Catchment management influence on the magnitude of the total solids load conveyed by the stormwater sewer system – a comparative case study

Kielce University of Technology, Faculty of Environmental, Geomatic and Energy Engineering, Al. Tysiąclecia Państwa Polskiego 7, Kielce, Poland

^* Corresponding author: jgorski@tu.kielce.pl

Abstract

The aim of the investigations was to make a comparative analysis of TSS concentration and variability in TSS loads as well as to analyse first flush phenomena. That issue is related to the characteristics of two urban catchments located in the city of Kielce. The runoff events observed in the period of investigations (years 2009 – 2016) showed a great diversity. The analyses performed for the study revealed substantial differences in the values of TSS concentration and loads in stormwater from the catchments of concern. The highest TSS concentration in the stormwater for the catchment located at the city outskirts was 252 mg.dm^-3, whereas for the catchment in the city centre that value was almost 30 – fold higher and amounted to 7432 mg.dm^-3. The analysis of the runoff first flush with respect to the mass of total solids in individual rainfall events showed substantial differences in the course of the process depending on the type of catchment management. In the densely built-up area, the initial 25% and 30% of the volume of runoff transported 25-41% and 30-48% of the solids mass, respectively. In the other catchment, with low and sparsely located buildings, the maximum values of TSS mass were considerably higher and amounted to 22-83% and 28-87%.