Evaluation of microbial quality of water in Kawempe Division, Kampala Surburb

Abstract

Objective: The aim of the study was to evaluate the microbial quality of water in Kawempe Division, Kampala district.

Design: A cross sectional study was conducted on two major water supplies used in the Kawempe division, Kampala district.

Setting: Between June 2015 and April 2016, total coliforms and Escherichia coli (E. coli) were investigated in two major sources of water during wet and dry seasons. Water samples from tap water and protected spring wells were collected and analyzed for total coliforms and E. coli.

Subjects: A total of 100 water samples were collected and analyzed for microbial quality. Plate count method was used. 10 ml of water sample was mixed with 90 ml of 1% peptone water saline. 1 ml of the inoculum was transferred to each of the two petri-dishes containing agar and mixed thoroughly. The solidified agar plates for total coliforms and E. coli were incubated at 37⁰C and 44.5 respectively and read after 24-48 hours. The results were expressed as Colony Forming Units (CFU) per milliliter (mL).

Results: Of the 100 samples analyzed, protected wells were more contaminated with E. coli (48%) and total coliforms (56%) than tap water with E.coli at (4%) and total coliforms (7%) respectively. Tap water had a significantly higher degree of mean microbial count of 362 CFU/mL (P<0.05) while protected spring well had mean microbial count of 83 CFU/mL. The microbial counts ranged between 5.0 x 10⁰ to 1.92 x 10³ CFU/mL in the wet season and 5.0 x 10⁰ to 6.4 x 10² CFU/mL in the dry season. Protected spring wells had a mean microbial count between 2.0 x 10⁰ to 2.6 x 10² CFU/mL in the wet season and 2.0 x 10⁰ to 2.6 x 10² CFU/mL in the dry season. There was a statistical significant difference between counts of total coliforms and E.coli in the wet season and dry season (P<0.05).

Conclusions: Tap water and protected spring wells in Kawempe Division, Kampala district are contaminated with total coliforms and E.coli. The presence of total Coliforms and E.coli in drinking water is of great public health significance and this may lead to the onset of various enteric diseases. Therefore, this calls for immediate response from health authority to enforce public health intervention measures in the area.