Dredging is the act of removing silt and other material from the bottom of bodies of water (NOAA). However, when we talk about dredging projects, they include all the relevant processes from the initial planning to the final disposal/use such as excavation activities, transport, placement, and treatment. Dredging is performed with various objectives such as for maintaining navigational channels, providing sands and gravel for construction and reclamation projects, or benefitting the environment (e.g., beach replenishment, or remediation). The use of dredged material is various, but the categories people use are slightly different.
In the US, in average 220 million cubic yards of dredged material were dredged annually from 1995 to 2011 (USACE, 2012). Though over 95% of the materials dredged are a clean and viable resource, which means that the materials can be used productively if they are placed in the proper location, large portion of them (about 60 million cubic yards) are still placed in ocean waters (Verna and Pointon 2000).
Now, the awareness of the environmental impacts associated with dredging made the emphasis shifted from on which was concerned with low cost to a balanced view with environmental concerns. There are increased regulations in many states. For example, in Maryland, the State law has banned open water disposal method since 2010.
The rest of presentation covered dredging statistics such as the quantity of material per work type and disposal type, and the contract cost of dredging projects.), complexity in decision making in dredging projects, the system components that are planned to be developed and their advantages, and the future plan of the study.