A Fairfax Media survey of bottled water sold in Sydney's cafes, supermarkets and convenience stores has found seven out of 34 brands are "purified" tap water. A glass of water from the tap just isn't cutting it any more, as Australians guzzle more bottled water than ever. Credit:James Brickwood The average price of bottled tap water is $2.75 per litre, with the cheapest being a Pureau 600ml in a six-pack at $1.41 a litre from Coles, and the priciest a Mount Everest 600ml at $4.17/lt from City Convenience – reflecting the logic that buying in bulk leads to a better deal. Sydney's most expensive water is Santa Vittoria in a green 250ml glass bottle at Woolworths. It is a staggering $12/lt – a price usually seen at fancy, hatted restaurants. The average price of spring and mineral water is $5.18/lt, with the bargain being a Harris Farm 600ml at 60¢/lt in a 12-pack.

Australians are guzzling more bottled water than ever before, with the latest Euromonitor figures showing annual sales of still bottled water soared to 466 million litres in 2015, 39 per cent more than in 2010. Judging by price per litre, Santa Vittoria 250ml at Woolworths is Sydney's most expensive bottled water. Credit:Nick Ryan "The two main reasons are health and convenience. A lot of people are switching from soft drink, and bottled water is an easy, on-the-go alternative," said Euromonitor's Sara Agostino. Fairfax Media spotted farcical claims on labels, such as "Suitable for vegetarians and vegans" on Aldi's Northbrook spring water. Fairfax Media's bottled water survey looked at 34 brands. Credit:James Brickwood

The label on Nature's Best carries lines such as "Refrigeration after opening is recommended" and "Not for re-use". Mr Peffer said his water tastes better cold: "If you drink lukewarm water that's been sitting in the car, it's just not so nice, so it's a recommendation to make it nicer." On its website, Saka Water Australia states its spring water from Turkey's Koroglu Mountain has "no sugar, no fat, no calories". Its director Richard Ayoub​ argued the claim is necessary to make people "aware that unlike soft drinks, sports drinks, energy drinks, with Saka Water you are not having any of the above." The website also declares Saka achieves "Better absorption than any other water brand".

Mr Ayoub said tests by a kinesiologist showed: "On average, most regular brands absorb at 60 per cent, tap water at 62 per cent, electric alkaline ioniser at 92 per cent and Saka Water at 99 per cent, 100 per cent with a squeeze of lemon." The survey also found Capi Mineral Water Still has the highest sodium content at 50 milligrams a litre. While sodium is an essential nutrient and consumed in large amounts in food, an official state health guideline suggests people with high blood pressure, heart disease, kidney problems and preparing baby formula should take extra care when the sodium content is above 20mg/lt. Ben Woysky​ from Capi said the bottle featured a typical water analysis of minerals at the source. "These minerals vary season to season and are very dependent on factors such as rainfall and drought periods, which can skew the level of minerals in water," he said.

"The contents of each bottle may not reflect what is actually stated on the label. It is not regulated in Australia." Sydney Water adds small but effective amounts of sodium, fluoride and chlorine, among other things, to produce high-quality tap water that's safe to drink. Its principal public health adviser Peter Cox said guidelines limit sodium to 180mg/lt, but its tap water was well below that and the focus was primarily on taste. Consumers are paying 2000 times more for the convenience of drinking out of a bottle. "We once considered bottling our drinking water, but we learned even if you take the cleanest water out of a spring, the micro-organisms will change the water quality," he said.

"People like to believe bottled water is pure, straight from nature, with no human intervention, but it has to be treated." The survey also found a third of the bottles were tinted blue, which strengthens the image of purity. Some have opted to use see-through labels, such as Capi, Fiji and the new-look Evian, which desires to "showcase the purity of the contents". Gary Mortimer, marketing expert at Queensland University of Technology, said manufacturers use labels, colours and design to appeal to different market segments. "Marketers can't claim bottled water is better for you than tap water, so they use things like 'fresh', 'natural' or use images like snow-cap mountains to lead us to believe that," he said. Of the 34 brands surveyed, eight were from overseas, with Evian, sourced from the French Alps, and Voss, from southern Norway, travelling the furthest.

Do you know more? ehan@fairfaxmedia.com.au Water terms Mineral Water – Ground water obtained from a subterranean water-bearing strata that, in its natural state, contains soluble matter. It must have a level of total dissolved solids of greater than 250 parts per million. No minerals may be added. Natural Water – Bottled spring, mineral or well water which is derived from an underground formation or water from surface water that only requires minimal processing, is not derived from a municipal system or public water supply, and is unmodified except for limited treatment.

Purified Water – Bottled water produced by distillation, deionisation, reverse osmosis. Spring water – Ground water obtained from a subterranean water-bearing stratum that, in its natural state, contains soluble matter. No minerals may be added. (credit: Australasian Bottled Water Institute)