Determination of Residual Chlorine in Uasin Gishu’s Country Water Supply

Abstract

The knowledge of residual chlorine (RC) is important at final check to the quality of water supplied to consumers. World Health Organization (WHO) recommends a standard at 0.2 - 0.3 mg/L of RC allowable. According to the Centers for Disease Control and Prevention (2020), RC is important for it shows that a significant amount chlorine was initially added to the water to inactivate bacteria and also that the water is safe from recontamination. Given the current discussion on the global effects of chlorine to health, it would be of great importance to determine the levels of RC on the water that is consumed by households in Uasin Gishu County. This research work was set to evaluate the concentration of RC within the water supply of Uasin Gishu County in Kenya. Ten points were chosen at strategic points where tap drinking water were to be sampled for tests between the month of January and March 2021. The samples were tested using a comparator which showed exactly how much chlorine (in mg/L) is in the water if present. Several factors may affect the amount of residual chlorine in water which include pH, temperature and chlorine decay. These factors greatly dictates the results depending on the time and conditions in which the sample is kept before the testing. This shows why water tests differently at different distance points from the treatment plant. The results were tabulated in excel spreadsheets while graphs and charts were used to show comparison of residual chlorine at different sampling points.