The Romans took a tested idea of transporting water and developed it into a system of networks that could help sanitize a city. The development of modern drainage systems was a giant leap in improving community hygiene and in reducing the spread of disease.
Older civilizations were slow to realize the connections between health and sanitation. And when the connection was made, it took time to understand how to sanitize a growing city. Toilets were simple holes in the ground, with the oldest recorded facility being used over six thousand years ago.
These non-flushing units were a hole cut into a seat and suspended over a deep cesspit. As the idea caught on, tens of people at a time would come to use these public toilet facilities rather than using a home chamber pot.
The big issue with a cesspit is controlling contamination of the groundwater at a time when most drinking water would come from wells. Then over five thousand years ago, ancient India began using street drains to carry away sewage from drinking wells.
These clay sewerage channels would direct the waste and rainwater to run off into nearby cesspits. A thousand years later, covers were laid over these channels for better hygiene. These covers were removable for regular cleaning during low-rainfall seasons.
Even with a dedicated path for sewage, bacteria were rampant and disease a major issue. Pieces of pottery or stones were a civilized way of cleaning off after defecating. Known as a pessoi, people would use these solid curved objects to scoop away faeces from their bottoms.
The pessoi were communal and available to everyone to use in public latrines. This was an effective way of spreading both viruses and parasites throughout the community. Then there was a small development from the pessoi to the tersorium.
The tersorium was a sea sponge on the end of a stick, which would act as both toilet paper and toilet brush. Though a step up in comfort, the hygiene of sharing the tersorium was far worse. The tersorium would stand in a bucket of stagnant saltwater or vinegar between latrine seats.
After use, the user would wash the tersorium in the bucket and then left for the next visitor to use. And without tools such as microscopes, there was little evidence that the tersorium was one of the causes of spreading illness
Pits to Plumbing
Both the Greek and Roman physicians at the time knew of pathogens and the dangers of dirty water. They knew that human waste could harbour and transmit disease and that it was necessary to dedicate an area away from freshwater wells.
These physicians also knew that flowing water was less likely to cause illness than stagnant water. There were public health warnings issued about the dangers of washing in still water and how it could lead to gangrene and other infections.
The earlier versions of Greek toilets were more like chamber pots. The contents of these pots were tipped into and washed down sewers. They would use buckets of greywater to wash the waste through clay pipes that led to a system of sewers.
The Minoans developed a way of flushing the sewage through the pipes to prevent blockages and for better hygiene. Ancient Greeks also discovered how to pressurize the water flow for showering and for improving the flow rate of latrines.
Aqueducts were technology perfected by the Greeks, two thousand years before the Roman empire, for irrigation of crops. By 310 BC, Rome had 11 major aqueducts, some over 150 Miles in length, and able to transport over 700-thousand cubic feet of water a day.
The Romans understood aqueducts as an innovation that could carry vast quantities of freshwater to cities. But instead of reserving them for agriculture, they could also use them for drinking, washing, and flushing.
Each aqueduct would carry different grades of water, with each grade going to an equivalent level of society. The highest grade of water went to the wealthy and the aristocratic, which was suitable for washing and drinking.
The lower grades went to the public latrines and bathhouses for washing away waste into the main sewer system. The Romans also built bathhouses so they could centralize the distribution of freshwater to the public for hygiene.
Romans were keen on the science of farming. The initial purpose of their drains was to prevent topsoil erosion and groundwater saturation. Around 800 BC, the Romans began building a network of drains to lower groundwater levels and to prevent flooding.
These early sewers connected to marshlands and low-lying farms. Since this infrastructure was in place, the logic followed that they could divert sewerage out through the same channels.
Whether by design or accident, the Romans had devised a perfect way of moving previously unmanageable amounts of human waste out of the city. Two thousand years ago, the network of sewers went from small scale to covering entire communities.
These new sewers would replace the procedure of the public dumping the contents of chamber pots out their windows and on to passers-by. Then a law made it illegal to hit pedestrians with human waste, further pushing the public to use the more hygienic latrines.
The Romans went on to expand these sewers to connect to the latrines of private residences. Even poorer homes could empty their chamber pots into sewers at designated intervals. The Roman drainage system was the first real attempt at building a city-wide sewer.
These small sewer drains would flow into larger tunnels and eventually into rivers and the sea. The problem with this system was that any river water flowing below the drain outlet was highly toxic and thick with untreated sewage.
Lifting the Lid to Modern Drainage
Roman drainage systems are still the gold standard of drainage and have led the way to our modern networks for centuries. The Roman sewers are so effective and robust that some European cities still use them.
John Harrington invented the seated-style flush toilet in 1596. And there was a further 200-year wait before the invention of the S-trap, a way of sealing the water and smell off from a sewer. But it is still odd to think that it took thousands of years to come up with a drainage system that is so essential to the health and progress of society.