28 Mar 2023

Waste Management and Landfill Facilities Assessment Using Unmanned Aircraft Systems

Abstract: Finite and decreasing landfill space on Army installations is a significant concern. Efficient waste management is essential for achieving resiliency and extending the lifespan of remaining landfills. The purpose of this demonstration was to conduct independent performance tests of small unmanned aircraft systems (sUAS) and their utility for providing landfill assessments in remote areas where physical presence is either dangerous or inefficient. An active, near capacity construction and demolition (C&D) landfill at Fort Gordon, Georgia, was identified for the demonstration. The flights, data requirements, and outputs generated by the sUAS flyovers were analyzed for efficacy in detecting cell capacity and subsidence. Each flight took 1–2 hours for mobilization, ground marker placement, flight, and postflight analysis. Volumetric and topographic surveys were analyzed in less time than is typical for traditional surveying methods. After initial setup of ground markers and rectification, sUAS flights save a significant amount of time. However, skilled individuals are required for flights and for processing and maintaining data. The technology is widely relevant to the Army, is commercially available, and offers an average of 30% cost savings in terms of manpower, repeatability, and equipment. The use of sUAS technology is recommended for monitoring and surveying Army landfills.

30 Mar 2022

Terrestrial Fate and Effects of Nanometer-Sized Silver

Abstract: Although engineered nanomaterials are active components in a wide variety of commercial products, there is still limited information related to the effects of these nanomaterials once released into the terrestrial environment. A high number of commercial applications use silver nanoparticles (nAg) due to its anti-microbial activity. This may be of concern for waste management since nAg could be applied to soil (e.g., biosolids) or disposed of in traditional landfills, which could lead to possible leaching into surrounding soil. This report aims to provide additional insight into the fate and effects of nAg in terrestrial systems. The studies in this report examine the leachability of nAg in field soil and compares the soil migration to bulk (i.e., micron-sized) silver; examine the ecotoxicity of nAg to earthworms in four field soils spanning several different soil orders; and examine the behavioral effects of earthworms when exposed to engineered nanoparticles in field soil. These data provide additional insight into engineered nanoparticle fate and effects to terrestrial receptors in field soils, an important distinction from laboratory-generated soils. These data will also assist ecological risk assessors to better determine the acute environmental risks of nAg in terrestrial ecosystems with different soil compositions.