Sydney
11.4 Wastewater collected

Supporting Information

The volume for the line item is 513,998 ML.

A breakdown of the wastewater collected by the urban system is provided in the following table.

Wastewater collected by urban system – summary

 Council/Corporation

Wastewater volume collected during 2010–11 (ML)

Sydney Water Corporation

502,308

Shoalhaven City Council

7,790

Wingecarribbee Shire Council

3,890

Total

513,998

Quantification Approach

Shoalhaven City Council

Data Source

NSW Office of Water calculations.

Provided by

Shoalhaven City Council (SCC).

Method

This item represents the total metered volume of wastewater collected by SCC's wastewater treatment plants.

The calculation includes:

  • grease trap waste
  • on-residential
  • residential
  • septic tank effluent
  • septic tank sludge/pan
  • tradewaste.

Assumptions, Limitations, Caveats and Approximations

The volume of wastewater collected/treated at sewerage treatment plants may also include any net ingress of stormwater or groundwater to the sewer system.

Uncertainty Information

The volume is based on measured data. Estimated uncertainty based on meter accuracy is +/– 5%.

Sydney Water Corporation

Data Source

Data managed and maintained in an internal data management system by Sydney Water Corporation's (SWC) Operations Division (Systems Assurance).

Provided by

SWC.

Method

The total volume of wastewater collected and treated at SWC's wastewater treatment plants and water recycling plants is detailed in the following table.

Wastewater collected by Sydney Water Corporation

Plant type

Wastewater treatment plant

Volume of effluent treated (excluding volume treated for on-site use) (ML)

Water recycling

Bombo

1,862

Castle Hill

3,053

Gerroa

323

Glenfield

156

Liverpool

1,597

Penrith

8,718

Picton

554

Quakers Hill

11,419

Richmond

685

Rouse Hill

6,137

St Marys

14,607

West Camden

3,864

Wollongong

21,703

Wastewater treatment

Bellambi1

504

Bondi

46,165

Brooklyn

94

Cronulla

20,643

Fairfield1

740

Hornsby Heights

2,250

Malabar

185,499

North Head

143,815

North Richmond

317

Port Kembla1

790

Riverstone

561

Shellharbour

7,031

Wallacia

227

Warriewood

6,815

West Hornsby

4,840

Winmalee

7,339

Total

 

502,308

1A wet-weather wastewater treatment plant, which is only used during major storms

 

Volumes for both components have been derived from metered outflow data from the plants. The flow meter data are continually monitored and recorded using the Integrated Instrumentation Control Automation and Telemetry System (IICATS). The data are stored within an internal data management system. Adjustments are made to the data (if necessary) to correct any interruptions, errors and so on. From the data management system, data have been extracted for the reporting period.

Assumptions, Limitations, Caveats and Approximations

  • The volume does not include water losses in the treatment process including biosolid removal, de-watering and evaporation.
  • Total wastewater treated can include net ingress from stormwater and groundwater.
  • At wet-weather wastewater treatment plants, wastewater treated usually also includes a certain volume of stormwater.

Uncertainty Information

The volume is based on measured data. Estimated uncertainty based on meter accuracy is +/– 2%.

Wingecarribee Shire Council

Data Source

Wingecarribee Shire Council (WSC) Plant SCADA (Citec) records and DECC annual return reports 2009–10.

Provided by

WSC.

Method

This item represents the total volume of wastewater collected at wastewater treatment plants.  The volume is derived from data from inflow meters at wastewater treatment plant where applicable.

Total wastewater treated for the 2010–11 year at WSC-operated wastewater treatment plants
Wastewater treatment plant Total wastewater treated in the 2010–11 year (ML)
Moss Vale 899
Bowral 1,594
Mittagong 1,013
Berrima 101
Bundanoon 283
Total 3,890

Assumptions, Limitations, Caveats and Approximations

Total wastewater received can include net ingress from stormwater and groundwater. Inflows to plants have only been measured at Moss Vale, Berrima and Bundanoon wastewater treatment plants. Therefore, treated volumes shown above are the same as discharge volumes shown under 'Volume of (treated) wastewater discharged to surface water' for these plants.

Uncertainty Information

The volume is based on measured data. Estimated uncertainty based on meter accuracy and professional judgment is +/– 7%.

Comparative year

The following table compares the value for the 2009–10 year reported in this account with the corresponding value reported in the 2010 Account.

 

Comparative information from the 2010 Account for line item 11.4

2011 Account line item

2010 Account line item

Value reported in the 2010 Account (ML)

Value reported in the 2011 Account (ML)

Additional information

11.4 Wastewater collected

Not applicable



Line item presentation: this is a new line item not reported in the 2010 Account

 

This is a new line item introduced to the account due to a change in the definition of the region. The 2011 Account considers that all individual users (including commercial and industrial sectors) are not part of the region. Therefore, wastewater from users that is collected by the wastewater collection system is considered to 're-enter' the region, which represents a water asset increase.

In the 2010 Account, individual users were considered to be part of the region. Therefore, the volume of wastewater collected from users was not a water asset increase.