Since the beginning of societies where people lived in one place (often starting when agriculture was developed), human communities have faced important problems related to keeping areas clean and ensuring access to safe drinking water. When water supplies, systems for moving water, or sanitation methods were not enough, diseases spread, causing illness and early deaths.

Large communities could only form in places with plenty of fresh surface water, such as near rivers or natural springs. Over time, different groups created systems to help people get clean water or safely remove and later treat wastewater.

For much of history, handling sewage meant moving raw waste to natural water sources like rivers or oceans, where it would mix with the water and eventually disappear.

Through many years, technological progress has made it possible to move water over much longer distances. Also, methods for cleaning drinking water and treating wastewater have become more effective.

Prehistory

During the Neolithic era, humans created the first long-lasting water wells, which allowed people to fill containers and carry water by hand. Wells from about 8500 BCE have been discovered on Cyprus, and wells from around 6500 BCE have been found in the Jezreel Valley. The size of human communities often depended on how much water was available nearby.

An early indoor system for moving fresh and used water included two stone channels covered with tree bark. This system was found in homes at Skara Brae and the Barnhouse Settlement in Orkney, dating back to about 3000 BCE. Some homes at Skara Brae also had a small room-like area, which may have been used as an early indoor toilet.

Using wastewater without cleaning it first has been a long-standing practice linked to improving sanitation. For many centuries, people used untreated wastewater from cities to move waste away from populated areas. Similarly, applying wastewater to land has been a common practice for a long time, with different methods used over time.

Ancient groups, such as those in Mesopotamia, the Indus Valley, and Minoan civilizations, used domestic wastewater for irrigation during the Bronze Age (about 3200–1100 BCE). Later, Hellenic and Roman civilizations used wastewater for disposal, irrigation, and fertilizing fields in areas near cities like Athens and Rome.

Bronze and early Iron Ages

In ancient Peru, the Nazca people used a system of connected wells and an underground water channel called puquios to manage water.

The Mayans were among the earliest civilizations to use indoor plumbing with pressurized water.

The Mesopotamians created clay sewer pipes around 4000 BCE. Early examples were found at the Temple of Bel in Nippur and Eshnunna, used to remove wastewater and collect rainwater in wells. In the city of Uruk, brick latrines from 3200 BCE show early examples of sanitation. Later, the Hittites in Hattusa used clay pipes with detachable parts that could be cleaned easily.

In prehistoric Iran, the first sanitation systems were built near Zabol. The Persian qanats and ab anbars were used for water supply and cooling.

Around 2400 BCE, the Pyramid of Sahure and its temple complex at Abusir had a network of copper drainage pipes.

Some of the earliest water wells were found in China. Neolithic Chinese people dug deep wells for drinking water. The ancient Chinese text The Book of Changes describes how they maintained and protected their wells. Archaeological evidence shows that Chinese people had the skills to dig deep wells as early as 6000 to 7000 years ago. A well found at Hemedu was built during the Neolithic era using logs and a square frame. Other tile wells near Beijing were built around 600 BCE for drinking and irrigation. Plumbing was also used in East Asia during the Qin and Han Dynasties.

The Indus Valley civilization in Asia had advanced public water and sanitation systems. In Lothal (around 2350–1810 BCE), the ruler’s house had a private bathing platform and latrine connected to a street drain that led to the town’s dock. Other homes had brick bathing platforms that drained into covered sewers made with gypsum mortar. These sewers led to soak pits outside the city. The lower town used soak jars, large buried urns with holes to let liquids drain, which were cleaned regularly. Water came from two wells in the town.

Indus Valley cities had public and private baths. Sewage was removed through underground drains made of precisely laid bricks. A sophisticated water system with reservoirs was used. House drains connected to larger public drains. Many buildings in Mohenjo-daro had two or more stories. Water from roofs and upper floors was carried through terracotta pipes or open chutes to street drains.

The earliest urban sanitation systems were found in Harappa, Mohenjo-daro, and Rakhigarhi. These cities had homes connected to wells, and wastewater from bathing areas was directed to covered drains along major streets.

Devices like shadoofs were used to lift water to ground level. Settlements like Mohenjo-daro in Pakistan and Dholavira in India had advanced sewage systems with drainage channels, rainwater harvesting, and street ducts.

Stepwells were mainly used in the Indian subcontinent.

The Minoan civilization on Crete built underground clay pipes for water and sanitation. Their capital, Knossos, had a well-organized system to bring in clean water and remove waste. One site may have had a flush toilet from the 16th century BCE. These systems were connected to stone sewers flushed by rain. The Ancient Greeks used indoor plumbing with pressurized showers. Heron of Alexandria used pressurized pipes for firefighting.

