Notes

Sewage is the term used for wastewater that often contains faeces, urine and laundry waste.
There are billions of people on Earth, so treating sewage is a big priority.
Sewage disposal is a major problem in developing countries as many people in these areas don’t have access to sanitary conditions and clean water.
Untreated sewage water in such areas can contaminate the environment and cause diseases such as diarrhoea.
Sewage in developed countries is carried away from the home quickly and hygienically through sewage pipes.
Sewage is treated in water treatment plants and the waste is often disposed into the sea.
Sewage is mainly biodegradable and most of it is broken down in the environment.
In developed countries, sewage often causes problems when people flush chemical and pharmaceutical substances down the toilet. When people are ill, sewage often carries harmful viruses and bacteria into the environment causing health problems.