The recent heavy rainfall in the Glenbawn Dam catchment has caused problems with effective water treatment making drinking water in the Scone water supply system register a poor raw water quality measurement.

Upper Hunter Shire Council is working to fix the problem and will notify residents as soon as the water quality risk has returned to normal.

"We ask residents not to be alarmed - this alert to boil all drinking water is a proactive and preventative measure to manage the risk and ensure the safety of residents," a spokesperson said.

WATER used for drinking or food preparation should be brought to a rolling boil to make it safe. Kettles with automatic shut off switches can do this. Water should then be allowed to cool and stored in a clean container with a lid and refrigerated.

Bottled water or cool boiled water should be used for drinking, washing uncooked food (e.g. salad vegetables and fruit), making ice, cleaning teeth, gargling and pet's drinking water.

Dishes should be washed in hot soapy water or in a dishwasher. Children should take bottled water or cool boiled water to school.

If you cannot boil the water, unscented household bleach (containing 4% - 5% available chlorine) may be used. Add 2 drops of bleach to 1 litre of water (or 4 drops if the water is cloudy), mix well, and allow to stand for 30 minutes before use.

The NSW Health website also includes special considerations for:

HEAVY continuous rainfall in the Glenbawn catchment has caused the Aberdeen River turbidity level to increase.

Based on the latest water quality results from the Scone water supply system, the turbidity is now too high to adequately guarantee the safety of the water for human consumption.

This does not mean the water is unsafe - only that the risk of it being unsafe is too high.

Based on NSW Health advice, Upper Hunter Shire Council have issued a boiled water alert.

Further information will be provided by council when available.