Any person who at the commencement of this Act is discharging effluent into coastal waters and who is not authorised to do so in terms of a general discharge authorisation under subsection (2) must apply to the Department for a coastal waters discharge permit-
(a) within 24 months of the date of commencement of this Act if the discharge is in terms of a licence or
authorisation under the National Water Act; or
(b) within 36 months of the date of commencement of this Act if the discharge is a continuation of an existing lawful water use within the meaning of section 32 or 33 of the National Water Act.