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 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 villagesfor getting freshwater <ref>For more on early sanitation, see: Mitchell, P. D. (Ed.). (2015). Sanitation, latrines and intestinal parasites in past populations. Farnham, Surrey ; Burlington, VT: Ashgate.</ref>.

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. Mohenjo-daro in the Indus may have developed the first toilets with seats and shaped as something similar to Western-style toilets. In Mesopotamiatoday <ref>For more on Indus sanitation systems, at about the same timesee: Angelakēs, sewers with clay pipes were used, although A. N. (Ed.). (2014). Evolution of sanitation and wastewater technologies through the system does not seem to be centralizedcenturies. London: IWA Publ.</ref>. RatherIn Mesopotamia, houses would have vertical shafts that would send waste far below a house, keeping clean and waste water seperated. Alternative horizontal pipe systems and drains moved waste and waster waste water out of structures and into larger drains or cesspits. By the second millennium BCE, toilets could be found in Southern Europe, Southeast Asia, Near East, Central Asia, India, China, and Southeast Asia. The Minoan city of Knossos in Crete had, by this time, developed a system that brought clean water, on the one hand, and an alternative system that took waste water away from the city, including developing a storm sewage canals for overflow during heavy rains<ref> For more on Bronze Age sanitation, see: Eslamian, S. (Ed.). (2014). Handbook of engineering hydrology. Environmental hydrology and water management. Boca Raton: Taylor & Francis.</ref>.