Snowy River Shire Council discovered last week that fluoride levels in local drinking water were almost double the guideline amount.
An electrical fault is suspected to have been the culprit but until this is proven the dosing plant will remain switched off.
The overly-high fluoride level was discovered by council on Monday December 2; but it only issued information about the incident to the Summit Sun last Friday afternoon.
The high level was found during routine daily monitoring. Drinking water delivered to Jindabyne was found, at its highest concentration, to have reached 2.8 milligrams per litre. The Australian Drinking Water Guideline is 1.5mg/L. According to council, this level has been set to protect against mottling of teeth by long-term exposure to high concentrations of fluoride. By Thursday evening the level had dropped significantly, down to 1.7mg/L.
For context and perspective, the United States Environmental Protection Agency's standard for the highest level of fluoride allowed in public water supplies is 4.0mg/L, council said.
Council deactivated the fluoride dosing plant on Monday December 9 and added water without fluoride into the supply to dilute the concentration of fluoride.
Council anticipated that the level would be back within the Australian guidelines during last Friday.
It said that NSW Health and the NSW Office of Water had been kept informed of the situation.
Council has initiated an investigation into the cause of the incident, suspecting an electrical fault in the dosing plant allowed fluoride to enter the supply in the absence of water flow.
NSW Health has confirmed that the levels of fluoride in Jindabyne's drinking water during this period did not present any short or long-term health effects to anyone, including babies, who consumed the water.
Not all properties in Jindabyne were affected. Only properties on Thredbo Terrace, the Old Shopping Town Precinct and on the lake side of
Kosciuszko Road are supplied from the system affected.
For further information contact Gnai Ahamat, Manager
Water and Waste Water, or Yvonne Menere, Manager Regulation and
Compliance, on 6451 1195.