11 Aug 2021

Preparative, Extraction, and Analytical Methods for Simultaneous Determination of Legacy and Insensitive Munition (IM) Constituents in Aqueous, Soil or Sediment, and Tissue Matrices

Abstract: No standard method exists for determining levels of insensitive munition (IM) compounds in environmental matrices. This project resulted in new methods of extraction, analytical separation and quantitation of 17 legacy and 7 IM compounds, daughter products of IM, and other munition compounds absent from USEPA Method 8330B. Extraction methods were developed for aqueous (direct-injection and solid-phase extraction [SPE]), soil, sediment, and tissue samples using laboratory-spiked samples. Aqueous methods were tested on 5 water sources, with 23 of 24 compounds recovered within DoD QSM Ver5.2 limits. New solvent extraction (SE) methods enabled recovery of all 24 compounds from 6 soils within QSM limits, and a majority of the 24 compounds were recovered at acceptable levels from 4 tissues types. A modified chromatographic treatment method removed analytical interferences from tissue extracts. Two orthogonal high-performance liquid chromatography-ultraviolet (HPLC-UV) separation methods, along with an HPLC–mass spectrometric (HPLC-MS) method, were developed. Implementing these new methods should reduce labor and supply costs by approximately 50%, requiring a single extraction and sample preparation, and 2 analyses rather than 4. These new methods will support environmental monitoring of IM and facilitate execution of risk-related studies to determine long-term effects of IM compounds.

10 Aug 2021

Record Package Guidance: Best Practices

Abstract: The CAD/BIM Technology Center receives numerous questions throughout the year regarding the development of a Record Package that shows as-built conditions. While the Center does produce Standards on the look and organization of CAD drawings that are used to show as-built conditions, users wanted guidance on the Record Package development. The Chicago District had undertaken the development of such guidance, but a formal document was never officially released. The CAD/BIM Community of Practice (CoP) Work Structure Committee finished this guidance and their efforts are reflected in this document.

9 Aug 2021

Metal Accumulation Capacity in Indigenous Alaska Vegetation Growing on Military Training Lands

Abstract: Permafrost thawing could increase soil contaminant mobilization in the environment. Our objective was to quantify metal accumulation capacities for plant species and functional groups common to Alaskan military training ranges where elevated soil metal concentrations were likely to occur. Plant species across multiple military training range sites were collected. Metal content in shoots and roots was compared to soil metal concentrations to calculate bioconcentration and translocation factors. On average, grasses accumulated greater concentrations of Cr, Cu, Ni, Pb, Sb, and Zn relative to forbs or shrubs, and bioconcentrated greater concentrations of Ni and Pb. Shrubs bioconcentrated greater concentrations of Sb. Translocation to shoots was greatest among the forbs. Three native plants were identified as candidate species for use in metal phytostabilization applications. Elymus macrourus, a grass, bioconcentrated substantial concentrations of Cu, Pb, and Zn in roots with low translocation to shoots. Elaeagnus commutata, a shrub, bioconcentrated the greatest amounts of Sb, Ni, and Cr, with a low translocation factor. Solidago decumbens bio-concentrated the greatest amount of Sb among the forbs and translocated the least amount of metals. A combination of forb, shrub, and grass will likely enhance phytostabilization of heavy metals in interior Alaska soils through increased functional group diversity.

9 Aug 2021

Simultaneous Mapping of Coastal Topography and Bathymetry from a Lightweight Multicamera UAS

Abstract: A low-cost multicamera Unmanned Aircraft System (UAS) is used to simultaneously estimate open-coast topography and bathymetry from a single longitudinal coastal flight. The UAS combines nadir and oblique imagery to create a wide field of view (FOV), which enables collection of mobile, long d Coastal mapping, multiview stereo (MVS), nearshore morphology, remote sensing, structure from motion (SfM), Unmanned Aircraft Systems (UAS)well timeseries of the littoral zone suitable for structure-from motion (SfM), and wave speed inversion algorithms. Resultant digital surface models (DSMs) compare well with terrestrial topographic lidar and bathymetric survey data at Duck, NC, USA, with root-mean-square error (RMSE)/bias of 0.26/–0.05 and 0.34/–0.05 m, respectively. Bathymetric data from another flight at Virginia Beach, VA, USA, demonstrates successful comparison (RMSE/bias of 0.17/0.06 m) in a secondary environment. UAS-derived engineering data products, total volume profiles and shoreline position, were congruent with those calculated from traditional topo-bathymetric surveys at Duck. Capturing both topography and bathymetry within a single flight, the presented multicamera system is more efficient than data acquisition with a single camera UAS; this advantage grows for longer stretches of coastline (10 km). Efficiency increases further with an on-board Global Navigation Satellite System–Inertial Navigation System (GNSS-INS) to eliminate ground control point (GCP) placement. The Appendix reprocesses the Virginia Beach flight with the GNSS–INS input and no GCPs.

6 Aug 2021

Print Time vs. Elapsed Time: A Temporal Analysis of a Continuous Printing Operation for Additive Constructed Concrete

Abstract: In additive construction, ambitious goals to fabricate a concrete building in less than 24 hours are attempted. In the field, this goal relies on a metric of print time to make this conclusion, which excludes rest time and delays. The task to complete a building in 24 hours was put to the test with the first attempt at a fully continuous print of a structurally reinforced additively constructed concrete (ACC) building. A time series analysis was performed during the construction of a 512 ft2 (16’x32’x9.25’) building to explore the effect of delays on the completion time. This analysis included a study of the variation in comprehensive layer print times, expected trends and forecasting for what is expected in future prints of similar types. Furthermore, the study included a determination and comparison of print time, elapsed time, and construction time, as well as a look at the effect of environmental conditions on the delay events. Upon finishing, the analysis concluded that the 3D-printed building was completed in 14-hours of print time, 31.2- hours elapsed time, a total of 5 days of construction time. This emphasizes that reports on newly 3D-printed constructions need to provide a definition of time that includes all possible duration periods to communicate realistic capabilities of this new technology.

