History of water supply and sanitation
Ever since the emergence of sedentary societies, 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.
Major human settlements could initially develop only where fresh surface water was plentifulfor instance, in areas near rivers or natural springs. Over time, various societies devised a variety of systems which made it easier to obtain clean water or to dispose of wastewater.
For much of this history, sewage treatment consisted in the conveyance of raw sewage to a natural body of watersuch as a river or oceanin which, after disposal, it would be diluted and eventually dissipate.
Over the course of millennia, technological advances have significantly increased the distances across which water can be practically transported. Similarly, treatment processes to purify drinking water and to treat wastewater have also improved.
Prehistory
During the Neolithic era, humans dug the first permanent water wells, from where vessels could be filled and carried by hand. Wells dug around 8500BCE have been found on Cyprus, and 6500 BCE in the Jezreel Valley. The size of human settlements was largely dependent on the amount of water available nearby.A primitive indoor fresh- and wastewater system, consisting of two stone channels lined with tree bark, appears to have featured in the houses of Skara Brae and the Barnhouse Settlement in Orkney from around 3000 BCE Combined with a cell-like enclave in a number of houses at Skara Brae, it has been suggested that these may have functioned as an early indoor latrine.
Wastewater reuse activities
Waste water reuse is an ancient practice connected to the development of sanitation provision. Reuse of untreated municipal wastewater has been practiced for many centuries with the objective of diverting human waste outside of urban settlements. Likewise, land application of domestic wastewater is an old and common practice, which has gone through different stages of development.Domestic wastewater was used for irrigation by ancient civilizations since the Bronze Age. Thereafter, wastewater was used for disposal, irrigation, and fertilization by Hellenic civilizations and later by Romans in areas surrounding cities.
Bronze and early Iron Ages
Ancient Americas
In ancient Peru, the Nazca people employed a system of interconnected wells and an underground watercourse known as puquios.The Mayans were the third earliest civilization to have employed a system of indoor plumbing using pressurized water.
Ancient Near East
Mesopotamia
The Mesopotamians introduced clay sewer pipes around 4000 BCE, with the earliest examples found in the Temple of Bel at Nippur and at Eshnunna, utilised to remove wastewater from sites, and capture rainwater, in wells. The city of Uruk also demonstrates the first examples of brick constructed latrines, from 3200 BCE. Clay pipes were later used in the Hittite city of Hattusa. They had easily detachable and replaceable segments, and allowed for cleaning.Ancient Persia
The first sanitation systems within prehistoric Iran were built near the city of Zabol. Persian qanats and ab anbars have been used for water supply and cooling.Ancient Egypt
The, Pyramid of Sahure, and adjoining temple complex at Abusir, was discovered to have a network of copper drainage pipes.Ancient East Asia
Ancient China
Some of the earliest evidence of water wells are located in China. The Neolithic Chinese discovered and made extensive use of deep drilled groundwater for drinking. The Chinese text The Book of Changes, originally a divination text of the Western Zhou dynasty, contains an entry describing how the ancient Chinese maintained their wells and protected their sources of water. Archaeological evidence and old Chinese documents reveal that the prehistoric and ancient Chinese had the aptitude and skills for digging deep water wells for drinking water as early as 6000 to 7000 years ago. A well excavated at the Hemedu excavation site was believed to have been built during the Neolithic era. The well was caused by four rows of logs with a square frame attached to them at the top of the well. Sixty additional tile wells southwest of Beijing are also believed to have been built around 600BCE for drinking and irrigation. Plumbing is also known to have been used in East Asia since the Qin and Han Dynasties of China.Indus Valley Civilization
The Indus Valley civilization in Asia shows early evidence of public water supply and sanitation. The system the Indus developed and managed included a number of advanced features. An exceptional example is the Indus city of Lothal. In Lothal, the ruler's house had their own private bathing platform and latrine, which was connected to an open street drain that discharged into the towns dock. A number of the other houses of the acropolis had burnished brick bathing platforms, that drained into a covered brick sewer, held together with a gypsum-based mortar, that ran to a soak pit outside the towns walls, while the lower town offered soak jars, the latter of which were regularly emptied and cleaned. Water was supplied from two wells in the town, one in the acropolis, and the other on the edge of the dock.The urban areas of the Indus Valley civilization included public and private baths. Sewage was disposed through underground drains built with precisely laid bricks, and a sophisticated water management system with numerous reservoirs was established. In the drainage systems, drains from houses were connected to wider public drains. Many of the buildings at Mohenjo-daro had two or more stories. Water from the roof and upper storey bathrooms was carried through enclosed terracotta pipes or open chutes that emptied out onto the street drains.
