment sites, the Superfund program must decide whether to leave the site 

alone (i.e., allow for natural recovery to occur), cap it, or dredge it. These decisions are based in 

part upon the relative risks to the environment and human health posed by each option. These 

risks, in turn, depend upon a variety of factors, including the toxicity of the chemicals of concern 

and the concentration of toxic chemicals likely to be found in the tissues of aquatic wildlife and 

aquatic-dependent wildlife. Based on an understanding of these factors, the Superfund program 

needs to develop critical residue values in target species for the chemicals of concern with the 

presumption that when the critical value or lower is achieved in the target species, the risks posed 

by contaminant releases from the site are acceptable. This project is focused on the second of 

these two factors. 

The relationships between exposure, accumulated chemical dose, and toxic effect or response 

must be linked in order to predict toxicity. Chemical doses are best expressed in terms of 

chemical residues in organisms (or one of its tissues) because these values integrate doses 

received from all environmental exposure pathways (e.g., food, water, sediment) (McCarty and 

Mackay 1993). Depending upon the effect and species, chemical residues might be expressed 

using different bases, e.g., residues in eggs or in liver, for different chemicals. To provide wellinformed projections of risk, the Superfund program needs to accurately predict the residues of 

chemicals in the wildlife of interest, and these predictions must be based upon an understanding 

of the relationship between chemical properties and concentrations in water, sediment, and biota. 

For aquatic and aquatic-dependent wildlife, chemical residues in organisms vary as a function of 

numerous factors. These factors include the nature of the chemical, the chemical concentrations 

in sediment and water, the exposure duration, and the nature of the organism of interest and its 

food web. Consequently, to make remedial decisions, the Superfund program needs methods to 

predict the chemical residues in tissue that would result from different chemical concentrations in 

sediment and water.

When Superfund assesses the relative risk of remediation options (i.e., to leave a site alone, 

cap it, or dredge it), inaccuracies in the assessment of the effects for chemical residues in 

organisms (and thus, populations and communities) will directly influence the decisions made 

concerning the remedial options. If the assessment of effects is based on inaccurate doseresponse predictions, Superfund might select options which require too much or too little 

remediation as compared to the option which would have been chosen if the actual risks posed 

to the environment and human health were more accurately understood. Because remediation 

of contaminated sediments is often very expensive, Superfund wants and needs the assessment 

of effects on human health and on aquatic wildlife and aquatic-dependent wildlife to be highly 

accurate and precise so that contaminated sites can be remediated most cost effectively.
25 Contaminated Sediment Research Multi-Year Implementation Plan

Superfund contaminated sediment sites are often physically and chemically complex ecosystems 

characterized by a variety of species, sediment types, and contaminants. In the face of this 

complexity, Superfund strives to be consistent in the manner in which it assesses risk and 

evaluates risk management options. Such consistency can most readily be achieved when 

the determining variables and parameters are understood. From the perspective of providing 

consistency, the most problematic chemicals at Superfund contaminated sediments sites are PBTs 

because of their prevalence, toxicity, persistence, and bioaccumulative behavior. An additional 

challenge exists when the individuals responsible for making difficult decisions at Superfund 

sites do not have the opportunity to develop a detailed understanding of all the factors involved. 

In this case, bioaccumulation of PBTs in the aquatic food chain and the factors which affect it 

must be clearly and understandably delineated to on-site decision makers.

Summary of the State of the Science

The link between chemical concentrations in water and sediment with residues in aquatic 

and aquatic-dependent wildlife has been an area of active research for the past 2 decades; 

consequently, much is known about this area. The relationship between chemical concentrations 

in water and those in biota are defined as bioaccumulation factors (BAFs); the relationship 

between chemical concentrations in sediment and those in biota are defined as biota-sediment 

accumulation factors (BSAFs). Bioaccumulation of PBTs in aquatic food webs (and hence BAFs 

and BSAFs) is primarily a function of three ecosystem properties and two chemical properties.

Food web models that consider these processes are available for predicting chemical residues 

(Gobas 1993, Thomann et al. 1992). For steady-state solutions, the model predictions are 

generally within a factor of 2-3 of mean measured values. Additionally, these models can be 

solved for dynamic conditions (i.e., varying concentrations of chemicals in water and sediment 

change over time) and can include multiple trophic levels and a variety of benthic and pelagic 

organisms. Nevertheless, food web models have limitations which include the following:

1. poor accuracy for highly hydrophobic chemicals, Kow > 107

;

2. require detailed calibration in order to have predictive power; 

Major determinants of bioaccumulation for PBTs in aquatic food webs:

Ecosystem Properties:

1. Sediment-water column chemical disequilibrium (Πsocw/Kow) where 

Πsocw = sediment-water column chemical concentration quotient;

2. Benthic-pelagic composition of the food web; and 

3. Length of the food web (trophic level). 

Chemical Properties:

1. Hydrophobicity (Kow) and 

2. Rate of metabolism of the chemical in the organism and in its food web 

(Burkhard et al. 2003a). 
26 Contaminated Sediment Research Multi-Year Implementation Plan

3. detailed (often unavailable) food web structure and composition; and 

4. are not appropriate for polar organic chemicals. 

Metabolism of chemicals can be described mathematically within food web models as an 

additional loss process (km), but applications of existing food web models to metabolizable 

chemicals has been extremely rare. In nearly all applications of food web models, km is set 

equal to zero (Burkhard 1998); and, when metabolism is significant, the zero assumption 

underestimates the degradation/loss rate of the chemical in the organism and/or its food web.

Accumulation of nonionic organic chemicals in fish and other aquatic organisms is controlled 

by the lipid content of the organism (Mackay 1982). Thus, lipid normalization of chemical 

residues reduces the variance of concentrations of chemicals among individuals. The variance of 

concentrations of chemicals in sediment and the water column can be minimized by correcting 

for bioavailability (normalizing for organic carbon in the sediment and expressing chemical 

concentrations on the basis of their concentration in the freely dissolved form; DiToro et al. 

1991, Burkhard et al. 2003b). These reductions in variances translate directly into reductions in 

variances of BAFs and BSAFs (Burkhard et al. 2003b) that are used to predict chemical residues 

in fish and other aquatic organisms.

Key gaps in our understanding of the linkage between the chemical concentrations in the tissue 

(or organism) and those in the environment include the following:

1. While approaches to field measurement of BSAFs and BAFs are available (Burkhard 

2003c), techniques generally are not available for predicting how field-measured 

BAFs and BSAFs (measured under one set of ecological conditions, i.e., chemical 

disequilibrium, and food web composition and organism trophic level) change when a 

different set of ecological conditions develop in the ecosystem;

2. Field-measured BSAFs and BAFs are limited; these limitations include number of 

chemicals, aquatic organisms, ecosystem types, and ecosystem conditions even though a 

database is available (ERDC, see http://el.erdc.usace.army.mil/dots/);

3. Techniques for extrapolating BSAF data across ecosystem and species are not available;

4. Rates of metabolism to use in food web models are, for all practical purposes, nonexistent; 

and

5. Prediction for very complex chemical mixtures where not all individual components can 

be quantified (e.g., toxaphene) is very difficult.

Research Needs

Based upon the issue summary, state of the science, and the gap analysis, the following key 

scientific challenges have been identified. 

1. Develop an approach to describe bioaccumulation of PBTs in aquatic food webs that 

enables non-bioaccumulation experts to easily understand the processes and conditions 

that control bioaccumulation; 
27 Contaminated Sediment Research Multi-Year Implementation Plan

2. Extend this approach to address the issues and uncertainties encountered when 

extrapolating bioaccumulation data across ecosystems, species, and time;

3. Broaden the range of chemical and ecosystem properties that can be addressed, i.e., the 

chemical’s rate of metabolism and hydrophobicity (Kow), ecosystem conditions of food 

web structure, organism trophic level, and sediment-water column concentration quotient 

(Πsocw)); and 

4. Validate approaches for conditions that are relevant to Superfund sites.

Proposed Research Targets

The steering committee identified the following research targets for this project after assessing 

research needs, the level of effort required to achieve them, and the expertise and resources 

available:

1. A methodology to extrapolate bioaccumulation data (BAFs/BSAFs) across ecosystems, 

species, and time for PBTs;

2. Demonstrations of applicability of BAFs/BSAFs for predicting ecological risks.

Research Steps/Approaches

To achieve these targets, three major steps must be taken:

1. Generation/assembly of high quality data sets,

2. Development of extrapolation techniques, and

3. Validation.

Overview of Research Steps 1, 2, and 3

The first two research steps are linked. The first step will assemble high quality 

bioaccumulation data sets from Lake Michigan and existing Superfund sites. The second step 

will use this data in developing the hybrid BSAF/BAF extrapolation approach and is composed 

of seven tasks:

Task 1: Develop theoretical/conceptual framework for performing the hybrid extrapolations. 

Task 2: Determine the level of complexity required with the food web models for predicting

the relative differences in bioaccumulation. 

Task 3: Determine the minimum data quality requirements for the extrapolation process. 

Task 4: Determine how to account for metabolism processes and their effects in the 

hybridBSAF/BAF extrapolation approach.

Task 5: Develop whole organism rates of chemical metabolism using field data; these results 

will feed back into Task 4.

Task 6: Evaluate the hybrid approach in field situations for prediction deficiencies and biases.

Task 7: Develop a software package (Visual Basic, Excel in-add or something else) which 

will perform the hybrid calculations.
28 Contaminated Sediment Research Multi-Year Implementation Plan

The third step, Validation, will use data from a variety of Superfund sites to define the accuracy 

and precision as well as the usefulness of the approach developed in the second step.

Step 1: Generation/assembly of high quality data sets

In order to develop techniques to extrapolate bioaccumulation data across ecosystem, species, 

and/or time, data sets for individual compounds (and not mixtures) such as the individual 

PCB congeners, p,p’-DDT, or p,p’-DDE are required for a variety of different ecosystems, 

e.g., streams, rivers, lakes, reservoirs, wetlands, marshes, tidal estuaries, freshwater and 

marine harbors, and large coastal ecosystems. Based upon MED’s experiences in generating 

chemical residue data for the Lake Michigan ecosystem (Burkhard et al. 2004), neither MED, 

nor NHEERL as a whole, has enough resources (within this area) to generate data needed for 

a database because this effort would require analyzing hundreds of fish, sediment, and water 

samples from a large variety of ecosystems. However, Superfund, as part of the Remedial 

Investigation/Feasibility Study (RI/FS) for each site, has been and will be performing such 

analyses. A detailed consideration of data requirements expected for Superfund sites resulted in 

the above table where importance of the data need was identified and ranked.

The ranking process considered the state of knowledge, general data availability for Superfund

sites, and the ability to increase the scientific understanding of bioaccumulation processes with 

the collected information. The highest ranked parameters in the table are those required for 

calculating BSAFs because the ability to calculate BSAFs for a Superfund site would be the 

minimum requirement for inclusion of the data into the database. Other parameters (i.e., the 

importance of having concentrations of chemicals in water, the composition/structure of the food 

web, and loading history for the chemicals of interest) were ranked lower because they are not 

required for calculating BSAFs. 

Site measurements for the lower ranked parameters would be very useful for interpreting the 

finer differences among BSAFs. Although concentrations of chemical in water are ranked 

lower, concentrations of chemicals in water are critical for making bioaccumulation predictions 

when predictions are made from chemical concentrations in sediment and water (Burkhard et al. 

2003a). There is too much uncertainty in the predicted residues if predictions are made using 

only either the chemical concentration in the sediment or the chemical concentration in the water. 

In this effort, we will have, at a minimum, the concentrations of chemicals in the sediment and 

Parameter Rank

Congener-Specific PCB or DDT data: fish 1°

 sediment 1°

 water 2°

Sediment TOC 1°

Structure/Composition of food web 2°

Lipid content of fish 1°

Knowledge of the spatial and temporal associations

 among fish, sediment, and water samples 1°

Loading history of the chemical 2°
29 Contaminated Sediment Research Multi-Year Implementation Plan

fish. With this data alone, a set of high quality BSAFs across a wide variety of Superfund sites 

can be assembled. Additionally, BSAFs are not very sensitive to changes in the sediment-water 

column chemical disequilibrium; thus, small differences in the sediment-water column chemical 

disequilibrium among Superfund sites would not cause large errors when evaluating across 

ecosystem extrapolation techniques when only BSAFs are available. 

The composition and structure of the food web information is also ranked as a lower priority. In 

most ecosystems and for most common species, reasonable estimates can be made or obtained 

from local fisheries experts if this information is not available for a Superfund site of interest. 

The third parameter given a lower ranking is the chemical’s loading history to the ecosystem. 

For most Superfund sites with contaminated sediments, inputs of the chemicals of concern to the 

ecosystem have been stopped for some time. These sites can be considered to be in a “pseudosteady-state” condition in which the chemical disequilibrium is declining slowly over time. This 

condition is a reasonable assumption for most Superfund sites and provides useful measured 

BSAFs. Although having loading information would be helpful in evaluating the measured 

BSAFs, given the above considerations, it was felt that this information was not essential for the 

assembling a useful BSAF database to cover a wide variety of Superfund sites. 

The first research effort for accomplishing this target (Step 1: Generation/assembly of high 

quality data sets) is an in-house effort to develop a high quality data set from the Lake Michigan 

ecosystem. This effort builds upon the EPA’s Lake Michigan Mass Balance Study [http://www.

epa.gov/glnpo/lmmb/project.html] in which considerable resources were expended to obtain 

much of the required ancillary data, e.g., diets of individual fish species, sedimentation rates, 

and spatial and temporal variabilities in chemical concentrations. This in-house effort will 

result in a very high quality data set of concentrations of chemicals in all the components of 

the food web, in the sediment, and in the water column with all of the required ancillary data, 

e.g., lipid contents of the biota, organic carbon contents of the sediments, diets of the forage and 

piscivorous fishes, and sedimentation rates. Development of the data set will be accomplished 

using sediment, water, and biota samples from the Lake Michigan ecosystem by analyzing for 

PCBs, PCDDs, PCDFs, and PAHs using stable isotopes and mass spectrometry. Biota samples 

will span the entire food web and will include forage fishes (i.e., rainbow smelt, alewife [two size 

classes], bloater chubs [two size classes], deepwater sculpin, and slimy sculpin), piscivorous fish 

(lake trout), benthic invertebrates (diporeia), and plankton. One of the most significant analytical 

challenges for this effort is to measure the concentrations of PCDDs and PCDFs in water column 

samples where concentrations for these chemicals are estimated to be in the range of 0.1 to 5 

fg/L in the dissolved phase, i.e., water after filtration using a 0.7 μm glass fiber filter. In order to 

obtain adequate chemical for mass spectrometry detection, 1,000 L water samples were collected 

and extracted using a continuous flow liquid-liquid extractor (Goulden extractor).

For this high quality data generation effort using the samples from the Lake Michigan ecosystem, 

many of the chemical analyses have been completed. On-going work includes the measurement 

of PCDDs and PCDFs in forage fish and PAHs in both forage and piscivorous fishes. Chemical 

analyses for the PCBs, PCDDs, and PCDFs will be completed in FY05; and with this data, a data 

set of BAFs and BSAFs will be determined for the fish species. This data set will have lower 

uncertainties than other data sets because all data will be measured on the same fish samples for 
30 Contaminated Sediment Research Multi-Year Implementation Plan

the PCBs, PCDDs, and PCDFs with high resolution mass spectrometry. The co-measurement 

of all analytes eliminates the biases from measurements performed on different fish samples 

(i.e., one set of samples used for the PCBs and another for the PCDDs and PCDFs); and high 

resolution mass spectrometry increases the specificity of the chemical analyses. The commonly 

used analysis technique of gas chromatography with electron capture detection detects all 

chemicals containing electronegative elements (e.g., halogens, oxygen, sulfur, and nitrogen); 

whereas high resolution analysis can detect specific ions with mass differences of 0.032 amu 

at a mass of 320.000 amu (M/ΔM = 10,000). We estimate that the overall uncertainties in the 

Lake Michigan data set will be smaller, at a minimum, by approximately a factor 21⁄2 over 

those observed by Oliver and Niimi (1988) based upon the tetra-, penta- and hexa-PCBs for the 

sediments. This difference does not include the temporal disconnects in the Oliver and Niimi 

(1988) data set among the collection dates for the forage fish, piscivorous fish, plankton, water 

and sediment samples. Sampling dates span the timeframe of 1981 through 1986. Therefore, 

differences in uncertainties are probably much larger than the 21⁄2 fold factor; factors may rise to 

a 10-fold difference. 

The second research effort for accomplishing this target (Step 1: Generation/assembly of high 

quality data sets) will consist of the building of data sets of BSAFs and BAFs from Superfund 

sites. This effort will involve culling through numerous Superfund RI/FS reports to find data 

of adequate quality and certainty to build the database. In general, RI/FS reports are large 

(multiple large 3-ring folders with hundreds of data tables); and the task of culling through the 

reports will take some time. For more recent RI/FS reports, site reports are available on CD-R. 

However, for most of the sites, the data are available only in paper copy; and inputting (scanning 

when possible or hand entry) and checking data will require some effort. The limitations of 

Superfund’s RI/FS reports are anticipated to fall in the following areas: (1) an insufficiency 

of ancillary data (such as lipid contents of fishes and other aquatic organisms, organic carbon 

contents of the sediments, and dissolved and particulate organic carbon in the water column); 

(2) uncertainty in determining the overlap of the fish home range and the locations of sediment 

and water column samples for the site; and (3) the lack of measurements for chemicals with 

low concentrations in water column. Water column measurements are often not performed at 

Superfund sites having contaminated sediments because only sediment and fish data are needed 

to calculate the BSAFs that are used for predicting residues in the fish. Emphasis will be placed 

on assembling data sets which span the ranges of conditions and chemical classes that occur at 

Superfund sites rather than on simply assembling all available data.

