24.—(1) Where the Scottish Ministers determine that either of the conditions specified in paragraph (2) is satisfied in respect of any area within the area of a monitoring local authority, they shall by notice in writing to that authority—
(a)specify that area;
(b)specify which condition or conditions in paragraph (2) is or, as the case may be, are satisfied; and
(c)confirm that any Type A supply in that area need not be monitored in respect of the parameter to which the relevant condition relates.
(2) The conditions specified in this paragraph are that Type A supplies in the area specified in the notice under paragraph (1) would—
(a)give rise to a calculated total indicative dose in respect of radioactivity that is well below the value specified in column (3) of Table C in Schedule 1; or
(b)as the case may be, contain a level of tritium that is well below the concentration specified in column (3) of Table C in Schedule 1.
(3) Where the Scottish Ministers determine that a condition in paragraph (2) specified in a notice under paragraph (1) is no longer satisfied, they shall, by notice in writing, revoke any notice given under paragraph (1) to the extent it applies in respect of that condition.
(4) Where a notice under paragraph (1) has been given to a monitoring local authority, and until such time as that notice is revoked, the monitoring local authority need not monitor any Type A supply in the area to which the notice relates in respect of a parameter to which the condition or conditions, as the case may be, in the notice applies.