Innovative Reuse of Baltimore Harbor Dredged Material as Vegetative Earthen Berms

Abstract

Dredged material (DM) is a sediment excavated from navigable waterways, which haslimited use due to the transport and accumulation of potentially hazardous metals and organic chemicals into these waterways. DM can be used as a recycled material in place of soil, depending on its environmental and physical characteristics, and the specific use. Vegetated Earthen Berms (VEBs), used for stormwater control, is one potential beneficial application of DM. The objective of this research is to assess the environmental and geotechnical suitability of DM in VEBs. A germination study and a battery of column tests were conducted to test the innate properties of the DM and DM amended with straw and sand, as DM blends. Straw and sand were chosen to observe potential improvements to the DM’s physical and chemical parameters. A nine-week mesocosm study was performed to simulate the overall performance of DM and DM blend constructed VEBs for the plant growth and water quality criteria, determined by US EPA water quality limits. Plant cover and growth measurements along with measuring effluent water characteristics were assessed. Straw amended DM was shown to have comparable vegetative establishment parameters relative to topsoil. For the water quality, concentrations of dissolved copper and zinc were reduced relative to typical median stormwater values in DM constructed VEBs. Based on the results of these tests, DM constructed VEBs had reflected desirable qualities for potential reuse based on water quality and vegetative establishment.