Soil contamination assessment and characterization in urban tunneling

Construction of the CA/T Project will require excavation of over 12 million cubic yards of fill, native soils and rock, and the dredging of approximately 2 million cubic yards of harbor sediments and marine clay. Disposal of this volume of material has been a matter of concern to stat and federal environmental reviewers since the inception of the project. In addition, reviewers and the Massachusetts Department of Environmental Protection (DEP) raised concerns about the threat to public health and the environment from excavation of potentially contaminated urban soils along the Project right of way. To address these concerns, MHD developed and implemented a comprehensive program to assess and characterize contamination. As a key part of this program, MHD entered into a Memorandum of Understanding (MOU) with the DEP. This paper describes the key elements of the CA/T Project right-of-way characterization and material disposal programs, including the right-of-way acquisition support process and the major issues that had to be resolved to conclude the MOU between MHD and DEP.