(a) One or more counties may petition the commission for approval to become part of an existing authority. The commission may approve the petition only if:
(1) the board has agreed to the addition; and
(2) the commission finds that the affected political subdivisions in the county or counties will be adequately represented on the board.
(b) One or more counties may petition the commission for approval to withdraw from an authority. The commission may approve the petition only if:
(1) the authority has no bonded indebtedness; or
(2) the authority has debt other than bonded indebtedness, but the board has agreed to the withdrawal.
(c) A county may not become part of an authority or withdraw from an authority without the approval of the commission.