Use of water turbidity as an identifier of microbiological contamination in the risk assessment of water consumer health

Laboratory tests of water in the water supply system (WSS) are the basic component of water quality control. One of the key parts of that control should be the analysis of the dynamics of changes when it is transported to the consumer. This is due to the dynamically changing local hydraulic conditions in distribution systems, resulting in exposure to secondary water contamination. The phenomenon results in loss of microbiological water safety and drinking such water poses a potential threat to its consumers’ health. The paper presents a procedure for assessing the risk of losing microbiological safety of water quality, taking into account the size of the population threatened with waterborne diseases. In the proposed analytical method, turbidity is used as an identifier of water microbial contamination. The areas of different risk categories (acceptable, controlled and not acceptable) are determined based on defined three range turbidity levels. The proposed procedures for estimating the turbidity limit value allow using online monitoring of turbidity in WSS for spatial interpretation of the health risk of the water consumer. Based on the research carried out with the use of analytical procedures in the GIS system, a risk map is developed taking into account the degree of population exposure to microbiological water stability loss. The risk map also includes the identification of critical areas of secondary microbial contamination of drinking water. The proposed risk assessment method is an innovative tool in the decision support system to make rational operational decisions as an effective safety barrier in risk management.