[en] A task group of members of the US Nuclear Regulatory Commission (NRC) staff has reviewed the ration ale for radiological environmental monitoring required by NRC. The group was unable to develop a tightly knit rationale for all the elements of such a program. Two major factors led to this: (1) the large number of possible nuclide pathway combinations threatened to result in specifying lower limits of detection (LLD's) much more restrictive than considered practicable; and (2) a significant number of public reassurance-type measurement requirements always remained which did not fit a dose rationale. Therefore, the topics discussed are a mixture of requirements related to dose rationale and public reassurance. The task group concluded that radiological environmental monitoring requires a blend of two types of measurements: one type based on strict dose-related considerations and another type related to a need to make measurements which have a reassurance function. Further, whether environmental measurement data are used to directly assess the dose, to complement radioactivity release measurements, or to confirm a negative impact on the environment, there is a need for adequate quality in the data obtained to demonstrate either a correlation or lack of a correlation between facility operation and measured radioactivity levels in the environment as compared with an environmental radiation dose criterion such as 25 mrem/year