22 May 2024

Beneficial Use of Dredged Material in the Atlantic Intracoastal Waterway: Approaching the Regulatory Process

Purpose: Following the Chief of Engineer’s January 2023 goal to expand the beneficial use of dredged material (BUDM), the US Army Corps of Engineers (USACE) strives to apply new and creative ways to increase utilization of dredged materials from a historic 30%–40% to 70% by 2030. As USACE Savannah District (SAS) increases BUDM efforts, a critical component of this transition is understanding and navigating the regulatory requirements. This Technical Note outlines the regulatory process for placement of dredged material in Georgia, identifies challenges and institutional barriers, and offers potential solutions to streamlining the overall process. By increasing the ease of navigating the regulatory process, USACE can facilitate an increase in BUDM and Engineering with Nature® (EWN®) projects in Georgia, and potentially other projects employing nature-based solutions (NBS). While regulatory details may vary from state to state, the Georgia example presented here can serves as a road map for the general types of regulatory procedures and potential hurdles found nationwide.

29 Jul 2022

Using Geophysical and Erosion Properties to Identify Potential Beneficial Use Applications for Atlantic Intracoastal Waterway Sediments

Abstract: In an effort to identify alternative and beneficial use placement strategies for dredged sediments from the Atlantic Intracoastal Waterway (AIWW), the US Army Corps of Engineers, Savannah District (SAS), and the US Army Engineer Research and Development Center (ERDC) performed a series of physical property tests of 34 core borings from the SAS AIWW. Physical property testing found that 14 of the borings were non-cohesive sandy materials that may be suitable for potential beach renourishment or berm construction. The remaining 20 borings had mud contents sufficient enough to result in cohesive behavior. A subset of six of these materials from across the geographic region were further evaluated to characterize their erosion behavior. Following a self-weight consolidation period of 30 days, erosion testing showed that the tested cohesive sediments had critical shear stress values that ranged from 1.7 Pa to 2.9 Pa, suggesting that these sediments would likely be resistant to erosion in most wetland environments after placement. Additionally, the cohesive sediments were found to produce gravel-sized mud clasts. These clasts could account for 20% or more of the eroded mass and significantly reduce the amount of silts and clays incorporated in suspended plumes during and immediately following placement.