Cal. Public Contract Code § 20211

(a) The purchase of all supplies, equipment, and materials, when the expenditure required exceeds one hundred thousand dollars ($100,000), shall be by contract let to the lowest responsible bidder, or, in the district’s discretion, to the responsible bidder who submitted a proposal that provides the best value to the district on the basis of the factors identified in the solicitation. “Best value” means the overall combination of quality, price, and other elements of a proposal that, when considered together, provide the greatest overall benefit in response to the requirements described in the solicitation documents. (b) To the extent practicable, the district shall obtain a minimum of three quotations, either written or oral, that permit prices and terms to be compared whenever the expected expenditure required for the purchase of supplies, equipment, or materials exceeds two thousand five hundred dollars ($2,500), but does not exceed one hundred thousand dollars ($100,000). (c) The construction of facilities and works, when the expenditure exceeds ten thousand dollars ($10,000), shall be by contract let to the lowest responsible bidder. (d) Notice requesting bids shall be published at least once in a newspaper of general circulation and on the district’s procurement Internet Web site, which publication shall be made at least 10 days before bids are received. The board may reject any and all bids and readvertise in its discretion.