What to expect
| Typical duration | New system 1–3 weeks · repairs 1–5 days |
|---|---|
| Cost band | Figures live in the cost index |
| Permit required | Usually — new systems and discharge arrangements |
| Seasonal constraint | Install off-season · failures cluster in August |
What your property is actually connected to
The first question on any renovation, and one many owners cannot answer. There are broadly four situations:
- Network sewerage
- Available in parts of the island. Straightforward, subject to the connection being in good condition and correctly sized for what you plan to add.
- A sealed cesspit (βόθρος)
- A holding tank emptied by tanker. Capacity and emptying frequency are the whole design. In peak season, tanker availability is itself a constraint.
- A septic arrangement with soakaway
- Treatment plus discharge to ground. Depends entirely on the ground's percolation, which in volcanic material varies enormously and is not assumable.
- Something undocumented
- Extremely common in older properties extended over decades. It goes somewhere, and nobody has traced it. Tracing it is part of any renovation survey.
The August problem
A system sized for a family occupying a house intermittently is a different system from one serving eight guests, several bathrooms and a washing machine running daily through August.
Converting a property to short-term rental multiplies both water use and wastewater load, and the failure — backing up, or a cesspit needing emptying every few days — arrives exactly when tanker services are busiest and when a room out of use costs the most.
- Capacity should be assessed against peak occupancy, not average.
- Emptying frequency and cost belong in the running-cost calculation for a rental, and they are frequently omitted.
- Access for a tanker is part of the design. On a property a tanker cannot reach, this is a fundamental constraint rather than an inconvenience.
- Grease from a busy kitchen accelerates problems considerably and warrants separate provision in food-serving properties.
Percolation in volcanic ground
Soakaway design depends on how fast the ground accepts water, and Santorini's layered deposits vary dramatically — loose pumice can be extremely permeable while a welded tuff band a metre below accepts almost nothing.
That means percolation is tested rather than assumed, and a system designed on an assumption is a system that either fails or discharges somewhere it should not. Where the ground will not accept discharge, the answer is a sealed tank and tanker emptying, which changes the running cost.
It also interacts with what is below and downhill. On a terraced hillside, discharge that finds a layer boundary can travel laterally and emerge in a neighbour's property or in a cave. That is both a nuisance and a liability.
What this trade covers
- Tracing and surveying existing drainage, including camera survey where the route is unknown.
- New drainage installations and connections to network where available.
- Cesspit and septic installation, replacement and upgrading, with capacity assessed against actual peak use.
- Percolation testing where a soakaway is proposed.
- Treatment systems where they are appropriate and permitted.
- Grease management for kitchens in commercial and rental properties.
- Blockage clearance and repair, including the recurring blockages that indicate a fall problem rather than a debris problem.
- Surface water drainage, which on a terraced property matters as much as foul. See retaining walls.
Questions people actually ask
How do I know if I am on the network or a cesspit?
Frequently you cannot tell without tracing it, and many owners are wrong about what they have. A survey establishes it definitively, which matters before you increase the load on it.
My drains keep blocking. Why?
Recurring blockages in the same place usually mean inadequate fall, a partial collapse, or a system at capacity — not user behaviour. Clearing it repeatedly treats the symptom; a camera survey finds the cause.
Do I need a bigger system for a rental?
Very likely, and it should be assessed before listing rather than after the first busy week. Peak occupancy load is several times a normal domestic load.
Do I need a permit for a new septic system?
Usually yes, and the discharge arrangement is part of the application. It is not something to install informally — an unauthorised discharge is a liability that surfaces at sale.
Can a tanker reach my property?
On stepped, vehicle-free lanes, frequently not directly, which fundamentally shapes the system design. It is one of the first things worth checking on an access-restricted property.