Treated wastewater is the effluent discharged from a wastewater treatment facility after it has been processed to reduce its organic contaminants and nutrient content.
Wastewater can undergo a high level of treatment which results in a product that has many practical uses similar to those of recycled stormwater.
A key objective in the South Australian Government Water For Good Plan is that by 2050 Greater Adelaide will have the capacity to recycle up to 75 gigalitres of wastewater in urban areas.
Annual wastewater reuse is reported by the National Water Commission as part of national performance reporting for Australia’s urban water utilities.
Our state is a national leader in wastewater recycling. The annual performance reports show that of the largest utilities (those with more than 100,000 connections), SA Water frequently achieves the highest per cent wastewater reuse, and significantly more than the national average. For example, the 2011-12 performance report indicates that 26 per cent of SA Water’s effluent was recycled, compared to the national median for the largest utilities of 13 percent.
SA Water collects and treats about 95,000 megalitres of wastewater in Adelaide and about 100,000 megalitres statewide every year.
Adelaide wastewater schemes
Significant projects include:
- SA Water’s Glenelg to Adelaide Parklands Recycled Water Project: this $75 million project is completed and is now providing tertiary filtration facilities, a 10 km pipeline from Glenelg to Adelaide’s CBD, and around 30 km of pipeline around the Park Lands. It has the capacity to provide an extra 3.8 billion litres of recycled water for reuse.
- SA Water’s Christies Beach Wastewater Treatment Plant: a $272 million upgrade of the plant is increasing its capacity and improving the quality of the treated wastewater being produced. This will enable further opportunities to increase reuse.
- The Southern Urban Reuse Scheme in the City of Onkaparinga began operations in May 2011. The capital cost of the scheme was $59 million. This included the Aldinga Recycled Water Treatment Plant, the pumping stations, and the pipelines that link the Christies Beach Wastewater Treatment Plant to the Aldinga site and the residential areas it serves. The scheme was mainly funded by SA Water and the Federal Government.
- The Mawson Lakes Recycled Water System in the City of Salisbury provides recycled water for open space and for residents to water gardens, wash cars and flush toilets. SA Water was a major funding contributor and owns the pipelines. The local council is implementing the stormwater management component of the project.
- The Virginia Pipeline Project is Australia’s, and one of the world's, largest high-quality water recycling initiatives and has helped pave the way for growing food crops with recycled water around the world.