Why poly is the modern default
For decades, concrete was the only option. That changed when polyethylene rotational moulding matured enough to produce one-piece septic tanks certified to AS/NZS 1546.1 — the same standard concrete is held to. Today, most new residential septic installs in Australia use poly because the certification is equivalent, the installed cost is dramatically lower, and the failure modes that limit concrete (H2S corrosion, cracking) don't apply.
Specs
- 1500L: 2,030 × 1,110 × 1,120mm, 61 kg empty, from $949
- 2500L three-chamber: 2,750 × 1,210 × 1,180mm, ~110 kg empty
- Wall thickness: ~5.3mm certified
- Material: UV-stabilised polyethylene, AS/NZS 1546.1
- Warranty: Extended manufacturer warranty; 30+ year design life
Where we ship
We service all of NSW, QLD and VIC, with pickup preferred where practical and delivery available statewide. Lead time is typically 3–10 working days from order.
Frequently asked questions
Are poly septic tanks legal in Australia?
Yes. Polyethylene septic tanks certified to AS/NZS 1546.1 are accepted by every Australian council. The certification is identical to that required for concrete tanks.
How long do poly septic tanks last?
30+ years in standard Australian soil conditions. Polyethylene is inert and immune to the H2S corrosion that limits concrete tank lifespan.
Are poly tanks cheaper than concrete?
Significantly — typically 30–50% cheaper all-in. Most of the saving comes from logistics: poly delivers on a ute, concrete needs a HIAB truck and crane.