Everything goes somewhere; tracking the movement of contaminated sediments in an industrialised estuary using dual signature sediment tracers

Abstract

Abstract. Source control i.e. the reduction of contamination from upstream or diffuse sources, is a critical element in any management plan for contaminated waterways. If source control measures are not successfully implemented, then a situation exists in which contamination will continue through time, and the cleanup of waterway segments becomes increasingly problematic. To provide greater understanding of the issues surrounding source control, it is essential to have some knowledge of contaminant sources and transport pathways of contaminated particulates. In port areas a plethora of factors interact to control contaminant transport pathways. These include: rain and river flow; tidal circulation, surface waves and wind drift, and temporally changing water column stratification. Particle tracking offers a practical means to map the transport pathways of contaminated sediments under these collective influences. This paper introduces a new and novel "dual signature" tracer product, and describes the particle tracking technique on a practical level through a study example in the Lower Duwamish Waterway, Washington, USA.

High precision tracing of soil and sediment movement using fluorescent tracers at hillslope scale

“…The D50 selection was arbitrary since our focus was on testing the tracer rather than mimicking the characteristics of the study soils. The tracer has been used widely in estuarine and marine studies, and to a lesser extent in terrestrial systems, and is known to be non‐toxic and stable in a variety of environments (Black et al ., ; Collins et al ., ).…”

Sediment deposition characteristics in shallow saturation excess overland flow for urban Stormwater applications

“…For this study, we relied on dual‐signature (fluorescent and paramagnetic) silt sized tracers (Black, 2013). Tracers have been applied to many field environments, most often in oceans, estuaries, rivers and streams (Allen et al, 2015; Black, 2013; Black et al, 2007; Black et al, 2013). However, use of these tracers in extremely shallow aquatic environments, like stormwater runoff, is far less common.…”

“…The experimental conditions are that of SEOF, and in this study a new methodology is introduced to measure the deposition in SEOF using sediment tracers. Sediment tracers are typically created by adding a “signature” to natural or artificial particles in order to track them in time and space (Black et al, 2013). For this study, we relied on dual‐signature (fluorescent and paramagnetic) silt sized tracers (Black, 2013).…”