No. Discharging foul wastewater into a surface water drain sends untreated sewage directly to a watercourse or to ground, which is a water pollution issue and can lead to enforcement by the local authority or the EPA. Misconnections found in existing houses should be corrected.
Surface water drains generally discharge without treatment to a stream, river or soakaway. Anything connected to them therefore reaches the environment directly. Washing machines, dishwashers, sinks, showers and toilets connected in error to a surface water line are a recognised source of urban water pollution.
Misconnections are often discovered during dye testing or CCTV surveys, or when a watercourse shows signs of pollution. Correcting them means rerouting the appliance or branch drain into the foul system, which should be carried out and verified by a competent drainage contractor.