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Melbourne

                                                                                                   

13.7.1 Discharge of urban wastewater to connected surface water

                             

Supporting information   


The volume recognised in the water accounting statements (8,063 ML) represents the total volume of wastewater discharged to surface water from Yarra Valley Water’s local treatment plants (LTPs) and South East Water’s sewage treatment plants (STPs).

The breakdown of discharge to surface water from each wastewater treatment plant (WWTP) is shown in the following table.

Discharge to surface water from each wastewater treatment plant
Utility Discharge location Volume (ML)
Yarra
Valley
Water
Brushy Creek LTP to Brushy Creek

3,302

Craigieburn LTP to Merri Creek

265

Healesville LTP to Yarra River

231

Upper Yarra LTP to Yarra River

673

Lilydale LTP to Olinda Creek

1,760

Monbulk LTP to Sassafras Creek

19

Yarra Valley Water subtotal

6,250

South East
Water
Pakenham STP to Deep Creek

792

Koo Wee Rup STP to Yallock Creek

0

South East Water subtotal

792

Western
Water
Sunbury WWTP to Jacksons Creek at Sunbury

806

Gisborne WWTP to Jacksons Creek at Gisborne

215

Western Water subtotal

1,021

Total wastewater discharge to surface water

8,063


 

Quantification approach   


Data source

Yarra Valley Water Local Treatment Plant: sewer flows and invoices database.
South East Water Sewage Treatment Plant: sewer flows spreadsheet.
Western Water: plant data.

Data provider

Yarra Valley Water, South East Water and Western Water.

Method

The volume of wastewater discharge to surface water was metered daily at Yarra Valley Water, South East Water and Western Water treatment plants.

Uncertainty

Derived from measured data. Estimated uncertainty is +/–5%.

The uncertainty values refer to the Essential Services Commission’s standard confidence grades, as detailed in its June 2005 guideline for Approving, Conducting and Reporting Audits for Victorian Water Businesses (ESC 2005).

Refer to Summary Audit Report – Regulatory Audit of AGL Energy Limited, October 2010 (ESC 2010) prepared individually for Yarra Valley Water and South East Water 2010.

Approximations, assumptions, caveats/limitations

Nil.