The earliest evidence of urban sanitation was seen in Harappa, Mohenjo-daro, and the recently discovered Rakhigarhi of Indus Valley civilization. This urban plan included the world's first urban sanitation systems. Within the city, individual homes or groups of homes obtained water from wells. From a room that appears to have been set aside for bathing, waste water was directed to covered drains, which lined the major streets.
Devices such as shadoofs were used to lift water to ground level. Ruins from the Indus Valley Civilization like Mohenjo-daro in Pakistan and Dholavira in Gujarat in India had settlements with some of the ancient world's most sophisticated sewage systems. They included drainage channels, rainwater harvesting, and street ducts.
Stepwells have mainly been used in the Indian subcontinent.
Southern Europe
Ancient Greece
The ancient Greek civilization of Crete, known as the Minoan civilization, built advanced underground clay pipes for sanitation and water supply. Their capital, Knossos, had a well-organized water system for bringing in clean water, taking out waste water and storm sewage canals for overflow when there was heavy rain. People constructed flushed toilets in ancient Crete, like in ancient Egypt and before them at places of the Indus Civilization, with the facilities on Crete possibly having a first flush installation for pouring water into, dating back to 16th century BCE. These Minoan sanitation facilities were connected to stone sewers that were regularly flushed by rain, flowing in through the collection system. In addition to sophisticated water and sewer systems they devised elaborate heating systems. The Ancient Greeks of Athens and Asia Minor also used an indoor plumbing system, used for pressurized showers. The Greek inventor Heron used pressurized piping for firefighting purposes in the City of Alexandria.An inverted siphon system, along with glass-covered clay pipes, was used for the first time in the palaces of Crete, Greece. It is still in working condition, after about 3000 years.
Roman Empire
In ancient Rome, the Cloaca Maxima, considered a marvel of engineering, discharged into the Tiber. Public latrines were built over the Cloaca Maxima.Beginning in the Roman era a water wheel device known as a noria supplied water to aqueducts and other water distribution systems in major cities in Europe and the Middle East.
The Roman Empire had indoor plumbing, meaning a system of aqueducts and pipes that terminated in homes and at public wells and fountains for people to use. Rome and other nations used lead pipes; while commonly thought to be the cause of lead poisoning in the Roman Empire, the combination of running water which did not stay in contact with the pipe for long and the deposition of precipitation scale actually mitigated the risk from lead pipes.
Towns and garrisons in the Roman Britain had complex water supply and sewer networks. Supply pipes were often lead but could also be wooden with iron-ring reinforcement at intervals, and some were hollowed logs, jointed together. Stone-lined drains connected to sometimes massive sewer tunnels, such as at York. Latrines, such as those for the Hadrian's Wall garrison located at Housesteads were flushed with collected standing or rainwater.
Medieval and early modern ages
Nepal
In Nepal the construction of water conduits like drinking fountains and wells is considered a pious act.A drinking water supply system was developed starting at least as early as 550 AD. This dhunge dhara or hiti system consists of carved stone fountains through which water flows uninterrupted from underground sources. These are supported by numerous ponds and canals that form an elaborate network of water bodies, created as a water resource during the dry season and to help alleviate the water pressure caused by the monsoon rains. After the introduction of modern, piped water systems, starting in the late 19th century, this old system has fallen into disrepair and some parts of it are lost forever. Nevertheless, many people of Nepal still rely on the old hitis on a daily basis.
In 2008 the dhunge dharas of the Kathmandu Valley produced 2.95 million litres of water per day.
Of the 389 stone spouts found in the Kathmandu Valley in 2010, 233 were still in use, serving about 10% of Kathmandu's population. 68 had gone dry, 45 were lost entirely and 43 were connected to the municipal water supply instead of their original source.