Abstract
This paper assesses the suitability of Rapid Assessment (RA) methodology as a tool for making an environmental pollution inventory in data poor situation. The RA method was applied to estimate Biological Oxygen Demand (BOD), nitrogen and phosphorous loading into the Msimbazi River in Dar es salaam, Tanzania. The Direct Measurement (DM) was done to validate the results obtained from RA. The methodology is based on estimating waste loads from function variables such as production rate, population, etc. and pollution intensities from domestic, industry and agricultural sources. The incorporation of penetration factors for waste loads reduction refines the assessment procedure. The RA results show that domestic source releases 7600, 390 and 3200 tons/year of BODs, Phosphorous and Nitrogen respectively. Industrial activities in the area release BODs loading of 2500 tons/year and it was found that Tanzania Breweries Ltd (TBL) and Murza oil Processing Industries were major contributors of BODs waste. Agriculture seemed to have less contribution with insignificant discharge of BODs, 3 and 14 tons/year of Phosphorous and Nitrogen, respectively. The results from DM were significantly different from those obtained using RA. For example at the point of discharge the difference observed was 23, 67 and 72%. This suggests that not all pollutants produced by a given anthropogenic activity reaches a water body as part of it undergoes natural decay or is entrapped by soils. These necessitated inclusions of Penetration Factors (PFs) which reduced the gap between the two methods to 4, 13 and 8% for BODs, phosphorous and nitrogen, respectively.
Recommended Citation
Katima, J. (2003). Evaluation of Pollution Loading Into Msimbazi River by Rapid Assessment and Direct Measurement Methods. Tanzania Journal of Engineering and Technology (TJET), 26(2), 28-36. https://doi.org/https://doi.org/10.52339/tjet.v26i2.329
Publisher Name
University of Dar es Salaam