5 Aug 2021

Changes in Climate and Its Effect on Timing of Snowmelt and Intensity-Duration-Frequency Curves

Abstract: Snow is a critical water resource for much of the U.S. and failure to ac-count for changes in climate could deleteriously impact military assets. In this study, we produced historical and future snow trends through modeling at three military sites (in Washington, Colorado, and North Dakota) and the Western U.S. For selected rivers, we performed seasonal trend analysis of discharge extremes. We calculated flood frequency curves and estimated the probability of occurrence of future annual maximum daily rainfall depths. Additionally, we generated intensity-duration-frequency curves (IDF) to find rainfall intensities at several return levels. Generally, our results showed a decreasing trend in historical and future snow duration, rain-on-snow events, and snowmelt runoff. This decreasing trend in snowpack could reduce water resources. A statistically significant increase in maximum streamflow for most rivers at the Washington and North Dakota sites occurred for several months of the year. In Colorado, only a few months indicated such an increase. Future IDF curves for Colorado and North Dakota indicated a slight increase in rainfall intensity whereas the Washington site had about a twofold increase. This increase in rainfall in-tensity could result in major flood events, demonstrating the importance of accounting for climate changes in infrastructure planning.

4 Aug 2021

An Assessment of Long-Term, Multipurpose Ecosystem Functions and Engineering Benefits Derived from Historical Dredged Sediment Beneficial Use Projects

Abstract: The beneficial use of dredged materials improves environmental outcomes while maximizing navigation benefits and minimizing costs, in accordance with the principles of the Engineering With Nature® (EWN) initiative. Yet, few studies document the long-term benefits of innovative dredged material management strategies or conduct comprehensive life-cycle analysis because of a combination of (1) short monitoring time frames and (2) the paucity of constructed projects that have reached ecological maturity. In response, we conducted an ecological functional and engineering benefit assessment of six historic (>40 years old) dredged material–supported habitat improvement projects where initial postconstruction beneficial use monitoring data was available. Conditions at natural reference locations were also documented to facilitate a comparison between natural and engineered landscape features. Results indicate the projects examined provide valuable habitat for a variety of species in addition to yielding a number of engineering (for example, shoreline protection) and other (for example, carbon storage) benefits. Our findings also suggest establishment of ecological success criteria should not overemphasize replicating reference conditions but remain focused on achieving specific ecological functions (that is, habitat and biogeochemical cycling) and engineering benefits (that is, storm surge reduction, navigation channel maintenance) achievable through project design and operational management.

30 Jul 2021

A Quantitative Risk Assessment Method for Synthetic Biology Products in the Environment

Abstract: The need to prevent possible adverse environmental health impacts resulting from synthetic biology (SynBio) products is widely acknowledged in both the SynBio risk literature and the global regulatory community. However, discussions of potential risks of SynBio products have been largely speculative, and the attempts to characterize the risks of SynBio products have been non-uniform and entirely qualitative. As the discipline continues to accelerate, a standardized risk assessment framework will become critical for ensuring that the environmental risks of these products are characterized in a consistent, reliable, and objective manner that incorporates all SynBio-unique risk factors. Current established risk assessment frameworks fall short of the features required of this standard framework. To address this, we propose the Quantitative Risk Assessment Method for Synthetic Biology Products (QRA-SynBio) – an incremental build on established risk assessment methodologies that supplements traditional paradigms with the SynBio risk factors that are currently absent and necessitates quantitative analysis for more transparent and objective risk characterizations. The proposed framework facilitates defensible quantification of the environmental risks of SynBio products in both foreseeable and hypothetical use scenarios. Additionally, we show how the proposed method can promote increased experimental investigation into the likelihood of hazard and exposure parameters and highlight the parameters where uncertainty should be reduced, leading to more targeted risk research and more precise characterizations of risk.

30 Jul 2021

Cyanobacteria Harmful Algal Blooms (HABs) and US Army Engineer Research and Development Center (ERDC): Research and Services

Abstract: This factsheet details the research and services available from the US Army Engineer Research and Development Center–Environmental Laboratory’s Harmful Algal Blooms team.

30 Jul 2021

Geotechnical Effects on Fiber Optic Distributed Acoustic Sensing Performance

Abstract: Distributed Acoustic Sensing (DAS) is a fiber optic sensing system that is used for vibration monitoring. At a minimum, DAS is composed of a fiber optic cable and an optic analyzer called an interrogator. The oil and gas industry has used DAS for over a decade to monitor infrastructure such as pipelines for leaks, and in recent years changes in DAS performance over time have been observed for DAS arrays that are buried in the ground. This dissertation investigates the effect that soil type, soil temperature, soil moisture, time in-situ, and vehicle loading have on DAS performance for fiber optic cables buried in soil. This was accomplished through a field testing program. Signal to Noise Ratio (SNR) of the DAS response was used for all the tests to evaluate the system performance. The results of the impact testing program indicated that the portions of the array in gravel performed more consistently over time. The results also indicated that time DAS performance does change somewhat over time. Performance variance increased in new portions of array in all material types through time. Overall, this dissertation provides guidance that can help inform the civil engineering community with respect to installation design recommendations related to DAS used for infrastructure monitoring.