Krysinska D. Assessment of the level of ecological safety of drinking water supply

The dissertation is devoted to solving an important scientific and practical problem assessing the level of environmental safety of drinking water supply. The degradation of the aquatic environment under the influence of anthropogenic activities, the shortage of fresh water due to irrational use of nature, led to the water crisis, which the world scientific community has officially classified as the 5 most important global risks for the next ten years. Given the importance of drinking water for human life, considered that the assessment of the level of ecological safety of drinking water should be carried out using a risk-based approach, moving from the existing differentiated definition of the concentration of drinking water quality and their comparison with normalized values to take into account negative effects for the human body due to the manifestations of the consequences of danger in the form of disease, disability, mortality, etc. The proposed comprehensive method for assessing the level of ecological safety of drinking water supply is based on the idea of calculating the risk of carcinogenic and non-carcinogenic origin. An algorithm for determining the level of ecological safety of drinking water supply has been developed. The ranges of the level of ecological safety of drinking water supply are determined, which are determined by the limits of the risk that does not threaten human health: 10–8 ≤ Rс ≤ 10–6 – for carcinogenic substances, 0,161 ≤ Rnс ≤ 0,160 – for non-carcinogenic substances (within the range – «safe» or outside «dangerous»). Laboratory field researches of drinking water quality of centralized water supply and underground water supply sources were carried out. The obtained results were used to confirm the effectiveness of the proposed method of assessing the level of environmental safety of drinking water supply. In the Curve Expert and MS Excel environment identified the existence of an environmental risk of carcinogenic origin for the health of Mykolaiv residents, which may be caused by the quality of drinking water. The degree of correlation between the number of detected malignancies and the concentration of chloroform in drinking water was determined. The main reasons for the deterioration of drinking water quality and the emergence of a dangerous state of the drinking water supply system have been studied. The main ones are outdated water supply network and use of disinfection technology with the use of chlorine-containing reagents. The ecological necessity of introduction of dual (double) water supply system in the settlement is substantiated and the problem of its economic efficiency is investigated. In the context of the implementation of an alternative dual (double) water supply system, the dissertation proposes to separate networks for drinking water supply and technical and to approve the concept of «technical water» in the main state documents governing the water supply industry. Key words: ecological safety, drinking water supply, ecological risk, drinking water, technical water, dual systems, algorithm for determining.