Ruin of a second-century public toilet in Roman Ostia.

Rats, Exploding Toilet Seats and Demons of the Deep: The Hazards of Roman Sewers

(Read the article on one page)

I have spent an awful lot of time in Roman sewers – enough to earn me the nickname Queen of Latrines from my friends. The Etruscans laid the first underground sewers in the city of Rome around 500 BC. These cavernous tunnels below the city’s streets were built of finely carved stones, and the Romans were happy to utilize them when they took over the city. Such structures then became the norm in many cities throughout the Roman world.

Focusing on life in ancient Rome, Pompeii, Herculaneum and Ostia, I’m deeply impressed by the brilliant engineers who designed these underground marvels and the magnificent architecture that masks their functional purpose. Sewer galleries didn’t run under every street, nor service every area. But in some cities, including Rome itself, the length and breadth of the main sewer, the Cloaca Maxima, rivals the extent of the main sewer lines in many of today’s cities. We shouldn’t assume, though, that Roman toilets, sewers and water systems were constructed with our same modern sanitary goals in mind.

The streets of a Roman city would have been cluttered with dung, vomit, pee, shit, garbage, filthy water, rotting vegetables, animal skins and guts, and other refuse from various shops that lined the sidewalks. We moderns think of urban sewers as the means to remove such filth from streets – and of course flush away human waste that goes down our toilets.

Researching Roman urban infrastructure for my new book  The Archaeology of Sanitation in Roman Italy  made me question whether the Romans shared the same vision. The archaeological evidence suggests that their finely constructed sewer systems were more about drainage of standing water than the removal of dirty debris. And Romans' sense of cleanliness and privacy around bathroom matters was quite different from our tender modern sensibilities.

Inside a tunnel of Rome’s sewer, the Cloaca Maxima.

Inside a tunnel of Rome’s sewer, the Cloaca Maxima. Ann Olga Koloski-Ostrow,  CC BY-ND

Sewers managed excess water more than waste

The Cloaca Maxima in Rome was not part of a  master plan to sanitize the city . Its purpose was removing water that pooled on the city’s uneven streets and draining water from low-lying areas when the adjacent Tiber River flooded, which happened quite frequently. Its main function was drainage – and what it drained ran right back into Rome’s major drinking supply before the aqueducts, the Tiber.

Roman sewers moved filthy water away from where it hindered cleanliness, economic growth, urban development and even industry. My work in the sewers of Herculaneum and Pompeii – both buried by the pyroclastic flow caused by Mount Vesuvius' volcanic eruption in AD 79 – has brought me to the same conclusion.

At the bottom of one sewer under a street in Herculaneum, the first excavators found an  ancient deposit of hardened sludge  measuring about 1.35 meters high. No amount of water, however fast-flowing, would have been able to remove that. Several ancient sources state that Roman sewers needed manual cleaning from time to time, a job often done by city slaves or  prisoners. I’d argue these urban sewer systems provided minimal sanitary benefits overall.

Map of Pompeii showing public and private toilets.

Map of Pompeii showing public and private toilets. Gemma C M Jansen

Plenty of toilets, few sewer hookups

Public and private toilets were sprinkled throughout the city of Pompeii. But despite the city’s sewer infrastructure, virtually none of these toilets had sewer connections. We have similar evidence for ancient Herculaneum.

In fact, almost every private house in these cities, and many apartment houses in Ostia, had private, usually one-seater, toilets not connected to the main sewer lines.

And these cesspit toilets were often situated in the kitchen, where food was prepared! The comforting smells from a hearty stew would have mingled with the gross odors from the nearby open cesspit. Collected waste was either sold to farmers for fertilizer or used in  household gardens  – which must have made for some pretty stinky garden parties from time to time.

According to Ulpian’s Digest, written between AD 211 and 222, connections to the sewers from private dwellings certainly were legal. So why didn’t property owners hook up to the public sewer lines?

A private toilet under the stairs in Herculaneum’s Casa del Gran Portale. Ann Olga Koloski-Ostrow,  CC BY-ND

One reason may be tied to that fact that Roman sewer openings had no traps. One never could be sure what might climb out of an open sewer pipe and into your house.

We have at least one dramatic ancient story that illustrates the danger of hooking your house up to a public sewer in the first or second century AD. The  author Aelian tells us about a wealthy Iberian merchant in the city of Puteoli; every night a giant octopus swam into the sewer from the sea and proceeded up through the house drain in the toilet to eat all the pickled fish stored in his well-stocked pantry.


Just a correction: the public latrine in Ostia is not from the second century, but from the fourth century.

Register to become part of our active community, get updates, receive a monthly newsletter, and enjoy the benefits and rewards of our member point system OR just post your comment below as a Guest.

Myths & Legends

Tracing the origins of the Serpent Cult
In mythology, the serpent symbolises fertility and procreation, wisdom, death, and resurrection (due to the shedding of its skin, which is not akin to rebirth), and in the earliest schools of...

Human Origins

Ancient Technology

Our Mission

At Ancient Origins, we believe that one of the most important fields of knowledge we can pursue as human beings is our beginnings. And while some people may seem content with the story as it stands, our view is that there exists countless mysteries, scientific anomalies and surprising artifacts that have yet to be discovered and explained.

The goal of Ancient Origins is to highlight recent archaeological discoveries, peer-reviewed academic research and evidence, as well as offering alternative viewpoints and explanations of science, archaeology, mythology, religion and history around the globe.

We’re the only Pop Archaeology site combining scientific research with out-of-the-box perspectives.

By bringing together top experts and authors, this archaeology website explores lost civilizations, examines sacred writings, tours ancient places, investigates ancient discoveries and questions mysterious happenings. Our open community is dedicated to digging into the origins of our species on planet earth, and question wherever the discoveries might take us. We seek to retell the story of our beginnings. 

Ancient Image Galleries

View from the Castle Gate (Burgtor). (Public Domain)
Door surrounded by roots of Tetrameles nudiflora in the Khmer temple of Ta Phrom, Angkor temple complex, located today in Cambodia. (CC BY-SA 3.0)
Cable car in the Xihai (West Sea) Grand Canyon (CC BY-SA 4.0)
Next article