(a) To be eligible to serve as a director, a person must be:
(1) at least 18 years of age; and
(2) a resident of the territory located in the authority or an employee of a sponsor.
(b) A director who also serves on the governing body of a sponsor is not a dual officeholder and is not prohibited by the common law doctrine of incompatibility from serving on both the board and the governing body.
(c) Service on the board by a public officeholder is an additional duty of that person's office.