The aim of the research was to study the effect of the surface runoff of urbanized areas on the chemical composition of the collector-waste waters of the Semikarakorsk branch of the federal state budgetary institution “Rostovmeliovodkhoz”. The drainage systems development on irrigated lands not only played a positive role, having created favorable conditions for increasing soil productivity, but also caused the issues with incoming collector-effluent waters, as they are one of the sources of salt and pollution to rivers and inlets. The collector-drainage and watershed networks built in 1970–1990 due to economic relations that were developed during the period of designing, constructing and operating the drainage systems including relief elements were not considered as sources of pollution to rivers and water inlets. The issues of wastewater treatment and their correspondence to the water intake background were not raised. It was found that the active economic and meliorative activity, the use of mineral fertilizers and pesticides in agriculture, the development of urbanized areas led to an increase of the maximum permissible concentrations of chemical elements in drainage-waste waters. The content of pollutants in waste and drainage waters is crucially heterogeneous in its qualitative and quantitative composition. Seasonal periodicity of pollutants fluctuations in waste and drainage waters on the territory of the south of Rostov region indicates the natural factors prevalence in intra-annual regime formation.
Key words: collector-waste waters, maximum permissible concentrations of chemical elements, water inlets, drainage systems on irrigated lands.
