Emergency Septic Tank Emptying: What to Do if It Is Overflowing
Immediate, sensible steps when a septic tank, cesspit or treatment plant is close to capacity, backing up or overflowing.
If wastewater is backing up, escaping outside or a cesspit is close to full, reduce water use and arrange urgent professional help. Do not enter, open or attempt to pump the tank yourself.
Reduce the load on the system
Stop non-essential water use: avoid baths, showers, washing machines and dishwashers until you understand the situation. Tell other people at the property what is happening.
Keep people and animals away
Wastewater can carry harmful organisms. Keep children and pets away from any standing water or open covers, and avoid driving over the tank or saturated ground.
Give the operator clear information
- Your full postcode and whether the property is rural or has restricted access.
- Whether it is a septic tank, cesspit or treatment plant — or that you are unsure.
- What is happening: full tank, indoor backup, alarm, smell or outdoor overflow.
- Whether a tanker can park close by and the likely hose distance.
After the immediate empty
Emptying removes the stored waste, but it may not solve a failed drainage field, damaged pipework or treatment-plant fault. If smells, pooling or poor drainage persist, ask about further investigation.