Water Quality Assessment of Ruvu River in Tanzania Using NSFWQI
Stephano M. Alphayo *
Water Quality Laboratory, Water Institute, P.O.Box 35059, Dar es Salaam, Tanzania.
M. P. Sharma
Environmental Laboratory, AHEC, Indian Institute of Technology Roorkee, Roorkee 247667, India.
*Author to whom correspondence should be addressed.
Abstract
The assessment of rivers by using different water quality indices like NSFWQI is very useful. However, Tanzania has not yet utilised these tools to assess the quality of its rivers. This paper attempts to assess the water quality of the Ruvu River by using NSFWQI. Physical, chemical and biological parameters like Temperature, pH, Turbidity, Total Solids (TS), Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD), Total Phosphates (PO43-), Nitrates (NO3-) and Faecal Coliforms (FC) collected from 14 sampling points in three years were used to assess NSFWQI. The results showed that overall NSFWQI score was 49.9, 52.0 and 57.8 for the year 2014, 2016 and 2017 respectively. The overall NSFWQI (51-70) is found as 53.2 indicating that water quality of river in study stretch is in the medium range. BOD, DO and FC was found to be most stressing parameters overall sampling locations due to improper sanitation systems, discharge of untreated and partially treated wastewaters from industries and domestic into the river. Watershed management and pre-treatment of wastewaters from Industries and domestic were recommended to improve the water quality of the river.
Keywords: National Sanitation Foundation Water Quality Index (NSFWQI), Biochemical Oxygen Demand (BOD), Dissolved Oxygen (DO), Faecal Coliforms (FC), pollution, Ruvu River