Mo. Rev. Stat. § 250.220
Any two or more municipalities through their respective governing bodies are hereby authorized and empowered to enter into and perform such contracts and agreements as they may deem proper for or concerning the planning, construction, lease or other acquisition and the financing of sewerage facilities, including facilities for the disposal of sewage and the maintenance and operation thereof. Any such municipalities so contracting with each other may also provide in any contract or agreement for a board, commission or such other body as their governing bodies may deem proper for the supervision and general management of the sewerage facilities and for the operation thereof, and may prescribe its powers and duties and fix the compensation of the members thereof.
§ 250.220, RSMo