Assembling BSAF and BAF data is not a small task. To help in this process, MED will work 

in coordination with the Superfund program office. Where possible with on going RI/FSs, 

MED will work with Superfund to have appropriate measurements performed so that these 

data sets can be included into the BSAF/BAF database as well. Additionally, MED will/has 

requested funds via ORD’s Contaminated Sediment Focus Group 1 for the data assemblage and 

compilation effort (see “Resources”). 

In this effort, we would like to obtain a minimum number of BSAF/BAF data sets (e.g., 5 to 

6) that span a variety of different ecosystems conditions and chemical parameters for adequate 

statistical comparisons in the subsequent analyses and calculations (see table below). This 
31 Contaminated Sediment Research Multi-Year Implementation Plan

table is based upon the major determinants of bioaccumulation of PBTs in aquatic food webs 

(Burkhard et al. 2003a) and reflects conditions and properties which would strongly influence the 

bioaccumulation of PBTs in different ecosystems. Although we target obtaining data sets with 

the above ecosystem conditions and chemical parameters, we will obtain as many data sets 

as possible given the availability of appropriate data. With these data sets, we will assess 

extrapolation errors and uncertainties using the developed theoretical framework. Further, 

we will determine the sources of the extrapolation errors and uncertainties (see Step 2). With 

this information, we address the question of whether the extrapolation errors and uncertainties 

are good enough, e.g., whether the extrapolation errors are within a factor of 2; and we will 

identify additional data sets that may be required for further refinement. Demonstrations of 

the usefulness and applicability of the extrapolation technique to a large number Superfund 

sites would lend tremendous support to the validity of the “hybrid modeling” approach for 

extrapolating BSAF and BAF data (see Step 2). Therefore, acquisition of additional BSAF/

BAFs data sets would greatly benefit this research effort. 

Step 2: Development of extrapolation techniques

Development of techniques for extrapolating BSAF/BAF data between times, sites, ecosystem 

conditions, species, and combinations thereof requires an understanding of the fundamental 

processes controlling the extent of bioaccumulation at individual sites. Past research has 

demonstrated that corrections for lipid content of the organisms and chemical bioavailability 

(i.e., freely dissolved concentrations of the chemical in the water column and concentrations 

in sediments normalized to organic carbon) can greatly reduce variances of concentrations of 

chemicals in fish and sediments and in the variances of BAFs across ecosystems (Figure 3) 

(Burkhard et al. 2003b). Further, data from MED’s research on Lake Michigan (Figure 4) and 

from preliminary comparisons (not shown here) of BSAFs suggest that BSAFs are consistent 

with each other within and across ecosystems. The within-ecosystem consistency is illustrated 

using BSAF data for lake trout from southern Lake Michigan (Figure 4). 

The demonstrated consistency of BSAFs (as well as BAFs), as illustrated in Figure 4, is 

Range of Ecosystems Conditions and Chemical Parameters

Ecosystem Conditions

1. Simple and complex food web structures

2. Cold and warm water conditions

3. Species with highly benthic and highly pelagic dietary preferences

4. Fresh and salt water 

5. Variety of sediment-water column disequilibriums (Πsocw / Kow)

Chemical Properties

6. Variety of chemical classes including metabolizable chemicals

7. Variety of chemical hydrophobicities (Kow)
32 Contaminated Sediment Research Multi-Year Implementation Plan

generally unappreciated by the general scientific community and needs to be communicated to 

the users of bioaccumulation data. Preliminary comparisons of BSAFs across ecosystems (data 

not shown) based upon data from the literature suggests that between-ecosystem relationships for 

BSAFs can be established. These comparisons are difficult because the data used for deriving 

the BSAFs are not always collected for the purposes of determining BSAFs. The number and 

types of ecosystems for which BSAFs are available in the scientific literature are limited. The 

lack of high quality BSAFs for a variety of well characterized ecosystems is precisely the need 

addressed by Step 1 of this project.

The MED visualization approach for depicting and interpreting bioaccumulation relationships 

and data is a way to portray the extrapolation process to non-bioaccumulation experts. This 

approach is also good for designing, conducting, and interpreting bioaccumulation modelbased sensitivity analyses in order to conceptualize, plan, and conduct research to develop 

extrapolation methods. We have characterized the use of complementary and iterative 

combinations of mechanistic bioaccumulation model predictions with consistent field data 

interpretations as a “hybrid modeling.” The visualization approach has become a primary tool 

for interpreting and communicating hybrid modeling results. Using the visualization approach, 

locations of measured BSAFs in water-sediment (X-Y) chemical concentration space can be 

defined with respect to the positions of BSAFs extrapolated from the measured BSAFs. Because 

2,3',4,4',5-pentachlorobiphenyl

(PCB 118) log Kow = 6.74

TL 3 L TL 3 T TL 4 L TL 4 T

Log BAF

3

4

5

6

7

8

9

10

2,2',3,4,4'-pentachlorobiphenyl

(PCB 85) log Kow = 6.30

TL 3 L TL 3 T TL 4 L TL 4 T

2,3,4'-Trichlorobiphenyl

(PCB 22) log Kow = 5.58

TL 3 L TL 3 T TL 4 L TL 4 T

Log BAF

3

4

5

6

7

8

9

10

2,2',3,4',5,5'-hexachlorobiphenyl

(PCB 146) log Kow = 6.89

TL 3 L TL 3 T TL 4 L TL 4 T

2,2',3,4',5',6-hexachlorobiphenyl

(PCB 149) log Kow = 6.67

TL 3 L TL 3 T TL 4 L TL 4 T

2,2',5,5'-tetrachlorobiphenyl

(PCB 52) log Kow = 5.84

TL 3 L TL 3 T TL 4 L TL 4 T

Figure 3. Comparison of log BAFs based upon concentrations of chemical in tissue (wet weight basis) and water 

(total chemical in bulk water) to log BAFs based upon concentrations of chemical in tissue (lipid basis) and water 

(freely dissolved basis) for fishes from trophic levels 3 and 4 from Green Bay, Hudson River, and Lake Ontario 

ecosystems for six PCB congeners. The median (line), 25th and 75th percentiles (end of rectangles), 10th and 

90th percentiles (whiskers), and 5th and 95th percentiles (dots) are shown in the box plots.
33 Contaminated Sediment Research Multi-Year Implementation Plan

chemical properties are fixed and lipid/organic carbon variations accounted for, the extrapolation 

methodology will focus on changes in disequilibrium factors (especially sediment to water); 

trophic level of the species of concern; relative benthic versus pelagic food chain; and if 

necessary, differences in metabolism rates associated with differences in species in food chains

Col 29 vs Col 60 

Col 30 vs Col 61 

Col 31 vs Col 62 

Col 32 vs Col 63 

Col 33 vs Col 64 

Col 34 vs Col 65 

Col 29 vs Col 60 

Col 30 vs Col 61 

Col 31 vs Col 62 

Col 32 vs Col 63 

Col 33 vs Col 64 

Col 34 vs Col 65 

BSAFs for 6 yrs

Lake Trout

1e-4

1e-3

1e-2

1e-1

1e+0

1e+1

1e+2

slope = 1.053

r = 0.9935

nPCB = 103

nD/F = 40

BSAFs for 2 yr old

Lake Trout

1e-5

1e-4

1e-3

1e-2

1e-1

1e+0

1e+1

1e+2

BSAFs for 8 yr old Lake Trout

1e-5

1e-4

1e-3

1e-2

1e-1

1e+0

1e+1

1e+2

slope = 1.068

r = 0.9913

nPCB = 104

nD/F = 39

Figure 4. Comparison of BSAF values for southern Lake Michigan Lake Trout of different age classes. The 

red, purple, blue, turquoise, and green points (circles) represent PCB congeners with 0, 1, 2, 3, and 4 orthochlorines, respectively; the yellow (squares) and orange (diamonds) points are the PCDDs and PCDFs, 

respectively. The encircled (PCBs), ensquared (PCDDs), and endiamonded (PCDFs) data points have nonzero mammalian toxicity equivalence factors (TEFs). For the ensquared and endiamonded data points with 

no internal data point, these points represent estimated BSAFs for PCDDs and PCDFs, respectively, using 1⁄2 

minimum detection limit.
34 Contaminated Sediment Research Multi-Year Implementation Plan

The actual process of taking BSAFs derived from high quality field measurements in one 

ecosystem and applying them to another ecosystem (with different conditions and food web 

structure and composition) would be accomplished using simple food web models. The simple 

food web models would be used to forecast relative differences in bioaccumulation using the 

conditions and parameters of the two ecosystems, and these forecasted relative differences would 

then be used to the adjust the BSAFs measured in one ecosystem to another ecosystem. To 

illustrate the hybrid modeling approach, BSAFs were predicted for trophic level four salmonids 

using the BSAFs measured for alewife in the Lake Ontario ecosystem and forecasted relative 

differences between fish of trophic levels three and four (see table).

Although relative differences in bioaccumulation potential between chemicals should be 

amenable to extrapolation as illustrated above, calibration through acquisition of a minimum 

data set for the ecosystem being evaluated may be required to achieve the desired accuracy 

for individual BSAFs and BAFs in the new ecosystem. The intent of this research effort is to 

organize and validate this hybrid BAF/BSAF extrapolation methodology and thereby define 

its potential for applications to site assessments at different levels of specificity and cost. The 

advantages of the hybrid BAF/BSAF approach would be great if successfully validated. The 

methodology would enable Superfund to make highly accurate predictions of bioaccumulation 

for different Superfund sites with minimal data collection efforts. Additionally, uncertainties in 

the BSAFs could be even further reduced by the collection of appropriate data and incorporation 

of that information into the extrapolations.

The hybrid BAF/BSAF approach is on a continuum between the use of purely empirical 

Across Species Extrapolation of BSAFs from the Hybrid Modeling Approach using Lake Ontario data of Oliver 

and Niimi (1988) Between Forage Fish (Alewife) and Salmonids in the Lake Ontario Ecosystem.

 Hybrid Modeling Approach* 

PCB log Kow

Field measured 

alewife BSAFs

Predicted 

relative 

difference

Predicted 

trophic level 

four BSAFs 

(salmonids)

Measured 

salmonid 

BSAFs

Difference 

between measured 

and predicted 

BSAFs for 

salmonids

47+48 5.82 0.579 1.996 1.155 1.227 0.072

49 5.85 0.491 2.040 1.001 0.692 -0.310

52 5.84 0.417 2.026 0.844 0.609 -0.235

101 6.38 1.571 2.591 4.071 2.455 -1.616

105 6.65 1.041 2.699 2.811 2.700 -0.111

110 6.48 0.813 2.644 2.150 1.526 -0.624

118 6.74 1.491 2.711 4.043 4.091 0.048

149 6.67 1.331 2.703 3.596 2.332 -1.264

180 7.36 1.424 2.468 3.515 3.776 0.261

*Relative differences were predicted using 5% lipid contents in all species, weights of 10 g and 1 kg in forage and 

piscivorous fishes (respectively), no metabolism, 50:50 pelagic:benthic diet for the forage fish, piscivorous fish 

eating only forage fish, and a disequilibrium of 25.
35 Contaminated Sediment Research Multi-Year Implementation Plan

BSAF/BAF measurements (in both ecosystems) and complete mechanistic food web modeling 

for both ecosystems (in an ecosystem where the BSAF was measured and in an ecosystem 

where the extrapolated BSAF is desired). Depending upon the effort undertaken in developing 

extrapolation ratios (i.e., predicted relative differences in bioaccumulation) from the mechanistic 

food web models, the approach allows predictions anywhere on the continuum. In application, 

we expect the hybrid approach to be used in an iterative process, incorporating additional data 

for the site of interest as it becomes available. The hybrid approach is entirely complimentary 

with the mechanistic modeling approaches. In an iterative application, the hybrid model would 

provide the data needed for the detailed mechanistic models when higher levels of accuracy 

might be required in the risk assessments. 

The following research tasks will be performed to determine the validity of the hybrid BAF/

BSAF approach for different extrapolation scenarios and degrees of specificity. In Task 1, 

the theoretical and conceptual framework for performing the extrapolations will need to be 

developed further to determine how one would optimally make a prediction. We believe that the 

hydrophobicity and tendency for metabolism of the particular chemical will strongly influence 

the extent of bioaccumulation for the chemical at the two sites or at a given site at different times. 

Having the framework will allow Task 2 to be initiated. In Task 2, we will need to determine 

the level of simplicity in the food web model that is required to forecast the relative differences 

in BAFs/BSAFs. To accomplish this task, forecasts for a number of different ecosystems that 

have differing complexity will be made and evaluated for predictive error and uncertainty. The 

forecasts would initially be performed using very generic conditions and parameters for the 

two respective ecosystems. Subsequently, forecasts would be made using more site-specific 

food web models, e.g., using actual lipid contents and weights for the fishes, site-specific 

diet information, sediment-water column chemical concentration quotients, etc., All of these 

forecasts would be evaluated for their predictive error and uncertainty. Concurrently with Task 

2, Task 3 will develop criteria for the data quality and requirements needed for the extrapolation 

process. Issues include establishing minimum data requirements and criteria to evaluate the 

appropriateness of the data from specific ecosystems for use in extrapolation elsewhere.

In Task 4 of Step 2, we will determine how to account for metabolism processes and their 

effects in the forecasts of relative differences with the food web model. The requirements for 

simple food web models to account for the differences in metabolic rates is unknown when large 

differences in metabolic abilities exist between species (e.g., eels might not be able to metabolize 

the 2,3,7,8-TCDD to the extent observed in teleost fish such as carp). Additionally, although 

food web models can account for metabolism processes in their predictions, the general lack of 

measured rates of metabolism for aquatic species limits our ability to account for the differences 

in rates of metabolism even if we wished to do so. Here, we will make forecasts for chemicals 

with highly differing metabolism rates (ideally including reference chemicals resistant to 

metabolism) and compare these forecasts to field data. Like Task 3, predictions would be made 

in a graded level of complexity, starting with forecasts of relative differences that assume no 

metabolism and moving to forecasts having more realistic metabolism rates. These predictions 

will allow the assessment of the importance of metabolism information into the forecasts of 

relative differences in the BAFs or BSAFs.
36 Contaminated Sediment Research Multi-Year Implementation Plan

Task 5 of Step 2 will aid in resolving the question addressed in Task 4. In Task 5, rates of 

metabolism for individual chemicals will be determined from the field data sets developed in 

Task 1. This effort will involve the solving of the food web model for the km parameter by 

inputting all other required parameters for the model. In essence, the approach accounts for 

the residual (difference between measured and predicted residues in a fish species) with the km 

term. Clearly, these calculations require very high quality data for all input parameters, e.g., 

chemical concentrations in sediment and water, diet, weights, lipid contents, trophic level, food 

web structure, etc., It is hoped that enough data sets which include common chemicals and 

species (e.g., 2,3,7,8-TCDD in carp) across different ecosystems can be assembled. If possible, 

a consensus rate of metabolism could be derived for individuals from the various ecosystems. 

With these values, relative differences forecast by the simple food web models with the 

adjustment for differing metabolism rates could be performed in Task 4. 

Task 6 of Step 2 will examine the theoretical framework and forecasting errors to determine 

whether the theoretical framework is adequate for performing the predictions. This evaluation 

would look for obvious and/or consistent biases in the predictions for specific chemical types 

or classes. If deemed necessary, Tasks 1 through 4 will be repeated until the strengths and 

limitations of the hybrid BAF/BSAF approach are defined sufficiently to allow methods 

development for Superfund applications. Task 7 of Step 2 will develop software that provides 

a user-friendly interface for the hybrid BAF/BSAF approach to predict relative differences and 

perform the extrapolations. We anticipate that the software will be written in Visual Basic and 

run on a PC with a Windows operating system.

An additional consideration throughout Tasks 2 through 7 is the transferability of the hybrid 

modeling approach to marine ecosystems which differ from freshwater systems in many 

ways including the widely differing set of potential species. We believe that bioaccumulation 

submodels for these specific species (e.g., blue crabs, lobster, scallops, and shrimp) will be 

required for making adequate predictions of the relative differences in bioaccumulation. 

Bioaccumulation models already exist for some but not all of these species. As we work through 

Tasks 2 through 7, this research effort will build the tools required to apply the hybrid modeling 

approach to marine ecosystems. Most importantly, Task 7, software for predicting the relative 

differences in bioaccumulation, will have to include bioaccumulation submodels for non-fish 

marine species.

Step 3: Validation

Assuming useful BAF/BSAF extrapolation methods emerge from development of the hybrid 

modeling approach, validation is required for successful completion of the research effort. This 

effort will make predictions of BSAFs that are based on extrapolation between ecosystems and 

(if possible) within ecosystems for pre- and post-sediment remedial action conditions. These 

predictions will then be compared to measured BSAFs for both relative (between chemicals) and 

absolute accuracies. In the critical path flowchart (see “Products” below), the validation effort 

is highlighted in blue and consists of a triangular flow of efforts among Prediction, Application, 

and Validation components. The validation effort is envisioned as a interactive exchange among 

these three components and would be performed for a variety of ecosystem types (e.g., rivers, 

lakes, estuaries, and harbors); ecosystem conditions and parameters (warm vs. cold water, 
37 Contaminated Sediment Research Multi-Year Implementation Plan

freshwater vs. saltwater, sediment-water column concentration relationships, food web structure 

and composition, and species differences); and classes of chemicals (e.g., PCBs, PAHs, PCDD/

Fs, and DDTs). 

