(1) National security concerns. A property located in an area to which the general public is denied access in the interest of national security (e.g., where a special pass or security clearance is a condition of entry to the property) will be determined unsuitable. Where alternative access can be provided for the public without compromising national security, the property will not be determined unsuitable on this basis.

(2) Property containing flammable or explosive materials. A property located within 2,000 feet of an industrial, commercial, or Federal facility handling flammable or explosive material (excluding underground storage) will be determined unsuitable. Above ground containers with a capacity of 100 gallons or less, or larger containers that provide the heating or power source for the property, and that meet local safety, operation, and permitting standards, will not affect whether a particular property is determined suitable or unsuitable. Underground storage, gasoline stations, and tank trucks are not included in this category, and their presence will not be the basis of an unsuitability determination unless there is evidence of a threat to personal safety as provided in paragraph (a)(5) of this section.

(3) Runway clear zone and military airfield clear zone. A property located within an airport runway clear zone or military airfield clear zone will be determined unsuitable.

(4) Floodway. A property located in the floodway of a 100-year floodplain will be determined unsuitable. If the floodway has been contained or corrected, or if only an incidental portion of the property not affecting the use of the remainder of the property is in the floodway, the property will not be determined unsuitable.

(5) Documented deficiencies. A property with a documented and extensive condition(s) that represents a clear threat to personal physical safety will be determined unsuitable. Such conditions may include, but are not limited to, contamination, structural damage, extensive deterioration, friable asbestos, PCBs, natural hazardous substances such as radon, periodic flooding, sinkholes, or earth slides.

(6) Inaccessible. A property that is inaccessible will be determined unsuitable. An inaccessible property is one that is not accessible by road (including property on small off-shore islands) or is land locked (e.g., can be reached only by crossing private property and there is no established right or means of entry).