Abstract:The non-storm water sources with inappropriate entries into storm drains, especially industrial sources, could have a severe detriment to the quality of receiving water body. This study assessed tracer parameters to identify electronic enterprises with inadvertent connections to storm drains and therefore quantified the industrial source flow using the identified tracer parameters. Among the 22 monitored water quality indicators, fluoride, chloride and sulphate are identified as the markers, which can be used to distinguish electronic industry wastewater from sanitary wastewater. Particularly, fluoride is the priority marker, showing most significant difference among the source types and less concentration range within the electronic industry source type, with a concentration level of (10.5±1.76) mg/L (i.e., standard± deviation). A case study at a catchment in the Shanghai downtown area was conducted based on fluoride mass balance within the storm pipes and Monte Carlo simulation. For the dry-weather discharge from the storm pipe network, the estimated electronic industrial flow ratio matches the data from field observations, with a relative error less than 15%. Moreover, from a wider perspective, the use of multi marker species is desired to provide clear evidence for the presence of a variety of industry trades with unexpected entry into storm drains.