An inverted siphon system with glass-covered clay pipes was first used in Crete’s palaces. This system is still functional after about 3000 years.

In ancient Rome, the Cloaca Maxima, a major engineering feat, discharged into the Tiber River. Public latrines were built over it.

During the Roman era, a water wheel called a noria supplied water to aqueducts and other systems in Europe and the Middle East.

The Roman Empire had indoor plumbing, with aqueducts and pipes delivering water to homes, public wells, and fountains. Lead pipes were used, but the flow of water and deposits of scale reduced the risk of lead poisoning.

In Roman Britain (46 BCE–410 CE), towns and military bases had complex water and sewer systems. Pipes were often made of lead, wood with iron rings, or hollowed logs. Stone-lined drains connected to large sewer tunnels, like those in York. Latrines, such as those at Housesteads on Hadrian’s Wall, were flushed with rainwater or collected standing water.

Medieval and early modern ages

In Nepal, building water conduits such as drinking fountains and wells is considered a holy act. A drinking water supply system was developed as early as 550 AD. This system, called the dhunge dhara or hiti, includes carved stone fountains that allow water to flow continuously from underground sources. These fountains are supported by ponds and canals that form a network of water bodies. This system provided water during dry seasons and helped manage water pressure from monsoon rains. After modern piped water systems were introduced in the late 19th century, the old system fell into disrepair, and some parts were lost. However, many people in Nepal still use the old hitis daily.

In 2008, the dhunge dharas in the Kathmandu Valley produced 2.95 million liters of water each day. In 2010, 389 stone spouts were found in the Kathmandu Valley. Of these, 233 were still in use, serving about 10% of Kathmandu’s population. Sixty-eight had dried up, 45 were completely lost, and 43 were connected to the city’s water supply instead of their original source.

Islam teaches the importance of cleanliness and personal hygiene. Islamic rules from the 7th century include detailed guidelines for purity. Taharah, or ritual purity, involves washing hands, arms, and feet before prayer (wudu) and full bathing (ghusl). These practices led to the construction of bathhouses across the Islamic world. Islamic hygiene also requires washing with water after using the toilet to maintain cleanliness and reduce germs.

During the Abbasid Caliphate (8th–13th centuries), Baghdad had 65,000 baths and a sewer system. Medieval Islamic cities had water supply systems powered by hydraulic technology that provided drinking water and large amounts of water for ritual washing in mosques and hammams (baths). Bathing establishments were described in Arabic travel guides. Cities like Baghdad, Córdoba, Fez, and Fustat had advanced waste disposal and sewage systems. Fustat also had multi-story buildings with flush toilets connected to water supplies and waste channels.

Al-Karaji, a scholar from around 953 to 1029, wrote a book called The Extraction of Hidden Waters. It included groundbreaking ideas about the water cycle, groundwater quality, and water filtration processes.

As the Islamic Golden Age declined, Arab and European scholars criticized the condition of canals, streets, and waterways in Egypt. In the 11th century, the Egyptian doctor Ali ibn Ridwan wrote that people in Fustat threw waste into streets and alleys, where it decayed and mixed with the air. Sewage from latrines also flowed into the Nile. In the 18th century, the French Consul in Egypt, De Pauw, blamed the abandonment of ancient Egyptian embalming practices for the spread of disease in the Nile Delta. Some colonial comments, like those by British doctor J. W. Simpson in 1883, claimed Egyptians did not value water and contaminated the Nile. Historians in 2023 noted these views reflected British colonial attitudes toward Egyptians.

In post-classical Kilwa, plumbing was common in the homes of local people. The Husani Kubwa Palace and other buildings for the ruling class had indoor plumbing.

In the Ashanti Empire, toilets were housed in two-story buildings that used boiling water to flush waste.

Christianity emphasizes hygiene. Although early Christian leaders criticized Roman-style mixed bathing and the practice of women bathing naked in front of men, they encouraged followers to use public baths for health. The Church built separate bathhouses for men and women near monasteries and pilgrimage sites. Popes placed baths in church basilicas and monasteries as early as the Middle Ages. Pope Gregory the Great promoted bathing as a necessary bodily practice.

Contrary to popular belief, bathing and sanitation were not lost in Europe after the fall of the Roman Empire. Public bathhouses were common in medieval cities like Constantinople, Paris, Regensburg, Rome, and Naples. Great bathhouses were also built in Byzantine cities such as Constantinople and Antioch.

