The tritium groundwater levels recently reported by Indian Point plant operations to the NRC and the State - while elevated, are still well under the EPA drinking water standard. Tritium is a radionuclide of the hydrogen atom and has a biological half-life of 10 days. Tritium is abundant in nature, and is also a byproduct of commercial nuclear reactor core cooling operations. It is routinely diluted on-site and released by every nuclear power plant - totally permissible by the NRC.
If the NRC reported elevated levels of Cesium-137 or Cobalt-60 in well water they would have shut that plant down in a heartbeat.
I used to work with this stuff all the time.