(a) No asphalt batching or continuous mix facility shall be located in an area which is less than one-third of a mile in linear distance from any hospital, nursing home, school, area of critical environmental concern, watercourse, or area occupied by residential housing. Such distance shall be measured from the outermost perimeter of such facility to the outermost point of such zones provided that any such facility in operation as of December 31, 1997, shall not be subject to the provisions of this section.

(b) Notwithstanding the provisions of subsection (a) of this section, this section shall not apply to any portable asphalt batching plant that does not require a permit from the Department of Energy and Environmental Protection pursuant to the provisions of any regulations adopted under § 22a-174.