Frequently asked questions

The CON29DW Residential contains 25 standardised questions and provides essential information for homebuyers and their advisers about a property’s water and sewerage assets, including confirmation on whether or not a property is connected to mains supply and drainage.

The CON29DW Residential informs homebuyers about the connection status of a property.

The CON29DW Residential confirms whether a property is connected to the public sewerage and water system as based on the billing records and an idea of the likely extent of the private liability for the water and sewerage pipework before connection into the public system. It also confirms whether a property is charged on a measured or unmeasured basis and whether this will remain the same following the change of occupancy, and the location of a water meter, if one exists. It also confirms if the property is at risk of internal flooding, low water pressure, and the hardness of the water supplied to the property. This information is obtained from records held by the relevant water company.

Water companies and their predecessors over many years have collected data on the services provided to a property. This information is then used to raise charges for that property which is why it is possible to derive if a property is connected for particular services by referring to the water bill.

Sewers are designated “public” when they are operated and maintained by the appropriate sewerage undertaker. Private sewers are the responsibility of the property owner. Following the transfer of private sewers and lateral drains on 1st October 2011 the majority of private sewers, serving more than one property and lateral drains that extend beyond the boundary of a property became the responsibility of the Statutory Sewerage Undertaker for your area. Therefore the only drains that the property owner should be responsible for are the drains within their boundary that only serve their property. However, owners were given the opportunity to opt out of the scheme and therefore there may be some sewers and lateral drains that remain private. Private sewers are those that have either never been offered to a sewerage undertaker for adoption, or have never been subject to mandatory transfer.

Foul sewers carry used water from properties to the water companies sewerage treatment works. Surface water sewers carry storm water away from a property. This might flow into a highway drain or a road gulley and then into a water company’s sewers, but in some cases the surface water drains into a soakaway in the garden, but it could also drain into a river, a reed bed or a private pond.

Where such separate sewerage networks are in place serving an area then the appropriate sewer should be utilised when making new connections to the network. However occasionally surface water can drain into a foul sewer where no other method of removal is available but this should only be a last resort because of the risk of foul water flooding. Used water should never be diverted into a surface water sewer because of the risk of pollution of a stream or aquifer. It is not uncommon in older developments to see combined sewers which are designed to carry both foul and surface water to an appropriate treatment facility.

The public sewer plan shows all the known public sewers in the area. Following the transfer of private sewers and lateral drains on 1st October 2011 the majority of private sewers serving more than one property and lateral drains that extend beyond the boundary of a property became the responsibility of the Statutory Sewerage Undertaker for your area. Many of these transferred assets have yet to be mapped and may not currently show on the statutory sewerage undertaker’s sewer record maps. However, owners were given the opportunity to opt out of the scheme and therefore there may be some sewers and lateral drains that remain private. You may need to check with your Statutory Sewerage Undertaker to understand how they are mapping the transferred assets.

The adoption process for water mains is a separate and distinct process to the adoption process for sewers.

A build-over is an agreement between the sewerage undertaker for the area and the homeowner that gives the homeowner permission to build over a public sewer, subject to stipulated conditions. Contact the Sewerage provider if you need further information on the specific conditions attached to your particular build-over agreement.

The search shows that there is a sewer running under the property, but Q 2.7 says that no sewerage undertaker (a water and sewerage company) has been consulted about plans to build or extend – what does this mean?

Records with regards to build-over agreements are known to be incomplete. Historically, the responsibility for maintaining sewer records rested with the local authority and comprehensive records were not always consistently maintained especially with regards to former Section 24 public sewers. In many instances the likely position of these sewers are only an approximation and therefore the sewer plan should be used for general guidance purposes only. Historically due to their prevalence and the low risk nature of these Section 24 sewers build overs have been allowed over these types of sewers. If retrospective consent is required it may be possible for the sewerage undertaker to issue approval subject to inspection of the sewer in order to check the suitability, position and condition of the public sewer in question. Buildings or extensions erected over a sewer in contravention of building controls may have to be removed or altered.

