But why would we drink it when we have bottled varieties that can be bought in any shop, café or restaurant for up to 10,000 times the cost?

It’s no exaggeration – that is literally what the Western consumer is willing to pay for a product that is very nearly free from every tap in our own homes. Bottled water is now the accepted norm for kitchen tables and top-notch eateries alike, not to mention offices, gyms, parks, train stations, schools and every other conceivable venue where you might likely be struck by thirst. And what’s the difference between the water in bottles and the water in taps? In a word, marketing.

Marketing would have us believe that bottled water is a safer, healthier and better tasting alternative to tap water. Science tells us otherwise.

The unprecedented and hugely profitable expansion of the bottled water industry over the last three decades started as – and indeed continues to be – a social fad. The fitness craze of the early 80’s was a major catalyst, and as public interest in healthy lifestyles gained momentum, so did corporate interest in the moneymaking potential of bottled water. That potential is currently realized at an estimated $46billion (USD) per annum worldwide.

Of course, the marketing guys couldn’t believe their luck when the brief landed on their desks. Here was a product that could be feasibly plugged as a cure-all to a substantial slice of Western health hang-ups. It provides energy, but no calories; it aids weight-loss; it complements fitness; it promotes clear skin and general wellbeing – in short, it’s a lazy step closer to looking like the supermodels who were quickly recruited to the cause. There is no denying water is good for you and, packaged in a convenient bottle, consumers were soon keen to be seen clutching the magical elixir as a the ultimate fashion accessory.

Around 150 billion litres of bottled water will have been sold this year, the vast majority to people with a safe and readily available public water supply. Meanwhile, in countries that aren’t so fortunate, 2.5 million people will have died as a direct result of drinking contaminated water.

However, the claim that bottled water is safer and healthier than tap water in developed countries is somewhat spurious. As a beverage, water is subject to far less stringent regulations and testing than as a public service. The stuff that comes out of a bottle is allowed to have higher concentrations of bacteria, nitrates and additives than the stuff that comes out a tap, and research finds that it regularly does.

A four-year American study of 103 brands (a thousand bottles of each) found that a third of them were found to contain contaminants such as arsenic and carcinogenic compounds in at least some bottles exceeding (self-regulated) industry standards. E.coli and faecal contamination were also occasionally present. By rough comparison, the Drinking Water Inspectorate reported an average compliance (to stricter standards) for the whole of England’s tap water as 99.94% over the 1.8 million tests in 2004. Anyone still cynical would do well to look to recyclable filters as an affordable, eco-friendly and safe alternative to both.

So what about the taste? Highly publicised blind tastings on both sides of the Atlantic confirm that around three quarters of us cannot differentiate between bottled and tap.

And that’s probably because some of it actually is identical. As much as 25% of bottled water is actually derived from municipal sources: in other words, it comes from a tap, gets put in a bottle and is sold back to us at a comfortable profit. Dasani – a fairly new brand owned by Coca Cola – admits that its UK source is the mains supply at its factory in Kent. They’re certainly not the only culprits, but there’s no law banning pretty pictures of glaciers and mountain springs on the labels. 

Part of the problem is that there are different types of bottled water, and each type is regulated in different ways in different countries. Mineral water in Europe, for example, must demonstrate constant levels of minerals and trace elements and cannot be tampered with in any way. In the US there is a level of dissolved solids that has to be met. Spring water there can be sourced from the surface, whereas in Europe it must be sourced underground. Purified or still water is the least regulated of all categories and can be highly treated: it differs from tap water only in distribution method and price.

But the real cost of bottled water is its environmental impact. More than 2 million tons of plastic in the form of packaging is needlessly discarded each year, whilst incalculable energy is used to pump, process and bottle it in the first place. Then take into account the implications of national and international transport and refrigeration and the pollution toll stacks up on top of that. Fragile rural ecosystems are endangered by unscrupulous corporate policies, interested only in extracting as much water for as much profit as possible. Many of these ecosystems also support human populations with too little purchasing power to buy the water that is being taken from them. Does a community leader in Brazil really stand a fighting chance in his battle against Nestlé’s illegal water operation in his hometown?

If Western consumers spend the same amount of money on water projects in developing countries as they undoubtedly will on bottled water in the next few years, we could conceivably eradicate the problem of unsafe drinking water – globally – in the very near future. Perhaps it’s time to appreciate what we have freely available to us and use bottled water only in the parts of the world where it’s actually needed.