Job Troubled water (Fallout 4)

This is where the robot gives the quest to go to vodoochistka the village and kill there a bunch of super mutants outside and inside a bunch of swampies. This is no problem. He clicked the button on the station, the water was gone, out into the street, passed the quest as it was said in the job managing white, appeared the following chain in the same quest to report to Preston Garvey. Here I stake was fucked. Preston is the type of Negro, which is pinned in the Sanctuary and builds a settlement there, either wandering around town or parked behind the house with workshops. Anyways a distinct personality in the hat. You can not miss. So where it Gad happened after he gave the surrender of the quest? None of the guide does not give me the answer. He is already 3 days can not find. Pliz help because I sense a bug here in the job.