14 ENVIRONMENT and ENERGY
An executive summary : the untapped resource
By Extracted from the United Nations World Water Development Report 2017
Most human activities that use water produce wastewater . As the overall demand for water grows , the quantity of wastewater produced and its overall pollution load are continuously increasing worldwide .
Untreated wastewater released back into the system has a major negative impact on the environment and contaminates clean water sources .
In all but the most highly developed countries , the vast majority of wastewater is released directly to the environment without adequate treatment , with detrimental impacts on human health , economic productivity , the quality of ambient freshwater resources , and ecosystems .
Although wastewater is a critical component of the water management cycle , water , after it has been used , is all too often seen as a burden to be disposed of or a nuisance to be ignored . The results of this neglect are now obvious . The immediate impacts , including the degradation of aquatic ecosystems and waterborne illness from contaminated freshwater supplies , have far-reaching implications on the well-being of communities and peoples ’ livelihoods .
Continued failure to address wastewater as a major social and environmental problem would compromise other efforts towards achieving the 2030 Agenda for Sustainable Development . In the face of ever-growing demand , wastewater is gaining momentum as a reliable alternative source of water , shifting the paradigm of wastewater management from ‘ treatment and disposal ’ to ‘ reuse , recycle and resource recovery ’. In this sense , wastewater is no longer seen as a problem in need of a solution ; rather , it is part of the solution to challenges that societies are facing today . Wastewater can also be a cost-efficient and sustainable source of energy , nutrients , organic matter , and other useful by-products . The potential benefits of extracting such resources from wastewater go well beyond human and environmental health , with implications on food and energy security as well as climate change mitigation . In the context of a circular economy , whereby economic development is balanced with the protection of natural resources and environmental sustainability , wastewater represents a widely available and valuable resource . The outlook is undeniably optimistic , provided action is taken now .
The world ’ s water : availability and quality Globally , water demand is predicted to increase significantly over the coming decades . In addition to the agricultural sector , which is responsible for 70 % of water abstractions worldwide , large increases in water demand are predicted for industry and energy production . Accelerated urbanization and the expansion of municipal water supply and sanitation systems also contribute to the rising demand .
Climate change scenarios project an exacerbation of the spatial and temporal variations of water cycle dynamics , such that discrepancies between water supply and demand are becoming increasingly aggravated . The frequency and severity of floods and droughts will likely change in many river basins worldwide . Droughts can have very significant socio-economic and environmental consequences .
Highly vulnerable areas , where non-renewable resources ( that is , fossil groundwater ) continue to decrease , have become highly dependent on transfers from areas with abundant water and are actively seeking affordable alternative sources . The availability of water resources is also intrinsically linked to water quality , as the pollution of water sources may prohibit different type of uses .
Pixabay
Increased discharges of untreated sewage , combined with agricultural runoff and inadequately treated wastewater from industry , have resulted in the degradation of water quality around the world . If current trends persist , water quality will continue to degrade over the coming decades , particularly in resource-poor countries in dry areas ,
September 2017 Volume 23 I Number 7 www . plumbingafrica . co . za