4 Apr 2024

Use of Sediment Tracers to Evaluate Sediment Plume at Beaufort Inlet and Adjacent Beaches, North Carolina

Abstract: This report documents a numerical modeling investigation on the transport of sediment material placed on designated disposal sites adjacent to Beaufort Inlet, North Carolina. Historical and newly collected wave and hydrodynamic data around the inlet are assembled and analyzed. The data sets are used to calibrate and validate a coastal wave, hydrodynamic and sediment transport model, the Coastal Modeling System. Model alternatives are developed corresponding to different material placement sites. Sediment transport and sediment plume distribution are evaluated within and around the immediate vicinity of the Beaufort Inlet estuarine system for a representative summer and winter month. Results of model simulations show that high flows occur along navigation channels and low flows occur outside the inlet in open ocean area. Sand materials placed in nearshore sites tend to be trapped in and move along navigation channels entering the inlet. In offshore placement sites the sediment plume shows slow spreading and no significant sand migration from its release locations. Simulations for the summer and winter month present similar distribution patterns of sediments originating from placement sites.

4 Apr 2024

Cut and Capture System Technology for Demilitarization of Underwater Munitions

Abstract: Munitions are encountered in a variety of underwater environments as unexploded ordnance (UXO) or munitions and explosives of concern (MEC). These items can cause unacceptable explosive risks to critical infrastructure, recreational divers, and fishermen. The primary goal of the demonstrations was to validate an underwater suite of tools that can be used to render underwater UXO and MEC safe in shallow water (i.e., up to 100 ft). US Navy underwater ranges in the Gulf of Mexico, south of the Naval Support Activity–Panama City, were selected for the first two demonstrations to fully display the integrated system by processing inert munitions, such as the Navy 5 in./38 cal and the Army 105 mm High Explosive (HE) M1 projectile. The third demonstration, however, occurred at the Naval Surface Warfare Center (NSWC), Crane, Lake Glendora Test Facility, in Sullivan, Indiana. Twenty US Army 105 mm HE M1 projectiles filled with TNT were successfully processed. Overall, this project showed that Gradient Technology’s high-pressure waterjet demilitarization technology can be reliably operated underwater at depths less than 100 ft of seawater when the supporting equipment is located on the deck of a vessel or floating pier system.

3 Apr 2024

Deployable Resilient Installation Water Purification and Treatment System (DRIPS): Geoenabled Water Production and Disinfection Systems for Installations

Abstract: The Deployable Resilient Installation water Purification and treatment System (DRIPS) was delivered to aid an Organic Industrial Base in increasing their Installation Status Report–Mission Capacity (ISR-MC) score from black to green as part of a Course of Action (COA) within their Installation Energy and Water Plan (IEWP). DRIPS was also intended to help them be better prepared for the future in meeting their water and energy requirement goals for sustainment of critical missions. The IEWP ISR-MC requirements were met upon implementation of this project. Overall, the purpose of the DRIPS is to be a critical asset in disaster response and military operations, providing a reliable and effective means of producing potable water and disinfection in challenging and unpredictable environments. Its adaptability, mobility, and comprehensive water treatment capabilities make it an invaluable resource for addressing water-related emergencies and water disruptions and for sustaining critical missions. It also addresses a point of need by improving the ability to meet demands, reducing convoy requirements and the logistical footprint, facilitating the endurance of expeditionary forces, and ensuring the well-being of affected installations during times of disaster response, training operations, normal water disruptions, and emergency preparation.

2 Apr 2024

Evaluation of an Operational Demonstration of a Potential Aquatic Plant Control and Nutrient Mitigation Technology in Lake Okeechobee, Florida

Purpose: This technical note describes the findings from a field-demonstration project conducted in 2022 that aimed to mechanically harvest water hyacinth (Eichhornia crassipes (Mart.) Solms) in Lake Okeechobee, Florida; macerate the harvested plant material; and pump it as a slurry to a terrestrial disposal site as a potential novel technology to reduce total phosphorus (TP) in the system.

2 Apr 2024

Employing Ultrafiltration and Reverse Osmosis (UF/RO) for Treatment of Source-Separated Graywater: ER-201636

Abstract: In field operating environments, military units must ensure access to a critical water supply to maintain mission readiness. Increasing complexity of logistics and costs to transport water and climate change are driving the development and demonstration of water treatment units. The treatment unit described uses ultrafiltration (UF) and reverse osmosis (RO) membrane technologies with a disinfection step to treat low-strength graywater from shower facilities at Camp Shelby Joint Force Training Center in Hattiesburg, Mississippi. Samples were collected from human shower sampling events. During the demonstration, greater than 100,000 gal. of graywater were treated, supplied by two battalion training rotations over a 6-month period. Characterization of the source graywater continued throughout the system demonstration. Based on the literature, these are among the largest source-separated graywater sampling events to date. The combined treatment train of UF/RO met all compliance metrics for all analytes of interest for potability and met nonpotable metrics except for special use cases in three states. Both the quality of the treated water and the effective volume gains from an 85% multiplier effect directly support DoD water sustainment goals for both installations and operational environments.

27 Mar 2024

Approach for On-Site, On-Demand Contaminant-Removal Devices Enabled by Low-Cost 3D Printing

Purpose: The purpose of this technical note is to disseminate methods to design and create a 3D device that could be used to determine relative toxicity potential of existing and emerging contaminants of concern in situ for sediment shoaled in federal navigation channels prior to being dredged. This device has the potential to reduce the cost of conventional sediment evaluations conducted prior to dredging operations.

