Thames Ward voters will have a binding referendum in 2015 to determine whether or not their water supply will continue to have fluoride added.

This referendum will be held in the second half of 2015, with details of dates and costs to be worked out next year.

A binding referendum will be held in 2015 on whether or not fluoride should continued to be added to Thames' water supply. Photo: File

The Thames Coromandel District Council made the decision at its final meeting for the year this week, fulfilling the expectation by many that the full council would consider the matter again.

Fluoride is only used in Thames and council records indicates it was first added with the opening of the area's water treatment in 1971 to protect teeth and limit tooth decay.

The Ministry of Health says fluoride does this in three ways by; increasing resistance to tooth decay, interfering with bacteria that causes decay, and helping repair teeth in early stages of decay.

The Drinking Water Assessor and the ministry recommends that 0.7 - 1.0 milligrams per litre of fluoride is added, which is safe for the purposes of oral hygiene.

The ministry's Public Health Unit notes its presence in its annual reports and the Drinking Water Assessor carries out audits on our entire water supply activity.

A referendum is a form of poll where, in this case, those on the electoral role registered in the Thames Ward will be able to vote. The largest number of votes will determine the outcome.

For more information about fluoridation of Thames's water supply click here.