Technology Transfer 

Transfer of the research results and efforts will occur through variety of mechanisms: 

1. A series of fact sheets describing research to date, progress, and the state of the science 

for specific issues will be prepared in consultation with OSRTI. Fact sheets will be also 

written for OSRTI to provide guidance and applications examples for using the hybrid 

modeling approach. These fact sheets will be written throughout the research effort. Final 

summaries of the overall projects will be written at the end of the project in FY08. 

2. Educational seminars will be given using a variety of mechanisms, including the ORDOSRTI seminar series, OSRTI’s ERAF semi-annual meetings, and at workshops on 

contaminated sediments organized by OSRTI. 

3. Peer reviewed journal reports will be written and published. These reports will also be 

provided to OSRTI.

4. Presentations will be given at regional/national/international scientific workshops and 

meetings.

Resources

NHEERL Category D Needs

In addition to the personnel costs, benefits, supplies, equipment, etc., that are specifically 

associated by ORD with FTE and 

considered intramural resources, 

NHEERL uses ORD planning 

resources to pay laboratory indirect 

costs (called “ABC costs”) and 

project-specific costs (called 

“Category D costs”). Listed below 

are the kinds of Category D needs 

associated with this project. Annual 

budget planning documents determine the dollar amounts needed.

Year Division FTEs

2004 MED 3.75

2005 MED 3.75

2006 MED 3.75

2007 MED 4

2008 MED 4

Year Division Supplemental 

Funding ECOTOX

2004 MED yes yes

2005 MED yes

2006 MED yes

2007 MED yes

2008 MED yes
38 Contaminated Sediment Research Multi-Year Implementation Plan

Critical Path

Products

By 2008 provide hybrid modeling approaches using empirical field data and 

bioaccumulation models to extrapolate BAFs and BSAFs for PBTs across 

ecosystems, species, and time.

FY08 NHEERL

Provide a hybrid modeling/empirical approach for predicting BAFs, BSAFs, 

and resulting risks from metabolized chemicals such as dioxins and PAHs 

(revised wording for APM 04-6)

FY04 NHEERL

Lawrence 

Burkhard

Provide the methods and data necessary to parameterize and apply the 

hybrid modeling/empirical approach to support ecological risk assessment 

of bioaccumulative sediment contaminants

FY06 NHEERL

Lawrence 

Burkhard

Provide a fully field validated hybrid modeling/empirical approach for 

extrapolating BAFs, BSAFs, and predicting the ecological effects of 

mixtures of PBTs with differing rates of metabolism on a site-specific basis

FY08 NHEERL

Lawrence 

Burkhard

Visualization

Approach

Determine Model

Complexity

Develop Hybrid

BAF/BSAF

Approach

Application of

Hybrid BAF/BSAF

Approach to

Superfund sites

Lake Michigan

high quality data

development

Metabolism

rates for PAHs,

PCBs, PCDD/Fs

Incorporating

metabolism

into food web

models

Prediction of

BSAFs using

hybrid approach

Validation of

hybrid

approach

BSAF data base

BSAF comparisons

across ecosystems,

species, & time

Superfund data

Gathering and evaluation

Focus Group

Supplemental Funding

Non-Superfund data

Hybrid Model Development

NHEERL Measurement of High Quality BSAFs

Development of high quality BSAF data from existing data sources

OSRTI

Gathering

and

evaluation

Determine Data

Requirements

Account for

Metabolism
39 Contaminated Sediment Research Multi-Year Implementation Plan

References

Burkhard, L.P. 1998. Comparison of two models for predicting bioaccumulation of hydrophobic 

organic chemicals in aquatic food webs. Environ Toxicol Chem 17:383-393. 

Burkhard, L.P., P.M. Cook, and M.T. Lukasewycz. 2004. Biota-sediment accumulation factors 

for polychlorinated biphenyls, dibenzo-p-dioxins, and dibenzofurans in southern Lake 

Michigan lake trout (Salvelinus namaycush). Environ Sci Technol 38:5297-5305.

Burkhard, L.P., P.M. Cook, and D.R. Mount. 2003a. The relationship of bioaccumulative 

chemicals in water and sediment to residues in fish: a visualization approach. Environ 

Toxicol Chem 22:2822-2830.

Burkhard, L.P., D.D. Endicott, P.M. Cook, K.G. Sappington, and E.L. Winchester. 2003b. 

Evaluation of two methods for prediction of bioaccumulation factors. Environ Sci Technol 

37:4626-4634.

Burkhard, L.P. 2003c. Factors influencing the design of BAF and BSAF field studies. Environ 

Sci Technol 22:351-360.

DiToro, D.M., et al. 1991. Technical basis for establishing sediment quality criteria for nonionic 

organic chemicals using equilibrium partitioning. Environ Sci Technol 10:1541-1583.

Gobas, F.A.P.C. 1993. A model for predicting the bioaccumulation of hydrophobic organic 

chemicals in aquatic food-webs: application to Lake Ontario. Ecol Model 69:1-17.

Mackay, D. 1982. Correlation of bioconcentration factors. Environ Sci Technol 16:274-278.

 McCarty, L.S. and D. Mackay. 1993. Enhancing ecotoxicological modeling and assessment: 

body residues and modes of toxic action. Environ Sci Technol 27:1719-1728.

Oliver, B.G. and A.J. Niimi. 1988. Trophodynamic analysis of polychlorinated biphenyl 

congeners and other chlorinated hydrocarbons in the Lake Ontario ecosystem. Environ Sci 

Technol 22:388-397.

Thomann, R.V., J.P. Connolly, and T.F. Parkerton. 1992. An equilibrium model of organic 

chemical accumulation in aquatic food webs with sediment interaction. Environ Sci Technol

11:615-629.
40 Contaminated Sediment Research Multi-Year Implementation Plan

Project IV: Research to Evaluate the Release and Bioavailability 

of Contaminants Associated with Resuspended Sediments and 

Post-Dredging Residuals at Superfund Sites

Summary of Issue

At contaminated sediment sites, the Superfund program usually must decide whether to leave 

the site alone, cap it, or dredge it. This decision is based in part upon the relative risks to the 

environment and human health posed by each option. If the risks associated with the site are 

determined to be sufficiently great, dredging will frequently be used to remove the contaminated 

sediments and reduce the risks. In practice, dredging is the most common remedy for sites 

containing contaminated sediments. There are several advantages to the use of dredging, 

principally the removal of most of the material causing the identified risk. Simultaneously, 

dredging is the most expensive remedy with the greatest potential to impart short-term adverse 

impacts on the site and on surrounding uncontaminated areas. These potential impacts 

are believed to be derived primarily from the effects of the resuspension of contaminated 

sediments during dredging. Based on the available information (e.g., Anchor Environmental 

2003, Palermo and Averett 2003, Eggleton and Thomas 2004), resuspension can result in the 

transport of contaminated particles from the site as well as the flux of dissolved and bioavailable 

contaminants into the water column. These fluxes may result in the contamination of previously 

clean areas.

It is worth noting that resuspension also occurs at Superfund sites under circumstances other than 

dredging. Natural phenomena including tidal action, currents, storm events, and bioturbation 

result in the resuspension of contaminated sediments (Davis 1993, Thibodeaux and Bierman 

2003). Additionally, anthropogenic activities other than dredging including ship traffic result 

in resuspension. Consequently, beyond the risk associated with dredging, resuspension of 

contaminated sediments at Superfund sites is likely to occur because of these other activities. At 

this time, it is unknown how the magnitude and duration of dredging related resuspension risk 

compares to the risk associated with natural and other anthropogenic phenomena. Of course, 

understanding this would contribute to a better assessment of risk at Superfund sites. 

Specifically for dredging and generally for other causes, the effects of resuspension occur across 

different temporal and spatial scales that can be placed into many categories. For example, in 

use at Superfund sites are the terms “near field” and “far field” effects. However, these terms 

can be relative and site-specific and cannot be defined as absolutes. For the research described 

here, the effects of interest on the basis of temporal and spatial scales are (1) transportation of 

dissolved and bioavailable contaminants from the immediate dredging area to areas of lesser 

contamination over a duration of days and (2) alteration of the bioavailability of contaminants 

associated with resuspended and resettled sediment (e.g., post-dredging residuals) within the 

dredging zone over months. In the context of this research, bioavailability is defined as the 

presence of the chemical form(s) of a contaminant, organic or inorganic, which readily interacts 

with an organism’s tissues resulting in adverse effects (toxicity) or uptake (bioaccumulation). 

Any geochemical, physical, or biological event associated with resuspension altering the amount

of bioavailable contaminant is of concern.
41 Contaminated Sediment Research Multi-Year Implementation Plan

This research will address the risk associated with the resuspension of contaminated sediments 

resulting primarily from dredging. Specifically, this research will evaluate modeling and 

empirical approaches for predicting and measuring the risk of increased bioavailability and 

bioaccumulation of organic and inorganic contaminants caused by dredging events at Superfund 

sites. This research will include evaluating the bioavailability of resettled contaminated 

sediments which constitute one form of post-dredging residuals.

Summary of the State of the Science

Methods and models are available for estimating the partitioning, bioavailability, and effects 

of contaminants in sediments under equilibrium or undisturbed conditions. For example, 

equilibrium-based models allow for accurate predictions of toxicity and bioaccumulation. 

However, when sediments are resuspended or enter a state of disequilibrium, studies have 

demonstrated that associated contaminants, including organic and inorganic pollutants, are 

released or remobilized into the water column and potentially made bioavailable (Valsaraj et al. 

1997, Latimer et al. 1999, Pedersen et al. 1999, Bonnet et al. 2000, Cantwell et al. 2002, Nayar 

et al. 2003, Eggleton and Thomas 2004). In one study, the magnitude of disequilibria resulted 

in suspended solids concentrations of approximately 20,000 mg/L as compared to essentially 

no suspended solids under equilibrium conditions (Cantwell et al. 2002). Furthermore, in the 

recent review of the Hudson River resuspension standard (Eastern Research Group, Inc. 2004), 

the peer-reviewers expressed concern about the release of dissolved-phase PCBs resulting from 

resuspension. Despite the evidence of release of contaminants from resuspended sediments, the 

bioavailability and effects of these contaminants in terms of toxicity to or bioaccumulation by 

aquatic life have not been studied extensively and are not very well understood.

A few models and methods exist for estimating the extent to which contaminant remobilization 

is likely to occur from resuspension of contaminated sediments. For example, fate and transport 

models like the Army Corps of Engineers Waterway Experiment Station’s (ACE-WES) 

ICM/TOXI, RECOVERY, and STFATE (U.S. ACE 2003). There are also some advanced, 

mathematically intensive fate and transport models like EFDC and ECOMSED (Imhoff et al. 

2003). Empirical methods include simple (Simpson et al. 1998, 2000) and complex (Gerringa 

1991, Chen et al. 2000, Gao et al. 2003) laboratory procedures while other approaches focus 

primarily on field studies (Calvo et al. 1991, van den Berg et al. 2001). Further, recent 

geochemical studies have investigated desorption mechanisms for organic contaminants under 

resuspension conditions (Shor et al. 2003). However, there are limitations that diminish the 

predictive ability and overall effectiveness of each of these methods. Models’ predictive 

accuracy is generally unknown because most often models’ results are not validated. A thorough 

evaluation of all such models should be performed. Methods often evaluate sediments under 

very specific conditions that do not reflect or approximate field conditions. Field studies do 

provide accurate and detailed data, but this information is site-specific and is expensive to 

generate. Finally, the linkage between the predicted release of contaminants and of contaminants 

bioavailability is weak. 

Starting in FY2004, we initiated an effort to evaluate the existing fate and transport models 

with regard to use with sediment resuspension. Thus far, the Army Corps of Engineers fate and 
42 Contaminated Sediment Research Multi-Year Implementation Plan

transport models and some advanced, mathematically intensive models have been investigated. 

The ACE models focus on predicting the transport of contaminants on sediment particles and do 

not consider the release of dissolved and bioavailable contaminants during resuspension (U.S. 

ACE 2003, T. Bridges, personal communication). The advanced, mathematically intensive 

models like EFDC are reputed to predict the release of dissolved and bioavailable contaminants 

during resuspension but have not undergone any rigorous verification under laboratory or field 

conditions (Imhoff et al. 2003, E. Hayter, personal communication). During the evaluation 

of these models, both ACE-WES and NERL (i.e., T. Bridges and E. Hayter, respectively) 

expressed interest in collaborating with NHEERL to better characterize the risk resulting from 

resuspension.

A shared goal for researchers from NHEERL, NERL, and ACE-WES is to improve our 

understanding of the risks associated with the release of contaminants during resuspension 

events. A result of this shared goal is the potential to generate multiple data sets of laboratory 

and field data to calibrate and validate model predictions of the dredging-related release of 

organic and inorganic contaminants. To this end, efforts are underway to identify mechanisms 

for enhancing collaborations between NHEERL, NERL, and ACE-WES.

The following figure illustrates a conceptual model of the relationship between method 

development, field measurements, and model predictions. In each box, the objective is to 

perform measurements or predictions of the concentrations of dissolved organic and inorganic 

contaminants.

Method development generates the tools for making the measurements and provides input for the 

sampling design of the field component. The field measurements are performed while dredging 

is occurring and are specifically designed to determine the magnitude of the released dissolved 

contaminants. Finally, results of the field measurements are compared to the concentrations 

Field

Measurements

• Dissolved Contaminant

Compare/Validate

Results

Method Development

• Dissolved Phase Analysis

• Instrumentation Evaluation

• Sampling Design

Model

Predictions

• Dissolved Contaminant

Field

Measurements

• Dissolved Contaminant

Compare/Validate

Results

Method Development

• Dissolved Phase Analysis

• Instrumentation Evaluation

• Sampling Design

Model

Predictions

• Dissolved Contaminant
43 Contaminated Sediment Research Multi-Year Implementation Plan

of dissolved contaminants predicted by the model. Below is a cartoon of a possible sampling 

design for a Superfund site undergoing dredging:

Another aspect of resuspension at Superfund sites is the resettlement of suspended sediments 

within the vicinity of the dredging operation (i.e., a form of residual). There is some evidence 

that when sediments are suspended, the bioavailability of associated organic and inorganic 

contaminants is altered as compared to that of the original sediment (e.g., Pedersen et al. 1999, 

Lin et al. 2003). Following resettlement, it is suspected that contaminants are more bioavailable 

(i.e., sequestering phase has been changed) or that the amount of bioavailable contaminant is 

greater than originally observed. One explanation for such effects are alterations of the organic 

carbon structure resulting from oxidation and other changes the sediment experiences when 

moving from reduced (sedimentary) to oxidized (water column) conditions. This issue has 

received very little scientific attention; research is required to determine the magnitude of any 

alteration in contaminant effects. Recently, NRMRL proposed to refocus part of their Superfund 

research effort on post-dredging residual-related research. Research in the project discussed here 

will seek to collaborate with the NRMRL effort wherever possible.

Based on the above discussion, the following are key gaps in our understanding of the 

environmental risks associated with resuspension of contaminated sediments at Superfund sites:

1. How effectively the current models of contaminant fate and transport predict the release of 

dissolved and bioavailable contaminants during resuspension;

2. The magnitude of release of dissolved and bioavailable contaminants during dredging from 

the dredging zone into the lesser contaminated areas; and

3. The effects of resuspension and resettlement on the bioavailability of sediment contaminants.

Primary Water Flow

Dissolved Phase

Sampling Site

Dredging Zone

Primary Water Flow

Dissolved Phase

Sampling Site

Dredging Zone
44 Contaminated Sediment Research Multi-Year Implementation Plan

Research Needs

Based upon the issue summary, state of the science, and the gap analysis, the following key 

scientific challenges have been identified. 

1. Link model development and field measurements to validate fate and transport models for 

predicting the release of dissolved and bioavailable contaminants from sediments during 

resuspension events;

2. Under field conditions, determine the potential for the release of dissolved and bioavailable 

contaminants from sediments during resuspension events; and

3. Conduct an assessment of the changes in the bioavailability of organic and inorganic 

contaminants occurring in contaminated sediments following resuspension and 

resettlement.

Proposed Research Targets

The steering committee identified the following research targets for this project after assessing 

research needs, the level of effort required to achieve them, and the expertise and resources 

available.

The objective of the resuspension research is to improve our understanding of the magnitude of 

risk associated with contaminated sediments resuspension. In particular, this work focuses on 

determining the risk associated with dredging sediments at Superfund sites contaminated with 

PCBs and other organic and inorganic toxic chemicals. The fundamental question involves 

the effects of dredging on the bioavailability of contaminants associated with sediments. 

Specifically, we wish to understand whether dredging causes a significant change in contaminant 

bioavailability via the release and transport of dissolved (and bioavailable) contaminants outside 

of the immediate dredging zone and/or via the alteration of the sediment phases controlling the 

partitioning and bioavailability of contaminants in resettled sediments.

Specific products/information resulting from this research will include the following:

1. Report evaluating fate and transport models for predicting dissolved concentrations of 

organic and inorganic contaminants in Superfund site sediments following resuspension 

events;

2. Evaluate concordance between field measurements and fate and transport model 

predictions of dissolved concentrations of organic and inorganic contaminants in 

Superfund site sediments following resuspension events (in collaboration with NERL and 

ACE-WES);

3. Report summarizing evaluation of approach for measuring the transport of dissolved 

contaminants beyond the dredging zone at selected Superfund sites; and

4. Report assessing significance of changes in bioavailability of organic and inorganic 

contaminants in Superfund site sediments following resuspension into the water column 

and resettlement to sediment bed (including residuals).
45 Contaminated Sediment Research Multi-Year Implementation Plan

Research Activities/Approaches

To achieve these targets, three major activities must be taken.

