(c) Level One (Formerly Controlled Area). Level One is
the least secure type of restricted area. It contains a security interest
which if lost, stolen, compromised, or sabotaged would cause unidentifiable
damage to the command mission or national security. It may also serve as a
buffer zone for Level Three and Level Two restricted areas, thus providing
administrative control, safety, and protection against sabotage, disruption,
or potentially threatening acts. Uncontrolled movement may or may not permit
access to a security interest or asset.
Facility-Specific Exterior Site Layout. The facility should be
located on site considering the minimum guidelines summarized in Figure 11.
In general, the layout should: (1) provide an adequate blast standoff
distance if the design threat includes vehicle-transported bombs, (2) limit
or preferably block all sightlines from potential vantage points if the
design threat includes line-of-sight standoff or ballistic weapons, (3)
maximize the threat ingress/egress time across the exterior site, and (4)
enhance the possibility of threat visual observation and interdiction by
on-site-stationed or responding guards.
Maintaining an Adequate Standoff Blast Zone for Vehicle Bomb
Threats. A blast zone is a controlled area that surrounds a facility by a
set standoff distance. This standoff distance limits structural damage to
the facility if a bomb explodes at that distance. Examples are shown in
Figure 13. Vehicular access to a blast zone should be limited only to
vehicles operated by the handicapped or maintenance and delivery personnel.
This implies adequate entry control into the blast zone where these vehicles
can be searched and cleared. Discussion of related exterior barriers and
entry control is discussed in pars. 4.3 and 4.4. The required standoff
distance associated with the blast zone is directly related to the facility
construction and the amount of explosive. This is discussed in Section 8.
Limit or Blocking Against Direct Line-of-Sight Weapons. The
facility should be sited to limit, or preferably block, attack sightlines
from potential vantage points. Options include: (1) the use of natural or
manmade obstructions such as trees, fences, land-forms or buildings to
obscure sight paths; (2) sighting the facility at a high point, if possible,
to force aggressors to fire up toward the target; and (3) causing the threat
to strike protective surfaces at an angle, reducing the effectiveness of the
attack. Specific standoff weapons and ballistic attacks design options are
addressed in Sections 6 and 7, respectively.