Perth
19.7 Wastewater discharge outside of region

Supporting Information

This line item refers to the treated wastewater discharged to the sea.

Total volume of treated wastewater discharged to the sea from each treatment plant during the 2010–11 year is given in the following table.

 

Volume of treated wastewater discharged to the sea from each treatment plant during the 2010–11 year

Wastewater treatment plant

Total outflow (ML)

Perth city area

 

Alkimos

1,074

Beenyup

43,166

Point Peron

6,081

Subiaco

21,220

Woodman Point

45,537

Total discharge to sea

117,078

 

Quantification Approach

Data Source

Water Corporation: Operational Data Storage System.

Provided by

Water Corporation.

Method

The total volume of wastewater discharged into the sea is not metered and is estimated as total inflow of wastewater into the treatment plant minus the volume of water recycled.

Assumptions, Limitations, Caveats and Approximations

Outflows from these treatment plants 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 there are no other losses.

Uncertainty Information

This value is estimated to be in the range of +/– 5–10%.

Comparative year

The following table presents substantive changes in the line item reported in this 2011 Account with the corresponding line item in the 2010 Account.

 

Comparative year information for line item 19.7

2011 Account line item

2010 Account line item

2011 Account volume for the 2009–10 year (ML)

2010 Account volume for the 2009–10 year (ML)

Change from the 2010 Account to the 2011 Account

19.7 Wastewater discharge outside of region

20.4.2 Wastewater discharge out of entity

116,507

116,507

Change in line item name and number