Per the data in the press, the Strontium-90 found at Vermont Yankee is already diluted to below the safe level. The site could be a playground now, as far as Sr90 is concerned.
The playgrounds in Brattleboro have Sr90 now from weapons testing fallout.
The river has uranium from rain falling on the granite mountains.
Since radiation and radioactivity are a natural part of the environment, what matters is, “How much?” The Nuclear Regulatory Commission and the scientific community work this way.
Some people are still using a basis of perfection: some radioactivity, bad; no radioactivity, good. Some might think no radioactivity is possible, but sensitive enough instruments will always find some.