Microbial safety assessment of recreation water at Lake Nabugabo, Uganda

Abstract

This study assessed the microbial safety of Lake Nabugabo beaches for recreation. Faecal microbial indicators and physico-chemical characteristics of beach recreational water were determined. Water sampling was done between 10.00 and 11.30 h and 1700 and 18.00 h. Data was analysed using student t-tests, ANOVA and spearman correlation (at 95%). Results were: total coliform (10.5-15.8 CFU/100 ml), faecal coliform (10-12.5 CFU/100 ml), Escherichia coli (0 2.63 CFU/100 ml), faecal streptococci (0-1.5 CFU/100 ml), all significantly different (P<0.05) from the control and electrical conductivity (27-32.6 μS/cm), pH (7.1), turbidity (12.6-26 NTU), total dissolved solids (13.2-15.4 mg/l), total suspended solids (12.6 - 13.4), colour (10.3 Pt-Co), alkalinity (29.3 mg/l), hardness (CaCO₃) (32.5 mg/l), total nitrogen (1.3 mg/l), ammonium-N (0.6 mg/l), nitrate (0.05 mg/l), total phosphorus (0.8 mg/l), orthophosphates (0.02 mg/l), iron (0.2-0.3 mg/l), calcium (1.2-1.8 mg/l), magnesium (0.4-0.6 mg/l), sodium (1.2-2 mg/l), potassium (1.8-2.6 mg/l), all not significantly different (P > 0.05) from the control. Total coliforms and faecal streptococci exhibited significant correlation with TSS (r = 0.9, p = 0.04). Results indicate that Lake Nabugabo water is safe (WHO, US-EPA) for recreation.

Keywords: Lake Nabugabo, microbial safety assessment, recreation water, water quality.