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You are here: Home > Developers > Local engineers


Sewerage and sewage treatment

We offer a range of services for members of the public, builders, local authorities and housing developers. We provide on line information and downloadable application forms for your water supply and drainage needs.

Adoption of new sewers

We promote the use of a Section 104 Agreement (under the Water Industry Act 1991) for the adoption of sewers that are to be constructed as part of new developments. Sewers must be constructed in accordance with the current edition of the publication Sewers for Adoption which is available from the Water Research Council. It should be noted that a new edition of Sewers for Adoption is now in force. We maintain the sewers as public following adoption.

Fees and costs are at national rates as set out in the publication above and are based on our estimate of the whole cost of the works being offered for adoption.

Inspection fees are set at 2.5% which covers technical assessment and site inspection (a minimum of £500) and legal agreement preparation of £325.

You should discuss your proposals beforehand with our local development engineer.

Under the current edition of sewers for adoption each sewerage undertaker has its own pumping station addendum. Our addendum can be found here.

Adoption of sewage treatment works

We can consider adopting private sewage treatment works. This type of works is often referred to as a ‘package plant’. 

UK Water Industry Research has published a national standard and adoption procedure. Wastewater Treatment Works for Adoption, UKWIR reference 13/RG/05/38, ISBN number 1-84057-696-0 is available from

You should discuss your proposals with our local developer services engineers using the contact details here.

Adoption of existing sewers

We can consider adopting existing sewers under Section 102 arrangements.

You should discuss your proposals beforehand with our local development engineer.

Diversion of existing sewers

If there are existing sewers crossing a new development site and the layout of the site cannot be designed to avoid them, the sewers must be diverted.

You should discuss your proposals beforehand with our local development engineer.

Building over/near to a public sewer

If you are planning an extension to an existing property, building a garage or a conservatory etc, there may be a public sewer in the way. If you want to build over or near to that sewer, you must agree protection measures for the sewer with us.

  • Guidance notes can be found here.
  • An application form can be found here.
  • Details of our fees can be found here.

You should discuss your proposals with our sewer protection team on 01225 526333 or email us.

Requisition of new sewers or laterals for domestic purposes

Where there is insufficient capacity in our system to accommodate your discharge we may require you to pay for any necessary improvements. It is important that you contact us at the earliest possible stage as major works may be required to accommodate your development.

If you have a new development site with no access to a public sewer because land owned by a third party is in the way, we can lay a sewer(s) to serve your site. We can negotiate land entry, easements and compensation for crossing the land.

You should discuss your proposals with our local development engineer.


First time sewerage schemes

You can ask Wessex Water to consider providing a new sewerage system in an area lacking public mains drainage. Applications are accepted from district councils, parish councils, or groups of householders. We will investigate if a scheme is viable, and if it is confirm when it may proceed. If a scheme is not viable, we can advise you on your alternatives.

You should have an initial discussion with our local Developer Services engineers using the contact details here.

An information leaflet can be found here.

A leaflet answering questions for when a scheme goes ahead can be found here.

Infrastructure charges

All new developments and connections place additional demands on our existing systems. Infrastructure charges were introduced by the government as a way of ensuring that all new developments and new connections make a contribution to the upkeep of public water mains and sewers. The infrastructure charge you pay depends on the type of development, although there is a standard charge for each house, flat or similarly occupied premises with its own standard size domestic water supply connection. It should be noted that the infrastructure charge is separate to any charges for obtaining a new connection to our water supply or sewerage system.

Connections can be direct to our systems or indirect via private mains, drains or sewers. The amount payable depends on the type of development and whether a supply and/or sewer connection is required. In the case of multi-occupation developments, ie, flat, offices etc, the charges will be based on the number of water taps and water using appliances.

For 25mm domestic water supply connections the standard amounts are:

Water £347
Sewerage £347

Infrastructure charges are zero rated for VAT.

All other properties are charged an amount calculated using the relevant multiplier, (RM). The RM is based on the number of taps and water fittings in the property. Each fitting is given a loading unit based on the amount of water it uses.

Further information you can email us.

Connecting to a public sewer

If you want to make a new foul or surface water connection from your new property or extension to a public sewer, you need to apply beforehand.

To discuss your proposals with our sewer connection team, call us on 01225 526333 or email

Asset information

If you wish to obtain sewer records information, please call our mapping department on 01225 526422, fax on 01225 528262 or email us. A charge will be made for this service. Alternatively, public sewer records can be viewed at local district council offices.

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