Section 10. If a relocation plan required by section four is disapproved under section five, or approval is suspended under section nine, because the bureau determines that adequate relocation housing is not available, the taking agency may file with the bureau its certificate that the project involved is an emergency project which must be carried out in spite of the unavailability of such housing. If the bureau, after considering the foregoing and such other evidence as is deemed pertinent, determines that the project involved is an emergency project and that the public interest demands the displacement of occupants even though adequate relocation housing may be unavailable, emergency approval may be given, provided the relocation plan is satisfactory to the bureau in other respects.