(a) It is a ground for removal from the board if a member:
(1) does not have at the time of appointment the qualifications required by § 58.012;
(2) does not maintain during service on the board the qualifications required by § 58.012;
(3) violates a prohibition established by § 58.0172;
(4) cannot because of illness or disability discharge the member’s duties for a substantial part of the term for which the member is appointed; or
(5) is absent from more than half of the regularly scheduled board meetings that the member is eligible to attend during a calendar year unless the absence is excused by majority vote of the board.
(b) The validity of an action of the board is not affected by the fact that it is taken when a ground for removal of a board member exists.