Eric Adams, Judy Pederson, Ole Madsen, Phil Gschwend, MIT
Gene Gallagher, UMass-Boston
Tim Ford, Harvard School of Public Health

Massachusetts Institute of Technology
77 Mass Ave., Room 48-325
Cambridge, MA 02139

The Boston Harbor Navigation Improvement Project (BHNIP) entails deepening portions of Boston's Inner Harbor, with disposal of the contaminated sediments in cells constructed in-channel and capped with 3 feet of clean sand. Motivated by this project, and other similar projects proposed nationally, the MIT Sea Grant College Program has funded a group of researchers from MIT, UMass-Boston, and the Harvard School of Public Health to begin studying basic physical, chemical and biological processes that take place when contaminated sediments are capped by coarser sediments. The goal is to provide a better scientific basis for assessing the technical and environmental risks of capping in relation to other disposal / isolation methods. Areas which we are investigating are listed below and initial results from some of this will be presented:

• Laboratory stratified tank studies of the behavior of particle clouds.

• Laboratory geotechnical studies of the time-varying stability and cohesiveness of remolded sediments.

• Mathematical models of sediment transport over bottoms with rapidly-varying sediment conditions.

• Field measurements of the sediment-water flux and bio-degradation potential of PAHs before, during and after dredging / capping operations.

• Studies of the effects of capping of sediment bio-mixing and benthic community structure.

• Decision analysis balancing the risks and benefits of capping in relation to other material management options.