Precipitation samples are collected at two locations on the Idaho National Laboratory (INL): the Central Facilities Area (CFA) and the Experimental Field Station (EFS). Precipitation from Idaho Falls, a location distant from the site, is sampled to serve as a control or background sample. The EFS location is sampled weekly. Idaho Falls and CFA locations are collected monthly.

The Idaho Falls station is operated as part of the Environmental Protection Agency (EPA) Environmental Radiation Ambient Monitoring System (RadNet) program.

Precipitation samples are used as a means of detecting airborne tritium.