Many people in the world still cannot access to the appropriate sanitation. To halve this population is the global target. In Bauniabad, which is one of the poor settlements in Dhaka, Bangladesh, small-scale biogas plants connected to the latrines of about 100 households have been installed as a sanitation option. The purpose of this study is to clarify the background of how the local people came to use the biogas plant for sanitation purpose, and to examine the performance of the biogas plant for the reduction of the pollution load to the surrounding water bodies. The questionnaire to the local people about their behaviors regarding sanitation was conducted to know the change of their attitudes and the situation of their living environment before and after the installation of the sanitation options. The water quality analysis was conducted to review the performance of the biogas plant. From the questionnaire, it was revealed that the hygiene condition of the latrines was improved after the connection to the biogas plants. On the other hand, from the water quality analysis, it was revealed that the anaerobic digestion of the biogas plants did not work sufficiently good due to lack of maintenance.