Contaminated Sediment Management
Challenges with Remedial Design
Industrial practices such as oil refineries and chemical plants commonly leave a long-term legacy of contaminated sediments. Sediment remediation is a costly and challenging undertaking. Design of remediation strategy involves methods to excavate and contain sediment hotspots, install permeable barriers, groundwater hydraulic containment systems, and isolate and cap the impacted sediments. 3D modeling of the hydrodynamics, sediment transport and specific contaminants is often required.
Solutions Provided by EEMS
EFDC_Explorer Modeling System has been used extensively in the simulation and analysis of contaminated sediment for remedial design studies. EE allows you to accurately characterize your site conditions, with tools to support the data processing, model building and the simulation of the specific processes for transport of PCBs, dioxins, herbicides and pesticides in 1-D, 2-D, and 3-D. EE helps you to clearly visualize the lateral and vertical extent of toxics in the sediment bed. Comparison of scenarios for source removal actions, such as dredging, allows efficient use of resources and cost savings. Analysis of bed shear in the model domain helps determine shear stress on sediment caps.
EEMS is also used evaluate recontamination scenarios in remedial design. The EFDC code includes several internal sub-models for simulating the transport and fate of toxic contaminants. A simple, single contaminant sub-model accounts for water and suspended sediment phase transport with equilibrium partitioning and a lumped first order reaction. Contaminant mass per unit area in the sediment bed is also simulated. A second, more complex, sub-model simulates the transport and fate of an arbitrary number of reacting contaminants in the water and sediment phases of both the water column and sediment bed. It includes the flexibility of simulating an arbitrary number of contaminants, and the improved accuracy of utilizing more complex three-dimensional physical transport fields in a highly accurate numerical transport scheme.
Examples of Studies Done with EEMS
Examples of some of the dozens of contaminated sediments projects carried out using EFDC include:
- Portland Harbor, OR, USA (client confidential)
- Newark Bay/Passaic River, NJ, USA (client confidential)
- Duwamish River, WA, USA (client confidential)
- Housatonic River PCB Study, MA, USA
- Danang Airport Dioxin Investigation, Vietnam
- Bien Hoa Airport Dioxin Investigation, Vietnam
- Port Augusta Hydrodynamic Model and Mercury Study, Sicily, Italy
- Little Lake Butte de Morts Sediment Dynamics, WI, USA
The animation below shows a water surface profile of a sedimentation erosion study in North America. This animation depicts PCB concentrations along the centerline of this river. Above the black line depicts toxics in the water column. Below the black line depicts toxics in the sediment bed.
Download Example EE Models
Download an example model and run with the free EEMS Demo Version.