Bacteriological Evaluation and Quality Assessment of Drinking Water From Water Refill Stations in Selected Estates in Nairobi County

Abstract

Background Safe, adequate and accessible water is crucial in human and animal lives. If the quality of drinking-water is not checked, there could be a major burden on the health of people as a result of contamination. One way through which drinking-water can become unsafe for consumption is through microbial contamination. These microbes may include but not limited to protozoa, fungi and bacteria such as total coliforms, fecal coliforms and heterotrophic bacteria. The main objective of this study was to determine the microbiological quality of drinking water from water refill stations in selected estates in Nairobi. Methodology An experimental cross-sectional study design was used. Samples of water (250ml per refill station) were collected into sterile containers. Water sold in 73 refill stations in15 major estates in Nairobi County was sampled and transported to the National Public Health Water Laboratory. The water samples were tested for the presence of total coliforms, E.coli and fecal enterococci to check for microbial contamination. The membrane filtration method was used to enumerate the total coliforms, E.coli and fecal enterococci per 100ml of the water. Data was collected and entered into Microsoft excel and then transferred to the Statistical Package for Social Sciences (SPSS) software version 20 for analysis. Descriptive analysis was used for analysis of categorical variables by utilizing frequencies/proportions. Results The estates included in the study had varying numbers of drinking water refill stations (DWRS). Eastleigh had the highest number while several Estates such as Lavington and Kileleshwa had a few DWRS. Most of the DWRS treated tap water (n = 50, 68.5%) or borehole water (n = 22, 30.1%) to produce the drinking water. Most of them reported that they followed standard operating procedures of running DWRS, had infrastructural integrity, and maintained their facilities as x

stipulated by the Water Services Regulatory Board and the World Health Organization. Microbial contamination was detected in 26 (35.6%) of the DWRS as indicated by detection of one or more coliforms per 100 milliliters. Discussion The quality of water sold in DWRS is generally acceptable but microbial contamination may compromise the quality. The contamination may be at the source, in the pipeline, or in the storage. Although the DWRS reported as being adherent to establishment and maintenance requirements, it is essential for regulatory authorities to ascertain the compliance since more than a third of them were selling contaminated water as safe quality drinking water. Conclusion Drinking water refill stations are rapidly meeting the need for quality drinking water in middle-low-income Estates in Nairobi. Owners of the refill stations self-reported compliance to requirements for running the DWRS. The detection of coliforms in more than a third of the samples indicates microbial contamination of the water. Recommendations Further studies are recommended for comprehensive assessment of the drinking water refill stations to identify their actual weaknesses in complying with the requirements for water quality. They should collect data through direct observation rather than relying on self-reporting. Assessment of the chemical quality of the drinking water in the DWRSs is also crucial