27 Sep 2024

Surveys in Native and Introduced Ranges (2018–2021) for Natural Enemies of Yellow Floating Heart, Nymphoides peltata Kunth

Abstract: Yellow floating heart (Nymphoides peltata), a widespread aquatic invasive plant in the US, is currently under investigation for biological control de-velopment. From 2018 to 2021, we conducted native (Europe: 14 loca-tions; Asia: 80 locations) and introduced (US: 39 locations) range surveys to create a list of candidate agents and collect baseline infestation data for comparison. We genetically characterized populations and determined those most-closely related to US N. peltata were European. However, we found no promising agents in that region, except for previously reported fungal pathogens. In Asia, several herbivores were identified as potential agents based on observed damage in situ and previous literature reports about host specificity. These included three species of Bagous weevils, one of which may be Bagous charbenensi, and an unidentified leaf-mining Hy-drellia fly. During domestic surveys, generalist leaf-cutting caterpillars were common, similar to the native range. A major discovery was the dam-aging fungal pathogen, Septoria villarsiae, isolated from plants in a pri-vate pond in Maine—the first record in the Western hemisphere. The next steps for this program should include preliminary host specificity and im-pact assessments of S. villarsiae, the fruit-feeding Bagous spp. in China and Korea, and the leaf-mining Hydrellia sp. fly from South Korea.

24 Sep 2024

Validation of Sample Extraction and Analysis Techniques for Simultaneous Determination of Legacy and Insensitive Munitions (IM) Constituents

Abstract: Currently, no standardized method exists for the analysis of insensitive munitions (IM) in environmental matrices such as water, soils, and tis-sues. However, standardized methods, such as United States Environmental Protection Agency (EPA) 8330B, exist for legacy munitions for water and soil matrices. The lack of standardized methods for IM analysis leads researchers to use a wide variety of incomplete and overlapping analytical methodologies. The overall project’s first phase, Strategic Environmental Research and Development Program (SERDP) Environmental Restoration (ER)–2722, was to develop and optimize methods to address these methodological gaps by creating analytical methods for simultaneous analysis of IM and legacy munitions in water, soil, and tissue matrices. The main objective of the current project phase, Environmental Security Technology Certification Program (ESTCP) ER19-5078, is to build upon the previous work in phase one and to focus on the validation of the newly developed methods. Synergizing with the main objective of the overall project, the methods were validated and submitted to the EPA for inclusion as a possible addendum to EPA 8330B.

19 Sep 2024

Case Study of Continental-Scale Hydrologic Modeling’s Ability to Predict Daily Streamflow Percentiles for Regulatory Application

Abstract: Regulatory practitioners use hydroclimatic data to provide context to observations typically collected through field site visits and aerial imagery analysis. In the absence of site-specific data, regulatory practitioners must use proxy hydroclimatic data and models to assess a stream's hydroclimatology. One intent of current-generation continental-scale hydrologic models is to provide such hydrologic context to ungaged watersheds. In this study, the ability of two state-of-the-art, operational, continental-scale hydrologic modeling frameworks, the National Water Model and the Group on Earth Observation Global Water Sustainability (GEOGloWS) European Centre for Medium-Range Weather Forecasts (ECMWF) Streamflow Model, to produce daily streamflow percentiles and categorical estimates of the streamflow normalcy was examined. The modeled stream-flow percentiles were compared to observed daily streamflow percentiles at four United States Geological Survey stream gages. The model's performance was then compared to a baseline assessment methodology, the Antecedent Precipitation Tool. Results indicated that, when compared to baseline assessment techniques, the accuracy of the National Water Model (NWM) or GEOGloWS ECMWF Streamflow Model was greater than the accuracy of the baseline assessment methodology at four stream gage locations. The NWM performed best at three of the four gages. This work highlighted a novel application of current-generation continental-scale hydrologic models.

17 Sep 2024

Human Well-Being and Natural Infrastructure: Assessing Opportunities for Equitable Project Planning and Implementation

Abstract: There is consensus within psychological, physiological, medical, and social science disciplines that active and passive exposure to nature enhances human well-being. Natural infrastructure (NI) includes elements of nature that can deliver these ancillary well-being benefits while serving their infrastructure-related purposes and, as such, offer great promise for agencies including the U.S. Army Corps of Engineers as a means of enhancing economic, environmental, and societal benefits in civil works projects. Yet, to date, NI are typically framed as alternatives to conventional infrastructure but are rarely competitive for project selection because there is no standardized approach to demonstrate their value or justify their cost. The infrastructure projects subsequently selected may not maximize societal well-being or distribute benefits equitably. A framework is needed to capture diverse and holistic benefits of NI. As part of ongoing research, this paper describes the components necessary to construct a framework for well-being benefits accounting and equitable distribution of NI projects and explores how they might be applied within a framework. We conclude with methodological examples of well-being accounting tools for NI that are based on ongoing research and development associated with this project. The findings provide insights and support for both the Engineering with Nature community and the community of NI practitioners at large.

16 Sep 2024

Toward Systemic Beneficial use of Dredged Sediments in San Pablo Bay: Demonstration of a Proposed Framework for Matching Sediment Needs with Dredging Requirements

Abstract: Coastal wetlands provide a suite of valuable ecosystem services, but they are rapidly disappearing due to reductions in sediment supply and rising sea levels, making them ideal candidates for restoration through beneficial use of dredged sediment. Because sediment dredged from navigation channels is a limited resource relative to the number of degraded wetlands, a framework has been developed to align coastal restoration sediment needs with dredging requirements to maximize social, environmental, and flood risk reduction benefits while also completing the navigation mission. The framework is comprised of four key steps: (1) geographic scoping and suitability considerations, (2) quantification of the dredged sediment available and restoration project sediment needs, (3) definition of cost and benefit objectives, and (4) optimization of costs and benefits to determine the most efficient solutions. This report is a demonstration of this framework on a subset of wetland sites and local federal navigation channels in San Pablo Bay, California.

