13 Aug 2025

Examination of Activated Carbon Losses During Open Water Placement of Amended Dredged Material for Bioaccumulation Control

Purpose: The purpose of this study was to evaluate the potential losses of both powdered and granular activated carbon (AC) resulting from open water placement of AC-amended dredged material to reduce contaminant bioaccumulation. The study examined the results of model predictions, a laboratory dump test, and a field demonstration project performed at the Ashtabula Lake Erie placement site.

12 Aug 2025

Applying the Working with Nature Philosophy to Navigation Infrastructure Projects

Abstract: In 2008, the World Association for Waterborne Transport Infrastructure published a position paper describing a Working with Nature philosophy aimed to change how the sector approaches navigation and port infrastructure projects. In 2018, Pianc published guidance on implementing WwN. Pianc’s guidance presents a six-step process that encourages consideration of site-specific ecosystem characteristics and WwN opportunities at early stages of project development, early stakeholder engagement and integration of WwN into the development of project objectives before design begins. By incorporating WwN applications during conception, the WwN approach provides the most promising opportunities to affect positive outcomes for the environment. This holistic understanding of ecosystem processes and socioeconomic interactions realises environmental impacts can be minimised while concomitantly seeking opportunities to enhance ecosystem functions at various spatial and temporal scales. Project delivery thus goes beyond avoiding or compensating for negative project impacts and seeks multi-sector ecosystem and socioeconomic benefits. Applied in practice, WwN can increase habitat functionality, reduce energy associated with construction or maintenance, and enhance the short- and long-term delivery of ecosystem services. Projects consistent with the WwN philosophy achieve their underlying engineering objectives, alongside various co-benefits, consistent with the environmental, societal and economic sustainability pillars.

7 Aug 2025

Financing Natural Infrastructure: Lightning Point, Alabama

Purpose: This technical note explores the restoration of Lightning Point, an award-winning natural infrastructure project led by The Nature Conservancy (TNC) in coastal Alabama. The story of Lightning Point provides an exemplar case study of successful coordination of cross-sector partnerships and the use of ecosystem services valuation to attract project funding.

7 Aug 2025

Continued Development of Methods for the Determination of Legacy and Insensitive Munitions from Environmental Matrices: Addition of Four Degradation Products and One Internal Standard to Previously Developed 29-Analyte Method

Abstract: To continue improving separation methods of explosive analytes and their degradation products, chromatographic methods from Environmental Protection Agency (EPA) 8330B, Strategic Environmental Research and Development Program (SERDP) 2722, and Environmental Sensors for Explosives were modified to include the separation of four additional analytes and one internal standard so that a total of 36 analytes could be resolved on a single column. Four degradation compounds, 3-amino-1,2,4-triazol-5-one (ATO); 1 methyl-3-nitroguandine (MeNQ); 2 methoxy-5-nitroaniline (MENA); and 4 methoxy-3-nitroaniline (iMENA) were added to the analytical method. The internal standard, 3,5-dinitrotoluene, was also added to the method to extend its application. Additionally, an analytical method on gas chromatography (GC) and gas chromatography–mass spectrometry (GC-MS) were explored for the analytes of interest.

7 Aug 2025

Thermodynamic Exposure Reductions of PCBs Available to Lumbriculus variegatus in Lake Erie Region Sediments Amended with Activated Carbon

Abstract: A chemical activity-based assessment of PCB bioaccumulation from Lake Erie region sediments was studied using polydimethylsiloxane coated fibers and Dow Corning silicone coated jars. Polymers equilibrated with the sediments were compared to bioaccumulation in blackworms, exposed to the sediments for 28 days. Sediments were from Cleveland Harbor, Ashtabula Harbor, and Buffalo River. Sediment from Ashtabula was amended with activated carbon. Using lipid-polymer partition coefficients, the polymers were able to estimate actual bioaccumulation in worms, with close to a 1:1 relationship and r2 = 0.94. If lipid normalized worm bioaccumulation was compared to equilibrated PDMS concentrations, there was a 20:1 ‘off-set,’ but the relation was still strong. Different doses of AC were mixed into Ashtabula sediment in the laboratory, corresponding to 1 %, 10 %, and 100 % of the native total organic carbon. Based on PCB concentrations in DC silicone, a target AC dose equal to 10 % of the TOC would substantially reduce bioaccumulation of the more hydrophobic PCBs from Ashtabula Harbor dredged material. Widespread AC amendment to surficial sediment of the eastern basin of Lake Erie may reduce the thermodynamic pressure of PCBs from that sediment source and allow for a continued decline in fish tissue concentrations.

4 Aug 2025

Acoustic and Seismic Wave Transmission Throughout the Multidomain Environment: Experimental Design, Methods, and Construction of a Prototypical Littoral Zone

Abstract: The future operational environment is projected to be a multidomain, transparent battlefield in which the Army must be able to act as both a supported and supporting force. An accurate detection and interpretation of acoustic and seismic signals propagating across land-air-water (LAW) interfaces are required to meet future requirements of a fully “transparent” domain. The LAW domains converge at the significant contested littoral zones. Historically, interpreting signals crossing media boundaries has been studied by stovepiping each distinct medium. These fragmented perspectives led to discrepancies in boundary and adjacent media descriptions and media-specific governing physics. No comprehensive physics framework exists to accurately predict how disorderly waveforms freely traverse LAW media boundaries. To understand these complex phenomena, a highly controlled physical experiment was designed and implemented. Repeatable controls were conducted. Epistemic uncertainty was decreased, and high waveform fidelity was maintained in the experimental setup by not interfering with wave transmission or sensor accuracy between controls. This report summarizes the experimental design, implementation, challenges, and repeatability.

