TY JOUR TI A Rational Relationship between the Water Quality of a Water Body and the Quality of Discharged Wastewater KW Water quality of water bodies KW watercourses KW water users KW water purity index KW concentration of pollutants KW environmental efficiency indicator KW maximum permissible discharge KW financing of water protection measures JO Proceedings of Petersburg Transport University AU Chernikov, N.A. AU Kudryavcev, A.V. PY 2023 IS 20 PB FSBEI HE "Emperor Alexander I St. Petersburg State Transport University"