Research Brief:
Ecological and Human Health Risk Associated with Upland Disposal of Dredged Material Research

Issue     

The risk associated with disposal of contaminated sediment in upland environments, e.g., within confined disposal facilities (CDF), is a function of the likelihood that an organism would be exposed to contaminants within the sediment and the likelihood that those contaminants can cause adverse effects in the exposed organisms. The Corps of Engineers and the U.S. EPA have identified a number of contaminant migration pathways by which ecological receptors or humans could potentially be exposed to contaminants from upland sites, including:

• Effluent discharged during disposal operations
• Surface water runoff from the site
• Leaching of contaminants into groundwater
• Volatilization of contaminants into the air
• Direct contact with in-place sediment
• Consumption of food organisms exposed to contaminated sediments

The Corps and the EPA have also developed a number of assessment tools for evaluating the potential for contaminant releases from upland disposal sites. As more restrictions are placed upon the use of open water disposal and management of dredged material, greater emphasis and use will be made of upland disposal sites. These sites must also be managed in a way that minimizes risks to human health and the environment.

Research/Objectives    

This research and development effort organizes the use of available tools within a tiered framework to evaluate and manage potential ecological and human health risks posed by upland disposal sites. The guidance will be composed of four tiers, similar to the Inland and Ocean testing manuals. Within tiers 1 and 2, screening level approaches will be applied to each of the contaminant migration pathways relevant to CDFs.
(Continued on reverse)

U.S. Army Engineer Research and Development Center

September 1999
www.erdc.usace.army.mil
www.wes.army.mil/el/dots/doer

The level of evaluation will increase in higher tiers where more definitive testing and modeling methods must be applied to resolve the extent and magnitude of potential risks. For each of the pathways of concern, an evaluation will proceed to a higher tier only when sufficient information is needed to confidently identify the need for risk management.

Results/Products    

A risk guidance document produced as a result of this research will be the fundamental tool used by the Corps and EPA to identify contaminants and pathways of concern, to assess the risks posed by these contaminants, and to identify the need for specific management actions to reduce exposure levels.

Research Team    

Todd S. Bridges, Ph.D., Jerome Cura, Ph.D., Donna Vorhees, Ph.D., ERDC; Richard Peddicord, Ph.D. contract support
U.S. Army Engineer Research and Development Center
Waterways Experiment Station
3909 Halls Ferry Road, Vicksburg, MS 39180