WAT/Specific/TBT-WAT-025

Pumping and Overpumping

Water Safety › Specific › Pumping and Overpumping

Presenter		Project
Location		Date

Pumping and overpumping involves managing water flows on construction and wastewater treatment sites.
Overpumping maintains sewage treatment during shutdowns by bypassing flows around offline assets.
Failure of overpumping systems can cause raw sewage to overflow into watercourses and public areas.
The Water Industry Act 1991 makes it a criminal offence to discharge polluting matter into controlled waters.
Pumps used for overpumping must be maintained, tested, and have standby backup systems available.
Hose connections, couplings, and pipework must be rated for the pressures and flows being handled.
Dewatering excavations requires consent if discharge enters a watercourse or public sewer system.
Workers near pumping operations face slip, trip, noise, vibration, and manual handling hazards.
Pump failures during overpumping are emergency situations requiring immediate escalation to the client.
All pumping operations must have a written procedure covering normal operation and emergency response.

Prevent pollution	A pump failure during overpumping can release thousands of litres of raw sewage into the environment within minutes.
Regulatory prosecution	The Environment Agency prosecutes sewage pollution incidents with unlimited fines — contractors share liability.
Client relationship	Causing a pollution incident on a client's operational site damages the working relationship and future opportunities.

Don't

Check all pump connections, hoses, and couplings before starting any pumping operation.
Ensure standby pumps are primed, tested, and ready for immediate changeover if needed.
Monitor pump performance continuously and record flow rates and pressures at set intervals.
Follow the written overpumping procedure and escalation plan for the specific site.
Obtain discharge consent before pumping any water into a watercourse or public sewer.
Use sediment settlement and filtration before discharging site water to any receiving body.
Secure all hoses and connections to prevent burst joints under pressure during operation.
Brief all operatives on the emergency response procedure for pump failure scenarios.
Maintain fuel supplies for diesel pumps to prevent generators running dry mid-operation.
Report any unusual pump noises, vibration, or drop in performance immediately.

DON'T leave pumping operations unattended without continuous monitoring in place.
DON'T discharge pumped water directly into watercourses without consent and treatment.
DON'T use hoses or fittings that are not rated for the system operating pressure.
DON'T allow sewage overpumping to operate without a tested standby pump available.
DON'T ignore a pump alarm or warning light — investigate and respond immediately.
DON'T walk over or drive vehicles across pumping hoses laid on the ground surface.
DON'T attempt to repair hose connections or couplings while the system is pressurised.
DON'T pump contaminated groundwater without testing and appropriate disposal arrangements.
DON'T assume overpumping is low risk — a failure has immediate regulatory consequences.
DON'T delay reporting a pump failure to the client — every minute increases pollution risk.

See also: Silt and Sediment Control | Pollution Incident Reporting

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