New appointment variations

Developers can request that a New Appointment and Variation (NAV or ‘new appointee’) supplies water and/or wastewater services to their development.

If you choose to work with a NAV to supply water and/or wastewater services, they will adopt, own and maintain your development network. It means as a Developer you can choose who supplies your development site and allows you to choose a NAV to replace us as the incumbent for a specific geographical area. In order to choose a NAV to service your site you must meet the criteria set out by Ofwat.

A NAV can choose to service its customers through its own resources, or by requesting use of our existing assets under a water ‘bulk supply’ or wastewater ‘bulk discharge’ agreement.

To find out more about using a NAV, visit Ofwat’s website.


NAV Applications

Below is a guide on what a NAV will need to do when making a bulk supply or discharge application.

Step 1 – Make a Site Status Request

As a NAV you will need to understand if the site is served or unserved. An unserved site will not include any existing water or sewer connections to our network. You can ask for a site status request by sending an email to or by stating this as a requirement in your NAV application.

Within 21 days we will confirm whether we currently serve the site or not.

If the site is currently served then we may ask for the geographical area to be revised by the NAV, or we would need to agree to give consent to transfer the existing connections. For some sites, the existing served properties are due for demolition as part of the new development plans, if this is the case you would need to officially confirm this to us and once all served properties have been demolished we would issue an unserved letter.

Step 2 - Make an Application

You can make a bulk service request by completing the NAV application form and sending this to

Please remember to pay your NAV application fee appropriate to the size of a development. Our NAV application fees can be found on our Connection charging page.

Before you apply, please read our NAV Application Form Guidance Notes which will take you through what is required, including:

  • A NAV site boundary plan (with boundary drawn in green).
  • A development site plan at 1:1250 (or larger); and if known the preferred point of water and/or waste connection marked on plans. If the scheme is part of a wider development, please included the scheme boundaries on the plan.
  • Drainage plans with levels.
  • Route of the rising main, if there is an onsite wastewater pumping station.
  • An intrusive soil analysis report (if commissioned).

Once your application has been made, our team will review the information submitted and we will respond within 5 days to confirm that the documentation is complete or ask for more information if required.

Step 3 – Receive Bulk Service Offer

Within 28 days we will carry out a capacity check on our network and evaluate any connection costs and design, before sending you an offer pack that will include:

•  A bulk service report, which details an asset plan, a proposed point of connection, bulk supply and bulk discharge connection costs (as applicable).

For bulk supply requests, we will also include:

•  A bulk supply design plan.

•  A point of connection calculation sheet.

•  A NAV customer acceptance form.

•  A ‘Ways to pay’ document.

The bulk supply estimate is valid for three months, after which you will need to request a requote detailing any changes to the site so we can update your estimate as required. If our charges have changed, we will also update the estimate to reflect this. The bulk discharge costs will be in line with the current charging arrangements. Please also see Methodology of NAV charges.

Step 4 – Bulk Agreement

If you are happy with the bulk service offer, you can email to ask for a WaterUK Bulk Discharge Agreement or a WaterUK Bulk Supply Agreement to be provided for your site. Within 28 days we’ll:

  • Acknowledge your request in the first 5 days.
  • Prepare and send the agreement via DocuSign to you for signing.
  • You sign and return the agreement to us (We’ll need two signed copies if sent by post).
  • We’ll counter-sign the agreement and provide you with a final copy.

For bulk service agreements, please ensure you have read through the general and special conditions (as applicable):

Step 5 – Awaiting Acceptance and Pay

Once you have received the bulk agreement and are ready to accept and pay the bulk service offer, you will need to do the following:

•  Ensure the bulk service offer is still valid, and if required request an updated estimate.

•  Make payment for the bulk supply and/or bulk discharge connection costs set out in the offer.

•  Sign and return the NAV customer acceptance form (if applicable).

Step 5a – Water Connection

After your acceptance and once we have countersigned the bulk supply agreement, we will pass the site to our Project Delivery team for the construction works. A pre-start meeting will be held at your development site, in which we will confirm the start date on site and agree a schedule for the programme of work required.

Our team will then install the apparatus and confirm it is ready for your connection. Once you are ready to connect you will need to submit a chlorination certificate, from which we will arrange a final inspection of the connection and activate the new connection to our network.

The connection will now be live and you will be responsible for the billing going forwards. Any financial reconciliation due will be carried out at this point.

Step 5b – Wastewater Connection

Once you have made payment and we have countersigned the bulk discharge agreement, you will need to complete the NAV Sewer Connection Notification Form and submit it to us via

If the following documents were not submitted as part of the original NAV Bulk Service application, we will require:

  • A site location plan at 1:1250 (or larger).
  • A drainage layout plan at 1:100 (or larger); showing the location of sewers and manholes on site and up to the connection point.
  • A copy of planning consent (if applicable).

We will then technically review the mode and method of connection and when the proposal meets our standards, we will provide you with the approval letter and let you know your Assistant Adoption Manager for your area.

You will now need to arrange to carry out the works on site to connect into our sewer. At least two working days before intending to carry out the works, you should contact your assigned Assistant Adoption Manager to arrange a mutually convenient inspection date so we can ensure the completed connection into our network has been carried out correctly.

Once we are happy that your connection to the public sewer complies with our requirements, we will provide you with a completion letter. The connection will now be live and you will be responsible for the billing going forwards. Any financial reconciliation due will be carried out at this point.

Useful Information

Our policies relating to NAVs can be found through our Technical Advisories.

Get in touch

Please send any correspondence about New Appointment and Variations to:

Close agent lightbox  Close box