Sydney
19.5 Urban water discharge to surface water

Supporting Information

The volume of water discharged from urban wastewater systems during 2010–11 was 64,591 ML.

A breakdown of treated water from wastewater treatment plants and water recycling plants discharged to the streams is provided in the following table. The discharged volume is a decrease to the water distribution system store.


Breakdown of treated and recycled water that was discharged to surface water

Plant operator and description of wastewater discharge

Plant

Discharging to watercourse

Volume discharged during 2010–11 (ML)

Goulburn Mulwaree Council — treated wastewater from wastewater treatment plants

Goulburn and Marulan

Not applicable

01

Lithgow City Council — treated wastewater from wastewater treatment plants

Lithgow

A tributary of the Coxs River

2,036

Wallerawang

Coxs River

177

Palerang Council — treated wastewater from wastewater treatment plants

Braidwood

A tributary of the Shoalhaven River

87

Shoalhaven City Council — treated wastewater from wastewater treatment plants

 

Berry

Broughton Creek

200

Bomaderry

Abernathys Creek

844

Nowra

Shoalhaven River

1,873

Sydney Water Corporation — treated wastewater from water recycling plants

 

Castle Hill

Cattai Creek

2,991

Glenfield

Georges River

156

Liverpool

Georges River

1,434

Penrith

Boundary Creek

1,526

Picton

Stonequarry Creek

220

Quakers Hill

Breakfast Creek

6,946

Richmond

Rickabys Creek

501

Rouse Hill

Second Ponds Creek

3,887

St Marys

Boundary Creek

15,989

St Marys

South Creek

3,662

West Camden

Matahil Creek

1,805

Sydney Water Corporation—treated wastewater from wastewater treatment plants

 

 

 

 

 

 

Brooklyn

Hawkesbury River

94

Fairfield

Orphan School Creek

740

Hornsby Heights

Calna Creek

2,250

North Richmond

Redbank Creek

317

Riverstone

Eastern Creek

561

Wallacia

Warragamba River

227

West Hornsby

Waitara Creek

4,840

Winmalee

Nepean River

7,339

Wingecarribee Shire Council — treated wastewater from wastewater treatment plants

 

 

 

Berrima

Olbury Creek

101

Bowral

Wingecarribee River

1,594

Braemar

Iron Mines Creek

1013

Bundanoon

Reedy Creek

283

Moss Vale

Whites Creek

898

Total

64,591

 12,517 ML was received at the plants for treatment. All treated water was used for irrigation.

Wallerawang Wastewater Treatment Plant receives wastewater generated from supplies made to the Lithgow City Council's distribution system from the Fish River Water Supply Scheme. Lithgow Wastewater Treatment Plant receives wastewater generated from supplies made to the distribution system from Oakey Park Water Treatment Plant. Wastewater received at these wastewater treatment plants includes inflow and infiltration resulting from stormwater.

Treated water released from some of the wastewater treatment plants included in the above table becomes inflow to downstream storages (counted in line item 9.4 Runoff to surface water)  as shown in the following table. (Line item 9.9 does not include these releases and, therefore, the volumes for the line item 19.5 and line item 9.9 are not equal.)



Treated wastewater released from wastewater treatment plants received at storages

Wastewater treatment plants releasing treated water

Reservoir receiving treated water

Wastewater treatment plant operator

Reservoir managing authority

Lithgow

Lake Lyell

Lithgow City Council

Delta Electricity

Wallerawang

Lake Wallace

Lithgow City Council

Delta Electricity

Berrima, Bowral, Braemar and Bundanoon

Lake Burragorang (Warragamba Dam)

Wingecarribee Shire Council

Sydney Catchment Authority

Moss Vale

Medway

Wingecarribee Shire Council

Wingecarribee Shire Council

Braidwood

Lake Yarrunga (Tallowa Dam)

Palerang Council

Sydney Catchment Authority

Quantification Approach

Lithgow City Council

Data Source

Data spreadsheets.

Provided by

Lithgow City Council.

Method

Flows were measured by water channel and height sensors, and converting water level to a volume in a spreadsheet using a rating table.

