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Sewer connection

If you're building a house extension, a new home or a commercial building, or simply making changes to your existing drainage, you may need a new wastewater connection to our sewer network.

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What is a wastewater connection, and when do I need one?

A new wastewater connection is a connection to the public sewer main, either directly or indirectly, through private drains. You'll need to apply for both of these.

It's illegal under Section 109 of the Water Industry Act 1991 to make a connection to the public sewer without our approval.

The Wastewater Connection application is only for approving the means and mode of construction. In other words, the way your drainage will physically connect to our network. So, it’s important that you also check that there is capacity to accommodate your proposed flows. If you are building a large development or a commercial property, you can assess available capacity with a pre-planning enquiry wastewater application.

Apply with GetConnected

In our GetConnected portal you can submit applications, track, pay for, and manage your projects.

Apply now

You may need a new wastewater connection if you're:

  • Undertaking building works
    Building a new property, building a house extension with a new kitchen, bathroom, or toilet
  • Converting a property
    Changing the use of the property (i.e., from a residential to a commercial property)
  • Increasing the number of properties
    Increasing the number of properties, including splitting the plot in two
  • Adding or changing the type of flow
    Adding or changing the type of flow (i.e., connecting foul sewerage that was previously discharged to a septic tank)
  • Connecting to the private sewer
    Connecting to the private sewer and adding an additional discharge load or splitting the property into additional units

You won't need to apply if:

  • You're connecting to your private sewer
    Providing there are no additional flows involved
  • You're not splitting the property
    In this case, you can make the connection yourself using a certified contractor without a sewer connection application. Your local building control officer will need to monitor and sign this off.

Applying to connect to a sewer

Within our network, we have several different types of sewers. The most common type of wastewater connection is that to the foul sewer. If you need to dispose of wastewater from the kitchen, baths, toilets, showers, washing machines, etc., you'll need to connect to the foul sewer. 

You can find out where the public sewers are in your area using sewer and water maps. If there are no records of the sewers on the map, you'll need to carry out a drainage survey to check what sewers are available to you. 
There are many contractors that can help with this, such as InSewer and Dyno (Isle of White area). Once you have identified the sewer, you'll need to discuss with your contractor the best way to connect.

You can submit one application form for multiple connections. However, there'll be a separate fee for each sewer connection approval you need. 
If you need separate foul and surface water connections, you will need to select the option “Combined sewer connection” and specify in the comments how many of each type you need.

Foul sewer connection Managing surface water Discharging surface water The application process
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Foul sewer connection request

When applying, please select the option “Foul sewer” and have the following information ready:

  • A site location plan.
  • A drainage layout plan showing the location of sewers and manholes on your site and up to the connection point (Sewer Connections Detailed Drainage Examples).
  • A copy of your planning consent (if applicable).
  • An application fee of £335.00 (inc 20% VAT) per connection. If you need a wastewater connection and a new manhole chamber, then your fee will be £413.00 (inc 20% VAT).

If you're connecting to the sewers five metres deep or 300mm and above, your contractor should have a Health and Safety policy. You will need to submit this and a site-specific risk assessment and method statement (RAMS) with your application.

1

Apply online

You can apply to connect to the foul sewer and pay the application fee through our GetConnected portal.

2

We'll send our approval

We’ll do a technical review of your application and send you our decision or request further information within seven days.

Please hold off starting any work until you receive our written approval. This is because we may ask for changes before granting approval, which may result in additional costs to your project. After we grant the approval, it will be valid for two years.

3

Carry out your work

Once you have received our approval and have obtained any necessary third-party consent, you will now need to arrange with your contractor to carry out your work.

Please share our technical guidance document with your contractor, to ensure that all pipework is compliant with our standards.

4

Book your site inspection

Contact us at least two working days before you start your connection to book an inspection. If the connection has not met our requirements, we’ll let you know what you will need to do to get approval. After this, you'll need to arrange a new inspection.

We have prepared a site inspection checklist so that inspection of your sewer connection can be passed first time.

5

We'll send your completion letter

Once we're happy that your connection complies with our requirements, we'll send you a completion letter within seven working days.

Your wastewater connection application is now complete.

Managing surface water

Surface water carries rainwater, which runs off roofs and paved areas. Where possible, it's good environmental practice for the surface water to be reused or returned to the environment on or near your site.

We recommend the following options, in preferential order, for managing your surface water runoff. If you've explored these options and none are achievable, only then will we consider discharging surface water into the foul sewer.

1

Water reuse

Explore installing rain harvesting solutions. These can reduce the demand on the water supply and the quantity of run-off discharged to the sewer.

2

Infiltration into local ground

Drain your surface water via soakaways or infiltration basins. You can request these in your planning application. Please note that you will need an approval from building control at your local council to install these assets.

