Demonstration of an In-Situ Friction-Sound Probe for Mapping Particle Size at Contaminated Sediment Sites

The Navy, Department of Defense (DoD), and other government and private entities are in the process of identifying, assessing, and remediating a large number of hazardous waste sites that are the result of decades of waste management practices resulting in the release of contaminants to soil, sediment, and groundwater in coastal environments. At contaminated sediment sites it is generally accepted that the affinities of contaminants for fine-grained sediment result in high contaminant concentrations in areas that are characterized by fine sediments. (Calvert, 1976; Warren, 1981) In contrast, at groundwater surface water interaction (GSI) sites, groundwater discharge of more mobile, dissolved-phase contaminants is often associated with course grained, permeable sediment units (Fetter, 1994). Knowledge of grain size at sediment study sites can provide lines of evidence that can be applied to identify potential areas of contaminated sediment and contaminant discharge zones. Field surveys for grain size can require a full sampling regime including substantial analytical costs. The sediment friction-sound probe (SED-FSP) technology was proposed as a remedy for quickly and cost effectively acquiring grain size information. The overall objective of this project was to field demonstrate the effectiveness of the SED-FSP for direct, in-situ measurement of grain size at contaminated sediment and GSI sites. The objective was accomplished through: Development of a commercial prototype friction-sound probe, Verification of sensor performance in the laboratory, and Field demonstration and validation at varying application regimes to delineate. Three types of sites were selected to field demonstrate the technology: (1) a GSI site, (2) a contaminated sediment site, and (3) a contaminated sediment thin-layer containment cap where the vertical profiling capabilities of the technology were demonstrated.