In the nineteenth century, when the stench of London’s almost non-existent drains penetrated the perceptions of even the denizens of the Houses of Parliament in Westminster, right beside the open sewer of the Thames, the civil engineer Joseph Bazalgette was commissioned to design and build a huge network of underground sewers. With Victorian efficiency he built tunnels tall enough for a man to stand upright in, and the system has remained in use, with routine maintenance, to this day.
However, just recently, there was a serious blockage in Kensington, where the rich people live, served by expensive fashionable restaurants. Workers were sent down to investigate and discovered a ten-ton lump of congealed fat. Comment seems superfluous.