Getting the dosage right equates to a clear supernatant

Desilting Solutions can provide tailored solutions to dewatering dredge spoil with their on-site, real-time, polymer dosing management system.

Critical to any environmentally sensitive dredging operation is the management of the dredge slurry, which apart from containing heavy metals and other toxic materials, is also heavily contaminated with course to colloidal particles which need to be managed.

Works on the Brisbane River necessitated the removal of 2000t of silt and sediment from inside stormwater infrastructure and the processing of nearly five million litres of dredged slurry during the process. Careful planning and onboard dosing with real-time management enabled the Desilting team to complete the task without incident by ensuring that the supernatant which was returned to the river was well within the EPA guidelines. Third-party monitoring, undertaken twice daily ensured this adherence and provided the client with unequivocal proof of service.

As part of the spoil management, two thirty-meter long GeoTubes were placed on a barge alongside the works and were utilised to separate the supernatant from the dredge slurry and store the spoil.

The GeoTubes did a phenomenal job, as designed, and allowed clarified supernatant to exit the tubes and flow back into the Brisbane River.

Spoil removal was undertaken by normal earthmoving equipment, with the spoil being trucked to the spoil site by tipper.