9.9 Discharge from urban water system
The volumetric value for the line item for the 2012–13 year was 31,636 ML. The volume represents treated urban wastewater discharge to surface water within ACT and Murrumbidgee NSW surface water resource plan areas. Information from other urban water systems, particularly within the Northern Basin, was not available. The line item value splits as follows:
- Lower Molonglo water quality control centre: 28,988 ML
- Uriarra wastewater treatment plant: 10 ML
- Queanbeyan wastewater treatment plant: 2,638 ML
When there is storage capacity, water diverted from the rivers is treated at Mount Stromlo water treatment plant and then transferred to Googong Reservoir via the water reticulation network. This transfer volume (of 66 ML) is not included in this line item value because this volume has already been accounted in line item 9.4 Runoff to surface water.