(a) The order to secure the site shall require, within five days after receiving notification of the order, the posting of the site with signs. The order shall also require, within five days after receiving notification of the order, that the site be enclosed with a fence, unless it is physically and economically infeasible or unless the fencing is unnecessary because it will not alleviate the danger to the public health.
(b) If fencing is ordered, the fences shall be maintained at the site to prevent unauthorized persons from gaining access to the site. The signs shall be maintained and shall meet all of the following requirements:
(1) The signs shall be bilingual, appropriate to the local area, and may include international symbols, as required by the department.
(2) The signs shall have lettering that is legible from a distance of at least 25 feet.
(3) The signs shall read: “Caution: Hazardous Substance Area, Unauthorized Persons Keep Out” and shall have the name and phone number of the department or the county health officer that ordered the posting.
(4) The signs shall be visible from the surrounding contaminated area and posted at each route of entry into the site, including those routes that are likely to be used by unauthorized persons, at access roads leading to the site, and facing navigable waterways where appropriate.
(5) The signs shall be of a material able to withstand the elements.