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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. © Owned by the authors, published by EDP Sciences, 2013.

Collins A.L.,Environment Group | Yusheng Z.,Environment Group | Walling D.E.,University of Exeter | Kevin B.,Partrac Ltd.
IAHS-AISH Publication | Year: 2010

A novel tracing framework combining conventional sediment source fingerprinting and a dual signature tracking method has recently been tested in a grassland catchment in Cumbria, northwest England, UK. The former component of the framework provided information on the relative importance of generic sediment sources characterised as pasture (75±1%) or arable (9±1%) surface soils, damaged road verges (6±1%), channel banks/subsurface sources (9±1%) and the local sewage treatment works (1±1%), whereas the latter component was used to apportion sediment loss from grass fields between poached gateways (1±1%) or cattle tracks (28±1%) and wider areas of general pugging and poaching damage (46±1%). Uncertainty and prior information are explicitly recognised by the novel source tracing framework. Copyright © 2010 IAHS Press.

Thompson C.E.L.,UK National Oceanography Center | Couceiro F.,University of Portsmouth | Fones G.R.,University of Portsmouth | Helsby R.,Partrac Ltd. | And 6 more authors.
Estuarine, Coastal and Shelf Science | Year: 2011

The in situ annular flume, Voyager II, was deployed at three sites in the North Sea in order to investigate resuspension events, to determine the physical characteristics of the seabed, to determine the threshold of resuspension of the bed and to quantify erosion rates and erosion depths. These are the first controlled, in situ flume experiments to study resuspension in the North Sea, and were combined with long-term measurements of waves and currents. Resuspension experiments were undertaken at two muddy, and one sandy site: north of the Dogger Bank (DG: water depths ~80. m, very fine, poorly sorted, very fine-skewed sediment experiencing seasonal thermal stratification of the water column along with oxygen depletion); the Oyster Grounds (OG: ~40. m, similar bed properties, year round water column thermal stratification, Atlantic forcing); and in the Sean Gas Field (SGF: ~20. m, moderately sorted, very coarse-skewed sand, and well mixed water column). The erosion thresholds of the bed were found to be 0.66-1.04. Pa (DG) and 0.91-1.27. Pa (OG), with corresponding erosion depths of 0.1-0.15. mm and 0.02-0.06. mm throughout the experiments.Evaluation of a year of current velocities from 2007 indicated that at OG, resuspension of the consolidated bed was limited to on average ~8% of the time as a result of tidal forcing alone for short (<30. min) durations, but would potentially increase during the winter as a result of wave influences. At DG, under similar conditions this would increase to 13%, and in the SGF, wave-induced resuspension events occurred throughout the year, with the potential exceedance of the threshold for suspension greater than 50% in January and March.Resuspension of bed material and erosion rates were closely related to applied bed shear stresses, and eroded depths were significantly correlated with the physical properties of the bed. Therefore, while complex variations in biogeophysical factors affected the critical threshold of erosion, once exceeded, erosion rates were related to the nature of the sediment. © 2011 Elsevier Ltd.

Black K.,Partrac Ltd. | Leggett D.,DLEnviro Ltd | Read K.,Dredging International NV
International Ocean Systems | Year: 2015

Dredge monitoring and oceanographic specialist Partrac Ltd was commissioned by Dredging International to deliver one of the largest marine monitoring networks associated with environmental compliance for the development of the London Gateway Port. One of the environmental mitigation measures was to place a network of 11 buoy monitoring stations around the dredging and reclamation activities, placed in-between the dredging and reclamation operations, and identified sensitive areas to landward. To seawards, measurements were made one meter above the bed to reflect the potential of sediment disturbance there, to detect any increase in SSC due to discharges from the reclamation moving along the bed, and to measure the higher values in SSC found in that part of the water column. To control the works, an approach to thresholds was identified to be applied in real-time. The setting of a Caution level aimed to allow sufficient time to be able to react to any changing SSC events whilst not being so sensitive that an unnecessary amount of cautions were triggered. The measurements made between March 2009 and March 2014 have demonstrated, in spite of slightly elevated SSC during Year One dredging, compared to the predredge baseline year, that the levels of change in the environment fall within or below those identified as 'potential impacts' through the extended environmental impact assessment process.

