No source at a Department of Energy facility shall emit more than 20 picocuries per square meter per second (pCi/(m2-sec)) (1.9 pCi/(ft2-sec)) of radon-222 as an average for the entire source, into the air. This requirement will be part of any Federal Facilities Agreement reached between Environmental Protection Agency and Department of Energy.
40 C.F.R. §61.192