What Is the Level of Lead in UK Water?
Updated: 1 day ago
Last reviewed: September 2026
Quick answer The legal limit for lead in UK drinking water is 10 micrograms per litre (10 µg/l, the same as 0.01 mg/l or 10 ppb), and it applies at your tap. Water leaving the treatment works doesn’t contain lead: it picks lead up from old pipes and fittings on the way to your kitchen. The only way to know your level is to test the water you drink.
Not sure if your home has lead pipes? The Lead Risk Check asks a few quick questions and shows the housing-age estimate for your postcode.
The UK standard for lead
The standard is the same in England, Wales and Scotland, and it is measured where you drink the water: at the tap.
Where | Standard | Source |
England and Wales | 10 µg/l at the consumer’s tap | |
Scotland | 10 µg/l, in force since December 2013 | |
In other units | 10 µg/l = 0.01 mg/l = 10 ppb | Conversion |
The Scottish regulator puts it plainly: “All drinking water is required to meet the standard for lead (10µg/l) that came into force in December 2013.” (DWQR)
Where lead in tap water comes from
“Water does not contain lead when it leaves the treatment works.” (DWQR) Lead gets in on the last stretch, from the pipes and fittings that carry water into older homes.
Lead service pipes. “Before 1970, lead pipework was commonly used to connect properties to the mains water network.” (DWI)
Standing water. “Lead from pipework can dissolve into the water whilst it stands in the pipe.” (DWI) That’s why water that has sat in the pipes overnight matters most.
Brass fittings and solder. “Older brass fittings can also be a source of lead.” (DWI) So can “the illegal use of lead-based solder to join sections of copper pipe” (DWI).
Water type and season. The DWI notes that “harder water tends to form a protective scale over the surface of the pipe which can reduce the concentration of lead in the water.” (DWI) and that “more lead will dissolve during the summer and autumn months” (DWI).
Water companies reduce the problem at source: “Where a risk of lead exists, water companies treat the water with orthophosphate to reduce the problem significantly.” (DWI) Lead in the ground itself is rare: “Occasionally lead occurs naturally in groundwater however, this is a rare situation in the UK and lead is not present in the water within our wider public water supply network.” (DWI)
Who is most at risk
“Those at particular risk are infants (including unborn babies) and children because lead can have an adverse impact on mental development.” (DWI)
For adults, the DWI says “it may impair kidney, heart and circulatory health.” (DWI) Its overall advice: “Lead can build up in the body and it is recommended that exposure to lead minimised as far as possible.” (DWI)
Making up baby formula in an older home? Read Can babies drink tap water?.
How to tell if your home has lead pipes
Check the age of the home. Homes built before 1970 are the ones to check. The UK water testing map shows the housing-age estimate for your postcode district.
Find the pipe by your inside stop tap. “This may be in or behind the cupboards in your kitchen or a downstairs toilet.” (DWI)
Look at it. “Unpainted lead pipes appear dull grey and often have a swollen joint next to the tap.” (DWI)
Try the coin test. “The metal is soft and, if gently scraped with a coin, you will see the shiny, silver-coloured metal beneath.” (DWI) “Wear disposable gloves while you do this and be careful not to breathe in any dust.” (DWI)
A modern pipe at the stop tap doesn’t rule out lead under the garden. The DWI says older homes may have lead “underground and/or inside the building.” (DWI)
How to find out your lead level
Ask your water company. “If you suspect that your home has lead pipes you can ask your water company to test the water at your kitchen tap.” (DWI)
In Scotland: “If you have reason to believe that lead is present in your supply you can contact Scottish Water and request that they take a sample of water from your property and inform you of the results.” (DWQR)
Screen it yourself. Test the cold kitchen tap, the water you drink, with a Lead Test. A home screen is a first check, not accredited lab confirmation.
Read your number. The Result Decoder shows how your reading compares with the 10 µg/l standard.
If lead is found
Today: “For drinking and cooking, run the tap to clear any water that has been standing in the pipework for while, for example, overnight.” (DWI) “A washing up bowl full is normally enough to clear the pipe of standing water, although if you have long service pipe you may need to run the tap for longer.” (DWI)
Don’t waste it: “This need not be wasted but can be used to water plants or for something other than drinking or cooking.” (DWQR)
For good: “This short-term measure will protect you and your family, but if there are lead pipes or another source of lead present, these should be replaced as soon as possible.” (DWI) “Ultimately, the only certain way to reduce exposure to lead is to remove all lead pipework from the property.” (DWQR)
Who pays for what: “All the plumbing inside your home to the kitchen tap is the responsibility of the property owner.” (DWI) If you replace your part, “you should also notify your water company because they are legally required to replace their communication pipe, if it is made of lead and is at risk of contributing to the amount of lead in the drinking water supply.” (DWI)
Use a qualified plumber: “we recommend that you employ a qualified plumber to carry out any plumbing work, for example one who is accredited through the WaterSafe scheme.” (DWI) After the work: “Flush the tap well for at least 10 minutes after carrying out any work on a lead pipe.” (DWI)
Frequently asked questions
What is the legal limit for lead in UK tap water?
10 micrograms per litre (0.01 mg/l), measured at the tap. See the DWI drinking water standards.
Is there lead in UK mains water?
Not when it leaves the works: “Water does not contain lead when it leaves the treatment works.” (DWQR) It comes from lead service pipes, old brass fittings and lead solder on the way to the tap.
Is lead only a problem in old houses?
Mostly. “Before 1970, lead pipework was commonly used to connect properties to the mains water network.” (DWI) Newer homes can still pick up lead from old brass fittings or illegal lead solder.
Should I check for lead when buying a house?
Yes. “Ask your surveyor to check the nature and condition of the outside and internal pipes as part of the survey, making special mention of lead.” (DWI) See Water testing before buying a house.
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