(1) Each of the original directors and all directors elected thereafter shall take the oath of office required by Arkansas Constitution, Article 19, § 20, and shall also swear that he will not directly or indirectly be interested in any contract made by the board.
(2) Any director failing to take the oath within thirty (30) days after his appointment or election shall be deemed to have declined the appointment or election and his place shall be filled as other vacancies.
(3) All oaths of directors shall be executed in writing and filed in the office of the circuit clerk in the county where the petition is originally filed.