Late game mechanics

What an amazing game. But it leaves me craving a single late game mechanic, which is cleaning up the bad water. I know it's meant to be open ended, but I crave some kind of end game where you build bad water filters which extracts the bad water into cubes or stored containers. And then the game switches to figuring out how to transport and store all that waste build up.
In the early and mid game space is valuable for resource production, but as the game goes on you can build more and more for yourself. This mechanic would invert that, causing all that extra space to have to be shared with an ever increasing build up of waste.
The final goal would be some huge amount of stored bad water waste that would then allow the local area (not the whole world, of course) to be purified and restored.

Thoughts?

I always feel like this is what these games are missing. Some late game huge resource dump that justifies everything. Beavers terraforming the whole planet is a bit much, but them cleaning up and fixing a local area is very on brand.