I've noticed it where I am too, between campus and Craddock. It seems like I've noticed it in the evenings more than other times. Of course, that's when I'm home. Duh!
I doubt it is your house, unless you live next door to me. The sewage treatment plant is way on the other side of town, by the animal shelter. The smell can be pretty bad over there, but I doubt it would carry all the way to us. If it did, that would mean most of the city probably could smell it, unless our elevation has something to do with it.