Mo. Rev. Stat. § 250.025: City board of public works may manage combined system, when.

If any city, town or village which has heretofore established or which may hereafter establish a board of public works under the provisions of sections 91.450 to 91.540 shall combine its waterworks and sewerage system pursuant to the provisions of sections 250.020 and 250.030, said city, town or village may by ordinance vest in said board of public works during the existence of said board the power and duty to take charge of and exercise control over said combined waterworks and sewerage system and thereafter said board shall have all of the powers and duties respecting said combined waterworks and sewerage system which are vested in said board with respect to the waterworks of said city under the provisions of sections 91.450 to 91.540.