The attributes that make this building unique include the circular plan, the engaged inverted engaged catenary arches on the lower wall and the taller engaged catenary arches on the upper wall with fins that extend beyond the original roofline. Unfortunately, the recently added metal penthouse (or cap on top) obscures these fins from view and diminishes the brilliant original design that you can see at http://commons.wikimedia.org/wiki/File:Pumping_station_in_Ashbridges_Bay_Toronto.jpg. This pumping station is officially known as the Mid-Toronto Interceptor Pumping Station but being a part of the Ashbridges Bay Treatment Plant, it goes by the name Building T.