Sustainability

Making the most of our precious water resources

Alice Springs Water Reuse Project

Power and Water Corporation has committed $10.4 million to the innovative Water Reuse in the Alice project.

The project will stop dry weather overflows from the Alice Springs waste stabilisation ponds into Ilparpa swamp. Rather than letting precious water go to waste, the effluent will be recycled so it can be reused.

Initially the project will recycle 600 megalitres of water a year. Water from the wastewater stabilisation ponds will undergo treatment in a Dissolved Air Floatation plant before it is pumped 6.2km to the Arid Zone Research Institute (AZRI). The reclaimed water will then be infiltrated through Soil Aquifer Treatment (SAT) basins and stored in an underground aquifer before being used to irrigate horticulture projects, helping create employment and economic opportunities for the region.

The land at AZRI will be suitable for horticultural production of high value crops such as table grapes, vegetables, herbs, native bush foods etc.

Not all of the reclaimed water will be sent to the SAT basins as some will be supplied to Blatherskite Park to help irrigate their grounds as well as the potential for other customers to be connected along the pipeline route such as Desert Knowledge Australia.

A sustainable building design was chosen in keeping with the Central Australian conditions for the Water Reclamation Plant and local architect Brendan Meney chosen to undertake this work. The building has now been nominated for a Royal Australian Institute of Architects award and landscaping will be undertaken in the near future by Greening Australia using native local plants.

Power and Water worked with the Department of Natural Resources, Environment, the Arts and Sport, the Department of Primary Industry, Fisheries and Mines and CSIRO to complete this important project.

Fact sheets

Achievements so far | Horticulture | FAQs | Project update | Soil Aquifer Treatment | Water Reclamation Plant | Making the most of our precious water | Water quality and treatment

Wastewater treatment

Wastewater consists of water returned to sewers from household toilets, sinks, showers and washing machines. Added to it is wastewater from some industrial processes, such as washdown of vehicle bays.

The aim of wastewater treatment is to reduce pollutants in the wastewater to very low levels and minimise environmental impacts. Treatment is achieved by a number of different processes. These include lagoons, chemically assisted sedimentation, and the activated sludge process. Effluent is the term given to treated wastewater.

Subject to the provisions of Section 74 of the Water Act, Power and Water is granted a Waste Discharge License (WDL) for selected wastewater treatment and discharge facilities. The WDL codifies operational practice for the management of waste discharges from the facility.

Recycled water

Recycled water is effluent that has gone through an additional treatment process. Recycled water is used on a limited basis in Darwin, Pine Creek, Katherine, and Alice Springs. However, the demand for recycled water from large irrigation customers is increasing. Benefits include the potential to reduce watering costs and potable water use, and extended watering during dry periods. Recycled water can be reused for watering public sports playing fields, golf courses, tree lots, pastures and public areas.

All recycled water used in the Northern Territory is in accordance with the National Health and Medical Research Council Guidelines for recycled water and is also subject to approval by the Department of Health and Community Services.

Biodiversity

Darwin River and Manton Dams

These catchments are the largest parcel of land managed by Power and Water. Power and Water recognises the value of the catchments as a significant conservation reserve with a diverse fauna. The Darwin River Dam catchment also contains the Northern Territory's largest body of permanent fresh water. Manton Dam management is the responsibility of Parks and Wildlife; Power and Water takes a closed catchment approach to protect the water quality in Darwin River Dam.

Power and Water worked with the Department of Planning and Infrastructure (DPI) to develop maps to provide a scientific basis for managing the Darwin River and Manton Dams catchments.

A management plan will be developed, in conjunction with the NT Government and other stakeholders, to ensure long-term water quality and yield from the dam while protecting conservation values. Specific issues to be addressed cover weeds, feral animals and bushfires.

Ilparpa Swamp

Ilparpa Swamp is located immediately south of Alice Springs, near Heavitree Gap. It is an ephemeral waterbody, and until the mid-seventies was characterised by claypans, stands of Coolibah trees and other remnant vegetation.

The bird life at the Waste Stabilisation Ponds is spectacular, with many rare species gathering around this body of water.

Access to Ilparpa Swamp for birdwatchers

Birdwatching groups will need to request permission to access to the Ponds.

Land in the vicinity was used as a nightsoil disposal site until the town was sewered in the early sixties. With the commissioning of the Ilparpa Sewerage Ponds, the practice was discontinued. However, as the town grew, overflows of treated effluent from the ponds were released into Ilparpa Swamp. This has created an artificial wetland with permanent water dominated by bullrushes (Typha domingensis) and mosquitoes, and represents a potential public health risk.

A management plan has been developed with Alice Springs stakeholders through a local group, the Ilparpa Swamp Rehabilitation Committee. The plan contains a number of short term through to long term actions designed to mitigate the risk and eventually achieve rehabilitation of the swamp.

Power and Water has made a commitment to fund these over the next three years.

Dugong and Sea Turtle Study

Power and Water sponsored a study by Biomarine International of dugongs and sea turtles near Channel Island Power Station (Darwin Harbour). The study focused on observing the behavior and movements of these animals in the area. Information presented in the report adds to the existing knowledge of dugongs and sea turtles in Darwin Harbour. This project provides the basis for further work on these species in Darwin Harbour.

Bio-monitoring in Darwin Harbour

As part of the 2003 Environmental Awards, Power and Water awarded an environmental research grant to the Charles Darwin University for a bio-monitoring project in Darwin Harbour, using corals as environmental data archives.

In corals, the structure and composition of calcium carbonate in annual skeletal growth bands reflect the environmental conditions in which the coral grows. For that reason, the analysis of coral skeletal composition can provide a cost-effective method of monitoring water quality, as well as providing comparative data on past pollutant levels.

The innovative corals project is in line with Power and Water’s objectives for managing wastewater discharges into Darwin Harbour. A successful project outcome will provide environmental managers with a powerful long-term management tool for Darwin Harbour.

For more information, contact Environmental Science at Charles Darwin University.