Again, then if this is the case they should all be dead. Deadly water should mean all life is dead. Which means they cannot eat. Which means without enough water they would all die regardless if some of them can have a glass a day.
Again, not really, they have plenty of anti-radiation drugs, and brahmin milk is also known to remove radiation. So long as they drink their milk they would be fine, as it would remove any rads one gets from eating the irradiated meat of animals and the like.
Whats more is that all the animals have mutated to negate most of the radiation. That has been lore since Fallout 1.
If they can't farm... where the fuck do they get their food? From surprisingly not looted supermarkets?
From all the animals they raise/hunt? There's over 26 brahmin being raised by people in Fallout 3(which is actually more then Fallout 1 showed)
On top of that, we know that
-Rivet City grows apples, carrots, potatoes, and pears, in its hydroponics lab, which it trades to other settlements for metal to do repairs on their ship.
-Rivet City also has a large supply of mirelurk meat, which they get from the mirelurks constantly trying to inhabit the lower levels of the ship.
-We see hunters roaming the wastes hunting yao guai, mole rats, mirelurks, and wild dogs, for meat.
-We know people eat fallout series staples of the always unseen iguanas and squirrels.
-People also mention eating radroaches, though it supposedly tastes like old boot.
-There are two kinds of mutfruit growing in the wasteland people harvest when they can.
-There is also enough trade with Point Lookout that they get a sizable amount of punga from there.
-People drink Brahmin milk, which supposedly has anti-radiation capabilities.
-Many raiders appear to be cannibals, so people are an option also.
There was even a fairly large mirelurk farm/meat processing facility inside the anchorage war memorial up until recently, when they were taken out by raiders and hired mercs.
