Sydney
9.9 Discharge from urban water system

Supporting information

Urban water discharge to surface water

The volume of water discharged from urban wastewater systems during 2011–12 was 92,868 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.

Sydney Water Corporation released 13,362 ML of recycled water from St Marys Water Recycling Plant to Boundary Creek (a tributary of the Nepean River). These releases are intended to replace outflows released for environmental purposes from Lake Burragorang (Warragamba Dam) to the river.


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 2011–12 (ML)

Goulburn Mulwaree Council—treated wastewater from wastewater treatment plants

Goulburn and Marulan

Not applicable

1,7161

Lithgow City Council—treated wastewater from wastewater treatment plants

Lithgow

A tributary of the Coxs River

2,148

Wallerawang

Coxs River

314

Palerang Council—treated wastewater from wastewater treatment plants

Braidwood

A tributary of the Shoalhaven River

120

Shoalhaven City Council—treated wastewater from wastewater treatment plants

 

Berry

Broughton Creek

332

Bomaderry

Abernathys Creek

844

Nowra

Shoalhaven River

2,150

Sydney Water Corporation—treated wastewater from water recycling plants

 

Castle Hill

Cattai Creek

3,673

Glenfield

Georges River

645

Liverpool

Georges River

5,160

Penrith

Boundary Creek

2,617

Picton

Stonequarry Creek

666

Quakers Hill

Breakfast Creek

11,153

Richmond

Rickabys Creek

774

Rouse Hill

Second Ponds Creek

5,456

St Marys

Boundary Creek

13,362

St Marys

South Creek

10,315

West Camden

Matahil Creek

4,172

Sydney Water Corporation—treated wastewater from wastewater treatment plants

 

 

 

 

 

 

Brooklyn

Hawkesbury River

100

Fairfield

Orphan School Creek

3,543

Hornsby Heights

Calna Creek

2,990

North Richmond

Redbank Creek

417

Riverstone

Eastern Creek

771

Wallacia

Warragamba River

372

West Hornsby

Waitara Creek

5,554

Winmalee

Nepean River

8,626

Wingecarribee Shire Council—treated wastewater from wastewater treatment plants

 

 

 

Berrima

Olbury Creek

128

Bowral

Wingecarribee River

1,892

Braemar

Iron Mines Creek

1,286

Bundanoon

Reedy Creek

352

Moss Vale

Whites Creek

1,220

Total

92,868

 1Water reported here is for Marulan WTP only, discharge volume from Goulburn was not quantified.

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. The volume of water that has become inflow to downstream storages (9,176 ML) is deducted from 9.4 Rainfall runoff.



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

Shoalhaven City Council

Data source

Shoalhaven City Council: Shoalhaven City Council telemetry system. Daily data registers in respect of the operations of the plants.

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 Sydney Water Corporation's Service Delivery Division (Systems Assurance and Monitoring); metered data reported in Sydney Water Corporation's Water Efficiency Report 2011–12.

Provided by

Sydney Water Corporation.

Method

Total metered volume of treated wastewater discharge to surface water from Sydney Water Corporation's wastewater treatment plants and water recycling plants is provided.  Details on recycled water discharge including water from St Marys Recycling plant can be found at in the Water Efficiency Report 2011–12.

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 2011–12 from the data management system.

Assumptions, limitations, caveats and approximations

The main difference between treated wastewater and recycled water produced by Sydney Water Corporation is quality, which 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 wastewater treatment levels in producing recycled water is available at Sydney Water Corporations website.

Uncertainty information

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