CA Pub Util Code Section 106057

(a)

The purchase of all supplies, equipment, and materials, when the expenditure required exceeds one hundred thousand dollars ($100,000), shall, by contract, be 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).