An authorised officer of the undertakers may, between the hours of eight in the forenoon and eight in the afternoon, on producing, if required, evidence of his authority, enter any premises supplied with water by the undertakers in order to ascertain if there be any waste or misuse of such water, and, if, after production of his authority, he is refused admittance to the premises or is obstructed in making his examination, the person refusing him admittance or so obstructing him shall be liable on summary conviction to a fine not exceeding F1level 3 on the standard scale.