1. Collaboration between NHEERL, NERL, and ACE-WES researchers to review 

and evaluate the effectiveness of existing resuspension models and compare field 

measurements (see below) with model predictions;

2. Research to develop a method for measuring dissolved organic and inorganic contaminants 

under field conditions; and

3. Research to assess changes in bioavailability of contaminated sediments resulting from 

resuspension and resettlement (including collaborations with NRMRL post-dredging 

residuals research effort).

1. Review and evaluate resuspension models

This activity has two components. In the first, available resuspension models will be reviewed 

for their ability to predict dissolved and bioavailable concentrations of organic and inorganic 

contaminants. The emphasis will be on assessing what the models under consideration do well 

and what they do poorly. Further, the review will inquire whether the models have undergone 

field verification.

For the second component, results of field measurements of dissolved organic and inorganic 

contaminants, discussed in detail below, will be compared to resuspension model predictions. A 

site visit to ACE-WES in September 2004, initiated collaboration between NHEERL and ACEWES scientists on this activity. Discussions from this visit indicated output from the ACE’s 

ICM/TOXI model are the data to compare with field measurements. As noted above, the data 

to be compared will include concentrations of dissolved organic and inorganic contaminants, as 

well as suspended solids and concentrations of particulate inorganic and organic contaminants. 

Additionally, discussions with NERL have started. Preliminary plans call for comparing 

the results of advanced, mathematically intensive model analyses (e.g., EFDC, ECOMSED) 

with results from field measurements. Based on these comparisons, model predictions and 

field measurements will be reviewed to ultimately calibrate and improve the operation of the 

model(s).

This activity will also include evaluating other relevant models by local, national, and 

international organizations including the United States Geological Survey (USGS) (e.g., http://

woodshole.er.usgs.gov/project-pages/sediment-transport) to determine whether these models may 

address Superfund needs.

2. Develop approaches/methods for measuring dissolved organic and inorganic contaminants 

under field conditions

In this activity, the objective is to develop an approach for measuring dissolved concentrations 

of organic and inorganic contaminants in the water column during dredging events under field 

conditions. The research will have two primary components. In the first, laboratory research 

will be performed to develop and evaluate the approach; in the second, the developed approach 

will be taken into the field and used to measure water column concentrations of dissolved organic

and inorganic contaminants in the waters outside of the dredging zone.
46 Contaminated Sediment Research Multi-Year Implementation Plan

In the laboratory component, the challenge will be to develop tools for measuring dissolved 

contaminant concentrations. A few promising technologies are available including 

semipermeable membrane devices (SPMDs) which serve as surrogate organisms (Huckins et al. 

1993, Hofelt and Shea 1997, Axelman et al. 1999), polyethylene (PE) samplers which use a thin 

synthetic film as an absorbing phase to collect dissolved contaminants (Vinturella et al. 2004, 

Lohmann et al. 2005), and solid-phase microextraction (SPME) in which polymer-coated fibers 

adsorb analytes from the dissolved phase (Arthur and Pawliszyn 1990, Mayer et al. 2000, Zeng 

et al. 2004). Dissolved inorganic contaminants will be investigated using iminodiacetate groupbased samplers (“gellyfish”) (Senn et al. 2004). To evaluate these tools, laboratory studies will 

be conducted using simulated resuspension events generated in exposure chambers. For these 

evaluations, the particle entrainment simulator (PES) (Tsai and Lick 1986) will be used. Since 

its development, the PES has also been used to evaluate the behavior of organic and inorganic 

contaminants in resuspended sediments (Lavelle and Davis 1987, Bedford 1994, Latimer et 

al., 1999, Cantwell et al. 2002, Cantwell and Burgess 2004). The PES is a fairly simple device 

consisting of a cylindrical chamber in which a sediment core from a site of interest is placed and 

overlying water is then added. Under “no energy” conditions, the system in the PES emulates 

a passive sediment-water interface. However, a perforated grid in the PES can be activated to 

impart known levels of energy to the sediment-water interface, causing sediment resuspension. 

While the simulated resuspension is occurring, the overlying water will be monitored for 

numerous water column parameters including pH, dissolved oxygen, and oxidation-reduction 

potential. Further, samples of the overlying water will be collected for measurement of the 

mass of suspended sediment and concentrations of contaminants in the particulate and dissolved 

phases including toxic metals (cadmium, copper, nickel, lead, and zinc) and organic pollutants 

(e.g., PCBs, PAHs). It is during these simulations that the SPMD and SPME approaches will be 

evaluated.

The laboratory component of the research will also serve to identify physical and chemical 

terms in the sediment and water column that have potential to serve as key predictors of 

resuspension and release of dissolved organic and inorganic contaminants. Likely key predictors 

include levels of AVS, organic carbon, grain size distribution, and extent of contamination. 

Resuspension variables (e.g., energy, duration) will also be considered.

For the field component of this activity, following the laboratory component and development of 

sound approaches/tools, at least three sites undergoing dredging will be studied. Field sites for 

consideration include New Bedford Harbor, MA; the Hudson River, NY; and one additional site 

not yet identified. These studies will serve to test the utility of tools developed in the laboratory 

and directly address the scientific needs of OSRTI. A significant part of this field work will be 

the development of a statistical sampling design which considers spatial and temporal variables. 

Consultation with AED’s statistician in the development of this design will complement this 

work. As discussed above, results of the field studies will be compared with model estimates of 

resuspension and dissolved organic and inorganic contaminants.

Another direction for this research to explore is the use of sophisticated chemical probes. Such 

probes would incorporate technology to allow in situ and rapid measurement of several classes 

of contaminants as they enter the water column during resuspension. Incorporation of these 

approaches to the design discussed here will depend on the results of the initial investigations.
47 Contaminated Sediment Research Multi-Year Implementation Plan

3. Assess changes in bioavailability of contaminated sediments resulting from resuspension and 

resettlement

Sediments from Superfund sites around the country (see sites sited above) will be used to assess 

whether or not the bioavailability of contaminants associated with resuspended sediments 

changes following settling (i.e., residuals). In these studies, sediment cores will be collected 

and sectioned into two identical portions. Using bioaccumulation by infaunal bivalves and/or 

polychaetes as the measure of bioavailability, one half of the sediments will be evaluated without 

any manipulation. The second half of the sediment sample will be vigorously mixed to mimic 

a dredging event and then allowed to settled. Because of the amounts of sediment needed for 

this study, the simulated dredging event will involve large-scale mechanical mixing. Following 

this mock dredging event, these sediments will be evaluated for bioavailability. The null 

hypothesis being tested is that the dredging event has no effect on contaminant bioavailability. 

A predominant alternative hypothesis is that dredging results in changes in bioavailability. If 

a change in bioavailability is observed soon after the resettlement, a second exposure maybe 

performed several months after the initial resuspension to evaluate the duration of the change. 

An extension of this study is an investigation of the effects of resuspension and resettlement 

on the texture of the sediments. While the focus above is on the change of contaminant 

availability, resuspension will also alter the sediment grain size distribution. This change may 

result in organisms selecting more contaminated fine grained sediments particles to feed upon. 

Such alterations may have food web consequences not immediately obvious based on using 

bioaccumulation of contaminants by benthic fauna as the effects endpoint. 

Technology Transfer 

Technology transfer of the results of this research will have two principle forms: client-oriented 

and scientific community-oriented. First, for the client-oriented form, guidance will be provided 

in the form of participation in site visits, travel to Headquarters to discuss findings, development 

of facts sheets, and presentation of seminars. The objective of this form of technology transfer 

will be to provide OSRTI Headquarters and Regional personnel with information to assist them 

in applying the findings of the research and informing them about how the new information and 

tools can be used to advance decision making at Superfund sites.

The second form of technology transfer will be to the scientific community. This will take 

the conventional forms of peer-reviewed scientific papers and presentations at national and 

international scientific meetings. The purpose of this technology transfer will be to demonstrate 

to the scientific community and OSRTI personnel that the work performed by NHEERL is 

scientifically sound and accepted. In turn, this step in the technology transfer process lends 

confidence to OSRTI’s use of NHEERL data in decision making at Superfund sites.
48 Contaminated Sediment Research Multi-Year Implementation Plan

Resources

Year Division FTEs

2004 AED 1.00

2005 AED 1.00

2006 AED 1.00

2007 AED 1.00

2008 AED 1.00

2009 AED 1.00

NHEERL Category D Needs

In addition to the personnel costs, benefits, supplies, equipment, etc., that are specifically 

associated by ORD with FTE and considered intramural resources, NHEERL uses ORD planning 

resources to pay laboratory indirect costs (called “ABC costs”) and project-specific costs (called 

“Category D costs”). Listed below are the kinds of Category D needs associated with this 

project. Annual budget planning documents determine the dollar amounts needed.

Year Division Analytical 

Chemistry GIS Statistics Field Support Modeling

2004 AED

2005 AED yes yes yes

2006 AED yes yes yes yes yes

2007 AED yes yes yes yes yes

2008 AED tbda tbd tbd tbd tbd

2009 AED tbd tbd tbd tbd tbd

a

tbd = to be determined
49 Contaminated Sediment Research Multi-Year Implementation Plan

Critical Path

(2) Research to Assess Risk Associated with

Transport of Dissolved Contaminants beyond

the Dredging Zone

Evaluate Approach at

Selected Superfund Sites

Develop Approach for

Measuring Transport of

Dissolved Contaminants

at Superfund Sites

FY05 FY06 FY07 FY08

(1) Evaluate Concordance Between Field Measurements and Resuspension Model Predictions

Evaluate Existing

Resuspension Models

FY08a

Report

Evaluate Concordance Between Field Measurements

and Resuspension Model Predictions

(collaborate with ACE and NERL)

FY08b

Report

(3) Research to Assess Changes in Bioavailability

of Contaminated Sediments Resulting from

Resuspension and Resettlement

Develop Experimental

Approach to Simulate Dredging

including Bioavailability

Evaluate with Selected

Superfund Site Sediments

FY07

Report

FY06

Report

(2) Research to Assess Risk Associated with

Transport of Dissolved Contaminants beyond

the Dredging Zone

Evaluate Approach at

Selected Superfund Sites

Develop Approach for

Measuring Transport of

Dissolved Contaminants

at Superfund Sites

FY04 FY05 FY06 FY07 FY08

(1) Evaluate Concordance Between Field Measurements and Resuspension Model Predictions

Evaluate Existing

Resuspension Models

FY08a

Report

Evaluate Concordance Between Field Measurements

and Resuspension Model Predictions

(collaborate with ACE and NERL)

FY08b

Report

(3) Research to Assess Changes in Bioavailability

of Contaminated Sediments Resulting from

Resuspension and Resettlement

Develop Experimental

Approach to Simulate Dredging

including Bioavailability

Evaluate with Selected

Superfund Site Sediments

FY07

Report

FY06

Report
50 Contaminated Sediment Research Multi-Year Implementation Plan

Products 

By 2008, provide monitoring, measurement, and benthic screening methods 

and tools to characterize, assess, and communicate current conditions and 

the long-term performance of remedial options associated with cleanup of 

contaminated sediments.

NHEERL

Report evaluating fate and transport models for predicting 

dissolved concentrations of organic and inorganic contaminants in 

Superfund site sediments following resuspension events

FY06 NHEERL

Rob Burgess and 

Mark Cantwell

Evaluate concordance between field measurements and fate 

and transport model predictions of dissolved concentrations of 

organic and inorganic contaminants in Superfund site sediments 

following resuspension events (in collaboration with NERL and 

ACE)

FY08a NHEERL

Rob Burgess and 

Mark Cantwell

Report summarizing evaluation of approaches for measuring the 

transport of dissolved contaminants beyond the dredging zone at 

selected Superfund sites

FY08b NHEERL

Rob Burgess and 

Mark Cantwell

Report assessing significance of changes in bioavailability of 

organic and inorganic contaminants in Superfund site sediments 

following resuspension into the water column and resettlement to 

sediment bed

FY07 NHEERL

Rob Burgess and 

Mark Cantwell

References

Anchor Environmental C.A.L.P. 2003. Literature review of effects of resuspended sediments 

due to dredging operations. Prepared for Los Angeles Contaminated Sediments Task Force. 

Irvine, CA.

Arthur, C.L. and J. Pawliszyn. 1990. Solid phase microextraction with thermal desoprtion using 

fused silica optical fibers. Anal Chem 62:2145-2148.

Axelman, J. K. Naes, C. Naf, and D. Broman. 1999. Accumulation of polycyclic aromatic 

hydrocarbons in semipermeable membrane devices and caged mussels (Mytilus edulis L.) in 

relation to water column phase distribution. Environ Sci Technol 18:2454-2461.

Bedford, K.W. 1994. In situ measurement of entrainment, resuspension, and related processes 

at the sediment-water interface. In Transport and Transformation of Contaminants Near the 

Sediment Water Interface. J.V. DePinto, W. Lick, and J.F. Paul (eds.). Boca Raton, Lewis 

Publishers p.59-93.

Bonnet, C., M. Babut,J.-F. Ferard, L. Martel, and J. Garric. 2000. Assessing the potential 

toxicity of resuspended sediment. Environ Sci Technol 19:1290-1296.

Calvo, C., R. Donazzolo, F. Guidi, and A.A. Orio. 1991. Heavy metal pollution studies by 

resuspension experiments in Venice Lagoon. Wat Res 25:1295-1302.

Cantwell, M.G. and R.M. Burgess. 2004. Variability of parameters measured during the 

resuspension of sediments with a particle entrainment simulator. Chemosphere 56:51-58.

Cantwell, M.G., R.M. Burgess, and D.R. Kester. 2002. Release and phase partitioning of metals 

from anoxic estuarine sediments during periods of simulated resuspension. Environ Sci 

Technol 36:5328-5334. 

Chen, W., A.T. Kan, G. Fu, M.B. Tomson. 2000. Factors affecting the release of hydrophobic 

organic contaminants from natural sediments. Environ Sci Technol 19:2401-2408.
51 Contaminated Sediment Research Multi-Year Implementation Plan

Davis, W.R. 1993. The role of bioturbation in sediment resuspension and its interaction with 

physical shearing. J Exp Mar Biol Ecol 171:187-200.

Eastern Research Group, Inc. 2004. Report on the Peer Review of the U.S. Environmental 

Protection Agency’s “Draft Engineering Performance Standards - Peer Review Copy” for 

the Hudson River PCBs Superfund Site. Prepared for U.S. EPA Region 2, New York, NY 

10007-1866.

Eggleton, J. and K.V. Thomas. 2004. A review of factors affecting the release and 

bioavailability of contaminants during sediment disturbances events. Environ Internat 30: 

973-980.

Goa, Y., A.T. Kan, and T.B. Tomson. 2003. Critical evaluation of desorption phenomena of 

heavy metals from natural sediments. Environ Sci Technol 37:5566-5573.

Gerringa, L.J.A. 1991. Mobility of Cu, Cd, Ni, Pb, Zn, Fe, and Mn in marine sediments slurries 

under anaerobic conditions and at 20 % air saturation. Netherlands J Sea Res 27:145-156.

Hofelt, C.S. and D. Shea. 1997. Accumulation of organochlorine pesticides and PCBs by 

semipermeable membrane devices and Mytilus edulis in New Bedford Harbor. Environ Sci 

Technol 31:154-159.

Huckins, J.N., G.K. Manuweera, J.D. Petty, D. Mackay, and J.A. Lebo. 1993. Lipid-containing 

semipermeable membrane devices for monitoring organic contaminants in water. Environ 

Sci Technol 27:2489-2496.

Imhoff, J.C., A. Stoddard, E.M. Buchak, E. Hayter. 2003. Evaluation of Contaminated Sediment 

Fate and Transport Models: Final Report. Technical Report. U.S. EPA, Office of Research 

and Development, National Exposure Research Laboratory, Athens, GA 30605.

Latimer, J., W. Davis, and D.J. Keith. 1999. Mobilization of PAHs and PCBs from in-place 

contaminated marine sediments during simulated resuspension events. Estuar Coast Shelf 

Sci 49:577-595.

Lavelle, J.W. and W.R. Davis. 1987. Measurement of Benthic Sediment Erodibility in Puget 

Sound, WA. ERL PMEL-72. National Oceanic and Atmospheric Administration.

Lin C.-H., J.A. Pedersen, and I.H. Suffet. 2003. Influence of aeration on hydrophobic organic 

contaminant distribution and diffusive flux in estuarine sediments. Environ Sci Technol

37:3547-3554.

Lohmann, R., J.K. MacFarlane, and P.M. Gschwend. 2005. Importance of black carbon to 

sorption of native PAHs, PCBs, and PCDDs in Boston and New York Harbor sediments. 

Environ Sci Technol 39:141-148.

Mayer, P., W.H.J. Vaes, F. Wijnker, K.C.H.M. Legierse, R.H. Kraaij, J. Tolls, and J.L.M. 

Hermens. 2000. Sensing dissolved sediment porewater concentrations of persistent and 

bioaccumulative pollutants using disposable solid-phase microextraction fibers. Environ Sci 

Technol 34:5177-5183.

Nayar, S., B.P.L. Goh, L.M. Chou, and S. Reddy. 2003. In situ microcosms to study the impact 

of heavy metals resuspended by dredging on periphyton in a tropical estuary. Aquatic Toxicol

64:293-306.

