Drainage and septic tanks
The report cannot say where the private drain becomes a public sewer. Is that a water-company search or a survey finding?
It is a water-company search, not a survey finding the visit could make. The report cannot say where the private drain becomes a public sewer because that change of responsibility is not written on the ground in a way a home survey can decide. The surveyor can record chambers that were seen and say the transfer point was not established. A drainage and water search, or the sewer map the water company holds, is the separate product that addresses the public sewer.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What is the fuller explanation?
Private drains are the owner’s pipes. A public sewer is adopted and maintained by the water company. The point they meet may sit under a pavement, in a neighbour’s land, or somewhere with no cover at all. Lifting a chamber in the garden shows the pipe at that hole. It does not show the legal status of the next length. The survey did not test the drain and did not map the public system. Saying the point is unknown is a limit, not a guess you should fill in.
Ask the solicitor for the drainage and water search and for any plan that marks where the sewer is adopted. Keep that search separate from this report. A lender may want the adopting authority identified from the search, not from the surveyor’s sentence that the point could not be stated. Do not tell anyone the survey traced the public sewer. It recorded that it could not.
What should you ask your surveyor?
- Which chambers were actually opened or seen?
- What sentence says the transfer point is unknown?
- Does the report claim a water-company map was checked?
What are the typical next steps?
- Order the drainage and water search through the solicitor.
- Keep the sewer map separate from this home survey.
- Do not describe the survey as having found the transfer.
Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.
Also asked about this
Does a manhole in the pavement prove the sewer is public?
No. A cover in the pavement shows a chamber in that place. It does not, by itself, prove where the private drain becomes a public sewer, and this visit did not make that decision. Status comes from the water-company records. The survey only records that it could not say where the change happens.
Was the drain tested while the point stayed unknown?
No. The drain was not tested. Not knowing where it becomes a public sewer is a records question, and the visit did not camera or water-test the run. The report can describe covers it saw. It cannot turn those covers into a map of adoption or into a test certificate.