Frequent Questions

How does the EPA sample precipitation for radionuclides?

Samples of precipitation such as rain, snow or sleet are collected at more than 25 stations across the U.S.  Samples are collected using specially designed precipitation collection devices which funnel the precipitation into a bucket for transfer to a shipping container. EPA’s National Analytical Radiation Environmental Laboratory (NAREL) receives the sample. Under routine circumstances, the EPA scientists composite the individual samples into one container each month and perform gamma analysis on the composite samples.  The results are posted to the RadNet Envirofacts database.


For more information, visit RadNet on

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