ABSTRACT
Wastewater and stormwater systems are major components of urban water resources systems, having the purposes of positive control of contaminated effluent, avoidance of off-site environmental contamination, and flooding. Sewage, or wastewater, is carried by sewer pipes and channels and may originate from domestic and industrial sources, storm runoff, infiltration, and inflow. Domestic and industrial sewage discharges are associated with sanitary facilities of houses and buildings, and from production processes of manufacturing and food processing; these sources are relatively constant but vary with the level of activity (e.g., diurnal variation, batch processing). Storm sewage results from runoff from precipitation events and includes wash-off of litter and wastes from roadways and the land surface (e.g., soil erosion). Infiltration is water that enters sewers from the ground through leaks; it can represent drainage of groundwater and is typically greater during periods of high water levels. Inflow is stormwater that enters sewers through leaks, broken pipes, connected roof drains, and sump pumps during storm runoff events.
