Storm water quality simulation for wet weather urban pollution control assessment in the Cascina Scala experimental catchment

Several studies have shown that urban storm waters constitute a significant source of pollution to receiving waters, due both to the presence of conventional pollutants (suspended solids, COD, BOD, PO 4 , etc.) and to that of toxic pollutants (metals: lead, copper, chromium, zinc, etc., hydrocarbons, and others) mainly due to vehicular traffic and to the corrosion of metal roofs and building parts by acidic rain. This paper describes an application of a numerical simulation model to the estimation of pollutant loads discharged to receiving surface waters by CSO’s: by applying the SWMM (Storm Water Management Model) to the experimental urban catchment of Cascina Scala (Pavia), 19 stormwater events chosen among those monitored in an obervation period between 1989 and 1996 have been simulated.