14 Feb 2024

Hydraulic Sorting of Dredged Sediment in a Pipeline: An Evaluation of the Sediment Distribution Pipe

Abstract: The US Army Corps of Engineers (USACE) recently established a goal to beneficially use 70% of material dredged from the nation’s navigable waterways by the year 2030. Most of the sediments dredged by the USACE are heterogeneous mixtures of mud and sand, which can limit beneficial use of dredged material (BUDM) applications. Innovative technologies that can sort material during the dredging process are needed to help increase BUDM practices. This investigation sought to evaluate the ability of a sediment distribution pipe (SDP) to sort particles during transport in a pipeline. Field demonstrations were conducted during dredged material placements at Sturgeon Island, New Jersey. Velocity within the pipeline was found to be inadequate for efficient hydraulic sorting of fines (<75 μm) and produced inconclusive results. Small scale laboratory SDP experiments found that effluent from the SDP holes had an altered sediment texture compared to the initial slurry and that hydraulic sorting was occurring within the pipeline. However, outflow from the SDP holes was inconsistent, and typically >90% of the sediment mass was discharged out the end of the pipeline. Sorting efficiency of the SDP could not be accurately assessed in the current experimental configuration.

29 Jan 2021

Environmental Applications of 3D Printing Polymer Composites for Dredging Operations

Abstract: This Dredging Operations Environmental Research (DOER) technical note disseminates novel methods to monitor and reduce contaminant mobility and bioavailability in water, sediments, and soils. These method advancements are enabled by additive manufacturing (i.e., three-dimensional [3D] printing) to deploy and retrieve materials that adsorb contaminants that are traditionally applied as unbound powders. Examples of sorbents added as amendments for remediation of contaminated sediments include activated carbon, biochar, biopolymers, zeolite, and sand caps. Figure 1 provides examples of sorbent and photocatalytic particles successfully compounded and 3D printed using polylactic acid as a binder. Additional adsorptive materials may be applicable and photocatalytic materials (Friedmann et al. 2019) may be applied to degrade contaminants of concern into less hazardous forms. This technical note further describes opportunities for U.S. Army Corps of Engineers (USACE) project managers and the water and sediment resource management community to apply 3D printing of polymers containing adsorptive filler materials as a prototyping tool and as an on-site, on-demand manufacturing capability to remediate and monitor contaminants in the environment. This research was funded by DOER project 19-13, titled “3D Printed Design for Remediation and Monitoring of Dredged Material.”

27 Apr 2020

PUBLICATION NOTICE: Benefits of Engineered Habitats to Seasonal Bird Communities on the Savannah Harbor Navigation Project, Dredged Material Containment Areas, 1994-2012

Abstract: This report presents the results of a long-term habitat and trend analyses of bird community data from a monitoring effort conducted on five Dredged Material Containment Areas (DMCAs) from 1994 to 2012. The USACE Savannah District developed and implemented a Long-Term Management Strategy (LTMS) for the DMCAs in 1996 to mitigate lost wetland habitat due to maintenance operations in the Savannah Harbor, and to provide habitat for the floral and faunal communities that otherwise would be available if not for the urban and economic development of the area. Bimonthly surveys were conducted from 1994 to 2012 to assess the effectiveness of the LTMS to provide seasonal habitat for the bird community. Archived quarterly satellite imagery was collected and analyzed from 2001 to 2011 to assess year-round seasonal habitat availability. All bird community data collected were fitted to a negative binomial (mean abundance) or Poisson distribution (mean species richness) and used to assess trends for 180 individual species and 12 species groups for spring, summer, fall, and winter seasons from 1994 to 2012. Results indicate that the Savannah DMCAs support stable to increasing populations of most species and species groups during each season, including many species ranked as regional priority species.