Drainage and septic tanks
Nothing on the visit sampled a reed bed, opened the treatment plant or tested a discharge the sample point was locked. What has to stay undecided?
The reed bed, the treatment plant and the discharge all stay undecided. Nothing on the visit sampled the bed, opened the plant or tested a discharge, and the sample point was locked. A reed bed and a package or other treatment plant are not the same unit, and neither is a cesspool, which only holds sewage until it is emptied. The survey can say the sample point could not be used. It has not judged water quality, plant condition or whether the bed is still doing any work.
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?
A treatment plant uses mechanical or biological stages inside a tank, while a reed bed is a planted area that effluent may pass through afterwards. Locking the sample point means the liquid leaving that route was not seen and was not tested. Crusts, smells or a green bed are not a laboratory result. The survey recorded the limit. It did not open covers that were not part of the visit and it did not decide that the discharge meets any consent.
Ask the solicitor for emptying records, any environmental permit or exemption, and the service log for the plant, and keep those papers off the survey text. A drainage firm can sample a discharge and open a plant if instructed later. That work is not this report. Tell a lender the sample point was locked so no quality result exists from the visit. Do not describe the reed bed as proved to be working because plants were visible.
What should you ask your surveyor?
- Was the sample point locked so no discharge was tested?
- Did the visit open the treatment plant or only see the reed bed?
- Has any consent or emptying record been left outside this report?
What are the typical next steps?
- Treat bed, plant and discharge quality as undecided.
- Ask the solicitor for permits, exemptions and service logs.
- Instruct a drainage firm if a sample is actually required.
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
Is a cesspool the same thing as this reed bed?
No. A cesspool holds sewage and is emptied. A septic tank and a treatment plant work differently from each other, and a reed bed is a further stage, not a holding tank. The survey only recorded what was seen, and the sample point was locked. It has not classed the system or measured what it holds.
Can the solicitor treat a green bed as a clean discharge?
No. Green growth is not a test of the liquid leaving the plant. The sample point was locked, so quality, odour of a sample and any consent limit stay outside this report. Pass the service log and any permit to the solicitor as papers, not as a survey result. A later sample would be new work.