95.540.  City may establish pension system for officers, employees and dependents — costs for utility, library, museum and zoo employees, how paid (cities over 450,000). — 1.  The following words and phrases as used in this section, unless a different meaning is plainly required by the context, shall mean:

  (1)  "Employee", any person regularly employed by any city, within the authorization of this section, who receives remuneration from the city for personal services rendered the city.  The term "employee" shall not include any person:

  (a)  Who is included as an active member in any other pension plan similar in purpose by reason of his employment with the city, except the federal Social Security Old Age, Survivors, and Disability Insurance Program, as amended; or

  (b)  Who acts for the city under contracts or is paid wholly on a fee basis; or

  (c)  Who is a city officer or elected official of the city as defined in this section; or

  (d)  Who is employed by the city as a "fireman" or "policeman";

  (2)  "Officer", any officer or elected official of the city who has been delegated some substantial part of the sovereign power to be independently exercised with some continuity and without control of a superior power other than the law.

  2.  Any city of this state that now has or may hereafter have a population of more than four hundred and fifty thousand inhabitants is hereby authorized to provide by ordinance or otherwise for the pensioning of its employees and officers, in one or more plans, whether performing city or county functions, and the widows and minor children of deceased employees and officers and to appropriate and utilize its municipal revenues and other available funds for such purposes.

  3.  The employees and officers of any municipally owned public utility may be included within the provisions of any pension plan adopted in pursuance of subsection 2, but the cost of paying pensions to such employees and officers and the widows and minor children thereof, as well as its pro rata share of the expenses of administration and the operation of the pension system, as a whole, shall be borne by the funds or revenues of such municipally owned public utility.

  4.  The employees and officers of any administrative board or board of control organized and existing under the general laws of the state of Missouri for the purpose of furnishing library services or maintaining and operating an art museum or a zoological park or similar public service to the inhabitants of such city may be included within the provisions of any pension plan adopted in pursuance of subsection 2, but the cost of paying pensions to such employees and officers and widows and minor children thereof, as well as their pro rata share of the expenses of administration and the operation of the pension system, as a whole, shall be borne by the funds or revenues of such administrative board or board of control; provided, however, that the employees and officers of any such board or board of control shall not be included in any such pension plan unless the ordinance of such city providing for the inclusion of such employees and officers shall be accepted by resolution of such administrative board or board of control.