Lead pipe replacement

How to tell if you have lead

1. Find the incoming pipeUsually where it enters near the stopcock, commonly under the kitchen sink.
2. Look at the colourLead is dull grey. Copper is orange-brown or green where it has oxidised. Plastic is blue, black or grey and obviously not metal. Galvanised steel is grey too, and harder to distinguish.
3. Scratch it gentlyWith a coin. Lead is soft and scratches to a bright silver very easily. Steel does not – it is hard and it will not mark.
4. Tap itLead gives a dull thud rather than a ring.
5. Look at the shapeLead pipe is often slightly irregular, with bulbous soldered joints rather than the crisp fittings of copper.
6. Check the age of the propertyLead supply pipes were common in housing built before the 1970s, and internal lead plumbing in earlier housing still.

Why it is worth replacing

Two reasons, and the first is the substantive one.

Water quality

Lead can dissolve into drinking water, and the amount depends on the water’s chemistry, its temperature, and critically how long it has been standing in the pipe. Water companies dose supplies to reduce lead solubility, which is effective and which is a mitigation rather than a removal.

Advice generally given where lead pipework is present:

• Run the tap before drinking first thing in the morning or after any period when water has been standing – a washing-up bowl’s worth, which can be used rather than wasted.
• Use cold water for drinking and cooking, never hot, because hot water dissolves more.
• Do not use water from a hot tap for making up infant formula.
• Ask your water supplier to test, which many will do free of charge. That gives you a figure rather than an assumption.

Flow

Lead supply pipes are usually narrow by modern standards, and after decades the bore has frequently reduced further. Replacement commonly improves flow throughout the property as a side benefit – see water main replacement.

Talk to your water company first

This genuinely matters and people skip it.

1. Many water companies operate lead replacement schemes, and will replace their communication pipe – the section from the main to your boundary – free or at reduced cost when you replace your supply pipe.
2. Free testing is frequently available, which tells you what your actual levels are.
3. Coordination matters. Replacing only your section while their lead section remains leaves lead in the run.
4. Notification may be required in some circumstances.

Internal lead

The supply pipe is not the only place lead appears in older property.

• Internal lead plumbing to taps and to a cold water tank, in earlier housing.
• Lead-lined cold water tanks, in Victorian and Edwardian property. These should be replaced.
• Leaded solder on copper joints, used before it was prohibited for potable water. Less significant than lead pipe and worth knowing about.
• Lead connections at the stopcock, where a short lead tail remains even though the rest was replaced.

A survey establishes what is actually there. It is common to find that a previous partial replacement left short lead sections at either end, which is exactly the situation worth resolving.

What replacement involves

The same work as any supply pipe replacement, with a couple of additions:

1. Survey the full runInside and out, identifying every lead section including short tails at connections.
2. Coordinate with the water supplierFor their section, and for any contribution.
3. Agree the route and methodMoling where the ground allows, open trench where it does not.
4. Replace in MDPECorrectly sized for the property, ducted under hardstanding, at proper depth.
5. Replace internal lead tooThere is little point removing the supply pipe and leaving lead tails inside.
6. New stopcockUsually a lever valve, with a drain point – see stopcocks and mains.
7. Disinfect and testNew potable pipework disinfected before use.
8. Dispose of the lead properlyIt is scrap with a value and it should not simply go in a skip.