Please contact your conveyancer in the first instance to query your search. If you need to further help then check which company provided your CON29DW and you can find our member contact details here.

If you are not happy with the service you have received then please take a look at our customer redress. If you haven’t spoken to the DWSN member who provided the report then this is your first step. Member contact details can be found here.

The CON29DW Residential contains 25 standardised questions and provides essential information for homebuyers and their advisers about a property’s water and sewerage assets, including confirmation on whether or not a property is connected to mains supply and drainage.

You can find the average DWSN member turnaround time (TAT) here. This is updated monthly providing the latest industry average TAT

The contact details should be provided within the report, but if you are unsure, follow the link to our members’ page and click on the provider’s logo to find their contact details.

From October 2011 the majority of private sewers and lateral drains connected to the public network as of 1st July 2011 transferred into public ownership and therefore it is possible there may be additional public assets which may not be shown on the public sewer plan. The main issues for householders will concern liability and the presence of public assets within their property boundary. They will no longer be accountable for costly repairs on assets beyond their boundary, but the majority of properties will now have public assets within their boundary, over which water authorities will have statutory rights of access. Public assets within a property boundary can also have an impact on future development of that property. For legal professionals, it will be vital to inform clients that there may be public assets close to, or within the property boundary that are not shown on the plans.

A sewer is “overloaded” when the flow from a storm is unable to pass through it due to a permanent problem, for example, flat gradient or small diameter. Flooding as a result of temporary problems such as blockages, siltation, collapses and equipment or operational failures are excluded. “Internal flooding” from public sewers is defined as flooding, which enters a building or passes below a suspended floor. For reporting purposes, buildings are restricted to those normally occupied and used for residential, public, commercial, business or industrial purposes. These are defined as properties that have suffered or are likely to suffer internal flooding from public foul, combined or surface water sewers due to overloading of the sewerage system more frequently than the relevant reference period, either once or twice in ten years, as determined by the sewerage undertaker’s reporting procedure.

Water pressure is a measure of the force that pushes water through the mains and into your pipes. It is measured in ‘bars’ – one bar is the force needed to raise water to a height of 10 metres. The amount of pressure at your tap depends on how high the reservoir or water tower that supplies you is above your home, how close you live to one of your supplier’s pumps or on how much water is being used by other people in your neighbourhood. Low water pressure means water pressure below the regulatory reference level which is the minimum pressure when demand on the system is not abnormal. The reference level of service to a single property is a flow of 9 litres/minute at a pressure of 10 metres head on the customer’s side of the main stop tap.

The CON29DW Commercial has been developed specifically for those purchasing or leasing land or commercial property and covers land or buildings used or proposed to be used for commercial activities. It covers the same key water and drainage questions as the CON29DW Residential as well as additional questions on trade effluent and wayleaves/easements.

Please follow the link to our members’ page and click on the relevant member logo to find their contact details.

From April 2017, all non-household customers in England were able to choose their supplier of water and sewerage retail services. This is a result of a change of law under the Water Industry Act 2014, designed to introduce competition into the water industry. The CON29DW Commercial search will no longer indicate who bills a property for water or drainage services and this information will need to be obtained from the current owner/occupier. For a list of all potential retailers of water and wastewater services for the property please visit www.open-water.org.uk.

Trade effluent is defined as ‘any liquid with or without particles of matter in suspension which is wholly or in part produced in the course of any trade or industry carried on at trade premises but does not include “domestic sewerage”.

Companies require consent to discharge trade effluent into the public sewer under S118 of the Water Industry Act, 1991. Effluent consent levels are determined by water companies and are set in order to protect the operational effectiveness of sewage works and to protect water courses, wildlife and the drinking water supply. A trade effluent consent would not be required for properties such as hotels, public houses, restaurants, canteens and takeaways, as the strength of effluent would not compromise the sewage. Trade effluent consents are based on the volume and type of effluent, and examples of companies that it would be required for are: industrial processes, commercial laundries, laundrettes, commercial swimming pools and food manufacturing sites.