The Cook Islands government must commit to genuine consultations on what it is planning for the Rarotonga water supply, a community group says.
Te Mato Vai - the new multi-million dollar water reticulation scheme is about to go online and the government wants to insure against impurities in the water.
The government said it had yet to decide what purification treatment it would use but the community group, Te Vai Ora Maori, suspects it will be chlorine, to which it is adamantly opposed.
The group's spokesperson, Anna Rasmussen, said it wanted open and fair discussions so the people can discuss the options.
"All of the options, not just chlorine - UV, ozone, analyte, filtration, whatever. This is such an important issue for every single person on the island of Rarotonga because it affects all of us on a day to day basis," she said.
"This is a very big issue. We need consultation on this issue."
Te Vai Ora Maori aims to launch a petition this week, Ms Rasmussen said.