Tests show tap water just as good as bottled varieties

11.45am

Millions of dollars are being wasted as the hype over bottled water sweeps the country.

Sales in New Zealand are valued at $58 million but an analysis conducted for The Aucklander newspaper by Hill Laboratories reveals ordinary tap water is every bit as good as bottled water.

Unless a consumer has a strong aversion to low levels of fluoride (tap 0.7, bottle 0.1), water drinkers can save thousands of dollars by using household supplies.

Anyone can go into the bottled water industry simply by adhering to sterile bottling standards and trade description limitations and match the big boys, courtesy of Watercare and the garden tap.

One alarm bell was the discovery of the possible carcinogen, bromate, in one of the bottled water samples.

The Aucklander sent 21 water samples to Hills for analysis. Twelve were water collected from domestic taps in households in the paper's six circulation areas in greater Auckland. The samples were taken at homes in Browns Bay, Ponsonby, Titirangi, Onehunga, Howick and Papakura.

One of the two household samples taken in each area was bottled straight from the tap. The second sample was boiled in a stainless steel pan until steaming and then poured into a sterile container.

Against these samples were nine popular bottled water brands sold at supermarkets or dairies.

The paper's shoppers randomly selected from the shelves: Pam's Natural Spring 600ml ($1.99); NZ Natural 725ml ($1.74); Evian 1.5litre ($2.89); Kiwi Blue 750ml ($1.59); Mizone Lemon 800ml ($2.39); Deep Spring 1.5litre ($1.09); Waiwera 750ml ($1.79); H2Go 425ml ($1.12) and Pump 750ml ($1.69).

Hill Laboratories Environmental Division manager Peter Robinson notes: "The only major difference between the tap and bottled waters was the level of fluoride in the tap water ( 0.7 against 0.1).

"Boiling the tap water removed the chlorine - but there were no other noticeable changes.

"Unless one has an aversion to the low levels of fluoride in tap water, there is no reason this shouldn't be your major water source."

Other comments:

"The bottled mineral water contained considerably more dissolved solids (salts) and in particular a higher level of calcium (78 vs around 10) so could be useful for calcium supplementation.

"One of the bottled waters contained boron at about four times the New Zealand Drinking Water Standards (5.9 vs 1.4).

"None of the samples contained arsenic and only insignificant amounts of other heavy metals (lead, copper, zinc, iron, manganese) were found.

"Sodium and nitrate levels were low in all samples - less than a tenth of the NZ Drinking Water Standards level.

"One sample had a very low ph (3.1 compared to rainwater at 5.6 and the tap samples at around 7.5). This could have an effect on teeth, but stomach acidity is also around 3.5.

"This sample also contained a significant level of bromate, a potential carcinogen."

Source of Auckland water

Watercare is the bulk supplier of water and wastewater services in Auckland and is owned by the six territorial local authorities.

The shareholding is: Auckland 41.6 per cent; Manukau 25.1 per cent; Waitakere 16.7 per cent; North Shore 11.5 per cent; Papakura 3.7 per cent; and Rodney 1.4 per cent.

Watercare's customers are the local councils and United Water (Papakura) who supply water to their areas.

* Watercare supplies around 340,000 cubic metres of water daily from two rivers and one underground source.

* In general, 60 per cent of the region's daily water needs come from the five Hunua dams; 25 per cent from the five Waitakere dams; 10 per cent from the Waikato River and 5 per cent from the Onehunga underground source.

* Just over 60 per cent of all the water supplied goes to households.

* Watercare operates seven water treatment stations in the Auckland region supplying drinking water.

* The newest treatment plant is the Waikato River Treatment Plant at Tuakau with a supply capacity of 50 million litres a day, around 15 per cent of Auckland's daily water needs.


- THE AUCKLANDER