Land extensive processes for treatment of wastewater have been used for pollution control for over a hundred years.
Recently more sophisticated demands related to protection of the environment, energy considerations, and costs related to conventional biological and physico-chemical processes, have been responsible for great scientific endeavour in the understanding, assessment of purification mechanisms, behaviour and performance, and the costs, of land extensive systems of treatment by lagoons and by land irrigation.
Favourable characteristics of these land extensive processes have led to their widespread application in suitable sparsely populated areas particularly in developing countries.
The paper details the processes, the factors which should influence their proper design and performance, and assesses their favourable and unfavourable characteristics.
Guidelines for the determination of their feasibility in a particular situation are given.