The quick answer
When a pond, dam or lagoon fills with settled sludge it loses the volume it was designed to hold — capacity drops, odour and algae flare up, and treatment or process performance suffers. Apex Envirocare desludges ponds across Western Australia and Australia-wide without draining them or taking them out of service. It uses MudCat remote-controlled electric auger dredges, IMS diesel-powered manned dredges and the GeoPro microdredger — all fitted with low-turbidity auger heads — to cut an even bottom profile and pump the sludge as a slurry to geotextile tubes, a filter press or a settling basin for dewatering. Sediment disposal, including contaminated and acid-sulfate material, is handled with methods aligned to WA DWER requirements.
Why WA ponds silt up — and why draining is the wrong first move
Every settling pond, tailings dam, wastewater lagoon or stormwater basin is built around a design volume. Fine solids drop out of suspension, consolidate on the floor, and over months or years that sludge blanket eats into the pond's working capacity. The symptoms are familiar: the pond no longer holds its rated volume, retention times shorten, discharge quality drifts, and stagnant organic sludge drives odour and algal blooms.
The instinct is often to drain the pond and dig it out with an excavator. On most live sites that's expensive, slow and disruptive — you have to take the asset offline, manage the displaced water, and expose a soft, unstable floor that plant can't safely work. On lined lagoons, tracked machinery risks tearing the liner.
In-situ dredging solves the same problem while the pond stays full and in service. Apex Envirocare floats a dredge on the pond, removes the sludge as a pumpable slurry, and dewaters the spoil separately — no drain-down, no offline period, no heavy plant on a fragile floor.
The Apex Envirocare method
Auger dredging that cuts an even floor
Apex Envirocare's dredges use auger cutter heads rather than open suction. The rotating auger shears the sludge and feeds it evenly to a centrally mounted slurry pump, which is why the dredge restores a clean, level bottom profile instead of leaving craters or short-circuit channels. The auger housing and low-turbidity design keep fines from clouding the water column — important where the pond stays in service and where discharge water quality matters.
Three dredge types, matched to the pond
- MudCat remote-controlled electric auger dredges (20E–100E): unmanned, operated from the bank by remote control. Standard dig depth is roughly 4.3–5.2 m, with a deep-dig option to about 9 m, and production ranging from around 28 to 200 m³/hr at 30% solids depending on the unit. Because they're electric and unmanned, they're the go-to for mine sites — mining safety regulations prohibit crew aboard a dredge on the water, so the MudCat runs with no operator on board.
- IMS diesel-powered manned auger dredges: operator-aboard machines suited to larger or open water bodies where a manned dredge is permitted.
- GeoPro microdredger: trailerable, with about a 4 m dig, ideal for small-to-medium ponds, farm dams, bore-field ponds and tight-access sites.
Apex Envirocare is the exclusive Australian distributor of MudCat and IMS dredges, so it both supplies the equipment and self-performs the works with its own crews and plant — the same fleet, operators and technical backing on every job.
Powering remote and mine-site work
Apex Envirocare routinely mobilises to remote and mine sites nationally. Where mains power isn't available, the electric dredges run off generators — so a remote WA tailings pond or a bore-field lagoon is no barrier to an electric, unmanned MudCat setup.
Dewatering the spoil
Dredging delivers a slurry, not dry spoil, so every job needs a dewatering and discharge destination. Apex Envirocare pumps the slurry to:
- Geotextile dewatering tubes/bags — the solids are captured and consolidate inside the fabric while filtrate drains off;
- A filter press — for a drier, more manageable cake; or
- A settling basin — where site layout allows.
Pump distance and lift to the discharge point are checked as part of the design, because they govern which pump and dredge configuration will actually deliver the slurry where it needs to go.
Lined lagoons: dredging without damaging the liner
Many WA treatment-plant and brine lagoons are poly (HDPE) or concrete lined. Running a bare cutter across a liner is a fast way to a costly repair. Apex Envirocare offers a liner-protection setup that lets the auger work close to a poly or concrete floor without cutting into it — so lined sewage lagoons, phosphorus-removal cells and HDPE brine basins can be desludged in place.
Environmental handling and DWER-aligned disposal
Pond sludge is rarely inert. Tailings, process-water and wastewater sediments can be contaminated, and acid-sulfate material needs careful management. Apex Envirocare's focus is on cost-effective, environmentally sensitive alternatives to traditional dig-and-cart methods, and it handles contaminated and acid-sulfate sediment with approved disposal, using methods aligned to WA DWER (Department of Water and Environmental Regulation) requirements. Dewatered spoil is characterised and directed to the disposal pathway the project's environmental approvals require.
Where Apex Envirocare desludges ponds
Apex Envirocare is headquartered in Western Australia and operates Australia-wide. Typical WA and national applications include:
Water and wastewater
Drinking-water, stormwater and municipal sewage treatment ponds; sludge and phosphorus-removal lagoons; and concrete- and poly-lined treatment-plant cells. Apex Envirocare works with water authorities and utilities including Water Corporation and SA Water.
Mining and resources
Metal, coal and bauxite tailings ponds; copper and lithium process ponds; sand, gravel and silica wash-plant ponds; coal-fines settling; and lined HDPE brine basins. Apex Envirocare has desludged tailings, process-water and wash-plant ponds for clients including BHP, Rio Tinto, Newcrest and Tropicana Gold Mine.
Agriculture, food processing, power and urban
Farm dams, bore-field ponds, food-processing lagoons, power-generation ponds and urban lakes — including work for energy and industrial clients such as Synergy and councils such as the City of Armadale.
What auger dredging is not for
Straight talk saves surprises. Auger dredging is the right tool for settled sludge and sediment — not for everything:
- Coarse rock, rubble or large debris — the auger and slurry pump pass solids only up to about 75–100 mm. Hard or compacted material needs assessment first.
- Deliberately uneven or pinpoint excavation — the auger cuts an even bottom, not narrow trenches or craters.
- Water deeper than the dredge's reach without a deep-dig/extension setup (standard ~4.3 m, up to ~5.2 m on larger units, ~9 m with the deep-dig option).
- Jobs with no dewatering or discharge destination — because the dredge delivers a slurry, the spoil has to go somewhere.
On these edge cases Apex Envirocare will assess the site rather than force the method — which is what you'd want from a self-performing contractor backing its own recommendation.
Getting a pond desludging job scoped
The key inputs are pond dimensions and water depth, sludge depth and type (organic, tailings, process fines, brine solids), whether the pond is lined, the target design volume to recover, power availability, and where dewatered spoil can be placed or disposed. With those, Apex Envirocare can match the dredge (MudCat, IMS or GeoPro), size the dewatering, and plan disposal to meet the project's environmental requirements — keeping the pond in service throughout.
