This report assesses the effectiveness of cleaning up contaminates sediments in aquatic environment, whether through dredging or other techniques, at sites at which remediation costs over $50 million. The authors held three public sessions at which they heard presentations on dredging projects and heard from interested parties, including the public. Here they describe what they learned about sediment management at superfund megasites, the framework for evaluation of effectiveness of environmental dredging in reducing risks, the factors affecting effectiveness, and means of monitoring sites, practices and projects. They make recommendations that will improve future decision-making.