More than 60 drinking water sampling locations reported results in the United States in 2016 as part of the RadNet monitoring network. Drinking water samples are typically collected four times a year from taps and are sent to the EPA’s National Analytical Radiation Environmental Laboratory (NAREL) for analysis. Each of these samples is analyzed for tritium (H-3) One sample per year from each location is analyzed for iodine-131 (I-131).
An annual composite sample from each sampling location is analyzed for gross alpha and beta radiation. Any sample with elevated gross alpha radiation (greater than 2 pCi/L) will be analyzed for radium-226 (Ra-226), plutonium (Pu-238, Pu-239 Pu-240), and uranium (U-234, U-235, and U-238). If the radium-226 result is between 3 and 5 pCi/L, then the sample is analyzed for radium-228 (Ra-228). All of the annual composite samples are also analyzed for gamma-emitting radionuclides. Twenty-five percent (25%) of the annual composite samples are analyzed for strontium-90 (Sr-90), rotating locations so Sr-90 is analyzed for each location every four years.
For more information, visit RadNet EPA.gov.
For more information about precipitation and drinking water sampling analysis, visit Envirofacts on EPA.gov.