Sustainable stormwater management: an analysis of the industrial area of Buia & Osoppo (Udine)

Abstract

In environmental engineering, stormwater can be a potential problem not on- ly because of the large quantities of liquid to be controlled, but also because a lot of pol- lution is conveyed with it; in fact, when water flows over impermeable surfaces, sub- stantial amounts of various contaminants are dragged away to the overflows. The pre- sent study aims to model and calculate the first foul flush phenomenon by using soft- ware EPA SWMM 5.0 in a case study. First foul flush makes reference to the higher lev- el of pollutants in stormwater flushing asphalt-concrete or concrete surfaces, mainly in industrial and parking areas, during the early phase of a precipitation event; this pollut- ed surface runoff needs to be collected and treated in a wastewater treatment plant. Be- fore proceeding with the calculations, current methodologies, as well as their theoreti- cal foundations, have been examined. In short, the study has aimed to provide a com- prehensive approach to first flush management, using theoretical bases, practical expe- riences and numerical models.

The case study concerns the hydro-environmental status of CIPAF (Consorzio per lo Sviluppo Industriale ed Economico della Zona Pedemontana Alto Friuli) industrial park. In this area stormwater flushing of impervious surfaces is a critical issue, since powders, scales and other residues resulting from the ordinary activities carried out by the factories located nearby produce, during a rain event, a huge amount of materials to be treated in the wastewater treatment plant. The present study tries to describe the phenomenon of polluted surface runoff, offering a contribution to understanding how and when contaminants reach the treatment plant with respect to waterflow rate peaks. A validated rainfall model has been used, with some considerations and analysis refer- ring to the specific case study.