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.
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.)
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
Provided by
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
Provided by
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
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
Provided by
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
Uncertainty Information
The volume is based on measured data. Estimated uncertainty based on meter accuracy is +/– 5%.
Sydney Water Corporation
Data Source
Provided by
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
Provided by
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
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.
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 |