IMO there should be an program for cities that can't afford to rebuild their collapsed infrastructure to use Federal/State funds to just buy the residents out and return the area to nature. After the state pays to fix this infrastructure, these low density, low value, high vacancy areas of Cahokia Heights (like former Alorton) will still be functionally insolvent. It's also hard to imagine these areas seeing growth anytime soon, even with new pipes. Alorton is arguably the least desirable location in the shrinking metro east, the streets don't even have sidewalks and are prone to flash flooding.
I'm not saying level the neighborhood, but strategic retreat on a block to block level seems like a more prudent strategy if Cahokia Height's wants to become more sustainable in the long term. I would bet that it would be cheaper to build relocated residents new houses a few blocks away on blocks deemed worth saving than it would be to rebuild an entire blocks sewer infrastructure to serve 1-2 derelict homes at a high risk of becoming vacant in the next decade anyways.