4.—(1) Part 2 of Schedule 1 to the principal Regulations is amended as follows.
(2) In Section 1.1 (combustion activities), after paragraph 1 of “interpretation and application of Part B” insert—
“1A. For the purpose of Part B(a) of this section, where 2 or more appliances with an aggregate net rated thermal input exceeding 20 megawatts are operated on the same site by the same operator, those appliances must be treated as a single appliance with a net rated thermal input exceeding 20 megawatts”.