In addition to all other project purposes, the joint system formed under the Joint Authority Water and Sewer Systems Act is authorized to purchase, construct, acquire, own, operate, maintain, repair, and improve any and all works, improvements, facilities, plants, equipment, transportation lines, pump stations, sewage treatment plants, apparatus, and appliances incidental, helpful, or necessary to its members upon request and approval of its members in accordance with the bylaws of the joint system.