If your home is off the mains sewer — as many are in the villages around Bath — septic tank emptying is a cost you budget for roughly once a year. Yet almost no local firm publishes a price, because the honest figure depends heavily on your tank and your property. This guide explains exactly what moves the price, how to get a fair fixed quote, and covers the rules sellers of off-mains properties need to know.
Why no one can honestly quote a flat price
Septic and cesspit emptying is quoted per job, not off a price list, because too many variables move the figure — tank size, how full it is, tanker access, and whether you have a septic tank or a cesspit all change the cost considerably. Any firm publishing a single flat price for every property in Somerset and North East Somerset is glossing over that. A reputable operator asks about your property before quoting, confirms the price in writing before booking the tanker, and charges no call-out fee.
What changes the price
Four things move the number more than anything else:
- Tank size and how full it is — more litres means more time and more disposal cost
- Tanker access — a tank set well back from the road, or down a narrow village lane, may need long hose runs
- Distance to a licensed disposal site — remote properties can carry a higher haulage element
- Septic tank versus cesspit — which brings us to the single biggest cost factor
Septic tank versus cesspit — why it matters for cost
A septic tank separates solids from liquid. The liquid soaks away through a drainage field, and only the settled sludge needs pumping out — so an average household needs emptying roughly once a year.
A cesspit (or cesspool) is a sealed holding tank with no outflow. Everything stays in it until it is emptied, so it fills far faster — sometimes every few weeks for a busy household — and each empty removes the full volume. Over a year, a cesspit almost always costs considerably more to run than a septic tank. Knowing which you have is the first step to budgeting accurately.
The 2020 rules every seller should know
If you are selling an off-mains property, there is one piece of regulation you cannot ignore. Under the general binding rules that came into force in January 2020, a septic tank that discharges directly to a watercourse — a ditch, stream or river — must be replaced or upgraded, for example to a sewage treatment plant or a compliant drainage field.
Buyers' solicitors routinely ask how a property's drainage complies, so this is best resolved early rather than at the last minute. Having the tank emptied and inspected, and keeping the waste transfer note from a registered waste carrier, all helps a sale go smoothly.
How often should you empty it?
As a rule of thumb, an average household septic tank should be emptied about once a year. Adjust for tank size and occupancy — a large family on a small tank will need it sooner. The warning signs that a tank is overdue are slow or gurgling drains indoors, wet or unusually green ground over the tank or soakaway, and sewage smells after heavy use or rain.
One important point: if a freshly emptied tank fills again within weeks, the problem is usually the soakaway, not the tank. A failing drainage field cannot take the liquid away, so no amount of emptying fixes it. A good operator checks the chambers and tells you honestly whether it is the tank or the soakaway that needs attention.
Booking without the hard sell
Bath Plumbers arranges septic tank and cesspit emptying for off-mains homes across the villages south of Bath, including Wellow, Timsbury, Peasedown St John, Norton St Philip and Leigh upon Mendip. Everything is booked through the online form with the price confirmed first, waste taken away by a registered carrier, and your waste transfer note provided. Request a quote online — no call-out fee.