(a) The governing board of any community college district shall let any contracts involving an expenditure of more than fifty thousand dollars ($50,000) for any of the following:

1. (1) The purchase of equipment, materials, or supplies to be furnished, sold, or leased to the district.
2. (2) Services, except construction services.

3. (3) Repairs, including maintenance as defined in Section 20656, that are not a public project as defined in subdivision (c) of Section 22002.

   The contract shall be let to the lowest responsible bidder who shall give security as the board requires, or else reject all bids.

(b) The governing board shall let any contract for a public project, as defined in subdivision (c) of Section 22002, involving an expenditure of fifteen thousand dollars ($15,000) or more to the lowest responsible bidder who shall give security as the board requires, or else reject all bids. 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:

1. (1) Cash.
2. (2) A cashier’s check made payable to the community college district.
3. (3) A certified check made payable to the community college district.

4. (4) A bidder’s bond executed by an admitted surety insurer, made payable to the community college district.

   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 district beyond 60 days from the time the award is made.