19.9 Managed aquifer recharge
a. Managed aquifer recharge
The volume reported (113 ML) represents the volume of recycled water injected to groundwater as part of the Aldinga Aquifer Storage and Recovery Scheme. The recycled water is supplied from the Christies Beach Wastewater Treatment Plant and injected to the Port Willunga Formation aquifer for temporary storage. The injected recycled water is subsequently supplied to the Willunga Basin Water Company for irrigation (refer to line item 12.3 Entitled extraction of non-allocated groundwater to irrigation scheme). The 2012–13 year was the first year that the Aldinga Aquifer Storage and Recovery Scheme operated.
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
Wastewater treatment plant (WWTP) records and Supervisory Control and Data Acquisition database (SCADA).
The metered volume of recycled water injected to groundwaterwas supplied 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 water injected to groundwater by managed aquifer recharge schemes that are not operated by SA Water.
Uncertainty is +/– 10 based on meter calibrations.