Septic tank emptying prices by tank size
| Tank size | Typical property | Typical Cornwall price |
|---|---|---|
| Up to 2,700 litres | 2–4 bed household | £150–£220 |
| 2,700–4,500 litres | Larger household / small holiday let | £200–£280 |
| 4,500–9,000 litres | Large property, farmhouse, multiple dwellings | £260–£400 |
| 9,000+ litres / agricultural | Farms, commercial, shared systems | Quoted individually |
Prices are indicative for a planned, routine empty with reasonable tanker access. Your matched specialist confirms a firm price before any work starts — request a free quote and you'll usually have numbers the same working day.
What moves the price up or down
- Access. The single biggest factor in Cornwall. Narrow lanes, long driveways and tanks far from the nearest hard-standing mean longer hose runs or a smaller tanker — both add time. This is why a quote for a Penwith farmhouse differs from an identical tank in a Truro suburb.
- Tank size and condition. A tank that hasn't been emptied for years has more settled sludge, which takes longer to remove properly.
- Distance to disposal. Waste goes to licensed treatment works. Jobs a long way from the operator's usual tipping point carry more transport cost.
- Urgency. Same-day and out-of-hours callouts typically start from £200+. A backed-up tank on a Saturday costs more than the same job booked two weeks ahead.
- Season. Cornwall demand peaks Easter–September (holiday season). October–March bookings get better availability and sometimes better pricing.
Cesspit emptying costs
Cesspits are sealed tanks — no soakaway, no discharge — so they fill much faster and need emptying every 4–6 weeks for a typical household. Per-visit prices start from £120, but the real number to budget is annual: £1,000–£3,000+ per year depending on size and household. If you're running a cesspit long-term, it's worth asking whether a septic tank or treatment plant conversion pays for itself — see our cesspit emptying page and installation guide.
What other septic work costs in Cornwall
| Service | Typical Cornwall price |
|---|---|
| Drain clearance (jetting) | £80–£150 |
| CCTV drain survey | £150–£250 |
| Minor repairs (pipes, baffles) | £500–£1,500 |
| Soakaway rebuild | £2,000–£5,000 |
| New septic tank installed | from £3,000 |
| Sewage treatment plant installed | £5,000–£15,000+ |
How to pay less (honestly)
- Book routine, not emergency. The cheapest empty is the one booked two weeks ahead in November. The dearest is the one begged for on an August Saturday. Annual emptying protects your soakaway too — a failed soakaway costs 10× more than a decade of emptying.
- Keep access clear. Unlock gates, move cars, and tell the operator about access quirks up front. Surprises on arrival are what turn quotes into bigger invoices.
- Ask about a regular schedule. Some operators price repeat annual customers better than one-offs — especially holiday lets that book season-long schedules.
- Don't skip years to save money. Sludge carried over into the soakaway is the main cause of system failure. Emptying is the cheap part of septic ownership; keep it that way.
Frequently asked questions
How often does a septic tank need emptying?
Most Cornwall households: every 6–12 months. A family of four on a 2,700-litre tank is typically annual. Holiday lets in peak season can need it far more often — occupancy is the driver, not the calendar.
Is the price different across Cornwall?
A little. The baseline is similar county-wide, but access-heavy areas (Penwith, the Lizard, Helford creeks) tend toward the top of the ranges above. See your local page for detail: Truro, Falmouth, Bodmin, Launceston, Liskeard, St Austell, Redruth, Penzance, Helston, St Ives, Newquay, Wadebridge and Camborne.
Does the price include disposal?
Yes — reputable quotes include transport and disposal at a licensed treatment facility. Ask for a waste transfer note if you want the paper trail; any licensed carrier can provide one.
Why do quotes vary between companies?
Distance to their tipping point, tanker size, and how busy they are. This is exactly why we exist: tell us the job once via the quote form and we match you with a licensed local specialist suited to your property, rather than you ringing round half of Cornwall.