30 Apr 2024

Evaluating Soil Conditions to Inform Upper Mississippi River Floodplain Restoration Projects

Abstract: The US Army Corps of Engineers (USACE) has designed and constructed thousands of acres of ecosystem restoration features within the Upper Mississippi River System. Many of these projects incorporate island construction to restore geomorphic diversity and habitat, including floodplain forests. Soils are the foundation of the ecological function and successful establishment of floodplain forests as they are the basis through which plants obtain water and nutrients and provide critical ecosystem services. To improve floodplain forest island restoration outcomes, three natural and four recently (<10 years) constructed restoration sites were studied to compare soil physical, chemical, microbial, and fungal characteristics. Constructed islands had lower soil organic matter and dissolved organic carbon and differed in nutrient concentrations, bacterial assemblages, and fungal communities compared to reference sites. However, soil enzyme activity and some microbial community characteristics were functionally similar between the natural and created sites. Results align with previously established restoration trajectory theories where hydrological and basic microbial ecosystem functions are restored almost immediately, but complex biologically mediated and habitat functions require more time to establish. Data from this and future studies will help increase the long-term success of USACE floodplain forest restoration, improve island design, and help develop region-specific restoration trajectory curves to better anticipate the outcomes of floodplain forest creation projects.

7 Jul 2022

Validation of the Automatic Dynamic Cone Penetrometer

Abstract: The U.S. military requires a rapid means of measuring subsurface soil strength for construction and repair of expeditionary pavement surfaces. Traditionally, a dynamic cone penetrometer (DCP) has served this purpose, providing strength with depth profiles in natural and prepared pavement surfaces. To improve upon this device, the Engineer Research and Development Center (ERDC) validated a new battery-powered automatic dynamic cone penetrometer (A-DCP) apparatus that automates the driving process by using a motor-driven hammering cap placed on top of a traditional DCP rod. The device improves upon a traditional DCP by applying three to four blows per second while digitally recording depth, blow count, and California Bearing Ratio (CBR). An integrated Global Positioning Sensor (GPS) and Bluetooth® connection allow for real-time data capture and stationing. Similarities were illustrated between the DCP and the A-DCP by generation of a new A-DCP calibration curve. This curve relates penetration rate to field CBR that nearly follows the DCP calibration with the exception of a slight offset. Field testing of the A-DCP showed less variability and more consistent strength measurement with depth at a speed five times greater than that of the DCP with minimal physical exertion by the operator.

14 Feb 2022

A Comparison of Handheld Field Chemical Sensors for Soil Characterization with a Focus on LIBS

Abstract: Commercially available handheld chemical analyzers for forensic applications have been available for over a decade. Portable systems from multiple vendors can perform X-ray fluorescence (XRF) spectroscopy, Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and recently laser-induced breakdown spectroscopy (LIBS). Together, we have been exploring the development and potential applications of a multisensor system consisting of XRF, Raman, and LIBS for environmental characterization with a focus on soils from military ranges. Handheld sensors offer the potential to substantially increase sample throughput through the elimination of transport of samples back to the laboratory and labor-intensive sample preparation procedures. Further, these technologies have the capability for extremely rapid analysis, on the order of tens of seconds or less. We have compared and evaluated results from the analysis of several hundred soil samples using conventional laboratory bench top inductively coupled plasma atomic emission spectroscopy (ICP-AES) for metals evaluation and high-performance liquid chromatography (HPLC) and Raman spectroscopy for detection and characterization of energetic materials against handheld XRF, LIBS, and Raman analyzers. The soil samples contained antimony, copper, lead, tungsten, and zinc as well as energetic compounds such as 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-triazine (RDX), nitroglycerine (NG), and dinitrotoluene isomers (DNT). Precision, accuracy, and sensitivity of the handheld field sensor technologies were compared against conventional laboratory instrumentation to determine their suitability for field characterization leading to decisional outcomes.

6 Dec 2021

Development of a Sand Boil Testing Laboratory and Preliminary Results

Purpose: To document the purpose, use, and preliminary results of a full-scale sand boil generator developed at the Geotechnical and Structures Laboratory.

