The authorities and powers herein conferred upon corporations created under this part may be exercised by two (2) or more such corporations acting jointly. Two (2) or more municipalities may by acting jointly incorporate a public corporation to effectuate the purposes of this part. When two (2) or more municipalities incorporate such a public corporation, each and every requisite pertaining to the application for incorporation, qualifications of applicants, certificate of incorporation and amendment of certificate shall be incumbent in like manner upon each municipality joining in the creation of this public corporation. Officers, but not employees, of a municipality within a public corporation organized among two (2) or more municipalities may serve as directors of such a corporation.