A recent report published by the United Nations Environment Program (UNEP) and the Stockholm Environment Institute (SEI) calls for wastewater to be reclassified as a renewable water resource rather than “waste” because it can help increase water availability and, at the same time, prevents environmental pollution. The report demonstrates the opportunities for recovery and re-use of the resources found in domestic waste flows in agriculture, energy production and other applications.
According to the report, water re-use allows communities to become less dependent on groundwater and surface water sources and can decrease the diversion of water from sensitive ecosystems. Additionally, water reuse may reduce the nutrient loads from wastewater discharges into waterways, thereby reducing and preventing pollution. This ‘new’ water source may also be used to replenish overdrawn water sources and rejuvenate or reestablish those previously destroyed.
The report concludes that 330 km3 of municipal wastewater produced globally each year is enough to irrigate 40 million hectares – equivalent to 15 percent of all currently irrigated land – or to power 130 million households through biogas generation.