Canberra
9.9 Discharge from urban water system
Supporting Information
(1) Overall
This line item is made up of several components. When capacity is available, treated water is transferred from Mount Stromlo Water Treatment Plant into Googong Reservoir via the water reticulation network. In addition to this there are two wastewater treatment plants (WWTPs) within the Canberra region that discharge treated water into the Molonglo River: the Lower Molonglo Water Quality Control Centre (LMWQCC) upstream from the Confluence with the Murrumbidgee, and the Queanbeyan WWTP upstream of Lake Burley Griffin. Only the LMWQCC and the Queanbeyan WWTP discharged treated wastewater to the surface water store.
The following table contains a breakdown of the volume of water discharge to surface water at each WWTP and the volume of water transferred to the Googong Reservoir.
Plant | Volume treated (ML) | |
Non-potable | Lower Molonglo Water Quality Control Centre | 32,243 |
Queanbeyan Wastewater Treatment Plant | 2,654 | |
Subtotal | 34,897 | |
Potable | Mount Stromlo Water Treatment Plant | 4,365 |
Subtotal | 4,365 | |
Total | 39,262 |
(2) ActewAGL – Potable water discharge
Under the urban water utility water access entitlement, ACTEW abstracts water from the regulated storages of Bendora and Cotter reservoirs, and the unregulated system of the Murrumbidgee River and transfers this water to Mount Stromlo Water Treatment Plant. If capacity is available, it is also possible to transfer treated water from Mount Stromlo Water Treatment Plant into Googong Reservoir via the water reticulation network.
(3) ActewAGL and Queanbeyan City Council – Treated wastewater discharge
The previous table provides a breakdown of the volume of wastewater discharge to surface water at each WWTP in the Canberra region for the 2010–11 year. Only the Lower Molonglo Water Quality Control Centre and the Queanbeyan WWTP discharged treated wastewater to the surface water store.
Quantification Approach
(1) ActewAGL – Potable water discharge
Data Source
Provided by
Method
ActewAGL's flow meter measures the release from the water distribution system to Googong Reservoir.
Assumptions, Limitations, Caveats and Approximations
Nil.
Uncertainty Information
Derived from measured data. Estimated uncertainty is +/– 5%.
(2) ActewAGL – Treated wastewater discharge
Data Source
Provided by
Method
Treated wastewater discharged to the surface water store was measured by WWTP outflow flow meters. The 2009–10 discharge volume was extracted from the ActewAGL Water Data Warehouse. The Lower Molonglo Water Quality Control Centre is the only ActewAGL WWTP that discharges treated wastewater to the surface water store. Fyshwick WWTP has not been included in this line item, as discharges from this facility are directed back to the wastewater system or to the recycled water system.
Assumptions, Limitations, Caveats and Approximations
Nil.
Uncertainty Information
Derived from measured data. Estimated uncertainty is +/– 5%.
(3) Queanbeyan – Treated wastewater discharge
Data Source
Provided by
Method
Treated wastewater discharged to the surface water store was measured by WWTP outflow flow meters. The 2009–10 discharge volume was extracted from the QCC database. The Queanbeyan WWTP is the only QCC WWTP that discharges treated wastewater to the surface water store.
Assumptions, Limitations, Caveats and Approximations
Nil.
Uncertainty Information
Derived from measured data. Estimated uncertainty is +/– 5%.