Every community produces both liquid and solid wastes.
If untreated wastewater is allowed to accumulate, the decomposition of the organic materials it contains can lead to the production of large quantities of malodorous gases. In addition, untreated wastewater usually contains numerous pathogenic, or disease-causing, microorganisms. Wastewater also contains nutrients which can stimulate the growth of aquatic plants, and it may contain toxic compounds. For these reasons, the immediate and nuisance-free removal of wastewater from its sources of generation, followed by treatment and disposal, is not only desirable but also necessary in each society. In a semi-arid area like Palestine which has a limited amount of potable water, wastewater treatment becomes an essential matter to protect the environment and to save large amounts of water which can be used in agriculture and industry.