Physicochemical and Bacteriological Water Quality Parameters in Relation to Land-use Practices at a Rural Catchment, Mbinga District, Tanzania

Abstract

Data on physicochemical water quality parameters and contamination levels is crucial for protection and sustainable utilization of water resources. This study assessed the physicochemical water quality parameters, faecal coliform bacteria and nutrient loads in water at a catchment used for municipal supply in Mbinga District, Tanzania. Samples were seasonally collected from three areas characterized by distinct geographical features, settlement patterns and land-use practices, and analyzed using standard analytical protocols. Data were subjected to paired-sampled t-test and cluster analysis. The parameters varied as follows: pH (4.75–6.83); temperature (16.4–26.2 ºC); electrical conductivity (14.6–121.1 µS/cm); total dissolved solids (7.0–23.2 mg/L); total suspended solids (BDL–35.5 mg/L); dissolved oxygen (8.6–23.8 mg/L); turbidity (0.1–68.1 NTU); faecal coliform (<1–76 FC/100 mL); nitrite (BDL–0.09 mg/L); nitrate and sulphate were not detected. Spatial variations were associated with land-use disparities. Comparison to risk-based regulatory thresholds for drinking water revealed the levels to be within the acceptable limits, with a few exceptions. Observed seasonal trends indicated an overall decrease in water quality during the wet season. Generally, results showed that water quality at the catchments satisfies requirements for domestic uses. However, the potential contamination risks from human activities call for regular monitoring.

Keywords:   Physicochemical parameters; faecal contamination; water quality; surface water; Mbinga District