Septic tanks and treatment systems compared
Which system suits your site, in plain English.
Septic tank
A traditional septic tank separates solids from wastewater, which then drains to a percolation area. It has no moving parts and costs less, but it needs ground that drains well.
Wastewater treatment system
A packaged treatment system (brands include Tricel, BioCycle and Klargester) treats the wastewater further using air and bacteria before it reaches the ground. It suits sites where the soil is poorer, but it uses electricity and needs regular servicing.
| Septic tank | Treatment system | |
|---|---|---|
| Cost to install | Lower | Higher |
| Electricity | None | Yes (small pump or blower) |
| Servicing | Emptying every 1–3 years | Emptying plus a yearly service |
| Suits | Good draining ground | Poorer ground, tighter sites |
Which one do I need?
It depends on your site. A site assessment tells you which system will work and what the planning or grant rules allow.
Common questions
Which brand is best?
Each brand has certified models. The right one depends on your site and household size, so we recommend after a site assessment.
Does a treatment system need servicing?
Yes. Most need a yearly service as well as emptying.
Can I upgrade my septic tank to a treatment system?
Often, yes. Some systems can be added to an existing tank.
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Areas we cover
Cork City · Ballincollig · Carrigaline · Midleton · Cobh · Mallow · Fermoy · Mitchelstown · Bandon · Clonakilty · Skibbereen · Bantry · Macroom · Kanturk · Youghal · Kinsale