It's sewage and often this happens in new builds as the infrastructure is of course new and there may be drainage problems that need to be reworked. The best thing you can do is MAN UP.
Coming from you, that's bloody rich. B*gger orf.
The volume of shit going through the sewers from the 2 Uni's and The Amex plus the residents of the village must be phenomenal.
Why should the club sort it out? It's nothing to do with the Amex. If you lived near a sewage plant would you be expected to "Sort it out?"
The stink was pre-game of a Saturday lunchtime, when the Uni was near empty and the Amex was only starting to fill up. Which, by process of elimination, just leaves the residents of the village as the source of the stench.