To start my wonderful, bright, and sunny Friday morning here in France, my class and I headed under the streets of pairs to visit the Sewer Museum. From 10 am-11 am, I spent my time walking around a sewer, stench and all, and learning everything I could about it. Dr. Smith is very knowledgeable about the pairs sewer system, and honestly, it was a great tour that I feel many people miss out on when traveling to Paris, France. Other than feeling like a lovely little sewer rat all morning, let’s get into what I learned about Parisian plumbing in the Paris Sewer Museum.
The first impressive fact we learned today is that the French sewer systems rely very little on pumps and instead focus more on gravity to move the contents of the pipes around. This uses much less energy and is extra beneficial in the case of a power outage. This precaution is necessary because it will greatly reduce the chance of the sewers flooding if a power outage occurs. Since the Seine River often does flood Paris, the sewage system was built to survive heavy flooding by depending mainly on gravity.
The layout of the sewer system here in Paris is also extremely interesting and productive! The sewage pipes have a variety of different shapes depending on what the area needs. There are cylindrical pipes just to move fluids and matter, large pathways that can be walked on for access and maintenance, as well as pipes just large enough for one person to stand up in. The electricity for the city is also laid out in these same underground passageways which increase the accessibility of main sewage/power lines. This aspect of the system is useful in case of an accident or for maintenance. I love consistency in city maintenance so this was great to hear! Also, the street signs underground were really engaging to see as a visitor at this museum. They are the same design as the street signs above ground, and they helped me to orient myself as well as visualize how extensive this system under the city really is.
Additionally, there are intuitive methods in place for when problems do occur in the pipes. Large sewer boats are used to sort of sift through the water and material in it to help prevent any blocks or buildups that may occur by the sewage and any items that may be in it. However, for the pipes that are smaller and entirely tubular with no room for these large boats to pass through, sewer balls are dropped into the pipes. Due to its self-healing properties, these large spherical balls are made of wood to prevent detrimental cracks/breaks from occurring while the balls are in the sewer pipes. They are also covered in tar to make cleaning purposes easier. The point of these large sewer balls is to unblock the pipes. If there is a clog, the balls will be sent down the pipes and, since the pipes are gravity based, the build-up behind the sewer ball will eventually have enough force to push it forward and through the original clog. It then will roll all the way through until it comes out the other end and is collected for cleaning and reuse.
Lastly, the cleanliness of the water system here in Paris is rather impressive, especially for such a large metropolitan area. There is an extensive filtration system that uses bio-mechanics to clean the sewer water before it is dumped back into the Seine. In the US, water from sewers often does not get filtered until after it has already been dumped into the rivers. This is why there is such a problem with sewer water runoff in the US leading to the eutrophication of wetlands and streams damaging an integral part of our natural environment. So, yet again, France does it better and has some of the cleanest water in the world as sewer water is filtered first and then released back to the Seine River to travel through aqueducts and be re-used in the city. In fact, these aqueducts carry water into the city from wayyy upstream which helps to ensure the Pairs water is extra clean and safe for drinking.
Even though it was really stinky and somewhat weird to be enjoying talking about Paris’ sewage, I have very high respect for the people who work underground and make clean and accessible water possible for this city and many others like it.
