Four Wastewater Treatment Methods Evaluated from a Sustainability Perspective in the Limbe Urban Municipality Cameroon (Central Africa)

Sammanfattning: Aggravated by rapid population growth, urbanization, and industrialization and most recently by climate change events, the availability of water especially in the third world is reaching critical proportions.  This is aggravated by the non treatment of wastewater (sewage) and discharged of untreated wastewater into water bodies. The study focused on identifying and reviewing four wastewater treatment methods from a sustainability perspective; waste stabilization pond, constructed wetland, up-flow anaerobic sludge blanket reactor and sedimentation/thickening tank systems suitable for the Limbe Urban Municipality (LUM) of Cameroon in Central West Africa with an estimated population of 120, 000 inhabitants and experiencing 4.7 per cent annual growth rate. The attractiveness of these four methods stems from their apparent energy efficiency, simplicity, robustness, low cost effectiveness in situations where as in the LUM, there are huge tracts of available land, warm temperatures, and their capacity to promote effluent re-use opportunities for various sectors. Issues of sustainability of the water supply and wastewater treatment systems, untreated sewage, and their contribution to escalating environmental and public health impacts in LUM (Cameroon) were critically evaluated and discussed with the aid of Kärrman (2000) framework approach that employs different sets of sustainability criteria (Environmental, Health and Hygiene, and Functional), sub-criteria and indicators. Results obtained reveal that water and wastewater treatment systems in LUM do not operate or conforms to sustainability perspectives. Inhabitants do not still have access to clean drinking water (an approximate 45 per cent) especially in the dry periods of the year, low sanitation coverage (with the tradition of sewage treatment in septic tanks and pit latrines), rising yearly public health impacts associated with water-borne (cholera, dysentery, malaria, typhoid fever and diarrhea) infections and 6 deaths reported in LUM. These leading problems are directly or indirectly linked to consumption of contaminated water or foods in different communities such as Mile II, Isokolo, Bonadikombo (Mile four) etc, and New Town areas and flood prone zones in the Limbe urban municipality.