Mundaring Wastewater Treatment Plant

The Mundaring Wastewater Treatment Plant was built in 1997 to serve Mundaring's town centre, the Mundaring Christian School and the Mundaring Primary School. The treatment plant is situated on the corner of Darken and Walker streets, Mundaring.

The treatment plant was built on a request from the Department of Health as the septic tanks in the town centre were not working efficiently and there were concerns by the Mundaring Shire Council that the raw wastewater would pollute Bugle Tree Creek. In addition, the Department of Education were paying costly transport fees to tanker the raw wastewater from the schools to Midland, where it entered the metropolitan wastewater collection system.

Two treatment modules were proposed to cater for the Mundaring town centre and the two schools. Each module has a capacity of 100kL/day and this is about the volumes of wastewater generated by 500 people. Only one module was built and commissioned in 1997 with the second module recommended to be built in 2006 depending on the growth in the town centre. Aerators were installed in 2007 to increase the capacity to 120kL/day while the plans for adding on the second module were being assessed.

The treatment plant now treats 120kL of raw wastewater a day, which is its full capacity. At this size, it is one of the smallest wastewater treatment plants in Perth. Wastewater enters through a 100mm pressure main from a pumping station delivering a flow of six litres a second.

Plant Operations 

Wastewater is treated using an activated sludge process. It treats the raw wastewater by aerating and decanting the wastewater alternately. The wastewater is then disinfected through an ultra violet light and sent to a constructed wetland where additional polishing occurs. The treatment process removes the nutrients and pathogens from the raw wastewater so it can be re-used safely without causing any public health or environmental impacts.

Plant Upgrade 

During summer, the treated wastewater is used to irrigate Harry Riseborough Oval. The irrigation program is managed by the Shire of Mundaring and regulated by the Department of Health. The Mundaring Shire Council obtained approval by the Department of Health for the re-use program and it undertakes monthly monitoring for pathogens to maintain compliance.

During winter, the treated wastewater is directed to Jarrah Creek via a 2km pipeline from the treatment plant down to Jarrah Road. The Corporation undertakes monthly monitoring of the water in the creek at a number of sites along Jarrah Road. Samples are taken to measure the concentrations of nutrients and pathogens upstream and downstream of the discharge point.

For further information contact:

Margaret Domurad
Supervising Engineer
Water Technologies Division
Phone: (08) 9420 3711