Changes

Sanitation is evident in the earliest settled societies. In the Indus Valley, Mesopotamia, and Iran, evidence exists for the use of sewers and clay pipes for removing human waste. With ceramics being present in societies by 7500-7000 BCE, this technology became utilised utilized for making clay pipes could safely transport waste. By the Neolithic in the Near East in the 7th and 6th millennia, vertical shafts were used for waste disposal and wells had begun to be utilized within villages. In the 3rd millennium BCE, clay pipes now extended into sewer systems within structures. In the Indus, urban planning included public sewers are evident at sites such as Lothal. In Mesopotamia, at about the same time, sewers with clay pipes were used, although the system does not seem to be centralized. Rather, houses would have vertical shafts that would send waste far below a house. Alternative systems moved waste and waster water out of structures and into larger drains or cesspits.