Material brought into suspension during dredging operations can, in certain circumstances, be detrimental to the environment through reduced water quality, benthic swamping or pollutant spreading. Neptune's spill / dredge monitoring system is designed to assist the dredging contractor to comply with the often strict environmental controls placed on a license to dredge.
The development of the spill monitoring system was based on experience gained over many years of involvement in dredging and sediment transport related projects around the world. The system is vessel based and continuously measures and displays the quantity of suspended material that is transported in the water column.
The vessel based monitoring system consists of an ADCP, an array of optical backscatter sensors (OBS), a near-surface electromagnetic flow meter (EMFM), pump samplers, differential GPS, gyro compass, echo sounder, software suites and associated computers.
Central to Neptune's spill monitoring system is an Acoustic Doppler Current Profiler (ADCP). The vessel mount ADCP gathers acoustic backscatter signals from a number of depths within the water column. The data are continuously processed to record and display sediment concentrations and water flow. By sailing defined boundary transects downstream of the dredging operations the total suspended sediment load can be determined. Background suspended sediment measurements are regularly conducted to allow the net dredging related load to be determined.