Assumptions, Limitations, Caveats and Approximations

Wastewater received at Lithgow and Wallerawang wastewater treatment plants includes inflow and infiltration resulting from stormwater, in addition to wastewater generated from potable water supplies made to the water distribution system. Therefore, all of these sources contribute to the volume of treated wastewater released from the plants to the streams.

Uncertainty Information

The volume was estimated from measured data. The uncertainty was not quantified.

Palerang Council

Data Source

Database maintained as spreadsheets.

Provided by

NSW Office of Water.

Method

For 2010–11, the wastewater treatment plant (now decommissioned) did not have any dedicated flow measurement at the outlet. The outflow from the plant was from a tertiary pond system. Measurement was made at the inlet to the plant only and this was done by an ABB Magmaster-type flow meter. The inflow measured from the flow meter has been approximated to the outflow, disregarding any inflow that may be lost through evaporation, or that may be supplemented through rainfall or infiltration to the pond system. 

Assumptions, Limitations, Caveats and Approximations

Nil.

Uncertainty Information

The volume was estimated from measured data. Estimated uncertainty based on meter accuracy and professional judgment is +/– 10%.

Shoalhaven City Council

Data Source

Shoalhaven City Council telemetry system. Daily data registers from the plant operations section.

Provided by

Shoalhaven City Council.

Method

Outflows from wastewater treatment plants were measured as follows:

  • Berry Wastewater Treatment Plant: Vega-type ultrasonic flow meter
  • Bomaderry and Nowra wastewater treatment plants: a Parshall flume with a venturi flow meter at each site.

Assumptions, Limitations, Caveats and Approximations

Nil.

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 Operations Division (Systems Assurance) of Sydney Water Corporation (SWC). Metered data reported in SWC's Water Efficiency Report 2010–11.

Provided by

Sydney Water Corporation.

Method

Total metered volume of treated wastewater discharge to surface water from SWC's wastewater treatment plants and water recycling plants is provided. Water from St Marys Recycling plant was measured using SWC's Water Efficiency Report 2010–2011.

The flow of wastewater and recycled water from plants was measured using flow meters. These measured data are continually monitored and recorded using the Integrated Instrumentation Control Automation and Telemetry System (IICATS). The data are stored within a complex data management system. Adjustments are made to the data (if necessary) to correct any interruptions, errors and so on. Data have been extracted for 2010–11 from the data management system.

Assumptions, Limitations, Caveats and Approximations

The main difference between treated wastewater and recycled water produced by SWC is quality, and quality is determined by the level of treatment. Recycled water is produced by treating water generated from sewage, greywater or stormwater systems to achieve high quality as required. Information on SWC's wastewater treatment levels in producing recycled water is available on their website.

Uncertainty Information

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

Wingecarribee Shire Council

Data Source

Supervisory Control and Data Acquisition (SCADA) data records from wastewater treatment plants.

Provided by

Wingecarribee Shire Council.

Method

The value represents the total volume of treated wastewater discharge to surface water from wastewater treatment plants.

The flow of wastewater from the plants was measured using ABB Magmaster flow meters installed on-site. The data from the flow meters are continually monitored and recorded.

Assumptions, Limitations, Caveats and Approximations

Nil.

Uncertainty Information

The volume is based on measured data. Estimated uncertainty based on meter accuracy and professional judgment is +/– 7%. External flow verification audits for the flow meters are conducted annually by Hydrometric Consulting Services.

Comparative year

The following table compares the value at 30 June 2010 reported in this account with the corresponding value reported in the 2010 Account.

 

Comparative information from the 2010 Account for line item 19.5

2011 Account line item

2010 Account line item

Value reported in the 2010 Account (ML)

Value reported in the 2011 Account (ML)

Additional information

19.5 Urban water discharge to surface water

20.4.1 Discharge of urban wastewater to connected surface water

59,475

61,455

Line item presentation: these 2 line items have been merged for the 2011 Account. The amended value is the merged volume  

20.5.1 Urban recycled water discharge to connected surface water

1,980