Reclaimed wastewater as a resource for sustainable water management

Population growth accompanied by higher standard of living and ongoing drought conditions caused by changing climatic patterns tend to make water availability as a key national issue not only at present but for the decades to come. The urban cities located around the coastal areas look for the possibility of desalination of sea water whereas the inland cities explore wastewater reuse as a last resort for indirect potable use to meet the envisaged water shortage. Toowoomba City Council acknowledged that Toowoomba would run out of water in two years if the current drought persisted and, therefore, is planning to augment the present water supply with highly treated wastewater using the best technologies available. The concept of reclaimed wastewater to be considered as a resource rather than a waste has been a subject of debate. There are many instances of communities practicing the unplanned indirect potable reuse unknowingly. Tertiary treated wastewater and sometimes untreated industrial and agricultural wastes are returned to the water body from where downstream utilities withdraw water for potable uses. The receiving water bodies have the natural assimilative capacity to clean up the waste discharged into them; however, their limits have been exhausted during the last decade or so due to increased loading discharged containing synthetic chemicals. Planned indirect potable reuse aims to remove these contaminants present in the tertiary treated effluent using advanced treatment technologies with multiple barriers before discharging them into the water bodies to augment the drinking water supply downstream or of their own. Considering the facts that many conventional sources of fresh water become scarcer and more contaminated but emerging innovative state-of-the-art technologies are available to remove the contaminants, planned indirect potable reuse could be a promising solution for sustainable water resources management. This has been reflected in that many utilities around the world have either been planning or already implementing the advanced reuse systems. This paper reviews some indirect potable reuses practiced in the world, the treatment methodologies adopted and discusses how stakeholders can contribute for continued sustainable supply of these water resources