- Project plans
- Project activities
- Legislation and standards
- Industry context
Last edited 14 Dec 2020
A pipe carrying sewage (waste water and excrement) that serves only one property is referred to as a drain. Drains are privately owned and maintained as far as the boundary of the property. Beyond the boundary of the property a drain is referred to as a public lateral drain.
Under the Public Health Act 1936 all sewers (as defined by the Public Health Act 1875) which were in existence on 1 October 1937 became public sewers. After 1937 new sewers were only public if they were laid or adopted by the sewerage undertaker.
However, on 1 October 2011 in England and Wales, private sewers and lateral drains that were connected to the public sewer before 1 July 2011 were transferred to the ownership of the regulated sewerage companies (generally water companies).
This means that property owners only remain responsible for drains that serve only their own property, up to the point they connect to another drain or sewer, or as far as the boundary of their property. In the case of blocks of flats, the property owner(s) are responsible for the drain as far as the boundary of the property.
Properties not connected to the public sewer network, for example if they have a septic tank or cesspit, are not affected by this change, and their sewers or drains remain private. In addition, large commercial sites with multiple occupants may have private sewers or drains, as may sites in which sewers or drains discharge to a watercourse. Sewers owned by Railway Authorities also remain private.
New or existing sewers or lateral drains can be adopted by a sewerage company under Section 102 of the Water Industry Act 1991 (existing sewers) or section 104 of the Water Industry Act 1991 (new sewers). The sewerage company will then maintain them at their own expense.
Successful ‘adoption’ of sewers requires that they are constructed to required standards. If they are not, it may then be necessary to carry out remedial works to bring them up to an adoptable standard.
For more information see:
 Related articles on Designing Buildings Wiki
- Difference between drains and sewers.
- Grease management.
- Public sewer.
- Safe working in drains and sewers.
- Sanitary pipework.
- Section 102 existing sewer adoption.
- Section 104 new sewer adoption.
- Septic tank.
- Sewer construction.
- Sustainable urban drainage systems SUDS.
- Thames Tideway Tunnel.
- Waste water.
Featured articles and news
Prioritising tax considerations.
The four D creative process: discover, define, develop and deliver.
National Cyber Security Centre initiative is announced.
Reviewing trends and projections.
Legislation will establish initiatives to move towards net zero.
How to document contractor employment status.
Tech tools to help manage people and space post-pandemic.
A style that ranges from mock Tudor to arts and crafts to the 'Wrenaissance'.
Free guide from Secured by Design.
BREEAM strategy for sustainability and the circular economy.
Free tool to improve the construction programming process.
Are buildings doing what they're supposed to be doing?
Cities with quick access to everything by foot or bike.
The pressures and pinch points of global destinations.