3

Drain surface water into a watercourse

If there is a stream of water such as a river, canal, or the channel, please drain the surface water that way. You may need to obtain a consent to discharge from the Environmental Agency or local council authority/drainage board.

4

Council or privately owned drainage systems

Discharge to a watercourse or other surface water body. These systems may be owned privately or by your local council authority and can include drainage such as a Culverted Watercourse, District Council Surface water or Private Network. You'll need to obtain separate approval from the Environment Agency or local council authority for these discharges.

5

Discharge into Southern Water surface water sewer

Discharge to our surface water sewer. You can check whether we have a surface water sewer in the local vicinity by obtaining a map of our assets for the area.

6

Discharge into Southern Water combined sewer

Connect to a combined sewer which drains foul and surface water if one is in the local vicinity. This must not increase the risk of a combined Sewer Overflow becoming overwhelmed in wet weather. You'll also need to check the available capacity at your point of connection before you can make a combined sewer connection. You can do this by submitting a pre-planning enquiry wastewater application.

Discharging surface water

Section 106 of the Water Industry Act does not permit the discharging of surface water into a foul-only sewer unless there are no other provisions available.

Discharging surface water into a foul-only sewer can increase the risk of that sewer becoming overwhelmed in wet weather. This can cause issues such as flooding and restricted use of facilities for customers. As such we will only permit it as the last available option.

Any surface water flows proposed for discharge into a foul-only sewer must be controlled and mitigated at the source. This is to ensure that the flow does not cause a reduction in the level of service provided to our customers.

If you need to discharge surface water into a foul-only sewer, you will need to provide the following evidence to support your application:

1

A capacity check report

You can get a capacity check report for the foul sewer you propose to discharge to by submitting a pre-planning enquiry wastewater application.

2

A percolation test

You will need to provide a percolation test that confirms you cannot discharge your surface water into the local ground.

3

Authority confirmation

Local Lead Flood Authority and Local Planning Authority will need to confirm that it is not reasonably practicable for you to discharge surface water to the ground via infiltration or to a watercourse for the whole or part of the site.

4

Written confirmation

We'll need written confirmation from you that there are no surface water sewers, drainage systems or watercourses that can receive the discharged surface water.

The application process

Below is a step-by-step guide to the surface water connection application.

When making your application, please select “Surface Water Sewer.” Or, select “Combined Sewer” if you need to make several connections to both foul and surface water sewers. Please also have the following information ready:

  • Your capacity check report.
  • A site location plan.
  • A drainage layout plan showing the location of sewers and manholes on your site and up to the connection point (Sewer Connections Detailed Drainage Examples).
  • A copy of your planning consent decision letter (if applicable).
  • Percolation test results (a test to determine the water absorption rate of soil).
  • Geographical survey showing no viable watercourse available.
  • An application fee of £335.00 (inc 20% VAT) per connection. If you need a wastewater connection and a new manhole chamber, then your fee will be £413.00 (inc 20% VAT).

If you're connecting to the sewers five metres deep or 300mm and above, your contractor should have a Health and Safety policy. You'll need to submit this and a site-specific risk assessment and method statement (RAMS) with your application.

1

Complete a capacity checks report

To complete your capacity checks, you'll need to apply for a wastewater pre-planning enquiry. This will help us identify any possible capacity constraints that may be associated with servicing your property/development site.

Please complete the wastewater pre-planning enquiry application form and email it to developer services.

2

Apply online

Fill in the online form using our GetConnected portal and pay your application fee. 

If we need any further information about your proposal, we'll notify you through the GetConnected dashboard.

3

We'll send our approval

If we have everything we need, we’ll complete a technical review of your application and send you our decision within the next seven days.

We may ask for an amendment and changes to your proposal before we grant the approval. So, please do not start any work until you receive our written approval as it may result in additional costs for you.

Under Section 109 of the Water Industry Act 1991, it's illegal to make a connection to the public sewer without our approval.

4

Carry out your work

Once you've received our approval, you'll need to obtain any necessary third-party consent and arrange with your contractor to carry out your work.

Please make sure to share our technical guidance document with your contractor, to ensure that all pipework is compliant with our standards.

5

Book a site inspection

Please contact us at least two working days before you start your connection to request a site inspection. This will ensure that your connection has been carried out correctly. If the connection has not met our requirements, we’ll let you know what you will need to do to get an approval. After you've made the requested changes, you'll need to arrange a new inspection.

We have prepared a site inspection checklist so that inspection of your sewer connection can be passed first time.

6

We'll send a completion letter

Once we're happy that your connection to the public sewer complies with our requirements, we'll send you a completion letter within seven working days. Your wastewater connection application is now complete.

Guides & Documents

Sewer Connection Guidance

Download

Wastewater pre-planning enquiry guidance notes

Download

Site inspection checklist

Download

Detailed Drainage Layout Examples

Download

Site plan example

Download

Standoff

Download

Easements

Download

Site Inspection Checklist

Download

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