This article was last updated comprehensively in January 2011. Water supply and sanitation in Turkey is characterized by achievements and challenges. Over the past decades access to drinking water has become almost universal and access to adequate sanitation has also increased substantially. Autonomous utilities have been created in the 16 metropolitan cities of Turkey and cost recovery has been increased, thus providing the basis for the sustainability of service provision. Intermittent supply, which was common in many cities, has become less frequent. In 2004, 61% of the wastewater collected through sewers was being treated.