17 Oct 2024

Literature Review of Microseira wollei Distribution, Environmental Drivers, and Risks: Lake St. Clair, Michigan, Case Study

Abstract: Microseira wollei (formerly Lyngbya wollei) has grown to noxious densities within Lake St. Clair, located between Lake Erie and Lake Huron. De-spite the limited data on this cyanobacterium within Lake St. Clair, data exists for M. wollei within the Great Lakes region and in the southeastern United States, where water resource managers have been managing growths for decades. These data provide pertinent insights into the environmental distribution, environmental drivers, risks, and management of M. wollei, which is mainly distributed within eastern states and provinces in North America, from Canada to Florida. Environmental drivers may be site-specific and specific to the M. wollei population; therefore, the environmental drivers identified in this literature review are a starting point to inform further investigations. M. wollei within Lake St. Clair may pose risks to humans. Risks may originate from toxins, disinfection by-products, and, potentially, fecal indicator bacteria. M. wollei has the potential to produce a range of toxins; however, the most prevalent toxins are saxitoxins, a group of neurotoxins. This literature review will help the US Army Corps of Engineers Detroit District; Macomb County, Michigan; and other interested parties understand potential triggers for growth, communicate risks, and help develop an adaptive management framework.

15 Oct 2024

Deployable Resilient Installation Water Purification and Treatment System (DRIPS): Relief Well Biofouling Treatment of Dams and Levees

Abstract: The US Army Corps of Engineers (USACE) conducts regular inspections and maintenance of relief wells to ensure their proper functionality and to identify early signs of malfunction or potential failure. Expenses associated with labor, materials, and transportation are the primary cost drivers of relief-well maintenance. To minimize labor hours and materials, a treatment approach intended to improve logistics and reduce material costs during relief-well treatment was developed and tested. This approach employed external UVC, mechanical brush treatments, and chlorinated-gas-infused water to produce liquid sodium hypochlorite (NaClO). Preliminary bench-scale testing with chlorine, oxalic acid, and UVC informed the selection of field testing methods and optimal amendment concentrations. Field demonstrations were conducted annually over three years. During the demonstrations, the system underwent continuous optimization to enhance its efficiency. Different locations in Mississippi (Grenada Dam, Eagle Lake, and Magna Vista) were selected for testing. Both new and traditional treatment approaches yielded adequate results, achieving microbial reduction at 96% to 100%. The development and refinement of this system demonstrated that relief wells can be treated within a comparable timeframe and with similar efficiency while utilizing fewer purchased chemicals and materials.

15 Oct 2024

Vegetation Establishment and Management in USACE Floodwater Detention Basins: Greens Bayou Flood Risk Management Mitigation Project

Abstract: This report documents efforts by the US Army Engineer Research and Development Center (ERDC) in assisting the US Army Corps of Engineers (USACE) Galveston District (SWG) in native vegetation establishment design, propagation, installation, monitoring, and adap-tive management for the mitigation requirements of the Greens Bayou Flood Risk Management Project. Specifically, to provide (1) a vegetation establishment design ensuring development of sustainable native plant communities compatible with flooding and drought events; (2) suitable native aquatic, wetland, and woody plants for project use; (3) implementation of plantings; (4) monitoring and adaptive management; and (5) vegetation establishment reports and an operations and maintenance manual for long-term vegetation management of the project site. The Greens Bayou Project included approximately 3.7 miles of channel conveyance improvements and 138 acres of storm-water basin detention storage to reduce flooding damage by safely storing excess stormwater during heavy rain events and slowly releasing it back into the bayou. The completed basin was designed to hold approximately 1,400 acre-ft, or 538 million gal., of stormwater. Vegetation establishment, monitoring, and adaptive management efforts in the mitigation features discussed herein occurred between 2019 and 2023.

9 Oct 2024

Performance of High-Resolution, Acoustic Mapping Systems in a Fluid-Mud Environment : Testing the Effectiveness and Viability of High-Resolution, Hydrographic Survey Systems in a Fluid-Mud Environment

Abstract: This study explores the use of high-resolution acoustic mapping systems to penetrate fluid-mud layers by quantitatively relating depth with operating frequency. Prior to this study, multibeam surveys have proven be an effective method to elucidate the seafloor and collect bathymetric data on various bodies of water including rivers, lakes, bays, and the oceans. These techniques are regularly used on US Army Corps of Engineers dredged and federally maintained navigation channels. The objective of the study was to test the effectiveness of commercial off-the-shelf, low-frequency, high-resolution acoustic survey systems to penetrate fluid mud and if so, determine the density at penetration. The testing method combined multibeam echosounder, sub-bottom profiler, and single-beam echo sounder. In addition, in situ testing was conducted to determine the density of fluid-mud layers using a RheoTune profiler and laboratory testing. Results indicate that the use of currently available, bathymetric mapping systems operating at 90 kHz and higher are incapable of penetrating fluid mud in riverine and coastal shallow water conditions. This study demonstrates that while multibeam technology is effective at penetrating the water column, current frequencies available on the market are unable to penetrate fluid-mud layers in a riverine and shallow-water environment.

