Is UK Tap Water Safe? Testing and Hardness

Tap water in England is tested millions of times a year.

The Drinking Water Inspectorate calls its quality excellent. Most everyday worries, from a chlorine taste to limescale in the kettle, have simple explanations. Old lead pipes are the one to take seriously.

Updated 14 October 2026 · 5 sources

Drink from the kitchen tap
Chill it for taste
Check pre-1970 pipes
Simple habits for a better glass

Check your tap

THE SHORT ANSWER

Safe to drink,
with a few quirks.

Taste and limescale are rarely a safety issue.
Lead pipes in older homes can be.

TESTING

Checked at the tap

Water companies in England carried out 3,632,669 compliance tests in 2024, at treatment works, reservoirs and consumers' taps.

See the numbers

HARDNESS

Limescale is calcium

Hard water carries dissolved calcium and magnesium. UK regulations set no standard for hardness, but it scales kettles and leaves scum on tea.

Hard or soft?

LEAD

Older homes, older pipes

Homes built before 1970 may have lead pipes. The regulator advises running the tap first and replacing lead pipework as soon as possible.

Check your tap

A dull grey old metal pipe with a swollen joint leading to a brass stop tap inside a kitchen cupboard — AI-generated image, not a photograph of a real person or place.

FOUR HABITS TO TRY

A better glass,
straight from the tap.

None of these needs a gadget. They come straight from the regulator's advice for households.

Drink from the kitchen tap
Use cold water from a kitchen tap fed directly from the mains, not hot water or a bathroom tap that may come from a loft tank.
Run it after a long gap
If no water has been used for several hours, run off about a washing-up bowl's worth before drinking.
Chill a jug for taste
Cooling is all that is needed to reduce a chlorine taste. Throw away unused water after 24 hours and clean the jug.
Ask for your water report
Your water company can send a free water quality report for your area, including the chlorine levels in your supply.

TWO NUMBERS WORTH KNOWING

Tested often,
passed almost always.

Both figures come from the Chief Inspector's
report for drinking water in England, 2024.

99.97%

Tests meeting the standards in England

Overall compliance with the regulatory standards in 2024. Microbiological parameters met 99.98% and pesticides 100%.

COMPLIANCE · DWI 2024

3.6 million

Compliance tests by water companies

The report lists 3,632,669 compliance tests in England in 2024, taken at treatment works, service reservoirs and consumers' taps.

TESTS · DWI 2024

The Chief Inspector says drinking water quality in England remains excellent, and that the challenge remains to achieve 100% compliance with the regulatory standards.

A QUICK TAP CHECK

What have you
noticed?

Pick what is bothering you about your tap water to see what the regulator advises. The bar shows how strongly the guidance points to taking action.

Based on Drinking Water Inspectorate consumer advice for England and Wales. Contact your water company about anything unusual.

Tap check

Choose what you noticedA slight chlorine tasteLimescale or scum on teaThinking of a water softenerA strong or TCP-like tasteA house built before 1970

A slight chlorine tasteChill it

Residual chlorine is typically 0.5 mg/l or less, against a WHO guideline maximum of 5 mg/l. Chill a jug in the fridge and throw away unused water after 24 hours.

Limescale or scum on teaHard water

That is calcium and magnesium from local rocks. UK drinking water regulations set no standard for hardness, calcium or magnesium.

Thinking of a water softenerNot the kitchen tap

It is a personal choice, but do not soften the kitchen tap used for drinking and cooking. Most softeners swap hardness for sodium.

A strong or TCP-like tasteTell the company

Contact your water company if a taste is strong, TCP-like or does not go away. It can come from home plumbing such as appliance hoses or some plastic kettles.

A house built before 1970Check for lead

Look for dull grey pipe at the stop tap. Run the tap after water has stood, ask your water company to test the kitchen tap, and replace lead pipework.

Sources: Drinking Water Inspectorate pages on chlorine, water hardness and lead in drinking water.

The inside of an electric kettle with a chalky white layer of limescale on its base — AI-generated image, not a photograph of a real person or place.

HARD OR SOFT?

Geology decides
what comes out.

The regulator grades hardness in mg/l as calcium carbonate: soft is up to 100, hard is 200 to 300 and very hard is over 300. The WHO says water at 200 mg/l or higher will produce scale.

Soft water is not automatically better: water at 100 mg/l or lower is more corrosive to pipework. Where companies soften water, the regulator recommends a minimum total hardness of 150 mg/l.

In conversation

Questions people ask

Is tap water in England safe to drink?

The Drinking Water Inspectorate says drinking water quality in England remains excellent. In 2024, 99.97% of regulatory tests met the standards.

Why does my tap water taste of chlorine?

Companies must keep a small residual of disinfectant in the pipes, typically 0.5 mg/l or less. A slight taste is often from nearby maintenance and usually passes. Chilling water in a jug reduces it.

Is hard water bad for you?

UK regulations set no standards for hardness, calcium or magnesium. Hard water scales kettles and appliances and leaves scum on tea, and the regulator notes limited evidence linking hardness to heart health.

Should I drink softened water?

The regulator advises not softening the kitchen tap used for drinking and cooking. Most softeners replace hardness with sodium, which is a concern for premature babies and people on low-sodium diets.

How do I know if I have lead pipes?

Homes built before 1970 may have them. At the stop tap, lead looks dull grey, often with a swollen joint, and shows shiny silver metal when gently scraped with a coin.

Sources

Each figure on this page comes from the sources below.

What is in
the tap?