19.7 Wastewater discharge outside of region
a. Wastewater discharge outside of region
The volume reported (63,032 ML) represents discharge from five wastewater treatment plants (WWTPs) in the Adelaide region to the sea. The wastewater discharge, itemised by WWTPs, during the 2011–12 year is shown in the following table.
|WWTP||Discharge volume (ML)|
|Bolivar High Salinity||7,974|
b. Wastewater system overview
The wastewater system is one of three sub-components of Adelaide's urban water system. The three sub-components are the:
- urban water supply system
- wastewater system
- recycled water system.
In the Adelaide region, wastewater is collected (line item 11.4) from users and treated by SA Water at one of their wastewater treatment plants.
During the 2011–12 year the majority (70%: line item 19.7) of treated wastewater was discharged to sea; approximately 25% was recycled (see recycled water system overview) and the remaining portion was discharged to surface water (2%: line item 19.5) or lost during wastewater treatment processes (3%: part of line item 19.20).
The following figure shows all the inflows and outflows associated with the wastewater system. For more detail on a particular flow associated with the wastewater system, refer to the line item notes. A small misbalance is shown and can be attributed to metering inaccuracies and unaccounted losses.
Note that volumes annotated with a * 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 for Adelaide's wastewater system during the 2011–12 year; line item numbers are provided in brackets
Five WWTPs discharge wastewater to the sea:
- Bolivar High Salinity
- Christies Beach
The metered volume of wastewater discharged from these WWTPs in 2011–12 was supplied from WWTP records held by SA Water. These metered flows are manually read and recorded by plant operators.
Assumptions, limitations, caveats and approximations
- This item does not include any community waste management schemes which are managed by local councils.
Uncertainty is +/– 10% based on meter calibrations.