19.6 Discharge from urban water system to irrigation scheme
a. Discharge from urban water system to irrigation scheme
The volume (21,586 ML) reported is the volume of recycled water supplied from SA Water's wastewater treatment plants (WWTP) to irrigation schemes within the Adelaide region during the 2012–13 year. The following table details the volume supplied from each WWTP to the respective irrigation scheme.
|WWTP||Irrigation scheme||Volume (ML)|
|Bolivar||Virginia Pipeline Scheme||18,247
|Christies Beach||Willunga Basin Water Company||2,939
|Aldinga||Willunga Basin Water Company||400
Barossa Infrastructure Limited does not receive recycled water from Adelaide's urban water system.
b. Recycled water system overview
- urban water supply system
- wastewater system
- recycled water system.
In the Adelaide region, the majority of wastewater treatment plants produce recycled water which is subsequently provided to users (including irrigation schemes) or used on-site.
During the 2012–13 year, the majority of recycled water produced (75%) was provided to the region's irrigation schemes (line item 19.6 Discharge from urban water system to irrigation scheme). Approximately 17% was supplied for urban consumption (part of line item 19.4 Delivery to urban water system users) and a very small volume (113 ML) was injected to groundwater for later use (line item 19.9 Managed aquifer recharge). The remaining recycled water (approximately 8%) was recirculated back into the wastewater system (and therefore not reported in the water accounting statements).
The following figure presents the inflows and outflows associated with the recycled water 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 asterisk (*) indicate flows between urban subcomponents and are not reported in the Account 2012. As such, these flows do not have an associated line item number or note.
Schematic diagram of water inflows and outflows for Adelaide's wastewater system during the 2012–13 year; line item numbers are provided in brackets
WWTP records and Supervisory Control and Data Acquisition database (SCADA).
The metered volume of recycled water transferred from Bolivar, Christies Beach and Aldinga WWTPs to the irrigation scheme was obtained from SA Water's WWTP records. Metered flows are either automatically logged by SCADA or manually read and recorded by plant operators.
Assumptions, limitations, caveats and approximations
The volume reported does not include any recycled water supplied from community waste management systems managed by local councils.
Uncertainty is +/– 10% based on meter calibrations.