INTRODUCTION
Water is crucial for all aspects of life, the defining feature of our planet. Ninety seven and a half per cent of all water is found in the oceans, of the remaining freshwater only one per cent is accessible for extraction and use. Functioning and healthy aquatic ecosys- tems provide us with a dazzling array of benefits – food, medicines, recreational amenity, shoreline protection, processing our waste, and sequestering carbon. At the beginning of the 21st century, the world faces a water crisis, both of quantity and quality, caused by continuous population growth, industrialization, food production practices, increased living standards and poor water use strategies. Wastewater management or the lack of, has a direct impact on the biological diversity of aquatic ecosystems, disrupting the fun- damental integrity of our life support systems, on which a wide range of sectors from urban development to food production and industry depend. It is essential that wastewa- ter management is considered as part of integrated, ecosystem-based management that operates across sectors and borders, freshwater and marine.
Fresh, accessible water is a scarce (figure 1) and unevenly dis- tributed resource, not matching patterns of human develop- ment. Over half the world’s population faces water scarcity. Be- cause it plays a vital role in the sustenance of all life, water is a source of economic and political power (Narasimhan, 2008) with water scarcity a limiting factor in economic and social development.
International attention has to date, focused on water quan- tity, the supply of drinking water and increasing access to sanitation with commitment expressed through the World Summit of Sustainable Development and the Millennium Development Goal 7 for Environmental Sustainability, tar- get 10 for safe drinking water and sanitation. 2005 – 2015 is the international decade for Action “Water for Life” (http://
www.un.org/waterforlifedecade/), with a focus on the Inter- national year of Sanitation in 2008 (
http://esa.un.org/iys/). Despite this high profile attention, these issues are proving difficult to resolve, requiring significant sums for invest- ment, over long periods of time and with jurisdiction often spread across several government departments. Worldwide,
nearly 900 million people still do not have access to safe wa- ter (UNDESA 2009), and some 2.6 billion, almost half the population of the developing world do not have access to ad- equate sanitation (WHO/UNICEF, 2010). Over 80 per cent of people with unimproved drinking water and 70 per cent of people without improved sanitation live in rural areas (DFID, 2008). This is also only part of the story.
What do we mean by wastewater?
Wastewater can mean different things to different people with a large number of definitions in use. However this report has tak- en a broad perspective, and defined wastewater as “a combina- tion of one or more of: domestic effluent consisting of black- water (excreta, urine and faecal sludge) and greywater (kitchen and bathing wastewater); water from commercial establish- ments and institutions, including hospitals; industrial effluent, stormwater and other urban run-off; agricultural, horticultural and aquaculture effluent, either dissolved or as suspended matter (adapted from Raschid-Sally and Jayakody, 2008).
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