Lueck R.,Rockland, Inc. | Wolk F.,Rockland, Inc. | Hancyck J.,Rockland, Inc. | Black K.,Partrac Ltd.
2015 IEEE/OES 11th Current, Waves and Turbulence Measurement, CWTM 2015 | Year: 2015

The Nemo turbulence measurement system is an anchored, buoyant float designed to measure time-series of current velocity, velocity shear, and turbulent kinetic energy (TKE) dissipation rates in swift tidal channels. The system consists of a 4.5 m long streamlined float made from syntactic foam, with cutouts to house various instrument components: a 600 kHz downward-looking acoustic Doppler current profiler (ADCP); an acoustic Doppler velocimeter (ADV); and a turbulence module equipped with velocity shear probes and fast-response thermistors The system was successfully deployed over a two-week period in Islay Sound, a tidal channel between Islay and Jura Islands, Scotland, where flow speeds exceed 3 m/s. The depth of the channel was 53 m and the system was deployed such that it remained within the depth aperture of a proposed tidal energy extraction rotor. This environment represented significant challenges for the design of the mooring and the turbulence instrumentation. We describe the measurement system and its performance in terms of attitude and flight dynamics including a synopsis of time series of current velocities and shear probe turbulence data. Scientific interpretation will be presented in subsequent publications. © 2015 IEEE.

Collins A.L.,ADAS | Zhang Y.S.,ADAS | Duethmann D.,ADAS | Walling D.E.,University of Exeter | Black K.S.,Partrac Ltd.
Hydrological Processes | Year: 2013

Although traditional sediment tracing approaches provide valuable information for characterising key generic sediment sources, Catchment Officers working as part of the Catchment Sensitive Farming initiative frequently require more detailed evidence to permit improved targeting of mitigation. Accordingly, a novel framework combining conventional sediment source fingerprinting and a dual signature tracking method has recently been used to improve sediment source information for the River Glaven (~115km2) priority catchment in eastern England. Conventional geochemical tracing incorporating a number of recent refinements to the mass balance modelling, including the combined use of local and genetic algorithm optimisation, was used to provide information on the average median relative contributions (±95% confidence limits) of generic sediment sources in three sub-catchments, categorised as grassland (1±1%-12±1%) or arable (25±1%-46±1%) surface soils, damaged road verges (2±1%-50±1%) and channel banks/subsurface sources (20±1%-50±1%) and to provide a framework for the spatial extrapolation of tracking data. Particle tracking using fluorescent-magnetic grains was used to provide preliminary sub-catchment scale information on sediment loss from key components of the primary arable topsoil and channel bank generic sources, characterised, respectively, as wheelings (18±1%-33±1%) or inter-wheelings (7±1%-13±1%) and poached (19±1%-47±1%) or fluvially eroded (1±1%-3±1%) channel margins. The insertion of high-strength magnets in watercourses ensured that the tracking component of the novel framework links sediment loss from labelled areas to river channels as opposed to providing information to edge-of-field only. Uncertainty and prior information on source contributions are explicitly recognised by the framework. This study represents the first in the UK to link wheeling sediment losses to river channels. The findings underpin the importance of compacted areas used for trafficking as sources of, and conduits for, sediment delivery in the lowland agricultural landscape of the UK. © 2012 John Wiley & Sons, Ltd.

Black K.,Partrac Ltd.
Coasts, Marine Structures and Breakwaters: Adapting to Change - Proceedings of the 9th International Conference | Year: 2010

Following introduction of the concept of Renewable Energy Zones (REZ) by the UK government, licensed marine windfarm developments are being sited in shallow coastal regions where the seabed sediments are potentially highly mobile. These present acute challenges to developers in terms of the stability, serviceability and longevity of the piles and turbines in these areas. A detailed knowledge of the sediment transport spatially at a proposed windfarm site is required in order to understand the risks presented by the sediment mobility. Current industry practice is reliant almost entirely on numerical models which are often calibrated for the hydrodynamics but are not validated. However, recent technological developments in marine instrumentation capable of gathering field data on the rates of seabed mobility, coupled to acquisition of wave, tide and wind data on a scale applicable to wind farm developments can for the first time permit geospatial, direct field measurement of sediment transport in support of site assessments for offshore windfarm developments. This presentation provides an overview of these technologies and presents a strategic framework within which data can be acquired and combined in order that informed decisions can be made regarding site selection, thus reducing the risk of turbines being located in areas not suitable due to high scour or mobile sand banks.

Black K.,Partrac Ltd. | Athey S.,Partrac Ltd. | Wilson P.,Partrac Ltd.
International Ocean Systems | Year: 2010

The Partrac founder Kevin Black, Sam Athey and Peter Wilson examine the 'new business of oceanography' in the context of one of the most exciting developments of the 21st century - marine renewables. There are extensions to some R2 offshore wind sites, consent for ten offshore wind farm sites within Scottish Territorial Waters and seven R3 wind sites which are larger and farther offshore. The development of the coastal zone for the generation of power in recent years has created a significant business opportunity. Moreover, it is big business being done mostly by the small companies. Coastal oceanographers have provided answers to these and many similar questions, and this is how we have increased the level of confidence in project developers. The industry has also thrown down some interesting challenges to us. The founders have been involved in a project recently to collect mid-water turbulence data for a tidal energy conversion partner.

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