At the turn of the 20th century, it was unhealthy to live in the industrial cities of the western world. However, even since the 19th century, technology, medicine, and biology were quickly evolving. The more pressing need was to find solutions for deadly epidemics hitting populous regions, such as cholera and typhoid fever. In nowadays, it is possible to develop the technology for freshwater, as well as for managing and disposing of sewage in the large urban centers.