Tuesday, February 10, 2009
The Design of Les Egouts: It's the S***
The Musée des Égouts showcases one of the most complex and carefully designed structures I have ever learned about: the sewage system in Paris. It is the world’s longest and first underground sewage system; if you lay out the sewers, they would stretch from Paris to Istanbul. The underground architectural masterpiece provides Parisians with 200 million cubic meters of water each year and 600,000 cubic meters of drinkable water each day in Paris. The water distributed from the system reaches each house in Paris as well as public areas, such as 900 points of free drinking water and 34 municipal pools.
The underground maze, better known as the sewage system, reminded me of a giant, cohesive museum. It features lake reservoirs of different shapes, patterns created by foot irons on bumpy walls in order for workers to descend into darkness and rescue people’s keys, overlapping pipes in and out of the house and twisting around the undergrounds of Paris, and charcoal-colored tubes with moving water. Each street in Paris has a sewer underneath it with a corresponding gallery name (“Gallerie des Champs Elyssées,” for example). Furthermore, the museum displays a collaboration of many artists’ work. Architects, a variety of engineers (town planning, water supply and wastewater treatment, etc.), prefects of the Seine Department, electricians, and many other types of designers have contributed to the final design that affects every Parisian. All of these artists learned from past artists to improve their specialty. For example, people in the Gallo-Roman period began the sewage system with an aqueduct of 20km that produced around 24 cubic meters of water per day. Each artist involved in the sewage project worked hard on specific parts of the “museum” to make their works functional and appealing to the public.
What’s more, like all good works of art, the sewage system in Paris has inspired many artists. Sculpture Rachid Khimoune molded manhole covers to create the statue “Children of the World” for the Parc de Bercy, film scenes took place inside the sewers, and Victor Hugo even wrote about it in his accounts of Jean Vljean’s adventures.
Each aspect of the underground architectural masterpiece serves a purpose. Before going underground and studying the construction, I had not pondered how well thought-out and engineered each part of the sewage system was. The system houses drinkable and polluted water pipes that go to each Parisian household (which makes the water bill cheaper, since not all of the water is drinkable), pneumatic tubes used to send letters between members of the National Assembly, and control cables for traffic lights. Designers carefully excluded gas pipes or electricity cables in the system for safety reasons.
Without a proper design, we could have dirty water in our sinks and therefore get ill more easily. In the Middle Ages, domestic waste water was thrown into the streets and the plague spread by rats created epidemic. Today, we have a sewage system that involves many steps to purify water that comes to our sinks. The sewage tunnels collect water from 150km around underground Paris as well as surface water from the Seine and La Marie. They then stretch over a large area of Paris to various water tanks: one for clarifying the water by naturally eliminating bacteria, one for refining the water by killing viruses and eliminating the odor, and one for disinfecting the water completely. Finally, the distribution of the clean water takes place over 1800km of piping.
Without a proper design, we could also have really smelly streets, as Parisians had during the Renaissance, when Hotel des Tournelles, a hotel near the river, was abandoned due its horrible smell. Lucky for me, the designers of the current sewage system have discovered a clever way to keep the smell of the sewers bearable. For example, there are 6000 automatic flushing reservoirs that clean the sewers on a regular basis. Architects also included many descending basins in the system design, tanks next to sewers that trap hybrid mixtures for later removal to special waste disposal sites. Furthermore, they designed emissaries and siphons, two sewers of different sizes to transport water from one the main sewers to treatment plants and from the Left to the Right Bank, respectively. The two types of sewers were specific sizes to fit balls that roll through the tunnels and clean the water, so that humans did not have to go into the tunnels to clean them and so that the streets did not smell as awful (because there were not as many holes in the ground). When the ball arrived at the end of the tunnel, the architects had designed a hole big enough so that the workers could take out the ball, clean it, and return it to the beginning of the cleaning cycle. Designers also ameliorated the city smell by irrigating and fertilizing 5000 hectares of land in Acheres, Carrieres-Triel, and Mery-Pierrelaye to spread sewage and purify naturally by going to Seine. They additionally included in the sewage system large surface holes used to evacuate over 1.2 million cubic meters of wastewater and 15000 cubic meters of solid waste per year.
The Paris sewage system is one of the most powerful architectural structures I have ever studied. Every aspect of it is well thought-out, with its practicality, design, size, usability, durability, public appeal and inspiration. It has developed over time, and it also has shaped other parts of Paris. It lessened the pollution, and it encouraged Baron Haussman to widen the streets in order to continue the improvement of air circulation. I am thus not surprised that my tour guide called the sewer manhole covers “symbols of Paris that no one ever thinks about.” As a result of this museum, now each time it rains, each time I use the sink, each time I step over a manhole on the streets, I appreciate the masterpiece and what it represents.