Perth
10.10 Urban water discharge to groundwater

Supporting Information

Treated wastewater from the Kwinana Wastewater Treatment Plant is infiltrated to the groundwater store to assist in maintaining environmental values at The Spectacles Wetlands on the Swan Coastal Plain. The groundwater in this region is also extracted and recycled by Alcoa as part of the overall allocation of groundwater in the region.

During the 2010–11 year, the total volume of aquifer recharge (1,504 ML from Kwinana and 680 ML from Beenyup – see line item 10.9) was equivalent to approximately 2% of the total treated wastewater discharged from treatment plants within the region.

Quantification Approach

Data Source

Water Corporation: Operational Data Storage System.

Provided by

Water Corporation.

Method

Treated wastewater from the Kwinana Wastewater Treatment Plant is infiltrated to the groundwater store via infiltration ponds. The volume of treated wastewater infiltrated to groundwater is based on metered data at the treatment plant, which is collected on an almost continuous basis.

Assumptions, Limitations, Caveats and Approximations

Nil.

Uncertainty Information

Expected error for water meters is +/– 5%.

The Department of Water requires that all water meters, when tested in situ conditions, must be within 5% accuracy across the full flow rate range (Guidelines for water meter installation 2009).

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 10.10

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

10.10 Urban water discharge to groundwater

15.2.6 Managed aquifer recharge

1,475

1,475

Change in line item name and number