Imagine the smell and pollution human waste would have made in this world if there were no sewage disposal systems. Without plumbing, as we know it today, the cities and towns would have been a great mess besides being breeding grounds of diseases that we cannot even think about. The London Sewage System serves the Greater London area and is one of the larger sewage systems in the world. Operated by Thames water, this system was developed in the later part of the 19th Century and as the city has grown, this system has expanded too.