Streets and Highways Code § 5896.15
CHAPTER 28. Conversion of Existing Overhead Electric and Communication Facilities to Underground Locations
Any written request executed pursuant to Section 5896.14 shall be filed with the clerk not later than the date fixed for commencement of construction of the conversion. A written request executed after such date shall not be accepted for filing by the clerk unless it shall contain the written approval of the contractor, public utility, public agency or city which is authorized to perform such work or improvement.