Bacteriological and physico-chemical quality of household drinking water in Kisii Town, Kisii County, Kenya

Water is a basic human need which is required in many operations especially in households. However, this essential commodity in most cases does not meet the generally accepted safety standards. The study was designed to investigate the physico-chemical and bacteriological quality of drinking water used in households in Kisii town, Kenya. Analytical cross-sectional study was conducted to obtain information concerning household drinking water quality and safety. Stratified random sampling was used to obtain 422 drinking water samples at the point of consumption from the 4 zones of Kisii town for analysis. From the study it was revealed that TDS and electrical conductivity of the analyzed water samples were within the recommended standards of less than 1000 ppm and 1500 μSCM(−1) respectively. Further, it was found that 69.4% of the samples had pH range of between 6.5-8.5, 91.9% had turbidity of less than 5NTU, 3.8% had temperature below 15 °C and 31.2% of the chlorinated samples had chlorine residue above 0.2 ppm. In terms of bacteriological analysis, 39.3% of the samples were contaminated with total coliforms and 17.5% with E. coli. The main finding from the study was that the household water samples were contaminated with bacteria and unfit for human consumption because both total coliforms and E. coli exceeded the recommended Kenya Bureau of Standards (KEBS) and WHO standards. Therefore, public health officers should not only collect water samples from sources but also from households regularly to ascertain its quality and provide water safety promotion education to the general public. There was a strong relationship between bacterial contamination and temperature as well as chlorine residue. The study recommends Gusii Water and Sanitation Company (GWASCO) whose treatment and distribution capacity is expected to increase 4.5 times the current capacity to improve on their chlorine dosage at the treatment plant to ensure a minimum chlorine residue of 0.2 ppm at the household and community taps.