Innovative and Reliable Assessment of Polluted Stormwater Runoff for Effective Stormwater Management

This article examines the pollution dynamics in urban wet-weather runoff, addressing the statistical characterization and systematic classification of water quality characteristics as key aspects of sustainable and effective urban stormwater quality control and treatment measures. A reliable first flush methodology is applied to discrete water quality data of different pollution parameters from an Italian database for the identification of the Bivio Vela catchment’s representative evolution of mean concentrations and the assessment of the required runoff volume to reduce stormwater pollutant concentrations to background levels. A comparison is carried out between results from two catchments with different land use types (industrial versus residential) and the complexity of the sewerage system, highlighting challenges in tracking pollution trends and delineating peculiar dynamics of different quality parameters in a specific geographic context. Despite appreciably different pollutant dynamics, both catchments achieve background levels for all the examined parameters after 6 mm runoff. The outcome of the analysis has clear implications for the design approach of sustainable stormwater management practices.