The Sweet Air of Freedom
before I forget to mention:
Due to the paranoia of the previous regime every building in the IZ is unconnected to sewer lines. This isn't such a bad thing since elsewhere in the city they're next to the water mains. Think of the ways this could go wrong.
Add to that the small issue that tanks and APCs are frigging heavy. And the concrete used to make the pipes is very old and very fragile.
One saving grace: water mains are kept at a much higher pressure than sewage pipes. Think of why that's a good thing.
The result is that with a population several hundred times larger than intended the septic tanks are ... well... "oversubscribed." The tanker trucks that pump the waste are constantly circling, parking, and sucking. The smell is remarkable. As is the occasional overflow.
So long story short: Keep your freaking boots off the couch.