印度德里地区的家庭中有90%据称拥有到位的下水道，因为它们拥有室内厕所，但几乎所有废水都不经处理即排入了亚穆纳河（Yamuna River ） ， 而该河是下游城市的饮用水源。
While nearly 90% of the households in the Indian region of Delhi are said to have adequate sanitation, because they have indoor toilets, nearly all of the untreated wastewater is discharged to the Yamuna River – a source of drinking water for cities downstream.