After something dependable and long-lasting? Concrete septic tanks are large underground chambers made from precast concrete. They collect and hold household wastewater, allowing solids to settle and partially break down before liquid effluent is discharged into a drain field.
Pros of concrete septic tanks:
Strong and durable – often last 30–40 years with proper care
Not prone to floating in high water table areas
Handle large household wastewater volumes
Widely available and historically reliable
Cons of concrete septic tanks:
Very heavy – requires specialised installation equipment
May not meet newer environmental regulations in some areas
| Brand | WaterFlow |
| Treatment level | Primary |
| Application | Residential homes, Off-grid, tiny homes, Baches |
| Material | Concrete |
| Brand | WaterFlow |
| Treatment level | Primary |
| Application | Residential homes, Off-grid, tiny homes, Baches |
| Material | Concrete |
Looking for something lightweight and easy to install? Plastic septic tanks are durable underground containers made from high-density polyethylene (HDPE) or similar materials. They collect household wastewater, allowing solids to settle and partially break down before the liquid effluent moves on to a drain field for final treatment.
Pros of plastic septic tanks:
Lightweight – easier to transport and install without heavy machinery
Corrosion-resistant – won’t rust or rot over time
Watertight – less risk of leaks compared to some concrete tanks
Suitable for sites with limited vehicle access
Cons of plastic septic tanks:
Less resistant to crushing from heavy loads (e.g., vehicles driving over them)
Smaller capacities than some concrete options
| Type | Vermifiltration |
| Treatment level | Advanced Primary |
| Application | Off-grid, tiny homes, Baches, Residential homes |
| Material | Plastic |
| Type | Vermifiltration |
| Treatment level | Secondary |
| Application | Off-grid, tiny homes, Baches, Residential homes, Commercial, community |
| Material | Plastic |
| Type | Vermifiltration |
| Treatment level | Advanced Primary |
| Application | Residential homes, Commercial, community, Maraes & light commercial |
| Material | Concrete |
| Type | Vermifiltration |
| Treatment level | Secondary |
| Application | Commercial, community, Maraes & light commercial |
| Material | Concrete |
| Type | Vermifiltration |
| Treatment level | Advanced Primary |
| Application | Off-grid, tiny homes |
| Material | Plastic |
Your site and dispersal field have the biggest say in which system will work best for you. Let our team take a look, either on site or via aerial mapping, and we can help you find a solution that works for you.
Whether it’s upgrading a water tank or installing a new water system, we always offer bespoke solutions designed to fit your environment and lifestyle. Take a look at our recent projects to be inspired.
Discover ways to maintain your systems in between servicing and how to contact our expert service technicians.
For trade professionals, working with WaterFlow means gaining a reliable lifelong partner committed to achieving project success, and a team that values collaboration, precision, and timely execution.
Your land and disposal field call the shots, and we’re here to find the perfect wastewater match for your patch.
Not sure what fits your backyard? Let us take a look.
