Water upgrades follow outbreak

22:05, Dec 19 2013

Cardrona water supplies have been upgraded with better bore protection and treatment of the source water, the Southern District Health Board says.

Public Health South is continuing to work with the Cardrona community, Queenstown Lakes District Council and the Otago Regional Council after an acute month-long outbreak during last year's ski season that caused at least 53 cases of norovirus.

The health board's medical director, , Marion Poore, said the water management system was upgraded after the outbreak, with better bore protection and treatment of source water.

"Outbreaks can occur if any part of the water reticulation system is breached. The steps taken following this outbreak will reduce the chance of further outbreaks," Dr Poore said.

The Queenstown Lakes District Council was working closely with the Otago Regional Council on implementing a strategy, she said.

Privately owned water bores in small communities are not subject to council-run monitoring programmes and are normally managed by the property owners or management companies.


Council general manager of infrastructure Erik Barnes said Cardrona water and sewerage systems were private schemes and not council assets.

"With that said, we played a vital role when the outbreak occurred to support the community in assessing the issues, cleaning the supply, and providing advice on fixing and maintenance," Mr Barnes said.

"Council also loaned the water company a surplus UV water treatment system to increase the level of safety for users."

The water supply was under new management and was actively monitored while the council worked on options for council- managed options, he said.

Piping waste to Wanaka was feasible although there were some technical hurdles to resolve. It was also possible to include the Cardrona skifield in a pipeline to remove waste from an alpine environment.

"The ultimate responsibility for the current private schemes lie with the owners. Council is here to help and work with the community on long-term options," he said.

An article in the New Zealand Medical Association journal by Dr Derek Bell, Susan Jack and Joanne Hewitt concluded a strategy was "urgently required" to decrease environmental contamination of drinking water supplies, improve sewage disposal and manage drinking water in Cardrona.

The report's authors believed there was a link between the contamination of drinking water and illness, and that problems with the hotel water system management and wastewater - specifically groundwater intake separation distance - contributed to the outbreak.

Water management for a neighbouring resort was inadequate, unfiltered and untreated from a bore that was not fully protected, the article said.

Public Health South investigated the waterborne gastroenteritis outbreak that infected at least 53 people in and around Cardrona in mid-August and early September last year.


The Southland Times