Water reuse and treatment

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

Wastewater is treated 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.

Wastewater can be recycled, if it 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.

Alice Water Smart

Alice Water Smart is about preserving our finite groundwater source and secure the long term sustainability of Alice Springs. Many of us believe our water supply will last forever, as it is drawn from the ancient Amadeus basin. However our water is precious and must be used wisely.

The project has helped Alice Springs residents to reduce water use by 1600 million litres per year, equivalent to two months average water supply.

Led by a consortium of government and community organisations, Alice Water Smart helped to drive smarter and more efficient use of water in homes, businesses, parks and gardens; and Alice Springs has become a role model for others to follow.

For more information visit www.alicewatersmart.com.au

Alice Springs Water Reuse Project

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

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

Initially the project recycled 600 megalitres of water a year. Water from the wastewater stabilisation ponds is treated in a Dissolved Air Floatation plant before it is pumped 6.2km to the Arid Zone Research Institute (AZRI). The reclaimed water is then 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 is 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. Some will be supplied to Blatherskite Park to help irrigate the grounds and there is 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 was nominated for a Royal Australian Institute of Architects award. Greening Australia was contracted for landscaping using local native plants.

Fact sheets

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