When you install or alter foul drainage in England, the work may fall under Building Regulations, and the practical guidance is set out in Approved Document H, Drainage and waste disposal.
For new sewage pump installations this matters because the regulations decide when a pumping installation is appropriate, how a foul water system should perform, and what an installation should be sized and built to. This page explains the points most relevant to choosing and installing a sewage pump, in plain terms. It is a guide to help you ask the right questions, not a substitute for the document itself or for advice from your local building control body.
The current version is published on gov.uk: Approved Document H, Drainage and waste disposal. Note that Approved Document H applies to England; Wales has its own published guidance.
What Approved Document H Covers
Approved Document H supports Part H of Schedule 1 to the Building Regulations 2010. It is split into sections, and the ones that impact on sewage pumping are H1 (foul water drainage), H4 (building over sewers) and H5 (separate systems of drainage). H1 sets out how foul water, meaning wastewater from toilets, bidets, appliances used to wash foul receptacles, and water used for food preparation, cooking or washing, should be carried away from a building.
Foul Drainage and the Priority Order
H1 establishes an order of priority for where foul water should drain to. The system should connect, in order of preference, to a public sewer; or where that is not reasonably practicable, to a private sewer that communicates with a public sewer; or where that is not practicable, to a septic tank with appropriate secondary treatment or another wastewater treatment system; and only where none of those is practicable, to a cesspool.
The point for a sewage pump buyer is simple: the preferred outcome is a connection to the public sewer, and a pump is the means of achieving that connection when the levels do not allow it to happen by gravity.
When a Pumping Installation Is Required
A pumping installation is appropriate where gravity drainage is not practicable, or where protection is needed against flooding caused by surcharge in the sewers downstream. That covers the most common reasons people fit a sewage pump: a basement or extension below sewer level, or a low lying site where waste cannot fall to the connection point.
For pumping installations used inside buildings, Approved Document H points to package units that conform to BS EN 12050, with the installation designed in accordance with BS EN 12056-4. Floor mounted units are noted as well suited to basements. For pumping installations outside buildings, the relevant guidance is BS EN 752-6. The lifting plant standard itself distinguishes plants for wastewater containing faecal matter (BS EN 12050-1) from those for faecal free wastewater (BS EN 12050-2), which is why it matters to choose a unit specified for sewage rather than for clean or grey water. A self-contained packaged pump station is often the way to meet this for a permanent foul installation.
Sizing: The 24-Hour Rule
Where foul water from a building is pumped, Approved Document H says the receiving chamber should be sized to hold a full day's inflow, so that waste can still be contained if the pump or power supply is disrupted. For domestic use, the minimum daily discharge is taken as 150 litres per person per day. For other building types the chamber capacity should be based on the calculated daily water demand of the building. This is why a properly specified packaged pump station is sized around the number of people it serves, not just the pump's flow rate.
Building Over or Near a Sewer
If your work is over or close to an existing sewer, H4 applies. Its provisions cover construction over or within three metres of the centreline of an existing drain or sewer. As a general guide it advises against building over a manhole or inspection chamber, keeping the length of sewer running under a building within reasonable limits without the owner's permission, and ensuring a satisfactory route remains for the sewer to be repaired or replaced. The records of public sewers are held by the sewerage provider, so check before you build.
What This Means When You Buy a Sewage Pump
In practice, the regulations point you toward a few decisions. Choose a pump or station specified for sewage, not for clean or grey water. Size the chamber around the number of people it serves, allowing for a day's inflow. Use automatic operation for an unattended foul water duty.
For help choosing a compliant pump, see our Ultimate Guide to Sewage Pumps and browse the sewage pumps collection. For a site with tricky levels, discharge routes or capacity questions, our Engineering Review Service can assess the installation, and our Pump Finder helps match a unit to your requirements.
Frequently Asked Questions
Does Approved Document H apply to my sewage pump installation? If you are installing or altering foul drainage in England, the Building Regulations apply and Approved Document H is the guidance used to demonstrate compliance. Wales has its own equivalent. Always confirm with your local building control body.
Do I have to connect to the public sewer rather than use a pump? The regulations prefer a connection to the public sewer, and a sewage pump is the means of making that connection where gravity drainage is not practicable. So in most cases the pump is what allows you to meet the priority order, not an alternative to it.
How big does the collection chamber need to be? Where foul water is pumped, the chamber should hold a full day's inflow in case of a fault, based on 150 litres per person per day for domestic use, or the calculated daily water demand for other buildings. A correctly specified packaged station accounts for this.
