History of water supply and sanitation
Ever since the emergence of sedentary societies (often precipitated by the development of agriculture), human settlements have had to contend with the closely-related logistical challenges of sanitation and of reliably obtaining clean water. Where water resources, infrastructure or sanitation systems were insufficient, diseases spread and people fell sick or died prematurely.
Source: Wikipedia — History of water supply and sanitation (CC BY-SA 4.0)