Introduction to special section: Finding achievable risk reduction solutions for contaminated sediments

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Finding Achievable Risk Reduction Solutions” was the theme of the Third International Conference on Remediation of Contaminated Sediments that was held in New Orleans, Louisiana, USA, 24–27 January 2005. Although advances in scientific understanding, decision-making approaches, and remediation technologies are slowly making a difference in our ability to manage contaminated sediment sites, we still face significant challenges in effectively achieving human health and environmental protection goals. The potentially high costs associated with contaminated sediment remediation require that we develop more effective risk reduction strategies and the policies to support them. To this end, the Conference program included 4 panel discussions that focused on some of the current issues of greatest concern within the sediment-management community, as identified by the Conference Steering Committee. Each session included 3 panelist presentations outlining key points and arguments, followed by an open discussion and question and answer with the audience. Selected papers from these panel sessions are included in this issue of Integrated Environmental Assessment and Management. It is our hope that these papers will be a useful resource for the sediment management community.

The panel “Sediment stability—How do we incorporate it into sediment-management decisions?” was moderated by W. Frank Bohlen of the University of Connecticut and Michael Erickson of Blasland Bouck & Lee, Inc. (Bohlen and Erickson 2006). Michael Erickson kicked off the session by discussing the use of multiple lines of evidence to characterize contaminated sediment transport. C. Kirk Ziegler of Quantitative Environmental Analysis LLC focused on the use of models to characterize and predict sediment stability and provided suggestions for effectively communicating model results to decision makers (Ziegler 2006). Lawrence Sanford of the University of Maryland discussed uncertainty in sediment erosion estimates due to lack of standardization in experimental protocols and data analysis procedures (Sanford 2006). Richard Jepsen of Sandia National Laboratories described currently available devices and methods for the measurement of sediment erosion (Jepsen 2006). The open discussion focused on problems with evaluating and communicating uncertainty with predictions about the mobility of contaminated sediment deposits. There was a general consensus that sediment stability conclusions are most effectively presented graphically in a conceptual site model framework. The audience was reminded to integrate sediment stability information with findings about other important fate and transport processes and to link sediment mobility predictions to risk analyses.

How do we make risk management decisions?” was moderated by Todd Bridges of the US Army Corps of Engineers Center for Contaminated Sediments (USACE CCS) and Sabine Apitz of SEA Environmental Decisions (Bridges et al. 2006). Panelist Kymberlee Keckler of the US Environmental Protection Agency (USEPA) provided perspectives on a number of factors that must be considered when selecting sediment remedies and the difficulties associated with balancing those factors. Ms. Keckler, who was unable to attend the conference, was represented by Mary Logan, also of the USEPA. Steve Nadeau, the Managing Director of the Sediment Management Work Group, proposed development of a standardized approach for conducting a comparative net-risk evaluation of remedial alternatives. Richard Wenning of ENVIRON International Corp. discussed specific aspects of evaluating risks from remedy implementation and longer term residual risks for various remedial alternatives (Wenning et al. 2006). As part of the open discussion, the panelists made suggestions for changes that they believe would improve how we make risk management decisions. These suggestions included development of a national sediment watershed policy, development of a framework for comparative net risk assessment for risk management purposes, commitment of sufficient resources and attention to regulatory programs to improve coordination and develop the best cleanup solutions for a given area, and the removal of barriers between risk assessors and risk managers in order to promote more cooperative decision making.

“Remedy effectiveness—What works, what doesn't?” was moderated by Craig Zeller of the USEPA and Brad Cushing of Applied Environmental Management Inc. (Zeller and Cushing 2006). This panel focused on key issues associated with performance of various response actions for contaminated sediments. Paul Doody of Blasland Bouck & Lee, Inc. summarized issues associated with the effectiveness of environmental dredging. Victor Magar of ENVIRON International Corp. discussed monitored natural recovery (Magar and Wenning 2006), and Thomas Fredette of the New England District of USACE assessed the benefits of contained aquatic disposal cells (Fredette 2006). Discussion points focused on the importance and difficulty of source control and our lack of ability to accurately predict postremediation concentrations of chemicals in dredging residuals and fish tissue. The length of time that might be necessary to demonstrate remedy effectiveness also was a concern.

“Defining remediation success—Are we reducing risk and achieving environmental protection?” was moderated by Stephen Ells of the USEPA and Michael Palermo of Palermo Consulting, with assistance from Todd Bridges of USACE CCS. Jason Speicher of the US Navy provided perspectives on defining remediation success before, during, and after a remedy is selected and implemented. Thomas Schadt of Anchor Environmental discussed important factors in post-remediation monitoring to assess risk reduction and presented several case studies. The panelists agreed that site managers need to have a well-defined plan for measuring success with carefully designed assessment criteria prior to remedy implementation. Other topics for discussion included the role of politics in decision making, establishing appropriate remediation goals for individual sites within a contaminated watershed, habitat-restoration issues, and the importance of incorporating stakeholder values into site decisions. The panel pointed out the critical need for institutionalizing lessons learned from previous sediment-management decisions.

Some of the recurring themes throughout the panel sessions, as well as the rest of the conference, were the importance of soliciting stakeholder input early and incorporating it into sediment management decisions as they take shape, the need to develop and apply multicriteria decision analysis and comparative net risk evaluation methods, the need to accept uncertainty and move forward with decision making based on hypothesis testing and adaptive management approaches, and the need to effectively capture information on remedy performance and transmit the lessons learned to the sediment management community.

The International Conference on Remediation of Contaminated Sediments is sponsored and organized by Battelle. The 2005 Conference was cosponsored by CH2M HILL, Environmental Security Technology Certification Program, ENVIRON Water Management Services, Malcolm Pirnie, Inc., Strategic Environmental Research & Development Program, and The US Army Corps of Engineers Center for Contaminated Sediments. The Fourth International Conference on Remediation of Contaminated Sediments will be held in early 2007. Details will be posted at www.battelle.org/sedimentscon as they become available.

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