Cal. Pub. Util. Code § 21668
The department may revoke any airport permit if it determines that any of the following conditions are present:
(e) The site may no longer be safely used by the general public because of a change in physical or legal conditions either on or off the airport site.
The department shall not revoke a permit under this section without prior notice or opportunity for hearing, unless the department determines in writing that public safety considerations require a summary revocation. In this event, any person aggrieved by the action of the department shall, upon request, be granted a hearing by the department to determine whether the revocation shall remain in effect.