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 May 2021

The Effectiveness of Laser-Induced Breakdown Spectroscopy (LIBS) as a Quantitative Tool for Environmental Characterization

Abstract: Laser-induced breakdown spectroscopy (LIBS) is a rapid, low-cost analytical method with potential applications for quantitative analysis of soils for heavy metal contaminants found in military ranges. The Department of Defense (DoD), Army, and Department of Homeland Security (DHS) have mission requirements to acquire the ability to detect and identify chemicals of concern in the field. The quantitative potential of a commercial off-the-shelf (COTS) hand-held LIBS device and a classic laboratory bench-top LIBS system was examined by measuring heavy metals (antimony, tungsten, iron, lead, and zinc) in soils from six military ranges. To ensure the accuracy of the quantified results, we also examined the soil samples using other hand-held and bench-top analytical methods, to include Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) and X-Ray Fluorescence (XRF). The effects of soil heterogeneity on quantitative analysis were reviewed with hand-held and bench-top systems and compared multivariate and univariate calibration algorithms for heavy metal quantification. In addition, the influence of cold temperatures on signal intensity and resulting concentration were examined to further assess the viability of this technology in cold environments. Overall, the results indicate that additional work should be performed to enhance the ability of LIBS as a reliable quantitative analytical tool.

24 Sep 2020

Fusion of Spectral Data from Multiple Handheld Analyzers (LIBS, XRF and Raman) for Chemical Analysis and Classification of Soil

 Abstract:  An 18-month multidisciplinary project was undertaken by JRPlumer & Associates, LLC and four subcontractors that had three technical objectives: (i) to upgrade current handheld technology for chemical analysis by X-ray fluorescence spectroscopy (XRFS), Raman spectroscopy (RS), and laser-induced breakdown spectroscopy (LIBS); (ii) to design a multisensor system based on these technologies for the rapid, in-situ chemical analysis of soils and other materials of military interest; and (iii) to investigate the classification/discrimination performance benefit that might be achieved through advanced signal pre-processing and data fusion with XRFS, RS, and LIBS analyses acquired for four suites of natural soils. Accomplishments of the program in the latter area are described in this report.

24 Sep 2020

Study of Sand Boil Development at Kaskaskia Island, IL, Middle Mississippi River Valley

Abstract: Mississippi River flooding in 2013 and 2016 caused severe underseepage and development of several medium to large high-energy sand boils behind the landside levee toe at Kaskaskia Island, IL. This levee system is located between St. Louis and Cape Girardeau, MO, and is part of the Kaskaskia Island Drainage and Levee District on the Middle Mississippi River. Flooding on the Mississippi River in 2013 and 2016 was below the design flowline for this levee. This report documents a case history study into the causes of seepage, piping, and sand boil development at a levee reach at Kaskaskia. Site-specific geotechnical data were collected and evaluated to determine the causes for poor performance at the studied levee reach locations. Data collected involved design documents, geologic and geotechnical borings, closely spaced cone-penetrometer tests (CPTs), electrical resistivity surveys, laboratory soil testing of sand boil ejecta, CPT samples from targeted stratigraphic horizons in the subsurface, and both piezometer and river-stage data. These data indicate sand boils present within this levee reach involved a chronic seepage condition that became progressively worse through time. This condition was directly related to the underlying site geology, namely the top stratum thickness and the depositional environment in this levee reach.

3 Feb 2020

Matrix andPUBLICATION NOTICE: Target Particle-Size Effects on LIBS Analysis of Soils

 Link: http://dx.doi.org/10.21079/11681/35374 Report Number: ERDC/CRREL TR-20-1Title: Matrix and Target Particle-Size Effects on LIBS Analysis of Soils By Samuel A. Beal, Ashley M. Mossell, and Jay L. Clausen Approved for Public Release; Distribution is Unlimited January 2020 ABSTRACT:  Laser-induced breakdown spectroscopy (LIBS) is a rapid,