Water treatment in the ACT

There are two primary water treatment plants in the ACT, both providing world-class water quality to ACT residents.

Mount Stromlo

The original Mount Stromlo water treatment plant was commissioned in June 1967. It contained facilities for the chlorination, fluoridation and pH correction of all water drawn from the Cotter system of rivers and dams.

However, after the 2003 bushfires, a new water treatment plant was needed to treat water from the damaged Cotter River catchment. A new, more sophisticated Mount Stromlo water treatment plant was therefore commissioned in November 2004.

Learn more about the New Mount Stromlo water treatment plant.

Googong

The Googong water treatment plant pumps water from the Queanbeyan River catchment, which feeds Googong Dam.

As the catchment area for this dam includes land used for rural purposes and the dam itself is used for some recreational activities, more treatment is required.

The treatment of the Googong reservoir water involves conventional treatment such as:

• coagulation by liquid alum and a polymer coagulant aid
• flocculation
• clarification and filtration
• disinfection by chlorination
• pH adjustment and stabilisation with lime
• fluoridation by sodium silico fluoride.

The associated costs of pumping and chemical dosing makes this treated water much more expensive than water treated at the Mt Stromlo WTP. The first stage capacity of the plant is about 180 million litres per day.

Legal requirement for clean water

There are laws to ensure that the ACT’s water supply provides healthy, high quality, water.

ACTEW Corporation has a licence under the Public Health Act (1997), which states the organisation must abide by the ACT Drinking Water Quality Code of Practice 2000 .

ACTEW monitors water quality at all stages of the urban water cycle including testing samples from household taps from around the ACT.

ActewAGL publishes a monthly Water and Wastewater Performance Report outlining the results of this water testing.