California Code, Public Contract Code - PCC § 20501

(a) The city council shall, within 10 days after the establishment of the district, invite bids for the making of the improvement by ordering a notice of the invitation to be published by two successive insertions in a daily or weekly newspaper published or circulated in the city and designated by the city council for that purpose.  However, if the city council determines that there is only one contractor practically capable of serving the street lighting system to be improved in the manner provided in the plans and specifications contained in the report provided for in Chapter 3 (commencing with Section 18040) of Part 1 of Division 14 of the Streets and Highways Code and that the contractor is subject to the jurisdiction of the Public Utilities Commission of the State of California, the city council may, in its discretion, without competitive bidding, order the improvement to be carried out by the contractor in accordance with rates and rules filed by it from time to time with the Public Utilities Commission.

(b) All bids for construction work shall be presented under sealed cover and shall be accompanied by one of the following forms of bidder's security which amounts to 10 percent of the bid: