Eco-health impacts of urban tropical wastewater in Dar es Salaam, Tanzania: Msimbazi River Case Study

Reliable water resources and wastewater disposal are among the most vital basic conditions for sanitary living, but are also amongst the most poorly developed infrastructures in developing countries. In Tanzania, inadequate wastewater and sewage treatment infrastructure is leading to high water pollution levels in urban river ecosystems, while declining water availability and limited water resource infrastructure is forcing many urban residents to use alternative water resources including the polluted rivers and shallow wells. Wastewater pollution negatively impacts the health of the aquatic ecosystems and threatens the health of humans using and living adjacent to polluted aquatic systems. We use a multidisciplinary approach to investigate what wastewater pollutants are impairing Msimbazi River, how polluted river water use may be affecting the health of the human community, and how effectively current wastewater treatment systems function. Preliminary river water quality analysis indicated extremely high, yet variable levels of fecal and bacterial pollution, with total and fecal coliform counts ranging from 10⁵ to 10⁷ per 100ml. Exploratory transect walks along the river and adjacent communities revealed the great extent and diversity of river uses, despite the apparent polluted state of the river, while initial stakeholder interviews indicated the need for public awareness of the local and downstream health risks associated with poor sanitation infrastructure and polluted water resources. Interviews of policy makers and managers made apparent a need for effective communication and clearly defined roles/responsibilities for the diverse policy makers and implementers in order to more collectively address the urban environmental and health problems associated with poor sanitation and wastewater disposal. It is imperative to investigate the eco-health impacts of wastewater pollution in these urban environments in order to better understand the local extent of the problem, to sensitize local stakeholders about the situation, and to help determine wastewater treatment priorities.