(1) The Public Utility Commission has the right and power of regulation, restriction and control over the budgets of expenditures of public utilities, as to all items covering:
(a) Proposed payment of salaries of executive officers;
(b) Donations;
(c) Political contributions and political advertising;
(d) Expenditures for pensions or for a trust to provide pensions for employees and officers;
(e) Other expenditures and major contracts for the sale or purchase of equipment; and
(f) Any payment or contemplated payment to any person or corporation having an affiliated interest for service, advice, auditing, associating, sponsoring, engineering, managing, operating, financing, legal or other services.
(2) On or before a date prescribed by the commission by rule, each public utility shall prepare a budget showing the amount of money which, in its judgment, shall be needed during the ensuing year for covering all such activities and expenditures, and file it with the commission.
(3) When any such budget has been filed with the commission, the commission shall examine into and investigate the same and unless rejected within 60 days thereafter, the proposed budget is presumptively fair and reasonable and not contrary to public interest.
(4) Proposed expenditures for pensions or for a trust to provide pensions for the employees and officers of such utility whether for future service or past service or both, shall be recognized as an operating expense if the trust fund is irrevocably committed to the payment of pensions or benefits to employees and if such pensions are reasonable and nondiscriminatory. The commission may disallow as an operating expense any expenditure for pension purposes in excess of the amount necessary and proper to maintain an actuarially sound retirement plan for the employees of the utility in Oregon.