California Code, Health and Safety Code - HSC § 115095

Any officer, employee, or agent of the department or of any state or local agency with which an agreement has been made pursuant to Section 114990 shall have the power to enter at all reasonable times upon any private or public property within the jurisdiction of the agency for the purpose of determining whether or not there is compliance with or violation of this chapter, building standards published in the State Building Standards Code relating to buildings in which there are sources of ionizing radiation, or of the regulations adopted pursuant to this chapter, and the owner, occupant, or person in charge of the property shall permit that entry and inspection. Entry into areas under the jurisdiction of the federal government shall be effected only with the concurrence of the federal government or its duly designated representative.