11 Aug 2023

Dredged Material Can Benefit Submerged Aquatic Vegetation (SAV) Habitats

Purpose: This technical note (TN) was developed by the US Army Engineer Research and Development Center–Environmental Laboratory (ERDC-EL) to provide an overview of the ecosystem services delivered by submerged aquatic vegetation (SAV) to estuarine and coastal ecosystems and to describe potential methods for the beneficial use of dredged material (BUDM) to aid in SAV restoration. Although dredging tends to have a negative association with SAV habitats, BUDM may provide an opportunity to expand suitable SAV habitat to areas where depth is the primary limiting factor. Recent in situ observations have shown that SAV has opportunistically colonized several dredged-material placement sites. This TN provides context on BUDM for SAV habitat restoration to encourage increased strategic placement.

19 Jul 2023

Adverse Outcome Pathways for Engineered Systems

Abstract: Companies and organizations around the world spend massive amounts of money each year to discover, predict, and remediate failures within engineered systems. These tasks require individuals with specialized knowledge in a variety of topics related to failure. This knowledge is often acquired through years of academic and on-the-job training centered around the review of scientific documentation such as books, reports, manuals, and peer-reviewed publications. The loss of this knowledge through employee attrition can be detrimental to a group as knowledge is often difficult to reacquire. The aggregation and representation of known failure mechanisms for engineered materials could aid in the sharing of knowledge, the acquisition of knowledge, and the discovery of failure causes, reducing the risk of failure. Thus, the current work proposes the Adverse Outcome Pathway for Engineered Systems (AOP-ES) framework, an extension of the Adverse Outcome Pathway used in toxicology. The AOP-ES is designed to document failure knowledge, enabling knowledge transfer and the prediction of failures of novel engineered materials based on the performance of similar materials. This paper introduces the AOP-ES framework and its key elements alongside the principles that govern the framework. An application of the framework is presented, and additional benefits are explored.

6 Jul 2023

A Review of Sensor-Based Approaches for Monitoring Rapid Response Treatments of cyanoHABs

Abstract: Water quality sensors are dynamic and vary greatly both in terms of utility and data acquisition. Data collection can range from single-parameter and one-dimensional to highly complex multiparameter spatiotemporal. Likewise, the analytical and statistical approaches range from relatively simple (e.g., linear regression) to more complex (e.g., artificial neural networks). Therefore, the decision to implement a particular water quality monitoring strategy is dependent upon many factors and varies widely. The purpose of this review was to document the current scientific literature to identify and compile approaches for water quality monitoring as well as statistical methodologies required to analyze and visualize highly diverse spatiotemporal water quality data. The literature review identified two broad categories: (1) sensor-based approaches for monitoring rapid response treatments of cyanobacterial harmful algal blooms (cyanoHABs), and (2) analytical tools and techniques to analyze complex high resolution spatial and temporal water quality data. The ultimate goal of this review is to provide the current state of the science as an array of scalable approaches, spanning from simple and practical to complex and comprehensive, and thus, equipping the US Army Corps of Engineers (USACE) water quality managers with options for technology-analysis combinations that best fit their needs.

7 Jun 2023

Investigating Minimum Exposure Time Requirements of Diquat for Flowering Rush (Butomus umbellatus) Control

PURPOSE: The purpose of this study was to investigate the minimum exposure time requirements for submersed treatments of diquat to effectively control flowering rush (Butomus umbellatus L.). Identifying these parameters will provide critical information for the operational management of this species in high water exchange scenarios.

31 May 2023

Small Plot Applications of Florpyrauxifen –Benzyl (Procellacor SC™) for Control of Monoecious Hydrilla in Roanoke Rapids Lake, NC

Abstract: Four demonstration plots were selected at Roanoke Rapids Lake, NC to evaluate water exchange and aqueous herbicide residues in stands of submersed aquatic vegetation (SAV) following treatment with rhodamine wt dye and florpyrauxifen-benzyl to control monecious hydrilla. Florpyrauxifen-benzyl (Procellacor™ SC) was applied in combination with Rhodamine WT (RWT) at two of the plots. Dye measurements and herbicide residue samples were collected at specific time intervals to draw comparisons between herbicide and RWT dye dissipation. The two additional plots served as reference plots to the treatment plots. Pre- and post-treatment vegetation surveys were conducted to evaluate monoecious hydrilla control and non-target species response. RWT dye and herbicide residue data indicated rapid water exchange was occurring with each treatment plot. As a result, florpyrauxifen-benzyl concentration and exposure times (CETs) towards monoecious hydrilla were not sufficient to achieve adequate control by 4 weeks after treatment (WAT). To reduce the impact of hydraulic complexity and improve herbicide efficacy, treatments should coincide with minimal reservoir discharge events to extend herbicide CET relationships. Evaluations of florpyrauxifen-benzyl on late season, mature plants may have impacted herbicide efficacy. Evaluations should be conducted earlier in the growing season, on young, actively growing plants, to discern potential differences in efficacy due to treatment timing and phenology. More information on herbicide concentration and exposure time relationships for monoecious hydrilla should be developed in growth chamber and mesocosm settings to improve species selective management of monoecious hydrilla in hydrodynamic reservoirs.

