Uncontrolled construction and environment management issues of the septic tanks in Bukavu city, eastern D.R. Congo

Uncontrolled construction of septic tanks is a serious problem for urban environment with negative issues on public health, air, soil and groundwater et rivers. This study aimed to assess the uncontrolled construction of septic tanks and its impact public health and environment management in two communes (Ibanda and Kadutu) of Bukavu city. To collect data, a mixed-methods survey was carried out in these communes. Results showed that the most houses are single storey in Kadutu (68%), whereas in Ibanda houses are multi-storey (73%). Most houses are durable in Ibanda (63%) and semi-durable in Kadutu (64%). The spatial variability of septic tanks was influenced by communes (p < 0.01). In Ibanda, 80% of houses have a septic tank comparatively to Kadutu (53%). The distance between the house and septic tank, the depth of tank and its capacity were also influenced by communes (p < 0.01). The time taken to fill the tank remained the same regardless of commune (1–4 years for most septic tanks). There is no system for disposing of wastewater and septic tank excreta in Ibanda and Kadutu. In terms of evacuation, rain is the only option: when it rains, the power stations are opened. There is no treatment for waste from septic tanks. The result is air pollution, groundwater and river pollution, soil pollution, conflicts between neighbors and public health problems.