9 Oct 2024

Unified Facilities Criteria and Unified Facilities Guide Specifications for Sustainable Military Construction : Concrete, Asphalt, Wood, and Life-Cycle Assessment Perspectives

Abstract: Construction materials such as concrete, asphalt, and wood are essential components for Department of Defense (DoD) Military Construction (MILCON) and construction for contingency operations around the world. From housing facilities, to airfields, to magazines and hardened structures, each of these materials fulfill numerous Army building applications. However, greenhouse gas (GHG) emissions stemming from the manufacturing, application, maintenance, and disposal of concrete and steel exact a significant climate burden. Thus, due to their pervasive use and commodity status, the advancement of sustainable concrete, asphalt, and wood materials are a critical driver for GHG mitigation. This report communicates a first step toward decarbonization-focused updates to UFC and UFGS by outlining major specifications related to concrete, asphalt, and wood with near- and long-term strategies to facilitate modernization. The Engineer Research and Development Center (ERDC) is poised to make a significant impact on the identification and integration of sustainable materials to meet regulatory goals for the re-duction of GHG emissions in MILCON. New guidance will be integrated into UFC and UFGS by leveraging unique re-search, development, test, and evaluation (RDT&E) capabilities in materials science, life-cycle assessment, and federal relationships with discipline working groups

8 Oct 2024

Remote Monitoring of Cathodic Protection Systems on Navigable Waterways

Abstract: Cathodic protection is one of the main modes of corrosion prevention for structures in navigable waterways. The rectifier output voltage must be in a specific range to provide effective protection against corrosion. This effort was designed to monitor, predict, and stabilize the efficacy of multiple cathodic protection systems. Copper/copper-sulfate half-cell electrode sensors, water quality sensors, and gauges for rectifier output were connected to modems at multiple locks so the data could be analyzed to create a predictive maintenance algorithm.

8 Oct 2024

Identifying Sustainability and Resilience Investments to Implement the 2022 US Army Climate Strategy: Fiscal Year 2023 Sustainable Design and Development Update

Abstract: This report offers a detailed assessment of the US Army’s adherence to sustainable design and development (SDD) policies, encompassing the US Army Sustainable Design and Development (SDD) Policy memorandum; Unified Facilities Criteria (UFC) 1-200-02, High Performance and Sustainable Building Requirements; Executive Orders 14,008 and 14,057; the Army Climate Strategy; and required LEED v4 certifications. The evaluation comprises five primary tasks, including quarterly reports on US Army military construction (MILCON) project LEED v4 certifications, analysis of US Army LEED v4 certifications and trends, research and implementation of the intermediate objectives in the 2022 US Army Climate Strategy focusing on strategies to achieve climate goals, an analysis ex-plaining the advantages of Performance Excellence in Electricity Renewal (PEER) certification for Army microgrids, and industry knowledge gained from participation in the Greenbuild 2022 conference. Key recommendations developed in this assessment include enhancing transparency in LEED reporting, considering PEER certification, expediting climate strategy implementation, and active participation in industry gatherings. This report serves as a comprehensive resource for informed decision-making, aiding the US Army in advancing its sustainable design and development initiatives to meet future environmental and sustainability objectives.

7 Oct 2024

Seismic analysis for Pohnpei Island, Federated States of Micronesia

Abstract: The purpose of this study was to determine the seismic hazards that can affect Pohnpei Island and provide estimates of the ground motion parameters. The primary parameters are peak ground acceleration (PGA), pseudo-spectral acceleration (PSA), and velocity. These values were determined both probabilistically and deterministically to illustrate the overall seismic hazard to Pohnpei Island. A review was conducted of the technical literature to determine geologic studies that have been performed for characterization of the island’s volcanism, stratigraphy, and tectonism. This report is a desktop study that examines the tectonism of the region, the geology of the island, its geologic history, and its seismic record. No liquefaction areas or tsunami hazards were identified by researchers on the island.

7 Oct 2024

Full-Scale Evaluation of Saltwater Concrete for Airfield Pavement Construction and Repair

Abstract: The US Navy has a need to rapidly construct concrete facilities onshore to support contingency operations. Mixing water for concrete is typically specified to be freshwater; however, in many scenarios there are limited amounts of freshwater available for construction. Thus, use of readily available saltwater would be advantageous. This project’s objective was to evaluate the suitability of saltwater as a replacement for freshwater for producing concrete airfield pavement under relevant operational scenarios. Three full-scale test sections were constructed, and performance was evaluated in the context of relatively short design life requirements. First, direct comparison slabs of freshwater and saltwater concrete were constructed and exposed to ambient environmental conditions for one year; periodic concrete strength measurements were made. Next, 8 in. thick and 11 in. thick saltwater concrete pavements were constructed then subjected to P-8 aircraft accelerated loading. Finally, four airfield damage repair techniques were executed using saltwater and subjected to accelerated P-8 aircraft loading. Saltwater concrete performance was found to be similar to freshwater concrete for all scenarios investigated. The overall conclusion was that saltwater can be used in place of freshwater for concrete airfield pavement construction and repair for short- to medium-term use (1–2 yr) with no meaningful impact to mission requirements.

3 Oct 2024

Comite Diversion Numerical Model Study

Abstract: The Comite River diversion project is designed to reduce flooding along the Comite and Amite Rivers during flood events by diverting flow from the Comite River into the Mississippi River above Baton Rouge, Louisiana. The flow is diverted from the Comite River along a diversion canal to the Lilly Bayou Control structure. This structure allows the Comite River flow to enter the Mississippi River floodplain. A numerical model was created to evaluate the impacts associated with this addition of water to the Mississippi River. A 2D Adaptive Hydraulics numerical model was created to quantify the system impacts associated with the diverted flow in conjunction with possible system modifications to control the flow pathway. The impact of the diversion was determined to be heavily dependent on the flow and stage of the Mississippi River. At higher stages and flows, the flow diverted by the Lilly Bayou Control structure is negligible in relation to the much larger Mississippi River flow and therefore the impacts of the added flow are significantly less than at lower Mississippi River stages. At lower Mississippi River flows and stages, the added flow from the Lilly Bayou Control structure has a larger impact on the inundation due to the larger relative amount of diverted flow in relation to the Mississippi River. Ultimately, the diverted Comite River flow has some incremental increase in water levels at all Mississippi River stages.