California Code, Public Resources Code - PRC § 44101

(a) In the investigation, the enforcement agency may inspect the facility, equipment, or vehicle used for storage, collection, transportation, processing, or disposal of solid waste, as necessary to ensure compliance with this division and to determine that the terms and conditions of solid waste facilities permits are being complied with.

(b) The inspection shall be made with the consent of the owner or possessor of the solid waste facilities permit or, if consent is refused, with a warrant duly issued pursuant to Title 13 (commencing with Section 1822.50) of Part 3 of the Code of Civil Procedure.  However, in the event of an emergency affecting the public health or safety, an inspection may be made without consent or the issuance of a warrant.