Off-mains drainage, sorted
Septic tanks & off-mains drainage,
explained without the jargon
Buying, selling or living with a septic tank in the UK? Get clear, independent guidance on the rules, the costs and your options — then find a vetted local specialist to do the work.
Free to use. We may earn a referral fee if you go on to use a specialist we introduce — it never adds to your cost.
Independent
We don't sell drainage, surveys or legal advice. We point you to vetted specialists and explain things plainly.
Plain English
No jargon and no scare tactics — just what the rules actually mean for buying, selling or owning.
Local specialists
We connect you with drainage firms that cover your area for emptying, surveys, repairs and replacement.
How it works
Three steps from question to a vetted specialist who can help.
Tell us about your property
Your postcode, situation and system type — takes a minute.
We match a vetted specialist
We find a drainage firm that covers your area and your job.
They get in touch
The specialist contacts you directly to help, quote or survey.
Start with a guide
The questions homeowners ask us most.
Do I need to upgrade my septic tank?
You usually need to upgrade your septic tank if it discharges directly to a stream, river or ditch — that is no longer allowed. The common fix is a sewage treatment plant or a new drainage field. A tank discharging to ground that meets the general binding rules generally does not need upgrading.
Selling a house with a septic tank: what you need to know
When you sell a home with a septic tank in England you must tell the buyer in writing that the property has one and how it is maintained. If the tank discharges to a stream, river or ditch, the rules require it to be upgraded or replaced — usually as part of the sale.
Septic tank replacement cost in 2026 (UK guide)
Replacing a septic tank in the UK typically costs around £4,000 to £12,000 in 2026, depending on whether you fit a sewage treatment plant or a new drainage field, ground conditions, access and pumping needs. Emptying is usually £200–£300 a visit, and a survey £150–£500.
Septic tank rules in 2026: the general binding rules explained
In England, septic tanks fall under the Environment Agency's general binding rules. A septic tank may discharge to ground via a drainage field, but since 1 January 2020 it must not discharge to a stream, river or ditch. Discharging to a watercourse needs a sewage treatment plant; some sites need a permit.
Septic tank vs treatment plant vs cesspit: what's the difference?
A septic tank settles waste and discharges liquid to ground via a drainage field. A sewage treatment plant cleans the effluent enough to discharge to a watercourse. A cesspit (or cesspool) just stores everything, with no discharge, and must be emptied regularly — making it the most expensive to run.
Get your septic tank sorted
Tell us your postcode and situation. We'll connect you with a vetted local drainage specialist — free, with no obligation.