One could spend months just in Paris museums. But if you are looking for something unusual, why not check out the Paris Sewer System Museum?

Paris Sewer System Museum (Musée des Égouts)

The depths of a major city sewer system, with water flowing under your feet, may seem like an unusual subject and location for a museum. But Musée des Égouts provides insight into how the sewers work and their history. 

On Joyce’s first trip here a long time ago, the museum wasn’t easy to find. After wandering in the area and asking many people, she finally found the entrance. Today it is easier to find. The museum has recently been renovated with a new building and new tours. 

Exploring the Sewers

After walking several stories below ground, you reach the section of the city’s main system. As you walk through the tunnels, with pumps humming, pipes overhead, and untreated sewer water flowing alongside and under your feet, you know you are in for a different experience.

The History of Paris Sewers

The museum traces the history of the city’s water and sewage system from the first century when inhabitants of Lutetia (the name of the first settlement on Île de la Cité) pulled their water directly from the Seine. They dumped their sewage onto the streets and the land where the earth served as a natural filter.

As the city grew, water needs and sewage problems emerged. In the 4^th century, the Romans had much greater needs. They wanted public water (including for the baths) to flow naturally into the city rather than having to get it up from an increasingly polluted river. They built a system of aqueducts to supply fresh water, albeit not enough for the city’s growing needs. Most people still had to carry or pay others to carry water required for their personal needs from the river.

They did provide open ditches for sewer water rather than let it flow through the streets. However, they did not address the growing sewage problem. By the Middle Ages, the sewer water that flowed in open ditches was largely responsible for plaques. By the 1300s, they began covering the ditches but still allowed the water to run directly into the river.

How To Solve the Problem

The first initial efforts at systematically addressing the problem came during the Renaissance. The first hydraulic pumps were installed. Between 1490 and 1550, all houses and businesses were required to dig and dispose of waste in cesspools. Although this helped somewhat, the modestly filtered waste still flowed into the river which was still the primary source of the city’s water.

By the 1800s, Napoleon I (Bonaparte) began installing steam pumps and digging new canals to bring fresh water in from less polluted sources. The river, however, was becoming more and more polluted.

The issue wasn’t seriously addressed until 1854. Napoleon 3 assigned Baron Haussmann to address many of the city’s problems. Haussmann designed the city to eliminate cramped, narrow streets. He created wide avenues and boulevards to open the city to light and to facilitate transportation and the creation of a long-term infrastructure.

He also appointed Eugene Belgrand to design and spearhead the creation of a water system. The goal was to bring a sustainable pure water supply to a growing city. A second goal was to create the foundations for a modern sewage system that would not only efficiently remove wastewater but also treat it before it was released into the river.

Creating a New Water System

Belgrand created a more modern system of aqueducts and built reservoirs to store it until it was needed. He created a system by which less pure, but still usable water (effectively gray water) could be used for less sensitive purposes (such as for washing streets). He created a long-term means of collecting and treating all wastewater before discharging it into the river. The plan mandated that by 1894, all buildings would have to install drainage systems that channeled rainwater and wastewater into the new sewer system (rather than into cesspools).

Not only did he create the system, but he also designed machines and processes to continually flush and cleanse the sewer system. Dirt and sand were filtered out and returned to the ground (especially farm fields). Bio-waste was separated. Water was aerated before being returned to the river. This system has been continually expanded and enhanced, but not significantly changed to the point that it now handled and treats more than 1.2 million liters of wastewater per day.

The museum not only traces the history and explains the details of the operation of the current system. It also shows you some of the actual equipment that is used, as well as models of historical gear—including the system of large hollow balls that Belgrand created to clean the sewers—a system that is still used today.