39. — (1) Where it appears to a local authority that the whole or any part of their functional area should, in order to prevent or limit air pollution, be declared to be a special control area, they may make an order (in this Act referred to as a “ special control area order ”) under this section.

(2) In deciding whether it is necessary or expedient to make a special control area order in relation to any area, the local authority shall have regard to—

(a) the incidence and cause of air pollution in the area, and

(b) any air quality management plan in force in relation to the area, and

(c) any relevant air quality standard, and

(d) the availability of the means necessary for compliance with the order, and

(e) the expense which would be incurred in complying with the order.

(3) A special control area order shall specify—

(a) the area to which it relates,

(b) the pollutant with which it is concerned, and

(c) the measures to be taken and the requirements which shall have effect in the area to which the order relates.

(4) The Minister may, if he considers it expedient so to do in order to prevent or limit air pollution, having regard to the provisions of paragraphs (a), (b), (c), (d) and (e) of subsection (2), direct a local authority to make a special control area order in relation to such area and such pollutant as may be specified in the direction and may, if he thinks fit, further direct the order should specify that particular measures shall be taken and that particular requirements shall have effect in such area and the local authority concerned shall comply with any direction of the Minister given under this subsection within such period as may be specified in the direction.

(5) A local authority may, with the consent of any other local authority concerned, make a special control area order in relation to an area which is within the functional area of the other authority.

(6) (a) Subject to paragraph (b), a local authority may, by order under subsection (1), revoke or amend a special control area order.

(b) A local authority may revoke or amend a special control area order which is made pursuant to a direction of the Minister under subsection (4) only with the consent of the Minister.

(7) A local authority shall, from time to time and at least once in every five years, review every special control area order made by them, and which is in operation, for the purpose of deciding whether it is necessary or desirable to revoke or amend the order.

(8) The making, revoking or amending of a special control area order and the giving of consent under subsection (5) to the making of such an order shall be a reserved function.