I mean, Yoon is right on this. Tritium is a very, very low level beta-emitter, and at the concentrations they're releasing (less than 1500 Bq/L, ~4E-8 Ci/L), drinking nothing but water contaminated at that level for an entire year would yield a dose of less than 4 mrem (based on the NRC math that 60,900 pCi/L for a year yields a dose of 4mrem). For context, 4 mrem (40 μSv) is the amount of exposure you receive in a flight from NYC to LA. That is damn near a rounding error on the average yearly exposure to members of the public.
But people gotta be scared because Joe Public doesn't really understand radiation, and fear sells.