Tetra Tech assists the U.S. EPA Great Lakes National Program Office (GLNPO) with design and construction management of sediment remediation projects in the Great Lakes region. Tetra Tech is currently managing two sediment remediation projects for GLNPO: the West Branch of the Grand Calumet River (WBGCR) in Hammond, Indiana, and the Ottawa River in Toledo, Ohio.
The WBGCR flows through an industrialized area in northwest Indiana. Mechanical excavation of 32,000 cubic yards of sediment was completed in August 2010. The design for additional sections of the river is underway with construction planned for December 2010.
The Ottawa River is part of the Maumee River Area of Concern in northwest Ohio. Hydraulic dredging of about 250,000 yards of sediment from the Ottawa River commenced in May 2010 and is scheduled to be completed in November 2010. The principal contaminant of concern is polychlorinated biphenyls at concentrations both above and below 50 ppm.
This paper will compare and contrast the methods for sediment dredging, focusing on the specific site conditions that influenced selection of each approach as well as lessons learned during construction activities at both locations. Factors influencing remedy selection include sediment physical and chemical characteristics, site hydraulics, and site access.
"Review of Mechanical and Hydraulic Dredging at Two Sediment Remediation Sites,"
Proceedings of the Annual International Conference on Soils, Sediments, Water and Energy:
Vol. 16, Article 9.
Available at: http://scholarworks.umass.edu/soilsproceedings/vol16/iss1/9