Which Water Should You Choose?

Switching from bottled to tap water

Tap vs bottled water

Which? Archive

This article, Switching from bottled to tap water , was last updated on 18 August 2010 and is now out of date and held in our online archive for reference. Explore our latest Home & garden articles.

Bottled water productionMost of the bottled water we buy is still, so could be replaced by tap water

Britons splashed out £1.68bn on 2.275bn litres of bottled water in 2006, but there are signs that our thirst for bottled is drying up. In our survey, nearly a quarter of Which? members said they’re drinking less bottled water than a year ago and according to one market research agency, sales of bottled water dropped by 9% in 2007.

There are plenty of good reasons to choose tap water instead:

  • Cheap: Tap water costs just 0.22p a litre – much cheaper than bottled mineral water.
  • Taste: Half of Which? members say they can’t taste the difference between bottled and tap water, with 18% actually preferring it from the tap.
  • Eco-friendly: 84% of Which? members in our survey believe tap water is better for the environment than bottled.
  • Safe: UK water is some of the safest in the world.


There’s no contest when it comes to cost. At 0.22p a litre, tap water is 141 times cheaper than the bestselling mineral water, Evian, which, even if you buy it in a supermarket, costs 31p a litre.

The costs of tap water against bottled water
Type of water Average cost
per litre
How many times more
expensive than tap water
Tap water 0.22p n/a
Supermarket own brand 8.5p 39
Evian water, average price 31p 141
SEI water at Selfridges £5.58 2,536
Berg at Claridges £30 13,636

Table notes

Where possible we collected prices of one litre bottles, or the nearest available size. We then converted prices to one litre for easy comparison. Smaller bottles of water are likely to work out more expensive. We checked prices in supermarkets – water is likely to be more expensive if you buy it from high-street shops or railway stations. The price of tap water is from Ofwat and based on average water rates in the UK

Quality and taste


  • If you choose tap:

  • Plan ahead and take a bottle of tap water when you go out
  • Don’t be afraid to ask for tap water when you are in any food or drink establishment
  • If your employer provides only water coolers in the office or bottled water in meetings, ask it to provide tap water, too
  • If you choose bottled:

  • Opt for a UK brand, such as Abbey Well, Highland Spring, Brecon Carreg or Buxton. Some supermarket brands are UK sourced, so check the bottle
  • Consider an ‘ethical’ brand but check what they are offering to do before deciding to buy. Some are better than others

Bottled water is marketed as pure, healthy, natural and clean, but that doesn’t mean tap water is unsafe or unhealthy. In fact, the UK has some of the best drinking water in the world. In our survey, half of our members said they didn’t think there was any difference between bottled water and tap water in terms of quality and taste.

Taste test

When we asked 48 Which? staff members to blind taste three waters – Evian, Tesco spring and London tap – about half couldn’t identify the tap water. Overall, the Evian scored highest, closely followed by the tap water and the Tesco spring water, which were rated the same.

Many tasters liked the fact that the tap water was ‘tasteless’. One described it as having ‘no taste at all’ and another said it had a ‘nice and pure taste’.

Regional differences in taste

UK tap water contains safe levels of chlorine to make sure it’s clean. But placing a covered jug of water in the fridge for a few hours before drinking can reduce the chlorine taste. Replace any leftover water in your fridge every 24 hours to keep it fresh.

Where you live can also affect the taste of your water. As water journeys through the ground it picks up minerals such as calcium and magnesium.

A man choosing water in supermarketHalf of Which? members can’t taste a difference between tap and bottled water

Water with lots of these minerals is described as ‘hard’ water. This does not pose any risk to health but, if you don’t like the taste, using a water filter can help reduce these minerals.

Environmental issues

There has been plenty of media coverage about the environmental damage caused by bottled water. The industry’s carbon footprint is made up in the following ways.


Energy and resources are used in obtaining mineral water from source and bottling it, as well as in manufacturing the actual bottles. As an example, an estimated two gallons of water are wasted for every gallon of water purified to put into a bottle (purified water is different to natural mineral and spring water and accounts for a very small proportion of the bottled water sold in the United Kingdom).


A bin with empty bottlesPlastic bottles take up to 450 years to decompose in landfill

Three in 10 Which? members who buy still bottled water make a point of choosing UK-sourced brands. Many waters are imported from abroad. Some, such as Evian, come from France, but others come from as far away as Fiji or New Zealand, accumulating thousands of ‘water miles’.


Some 83% of the water we buy comes in plastic bottles. Although these bottles can be recycled, most of them go to landfill where they can take up to 450 years to decompose. The number of plastic water bottles sent to UK landfill sites each year would fill Wembley stadium twice over. See ouressential recycling guide for advice on recycling plastic.

Ethical water brands

In response to growing environmental concerns several ethical water brands, such as Belu and Thirsty Planet, have been developed. They claim to donate money from each bottle sold to fund clean water projects in places that need it, such as Africa.

Kids in Africa showing "thumbs up"‘Ethical’ water brands fund clean water projects in places that need it, like Africa

Volvic’s ‘1L for 10L’ campaign provides Africa with 10 litres of drinking water for every litre of Volvic sold. Schemes like this, while very commendable, don’t actually reduce the environmental impact of producing and transporting bottled water.

Which? research

We surveyed 3,039 members of the Which? online panel in April and May 2008 about their water-drinking habits. We asked 48 Which? staff members to see whether they could differentiate between Evian mineral water, Tesco spring water and London tap water. The tap water was chilled overnight to bring it to the same temperature as the bottled water.

In April 2008 we collected prices of Evian and five own-brand waters in Asda, Morrisons, Sainsbury’s, Tesco and Waitrose. We obtained Selfridges and Claridges water prices directly from them.