Bacteriological Analysis of Drinking Water in Port Sudan City, Red Sea State, Sudan

Abstract

This study was a descriptive study to assess the bacteriological quality of Port Sudan drinking water sources and its subsidiary network until it reaches the consumers; in the period October 2005 and April 2007. Ten samples as negative control, and ninety samples were collected from seven different sources and examined bacteriologically to detect the possible bacterial contamination according to the detection of indicator organisms (total coliform, faecal coliform and Escherichia Coli) and their count. Analysis was done by two methods including multiple tube method (also named most probable number (MPN)) and membrane filtration method (MF). Results obtained revealed the analysis of negative control showed no bacterial detection. The analysis of surface water (fresh water) indicated the presence of the indicator organisms (all three types) with the highest average concentrations 1800+org/100 ml by MPN and (1567 org/ 100 ml by MF. Tubes from wells at the water source were contaminated with total coliform only and with low average concentration of 10.6 org/100ml by MPN and 9.8 org/100ml by MF. Drinking water samples, after treatment also indicated presence of contamination due to the presence of three types of indicator organisms with figures 793 org /100ml by MPN and 542 org/100ml by MF (average). This may indicate that the chemical used in treatment or methods of application are questionable. Desalination water, on the other hand, showed minimal contamination at the site of desalination plant. However, the same water was found to be contaminated during distribution (tankers & jericans). Samples taken from the drinking water network (houses, reservoirs) were highly contaminated by the three groups of indicator organisms. Therefore, it was not suitable for human consumption. Also the study has shown the following grade, 24.4% of all tested samples were excellent, 5.6% of all tested samples were satisfactory, 12.2% of all tested samples were suspicious, 57.8% of all tested samples were unsatisfactory.