California Code, Public Utilities Code - PUC § 106057

(a) The purchase of all services, supplies, equipment, and materials, when the expenditure required exceeds one hundred fifty thousand dollars ($150,000), 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 services, supplies, equipment, or materials exceeds five thousand dollars ($5,000), but does not exceed one hundred fifty thousand dollars ($150,000).

(c) For purposes of this section, the term “services” shall not include construction of public projects, as defined in Section 22002 of the Public Contract Code, or those services described in Section 4525 of the Government Code.

(d) This section shall remain in effect only until January 1, 2030, and as of that date is repealed.