Levels of industrial pollutants and their effects on water resources and livelihoods along Msimbazi sub catchment Dar es Salaam, Tanzania

Abstract

Water is considered fundamental to development due to its contribution to economic growth and human welfare. Yet, most human activities such as agriculture, domestic and industrial pollute water resources. Industries use water in different processes and if not well managed, they pollute water bodies. The study assessed the levels of industrial pollutants and their effects on water resources and livelihoods along Msimbazi sub catchment. Specifically, the study determined the types and abundance of pollutants discharged by industries, levels of industrial pollutants and their effects on water resources and livelihoods. It also reviewed relevant aspects of the implementation of the relevant aspect of Tanzania National Industrial Policy on cleaner production and how they relate with industrial pollutants. Primary and secondary methods of data collection were used. Primary methods of data collection such as in situ measurements, laboratory analysis of water samples, structured questionnaires, interview guides as well as observation. Secondary data were collected from the National Bureau of Statistics (NBS). Different documentations were reviewed to compare data collected through primary methods. Data were analyzed using both quantitative and qualitative methods. The quantitative techniques included descriptive statistics such as cross-tabulation, frequencies, percentages and means which was done using Statistical Packages for Social Sciences (SPSS) software version 18.0 and Microsoft Excel 2007. Qualitative data was analyzed using Strengths, Weaknesses, Opportunities and Threats (SWOT) analysis. The results show that the types and abundance of pollutants discharged by industries along the sub catchment were higher and to some points exceeding the World Health Organization (WHO) and Tanzania Bureau of Standards (TBS) standards. Pollutants such as COD was found to be the highest at Vingunguti with the COD of 2451.57mg/l and Tabata 1 recorded 879.39mg/l. Turbidity was higher at Vingunguti with 674NTU and Kigogo 2 which had 357NTU exceeded the TBS and WHO acceptable levels. DO was exceeding the standards in stations like Vingunguti and Kigogo1 which had 0.00mg/l. DO was within the standards at upstream from the industries station. Chromium concentration was higher at Tabata 2 and Kigogo 2 and it was within the standards at the station upstream from the industries. Furthermore the results show that industrial pollutants was found to be affecting the water resources in terms of quality where the water quality parameters in some stations were exceeding the WHO and TBS permissible limits also livelihoods were found to be affected by the industrial pollutants in terms of health, agriculture and settlement. Moreover, the study found that industries are still discharging pollutants into the sub catchment despite the implementation of the Tanzania National Industrial Policy. The study recommends improvement of law enforcement in order to control industrial pollutants . Further; the authorities like NEMC should ensure that industries adopt efficient technology such as Effluent treatment Plants (ETP’s) in order to minimize the effects of industrial pollutants into water resources and livelihoods. The findings will add to documentation on levels of industrial pollutants and their effects on water resources and on livelihoods along Msimbazi sub catchment which will be essential to community, water managers and other conservationists. In addition, the study provides practical recommendations on industrial policy implementations to the Ministry for Industry & Trade and NEMC