IIRC in the initial plans way back, there was something regarding the sewerage works along the lines of they were to be house indoors (In other words just bang a roof over them) due to, and I don’t know this as gospel, that the one in Urmston was one of the biggest uncovered sewerage in Europe and due to new laws it could have to be covered.
Not sure what happened about that but that was a big selling point of the stadium plans with the local residents the fact that the stadium would hasten this action and make lives better with a little more fresh air during the summer.