There was a sewage works plant in Glasgow, Scotland. In Marauding with Monsters, Gilderoy Lockhart wrote about his adventures along the banks of the River Clyde in search of the Weetimorousbeastie, ending up defeating an Imp colony instead. According to him, the leader of the Imps ran away to the nearby sewage works. The veracity of these events is doubtful, given Lockhart's theft of other people's achievements.