Are barracks and family housing units on military bases considered public receptors?
Barracks are not considered public receptors, family housing units are. Public receptors include any "offsite residences ... inhabited or occupied by the public at any time without restriction by the stationary source where members of the public could be exposed to toxic concentrations, radiant heat, or overpressure, as a result of an accidental release" (40 CFR §68.3). "Offsite" means "areas beyond the property boundary of the stationary source, and areas within the property boundary to which the public has routine and unrestricted access during or outside business hours" (40 CFR §68.3). "Public" means "any person except employees or contractors at the stationary source" (40 CFR §68.3).
Even when family housing units are located within the property boundary of a military base, they are considered public receptors. Family housing units are, by definition, residences occupied by the "public," since at least some family members will not be employees of the military. They are also "offsite" because the "public" has routine and unrestricted access to them. By contrast, barracks on a military base are not public receptors since they are intended only for the use of military personnel.