Chlorine will be used to disinfect the new pipes being laid to supply potable water in Rarotonga, says the project management unit.
But anti-chlorine group Te Vai Ora Maori wants the unit overseeing the multi-million dollar Te Mato Vai project to look into “safer” methods.
Project Management Unit spokesperson Kate Woodruffe said the new pipes would be disinfected using a one-off “flushing” with chlorine, before the water supply was connected to households.
She was responding to queries about the new polyethylene pipes for the stage one remedial work, which had been left in the open without any endcaps. These pipes have been left without any cover by contractors Landholdings Ltd.
In 1960s, asbestos-cement pipes left in the open before they were connected to the water supply resulted in a gastro outbreak that is believed to have caused three deaths.
An inquiry found the outbreak was caused by people drinking water from an untreated pipeline. The pipes left in the open for a period of time were contaminated by rats and mice faeces.
Woodruffe said they would clean the new pipes before they were used to carry water, to ensure they did not contaminate the water supply. Chlorine is the option being planned.
But Te Vai Ora Maori’s Justine Flanagan said there were other methods of disinfecting the pipes.
The group is suggesting two methods; one using high pressure water and other way by using anolyte. “Anolyte does not have negative impact on the biodiversity while chlorine does,” Flanagan said.
Woodruffe also said after flushing, the chlorinated water would be “removed and disposed of responsibly”.
“No chlorine will be added to the water supply at this time,” she said.
However Flanagan said the unit needed to provide details on how the chlorinated water would be removed and disposed of responsibly. “They need to come out clear and define what they mean when they say the chlorinated water will be disposed of responsibly.”
Woodruffe said the remedial work fixing the substandard work done by the Chinese contractors in stage one of the Rarotonga’s water project was on schedule. The upgrade work which was supposed to start last weekend is expected to be completed by mid-2020.