Product
Dewatering Bag
A woven geotextile bag that drains water and retains solids, so sludge and sediment are moved and disposed of at a fraction of their wet volume.
A dewatering bag is a filter made of woven geotextile. Sludge or sediment is pumped or tipped in, water drains through the fabric, and the solids stay inside. What is left after draining is a fraction of the original volume, which is what the site finally lifts away.
It is a batch process rather than a continuous one. Bags are filled, left on a prepared pad to drain for days or weeks, and then removed one by one. That is why the layout of the pad and the number of bags a site can work with matter as much as the bag itself.
Two things decide the bag: the fabric opening size, which follows the solids that must be retained, and the bag size, which follows the volume per fill and the space available. We confirm both with a trial bag and your own material, because drainage and retention depend on your solids and chemistry, not on a catalogue table.
Product Summary
A woven bag made with geotextile fabric so water drains out while the solids stay in. It is sized from the sludge, the flow and the containment requirement rather than from a working load alone.
Core Construction
The body is sewn from a woven geotextile rather than from coated PP. The fabric is chosen for its opening size and permeability, so water passes through the weave while the solid fraction is retained inside the bag. Lifting loops are sewn into the top seam and the base is closed flat, because the bag has to hold a wet load without leaking at the base.
The two decisions that set the bag are the fabric and the size. Fabric opening size follows the solids you need to keep in, and the bag size follows the volume of sludge and the number of bags the site can handle at once. A dewatering bag is a filter first and a container second.
Key Benefits
| Benefit | Why It Matters |
|---|---|
| Volume drops before haulage | Water leaves the bag on site, so the material that is finally moved and disposed of weighs and occupies far less. |
| Solids stay where they belong | Fabric opening size is matched to the solids so the retained fraction stays in the bag instead of running off. |
| Fits existing lifting equipment | Top loops let the bag be lifted by forklift or crane once it has drained, with no separate handling frame. |
| Works as a batch process | Bags are filled, left to drain and then removed one by one, which suits sites with limited lagoon or pad space. |
Configuration Options
| Option Group | Available Range | Notes |
|---|---|---|
| Bag size | Circumference 2-9 m, height 1-2 m (typical) | Size is set from the sludge volume and the space available to lay bags out to drain. |
| Fabric | Woven geotextile, selected by opening size and permeability | The opening size follows the solids you must retain. |
| Filling | Top fill port or open top | A fill port keeps the bag closed while a pump discharges into it. |
| Lifting loops | Four corner loops, reinforced | Loops are sized for the drained weight, not the wet weight. |
| Base | Closed flat base | The base seam is the main leakage risk and is checked on each batch. |
| Seams | Double-row stitched | Seam type is chosen so the fabric does not pull out under a wet load. |
| Drainage support | Used on a prepared pad or in a frame | Drainage rate depends on how the bag is supported, which is the site's decision. |
Performance & Range
Working range depends on the solids and the site: typical sludge projects use bags from about 2 m to 9 m circumference, filled in batches and left to drain for days or weeks. Retention and drainage figures are confirmed against a sample of your material rather than quoted from a table, because both depend on the solids and the chemistry.
Validation & Testing
In-house checks cover fabric weight, opening size against the agreed specification, seam stitch counts and bag dimensions. A trial bag filled with the customer's own material is the normal way to confirm drainage and retention before a full order. Third-party testing is arranged on request.
Limitations
Not a containment device for hazardous or regulated waste unless the whole system is designed for it: the bag drains, so anything dissolved in the water leaves with it, and local discharge rules remain the site's responsibility. Drainage also slows as the cake builds up, so the process needs space and time rather than a single pass.
Selection Guidance
- Best For
- Sludge, sediment and dredgings where the site needs to reduce water content before haulage or disposal and has space to drain bags in batches.
- Consider Alternatives When
- The material must stay fully contained with no discharge, the site has no space for a drainage pad, or the solids are too fine for a woven fabric to retain without a treatment step.
- Must Confirm Before Quoting
- Solids content and particle size, chemistry and pH, the volume per batch, the discharge route and its local rules, drained weight for lifting, and the space available.
Test & Production Evidence
| Evidence Type | Evidence Note | Stage |
|---|---|---|
| Sample | Fabric sample and trial bag used to confirm drainage and retention with the customer's material. | Sampling |
| Inspection Record | Batch sheet recording fabric specification, seam stitch counts and bag dimensions. | Production |
Evidence Note
Fabric specification sheets, batch records and trial bag results can be shared with a named buyer on request. Discharge compliance remains the customer's responsibility.
Related Applications
Information Required for Quote
Material to be dewatered and its solids content Required
Percentage solids and whether the material is fine or gritty — both change the fabric choice.
Volume per batch and how often Required
Volume per fill and the cycle time you can accept, so the bag size can be matched to the pad.
Chemistry and pH of the material Required
Chemistry affects fabric selection and must be stated; discharge rules stay with your site.
Lifting method and drained weight Required
Loops are sized for the drained weight, so tell us how the bag is lifted out.
Discharge route for the water
Where the drained water goes, so we can flag anything that needs your own treatment step.