Australia is falling well behind in the targets it has set itself for wastewater reuse, according to a study carried out for the Department of Sustainability, Environment, Water, Population & Communities by Marsden Jacob Associates (MJA).
A national target of wastewater recycling of 30% by 2015 was set in 2007 with government support to help to achieve it. On current estimates, national wastewater recycling by 2015 is expected to be 18.7‑20.3%.
However, the report, Progress against the national target of 30% of Australia’s wastewater being recycled by 2015, notes that if existing key projects operated at maximum capacity, the national target would be much closer to realisation by 2015. For example, South East Queensland’s Western Corridor project (see D&WR cover feature February/March 2012) is capable of outputting 85 million m³/year, but by 2015 will probably be producing only 14‑22 million m³/year because of demand shortfalls.
Across Australia in 2009/10, 16.8% of wastewater flows were recycled. While most of this stemmed from urban reuse, authorities outside state capitals are recycling a greater proportion (21.7%) of wastewater flows than inside the cities (15.2%).
Stormwater reuse projects almost invariably contribute to potable substitution, says MJA, supplementing for urban irrigation and industrial use, and contributing to water supply security. South Australia’s government leads the way with plans to increase stormwater reuse to 70 million m³/year by 2050.
By contrast, indirect potable reuse has not really taken off, although, as well as the Western Corridor project in Queensland, Perth’s Groundwater Replenishment project should form an ongoing part of future potable supplies for Perth’s water supply system.
By 2015, subject to approval, the project would produce between 25‑35 million m³/year, with long-term volumes up to 70 million m³/year.