Is my septic tank failing?
Tick what you're noticing. We'll point you to the most likely cause and the cheapest sensible first step, so you don't pay for a new tank when it only needed emptying.
Most likely cause
Tick at least one thing you're noticing and your result appears here.
Stay safe. Lifting a lid to look is fine. Never lean into, climb into or put your head inside a tank: the gases can kill within minutes. Keep lids secured and children well away.
Tank or drainage field?
People say "the septic tank's failed" when it's often the drainage field: the network of perforated pipes in gravel that lets the liquid soak away. Fats, wipes and solids that escape an overfull tank gradually clog the soil, and the water has nowhere to go.
The simplest test costs a couple of hundred pounds: have the tank emptied. If the symptoms disappear and stay away, the tank was just full. If they're back within weeks, the field is struggling, and that's a bigger job, so get a drainage survey before anyone quotes for a new tank.
Stop it happening again
- Empty it at least once a year, or as often as the maker advises
- Wipes, nappies and sanitary products go in the bin, never the toilet
- Pour fat and cooking oil into a jar, not the sink
- Go easy on bleach and drain cleaners: they kill the bacteria the tank runs on
- Spread out washing machine loads instead of doing five in a day
- Keep cars, sheds and tree roots off the drainage field