There is little record of sanitation systems in Europe before the High Middle Ages, except for those in ancient Rome. Unsanitary conditions and overcrowding were widespread during the Middle Ages, leading to pandemics like the Plague of Justinian (541–542) and the Black Death (1347–1351), which killed millions. High infant and child mortality in Europe was partly due to poor sanitation.

In medieval European cities, natural waterways were used to carry wastewater. These were later covered to function as sewers. In London, the River Fleet was such a system. Open drains, called "kennels" in Paris, ran along streets. The first closed sewer in Paris, built in 1370 by Hugues Aubird, was 300 meters long. It was designed less for waste management and more to control the smell of wastewater.

In Dubrovnik (then called Ragusa), the Statute of 1272 outlined rules for building septic tanks and sewage channels. The city’s sewage system, constructed in the 14th and 15th centuries, is still operational today with minor updates.

Pail closets, outhouses, and cesspits were used to collect human waste. In China and Japan, human waste was used as fertilizer because cattle manure was less available. However, most cities lacked sewer systems before the Industrial era and relied on rivers or rain to wash away waste. In some places, wastewater ran down streets with stepping stones for pedestrians and eventually drained into local water sources.

In the 16th century, Sir John Harington invented a flush toilet for Queen Elizabeth I (his godmother), which released waste into cesspools.

After the use of gunpowder, municipal outhouses became a source of raw material for the…

Modern age

London's water supply system developed over many centuries. It began with early water channels during the medieval period, then grew with major water treatment projects in the 19th century to fight cholera, and now includes large reservoirs. In the early 1600s, Hugh Myddleton led an engineering project to bring fresh water from Hertfordshire to London. He built the New River between 1609 and 1613. The New River Company became one of the largest private water companies in England, providing water to the city and other central areas. The first piped water system in England was built in Derby in 1692. It used wooden pipes, which were common for many years. The Derby Waterworks included pumps powered by waterwheels to lift water from the River Derwent and storage tanks for distribution.

Before the Enlightenment, little progress was made in water supply or sanitation. In the 18th century, London's growing population led to the creation of many private water networks. The Chelsea Waterworks Company was formed in 1723 to supply water to Westminster and nearby areas. It built ponds near Chelsea and Pimlico using water from the tidal Thames. Other waterworks were built in London, including at West Ham in 1743, Lea Bridge before 1767, Lambeth Waterworks Company in 1785, West Middlesex Waterworks Company in 1806, and Grand Junction Waterworks Company in 1811.

The S-bend pipe was invented by Alexander Cummings in 1775. It later became known as the U-bend after Thomas Crapper introduced the U-shaped trap in 1880. The first screw-down water tap was patented in 1845 by Guest and Chrimes, a brass foundry in Rotherham.

The first use of sand filters to clean water was in 1804. John Gibb, a bleachery owner in Paisley, Scotland, installed an experimental filter and sold extra water to the public. In 1829, engineer James Simpson built the first treated public water supply for the Chelsea Waterworks Company in London. Water treatment became common after Dr. John Snow's research during the 1854 Broad Street cholera outbreak showed how water spread the disease.

A major development was the creation of sewer systems to collect wastewater. In cities like Rome, Istanbul (Constantinople), and Fustat, ancient sewer systems still work today, connecting to modern treatment facilities. Before sewers, people used cesspools to store waste. In ancient Mesopotamia, waste was carried into cesspools through vertical shafts. Similar systems existed in the Indus Valley (modern Pakistan), Ancient Crete, and Greece. During the Middle Ages, waste was stored in cesspools and emptied by workers called "rakers," who sold it as fertilizer.

Archaeological findings show that the earliest sewer systems were built around 3000 BCE in Harappa and Mohenjo-daro (modern Pakistan). These early sewers were carved into the ground next to buildings, showing early civilizations understood waste disposal.

The rapid growth of cities in Europe and North America during the Industrial Revolution caused overcrowding and disease. By the 19th century, public health concerns led to the construction of gravity sewer systems to control diseases like typhoid and cholera. Storm and sanitary sewers were built alongside cities. By the 1840s, indoor plumbing, which uses water to flush waste, replaced cesspools.

Modern sewer systems began in the mid-1800s to improve sanitation after industrialization. Baldwin Latham, a British engineer, helped design oval-shaped sewage pipes to improve drainage and prevent flooding. Cholera outbreaks in London in 1832, 1849, and 1855, along with the Great Stink of 1858 (when the Thames smelled strongly of waste), and a report by Edwin Chadwick, led to the creation of a new sewer system. Joseph Bazalgette was chosen to build it, but unlike Chadwick's plan, the system did not use sewage as fertilizer. Instead, waste was sent to natural waterways away from cities.

