(a) The articles of any authority may at any time and from time to time be amended in the manner provided in this section. The board of directors shall first adopt a resolution proposing an amendment to the articles, which amendment shall be set forth in full in the said resolution and which may include any matters that might have been included in the original articles. Such amendment may be made for the sole purpose of altering, in accordance with the provisions of this chapter, the authorized operational area of the authority.
(b) After the adoption by the board of directors of a resolution proposing an amendment to the articles, the chairman and the secretary of the authority shall sign and file with the governing body of each county within the existing authorized operational area of the authority, and with the governing body of each county proposed to be added to the authorized operational area of the authority, if any, a written application in the name and on behalf of the authority, under its seal, requesting that such governing body or bodies adopt a resolution approving the proposed amendment, and accompanied by a copy of the resolution adopted by the board of directors proposing the amendment to the articles. As promptly as may be practicable after the filing of the application, the governing bodies shall review the application and shall adopt a resolution either denying the application or approving and authorizing the proposed amendment. Such resolution need not be published or posted and need not be offered for more than one reading.
(c) Following the adoption of a resolution approving the proposed amendment by the governing body of each county with which such application was filed pursuant to this section, the chairman and the secretary of the authority shall sign and file for record in the office of the probate judge a certificate in the name and on behalf of the authority, under its seal, reciting the adoption of resolutions by the board and by the governing body of the county of incorporation and setting forth the proposed amendment. The probate judge shall thereupon record such certificate in an appropriate book in his office. When such certificate has been so filed and recorded, such amendment shall become effective, and the articles shall thereupon be amended to the extent provided in such amendment.
(d) The failure of any one governing body of a county receiving an application filed pursuant to this section to approve an application made pursuant to this section shall invalidate such application.