Evaluation of turbidity impact on the microbiological quality of water with usage of bayes’ theorem

Water treatment technologies applied today guarantee feeding the water supply network with water of quality which meets all requirements imposed on water intended for human consumption. However, at the stage of distribution, the phenomenon of microbiological water contamination is encountered and drinking of such water may pose a threat to health of the consumers. Therefore, the World Health Organisation recommends application of management of water supply systems according to the recommended procedures of the water safety plan. It covers identification of threats as well as risk assessment and management in the entire chain of supply from source to the consumer’s tap. Water quality monitoring and testing constitute the corpus of operational actions allowing to control the safety of water supplies. Essential elements of this control are microbiological parameters, because this contamination may in a short time lead to a potential threat to health and even life of the consumers. For this reason, flexible rules and procedures of water quality monitoring are sought that will ensure safety of water supplies and will not generate significant service costs. In this paper, an attempt is made to assess the microbiological threat based on the results of turbidity tests using the Bayes’ theorem on the example of water supply system providing water to the inhabitants of the Silesian agglomeration.