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EPA'S FIELD DEMONSTRATION OF INNOVATIVE CAPPING TECHNOLOGIES FOR THE RISK MANAGEMENT OF CONTAMINATED SEDIMENTS
Citation:
RANDALL, P. M., T. LYONS, S. CHATTOPADHYAY, A. R. GAVASKAR, O. GUZA, B. WALDEN, G. BAUMGARTEN, AND M. NEARMAN. EPA'S FIELD DEMONSTRATION OF INNOVATIVE CAPPING TECHNOLOGIES FOR THE RISK MANAGEMENT OF CONTAMINATED SEDIMENTS. Presented at Fourth International Conference on Remediation of Contaminated Sediments, Savannah, GA, January 22 - 25, 2007.
Impact/Purpose:
To inform the public.
Description:
Research on capping technologies is directed at assessing the effectiveness of innovative capping materials, factors that control contaminant release at the sediment-water interface, installation of cap, resuspension mechanism, and gas ebullition. U.S. EPA's Land Remediation and Pollution Control Division's (LRPCD) Superfund Innovative Technology Evaluation (SITE) program is sponsoring a capping demonstration using bauxite at the Navy's Dodge Pond site in Niantic, Connecticut. Conventional sand caps have to be several feet thick, which may impact navigational and other uses of the water body. Metal contaminants tend to be more soluble than organic contaminants and can migrate to the water column through advection, diffusion and/or gas ebullition. Natural minerals are a potential source of readily available, relatively inexpensive capping materials. Bauxite contains a combination of metal oxides through which metals, such as mercury, arsenic, chromium, lead, cadmium, and zinc, and certain organic pollutants are sorbed by the cap. In a separate project, LRPCD, is also collaborating with EPA Region 4 to conduct a bench scale study to understand Hg methylation in the sediment-water system. For this study, samples were collected at the Olin McIntosh plant in Alabama. Testing was conducted to understand the impact of sulfur and other factors that influence methyl mercury (MeHg) production. In a separate study, LRPCD is collaborating with EPA Region 6 and Alcoa at the Lavaca Bay site to develop a lesson learned document on the significant clean-up efforts at this mercury contaminated Superfund site. To understand the mechanisms associated with sediment resuspension, LRPCD led an interagency investigation at various contaminated sites in the U.S. (e.g., Boston Harbor, MA; Eagle Harbor, WA and others). The research indicated that resuspension can be minimized by using improved release techniques resulting in significantly less disturbances of the contaminated sediments. This presentation will provide the lessons learned from these U.S. EPA's collaborative programs and how the results can be used in remediation of contaminated sediments and development of the future design of the cap.