Lead pipes and drinking water
Lead pipe is visible before the internal stopcock and copper after it. Which length has not been replaced, and who should advise on the drinking water?
Not the copper: the visible lead length before the internal stopcock has not been replaced. Copper after the stopcock is a later piece of pipe. It does not erase the lead that is still in view on the incoming side. The survey can record those two lengths. It does not replace either of them, and it does not sample the water. If you suspect lead, the Drinking Water Inspectorate says you can ask the water company to test at the kitchen tap and to advise.
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?
People see the bright copper and treat the whole supply as renewed. That skips the dull length on the house side of the stopcock, which is the length still described as lead. Buried pipe in the path is a further limit: the surveyor does not excavate it, so 'lead seen here' is not a map of every pipe. The finding to keep is narrow and exact. The visible lead before the internal stopcock is still there. The copper after it is a different length.
Ask the surveyor to say, in plain words, which side of the stopcock is lead and how far that lead could be seen. Then ask the water company for a test at the kitchen tap if drinking water is the worry. Do not invent a concentration, and do not let a plumber's guess stand in for that test. The home survey has identified a visible lead length that has not been replaced. Advice on the water belongs with the company.
What should you ask your surveyor?
- How much lead pipe was visible before the internal stopcock?
- Did the copper start immediately after that stopcock, and nowhere before it?
- Are you leaving the water test to the water company rather than sampling it yourself?
What are the typical next steps?
- Record that the visible lead before the stopcock has not been replaced.
- Ask the water company to test the kitchen tap if you suspect lead.
- Do not treat the copper after the stopcock as a replaced supply.
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
If the lead run is only short, has it been dealt with?
No. A short visible lead length is still lead that has not been replaced. The survey has not cleared it because the piece looks brief.
Does new copper under the sink clear the incoming lead?
No. Copper under the sink is downstream of what you can see. It does not replace the lead pipe before the internal stopcock.