12 Sep 2024

Pollinator Garden Playbook: Supporting the Western North American Population of Monarch Butterfly (Danaus plexippus) and the Endangered Smith’s Blue Butterfly (Euphilotes enoptes smithi) on Military Lands

Abstract: The US Army Engineer Research and Development Center–Environmental Lab (ERDC-EL) researchers assisted the US Army Garrison Presidio of Monterey in 2021 to assess the feasibility of pollinator gardens at select locations in Monterey, California. The proposed pollinator gardens were to be designed to support the western population of the North American monarch butterfly (Danaus plexippus), the federally endangered Smith’s blue butterfly (Euphilotes enoptes smithi), and other pollinators found in the Monterey area. This technical report documents planning and design considerations for these pollinator gardens situated on the grounds of the Presidio of Monterey (POM) and the Ord Military Community (OMC). Site preparations, recommended plant species, garden designs, installation methods, and invasive species management are discussed. The contents herein can be used as a general playbook for similar pollinator habitat improvement projects on military lands.

5 Sep 2024

Extending CEMHYD3D to Simulate Hydration of Portland Cement Pastes with High Volumes of Silica Fume

Abstract: Silica fume (SF) influences the hydration rate of Portland cement in differ-ent ways depending on the physical and chemical properties of the SF. This study reports the impact of SiO2 content (%), loss on ignition (%), and Brunauer–Emmett–Teller (BET) specific surface area on the hydration re-action of SF-cement paste mixtures. This study used five types of SFs with varying SiO2 content, loss on ignition (%), and particle morphology. Five SFs were mixed with Class H oil well cement at each of two different re-placement levels (20% or 30% by mass), and the released heat of hydra-tion was measured using isothermal calorimetry. The results were used to improve the pozzolanic reaction simulation feature of the original Virtual Cement and Concrete Testing Laboratory software, which enabled the soft-ware to simulate a higher SF replacement ratio in a cement mixture with higher fidelity. Results showed that a silica fume’s SiO2 content (%), loss on ignition (%), and BET specific surface area significantly influence the heat release rate. The new simulation model agrees well with the measure-ments on all the pastes tested.

5 Sep 2024

Next-Generation Water Quality Monitoring during Dredging Operations: Knowns, Unknowns, and Path Forward

Abstract: Water quality monitoring data are routinely collected during dredging and placement operations to address various state and federal requirements, including water quality standards, with the intention of protecting ecosystem health. However, such efforts may be limited by the lack of a standardized national strategic focus and user-friendly streamlined interfaces to interpret the data. Inconsistencies in how and what data are collected and lack of consensus on scientifically backed biological-effects thresholds make it difficult to quantify potential dredging operations impacts (or lack thereof) both within individual projects over time and across multiple projects of differing characteristics. Summarized herein is an initial effort to define a scientifically backed path forward to improve the value of current and future water quality monitoring and management decisions based on water quality data collected. The provided turbidity data were generally below applicable state thresholds for two case studies but for a third case study did periodically exceed thresholds at depth. This includes providing rationale for strategic focus on the most relevant dredging operations and projects, based on three general site-specific data categorizations: (1) sediment type, (2) dredge type, and (3) ecosystem type.

28 Aug 2024

Integrating NOAA’s National Water Model (NWM) into the Antecedent Precipitation Tool (APT) to Support Clean Water Act Decision-Making

Abstract: This study examines the effectiveness of the National Water Model (NWM) in assessing streamflow normalcy under the Clean Water Act, compared to the commonly used Antecedent Precipitation Tool (APT). The APT, used by the Environmental Protection Agency, US Army Corps of Engineers, and environmental consultants, evaluates waterbody conditions based on precipitation data. However, it was found to be less accurate in predicting streamflow normalcy compared to USGS gage data. The NWM, on the other hand, showed promising results in preliminary analyses, outperforming the APT when compared to USGS gage records. This research expands on these initial findings, evaluating the NWM’s performance across the contiguous United States (CONUS) at gage locations indexed to the NHDPlus Version 2.1 stream network. The results suggest that the NWM provides adequate performance for assessing streamflow normalcy where USGS gages are not present, with accuracy ranging from 40% to 60% in the western half of CONUS and 60% to 80% in the eastern half.

22 Aug 2024

Application of Existing Tools to Systematically Identify Nearshore Placement Sites for Beneficial Use of Navigation Sediments in Lake Michigan

Purpose: The Great Lakes includes 140 federally maintained harbors with an annual dredging program of 2–4 million cubic meters (3–5 million cubic yards)[1] of sediment. Many small harbors are not dredged regularly, and there is an undredged backlog of over 9 million cubic meters (12 million cubic yards) of sediment (USACE-LRD 2021). Current policy (Spellmon 2023) is to maximize the beneficial use (BU) of sediment, with a goal of beneficially reusing 70% of the federal navigation dredging volume by 2030 (that is, the 70/30 goal). In the Great Lakes, clean sands have often been placed on beaches or in the nearshore littoral zone to beneficially nourish the shoreline, but since many harbors are not dredged regularly, no plans exist to beneficially reuse dredged sediments. This lack of existing BU plans is particularly true for harbors with finer grained or mixed sediment. To achieve the 70/30 BU goal and support navigation maintenance and coastal management requires a strategic and systematic approach to identifying BU sites. The purpose of the technical note is to (1) provide an approach to identify potential nearshore placement sites using existing information and models; (2) describe available tools for placement site identification, coastal condition information, and the long-term fate of the sediment; and (3) provide a pertinent case study to describe this approach in practice.