Ports, marinas, councils & environmental project teams · Australia-wide
Plan where dredged sediment and water will go before dredging starts.
A marina maintenance campaign, drainage-channel clean-out or river remediation project needs a workable destination for both solids and water. Kontain develops geobag dewatering layouts and lining material packages with the owner’s environmental consultant, designer and dredging contractor. Lining specifications and supply are also available for containment areas without geobags.
First decision
Is onshore dewatering practical for this sediment?
Assess the sediment, available land, dredging rate, filtrate requirements and final solids destination together. Geobags can provide a contained dewatering step where testing supports it. They do not, by themselves, establish that contaminated sediment or released water is suitable for reuse or discharge.
Agree the sediment and treatment basis
Representative sampling and the site's environmental assessment should inform the options. Contaminants, salinity, particle size, organic content and potential acid sulfate soils can change treatment, material compatibility and water-management needs.
Where treatment is required, evaluate it with the environmental consultant and conditioning specialist. Inline treatment before bag filling and treatment of recovered solids after dewatering are options to investigate through trials; neither should be assumed effective without evidence.
Match the dredging programme to the footprint
An in-situ sediment volume is different from a pumped slurry volume. Record pumping hours, slurry flow and solids concentration so the layout reflects the actual dry-solids load and water flow.
Allow space and time for filling, drainage, consolidation and access. Staged operation can be compared with a larger single campaign. Stacking requires assessment of the foundation, bag behaviour, interfaces, drainage and stability; it is a project-specific design decision.
Design the full containment and water pathway
The working pad needs a defined foundation, lining arrangement, collection system and route to treatment, return or approved discharge. Plan rainfall management and access alongside the bags, pipework and dosing equipment.
Agree how filtrate and retained solids will be tested, who will make acceptance decisions and what happens if results fall outside the project criteria. Bag selection and layout should support that management plan.
Kontain can prepare the lining material specification and assess the polymer liner, GCL, protection and drainage arrangement for the pad or containment cell. Optimisation considers exposure, ground conditions, interfaces, seams, roll formats and installation alongside the required barrier performance.
Questions before committing
Do geobags remove dissolved contaminants?
Geobags are a solids-retention and dewatering system. They are not a general treatment for dissolved contaminants. The sediment and water assessment must determine whether additional treatment is needed, and testing must confirm the outcome.
Can acid sulfate sediments be dewatered in geobags?
This needs a site-specific assessment of acid generation, treatment and water management. The environmental consultant should establish the management basis, with trials used to assess any conditioning or neutralisation sequence. Dewatering alone does not resolve acid sulfate soil risk.
Can the solids stay on site after dewatering?
That depends on the material's classification, the proposed end use, site conditions and applicable approvals. Confirm the retention, reuse or disposal route before fixing the dewatering layout. An enclosed bag does not itself make a permanent disposal arrangement acceptable.