This agreement allows us to adopt and maintain the sewer once it has been built to the required standards.

You may need a sewer adoption agreement if:

• The new sewer is located outside your property boundary.
• The sewer will serve more than one property.
• You're building a lateral drain that will connect to our public sewer network.

Before you apply

We recommend reading our guidance notes before starting your application:

• Single property developments – view guidance notes here.
• Multiple property developments – view guidance notes here.

Once you're happy that your proposed sewer meets our requirements, you can complete the application form and tell us more about your development. This is sometimes referred to as a Section 104 (S104) application.

Our team will review your proposal and be on hand to provide advice and support throughout the process.

How much does it cost?

The cost of a sewer adoption agreement includes:

• A technical vetting and inspection fee.
• A legal fee to prepare the adoption agreement.

These charges vary depending on the size and complexity of the development and are only payable once we've reviewed and accepted your proposed design.

Inspection fees

Developments without an adoptable pumping station

Developments with an adoptable pumping station

Legal fees

Legal fees depend on the type of agreement required and any land registration work that may be needed.

As an example, a lateral drain agreement with no associated Deed of Grant of Easement starts from £217.14.

Surety or bond

As part of the adoption agreement, a refundable surety or bond will be required. This provides assurance that the works will be completed to the required standard.

The bond will be returned once the works have been completed successfully and the defects liability period has ended.

For full details of our charges, please view our Schedule of Charges.

Things to be aware of

• New private sewers that connect to the public sewer network may need to be adopted by us.
• If you're building a lateral drain outside your property boundary, you'll normally need an adoption agreement in place before any construction work begins.
• New sewers and lateral drains must be designed and constructed in line with the relevant Welsh Ministers' standards.
• Adoptable surface water sewers and lateral drains should comply with the requirements set out in Sewers for Adoption.

If you'd like more information about sewer adoption requirements, visit our Help and Advice pages.

Don't forget

A sewer adoption agreement does not give permission to connect to our sewer network.

You'll also need to apply separately for a sewer connection.