A small treatment plant at Southwell Park supplies treated effluent for irrigation of 10 hectares of sporting fields. This process is known as Watermining®.
Wastewater is extracted from a sewer, treated, and used for irrigation. Solids are returned to the sewer for further treatment at the central treatment plant, the Lower Molonglo Water Quality Control Centre (LMWQCC).
The big benefit of Watermining® is that water does not have to be brought back from larger treatment plants to where it is needed, which means money does not have to be spent on large underground pipe systems.
Please contact us if you have any queries or require any additional information about ACTEW's Watermining® facility.
Is the recycled water safe?
The Watermining® facility provides water of a high enough quality for irrigating the playing fields of Southwell Park. It may also be used around the home for watering the garden or washing the car.
Protecting the health of the public has been a major consideration in the design and operation of the ACTEW Watermining® facility. The plant uses two disinfection processes working in combination, which satisfy the strict standards of the ACT Department of Health.
All solids are returned to the sewer to be treated at LMWQCC, so there is no solids treatment and disposal at Southwell Park.
About the treatment process
The treatment processes employed in the Watermining® facility include:
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1. Sewage extraction
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- Wastewater is pumped from a main sewer
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2. Primary treatment
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- A screen keeps the larger solids out of the treatment system
- Lime is added to assist treatment
- Smaller solids are separated from the water by allowing them to settle
- All the solids are returned to the sewer
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3. Secondary treatment
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- Soluble impurities and ammonia are removed by biological treatment
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4. Tertiary treatment
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- Microfiltration removes fine solids and bacteria (the first health protection barrier)
- Hypochlorite disinfection kills any remaining bacteria (the second health protection barrier)
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5. Water recycling
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- The recycled water is then used to irrigate Southwell Park, adjoining the ACTEW Watermining® facility.
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6. Solids disposal
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- The solids separated during the treatment process are returned to the sewer, for treatment at Canberra's major plant, the Lower Molonglo Water Quality Control Centre (LMWQCC).
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The NCWRS scheme began as a pilot in 1972 and was commissioned on a large scale in 2004.
ActewAGL, on behalf of ACTEW, operates and maintains the NCWRS and has an extensive ongoing monitoring program in place to ensure the use of recycled water meets necessary requirements.
How the water re-use scheme works
The scheme treats wastewater at the Fyshwick Sewage Treatment Plant (FSTP) before being pumped to the North Canberra Water Re-use Facility (NCWRF) for further treatment. Once fully treated the water is pumped up to the Lower Russell Hill water reservoir.
From 1972 to 1999 treated wastewater from the FSTP was used to water 40 hectares of the golf course and sports grounds at the Royal Military College Duntroon and the Australian Defence Force Academy.
New treatment facilities (the Water Re-use Facility) were commissioned in 2004 to comply with the 1999 ACT Effluent Re-use Guidelines.
Prior to connecting customers, an extended testing period was undertaken to guarantee high quality targets for the recycled water were met. The quality of the recycled water meets stringent environmental and public health requirements established by the Environment Protection Authority and ACT Health.
After this testing, the scheme started delivering water for irrigation to seven sites totalling 70 hectares across North Canberra.
Fyshwick Sewage Treatment Plant
The Fyshwick Sewage Treatment Plant (FSTP) partially treats some of the industrial and domestic sewage from the industrial area of Fyshwick and adjacent suburbs. The treatment process consists of mechanical coarse screening, primary sedimentation tanks, trickling filters, humus tanks, maturation lagoons, emergency storage lagoon, and sludge digesters.
Digested sludge is diluted with non-potable water and returned to the main sewer. Effluent from the final maturation lagoon is also pumped to the mains sewer for full treatment at Lower Molonglo Water Quality Control Centre (LMWQCC).
North Canberra Water Re-use Facility
The North Canberra Water Re-use Facility (NCWRF) was developed as part of the North Canberra Effluent Reuse Scheme to filter FSTP lagoon effluent to supply irrigation water for fields in North Canberra. Partially treated effluent from the lagoons is passed through an ultrafiltration treatment process at approximately 20 litres per second.
The filtered effluent flows into a balance tank from which it is pumped into a reservoir. Filtered effluent is disinfected by dosing with gaseous chlorine into the rising main downstream of the balance tank. The treated effluent is produced to a high quality as required by strict Environmental and Health guidelines.
The new treatment facility cost about four million dollars and can deliver up to 500 megalitres per year of high quality recycled water.
Lower Russell Reservoir
The treated effluent from the NCWRF is pumped into the Lower Russell Reservoir, which supplies the irrigation water for various North Canberra water reuse sites including ovals, playing fields and a golf course.
The Lower Russell Reservoir is also supplied with potable water from the Upper Russell Reservoir as a backup supply source if required. The scheme is monitored and controlled remotely at LMWQCC.
A proportion of the wastewater treated at LMWQCC is supplied to nearby vineyards (100 hectares) and a golf course (30 hectares) for irrigation.
LMWQCC is remote from the rest of the city and major reuse opportunity from here is driven by agricultural or industrial activity near the plant.
The LMWQCC also has a role in remotely monitoring and controlling the North Canberra Effluent Re-use Scheme.