Building and Developing

Sewer adoptions - New site  

Step 1: Before you apply

If you are building a sewer or lateral drain which is intended to connect to one of our public sewers, you must enter in a S104 adoption agreement with Hafren Dyfrdwy before applying to connect to the sewer or beginning construction work related to the sewers.

S106 of The Water Industry Act 1991 sets out the legislation which governs new sewer connections. This was amended by Section 42 of the Flood and Water Management Act 2010, which does not allow any new connection to a public sewer without a S104 adoption agreement in place. This ensures all sewers and lateral drains will be the responsibility of the undertaker and secure their future maintenance. S104 of the Water Industry Act provides the legislation in respect of adoption agreements.

Foul sewers must comply with the standards set out in The Welsh Ministers Standards for Gravity Sewers and Lateral Drains (PDF).

Adoptable foul & surface water pumping stations, surface water sewers and lateral drains should comply with standards set out within Sewers for Adoption 7th Edition, published by WRc, along with the Hafren Dyfrdwy Addendum (PDF).

Step 2: Apply

How do I apply?

You’ll need to submit one of the following forms:  

You should apply using option one if you are building a new sewer. A sewer is any pipework that serves more than one property belong to different sites.

You should apply using option two if you are building a new lateral drain only. This form will be for single property adoptions or single site curtilage adoptions (such as a school).

For full details about what to submit with each application, please see the check list provided at the back of each form. 

There is no initial application fee when submitting a S104 application.


Step 3: Technical assessment

What does this include?

We will assess your application and consider the impact of your developments flow on the existing network. We may come back to you at this point if we have any questions regarding the development strategy. At this stage we will advise you of any existing capacity problems within the network (if we haven’t already done so within a Development Enquiry Application (PDF) and if we will need to commission a reinforcement scheme.

A complete technical review of your submission will then be undertaken to determine if your design meets the Welsh Ministers Standards for Gravity Sewers and Lateral Drains, along with Sewers for Adoption 7th Edition and the Hafren Dyfrdwy Addendum.

You will receive a technical approval within 28 days of us receiving a complete application that meets the required technical standards.


Step 4: Agreement 

How do I get this agreed?

Your technical approval will contain a form for you to fill in and return to us, providing details on the parties to be signed into the S104 agreement. When you return this to us along with your inspection fees, bond/surety and agreement fee, we will issue your agreement within 14 days.

Once you have received the agreement, you need to arrange for all parties to sign before returning to Hafren Dyfrdwy for completion. 

We will provide you and all parties with a copy of the agreement on completion.

Full details on the applicable charges can be found on our charges page.


Step 5: Inspection 

Who will complete my inspection?

Where you are construction sewers, once an agreement is in place, we will provide you with the details of a Hafren Dyfrdwy inspector to arrange a pre-start meeting with. Our inspector will then supervise the installation of the new assets to ensure they meet the required standard.

If you have applied to have a lateral drain adopted only, then before you begin construction you will need to apply to connect to the sewer.


Step 6: Connection 

How do I get connected?  

When you are ready to make your connection, let us know and we will send you a S106 Connection form. Alternatively you can download our application form (PDF).

Once we received your completed form and your contractor’s site and connection specific risk assessment and method statement we will issue an approval notice within 21 days. We recommend you leave yourself 4 weeks between applying and wanting to connect to the sewer.

For sewers connections, just inform your site inspector when you are intending to make the connection.

For lateral drains, once you've received your approval letter you'll need to inform us when the connection is being made allowing 48 hours notice. Your approval letter will provide details on who to call to arrange your inspection.

Step 7: Adoption

What happens next?

For sewer adoptions, following completion of the work and satisfactory inspection, we will request As-Built information before placing the site onto a 12 month maintenance period. Subject to completion of this, we will complete a final inspection before vesting the sewers.

For lateral drains, following the completion of the work and satisfactory inspection, the asset will be vested by us.