Sewer connection

If your new bathroom or kitchen needs a new connection into a public sewer or you’re changing the flow that discharges into it, you’ll need our approval first.  If you are connecting to a private sewer and adding extra flow or you’re splitting the property into additional units, you will also need to apply for a sewer connection (Section 106).  

You will not need to apply, if you're connecting to your private sewer and there are no additional flows or you're not splitting the property into additional units. You can make this connection yourself using certified contractor. This will need to be monitored/signed off by your local building control officer. 

As a property owner, you’re usually responsible for drains within your property boundary, as long as they’re not shared with neighbours. Private cesspits, septic tanks, and their pipework are also your responsibility, as are private pumping stations that serve only your property. For more details, see Water UK’s guide on sewer transfer. 

You can connect directly to a public sewer or indirectly through a private drain that leads to one of our sewers. If your pipe needs to cross someone else’s land, like a neighbour’s property, you’ll need their permission first. 

You’ll need qualified contractor to carry out the connection work. Our sewer connection application only approves that the connection meets our standards – it doesn’t cover the actual installation. Your contractor will handle the physical connection to the sewer main. 

A foul sewer takes used water from your home — like water from toilets, sinks, baths, showers, washing machines and dishwashers — to a treatment works. 

A surface water sewer carries clean rainwater straight to a local river or stream. Only rainwater from roofs or land around your property should go into a surface water sewer. All other wastewater must go into a foul sewer. 

So we can access connection to the surface water sewer or to a combined sewer, you must show that you’ve explored all alternatives. 

The Building Regulations (Part H3) set out the order you need to follow and what’s required for compliance.

If every other option has been ruled out and your evidence shows the only practical solution is to discharge surface water into a surface water sewer or combined sewer, you’ll need to ask for a surface water connection as part of your application. You must include detailed proof explaining why this is the only option.

Adding surface water to a combined sewer can increase the risk of flooding during heavy rain, so this is only allowed as a last resort. Any approved connection must include measures to slow the flow and store water at the source, helping protect the network from overload.

Important: We never allow surface water to be connected to a foul-only sewer under any circumstances. 

If your sewer connection has been approved, it’s valid for two years. You’ll need to apply again if: 

• your approval has expired after two years.
• you change the applicant or contractor doing the work.

In this case, we’re approving the new connection to the public sewer — not the physical work. We also need an application, so we have details of the connected properties for billing. If you don’t own the private drain or sewer, you’ll need permission from the owner before you apply to us. 

No, our policy — along with Building Regulations 2010 (Approved Document H) and the Water Industry Act 1991 — requires that foul water and surface water drain to their own separate sewers where these are provided. 

If there’s no surface water sewer nearby, you should look at other options – such as draining water into the ground using soakaways or discharging to a local watercourse.

No, land drainage and highway drainage must not be discharged into the public sewer. 

• Land drainage: This should be managed on site or through other options, such as soakaways or discharging to a watercourse.
• Highway drainage: Any surface water connections to highway drains need approval from the relevant highway authority.  

A direct connection means linking straight to a public sewer. An indirect connection is when you connect to a private drain or sewer that then flows into a public sewer. 

A private drain is an existing pipe that serves only one property and sits within the property boundary. 

An infrastructure charge applies to all properties connecting to the public sewer, or to a sewer or drain that eventually flows into the public sewer. This charge is in addition to your application fees. 

Infrastructure charges still apply if you connect via a private sewer, as long as it ultimately discharges into the public system. These costs don’t cover laying the drain from your property or making the physical connection — you’ll need to arrange that with a qualified contractor. You can find out more in our connection charging arrangements.