The Ministry may, by order made subject to affirmative resolution, provide that this Part shall apply in relation to liquid or other matter of any description specified in the order which is discharged from any premises into the sewers or sewage treatment works of the Ministry as it applies in relation to trade effluent, but subject to such modifications, if any, as may be specified in the order, and in particular subject to any modification of the definition of trade premises in this Order which may be so specified.