Not sure about Gtown but farther out it is from sewage vents that are slowly being replaced with ones that don't vent directly. I used to think it was from the still water in the canal but that is not the case.

Any of you regular Canal Road commuters notice the terrible stench lately in a couple of key places along your route? Most noticed in the evenings just as you exit Georgetown, but pretty bad in several places along the way. Is it sewage?