Existing law vests the Public Utilities Commission with regulatory authority over public utilities, including electrical corporations and gas corporations. Existing law authorizes the commission to fix the rates and charges for every public utility and requires that those rates and charges be just and reasonable. Existing law requires the commission, for purposes of establishing rates for any electrical corporation or gas corporation, to disallow expenses reflecting the direct or indirect costs resulting from any unreasonable error or omission relating to the planning, construction, or operation of any portion of the corporation’s plant that cost, or is estimated to have cost, more than $50,000,000, including any expenses resulting from delays caused by any unreasonable error or omission, as specified.