Canberra
19.1 Evaporation from urban water system

This line item refers to the volume of water that was calculated as loss through evaporation at the sewage treatment plants (STPs) in the Canberra region:  Lower Molonglo Water Quality Control Centre (LMWQCC), Fyshwick, Uriarra, Outward Bound operated by ACTEW Water, and the Queanbeyan STP operated by Queanbeyan City Council (QCC). The total volume reported in the 2013 Account is 3,877 ML.

The following figure shows all the inflows and outflows associated with the wastewater system.

The treated wastewater volume discharged to surface water after treatment was 31,636 ML, approximately 77% of total treated wastewater volume, 41,114 ML.

During the 2012–13 year, approximately 12% of treated wastewater was recycled; the rest was the losses. The following figure shows all the inflows and outflows associated with the wastewater system.

For more detail on a particular flow associated with the recycled water system, refer to the line item notes. Note that volumes annotated with an * indicate flows between sub-components and are not reported in the account. As such, these flows do not have an associated line item number.

Schematic diagram of water inflows and outflows during the 2012–13 year for Canberra's wastewater system. Line item numbers are provided in brackets.

The reported volume of water lost through evaporation is calculated as the difference between the known inflows and outflows to Sewerage treatment plants:  LMWQCC, Fyshwick Wastewater, Uriarra, and Outward Bound.

Nil.

The uncertainty estimate was not quantified.

Evaporation was measured from four lagoons, two sludge lagoons, and other smaller open water bodies such as aeration tanks. The moisture content of sludge was not was not included.