The powers conferred upon authorities created under this chapter may be exercised by two (2) or more such authorities acting jointly. Two (2) or more municipalities may, by acting jointly, incorporate an authority to effectuate the purposes of this chapter. When two (2) or more municipalities incorporate such an authority, 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 such authority.