The Slide Show of Commodes at Christine Gorman's A Brief History of the Toilet really brings this month's Special Edition on Cities home. After all, everybody poops; and in urban areas dealing with all the waste from the thousands or millions of bottoms of residents and visitors each day is perhaps the very first necessity of urban living. I would wager it was the first order of business in social communities: Where to go and where it all goes.

Forget about skyscrapers, protected harbors or capital markets. The lowly toilet is key to what makes modern cities possible

Quick Tutorial in Urban Sewage Facilities at Urban Science Adventures! ©

A great deal of our municipal taxes is dedicated to waste removal – garbage and sewage. And let’s be appreciative, one the most important technologies ever is municipal sewage facilities. Municipal sewage handling dates back to the Roman Empire. The Cloaca Maxima was a marvel. Using running water, the Romans were able to wash waste away from public baths and relief spots. For communities without such technologies, they use latrines or other set aside areas - like outhouses.

Thus sewer facilities are definitely an urban technology, and the most important technology benefiting human-kind. Urban areas, unlike rural or even traditional suburban areas, are densely populated – lots of people and buildings, all stacked up on each other. If we were still using a latrine system the situation would be bad – for us and the native wildlife with which we share this precious space. Thanks to waste handling technologies, we have nipped diseases like cholera, typhoid, and dysentery in the bud. Societies with properly functioning waste water handling have virtually no incidences of these horrible diseases that claim countless lives each year.

We flush and it all goes away, but it's no mystery. Thanks to How Stuff Works, you can read and see for yourself how Urban Wastewater Sewage Systems work.