Soak-away systems and possible groundwater pollution problems in developing countries.

Abstract

People in the developing countries do not have adequate sanitation and everyone defaecates somewhere. Those who do not have a toilet or latrine have to resort to indiscriminate defaecation either in the sea shore such as in the Lagos lagoon in Nigeria, or vacant plots and open drains as in Iddo area of Lagos and sides of rural footpaths. Water closets (W.C.s) are the most accepted sanitation system, but the cost of operating and maintaining them is high. As a result sewerage is not appropriate for the majority of people in developing countries whose greater population live in rural areas and small towns. The majority of people in urban areas use septic tanks and very often most of these septic tanks are not properly designed or sometimes located too close to sources of water supply, which then become contaminated. It is generally believed that systems like septic tanks, pit latrines and aqua privies are capable of totally eliminating these pathogens. There are many problems associated with the physical, chemical and biological processes that may result in groundwater pollution from septic tanks. Many experiments have shown that faecal organisms do not travel any significant distance radially as a result of concentration gradient. They are, however, carried with groundwater flow. The task is to prevent pathogens from getting into the aquifer. This paper attempts to highlight the ability of some enteric viruses to survive septic tank wastewater treatment.