If you need to abandon a sewer to make site remediation works easier or remove a restriction from future development, we may close part of the public sewer network.
Before closing a sewer, we need to be absolutely certain that it's no longer in use or required.
This usually requires a closed circuit television [CCTV] survey of the public sewer and any private drainage connections, together with written evidence. For a closure to take place, a manhole is required at the new 'head' (i.e. upstream point) of the public sewer. If there's no existing manhole, a new one needs to be constructed to meet our requirements. Once a public sewer has been closed, we usually issue a certificate. Once issued, the sewer must be abandoned as soon as practicable. This will be monitored by our inspector.
Our preferred method for abandoning a sewer is for it to be grubbed up (excavated) together with any redundant chambers. Where this isn't practical, the closed public sewer should be sealed and filled with grout.
We'll update the Statutory Sewer Map to reflect any closure. Generally, grubbed up sewers are removed from the map and grouted ones are shown as abandoned.
All of the costs involved in a public sewer closure are the responsibility of the applicant.
Following any formal closure of a public sewer, the abandonment works (i.e. grubbing out/grouting up etc.) are at the applicant/developer's expense and are usually carried out by them to our satisfaction.
Even when a public sewer is closed, it remains our responsibility and can't be transferred to private ownership.