This line item refers to the treated wastewater discharged to the sea.
The total volume of treated wastewater discharged to the sea from each treatment plant during 2009-10 is given below.
|
Wastewater treatment plant |
Total outflow (ML) |
|---|---|
|
Perth city region |
|
|
Beenyup |
46,534 |
|
Point Peron |
5,922(1) |
|
Subiaco |
21,033 |
|
Woodman Point |
42,895(1) |
|
Yanchep |
123 |
|
Total discharge to sea |
116,507 |
(1) Based on measured data
Water Corporation: Operational Data Storage System.
Water Corporation.
There are 14 wastewater treatment plants within the Perth region, only five of which discharge treated wastewater into the sea (Woodman Point, Beenyup, Point Peron, Subiaco and Yanchep).
The outflow volume from Woodman Point and Point Peron treatment plants are based on measured discharge data collected by flow meters installed at each site.
For the remaining three treatment plants, outflow data are not collected and, therefore, the total volume of wastewater discharged into the sea is estimated as total inflow of wastewater into the treatment plant minus the volume of water recycled. Both inflow and recycled volume data are based on measured discharge data collected at each site.
This value is estimated to be in the range of +/- 5-10%.
At the treatment plants where outflow data are not measured, it is assumed that the volume of wastewater discharged into the sea is simply the total inflow of wastewater into the treatment plant minus the volume of water recycled, and that there are no other losses.