When you need a survey
- Buying a property that is not on mains drainage. You take on the system and the legal duties that come with it.
- Selling. A survey done in advance answers the buyer's questions before they delay the sale.
- A problem you cannot explain. Slow drains, smells, wet ground or sewage backing up.
- You do not know what you have. Many owners are unsure whether they have a septic tank, a cesspit or a treatment plant, or where it discharges.
What a survey checks
The scope varies between firms, so ask for it in writing. A full survey of an off-mains system normally covers:
- What type of system it is, its size, and where it sits on the plot.
- The condition of the tank: walls, base, covers, and the inlet and outlet pipes inside it.
- A camera inspection of the drains running to and from the tank.
- Where the system discharges: a drainage field in the ground, or a ditch, stream or river.
- Whether the drainage field is working, or is waterlogged or blocked.
- For a treatment plant, whether the blower, motor and alarm work.
- Whether the system meets the rules that apply to it.
- A written report with photographs, and the work needed if any.
The rules a survey checks against
In England, a septic tank or small sewage treatment plant must meet the general binding rules, or have an environmental permit. The rule that most often affects a sale is that a septic tank must not discharge directly to a watercourse. The government's guide to septic tanks and sewage treatment plants lists what an owner must do. The rules are different in Wales, Scotland and Northern Ireland, where systems are registered with or consented by the environmental regulator.
Our guide to buying a house with a septic tank explains what to ask the seller, and septic tank regulations covers the rules in more detail.
How to get a quote
Use the form at the top of the page. Tell us whether you are buying, selling or already own the property, and your deadline if you have one. We pass your request to firms that survey off-mains drainage in your area. Surveying is specialist work and not every emptying firm offers it, so we match the request to the work.