Drinking Water Quality: Temporary Deviations from Hygienic Standards

Abstract

Introduction: Current legislation permits a phased achievement of drinking water quality standards by making decisions on temporary deviations from hygienic standards for the period of design, construction, and/or upgrade of water supply facilities. Objective: To substantiate the mechanism for coordinating temporary deviations of concentrations of certain chemicals in drinking water from hygienic standards for the period of implementing measures for water quality improvement. Materials and methods: We applied methods of sanitary and epidemiological expert examination and assessment and the method of system analysis to review and study current regulations, results of laboratory testing of water quality in centralized cold water supply systems for 2011–2019, and action plans of 83 constituent entities of the Russian Federation for improvement of tap water quality. Results: We established that violation of hygienic standards was most often registered for aluminum, boron, bromine, iron, silicon, lithium, magnesium, manganese, sodium, and chloroform. Hygienic requirements for tap water quality determine necessary technological solutions to be implemented at water treatment facilities; yet, their implementation requires a certain amount of time and might cause temporary tap water quality deterioration making it necessary to agree with the local bodies in charge of federal sanitary and epidemiological surveillance a phased transition to eliminating threat to public health from poor quality drinking water. Conclusions: The authors propose an algorithm for conducting a risk assessment and a mechanism for decision making on temporary deviations.