As late as the 19th century, some parts of the UK still had poor sewer systems, leading to risks of cholera and typhoid. Efforts to stop polluting the River Thames began in 1535 with a law banning waste dumping. Before the Industrial Revolution, the Thames was described as thick, black, and smelling strongly of sewage.

As the first country to industrialize, Britain faced major health problems from overcrowding and was the first to build a modern sewer system. In the early 1800s, the Thames was an open sewer, causing frequent cholera outbreaks. Plans to improve sewers were made in 1856 but delayed due to lack of money. After the Great Stink of 1858, Parliament acted to build a new system.

In 1847, James Newlands, a Scottish engineer, was appointed Borough Engineer of Liverpool under the Liverpool Sanitory Act. He conducted detailed surveys of the city, creating a contour map of Liverpool and its surroundings. Using this map, he designed a sewer system with nearly 300 miles of outlet and contributory sewers, main and subsidiary drains. His plans were presented to the Corporation in April 1848.

Understanding of health aspects

The Greek historian Thucydides (c. 460 – c. 400 BCE) was the first person to write, in his account of the plague of Athens, that diseases could spread from an infected person to others.

The Mosaic Law, found in the first five books of the Hebrew Bible, contains the earliest recorded thoughts about how diseases spread. It includes instructions about quarantine and washing to prevent the spread of leprosy and venereal disease.

One theory about how some diseases spread without direct contact was that they were carried by spore-like "seeds" (Latin: semina) in the air. In his poem De rerum natura (On the Nature of Things, c. 56 BCE), the Roman poet Lucretius (c. 99 – c. 55 BCE) described how the world contained "seeds," some of which could make people sick if inhaled or eaten.

The Roman statesman Marcus Terentius Varro (c. 116 – c. 27 BCE) wrote in Rerum rusticarum libri III (Three Books on Agriculture, 36 BCE): "Precautions must also be taken near swamps because tiny creatures, invisible to the eye, float in the air and enter the body through the mouth and nose, causing serious diseases."

The Greek physician Galen (129 CE – c. 216 CE) wrote in On Initial Causes (c. 175 CE) that some patients might have "seeds of fever." In On the Different Types of Fever (c. 175 CE), he suggested that plagues were spread by "seeds of plague" in the air. In Epidemics (c. 176 – c. 178 CE), Galen explained that patients might relapse during recovery from fever if "seeds of the disease" remained in their bodies and were not treated properly.

The Islamic scholar Ibn al-Haj al-Abdari (c. 1253 – 1336) discussed hygiene and warned about impurities in water, food, and clothing that could spread disease through water supplies.

Before the germ theory of disease was discovered or the role of water in spreading illness was understood, traditional beliefs warned against drinking water and favored processed drinks like beer, wine, and tea. For example, in the 1928 study of camel caravans on the Silk Road, the explorer Owen Lattimore noted that people drank tea instead of unboiled water because of a belief that it caused blisters on the feet.

In the 19th century, Europe began to understand waterborne diseases during the Industrial Revolution. At first, diseases like cholera were wrongly explained by the miasma theory, which claimed that "bad air" caused illness. However, people started to notice that poor water quality was linked to disease. This led to new methods to purify water, such as sand filtering and chlorination.

The founders of microscopy, Antonie van Leeuwenhoek and Robert Hooke, used microscopes to observe tiny particles in water for the first time. Their work helped scientists later understand waterborne pathogens and diseases.

In the 19th century, Britain experienced rapid urbanization, leading to health problems like cholera outbreaks. Before the link between contaminated water and disease was known, the miasma theory was used to explain these illnesses. However, the physician John Snow studied the 1854 Broad Street cholera outbreak and used a dot map and statistical data to show that cholera spread through polluted water. His 1855 essay On the Mode of Communication of Cholera proved that the Broad Street water pump was the source of the outbreak. After his findings, the local council removed the pump handle, stopping the epidemic.

Edwin Chadwick played a key role in improving sanitation in Britain, using the miasma theory to support his plans. However, John Snow and William Budd later showed that cholera was caused by contaminated water, proving that diseases could be spread through drinking water.

People discovered that purifying and filtering water improved its quality and reduced waterborne diseases. In the German town of Altona, a sand filtering system helped prevent an outbreak, while a nearby town without filtering suffered from the disease. This evidence led Britain and Europe to adopt water filtration and chlorination to fight diseases like cholera.