Because it is a video game, they can give radioactivity any property they want even impossible ones.
Depending on the cause there could be "harmless" levels of residual radiation (a few times "normal background) after that time period. For example the area around Chernobyl was seriously contaminated in the disaster in 1986 and is still considered too radioactive for human occupation, but healthy wildlife is flourishing there now with no identifiable radiation caused health issues.
Washington D.C. is really far away from Boston and water doesn’t connect the two
Dust storms, Radiation, Water may get irradiated and undrinkable, acid rain. Basically, the shittiest, pardon my french, weather ever.
you get helath
yes it is harmful
Yes, water can be irradiated. Irradiation of water is the process of exposing it to ionizing radiation, such as gamma rays or electron beams, to kill harmful bacteria and pathogens. This treatment can make water safe for consumption by disinfecting it without leaving any chemical residues.
waterfall fallout
Yes. Water does not cancel out poison.
Water pollution; it is important to know the quantity spilled, the possibility of dilution, the estimated concentration, if it is irradiated uranium, etc.
Generally, water molecules when irradiated, do ionize into oxygen and hydrogen. There are hydrogen recombiners in the system to protect the reactor from the possibility of hydrogen explosions. Generally, water does not become radioactive. It only ionizes. But, in the core of the reactor, where there is a heavy flux of neutrons, the oxygen atoms can "activate" into Nitrogen-16, which is highly radioactive, though with a very short half-life of about 7.13 seconds. This is why the steam tunnel of a BWR is highly shielded and quite long - giving the 16N a chance to decay.
yes
You will have to find some because you will die from dehydration, it is good if you keep a couple of spare bottles with you so that they buy time for you to find a town or water fountain or something.
Nothing, Its still water. Boats and animals swim around the dam. So the water stays the same!