This is an interesting angle, one which I had not thought of but which makes sense - anti-biotic resistant bacteria excreted from an infected person into wasterwater. On the good side, once the bacteria is out of the patient we can use stronger methods to kill it (scary thought - resistance could build up there also).
I wonder what the economies of this would be though. Would it make more sense to treat the water at the hospital (where most of this bacteria probably(?) exists and there is a smaller volume of waste water) than at the municipal centers (where more water exists and the bacterial levels are probably more dilute)?
Interesting stuff though.