Each year, 400 million cubic yards of sediment are dredged in the United States of which 3 to 5 percent is polluted and cannot be used beneficially or returned to the environment near dredging sites. Disposal of this polluted, dredged material is a national problem. One solution to this problem is to relocate and isolate polluted dredged material to the seafloor of the abyssal ocean, considered to include those depths greater than 300 m. SimDOR, a project sponsored by the Defense Advanced Research Projects Agency, focused on simulation of the scientific and technical issues involved with this disposal option. SimDOR, which stands for Simulation of Deep Ocean Relocation of Dredged Material, concentrated primarily on sites of the abyssal seafloor of the North Atlantic Ocean and considered dredged material coming from to the eastern seaboard of the United States. Results from the SimDOR project are also generally applicable to west coast and Gulf of Mexico ports. The SimDOR project took advantage of recent advances in numerical modeling capabilities, simulation concepts, and visualization technology. Simulations identified are predicted effects of this disposal option including the dredging and relocation procedures as well as the resulting environmental impact. Simulation of the entire process from dredging through long-term impact on the abyssal environment allowed engineers, scientists. environmentalists, and the public an opportunity to study and understand all aspects of this option. Systems to dredge sediments, load containers, transport them to the ocean site, and ensure their safe descent to the abyssal seafloor were designed, simulated and evaluated.