The main source of pollution is untreated domestic and industrial wastewater.

Water pollution is also a chronic problem, with domestic wastewater identified as the as the primary pollution source.

In many developing countries the bulk of domestic and industrial wastewater is discharged without any treatment or after primary treatment only.

However, water pollution due to domestic and agricultural wastewater remains a serious concern.

Alternatively, domestic wastewater may be sent to a nearby privately owned treatment system (e.g. in a rural community).

There is a large gap between generation and treatment of domestic wastewater in India.

This is mainly due to discharge of domestic wastewater in untreated form, mostly from the urban centers of India.

Facultative lagoons are a type of stabilization pond used for biological treatment of industrial and domestic wastewater.

Modern sanitary sewers are designed to transport domestic and industrial wastewater directly to treatment facilities without dilution.

Agricultural runoff is one of the main contributors to water pollution in Bolivia, together with domestic municipal wastewater and dumping by industries and mines.