A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Environment, Resources and Development

Thesis (M.Eng.) - Asian Institute of Technology, 1987

This study looked into the risk of groundwater pollution from on-site sanitation in Dhaka, Bangladesh. A sizable proportion of the city population do not have access to adequate water supply. Groundwater is the major source of potable water for domestic use. Safe excreta disposal facilities are also very limited in the area. This study also evaluated the extent of groundwater pollution in relation ' to on-site sanitation systems in the project area. Groundwater quality was monitored at selected points for specified time at regular interval. Later the data were analyzed for identifying the probable sources of the pollutants; and investigating the factors controlling their movement in the soil-water system. In addition, the present water supply, sanitation, and health status of the area has also been reviewed. The results from t he experiments indicated the presence of pollutants of fecal origin, such as fecal coliform, bacteriophage, and nitrate, in almost all the samples analyzed. The extensive use of unsewered disposal system has been identified as the major source of pollutants. The hydrogeologic condition was found to be unsuitable for the traditional methods of on-site sanitation. Routine monitoring and detailed study has to be carried out for having a c l ear view of the potential of groundwater pollution by on-site sanitation facilities in the study area.