9.—(1) The holder of a licence under section 7A(1) of the Act (“the licensee”) which authorises only the supply to premises specified in the licence (“the relevant premises”) of gas which has been conveyed to those premises otherwise than by a gas transporter is an exempt transporter when—
(a)conveying gas to the relevant premises for the purpose of supplying the relevant premises in accordance with the licence;
(b)that gas is a by-product of a manufacturing or other industrial or agricultural process carried on by the licensee; and
(c)the licensee expects to supply the relevant premises with that gas at a rate in excess of 73,200 kilowatt hours per year.
(2) For the purposes of paragraph (1)(b), the treatment of sewage is an industrial process.