Palermo, M.R. and D.E. Averett. 2003. Environmental Dredging - A State of the Art Review. In 

2nd International Symposium on Contaminated Sediments: Characterization, Evaluation, 

Mitigation/Restoration, Monitoring, and Performance. Quebec, Canada.

Pedersen, J.A., C.J. Gabelich, C.-H. Lin, and I.H. Suffet. 1999. Aeration effects on the 

partitioning of a PCB to anoxic estuarine sediment pore water dissolved organic matter. 

Environ Sci Technol 33:1388-1397.
52 Contaminated Sediment Research Multi-Year Implementation Plan

Senn, D.B., S.B. Griscom, C.G. Lewis, J.P. Galvin, M.W. Chang, and J.P. Shine. 2004. 

Equilibrium-based sampler for determining Cu+2 concentrations in aquatic ecosystems. 

Environ Sci Technol 38:3381-3386.

Shor, L.M., K.J. Rockne, G.L. Taghon, L.Y. Young, and D.S. Kosson. 2003. Desorption kinetics 

for field-aged polycyclic aromatic hydrocarbons from sediments. Environ Sci Technol

37:1535-1544.

Simpson, S.L., S.C. Apte, and G.C. Batley. 1998. Effect of short-term resuspension events on 

trace metal speciation in polluted anoxic sediments. Environ Sci Technol 32:620-625.

Simpson, S.L., S.C. Apte, and G.C. Batley. 2000. Effect of short-term resuspension events 

on the oxidation of cadmium, lead, and zinc sulfide phases in anoxic estuarine sediments. 

Environ Sci Technol 34:4533-4537.

Thibodeaux, L.J., and V.J. Bierman. 2003. The bioturbation-driven chemical release process. 

Environ Sci Technol 37:252A-258A.

Tsai, C.-H. and W. Lick . 1986. A portable device for measuring sediment resuspension. J 

Great Lakes Res 12:314-321.

U.S. Army Corps of Engineers. 2003. Dredging Operations Technical Support Program 

Models. http://www.wes.army.mil/el/dots/models.html.

Valsaraj, K.T., R. Ravikrishna, J.J. Orlins, J.S. Smith, J.S. Gulliver, D.D. Reible, and L.J. 

Thibodeaux. 1997. Sediment-to-air mass transfer of semi-volatile contaminants due to 

sediment resuspension in water. Adv Environ Res 1:145-156.

Van den Berg, G.A., G.A. Gorgias, G.A. Meijers, L.M. Van der Heijdt, and J.J.G. Zwolsman. 

 2001. Dredging-related mobilization of trace metals: a case study in The Netherlands. 

Water Res 35:1979-1986.

Vinturella, A.E., R.M. Burgess, B.A. Coull, K.M. Thompson, and J.P. Shine. 2004. Use 

of passive samplers to mimic uptake of polycyclic aromatic hydrocarbons by benthic 

polychaetes. Environ Sci Technol 38:1154-1160.

Zeng, E.Y., D. Tsukada, D.W. Diehl. 2004. Development of a solid-phase microextractionbased method for sampling of persistent chlorinated hydrocarbons in an urbanized coastal 

environment. Environ Sci Technol 38:5737-5743.
53 Contaminated Sediment Research Multi-Year Implementation Plan

Project V: Preparation of Equilibrium Partitioning Sediment 

Benchmark Documents for the Assessment of Contaminated 

Sediments at Superfund Sites

Summary of Issue

This activity will publish a series of benchmark documents to assist OSRTI, the Regions, states, 

other federal agencies, and other entities in the assessment of contaminated sediments.

Resources

Year Division FTEs

2004 AED 0.10

2005 AED 0.10

2006 AED 0.10

NHEERL Category D Needs

In addition to the personnel costs, benefits, supplies, equipment, etc., that are specifically 

associated by ORD with FTE and considered intramural resources, NHEERL uses ORD planning 

resources to pay laboratory indirect costs (called “ABC costs”) and project-specific costs (called 

“Category D costs”). Listed below are the kinds of Category D needs associated with this 

project. Annual budget planning documents determine the dollar amounts needed.

 

Year Division

2004 AED No Category D needs

2005 AED No Category D needs

2006 AED No Category D needs

 
54 Contaminated Sediment Research Multi-Year Implementation Plan

Products

By 2008, provide monitoring, measurement, and benthic screening methods 

and tools to characterize, assess, and communicate current conditions and 

the long-term performance of remedial options associated with cleanup of 

contaminated sediments.

NHEERL

U.S. EPA. 2003. Procedures for the Derivation of Equilibrium 

Partitioning Sediment Benchmarks (ESBs) for the Protection of 

Benthic Organisms: Endrin. EPA-600-R-02-009. Office of Research 

and Development. Washington, DC 20460.

U.S. EPA. 2003. Procedures for the Derivation of Equilibrium 

Partitioning Sediment Benchmarks (ESBs) for the Protection of 

Benthic Organisms: Dieldrin. EPA-600-R-02-010. Office of 

Research and Development. Washington, DC 20460.

U.S. EPA. 2003. Procedures for the Derivation of Equilibrium 

Partitioning Sediment Benchmarks (ESBs) for the Protection of 

Benthic Organisms: PAH Mixtures. EPA-600-R-02-013. Office of 

Research and Development. Washington, DC 20460.

FY04 NHEERL

Rob Burgess

U.S. EPA. 2005. Procedures for the Derivation of Equilibrium 

Partitioning Sediment Benchmarks (ESBs) for the Protection of 

Benthic Organisms: Nonionics Compendium. EPA-600-R-02-016. 

Office of Research and Development. Washington, DC 20460.

FY05 NHEERL

Rob Burgess

U.S. EPA. 2006. Procedures for the Derivation of Site-Specific 

Equilibrium Partitioning Sediment Benchmarks (ESBs) for the 

Protection of Benthic Organisms: Nonionic Organics. EPA-600-

R-02-012. Office of Research and Development. Washington, DC 

20460.

FY06 NHEERL

Rob Burgess
55 Contaminated Sediment Research Multi-Year Implementation Plan

Project VI: Preparation of Whole Sediment and Interstitial 

Water Freshwater and Marine Toxicity Identification 

Evaluations (TIEs) Guidance Document for Use at 

Superfund Sites

Summary of Issue

This activity will publish a guidance document to assist OSRTI, the Regions, states, other federal 

agencies, and other entities in the assessment of contaminated sediments.

Resources

Year Division FTEs

2004 AED 0.20

2005 AED 0.20

NHEERL Category D Needs

In addition to the personnel costs, benefits, supplies, equipment, etc., that are specifically 

associated by ORD with FTE and considered intramural resources, NHEERL uses ORD planning 

resources to pay laboratory indirect costs (called “ABC costs”) and project-specific costs (called 

“Category D costs”). Listed below are the kinds of Category D needs associated with this 

project. Annual budget planning documents determine the dollar amounts needed.

 

Year Division

2004 AED No Category D needs 

2005 AED Technical Editing

Products

By 2008, provide monitoring, measurement, and benthic screening methods 

and tools to characterize, assess, and communicate current conditions and 

the long-term performance of remedial options associated with cleanup of 

contaminated sediments.

NHEERL

Ho et al. 2005. Whole Sediment and Interstitial Water Toxicity 

Identification Evaluation Guidance Document for Freshwater 

and Marine Applications. Office of Research and Development. 

Washington, DC 20460.

FY05 NHEERL

Kay Ho
56 Contaminated Sediment Research Multi-Year Implementation Plan

Project VII: Development of Appropriate Remedial Goals for 

Non-Bioaccumulative Contaminants in Sediment

Summary of Issue

This issue is not a single issue, but an aggregation of a diverse group of issues. The common 

thread for these issues is that they involve difficulties in assessing/predicting the toxic effects of 

sediment contaminants that are “non-bioaccumulative.” In this context, “non-bioaccumulative” 

does not mean strictly that the chemicals do not bioaccumulate to any degree, but rather that 

the assessment of these chemicals (or exposure pathways) is not pursued using the same tools 

commonly applied to classic bioaccumulative chemicals such as PCBs. In general, this would 

mean chemicals whose primary toxic effects are expressed directly in organisms living in or 

on sediments (as opposed to organisms exposed to sediment-associated chemicals via the food 

chain). However, even this definition is not without exception.

For chemicals causing direct effects on benthic organisms, there are three primary classes of 

tools used to assess the likely effects of chemicals in sediments: (1) sediment quality guidelines 

(SQGs), (2) sediment toxicity tests, and (3) benthic community surveys. As described below, 

each of these have particular strengths, weaknesses, and uncertainties in their application. The 

uncertainties associated with these tools spawn corresponding uncertainties and controversy in 

ecological risk assessments conducted within the Superfund program and elsewhere.

Beyond issues surrounding these three sediment assessment tools, there are some additional 

noteworthy issues that have arisen in Superfund ecological risk assessments but that are not 

addressed explicitly elsewhere and are therefore included here. These issues include heightened 

toxicity of polycyclic aromatic hydrocarbons (PAHs) in the presence of UV light, often called 

“photo-activated toxicity.” Another of these is the potential for adverse effects from dietary 

exposure of fish to metals (e.g., Cd, Cu, Zn) accumulated by their prey.

Summary of the State of the Science

1. Sediment Quality Guidelines

Sediment quality guidelines (SQGs) are chemical concentrations in sediment that are expected to 

cause some specified degree or probability of adverse effect in organisms exposed to the sediment. 

SQGs have been developed using a number of different approaches (see Batley et al. 2004), and 

each has its own set of strengths and weaknesses. They can be loosely grouped into two subsets, 

so-called “empirical” guidelines and “mechanistic” guidelines. Empirical guidelines are derived 

from large data sets of paired chemical concentration and sediment toxicity (effect) data, usually 

from field-collected sediments. Data are arrayed according to increasing degree of contamination, 

and specific benchmarks are chosen along this concentration gradient to delineate concentrations 

that are associated with varying levels or probabilities of adverse effects. As they are based 

on correlation, they reflect empirical association but not necessarily causation. Mechanistic 

guidelines are based on models of chemical/toxicological behavior of chemicals in sediment. 

Current mechanistic guidelines all have their roots in “Equilibrium Partitioning Theory” (Di Toro 

et al. 1991) which uses chemical partitioning models as the basis for predicting the toxicological 

potency of sediment-associated chemicals.
57 Contaminated Sediment Research Multi-Year Implementation Plan

While there is a considerable body of work supporting the development of these guidelines, their 

application in sediment assessment/management frameworks remains a topic of considerable 

controversy. Reasons for this controversy are varied but range from misuse of the guidelines 

(i.e., application of the guidelines in ways inconsistent with their derivation or narrative intent) to 

actual scientific uncertainties in their interpretation. Details of these issues are discussed under 

Research Needs below. In addition, development of SQG has been focused on some of the more 

commonly studied sediment contaminants, such as DDT, PAHs, and common cationic metals. 

There are many chemicals for which SQG have not been developed.

2. Sediment Toxicity Tests

Sediment toxicity tests are the primary means of assessing the direct toxicological effects of 

field-collected sediments or of sediments spiked with known chemicals. Initial development 

of sediment toxicity tests focused on comparatively short-term (e.g., 10-day) exposures and on 

lethality as the primary endpoint. Protocols for these short-term methods are relatively well 

developed for several marine and freshwater test organisms. Fewer protocols for measuring 

longer-term and/or sublethal effects have been developed, but some are available for a subset 

of benthic test organisms. While the methods for these tests are fairly well standardized, their 

application in sediment assessment is still affected by lingering uncertainties related to their 

appropriate application and interpretation.

3. Benthic Community Surveys

Field surveys of benthic community composition have been conducted for decades and pre-date 

development of either SQGs or sediment toxicity tests. Perhaps because benthic community 

surveys have been conducted for a great variety of reasons beyond assessment of contaminated 

sediments (e.g., natural history evaluation, habitat assessment) and because the appropriateness 

of different techniques varies among physical habitats (e.g., stream, river, lake, estuary), there 

is a wide range of techniques available and relatively little overall standardization (that is not to 

say there are not standardized methods, but that no single method is recognized as intrinsically 

superior to others). Data from benthic community surveys are highly valued in ecological risk 

assessment because they reflect exposure of the organisms of interest to the contamination 

of interest. That said, these data are sometimes difficult to interpret because of intrinsic 

uncertainties and complexities, such as the effects of habitat (e.g., substrate type) and sampling 

bias, as well as uncertainties regarding what constitutes an meaningful adverse effect.

4. Photo-activated Toxicity of PAHs

Because PAHs are common sediment contaminants at Superfund sites, it is important that we 

have sufficient understanding of their ecological effects to assess risks appropriately. Photoactivated toxicity of PAHs results from an interaction of UV light, such as that in sunlight, with 

certain PAHs that have accumulated in the tissues of aquatic organisms. This interaction can lead 

to toxicity 2 or even 3 orders of magnitude more severe than that occurring in the absence of UV

light. Because most toxicity data for PAHs are generated under laboratory lighting containing 

very little UV, there is clear potential for ecological risk from PAHs under field conditions to be 

underestimated. While there have been a number of studies published which demonstrate hazard 

from this mechanism, there is not currently an accepted approach for predicting risk from photoactivated toxicity. This shortcoming is clearly visible through controversies associated with 
58 Contaminated Sediment Research Multi-Year Implementation Plan

several Superfund sites where ecological risk assessors have attempted to include photo-activated 

toxicity in site risk assessments.

5. Dietary Exposure to Metals

Conventional wisdom has been that common metals such as copper, cadmium, and zinc express 

their effects primarily through waterborne exposure. This was not to say that dietary exposure 

did not exist, but that waterborne metal was the primary determinant of toxic effects. Studies by 

Woodward et al. (1994, 1995) and Farag et al. (1999) conducted at the Clark Fork River (CFR) 

and Coeur d’Alene River (CDA) Superfund sites introduced considerable controversy about this 

assumption by demonstrating reduced growth of trout fed diets prepared from field-collected 

invertebrates from these systems. Because these are metal-contaminated systems, the clear 

suggestion was that the elevated metals concentrations in the invertebrates were the cause of the 

reduced growth. While this appears to be a logical conclusion, there are many other published 

studies which indicate little effect from dietary exposure to some of the same metals elevated in 

the CFR and CDA. Other studies published by Hook and Fisher (2000) and Hornberger et al. 

(2000) have suggested effects from dietary exposure in invertebrates. Resolution of these issues 

is very important to Superfund risk assessments for metal contaminated sediments.

Research Needs

Each of the areas identified above involves a number of sub-issues for which research is needed 

to improve the ability of the Superfund program to assess and manage ecological risks. 

1. Sediment Quality Guidelines 

a. Refine bioavailability models

b. Address unusual/non-traditional partitioning phases (e.g., soot)

c. Develop partitioning models for additional chemical classes (e.g., metal oxy-anions, polar 

organic chemicals)

d. Evaluate assumptions regarding route of exposure (ingestion vs. interstitial water)

2. Sediment Toxicity Test

a. Establish and verify appropriate sediment collection, handling, and equilibration 

techniques

b. Evaluate means to insure exposure conditions are relevant to the field

c. Establish test methods for poorly represented taxa

d. Have greater assessment of sublethal endpoints

3. Benthic Community Surveys

a. Establish appropriate metrics for assessing adverse effects

b. Determine the magnitude of effects to be considered adverse

c. Account for habitat influences on survey data

d. Establish appropriate sampling methods
59 Contaminated Sediment Research Multi-Year Implementation Plan

4. Photo-activated Toxicity of PAHs

a. Establish appropriate framework for assessing risk

b. Better understand UV exposure for free-living organisms

c. Determine degree of UV exposure received by benthic organisms

d. Develop means to accurately predict body residues

5. Dietary Exposure to Metals

a. Understand metal speciation in the context of metal uptake and toxicity

b. Assess relative contributions of waterborne and dietary pathways to toxicity under field 

exposure conditions

c. Establish a framework for integrating dietary exposure into overall risk estimate

Proposed Research Targets

While all of the above issues have scientific merit and involve research questions relevant to 

NHEERL’s mission, it was decided that none clearly possessed greater urgency than do others 

described in this document. For the immediate future, no active research will be taken under this 

implementation plan within the realm of assessing non-bioaccumulative contaminants.

References

Batley, G.E., R.G. Stahl Jr., M.P. Babut, T.L. Bott, J.R. Clark, L.J. Field, K.T. Ho, D.R. Mount, 

R.C. Swartz, and A. Tessier. 2004. The scientific underpinnings of sediment quality 

guidelines, Chapter 2. In: R.J. Wenning and C.G. Ingersoll (eds.), Sediment Quality 

Guidelines: State of the Science. SETAC Press, Pensacola, FL (in press).

Di Toro, D.M., C.S. Zarba, D.J. Hansen, W.J. Berry, R.C. Swartz, C.E. Cowan, S.P. Pavlou, 

A.E. Allen, N.A. Thomas, and P.R. Paquin. 1991. Technical basis for establishing sediment 

quality criteria for nonionic organic chemicals using equilibrium partitioning. Environ 

Toxicol Chem 10:1541-1583.

Farag, A.M., D.F. Woodward, W. Brumbaugh, J.N. Goldstein, E. MacConnell, C. Hogstrand, and 

F.T. Barrows. 1999. Dietary effects of metals-contaminated invertebrates from the Coeur 

d’Alene River, Idaho, on cutthroat trout. Trans Am Fish Soc 128:578-592.

