Question: what is the difference between foul water drainage and surface water drainage?
Answer: The foul sewer carries used wastewater to a sewage works for treatment. The surface water sewer carries uncontaminated rainwater directly to a local river, stream or soak away. ... All other waste water from sinks/toilets/baths/showers/washing machines/dishwashers/process water should be connected to a foul sewer.