Fallout's outposts are not well thought out. They're just backdrops for quests. As for their water, follow the pipes in the underground hall. They have water purifiers. Looks like a super large industrial unit.
As far as I’m aware, the water tanks at the front of foundation say Toxic water, but if you collect it it’s just Dirty water. It has certainly been that way for a long time now, I don’t think that it has been changed.
The real answer, like most of Fallout’s locations, is that Foundation isn’t what is “really” there. It’s a representation of the reality they are trying to represent with all the boring and empty bits cut out. So like Monongah or whatever in Fallout is probably actually the same size as it is in real life, but in the game it’s only like 6 blocks. We’re not seeing everything that’s there.
Also the big underwater aquifer you found has that giant machine hooked up to it. They’re pumping and purifying it using that thing and then we just don’t get to see where they’re actually getting it from after for that reason above.
22:23 You did solve it, they are not shipping water in, they are doing what people did historically, they are drinking wine. This would be correct historically. Wine is processed and heated, it has to be clean. You noticed all the whiskey and vodka bottles likewise. The water under that you discovered that was very radiated is likely being processed into wine. In countries without unsafe fresh water they mostly drink liquids that require heat to be processed. The answer was on all the tables you went by. The bottles gave it away. Toilets do not require fresh water, so they had enough of that to supply that need. Cholera was a deadly issue, this is why many Westen USA towns in the Wild West had a lot of bars. It was a safety concern, everyone drink at that time. This was true in England with pubs. When travelling it was the safest place to drink. We do not have to worry on that now, but the pubs still exist. But if world had a nuke war like Fallout, people be searching for beer and spirts. Wine and Whiskey. That sort of item. Because they would be processed and safe to drink.
Cool waste of time,but they get their clean water the SAME way every other NPC does.By literal magic.They just dont need it.They are digital,and not real.