Off-site treatment is the treatment of wastewater that has been conveyed using a sewerage system. Large-scale off-site treatment of sewage and industrial wastewater is most of the time preformed by wastewater treatment plants, which are described first under the following methods. However, there are other and simpler methods, which are as effective concerning sewage treatment. These include lagoons, land based treatment (sewage farming) and constructed wetlands. (UNEP 2000)

• Wastewater treatment plants

• Lagoons

• Land based treatment

• Constructed wetlands