Hook, S.E. and N.S. Fisher. 2001a. Sublethal effects of silver in zooplankton: Importance of 

exposure pathways and implications for toxicity testing. Environ Toxicol Chem 20:568-574.

Hook, S.E. and N.S. Fisher. 2001b. Reproductive toxicity of metals in calanoid copepods. Mar 

Biol 138:1131-1140.

Hornberger, M.I., S.N. Luoma, D.J. Cain, F. Parchaso, C.L. Brown, R.M. Bouse, C. Wellise, 

and J.K. Thompson. 2000. Linkage of bioaccumulation and biological effects to changes in 

pollutant loads in South San Francisco Bay. Environ Sci Technol 34:2401-2409.

Woodward, D.F., W.G. Brumbaugh, A.J. DeLonay, E.E. Little, and C.E. Smith. 1994. Effects on 

rainbow trout fry of a metals-contaminated diet of benthic invertebrates from the Clark Fork 

River, Montana. Trans Am Fish Soc 123:51-62.

Woodward, D.F., A.M. Farag, H.L. Bergman, A.J. DeLonay, E.E. Little, C.E. Smith, and F.T. 

Barrows. 1995. Metals-contaminated benthic invertebrates in the Clark Fork River, Montana: 

Effects on age-0 brown trout and rainbow trout. Can J Fish Aquat Sci 52:1994-2004.
60 Contaminated Sediment Research Multi-Year Implementation Plan

Program Summary and Management

This Research Implementation Plan document describes NHEERL’s contaminated sediment 

research program for the fiscal years 2004-2008. To the extent feasible, projects in the Plan 

are a blend of empirical and modeling approaches designed to solve key scientific problems 

associated with contaminated sediments. This plan is the result of a through planning process 

that considered a large number of scientific uncertainties raised by Superfund and distilled the 

research needs into four research projects. These projects were developed with recognition 

that success depends upon NHEERL’s research products being adopted and used by OSRTI 

at Superfund sites. A breakdown of the FTEs assigned to each project and the total FTEs for 

contaminated sediments research across NHEERL is provided below. Although the number of 

FTEs available for this effort is small, these projects have the potential to significantly improve 

the risk assessments performed and decisions that are made at contaminated sediment Superfund 

sites.

Distribution of Effort by Project, Year, and Division

Project

ID I II III IV V VI

All 

Projects Project 

Name 

Benthic 

Recovery

Residues 

to Effects

Water and 

Sediment 

Concentration 

to Residues

Resuspension ESB guidance 

documents

TIE guidance 

document

Division FTEs

Year AED MED MED AED AED AED

2004 2.5 0.25 3.75 1 0.1 0.20 7.8

2005 2.5 0.25 3.75 1 0.1 0.20 7.8

2006 2.5 0.25 3.75 1 0.1 0 7.6

2007 2.5 0 4 1 0 0 7.5

2008 2.5 0 4 1 0 0 7.5

By 2008, the research program expects to provide the following:

- Assessment of the applicability of sediment profile imagery (SPI) as a quick and accurate 

tool for monitoring effects of and recovery from dredging at a Superfund sediment site 

(Project I);

- Assessment of PCB residue-effects relationships and data gaps for fish, birds, and 

mammals for Superfund applications (Project II); 

- A fully field-validated hybrid modeling/empirical approach for extrapolating BAFs, 

BSAFs, and predicting the ecological effects of mixtures of PBTs with differing rates of 

metabolism on a site-specific basis (Project III);

- Assessment of the concordance between field measurements and fate and transport 

model predictions of dissolved concentrations of organic and inorganic contaminants in 

Superfund sites following resuspension events (Project IV); and
61 Contaminated Sediment Research Multi-Year Implementation Plan

- Assessment of the changes in bioavailability of organic and inorganic contaminants in 

Superfund site sediments following resuspension into the water column and resettlement to 

the sediment bed (Project IV).

The research program will be managed at the Division/Branch level. The investigators 

and steering committee will convene annually to review progress and to reassess projected 

commitments. In the event that resource changes or research findings indicate changes in 

emphasis are necessary, adjustments will be made to this plan. Because this research is based 

upon strategic research directions provided at the ORD level, findings from this program will 

be communicated not only to the client directly, but also through the ORD research planning 

process. Similarly, changes in strategic direction provided by ORD may impact this program.
62 Contaminated Sediment Research Multi-Year Implementation Plan
A-1 Contaminated Sediment Research Multi-Year Implementation Plan

Appendix A: Superfund Program Research Priorities

This list of Superfund Program Research priorities was created by the Superfund program office 

(currently, OSRTI) and is a description of research priorities for ORD from Superfund. This list 

was used as a starting point for discussions by the NHEERL Contaminated Sediments Steering 

Committee. 

Superfund Program Research Priorities for ORD – December 12, 2002, Working Draft 

(See separate list for Oil Program Research Priorities)

The program’s highest priority for ORD support continues to be site-specific technical support 

(provided both by through the Technical Support Centers and through other mechanisms) and 

technical support to OSRTI staff on guidance development. 

The Superfund research needs are organized into the following catagories:

I. Ground Water Research Needs 

II. Sediment Research Needs

III. Soil/Waste Research Needs

IV. Multi-Media and Analytical Research Needs

V. Human Health Research Needs

VI. Ecological Research Needs 

I. GROUND WATER RESEARCH NEEDS

OSRTI Contact: Ken Lovelace 

Although they are generally listed in order of priority, all of the items within this category are of 

high priority. 

GW-1. Technical Support

1a. Providing technical assistance to EPA regional staff for site specific issues related to 

characterization, evaluation (e.g., modeling), and remediation of contaminated ground 

water.

1b. Providing technical assistance to EPA HQ staff for guidance development (e.g., serving 

on workgroups and/or technical reviews of draft documents).

GW-2. Natural Attenuation/Bioremediation Processes

2a. Research of attenuation (physical, chemical, biologic) processes affecting inorganic 

(metals and metalloids) and radiologic contaminants in ground water. This includes 

basic research on relevant processes and potential methods for enhancing natural 

processes. [Includes Projects H1, H4, and H9 on previous list]

2b. Research of attenuation (physical, chemical, biologic) processes affecting recalcitrant 
A-2 Contaminated Sediment Research Multi-Year Implementation Plan

organic contaminants (e.g., semivolatile compounds, pesticides) in ground water. This 

includes basic research on relevant processes and potential methods for enhancing natural 

processes. [Includes Projects H1, H4, and H9 on previous list]

2c. Research of methods to enhance bioremediation of contaminants in ground water. 

[Project H7 on previous list]

2d. Research and development of improved methods for evaluating long-term performance 

of monitored natural attenuation (MNA) remedies, including plume stability, changes 

in hydraulic conditions, changes in biogeochemical environment, discharges to surface 

water (see “Emerging Issues” below), and impacts on indoor air (see “Emerging Issues” 

below). [Not on previous list]

2e. Development and application of natural attenuation research. This includes site 

characterization methods, field demonstration projects, workshops, workshop reports, and 

training courses. [Includes Projects H1 and M28 on previous list]

GW-3. Dense, Non-Aqueous Phase Liquid Characterization and Remediation

3a. Research on improved methods for locating and characterizing dense, non-aqueous phase 

liquids (DNAPLs) in the subsurface. This includes geophysical methods and techniques 

for measuring mass flux from DNAPL source areas. [Projects H5 and NH2 on previous 

list]

3b. Research on improved methods for remediating DNAPLs in the subsurface. This 

includes all possible methods for in-situ treatment of DNAPLs (e.g., thermal, chemical 

oxidation, surfactant flushing, reactive barriers, enhanced bioremediation, and other 

methods). [Project H3 on previous list]

3c. Development and application of DNAPL-related research. This includes field 

demonstration projects, workshops, workshop reports, and training courses. [Includes 

Project NH2 (mass flux) on previous list]

GW-4. Emerging Issues

4a. Research on improved methods for assessing migration of contaminants from ground 

water to indoor air. This includes improved site characterization techniques, model 

verification studies, and improved guidelines for use of models. [Note: an indoor air 

research topic should also be included under the risk issue] [Not on previous list]

4b. Research on improved methods for assessing migration of contaminants from ground 

water to surface water as needed to provide input for evaluation of environmental 

impacts/risks (see “Risk Issue”). This includes improved site characterization techniques. 

[Not on previous list]
A-3 Contaminated Sediment Research Multi-Year Implementation Plan

GW-5. Field Characterization–Sampling and Monitoring Methods

5a. Research and development of improved methods for detection and measurement of 

contaminants in ground water. This includes basic research as well as development and 

field testing of methods to be used in initial site characterization as well as in long-term 

site monitoring. [Includes Project NH1 on previous list]

GW-6. Long-Term Remedy Performance

6a. Research and development of improved methods for evaluating long-term performance 

of pump and treat systems, including capture zone analysis, evaluation of monitoring 

effectiveness, optimization methods, etc., This could include improved methods for 

collection, tabulation, plotting, and statistical evaluation of large data sets. [Projects H10, 

H8 and M1 on previous list]

6b. Research and development of improved methods for evaluating long-term performance 

of permeable reactive barriers (PRBs). This could include research and development 

of methods for enhancing performance of PRBs, evaluation of treatment effectiveness, 

monitoring effectiveness, and optimization methods, etc., [Project H6 on previous list]

6c. Research and development of improved methods for evaluating long-term performance of 

vertical containment barriers. This could include research and development of methods 

for verifying barrier continuity, wall embedment, and leak detection. [Project H2 on 

previous list] 

II. SEDIMENT RESEARCH NEEDS

OSRTI Contact: Steve Ells

[Some additions still to be incorporated from focus group write-ups, plus current prioritization is 

still underway.]

Site Characterization Issues

SED-1. Development of Sediment Contaminant Screening Levels

SED-1. Fate and Transport Model Recommendations

What models should be recommended for various common types of sediment sites?

SED-2. Measuring Effects of Large Events on Sediment Transport

It is difficult to monitor during some large hydrologic events, especially those which involve 

ice scour, both because they are not easy to predict and because of physical dangers. Lacking 

that, are there practices we can recommend for after-the-fact measuring the effects of these 

events on sediment movement? [This may be a literature survey question.]

SED-3. Tools for Locating Debris

What are the best tools for locating and identifying debris (buried and surficial) in sediment 

(e.g., during evaluation of dredging alternatives)?
A-4 Contaminated Sediment Research Multi-Year Implementation Plan

SED-4. Determination of Background Levels in Biota and Sediment

SED-5. Sampling Surface Sediments

e.g., How to sample surface fluff layer?

SED-6. Ground Water/Sediment Interactions

When should you evaluate GW-Sediment interactions?

SED-7. Evaluating Past Erosion and Deposition

What suite of empirical methods can we recommend for assessing the extent to which 

deposits of contaminated sediment are the result of deposition only versus the result of 

alternating erosion and deposition? Do we recommend a different suite of methods for 

different types of water bodies? Where deposits are the result of alternating erosion and 

deposition, are there empirical methods available to evaluate the horizontal and vertical 

scale of that movement, or can this only be estimated through modeling? What are common 

rates of erosion and deposition in various environments which are typical of Superfund 

contaminated sediment sites? 

SED-8. Biota and Sediment Sampling Procedures

What are our research needs in this area?

SED-9. Fish Ingestion Rates

What are best practices for selecting fish ingestion rates for risk assessment and selection of 

cleanup levels?

SED-10. Chemical Fingerprinting to Tie Risk Drivers to Sources 

For contaminants such as PCBs and others which undergo some degree of biodegradation in 

sediment, is research needed to better tie drivers to sources or to risk?

SED-11. Rates of Contaminant Transport through Bioturbation

How important is bioturbation in contaminant transport in different habitats? What are ranges 

of rates of contaminant transport for common Superfund contaminants in sediment (PCBs, 

metals, PAHs) in Superfund contaminated sediment environments where bioturbation may be 

a key transport element (e.g., estuaries, freshwater harbors, and lakes)? [Need to think more 

about what the real question should be here. Are more biota at risk if contaminants are moved 

closer to the surface, or is it a question of being more susceptible to transport by erosion?]

SED-12. Community Involvement at Large Sediment Sites

How best to collect/know community concerns at big sites? 

Ecological and Human Health Risk Issues 

SED-13. Prediction of Safe Biota Residue Levels and Population Recovery Times 

How can we better predict time to safe contaminant residue levels in biota and biota 

population recovery times? What are the most uncertain elements of the models we use 

to make these predictions? What is driving that uncertainty? Some answers will vary by 
A-5 Contaminated Sediment Research Multi-Year Implementation Plan

cleanup method (e.g., dredging residuals, rates of natural sedimentation); others are expected 

to be universal (e.g., recontamination from uncontrolled sources, large-ranging species). How 

can we reduce that uncertainty in some of those areas? [This may need to be broken up into 

several priorities.]

SED-14. Critical Residue Levels for Bioaccumulative Contaminants

What are the critical tissue residue levels for bioaccumulative contaminants?

SED-15. Cleanup Levels for Eco-Risks

How best to determine acceptable cleanup levels for eco-risks?

SED-16. Dermal Exposure/Uptake from Sediment

SED-17. Fish Ingestion Rates

What are best methods for determining what fish ingestion rates to use for risk assessments 

and determination of cleanup levels?

SED-18. Standardized Process to Characterize Human Health and Ecological Risks from 

Ingestion of PCB-contaminated Fish on a Congener Basis

Development and Evaluation of Remedies

SED-19. Monitoring Methods and Protocols

What are the best remedial action and long-term monitoring methods for various sediment 

remedies? Are new methods needed? Are protocols needed?

SED-20. Effectiveness of Containment During Dredging

How effective are silt curtains and screens? What are the best practices for monitoring and 

increasing their effectiveness? 

SED-21. Dredging Residuals

How can we better predict dredging residuals in different sediment habitats. What are 

achievable cleanup levels?

SED-22. Dredging Resuspension

What are the impacts from resuspension caused by dredging? Does dredging result in 

increased environmental risks to aquatic receptors?

SED-23. Beneficial Use of Dredged Material

How to identify beneficial uses for contaminated sediments at a site?

SED-24. Cost-Effective Treatment Technologies for Dredged Material

SED-25. Effectiveness of In-Situ Remedies

How effective are existing monitored natural recovery (MNR) and capping remedies? 

What are theoretical “break-through” times for typical caps and natural deposits overlying 

contaminated sediment?

SED-26. In-Situ Reactive Caps and Enhanced Bioremediation Technologies
A-6 Contaminated Sediment Research Multi-Year Implementation Plan

SED-27. Designing In-Situ Caps to Accommodate Habitat Restoration/Recovery

SED-28. Enhanced Monitored Natural Recovery

Are there effective measures to enhance MNR? Does thin layer placement speed up natural 

recovery? (a) Evaluate, to the extent possible, actual effectiveness of thin layer placement 

as a method to speed up natural recovery at contaminated sediment sites in quiescent 

environments. (b) Evaluate theoretical effectiveness of thin layer placement as a method to 

speed up natural recovery in quiescent environments, including the following aspects: What 

are some theoretical combinations of thickness of placed layer and contaminant movement 

through bioturbation in underlying sediment that result in predicted outcomes? 

III. SOIL/WASTE RESEARCH NEEDS

OSRTI Contact for Landfills/Containment: Ken Skahn

OSRTI Contact for Mining: Shahid Mahmud

High Priority

SOIL/WASTE-1. Performance Monitoring for Landfill Caps

Determine appropriate methods and equipment to monitor the performance of landfill caps. 

What monitoring methods are needed to detect barrier breaches? What modeling methods 

should be used? How do contaminants affect the long-term integrity of barrier materials? 

OSWER is revising the landfill capping guidance document issued in July 1989 and will add 

requirements for monitoring the performance (prevention of infiltration) of installed landfill 

caps. The information prepared under this project will be the background support needed to 

support the new requirements. [Previously H39]

SOIL/WASTE-2. Long-Term Remedy Performance for Containment Systems

For example, persistence of contaminants and their effects if they have been stabilized or 

solidified; design life of physical barriers, e.g., caps, slurry walls. [Previously H40]

SOIL/WASTE-3. Management of Landfill Gas

Determine appropriate methods to monitor and measure the gas escaping from landfill units. 

Determine the point at which measurements would indicate it would be acceptable (based 

on existing regulations) to vent landfill gas in lieu of collecting the gas for beneficial use or 

treatment. Determine appropriate collection systems. Determine appropriate technologies for 

treatment of the collected landfill gas. Determine the point at which collection is no longer 

required and gas could be vented directly to the atmosphere. How to manage LF gas and 

understand its movement in capped LFs and under clay vs. phyto caps. [Previously H41]

Medium Priority

SOIL/WASTE-4. Landfills

(1) Upgrade guidance [is this same guidance as #1 above?]; (2) Need data to show if 

evapotranspiration and capillary barrier covers will work in arid conditions. Need criteria for 

designing these types of covers. [Previously M20]
A-7 Contaminated Sediment Research Multi-Year Implementation Plan

SOIL/WASTE-5. Seismic Considerations for Landfill Caps and Vertical Barriers

EPA has not addressed the need to consider the effect of seismic events in the design of 

landfill caps and vertical containment barriers. This project would entail the search of 

literature for relevant research papers, reports on actual impacts to caps, and data to support 

recommendations on design guidelines for capping landfills in areas subject to seismic 

events. This information will help to support guidelines developed for the capping guidance 

document and determine whether subsequent guidelines are needed for vertical barriers. 

