WATER QUALITY FEATURES OF THE PODPOLNAYA SMALL RIVER AT THE COLLECTOR-DRAINAGE WATER DISCHARGE

Purpose: to conduct a comprehensive water quality assessment based on hydrochemical indicators using two generally accepted methods in the small Podpolnaya River, into which collector and drainage runoff is discharged, and to assess the convergence of the results obtained. Materials and methods. The research materials were test reports submitted by the hydrogeological-reclamation party of the Federal State Budgetary Institution “Rostovmeliovodkhoz Administration” for 2019–2024. The subject of the study were environmental indicators: specific combinatorial water pollution index and maximum pollution coefficient. Results and discussion. The calculation results showed that for the period 2019–2024 at the background section the value of the specific combinatorial water pollution index varied from 2.27 to 3.69, which characterizes the water quality as “dirty”. At the discharge section for the same period, the value of the specific combinatorial water pollution index varied from 1.9 to 3.1, which characterizes the water quality as “polluted”. For the period 2019–2024, at the background section, the value of the maximum pollution coefficient varied from 0.1 to 0.88, which characterizes the water quality as “moderately polluted”. At the discharge section for the same period, the value of the maximum pollution coefficient varied from minus 0.23 to 0.13, which characterizes the water quality as “moderately polluted”. Conclusions. When comparing the results of the water quality assessment of the Podpolnaya River based on the estimated indicators of the specific combinatorial pollution index and the maximum pollution coefficient, a discrepancy by 30 % was found in the characteristics of the water class and quality for the background section and by 40 % – for the collector-drainage water discharge section.