7The enactments relating to trade effluents mentioned in section 38 (1) of this Act shall apply to any part of Greater London which does not form part of the sewerage area of the Greater London Council as they apply elsewhere in England and Wales, and accordingly the local authority for the purposes of those enactments in their application to any such part of Greater London shall as respects a London borough be the council of the borough; but the foregoing provision shall not affect the application of paragraphs 4 and 5 of this Schedule or of any local statutory provision having effect in the district of the West Kent Main Sewerage Board.