Waikato residents told dirty, smelly water safe

By ELIZABETH BINNING

Waikato's water may smell strange and taste awful but it still meets New Zealand standards and is safe to drink.

Algal blooms growing in the Waikato River have affected the taste and odour of drinking water in several parts of the Waikato, including Hamilton, Cambridge and Huntly.

Auckland, which receives about 10 per cent of its water from the Waikato River, has not suffered because technology at the new Tuakau treatment plant is advanced enough to filter out the algae.

The naturally occurring algae have been growing in the river since the warmer weather started last month.

Since then, councils which draw their drinking water from the river have been contacted by dozens of residents who are unhappy with the musty taste and smell of the water.

In Hamilton, where 120,000 get their drinking water from the river, residents have also complained about the colour of the water.

Hamilton City's water and wastewater plants manager, Marcus Shipton, said it was not unusual for the algae to appear each summer as the river water heated up.

But this year the algae are worse than normal and Hamilton's treatment plant, which is due for a $5 million upgrade in 2006, is not able to filter them out.

The council will start investigating ways of removing the musty taste and smell from the contaminated water next week.

A second investigation is also being held to try to establish the cause of brown water in the Melville and Chartwell area.

Options for dealing with the algae include using chemicals or activated carbon to treat the odour and neutralise the taste.

However, Mr Shipton said it might take a while, possibly the whole of this summer, to find a suitable solution.

"We will then do a trial at the water treatment station and check the results.

"It may take a few trials to find a solution."

A permanent treatment for the algal bloom, possibly similar to the filtration system built into the Watercare Services plant at Tuakau, will be included in the 2006 upgrade.

In the meantime, many people have resorted to drinking bottled water from the supermarket rather than risk what is coming out of their tap.

But despite the taste, Mr Shipton said, the water was regularly monitored and safe to drink. It continues to comply with New Zealand drinking water standards.

Waikato medical officer of health Felicity Dumble said there had not been any reported health effects from the algae-infested water so far.

"We are however keeping a close eye on it and Environment Waikato is taking samples."

Dr Dumble said people who drank directly from the river could experience conditions such as stomach aches or diarrhoea.

People concerned about the taste of their water are advised to cool it in the fridge and let it stand for a while. This helps reduce the bad taste.

Other councils in the Waikato are also working on ways to minimise the algae's effects.

They are also reassuring residents that the water is safe to drink.

Herald feature: Environment