Inflow of external water of a city into its drainage pipelines impacts the efficiency and energy cost in sewage treatment works

increasing the risk of overflow and environmental pollution. This study is aimed at constructing a water quality characteristic factor library for the drainage network of a typical city

Foshan

laying a technical basis for subsequent identification of external water infiltration. Through a comprehensive analysis of the functional areas of a typical region in the city

we identify and focus on five water categories－domestic sewage

industrial wastewater

agricultural water

river water

and rainwater. Their quality characteristics are determined through sampling and laboratory measurements we have conducted in this study. For the five categories

characteristic factors are total phosphorus and nitrogen

chemical oxygen demand and manganese

nitrate

dissolved organic carbon

and salinity

respectively.