An assurance that Masterton's water supply meets national standards and is safe to drink for the foreseeable future has been given by the chief medical officer of health Dr Don Mackie.

Masterton District Council's Policy and Finance Committee yesterday received an assurance from Dr Mackie to that effect, in answer to concerns raised by Masterton resident Stephen Butcher over water standards.

Dr Mackie said Mr Butcher had written repeatedly to the Minister of Health and health officials over chlorination of water supplies.

He had been told standards have been prepared "in close accordance with the latest editions of the Guidelines for Drinking Water Quality produced by the World Health Organisation".


Chlorine, said Dr Mackie, was not in itself carcinogenic.

"However, chlorine combined with organic matter can form by-products that may be carcinogenic and the standards are designed to limit the formation of chlorine by-products by ensuring chlorine is added to water of low turbidity."

The acceptable cancer risk used in New Zealand relating to carcinogens in the water standard is one additional incidence of cancer in a population of 100,000 for someone drinking two litres of water every day for 70 years.

Dr Mackie said by meeting drinking water standards the Masterton supply was safe to drink "throughout your residents' lifetimes."

"If Mr Butcher remains concerned about the quality of his water, he may wish to seek an alternative drinking water source for his personal consumption," Dr Mackie said.

Receiving the report from Dr Mackie councillors at the meeting questioned whether discussions on such health matters as chlorine in water, or fluoridation should be in the council's domain.

Councillor Brent Goodwin said it seemed they were issues that should be addressed by Wairarapa District Health Board.

The committee thanked Mr Butcher for his on-going research and interest in water standards, which has also involved research into pH levels in water.

Councillor Gary Caffell said he didn't appreciate Dr Mackie's reference to Mr Butcher being at liberty to seek his own personal water source if he was not satisfied with the town supply, calling it "cheeky."

Assets manager David Hopman, who has been involved in water discussions with Mr Butcher, said he could assure councillors Mr Butcher already had his own water supply.