29 Jul 2025

Engineering Practice Guide for Floodplain Benching: A Natural Infrastructure Approach for Riverine Systems

Abstract: Floodplain benches are a potential solution for inland river systems where out-of-bank flooding generates unacceptable flood risk and access to riverine floodplains has become restricted over time. Benches are a naturally forming geomorphic feature between the riverbed and a higher floodplain or terrace. In addition to reducing flood risk, benches reduce erosion risk, improve aquatic ecosystems, enhance plant and wildlife diversity, expand recreational opportunities, and may be places of cultural and tribal value. This document informs engineering activities related to site investigation and design of floodplain benches. It is intended to be used by engineers and ecologists to inform the design of floodplain benches in a manner that is consistent with and augments other planning, design, and engineering guidance. A well-designed floodplain bench can improve ecological and biological functions while also reducing flood risk by creating a channel in geomorphic equilibrium with current conditions and resilience to anticipated changes in hydrology and sediment supply rates. This publication is among a series of planned technical reports providing guidance on how to identify, conceptualize, and design natural infrastructure solutions for riverine and coastal systems. It has been produced by the US Army Corps of Engineers (USACE) Engineering With Nature® Program.

17 Jul 2025

Regulatory Considerations in the Development and Implementation of Biological Control for Invasive Mussels and Other Nontraditional Targets in the United States

Abstract: Ongoing research within the Department of the Interior, Bureau of Reclamation, the Department of Defense, and the US Army Corps of Engineers (USACE), in partnership with Molloy & Associates, aims to discover and develop biological controls to mitigate the negative effects of non-native dreissenid mussels on natural and human-made environments in the US. Although biological control technologies have been employed for decades to manage arthropod and plant pests, the workflow required to successfully develop and permit an agent for invasive bivalves has been unclear. Since 2020, the US Army Engineer Research and Development Center (ERDC) has been collaborating with the project team to compile the information needed to permit biological control agents for Dreissena spp. (i.e., zebra and quagga mussels) in the US. Permitting should cover (1) collection in the native or source country and export to the US, (2) importation (nonrelease) into the US, and (3) field (environmental) release of agents. Because Dreissena are nontraditional targets for biological control, the regulatory issues surrounding their management will differ from other common targets, such as invasive plants and arthropods. This document provides background information on biological control, describes how this project is different from most programs implemented in the US, speculates on what invasive mussel biological controls might be, and provides a road map for successful permitting of Dreissena biological controls. Additionally, other nontraditional, but good, targets for biological control may exist and have been overlooked. These other opportunities are briefly discussed. This report is the result of conversations between the project team and federal regulators, and it represents the best possible information needed to permit agents for invasive mussels in the US.

14 Jul 2025

Submerged Aquatic Vegetation Monitoring for Process-Based Model Development

Purpose: Submerged aquatic vegetation (SAV) habitat conservation and restoration are necessary actions to counteract the loss of these critical habitats and their associated ecosystem services, such as habitat provisioning and water quality improvements. Process-based numerical models are essential for planning effective and enduring SAV management strategies but require robust datasets to realistically represent processes at high spatial and temporal resolutions. This technical note (TN), developed by the US Army Engineer Research and Development Center–Environmental Laboratory (ERDC-EL), describes an SAV data collection framework that is being applied at freshwater pond mesocosms to better capture intra-annual SAV growth and mortality processes needed to parameterize process-based models.

11 Jul 2025

Lower Mississippi River Resource Assessment: Library of Aquatic Habitat Models

Abstract: Six ecosystem models were developed to evaluate restoration measures for the Lower Mississippi River Resource Assessment that considered connectivity between river and floodplain, substrate quality in riverine habitats, and targeted species of special interest including Paddlefish and wetland fish assemblages. A total of 85 restoration measures in the Hatchie to Loosahatchie reach were identified by the Project Delivery Team that had different modeling requirements. Field data collected by the Engineer Research and Development Center–Environmental Laboratory in the Lower Mississippi River and floodplain identified ecological guilds of fish and aquatic invertebrates representative of different fluvial habitats. Regression and frequency bar chart models developed from this database predicts a biotic response as a function of habitat quality. Six models applicable to either riverine (unidirectional flow) or floodplain (bidirectional flow) environments were used to evaluate measures for enhancing benthic substrates, reestablishing woody debris, and formation of eddies to diversify habitat. Outputs were normalized as a Habitat Suitability Index on a 0–1 scale and a spreadsheet developed to calculate and annualize Habitat Units for selected restoration measures. Models were certified by US Army Corps of Engineers National Ecosystem Restoration Planning Center of Expertise for regional use in the Lower Mississippi River.