Measures to supply Samara Urban District with drinking water from surface and underground water sources in accordance with 2.1.3684-21 and 1.2.3685-21 Sanitary Rules and Regulations

Summary

In accordance with the Resolution of the Chief Sanitary Doctor of the Russian Federation dated January 28, 2021 No. 3, new sanitary rules and regulations have been approved and in force in the Russian Federation from March 1, 2021, requiring a more stringent approach to the quality of purified water: SanPiN 2.1.3684-21 «Sanitary and epidemiological requirements to the maintenance of the territories of urban and rural communities, to water bodies, drinking water and drinking water supply, atmospheric air, soil, residential premises, operation of industrial and public premises, arrangement and implementation of sanitary and antiepidemic (preventive) measures» and SanPiN 1.2.3685-21 «Hygienic standards and requirements to ensure the safety and (or) harmlessness of environmental factors to humans». In this regard, the specialists of Samara Utility Systems LLC are carrying out a comprehensive upgrade and reconstruction of the water supply and wastewater disposal systems in Samara with the purpose of improving integrally the qualitative and quantitative performance of the systems. Measures have been developed for the reconstruction and modernization of water treatment facilities to provide for the concentration of residual aluminum and chloroform meeting the sanitary standards. The implementation of the activities is planned for the period from 2024 to 2041.

Key words

monitoring , water treatment , potable water quality , manganese , residual aluminium , chlororganic compounds , total iron , sanitary regulations and standards , surface water supply source , underground water sources , total hardness

Estimation of the trends of daily values of the river water total hardness

Summary

While controlling water treatment processes, monitoring water quality indicators is essential, since modeling their seasonal variations provides for predicting changes in river water. Time series of daily total hardness values in river water over a 28-year period were analyzed. Regression analysis was used to describe the trend of the indicator of river water. Parameters of the linear regression equations were determined using the Regression tool built in the Data Analysis Package in MS Excel. Prediction of changes in daily total hardness values in the river water was made through statistical modeling – constructing discrete Markov chains that account for the changes in the indicator owing to the random factors. Using the linear regression method, an equation was obtained that described the trend of the total hardness in river water over time. The F-test value revealed statistical significance of the equation. It was established that the total hardness of river water exhibits an upward trend. Using a statistical method – constructing finite Markov chains – a short-term prediction of the total hardness values in river water for the next 10 days was made. It was found that the probability of the total hardness values falling within the first region of the lowest potential risk (S1 state up to 3.5 °H) increases, while the probability of values falling within the second region (S2 state from 3.5 to 7 °H) decreases. While the probability of the values falling within the third region (S3 state above 7 °H, increased potential risk) increases, the increase is no more than 0.2%. Therefore, no increase in the river water hardness values is expected in the next 10 days following the study period.

Key words

water quality , control arrangements , total hardness , regression , stochastic system , Markov processes , probability of event