• 663 million people still lack improved drinking water sources . 4
• By 2050 , close to 70 % of the world ’ s population will live in cities , compared to 50 % today 5 . Currently , most cities in developing countries do not have adequate infrastructure and resources to address wastewater management in an efficient and sustainable way .
• The opportunities from exploiting wastewater as a resource are enormous . Safely managed wastewater is an affordable and sustainable source of water , energy , nutrients and other recoverable materials .
TOP LINE MESSAGES
• Globally , over 80 % of the wastewater generated by society flows back into the ecosystem without being treated or reused . 1
• 1.8 billion people use a source of drinking water contaminated with faeces 2 , putting them at risk of contracting cholera , dysentery , typhoid and polio . Unsafe water , poor sanitation and hygiene cause around 842,000 deaths each year . 3
• The costs of wastewater management are greatly outweighed by the benefits to human health , economic development and environmental sustainability – providing new business opportunities and creating more ‘ green ’ jobs .
WASTEWATER AND THE WATER CYCLE
Water has to be carefully managed during every part of the water cycle : from fresh water abstraction , pre-treatment , distribution , use , collection and post-treatment , to the use of treated wastewater and its ultimate return to the environment , ready to be abstracted to start the cycle again .
1 On average , high-income countries treat about 70 % of the wastewater they generate , while that ratio drops to 38 % in upper-middle-income countries and to 28 % in lower-middle-income countries . In low-income countries , only 8 % of industrial and municipal wastewater undergoes treatment of any kind ( Sato et . al , 2013 ).
2 WHO / UNICEF ( 2014 ), Progress on drinking water and sanitation : 2014 update : https :// www . unicef . org / gambia / Progress _ on _ drinking _ water _ and _ sanitation _ 2014 _ update . pdf
3 WHO ( 2014 ), Preventing diarrhoea through better water , sanitation and hygiene : exposures and impacts in low- and middle-income countries : http :// apps . who . int / iris / bitstream / 10665 / 150112 / 1 / 9789241564823 _ eng . pdf
4 WHO / UNICEF ( 2015 ) Progress on sanitation and drinking water , 2015 Update and MDG Assessment https :// www . wssinfo . org / fileadmin / user _ upload / resources / JMP-Update-report-2015 _ English . pdf
5 UN Department of Economic and Social Affairs ( 2014 ), World Urbanization Prospects : 2014 : https :// esa . un . org / unpd / wup / Publications / Files / WUP2014-Highlights . pdf
14 Africa Water , Sanitation & Hygiene • March - April 2017