Below-Ground Pump Stations & Tanks

A packaged pump station is a sealed below-ground chamber that collects water or effluent and pumps it up to the sewer, drain or discharge point wherever gravity will not do the job. It arrives as a complete unit: the chamber, the pump or pumps, pipework, controls and a high-level alarm. For foul water they conform to BS EN 12050 and are designed in line with BS EN 12056-4, as referenced in the Building Regulations.

The right size depends on how many people or how much water the system serves, and on the depth of your inlet and outlet. Rather than list dozens of fixed products, we size the chamber to your duty from a defined range and pair it with the right pump. For ready-to-ship stations, browse our stocked packaged pump stations.

One thing to be clear about: a quote from this page is a supply price for a specified chamber and pump, built to the size you need. It is not a drainage design. If you need the scheme itself designed and approved, that is our Engineering Review service, covered below.

Where foul drainage cannot reach the sewer by gravity, a foul pump station collects it and lifts it up to the main. Foul water is the one application with a clear Building Regulations sizing rule, so the calculator above sizes it for you: it holds a full 24 hours of inflow at 150 litres per person per day, then rounds up to the next standard chamber. The detail is set out in the Building Regulations section below.

Rainwater and run-off from roofs, drives and yards, pumped on where it cannot drain or soak away naturally. Surface water cannot be sized from a single figure. It has to be worked out as part of a surface water drainage design, balancing the discharge rate you are allowed, attenuation storage and SuDS requirements. That is a design exercise, not an off-the-shelf spec, so surface water schemes go through our Engineering Review. Tell us about the site and we will point you the right way.

Basements, lift pits, car parks and below-ground rooms need any water that collects to be pumped out. A sealed chamber with a reliable pump and a high-level alarm keeps the space dry. Sizing follows the expected rate of water ingress and the headroom available on site, so send us the detail and we will recommend a chamber.

A below-ground tank stores roof water for re-use on the garden, inside the building or across a farm. This page sizes the tank itself. For the pump that empties it and turns a full tank into usable water, see our rainwater harvesting pumps guide.

Approved Document H of the Building Regulations, which covers drainage and waste disposal, is clear on foul pumping. Where foul water has to be pumped because it cannot reach the sewer by gravity, the receiving chamber must be sized to hold a full 24 hours of inflow, so nothing backs up if the power or the pump fails. For domestic use the daily flow is taken as 150 litres per person per day. A building serving 12 people therefore needs 12 times 150, which is 1800 litres of storage, and we supply the next chamber size up. For non-domestic buildings the figure is based on the calculated daily water demand instead, and where only part of the flow is pumped the storage is worked out pro-rata. The calculator above applies this rule and rounds up to the next real chamber.

The same guidance sets the standards the equipment must meet. Packaged pumping installations for use inside buildings should conform to BS EN 12050 and be designed in line with BS EN 12056-4. For installations outside buildings, BS EN 752 applies. Every foul station we supply is built around equipment that meets these standards, with the chamber, pump, pipework, non-return valve, controls and high-level alarm supplied as one unit. A pumping installation is needed wherever gravity drainage is impractical, or where protection is required against flooding from a surcharged downstream sewer.

It is worth being clear: the 24-hour, 150 litre rule is a foul water rule. It does not set the size for surface water, basement dewatering or rainwater harvesting. Surface water in particular has to be designed as part of a wider surface water drainage scheme, balancing the permitted discharge rate, attenuation and SuDS, which is a design exercise rather than a fixed spec. If your project is surface water, or you need the whole scheme designed, sized and taken through planning, that is the job of our Engineering Review service and our sister company FPS Environmental.