Where an application for consent in pursuance of section 34 of the Control of Pollution Act 1974 in respect of any discharge is duly made to a water authority before 15th October 1987 and the discharge in question is substantially a continuation of a previous discharge which during the year ending on 14th October 1987 was by virtue of article 3 of the 1983 Order lawfully made without such consent (any reduction of the temperature, volume or rate of the discharge as compared with that of the previous discharge being disregarded), the authority shall be deemed to have given unconditionally the consent applied for—
(a) until the authority actually gives the consent unconditionally; or
(b) if the authority refuses consent or gives it subject to conditions, until the expiration of the period of three months beginning with the date when the authority serves on the applicant notice of the refusal or the conditions subject to which consent is given; or
(c) if during that period the applicant appeals to the Secretary of State against the decision in pursuance of section 39 of that Act, until the determination of the appeal.