Services Rendered:

EPA Peer Review

EFDC Hydrodynamic Modeling

EFDC Sediment Transport Modeling

HEC-6 Sediment Transport Modeling

HSPF Watershed Modeling

PCB Fate and Transport Modeling

Code Testing and Revision

Development of Modeling Tools

Sophisticated Data Analysis

Sediment Stability Study

Bank Erosion/Stability

For decades, PCBs had been released onto the soil near and into the Housatonic River from a GE facility in Pittsfield, MA. In 1998, after years of scientific investigations and regulatory actions, a comprehensive agreement was reached between GE and various governmental entities, providing for the investigation and cleanup of the Housatonic River and associated areas. Under the terms of the Consent Decree, EPA is conducting a detailed modeling study of hydrodynamics, sediment transport, and PCB fate and bioaccumulation in the Housatonic River below the confluence of the East and West Branches and encompassing watershed.

DSI managed all aspects of work performed by the modeling team for this very high visibility project. DSI had responsibility for the development of the model grid, hydrodynamic model, sediment transport model, and the PCB transport and fate model. Modeling efforts included an evaluation of the hydrodynamic and sediment transport effects of rare flood events on the re-introduction of contaminated sediments into the surface water environment. In support of modeling efforts related to the implementation of EFDC, an advanced hydrodynamic and water quality model, DSI developed EFDC_Explorer as an innovative GUI software tool.

A process for Peer Reviews was also negotiated by EPA and followed through each major phase of the Housatonic project. DSI was helped expedite and participated in the processes. After Pre-Peer Review activities and the Peer Review were conducted, DSI compiled all Peer Review Comments and prepared a detailed Responsiveness Summary to document response to the Peer Review Panel for the Public Record.