TopTank 2000L Horizontal Septic Tank, Polyethylene Underground

TopTank 2000L Horizontal Septic Tank

The TopTank 2000L Septic Tank provides a heavy-duty underground sewage treatment solution for residential and commercial properties. This horizontal unit utilizes high-density polyethylene to withstand constant soil pressure and chemical corrosion. It manages domestic wastewater through anaerobic decomposition before discharging effluent into a soakaway system or drainage field.

Built for the Job

Site supervisors and plumbers select this horizontal profile when excavation depth is limited or when the water table prevents deep vertical digging. The ribbed exterior provides the structural rigidity required to resist ground movement and backfill weight. This specific capacity typically supports a household of 8 to 12 people, making it a standard choice for medium-sized residential builds or remote site offices. Because the material is non-porous, it prevents groundwater contamination and resists root penetration which often compromises traditional masonry tanks.

• Primary sewage containment for residential off-grid housing.

• Waste management for temporary construction site facilities.

• Replacement of failing or cracked concrete septic systems.

Product Highlights

Rotomolded Construction

The one-piece molding process eliminates seams and joints, significantly reducing the risk of structural leaks or environmental seepage.

Corrosion Resistance

• Resists sulfuric acid and methane gases generated during decomposition.
• UV-stabilized material prevents degradation during on-site storage before burial.

Structural Ribbing

Engineered horizontal ribs distribute external soil loads evenly across the tank surface to prevent wall buckling after installation.

Technical Specifications

What’s Included

• 1 x 2000 Litre Horizontal Septic Tank Body

• 1 x Heavy-duty Inspection Manhole Cover

• Pre-installed Inlet and Outlet Grommets

On-Site & Workshop Notes

• Ensure the excavation floor is level and lined with a 100mm sand blinding layer to prevent point loading on the tank base.

• Fill the vessel with water simultaneously while backfilling with soil or stabilized sand to equalize internal and external pressure.

• Install a proper ventilation pipe to allow the escape of anaerobic gases and maintain system health.

• This underground unit is not rated for vehicular traffic; if installed under driveways, a reinforced concrete slab must be engineered to bridge the tank.