Cal. Public Contract Code § 20867

The legislative body shall award the contract for doing the work to the lowest responsible bidder. 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: (a) Cash. (b) A cashier’s check made payable to the public entity. (c) A certified check made payable to the public entity. (d) A bidder’s bond executed by an admitted surety insurer, made payable to the public entity. The bids shall be delivered, opened, and award of contract made, all as provided by Chapter 9 (commencing with Section 5240) of Part 3 of Division 7 of the Streets and Highways Code, except that no notice of award shall be published. Upon the award being made, the superintendent of streets shall enter into a contract with the person to whom the contract was awarded for doing the work described in the notice inviting bids, and at the price stated in the bid. The contractor shall execute a bond in the manner required by Section 5254 of the Streets and Highways Code. Upon an award to the lowest bidder, the security of an unsuccessful bidder shall be returned in a reasonable period of time, but in no event shall that security be held by the public entity beyond 60 days from the time the award is made.