(1)  The Director of Public Health may, by written instrument, delegate the performance of his or her functions, or the exercise of his or her powers, under this Act, other than this power of delegation, to an environmental health officer or to a person employed as an environmental health officer by a council.

(2)  The Director of Public Health may, by written instrument, revoke wholly or in part any such delegation.

(3)  Notwithstanding any delegation under this section, the Director of Public Health may continue to exercise all or any of the functions or powers delegated.

(4)  An instrument purporting to be signed by a delegate of the Director of Public Health in his capacity as such a delegate may in all courts and before all persons acting judicially be received in evidence as if it were an instrument executed by that Director and, until the contrary is proved, is taken to be an instrument signed by a delegate of that Director under this section.