Partrac Demonstrates Practicle Tracing Technology
Partrac Ltd has recently completed a survey to demonstrate its particle tracing technology for aiding the management of contaminated sediments. This was for the SPAWAR (Space and Naval Warfare) Systems Centre Pacific in San Diego.
The study is being undertaken under a grant funded by the US Department of Defense (DoD) ESTCP programme. This is the DoD’s environmental technology demonstration and validation program, which aims to promote the transfer of innovative technologies that have successfully established proof of concept to field or production use.
Partrac, a UK based contractor, has developed the particle tracing field tool and methodology over the past 10 years. This allows sediments and other particles to be tracked through time and across space in aquatic and terrestrial systems. It is a simple to use but highly practical tool. Partrac was commissioned to undertake the demonstration project to illustrate how the tool can be applied on a practical level to underpin the management of contaminated sediments in military waters.
Contaminated sediments are a continuing regulatory issue for the Department of Defense facilities in the USA. There is continued regulatory scrutiny of contaminated sediments located in proximity to multiple DoD discharges into aquatic environments. In complex industrial settings, both the DoD and Environmental Protection Agency (EPA) have great interest in determining which nearshore discharges contribute contaminated sediments to particular areas of the depositional environment. Source control (i.e. the reduction of contamination from upstream point or diffuse sources) is a critical element in any management plan for contaminated waterways. In order to understand the issues surrounding source control, it is essential to have some understanding of contaminant sources and transport pathways of contaminated particulates.
The Partrac particle tracing field tool uses proprietary dual signature (DS) tracer technology where the tracers for the study are natural sediment (silt) particles modified to be both fluorescent in character and para-magnetic. These two signatures allow for unequivocal identification of the particles following release, thereby providing a means of tracking their movement. The magnetic character also allows the use of powerful permanent magnets, both in situ and in the laboratory, for tracer recovery.
Partrac recently completed the first of two surveys for the Client. Partrac scientists co-designed the study with Dr Jim Leather and his colleagues of the Environmental Assessment and Sustainability branch of SPAWAR.
Dr Leather said, “This is a great opportunity to trial the Partrac particle tracing technology for monitoring the movement of contaminated sediment, which could be invaluable for future environmental impact assessments”. Dr Kevin Black, Technical Director for Partrac said, “800 kg of silt tracer slurry (< 63 microns) was introduced into the ocean mimicking the discharge from an outfall during a flash flood. Many different sampling activities, which included in situ magnet moorings, conventional water sampling, in situ fluorimetry and seabed grab sampling, were undertaken in a systematic manner to track the plume, and delineate its’ depositional footprint, over four tidal cycles. We are now processing the data from the survey and results should be available in the near future”.
A second survey is planned for the spring of 2015.
Press Release; Image: Partrac