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Lower Molonglo Water Quality Control Centre

The Lower Molonglo Water Quality Control Centre (LMWQCC) is the main treatment facility for Canberra and is the largest inland treatment facility in Australia.

Sewage is treated and released into the Molonglo River. It then flows into the Murrumbidgee River and drains into the Murray-Darling Basin river system, ultimately discharging into the ocean south of Adelaide. Water leaving this plant has been thoroughly treated, so it returns to the natural water cycle free of pollution and can be reused by other towns further downstream. The process includes physical, chemical, and biological treatment processes before the water is discharged into the Molonglo River.

Icon Water's treatment process ensures that the water that is discharged into the Molonglo River has minimal impact on the environment and downstream users. The ACT Environmental Protection Act 1997, under which LMWQCC operates, sets strict licence conditions aimed at protecting the rivers into which water is discharged. LMWQCC meets these licence requirements, including chemical testing and biological monitoring programs. 

Extensive monitoring is undertaken to ensure water quality, and ecological monitoring, such as the Fish Monitoring Program, provides information on the river's health. The numbers of macro invertebrates, which are small crustaceans and insects, are also monitored regularly. The treated water from LMWQCC plays an important role in keeping the rivers flowing, especially during dry periods.

In line with Icon Water's commitment to ecological sustainability, LMWQCC has developed an Environmental Management Program.


LMWQCC was the first sewage treatment facility in Australia to gain certification for the following International Standards:

  • AS/NZS ISO 9002 - Quality Management Systems

  • AS/NZS ISO 14001 - Environmental Management Systems

During the treatment process all of the solid material, which is called "sewage sludge", is removed and incinerated in a high temperature furnace. The resulting ash, Agri-Ash, is sold to farmers as a soil conditioner.


Each day LMWQCC:

  • treats up to treats 80 to 90 million litres of wastewater

  • reuses an average of 10 million litres of non-potable water for plant operations

  • removes 4 to 5 million litres of sludge from the process for dewatering and incineration

  • produces approximately 16 tonnes of Agri-Ash.

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