This layer shows the volume of collected wastewater in the Arab States, expressed in millions of cubic meters. Access to improved sanitation is largely prevalent in the Arab region, but connections to sewerage networks and wastewater treatment facilities remain more limited. Network coverage is generally provided in larger urban centers, while septic tanks and cesspits remain common in rural areas and in the region's least developed countries. Off-network sanitation systems, however, complicate te collection and treatment of wastewater and reduce the ability to sustainably manage wastewater as a resource in most areas. For more information, acces the 2017 UN World Water Development Report: http://www.unesco.org/new/en/natural-sciences/environment/water/wwap/wwdr/2017-wastewater-the-untapped-resource/