[Previously M21]

SOILWASTE-6. Evaluation of Alternative Designs and Materials for Caps and Barrier Walls

A newly developed landfill cap design has emerged which shows promise for use in arid 

environments. The evapo-transpiration cap does not rely on traditional impermeable 

barriers to prevent infiltration from passing through the cap, but instead relies on the 

depth of materials in the cap and vegetation to release moisture back to the atmosphere 

before the moisture can reach the bottom of the cap material. Other designs may also be 

viable. Information on the performance, durability, and design parameters and minimum 

standards for these new caps must be collected and analyzed. Performance data and design 

criteria recommendations for revised capping guidance are needed. New materials for 

landfill cap and barrier wall construction are emerging on a regular basis. Data is needed 

on the acceptability of these materials with regard to meeting performance requirements, 

durability, and relative cost. This project would require review of technical papers, data 

from independent testing, and consultation with other federal agencies (i.e., Army Corps 

of Engineers, Bureau of Reclamations, Department of Energy, etc.) to collect the needed 

information. [Previously M22]

SOIL/WASTE-7. Verification of HELP Model

EPA has recommended use of the HELP (Hydrogeologic Evaluation of Landfill Performance) 

Model in past guidance documents. The HELP Model is used widely for the design of 

drainage features for landfill caps as well as predicting leachate generation for municipal 

landfills. There is concern among designers as to the accuracy of the model. This would 

entail making an assessment of the accuracy of the model in predicting infiltration rates and 

recommendations as to the extent it should be used in the future. The effort should also 

include an assessment of other available models. [This is an on-going research area that may 

be complete by FY03? But FY02 note says “Per discussion with NRMRL, clarification is 

that for the short-term (and about $25-50K) need to communicate to users exactly what the 

model should and should not be used for. Longer-term and more expense would include 

expansion/correction of model.”] [Previously M24]

SOIL/WASTE-8. Mining Site Research [Previously M25]

OSRTI Contact Shahid Mahmud

a. Analysis and Development of Mine Waste Technologies

Short term: analysis/inventory of existing technologies to address mine waste.

Long term: development of cost-effective technologies to address mine waste. Mine 
A-8 Contaminated Sediment Research Multi-Year Implementation Plan

waste includes all types including uranium. [Note: Mine Waste Technology Program 

(Butte, MT?) is implementing this.]

b. Mapping System/Inventory of Mine-Affected Watersheds

Need for a mapping/database system containing contaminated watersheds resulting from 

mining; continue using AVRIS to map mine sites. 

c. Inventory of Naturally-Occurring High Arsenic

A paper study of where As is naturally occurring at high levels. Start with USGS 

conference proceedings May 2002 in Denver? Potential contacts: NRMRL - Paul 

Randall; NERL - Jane Denne 

d. Develop Predictive Site Characterization Tools for Acid Mine Drainage. 

[USGS may be doing this.]

SOIL/WASTE-9. Optimization of SVE

How best to sequence pumping; how to know when remedy is close to asymptotic levels. 

[Previously M27] OSRTI contact - Mike Bellot(?) [Is this still needed after NRMRL 

technical report FY01?]

SOIL/WASTE-10. Bioavailability of Metals and Organics from Soils (Human Health and 

Ecological) [Not sure what category this belongs in.]

Contacts: OSRTI - Steve Ells, Janine Dinan; Regions 7 & 9

Determine bioavailability of contaminants through human ingestion to support both 

risk assessment of contaminants in residential and industrial/commercial scenarios and 

to determine cleanup goals for soil remediation technologies. In particular, assess the 

bioavailability of lead, mercury, chromium, arsenic, and cadmium. Reference doses, 

benchmark guidance and RfC values need development and communication. Children of 

different ethnic backgrounds may have different exposures. Fish advisory values /effects 

differ among federal agencies. The question, then, is “If a child or adult ingests soil, what 

is the internal dose relative to the contaminant concentration in the soil?” A core part of this 

research should be a strategy for relating in vitro studies to empirical animal studies to human 

biomarker/epidemiological data. Develop and evaluate processes to reduce contaminant 

bioavailability. [Previously H27] 
A-9 Contaminated Sediment Research Multi-Year Implementation Plan

IV. MULTI-MEDIA & ANALYTICAL RESEARCH NEEDS

Analytical Research Needs - OSRTI Contact: Dana Tulis

High Priority

MULTI-1. Statistical Expertise to Support Background Policy

OSRTI Contact - Jayne Michaud

Provide technical expertise for statistical problems related to Superfund site activities and 

for implementing the new Superfund technical guidance for determining background. 

[Previously H32] 

MULTI-2. Support on-site Audits of Non-CLP Labs

[Not currently being done by ORD] [Previously H37]

MULTI-3. Peer Review of New Analytical Methodologies

On-going need, e.g., PCBs [Previously H38]

Medium Priority

MULTI-4. Phytoremediation

OSRTI Contacts: Scott Fredericks, Steve Ells, Robin Anderson

Develop improved methods of remediating soil and ground water using vegetation planted 

and grown in the contaminated areas. Questions remain concerning what are the tolerant 

plant species, mechanisms of contaminant breakdown, and the rates of cleanup for key 

contaminants found at Superfund sites. [Previously M22]

MULTI-5. Analytical Detection Limits for Bioaccumulative Chemicals

OSRTI Contact – Steve Ells

The goal of this project is to develop lower analytical detection limits for chemical analyses 

of known bioaccumulators in water, soil, sediment, and tissue samples. [Previously M13] 

MULTI-6. Arsenic and Mercury

OSRTI contact - Robin Anderson

Short term - engineering bulletin. Long term - if there are technologies on the horizon, 

it would be good to know more about them. [Note: Have fact sheets on Pb remediation 

methods - what we have learned. Need to know for As and Hg what technologies will and 

will not work. FY02 note: NRMRL suggests that OSRTI follows up with Paul Randall, 

NRMRL. DOE has done a number of studies/demos on cleanup of Hg-contaminated soils. 

There were discussions in Denver (week of May 7) about cleanup of Hg-contaminated soils. 

Robert Puls in Ada is contact for As-contaminated ground water.] [Previously M26]

MULTI-7. May be a need for dioxin research

Depending on the results of the reassessment, e.g., current technologies may be unable to 

reach new levels. [Previously L1]

MULTI-8. Support of sample preparation for high concentration analyses

OSRTI Contact - Dana Tulis

[Previously L6]
A-10 Contaminated Sediment Research Multi-Year Implementation Plan

V. HUMAN HEALTH RESEARCH NEEDS

OSRTI Contact: Jayne Michaud

High Priority

HH-1. Reduce Uncertainties Associated with Dermal Exposure Assessments - Water Exposure

OSRTI contact: Dave Crawford

For water exposures, is model in Part E over- or under-estimating actual absorption, or 

are assumptions reasonably accurate? Additional research is necessary to determine the 

absorption of lipophilic contaminants (e.g. PCBs, dioxins) through the skin barrier. (Part E, is 

Part E of Risk Assessment Guidance for Superfund (RAGS) and addresses dermal exposures. 

This is Superfund’s current draft guidance on dermal risk. It is considered an extension of the 

ORD guidance on dermal exposure, known as “Dermal Exposure Assessment” or “DEA.”) 

[Short-term project] [Previously H20]

HH-2. Dermal Exposure Model

OSRTI contact: Dave Crawford

Refine (Part E) or develop model for estimating dermal absorption of contaminants from soil 

using permeability coefficients. Consider issuing as an update of DEA or Part E and evaluate 

efficacy of on-going methodolgy developed for reoccupancy of buildings in the vicinity of the 

World Trade Center. [long-term project] [Previously H21] 

HH-3. Determine Dermal Toxicity Effects and Develop Dermal Toxicity Values

OSRTI point of contact: Dave Crawford

For contaminants without dermal toxicity values in IRIS, expand the database of toxicity 

values. For noncancer toxicity, expand the database of values (i.e., RfDs) for subchronic and 

acute exposures, as well as chronic RfDs. Develop values for for “point-of-contact (on skin) 

toxicity,” including PAHs. Recommend that such values loaded into OSRTI’s database of 

NCEA peer reviewed toxicity values. [medium-term project] [Formerly H23, and before that, 

part of H22, H24, and H25]

HH-4. Develop Methodology for Integrated Assessment for Residential Exposures

OSRTI point of contact: Jayne Michaud and Dave Crawford (dermal)

For various media, including vapor intrusion (indoor air), dermal exposure to building 

surfaces (as well as soil and water), and soil ingestion. Consider an update to Part E for 

dermal, use of the World Trade Center reoccupancy assessment and the recent Vapor Intrusion 

Guidance for the Integrated Assessment. [short-, medium-, and long-term project] [Formerly 

H24, and before that, part of H24]

HH-5. Improve Dose-Response Assessment

OSRTI point of contact: Jayne Michaud 

Improve dose-response assessments for contaminants occurring frequently at Superfund sites 

considering the use of additional pharmaco-kinetic physiological models. When scientifically 

appropriate, develop special assessments applicable to children and women as sensitive 

subpopulations. When appropriate, provide methodology for assessing more sensitive or 

highly exposed subpopulations. Recommend that such values be considered for inclusion in 
A-11 Contaminated Sediment Research Multi-Year Implementation Plan

IRIS, or, alternately, the PRTV database. [Formerly H26] [Medium-term Project] 

Medium Priority

HH-6. Reduce Uncertainties Associated with Dermal Exposure Assessments - Soil Exposure

OSRTI contact: Dave Crawford

Generate and intepret additional experimental data to assess reliability of Part E’s estimation 

of dermal exposures to soil. [Medium-term project] [Previously part of H20]

HH-7. Support for the Exposure Factors Handbook

OSRTI contact: Jayne Michaud, Steve Chang

Update and expand assumptions and supporting justification for human health exposure 

assumptions, including soil ingestion. Questions: Will this provide sufficient information for 

use in Probablistic Risk Assessments? [Medium-term project] [Previously H19]

VI. ECOLOGICAL RESEARCH NEEDS

OSRTI Contact: David Charters

High Priority

ECO-1. Define Ecological Significance

Contacts: OSRTI - Steve Ells; ERASC; ORD - Focus Group 7 (has detailed plans for this 

FY02 - FY07)

Goal is to clearly define and describe ecological significance and to determine what levels 

of population and community effects are generally acceptable; i.e., will a 20% reduction in 

a specific endpoint still sustain a functioning, healthy ecosystem? How does EPA determine 

that (1) the observed or predicted adverse effects on a structural or functional component 

of the site’s ecosystem is of sufficient type, magnitude, areal extent, and duration that 

irreversible effects have occurred or are likely to occur and (2) these effects appear to exceed 

the normal changes in the structural or functional components typical of similar unimpacted 

ecosystems? [Previously H28]

ECO-2. Balancing the Benefits of Remedial Action versus Destruction of Valuable Habitats 

The goal of this project would be to develop criteria and provide guidance on how to 

determine when there is more benefit to the existing ecosystem from leaving soil or sediment 

contamination in place and preserving the current habitat (although stressed) versus a 

destructive remedy that removes the contamination and destroys the current habitat. How 

do you value a habitat that is functioning, but at less-than-optimal levels versus the short- to 

long-term impacts on destroying the same habitat and then trying to restore it? [Previously 

H29]

ECO-3. Develop Predictive Models for Determining the Potential Population Level Effects

How much sediment toxicity is needed before anyone can predict that there will be significant 

effects on the population of concern; e.g, how many bass or mink or kingfishers can be killed 
A-12 Contaminated Sediment Research Multi-Year Implementation Plan

before the mortality levels is expected to impact the ability of the population of biota to 

sustain itself at a healthy level in the area impacted by the site. [Previously H31] 

ECO-4. Weight-of-Evidence Approach for Ecological Effects/Cleanup Levels

There are published papers on this process. Should Superfund adopt a similar process for 

consistent use at our sites? [Previously H33]

ECO-5. Support Development of EcoSSLs for Mammals, Birds, Plants, and Soil Invertebrates

[Previously H34]

ECO-6. Continue to Support and Maintain the ECOTOX Database

[Previously H35] 

ECO-7. Design Toxicity Testing Procedure to Develop Toxicity Reference Values for Non-EcoSL Contaminants

Utilize the criteria developed by the Ecological Soil Screening Level (Eco-SSL) workgroup to 

design a toxicity testing procedure to meet these criteria in order to generate toxicity reference 

values (TRVs) for additional contaminants not being addressed by the Eco-SSL workgroup or 

for which TRVs are lacking. [Previously H36]

Medium Priority

ECO-8. Determine Bioavailablity of Chemicals for Different Media

The central question is how does one relate concentration of a contaminant in a medium (even 

the medium for animal dose/response studies) to the delivered or internal dose. Answering 

this question would reduce a major source of uncertainty in risk assessments. [Previously 

M6]

ECO-9. Develop a Methodology to Evaluate the Inhalation Exposure Pathway for Mammals

[Previously M10] 

ECO-10. Development of Recommended Performance Criteria to Measure the Success of 

Wetlands Restoration/Creation

FY02 note: No expertise within ORD. What about Midwest Hazardous

Substances Research Center (HSRC)? [Previously M11] 

ECO-11. Support Wildlife Research Strategy

[Previously M12]

ECO-12. Develop Terrestrial Risk Assessment Models for Various Habitats from Deciduous 

Forests to Deserts

[Previously M14]

ECO-13. Develop Toxicity Testing Methodologies for Amphibians, Reptiles, and Microbial 

Communities

[Previously M15] 

ECO-14. Develop an Approach for Incorporating Dose Response Information into Ecological 
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Risk Assessments that Go beyond the Hazard Quotient Approach

How can the likelihood of risk be quantified when the hazard quotient is greater than 1? 

Develop an approach for conducting uncertainty assessment using site-specific case studies. 

[Previously M16]

ECO-15. Develop Tools and Methods to Better Characterize the Ecological Exposure and 

Effects of Multiple Chemicals, i.e., Mixtures

[Previously M17]

ECO-16. Develop an Approach for Assessing the Exposure and Effects of Contaminants to 

Corals

[Previously L no-number]
A-14 Contaminated Sediment Research Multi-Year Implementation Plan
B-1 Contaminated Sediment Research Multi-Year Implementation Plan

Appendix B: Expanded Descriptions of Ten Issues Resulting 

from May 2003 AED Meeting

This list of Sediment Research Issues resulted from the discussions of the twenty-eight sediment 

research issues of Superfund (see Appendix A) by the Steering Committee in May 2003. These 

discussions evaluated the appropriateness of the research issue to the mission and capabilities of 

NHEERL. For each of the ten research issues, an expanded description is provided below. 

Sediment Research Issues

The sediment research issue descriptions were developed from a list of priorities provided by 

Superfund, see Superfund Program Research Priorities for ORD - December 12, 2002, Working 

Draft, discussed at the May 1 kickoff meeting at AED in Narragansett, RI. The following 

descriptions are based around the following schematic of the Superfund remediation process for 

contaminated sediments:

Developing Sediment Contaminant Screening Levels (SED-1)

Screening levels are used in the Superfund program as an initial evaluation as to whether 

individual contaminants should be included in more detailed risk assessments. They are 

indicators of potential risk and are not designed to be used as remedial goals; their purpose 

is simply to “screen in” chemicals for further evaluation. As such, their primary emphasis 

is to avoid false negatives; however, to be efficient screening tools, they should not be so 

conservative that they provide no discrimination. While screening values for direct toxic effects 

Is there

unacceptable

risk?

Was the

risk addressed?

Dredging Capping

Monitored

Natural Recovery

What is clean?

Which technology

will deliver?

What short-term risks

result from the remedy?

• resuspension

• habitat damage

Is there

unacceptable

risk?

Was the

risk addressed?

Dredging Capping

Monitored

Natural Recovery

Is there

unacceptable

risk?

Was the

risk addressed?

Dredging Capping

Monitored

Natural Recovery

What is clean?

Which technology

will deliver?

What short-term risks

result from the remedy?

• resuspension

• habitat damage
B-2 Contaminated Sediment Research Multi-Year Implementation Plan

of contaminated sediments have been developed using several methods (e.g., EqP, ERL/ERM, 

TEL/PEL, AET, logistic regression), there are no widely accepted screening values for sedimentassociated chemicals that cause their effects on pelagic aquatic or terrestrial wildlife species 

through bioaccumulation pathways.

Because they are to be used broadly, their derivation must account for a wide variety of exposure 

scenarios and receptors. The key scientific challenges to developing screening values arise from 

the differing amounts and types of available toxicological data available (differences in species, 

endpoints, life stage, exposure, etc.,) and the necessity of defining the linkages between the 

chemical concentrations in the sediment and the biota of interest. In describing these linkages, 

one must account for the effects upon the bioaccumulation of the chemical attributable to 

differences in chemical exposure arising from ecosystem conditions, food web structure, and 

species composition.

From a implementation perspective, screening values based upon a standardized and peerreviewed and accepted numeric derivation technique using robust data sets are most desirable. 

These screening levels can be based upon a number of “indicator” species and toxicological 

endpoints. Effort is required to derive a generalized conceptual model (exposures, receptors, 

endpoints) and to develop sets of standardized procedures to be applied in deriving estimates of 

bioaccumulation and in establishing effect concentrations in tissues of predator and/or prey.

Establishing Guidance on Sampling Biota and Surface Sediments at Superfund Sites 

(SED-5, SED-8)

Several existing protocols provide guidance for sampling biota and sediments at contaminated 

sites (e.g., U.S. EPA, Environment Canada). However, because of the remedial activities 

occurring at Superfund sites, they often represent unique settings for collecting biota and 

sediments. For example, values that can be standardized at regular field sites like depth of 

sampling may not be readily determined at a Superfund site because of the presence of a cap or 

effects of MNR. Further, how to sample a site for surface sediments or resident biota following 

a dredging event may not be clear if sediments have been altered in consistency and mixed 

vertically or biota are no longer present. Research is needed to determine the best practices 

for sampling biota and surface sediments at Superfund sites, especially when measuring risk 

reduction after remedy implementation. Also see “Assessing the Effects of Contaminated 

Sediment Resuspension” discussed below.

