The science behind your water

Have you ever stopped to consider the science behind how we make sure that the water flowing from your taps is great quality and safe?


As an island nation we are never further than 70 miles from the sea - with over 200,000km of waterways and 40,000 lakes, sometimes we can take our water for granted.

We caught up with Head of Analytical Services, Sue Clancy, at our bustling scientific laboratory in Saltford, near Bath, to find out more.

How many people work in the labs, and what do they do?

We have around 100 people working in or as part of our labs team – including microbiologists and chemists, and there’s also our sampling team out and about across our region. Alongside everyone else at Wessex Water, we’re all working hard to provide wholesome drinking water for our customers.

We also perform tests to help ensure treated wastewater that we return to the environment is safe and meets the required standards. Protecting public health and the environment is our priority.

What's involved?

We receive around 1,000 sample bottles every day and work 365 days a year, including Christmas Day, to undertake all sorts of tests – making sure things like pesticides, metals and algae aren’t present and that pH levels are correct.

We also undertake taste and odour assessments. Last year we completed 1.2 million tests.

Can you tell us what is in our water?

This depends on where you live, and you might notice a difference if you holiday elsewhere in the UK. Most of the water we supply to your taps originally comes from groundwater, filtered through rocks beneath our feet.

Groundwater tends to be hard water, which is why you might get limescale in your kettle. While some people might prefer soft water for washing their hair and cleaning, customers tell us harder water tastes better. It also contains more minerals like calcium and magnesium to help keep you healthy.

We are often asked about fluoride; do we have it in our water?

We don't add fluoride to our water supply, but traces of fluoride do occur naturally in many water sources.

It’s a much-debated issue – but any decision to add fluoride to water wouldn’t be made by us – it would be made by local authorities and, through them, the Department of Health and Social Care. We haven't been approached by any authority to do this in our region.

Where can people learn more about water quality?

The water quality section of our website is full of useful information about the different factors that affect water quality.

You can also find out more about the causes and fixes for limescale, tastes, odours and discolouration.