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Water quality

We work hard to ensure the quality of your drinking water.

Every year we carry out more than 500,000 tests. We take samples from our water mains and pipes, as well as from customers’ taps.

Since 2010, more than 99.95% of tests taken from customers’ taps met the standard required by UK and European legislation.

If you want to check out the water quality in your local area, all you need is your postcode.

Check your water quality

A Thames worker holding up a jar of water carrying out a water quality test

Our range of water quality topics

We go through common water quality topics you may have about your water:

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Hard water

Minerals such as calcium and magnesium cause hard water.

View hard water

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Water looks different

There could several reasons why your water looks different.

View water looks different

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Different smell or taste

Why your water smells or tastes different could be due to several reasons.

 View smell or taste

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Other water issues

We go through other water issues such as pink, orange or grey stains and insects.

View other issues

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Lead pipes

You may have lead pipes if your property was built before 1970.

View lead pipes

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