Geoenvironmental behavior of lime-treated marine sediments

Several hundred million cubic meters of sediment are dredged from various U.S. ports, harbors, and waterways annually to maintain and improve the nation’s navigation system for commercial, national defense, and recreational purposes. The United States Environmental Protection Agency mandated containment of dredged sediments in designated containment facilities. The current study aims to explore the use of sediments dredged from Baltimore Harbor as a potential highway embankment material. Lime-based additives have been added to the dredged material and geotechnical analysis is coupled with environmental assessment in this study. Long-term sequential column leaching test results showed that aluminum, arsenic, nickel, cobalt, and zinc leached from the dredged sediments, but the metal concentrations quickly decreased to EPA water quality limits for protection of aquatic life and human health in freshwaters. Addition of lime kiln dust and quick lime lowered the amount of metals leaching from the material. Contaminant concentrations originating from the dredged sediment in an embankment are reduced up to 80 times in surface waters and decreased to negligible levels upon reaching groundwater.