Methodological approaches to assessing the negative impact of drainage water on a water body

Abstract

The purpose of the work is to apply existing methodological approaches to assessing the negative impact of drainage water on a water body, to establish the dynamics of concentrations of substances in the area from the place of discharge of wastewater/ drainage water to the control gate. The object of the study was a collector diverting drainage runoff into the Don River. The problem under study is especially relevant in connection with the ongoing measures to prevent degradation of a water body in accordance with the decree of the Government of the Russian Federation dated 07.21.2021 № 2012-r. The concentrations of substances in the most polluted jet in the area from the place of discharge of wastewater/drainage water to the control gate (l = 500 m) were calculated using the example of a collector diverting drainage runoff into the Don River. It is shown that if the concentration of a substance in the background is equal to or below the maximum permissible concentration, then when drainage water are discharged with excess of the standard concentrations of substances and their subsequent dilution by the flow rate of the river with its multiple excess over the flow rate of drainage water (q/Q = 0,0002), the maximum permissible concentration can be reached in the control range, or the actual concentration exceeds the standard is 1,2 – 2 times lower than that for the outlet. Accordingly, it is recommended that, when determining the amount of damage caused to a water body from the discharge of drainage water, be guided by the actual concentrations in the control range, and not in the drainage water discharge range.