20.—(1) If the Department is satisfied that the disease may be present on premises in the Republic of Ireland it may declare an area to be a protection zone if those premises are situated within 5 kilometres of the border with Northern Ireland.
(2) A declaration under this article shall designate the extent of any protection zone declared and the Department shall ensure that—
(a)any such zone abuts the border with the Republic of Ireland;
(b)any protection zone extends from that border such that its boundary is at least five kilometres from the infected premises.