26 Mar 2024

Risk-Based Prioritization of Operational Condition Assessments: Trinity River and Willamette River Case Studies

Abstract: The US Army Corps of Engineers (USACE) operates, maintains, and man-ages over 700 dams and 4,000 miles of levees, providing approximately $257 billion worth of economic benefit to the Nation. USACE employs the Operational Condition Assessment (OCA) process to understand the condition of those assets and allocate resources to minimize risk associated with performance degradation. Understanding risk in flood risk management (FRM) assets requires an understanding of consequence of asset failure from a systemwide FRM watershed perspective and an understanding of likelihood of degradation based on the condition of the low-level components derived from OCA ratings. This research demonstrates a case-study application of a scalable methodology to model the likelihood of a dam performing as expected given the state of its gates and their components. The research team combines this likelihood of degradation with consequences generated by the application of designed simulation experiments with hydrological models to develop risk measures. These risk measures can be developed for all FRM gate assets in order to enable traceable, consistent resource allocation decisions. Two case study applications are provided.

25 Mar 2024

Improving Chemical Control of Nonnative Aquatic Plants in Run-of-the-River Reservoirs

Abstract: Current dam discharge patterns in Noxon Rapids Reservoir reduce concentration and exposure times (CET) of herbicides used for aquatic plant management. Herbicide applications during periods of low dam discharge may increase herbicide CETs and improve efficacy. Applications of rhodamine WT dye were monitored under peak (736 to 765 m3 s−1) and minimum (1.4 to 2.8 m3 s−1) dam discharge patterns to quantify water-exchange processes. Whole-plot dye half-life under minimal discharge was 33 h, a 15-fold increase compared with the dye treatment during peak discharge. Triclopyr concentrations measured during minimum discharge within the treated plot ranged from 214 ± 25 to 1,243 ± 36 μgL−1 from 0 to 48 h after treatment (HAT), respectively. Endothall concentrations measured during minimum discharge in the same plot ranged from 164 ± 78 to 2,195 ± 1,043 μgL−1 from 0 to 48 HAT, respectively. Eurasian water-milfoil (Myriophyllum spicatum L.) occurrence in the treatment plot was 66%, 8%, and 14%during pretreatment, 5 wk after treatment (WAT), and 52 WAT, respectively. Myriophyllum spicatum occurrence in the nontreated plot was 68%, 71%, and 83% during pre-treatment, 5 WAT, and 52 WAT, respectively. Curlyleaf pondweed (Potamogeton crispus L.) occurrence in the treatment plot was 29%, 0%, and 97% during pretreatment, 5 WAT, and 52 WAT, respectively. Potamogeton crispus increased from 24% to 83% at 0 WAT to 52 WAT, respectively, in the nontreated plot. Native species richness declined from 3.3 species per point to 2.1 in the treatment plot in the year of treatment but returned to pretreatment numbers by 52 WAT. Native species richness did not change during the study in the nontreated reference plot. Herbicide applications during periods of low flow can increase CETs and improve control, whereas applications during times of high-water flow would shorten CETs and could result in reduced treatment efficacy.

21 Mar 2024

Pilot Project Using Tickler Chains in Lieu of Deflectors at Fire Island Inlet to Moriches Inlet, New York, Borrow Sites

Abstract: Risk for incidental take of sea turtles and sturgeon exists during hopper dredging operations throughout turtle and sturgeon habitats. Since 1992, draghead deflectors have been the main engineering tool used to minimize incidental hopper dredging takes of sea turtles and are also thought to reduce the chance of sturgeon impingement entrainment. Although reduced, turtle takes still happen annually, and the draghead deflectors reduce dredging productivity, increase fuel usage, and increase costs of operations. As such, there remains a need to research alternative turtle avoidance measures. The non-US dredging industry has used various versions of an engineering control called tickler chains (TC) in lieu of deflectors. If effective, TC could lower dredging costs and increase production in comparison to deflectors. This technical report describes a pilot study where TC were used in lieu of deflectors at Fire Island Inlet, New Y0rk. To the authors’ knowledge, this is the first time since the early 1990s that hopper-dredging has occurred without draghead deflectors along the east coast. No takes were recorded during the pilot study; however, no research was done to determine if sea turtles or sturgeon interacted with the TC. Recommendations for future TC research is provided in this technical report.

21 Mar 2024

A Beneficial Placement Decision Support Framework for Wetlands: Case Study for Mobile Harbor, USA

Abstract: The US Army Corps of Engineers, in the responsibility of maintaining navigational infrastructure, has a unique opportunity to improve coastal wetland resiliency and conserve coastal natural infrastructure through the beneficial use of dredged material for wetland restoration. Opportunities are widespread, and tools such as biophysical models can aid coastal managers in assessing habitat vulnerability and planning restoration. In this study, the Marsh Equilibrium Model was utilized in concert with observed data to predict future conditions and evaluate potential effects of beneficial use of dredged material to restore marshes in Mobile Harbor, Alabama. A range of site conditions and two restoration strategies were considered, and the subsequent impact to dredged material management area volumes evaluated. Results showed that wetland restoration via the thin-layer placement of dredged material can restore marsh elevation to combat sea level rise and conserve fill capacity at dredged material management areas. This approach is demonstrated for adoption nationwide by coastal managers.