31 May 2023

Extraction and Analysis of Per- and Polyfluoroalkyl Substances (PFAS) from Meals Ready-to-Eat (MRE) Films Using GC-MS and LC-MS/MS

OBJECTIVE: This work was in response to the Defense Logistic Agency’s (DLA) Subsistence Network Broad Agency Announcement, BAA-0003-16 addressing 2019 NDAA Section 329 that states packaging materials used for Meals Ready-to-Eat (MRE) that contact food products must be free of per- and polyfluoroalkyl substances (PFAS). This was addressed by determining the presence or absence of PFAS on MREs by extraction followed by gas chromatography mass spectrometry (GC-MS) and liquid chromatography tandem mass spectrometry (LC-MS/MS). Any samples positive for PFAS were quantitated using LC triple quadrupole (QqQ) MS at the US Army Engineering and Research Development Center (ERDC) and by high resolution quadrupole time-of-flight (qTOF) MS and GC-MS at Oregon State University (OSU).

22 May 2023

Advances in Dredged Material Evaluations for Inland and Ocean Aquatic Placement: Modernized Processes and Supportive Tools

Abstract: As part of the US Army Corps of Engineers’ mission to evaluate and move dredged material (DM) to maintain navigation channels, environmental evaluation of the prospective material is required by the Code of Federal Regulations. While existing guidance manuals provide useful guidance to DM regulators, they are over 30 years old and not reflective of the latest science. However, efforts to update procedures and publish the documents individually or as a combined dredging manual have been thus far unsuccessful. These issues, coupled with a lack of consistent reporting and decision documentation, lead to delays arising from challenges addressing project-specific issues not clearly covered within the existing guidance, revisiting previously resolved issues or negotiating disputes between permitting authorities. This technical report provides a path toward modernization of the environmental compliance aspects of DM evaluation guidance in part through software executables guiding the management and decision process and through a structured, evidence-based approach. The value added is an updated approach to DM testing and evaluation decisions.

27 Apr 2023

Stormwater Management Practices, Monitoring, and Maintenance Plan for US Army Garrison at West Point, NY

Abstract: Structural stormwater management practices (SMPs) are designed and installed with the goal of reducing runoff and improving water quality through a variety of built (e.g., underground chamber and filter systems), nature-based and natural features (e.g., rain gardens, swales). In compliance with Section 402 of the US Clean Water Act (CWA), US Army Garrisons at West Point MS4 operators are required to obtain a National Pollutant Discharge Elimination System permit or a New York State Pollutant Discharge Elimination System (SPDES). These permits require development of stormwater management plans to reduce pollutants to meet the appropriate water quality standards. Over 62 structural SMPs have been installed at the US Army Garrison (USAG) to meet permit requirements. Monitoring and maintenance are essential to maintain and understand the effectiveness of these structures, track their maintenance needs, and improve their function. This document provides guidance for conducting stormwater management practice, inspection, and maintenance at the United States Army Garrison at West Point. The objectives are to inform installation managers on general SMP functions and designs, highlight key maintenance triggers affecting SMP functionality, and provide guidance on when and how to conduct inspections and maintenance actions specific to USAG SMPs and in accordance to NYS DEC.

27 Apr 2023

Technical Guide for the Development, Evaluation, and Modification of Wetland Rapid Assessment Methods for the Corps Regulatory Program

Abstract: The US Army Corps of Engineers (Corps) Regulatory Program considers the loss (decrease) and gain (improvement) of wetland functions as part of Clean Water Act Section 404 permitting and compensatory mitigation decisions. To better inform this regulatory decision-making, the Regulatory program needs accurate, transparent, objective, and defensible approaches to assess the function and condition of wetlands. Additionally, wetland assessments must balance the need for objective decision-making with the concurrent need to make Regulatory program decisions in a timely manner. Consequently, it is often necessary to assess wetlands using rapidly attainable proxy measures of ecological function or condition by evaluating a suite of metrics that represent structural and compositional attributes of a wetland. In response, this document describes a set of guidelines to effectively develop, evaluate, and modify wetland assessment methods, specifically for the Corps Regulatory Program.

6 Apr 2023

Eelgrass Functions, Services, and Considerations for Compensatory Mitigation

Abstract: Coastal-marine eelgrass habitat is a critical resource within New England and throughout the world. Eelgrass habitat provides functions and services including providing structure, biogeochemical cycling, erosion reduction, habitation provision, and water quality improvement. Declines in eelgrass distribution are often due to anthropogenic processes impacting temperature and water quality. Declines in distribution and abundance highlight the importance of protecting the existing eelgrass, improving environmental conditions allowing for ecosystem restoration, and identifying viable in-kind and out-of-kind compensatory mitigation measures. Considering the limited availability of New England sites for in-kind compensatory mitigation, additional approaches for out-of-kind compensatory mitigation should be considered. These include (1) creation of alternative plant or kelp habitat, (2) using a multi-pronged, multi-habitat and structure approach, (3) contributing to the development of water quality improvement initiatives to encourage current eelgrass bed expansion over time, (4) reduce physical impacts to eelgrass habitat, (5) and identifying locations for future eelgrass habitat suitability based on climate predictions and investing to create future compensatory mitigation habitat in these locations.