Synopsis

The Shire of Mundaring, a Water Campaign™ participant since 2004, is located in Perth’s Eastern Metropolitan region.

Council is playing an important part in meeting the state’s wastewater reuse goal and improving the water quality of a local creek through a joint wastewater reuse project with the Water Corporation.

In the Perth metropolitan area the Water Corporation’s wastewater treatment plants treat and discharge approximately 100GL of water a year. This wastewater is a valuable resource which could be used to substitute scheme and groundwater supplies (Government of Western Australia 2003).

The State Water Strategy sets a target of 20 per cent wastewater reuse in Western Australia by 2012. Currently in the Perth metropolitan area only 3 per cent of wastewater is recycled. Parks and gardens irrigation has been identified as an important recipient of this water within the State Water Strategy (Government of Western Australia 2003). Wastewater recycling on public ovals and playing fields has been operating successfully in rural and regional Western Australia for many years. In these areas, approximately 40 per cent of wastewater is reused.

Approach underway

Wastewater from the local Mundaring Wastewater Treatment plant, which treats water from the central business district and surrounding area is being combined with groundwater and used to irrigate one of the Shire’s most popular sporting venues, Harry Riseborough Oval.

Health implications: 

In order to ensure that there is no community health problems associated with the use of the wastewater, the scheme operates within strict Department of Health guidelines. Water quality testing is conducted regularly by the Shire to ensure water quality is maintained. If pathogens within the water exceed set standards the irrigation is switched back to scheme and ground water.

As an extra precaution watering is confined to between midnight and 4am. This will allow any bacteria to die prior to use by the public. Signs are also installed around the oval to inform the public that treated wastewater is used in that area.

Maintenance issues:

Aside from regular water testing, irrigating with treated wastewater does not require any changes in the irrigation infrastructure or maintenance.

Savings and Benefits

The project will save an estimated 3700KL of drinking water and groundwater each year while significantly reducing the treated wastewater flow into Jarrah Creek.

Mundaring Wastewater Treatment Plant treats 80KL of water a day. During the months when the oval needs to be watered (generally November to March), all of the treated wastewater is reused at Harry Riseborough Oval (Water Corporation 2003).

The wastewater also contains higher levels of nitrogen and phosphorous than other sources of water. If the water is applied properly it can offset the need for fertilisers. Ongoing soil testing will ensure that the water doesn’t become a source of pollution for surface and ground water bodies.

Learnings

The Shire found that extensive community and staff consultation and communication was vital to the success of the project. For the community to accept the use of the treated wastewater they must be satisfied that their health concerns have been addressed.

The project was also successful because the Shire was involved at an early stage of the construction of the wastewater treatment plant. In the original design of the treatment plant, provision was made for a pipe to deliver the wastewater to the Harry Riseborough Oval for reuse. The pipe was left unused until the approvals could be obtained from the relevant authorities. The fact that the infrastructure to transport the wastewater was integrated into the initial design of the treatment plant allowed the project to be implemented without the technical difficulties that might be associated with constructing infrastructure around an existing plant.

References

1. Government of Western Australia (2003) Securing Our Water Future A State Water Strategy for Western Australia Perth WA
2. Water Corporation (2003) Wastewater Treatment Branch Annual Report 2002/2003 http://www.watercorporation.com.au/wastewater/wastewater_wwreport.cfm (accessed 27th June 2005)

ICLEI-A/NZ would like to acknowledge the assistance of Mr Adrian Dyson and the Shire of Mundaring in the production of this case study.
For further information about this project contact:

Adrian Dyson
Manager Health Service
Shire of Mundaring
7000 Great Eastern Highway
Mundaring WA 6073
Tel: (08) 9290 6659
Email:adriandyson@mundaring.wa.gov.au

 

To top