Linking Chemical Residues in Aquatic Biota to Levels of Ecological Risk for Aquatic 

and Aquatic-Dependent Wildlife (SED-13 [partial], 14)

Doses of bioaccumulative chemicals to fish and wildlife are best expressed on the basis of 

tissue residues, in part because tissue residues integrate doses received from multiple exposure 

pathways (e.g., food, water, sediment). However, to use tissue residue as the basis for predicting 

risk, there must be an unambiguous means to link specific residue concentrations to the 

biological effects they cause. Ideally, the conceptual basis for this would be robust enough to be 

used for different chemicals and for different sites, thus providing consistency and transparency 

to risk assessments throughout the Superfund program. Key challenges to establishing this 
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linkage arise from the differing amounts and types of toxicological data available; these include 

differences in species, endpoints, life stage tested, exposure methods (e.g., food versus water), 

exposure duration, and methods of quanitfying or expressing exposure.

Another need for a residue-based approach is a reliable means of relating concentrations in the 

physical environment (water, sediment, food chain) to residues expected in consumer organisms 

and/or prey for organisms of interest to the risk assessment. While direct measurements 

may suffice for the initial risk assessment, comparing changes in risk from different remedial 

alternatives will require a means to predict tissue residues resulting for altered concentrations in 

sediment and water as a result of remedial actions.

From the broadest perspective, tools are needed to extrapolate toxicological data, particularly 

among different receptor organisms. Aquatic or aquatic-dependent wildlife species of interest 

at different sites will likely vary; and, in many cases, available toxicological data will be 

available only for species other than the actual receptor species. This requires extrapolation of 

toxicological data among species, which relies on an understanding of the toxic mechanisms for 

the chemicals of concern, and extrapolation tools such as PB/TK models to predict effects in 

untested species.

Predicting Rates of Recovery Following Remedial Actions (SED-13 [partial])

As part of selecting and implementing a remedial alternative, it is important to have sound 

expectations of the rates at which reduction in risk can be expected, whether it be in the form 

of reduced residues in prey organisms or recovery of affected organism populations and 

communities. Additionally, it is important to have sound expectations of the rates at which the 

ecosystem recovers from the short-term impacts of the remedial alternative (e.g., understanding 

how fast an area recolonizes after dredging and/or deposition of capping materials and whether 

different types of capping material influence biological recovery). For the reduction in risk, 

an understanding of both the rate and magnitude of the change in exposure created by the 

remedial alternative (from physical/chemical modeling), as well as an understanding of the 

mechanisms governing the response of organisms to changes in exposure (from kinetically based 

bioaccumulation modeling), is required. Predicting the recovery of impacted populations and 

communities, as well as the recolonization of the remediated site, will require an understanding 

of the ecology of those organisms and of the factors and environmental conditions governing 

population growth and community structure. 

Development of Appropriate Remedial Goals for Non-Bioaccumulative Chemicals 

(SED-15)

While the ecological risks from chemicals such as PCBs arise from bioaccumulation-enhanced 

exposure of pelagic or non-aquatic organisms, risk from other sediment contaminants is created 

by direct toxicity to organisms living in contact with contaminated sediments. These “nonbioaccumulative” effects may be assessed through a variety of means, including comparison 

of chemical concentrations in water and/or sediment to chemical specific benchmarks (e.g., 

sediment quality guidelines), sediment toxicity testing, toxicity identifications evaluations (TIE), 

or benthic community assessments. Experience has shown that at some sites, evaluations of 
B-4 Contaminated Sediment Research Multi-Year Implementation Plan

potential risk via these different lines of evidence suggest different levels of risk or even appear 

to conflict. Assessment approaches are needed through which to reconcile information from 

these different lines of evidence and arrive at a consistent and transparent establishment of 

remedial objectives that will adequately address ecological risks.

Delineation of Appropriate Uses of Total PCBs, Aroclor-Based, and Congener-Specific 

PCB Concentrations as the Basis for Assessing and Managing Risks from PCBs 

(SED-18)

PCBs occur in the environment as mixtures of up to 209 different congeners, each with unique 

physical, chemical, and toxicological behaviors that influence risk. Early measurement and 

assessment techniques were developed using expressions of “total PCBs” or of “Arochlor” 

mixtures which are related to different formulations of PCB congeners released to the 

environment. These aggregate expressions of PCB exposures can lead to inaccuracies in 

assessing and predicting ecological risks because they fail to recognize differences in exposure 

and risk that result from the different environmental fate and effects of the individual congeners 

that comprise the environmental mixtures. Our advancing understanding of PCB risk assessment 

has led to the development of risk assessment techniques based on the concentrations of 

individual congeners and the way in which each contributes to cumulative risk. While the 

scientific community is in broad agreement that congener-specific assessment provides the most 

accurate estimates of ecological risk, implementation of this approach is impeded by concerns 

over differences in required analytical procedures and by selection of methods for assigning and 

aggregating potencies of individual congeners. Research is needed to quantify the degree to 

which the accuracy of risk assessment is improved by congener-specific analysis and to articulate 

a consistent and transparent approach for congener-specific estimation of risk into the context of 

Superfund sites.

Assessing the Toxic and Bioaccumulative Effects of Contaminated Sediment 

Resuspension (SED-22)

Dredging is the most common remedy for sites containing contaminated sediments. There 

are several advantages to dredging, principally, the effective removal of material causing the 

environmental risk. Simultaneously, dredging is the most expensive remedy with the most 

potential to impart short-term adverse impacts on the site and, in particular, on surrounding 

uncontaminated areas. These impacts derive primarily from the effects of resuspension of 

contaminated sediments during dredging. Based on the available data, resuspension results 

in the transport of contaminated sediments from the site as well as the flux of bioavailable 

contaminants into the water column. The resuspension of sediments may also result in the 

contamination of previously clean areas.

Methods are available for modeling the partitioning, bioavailability, and effects of contaminants 

in sediments under “equilibrium” or undisturbed conditions. However, when sediments are 

resuspended or enter “disequilibrium,” several studies have demonstrated that associated 

contaminants, including organic and metal pollutants, are remobilized. However, the 

bioavailability and effects of these contaminants in terms of toxicity to or bioaccumulation by 

aquatic life have not been extensively studied and are not very well understood. Similarly, 
B-5 Contaminated Sediment Research Multi-Year Implementation Plan

the development of predictive models of resuspended contaminant bioavailability and toxic or 

bioaccumulative effects is in its infancy.

Research in this area is needed to determine the magnitude of risk associated with the 

resuspension of contaminated sediments resulting from dredging and other energetic events 

including tidal action, bioturbation, and ship traffic. This research should address the risk of 

toxicity and increased bioaccumulation of organic and metal contaminants during resuspension 

events at Superfund sites.

Monitoring Methods and Protocols (SED-19)

Superfund has an immediate need for better monitoring methods and protocols to document 

remedial effects and the long-term effectiveness of remedial actions. While individual measures 

exist (toxicity tests, bioaccumulation measurements, chemistry data, etc.), protocols to assemble 

these disparate measures together in a consistent manner to make management decisions at 

sediment sites are lacking. In addition, while it is known that the methods to monitor remedial 

effects and the methods to monitor long-term effectiveness are different, the pros and cons of 

each approach are not clearly articulated. Fact sheets are being planned which will discuss 

individual monitoring methods in detail; however, the protocol for an all-inclusive weight-ofevidence (WOE) approach to monitoring requires further research. The statistical sampling 

approaches, inherent uncertainty, and combined assessment methods for chemical, biological, 

and physical data need to be determined and tested at actual sites. The WOE approach also 

needs to be placed in a tiered format so that it can applied at a variety of sediment sites, 

regardless of size or funds available. 

Dredging Residuals (SED-21a)

Dredging is the most commonly selected remedial option at sediment sites and the only one 

that removes contamination from the aquatic environment. However, there is still a significant 

amount of uncertainty about how effective dredging is and the amount of post-remedial 

contamination left. Is this “dredging residual” the result of careless dredging and/or the use 

of older equipment, or is it inevitable no matter which dredging equipment is selected? Is 

the residual dangerous relative to the benefit of mass removal? Does the risk-benefit vary in 

different water bodies (e.g., rivers vs. estuaries)? Quantifying and reducing this uncertainty is 

vital and must be accomplished soon as several “megasite” cleanups (e.g. New Bedford Harbor, 

Hudson River, Fox River) have selected dredging. These results could have a significant effect 

on the future selection of the dredging remedy. 

Cleanup Levels (SED 21b)

The cleanup level at a sediment site determines the volume of sediment to be remediated. The 

sediment volume is a driving factor of remedial costs. Disagreements over whether cleanup 

levels are reached is one of the most significant arguments against active sediment remediation, 

particularly the use of dredging. A recent review of 50 dredging projects worldwide found 

extensive documentation of how cleanup levels were chosen (based on the human health and 

ecological risk assessments), but there was very little documentation of how it was determined 

that those results were or were not achieved. None of the projects had a statistically valid 
B-6 Contaminated Sediment Research Multi-Year Implementation Plan

approach to determine how cleanup levels would be evaluated (number of samples to be taken, 

spatially averaged approach, etc.). It would be valuable to Superfund to promulgate guidance 

on a consistent approach to verify post-remedial cleanup levels. Research in this area would 

be integrated with studies of dredging residuals in that it is necessary to understand residual 

amounts and risks in order to decide on the most effective, achievable, and environmentally 

protective cleanup levels. 
C-1 Contaminated Sediment Research Multi-Year Implementation Plan

Appendix C: Description of Science Tasks and Level of Effort 

for Eight Research Issues

The descriptions below were developed after critical discussion of the ten issues (see Appendix 

B) by the Steering Committee via a series conference calls. Of the ten research issues identified 

in Appendix B, two issues (SED-21a and SED-21b) were removed from further consideration 

during these discussions because the primary research needed to address the research questions 

were outside NHEERL’s mission. The descriptions below provide a listing of tasks and the 

amount of effort for the eight remaining research issues.

A. Developing sediment contaminant screening levels (SED-1)

1. This is a paper exercise.

2. The science tasks are

a. Assembling a methodology for deriving;

b. Evaluating its usefulness (e.g., too many false positives or negatives); and

c. Refining methodology. 

3. As we have learned in discussions with Superfund, development of an actual methodology 

and values will require a stakeholder process in order to move forward politically. 

B. Establishing guidance on sampling biota and surface sediments at Superfund sites 

(SED-5, SED-8)

1. This is a paper exercise.

2. The exercise will pull together existing sampling protocols and scientific expertise to 

assemble useful guidance for Superfund sites.

C. Linking chemical residues in aquatic biota to levels of ecological risk to aquatic and

 aquatic-dependent wildlife (SED-13 [partial], 14)

1. This effort will require new science research.

2. The science tasks are

a. Development of visualization approach,

b. Extension of visualization approach to include extrapolation,

c. Development of high quality field data sets to validate visualization approach for 

extrapolation across species and ecosystems,

d. Development of high quality field data sets for metabolizable chemicals in aquatic 

ecosystems,

e. Development of approaches for parameterizing bioaccumulation models for 

metabolizable chemicals,

f. Evaluation of uncertainties in predicting chemical residues in aquatic organisms 

using food web models with generic and site-specific parameters and conditions, and

g. Demonstrations and applications of the hybrid BAF/BSAF methods to Superfund 

applications
C-2 Contaminated Sediment Research Multi-Year Implementation Plan

D. Predicting rates of recovery following remedial actions (SED-13 [partial])

1. Paper research will be required to determine whether new research is needed.

2. The science tasks are:

a. Recovery from reduction in contamination with bioaccumulative chemicals

(i) Apply concepts from category C above to evaluate rates of residue reduction 

following reduction in exposure [Note: need good information on reduction in 

exposure; not an effects issue.]

(ii) Will probably need a demonstration for “validation” – may already be done 

(New Bedford?).

b. Recovery from physical disturbance of removal and/or capping

(i) Determine depth of information already available from disturbance ecology 

literature, and

(ii) If existing literature is insufficient, conduct new experiments to measure 

recovery rates, either in experimental manipulations or by monitoring postremedy at specific sites.

E. Development of appropriate remedial goals for non-bioaccumulative chemicals

(SED-15)

1. This effort will require new research.

2. The science tasks include

a. Develop bioavailability-based approaches for predicting the toxicity of specific 

chemicals (arsenic, chromium, others?) important to Superfund program, and

b. Develop a means to assess risk from dietary exposure to metals.

F. Delineation of appropriate uses of total PCBs, Arochlor-based, and congener-specific 

PCB concentrations as the basis for assessing and managing risks from PCBs (SED-18) 

1. This is a paper exercise.

2. The science tasks are

a. Assembling PCB data sets which have the complete congener-specific PCB analyses 

(Method 1668A) for a number of Superfund sites, and

b. Performing risk calculations and comparing results.

G. Assessing the toxic and bioaccumulative effects of contaminated sediment resuspension 

(SED-22)

1. This effort will require new science.

2. The science tasks are

a. Development of toxicity and bioaccumulation testing methodology where the 

exposure water is created using particle entrainment simulator (PES) of Tsai and 

Lick (1986). The PES devices simulates resuspension of sediments in the laboratory 

using field collected sediment cores;

b. Performance of testing methodology on sediment cores from Superfund sites, i.e., 

Passaic River (NJ), Elizabeth River (VA), New Bedford Harbor (MA), Hudson 
C-3 Contaminated Sediment Research Multi-Year Implementation Plan

River (NY), Anacostia River (Washington, DC), Trace Rios (AZ), Black Stone/

Woonasatocket (RI), and Taunton River (MA); and

c. Field validation of the PES-based toxicity and bioaccumulation testing methodology.

H. Monitoring methods and protocols (SED-19)

1. Initially, this is a paper exercise, and will result in a OSRTI “Weight of Evidence SMART 

Sheet.” 

2. It is hoped that exact research questions will fall out of the paper exercise.
C-4 Contaminated Sediment Research Multi-Year Implementation Plan
D-1 Contaminated Sediment Research Multi-Year Implementation Plan Appendix D: Candidates for NHEERL Research in Contaminated Sediments This table was developed by the Steering Committee after discussing the science tasks and level of effort assessments for the eight remaining sediment research issues (see Appendix C). These discussions ultimately ranked these issues into highest, high, and lower priorities. The table contains the eight sediment research issues along with the two issues eliminated (issues 9 and 10) in a prior round of discussions. Issue Status Highest Priority 1. Residue/effect relationships: Linking chemical residues in aquatic biota to levels of ecological risk to aquatic and aquatic-dependent wildlife. (SED-13 [partial], 14) This issue requires new science and is within NHEERL’s mission. The two components of the issue are exposure to residue in the organism and residue- effect relationships. 2. Non-Bioaccumulatives: Development of appropriate remedial goals for non- bioaccumulative chemicals. (SED-15) This issue requires new science and is within NHEERL’s mission. Some further discussions are required to work out the non-bioaccumulative chemicals of concern. 3. Resuspension: Assessing the toxic and bioaccumulative effects of contaminated sediment resuspension (SED-22) This issue requires new science and is within NHEERL’s mission. The OSRTI’s research questions are “What are the impacts from resuspension during dredging?” and “Does dredging result in increased environmental risks to aquatic organisms?” High Priority 4a. Predicting rates of recovery following remedial actions (SED-13 [partial]) (Sub-issue D1 Short-term impacts) Short-term impacts: NHEERL needs to do some background research on “disturbance ecology” to determine if new science is required. If it is required, this issue would warrant further discussion for the MYIP. 5. Monitoring Methods and Protocols (SED-19) Further clarification needed to focus research issue/allow determination of “new science.” Table continued on following page
D-2 Contaminated Sediment Research Multi-Year Implementation Plan Lower Priority 4b. Predicting rates of recovery following remedial actions (SED-13 [partial]) (Subissue D2 Long-term prediction of chemical residues in fish) Long-term prediction: NHEERL in supporting role to other ORD laboratories (assumes that the problem is a fate and transport question; i.e., getting chemical concentrations in water and sediment correct in the future). 6. Developing sediment contaminant screening levels (SED-1) NHEERL in supporting role to NCEA and/or OSRTI. 7. Delineation of appropriate uses of total PCBs, Arochlor-based, and congener-specific PCB concentrations as the basis for assessing and managing risks from PCBs (SED-18) NHEERL should be involved in this issue. This is a technical support effort and not a research effort. Could possibility be done with contract dollars. 8. Establishing guidance on sampling biota and surface sediments at Superfund sites. (SED-5, SED-8) NHEERL in supporting role to other ORD laboratories. Research Issues Eliminated in Prior Round of Discussions 9. Dredging Residuals (SED-21a) Not within NHEERL’s mission. 10. Cleanup Levels (SED 21b) Not within NHEERL’s mission.
Contaminated Sediment Research Multi-Year Implementation Plan

Appendix E: Commitments and Endorsements

Elizabeth Southerland, Director

 OSWER, OSRTI, Assessment & Remediation Division

Jonathan Garber, Director

 ORD, NHEERL, Atlantic Ecology Division

Janet Keough, Acting Director

 ORD, NHEERL, Mid-Continent Ecology Division

E-1
E-2 Contaminated Sediment Research Multi-Year Implementation Plan
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