This article examines the environmental monitoring (EM) program, its sample sites, frequency of testing, and establishment of alert and action levels. A method to qualify andjustify the selection ofthe sample sites within a facility used for routine environmental monitoring is presented. This discussion is not meant to describe the only possible approach to this selection but rather one that the author has used in the past with success. Due to the limitations of space, this discussion does not include sampling of the water system, gasses, or personnel which have distinct considerations.